CN118944458A

CN118944458A - An intelligent control method and system for a power frequency series resonance device

Info

Publication number: CN118944458A
Application number: CN202410960459.XA
Authority: CN
Inventors: 陈智恒; 周洪; 查雪良; 姜杏辉
Original assignee: Suzhou Huadian Electric Co Ltd
Current assignee: Suzhou Huadian Electric Co Ltd
Priority date: 2024-07-17
Filing date: 2024-07-17
Publication date: 2024-11-12

Abstract

The invention relates to the technical field of resonance test equipment, in particular to an intelligent control method and system of a power frequency series resonance device. Acquiring historical partial discharge test data of a power frequency series resonance device on power equipment to be tested, and calculating mutation probability of voltage mutation points generated during series circuit resonance test according to the historical partial discharge test data; if the mutation probability is larger than the preset mutation probability, the topology node is not in the topology node area where the voltage mutation point is in the output voltage topology diagram of the series resonant circuit, and then frequency drift generated when the adjusting frequency strategy is adjusted to the frequency signal is adjusted; if so, the gain control of the operational amplifier by the feedback network is calibrated according to the gain difference between the actual resonance point distribution diagram and the accurate resonance point distribution diagram, and the calibrated negative feedback network is secondarily optimized. The invention can intelligently control the power frequency series resonance device when the voltage withstand test is executed, thereby ensuring the stability of the resonance state.

Description

Intelligent control method and system for power frequency series resonance device

Technical Field

The invention relates to the technical field of resonance test equipment, in particular to an intelligent control method and system of a power frequency series resonance device.

Background

The power frequency series resonance device is a device which generates resonance phenomenon in a circuit by adjusting circuit parameters and using proper power electronic equipment under alternating current power frequency. In power systems, power frequency series resonant devices are commonly used to test the insulation properties of high voltage power equipment, such as transformers, cables, circuit breakers, and the like. The power frequency series resonance device can simulate the voltage waveform under the actual running condition so as to detect the partial discharge of equipment and the insulation performance under overvoltage, and more accurately evaluate the insulation performance of the equipment. However, due to long-term operation and performance degradation of the series resonant circuit and the control system of the power frequency series resonant device, the accuracy of controlling the power frequency series resonant device is greatly reduced, the bandwidth is increased and the frequency response is poor when the power frequency series resonant device identifies a resonance point, and the situations of missing and incorrect identification of the resonance point are caused, so that a stable resonance state is difficult to maintain, and finally, abrupt phenomena such as interruption or attenuation and the like of voltage of a withstand voltage test occur, the accuracy of the result of the withstand voltage test is reduced, high-voltage test safety accidents are easily caused, and the stable operation of the power frequency series resonant device is not facilitated.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides an intelligent control method and system of a power frequency series resonance device.

In order to achieve the above purpose, the invention adopts the following technical scheme:

The first aspect of the invention provides an intelligent control method of a power frequency series resonance device, which comprises the following steps:

Acquiring historical partial discharge test data of a power frequency series resonance device on power equipment to be tested, analyzing the historical partial discharge test data to construct a series resonance circuit output voltage topological graph, and calculating a transition probability matrix of voltage mutation points generated during series resonance circuit test according to the series resonance circuit output voltage topological graph to obtain mutation probability of the voltage mutation points in the series resonance circuit output voltage topological graph;

If the mutation probability is larger than the preset mutation probability, the topology node is not in the topology node area where the voltage mutation point is in the output voltage topology diagram of the series resonant circuit, acquiring a frequency signal of a resonance frequency point, and adjusting frequency drift generated when the adjusting frequency strategy is adjusted to the frequency signal, so as to obtain a first intelligent control scheme;

If the mutation probability is larger than the preset mutation probability, and the topology node is in a topology node area where the voltage mutation point is in the output voltage topology graph of the series resonant circuit, calibrating gain control of the feedback network to the operational amplifier according to gain difference between the actual resonance point distribution graph and the accurate resonance point distribution graph, and performing secondary optimization on the calibrated negative feedback network to obtain a second intelligent control scheme;

After the first intelligent control scheme or the second intelligent control scheme is operated, actual partial discharge test data of the power equipment to be tested are obtained, a tree-shaped discharge dynamic model is built according to the actual partial discharge test data, partial discharge amplitude is predicted and analyzed based on the tree-shaped discharge dynamic model, and an early warning signal and instantaneous protection control signal cut-off circuit are generated so as to improve the withstand voltage test safety of the power frequency series resonance device.

