Cable two-end phasor synchronous measurement error correction method and system, terminal and medium

Abstract

The invention discloses a cable two-end phasor synchronous measurement error correction method, a cable two-end phasor synchronous measurement error correction system, a cable two-end phasor synchronous measurement error correction terminal and a cable two-end phasor synchronous measurement error correction medium, and relates to the technical field of electric power measurement. Comparing and analyzing the difference value of the actually measured phase angles at the two ends of the target cable with an initial phase angle calculated by analyzing the stable propagation of the traveling wave signal, and then determining the minimum time error of the two ends of the target cable; the minimum time error corresponding to the plurality of different first amplitudes is decomposed into a qualitative time error and a random time error, and error correction processing is performed on the sampling timestamps of the corresponding first endpoint and the second endpoint according to the qualitative time error, so that the error range of phasor synchronous measurement at the two ends of the cable can be continuously reduced; the method is suitable for various complex working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power measurement, and more specifically, to a method, system, terminal and medium for correcting synchronous measurement errors of phasors at both ends of a cable. Background Art

[0002] The synchronous measurement of phasors at both ends of a cable refers to the simultaneous measurement of the phasors of voltage and current at both ends of the cable to ensure the synchronization and accuracy of the measured data. It is widely used in fault location, condition monitoring, and system analysis. For example, when a cable fails, a transient traveling wave will be generated at the fault point, and these traveling waves will propagate along the cable. At this time, the synchronous measurement of phasors at both ends of the cable uses a synchronous phasor measurement unit (PMU) or similar equipment to measure the voltage and current phasors at both ends of the cable in real time. Based on the propagation time of the fault transient traveling wave between the fault point and both ends of the cable, combined with the cable length, the distance between the fault point and either end of the cable can be calculated, thereby obtaining the precise location of the fault point.

[0003] However, the synchronous phasor measurement unit relies on the global positioning system (GPS) or Beidou satellite system to provide accurate time synchronization signals. If the timing signal is unstable or has errors, the time base of the measured data will be inconsistent, resulting in errors. When the timing signal is normal, the clock inside the PMU may also have a slight drift, which will affect the synchronization of the measured data. In addition, the measurement error of the current transformer and the voltage transformer during the sampling process is also an important source of phasor measurement errors. At the same time, the transformer may exhibit nonlinear characteristics under high current or high voltage, resulting in measurement errors. In addition, changes in ambient temperature and humidity will also affect the performance of the measurement equipment, resulting in measurement errors. It can be seen that the error sources of synchronous phasor measurement at both ends of the cable are multifaceted.

[0004] At present, the error problem of synchronous measurement of phasors at both ends of the cable is mainly optimized from the hardware perspective, such as using high-precision and high-performance measuring equipment. This not only has high application costs, but also as the service time of the equipment continues to increase, the performance of the measuring equipment will also decrease, making it difficult to overcome the error problem of synchronous measurement of phasors at both ends of the cable for a long time. Therefore, how to study and design a method, system, terminal and medium for correcting the error of synchronous measurement of phasors at both ends of the cable that can overcome the above defects is a problem that we urgently need to solve. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a method, system, terminal and medium for correcting the error of synchronous measurement of phasors at both ends of a cable. According to the principle that the voltage and current distribution along the cable are continuous and relatively stable in a short period of time, the difference in the phase angle actually measured at both ends of the target cable is compared with the initial phase angle calculated by analyzing the stable propagation of the traveling wave signal to determine the minimum time error at both ends of the target cable, and the minimum time error corresponding to multiple different first amplitudes is decomposed into a qualitative time error and a random time error, and the sampling timestamps of the corresponding first endpoint and second endpoint are error corrected according to the qualitative time error, which can continuously reduce the error range of the synchronous measurement of the phasors at both ends of the cable and can be applied to various complex working conditions.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] In a first aspect, a method for correcting phase synchronous measurement errors at both ends of a cable is provided, comprising the following steps:

[0008] The transmission time and the initial phase angle are calculated based on the propagation speed of the traveling wave signal in the target cable and the length of the target cable;

