Application Report SPRA524 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns Zhenyu Yu Digital Signal Processing Solutions Abstract Space-vector (SV) pulse width modulation (PWM) technique has become a popular PWM technique for three-phase voltage-source inverters (VSI) in applications such as control of AC induction and permanent-magnet synchronous motors. This document gives an in-depth discussion of the theory and implementation of the SV PWM technique. Two different SV PWM waveform patterns, one using the regular compare function on the Texas Instruments (TIä) TMS320C24x/F24x digital signal processors (DSPs) and another implemented with the SV PWM hardware module on the TI TMS320C24x/F24x DSPs are presented, with complete code examples for the TMS320F243/1. At the end, a complete AC induction motor control application is discussed to show the effectiveness of both approaches. PWM waveforms of the presented implementations and experimental data in the form of motor currents are shown and discussed. A full TMS320F243/1 program example is attached. The observation of dead band imbalance for the hardware-implemented SVPWM pattern in this report has not been seen in other publications. Contents Introduction ......................................................................................................................................................2 Background......................................................................................................................................................3 Theory of SV PWM Technique..................................................................................................................3 SV PWM Waveform Patterns....................................................................................................................9 Application in Three-Phase AC Induction Motor Control ................................................................................20 Experimental Results .....................................................................................................................................22 Conclusions ...................................................................................................................................................22 References.....................................................................................................................................................24 Appendix A. Program for Open-Loop Three-Phase AC Induction Motor Control With SV PWM Technique and Constant V/Hz Principle ..........................................................................................................................25 Digital Signal Processing Solutions March 1999 Application Report SPRA524 Figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Symmetric and Asymmetric PWM Signals .....................................................................................2 Three-Phase VSI Diagram .............................................................................................................3 The Basic Space Vectors (Normalized w.r.t. V dc) and Switching States ........................................5 Software Determined SV PWM Waveform Pattern ......................................................................10 Switching Direction for Software Determined SV PWM Pattern...................................................11 SV PWM Outputs With Carrier Filtered Out .................................................................................13 SV PWM Outputs With Carrier Filtered Out and Dead Band Enabled .........................................14 Hardware-Implemented SV PWM Waveform Pattern ..................................................................15 SV PWM Outputs With Carrier Filtered Out .................................................................................19 SV PWM Outputs With Carrier Filtered Out and Dead Band Enabled .........................................19 Program Flow Chart .....................................................................................................................20 Block Diagram of an Open-Loop AC Induction Motor Control System .........................................22 Motor Current and Spectrum Obtained With the Software Approach...........................................23 Motor Current and Spectrum Obtained With the Hardware Approach .........................................23 Tables Table 1. Device On/Off States and Corresponding Outputs of a Three-Phase VSI ........................................4 Table 2. Determination of the Sector of Uout Based on N ................................................................................8 Table 3. Hardware and Software Determined SV PWM Switching Pattern Comparison.................................9 Introduction Because of advances in solid state power devices and microprocessors, PWM inverters are becoming more and more popular in today’s motor drives. PWM inverters make it possible to control both the frequency and magnitude of the voltage and current applied to a motor. As a result, PWM inverter-powered motor drives offer better efficiency and higher performance compared to fixed frequency motor drives. The energy that a PWM inverter delivers to a motor is controlled by PWM signals applied to the gates of the power transistors, as shown in Figure 1. Figure 1. Symmetric and Asymmetric PWM Signals Symmetric PWM PWM period PWM period PWM period PWM period Asymmetric PWM Different PWM techniques (ways of determining the modulating signal and the switchon/switch-off instants from the modulating signal) exist. Popular examples are sinusoidal PWM, hysteric PWM and the relatively new space-vector (SV) PWM. These techniques are commonly used for the control of AC induction, BLDC and Switched Reluctance (SR) motors. The SV PWM technique for three-phase voltage-source inverter (VSI) is addressed in this application. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 2 Application Report SPRA524 Background Theory of SV PWM Technique The structure of a typical three-phase VSI is shown in Figure 2. As shown below, Va, Vb and Vc are the output voltages of the inverter. Q1 through Q6 are the six power transistors that shape the output, which are controlled by a, a’, b, b’, c and c’. When an upper transistor is switched on (i.e., when a, b or c is 1), the corresponding lower transistor is switched off (i.e., the corresponding a’, b’ or c’ is 0). The on and off states of the upper transistors, Q1, Q3 and Q5, or equivalently, the state of a, b and c, are sufficient to evaluate the output voltage for the purpose of this discussion. Figure 2. Three-Phase VSI Diagram Q1 Q3 a V dc Q5 b c + Q2 Q4 a' Q6 c' b' Va Vb Vc motor phases t The relationship between the switching variable vector [a, b, c] and the line-to-line output t voltage vector [Vab Vbc Vca] and the phase (line-to-neutral) output voltage vector [Va Vb t Vc] is given by equation 1 and equation 2 below. éVab ù é 1 - 1 0 ù éa ù ê ú ê úê ú 1 - 1ú êb ú êVbc ú = Vdc ê 0 êëVca úû êë- 1 0 1 úû êë c úû (equation 1) éVa ù é 2 - 1 - 1ù éa ù ê ú 1 ê úê ú êVb ú = 3 Vdc ê- 1 2 - 1ú êb ú êëVc úû êë- 1 - 1 2 úû êë c úû (equation 2) where Vdc is the DC supply voltage, or bus voltage. As shown in Figure 2, there are eight possible combinations of on and off states for the three upper power transistors. The eight combinations and the derived output line-to-line and phase voltages in terms of DC supply voltage Vdc, according to equations 1 and 2, are shown in Table 1. SV PWM refers to a special way of determining the switching sequence of the upper three power transistors of a three-phase VSI. It has been shown to generate less harmonic distortion in the output voltages and or currents in the windings of the motor load and provides more efficient use of DC supply voltage, in comparison to direct sinusoidal modulation technique. