Phase angle measurement method, system and equipment based on construction of virtual phasors and medium

Abstract

The invention discloses a phase angle measurement method, system and device based on construction of a virtual phasor, and a medium. The method comprises the following steps: obtaining an actual phasor of current sampling data of a signal; respectively moving the phase angle of the actual phasor leftwards and rightwards by the same offset phase angle, and calculating a sampling data window of the moved virtual phasor in combination with the power frequency and the frequency offset of the signal to obtain a corresponding virtual phasor; synthesizing the actual phasor and the virtual phasor to obtain a synthetic phasor calculation function, and extracting a corresponding phase angle dynamic error reduction coefficient from the synthetic phasor calculation function; calculating a phase angle dynamic error reduction coefficient through the offset phase angle; and substituting the calculated phase angle dynamic error reduction coefficient into a synthetic phasor calculation function to obtain a corresponding synthetic phasor calculation result, and obtaining a corresponding phase angle measurement result through the synthetic phasor calculation result. By adopting the technical scheme, the phase angle measurement result is more accurate, and the offset and harmonic interference of the fundamental frequency of the power grid can be effectively inhibited.

Description

Technical Field

[0001] The present invention relates to the field of signal measurement technology, and in particular to a phase angle measurement method, system, device and medium based on building a virtual phasor. Background Art

[0002] Phase angle is a core parameter for power system regulation, state estimation, and monitoring. Based on accurate phase angle information, grid dispatchers can accurately obtain parameters such as generator power angle, voltage phase angle difference between important buses, and power factor angle of important nodes in real time, and then issue correct dispatch instructions to maintain safe and stable operation of the grid. Using the phase angle information of important nodes monitored for power flow calculations for power system state estimation will also greatly improve the speed and accuracy of state estimation. In addition, the accuracy of real-time measurement of phase angle in the power grid also directly affects the performance of other high-level applications such as online grid identification and relay protection action.

[0003] Therefore, it has become an important research direction to realize the accurate measurement of synchronized phasors and make necessary preparations for subsequent grid control, parameter online identification and other tasks. The synchronized phasor measurement algorithms in the prior art mainly include: Kalman filter-based method, wavelet transform method, Taylor model method, least square method and discrete Fourier transform (DFT) method.

[0004] Among the above-mentioned synchronized phasor measurement algorithms, the DFT algorithm has the characteristics of simple principle, fast calculation speed, strong harmonic suppression ability, etc., and is currently the most widely used synchronized phasor measurement method. However, it also has certain problems, including sudden changes in load, nonlinear loads and other factors that may cause the offset of the grid base frequency and harmonic interference, resulting in asynchronous signal sampling, and then causing the spectrum leakage and fence effect of the DFT algorithm, which aggravates the phase angle measurement error. The traditional synchronized phasor measurement method can no longer meet the development requirements of modern new power grids. Summary of the invention

[0005] Purpose of the invention: The present invention provides a phase angle measurement method, system, device and medium based on constructing a virtual phasor, aiming to solve the technical problem of large phase angle measurement error caused by factors such as power grid fundamental frequency offset and harmonic interference existing in the prior art.

[0006] Technical solution: The present invention provides a phase angle measurement method based on constructing a virtual phasor, including: obtaining the actual phasor of the current sampling data of a signal; moving the phase angle of the actual phasor to the left and right by the same offset phase angle respectively, and combining the power frequency and frequency offset of the signal to calculate the sampling data window of the moved virtual phasor to obtain the corresponding virtual phasor; synthesizing the actual phasor and the virtual phasor to obtain a synthesized phasor calculation function, and extracting the corresponding phase angle dynamic error reduction coefficient from the synthesized phasor calculation function; calculating the phase angle dynamic error reduction coefficient by offsetting the phase angle; substituting the calculated phase angle dynamic error reduction coefficient into the synthesized phasor calculation function to obtain the corresponding synthesized phasor calculation result, and obtaining the corresponding phase angle measurement result through the synthesized phasor calculation result.

[0007] Specifically, the phase angle of the actual phasor is shifted to the left by π / 3 and 2π / 3, and the phase angle of the actual phasor is shifted to the right by π / 3 and 2π / 3.

