A method and apparatus for measuring the loss of an SVG

Abstract

The application relates to an SVG body loss measuring method and device, which comprises the following steps: acquiring three-phase fundamental wave voltage amplitude and phase, three-phase fundamental wave current amplitude and phase under a rated capacity inductive reactive power output working condition, three-phase fundamental wave voltage amplitude and phase, three-phase fundamental wave current amplitude and phase under a rated capacity capacitive reactive power output working condition, calculating active power under the rated capacity inductive reactive power output working condition and active power under the rated capacity capacitive reactive power output working condition; and calculating the body loss of the SVG according to the active power under the rated capacity inductive reactive power output working condition and the active power under the rated capacity capacitive reactive power output working condition to eliminate phase angle error, so that the technical problem that the SVG body loss measuring result is not reliable due to the fixed phase angle error of a sensor can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of device loss measurement, and particularly relates to an SVG body loss measurement method and device. BACKGROUND

[0002] A static var generator (hereinafter referred to as SVG) is a voltage source converter composed of a self-commutated bridge circuit of power electronic devices (IGBT) and a DC capacitor, which is connected in parallel to a power grid through a transformer or a reactor, and controls the voltage amplitude and phase of DC inversion to AC by adjusting the switching of IGBT devices in the bridge circuit, so as to rapidly absorb or emit the required reactive power, achieve the purpose of fast dynamic bidirectional reactive power compensation, and also has the functions of harmonic compensation, unbalanced compensation and voltage flicker suppression, and has been widely applied.

[0003] At present, the state pays more and more attention to energy saving and emission reduction, and users pay more and more attention to the body loss of SVG. The existing SVG related technical standards also make clear provisions for device loss. Section 7.8.7 of NB / T 42043-2014 "High Voltage Static Synchronous Compensation Device" stipulates the devices included in the rated loss of high voltage SVG device and the rated loss limit corresponding to different rated capacities of the device, and section 7.8.8 of NB / T 42057-2015 "Low Voltage Static Var Generator" stipulates the devices included in the rated loss of low voltage SVG device and the rated loss limit, which continuously improves the requirement for SVG body loss measurement.

[0004] At present, the power measurement of static var generator (SVG) all uses the current signal and voltage signal sampled by a sensor to calculate, and when the SVG body loss (active power) is measured, the SVG is in an idle state, the fundamental current is small, and the sampling current transformer has a large range, so that the measurement accuracy cannot meet the requirements. In the working process of SVG, inductive or capacitive reactive power is generated according to the system demand, the corresponding fundamental current lags or leads the voltage by nearly 90°, and the current measurement amplitude accuracy can meet the requirements, but there is a fixed phase angle error in different sensors, the measured active power has a large deviation, and the measured active power (loss value) is often negative, so that the SVG body loss measurement result is not reliable. SUMMARY

[0005] The present application aims to provide an SVG body loss measurement method and device to solve the technical problem that different sensors have a fixed phase angle error and the SVG body loss measurement result is not reliable.

[0006] To achieve the above-mentioned purpose, the present application provides an SVG body loss measurement method, which comprises the following steps:

[0007] acquire the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity inductive reactive power output working condition, and the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity capacitive reactive power output working condition;

[0008] calculate the active power under the rated capacity inductive reactive power output working condition and the active power under the rated capacity capacitive reactive power output working condition according to the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity inductive reactive power output working condition and the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity capacitive reactive power output working condition;

[0009] calculate the corrected active power output value by eliminating the sensor fixed phase angle error according to the active power under the rated capacity inductive reactive power output working condition and the active power under the rated capacity capacitive reactive power output working condition, as the SVG body loss;

[0010] output and display the active power output value.

[0011] Preferably, the acquiring the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity inductive reactive power output working condition and the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity capacitive reactive power output working condition comprises:

[0012] set the SVG to be tested to a manual constant reactive power operation mode;

[0013] set the SVG running working condition to output inductive reactive power of the rated capacity, acquire the SVG three-phase voltage waveform signal and three-phase current waveform signal under the working condition, and use fast Fourier transform to calculate the SVG n three-phase fundamental voltage amplitude and phase and n three-phase fundamental current amplitude and phase under the working condition in real time;

[0014] set the SVG running working condition to output capacitive reactive power of the rated capacity, acquire the SVG three-phase voltage waveform signal and three-phase current waveform signal under the working condition, and use fast Fourier transform to calculate the SVG n three-phase fundamental voltage amplitude and phase and n three-phase fundamental current amplitude and phase under the working condition in real time.