Further, in a preferred embodiment of the present invention, the method for obtaining historical partial discharge test data of a power frequency series resonance device on a power device to be tested, analyzing the historical partial discharge test data to construct a series resonance circuit output voltage topology, and calculating a transition probability matrix of voltage mutation points generated during testing of the series resonance circuit according to the series resonance circuit output voltage topology to obtain mutation probability of the voltage mutation points in the series resonance circuit output voltage topology, specifically includes the following steps:

acquiring power equipment to be tested and a test log of a power frequency series resonance device, and calling historical partial discharge test data of the power equipment to be tested through the test log;

Constructing an accumulated distribution partial discharge map according to the historical partial discharge test data, and stripping a historical output voltage regulation map of the power equipment to be tested based on the accumulated distribution partial discharge map;

Acquiring an initialization parameter configuration when the power frequency series resonance device generates the historical output voltage regulation map, extracting a normal output voltage waveform of the power equipment to be tested through the initialization parameter configuration, and presetting an allowable regulation fluctuation interval of output voltage according to the normal output voltage waveform;

Calibrating an output voltage regulation value outside the allowable regulation fluctuation interval as a voltage mutation point by taking the allowable regulation fluctuation interval as a reference, and calculating a topology history output voltage regulation map according to kirchhoff's law if at least one or more voltage mutation points exist in the history output voltage regulation map to obtain a series resonance circuit output voltage topology map of the power frequency series resonance device;

Acquiring voltage distribution input nodes of a series resonant circuit output voltage topological graph, marking a topological node area where a voltage mutation point is located in the series resonant circuit output voltage topological graph, acquiring voltage distribution of the topological node area, and presetting restarting probability according to the voltage distribution of the topological node area;

calculating probability vectors transferred from the initial nodes to the topological node area by using the voltage distribution input nodes as initial nodes through restarting probability to obtain a transfer probability matrix of the output voltage topological graph of the series resonant circuit, and continuously updating the iterative transfer probability matrix by repeating the steps;

presetting iteration frequency, and executing convergence processing after updating iteration reaches the iteration frequency to generate a final transition probability matrix of the output voltage topological graph of the series resonant circuit, and acquiring mutation probability of the voltage mutation point in the output voltage topological graph of the series resonant circuit according to the final transition probability matrix.

Further, in a preferred embodiment of the present invention, if the topology node with the mutation probability greater than the preset mutation probability is not located in the topology node area where the voltage mutation point is located in the output voltage topology diagram of the series resonant circuit, a frequency signal of the resonant frequency point is obtained, and frequency drift generated when the adjusting frequency strategy is adjusted to the frequency signal is adjusted, so as to obtain a first intelligent control scheme, which specifically includes the following steps:

A topological node with mutation probability larger than preset mutation probability is identified in a topological graph of the output voltage of a series resonant circuit of the power frequency series resonant device, the topological node is defined as a series resonant circuit abnormal control topological node, and whether the series resonant circuit abnormal control topological node is positioned in a topological node area where the voltage mutation point is positioned in the topological graph of the output voltage of the series resonant circuit is judged;

if the voltage abrupt change point is not located in the topological node area where the voltage abrupt change point is located in the output voltage topological graph of the series resonant circuit, extracting a preset frequency step length and a preset frequency range of the power frequency series resonant device for the power equipment to be tested through initializing parameter configuration;