[0009] Acquire a first sampling signal of a first end point in a target cable, and use a fast Fourier transform to convert the first sampling signal into a time-frequency domain and then extract a first amplitude and a first phase angle of a phasor;

[0010] Acquire a second sampling signal from a second endpoint in the target cable, and use fast Fourier transform to perform time-frequency domain conversion on the second sampling signal to extract a second amplitude and a second phase angle of the phasor, wherein the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time;

[0011] When the difference between the first amplitude and the second amplitude does not exceed the error range, determining the minimum time error of the first endpoint and / or the second endpoint according to the difference between the second phase angle and the first phase angle and the initial phase angle;

[0012] Determine a qualitative time error of the first endpoint and / or the second endpoint according to a minimum time error corresponding to a plurality of different first amplitudes;

[0013] An error correction iterative process is performed on the sampling time stamp of the corresponding first endpoint and / or second endpoint according to the qualitative time error.

[0014] Furthermore, the first amplitude adopts a pole amplitude, and the pole amplitude is divided into an upper pole amplitude and a lower pole amplitude;

[0015] The determination process of the extreme point amplitude is specifically as follows:

[0016] Acquire a plurality of continuous sampling signals of a first end point in a target cable within a sliding period;

[0017] The fast Fourier transform is used to convert the sampling signal into time-frequency domain and then extract the amplitude and phase angle of the phasor;

[0018] If the amplitudes at time t-1 and time t+1 are both less than or equal to the amplitude at time t, then the amplitude at time t is the upper extreme amplitude;

[0019] If the amplitudes at time t-1 and time t+1 are both greater than the amplitude at time t, then the amplitude at time t is the lower extreme amplitude.

[0020] Furthermore, the process of determining the minimum time error is specifically as follows:

[0021] Subtracting the first phase angle from the second phase angle to obtain a first phase angle difference;

[0022] The second phase angle difference whose absolute value does not exceed π is calculated by subtracting the initial phase angle from the first phase angle difference;

[0023] The propagation time corresponding to the second phase angle difference is taken as the minimum time error.

[0024] Furthermore, the method also includes:

[0025] If the second phase angle difference is greater than 0° and less than or equal to 180°, the minimum time error is used as the synchronization measurement delay error of the first endpoint;

[0026] If the second phase angle difference is less than 0° and greater than or equal to −180°, the minimum time error is used as the synchronization measurement delay error of the second endpoint.

[0027] Furthermore, the calculation formula of the second phase angle difference is specifically:

[0028]

[0029] Wherein, Δθ1 represents the first phase angle difference; θ0 represents the initial phase angle; Δθ2 represents the second phase angle difference; and n represents an integer.

[0030] Furthermore, the determination process of the qualitative time error is specifically as follows:

[0031] Counting the minimum time errors corresponding to a plurality of different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint;

[0032] The smallest minimum time error in the minimum time error sequence is used as the qualitative time error corresponding to the first endpoint or the second endpoint.

[0033] Furthermore, the determination process of the qualitative time error is specifically as follows:

[0034] Counting the minimum time errors corresponding to a plurality of different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint;

[0035] The average value of each minimum time error in the minimum time error sequence is taken as the qualitative time error corresponding to the first endpoint or the second endpoint.

[0036] In a second aspect, a system for correcting synchronous measurement errors of phasors at both ends of a cable is provided, the system being used to implement the method for correcting synchronous measurement errors of phasors at both ends of a cable as described in any one of the first aspects, comprising:

[0037] The signal initial analysis module is used to calculate the transmission time and the initial phase angle according to the propagation speed of the traveling wave signal in the target cable and the length of the target cable;

[0038] A first sampling analysis module is used to obtain a first sampling signal of a first end point in a target cable, and extract a first amplitude and a first phase angle of a phasor after performing time-frequency domain conversion on the first sampling signal using a fast Fourier transform;

[0039] A second sampling analysis module is used to obtain a second sampling signal from a second endpoint in the target cable, and extract a second amplitude and a second phase angle of the phasor after performing time-frequency domain conversion on the second sampling signal using a fast Fourier transform, wherein the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time;

