Short-circuit fault suppression method based on transient recovery voltage

Abstract

The invention discloses a short-circuit fault suppression method based on transient recovery voltage, and the method comprises the steps: monitoring the transient recovery voltage during a short-circuit fault in real time, and predicting the amplitude of the transient recovery voltage possibly caused by the short-circuit fault based on a monitoring result; on the basis of the prediction result, the circuit breaker is controlled to carry out split-phase opening according to a preset sequence, and the rising rate of the high-frequency transient voltage is further adjusted by adaptively adjusting the shunt path of the short-circuit current; the arc reignition phenomenon in the opening period of the circuit breaker is monitored, prevented and controlled in real time, and meanwhile a signal opposite to the transient recovery voltage harmonic component is generated to counteract higher harmonics. The method is not only suitable for various types of short circuit fault scenes, but also can prolong the service life of power grid equipment, and provides technical guarantee for safe and stable operation of a power system.

Description

Technical Field

[0001] The present invention relates to the technical field of short-circuit fault suppression, and in particular to a short-circuit fault suppression method based on transient recovery voltage. Background Art

[0002] In the power system, transient recovery voltage (TRV) is the voltage that is instantly restored after the circuit breaker is opened, which is usually accompanied by high-frequency oscillations and harmonic components. Especially when a short-circuit fault occurs, the amplitude and frequency of the transient recovery voltage will increase significantly, which will put great pressure on the insulation performance of power grid equipment and circuit breakers. Current short-circuit fault suppression methods focus on the improvement of hardware equipment, such as lightning arresters and reactors, but these devices cannot be adjusted dynamically in real time, and it is difficult to effectively deal with the complex fluctuation characteristics of transient recovery voltage during the short-circuit process. In addition, high-order harmonic components are easily superimposed in the TRV waveform, resulting in an increase in voltage peak and resonance, which aggravates the power loss and equipment wear of the power grid. Therefore, a method based on real-time monitoring, dynamic control and signal cancellation is proposed to suppress transient recovery voltage through intelligent means, which has become an important requirement for the stable operation of power systems. Summary of the invention

[0003] In view of the above existing problems, the present invention is proposed.

[0004] Therefore, the present invention provides a short-circuit fault suppression method based on transient recovery voltage. In view of the high amplitude, high-frequency oscillation and harmonic superposition of transient recovery voltage during short-circuit faults, a short-circuit fault suppression method capable of dynamic monitoring and adaptive adjustment is proposed, aiming to effectively manage the rising rate and harmonic components of TRV, and to regulate the offset signal in real time through a feedback mechanism to synchronize it with the transient recovery voltage, thereby reducing the high-order harmonic components in TRV. After a fault occurs, this method uses fast Fourier transform (FFT) to analyze harmonic characteristics, generates an offset signal with a phase opposite to the target harmonic, and reduces the fluctuation amplitude of the transient recovery voltage by dynamically adjusting the opening order, adaptive shunt path and other measures, so that the transient voltage suppression process maintains efficient response under different fault conditions, thereby solving the problem of refined dynamic control that traditional equipment cannot achieve.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution, a short circuit fault suppression method based on transient recovery voltage, comprising:

[0006] Monitor the transient recovery voltage during a short-circuit fault in real time, and predict the transient recovery voltage amplitude that may be caused by the short-circuit fault based on the monitoring results;

[0007] Based on the prediction results, the circuit breaker is controlled to open the circuits in phases according to the preset sequence, and the rising rate of the high-frequency transient voltage is further adjusted by adaptively adjusting the shunt path of the short-circuit current.

[0008] Real-time monitoring and prevention of arc reignition during circuit breaker opening, while generating a signal opposite to the harmonic component of transient recovery voltage to offset high-order harmonics.

[0009] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, the real-time monitoring of the transient recovery voltage during the short-circuit fault includes using a high-speed data acquisition module to collect voltage and current waveform data, obtaining electrical parameters related to the transient recovery voltage, filtering and normalizing the collected data for preprocessing, removing high-frequency noise and outliers, and inputting the preprocessed data into the prediction model to form real-time monitoring of the transient recovery voltage state.

[0010] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, the prediction based on monitoring results includes: using historical fault data to train a machine learning model, extracting the characteristic pattern of the transient recovery voltage during the fault, establishing a prediction model based on a long short-term memory network LSTM or a convolutional neural network CNN, improving the accuracy of the prediction through deep learning of the characteristic pattern, and using the prediction model to analyze the real-time collected data to output the predicted amplitude and time characteristics of the transient recovery voltage.

