Voltage transformer transformation ratio direction compensation method, device and equipment and storage medium

Abstract

The invention relates to the technical field of transformation ratio direction compensation, and discloses a voltage transformer transformation ratio direction compensation method, device and equipment and a storage medium, and the method comprises the steps: collecting a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side of the voltage transformer; determining a cross correlation coefficient and a transformation ratio error based on the first voltage signal and the second voltage signal; determining a phase difference according to the cross correlation coefficient; and performing transformation ratio direction compensation on the voltage transformer according to the transformation ratio error and the phase difference, the transformation ratio direction compensation at least comprising transformation ratio compensation, phase compensation and direction compensation, and realizing the transformation ratio direction compensation on the voltage transformer by combining the transformation ratio compensation, the phase compensation and the direction compensation. And the compensation efficiency and accuracy are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformation ratio direction compensation, and particularly to a voltage transformer transformation ratio direction compensation method, device, equipment and storage medium. BACKGROUND

[0002] Voltage transformers (VT) are widely used in power systems to convert high-voltage signals into low-voltage signals for measurement, protection and control. However, due to the working principle of voltage transformers and possible errors in their manufacturing process, there are often transformation ratio deviation, phase difference and direction error problems in actual operation. These errors not only affect the measurement accuracy of the power system, but also may cause inaccurate action of protection devices, thereby negatively affecting the stability and safety of the power system.

[0003] Traditional voltage transformer compensation methods usually only focus on errors in one aspect, such as transformation ratio error or phase error, ignoring the interaction between these errors and their impact on the overall performance of the power system. The disadvantage of these traditional methods is that they cannot handle transformation ratio error, phase error and direction error at the same time, resulting in low compensation efficiency and insufficient accuracy, especially in cases where the load of the power grid changes greatly, the compensation effect is difficult to guarantee. SUMMARY

[0004] The main purpose of the present application is to provide a voltage transformer transformation ratio direction compensation method, device, equipment and storage medium, which aims to solve the technical problem of poor efficiency and accuracy of traditional transformation ratio direction compensation.

[0005] To achieve the above-mentioned purpose, the present application provides a voltage transformer transformation ratio direction compensation method, which comprises: collecting a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side of the voltage transformer; determining a cross-correlation coefficient and a transformation ratio error based on the first voltage signal and the second voltage signal; determining a phase difference according to the cross-correlation coefficient; compensating the transformation ratio direction of the voltage transformer according to the transformation ratio error and the phase difference, wherein the transformation ratio direction compensation at least includes transformation ratio compensation, phase compensation and direction compensation.

[0006] In an embodiment, the cross-correlation coefficient is determined based on the first voltage signal and the second voltage signal, comprising: performing time delay processing on the first voltage signal and the second voltage signal to obtain a series of voltage signal pairs with different time delays; calculating a cross-correlation value between each pair of voltage signals to obtain a cross-correlation value sequence; constructing a cross-correlation function according to the cross-correlation value sequence, the cross-correlation function being used to represent a change relationship of a similarity degree between the first voltage signal and the second voltage signal with respect to a time delay; determining the cross-correlation coefficient according to a shape and a peak position of the cross-correlation function.

[0007] In an embodiment, the determining a ratio error based on the first voltage signal and the second voltage signal comprises: preprocessing the first voltage signal and the second voltage signal to obtain a preprocessed first voltage signal and a preprocessed second voltage signal; determining an actual ratio value according to the preprocessed first voltage signal and the preprocessed second voltage signal, the actual ratio value being a ratio of the first voltage signal to the second voltage signal; determining a ratio error according to the actual ratio value and a preset ratio value.

[0008] In an embodiment, the determining a phase difference according to the cross-correlation coefficient comprises: comparing the cross-correlation coefficient with a preset cross-correlation coefficient threshold value; if the cross-correlation coefficient is greater than or equal to the cross-correlation coefficient threshold value, determining that a phase difference between the first voltage signal and the second voltage signal is zero; if the cross-correlation coefficient is less than the cross-correlation coefficient threshold value, performing phase analysis on the first voltage signal and the second voltage signal by a phase resolving algorithm to obtain a phase difference.

[0009] In an embodiment, the performing phase analysis on the first voltage signal and the second voltage signal by a phase resolving algorithm to obtain a phase difference comprises: performing Fourier transform on the first voltage signal and the second voltage signal respectively to obtain first frequency spectrum information and second frequency spectrum information; determining a fundamental frequency component according to the first frequency spectrum information and the second frequency spectrum information; calculating an initial phase difference between the first voltage signal and the second voltage signal based on the fundamental frequency component; performing filtering processing on the initial phase difference to obtain a smoothed phase difference curve; determining a phase difference according to the smoothed phase difference curve.

