CN109085425B - Impact load calculation method - Google Patents

Impact load calculation method Download PDF

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CN109085425B
CN109085425B CN201810806486.6A CN201810806486A CN109085425B CN 109085425 B CN109085425 B CN 109085425B CN 201810806486 A CN201810806486 A CN 201810806486A CN 109085425 B CN109085425 B CN 109085425B
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instantaneous
power
calibration
current
voltage
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CN109085425A (en
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熊德智
陈向群
胡军华
刘小平
杨茂涛
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State Grid Corp of China SGCC
State Grid Hunan Electric Power Co Ltd
Metering Center of State Grid Hunan Electric Power Co Ltd
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State Grid Corp of China SGCC
State Grid Hunan Electric Power Co Ltd
Metering Center of State Grid Hunan Electric Power Co Ltd
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    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R22/00—Arrangements for measuring time integral of electric power or current, e.g. electricity meters
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Abstract

The invention provides an impact load calculation method, which comprises the following steps: calculating instantaneous power point by point; calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; and performing IIR low-pass filtering on the instantaneous electric quantity in the single pulse period to obtain the stable electric quantity in the single pulse period. In the invention, instantaneous power is directly accumulated in a pulse time interval, and when the accumulated value of the instantaneous power is greater than the electric quantity threshold value of a single pulse time interval, a pulse is sent out; calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; and performing IIR low-pass filtering according to the instantaneous electric quantity in the single pulse time interval to obtain the stable electric quantity in the single pulse time interval, namely counting the electric quantity consumed by the impact load in the single pulse time interval. The intelligent electric meter can accurately measure the electric quantity consumed by the impact load when the nonlinear dynamic impact load is generated, so that the intelligent electric meter can reasonably and equitably charge, and the national economic loss is reduced.

Description

Impact load calculation method
Technical Field
The invention relates to the field of electric energy metering, in particular to an impact load calculation method.
Background
With the rapid development of industry and continuous innovation of technology, various new energy sources such as light energy, wind energy, tidal energy and other grid-connected technologies are popularized, and various nonlinear, impact and asymmetric loads are put into use in large quantities, such as electrified rail transit, a distributed power supply, a silicon controlled rectifier, an electric arc furnace, a rolling mill, an electric locomotive and the like. The current of the electric load of the nonlinear dynamic impact load dynamically changes along with time, even fluctuates greatly in short time, so that the problems of frequency deviation, voltage fluctuation, voltage flicker, voltage instability, harmonic distortion, direct current injection and the like can be caused, the electrical performance and the stability of the intelligent ammeter are greatly hidden, the electric energy metering error is caused, the intelligent ammeter cannot be charged reasonably and justly, and the economic loss is brought for the country.
The impact load belongs to dynamic load, the mode of pulse number is generally adopted by considering the accumulated electric energy of the current intelligent electric meter, and under the condition of determining a pulse constant, one pulse electric quantity is also fixed. The theoretical basis for calculating power is not problematic, but the metering difference under dynamic and impact loads is mainly reflected in that the mode of accumulating one pulse electric quantity is different, the average power within a certain window time is calculated, and the pulse interval is calculated through the average power. The mode can make the electric energy error not easy to jump and has higher precision. However, under dynamic and impact loads, the error fluctuation is large due to the delay of power calculation, and the requirements are difficult to meet.
Disclosure of Invention
In order to solve the problems that the error fluctuation is large and reasonable charging cannot be realized due to the delay of power calculation in the metering mode of the intelligent electric meter under dynamic and impact load at present, the invention provides an impact load metering method, which comprises the following steps:
calculating instantaneous power point by point; calculating instantaneous electric quantity of a single pulse period according to the instantaneous power; and performing IIR low-pass filtering on the instantaneous electric quantity in the single pulse period to obtain the stable electric quantity in the single pulse period.
Preferably, the instantaneous power is calculated by the formula:
Figure BDA0001738280100000021
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure BDA0001738280100000022
is the phase difference between the instantaneous voltage and the instantaneous current.
Preferably, the impact load calculation method further includes a compensation algorithm, and the compensation algorithm includes: removing direct current component calibration, voltage and current gain calibration, voltage and current imbalance calibration, active and reactive gain calibration and active and reactive imbalance calibration; the compensation algorithm is used to calibrate the instantaneous voltage, the instantaneous current, the active power, the reactive power, and the phase difference between the instantaneous voltage and the instantaneous current.