[0011] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, wherein: the controlling circuit breaker to perform phase-by-phase opening in a preset order includes: after detecting a short-circuit fault, the system generates real-time prediction data through a transient recovery voltage prediction model to judge the fluctuation of each phase voltage and the maximum possible amplitude of the transient recovery voltage, and determine the priority opening strategy of the fault phase;

[0012] Based on the prediction results, the faulty phase is selected for opening operation to quickly cut off the current of this phase; the remaining two phases are opened in sections in sequence according to the preset time interval. The control logic of the section-by-section opening is set based on the time phase difference between the transient recovery voltage and the voltage of each phase, so that the opening operation interval is within a specific delay window, thereby distributing the current fluctuations during the opening process to different time points;

[0013] The system is equipped with a real-time monitoring feedback mechanism to monitor the real-time effect of the opening operation by continuously collecting and analyzing transient recovery voltage and current data. The feedback mechanism dynamically adjusts the opening sequence and time interval during the opening process.

[0014] If the system detects that the current fluctuation of the other two phases reaches the preset threshold, the two-phase opening time interval is dynamically adjusted according to the feedback to ensure that the opening operation remains in the optimal delay window. The control step dynamically realizes sequential phase opening according to the transient recovery voltage state of the faulty phase and the remaining phases.

[0015] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, wherein: the control circuit breaker performs phase-by-phase opening according to a preset sequence, including: if the transient recovery voltage TRV prediction result shows that the amplitude is lower than the preset standard and the voltage fluctuation is stable, then the operation is performed according to the standard opening sequence, the fault phase is opened first, and the other two phases are opened in sequence according to the preset time interval;

[0016] When real-time monitoring confirms that TRV fluctuations continue to be within a low range, there is no need to adjust the time interval. If the TRV prediction results show that the amplitude is within the preset standard medium range and the voltage fluctuation has an upward trend, the time interval for two-phase disconnection will be appropriately extended, with the fault phase being disconnected first, the second phase disconnected at a slightly longer time interval, and the third phase disconnected after the second phase;

[0017] When it is found in real-time monitoring that the TRV amplitude of the second and third phases continues to rise, the delay time is further increased; if the prediction results show that the TRV amplitude is high and the voltage fluctuates violently, phase-splitting and staggered segmented operations are adopted to extend the time interval of each phase disconnection, give priority to disconnecting the faulty phase, and significantly increase the interval between the second and third phases; when the real-time fluctuation drops to the set threshold, the next phase is disconnected; if the prediction results show that the TRV amplitude is extremely high and the voltage fluctuation is unstable, the disconnection operation is divided into multiple steps, and the segmented interval of each phase is controlled, the segmented disconnection of the faulty phase is executed, the current value of the phase is gradually reduced, and the segmented delay operation is performed on the other two phases, and a longer time interval is arranged between each segment; when real-time feedback shows that the TRV is still beyond the safety limit, the segmented interval is further increased, and the disconnection of the next phase is suspended, and the disconnection operation is continued after the voltage fluctuation meets the preset standard.

[0018] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, wherein: the adaptive adjustment of the shunt path of the short-circuit current includes, when a short-circuit fault occurs, firstly, real-time collection of current, voltage and phase angle data is performed through a transient recovery voltage monitoring system, and the peak value, flow direction and fluctuation trend of the short-circuit current on the main line are identified; through data analysis, the system calculates the transient recovery voltage value on the main line and the transient current impact amplitude caused by it in real time, and optimizes the shunt path of the short-circuit current by using an adaptive control algorithm, and redistributes the excessive short-circuit current on the main line to other branches, so as to ensure that the current load carried by each branch is within a safe range;

[0019] The specific operation of shunting is controlled by adaptive shunting ratio ASR, which is dynamically adjusted according to the real-time amplitude and direction of the current so that the current load on each branch matches the transient voltage fluctuation of the system.