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 3 Application Report SPRA524 Table 1. Device On/Off States and Corresponding Outputs of a Three-Phase VSI a b c va vb vc vab vbc vca 0 0 0 0 0 0 0 0 0 1 0 0 2/3 –1/3 –1/3 1 0 –1 1 1 0 1/3 1/3 –2/3 0 1 –1 0 1 0 –1/3 2/3 –1/3 –1 1 0 0 1 1 –2/3 1/3 1/3 –1 0 1 0 0 1 –1/3 –1/3 2/3 0 –1 1 1 0 1 1/3 –2/3 1/3 1 –1 0 1 1 1 0 0 0 0 0 0 Assume d and q are the fixed horizontal and vertical axes in the plane of the three motor phases. The vector representations of the phase voltages corresponding to the eight combinations can be obtained by applying the following so-called d-q transformation to the phase voltages: Tabc-dq = 1 1 ù é 1 2ê 2 2 ú ê ú 3 3ú 3ê 0 2 2 ûú ëê (equation 3) t This transformation is equivalent to an orthogonal projection of [ a, b, c] onto the two t dimensional plane perpendicular to the vector [1, 1, 1] in a three-dimensional coordinate system, the results of which are six non-zero vectors and two zero vectors as shown in Figure 3. The nonzero vectors form the axes of a hexagonal. The angle between any adjacent two non-zero vectors is 60 degrees. The zero vectors are at the origin and apply zero voltage to a three-phase load. The eight vectors are called the Basic Space Vectors and are denoted here by U0, U60, U120, U180, U240, U300, O000 and O111. The same d-q transformation can be applied to a desired three-phase voltage output to obtain a desired reference voltage vector Uout in the d-q plane as shown in Figure 3. Note that the magnitude of Uout is the rms value of the corresponding line-to-line voltage with the defined d-q transform. The objective of SV PWM technique is to approximate the reference voltage Uout instantaneously by combination of the switching states corresponding the basic space vectors. One way to achieve this is to require, for any small period of time T, the average inverter output be the same as the average reference voltage Uout as shown in equation 4. Note, T1 and T2 in equation 4 are the respective durations for which switching states corresponding to Ux and Ux+60 (or Ux-60) are applied. Ux and Ux+60 (or Ux-60) are the basic space vectors that form the sector containing Uout. However, if we assume that the change in reference voltage Uout is tiny within T, then equation 4 becomes equation 5, where T1 + T2 £ T . Therefore, it is critical that T be small with respect to the speed of change of Uout. In practice the approximation is done for every PWM period, Tpwm. Therefore it is critical that the PWM period be small with respect to the speed of change of Uout. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 4 Application Report SPRA524 Figure 3. The Basic Space Vectors (Normalized w.r.t. Vdc) and Switching States (- 1 6, 1 2 ) U 12 0 (010) 2 3, 0 ) ( n +1)T òU out (t ) = nT U out (nT ) = O 111 (111) 6, - 1 2 ) U 240 (001) 6, 1 U out O 000 (000) (- 1 1 T (1 T1 U 180 (011) (- U 60 (110) q axis ( 1 (T1U x + T2 U x ± 60 ) T (1 ) U0 (100) T2 U 300 (101) 2 6, - 1 2 2 d axis 3, 0 ) ) (equation 4) 1 (T1U x + T2 U x ± 60 ) T (equation 5) Equation 5 means that for every PWM period, Uout can be approximated by having the inverter in switching states Ux and Ux+60 (or Ux-60) for T1 and T2 duration of time respectively. Since the sum of T1 and T2 should be less than or equal to Tpwm, the inverter needs to be in O000 or O111 state for the rest of the period. Therefore, equation 5 becomes equation 6 in the following, where T1 + T2 + To = Tpwm =T. Tpwm U out = T1 U x + T2 U x ± 60 + T0 (0 000 or 0111 ) (equation 6) From equation 6, we get equation 7 for T1 and T2. [T1 T2 ] = T pwm [U x where t [U x U x ± 60 ] U out -1 (equation 7) -1 U x ± 60 ] is the normalized decomposition matrix for the sector. Assume the angle between Uout and Ux is 8 in the following for T1 and T2. T1 = 2T pwm U out cos(a + 30°) T2 = 2T pwm U out sin(a ) a . From Figure 3, we can also obtain equation (equation 8) Depending on specific application, calculation of T1 and T2 can be done either with equation 7 or equation 8. Equation 7 is sector dependent. However, the matrix inverse can be calculated off-line for each sector and obtained via a look-up table during on-line t calculation. This approach is useful when Uout is given in the form of vector [Ud, Uq] . Equation 8 is independent of sector and is useful when Uout is given in the form of magnitude and phase angle. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 5 Application Report SPRA524 Ux can be the closest basic space vector on either side of Uout. Ux+60 (or Ux-60) is then the basic space vector on the opposite side. In either case, T1 represents the component on Ux, T2 represents the component on the other basic space vector. The following is a code example to calculate T1 and T2 (as compare values) using equation 7. Example 1. Code Example for Calculation of T1 and T2 Using Equation 7 .data ******************************************************************** ** Decomposition matrices indexed by the sector, s, Uout is in ** ******************************************************************** decomp_ .WORD 20066 ; D1–scaled by 2 to the 14th power .WORD -11585 .WORD 0 .WORD 23170 ; ; .WORD .WORD .WORD .WORD -20066 11585 20066 11585 .WORD .WORD .WORD .WORD 0 23170 -20066 -11585 .WORD .WORD .WORD .WORD 0 -23170 -20066 11585 .WORD .WORD .WORD .WORD -20066 -11585 20066 -11585 .WORD 20066 .WORD 11585 .WORD 0 .WORD -23170 . . .bss decomp,24 .bss temp,1 ; decomposition matrices ; temporary storage .txt ******************************************************************** ** Initialize the decomposition matrices ** ******************************************************************** LAR AR0,#decomp ; Point to 1st destination LAR AR1,#(24-1) ; 24 entries LACC #decomp_ ; Point to 1st data item MAR *,AR0 ; Point to AR0 init_table Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 6 Application Report SPRA524 TBLR *+,1 ; Move data&pnt to nextdesti. ADD #1 ; Point to next data item BANZ init_table,0 ; Continue if there is more ; . ; . ;------------------------------------------------------------------; Calculate T1&T2 as compare values based on: Tpwn Uout=V1*T1+V2*T2 ; ; i.e. [T1 T2]=Tpwn*inverse[V1 V2]*Uout ; i.e. [0.5*T1 0.5*T2]=Tp*inverse[V1 V2]*Uout ; i.e. [0.5*C1 0.5*C2]=inverse[V1 V2]*Uout=M(sector)*Uout ; where C1=T1/Tp, C2=T2/Tp, are normalized T1&T2 wrt Tp ; M(sector)=inverse of [V1 V2] = decomposition matrix ; obtained through table lookup ; Uout=Transpose of [Ud Uq] ; Tp=Timer 1 period = 0.5*Tpwm ; Tpwm=PWM period Tpwm S: sector of Uout (0-5) ; Input ; Ud: d compo. of Uout(0-1/sqrt(2)), D2(Scaled by 2**13) ; Uq: q compo. of Uout(0-1/sqrt(2)), D2(Scaled by 2**13) ; t1_period_: Timer period (for PWM freq) ; t1_periods: Timer period in D10 (Scaled by 2**5) ; Output cmp_0: 0.5(1-0.5C1-0.5C2)Tp cmp value for 1st-to-tog ch ; cmp_1: cmp_0+0.5C1Tp cmp value for 2nd-to-tog ch ; cmp_2: cmp_1+0.5C2Tp cmp value for 3rd-to-tog ch ;-------------------------------------------------------------------LACC #decomp ; ADD S,2 ; SACL temp ; get the pointer LAR AR0,temp ; point to parameter table ; Calculate 0.5C1 based on 0.5C1=Ud*M(1,1)+Uq*M(1,2) LT Ud ; D2 MPY *+ ; M(1,1) Ud: D2*D1=D(3+1) PAC ; D4 LT Uq ; D4 MPY *+ ; M(1,2) Uq: D2*D1=D(3+1) APAC ; 0.5*C1: D4+D4=D4 BGEZ cmp1_big0 ; continue if bigger than zero ZAC ; set to 0 if less than zero cmp1_big0 SACH temp ; D4 LT temp ; D4 MPY t1_periods ; *Tp: D4*D10 = D(14+1) PAC ; Sach cmp_1 ; 0.5C1Tp: D15 (integer) ; Calculate 0.5C2 based on 0.5C2=Ud*M(2,1)+Uq*M(2,2) LT Ud ; D2 MPY *+ ; M(2,1) Ud: D2*D1=D(3+1) PAC ; D4 LT Uq ; D4 MPY *+ ; M(2,2) Uq: D2*D1=D(3+1) APAC ; 0.5*C2: D4+D4=D4 BGEZ cmp2_big0 ; continue if bigger than zero ZAC ; zero it if less than zero cmp2_big0 SACH temp ; D4 LT temp ; D4 MPY t1_periods ; *Tp: D4*D10 = D(14+1) Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 7 Application Report SPRA524 PAC Sach ; ; 0.5C2Tp: D15 (integer) cmp_2 ; Calculate compare value 3 based on 0.5C0Tp=(1-0.5C1-0.5C2)Tp LACC #t1_period_ ; Calculate 0.5*C0 SUB cmp_1 ; SUB cmp_2 ; 0.5*C0Tp = (1-0.5*C1 -0.5*C2)Tp: D15 BGEZ cmp0_big0 ; continue if bigger than zero ZAC ; zero it if less than zero cmp0_big0 sfr ; divide by 2 SACH cmp_0 ; 0.25*C0Tp: D15 (integer) Note that the D scaling notation is equivalent to the more popular Q notation. Their relationship is Qx=D(15-x). Therefore, the notation Dx means that the decimal point is at bit[15-x]. Whenever possible, the code examples in this report use maximum scaling to increase resolution and accuracy. For example, since the range of phase angle, q, is 0 to 2*pi (or 0 to 6.283), it is designated as a D3 (or Q12) number for maximum resolution. 12 Therefore the digital representation, qd, for q is related to q by qd=q*2 , i.e., scaled up by th 2 to the 12 power. It is necessary to know which sector the reference output voltage is in to determine the switching time instants and sequence. For applications where the reference output voltage vector is given in the form of magnitude and phase angle, such as the program example attached, sector determination is obvious. For applications where the reference t output voltage is in terms of vector [Ud, Uq] , such as where the output voltage vector is derived from an inner current control loop in the d-q frame, the following algorithm can be used to determine the sector of the reference voltage vector. First calculate vref1, vref2 and vref3 based on equation 9, below. v ref 1 = Uq v ref 2 = sin 60 0 U d - sin 30 0 U q (equation 9) v ref 3 = - sin 60 0 U d - sin 30 0 U q Secondly, calculate N=sign(vref1)+2*sign( vref2)+4*sign(vref3). Thirdly, refer to Table 2 below to map N to the sector of Uout. Table 2. Determination of the Sector of Uout Based on N N 1 2 3 4 5 6 Sector 1 5 0 3 2 4 The code examples in this document are based on knowing the phase angle of the reference voltage Uout. Therefore, the look-up tables are all in term of sector number of Uout. The same look-up tables can easily be rearranged in terms of N instead when the t reference voltage is given in terms of vector [Ud, Uq] . Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 8 Application Report SPRA524 As mentioned above, the reference voltage vector Uout is actually the desired three-phase output voltages mapped to the d-q frame through d-q transformation. When the desired output voltages are three-phase sinusoidal voltages with 120-degree phase shift, Uout becomes a revolving vector with the same frequency and a magnitude equal to the corresponding line-to-line rms voltages. The envelope of the hexagonal formed by the basic space vectors, as shown in Figure 3, is the locus of maximum Uout. Therefore, the magnitude of Uout must be limited to the shortest radius of this envelope when Uout is a revolving vector. This gives a maximum magnitude of Vdc 2 for Uout. Correspondingly, the maximum rms values of the line-to-line and phase output voltages are Vdc 2 and Vdc 6 , which is 2 3 times higher than that which an original sinusoidal PWM technique can generate. For the same reason, the bus voltage ( Vdc ) needed for a motor rated at Vrate is determined by Vdc = 2 Vrate for SV PWM technique. SV PWM Waveform Patterns The arrangement of the order of Ux, Ux±60, O000 and or O111 in each PWM period is another problem that must be resolved. Different switching orders result in different waveform patterns. Two symmetric switching orders, one that can be easily implemented with TMS320C24x/F24x by software-determined toggling sequences and another implemented by the SV PWM hardware module on the TMS320C24x/F24x, are discussed in this section. Table 3 is a brief comparison between the two switching patterns. Table 3. Hardware and Software Determined SV PWM Switching Pattern Comparison Switching Pattern CPU Overhead (Instruction Cycle) Memory Usage (Word) # Switching Dead Band Imbalance H/W determined 27 31 4 Yes S/W determined 33 41 6 No Software-Determined Switching Pattern Figure 4 below shows the waveform for each sector of a symmetric switching scheme. This scheme can easily be implemented with the TMS320C24x/F24x using software determined switching order for the three PWM channels. Figure 5 is another illustration of the switching scheme, where the arrows indicate for each sector the order of the first and second basic space vectors. This switching scheme can be represented by (O000, Ux, Ux±60, O111, O111, Ux±60, Ux, O000), where x can be 0, 120 and 240. It has the following properties: r r r r Each PWM channel switches twice per every PWM period except when the duty cycle is 0% or 100%. There is a fixed switching order among the three PWM channels for each sector. Every PWM period starts and ends with O000. The amount of O000 inserted is the same as that of O111 in each PWM period. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 9 Application Report SPRA524 Figure 4. Software-Determined SV PWM Waveform Pattern T0/4 T1/2 T2/2 T0/2 T2/2 T1/2 T0/4 T0/4 a a b b c c T1/2 T2/2 T0/2 T2/2 T1/2 T0/4 (000) (100)(110) (111) (110) (100) (000) O000 U120 U60 O111 U60 U120 O000 (000) (010)(110) (111) (110) (010) (000) Uout in sector of U0 – U60 Uout in sector of U60 – U120 O000 T0/4 U0 U60 T1/2 T2/2 O111 T0/2 U60 U0 T2/2 T1/2 O000 T0/4 a a b b c c O000 U120 U180 O111 U180 U120 O000 T0/4 T1/2 T2/2 T0/2 T2/2 T1/2 T0/4 O000 U240 U180 O111 U180 U240 O000 (000) (010)(011) (111) (011) (010) (000) (000) (001)(011) (111) (011) (001) (000) Uout in sector of U120 – U180 Uout in sector of U180 – U240 T0/4 T1/2 T2/2 T0/2 T2/2 T1/2 T0/4 a a b b c c O000 U240 U300 O111 U300 U240 O000 (000) (001)(101) (111) (101) (001) (000) Uout in sector of U240 – U300 T0/4 T1/2 T2/2 T0/2 T2/2 T1/2 T0/4 O000 U0 O111 U300 U0 O000 U300 (000) (100)(101) (111) (101) (100) (000) Uout in sector of U300 – U0 Implementation of this switching scheme with TMS320C24x/F24x involves two steps: 1) Initialization of the compare units and selected GP Timer for symmetric PWM 2) Determination of the channel-toggling sequence based on the look-up table and the load of compare registers based on which sector (s) Uout is in. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 10 Application Report SPRA524 Figure 5. Switching Direction for Software Determined SV PWM Pattern (- 1 6, 1 2 ) U 12 0 (010) 2 3, 0 (1 T1 U 1 80 (011) (- U 60 (110) q axis U out O 000 (000) ) (- 1 O 111 (111) 6, - 1 2 )U 240 (001) 6, 1 ( (1 ) U0 (100) T2 U 300 (101) 2 6, - 1 2 2 d axis 3, 0 ) ) Example 2 shows a TMS320C24x/F24x code example that implements this SV PWM scheme. Example 2. TMS320F243/1 Code for Software Determined Switching Pattern .data ******************************************************************** ** Addresses of compare registers corresponding to the 1st-to toggle* ** channels in a given period indexed by the sector, s, Uout is in. * ******************************************************************** first_ .WORD CMPR1 ; .WORD CMPR2 ; .WORD CMPR2 ; .WORD CMPR3 ; .WORD CMPR3 ; .WORD CMPR1 ; ******************************************************************** ** Addresses of compare registers corresponding to the 2nd-to toggle* ** channels in a given period indexed by the sector, s, Uout is in. * ******************************************************************** second_ .WORD CMPR2 ; .WORD CMPR1 ; .WORD CMPR3 ; .WORD CMPR2 ; .WORD CMPR1 ; .WORD CMPR3 ; .bss .bss .bss temp0,1 temp1,1 temp2,1 ; temporary storage ; temporary storage ; temporary storage .text ******************************************************************** ** Initialize GP Timer 1 and full compare units for symmetric PWM ** ******************************************************************** ; Set GP Timer 1 period according to PWM period. ; GP Timer 1 period = PWM period/50nS/2: t1_period_ SPLK #t1_period_,T1PER Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 11 Application Report SPRA524 ; Set GP Timer 1 mode. ; Put GP Timer 1 in continuous-up/down mode for symmetric PWM SPLK #1000100000000010b,T1CON ; Set PWM output polarities. ; PWM1,3&5 are active high. PWM2,4&6 are active low. SPLK #0000011001100110b,ACTR ; Define and enable dead band. ; Set dead band to 1*32*50nS=1.6uS SPLK #1f4h,DBTCON ; Enable PWM outputs and compare operation SPLK #1000001000000111b,COMCON ; . ; . ******************************************************************** ** Determine channel toggling sequence and load compare registers ** ** Input: s(0-5)-sector number ** ** cmp_0(0.25C0Tp), cmp_1(0.5C1Tp), cmp_2(0.5C2Tp) ** ** Output: compare values in compare registers CMPR1,2,3 ** ******************************************************************** LACC #first_ ; ADD s ; point at entry in ; 1st-to-toggle lookup table TBLR temp0 ; get compare register addr of ; 1st-to-toggle channel LAR AR0, temp0 ; point at the compare register LACC cmp_0 ; get cmp_0 SACL * ; load compare register LACC ADD #second_ s TBLR temp1 LAR LACC ADD SACL AR0,temp1 cmp_0 cmp_1 * LACC SUB ADD SUB ADD SACL #CMPR3 temp0 #CMPR2 temp1 #CMPR1 temp2 LAR LACC ADD ADD SACL AR0, temp2 cmp_0 cmp_1 cmp_2 * ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; point at entry in 2nd-to-toggle lookup table get the compare register addr of 2nd-to-toggle channel point at the compare register cmp_0+cmp_1 load compare register get the compare register addr of 3rd-to-toggle channel point at the compare register cmp_0+cmp_1+cmp_2 load compare register Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 12 Application Report SPRA524 Notice that the compare values must be integers; i.e., their scaling must be D15 (or Q0). For this code example, a, b and c in Figure 4 represent, respectively, the state of the PWM1, 3 and 5 outputs and the polarities of these PWM channels are ACTIVE HIGH. Figure 6 shows the PWM outputs, i.e., the inverter outputs, of this PWM waveform pattern after the carrier has been taken out with a low-pass filter. The first and third waveforms in the figure are two of the three PWM outputs. The waveform in the middle is the difference between the two, representing the line-to-line inverter output voltage applied to a motor load. Figure 7 shows the same PWM outputs when dead band is enabled. The waveforms are essentially the same. Figure 6. SV PWM Outputs With Carrier Filtered Out Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 13 Application Report SPRA524 Figure 7. SV PWM Outputs With Carrier Filtered Out and Dead Band Enabled Hardware-Implemented Switching Pattern Figure 8 below shows two symmetric switching patterns implemented by the SV PWM hardware module on the TMS320C24x/F24x for each sector. The rule of these switching patterns can be summarized as (Ux, Ux±60, Oyyy, Oyyy, Ux±60, Ux), where Oyyy can be O000 or O111, whichever differs from Ux±60 by the state of only one channel, and x can be 0, 60, 120, 180, 240, or 300. The following are some remarks about this switching scheme: r r r There is always a channel staying constant for the entire PWM period. So the number of switching times for this scheme is less than the software-determined scheme. The obvious result of this is reduced switching losses. For the type of application addressed, dead band is necessary between the complimentary pairs of PWM channels, i.e., PWM1 and 2, PWM3 and 4, and PWM5 and 6 on the TMS320C24x/F24x to avoid shoot-through faults. Dead band is inserted only when there is a transition to turn off one device and turn on the other device on the same inverter leg. Therefore dead band does not affect the channel that stays unchanged. Since the same channel may stay unchanged for the entire sector, this may be true for a long time duration depending on the commanding frequency. As a result, the dead band will affect the three PWM outputs unevenly, resulting in small harmonics in the inverter line-to-line outputs. Depending on the application, this drawback may or may not be an important issue. The two switching patterns for each sector are results of two switching directions. Theoretically, different switching directions can be combined in different ways to obtain a composite switching order. However, no advantage has been observed until now to use a composite order other than maintaining a constant direction for all the sectors. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 14 Application Report SPRA524 Figure 8. Hardware-implemented SV PWM Waveform Pattern T 1 /2 T 2 /2 T0 T 2 /2 T 1 /2 T 1 /2 PWM1 PWM1 PWM3 PWM3 PWM5 PWM5 U0 U 60 (100) (110) O 111 (111) U 60 U0 (110) (100) U 60 U0 (110) (100) U out in sector of U 0 - U 60 , SVRDIR=0, (D 2 D 1 D 0 )=(001) T 1 /2 T 2 /2 T0 T 2 /2 T 1 /2 T 1 /2 PWM1 PWM3 PWM3 PWM5 PWM5 O 000 (000) U 120 U 60 (010) (110) T 2 /2 T0 T 2 /2 T 1 /2 T 1 /2 PWM1 PWM3 PWM3 PWM5 PWM5 O 111 (111) U 180 U 120 (011) (010) U out in sector of U 120 - U 180 , SVRDIR=0, (D 2 D 1 D 0 )=(010) O 000 (000) T 2 /2 T 1 /2 U0 U 60 (100) (110) T0 O 111 (111) T 2 /2 T 1 /2 U 60 U 120 (110) (010) U out in sector of U 60 - U 120 , SVRDIR=1, (D 2 D 1 D 0 )=(010) PWM1 U 120 U 180 (010) (011) T 2 /2 U 120 U 60 (010) (110) U out in sector of U 60 - U 120 , SVRDIR=0, (D 2 D 1 D 0 )=(011) T 1 /2 T0 U out in sector of U 0 - U 60 , SVRDIR=1, (D 2 D 1 D 0 )=(011) PWM1 U 60 U 120 (110) (010) T 2 /2 T 2 /2 U 180 U 120 (011) (010) T0 O 000 (000) T 2 /2 T 1 /2 U 120 U 180 (010) (011) U out in sector of U 60 - U 120 , SVRDIR=1, (D 2 D 1 D 0 )=(110) Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 15 Application Report SPRA524 Figure 8. Hardware-implemented SV PWM Waveform Pattern (continued) T 1/2 T 2/2 T0 T 2/2 T 1/2 T 1/2 PWM1 PWM1 PWM3 PWM3 PWM5 PWM5 U 180 U 240 (011) (001) O 000 (000) U 240 (001) U 180 (011) U 240 U 120 (001) (011) U out in sector of U 180 - U 240 , SVRDIR=0, (D 2 D 1 D 0 )=(110) T 1/2 T 2/2 T0 T 2/2 T 1/2 T 1/2 PWM1 PWM3 PWM3 PWM5 PWM5 O 111 (111) U 300 (101) U 240 (001) T 2/2 T0 T 2/2 T 1/2 T 1/2 PWM1 PWM3 PWM3 PWM5 PWM5 O 000 (000) U0 (100) U 300 (101) U out in sector of U 300 - U 0 , SVRDIR=0, (D 2 D 1 D 0 )=(101) T 2/2 T 1/2 O 111 (111) U 120 (011) U 240 (001) T0 T 2/2 T 1/2 O 000 (000) U 240 (001) U 300 (101) U out in sector of U 240 - U 300 , SVRDIR=1, (D 2 D 1 D 0 )=(101) PWM1 U 300 U0 (101) (100) T 2/2 U 300 U 240 (101) (001) U out in sector of U 240 - U 300 , SVRDIR=0, (D 2 D 1 D 0 )=(100) T 1/2 T0 U out in sector of U 180 - U 240 , SVRDIR=1, (D 2 D 1 D 0 )=(001) PWM1 U 240 U 300 (001) (101) T 2/2 T 2/2 U0 U 300 (100) (101) T0 T 2/2 T 1/2 O 111 (111) U 300 (101) U0 (100) U out in sector of U 300 - U 0 , SVRDIR=1, (D 2 D 1 D 0 )=(011) The SV PWM hardware on the TMS320C24x/F24x requires the application software to generate Uout, determine that the sector Uout is in, and perform the decomposition to get T1 and T2 (in terms of timer counts) for each PWM period. Then, for each PWM period, the software only needs to accomplish the following steps: 1) Load the binary bit pattern corresponding to the starting basic space vector into bits[12-14] of the Action Control Register (ACTR), and the switching direction into bit[15] of ACTR, with 0 representing anti-clockwise and 1 representing clockwise. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 16 Application Report SPRA524 2) Load 0.5*T1 into the Full Compare Register 1 (CMPR1) and 0.5*T1+0.5*T2 into the Full Compare Register 2 (CMPR2). The state machine in the hardware SV PWM logic monitors the register configurations and respective compare matches for the whole PWM period and does what is necessary to generate the waveform patterns in Figure 5 according to the configuration. Therefore, implementation of SV PWM becomes even simpler with the help of the hardware SV PWM module, as shown in the following TMS320C24x/F24x code example: Example 3. TMS320F243/1 Code Example Using the Hardware SV PWM Module .data ******************************************************************** ** Lookup table for ACTR[15-12] for SV pulse-width ** ** modulation when the direction is clockwise, indexed by sector ** ** number ** ******************************************************************** clkwise_ .WORD 1011000000000000b .WORD 1010000000000000b .WORD 1110000000000000b .WORD 1100000000000000b .WORD 1101000000000000b .WORD 1001000000000000b ******************************************************************** ** Lookup table for ACTR[15-12] for SV pulse-width ** ** modulation when the direction is clockwise indexed by sector ** ** number ** ******************************************************************** cckwise_ .WORD 0001000000000000b .WORD 0011000000000000b .WORD 0010000000000000b .WORD 0110000000000000b .WORD 0100000000000000b .WORD 0101000000000000b .bss svpat,1 ; temporary storage .text ******************************************************************** ** Initialize GP Timer 1 and full compare units for symmetric PWM ** ******************************************************************** ; Set GP Timer 1 period according to PWM period. ; GP Timer 1 period = PWM period/50nS/2: t1_period_ SPLK #t1_period_,T1PER ; Set GP Timer 1 mode. ; Put GP Timer 1 in continuous-up/down mode for symmetric PWM SPLK #1000100000000010b,T1CON ; Set PWM output polarities. ; PWM1,3&5 are active high. PWM2,4&6 are active low. SPLK #0000011001100110b,ACTR ; Define and enable dead band. ; Set dead band to 1*32*50nS=1.6uS Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 17 Application Report SPRA524 SPLK #1f4h,DBTCON ; Enable PWM outputs and compare operation SPLK #1000001100000111b,COMCON ; . ; . ******************************************************************** ** Determine ACTR pattern and reload ACTR and CMPR1&2 ** ** based on sector, s, Uout is in. ** ** Input: s(0-5)-sector number ** ** t1_period_: timer period (for PWM freq) ** ** Output: compare values in compare registers CMPR1,2 ** ******************************************************************** LACC #cckwise_ ADD s ; point to entry in lookup table TBLR svpat ; get the pattern LAR AR0,#ACTR ; point to ACTR LACC * ; read ACTR AND #0FFFh ; clear sv pattern bits OR svpat ; re-configure sv pattern bits SACL * ; re-load ACTR LAR LACC SACL AR0,#CMPR1 ; point to CMPR1 cmp_1 ; *+ ; cmp_1=>CMPR1, point to CMPR2 ADD SACL cmp_2 * SUB BLEZ SPLK #t1_period_ ; limit CMPR2 in_lmt ; # t1_period _,* ; ; ; cmp_2=>CMPR2 in_lmt Figure 9 shows the PWM outputs of this waveform pattern after the carrier is taken out with a low-pass filter. Again, the first and third waveforms are two of the three PWM outputs. The waveform in the middle is the difference between the two PWM outputs, representing the line-to-line inverter voltage output applied to a motor load. Figure 10 shows the same PWM outputs when dead band is enabled. The effects of dead band imbalance are seen as distortion or harmonics in the line-to-line inverter voltage output in Figure 10. This distortion can become significant when the dead band is big with respect to the magnitude of inverter voltage output. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 18 Application Report SPRA524 Figure 9. SV PWM Outputs With Carrier Filtered Out Figure 10. SV PWM Outputs With Carrier Filtered Out and Dead Band Enabled Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 19 Application Report SPRA524 Application in Three-Phase AC Induction Motor Control An example of the application of SV PWM techniques in open-loop three-phase AC induction motor control is described in this section. Figure 11 shows the program flow chart of the example. Figure 11. Program Flow Chart PWM ISR Start Integrate speed to get phase THETA of Uout System configuration Initialize peripherals: I/O pins GP Timers PWM Int control Initialize variables Reset flags Clear pending ints Enable interrupt Enable GP Timer Background tasks: Update set F V/Hz profile Update display Reset watchdog Determine quadrant of U out and perform quarter mapping Obtain SIN(THETA) and COS(THETA) Calculate d-q components of U out Determine sector of U out Calculate T 1, T 2 & T 0 (as comp values) Determine toggling sequence Load compare registers Enable interrupt Return Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 20 Application Report SPRA524 The following are steps in the main program: 1) Configure the timers and compare units for symmetric PWM. 2) Input desired speed. 