BELLING BL0952A Three-phase active energy meter Datasheet

ThreeThree-phase Active
Energy Meter
BL0952A/BL6513/BL6511
FEATURES
GENERAL DESCRIPTION
High accuracy, less than 0.1% error over a
The BL0952A/BL6513/BL6511 is the chief IC of
dynamic range of 500:1
the three-phase electrical meter and a high accuracy
energy measurement IC. With low power design,
High stability during calibration, the fluctuation
of output CF is less than 0.1%.
static power is only 25mW. Based on the features such
as superior accuracy, high stability and simple
Low drift, the gain variety is less than 0.1%
when input frequency changes from 45Hz to 65Hz
peripheral circuit, the BL0952A/BL6513/BL6511 is
compatible with 3-phase 3-wire and 3-phase 4-wire
Single 5V Supply, Static Power 25mW(typical),
Power solution only with Resistor & Capacitor can be
BL0952A/BL6513/BL6511 is based on digital
adopted.
configurations.
The Low Frequency Output (F1, F2) can drive
signal processing. BL0952A/BL6513/BL6511 can
motor directly;
measure positive active power and negative active
power; can select the way to calculate the sum of the
The High Frequency Output (CF) can be used in
calibration and data processing.
three-phase active powers, between the arithmetic
sum and the absolute value sum.
Selectable between the arithmetic sum of the
three-phase active energies and the absolute value
The high frequency output CF can be used in
sum of these energies.
calibration and data processing. The low frequency
outputs F1 and F2 can be used to drive a pulse-motor
Measure positive active power and negative
active power.
or an electromechanical counter. In this way, the
power can be measured and the energy can be
Anti-Fault, the Logic Output REVP indicates a
Potential Miswiring or Negative Power for each
phase.
recorded.
The internal phase matching circuitry ensures
On-chip Creep Protection.
that the current and voltage channels are phase
On-chip Power Supply Monitoring.
matched.An internal no-load threshold ensures that
On-chip Reference 2.42V ± 8%,with External
the BL0952A/BL6513/BL6511 does not exhibit any
Overdrive Capability.
creep when there is no load.
SOP24 package.
The
BL0952A/BL6513/BL6511
consider
emphatically the need of stability during calibration,
the measure data of mass products show that the
Interrelated patents are pending
output pulse ripple of CF is less than 0.1%.
System Diagram Block
Fig.1 Functional block diagram
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
PIN FUNCTION DESCRIPTION
Pin No.
Mnemonic
Description
1
CF
High frequency calibration logic output. The output frequency is
proportional to the average active power.
2
DGND
3
VDD
Power supply. This pin provides the supply voltage for the digital
circuitry. The supply voltage should be maintained at 5V ± 5% for
specified operation.
4
REVP
This logic output will go logic high when negative power is detected on
any of the three phase inputs, i.e., when the phase angle between the
voltage and the current signals is greater than 90°.
5,6;
7,8;
9,10
IAP,IAN;
IBP,IBN;
ICP,ICN
Analog inputs for current channel. These inputs are fully differential
voltage inputs with maximum differential input signal levels of
±500mV
11
AGND
12
REF
This pin provides access to the on-chip voltage reference. The on-chip
reference has a nominal value of 2.42V ± 8% and a typical temperature
coefficient of 30ppm/°C. An external reference source may also be
connected at this pin.
13,14,
15,16
VN,VCP
VBP,VAP
Analog inputs for the voltage channel. This channel is intended for use
with the voltage VBP, VAP transducer and is referenced as the voltage
channel in this document. These inputs are single-ended voltage inputs
with maximum signal level of ±500mV with respect to VN for
specified operation.
17
ADDSEL
The logic input is used to select the way the three active energies from
the three phases are summed. This offers the designer the capability to
do the arithmetic sum of the three energies (ADDSEL logic High) or
the sum of the absolute value (ADDSEL logic low).