[0010] In an embodiment, the compensating a ratio direction of the voltage transformer according to the ratio error and the phase difference comprises: According to the transformation ratio error, the amplitude of the second voltage signal is compensated by a PID control algorithm to obtain a compensated amplitude; According to the phase difference, the phase of the second voltage signal is compensated by a Kalman filtering algorithm to obtain a compensated phase; According to the compensated amplitude and the compensated phase, the direction of the second voltage signal is determined; According to the direction of the second voltage signal, the output direction of the voltage transformer is directionally compensated.

[0011] In an embodiment, the compensation of the amplitude of the second voltage signal according to the transformation ratio error by the PID control algorithm includes: The PID controller is designed, wherein the design of the PID controller includes determining the proportional coefficient, the integral coefficient and the differential coefficient; The transformation ratio error is taken as the input of the PID controller, and the control amount is calculated through the proportional, integral and differential links of the PID controller; The amplitude of the second voltage signal is adjusted according to the control amount to obtain an adjusted amplitude; The adjusted amplitude of the second voltage signal is limited to obtain a compensated amplitude.

[0012] In addition, to achieve the above-mentioned purpose, the present application also provides a voltage transformer transformation ratio direction compensation device, which comprises: The acquisition module is configured to acquire the first voltage signal on the primary side of the voltage transformer and the second voltage signal on the secondary side of the voltage transformer; The determination module is configured to determine the cross-correlation coefficient and the transformation ratio error based on the first voltage signal and the second voltage signal; The determination module is further configured to determine the phase difference according to the cross-correlation coefficient; The compensation module is configured to compensate the voltage transformer in terms of transformation ratio direction, wherein the compensation at least includes compensation of transformation ratio, compensation of phase and compensation of direction.

[0013] In addition, to achieve the above-mentioned purpose, the present application also provides a voltage transformer transformation ratio direction compensation device, which comprises:

[0014] In addition, to achieve the above-mentioned purpose, the application further provides a storage medium, which is a computer readable storage medium, and a computer program is stored on the storage medium, and the computer program is executed by a processor to implement the steps of the voltage transformer ratio direction compensation method.

[0015] In addition, to achieve the above-mentioned purpose, the application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the voltage transformer ratio direction compensation method.

[0016] The one or more technical solutions provided by the application collect a first voltage signal on a primary side of a voltage transformer and a second voltage signal on a secondary side of the voltage transformer; determine a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal; determine a phase difference based on the cross-correlation coefficient; and perform ratio direction compensation on the voltage transformer based on the ratio error and the phase difference, wherein the ratio direction compensation at least comprises ratio compensation, phase compensation, and direction compensation. In this way, by combining ratio compensation, phase compensation, and direction compensation, the ratio direction compensation of the voltage transformer is realized, and the compensation efficiency and accuracy are effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the application and, together with the specification, serve to explain the principles of the application.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor.

[0019] Figure 1 The flowchart provided for the voltage transformer ratio direction compensation method embodiment one of the application; Figure 2 The flowchart provided for the voltage transformer ratio direction compensation method embodiment two of the application; Figure 3 The module structure diagram of the voltage transformer ratio direction compensation device of the embodiment of the application; Figure 4 The device structure diagram of the hardware running environment involved in the voltage transformer ratio direction compensation equipment in the embodiment of the application.

[0020] The purpose implementation, functional characteristics and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0021] It should be understood that the specific embodiments described herein are merely for the purpose of illustration of the technical solutions of the present application and are not used to limit the present application.

[0022] In order to better understand the technical solutions of the present application, the following will be described in detail in combination with the drawings of the specification and specific embodiments.

[0023] The main solution of the embodiment of the present application is: collecting a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side of the voltage transformer; determining a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal; determining a phase difference according to the cross-correlation coefficient; and performing ratio direction compensation on the voltage transformer according to the ratio error and the phase difference, wherein the ratio direction compensation at least includes ratio compensation, phase compensation and direction compensation.

[0024] The traditional voltage transformer compensation method usually only focuses on the error of one aspect, such as ratio error or phase error, ignoring the interaction between these errors and their influence on the performance of the entire power system. The disadvantage of these traditional methods is that they cannot handle ratio error, phase error and direction error at the same time, resulting in low compensation efficiency and insufficient accuracy, especially in the case of large changes in power grid load, the compensation effect is difficult to guarantee The present application provides a solution, which realizes the ratio direction compensation of the voltage transformer by combining the ratio compensation, the phase compensation and the direction compensation, and effectively improves the compensation efficiency and accuracy.

[0025] It should be noted that the execution subject of the present embodiment can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a voltage transformer ratio direction compensation device, etc. The present embodiment and the following embodiments will be described below taking the voltage transformer ratio direction compensation device as an example.

[0026] Based on this, the present embodiment provides a voltage transformer ratio direction compensation method, which refers to Figure 1 , Figure 1 The flowchart of the first embodiment of the voltage transformer ratio direction compensation method of the present application is shown in the figure.

[0027] In the present embodiment, the voltage transformer ratio direction compensation method includes steps S10-S40: Step S10: Collecting a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side of the voltage transformer.