[0040] A minimum error determination module, configured to determine a minimum time error of the first endpoint and / or the second endpoint according to a difference between the second phase angle and the first phase angle and an initial phase angle when a difference between the first amplitude and the second amplitude does not exceed an error range;

[0041] A qualitative error analysis module, used to determine the qualitative time error of the first endpoint and / or the second endpoint according to the minimum time error corresponding to a plurality of different first amplitudes;

[0042] The error correction processing module is used to perform error correction iterative processing on the sampling time stamp of the corresponding first endpoint and / or second endpoint according to the qualitative time error.

[0043] In a third aspect, a computer terminal is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for correcting the synchronous measurement error of the phasors at both ends of the cable as described in any one of the first aspects is implemented.

[0044] In a fourth aspect, a computer-readable medium is provided, on which a computer program is stored, and the computer program is executed by a processor to implement the method for correcting the synchronous measurement error of the phasor at both ends of the cable as described in any one of the first aspects.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The method for correcting the error of synchronous measurement of phasors at both ends of a cable provided by the present invention is based on the principle that the voltage and current distribution along the cable are continuous and relatively stable in a short period of time. The difference in the phase angle actually measured at both ends of the target cable is compared with the initial phase angle calculated by analyzing the stable propagation of the traveling wave signal to determine the minimum time error at both ends of the target cable, and the minimum time error corresponding to multiple different first amplitudes is decomposed into a qualitative time error and a random time error. The sampling timestamps of the corresponding first endpoint and the second endpoint are corrected according to the qualitative time error, which can continuously reduce the error range of synchronous measurement of phasors at both ends of the cable and can be applied to various complex working conditions.

[0047] 2. The first amplitude in the present invention adopts the extreme amplitude, which can realize the adaptive start of the phasor synchronous measurement error correction at both ends of the cable when the operating conditions such as ambient temperature, humidity and load change greatly, thereby solving the problem of resource waste caused by the continuous operation of the phasor synchronous measurement error correction at both ends of the cable;

[0048] 3. When calculating the second phase angle difference, the present invention optimizes the calculation of the second phase angle difference under the condition that the absolute value does not exceed π, and can determine which end point the minimum time error belongs to based on the positive and negative distribution of the second phase angle difference, thereby effectively realizing independent correction of the time error at both ends of the cable;

[0049] 4. The present invention takes into account the influence of the periodicity of the traveling wave signal, and the calculated qualitative time error may only include part of the synchronous measurement time error that actually exists and has a certain regularity. By performing multiple error correction iterative processing on the sampling timestamp, the error can be continuously reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0051] Figure 1 is a flow chart of Embodiment 1 of the present invention;

[0052] Figure 2 It is a system block diagram in Example 2 of the present invention. DETAILED DESCRIPTION

[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0054] Embodiment 1: A method for correcting the synchronous measurement error of phase quantities at both ends of a cable, such as Figure 1 As shown, the following steps are included:

[0055] S1: The transmission time and initial phase angle are calculated based on the propagation speed of the traveling wave signal in the target cable and the length of the target cable;

[0056] S2: Acquire a first sampling signal of a first endpoint in the target cable, and use fast Fourier transform to perform time-frequency domain conversion on the first sampling signal to extract a first amplitude and a first phase angle of the phasor;

[0057] S3: Acquire a second sampling signal from a second endpoint in the target cable, and extract a second amplitude and a second phase angle of the phasor after performing time-frequency domain conversion on the second sampling signal using a fast Fourier transform, wherein the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time;

[0058] S4: when the difference between the first amplitude and the second amplitude does not exceed the error range, determine the minimum time error of the first endpoint and / or the second endpoint according to the difference between the second phase angle and the first phase angle and the initial phase angle;

[0059] S5: determining a qualitative time error of the first endpoint and / or the second endpoint according to the minimum time error corresponding to the plurality of different first amplitudes;

[0060] S6: Perform error correction iterative processing on the sampling time stamp of the corresponding first endpoint and / or second endpoint according to the qualitative time error.

