Technical Explanation Board SKiM4 MLI / TMLI Revision: 00 Issue date: 2015-11-12 Prepared by: Ingo Rabl Approved by: Johannes Krapp Keyword: SKiM4, MLI, TMLI, IGBT driver, SKYPER 42LJ, performance, application 1. Introduction ...............................................................................................................................1 1.1 Features ..............................................................................................................................2 1.2 Hardware of the SKiM4 MLI/TMLI driver boards .........................................................................3 2. Safety Instructions .....................................................................................................................5 3. Technical Data ...........................................................................................................................7 3.1 Board SKiM4 MLI / TMLI block diagram ....................................................................................7 3.2 Electrical and mechanical characteristics ..................................................................................7 3.3 Integrated functions ..............................................................................................................9 3.3.1 Thermal protection ..........................................................................................................9 3.3.2 Short circuit protection ....................................................................................................9 3.3.3 Desaturation detection at T1 and T4 ..................................................................................9 3.3.4 Desaturation detection at T2 and T3 ..................................................................................9 3.4 Board description ................................................................................................................ 10 3.4.1 Adjustment of temperature error threshold ...................................................................... 11 3.4.2 Gate resistors ............................................................................................................... 12 3.4.3 Gate-Emitter (GE) components ....................................................................................... 12 3.4.4 VCE,Desat components ...................................................................................................... 13 3.4.5 Error interaction of driver T1/T4 and driver T2/T3 ............................................................. 13 3.4.6 Error handling of driver T1/T4 and driver T2/T3 ................................................................ 13 3.4.7 Interlock time of driver T1/T4 and driver T2/T3 ................................................................ 14 4. User Interface .......................................................................................................................... 15 4.1 Board SKiM4 MLI / TMLI interface.......................................................................................... 15 4.1.1 Module interface ........................................................................................................... 15 4.1.2 Temperature sensing interface ........................................................................................ 16 4.2 User interface ..................................................................................................................... 17 5. Restrictions and Requirements ................................................................................................... 17 5.1 Switching pattern of TMLI modules ........................................................................................ 17 5.2 Error treatment ................................................................................................................... 18 5.2.1 Secondary error at T1 (T4) ............................................................................................. 18 5.2.2 Secondary side error at T2 (T3) ...................................................................................... 18 5.2.3 Error treatment in parallel operation ................................................................................ 18 5.2.4 Error treatment in 3-phase systems ................................................................................ 18 5.3 Design limits gate resistors................................................................................................... 19 5.3.1 Minimum gate resistor ................................................................................................... 19 5.3.2 Power rating of the gate resistors .................................................................................... 19 5.4 Design limits switching frequency .......................................................................................... 19 5.5 Design limits ambient temperature ........................................................................................ 19 5.6 SEMIKRON assembly ........................................................................................................... 