18
SCF
Select Calibration Frequency. This logic input is used to select the
frequency on the calibration output CF.
19
CLKIN
Master clock for ADCs and digital signal processing. An external clock
can be provided at this logic input.3.58MHz
20
CLKOUT
A crystal can be connected across this pin and CLKIN as described
above to provide a clock source.
21,22
S0,S1
These logic inputs are used to select one of four possible frequencies
for the digital-to-frequency conversion. This offers the designer greater
flexibility when designing the energy meter.
23,24
F1,F2
Low Frequency Logic Outputs. F1 and F2 supply average real power
information. The logic outputs can be used to directly drive
electromechanical counters and two-phase stepper motors.
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This provides the ground reference for the digital circuitry .
This pin provides the ground reference for the analog circuitry.
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
PACKAGE DIMENSIONS
24 PIN SOP
Fig.2
Package of BL0952A/BL6513/BL6511
Absolute Maximum Ratings
( T = 25℃ )
Item
Symbol
Extremum
Unit
Power Voltage VDD
VDD
-0.3~+7(max)
V
Input Voltage to AGND
VV
-VDD+0.5≤VV≤VDD-0.5
V
Input Current to AGND
VI
-VDD+0.5≤VI≤VDD-0.5
V
Operating Temperature Range
Topr
-40~+85
℃
Storage Temperature Range
Tstr
-55~+150
℃
80
mW
Power Dissipation(SOP24)
Electronic Characteristic Parameter
(T=25℃, VDD=5V, CLKIN=3.58MHz)
Parameter
1 Power Current
Symbol
Test Condition
Measure
Pin
IVDD
Min
Value
Typical
Value
Pin3
2 Logic Input Pins
SCF,S0,S1, ADDSEL
Max
Value
Unit
8
mA
Pin17,
18,21,22
Input High Voltage
VIH
Input Low Voltage
VIL
Input Capacitance
CIN
VDD=5V
3
V
1
10
3 Logic Output Pins F1/F2
V
pF
Pin23,24
Output High Voltage
VOH1
IH=10mA
Output Low Voltage
VOL1
IL=10mA
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BL0952A/BL6513
Output Current
IO1
ThreeThree-phase Active
Energy Meter
10
4 Logic Output Pins
REVP, CF
mA
Pin1,4
Output High Voltage
VOH2
IH=10mA
Output Low Voltage
VOL2
IL=10mA
Output Current
IO2
5 On-chip Reference
Vref
4.4
0.5
VDD=5V
Pin12
Temperature Coefficient
6 Analog Input Pins
IAP,IAN,IBP,IBN,ICP,ICN,
VN,VCP,VBP,VAP
Maximum Input Voltage
V
V
5
mA
2.42
V
30
ppm/°C
±500
330
mV
Pin5,6,7,
8,9,10,13
,14,15,16
VAIN
DC Input Impedance
Input Capacitance
6
Kohm
10
pF
±15
mV
Pin1
0.1
%
Channel 1 Lead 37°C
(PF=0.8Capacitive)
Pin1
0.1
Degrees
Channel 1 Lags 60°C
(PF=0.5Inductive)
Pin1
0.1
Degrees
Pin5,6,7,
8,9,10
0.2%Ib
A
Pin1
0.1
%
Pin1
±5
ADC offset
Voff
7 Accuracy
Measurement Error on
Current Channel
CFA,CFB,CFC,CF
Phase Error
Channels
Input on the
voltage channel,
±500mVrms
The dynamic
range 500:1
between
8 Start Current
ISTART
Ib=5A
C=800,cosϕ=1,
Voltage Channel
Inputs
±110mVrms
9 Positive and Negative
Real Power Error (%)
ENP
Vv=±110mVrms
,V(I)=50mVrms,
cosϕ=±1
10 Gain Error
Gain
error
Internal
reference.