[0061] In step S1, since the traveling wave signal includes multiple complete waves and an incomplete wave during the propagation process, the present invention can assume that the phase angle of the traveling wave signal propagating from the first endpoint is 0, and the phase angle transmitted to the first endpoint is the initial phase angle.

[0062] In step S2, the phasor may be a voltage phasor or a current phasor, which is not limited here.

[0063] In addition, the first amplitude may be a fixed value or a pole amplitude, and the pole amplitude is divided into an upper pole amplitude and a lower pole amplitude.

[0064] Specifically, the process of determining the pole amplitude is as follows: obtaining multiple continuous sampling signals of the first endpoint in the target cable within the sliding period; extracting the amplitude and phase angle of the phasor after performing time-frequency domain conversion on the sampling signal using fast Fourier transform; if the amplitudes at time t-1 and time t+1 are both less than or equal to the amplitude at time t, then the amplitude at time t is the upper pole amplitude; if the amplitudes at time t-1 and time t+1 are both greater than the amplitude at time t, then the amplitude at time t is the lower pole amplitude.

[0065] The first amplitude in the present invention adopts the extreme amplitude, which can realize the adaptive start of the phasor synchronous measurement error correction at both ends of the cable when the operating conditions such as ambient temperature, humidity and load change greatly, thereby solving the problem of resource waste caused by the continuous operation of the phasor synchronous measurement error correction at both ends of the cable.

[0066] It should be noted that the window width of the sliding period remains unchanged, but moves dynamically over time.

[0067] In step S3, since the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time, in the absence of a synchronous measurement time error, the difference between the second phase angle obtained by the second sampling signal and the first phase angle obtained by the first sampling signal should be equal to the initial phase angle. If there is a difference, it can be regarded as caused by the synchronous measurement time error.

[0068] In step S4, if the difference between the first amplitude and the second amplitude does not exceed the error range, it means that the data is reliable; if the difference between the first amplitude and the second amplitude exceeds the error range, the data collected this time is ignored and no error correction processing is performed.

[0069] In this embodiment, the process of determining the minimum time error is specifically as follows: the first phase angle difference is calculated by subtracting the first phase angle from the second phase angle; the second phase angle difference is calculated by subtracting the initial phase angle from the first phase angle difference, whose absolute value does not exceed π; and the propagation time corresponding to the second phase angle difference is used as the minimum time error.

[0070] For example, the calculation formula of the second phase angle difference is specifically:

[0071]

[0072] Wherein, Δθ1 represents the first phase angle difference; θ0 represents the initial phase angle; Δθ2 represents the second phase angle difference; and n represents an integer.

[0073] When calculating the second phase angle difference, the present invention optimizes the calculation of the second phase angle difference under the condition that the absolute value does not exceed π, and can determine which endpoint the minimum time error belongs to based on the positive and negative distribution of the second phase angle difference, thereby effectively realizing independent correction of the time error at both ends of the cable.

[0074] Based on the calculation results of the above-mentioned second phase angle difference, the positive and negative distribution of the second phase angle difference is analyzed, specifically: if the second phase angle difference is greater than 0° and less than or equal to 180°, the minimum time error is used as the synchronous measurement delay error of the first endpoint; if the second phase angle difference is less than 0° and greater than or equal to -180°, the minimum time error is used as the synchronous measurement delay error of the second endpoint.

[0075] In step S5, as an optional implementation, the process of determining the qualitative time error is specifically as follows: counting the minimum time errors corresponding to multiple different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint; and taking the smallest minimum time error in the minimum time error sequence as the qualitative time error corresponding to the first endpoint or the second endpoint.

[0076] As another optional implementation, the process of determining the qualitative time error is specifically as follows: counting the minimum time errors corresponding to multiple different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint; and taking the average value of each minimum time error in the minimum time error sequence as the qualitative time error corresponding to the first endpoint or the second endpoint.

[0077] In step S6, the present invention also takes into account that due to the periodicity of the traveling wave signal, the calculated qualitative time error may only include part of the synchronous measurement time error that actually exists and has a certain regularity. By performing multiple error correction iterative processing on the sampling timestamp, the error can be continuously reduced.