[0020] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, wherein: the adjustment of the rising rate of the high-frequency transient voltage includes, at the initial stage of the short-circuit fault, the transient recovery voltage monitoring system collects and calculates the voltage rising rate dV / dt in real time, and compares the rate with the preset rising threshold dV / dt threshold For comparison; when it is monitored that the voltage rise rate exceeds the threshold, the high-speed control module automatically triggers the peak clipping control measure. The control system absorbs part of the transient energy and smoothes the rapid rise of voltage by turning on additional resistive elements or increasing the inductance in the line. At the same time, by dynamically adjusting the capacitive reactance characteristics of the load, the capacitive element bears the transient current, reduces the voltage rise amplitude, and suppresses high-frequency transient fluctuations. The peak clipping control process runs continuously in real time, and dynamically adjusts the adjustment parameters according to the feedback signal of the transient recovery voltage to ensure that the voltage change rate always remains within a safe range.

[0021] As a preferred solution of the short-circuit fault suppression method based on transient recovery voltage described in the present invention, wherein: the real-time monitoring and prevention and control of arc reignition during the opening of the circuit breaker includes, at the moment when the circuit breaker performs the opening operation, real-time recording of arc characteristics through a high-frequency data acquisition module, specifically collecting parameters including arc length, arcing current and current change rate, and transmitting the data to an arc reignition monitoring system, which establishes an arc reignition model based on historical data and arc characteristics, identifies the arc reignition trend and estimates the possibility of reignition, and calculates the rising rate of arcing current and the current peak value to determine whether the current current is close to the reignition sensitive area;

[0022] When the system determines through the model that the arc has the risk of reignition, it immediately adjusts the opening angle of the circuit breaker to avoid the current range with high incidence of reignition. The opening angle is adjusted by controlling the time point of separation of the circuit breaker contacts so that they separate when the current drops below the preset level.

[0023] The generating of the signal opposite to the harmonic component of the transient recovery voltage includes: after the short circuit fault occurs, the system performs frequency domain conversion on the time domain signal of the transient recovery voltage through fast Fourier transform FFT, identifies and decomposes the harmonic components therein, obtains the frequency and phase information of each higher harmonic in the transient recovery voltage through FFT processing, takes the harmonic components with higher frequency as the focus of analysis, and extracts the characteristic parameters of the higher harmonics;

[0024] Based on the extracted harmonic frequency and phase, the control system generates a cancellation signal opposite to the harmonic phase, that is, the phase of the cancellation signal is adjusted to be 180 degrees different from the target harmonic phase, and the frequency of the cancellation signal is matched to the extracted high-order harmonic frequency, and the generated cancellation signal is superimposed on the transient recovery voltage waveform in real time, thereby achieving mutual cancellation of harmonic components in frequency and phase;

[0025] The harmonic component changes in the transient recovery voltage are monitored in real time through the feedback mechanism to ensure that the generated cancellation signal keeps the frequency and phase synchronization with the target harmonic component. During the transient recovery voltage fluctuation process, the system continuously collects and analyzes the feedback signal to obtain the changes in harmonic frequency and phase. If the harmonic frequency or phase of the transient recovery voltage is detected to be offset, the system immediately adjusts the parameters of the cancellation signal to realign its frequency and phase with the target harmonic.

[0026] When the harmonic frequency shifts, the system will automatically adjust the frequency of the cancellation signal to match the new harmonic frequency, and at the same time fine-tune the phase so that the cancellation signal maintains a phase difference of 180 degrees with the target harmonic.

[0027] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of a short-circuit fault suppression method based on transient recovery voltage are implemented.

[0028] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of a short-circuit fault suppression method based on transient recovery voltage.

[0029] Beneficial effects of the present invention: The present invention provides a short-circuit fault suppression method based on transient recovery voltage, which has the advantages of real-time monitoring, rapid response and dynamic adjustment. By controlling the circuit breaker opening sequence in stages, adaptively adjusting the shunt path of the short-circuit current, and analyzing and phase-offsetting the harmonics of the transient recovery voltage, the present invention achieves precise suppression of transient voltage peaks and higher harmonics, effectively reducing the impact of short-circuit faults on the power grid. At the same time, the frequency and phase of the offset signal are dynamically adjusted through the feedback mechanism, so that the voltage suppression effect remains consistent under different load and fault conditions, thereby improving the stability of the power system and the durability of the equipment. The present invention is not only suitable for various types of short-circuit fault scenarios, but also can extend the service life of power grid equipment, providing technical guarantees for the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 A schematic flow chart of a short-circuit fault suppression method based on transient recovery voltage is provided in accordance with an embodiment of the present invention.