Acquiring a voltage-current curve graph of the preset frequency range scanned according to a preset frequency step by a frequency scanning technology, marking a frequency point with the maximum current value and the minimum voltage value according to the voltage-current curve graph, and obtaining a plurality of resonance frequency points;

acquiring current distribution and voltage distribution of each resonant frequency point in a series resonant circuit output voltage topological graph, presetting a search range of each resonant frequency point based on the current distribution and the voltage distribution, and drawing frequency signals of each resonant frequency point;

acquiring a communication protocol and a control technology of the power frequency series resonance device, determining a frequency adjustment mechanism of the power frequency series resonance device according to the communication protocol and the control technology, and calling a frequency adjustment strategy of the frequency adjustment mechanism on the power frequency series resonance device;

extracting a finally generated adjusting frequency signal when the input voltage of the variable frequency power supply is adjusted to the frequency signal of each resonance frequency point through the frequency adjusting strategy, and judging whether the adjusting frequency signal is positioned in a searching range corresponding to each resonance frequency point;

If not, performing Hilbert transformation on the adjusting frequency signal which is not in the searching range of the resonant frequency point and the corresponding frequency signal to obtain an envelope arctangent value of the adjusting frequency signal and an envelope arctangent value of the frequency signal, and calculating a phase difference between the envelope arctangent value of the adjusting frequency signal and the envelope arctangent value of the frequency signal to obtain an instantaneous phase difference;

presetting a solution Bao Xiangwei section, expanding the instantaneous phase difference in a unpacking phase section to solve the time derivative of the instantaneous phase difference, and calculating the frequency offset according to the time derivative to obtain the frequency drift amount of the frequency signal;

and re-adjusting a frequency adjustment strategy of the frequency adjustment mechanism to the power frequency series resonance device based on the frequency drift amount to obtain a first intelligent control scheme.

Further, in a preferred embodiment of the present invention, if the topology node with the mutation probability greater than the preset mutation probability is located in a topology node area where the voltage mutation point is located in the output voltage topology graph of the series resonant circuit, the gain control of the operational amplifier by the feedback network is calibrated according to the gain difference between the actual resonance point distribution graph and the accurate resonance point distribution graph, and the calibrated negative feedback network is secondarily optimized, so as to obtain a second intelligent control scheme, which specifically includes the following steps:

If the abnormal control topological node of the series resonant circuit is in the topological node area where the voltage abrupt change point is in the output voltage topological graph of the series resonant circuit, acquiring a preset frequency step length and a preset frequency range of the power frequency series resonant device for the power equipment to be tested through initializing parameter configuration;

acquiring layout information of all operational amplifiers of the power frequency series resonance device arranged in a series resonance circuit, dividing a preset frequency range into a plurality of sub-frequency ranges based on the layout information, and performing accurate step-by-step scanning on each sub-frequency range based on the preset frequency step length so as to acquire an accurate resonance point distribution diagram;

acquiring an actual resonance point distribution diagram corresponding to each sub-frequency range when the power frequency series resonance device generates the historical output voltage regulation map, planning a frequency range with missing accurate resonance points in the actual resonance point distribution diagram of each sub-frequency range by taking the accurate resonance point distribution diagram as a reference standard, and defining the frequency range as a low frequency response area;

Acquiring a negative feedback network of an operational amplifier, simultaneously acquiring actual gain adjustment values of the negative feedback network in each low-frequency response region, calculating deviation between each actual gain adjustment value and an accurate gain adjustment value to obtain gain deviation, and determining a quality factor of the bandwidth of the negative feedback network control series resonant circuit according to the gain deviation;

Presetting an ideal quality factor, calibrating and initializing gain control of a feedback network to an operational amplifier according to the quality factor until the quality factor approaches the ideal quality factor, and obtaining a calibrated negative feedback network;

And outputting new inductance-inductance parameters and new capacitance-capacitance parameters through the calibrated negative feedback network to accurately control the power frequency series resonance device, and if the phenomenon of missing accurate resonance points still exists in the resonance point distribution diagram after calibration scanning, constructing an adjusted feedback loop compensation network to improve the control precision of the operational amplifier, so as to obtain a second intelligent control scheme.