[0015] Preferably, the calculating the active power under the rated capacity inductive reactive power output working condition and the active power under the rated capacity capacitive reactive power output working condition according to the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity inductive reactive power output working condition and the SVG three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase under the rated capacity capacitive reactive power output working condition comprises:

[0016] The active power under the rated capacity inductive reactive power output condition is calculated based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents.

[0017] The active power under the rated capacity capacitive reactive power output condition is calculated based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents.

[0018] Preferably, the step of calculating the active power under the rated capacity inductive reactive power output condition based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents includes:

[0019] The active power P1[i] under each rated capacity inductive reactive power output condition is calculated according to the following formula.

[0020]

[0021]

[0022]

[0023] P1[i]=P A1 [i]+P B1 [i]+P C1 [i]

[0024] Among them, P A1 [i]、P B1 [i]、P C1 [i] represent the active power of phase A, phase B, and phase C respectively under the i-th rated capacity inductive reactive power output condition; U A1 [i]、U B1 [i]、U C1 [i] represent the fundamental voltage amplitudes of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, respectively. A1 [i]、I B1 [i]、I C1 [i] represents the amplitudes of the fundamental current in phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, respectively. The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition are, in sequence, those of phase i. These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, where i is any integer from 1 to n.

[0025] Preferably, the step of calculating the active power under the rated capacity capacitive reactive power output condition based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents includes:

[0026] The active power P2[i] under each rated capacity capacitive reactive power output condition is calculated using the following formula.

[0027]

[0028]

[0029]

[0030] P2[i]=P A2 [i]+P B2 [i]+P C2 [i]

[0031] Among them, P A2 [i]、P B2 [i]、P C2 [i] represent the active power of phase A, phase B, and phase C respectively under the i-th rated capacity capacitive reactive power output condition; U A2 [i]、U B2 [i]、U C2 [i] represents the fundamental voltage amplitudes of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, respectively. A2 [i]、I B2 [i]、I C2 [i] represents the amplitudes of the fundamental current of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, respectively. The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition are, in sequence, those of phase i. These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, where i is any integer from 1 to n.

[0032] Preferably, the step of calculating the corrected active power output value by eliminating phase angle error based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, and using this value as the SVG's body loss, includes:

[0033] The compensation and correction are performed according to the following formula.

[0034]

[0035] Wherein, P1(i) is the active power under the i-th rated capacity inductive reactive power output condition, and P2(i) is the active power under the i-th rated capacity capacitive reactive power output condition.

[0036] The present invention also proposes an SVG body loss measurement device for implementing the above-described SVG body loss measurement method, the device comprising:

[0037] The electrical signal acquisition module is used to acquire the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition of the SVG, as well as the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition.

[0038] The power calculation module is used to calculate the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition based on the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition and the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition.

[0039] The compensation module is used to calculate the corrected active power output value by eliminating phase angle error based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, which is used as the main body loss of the SVG.

[0040] The display module is used to output and display the active power output value.

[0041] The present invention has at least the following beneficial effects:

[0042] This invention effectively eliminates the problem of deviation in the test value of the SVG body loss caused by the fixed phase angle error of the sensor. The invention incorporates an algorithm to eliminate the phase angle error of the sensor during measurement, and enables the SVG body loss measurement results to be directly displayed and read through the display module. The test value reading is intuitive and the result is reliable. At the same time, this invention is not only applicable to the loss measurement of SVG, but also can be used to test low-voltage active power imbalance devices and active power filters (APF).

[0043] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart of an SVG body loss measurement method according to an embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of the power supply bus voltage and incoming current of the SVG in an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram showing that the power deviation caused by the fixed phase angle error of the sensor in this embodiment of the invention is opposite to that under rated capacity inductive reactive power output and rated capacity capacitive reactive power output.

[0048] Figure 4 This is a trend chart of loss measurement values ​​for a 35kV SVG compensation device with a rated capacity of ±70Mvar, according to an embodiment of the present invention.