[0028] It should be noted that the voltage transformer is a common device in power systems, which is used to convert high voltage into low voltage for measurement and protection. In practical applications, due to various reasons, the voltage transformer may have ratio error, phase error and direction error, which will affect the stability and accuracy of the power system. Therefore, it is necessary to compensate the voltage transformer.

[0029] It can be understood that the primary side refers to the high voltage side of the voltage transformer, which is usually connected to the high voltage part of the power system, while the secondary side refers to the low voltage side of the voltage transformer, which is usually connected to the measurement or protection equipment. When collecting voltage signals, the voltage signals of the primary and secondary sides can be obtained through sensors or other measurement devices. These voltage signals are digitized and can be further processed and analyzed by processors or computer programs.

[0030] It should be noted that the first voltage signal and the second voltage signal are the voltage signals of the primary and secondary sides of the voltage transformer, which represent the voltage conditions of the high voltage side and the low voltage side respectively.

[0031] Step S20: determining the cross-correlation coefficient and the ratio error based on the first voltage signal and the second voltage signal.

[0032] It should be noted that the cross-correlation coefficient is an index for measuring the similarity between two signals. By calculating the cross-correlation coefficient between the first voltage signal and the second voltage signal, the correlation between them can be understood. The ratio error is the difference between the actual ratio of the voltage transformer and the theoretical ratio, which is one of the important indicators for evaluating the performance of the voltage transformer.

[0033] In one possible implementation, the step S20 of "determining the cross-correlation coefficient based on the first voltage signal and the second voltage signal" can include steps A11-A14: Step A11: time delay processing of the first voltage signal and the second voltage signal to obtain a series of voltage signal pairs with different time delays.

[0034] It should be noted that time delay processing is to simulate the delay that may exist in the transmission process of voltage signals, so as to find the voltage signal pair that best fits the actual situation. By calculating the cross-correlation of voltage signal pairs with different time delays, the similarity between them can be found, and the optimal time delay and cross-correlation coefficient can be determined.

[0035] In a specific implementation, for a given first voltage signal v1(t) and second voltage signal v2(t), a series of different time delays are applied to them to generate a pair of voltage signals. For a time delay τ, the resulting signal pair is: v1(t) and v2(t+τ), where τ represents the size of the time delay, which can be a number of different delay values, forming a delay sequence τ1, τ2, …, τn.

[0036] Step A12: Calculate the cross-correlation value between each pair of voltage signals to obtain a cross-correlation value sequence.

[0037] It should be noted that the cross-correlation operation is performed on each pair of voltage signals, and the cross-correlation operation is used to measure the similarity of two signals at different time delays. The formula for calculating the cross-correlation value is:

[0038] wherein, is the cross-correlation value between the first signal v1(t) and the delayed second voltage signal v2(t+τ).

[0039] Step A13: Construct a cross-correlation function based on the cross-correlation value sequence, the cross-correlation function being used to represent the change relationship of the similarity between the first voltage signal and the second voltage signal with time delay.

[0040] It should be noted that the cross-correlation function is a mathematical tool for describing the similarity between two signals. In this embodiment, the cross-correlation function is used to represent how the similarity between the first voltage signal and the second voltage signal changes with time delay. This change relationship can help determine the optimal time delay, i.e. the time delay value that makes the two signals most similar.

[0041] It can be understood that the cross-correlation function is:

[0042] wherein T is the total length of the signal, t is the time index, and the cross-correlation function is a function reflecting the similarity between signals as the time delay τ changes.

[0043] Step A14: Determine the cross-correlation coefficient based on the shape and peak position of the cross-correlation function.

[0044] It should be noted that the cross-correlation coefficient can be determined based on the shape and peak position of the constructed cross-correlation function . The cross-correlation coefficient is the value at the time delay τ max corresponding to the maximum value of the cross-correlation function. The formula for calculating the cross-correlation coefficient is:

[0045] wherein, is the value of the autocorrelation function of the first voltage signal v1(t) itself at τ = 0, is the value of the autocorrelation function of the second voltage signal v2(t) itself at τ = 0, is the peak position of the cross-correlation function .

[0046] In a feasible implementation, the step S20 of "determining the ratio error based on the first voltage signal and the second voltage signal" can include steps B11-B14: Step B11: pre-processing the first voltage signal and the second voltage signal to obtain a pre-processed first voltage signal and a pre-processed second voltage signal.

[0047] It should be noted that the pre-processing step is to improve the accuracy and reliability of the voltage signal. The pre-processing includes filtering, denoising, smoothing, etc. to reduce the interference and noise in the signal, so that it can more truly reflect the working state of the voltage transformer.

[0048] Step B12: determining the actual ratio value according to the pre-processed first voltage signal and the pre-processed second voltage signal, the actual ratio value being the ratio of the first voltage signal to the second voltage signal.

[0049] It should be noted that the actual ratio value is the actual ratio between the primary side voltage and the secondary side voltage of the voltage transformer, which reflects the ratio error of the voltage transformer. By calculating the actual ratio value, the error size of the voltage transformer can be quantified.