19 1. Introduction SEMIKRON set up a driver kit for SKiM4 MLI and SKiM4 TMLI modules for evaluation purposes. The SKiM4 driver boards are able to operate the modules up to a DC-link voltage of 1500V (MLI) respectively 1200V © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI PROMGT.1023/ Rev.4/ Template Technical Explanation Page 1/22 (TMLI) at a maximum switching frequency of 20kHz for SKiM 301 MLI 12E4 and SKiM 601 TMLI 12E4B which are the most powerful modules available. Two standard 2L drivers (SKYPER 42 LJ) are used to operate the two parallel 3L TMLI modules; one driver operates switches T1 and T4 (the outer switches), the other operates the inner switches T2 and T3. The failure management of the two SKYPER 42 LJ drivers detects desaturation events at all four switch positions and also monitors the modules’ built-in temperature sensors. While desaturation of the inner switches (IGBTs T2 and T3) just produces an error message sent to the user interface, desaturation of the outer switches (IGBTs T1 and T4) as well as exceeding a set sensor temperature leads to immediate safe shut-off of the outer IGBTs and an error signal. Figure 1: MLI (left) and TMLI (common emitter; right) DC+ T1 D1 T2 D2 DC+ D5 N D1 T1 D2 AC T3 AC N T3 D3 D6 T2 D3 T4 D4 D4 T4 DC- DC- This Application Sample is dedicated to both universities and professional development engineers. It offers an easy way to set up high power inverters with SKiM4 MLI and TMLI modules using 2L drivers. 1.1 Features The SKiM4 driver boards are designed for the SKiM4 MLI modules with 650V or 1200V semiconductors at all switch positions (“Board SKIM4 MLI”) respectively SKiM4 TMLI modules with 1200V semiconductors at the vertical and 650V semiconductors at the horizontal branch (“Board SKiM4 TMLI”). All MLI/TMLI modules (different current rating, different voltage rating) can be operated with this driver board as long as they are pin-compatible (this is valid for all SEMIKRON SKiM4 modules) and the design limits are met (e.g. maximum DC voltage and maximum SKYPER 42 LJ output power may not be exceeded). Please note that MLI modules may only be operated with the Board SKiM4 MLI and TMLI modules may only be operated with the Board SKiM4 TMLI in order to avoid malfunction or damage. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 2/22 Figure 2: SKiM4 1.2 Hardware of the SKiM4 MLI/TMLI driver boards The SKiM4 MLI/TMLI driver boards consist of one printed circuit board (PCB) each; the PCB is directly mounted onto the SKiM4 module (item number 45120701 for MLI and 45121301 for TMLI). The PCBs provide sockets for two SKYPER 42 LJ drivers and a user interface. Figure 3: SKiM4 MLI driver board © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 3/22 The SKiM4 modules (voltage / current rating, MLI / TMLI) may be chosen according to the desired application. Figure 4: SKiM4 TMLI driver board Depending on the power rating and the operating conditions (voltage, current, inductance of the DC-link connection) it might be necessary to adjust gate resistors, clamping voltage and trip levels of the safety circuits. The Gerber files of both boards are available on request. For ordering the boards or the files please contact your SEMIKRON sales partner. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 4/22 2. Safety Instructions The Board SKiM4 MLI / TMLI bares risks when put in operation. Please carefully read and obey the following safety instructions to avoid harm or damage to persons or gear. Table 1: Safety instructions In operation the Board SKiM4 MLI / TMLI inherits high voltages that are dangerous to life! Only qualified personnel should work with this Application Sample. Some parts of the Board SKiM4 MLI / TMLI or connected devices (e.g. heatsink) may reach high temperatures that might lead to burns when touched. When connected to DC-link capacitors it must be made sure that the DC-link voltage is reduced to values below 30V before touching the system. Insulation coordination and testing has been performed regarding a PE connection of one potential. It is mandatory to provide a PE connection with sufficient cross section when operating the Board SKiM4 MLI / TMLI. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 5/22 Table 2: Safety regulations for work with electrical equipment Safety Regulations for work with electrical equipment 1) Disconnect mains! 2) Prevent reconnection! 3) Test for absence of harmful voltages! 4) Ground and short circuit! 5) Cover or close of nearby live parts! To energize, apply in reverse order! Please follow the safety regulations for working safe with the Board SKiM4 MLI / TMLI. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 6/22 3. Technical Data 3.1 Board SKiM4 MLI / TMLI block diagram The electrical block diagrams in Figure 5 and Figure 6 show two parts: the blue marked part is the driver part with gate resistors, clamping circuitry and sockets for the SKYPER 42 LJ drivers. The red part symbolizes the 3-level modules. Figure 5: Board SKiM4 MLI block diagram Board SKiM4 MLI SKiM4 MLI DC+ Driver T1 RG,T1 T1 D1 T2 D2 D5 RG,T2 T2 VCE,T3 SKYPER42 LJ T1 VCE,T2 Driver T4 Interface SKYPER42 LJ VCE,T1 RG,T3 AC N T3 Driver T2 VCE,T4 Driver T3 RG,T4 T3 D3 T4 D4 D6 T4 NTC DC- Figure 6: Board SKiM4 TMLI block diagram Board SKiM4 TMLI SKiM4 TMLI Driver T1 RG,T1 T1 VCE,T2 RG,T2 D1 T1 T2 D2 VCE,T3 SKYPER42 LJ DC+ Driver T4 Interface SKYPER42 LJ VCE,T1 RG,T3 T3 T3 N AC T2 D3 Driver T2 VCE,T4 Driver