[0008] Specifically, the phase difference between the sampling data window of the current sampling data and the virtual phasor sampling data window is:

[0009] α(1+△f / f 0 ) and β(1+△f / f 0 ),

[0010] Where α and β represent the offset phase angles, which are π / 3 and 2π / 3 respectively, and f 0 represents the power frequency, and △f represents the frequency offset.

[0011] Specifically, the actual phasor and four virtual phasors are synthesized to obtain the following synthetic phasor calculation function:

[0012]

[0013] in, represents the result of synthetic phase calculation, A and B represent the first leakage and the second leakage caused by frequency offset in the fundamental wave of the signal, respectively, and X and Represents the amplitude and initial phase angle of the subharmonic of the signal, k 1 'and k' 2 represents the first synthesis coefficient and the second synthesis coefficient respectively, λ=△f / f 0 , j represents the imaginary unit.

[0014] Specifically, in the synthetic phasor calculation function, extract The coefficient of is used as the phase angle dynamic error reduction coefficient.

[0015] Specifically, the phase angle dynamic error reduction coefficient is (πλ) 2 / 27.

[0016] Specifically, the phase angle measurement results are as follows:

[0017]

[0018] The present invention also provides a phase angle measurement system based on constructing a virtual phasor, comprising: a sampling unit, a virtual phasor construction unit, a synthesis unit, an error reduction coefficient calculation unit and a measurement unit, wherein: the sampling unit is used to obtain the actual phasor of the current sampling data of the signal; the virtual phasor construction unit is used to move the phase angle of the actual phasor to the left and right by the same offset phase angle respectively, and calculate the sampling data window of the virtual phasor after the move in combination with the power frequency and frequency offset of the signal to obtain the corresponding virtual phasor; the synthesis unit is used to synthesize the actual phasor and the virtual phasor to obtain a synthesized phasor calculation function, and extract the corresponding phase angle dynamic error reduction coefficient from the synthesized phasor calculation function; the error reduction coefficient calculation unit is used to calculate the phase angle dynamic error reduction coefficient by offsetting the phase angle; the measurement unit is used to substitute the calculated phase angle dynamic error reduction coefficient into the synthesized phasor calculation function to obtain the corresponding synthesized phasor calculation result, and obtain the corresponding phase angle measurement result through the synthesized phasor calculation result.

[0019] The present invention also provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program executable by the processor, and when the computer program is executed by the processor, any phase angle measurement method based on constructing a virtual phasor provided by the present invention is executed.

[0020] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any one of the phase angle measurement methods based on constructing a virtual phasor provided by the present invention are implemented.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the phase angle measurement result is more accurate, and can effectively suppress the deviation of the fundamental frequency of the power grid and harmonic interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a DFT data window intercepting a signal during synchronous sampling provided by the present invention;

[0023] Figure 2 A schematic diagram of a DFT data window intercepted signal during asynchronous sampling provided by the present invention;

[0024] Figure 3 A dynamic error phasor diagram provided by the present invention;

[0025] Figure 4 A total phase angle error curve diagram provided by the present invention;

[0026] Figure 5 Phase angle error diagram of the four virtual phasor algorithm when the fundamental frequency is offset provided by the present invention;

[0027] Figure 6 Phase angle error diagram of the four virtual phasor algorithm under harmonic interference provided by the present invention;

[0028] Figure 7 This is a schematic diagram of the response process of the four virtual phasor algorithm under a step signal provided by the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0030] In a specific implementation, the single-phase signal x(t) in the power grid can be expressed as:

[0031]

[0032] Where X represents the effective value of the signal, ω=2π(f 0 +△f), ω represents the signal angular frequency, f 0 represents the power frequency, △f represents the frequency offset, Indicates the initial phase angle of the signal.

[0033] Sampling rate f s It can be expressed as:

[0034] f s =Nf 0 , formula (2),

[0035] Where N represents the number of sampling points in each cycle.

[0036] By sampling the signal at equal intervals, the discrete form x(n) of the sampled signal can be obtained:

[0037]

[0038] Wherein, n represents a specific sampling point in the N-sequence of periodic sampling points, that is, the nth sampling point.