[0050] Step B13: determining the ratio error according to the actual ratio value and a preset ratio value.

[0051] It should be noted that the ratio error is the difference or ratio between the actual ratio value and the preset ratio value. The preset ratio value is the ideal ratio value specified when the voltage transformer is designed or manufactured. By comparing the actual ratio value with the ideal ratio value, the ratio error of the voltage transformer can be obtained, which reflects the deviation degree of the voltage transformer in the ratio aspect.

[0052] Step S30: determining the phase difference according to the cross-correlation coefficient.

[0053] It should be noted that the phase difference refers to the difference in phase between two voltage signals, which reflects the phase transmission characteristics of the voltage transformer. The cross-correlation coefficient can be used to determine the phase difference, because the cross-correlation coefficient not only contains the similarity information between the two signals, but also implies the phase relationship between them. When the phases of the two signals are completely aligned, the cross-correlation coefficient reaches the maximum value. By analyzing the change of the cross-correlation coefficient with the phase, the phase difference that makes the cross-correlation coefficient maximum, i.e. the actual phase difference between the two voltage signals, can be determined. The determination of this phase difference is of great significance for understanding the phase transmission characteristics of the voltage transformer and performing phase compensation. After the phase difference is determined, appropriate measures can be taken for phase compensation to improve the accuracy and stability of the voltage transformer measurement.

[0054] In a possible implementation, step S30 can include: comparing the cross-correlation coefficient with a preset cross-correlation coefficient threshold; if the cross-correlation coefficient is greater than or equal to the cross-correlation coefficient threshold, determining that the phase difference between the first voltage signal and the second voltage signal is zero; and if the cross-correlation coefficient is less than the cross-correlation coefficient threshold, performing phase analysis on the first voltage signal and the second voltage signal by a phase resolving algorithm to obtain the phase difference.

[0055] It should be noted that the preset cross-correlation coefficient threshold is a pre-set value for judging whether the similarity between the two voltage signals is high enough. When the cross-correlation coefficient is greater than or equal to the threshold, it can be considered that the phases of the two voltage signals have been aligned, and therefore the phase difference is zero. When the cross-correlation coefficient is less than the threshold, it is necessary to further analyze the phase relationship between the two voltage signals by the phase resolving algorithm to determine the phase difference between them.

[0056] It can be understood that the phase resolving algorithm is a mathematical method for determining the phase difference between two signals, which can obtain the phase difference between signals according to the waveform and frequency characteristics of the signals. By applying the phase resolving algorithm, more accurate and reliable phase difference results can be obtained.

[0057] In a possible implementation, the phase analysis on the first voltage signal and the second voltage signal by the phase resolving algorithm to obtain the phase difference includes: performing Fourier transform on the first voltage signal and the second voltage signal respectively to obtain first frequency spectrum information and second frequency spectrum information; determining a fundamental frequency component according to the first frequency spectrum information and the second frequency spectrum information; calculating an initial phase difference between the first voltage signal and the second voltage signal based on the fundamental frequency component; performing filtering processing on the initial phase difference to obtain a smooth phase difference curve; and determining the phase difference according to the smooth phase difference curve.

[0058] It should be noted that the Fourier transform is a mathematical method for converting time-domain signals into frequency-domain signals, which can help us analyze the frequency components of the signals. By performing Fourier transform on the first voltage signal and the second voltage signal, we can obtain their respective frequency spectrum information, i.e., the amplitude and phase information of the signals at different frequencies.

[0059] It can be understood that the fundamental frequency component is the main frequency component in the signal, which reflects the basic characteristics of the signal. After determining the fundamental frequency component, the initial phase difference between the first voltage signal and the second voltage signal can be calculated based on this component, i.e., for the first voltage signal and the second voltage signal, the phase at the fundamental frequency is calculated respectively. Assuming that the fundamental frequency phase of the first signal is and the fundamental frequency phase of the second signal is , then the initial phase difference can be calculated by the following formula:

[0060] wherein, and are the phases of the fundamental frequency components of the two signals.

[0061] However, due to noise and interference that may exist in the signals, the initial phase difference may fluctuate. Therefore, it is necessary to filter the initial phase difference to obtain a smooth phase difference curve. The smooth phase difference curve can more truly reflect the phase relationship between the two voltage signals. Finally, according to the smooth phase difference curve, the phase difference between the two voltage signals can be determined, which can be used for subsequent phase compensation operation.

[0062] Step S40: performing ratio direction compensation on the voltage transformer according to the ratio error and the phase difference, wherein the ratio direction compensation at least includes ratio compensation, phase compensation and direction compensation.

[0063] It should be noted that the ratio direction compensation is a process of comprehensive correction of the error of the voltage transformer. The ratio compensation is used to adjust the ratio value of the voltage transformer, so that it approaches the preset ideal ratio value, thereby reducing the ratio error. The phase compensation is for the error of the voltage transformer in phase transmission, by adjusting the phase of the signal, so that the phase of the output signal is consistent with the phase of the input signal. The direction compensation takes into account the directional error of the voltage transformer in actual application, i.e., the error is different when measuring in forward and reverse directions, and through the direction compensation, the error can be effectively corrected whether measuring in forward or reverse direction.