Further, in a preferred embodiment of the present invention, the negative feedback network after calibration outputs a new inductance-inductance parameter and a new capacitance-capacitance parameter to precisely control the power frequency series resonance device, if the calibration scanned resonance point distribution diagram still has a phenomenon of missing an accurate resonance point, an adjusted feedback loop compensation network is constructed to improve the control precision of the operational amplifier, so as to obtain a second intelligent control scheme, and the method specifically includes the following steps:

Outputting new inductance-inductance parameters and new capacitance-capacitance parameters through the calibrated negative feedback network, accurately controlling the power frequency series resonance device to rescan a preset frequency range, and obtaining a resonant point distribution diagram after calibration scanning;

If the calibration scanned resonance point distribution diagram still has the phenomenon of missing accurate resonance points compared with the accurate resonance point distribution diagram, model specifications for controlling all operational amplifiers in the series resonance circuit are obtained, and the preset gain bandwidth products of all the operational amplifiers are obtained in a large data network search based on the model specifications;

Acquiring accurate resonance points in a current peak value and a voltage peak value in an accurate resonance point distribution diagram, defining the accurate resonance points as peak resonance points, extracting a target frequency response value of a negative feedback network of an operational amplifier in response to the peak resonance points, and determining a preset feedback coefficient of a feedback loop compensation network according to the target frequency response value and a preset gain bandwidth product;

a pole analysis algorithm is introduced to analyze the pole position change of the series resonant circuit in the power frequency series resonant device when the preset frequency range is scanned, so as to determine the pole position change and the corresponding phase margin of the series resonant circuit under the scanning frequency range change, and the actual frequency response value of the scanning peak resonant point of the series resonant circuit in the power frequency series resonant device is calculated according to the pole position change and the corresponding phase margin;

acquiring a series resonance knowledge graph based on a big data network, importing the model specification of an operational amplifier into the series resonance knowledge graph for identification, determining a feedback loop compensation network architecture, and initializing the feedback loop compensation network architecture through a preset feedback coefficient;

Adjusting phase delay existing between the actual frequency response value and the target frequency response value in the initialized feedback loop compensation network architecture until a feedback coefficient in the output voltage topological graph of the series resonant circuit reaches a preset feedback coefficient, thereby obtaining an adjusted feedback loop compensation network;

and uploading the adjusted feedback loop compensation network to a series resonance circuit control terminal of the power frequency series resonance device to improve the frequency response performance of the amplifier in different frequency ranges of the adjustment inductance and the capacitance scanning, so as to obtain a second intelligent control scheme.

Further, in a preferred embodiment of the present invention, after the first intelligent control scheme or the second intelligent control scheme is operated, actual partial discharge test data of the power equipment to be tested is obtained, a tree-shaped discharge dynamic model is constructed according to the actual partial discharge test data, and partial discharge amplitude is predicted and analyzed based on the tree-shaped discharge dynamic model, so as to generate an early warning signal and an instantaneous protection control signal cut-off circuit, so as to improve the withstand voltage test safety of the power frequency series resonance device, and specifically includes the following steps:

the power frequency series resonance device is used for carrying out actual test on the power equipment to be tested, the first intelligent control scheme or the second intelligent control scheme is operated in the test process to adjust the resonance steady state of the power frequency series resonance device and record test data, so that the actual partial discharge test data of the power equipment to be tested are obtained;

Presetting a plurality of uniform time sequence test intervals, extracting actual partial discharge test data corresponding to each uniform time sequence test interval based on the actual partial discharge test data, and defining the actual partial discharge test data as a sub-test data set;

acquiring the intensity of a discharge signal and the distribution of the discharge signal applied by a power frequency series resonance device to the power equipment to be tested on each uniform time sequence test interval according to a plurality of groups of sub-test data groups, and performing model fitting on the basis of the intensity of the discharge signal and the distribution of the discharge signal to construct an electric tree effect time sequence discharge model corresponding to each group of sub-test data groups;

Introducing an LSTM algorithm to perform time sequence dynamic calculation on the electrical tree effect time sequence discharge model corresponding to each group of sub-test data groups, and constructing a model to generate a tree discharge dynamic model;

Presetting a future time sequence test interval, and predicting a discharge state trend of the future time sequence test interval through the tree-shaped discharge dynamic model to determine an actual partial discharge amplitude of the power frequency series resonance device to the circuit equipment to be tested when the power frequency series resonance device is in the future time sequence test interval;