T3 RG,T4 D4 T4 T4 NTC DC- 3.2 Electrical and mechanical characteristics With regard to the requirement specification the Board SKiM4 MLI / TMLI allows for operation within the following boundaries: - Max. DC-link voltage VDC = 1500V (1200V) in total, max. 750V (600V) per individual DClink half for MLI (TMLI) - Max. AC voltage VAC = 1000VRMS (690VRMS) line-to-line for MLI (TMLI) Max. switching frequency fsw = 20kHz (see chapter 5.4 for further information) Ambient temperature Ta = 0°C…40°C (see chapter 5.5 for further information) Installation altitude ≤ 2000m above sea level IP rating IP 00 Pollution degree PD 2 © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 7/22 Neglecting the above mentioned boundaries may lead to malfunction or damage of the Board SKiM4 MLI / TMLI. Concerning insulation coordination the driver boards have been developed with respect to EN50178. An electrically protective separation is implemented between the user interface (PELV – Protective Extra Low Voltage) and the high voltage connections by using the SKYPER 42 LJ’s protective separation. Up to a DC-link voltage of 1200V reinforced insulation, between 1200V and 1500V basic insulation is realized. The boards are 125mm long and 103mm wide, see Figure 7 and Figure 8. To prevent driver board and the SKYPER 42 LJ drivers from loosening from each other both boards come with mounting holes for dual lock support posts. SEMIKRON recommends nylon support posts from Richco with item no. DLMSPM-8-01. Please find further information in the technical explanation of SKYPER 42 LJ [1]. Figure 7: Dimensions of Board SKiM4 MLI 103mm 125mm The driver boards can be mounted to the modules in two steps. First the particular board needs to be fixed on the module by pressing it to the white plastic hooks until it snaps. Secondly the boards are mounted to the module using ten self-tapping screws of the type “EJOT PT WN1452 K30x8”. The screw head may be chosen by the user. Further information on the mounting process can be found in the technical explanation of SKiM4 [1]. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 8/22 Figure 8: Dimensions of Board SKiM4 TMLI 103mm 125mm The blue marked areas in Figure 7 and Figure 8 indicate the PELV area with the user interface socket. The insulation is provided by the galvanic insulation of the SKYPER 42 LJ drivers. All area besides the blue marking may be considered as high voltage area. 3.3 Integrated functions The Board SKiM4 MLI / TMLI have some integrated safety functions to protect the device from certain harmful conditions. 3.3.1 Thermal protection The module’s built-in NTC temperature sensor is monitored. At a pre-defined temperature (to be defined by the user by adjusting a resistor; standard setting is 115°C) a secondary-side error triggers the error-input of the SKYPER 42 LJ responsible for IGBTs T1 and T4. IGBTs T1 and T4 are switched off immediately and the error is transmitted from secondary side (high voltage) to primary side (PELV) by the driver. On the primary side an error is set and the user can react accordingly. 3.3.2 Short circuit protection A shoot-through from DC+ to DC- by applying incorrect PWM pattern is prohibited by the interlock function between T1 and T4: it is not possible to turn on both IGBTs at the same time. The interlock time is 2µs. 3.3.3 Desaturation detection at T1 and T4 The voltage drop across the outer IGBTs T1 and T4 is measured while conducting. As soon as the voltage rises above a pre-defined value (that correlates to very high current of a desaturation event) an error message is generated by the driver which the user shall react to. The driver automatically turns off the particular IGBT using the soft-turn-off gate resistor. 3.3.4 Desaturation detection at T2 and T3 The voltage drop across the inner IGBTs T2 and T3 is also measured while conducting. As soon as the voltage rises above a pre-defined value (that correlates to very high current of a desaturation event) an error message is generated by the driver which the user shall react to. The driver does not turn off the desaturated IGBTs by itself; this must be done by the user. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 9/22 3.4 Board description On both boards several components are meant to be changed by the user to achieve an adaptation to the application conditions. The changeable components of the contact board are marked with different coloured frames in Figure 9 and Figure 10; function and possible values are explained in chapters 3.4.1 to 3.4.7. Figure 9: Board SKiM4 MLI; user-changeable components are framed R123 for adjustment of temperature error threshold User access to module built-in NTC 3x MiniMELF pads for turn-on resistors R10, interconnection of errors of the two SKYPER 42 LJ drivers R21 R22 R20 R19 2x MiniMELF pads for turn-off resistors R10 R15 – R18, configuration of error handling of SKYPER 42 LJ drivers 1x MiniMELF pad for softturn-off resistor R19 – R22, configuration of interlock time of the two SKYPER 42 LJ drivers G-E suppressor diode G-E resistor G-E capacitor Aux. power supply 23V, 4mA Pads for adjustment of VCE_Desat detection level Figure 10: Board SKiM4 TMLI; user-changeable components are framed R123 for adjustment of temperature error threshold User access to module built-in NTC 3x MiniMELF pads for turn-on