[0049] Figure 5 This is a structural diagram of an SVG body loss measurement device according to an embodiment of the present invention. Detailed Implementation

[0050] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, numerous specific details are set forth in the following detailed embodiments to better illustrate the invention. Those skilled in the art will understand that the invention can be practiced without certain specific details. In some instances, means well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0051] See Figure 1 An embodiment of the present invention provides a method for measuring the loss of an SVG body, comprising the following steps:

[0052] Step S1: Obtain the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition of the SVG, as well as the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition.

[0053] Step S2: Based on the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition, and the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition, calculate the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition.

[0054] Step S3: Based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, calculate the corrected active power output value to eliminate phase angle error, and use it as the main body loss of SVG;

[0055] Step S4: Output and display the active power output value.

[0056] In some embodiments, step S1 includes:

[0057] Step S11: Set the SVG to be tested to manual constant reactive power operation mode;

[0058] Step S12: Set the SVG operating condition to output reactive power at the rated capacity of inductive circuitry, and collect the three-phase voltage waveform and three-phase current waveform signals of the SVG under this condition; and use Fast Fourier Transform (FFT) to perform real-time calculations on the three-phase voltage waveform and three-phase current waveform signals. The FFT window width is set to 200ms and the statistical interval is set to 3s to obtain the n three-phase fundamental voltage amplitudes and phases, and the n three-phase fundamental current amplitudes and phases of the SVG under this condition.

[0059] Specifically, the embodiments of the present invention are based on an SVG body loss measurement device, which can use voltage test leads and test current clamps to simultaneously collect the SVG power supply bus voltage and the current signal on the incoming line side into the SVG body loss measurement device. Figure 2 The diagram shows the connection between the SVG body loss measurement device and the power grid. The SVG power supply bus voltage can be obtained by directly connecting the voltage test line to the bus (applicable to low voltage SVG) or by connecting the voltage test line to the secondary side of the power supply bus voltage transformer (applicable to high voltage SVG). The SVG incoming current is obtained by clamping it into the secondary side of the incoming current transformer using a high-precision current clamp.

[0060] Step S13: Set the SVG operating condition to output reactive power at the rated capacitive capacity, collect the three-phase voltage waveform and three-phase current waveform of the SVG under this condition, and use Fast Fourier Transform (FFT) to perform real-time calculation on the three-phase voltage waveform and three-phase current waveform. Set the FFT window width to 200ms and the statistical interval to 3s to obtain the n three-phase fundamental voltage amplitudes and phases, and the n three-phase fundamental current amplitudes and phases of the SVG under this condition.

[0061] In some embodiments, step S2 includes:

[0062] Step S21: Calculate the active power under the rated capacity inductive reactive power output condition based on the n three-phase fundamental voltage amplitudes and phases, and the n three-phase fundamental current amplitudes and phases.

[0063] Step S22: Calculate the active power under the rated capacity capacitive reactive power output condition based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents;

[0064] Specifically, the measured value of active power includes the true value of active power and the deviation value of active power mainly caused by the fixed phase angle error of the sensor. Each active power under rated capacity inductive reactive power and rated capacity capacitive reactive power output can be expressed as follows:

[0065] P1[i]=P 1,真实 [i]±P 1,偏差 [i]

[0066]

[0067] In some embodiments, step S21 includes:

[0068] The active power P1[i] under each rated capacity inductive reactive power output condition is calculated according to the following formula.

[0069]

[0070]

[0071]

[0072] P1[i]=P A1 [i]+P B1 [i]+P C1 [i]

[0073] Among them, P A1 [i]、P B1 [i]、P C1 [i] represent the active power of phase A, phase B, and phase C respectively under the i-th rated capacity inductive reactive power output condition; U A1 [i]、U B1 [i]、U C1 [i] represent the fundamental voltage amplitudes of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, respectively. A1 [i]、I B1[i]、I C1 [i] represents the amplitudes of the fundamental current in phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, respectively. The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition are, in sequence, those of phase i. These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, where i is any integer from 1 to n.

[0074] In some embodiments, step S22 includes:

[0075] The active power P2[i] under each rated capacity capacitive reactive power output condition is calculated using the following formula.