Acquiring historical withstand voltage evaluation information of the power equipment to be tested, presetting a breakdown critical value of a partial discharge test according to the historical withstand voltage evaluation information, acquiring the minimum partial discharge amplitude required for reaching the breakdown critical value, and judging whether the actual partial discharge amplitude exceeds the minimum partial discharge amplitude;

If the current value exceeds the current value, controlling an early warning mechanism of the power frequency series resonance device to send out an alarm signal, and calculating the difference value between the actual partial discharge amplitude and the lowest partial discharge amplitude at the moment to obtain an amplitude deviation rate;

When the amplitude deviation rate is larger than a preset amplitude deviation rate, generating an instantaneous protection control signal based on the amplitude deviation rate, and immediately cutting off the power supply operation of the power frequency series resonance device when a breakdown phenomenon occurs through the instantaneous protection control signal so as to improve the safety coefficient of the power frequency series resonance device during withstand voltage test.

The second aspect of the present invention provides an intelligent control system for a power frequency series resonance device, the intelligent control system for a power frequency series resonance device includes a memory and a processor, the memory stores an intelligent control method program for a power frequency series resonance device, and when the intelligent control method program for a power frequency series resonance device is executed by the processor, the following steps are implemented:

The invention solves the technical defects existing in the background technology, and has the beneficial technical effects that:

Acquiring historical partial discharge test data of a power frequency series resonance device on power equipment to be tested, and calculating a transition probability matrix of voltage mutation points generated during resonance test of a series resonance circuit according to the historical partial discharge test data to obtain mutation probability of the voltage mutation points in an output voltage topological graph of the series resonance circuit; if the mutation probability is larger than the preset mutation probability, the topology node is not in the topology node area where the voltage mutation point is in the output voltage topology diagram of the series resonant circuit, and then frequency drift generated when the adjusting frequency strategy is adjusted to the frequency signal is adjusted; if the voltage abrupt change point is positioned in a topological node area in which the voltage abrupt change point is positioned in the output voltage topological graph of the series resonant circuit, calibrating gain control of the feedback network to the operational amplifier according to gain difference between the actual resonant point distribution graph and the accurate resonant point distribution graph, and performing secondary optimization on the calibrated negative feedback network; and constructing a tree-shaped discharge dynamic model according to the actual partial discharge test data, predicting and analyzing the partial discharge amplitude based on the tree-shaped discharge dynamic model, and generating an early warning signal and an instantaneous protection control signal cut-off circuit. The invention can intelligently control the power frequency series resonance device when the voltage withstand test is executed, thereby ensuring the stability of the resonance state and improving the safety coefficient of the voltage withstand test.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other embodiments of the drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows a first method flow diagram of an intelligent control method for a power frequency series resonant device;

FIG. 2 is a second method flow diagram of an intelligent control method for a power frequency series resonant device;

FIG. 3 shows a third method flow chart of an intelligent control method of a power frequency series resonant device;

Fig. 4 shows a system frame diagram of an intelligent control system for a power frequency series resonant device.

Detailed Description

In order that the above-recited objects, features and advantages of the present application will be more clearly understood, a more particular description of the application will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.

The first aspect of the present invention provides an intelligent control method for a power frequency series resonance device, as shown in fig. 1, including the following steps:

s102: acquiring historical partial discharge test data of a power frequency series resonance device on power equipment to be tested, analyzing the historical partial discharge test data to construct a series resonance circuit output voltage topological graph, and calculating a transition probability matrix of voltage mutation points generated during series resonance circuit test according to the series resonance circuit output voltage topological graph to obtain mutation probability of the voltage mutation points in the series resonance circuit output voltage topological graph;

S104: if the mutation probability is larger than the preset mutation probability, the topology node is not in the topology node area where the voltage mutation point is in the output voltage topology diagram of the series resonant circuit, acquiring a frequency signal of a resonance frequency point, and adjusting frequency drift generated when the adjusting frequency strategy is adjusted to the frequency signal, so as to obtain a first intelligent control scheme;