[0039] When traditional DFT processes a signal, it is necessary to first intercept the signal with a window function of length N. When the frequency is offset, it is difficult to use a rectangular window to intercept the measured signal for a whole period, resulting in asynchronous sampling, which reduces the accuracy of synchronous phasor calculation. The effect of DFT data window interception of signals during synchronous sampling and asynchronous sampling is shown in Figure 1 and Figure 2 .

[0040] According to Euler's formula, the discrete sampling signal can be expressed as:

[0041]

[0042] Wherein, j represents the imaginary unit and e represents the natural logarithm.

[0043] The DFT of the rectangular window function d(n) can be expressed as:

[0044]

[0045] in,

[0046] Use the rectangular window d(n) to truncate x(n), perform DFT transformation, and substitute equation (5) into equation (7) to obtain the actual phasor of the current sampling data of the signal:

[0047]

[0048] Wherein, A and B represent the first leakage amount and the second leakage amount caused by the frequency offset in the signal fundamental wave, respectively. Specifically:

[0049]

[0050]

[0051] In order to analyze the phase angle error, formula (7) can be written as:

[0052]

[0053] In formula (10), sin(πΔf / f 0 ) / Nsin(πΔf / Nf 0 ) is the phasor The amplitude attenuation factor only affects the amplitude of the phasor but not the phase angle. The exponential term in (N-1)πΔf / Nf 0 It is the static error part of the phase angle.

[0054] Since in formula (7) The existence of the term, the third term in formula (10) is not 1, and it can be considered that the phase angle dynamic error is given by Item causes, therefore, reduction This term is equivalent to reducing the phase angle dynamic error.

[0055] To further seek The phasor relationship of Figure 3 shown.

[0056] exist Figure 3 middle, Then we have:

[0057]

[0058] Can be considered as a phase By unit phasor And in unit phasor Small amplitude phasor rotating at the end Together, if we want to obtain the phasor The phase angle of is obtained, that is, the phase angle dynamic error is obtained.

[0059] From the trigonometric relationship we can get:

[0060]

[0061] because By equivalent infinitesimal substitution we can get:

[0062]

[0063] The phase angle error of the DFT algorithm under asynchronous sampling is:

[0064]

[0065] Phase angle dynamic error and frequency deviation △f and initial phase angle Related to the initial phase angle It is approximately a sinusoidal relationship, and the phase angle error curve is as follows Figure 4 shown.

[0066] Then the phase angle error can be written as:

[0067]

[0068] in, represents the total phase angle error, Indicates the static error of the phase angle, which is only related to the frequency deviation △f. Indicates the dynamic phase angle error, which is related to the frequency deviation △f and the initial phase angle related.

[0069] The phase angle dynamic error The initial phase angle of the signal It is approximately a sinusoidal relationship and is not easy to perform real-time correction through frequency tracking. Therefore, the present invention constructs a virtual phasor, uses the virtual phasor and the original phasor to calculate the synthetic phasor value, and uses the balance relationship between the phasors during the calculation process to reduce the dynamic error of the phase angle, thereby achieving high-precision measurement of the phase angle.

[0070] In the embodiment of the present invention, the phase angle of the actual phasor is moved leftward and rightward by the same offset phase angle respectively, and the sampling data window of the moved virtual phasor is calculated in combination with the power frequency and frequency offset of the signal to obtain the corresponding virtual phasor.

[0071] In the embodiment of the present invention, the phase angle of the actual phasor is shifted to the left by π / 3 and 2π / 3, and the phase angle of the actual phasor is shifted to the right by π / 3 and 2π / 3.

[0072] By constructing a virtual phasor group with a phase difference of positive or negative π / 3 and 2π / 3 from the current phasor, the balance relationship between phasors is utilized to reduce the sinusoidal dynamic error to improve the phase angle measurement accuracy. At the same time, the amplitude of the third harmonic is also reduced to improve the method's ability to resist harmonic interference.