Preferably, the instantaneous electric quantity of a single pulse period is calculated by the formula:
Figure BDA0001738280100000023
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure BDA0001738280100000024
is the phase difference between the instantaneous voltage and the instantaneous current, TaccuAs a single pulse period.
The calculation formula of the steady-state electric quantity of a single pulse time interval is as follows:
WA＝Pconst·Taccu
wherein, WASteady state electric quantity for a single pulse period, PconstIs the sum of the actual three-phase powers, TaccuAs a single pulse period.
Preferably, the calculation formula of the dc component removal calibration is:
Figure BDA0001738280100000025
wherein, IGo straightIs total DC component, n is the number of acquisition points, InAnd the direct current component corresponding to the nth acquisition point.
Preferably, the calculation formula of the voltage gain calibration is as follows:
Figure BDA0001738280100000031
wherein, VnEffective value, V, after voltage gain calibration for a certain phase voltagerThe VRMSGAIN is an effective value before voltage gain calibration of the phase voltage, and is a value of a voltage gain calibration register;
the calculation formula of the current gain calibration is as follows:
Figure BDA0001738280100000032
wherein, ImaxEffective value after current gain calibration for a certain phase current, IrIGAIN is the value of the current gain calibration register for the value of the phase current prior to current gain calibration.
Preferably, the calculation formula of the voltage offset calibration is as follows:
VRMS＝VRMS0+VRMSOS×64
wherein VRMS is the effective value after voltage offset calibration of a certain phase voltage, VRMS0The VRMSOS is the effective value before the voltage offset calibration of the phase voltage, and is the value of a voltage offset calibration register;
the calculation formula of the current offset calibration is as follows:
Figure BDA0001738280100000033
wherein IRMS is the effective value after current offset calibration of a certain phase current, IRMS0IRMSOS is the value of the current offset calibration register for the effective value of the phase current prior to current offset calibration.
Preferably, the calculation formula of the active gain calibration is as follows:
Figure BDA0001738280100000034
wherein power is the active power after the active gain calibration0Active power before active gain calibration; AWG is the value of an active gain calibration register;
the calculation formula of the reactive gain calibration is as follows:
Figure BDA0001738280100000035
wherein, the power is the reactive power after the reactive gain calibration, and the power0AVARG is the value of the reactive gain calibration register for the reactive power before reactive gain calibration.
Preferably, the active and reactive imbalance calibration specifically comprises:
the value WATTOS of the reactive offset calibration register is 0 and the value VAROS of the reactive offset calibration register is 0; respectively reading active power and reactive power; and respectively adjusting the active offset calibration register WATTOS and the reactive offset calibration register VAROS so that the active power and the reactive power are both read as 0.
Preferably, the calculation formula of the phase difference calibration of the instantaneous voltage and the instantaneous current is as follows:
APHCAL＝arcsin(Er/1.732)×4×2083/360
APHCAL is a phase difference calibration value of instantaneous voltage and instantaneous current, and Er is an electric energy error.
The invention provides an impact load calculation method, which comprises the steps of calculating instantaneous power point by point in a pulse time interval and accumulating, and sending out a pulse when the accumulated value of the instantaneous power is greater than the electric quantity threshold value of a single pulse time interval; calculating the instantaneous electric quantity of a single pulse period according to the instantaneous power; and performing IIR low-pass filtering according to the instantaneous electric quantity in the single pulse time interval to obtain the stable electric quantity in the single pulse time interval, namely counting the electric quantity consumed by the impact load in the single pulse time interval. The intelligent electric meter can accurately measure the electric quantity consumed by the impact load when the nonlinear dynamic impact load is generated, so that the intelligent electric meter can reasonably and equitably charge, and the national economic loss is reduced.
Drawings
FIG. 1 is a schematic flow chart of an impact load calculation method according to a preferred embodiment of the present invention;
FIG. 2 is a flow chart of a compensation algorithm according to a preferred embodiment of the present invention;
FIG. 3 is a IIR low pass filter frequency response curve according to a preferred embodiment of the present invention;
fig. 4 is a software framework diagram of an impact load calculation method according to a preferred embodiment of the present invention.
Detailed Description
Preferred embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The current intelligent electric meter accumulates electric energy by generally adopting a mode of counting the number of pulses, and under the condition that the pulse constant is determined, the electric quantity of one pulse is also fixed. The theoretical basis of calculating power is not a problem, but the metering difference under dynamic and impact loads is mainly reflected in that the mode of accumulating one pulse electric quantity is different, the average power within a certain window time is calculated, and the pulse interval is calculated through the average power. The mode can make the electric energy error not easy to jump and has higher precision. However, under dynamic and impact loads, due to the delay of power calculation, the error fluctuation is large, and the requirements are difficult to meet.