[0078] Embodiment 2: A system for correcting the synchronous measurement error of phasors at both ends of a cable, the system is used to implement the method for correcting the synchronous measurement error of phasors at both ends of a cable as described in Embodiment 1, Figure 2 As shown, it includes a signal initial analysis module, a first sampling analysis module, a second sampling analysis module, a minimum error determination module, a qualitative error analysis module and an error correction processing module.

[0079] Among them, the signal initial analysis module is used to calculate the transmission time and the initial phase angle according to the propagation speed of the traveling wave signal in the target cable and the length of the target cable; the first sampling analysis module is used to obtain the first sampling signal of the first endpoint in the target cable, and extract the first amplitude and the first phase angle of the phasor after performing time-frequency domain conversion on the first sampling signal by fast Fourier transform; the second sampling analysis module is used to obtain the second sampling signal of the second endpoint in the target cable, and extract the second amplitude and the second phase angle of the phasor after performing time-frequency domain conversion on the second sampling signal by fast Fourier transform, and the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time; the minimum error determination module is used to determine the minimum time error of the first endpoint and / or the second endpoint according to the difference between the second phase angle and the first phase angle and the initial phase angle when the difference between the first amplitude and the second amplitude does not exceed the error range; the qualitative error analysis module is used to determine the qualitative time error of the first endpoint and / or the second endpoint according to the minimum time error corresponding to multiple different first amplitudes; the error correction processing module is used to perform error correction iterative processing on the sampling timestamps of the corresponding first endpoint and / or the second endpoint according to the qualitative time error.

[0080] The present invention also records a computer terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for correcting the synchronous measurement error of the phasors at both ends of the cable as described in Example 1 is implemented.

[0081] The present invention also records a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the method for correcting the synchronous measurement error of the phasors at both ends of the cable as described in Example 1.

[0082] Working principle: The present invention is based on the principle that the voltage and current distribution along the cable are continuous and relatively stable in a short period of time. The difference in the phase angle actually measured at the two ends of the target cable is compared and analyzed with the initial phase angle calculated by analyzing the stable propagation of the traveling wave signal to determine the minimum time error at the two ends of the target cable. The minimum time error corresponding to multiple different first amplitudes is decomposed into qualitative time error and random time error, and the sampling timestamps of the corresponding first endpoint and second endpoint are corrected according to the qualitative time error. This can continuously reduce the error range of the synchronous measurement of the phase quantities at both ends of the cable and can be applied to various complex working conditions.

[0083] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0084] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0085] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0087] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for correcting phase synchronous measurement errors at both ends of a cable, characterized in that: The following steps are involved: The transmission time and the initial phase angle are calculated based on the propagation speed of the traveling wave signal in the target cable and the length of the target cable; Acquire a first sampling signal of a first end point in a target cable, and use a fast Fourier transform to convert the first sampling signal into a time-frequency domain and then extract a first amplitude and a first phase angle of a phasor; Acquire a second sampling signal from a second endpoint in the target cable, and use fast Fourier transform to perform time-frequency domain conversion on the second sampling signal to extract a second amplitude and a second phase angle of the phasor, wherein the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time; When the difference between the first amplitude and the second amplitude does not exceed the error range, determining the minimum time error of the first endpoint and / or the second endpoint according to the difference between the second phase angle and the first phase angle and the initial phase angle; Determine a qualitative time error of the first endpoint and / or the second endpoint according to a minimum time error corresponding to a plurality of different first amplitudes; An error correction iterative process is performed on the sampling time stamp of the corresponding first endpoint and / or second endpoint according to the qualitative time error.