[0073] The virtual phasor method is a method for constructing a virtual phasor that differs from the current phasor by a certain angle, and using the measurement results of the virtual phasor and the original phasor to calculate the phasor result of the current data window. The reduction of the term is equivalent to the reduction of the dynamic phase angle error. Under the working frequency of 50 Hz, a virtual phasor is constructed with a positive or negative α and a positive or negative β difference from the current phasor, that is, the current sampling data is shifted to the left and right by αN / (2π) and βN / (2π) points respectively.

[0074] In the embodiment of the present invention, under actual working conditions, when frequency offset occurs, the current sampling data window is shifted to the left and right by αN / (2π) and βN / (2π) points respectively, and the phase difference between the sampling data window of the current sampling data and the virtual phasor sampling data window is:

[0075] α(1+△f / f 0 ) and β(1+△f / f 0 ), f 0 represents the power frequency, △f represents the frequency offset, and the DFT calculation results can be expressed as:

[0076]

[0077] Where λ = △f / f 0 , since the frequency deviation is very small compared to the power frequency, λ can be approximately regarded as an infinitesimal quantity. α and β represent the angle between the virtual phasor and the current phasor respectively. In the process of deriving and solving α and β, it is assumed that α<β.

[0078] In the embodiment of the present invention, the actual phasor and the virtual phasor are synthesized to obtain a synthesized phasor calculation function, and the corresponding phase angle dynamic error reduction coefficient is extracted from the synthesized phasor calculation function.

[0079] The composite phasor of the five phasors in formula (17) is constructed as follows:

[0080]

[0081] In engineering, the coefficient k 1 to k 5Integers or rational numbers should be used to avoid errors caused by rounding. Considering the symmetry of the positive and negative α and positive and negative β virtual phasors with respect to the current actual phasors, k 2 =k 3 , k 4 =k 5 At the same time, in order to facilitate calculation, take k 1 '=k 1 / k 4 , k' 2 =k 2 / k 4 , then formula (18) can be further expressed as:

[0082]

[0083] In formula (19), cos(αλ) and cos(βλ) are approximately 1, which can be written as:

[0084]

[0085] In the embodiment of the present invention, in the synthetic phase calculation function, extract The coefficient of is used as the phase angle dynamic error reduction coefficient.

[0086] From formula (20), we can know that reducing term, that is, it can be multiplied by a coefficient as small as possible through the virtual phasor method, and the The coefficient expansion of the term yields:

[0087]

[0088] Among them, the The reduction of the term is equivalent to the reduction of the phase angle dynamic error. If the γ coefficient is less than 1, it means that the method provided by this patent is The reduction of the term is effective, that is, the reduction of the phase angle dynamic error is effective. The size of γ characterizes the ability of the method provided by this patent to reduce the phase angle dynamic error.

[0089] The denominator in formula (21) is k 1 'and k' 2 The constant determined by λ can be Taylor expanded to the second-order infinitesimal by the numerator. If the measurement accuracy of the method provided by this patent is to be improved, that is, γ must be small enough, the following constraints can be obtained:

[0090] (1) The absolute values ​​of the constant term and the first-order and second-order infinitesimal terms of the γ numerator term are as small as possible.

[0091] Among them, the constant term is k 1 '+2k 2'cos(2α)+2cos(2β);

[0092] The first-order infinitesimal term is -2k 2 'sin(2α)×(αλ)-2sin(2β)×(βλ);

[0093] The second-order infinitesimal term is -k' 2 cos(2α)×(αλ) 2 -cos(2β)×(βλ) 2 .

[0094] (2)γ denominator k 1 '+2k' 2 The absolute value of +2 is as large as possible, that is, k 1 ', k' 2 Try to keep it as positive as possible.

[0095] Considering making γ as small as possible, the first thing is to make the infinitesimal order of the numerator as high as possible, and set its constant term and first-order infinitesimal term to 0, and we get:

[0096]

[0097] When the second-order infinitesimal term is set to 0, k' 2 The value of conflicts with formula (22), so the infinitesimal order of γ can be up to the second order. After determining the values ​​of α and β, k is determined according to formula (22). 1 ', k' 2 By calculating the value of , we can determine that γ is a second-order infinitesimal of λ.