3) Obtain the magnitude of reference voltage vector Uout (based on constant V/Hz profile). 4) Update display, reset watchdog timer and loop back to 2. The following are the steps in the interrupt driven SV PWM routine: 1) Obtain the phase (q) of Uout by integrating the command speed. 2) Obtain the sine and cosine of q with quarter mapping and table look-up, and calculate the d-q component of Uout. 3) Determine which sector Uout is in. 4) Decompose Uout to obtain T1, T2 and T0 as compare values. 5) Determine the switching pattern (for hardware approach) or sequence (for software approach) and load the obtained compare values into corresponding compare registers. The major features of this implementation are: r r r r r 32-bit integration to obtain the phase of the reference voltage vector Quarter mapping to calculate SIN and COS functions Sector-based table look-up for decomposition matrix Sector-based table look-up for channel toggling order or Action Control Register reload pattern 20-KHz PWM and sampling frequency The block diagram of the implementation is shown in Figure 12. The on-line background program takes about 4 ms of CPU time. The interrupt driven SV PWM routine takes about 9 ms for the software determined switching pattern and about 8.5 ms for the hardware implemented switching pattern. The difference in code size is about 10 instruction words. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 21 Application Report SPRA524 Figure 12. Block Diagram of an Open-Loop AC Induction Motor Control System Constant V/Hz profile DC Supply Voltage U out Vcc ADC I/F w Obtain U d & Uq Obtain SIN/COS 32-bit integrator Q Obtain Quadrant Decompose T1,T2&T0 Matrix M Table look-up Load cmp registers PWM H/W Inverter Toggling sequence Obtain Sector Table look-up Experimental Results Experimental results are presented below to demonstrate the effectiveness of the discussed algorithms. Figure 13 is the motor current waveform and spectrum obtained with the first scheme, which we call the software approach. Figure 14 is the motor current waveform and spectrum obtained with the second scheme, which makes use of the hardware SV PWM module. The inverter, LabDrive, used in the experiments is from Spectrum Digital. The inverter is interfaced with a TMS320F243 EVM on which the motor control program runs. A motor with a fan on the shaft was used as the load in the experiments. The motor is a 4-pole, 3-phase AC induction motor rated at 60 Hz, 144 V and 1/3 hp. It can be seen that little or no harmonics are present in the current spectrums, demonstrating the effectiveness of the implemented SV PWM technique. Conclusions It has been shown that the SV PWM technique utilizes DC bus voltage more efficiently and generates less harmonic distortion in a three-phase voltage-source inverter. This document has presented an overview of SV PWM theory and two ways of SV PWM implementation. Program examples for both approaches are given for Texas Instrument’s TMS320C24x/F24x DSP controllers. The approach implemented with the hardware SV PWM module on TMS320C24x/F24x reduces the number of switching times as compared with the software-based approach. The direct result of this is switching reduced losses, which may become significant if the power rating of the inverter is high. Experimental results proved both implementations to be very effective. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 22 Application Report SPRA524 Figure 13. Motor Current and Spectrum Obtained With the Software Approach Figure 14. Motor Current and Spectrum Obtained With the Hardware Approach Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 23 Application Report SPRA524 References 1) Trzynadlowski, A. M.; The Field Orientation Principle in Control of Induction Motors; Kluwer Academic, 1994. 2) Trzynadlowski, A. M., Kirlin, L, and Legowski, S. F.; “Space-Vector PWM Technique With Minimum Switching Losses and a Variable Pulse Rate;” IEEE Transactions on Industrial Electronics, Vol. 44, No. 2, April 1997. 3) Trzynadlowski, A. M.; “An Overview of Modern PWM Techniques for Three-Phase, Voltage-Controlled, Voltage-Source Inverter;” International Symposium on Industrial Electronics 1996. 4) Ogasawara, S., Akagi, H. et al; “A Novel PWM Scheme of Voltage Source Inverters Based on Space Vector Theory;” EPE, Aachen, 1989. 5) Zhenyu Yu, Figoli, David; AC Induction Motor Control Using Constant V/Hz Principle and Space-Vector PWM Technique With TMS320C240; Texas Instruments Literature Number SPRA284. 6) Van der Broeck, F. G., Skudelny, H. C., Stanke, G.; “Analysis And Realization of a Pulse Width Modulator Based on Voltage Space Vectors;” IEEE Transactions on Industrial Applications, vol. IA-24, no.1, 1988, pp.142-150. 7) Stefanovic, V. R.; Space-Vector PWM Voltage Control With Optimized Switching Strategy; IEEE/IAS Annual Meeting, pp.1025-1033, 1992. 8) Boglietti A., Griva G., Pastorelli M., Portumo F., Adam T.; Different PWM Modulation Techniques Indexes Performance Evaluation; IEEE International Symposium on Industrial Electronics, June1-3, 1993, Budapest, Hungary, pp.193-199. 9) Mallinson, N.; “Plug & Play” Single Chip Controllers for Variable Speed Induction Motor Drivers in White Goods and HVAC Systems; 1998 IEEE Applied Power Electronics Conference. 10) Lai, Y-S, and Bowes, S. R.; “A Novel High Frequency Universal Space-Vector Modulation Control Technique;” Proceedings of 1997 International Conference on Power Electronics and Drive Systems, 1997, pp. 510-507. 11) Bowes, S. R., and Lai, Y-S; “The Relationship Between Space-vector Modulation and Regular-Sampled PWM;” IEEE Transactions on Industrial Electronics, Vol. 44, No. 5, October 1997. 12) Liu, Y-H, Chen, C-L, and Tu, R-J; “A Novel Space-Vector Current Regulation Scheme for a Field-Oriented-Controlled Induction Motor Drive;” IEEE Transactions on Industrial Electronics, Vol. 45, No. 5, October 1998. 13) Tzou, Y-Y, and Hsu, H-J; “FPGA Realization of Space-Vector PWM Control IC for Three-Phase PWM Inverters;” IEEE Transactions On Power Electronics, Vol. 12, No. 6, November 1997. Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 24 Application Report SPRA524 Appendix A. Program for Open-Loop Three-Phase AC Induction Motor Control With SV PWM Technique and Constant V/Hz Principle ******************************************************************** ** File Name : sv20b.asm ** ** Project : ACI motor control ** ** Originator : Zhenyu Yu ** ** Texas Instruments ** ** DSP Digital Control Systems Applications ** ** Target : TMS320F243 EVM + SD i/f + SD inverter ** ******************************************************************** ; Description ;------------------------------------------------------------------; This program implements an open-loop speed control algorithm for ; three-phase AC induction motors using constant v/f principle and ; SV PWM technique. The program allows the usage of either ; h/w or s/w determined switching patterns by changing the assembly ; directives. ;******************************************************************* ; Status : Worked correctly ; Last update : 2/1/99 ;___________________________________________________________________ ; Notes ;------------------------------------------------------------------; 1. This program implements an INT driven sampling and control loop ; for three-phase AC induction motor control through a three-phase ; voltage source inverter. ; 2. Constant v/f principle is used to generate the magnitude of ; reference voltage from frequency input. ; 3. SV PWM technique is employed to generate a sinusoidal ; type of three-phase voltage output from the inverter. ; 4. Both PWM and sampling frequencies are 20KHz. ; 5. Maximum scaling and 32 bit integration are used to maximize the ; accuracy of integer math. ; 6. The motor is assumed to be rated at 60Hz, i.e., maximum voltage ; output magnitude is achieved when freq (speed) input is 60Hz. ; 7. Frequency input is through push buttons connected to the IOPB6 ; (UP) and IOPB7 (DOWN). Frequency range is 0-120Hz. ; 8. The D scaling notation used here is related to the popular Q ; scaling notation by Dx=Q15-x. ;=================================================================== ; Switching pattern ;------------------------------------------------------------------SWPAT .set 0 HWPAT .set 1 ; -- Comment in one at a time SVPAT .set SWPAT ; Comment in to use s/w pattern ;SVPAT .set HWPAT ; Comment in to use h/w pattern ;------------------------------------------------------------------; Processor ;------------------------------------------------------------------F241 .set 1 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 25 Application Report SPRA524 F243 .set 3 ; -- Comment in one at a time ;DEVICE .set F241 DEVICE .set F243 ; Comment in for F241 ; Comment in for F243 ;------------------------------------------------------------------; Peripheral Registers and constants of TMS320C24x/F24x ;------------------------------------------------------------------.include "X24x.h" ; X24x register addresses ST0 .set 0 ; status register ST0 ST1 .set 1 ; status register ST1 wd_rst_1 .set 055h ; watchdog timer reset string wd_rst_2 .set 0aah ; watchdog timer reset string LED_ADDR .set 0ch ; addr of LED display on EVM ;------------------------------------------------------------------; Variables ;------------------------------------------------------------------.bss error,1 ; Number of errors .bss temp,1 ; temporary storage .bss one,1 ; +1 .bss upbutcntr,1 ; UP count push button .bss dnbutcntr,1 ; Down count push button .bss set_f,1 ; set F: D0 (-1.0-1.0, 1.0-120Hz) .bss f_omega,1 ; set F to angular speed ratio: D10 .bss omega,1 ; set angular speed: D10 .bss omega_v,1 ; angular speed to voltage ratio:D-9 .bss set_v,1 ; set voltage: D1 .bss t_sample,1 ; sampling period: D-9 .bss theta_h,1 ; phase of ref vector hi word: D3 .bss theta_l,1 ; theta lo word .bss theta_r,1 ; rounded theta_h: D3 .bss theta_m,1 ; theta mapped to 1st quadrant: D3 .bss theta_i,1 ; theta to index for sine table: D6 .bss SS,1 ; sin sign modification: D15 .bss SC,1 ; cos sign modification: D15 .bss sin_indx,1 ; index to sine table: D15 .bss sin_entry,1 ; beginning of sin table .bss sin_end,1 ; end of sin table .bss sin_theta,1 ; sin(theta): D1 .bss cos_theta,1 ; cos(theta): D1 .bss Ud,1 ; voltage Ud: D2 .bss Uq,1 ; voltage Uq: D2 .bss theta_s,1 ; theta to sector mapping: D0 .bss sector,1 ; sector reference U is in: D15 .bss theta_90,1 ; 90: D3 .bss theta_180,1 ; 180: D3 .bss theta_270,1 ; 270: D3 .bss theta_360,1 ; 360: D3 .bss dec_ms,24 ; Decomposition matrices: D1 .bss t1_periods,1 ; scaled Timer 1 period: D10 .bss cmp_1,1 ; decomp on 1st basic sp vector: D15 .bss cmp_2,1 ; decomp on 2nd basic sp vector: D15 .bss cmp_0,1 ; decomp on 0 basic sp vector /2: D15 .bss first_tog,1 ; the 1st-to-toggle channel .bss sec_tog,1 ; the 2nd-to-toggle channel .bss svpat,1 ; S/V pattern for ACTR .bss led_dir,1 ; LED direction (1: left, 0: right) Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 26 Application Report SPRA524 led_freq_ .bss .set .bss led_data,1 3000 led_subdvdr,1 ; LED display ; LED update sub-divider ; sub-divider counter for led ;------------------------------------------------------------------; Context ;------------------------------------------------------------------ST0_save .usect ".context",1 ; saved status register ST0 ST1_save .usect ".context",1 ; saved status register ST1 ACCH .usect ".extcont",1 ; saved accumulator high ACCL .usect ".extcont",1 ; saved accumulator low AR0_save .usect ".extcont",1 ; saved AR0 content AR1_save .usect ".extcont",1 ; saved AR1 content P_hi .usect ".extcont",1 ; saved P high byte P_lo .usect ".extcont",1 ; saved P low byte T_save .usect ".extcont",1 ; saved T content ;------------------------------------------------------------------; Program parameters ;------------------------------------------------------------------debug_data .set 3FFFh ; 60Hz-3FFF, 30Hz-1FFF, 25Hz-1AAB ; Scaled sampling period ; Ts*D-9=Ts*2**24, Ts=50uS t_sample_ .set 0346h ; D-9 ; Set frequency to radian frequency conversion ratio ; 120*2*pi/7FFFh/D0 = 754.0052472756 ; 7FFFh corresponds to 120Hz=753.9822368616 rad/sec f_omega_ .set 24128 ; D10 ; Minimum radian frequency ; min_F*2*pi*D10=12*2*pi*D10=75.39822368616*D10 ; min_F=12Hz is the minimum frequency input, D10=2**5 min_omega_ .set 2413 ; D10 ; Radian frequency to ref voltage conversion ratio -> V/Hz constant ; 1.0/sqrt(2)/(60*2*pi)*D24 = 0.001875658991994*D24 omega_v_ .set 31468 ; D-9 ; Max magnitude of reference voltage ; 1.0/sqrt(2)*D1 = 0.7071067811865*D1 max_v_ .set 11585 ; D1. 1b less res to reduce # shiftingsa ; Min magnitude of reference voltage given by ; 1.0/sqrt(2)*min_F/60Hz*D1 = 0.1414213562373*D1 min_v_ .set 2317 ; D1 ; Conversion from theta to index for sine table ; 360/(0.5pi)*D8, D8=2**(15-8)=2**7 ; 360 entry sine table ; theta_i_ .set 29335 ; D8 ; 90/(0.5pi)*D6, D6=2**9 ; 90 entry sine table theta_i_ .set 29335 ; D6 ; Conversion from theta to sector ; 6/(2*pi)*D0, D0=2**(15-0) theta_s_ .set 31291 ; D0 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 27 Application Report SPRA524 ; No of cycles needed to qualify a button push but_qual_ .set 100 ; 20*t_sample .sect ".vectors" ;=================================================================== ; Reset and interrupt vector table ;------------------------------------------------------------------RESET B _c_int0 ; PM 0 Reset Vector INT1 B _c_int1 ; PM 2 Int level 1 INT2 B _c_int2 ; PM 4 Int level 2 INT3 B INT3 ; PM 6 Int level 3 INT4 B INT4 ; PM 8 Int level 4 INT5 B INT5 ; PM A Int level 5 INT6 B INT6 ; PM C Int level 6 .text ;=================================================================== ; Start of main body of code ;------------------------------------------------------------------_c_int0 DINT ; Set global interrupt mask cfg_wsgr reset_wd0 ; ; ; ; ; ; ; .ifDEVICE=F243 LDP #temp SPLK #0,temp OUT temp,0ffffh .endif LDP SPLK SPLK SPLK ; Configure WSGR ; temp<=0 ; WSGR <= (temp) #WDKEY>>7 ; Reset WD timer #wd_rst_1,WDKEY #wd_rst_2,WDKEY #01101111b,WDCR Configure Shared Pins Group A shared pins all used for primary functions except TDR/IOPB6 and TLKIN/IOPB7 used as UP and DN on SD platform Group B shared pins all used as default. SPISIMO/IOPC2, SPISOMI/IOPC3 used as digital output timing marks XF/IOPC2 as dr fault clr, BIO/IOPC1 as dr enable in, SPISTE/IOPC5 as dr reset IOPD4 as dr enable cfg_pins LDP SPLK SPLK splk #OCRA>>7 #03FFFh,OCRA #0,OCRB #02C00h,PCDATDIR t1_period_ .set t1_periods_ .set t2_period_ .set 500 500*32 1000 init_ev #T1CMPR>>7 ; set DP #10,T1CMPR ; Init GPT comp registers #10,T2CMPR ; #t1_period_,T1PR ; Init GPT1 period reg #t2_period_,T2PR ; Init GPT2 period reg #0000001010101b,GPTCON ; set timer comps to active low #1000100000000010b,T1CON ldp splk splk SPLK SPLK splk SPLK ; Tpwm/50nS/2=50uS/50nS/2=500 ; D10, scaled Timer 1 period ; Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 28 Application Report SPRA524 SPLK SPLK SPLK SPLK SPLK SPLK ; Set GPT1 in Up/Dn mode for symm PWM #1000100010000010b,T2CON ; Set GPT2 in Up/Dn mode #t1_period_,CMPR1 ; Init. PWM duty cycle to 0% #t1_period_,CMPR2 #t1_period_,CMPR3 #0000011001100110b,ACTR ; Cfg PWM outputs #01F4h,DBTCON ; Cfg deadband 1*32*50nS=1.6uS .ifSVPAT=SWPAT SPLK #1000001000000000b,COMCON ; Enbl PWM outputs&cmp opera .endif .if SPLK SVPAT=HWPAT #1001001000000000b,COMCON ; Enbl PWM outputs&cmp op&svpwm .endif init_vars LDP SPLK SPLK SPLK SPLK splk splk splk SPLK SPLK SPLK SPLK init_tbl LAR LAR LACC LARP TBLR ADD BANZ splk splk SPLK SPLK .if splk out splk splk .endif ldp #error ; Point to B1 page 0 #0,error ; Reset error counter #1,one ; +1 => one #t_sample_,t_sample ; sampling period #t1_periods_,t1_periods ; max compare value #0,set_f ; zero set F. #0,upbutcntr ; zero up count #0,dnbutcntr ; zero down count #f_omega_,f_omega ; set F to angular speed ratio #omega_v_,omega_v ; angular speed to voltage ratio #0,theta_l ; theta low byte #0,theta_h ; theta high byte AR0,#theta_90 ; point to 1st destination AR1,#(28-1) ; 32 entries #angles_ ; point to 1st data item AR0 ; *+,1 ; move and point to next destination one ; point to next data item init_tbl,0 #theta_i_,theta_i ; theta to sin_index ratio #theta_s_,theta_s ; theta to sector ratio #sin_entry_,sin_entry ; init 1st and last entries of sin tb #(sin_entry_+90),sin_end DEVICE=F243 #1,led_data ; Reset LED display on EVM led_data,LED_ADDR ; Set LED display #led_freq_,led_subdvdr ; reset sub-divider counter #1,led_dir ; set LED display direction #_OVERCURRENT_TRIP_FLAG ; set DP Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 29 Application Report SPRA524 splk #0,_OVERCURRENT_TRIP_FLAG ; reset overcurrent flag ldp splk #phantom_int #0,phantom_int ; enbl_sd LDP lacc or sacl lacc or and sacl #PCDATDIR>>7 PCDATDIR #00020h PCDATDIR PDDATDIR #01000h #0FFEFh PDDATDIR ; Enable SD inverter ; ; ; pull LabDrive reset high ; ; ; ; Enable LabDrive enbl_pwmg LDP SPLK #T1CON>>7 ; Enable GPT1 and PWM'ing #1000100001000010b,T1CON cfg_ints ldp SPLK #EVIFRA>>7 #0fffh,EVIFRA SPLK #0ffh,EVIFRB SPLK #0fh,EVIFRC SPLK #0201h,EVIMRA SPLK SPLK LDP SPLK splk #0,EVIMRB ; #0,EVIMRC ; #0 ; #0ffh,IFR ; #00001111b,IMR EINT ; Cfg interrupts ; Clear all Group A ; interrupt flags ; Clear all Group B ; interrupt flags ; Clear all Group C ; interrupt flags ; Mask all but GPT1 UF&PDPINT ; Group A ints Mask all ints Mask all Grp C ints point to memory page 0 Clear all core interrupt flags ; Unmask all EV ; interrupts+INT1 to CPU ; Enable global interrupt ;=================================================================== ; Start of background loop ;------------------------------------------------------------------main_loop ldp #PCDATDIR>>7 ; set DP lacc PCDATDIR ; and #0FFFBh ; IOPC[2] to 0 sacl PCDATDIR ; update_f up_butn ldp BIT Ldp BCND SPLK #PBDATDIR>>7 