11 Power Supply
Monitor Voltage
Vdown
Power Supply
vary from 3.5V
to 5V, and
Current Channel
with Full-Scale
Signal
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
TERMINOLOGY
1) MEASUREMENT ERROR
The error associated with the energy measurement made by the BL0952A/BL6513/BL6511 is
defined by the following formula:
Pencentage Error =
Energy Registered by the BL6513 − True Energy
× 100%
True Energy
2) NONLINEAR ERROR
The Nonlinear Error is defined by the following formula:
eNL%=[(Error at X-Error at Ib)/(1+Error at Ib )]*100%
When V(V)= ±110mV, cosϕ=1, over the arrange of 5%Ib to500%Ib, the nonlinear error
should be less than 0.1%.
3) POSITIVE AND NEGATIVE REAL POWER ERROR
When the positive real power and the negative real power is equal, and V(V) =±110mV, the
test current is Ib, then the positive and negative real power error can be achieved by the following
formula:
eNP%=|[(eN%-eP%)/(1+eP%)]*100%|
Where: eP% is the Positive Real Power Error; eN% is the Negative Real Power Error.
4) START-UP CURRENT
When Ib=5A,C=800,cosϕ=1,Voltage Channel Input ±110mV rms, 5%Ib error in normal
range, the min AC current in current loop.
5) GAIN ERROR
The gain error of the BL0952A/BL6513/BL6511 is defined as the difference between the
measured output frequency (minus the offset) and the ideal output frequency. The difference is
expressed as a percentage of the ideal frequency. The ideal frequency is obtained from the
BL0952A/BL6513/BL6511 transfer function.
6) POWER SUPPLY MONITOR
BL0952A/BL6513/BL6511 has the on-chip Power Supply monitoring The
BL0952A/BL6513/BL6511 will remain in a reset condition until the supply voltage on VDD
reaches 4 V. If the supply falls below 4 V, the BL0952A/BL6513/BL6511 will also be reset and no
pulses will be issued on F1, F2 and CF.
Timing Characteristics
(VDD=5V, AGND=DGND=0V, on chip Reference, CLKIN=3.58MHz, TMIN to TMAX =
-40~+85°C)
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
Fig.3 time characteristics of CF, F1 and F2
Parameter
T1
Value
Description
145ms
Pulse-width (Logic High) of F1 or F2. At small load, the pulse-widths of
F1 and F2 are specified as 145ms. When the power is high, the output
periods of F1 and F2 is less than 290ms, and the pulse-widths of F1 and
F2 equal half of the F1 period.
T2
The low output pulse period. (see the formula of operation)
T3
1/2
T4
90ms
t2
Time between F1 Rising Edge and F1 Rising Edge.
CF Pulse-width. At small load, the pulse-width of CF is specified as
90ms. When the power is high, the output period of CF is less than
180ms, and the pulse-width of CF equals half of the CF period.
T5
T6
CF output high frequency. (see the relative between CF and F1, F2)
CLKIN/4
Minimum time between F1 and F2 pulse.
Notes
1) CF is not synchronous to F1 or F2 frequency outputs.
2) Sample tested during initial release and after any redesign or process change that may affect
this parameter.