resistors R20 R21 R19 R22 2x MiniMELF pads for turn-off resistors R10, interconnection of errors of the two SKYPER 42 LJ drivers R10 1x MiniMELF pad for softturn-off resistor G-E suppressor diode G-E resistor G-E capacitor Pads for adjustment of VCE_Desat detection level © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI R15 – R18, configuration of error handling of SKYPER 42 LJ drivers R19 – R22, configuration of interlock time of the two SKYPER 42 LJ drivers Aux. power supply 23V, 4mA Page 10/22 3.4.1 Adjustment of temperature error threshold A thermal overload can be detected by evaluating the modules’ built-in NTC sensors. In case a thermal overload is detected the comparator shown in Figure 11 pulls the SKYPER’s error input to GND and so the driver can communicate an error message. The resistor R123 (framed brown in Figure 9 and Figure 10) can be used for adjusting the error temperature threshold. Figure 11: Schematic of NTC evaluation 5k T- T+ 30k1 30k1 NTC inside SKiM4 module 0R to SKYPER 42 LJ error input R123 0R 332R J The standard value for R123 is 332 which refers to a temperature threshold of approximately 115°C. The thermal overload detection is deactivated by removing the two 0 resistors shown in Figure 11. An error is detected, when the voltage at the negative input of the comparator is greater than the voltage at the positive input. The resistance of the NTC at a desired shut-off temperature can be taken from the diagram in Figure 12. With this resistance value the value of R123 can be calculated. Chip resistors with the size 0805 can be used for R123 and the two 0 jumpers. Figure 12: SEMiX5 TMLI NTC characteristic (excerpt) 1000 900 800 700 [] 600 500 400 300 200 100 0 70 80 90 100 110 120 130 140 150 [°C] © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 11/22 Figure 12 shows an excerpt of the SKiM4 MLI/TMLI NTC characteristic which includes the most interesting temperature range between 70°C and 150°C. The full characteristic can be found in the Technical Explanations or can be calculated from the formula given in the SKiM4 MLI/TMLI datasheets [1]. 3.4.2 Gate resistors What is called gate resistor in this document for the sake of convenience is realized by three resistors on the contact board. The SKYPER 42 LJ offers separate connections for turn-on (RGon), turn-off (RGoff) and soft-turn-off (Rsoft), see Figure 13. RGon is used for every turn-on process, RGoff for every turn-off action. In case of an error the driver uses Rsoft instead of the standard RGoff. All resistor positions must be populated for proper operation. Figure 13: Schematic of gate resistor arrangement SKYPER 42 LJ connected to turn-on pin of driver connected to turn-off pin of driver connected to soft-turn-off pin of driver RGon RGoff Rsoft connected to emitter pin of driver Turn-on resistor (RGon) / capacitor The boards offer three pads per IGBT (framed blue in Figure 9 and Figure 10) taking MiniMELF or 1206 sized components. Resistor/capacitor values need to be chosen according to the particular application (DClink voltage, DC-link inductance, switching frequency, switching losses, etc.) so there is no general recommendation. However, the boards come with 3x 13.7 resistors in parallel for immediate start of operation. It is necessary to calculate the power losses of the gate resistor in order not to overload and damage it. Please refer to chapter 5.3 for further information. Turn-off resistor (RGoff) / capacitor The boards offer three pads per IGBT (framed orange in Figure 9 and Figure 10) taking MiniMELF or 1206 sized components. Resistor/capacitor values need to be chosen according to the particular application (DClink voltage, DC-link inductance, switching frequency, switching losses, etc.) so there is no general recommendation. However, the boards come with 3x 13.7 resistors in parallel for immediate start of operation. It is necessary to calculate the power losses of the gate resistor in order not to overload and damage it. Please refer to chapter 5.3 for further information. Soft-turn-off resistor (Rsoft) The boards offer one pad per IGBT (framed green in Figure 9 and Figure 10) taking a MiniMELF or 1206 sized component. The resistor value needs to be chosen according to the particular application (DC-link voltage, DC-link inductance, switching frequency, switching losses, etc.) so there is no general recommendation. However, the boards come with a 47.5 resistor for immediate start of operation. It is recommended to calculate the power losses of the gate resistor in order not to overload and damage it. Please refer to chapter 5.3 for further information. 3.4.3 Gate-Emitter (GE) components For every IGBT the boards offer one pad sized SMB and two pads sized 0805 (framed red in Figure 9 and Figure 10). SEMIKRON recommends to use one of the 0805 sized pads for placing a 10k resistor and the SMB sized pad for placing a 15V bidirectional breakdown-diode for gate protection which is also the standard value the boards are equipped with. The additional 0805 sized pad may be used for a GE capacitor if required. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 12/22 3.4.4 VCE,Desat components For every IGBT the boards offers two pads sized 0805 (framed purple in Figure 9 and Figure 10) for adjusting the VCE,Desat detection level. The standard values are 10k and 820pF for the outer IGBTs T1 and T4 and 15k and 820pF for the inner IGBTs T2 and T3. With these values the detection at the outer switches is more sensitive and it can be made sure that the inner switches will not detect an error before the outer switches. For further information please refer to the technical explanation of SKYPER 42 LJ [1]. 3.4.5 Error interaction of driver T1/T4 and driver T2/T3 The 0805 sized R10 (framed orange-dotted in Figure 9 and Figure 10) on the driver board may either be left open or equipped with a 0 jumper. In case of 0 the error outputs/inputs of the two SKYPER 42 LJ drivers are connected. In case R10 is not connected an error output of one driver would not be communicated to the error input of the other driver immediately. SEMIKRON recommends to equip R10 with 0. Please refer to chapter 5.2 for detailed information. 3.4.6 Error handling of driver T1/T4 and driver T2/T3 The 0805 sized resistors R15-R18 (framed green-dotted in Figure 9 and Figure 10) may be equipped as shown in Table 3 and Table 4. While R15 and R16 set the error handling for the driver of T1 and T4, R17 and R18 set the error handling for the driver of T2 and T3. Any other combination (e.g. all resistors 0 or all resistors not connected) will lead to malfunction and may damage the system. Table 3: Functional table for R15 – R16 (error handling setup for T1 and T4) R15 0 n.c. R16 n.c. 0 The particular driver generates an error signal when a secondary side error occurs, but the concerned IGBTs are not turned off. The driver does not react to an external error signal; it stays in the previous state until it is turned off by PWM (in case of a previous error, the soft-turn-off resistor is used). A continuous error signal prevents the driver from turning on. The particular driver generates an error signal and immediately turns off the concerned IGBTs using the soft-turn-off resistors when a secondary side error occurs. In case an external error signal is applied the driver turns off the two IGBTs. A continuous error signal prevents the driver from turning on. Default setup (recommended) Function ➔ © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 13/22 Table 4: Functional table for R17 – R18 (error handling setup for T2 and T3) R17 0 n.c. R18 n.c. 0 The particular driver generates an error signal when a secondary side error occurs, but the concerned IGBTs are not turned off. The driver does not react to an external error signal; it stays in the previous state until it is turned off by PWM (in case of a previous error, the soft-turn-off resistor is used). A continuous error signal prevents the driver from turning on. Default setup (recommended) The particular driver generates an error signal and immediately turns off the concerned IGBTs using the soft-turn-off resistors when a secondary side error occurs. In case an external error signal is applied the driver turns off the two IGBTs. A continuous error signal prevents the driver from turning on. Function ➔ 3.4.7 Interlock time of driver T1/T4 and driver T2/T3 The 0805 sized resistors R19-R22 (framed red-dotted in Figure 9 and Figure 10) may be equipped as shown in Table 5 and Table 6. R19 and R20 set the interlock function for the driver of T2 and T3, R21 and R22 set the interlock time for the driver of T1 and T4. Any other combination (e.g. all resistors 0 or all resistors not connected) will lead to malfunction and may damage the system. Table 5: Functional table for R19 – R20 (interlock setup for T2 and T3) R19 0 n.c. R20 n.c. 0 The interlock time between T2 and T3 is set to 0. That means that both IGBTs may be switched on at the same time. Default setup (recommended) The interlock time between T2 and T3 is activated and set to 2µs. That means that one IGBT may be switched on 2µs after the other IGBT switched off. The two IGBTs cannot be turned on at the same time. Function ➔ Table 6: Functional table for R21 – R22 (interlock setup for T1 and T4) R21 0 n.c. R22 n.c. 0 The interlock time between T1 and T4 is set to 0. That means that both IGBTs may be switched on at the same time. The interlock time between T1 and T4 is activated and set to 2µs. That means that one IGBT may be switched on 2µs after the other IGBT switched off. The two IGBTs cannot be turned on at the same time. Default setup (recommended) Function ➔ © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 14/22 4. User Interface 4.1 Board SKiM4 MLI / TMLI interface The two driver boards connect to a SKiM4 MLI or a SKiM4 TMLI (or compatible) module on the bottom side, to two SKYPER 42 LJ and the user on the top side. 4.1.1 Module interface The pinout of a SKiM4 MLI and SKiM4 TMLI module is shown in Figure 14 and explained in Table 7. All modules that are pin-compatible may be used with the driver kit. Figure 14: SKiM4 interface © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 15/22 Table 7: SKiM4 MLI (TMLI) pin description Pin Description Pin Description 1 n.c. (n.c.) 20 n.c. (n.c.) 2 n.c. (n.c.) 21 n.c. (Emitter IGBT T3) 3 Collector IGBT T1 (n.c.) 22 n.c. (n.c.) 4 DC+ terminal (DC+ terminal) 23 n.c. (Gate IGBT T3) 5 N terminal (N terminal) 24 AC terminal (AC terminal) 6 N auxiliary (Gate IGBT T2) 25 Gate IGBT T2 (n.c.) 7 n.c. (n.c.) 26 n.c. (n.c.) 8 n.c. (Emitter IGBT T2) 27 Emitter IGBT T2 (n.c.) 9 N terminal (N terminal) 28 n.c. (n.c.) 10 DC- terminal (DC- terminal) 29 n.c. (Emitter IGBT T1) 11 Emitter IGBT T4 (Collector IGBT T2) 30 n.c. (n.c.) 12 n.c. (n.c.) 31 n.c. (Gate IGBT T1) 13 Gate IGBT T4 (n.c.) 32 Emitter IGBT T1 (n.c.) n.c. (n.c.) 33 n.c. (n.c.) 15 n.c. (n.c.) 34 Gate IGBT T1 (n.c.) 16 n.c. (n.c.) 35 NTC sensor (NTC sensor) 17 Emitter IGBT T3 (Emitter IGBT T4) 36 n.c. (n.c.) 18 n.c. (n.c.) 37 NTC sensor (NTC sensor) 19 Gate IGBT T3 (Gate IGBT T4) 38 n.c. (n.c.) 14 Further information about module mounting, etc. may be found in the module datasheets and the SKiM4 technical explanation [1]. 