PBDATDIR,BIT6 #upbutcntr up_butn,TC #0,upbutcntr ; ; ; ; ; Has UP been pushed? point at page 0 of B1 UP button if yes Clear UP count if no Ldp BIT ldp BCND SPLK B #PBDATDIR>>7 PBDATDIR,BIT7 #dnbutcntr dn_butn,TC #0,dnbutcntr pbutnend ; ; ; ; ; ; point at sys reg page 1 Has DN been pushed? point at page 0 of B1 DN button if yes? Cleat DN count if no Return LACC ADD upbutcntr one ; Inc. UP count Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 30 Application Report SPRA524 dn_butn SACL SUB BCND SPLK LACC ADD SACL SUB BCND SPLK B upbutcntr #but_qual_ pbutnend,LT #0,upbutcntr set_f one set_f #7fe0h pbutnend,LEQ #7fe0h,set_f pbutnend LACC ADD SACL SUB BCND SPLK LACC SUB SACL BCND SPLK dnbutcntr one dnbutcntr #but_qual_ pbutnend, LT #0,dnbutcntr set_f one set_f pbutnend,GEQ #0,set_f ; Qualified? ; Return if no ; Reset count if yes & ; Inc set frequency ; ; ; ; Bigger than max? Return if no Saturate if yes & return ; Inc. DN count ; ; ; ; Qualified? Return if not Reset count if yes & Dec set frequency ; Return if no ; Saturate if yes & pbutnend ; Comment out following line to use push button to control speed SPLK #debug_data,set_f ; Replace with debug data f2omega LT MPY PAC SACH lacc sub BGZ splk set_f f_omega ; set f -> omega: D0 ; D0*D10=D(10+1) ; product -> ACC: D11 omega,1 ; -> set angular speed: D10 omega ; #min_omega_ ; compare W with its lower limit winlimit ; continue if within limit #min_omega_,omega ; saturate if not winlimit ; Note the following implies constant v/f omega2v LT omega ; set angular speed -> T: D10 MPY omega_v ; D10*D-9=D(1+1) PAC ; product -> ACC: D2 SACH set_v,1 ; -> mag of ref voltage and -> D1 lacc set_v ; sub #max_v_ ; compare Uout w/ its upper limit BLEZ uinuplim ; continue if within limit splk #min_v_,set_v ; saturate if not B uinlolim ; uinuplim LACC set_v ; SUB #min_v_ ; compare Uout with its lower limit BGEZ uinlolim ; continue if within limit splk #min_v_,set_v ; saturate if not uinlolim update_led .if ldp lacc DEVICE=F243 #led_subdvdr led_subdvdr ; ; Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 31 Application Report SPRA524 sub sacl BNZ splk right_shift updateled noledupdate one ; update sub_divide counter led_subdvdr ; time to update LED display? noledupdate ; no #led_freq_,led_subdvdr ; yes, reset ; subdivide counter bit led_dir,BIT0 ; left shift? bcnd right_shift,NTC ; no lacc led_data,1 ; yes sacl led_data ; left shift one bit bitled_data,BIT7 ; time to change direction? bcnd updateled,NTC ; no splk #0,led_dir ; yes b updateled ; lacc led_data,15 ; sach led_data ; right shift one bit bit led_data,BIT0 ; time to change direction? bcnd updateled,NTC ; no splk #1,led_dir ; yes out led_data,LED_ADDR ; update LED display .endif reset_wd LDP SPLK SPLK SPLK #WDKEY>>7 ; Reset WD timer #wd_rst_1,WDKEY ; #wd_rst_2,WDKEY #0000000001101111b,WDCR Ldp lacc or sacl B #PCDATDIR>>7 PCDATDIR #00004h PCDATDIR main_loop ; set DP ; ; IOPC[2] to 1 ; ; End of background loop ;================================================================== ; Phantom interrupt ;-----------------------------------------------------------------.bss phantom_int,1 ; phantomisr ldp #phantom_int splk #0badh,phantom_int ; ret ;=================================================================== ; PDPINT interrupt service ;------------------------------------------------------------------.bss _OVERCURRENT_TRIP_FLAG,1 ; _c_int1 SST SST LDP SACH SACL #ST0,ST0_save #ST1,ST1_save #ACCH ACCH ACCL Ldp LACC #PIVR>>7 PIVR SUB #020h ; ; ; ; ; ; INT1 dispatcher save status register ST0 save status register ST1 set DP save ACC ; set DP ; load peripheral INT ; vector/ID/offset ; PDPINT? Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 32 Application Report SPRA524 bcnd call b not_pdp,NEQ pdp_isr rest_int1 not_pdp call phantomisr ; got a phantom int if not rest_int1 ldp ZALH ADDS LDP LST LST EINT RET #ACCH ACCH ACCL #0 #ST1,ST1_save #ST0,ST0_save ; ; ; ; ; ; ; ; ldp splk ret #_OVERCURRENT_TRIP_FLAG #1,_OVERCURRENT_TRIP_FLAG pdp_isr ; not pdp ; pdp_isr ; set DP restore ACC high restore ACC low point to B2 restore status register ST1 restore status register ST0 return ; set DP ; set flag ;=================================================================== ; Interrupt driven inner loop for PWM ;------------------------------------------------------------------_c_int2 SST #ST0,ST0_save ; save status register ST0 SST #ST1,ST1_save ; save status register ST1 LDP #ACCH ; set DP MAR *,AR0 ; set ARP SACH ACCH ; SACL ACCL ; save ACC Sph P_hi ; spl P_lo ; save P register mpy #1 ; P<=T spl T_save ; save T register sar AR0,AR0_save ; save AR0 rest_cntxt ldp LACC SUB cc b #PIVR>>7 PIVR #029h t1uf_isr,EQ rest_cntxt ; ; ; ; set DP read id of int GPT1 UF INT? T1UF isr if yes call phantomisr ; got a phantom int if not LDP lar lt mpy lph lt ZALH ADDS LDP LST LST EINT RET #ACCH AR0, AR0_save P_lo #1 P_hi T_save ACCH ACCL #0 #ST1,ST1_save #ST0,ST0_save ; ; ; ; ; ; ; ; ; ; ; ; ; set DP restore AR0 T<=P_lo P (low byte) <=1*P_lo P high byte <=P_hi restore T restore ACC point to B2 restore status register ST1 restore status register ST0 return ;=================================================================== ; SV PWM routine Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 33 Application Report SPRA524 ; The routine refers to the following variables: ; omega - set angular frequency with scale of D10 in unit of rad ; t_sample - sampling period with scale of D-9 in unit of second ; t1_period_ - T1 period, the maximum compare value ;------------------------------------------------------------------t1uf_isr ldp #EVIFRA>>7 ; splk #0200h,EVIFRA ; clear GPT1 UF INT flag ldp #PCDATDIR>>7 ; set DP lacc PCDATDIR ; and #0FFF7h ; IOPC[3] to 0 sacl PCDATDIR ; ;------------------------------------------------------------------; Generate revolving voltage vector Uout=trans(Ud Uq) ;------------------------------------------------------------------ldp #omega ; Integrate speed to get phase LT omega ; set W -> T: D10 MPY t_sample ; D10*D-9=D(1+1) PAC ; product -> ACC: D2 SFR ; -> D3 ADDH theta_h ; D3+D3=D3 (32 bit) ADDS theta_l ; SACH theta_h ; save SACL theta_l ; chk_lolim bcnd chk_uplim,GEQ ; check upper limit if positive ADDH theta_360 ; D3+D3=D3, rollover if not SACH theta_h ; save B rnd_theta ; chk_uplim SUBH bcnd SACH B theta_360 ; D3-D3=D3 compare with 2*pi rest_theta,LEQ ; resume theta_h if within limit theta_h ; rollover if not rnd_theta ; rest_theta rnd_theta ADDH ADD SACH theta_360 #1,15 theta_r ; resume theta high ; round up to upper 16 bits ; ;------------------------------------------------------------------; Quadrant mapping ;------------------------------------------------------------------LACC one ; assume theta (theta_h) is in ; quadrant 1 SACL SS ; 1=>SS, sign of SIN(theta) SACL SC ; 1=>SC, sign of COS(theta) LACC theta_r ; SACL theta_m ; theta=>theta_m SUB theta_90 ; BLEZ E_Q ; jump to end if 90>=theta splk LACC SUB SACL BGEZ ; assume theta (theta_h) is in quadrant 2 #-1,SC ; -1=>SC theta_180 ; theta_r ; 180-theta theta_m ; =>theta_m E_Q ; jump to end if 180>=theta ; assume theta (theta_h) is in quadrant 3 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 34 Application Report SPRA524 splk LACC SUB SACL LACC SUB BGEZ #-1,SS theta_r theta_180 theta_m theta_270 theta_r E_Q ; ; ; ; ; ; ; -1=>SS splk LACC SUB SACL #1,SC theta_360 theta_r theta_m ; theta (theta_h) is in quadrant 4 ; 1=>SC ; ; ; 360-theta_h=>theta_m theta-180 =>theta_m jump to end if 270>=theta E_Q ;------------------------------------------------------------------; sin(theta), cos(theta) ;------------------------------------------------------------------lt theta_m ; D3. Find index mpy theta_i ; D3*D6=D(9+1) pac ; D10 sach sin_indx ; D10 lacc sin_indx,11 ; r/s 5 by l/s 11 -> integer (D15) sach sin_indx ; right shift 5 bits => D15 lacc add tblr lacc sub tblr sin_entry sin_indx sin_theta sin_end sin_indx cos_theta ; Look up sin ; ; ; ; ; LT MPY PAC SACL LT MPY PAC SACL SS sin_theta ; ; ; ; ; ; ; ; sin_theta SC cos_theta cos_theta Look up cos modify sign: D15*D1=D(16+1) left shift 16 bits and save: D1 modify sin: D15*D1=D(16+1) left shift 16 bits and save: D1 ;------------------------------------------------------------------; The following 4 lines are for purpose of debugging ;------------------------------------------------------------------; lacc sin_theta,10 ; ; add #04000h,10 ; Add 1 ; ldp #T2CMPR>>7 ; ; sach T2CMPR ; save to T2CMPR for debug ;------------------------------------------------------------------; Calcualte Ud & Uq ;------------------------------------------------------------------LT set_v ; set v -> T: D1 MPY cos_theta ; set v*cos(theta): D1*D1=D(2+1) PAC ; product -> ACC: D3 SACH Ud,1 ; d component of ref Uout: D2 MPY sin_theta ; set v*sin(theta): D1*D1=D(2+1) PAC ; product -> ACC: D3 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 35 Application Report SPRA524 SACH Uq,1 ; q component of ref Uout: D2 ;------------------------------------------------------------------; Determine