BASIC THEORY OF OPERATION
ENERGY MEASURE THEORY
In energy measure, the power information varying with time is calculated by a direct
multiplication of the voltage signal and the current signal. Assume that the current signal and the
voltage signal are cosine functions; Umax, Imax are the peak values of the voltage signal and the
current signal; w is the angle frequency of the input signals; the phase difference between the
current signal and the voltage signal is expressed as
ϕ . Then the power is given as follows:
p (t ) = U max cos( wt ) × I max cos( wt + ϕ )
If ϕ = 0 : p (t ) =
U max I max
[1 + cos(2 wt )]
2
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
If ϕ ≠ 0 :
p (t ) = U max cos(ωt ) × I max cos(ωt + Φ )
= U max cos(ωt ) × [I max cos(ωt ) cos(Φ ) + I max sin(ωt ) sin(Φ )]
U max I max
[1 + cos(2ωt )] cos(Φ ) + U max I max cos(ωt ) sin(ωt ) sin(Φ )
2
U I
U I
= max max [1 + cos(2ωt )] cos(Φ ) + max max sin( 2ωt ) sin(Φ)
2
2
U max I max
U max I max
=
cos(Φ) +
[cos(2ωt ) cos(Φ) + sin(2ωt ) sin(Φ)]
2
2
U I
U I
= max max cos(Φ) + max max cos(2ωt + Φ)
2
2
=
p (t ) is called as the instantaneous power signal. The ideal p (t ) consists of the dc
component and ac component whose frequency is 2 w . The dc component is called as the average
active power, that is:
P=
U max I max
cos(ϕ )
2
The average active power is related to the cosine value of the phase difference between the
voltage signal and the current signal. This cosine value is called as Power Factor (PF) of the two
channel signals.
Fig.4
The Effect of phase
When the phase difference between the voltage signal and the current signal is more than 90
°, the average active power is negative. This case indicates the user is using the electrical energy
reversely.
The main function of the three phase measurement IC is calculating the sum of the three
phase active power (the arithmetic sum or the absolute value sum), and supplying the frequency
signals proportional to the active powers.
If the BL0952A/BL6513/BL6511 is configured to execute the arithmetic sum of the three
active powers, the sum of the three-phase power is calculated as follows:
PTOTAL = PA + PB + PC
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
When one phase power of three phases is negative, it’s value will counteract the other
positive terms.
If the BL0952A/BL6513/BL6511 is configured to execute the absolute value sum of the three
active powers, the sum of the three-phase power is calculated as follows:
PTOTAL = PA + PB + PC
THE OPRATION PROCESS OF THREE PHASE ENERGY MEASURE SIGNAL
Fig.5
Signal Processing Block Diagram
In BL0952A/BL6513/BL6511, the six voltage signals from the current and voltage
transducers are digitized with ADCs. The instantaneous power signal P(t) is generated by a direct
multiplication of the current and voltage signals of each phase. In order to extract the real power
component (i.e., the dc component), the instantaneous power signal is low-pass filtered on each
phase. Then, The total real power information is then obtained by adding the individual phase real
power (the arithmetic sum or the absolute value sum).
The output of three-phase power sum is sent to the digital-frequency module. In this module,
the total real power is accumulated during the given time, and converted to the periodic frequency
output which is therefore proportional to the average real power. Because of its high output
frequency and therefore, shorter integration time, the CF output is proportional to the
instantaneous real power. This pulse is useful for system calibration purposed that would take
place under steady load conditions.
By dividing the high output CF, F1 and F2 can be obtained. The outputs F1 and F2 operate at
a much lower frequency, which can drive the 2-phase stepper motors by eight kinds modes. The
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
output pulse is given to the counter motor out of the chip, and then the counter value proportional
to the consumed energy is obtained.
Offset Effect
The dc offsets come from the input signals and the forepart analog circuitry.
Assume that the input dc offsets on the voltage channel and the current channel are U offset
and I offset , and PF equals 1 ( ϕ = 0 o ).
p (t ) = [U cos(ωt ) + U offset ] × [ I cos(ωt + Φ ) + I offset ]
=
UI
UI
+ I offsetU cos(ωt ) + U offset I cos(ωt ) +
cos(2ωt )
2
2
Fig.6
Effect of different offset cancellation methods
As can be seen, for each phase input, if there are simultaneous dc offsets on the voltage
channel and the current channel, these offsets contribute a dc component for the result of
multiplication. That is, the offsets bring the error of U offset × I offset to the final average real power.
Additionally, there exists the component of U offset × I + I offset × U at the frequency of w . The
dc error on the real power will result in measure error, and the component brought to the
frequency of w will also affect the output of the average active power when the next low-pass
filter can’t restrain the ac component very completely.