4.1.2 Temperature sensing interface In case the internal temperature shut-off shall be replaced by an external (user-side) temperature evaluation, the two 0 jumpers need to be removed; that deactivates the internal temperature error detection and disconnects the NTC sensor from the on-board circuits. The user can access the NTC directly using the solder pads T+ and T- (framed blue-dotted in Figure 9 and Figure 10). If required the auxiliary power supply of the driver’s secondary side can supply 23V at max. 4mA for the user’s temperature evaluation circuit. The power supply can be found in the purple-dotted box in Figure 9 and Figure 10. Please note that the temperature sensor and the aforementioned power supply has no protective separation from high voltage circuits! © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 16/22 4.2 User interface The user interface is the 20-pin connector X10 located in the middle of the driver board. The pin description is given in Table 8 and is valid for both MLI and TMLI driver board. Table 8: X10 pin description Pin Signal name Description Voltage level 1 IF_PWR_VP Driver supply voltage 2 IF_PWR_VP Driver supply voltage 3 GND Ground 0V 4 GND Ground 0V 5 GND Ground 0V 6 IF_CMN_T1 PWM pattern IGBT T1 Off=0V / On=15V; Rin=10k / 1nF 7 GND Ground 0V 8 IF_CMN_T2 PWM pattern IGBT T2 Off=0V / On=15V; Rin=10k / 1nF 9 GND Ground 0V 10 IF_CMN_T3 PWM pattern IGBT T3 Off=0V / On=15V; Rin=10k / 1nF 11 GND Ground 0V 12 IF_CMN_T4 PWM pattern IGBT T4 Off=0V / On=15V; Rin=10k / 1nF 13 GND Ground 0V 14 GND Ground 0V 15 IF_CMN_NERR_1 Error input/output T1/T4 Error=0V / ready-for-operation=15V (Pull-Up to 15V on user-side; Rpull-up=1.8k..10k) 16 GND Ground 0V 17 IF_CMN_NERR_2 Error input/output T2/T3 Error=0V / ready-for-operation=15V (Pull-Up to 15V on user-side; Rpull-up=1.8k..10k) 18 GND Ground 0V 19 GND Ground 0V 20 GND Ground 0V 5. 15VDC±4%, max. 0.5A Restrictions and Requirements This chapter claims some restrictions that must be paid attention to in order to avoid damage to driver kit or power semiconductor. 5.1 Switching pattern of TMLI modules A detailed explanation of the TMLI switching pattern is given in the SEMIKRON Application Note AN11001 [3]. Summed up always an inner IGBT (T2 or T3) may be switched on first, the corresponding outer IGBT (T1 or T4) after a short while, namely when the inner IGBT is entirely switched on. For switch-off this sequence must be maintained in reverse order: it must be made sure that T1 (T4) is thoroughly turned off before T2 (T3) may be switched off. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 17/22 This sequence is recommended to be maintained at any time, even and especially in case of emergency shut-down (e.g. because of over current or desaturation). In case all IGBTs are turned off simultaneously a current through T1 would not commutate to T2 but to D4 instead. As this commutation loop inherits a higher inductance a higher voltage overshoot would happen at the turning-off IGBT (here: T1). If the voltage applied to T1 exceeded the blocking voltage T1 would be destroyed. If switching off all IGBTs simultaneously is recommended it must be made sure that the voltages across the semiconductors do never exceed the blocking voltages. 5.2 Error treatment If a desaturation event occurs, the desaturated IGBT must be turned off within 10µs, otherwise it might be destroyed by this extreme overload. The correct turn-of sequence (inner IGBT first, outer IGBT afterwards) is recommended to be maintained to prevent the commutating semiconductors from overvoltage. The user can influence the error management by equipping or not connecting R10 on the driver board; SEMIKRON recommends to equip R10 with 0W. For an error at T1 (T4) it makes no difference if it is equipped or not, but in case of an error at T2 (T3) the turn-off sequence is faster. The error treatments are described below. In any case the user needs to react appropriately to error messages sent from the Board SKiM4 MLI / TMLI: the correct switching pattern is recommended and a switch-off time below 10µs ins mandatory to avoid damage. 