[0098] The values ​​of α and β are symmetrical about the original phasor and appear in pairs, so α<π and β<π. On this basis, it can be seen from formula (16) that if k' is to be guaranteed 2 If it is a positive number, the numerator and denominator must have different signs, that is, β>π / 2 and α<π / 2.

[0099] To ensure k' 2 is a rational number, that is, the sine value expressions of α and β cannot be too complicated. Recommended values ​​of α and β include: π / 6, π / 4, π / 3, π / 2, 2π / 3 and 5π / 6.

[0100] α and β are the phase angle differences between the virtual phasor and the current phasor. If the value of β is too large, the longer the equivalent time window required by the method provided by this patent is, the longer the delay time of the method provided by this patent under the step signal condition is. At the same time, based on the consideration of making β>π / 2 as much as possible, the reference value of β is β=2π / 3.

[0101] Considering the superior performance of the π / 3 method in resisting third harmonic interference, as well as the good measurement accuracy of the method, and the value of α will not affect the window length, the value of α is considered to be α=π / 3.

[0102] In the embodiment of the present invention, the phase angle dynamic error reduction coefficient is (πλ) 2 / 27.

[0103] In summary, according to the values ​​of α and β, k is determined 1 ', k' 2 The value is: k 1 '=3, k' 2 =2.

[0104] Four virtual phasors with phase angles different from the current phasor by ±π / 3 and ±2π / 3 are constructed. The current sampling data window is shifted to the left and right by N / 6 and N / 3 points respectively to realize the construction of the virtual phasors. DFT calculations are performed on the sampling data to obtain the synthetic phasors, and finally the DFT dynamic error is corrected.

[0105] According to the method proposed in this patent, the synthetic phase calculation result is:

[0106]

[0107] The phase angle error results are:

[0108]

[0109] After correction using the four virtual phasor method proposed in this patent, the phase angle dynamic error is given a reduction coefficient (πλ) 2 / 27, significantly reducing the phase angle dynamic error and improving the measurement accuracy. The phase angle error diagram of the four virtual phasor algorithm when the fundamental frequency is offset is shown in the figure below. Figure 5 shown.

[0110] In a specific implementation, based on the method provided by the present invention, a model for reducing harmonic interference under the virtual phasor method is constructed.

[0111] Due to the existence of nonlinear loads in actual power grids, third harmonics are inevitably introduced into the power grid, which greatly affects the phase angle measurement accuracy of the DFT algorithm. The method provided by the patent is also very effective in resisting harmonic interference, and the anti-harmonic interference includes the reduction of each harmonic interference.

[0112] Assume the input signal is:

[0113]

[0114] In the formula: X m3 is the third harmonic amplitude; is the initial phase angle of the third harmonic component.

[0115] Due to the linear nature of the DFT algorithm, the fundamental and harmonic components can be calculated separately. This paper focuses on analyzing the anti-harmonic interference performance of the four virtual phasor method of this patent.

[0116] The third harmonic component of the signal can be written as:

[0117]

[0118] Similar to the fundamental signal, the third harmonic signal is sampled at a fixed sampling rate, replaced by the Euler formula, truncated by a rectangular window, and transformed by DFT, and the DFT transformation result is obtained:

[0119]

[0120]

[0121] In the actual process, since the fundamental frequency of the input signal will shift, the current sampling data window is shifted by N / 6 points and N / 3 points respectively. The corresponding phase offsets of the third harmonic should be π(1+λ) and 2π(1+λ). At this time, the four virtual phasors of the third harmonic are:

[0122]

[0123] The synthetic phase of the third harmonic after correction by the method provided by this patent for:

[0124]

[0125] From formula (31), it can be seen that the patented method can effectively reduce the third harmonic interference in the power grid and reduce the third harmonic to (πλ) of the traditional DFT algorithm. 2 / 3. Compared with traditional DFT, the method provided by this patent has a better reduction effect on third harmonic interference and significantly improves the measurement accuracy under third harmonic interference. The phase angle error diagram of the four virtual phasor algorithm under harmonic interference is shown in Figure 6 shown.

[0126] In addition to the third harmonic, the a-th harmonic component of the signal can be written as:

[0127]

[0128] In the formula: X ma is the harmonic amplitude, is the initial phase angle of harmonics.