Fig. 1 is a schematic flow chart of an impact load calculation method according to a preferred embodiment of the present invention, and as shown in fig. 1, the present invention provides an impact load measurement method, including: calculating instantaneous power point by point; calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; and performing IIR low-pass filtering on the instantaneous electric quantity in the single pulse period to obtain the stable electric quantity in the single pulse period.
Specifically, in the embodiment, instantaneous power is adopted to be directly accumulated in one pulse period, and when the accumulated value of the instantaneous power is larger than the electric quantity threshold value of a single pulse period, one pulse is sent out; calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; and performing IIR low-pass filtering according to the instantaneous electric quantity of the single pulse time interval to obtain the stable electric quantity of the single pulse time interval, namely counting the electric quantity consumed by the impact load in the single pulse time interval.
Based on the above embodiment, the calculation formula of the instantaneous power is:
Figure BDA0001738280100000051
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure BDA0001738280100000052
is the phase difference between the instantaneous voltage and the instantaneous current.
Specifically, the calculation formulas of the active power M and the reactive power N are as follows:
Figure BDA0001738280100000053
Figure BDA0001738280100000054
wherein, UA、UB、UCA, B, C phase voltages, IA、IB、ICRespectively, A, B, C phase currents are set,
Figure BDA0001738280100000061
is UAAnd IAThe phase difference between the two phases is small,
Figure BDA0001738280100000062
is UBAnd IBThe phase difference between the two phases is small,
Figure BDA0001738280100000063
is UCAnd ICThe phase difference between them.
Further, the sum P of the actual three-phase powersconstThe calculation formula of (2) is as follows:
Figure BDA0001738280100000064
wherein, UA、UB、UCA, B, C phase voltages, IA、IB、ICRespectively, A, B, C phase currents are set,
Figure BDA0001738280100000065
is UAAnd IAThe phase difference between the two phases is small,
Figure BDA0001738280100000066
is UBAnd IBThe phase difference between the two phases is small,
Figure BDA0001738280100000067
is UCAnd ICThe phase difference between them.
Based on the above embodiment, the instantaneous electric quantity of a single pulse period
Figure BDA0001738280100000068
The calculation formula of (2) is as follows:
Figure BDA0001738280100000069
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure BDA00017382801000000610
is the phase difference between the instantaneous voltage and the instantaneous current, TaccuAs a single pulse period.
Specifically, as can be seen from equation (1), the instantaneous power PALLIs the sum P of the actual three-phase powerconstBy superimposing a sinusoidal curve with a frequency of 2 omega, the instantaneous electric quantity of a single pulse period can be seen from equation (5)
Figure BDA00017382801000000611
Is the sum P of the actual three-phase powerconstThe electrical quantity during a single pulse period is superimposed with a sinusoidal curve with a frequency of 2 omega. Under dynamic load, the average power algorithm has hysteresis, the instantaneous power is directly accumulated to have better real-time effect, and a low-pass filter is designed to filter out
Figure BDA00017382801000000612
To obtain a stable amount of electricity in a single pulse period, i.e., an amount of electricity counted for the impact load consumption in a single pulse period.
If an input impulse is given to the IIR filter, the impulse response of the IIR filter is self-excited and never stops theoretically. FIR then refers to finite impulse response. FIR filters are purely digital and cannot be built with electronic components. After giving it an impact, the resulting impact response is limited.
In this embodiment, the IIR low-pass filter in this embodiment is indicated as follows: the passband edge frequency is 10Hz, the passband ripple factor is 0.001, the stopband edge frequency is 90Hz, and the attenuation factor is 0.3. A second order IIR butterworth filter.
The difference equation of the IIR low-pass filter employed in this embodiment is as follows:
y(i)＝b0*x(i)+b1*x(i-1)+b2*x(i-2)-a1*y(i-1)-a2*y(i-2) (6)
wherein, b0, b1, b2, a1 and a2 are IIR filter parameters designed according to four parameters of passband edge frequency, passband ripple coefficient, stopband edge frequency and attenuation coefficient.