[0032] Figure 2 A schematic diagram of phases A, B, and C without overvoltage protection measures in a short-circuit fault suppression method based on transient recovery voltage provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0036] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0037] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Example 1, reference Figure 1 , which is the first embodiment of the present invention, provides a short-circuit fault suppression method based on transient recovery voltage, comprising:

[0040] S1: Monitor the transient recovery voltage during the short-circuit fault in real time, and predict the transient recovery voltage amplitude that may be caused by the short-circuit fault based on the monitoring results.

[0041] S2: Based on the prediction results, the circuit breaker is controlled to perform phase opening in a preset order, and the rising rate of the high-frequency transient voltage is further adjusted by adaptively adjusting the shunt path of the short-circuit current.

[0042] S3: Real-time monitoring and prevention of arc reignition during circuit breaker opening, while generating a signal opposite to the harmonic component of transient recovery voltage to offset higher harmonics.

[0043] The real-time monitoring of the transient recovery voltage during a short-circuit fault includes using a high-speed data acquisition module to collect waveform data of voltage and current, obtaining electrical parameters related to the transient recovery voltage, filtering and normalizing the collected data for preprocessing, removing high-frequency noise and outliers, and inputting the preprocessed data into a prediction model to form real-time monitoring of the transient recovery voltage state.

[0044] The prediction based on monitoring results includes using historical fault data to train a machine learning model, extracting characteristic patterns of transient recovery voltage during faults, establishing a prediction model based on a long short-term memory network (LSTM) or a convolutional neural network (CNN), improving the accuracy of prediction through deep learning of characteristic patterns, and using the prediction model to analyze real-time collected data to output predicted amplitude and time characteristics of transient recovery voltage.

[0045] Predicting the transient recovery voltage amplitude includes training a machine learning model with historical fault data, extracting the characteristic pattern of the transient recovery voltage during the fault, establishing a prediction model based on a long short-term memory network (LSTM) or a convolutional neural network (CNN), improving the accuracy of the prediction through deep learning of the characteristic pattern, and using the prediction model to analyze the real-time collected data to output the predicted amplitude and time characteristics of the transient recovery voltage.

[0046] The control circuit breaker performs phase-by-phase opening in a preset order, including: after detecting a short circuit fault, the system generates real-time prediction data through a transient recovery voltage prediction model to judge the fluctuation of each phase voltage and the maximum possible amplitude of the transient recovery voltage, and determine the priority opening strategy of the fault phase;

[0047] Based on the prediction results, the faulty phase is selected for opening operation to quickly cut off the current of this phase; the remaining two phases are opened in sections in sequence according to the preset time interval. The control logic of the section-by-section opening is set based on the time phase difference between the transient recovery voltage and the voltage of each phase, so that the opening operation interval is within a specific delay window, thereby distributing the current fluctuations during the opening process to different time points;

[0048] The system is equipped with a real-time monitoring feedback mechanism to monitor the real-time effect of the opening operation by continuously collecting and analyzing transient recovery voltage and current data. The feedback mechanism dynamically adjusts the opening sequence and time interval during the opening process.

[0049] If the system detects that the current fluctuation of the other two phases reaches the preset threshold, the two-phase opening time interval is dynamically adjusted according to the feedback to ensure that the opening operation remains in the optimal delay window. The control step dynamically realizes sequential phase opening according to the transient recovery voltage state of the faulty phase and the remaining phases.

[0050] The control circuit breaker performs phase-by-phase opening according to a preset sequence, including: if the transient recovery voltage TRV prediction result shows that the amplitude is lower than the preset standard and the voltage fluctuation is stable, the standard opening sequence is operated, the fault phase is opened first, and the other two phases are opened in sequence according to the preset time interval;

[0051] When real-time monitoring confirms that TRV fluctuations continue to be within a low range, there is no need to adjust the time interval. If the TRV prediction results show that the amplitude is within the preset standard medium range and the voltage fluctuation has an upward trend, the time interval for two-phase disconnection will be appropriately extended, with the fault phase being disconnected first, the second phase disconnected at a slightly longer time interval, and the third phase disconnected after the second phase;