[0064] In a specific implementation, the amplitude of the second voltage signal can be adjusted according to the size and direction of the transformation ratio error to achieve transformation ratio compensation. For phase compensation, the phase difference calculated can be used to adjust the phase of the second voltage signal through a phase adjustment circuit or algorithm to align it with the phase of the first voltage signal. Direction compensation is aimed at the directional deviation that may occur in the voltage transformer, i.e., the error may not be consistent when measuring in different directions. Through direction compensation, the voltage transformer can maintain high accuracy when measuring in any direction.

[0065] The embodiment provides a voltage transformer transformation ratio direction compensation method, which acquires a first voltage signal on a primary side of a voltage transformer and a second voltage signal on a secondary side of the voltage transformer; determines a cross-correlation coefficient and a transformation ratio error based on the first voltage signal and the second voltage signal; determines a phase difference based on the cross-correlation coefficient; and performs transformation ratio direction compensation on the voltage transformer based on the transformation ratio error and the phase difference, wherein the transformation ratio direction compensation at least includes transformation ratio compensation, phase compensation, and direction compensation. In this way, the transformation ratio direction compensation of the voltage transformer is achieved by combining the transformation ratio compensation, the phase compensation, and the direction compensation, and the compensation efficiency and accuracy are effectively improved.

[0066] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as the above-mentioned first embodiment can be referred to the above introduction, and will not be described in detail. On this basis, please refer to Figure 2 , step S40 includes steps S401-S404: Step S401: performing transformation ratio compensation on the amplitude of the second voltage signal through a PID control algorithm according to the transformation ratio error, to obtain a compensated amplitude.

[0067] It should be noted that the PID control algorithm is a commonly used control algorithm, which adjusts the control quantity through the proportional (P), integral (I), and differential (D) links to achieve the desired control effect. In the present embodiment, the PID control algorithm is used to adjust the amplitude of the second voltage signal according to the transformation ratio error, thereby achieving transformation ratio compensation.

[0068] It can be understood that the proportional link (P) is used to quickly respond to the error, and when the transformation ratio error is detected, the proportional link will immediately generate a proportional adjustment quantity to reduce the error. The integral link (I) is used to eliminate static error, which integrates the cumulative error to generate an adjustment quantity that gradually increases over time until the error is zero. The differential link (D) is used to predict the trend of error change, which predicts the future change of error through the differential of error, so as to adjust in advance and avoid further expansion of error.

[0069] It is worth noting that through the comprehensive action of the PID control algorithm, the amplitude of the second voltage signal can be accurately adjusted to match the ideal transformation ratio, thereby reducing the transformation ratio error. The amplitude after compensation will be closer to the voltage value required in actual measurement, improving the accuracy of measurement.

[0070] In a possible implementation, step S401 can include designing a PID controller, wherein the design of the PID controller includes determining a proportional coefficient, an integral coefficient and a differential coefficient; taking the transformation ratio error as the input of the PID controller and calculating a control amount through the proportional, integral and differential links of the PID controller; adjusting the amplitude of the second voltage signal according to the control amount to obtain an adjusted amplitude; and performing amplitude limiting processing on the adjusted amplitude of the second voltage signal to obtain a compensated amplitude.

[0071] It should be noted that the proportional coefficient, the integral coefficient and the differential coefficient are key parameters of the PID controller, which determine the response speed and stability of the controller. The proportional coefficient determines the sensitivity of the controller to error, the integral coefficient determines the ability of the controller to eliminate static error, and the differential coefficient determines the accuracy of the controller in predicting error trend. By reasonably designing the three coefficients, the PID controller can quickly respond to error while maintaining the stability of the system, avoiding overshoot and oscillation.

[0072] In a specific implementation, the transformation ratio error is taken as the input of the PID controller, and through the accurate calculation of the PID controller, a suitable control amount can be obtained for adjusting the amplitude of the second voltage signal. The calculation formula of the control amount is:

[0073] wherein, is the output (control amount) of the controller, is the transformation ratio error, is the proportional coefficient, the proportional gain of the controller, is the integral coefficient, the integral gain of the controller, is the differential coefficient, the differential gain of the controller.

[0074] The adjusted amplitude will be closer to the ideal transformation ratio, thereby effectively reducing the transformation ratio error. However, in order to avoid the adjusted amplitude being too large or too small, causing the system to be unstable or the measurement to be inaccurate, amplitude limiting processing also needs to be performed on the adjusted amplitude of the second voltage signal to ensure that it fluctuates within a reasonable range, and finally a compensated amplitude is obtained. Amplitude limiting processing is a technical means to ensure that the amplitude of the signal does not exceed the preset range, which can effectively prevent equipment damage or measurement error caused by excessive signal amplitude.