The values of b0, b1, b2, a1 and a2 in the embodiment are as follows:
b0＝1.0e-003*0.33573065661152
b1＝1.0e-003*0.67146131322371
b2＝1.0e-003*0.33573065661141
a1＝-1.94750774756393
a2＝0.94885067019037
based on the above example, fig. 3 is a frequency response curve of an IIR low-pass filter according to a preferred embodiment of the present invention, as shown in fig. 3, in this example, the indices of the IIR low-pass filter are: the passband edge frequency is 10Hz, the passband ripple factor is 0.001, the stopband edge frequency parameter is 90Hz, and the attenuation coefficient is 0.3.
According to the filter parameters, performing IIR low-pass filtering to obtain instantaneous power PALLFiltering out the sine curve with frequency of 2 omega, instantaneous power PALLSum P of actual three-phase powerconstAre equal.
Based on the above example, fig. 2 is a flowchart of a compensation algorithm according to a preferred embodiment of the present invention, and as shown in fig. 2, the impact load calculation method further includes a compensation algorithm, and the compensation algorithm includes: removing direct current component calibration, voltage and current gain calibration, voltage and current imbalance calibration, active and reactive gain calibration and active and reactive imbalance calibration; the compensation algorithm is used to calibrate the instantaneous voltage, the instantaneous current, the active power, the reactive power, and the phase difference between the instantaneous voltage and the instantaneous current.
The compensation algorithm is a calibration link of various parameters, and the calibration should be completed before the actual operation. The link part for these corrections. Not every one needs to be corrected. The current correction idea is as follows: to achieve a certain accuracy, the correction must be performed at intervals. It is clear that no correction is necessary each time. However, in order to find a balance between accuracy and computation amount, such an experiment may be performed several times more.
It should be noted that the sequence of the calibration links included in the compensation algorithm is not limited, and the calibration links may be adjusted and replaced according to the actual requirements of the impact load calculation process.
Based on the above embodiment, the calculation of the dc component may acquire the entire acquired data n points first. And then accumulate them. The direct current component is obtained by dividing the direct current component by the value of n, wherein n is a positive number. Reference is made to n as 1024. The calculation formula for the calibration of the DC component is as follows:
Figure BDA0001738280100000081
wherein, IGo straightIs total DC component, n is the number of acquisition points, InAnd the direct current component corresponding to the nth acquisition point.
Based on the above embodiment, the calculation formula of the voltage gain calibration is as follows:
VARG＝(1/Er-1)×4096 (8)
wherein, VnEffective value, V, after voltage gain calibration for a certain phase voltagerThe VRMSGAIN is an effective value before voltage gain calibration of the phase voltage, and is a value of a voltage gain calibration register;
specifically, during voltage gain calibration, three-phase voltage V is addednThe voltage gain VRMSGAIN of a certain phase voltage registered by the voltage gain calibration register is equal to 0, and the effective value V of the voltage of the certain phase is read respectivelyrThe voltage gain V of each phase is calculated according to equation (8)nThe results are placed into the VRMSGAIN registers of each phase, respectively. This indicates that at the time of the true operation, Avr is the operation result V of the acquired signal through the formulanParticipate in the actual processing. This is purely dependent on the significance in the signal path. Without the need for this gain calibration procedure for the instantaneous power being directly accumulated. Here only one adjustment of the phase of the voltage is needed. And then the system can directly participate in the operation process of the active power. Changes in VRMSGAIN affect the apparent power.
Further, the calculation formula of the current gain calibration is as follows:
Figure BDA0001738280100000082
wherein, ImaxEffective value after current gain calibration for a certain phase current, IrIGAIN is the value of the current gain calibration register for the value of the phase current prior to current gain calibration.
Specifically, three-phase currents are added, and effective values I of the three-phase currents are respectively readrCalculating the current gain of each phase according to the formula (9), and respectively placing the result into an IGAIN register of the current gain of each phase; similarly, Imax is also really involved in the calculation. The collected current signal is Air. The current signal appearing later is this Imax. Changes in IGAIN have an effect on both the active and reactive apparent power.
Based on the above embodiment, the calculation formula of the voltage offset calibration is as follows:
VRMS＝VRMS0+VRMSOS×64 (10)
wherein VRMS is an effective value after voltage offset calibration of a certain phase voltage, VRMS0The VRMSOS is the effective value before voltage offset of the phase voltage, and is the value of a voltage offset calibration register;
further, the calculation formula of the current offset calibration is as follows:
Figure BDA0001738280100000091
wherein IRMS is effective value after current offset calibration of the phase current, IRMS0IRMSOS is the value of the current offset calibration register for the effective value of the phase current prior to current offset calibration.