[0052] When it is found in real-time monitoring that the TRV amplitude of the second and third phases continues to rise, the delay time is further increased; if the prediction results show that the TRV amplitude is high and the voltage fluctuates violently, phase-splitting and staggered segmented operations are adopted to extend the time interval of each phase disconnection, give priority to disconnecting the faulty phase, and significantly increase the interval between the second and third phases; when the real-time fluctuation drops to the set threshold, the next phase is disconnected; if the prediction results show that the TRV amplitude is extremely high and the voltage fluctuation is unstable, the disconnection operation is divided into multiple steps, and the segmented interval of each phase is controlled, the segmented disconnection of the faulty phase is executed, the current value of the phase is gradually reduced, and the segmented delay operation is performed on the other two phases, and a longer time interval is arranged between each segment; when real-time feedback shows that the TRV is still beyond the safety limit, the segmented interval is further increased, and the disconnection of the next phase is suspended, and the disconnection operation is continued after the voltage fluctuation meets the preset standard.

[0053] The adaptive adjustment of the short-circuit current shunt path includes: when a short-circuit fault occurs, firstly, the current, voltage and phase angle data are collected in real time through the transient recovery voltage monitoring system, and the peak value, flow direction and fluctuation trend of the short-circuit current on the main line are identified; through data analysis, the system calculates the transient recovery voltage value on the main line and the transient current impact amplitude caused by it in real time, and optimizes the short-circuit current shunt path by using an adaptive control algorithm, and redistributes the excessive short-circuit current on the main line to other branches, so as to ensure that the current load carried by each branch is within a safe range;

[0054] The specific operation of shunting is controlled by adaptive shunting ratio ASR, which is dynamically adjusted according to the real-time amplitude and direction of the current so that the current load on each branch matches the transient voltage fluctuation of the system.

[0055] Specifically, it can be expressed as the system real-time acquisition and calculation of the short-circuit current peak value I peak and flow direction θ, where:

[0056] I peak =max(|I(t)|)

[0057] The current direction θ is determined by combining the transient recovery voltage data TRV(t) with the current phase angle information and used as the input for dynamic current shunt control.

[0058] According to the current peak and transient recovery voltage changes, the adaptive shunt ratio ASR is designed. Set the shunt ratio to α i (represents the proportion of current distributed to the i-th branch), then:

[0059]

[0060] Where N is the total number of branches in the system. To dynamically optimize current splitting, the ASR calculation formula is designed as:

[0061]

[0062] Among them, I max,i is the maximum allowable current of branch i, β is the shunt sensitivity adjustment parameter, TRV ref is the reference value of transient recovery voltage, |TRV(t)-TRV ref |Indicates the deviation of transient recovery voltage, which is used to measure the impact of transient recovery voltage fluctuation on the shunt path.

[0063] After calculating the diversion ratio of each branch, the system i Adjust the distribution path of the main line current in real time. Assuming the main line current I main (t) is distributed to N branches, then the shunt current of each branch i is:

[0064] I i (t) = α i I main (t)

[0065] As the transient recovery voltage fluctuates, the system automatically updates the shunt ratio based on the real-time feedback of current and voltage changes, making α i Dynamically adjusted according to the amplitude of transient recovery voltage.

[0066] Among them, I peak Indicates the peak value of the short-circuit current of the main line, which is the maximum instantaneous value of the short-circuit current under the current fault condition. I(t) represents the instantaneous current, which represents the current signal that changes with time t. θ represents the current flow angle, which represents the phase angle of the short-circuit current at a specific moment, and is used to determine the flow direction of the short-circuit current. α i The current splitting factor indicates the proportion of the short-circuit current redistributed to branch i, and its value range is 0 to 1. This factor changes dynamically to adapt to the current carrying requirements of different branches. N The total number of branches in the system, that is, the number of different branches to which the short-circuit current of the main line can be distributed. w i The shunt weight factor is used to determine the priority of branch i in the shunt. The weight factor is adaptively adjusted based on the branch's carrying capacity and the fluctuation of the transient recovery voltage. max,i The maximum allowable current of branch i indicates the maximum current amplitude that branch i can withstand under current conditions. It is used to control the load of each branch in the shunt. β Shunt sensitivity adjustment parameter controls the effect of transient recovery voltage fluctuation on the shunt ratio. The higher the β value, the more sensitive the effect of transient recovery voltage fluctuation on the shunt ratio. TRV(t) transient recovery voltage, indicates the voltage waveform that changes with time t, reflecting the voltage fluctuation on the line when a short circuit fault occurs. TRV refThe reference value of the transient recovery voltage is usually the voltage reference value during normal operation, which is used to measure the deviation between the actual voltage fluctuation and the reference value.