[0076]

[0077]

[0078]

[0079] P2[i]=P A2 [i]+P B2 [i]+P C2 [i]

[0080] Among them, P A2 [i]、P B2 [i]、P C2 [i] represent the active power of phase A, phase B, and phase C respectively under the i-th rated capacity capacitive reactive power output condition; U A2 [i]、U B2 [i]、U C2 [i] represents the fundamental voltage amplitudes of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, respectively. A2 [i]、I B2 [i]、I C2 [i] represents the amplitudes of the fundamental current of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, respectively. The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition are, in sequence, those of phase i. These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, where i is any integer from 1 to n.

[0081] In some embodiments, step S3 includes:

[0082] The compensation and correction are performed according to the following formula.

[0083]

[0084] Among them, P 输出 The corrected active power output value is the SVG's body loss. P1(i) is the active power under the i-th rated capacity inductive reactive power output condition, and P2(i) is the active power under the i-th rated capacity capacitive reactive power output condition.

[0085] Specifically, such as Figure 3 As shown, Figure 3 In the middle, P L真实 P L实测 P represents the true and measured values ​​of active power under rated capacity inductive reactive power output conditions. C真实 P C实测 The active power values ​​are the true and measured values ​​under rated capacity inductive reactive power output conditions. The power deviation caused by the fixed phase angle error of the sensor is opposite to that under rated capacity inductive and rated capacity capacitive reactive power output conditions. Therefore, the two pairs of active power arrays are corrected by compensation method.

[0086] Here is an example to illustrate:

[0087] A set of 35kV SVG compensation devices with a rated capacity of ±70Mvar, according to Figure 2 The method synchronously acquires the power supply bus voltage and incoming current of the SVG. The SVG under test is set to manual constant reactive power operation mode. Under operating condition one, the output is set to inductive 70Mvar reactive power, and the test time is 3 minutes. The measuring device records the three-phase voltage and current waveforms under this condition. Fast Fourier Transform (FFT) is used to perform real-time calculations on the three-phase voltage and current waveforms. The FFT window width is set to 200ms, and the statistical interval is set to 3s, resulting in 60 sets of amplitude and phase arrays for the three-phase fundamental voltage and current, and 60 sets of amplitude and phase arrays for the three-phase fundamental current. Using the amplitude and phase data of the three-phase fundamental phase voltage and current, 60 sets of three-phase active power arrays are calculated. Similarly, under operating condition two, the output is set to capacitive 70Mvar reactive power, and the test time is 3 minutes, resulting in 60 sets of three-phase active power arrays. Figure 4As shown, the average three-phase active power under inductive reactive power output is 305.0kW, and the average three-phase active power under capacitive reactive power output is 1819.4kW. After correction by the compensation method, the final SVG body loss is 1062.2kW, which is 1.5% of the rated output. This is within the loss limit specified in NB / T 42043-2014, and the test results are reliable.

[0088] See Figure 5 Another embodiment of the present invention provides an SVG body loss measurement device for implementing the SVG body loss measurement method described in the above embodiments, the device comprising:

[0089] Electrical signal acquisition module 1 is used to acquire the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition of SVG, as well as the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition.

[0090] The power calculation module 2 is used to calculate the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition based on the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition and the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition.

[0091] The compensation module 3 is used to calculate the corrected active power output value by eliminating phase angle error based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, and use it as the main body loss of the SVG.

[0092] Display module 4 is used to output and display the active power output value.

[0093] The apparatus of the embodiments described above is merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the apparatus of the embodiments according to actual needs.

[0094] It should be noted that the apparatus of the above embodiments corresponds to the method of the above embodiments. Therefore, the parts of the apparatus of the above embodiments that are not described in detail can be obtained by referring to the content of the method of the above embodiments. That is, the specific steps of the method of the above embodiments can be understood as the functions that the apparatus of the above embodiments can achieve, and will not be described again here.

[0095] As can be seen from the above description of the embodiments, the embodiments of the present invention effectively eliminate the problem of deviation in the test value of the body loss caused by the fixed phase angle error of the sensor. The embodiments of the present invention incorporate an algorithm to eliminate the phase angle error of the sensor during measurement, and make the body loss measurement result of the SVG directly displayed and read through the display module. The test value reading is intuitive and the result is reliable. At the same time, the embodiments of the present invention are not only applicable to the loss measurement of SVG, but also can be used to test low-voltage active power imbalance devices and active power filters (APF).