Specifically, the voltage offset adjustable current offset calibration register VRMSOS is implemented; the power loss can be adjustedAdjusting a current offset calibration register IRMSOS. This step is the adjustment process performed after the root number is opened. The voltage effective value VRMS and the current effective value IRMS must be read at the voltage zero crossing point, otherwise the values fluctuate. Removing three-phase current, setting a current offset calibration register IRMSOS (equal to 0), and respectively reading three-phase current effective values IroAccording to the formula IRMSOS ═ Iro×IroAnd/16384 (12), calculating the power loss regulation value of each phase, and respectively putting the result into the current imbalance calibration register IRMSOS of each phase. Removing three-phase voltage, placing a certain phase VRMSOS registered by a voltage imbalance calibration register, and respectively reading the effective value Vr of the three-phase voltage0According to the formula
Figure BDA0001738280100000092
And calculating the voltage offset value of each phase, and respectively putting the result into the voltage offset calibration register VRMSOS of each phase.
Based on the above embodiment, the calculation formula of the active gain calibration is as follows:
Figure BDA0001738280100000101
wherein power is the active power after the active gain calibration0Active power before active gain calibration; AWG is the value of an active gain calibration register;
specifically, if only A phase voltage V is appliednCurrent I ofnSetting power factor to 1, reading out electric energy error Er according to the formula WG ═ 1/Er-1) multiplied by 4096, active gain is calculated, an active gain calibration register AWG is arranged, and active gain calibration of B and C phases is the same as that of A phase.
Further, the calculation formula of the reactive gain calibration is as follows:
Figure BDA0001738280100000102
wherein, the power is the reactive power after the reactive gain calibration, and the power0For reactive power before reactive gain calibration, AVARG is the value of the reactive gain calibration register.
Specifically, if the A phase voltage, the current and the power factor are set to 0, the reading power error E is calculatedrAccording to the formula AVARG ═ (1/E)r-1) x 4096(16), calculating the value of the reactive gain calibration register, and placing the value into the reactive gain calibration register AVARG, wherein the reactive gain calibration of the B phase and the C phase is the same as the A phase.
Based on the above embodiment, the active and reactive imbalance calibration specifically includes:
the value WATTOS of the reactive offset calibration register is 0 and the value VAROS of the reactive offset calibration register is 0; respectively reading active power and reactive power; and respectively adjusting the active offset calibration register WATTOS and the reactive offset calibration register VAROS so that the active power and the reactive power are both read as 0. For real power, 1 watts would correspond to 1/16 for the minimum real power output value. The reactive power detuning calibration procedure is also similar.
Based on the above embodiment, the calculation formula of the phase difference calibration of the instantaneous voltage and the instantaneous current is:
APHCAL＝arcsin(Er/1.732)×4×2083/360 (17)
APHCAL is a phase difference calibration value of instantaneous voltage and instantaneous current, and Er is an electric energy error.
Specifically, consider the a-phase voltage VnCurrent I ofnPower factor is set to 0.5, reading power error ErThe phase compensation value is calculated according to the formula (17) and is put into the phase calibration register APHCAL.
Fig. 4 is a diagram of a software framework of an impact load calculation method according to a preferred embodiment of the present invention, and as shown in fig. 4, when the impact load calculation method is implemented by applying to a software scheme, the software scheme framework includes a plate layer, an intermediate layer, and an application layer.
The plate layer mainly drives bottom-layer components and interacts with the same components to complete hardware initialization, drive code realization and related calculation part variable initialization; the middle layer is mainly used for carrying out interaction between the plate layer and the application layer and unifying a program interface to the application layer. The functions of realizing the separation of hardware and software drive of a plate layer, realizing an AD sampling interruption function, a timing pulse sending function, a protocol part link layer and the like are realized; the application layer mainly calls a database, calculates data, displays liquid crystal, calculates RMS (root mean square), realizes impact load algorithm, corrects the meter, realizes the functions of a conventional meter and the like.
The invention provides an impact load calculation method, which adopts the direct accumulation of instantaneous power in a pulse time interval, and sends out a pulse when the accumulated value of the instantaneous power is larger than the electric quantity threshold value of a single pulse in a single pulse time interval; calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; and performing IIR low-pass filtering according to the instantaneous electric quantity in the single pulse time interval to obtain the stable electric quantity in the single pulse time interval, namely counting the electric quantity consumed by the impact load in the single pulse time interval. The invention can accurately measure the electric quantity consumed by the impact load when the nonlinear dynamic impact load is generated, so that the intelligent electric meter can reasonably and fairly charge and reduce the national economic loss.