When the offset on the one of the voltage and the current channels is filtered, for instance, the
offset on the current channel is removed; the result of multiplication is improved greatly. There is
no dc error, and the additional component at the frequency of w is also decreased.
When the offsets on the voltage channel and the current channel are filtered respectively by
two high-pass filters, the component at the frequency of w (50Hz) is subdued, and the stability
of the output signal is advanced. Moreover, in this case, the phases of the voltage channel and the
current channel can be matched completely, and the performance when PF equal 0.5C or 0.5L is
improved. In BL0952A/BL6513/BL6511, this structure is selected. Though it is given in the
system specification that the ripple of the output signal is less than 0.1%, in real measure of
BL0952A/BL6513/BL6511, the calibration output is very stable, and the ripple of the typical
output signal is less than 0.05%.
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
Additionally, this structure can ensure the frequency characteristic. When the input signal
changes from 45Hz to 65Hz, the complete machine error due to the frequency change is less than
0.1%. In such, the meter designed for the 50Hz input signal can be used on the transmission-line
system of electric power whose frequency is 60Hz.
Current Channels
The voltage outputs from the current transducers are connected to the
BL0952A/BL6513/BL6511 current channels, which are fully differential voltage inputs. IAP, BP,
and ICP are the positive input for IAN, IBN, and ICN, respectively. The maximum peak
differential signal on the current channel should be less than ± 500mV ( 353mV rms for a pure
sinusoidal signal) for the specified operation.
Fig.7 shows a typical connection diagram for the one current channel (IA).
RF
CT
IAP
CF
±500mV
Rb
RF
IP
AGND
IAN
+
-
CF
AGND
PHASE NEUTRAL
AGND
Fig.7 Typical Connection for Current Channels
Voltage Channels
The output of the line voltage transducer is connected to the BL0952A/BL6513/BL6511 at
this analog input. Voltage channels are a pseudo-differential voltage input. VAP, VBP, and VCP are
the positive inputs with respect to VN. The maximum peak differential signal on the voltage
channel is ± 500mV ( 353mV rms for a pure sinusoidal signal) for the specified operation.
RF
PT
VAP
CF
±500mV
RF
AGND
VN
+
-
CF
PHASE NEUTRAL
AGND
AGND
CF
Ra
Rb
AGND
Rv
AGND
±500mV
VAP
PHASE NEUTRAL
RF
AGND
VN
Ra >> RF
Rb+Rv=RF
+
-
CF
AGND
AGND
Fig.8 Typical Connections for Voltage Channels
Notes: Because of the various external devices, the current channel and the voltage channel
may have the phase match error (mainly due to different RC constant and different phase delay).
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
By adjusting the external capacitor Cf, the phase error can be corrected. The phase error will affect
the system gain when PF is 0.5, and bring error.
The process of BL0952A/BL6513/BL6511 can ensure the consistent compensatory value.
Power Supply Monitor
The BL0952A/BL6513/BL6511 contains an on-chip power supply monitor. If the supply is
less than 4V ± 5% then the BL0952A/BL6513/BL6511 will go in an inactive state, i.e. no
energy will be accumulated when the supply voltage is below 4V. This is useful to ensure correct
device operation at power up and during power down. The power supply monitor has built-in
hysteresis and filtering. This gives a high degree of immunity to false triggering due to noisy
supplies.
The trigger level is nominally set at 4V, and the tolerance on this trigger level is about
± 5% . The power supply and decoupling for the part should be such that the ripple at VDD does
not exceed 5V ± 5% as specified for normal operation.
Digital-To-Frequency Conversion
After multiplication,the low-pass filter is used to attenuate the ac components at the line
frequency and its harmonics. Then the three phase real powers are sent to the adder, and the
arithmetic sum or the absolute value sum (selectable by the pin ADDSEL) can be obtained. The
power sum is passed to the digital-to-frequency converter. In the digital-to-frequency, the power
signal is integrated over time to produce an output frequency. This accumulation of the signal will
suppress any non-dc component in the instantaneous real power signal. Because the average value
of a sinusoidal signal is zero, the frequency generated by the digital-to-frequency is proportional
to the average real power.