S106: if the mutation probability is larger than the preset mutation probability, and the topology node is in a topology node area where the voltage mutation point is in the output voltage topology graph of the series resonant circuit, calibrating gain control of the feedback network to the operational amplifier according to gain difference between the actual resonance point distribution graph and the accurate resonance point distribution graph, and performing secondary optimization on the calibrated negative feedback network to obtain a second intelligent control scheme;

S108: after the first intelligent control scheme or the second intelligent control scheme is operated, actual partial discharge test data of the power equipment to be tested are obtained, a tree-shaped discharge dynamic model is built according to the actual partial discharge test data, partial discharge amplitude is predicted and analyzed based on the tree-shaped discharge dynamic model, and an early warning signal and instantaneous protection control signal cut-off circuit are generated so as to improve the withstand voltage test safety of the power frequency series resonance device.

It should be noted that, the power frequency series resonance device is mainly connected by a resistor, an inductor and a capacitor in a specific manner, when the frequency of the alternating voltage in the circuit is matched with the natural resonance frequency of the circuit, the inductance of the inductor and the capacitance of the capacitor can be exactly equal to each other to generate resonance. Therefore, when the power frequency series resonance device performs partial discharge test on the power equipment, if the test voltage has the phenomena of intermittent supply, instability and the like, the power frequency series resonance device may have a circuit control error of frequency response delay caused by higher bandwidth of inductance and capacitance in a series circuit after controlling the variable frequency power supply to boost, or may have a frequency deviation when the control system of the power frequency series resonance device adjusts the variable frequency power supply to the resonance frequency, and both the above two conditions cause the situation that the power frequency series resonance device cannot reach the resonance steady state all the time and generate output voltage mutation, thereby influencing the quality and the result accuracy of the voltage withstand test of the electric equipment. Therefore, the method calculates the mutation probability of the historical voltage mutation data of the power equipment in the series circuit of the power frequency series resonance device; if the mutation probability is larger than the preset mutation probability, it is indicated that a certain specific circuit node in the series resonant circuit may have series control abnormality, and if yes, it is indicated that the reason for unstable output voltage of the power frequency series resonant device is related to control errors of the series resonant circuit, otherwise, the possibility of control errors of the series resonant circuit is eliminated, frequency adjustment error factors of a control system are further considered, accurate judgment and abnormality tracing are realized for the behavior affecting abnormal voltage output of the power frequency series resonant device, the capability of intelligently solving resonance steady state abnormality of the power frequency series resonant device is optimized, and the test stability of the power frequency series resonant device is improved.

It should be noted that, through analysis of the previous step, if the circuit node with abnormal series control is not located in the topology node area where the voltage abrupt change point is located in the topology chart of the output voltage of the series circuit, the reason for the unstable output voltage of the power frequency series resonance device may be that the error exists in the frequency adjustment strategy preset by the control system, and some error frequency adjustment parameters of the error frequency adjustment parameters cause deviation between the finally generated adjustment frequency signal and the resonance frequency when the power frequency series resonance device raises the variable frequency voltage frequency on a certain node, so that the error frequency adjustment parameters cannot be matched with the resonance frequency, and a phenomenon that a stable resonance state is difficult to keep all the time is caused, so that the unstable condition of the output voltage when the power frequency series resonance device tests the power equipment is caused, and the test accuracy of the power frequency series resonance device is greatly reduced. The method can determine the frequency signal of the resonance frequency point and the search range of the resonance frequency point, wherein the search range of the resonance frequency point is an allowable range capable of searching the resonance frequency point; whether the finally generated adjusting frequency signal is located in the searching range of the corresponding resonance frequency point or not after the variable frequency power supply is subjected to frequency modulation in the frequency adjusting strategy is analyzed, if not, the deviation, namely the drift phenomenon, is generated between the adjusting frequency signal generated by actual frequency modulation and the preset frequency signal of the corresponding resonance frequency point is illustrated, so that the instantaneous phase difference appearing between the adjusting frequency signal and the preset frequency signal is calculated through Hilbert transformation, the frequency drift quantity existing between the adjusting frequency signal and the preset frequency signal can be further determined according to the instantaneous phase difference, the boosting control error of the variable frequency power supply by the adjusting strategy of the power frequency series resonance device is adjusted and repaired, the high consistency of the boosting frequency of the power supply and the resonance frequency is realized, the resonance matching quality is improved, the power frequency series resonance device is always in a stable resonance state, the testing stability is greatly improved, and the reliability is high.