2. The method for correcting the synchronous measurement error of the phasor at both ends of the cable according to claim 1, characterized in that: The first amplitude adopts the pole amplitude, and the pole amplitude is divided into an upper pole amplitude and a lower pole amplitude; The determination process of the extreme point amplitude is specifically as follows: Acquire a plurality of continuous sampling signals of a first end point in a target cable within a sliding period; The fast Fourier transform is used to convert the sampling signal into time-frequency domain and then extract the amplitude and phase angle of the phasor; If the amplitudes at time t-1 and time t+1 are both less than or equal to the amplitude at time t, then the amplitude at time t is the upper extreme amplitude; If the amplitudes at time t-1 and time t+1 are both greater than the amplitude at time t, then the amplitude at time t is the lower extreme amplitude.

3. The method for correcting the synchronous measurement error of the phasor at both ends of a cable according to claim 1, characterized in that: The process of determining the minimum time error is specifically as follows: Subtracting the first phase angle from the second phase angle to obtain a first phase angle difference; The second phase angle difference whose absolute value does not exceed π is calculated by subtracting the initial phase angle from the first phase angle difference; The propagation time corresponding to the second phase angle difference is taken as the minimum time error.

4. The method for correcting the synchronous measurement error of the phasor at both ends of a cable according to claim 3, characterized in that: The method further includes: If the second phase angle difference is greater than 0° and less than or equal to 180°, the minimum time error is used as the synchronization measurement delay error of the first endpoint; If the second phase angle difference is less than 0° and greater than or equal to −180°, the minimum time error is used as the synchronization measurement delay error of the second endpoint.

5. The method for correcting the synchronous measurement error of the phasor at both ends of a cable according to claim 3, characterized in that: The calculation formula of the second phase angle difference is specifically: Wherein, Δθ1 represents the first phase angle difference; θ0 represents the initial phase angle; Δθ2 represents the second phase angle difference; and n represents an integer.

6. The method for correcting the synchronous measurement error of the phasor at both ends of a cable according to claim 1, characterized in that: The determination process of the qualitative time error is specifically as follows: Counting the minimum time errors corresponding to a plurality of different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint; The smallest minimum time error in the minimum time error sequence is used as the qualitative time error corresponding to the first endpoint or the second endpoint.

7. The method for correcting the synchronous measurement error of the phasor at both ends of a cable according to claim 1, characterized in that: The determination process of the qualitative time error is specifically as follows: Counting the minimum time errors corresponding to a plurality of different first amplitudes in the first endpoint or the second endpoint to obtain a minimum time error sequence corresponding to the first endpoint or the second endpoint; The average value of each minimum time error in the minimum time error sequence is taken as the qualitative time error corresponding to the first endpoint or the second endpoint.

8. The phase synchronous measurement error correction system at both ends of the cable is characterized by: The system is used to implement the method for correcting the synchronous measurement error of the phasor at both ends of the cable as claimed in any one of claims 1 to 7, comprising: The signal initial analysis module is used to calculate the transmission time and the initial phase angle according to the propagation speed of the traveling wave signal in the target cable and the length of the target cable; A first sampling analysis module is used to obtain a first sampling signal of a first end point in a target cable, and extract a first amplitude and a first phase angle of a phasor after performing time-frequency domain conversion on the first sampling signal using a fast Fourier transform; A second sampling analysis module is used to obtain a second sampling signal from a second endpoint in the target cable, and extract a second amplitude and a second phase angle of the phasor after performing time-frequency domain conversion on the second sampling signal using a fast Fourier transform, wherein the timestamp of the second sampling signal is equal to the sum of the timestamp of the first sampling signal and the transmission time; A minimum error determination module, configured to determine a minimum time error of the first endpoint and / or the second endpoint according to a difference between the second phase angle and the first phase angle and an initial phase angle when a difference between the first amplitude and the second amplitude does not exceed an error range; A qualitative error analysis module, used to determine the qualitative time error of the first endpoint and / or the second endpoint according to the minimum time error corresponding to a plurality of different first amplitudes; The error correction processing module is used to perform error correction iterative processing on the sampling time stamp of the corresponding first endpoint and / or second endpoint according to the qualitative time error.

9. A computer terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for correcting the synchronous measurement error of the phasors at both ends of the cable as described in any one of claims 1 to 7 is implemented.

10. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the method for correcting errors in synchronous measurement of phase quantities at both ends of a cable as described in any one of claims 1 to 7.

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