Figure 9 shows the calculating process of the output CF:
Fig.9 Real Power-to-Frequency Conversion
As can be seen in the diagram, the output frequency CF is generated by accumulating the
instantaneous real power signal over a much shorter time, while converting it to a frequency. Due
to the short accumulating time, there are still ripple in the CF. This will not be a problem in the
application. Where CF is used for calibration purposes, the frequency should be averaged by the
frequency counter. This will remove any ripple. After the output frequency CF, by other
digital-to-frequency converter, the lower output frequency F1 and F2 are obtained. Because the
outputs F1 and F2 operate at a much lower frequency, much more averaging of the instantaneous
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
real power signal is carried out. Thus the stability of the output frequency is ensured.
Mode Selection of the Sum of the Three Active Energies
The BL0952A/BL6513/BL6511 can be set to execute the arithmetic sum of the three active
energies,
Wh = WhφA + WhφB + WhφC
Or the sum of the absolute value of these energies,
Wh = WhφA + WhφB + WhφC
.
The selection between the two modes can be made by setting the ADDSEL pin. Logic high
and logic low applied on the ADDSEL pin correspond to the arithmetic sum and the sum of
absolute values, respectively.
Anti-Creep Threshold
In BL0952A/BL6513/BL6511, when the rms of current and the rms of voltage are 500mV,
the anti-creep threshold is set as the 0.0020 percent of full-scale power. There are anti-creep logics
in three phase circuits.
SCF
S0
S1
Min Freq On F1/F2
For AC input[Hz]
Min Freq On CF For
AC input[Hz]
1
1
1
9.76E-06
1.56E-04
0
0
0
1.56E-05
2.50E-03
1
0
0
1.95E-05
1.56E-04
0
0
1
3.13E-04
5.00E-03
1
0
1
3.13E-04
2.50E-03
0
1
0
6.25E-05
1.00E-02
1
1
0
7.81E-05
1.25E-03
0
1
1
1.25E-03
1.00E-02
OPERATION MODE
FORMULA of OPERATION
In the BL0952A/BL6513/BL6511, the output frequency or pulse rate is related to the input
voltage signals by the following equation:
Freq =
13.25 × (U AP × I A + U BP × I B + U CP × I C ) × F1− 5
2
VREF
Freq = Output frequency on F1 and F2 (Hz)
UAP, UBP, UCP = Differential rms voltage signal on voltage channels (volts)
IA, IB, and IC = Differential rms voltage signal on current channels (volts)
Vref = The reference voltage (2.42 V ± 8%) (volts)
F1-5 = One of five possible frequencies selected by using the logic inputs SCF, S0, and S1.
Selecting the operation mode
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BL0952A/BL6513
ThreeThree-phase Active
Energy Meter
In BL0952A/BL6513/BL6511, the different operation modes can be selected by the input
SCF, S0 and S1. Table I shows how the two frequencies are related, depending on the states of the
logic inputs S0, S1, and SCF.
SCF
S0
S1
F1-5
Max Freq On F1/F2
For AC input[Hz]
CF vs.
F1/F2
Max Freq On CF For
AC input[Hz] ①
1
1
1
0.575
0.488
16
7.8
0
0
0
0.921
0.781
160
125
1
0
0
1.150
0.976
8
7.8
0
0
1
18.42
15.625
16
250
1
0
1
18.42
15.625
8
125
0
1
0
3.683
3.125
160
500
1
1
0
4.604
3.906
16
62.5
0
1
1
73.67
62.5
8
500
① The frequency of output CF when input current and Voltage are ±500mV AC signal.
Application circuit
Notice: Sample tested during initial release and after any redesign or process change
that may affect parameter. Specification subject to change without notice. Please ask
for the newest product specification at any moment.
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