[0067] During the shunt path adjustment process, the system monitors the shunt effect in real time through the feedback control mechanism and adjusts the value of the sensitivity parameter β. max,i When α is reached, the system automatically reduces the diversion ratio of the branch. i , and recalculate the allocation ratio of other branches to ensure that the shunt path dynamically adapts to real-time current fluctuations.

[0068] The method of adjusting the rising rate of the high-frequency transient voltage includes: at the beginning of the short-circuit fault, the transient recovery voltage monitoring system collects and calculates the rising rate dV / dt of the voltage in real time, and compares the rate with the preset rising threshold dV / dt threshold For comparison; when it is monitored that the voltage rise rate exceeds the threshold, the high-speed control module automatically triggers the peak clipping control measure. The control system absorbs part of the transient energy and smoothes the rapid rise of voltage by turning on additional resistive elements or increasing the inductance in the line. At the same time, by dynamically adjusting the capacitive reactance characteristics of the load, the capacitive element bears the transient current, reduces the voltage rise amplitude, and suppresses high-frequency transient fluctuations. The peak clipping control process runs continuously in real time, and dynamically adjusts the adjustment parameters according to the feedback signal of the transient recovery voltage to ensure that the voltage change rate always remains within a safe range.

[0069] The real-time monitoring and prevention of the arc reignition phenomenon during the circuit breaker opening period includes: at the moment when the circuit breaker performs the opening operation, the arc characteristics are recorded in real time through the high-frequency data acquisition module, specifically collecting parameters including arc length, arcing current and current change rate, and transmitting the data to the arc reignition monitoring system, which establishes an arc reignition model based on historical data and arc characteristics, identifies the arc reignition trend and estimates the possibility of reignition, and calculates the rising rate of the arcing current and the current peak value to determine whether the current current is close to the reignition sensitive area;

[0070] When the system determines through the model that the arc has the risk of reignition, it immediately adjusts the opening angle of the circuit breaker to avoid the current range with high incidence of reignition. The opening angle is adjusted by controlling the time point of separation of the circuit breaker contacts so that they separate when the current drops below the preset level.

[0071] The generating of the signal opposite to the harmonic component of the transient recovery voltage includes: after the short circuit fault occurs, the system performs frequency domain conversion on the time domain signal of the transient recovery voltage through fast Fourier transform FFT, identifies and decomposes the harmonic components therein, obtains the frequency and phase information of each higher harmonic in the transient recovery voltage through FFT processing, takes the harmonic components with higher frequency as the focus of analysis, and extracts the characteristic parameters of the higher harmonics;

[0072] Based on the extracted harmonic frequency and phase, the control system generates a cancellation signal opposite to the harmonic phase, that is, the phase of the cancellation signal is adjusted to be 180 degrees different from the target harmonic phase, and the frequency of the cancellation signal is matched to the extracted high-order harmonic frequency, and the generated cancellation signal is superimposed on the transient recovery voltage waveform in real time, thereby achieving mutual cancellation of harmonic components in frequency and phase;

[0073] The harmonic component changes in the transient recovery voltage are monitored in real time through the feedback mechanism to ensure that the generated cancellation signal keeps the frequency and phase synchronization with the target harmonic component. During the transient recovery voltage fluctuation process, the system continuously collects and analyzes the feedback signal to obtain the changes in harmonic frequency and phase. If the harmonic frequency or phase of the transient recovery voltage is detected to be offset, the system immediately adjusts the parameters of the cancellation signal to realign its frequency and phase with the target harmonic.

[0074] When the harmonic frequency shifts, the system will automatically adjust the frequency of the cancellation signal to match the new harmonic frequency, and at the same time fine-tune the phase so that the cancellation signal maintains a phase difference of 180 degrees with the target harmonic.

[0075] A simulation experiment is performed to compare with the present invention, such as Figure 2 The overvoltage caused by the opening operation is analyzed by cutting off the line where the factory power is located, and no overvoltage protection measures are added.