[0129] Similar to the third harmonic, after the a-th harmonic signal is sampled at a fixed sampling rate, replaced by the Euler formula, truncated by a rectangular window, and transformed by DFT, the result is:

[0130]

[0131] The corresponding virtual phasor and the corrected synthetic phasor They are:

[0132]

[0133] Substituting the value of harmonic order a, and simplifying the coefficient terms containing trigonometric functions by sum angle formula and Taylor formula, the reduction result of the harmonic by the method provided by this patent can be obtained. Among them, the reduction results of the fifth and seventh harmonics are:

[0134]

[0135] Under the a-th harmonic condition, the harmonic synthetic phasor corrected by the method provided by this patent is for:

[0136]

[0137] In the formula, A ma and B ma are the leakage caused by frequency deviation in the corresponding subharmonics, X ma and is the amplitude and initial phase angle of the corresponding subharmonic.

[0138] In a specific implementation, based on the method provided by this patent, a four-virtual phasor DFT phase angle measurement model based on offset π / 3 and 2π / 3 is constructed.

[0139] The specific implementation method of the accurate measurement of the phase angle of the synchronized phasor is as follows:

[0140]

[0141] The constructed virtual phasor expression is:

[0142]

[0143] The synthetic phase quantity is calculated as follows:

[0144]

[0145] The principle diagram of the response process of the four virtual phasor algorithm under the step signal provided by the present invention is as follows Figure 7 As shown, when the fundamental signal frequency is offset, the phasor result obtained by the patent method is:

[0146]

[0147] The frequency leakage term in the synthetic phasor result was significantly suppressed.

[0148] The suppression result of the a-th harmonic by this patented algorithm is:

[0149]

[0150] Among them, the results after the third, fifth and seventh harmonics are suppressed can be expressed as:

[0151]

[0152] The results of formulas (44) to (48) show that the method proposed in this patent not only has good measurement accuracy, but also has a certain degree of suppression of each harmonic, and has good measurement performance.

[0153] The present invention also provides a phase angle measurement system based on constructing a virtual phasor, comprising: a sampling unit, a virtual phasor construction unit, a synthesis unit, an error reduction coefficient calculation unit and a measurement unit, wherein: the sampling unit is used to obtain the actual phasor of the current sampling data of the signal; the virtual phasor construction unit is used to move the phase angle of the actual phasor to the left and right by the same offset phase angle respectively, and calculate the sampling data window of the virtual phasor after the move in combination with the power frequency and frequency offset of the signal to obtain the corresponding virtual phasor; the synthesis unit is used to synthesize the actual phasor and the virtual phasor to obtain a synthesized phasor calculation function, and extract the corresponding phase angle dynamic error reduction coefficient from the synthesized phasor calculation function; the error reduction coefficient calculation unit is used to calculate the phase angle dynamic error reduction coefficient by offsetting the phase angle; the measurement unit is used to substitute the calculated phase angle dynamic error reduction coefficient into the synthesized phasor calculation function to obtain the corresponding synthesized phasor calculation result, and obtain the corresponding phase angle measurement result through the synthesized phasor calculation result.

[0154] In a specific implementation, a phase angle measurement system based on constructing a virtual phasor includes a PMU phasor measurement data system including a Beidou / GPS receiver, a phase-locked oscillator, a signal converter, a low-pass filter, a digital-to-analog converter, and a phasor calculation microprocessor. The phasor calculation microprocessor is used to execute the contents of the phase angle measurement method provided by the present invention.

[0155] The present invention also provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program executable by the processor, and when the computer program is executed by the processor, any phase angle measurement method based on constructing a virtual phasor provided by the present invention is executed.

[0156] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any one of the phase angle measurement methods based on constructing a virtual phasor provided by the present invention are implemented.