[0075] Step S402: Phase compensation is performed on the phase of the second voltage signal according to the phase difference through a Kalman filter algorithm, to obtain a compensated phase.

[0076] It should be noted that the Kalman filter algorithm is a kind of efficient recursive filter, which can estimate the state of a dynamic system from a series of incomplete or noisy measurement data in the presence of noise and uncertainty. In this embodiment, the Kalman filter algorithm is used to adjust the phase of the second voltage signal according to the phase difference, so as to realize phase compensation.

[0077] It is worth noting that the core idea of Kalman filter algorithm is to use the optimal estimate of the previous state and the measurement value of the current state to determine the optimal estimate of the current state together. It contains two main steps: prediction and update. In the prediction step, the algorithm predicts the value of the current state based on the optimal estimate of the previous state. In the update step, the algorithm compares the predicted value with the measurement value of the current state, and adjusts the predicted value according to the comparison result to obtain the optimal estimate of the current state.

[0078] In specific implementation, Kalman filter algorithm can effectively smooth the phase difference curve and reduce the phase fluctuation caused by noise and interference. By continuously adjusting the phase of the second voltage signal, Kalman filter algorithm can ensure that the phase of the output signal is consistent with the phase of the input signal, thereby improving the accuracy of measurement. The compensated phase will be closer to the true value.

[0079] Step S403: Determine the direction of the second voltage signal according to the compensated amplitude and the compensated phase.

[0080] It should be noted that the direction determination is based on the comprehensive judgment of the compensated amplitude and phase. The direction of voltage signal is often closely related to the physical quantity it represents (such as current direction, power flow direction, etc.). Therefore, accurately determining the direction of voltage signal is of great significance to ensure the stable operation of the entire power system.

[0081] It can be understood that in determining the direction, a comprehensive judgment method based on amplitude and phase information is adopted. According to the compensated amplitude, the size of the voltage signal, i.e. its intensity, can be determined. Then, combined with the compensated phase information, the phase relationship of the voltage signal, i.e. its position relative to the reference signal, can be further determined. By comprehensively considering these two aspects of information, the direction of the voltage signal can be accurately determined.

[0082] It is worth pointing out that in the process of determining the direction, the actual situation in the power system and various possible interference factors are considered. For example, the interference signals such as harmonics, noise and the like that may exist in the power system, and the nonlinear characteristics of the voltage transformer itself, etc., may all affect the accuracy of the direction determination. Therefore, various technical means are adopted in the algorithm design to suppress these interference factors and improve the accuracy of the direction determination.

[0083] In a specific implementation, a direction determination method based on digital signal processing (DSP) technology is adopted. This method realizes fast and accurate determination of the direction of the voltage signal by high-speed acquisition of the voltage signal and processing and analysis of the signal using advanced algorithms.

[0084] Step S404: direction compensation is performed on the output direction of the voltage transformer according to the direction of the second voltage signal.

[0085] It should be noted that once the direction of the voltage signal is determined, the output direction of the voltage transformer can be compensated accordingly. The output direction of the voltage transformer is usually affected by the system configuration, so the output direction needs to be adjusted to match the compensated direction. If the direction is positive or negative (for example, clockwise or counterclockwise), the output of the voltage transformer needs to be adjusted in the reverse or forward direction, usually by controlling the feedback signal of the voltage transformer to compensate for the direction.

[0086] In a specific implementation, if the direction is positive, no reverse compensation is performed on the output voltage. If the direction is negative, the output voltage is processed in the reverse direction (for example, the sign of the output voltage is changed or its direction is changed through gain adjustment).

[0087] In this embodiment, the amplitude is compensated by the PID control algorithm, the phase is compensated by the Kalman filter algorithm, the direction of the voltage signal is determined based on the compensated amplitude and phase, and finally the output direction of the voltage transformer is compensated, effectively improving the efficiency and accuracy of the ratio direction compensation.

[0088] It should be noted that the above examples are only for understanding the present application and do not constitute a limitation on the voltage transformer ratio direction compensation method of the present application. Further simple transformations based on this technical concept are within the scope of protection of the present application.

[0089] The present application also provides a voltage transformer ratio direction compensation device, please refer to Figure 3 The voltage transformer ratio direction compensation device comprises: The acquisition module 10 is configured to acquire a first voltage signal on the primary side of the voltage transformer and a second voltage signal on the secondary side of the voltage transformer.

[0090] The determining module 20 is configured to determine a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal.

[0091] The determining module 20 is further configured to determine a phase difference based on the cross-correlation coefficient.

[0092] The compensating module 30 is configured to perform ratio direction compensation on the voltage transformer based on the ratio error and the phase difference, wherein the ratio direction compensation at least includes ratio compensation, phase compensation, and direction compensation.