Meanwhile, in the calculation process of the impact load, the offset calibration, the gain calibration or the phase calibration are carried out on the instantaneous current, the instantaneous voltage, the active power and the reactive power and the phase difference between the instantaneous current and the instantaneous voltage through a compensation algorithm, so that the calculation method of the impact load is higher in precision and more accurate in calculation.
Finally, the method of the present invention is only a preferred embodiment and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. An impact load calculation method, characterized by comprising:
calculating instantaneous power point by point;
calculating the instantaneous electric quantity of a single pulse time interval according to the instantaneous power; performing IIR low-pass filtering on the instantaneous electric quantity in the single pulse time interval to obtain stable electric quantity in the single pulse time interval;
the calculation formula of the instantaneous power is as follows:
Figure FDA0002543052190000011
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure FDA0002543052190000012
is the phase difference between the instantaneous voltage and the instantaneous current;
the calculation formula of the instantaneous electric quantity of a single pulse period is as follows:
Figure FDA0002543052190000013
wherein, PALLFor instantaneous power, PconstIs the sum of actual three-phase power, M is active power, N is reactive power, omega is period, t is time,
Figure FDA0002543052190000014
for the phase difference between instantaneous voltage and instantaneous current, TaccuA single pulse period;
the calculation formula of the steady-state electric quantity of a single pulse time interval is as follows:
WA＝Pconst·Taccu
wherein, WASteady state electric quantity for a single pulse period, PconstIs the sum of the actual three-phase powers, TaccuAs a single pulse period.
2. The impact load calculation method according to claim 1, further comprising a compensation algorithm, the compensation algorithm comprising: removing direct current component calibration, voltage and current gain calibration, voltage and current imbalance calibration, active and reactive gain calibration and active and reactive imbalance calibration; the compensation algorithm is used for calibrating the instantaneous voltage, the instantaneous current, the active power, the reactive power and the phase difference of the instantaneous voltage and the instantaneous current.
3. The method of claim 2, wherein the dc component removal calibration is calculated by the formula:
Figure FDA0002543052190000021
wherein, IGo straightIs total DC component, n is the number of acquisition points, InThe corresponding direct current component for the nth acquisition point.
4. The method of claim 2, wherein the voltage gain calibration is calculated by the formula:
Figure FDA0002543052190000022
wherein, VnEffective value, V, after voltage gain calibration for a certain phase voltagerThe VRMSGAIN is an effective value before voltage gain calibration of the phase voltage, and is a value of a voltage gain calibration register;
the calculation formula of the current gain calibration is as follows:
Figure FDA0002543052190000023
wherein, ImaxEffective value after current gain calibration for a certain phase current, IrIGAIN is the value of the current gain calibration register for the current gain calibration prior to the current gain calibration for that phase current.
5. The method of claim 2, wherein the voltage offset calibration is calculated by the formula:
VRMS＝VRMS0+VRMSOS×64
wherein VRMS is a voltage offset calibration of a certain phase voltageThe latter significant value, VRMS0The VRMSOS is the effective value before voltage offset calibration of the phase voltage, and is the value of a voltage offset calibration register;
the calculation formula of the current offset calibration is as follows:
Figure FDA0002543052190000024
wherein IRMS is the effective value after current offset calibration of a certain phase current, IRMS0IRMSOS is the value of the current offset calibration register for the effective value of the phase current prior to current offset calibration.
6. The method of claim 2, wherein the active gain calibration is calculated by the formula:
Figure FDA0002543052190000031
wherein power is the active power after the active gain calibration0Active power before active gain calibration; AWG is the value of an active gain calibration register;
the calculation formula of the reactive gain calibration is as follows:
Figure FDA0002543052190000032
wherein, the power is the reactive power after the reactive gain calibration, and the power0AVARG is the value of the reactive gain calibration register for the reactive power before reactive gain calibration.
7. The method according to claim 2, wherein the active and reactive imbalance calibration specifically comprises:
the value WATTOS of the offset calibration register is 0 and the value of the offset calibration register is not added
VAROS＝0；
Respectively reading active power and reactive power;
and respectively adjusting the active offset calibration register WATTOS and the reactive offset calibration register VAROS so that the active power and the reactive power are both 0.
8. The impulse load calculation method according to claim 2, wherein the phase difference between the instantaneous voltage and the instantaneous current is calibrated by the formula:
APHCAL＝arcsin(Er/1.732)×4×2083/360
and APHCAL is a phase difference calibration value of the instantaneous voltage and the instantaneous current, and Er is an electric energy error.
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