Claims

1. A phase angle measurement method based on constructing a virtual phasor, characterized in that: include: Get the actual phasor of the current sampling data of the signal; The phase angle of the actual phasor is moved leftward and rightward by the same offset phase angle respectively, and the sampling data window of the virtual phasor after the shift is calculated by combining the power frequency and the frequency offset of the signal to obtain the corresponding virtual phasor; The actual phasor and the virtual phasor are synthesized to obtain a synthesized phasor calculation function, and the corresponding phase angle dynamic error reduction coefficient is extracted from the synthesized phasor calculation function; By shifting the phase angle, the phase angle dynamic error reduction coefficient is calculated; The calculated phase angle dynamic error reduction coefficient is substituted into the synthetic phasor calculation function to obtain the corresponding synthetic phasor calculation result, and the corresponding phase angle measurement result is obtained through the synthetic phasor calculation result.

2. The phase angle measurement method based on constructing a virtual phasor according to claim 1, characterized in that: The step of moving the phase angle of the actual phase quantity to the left and to the right by the same offset phase angle comprises: The phase angle of the actual phasor is shifted to the left by π / 3 and 2π / 3, and the phase angle of the actual phasor is shifted to the right by π / 3 and 2π / 3.

3. The phase angle measurement method based on constructing a virtual phasor according to claim 2, characterized in that: The method combines the power frequency and the frequency offset of the signal to calculate the sampling data window of the moved virtual phasor to obtain the corresponding virtual phasor, including: The phase difference between the sampling data window of the current sampling data and the virtual phasor sampling data window is: α(1+△f / f0) and β(1+△f / f0), Among them, α and β represent the offset phase angles, which are π / 3 and 2π / 3 respectively, f0 represents the power frequency, and △f represents the frequency offset.

4. The phase angle measurement method based on constructing a virtual phasor according to claim 3 is characterized in that: The step of synthesizing the actual phasor and the virtual phasor to obtain a synthesized phasor calculation function includes: The actual phasor and four virtual phasors are synthesized to obtain the following synthetic phasor calculation function: in, represents the result of synthetic phase calculation, A and B represent the first leakage and the second leakage caused by frequency offset in the fundamental wave of the signal, respectively, and X and represents the amplitude and initial phase angle of the subharmonic of the signal, k1' and k'2 represent the first synthesis coefficient and the second synthesis coefficient respectively, λ=△f / f0, and j represents the imaginary unit.

5. The phase angle measurement method based on constructing a virtual phasor according to claim 4, characterized in that: The step of extracting the corresponding phase angle dynamic error reduction coefficient from the synthetic phase calculation function includes: In the synthetic phasor calculation function, extract The coefficient is used as the phase angle dynamic error reduction coefficient.

6. The phase angle measurement method based on constructing a virtual phasor according to claim 5, characterized in that: The calculation of the phase angle dynamic error reduction coefficient by shifting the phase angle includes: The phase angle dynamic error reduction coefficient is (πλ) 2 / 27.

7. The phase angle measurement method based on constructing a virtual phasor according to claim 6, characterized in that: The phase angle measurement results are as follows:

8. A phase angle measurement system based on constructing a virtual phasor, characterized in that: include: A sampling unit, a virtual phasor construction unit, a synthesis unit, an error reduction coefficient calculation unit and a measurement unit, wherein: The sampling unit is used to obtain the actual phasor of the current sampling data of the signal; The virtual phasor construction unit is used to move the phase angle of the actual phasor to the left and right by the same offset phase angle, and calculate the sampling data window of the virtual phasor after the shift in combination with the power frequency and the frequency offset of the signal to obtain the corresponding virtual phasor; The synthesis unit is used to synthesize the actual phasor and the virtual phasor to obtain a synthesized phasor calculation function, and extract the corresponding phase angle dynamic error reduction coefficient from the synthesized phasor calculation function; The error reduction coefficient calculation unit is used to calculate the phase angle dynamic error reduction coefficient by offsetting the phase angle; The measuring unit is used to substitute the calculated phase angle dynamic error reduction coefficient into the synthetic phasor calculation function to obtain the corresponding synthetic phasor calculation result, and obtain the corresponding phase angle measurement result through the synthetic phasor calculation result.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program executable by the processor is stored in the memory, and when the computer program is executed by the processor, the phase angle measurement method based on constructing a virtual phasor as described in any one of claims 1 to 7 is executed.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the phase angle measurement method based on constructing a virtual phasor are implemented as claimed in any one of claims 1 to 7.

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