[0096] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for measuring the loss of an SVG body, characterized in that, Includes the following steps: This method acquires the three-phase fundamental voltage amplitude and phase, and three-phase fundamental current amplitude and phase of the SVG under rated capacity inductive reactive power output conditions, as well as the three-phase fundamental voltage amplitude and phase, and three-phase fundamental current amplitude and phase of the SVG under rated capacity capacitive reactive power output conditions. This includes: setting the SVG under test to manual constant reactive power operation mode; setting the SVG's operating condition to output rated capacity inductive reactive power; acquiring the three-phase voltage waveform and three-phase current waveform signals of the SVG under this condition; and using Fast Fourier Transform to analyze the three-phase voltage waveform signals and... The three-phase current waveform signal is calculated in real time to obtain the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents of the SVG under this operating condition; the SVG operating condition is set to output the rated capacity capacitive reactive power, and the three-phase voltage waveform signal and the three-phase current waveform signal of the SVG under this operating condition are collected; and the three-phase voltage waveform signal and the three-phase current waveform signal are calculated in real time using fast Fourier transform to obtain the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents of the SVG under this operating condition. Based on the three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase of the SVG under rated capacity inductive reactive power output condition, and the three-phase fundamental voltage amplitude and phase, three-phase fundamental current amplitude and phase of the SVG under rated capacity capacitive reactive power output condition, calculate the active power under rated capacity inductive reactive power output condition and the active power under rated capacity capacitive reactive power output condition; including: calculating the active power under n rated capacity inductive reactive power output conditions based on the n three-phase fundamental voltage amplitude and phase, and n three-phase fundamental current amplitude and phase; calculating the active power under n rated capacity capacitive reactive power output conditions based on the n three-phase fundamental voltage amplitude and phase, and n three-phase fundamental current amplitude and phase. The corrected active power output value is obtained by eliminating phase angle error based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, and is used as the SVG's body loss; including: compensation correction according to the following formula, ,in, Let i be the active power under the i-th rated capacity inductive reactive power output condition. The active power under the i-th rated capacity capacitive reactive power output condition; The active power output value is displayed.

2. The SVG body loss measurement method as described in claim 1, characterized in that, The calculation of the active power under the rated capacity inductive reactive power output condition based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents includes: The active power under the inductive reactive power output condition for each rated capacity is calculated using the following formula. , in, , , The active power of phase A, active power of phase B, and active power of phase C under the i-th rated capacity inductive reactive power output condition are respectively. , , The values ​​are, in order, the amplitudes of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition. , , The values ​​are, in order, the amplitudes of the fundamental current in phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition. , , The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition are, in sequence, those of phase i. , , These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity inductive reactive power output condition, where i is any integer from 1 to n.

3. The SVG body loss measurement method as described in claim 1, characterized in that, The calculation of n rated capacity capacitive reactive power output conditions based on the amplitude and phase of the n three-phase fundamental voltages and the amplitude and phase of the n three-phase fundamental currents includes: The active power under capacitive reactive power output conditions for each rated capacity is calculated using the following formula. , in, , , The active power of phase A, active power of phase B, and active power of phase C under the i-th rated capacity capacitive reactive power output condition are respectively. , , The values ​​are, in order, the amplitudes of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition. , , The values ​​are, in order, the amplitudes of the fundamental current in phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition. , , The phases of the fundamental voltage of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition are, in sequence, those of phase i. , , These are, in turn, the fundamental current phases of phase A, phase B, and phase C under the i-th rated capacity capacitive reactive power output condition, where i is any integer from 1 to n.

4. An SVG body loss measuring device, characterized in that, The apparatus for implementing the SVG body loss measurement method according to any one of claims 1-3 includes: The electrical signal acquisition module is used to acquire the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition of the SVG, as well as the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition. The power calculation module is used to calculate the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition based on the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity inductive reactive power output condition and the amplitude and phase of the three-phase fundamental voltage and the amplitude and phase of the three-phase fundamental current under the rated capacity capacitive reactive power output condition. The compensation module is used to calculate the corrected active power output value by eliminating the fixed phase angle error of the sensor based on the active power under the rated capacity inductive reactive power output condition and the active power under the rated capacity capacitive reactive power output condition, and use it as the main body loss of the SVG. The display module is used to output and display the active power output value.

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