[0076] The random single tripping time is set to 0.0239 for phase A, 0.0259 for phase B, and 0.0269 for phase C. The maximum amplitude of the operating overvoltage after tripping is 3.9 pu.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0078] Example 2

[0079] The second embodiment of the present invention is different from the previous embodiment in that:

[0080] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0085] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A short-circuit fault suppression method based on transient recovery voltage, characterized in that: include, Monitor the transient recovery voltage during a short-circuit fault in real time, and predict the transient recovery voltage amplitude that may be caused by the short-circuit fault based on the monitoring results; Based on the prediction results, the circuit breaker is controlled to open the circuits in phases according to the preset sequence, and the rising rate of the high-frequency transient voltage is further adjusted by adaptively adjusting the shunt path of the short-circuit current. Real-time monitoring and prevention of arc reignition during circuit breaker opening, while generating a signal opposite to the harmonic component of transient recovery voltage to offset high-order harmonics.

2. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 1, characterized in that: The real-time monitoring of the transient recovery voltage during a short-circuit fault includes using a high-speed data acquisition module to collect waveform data of voltage and current, obtaining electrical parameters related to the transient recovery voltage, filtering and normalizing the collected data for preprocessing, removing high-frequency noise and outliers, and inputting the preprocessed data into a prediction model to form real-time monitoring of the transient recovery voltage state.

3. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 2, characterized in that: The prediction based on monitoring results includes using historical fault data to train a machine learning model, extracting characteristic patterns of transient recovery voltage during faults, establishing a prediction model based on a long short-term memory network (LSTM) or a convolutional neural network (CNN), improving the accuracy of prediction through deep learning of characteristic patterns, and using the prediction model to analyze real-time collected data to output predicted amplitude and time characteristics of transient recovery voltage.

4. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 3, characterized in that: The control circuit breaker performs phase-by-phase opening in a preset order, including: after detecting a short circuit fault, the system generates real-time prediction data through a transient recovery voltage prediction model to judge the fluctuation of each phase voltage and the maximum possible amplitude of the transient recovery voltage, and determine the priority opening strategy of the fault phase; Based on the prediction results, the faulty phase is selected for opening operation to quickly cut off the current of this phase; the remaining two phases are opened in sections in sequence according to the preset time interval. The control logic of the section-by-section opening is set based on the time phase difference between the transient recovery voltage and the voltage of each phase, so that the opening operation interval is within a specific delay window, thereby distributing the current fluctuations during the opening process to different time points; The system is equipped with a real-time monitoring feedback mechanism to monitor the real-time effect of the opening operation by continuously collecting and analyzing transient recovery voltage and current data. The feedback mechanism dynamically adjusts the opening sequence and time interval during the opening process. If the system detects that the current fluctuation of the other two phases reaches the preset threshold, the two-phase opening time interval is dynamically adjusted according to the feedback to ensure that the opening operation remains in the optimal delay window. The control step dynamically realizes sequential phase opening according to the transient recovery voltage state of the faulty phase and the remaining phases.

5. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 4, characterized in that: The control circuit breaker performs phase-by-phase opening according to a preset sequence, including: if the transient recovery voltage TRV prediction result shows that the amplitude is lower than the preset standard and the voltage fluctuation is stable, the standard opening sequence is operated, the fault phase is opened first, and the other two phases are opened in sequence according to the preset time interval; When real-time monitoring confirms that TRV fluctuations continue to be within a low range, there is no need to adjust the time interval. If the TRV prediction results show that the amplitude is within the preset standard medium range and the voltage fluctuation has an upward trend, the time interval for two-phase disconnection will be appropriately extended, with the fault phase being disconnected first, the second phase disconnected at a slightly longer time interval, and the third phase disconnected after the second phase; When the TRV amplitude of the second and third phases continues to rise in real-time monitoring, the delay time is further increased; if the prediction results show that the TRV amplitude is high and the voltage fluctuates violently, phase-by-phase staggered operation is adopted to extend the time interval of each phase opening, give priority to opening the faulty phase, and significantly increase the interval between the second and third phases; When the real-time fluctuation drops to the set threshold, the next phase is tripped; if the prediction result shows that the TRV amplitude is extremely high and the voltage fluctuation is unstable, the tripping operation is divided into multiple steps, and the segmented interval of each phase is controlled, and the segmented tripping of the faulty phase is performed, gradually reducing the current value of the phase, and performing segmented delay operations on the other two phases, arranging a longer time interval between each segment; when the real-time feedback shows that the TRV is still beyond the safety limit, the segmented interval is further increased, and the next phase tripping is suspended, and the tripping operation is continued after the voltage fluctuation meets the preset standard.

6. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 5, characterized in that: The adaptive adjustment of the short-circuit current shunt path includes: when a short-circuit fault occurs, firstly, the current, voltage and phase angle data are collected in real time through the transient recovery voltage monitoring system, and the peak value, flow direction and fluctuation trend of the short-circuit current on the main line are identified; through data analysis, the system calculates the transient recovery voltage value on the main line and the transient current impact amplitude caused by it in real time, and optimizes the short-circuit current shunt path by using an adaptive control algorithm, and redistributes the excessive short-circuit current on the main line to other branches, so as to ensure that the current load carried by each branch is within a safe range; The specific operation of shunting is controlled by adaptive shunting ratio ASR, which is dynamically adjusted according to the real-time amplitude and direction of the current so that the current load on each branch matches the transient voltage fluctuation of the system.

7. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 6, characterized in that: The method of adjusting the rising rate of the high-frequency transient voltage includes: at the beginning of the short-circuit fault, the transient recovery voltage monitoring system collects and calculates the rising rate dV / dt of the voltage in real time, and compares the rate with the preset rising threshold dV / dt threshold For comparison; when it is monitored that the voltage rise rate exceeds the threshold, the high-speed control module automatically triggers the peak clipping control measure. The control system absorbs part of the transient energy and smoothes the rapid rise of voltage by turning on additional resistive elements or increasing the inductance in the line. At the same time, by dynamically adjusting the capacitive reactance characteristics of the load, the capacitive element bears the transient current, reduces the voltage rise amplitude, and suppresses high-frequency transient fluctuations. The peak clipping control process runs continuously in real time, and dynamically adjusts the adjustment parameters according to the feedback signal of the transient recovery voltage to ensure that the voltage change rate always remains within a safe range.

8. A short-circuit fault suppression method based on transient recovery voltage as claimed in claim 7, characterized in that: The real-time monitoring and prevention of the arc reignition phenomenon during the circuit breaker opening period includes: at the moment when the circuit breaker performs the opening operation, the arc characteristics are recorded in real time through the high-frequency data acquisition module, specifically collecting parameters including arc length, arcing current and current change rate, and transmitting the data to the arc reignition monitoring system, which establishes an arc reignition model based on historical data and arc characteristics, identifies the arc reignition trend and estimates the possibility of reignition, and calculates the rising rate of the arcing current and the current peak value to determine whether the current current is close to the reignition sensitive area; When the system determines through the model that the arc has the risk of reignition, it immediately adjusts the opening angle of the circuit breaker to avoid the current range with high incidence of reignition. The opening angle is adjusted by controlling the time point of separation of the circuit breaker contacts so that they separate when the current drops below the preset level. The generating of the signal opposite to the harmonic component of the transient recovery voltage includes: after the short circuit fault occurs, the system performs frequency domain conversion on the time domain signal of the transient recovery voltage through fast Fourier transform FFT, identifies and decomposes the harmonic components therein, obtains the frequency and phase information of each higher harmonic in the transient recovery voltage through FFT processing, takes the harmonic components with higher frequency as the focus of analysis, and extracts the characteristic parameters of the higher harmonics; Based on the extracted harmonic frequency and phase, the control system generates a cancellation signal opposite to the harmonic phase, that is, the phase of the cancellation signal is adjusted to be 180 degrees different from the target harmonic phase, and the frequency of the cancellation signal is matched to the extracted high-order harmonic frequency, and the generated cancellation signal is superimposed on the transient recovery voltage waveform in real time, thereby achieving mutual cancellation of harmonic components in frequency and phase; The harmonic component changes in the transient recovery voltage are monitored in real time through the feedback mechanism to ensure that the generated cancellation signal keeps the frequency and phase synchronization with the target harmonic component. During the transient recovery voltage fluctuation process, the system continuously collects and analyzes the feedback signal to obtain the changes in harmonic frequency and phase. If the harmonic frequency or phase of the transient recovery voltage is detected to be offset, the system immediately adjusts the parameters of the cancellation signal to realign its frequency and phase with the target harmonic. When the harmonic frequency shifts, the system will automatically adjust the frequency of the cancellation signal to match the new harmonic frequency, and at the same time fine-tune the phase so that the cancellation signal maintains a phase difference of 180 degrees with the target harmonic.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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