[0093] The voltage transformer ratio direction compensation device provided by the present application adopts the voltage transformer ratio direction compensation method in the above embodiments, and can solve the technical problem of poor efficiency and accuracy of the conventional ratio direction compensation. Compared with the prior art, the voltage transformer ratio direction compensation device provided by the present application has the same beneficial effects as the voltage transformer ratio direction compensation method provided by the above embodiments, and other technical features in the voltage transformer ratio direction compensation device are the same as the features disclosed in the above embodiments, which will not be repeated here.

[0094] The present application provides a voltage transformer ratio direction compensation device, which includes at least one processor and a memory connected to the at least one processor in communication. The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the voltage transformer ratio direction compensation method in the above embodiment one.

[0095] Reference will now be made to the following description Figure 4 which shows a structural diagram of a voltage transformer ratio direction compensation device suitable for implementing the embodiments of the present application. The voltage transformer ratio direction compensation device in the embodiments of the present application can include, but is not limited to, mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), and vehicle terminals (such as vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 4 The voltage transformer ratio direction compensation device shown is only an example, and should not impose any limitation on the functions and use range of the embodiments of the present application.

[0096] As Figure 4As shown, the voltage transformer ratio direction compensation device can include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes according to programs stored in a ROM (Read Only Memory) 1002 or programs loaded from a storage device 1003 into a RAM (Random Access Memory) 1004. Various programs and data required for the voltage transformer ratio direction compensation device to operate are also stored in the RAM 1004. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, an LCD (Liquid Crystal Display), a speaker, a vibrator, etc.; the storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the voltage transformer ratio direction compensation device to communicate with other devices wirelessly or by wire to exchange data. Although the voltage transformer ratio direction compensation device with various systems is shown in the figure, it should be understood that all the systems shown are not required to be implemented or possessed. More or fewer systems can be alternatively implemented or possessed.

[0097] In particular, according to embodiments of the present disclosure, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, embodiments of the present disclosure include a computer program product comprising a computer program carried on a computer readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by a communication device, or installed from the storage device 1003, or installed from the ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the methods of the embodiments of the present disclosure are performed.

[0098] The voltage transformer ratio direction compensation device provided by the present disclosure adopts the voltage transformer ratio direction compensation method in the above-mentioned embodiments, and can solve the technical problems of poor efficiency and accuracy of traditional ratio direction compensation. Compared with the prior art, the voltage transformer ratio direction compensation device provided by the present disclosure has the same beneficial effects as the voltage transformer ratio direction compensation method provided by the above-mentioned embodiments, and other technical features in the voltage transformer ratio direction compensation device are the same as the features disclosed in the previous embodiment method, which will not be repeated here.

[0099] It should be understood that various aspects of the disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the description of the embodiments above, specific features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0100] The above description is only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0101] The present application provides a computer readable storage medium having stored thereon computer readable program instructions (i.e. computer programs) for performing the voltage transformer ratio direction compensation method in the above embodiments.

[0102] The computer readable storage medium provided by the present application may, for example, be a U disk, but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system or device, or any combination thereof. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection having one or more conductive wires, a portable computer disk, a hard disk, a RAM (Random Access Memory), a ROM (Read Only Memory), an EPROM (Erasable Programmable Read Only Memory or flash memory), an optical fiber, a CD-ROM (CD-Read Only Memory), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present embodiment, the computer readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system or device. The program code contained on the computer readable storage medium can be transmitted by any suitable medium, including but not limited to electrical wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0103] The above computer readable storage medium can be included in the voltage transformer ratio direction compensation device; or can exist separately without being assembled into the voltage transformer ratio direction compensation device.

[0104] The computer readable storage medium described above carries one or more programs, when the one or more programs are executed by the voltage transformer ratio direction compensation device, the voltage transformer ratio direction compensation device is caused to: collect a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side; determine a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal; determine a phase difference according to the cross-correlation coefficient; and perform ratio direction compensation on the voltage transformer according to the ratio error and the phase difference, wherein the ratio direction compensation at least includes ratio compensation, phase compensation, and direction compensation.

[0105] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0106] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0107] The modules described in the embodiments of the present application can be implemented in the form of software or in the form of hardware. In some cases, the name of the module does not constitute a limitation on the module itself.

[0108] The readable storage medium provided by the present application is a computer readable storage medium, which stores computer readable program instructions (i.e., a computer program) for executing the voltage transformer ratio direction compensation method described above, and can solve the technical problem of poor efficiency and accuracy of traditional ratio direction compensation. Compared with the prior art, the computer readable storage medium provided by the present application has the same beneficial effects as the voltage transformer ratio direction compensation method provided by the above embodiments, and will not be described here.

[0109] The present application also provides a computer program product comprising a computer program, which, when executed by a processor, implements the steps of the voltage transformer ratio direction compensation method as described above.

[0110] The computer program product provided by the present application can solve the technical problem of poor efficiency and accuracy of traditional ratio direction compensation. Compared with the prior art, the computer program product provided by the present application has the same beneficial effects as the voltage transformer ratio direction compensation method provided by the above embodiments, and will not be described here.

[0111] The above only describes some embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the present application, and the contents of the present application and the accompanying drawings are included in the patent protection scope of the present application.