sector ;------------------------------------------------------------------lt theta_r ; D3 mpy theta_s ; D3*D0=D4 pac sach sector ; lacc sector,5 ; r/s 11 by l/s 5 -> integer (D15) sach sector ; right shift 11 bits ;------------------------------------------------------------------; Calculate T1&T2 based on: Tpwn Uout=V1*T1+V2*T2 ; ; i.e. [T1 T2]=Tpwn*inverse[V1 V2]*Uout ; i.e. [0.5*T1 0.5*T2]=Tp*inverse[V1 V2]*Uout ; i.e. [0.5*C1 0.5*C2]=inverse[V1 V2]*Uout=M(sector)*Uout ; ; where C1=T1/Tp, C2=T2/Tp, are normalized wrt Tp ; M(sector)=inverse of [V1 V2] = decomposition matrix ; obtained through table lookup ; Uout=Transpose of [Ud Uq] ; Tp=Timer 1 period = 0.5*Tpwm ; Tpwm=PWM period Tpwm ;------------------------------------------------------------------LACC #dec_ms ADD sector,2 ; SACL temp ; get the pointer LAR AR0,temp ; point to parameter table ; Calculate 0.5*C1 based on 0.5*C1=Ud*M(1,1)+Uq*M(1,2) LT Ud ; D2 MPY *+ ; M(1,1) Ud: D2*D1=D(3+1) PAC ; D4 LT Uq ; D4 MPY *+ ; M(1,2) Uq: D2*D1=D(3+1) APAC ; 0.5*C1: D4+D4=D4 BGEZ cmp1_big0 ; continue if bigger than zero ZAC ; set to 0 if less than 0 cmp1_big0 SACH temp ; 0.5*C1: D4 LT temp ; D4 MPY t1_periods ; D4*D10 = D(14+1) PAC ; D15 .if SVPAT=HWPAT ADD one,16 .endif ; Avoid C1=0 SACH ; 0.5*C1*Tp: D15 cmp_1 ; Calculate 0.5*C2 based on 0.5*C2=Ud*M(2,1)+Uq*M(2,2) LT Ud ; D2 MPY *+ ; M(2,1) Ud: D2*D1=D(3+1) PAC ; D4 LT Uq ; D2 MPY *+ ; M(2,2) Uq: D2*D1=D(3+1) APAC ; 0.5*C2: D4+D4=D4 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 36 Application Report SPRA524 cmp2_big0 BGEZ ZAC SACH LT MPY PAC cmp2_big0 temp temp t1_periods ; ; ; ; ; ; continue if bigger than zero zero it if less than zero 0.5*C2: D4 D4 D4*D10 = D(14+1) D15 .if SVPAT=HWPAT ADD one,16 .endif ; Avoid 0 C2 = 0 SACH ; 0.5*C2*Tp: D15 cmp_2 ; Calculate 0.5*C0 based on 0.5*C3*Tp=Tp*(1-0.5*C1-0.5*C2) LACC #t1_period_ ; SUB cmp_1 ; SUB cmp_2 ; D15 BGEZ cmp0_big0 ; continue if bigger than zero ZAC ; zero it if less than zero cmp0_big0 SACL cmp_0 ; LACC cmp_0,15 ; right shift 1b (by l/s 15b) SACH cmp_0 ; 0.25*C0*Tp .if SVPAT=HWPAT ;------------------------------------------------------------------; Determine the ACTR pattern and reload ACTR and CMPR1&2 ;------------------------------------------------------------------LACC #cckwise_ ADD sector ; point to entry in lookup table TBLR svpat ; get the pattern LAR AR0,#ACTR ; point to ACTR LACC * ; Read ACTR AND #0FFFh ; Clear sv pattern bits OR svpat ; Re-configure sv pattern bits SACL * ; Re-load ACTR LAR LACC SACL AR0,#CMPR1 cmp_1 *+ ; point to CMPR1 ; ; cmp_1=>CMPR1, point to CMPR2 ADD SACL cmp_2 * ; ; cmp_2=>CMPR2 SUB BLEZ SPLK #t1_period_ ; limit CMPR2 in_lmt ; #t1_period_,* in_lmt .endif .if SVPAT=SWPAT ;------------------------------------------------------------------; Determine channel toggling sequence and load compare registers ;------------------------------------------------------------------LACC #first_ ; ADD sector ; point to entry in look up table TBLR first_tog ; get 1st-to-toggle channel LAR AR0,first_tog ; point to the channel LACC cmp_0 ; Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 37 Application Report SPRA524 SACL * ; cmp_0 => the channel LACC ADD TBLR LAR LACC ADD SACL #second_ sector sec_tog AR0,sec_tog cmp_0 cmp_1 * ; ; ; ; ; ; ; LACC #CMPR3 SUB first_tog ADD #CMPR2 SUB sec_tog ADD #CMPR1 SACL temp LAR AR0,temp LACC cmp_0 ADD cmp_1 ADD cmp_2 SACL * .endif ldp lacc or sacl RET #PCDATDIR>>7 PCDATDIR #00008h PCDATDIR ; ; ; ; ; ; ; ; ; ; ; point to entry in look up table get 2nd-to-toggle channel point to the channel cmp_0+cmp_1 => the channel get 3rd-to-toggle channel point to the channel cmp_0+cmp_1+cmp_2 =>the channel ; set DP ; ; IOPC[3] to 1 ; ; return .data ;------------------------------------------------------------------; Frequently used angles ;------------------------------------------------------------------******************************************************************** ** The order between these angles and the decomposition ** ** matrices in the following must not be changed. ** ******************************************************************** angles_ .WORD 01922h ; pi/2: D3 .WORD 03244h ; pi: D3 .WORD 04b66h ; 3*pi/2: D3 .WORD 06488h ; 2*pi: D3 .if SVPAT=SWPAT ;------------------------------------------------------------------; Decomposition matrices indexed by the sector Uout is in for s/w ; implemented SV PWM scheme ;------------------------------------------------------------------.WORD 20066 ; D1 .WORD -11585 .WORD 0 .WORD 23170 .WORD .WORD .WORD .WORD -20066 11585 20066 11585 .WORD 0 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 38 Application Report SPRA524 .WORD .WORD .WORD 23170 -20066 -11585 .WORD .WORD .WORD .WORD 0 -23170 -20066 11585 .WORD .WORD .WORD .WORD -20066 -11585 20066 -11585 .WORD .WORD .WORD .WORD .endif 20066 11585 0 -23170 .if SVPAT=HWPAT ;------------------------------------------------------------------; Decomposition matrices indexed by the sector Uout is in for h/w ; implemented SV PWM scheme ;------------------------------------------------------------------.WORD 20066 ; D1 .WORD -11585 .WORD 0 .WORD 23170 .WORD .WORD .WORD .WORD 20066 11585 -20066 11585 .WORD .WORD .WORD .WORD 0 23170 -20066 -11585 .WORD .WORD .WORD .WORD -20066 11585 0 -23170 .WORD .WORD .WORD .WORD -20066 -11585 20066 -11585 .WORD .WORD .WORD .WORD .endif 0 -23170 20066 11585 .if SVPAT=SWPAT ;------------------------------------------------------------------- Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 39 Application Report SPRA524 ; Addresses of compare registers of the 1st-to-toggle channels ; indexed by the sector, ref v is in ;------------------------------------------------------------------first_ .WORD CMPR1 ; .WORD CMPR2 ; .WORD CMPR2 ; .WORD CMPR3 ; .WORD CMPR3 ; .WORD CMPR1 ; ;------------------------------------------------------------------; Addresses of compare registers of the 2nd-to-toggle channels ; indexed by the sector, ref v is in ;------------------------------------------------------------------second_ .WORD CMPR2 ; .WORD CMPR1 ; .WORD CMPR3 ; .WORD CMPR2 ; .WORD CMPR1 ; .WORD CMPR3 ; .endif .if SVPAT=HWPAT ;------------------------------------------------------------------; Lookup table for ACTR[15-12] indexed by sector number ;------------------------------------------------------------------cckwise_ .WORD 0001000000000000b .WORD 0011000000000000b .WORD 0010000000000000b .WORD 0110000000000000b .WORD 0100000000000000b .WORD 0101000000000000b .endif ;----------------------------------------------------------; sine table for theta from 0 to 90 per every 1 degree ;----------------------------------------------------------sin_entry_ ; sin table .WORD 0 ; D1 .WORD 286 .WORD 572 .WORD 857 .WORD 1143 .WORD 1428 .WORD 1713 .WORD 1997 .WORD 2280 .WORD 2563 .WORD 2845 .WORD 3126 .WORD 3406 .WORD 3686 .WORD 3964 .WORD 4240 .WORD 4516 .WORD 4790 .WORD 5063 .WORD 5334 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 40 Application Report SPRA524 .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD 5604 5872 6138 6402 6664 6924 7182 7438 7692 7943 8192 8438 8682 8923 9162 9397 9630 9860 10087 10311 10531 10749 10963 11174 11381 11585 11786 11982 12176 12365 12551 12733 12911 13085 13255 13421 13583 13741 13894 14044 14189 14330 14466 14598 14726 14849 14968 15082 15191 15296 15396 15491 15582 15668 15749 15826 15897 15964 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 41 Application Report SPRA524 .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD .WORD 16026 16083 16135 16182 16225 16262 16294 16322 16344 16362 16374 16382 16384 Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined Switching Patterns 42 Application Report SPRA524 TI Contact Numbers INTERNET TI Semiconductor Home Page www.ti.com/sc TI Distributors www.ti.com/sc/docs/distmenu.htm PRODUCT INFORMATION CENTERS Americas Phone +1(972) 644-5580 Fax +1(972) 480-7800 Email [email protected] Europe, Middle East, and Africa Phone Deutsch +49-(0) 8161 80 3311 English +44-(0) 1604 66 3399 Español +34-(0) 90 23 54 0 28 Francais +33-(0) 1-30 70 11 64 Italiano +33-(0) 1-30 70 11 67 Fax +44-(0) 1604 66 33 34 Email [email protected] Japan Phone International +81-3-3457-0972 Domestic 0120-81-0026 Fax International +81-3-3457-1259 Domestic 0120-81-0036 Email [email protected] Asia Phone International +886-2-23786800 Domestic Australia 1-800-881-011 TI Number -800-800-1450 China 10810 TI Number -800-800-1450 Hong Kong 800-96-1111 TI Number -800-800-1450 India 000-117 TI Number -800-800-1450 Indonesia 001-801-10 TI Number -800-800-1450 Korea 080-551-2804 Malaysia 1-800-800-011 TI Number -800-800-1450 New Zealand 000-911 TI Number -800-800-1450 Philippines 105-11 TI Number -800-800-1450 Singapore 800-0111-111 TI Number -800-800-1450 Taiwan 080-006800 Thailand 0019-991-1111 TI Number -800-800-1450 Fax 886-2-2378-6808 Email [email protected] TI is a trademark of Texas Instruments Incorporated. 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