5.2.1 Secondary error at T1 (T4) In case a secondary side error (e.g. desaturation) occurs at an outer IGBT (T1 or T4) the error signal is communicated to the driver’s primary side and an error message is produced and sent to the user interface using pin 15 of X10 (see Table 8). At the same time the particular IGBT (T1 or T4) is turned off using the soft-turn-off resistor. When resistor R10 on the driver board is equipped with 0 the error message from driver of T1 and T4 is sent to the error input of the driver of T2 and T3. This error message at the input prevents the driver from turning on as long as the error message is active. If IGBTs T2 or T3 are in on-state when the error message is received by the error input, however, the IGBTs are not turned off as long as the PWM signal of T2 (T3) is active. As soon as the PWM signal turns off the IGBTs are turned off. Not connecting R10 does not make a difference: the error message from driver of T1 and T4 will not be sent to driver of T2 and T3 and the correct and in-time shut-off needs to be ensured by the user. 5.2.2 Secondary side error at T2 (T3) In case a secondary side error (e.g. desaturation) occurs at an inner IGBT (T2 or T3) the error signal is communicated to the driver’s primary side and an error message is produced and sent to the user interface using pin 17 of X10 (see Table 8). In order to maintain the correct turn-off sequence the inner IGBTs are not turned off automatically. When resistor R10 on the driver board is equipped with 0 the error message from driver of T2 and T3 is sent to the error input of the driver of T1 and T4 indicating an immediate turn-off of T1 and T4. When resistor R10 on the driver board is not connected the error message from driver of T2 and T3 is not sent to the error input of the driver of T1 and T4. It is in the responsibility of the user to take care of switching off the short circuit within 10µs using the correct turn-off sequence. In both cases the IGBTs T2 or T3 are switched off with the next regular PWM turn-off. The IGBT which detected the error is switched off using the soft-turn-off resistor, the IGBT without error is turned off using the standard resistors. 5.2.3 Error treatment in parallel operation It is possible to use several driver boards in parallel to increase the inverter’s output power by simply plug all parallel drivers to one controller cable. This methods parallels all PWM signals and also the error messages. The errors of one Board SKiM4 MLI / TMLI would be communicated to the other drivers of one phase leg leading to the error handling as describes above. 5.2.4 Error treatment in 3-phase systems In 3-phase systems there is no direct connection of the driver’ error signals. This connection must be provided by the user; either by a hardware connection of the particular error lines or by routing the error © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 18/22 messages and appropriate handling on the controller side. Please note that time is critical when an error occurs and therefore error treatment shall be performed using fast hardware. 5.3 5.3.1 Design limits gate resistors Minimum gate resistor The minimum gate resistor is determined by the maximum voltage change of the driver during switching; it turns from -8V to +15V or back, so the voltage change is 23V. The peak current SKYPER 42 LJ is capable of driving 20A, so the minimum total gate resistor that needs to be used is 1.15. The total gate resistor consists of the internal gate resistor of the two module (that can be found in the module datasheet) and the gate-turn-on or gate-turn-off resistors RGon and RGoff. The minimum gate resistors can be calculated according to: 𝑅𝐺𝑜𝑛,𝑚𝑖𝑛 = 𝑅𝐺𝑜𝑓𝑓,𝑚𝑖𝑛 = 1.15 − 𝑅𝐺𝑖𝑛𝑡 If this value is ≤0 the value for RGon or RGoff can be chosen to 0 without overpowering the driver. Otherwise this minimum gate resistance must be used to avoid damage to the SKYPER 42 LJ. 5.3.2 Power rating of the gate resistors Depending on the ohmic value of the gate resistors also their power rating needs to be chosen sufficiently high to avoid overload. The gate resistors need to be able to withstand high pulse load. It needs to be made sure by the user to choose suitable resistors. Please note that 1206 sized chip resistors have a lower power and pulse load rating than MiniMELF resistors. Further information about the power rating and correct choice of gate resistors can be found in Application Note AN7003. 5.4 Design limits switching frequency The maximum switching frequency is determined by the used modules and their gate charge and the power of the SKYPER 42 LJ drivers. Further information on calculating the switching frequency limit can be found in Application Note AN7004. 5.5 Design limits ambient temperature This Application Sample has been developed as reference design for laboratory use and tested in the range of 0°C to 40°C accordingly. However, it might be possible to extend the ambient temperature range; the responsibility to test and qualify this larger range remains with the user. 5.6 SEMIKRON assembly SEMIKRON has tested the Application Sample with a specific DC-link, DC-link connection and snubber capacitors. All variable parts (resistors / capacitors, e.g. RGon, RGoff, etc.) are chosen to allow for immediate start of operation. These values are not suitable for optimal operation (e.g. optimized switching losses or minimized voltage overshoots). This work needs be done in the final setup. © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 19/22 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Table Table Table Table Table Table Table Table 1: MLI (left) and TMLI (common emitter; right) .........................................................................2 2: SKiM4 ...............................................................................................................................3 3: SKiM4 MLI driver board ..................................................................................................3 4: SKiM4 TMLI driver board .....................................................................................................4 5: Board SKiM4 MLI block diagram ...........................................................................................7 6: Board SKiM4 TMLI block diagram .........................................................................................7 7: Dimensions of Board SKiM4 MLI ...........................................................................................8 8: Dimensions of Board SKiM4 TMLI .........................................................................................9 9: Board SKiM4 MLI; user-changeable components are framed .................................................. 10 10: Board SKiM4 TMLI; user-changeable components are framed .............................................. 10 11: Schematic of NTC evaluation ........................................................................................... 11 12: SEMiX5 TMLI NTC characteristic (excerpt) ......................................................................... 11 13: Schematic of gate resistor arrangement ............................................................................ 12 14: SKiM4 interface .............................................................................................................. 15 1: 2: 3: 4: 5: 6: 7: 8: Safety instructions ..............................................................................................................5 Safety regulations for work with electrical equipment ..............................................................6 Functional table for R15 – R16 (error handling setup for T1 and T4) ........................................ 13 Functional table for R17 – R18 (error handling setup for T2 and T3) ........................................ 14 Functional table for R19 – R20 (interlock setup for T2 and T3) ................................................ 14 Functional table for R21 – R22 (interlock setup for T1 and T4) ................................................ 14 SKiM4 MLI (TMLI) pin description ........................................................................................ 16 X10 pin description ............................................................................................................ 17 © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 20/22 Symbols and Terms Letter Symbol Term 2L Two level 3L Three level DC- Negative potential (terminal) of a direct voltage source DC+ Positive potential (terminal) of a direct voltage source fsw Switching frequency GND Ground IGBT Insulated Gate Bipolar Transistor N Neutral potential (terminal) of a direct voltage source; midpoint between DC+ and DC- n.c. not connected NTC Temperature sensor with negative temperature coefficient PELV Protective Extra Low Voltage PWM Pulse Width Modulation RGint Internal gate resistance RGoff External gate series resistor at switch-off RGon External gate series resistor at switch-on RMS Root Mean Square SELV Safety Extra Low Voltage t Time Ta Ambient temperature Tj Junction temperature TNPC T-type Neutral Point Clamped VCE Collector-emitter voltage VDC Total supply voltage between DC+ and DC- A detailed explanation of the terms and symbols can be found in the "Application Manual Power Semiconductors" [2] References [1] www.SEMIKRON.com [2] A. Wintrich, U. Nicolai, W. Tursky, T. Reimann, “Application Manual Power Semiconductors”, ISLE Verlag 2011, ISBN 978-3-938843-666 [3] I. Staudt, “3L NPC & TNPC Topology”, SEMIKRON Application Note, AN11001 - rev05, Nuremberg, 2015 [4] M. Hermville, “Gate Resistor – Principles and Applications”, SEMIKRON Application Note, AN7003 rev00, Nuremberg, 2007 [5] M. Hermville, “IGBT Driver Calculation”, SEMIKRON Application Note, AN7004 - rev00, Nuremberg, 2007 © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 21/22 HISTORY SEMIKRON reserves the right to make changes without further notice herein DISCLAIMER SEMIKRON reserves the right to make changes without further notice herein to improve reliability, function or design. Information furnished in this document is believed to be accurate and reliable. However, no representation or warranty is given and no liability is assumed with respect to the accuracy or use of such information, including without limitation, warranties of non-infringement of intellectual property rights of any third party. SEMIKRON does not assume any liability arising out of the application or use of any product or circuit described herein. Furthermore, this technical information may not be considered as an assurance of component characteristics. No warranty or guarantee expressed or implied is made regarding delivery, performance or suitability. This document supersedes and replaces all information previously supplied and may be superseded by updates without further notice. SEMIKRON products are not authorized for use in life support appliances and systems without the express written approval by SEMIKRON. SEMIKRON INTERNATIONAL GmbH P.O. Box 820251 • 90253 Nuremberg • Germany Tel: +49 911-65 59-234 • Fax: +49 911-65 59-262 [email protected] • www.semikron.com © by SEMIKRON / 2015-11-12 / Technical Explanation / Board SKiM4 MLI / TMLI Page 22/22