Claims

1. A method of ratio direction compensation for a voltage transformer, characterized by, The method comprises: collecting a first voltage signal of a primary side of a voltage transformer and a second voltage signal of a secondary side of the voltage transformer; determining a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal; determining a phase difference according to the cross-correlation coefficient; performing ratio direction compensation on the voltage transformer according to the ratio error and the phase difference, wherein the ratio direction compensation at least comprises ratio compensation, phase compensation and direction compensation.

2. The method of claim 1, wherein, The determination of the cross-correlation coefficient based on the first voltage signal and the second voltage signal comprises: performing time delay processing on the first voltage signal and the second voltage signal to obtain a series of voltage signal pairs with different time delays; calculating the cross-correlation value between each pair of voltage signals to obtain a cross-correlation value sequence; constructing a cross-correlation function according to the cross-correlation value sequence, wherein the cross-correlation function is used to represent the change relationship of the similarity between the first voltage signal and the second voltage signal with time delay; determining the cross-correlation coefficient according to the shape and peak position of the cross-correlation function.

3. The method of claim 1, wherein, The determination of the ratio error based on the first voltage signal and the second voltage signal comprises: performing preprocessing on the first voltage signal and the second voltage signal to obtain a preprocessed first voltage signal and a preprocessed second voltage signal; determining an actual ratio value according to the preprocessed first voltage signal and the preprocessed second voltage signal, wherein the actual ratio value is the ratio of the first voltage signal to the second voltage signal; determining the ratio error according to the actual ratio value and a preset ratio value.

4. The method of claim 1, wherein, The determination of the phase difference according to the cross-correlation coefficient comprises: comparing the cross-correlation coefficient with a preset cross-correlation coefficient threshold value; if the cross-correlation coefficient is greater than or equal to the cross-correlation coefficient threshold value, determining that the phase difference between the first voltage signal and the second voltage signal is zero; if the cross-correlation coefficient is less than the cross-correlation coefficient threshold value, performing phase analysis on the first voltage signal and the second voltage signal through a phase resolving algorithm to obtain the phase difference.

5. The method of claim 4, wherein, The phase analysis on the first voltage signal and the second voltage signal through the phase resolving algorithm to obtain the phase difference comprises: performing Fourier transform on the first voltage signal and the second voltage signal respectively to obtain first frequency spectrum information and second frequency spectrum information; determining a fundamental frequency component according to the first frequency spectrum information and the second frequency spectrum information; calculating an initial phase difference between the first voltage signal and the second voltage signal based on the fundamental frequency component; performing filtering processing on the initial phase difference to obtain a smooth phase difference curve; determining the phase difference according to the smooth phase difference curve.

6. The method of claim 1, wherein, The ratio direction compensation on the voltage transformer according to the ratio error and the phase difference comprises: performing ratio compensation on the amplitude of the second voltage signal through a PID control algorithm according to the ratio error to obtain a compensated amplitude; performing phase compensation on the phase of the second voltage signal through a Kalman filtering algorithm according to the phase difference to obtain a compensated phase; determine a direction of the second voltage signal according to the compensated amplitude and the compensated phase; directionally compensate an output direction of the voltage transformer according to the direction of the second voltage signal.

7. The method of claim 6, wherein, the ratio error is compensated by a PID control algorithm to the amplitude of the second voltage signal to obtain a compensated amplitude, including: designing a PID controller, wherein the design of the PID controller includes determining a proportional coefficient, an integral coefficient and a differential coefficient; taking the ratio error as an input of the PID controller and calculating a control amount through proportional, integral and differential links of the PID controller; adjusting the amplitude of the second voltage signal according to the control amount to obtain an adjusted amplitude; limiting the amplitude of the adjusted second voltage signal to obtain the compensated amplitude.

8. A voltage transformer ratio direction compensation device, characterized by, The voltage transformer ratio direction compensation device includes: a collection module configured to collect a first voltage signal at a primary side of a voltage transformer and a second voltage signal at a secondary side of the voltage transformer; a determination module configured to determine a cross-correlation coefficient and a ratio error based on the first voltage signal and the second voltage signal; the determination module is further configured to determine a phase difference according to the cross-correlation coefficient; a compensation module configured to compensate a ratio direction of the voltage transformer according to the ratio error and the phase difference, wherein the ratio direction compensation at least includes ratio compensation, phase compensation and direction compensation.

9. A voltage transformer ratio direction compensation device, characterized by, The voltage transformer ratio direction compensation device includes a memory, a processor and a voltage transformer ratio direction compensation program stored on the memory and executable on the processor, and the voltage transformer ratio direction compensation program is configured to implement the voltage transformer ratio direction compensation method in any one of claims 1 to 7.

10. A storage medium, characterized by The storage medium stores a voltage transformer ratio direction compensation program, and the voltage transformer ratio direction compensation program is executed by the processor to implement the voltage transformer ratio direction compensation method in any one of claims 1 to 7.

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