Further, in a preferred embodiment of the present invention, if the topology node with the mutation probability greater than the preset mutation probability is located in the topology node area where the voltage mutation point is located in the output voltage topology graph of the series resonant circuit, the gain control of the operational amplifier by the feedback network is calibrated according to the gain difference between the actual resonance point distribution graph and the accurate resonance point distribution graph, and the calibrated negative feedback network is secondarily optimized, so as to obtain a second intelligent control scheme, as shown in fig. 2, specifically including the following steps:

s202: if the abnormal control topological node of the series resonant circuit is in the topological node area where the voltage abrupt change point is in the output voltage topological graph of the series resonant circuit, acquiring a preset frequency step length and a preset frequency range of the power frequency series resonant device for the power equipment to be tested through initializing parameter configuration;

S204: acquiring layout information of all operational amplifiers of the power frequency series resonance device arranged in a series resonance circuit, dividing a preset frequency range into a plurality of sub-frequency ranges based on the layout information, and performing accurate step-by-step scanning on each sub-frequency range based on the preset frequency step length so as to acquire an accurate resonance point distribution diagram;

S206: acquiring an actual resonance point distribution diagram corresponding to each sub-frequency range when the power frequency series resonance device generates the historical output voltage regulation map, planning a frequency range with missing accurate resonance points in the actual resonance point distribution diagram of each sub-frequency range by taking the accurate resonance point distribution diagram as a reference standard, and defining the frequency range as a low frequency response area;

s208: acquiring a negative feedback network of an operational amplifier, simultaneously acquiring actual gain adjustment values of the negative feedback network in each low-frequency response region, calculating deviation between each actual gain adjustment value and an accurate gain adjustment value to obtain gain deviation, and determining a quality factor of the bandwidth of the negative feedback network control series resonant circuit according to the gain deviation;

S210: presetting an ideal quality factor, calibrating and initializing gain control of a feedback network to an operational amplifier according to the quality factor until the quality factor approaches the ideal quality factor, and obtaining a calibrated negative feedback network;

S212: and outputting new inductance-inductance parameters and new capacitance-capacitance parameters through the calibrated negative feedback network to accurately control the power frequency series resonance device, and if the phenomenon of missing accurate resonance points still exists in the resonance point distribution diagram after calibration scanning, constructing an adjusted feedback loop compensation network to improve the control precision of the operational amplifier, so as to obtain a second intelligent control scheme.

The power frequency series resonance device adjusts parameters of inductance and capacitance to make a loop resonate at power frequency so as to generate high voltage on the tested equipment. When the circuit node with abnormal series control is not in the topological node area where the voltage abrupt change point is in the topological graph of the output voltage of the series circuit, the adjustment parameters of the inductance and the capacitance are explained to increase and widen the bandwidth of the series circuit, so that the selection accuracy and the high transmission efficiency near the resonance frequency point are reduced, the frequency response capability of the series resonance circuit is poor, and the output voltage of the power frequency series resonance device is unstable. According to the method, the missing condition of the accurate resonance points in the actual resonance point distribution diagram is analyzed by taking the accurate resonance point distribution diagram as a reference, so that a resonance point area with low frequency response in the historical test process of the power equipment, namely a bandwidth increasing area, is determined; as is known from the frequency transmission characteristics of the series resonant circuit, in order to improve the identification and pass ability of the resonant frequency, the bandwidth in the series resonant circuit should be kept at a certain degree of narrowness; the quality factor of the bandwidth of the negative feedback network control series circuit is determined according to the gain deviation between the actual gain adjustment value and the accurate gain adjustment value output by the negative feedback network of the operational amplifier in the series resonant circuit; the quality factor is an important parameter representing the selectivity and bandwidth of the series circuit, and is often controlled by adjusting the element parameters of the inductance, capacitance and resistance, while the high quality factor circuit has a narrower bandwidth and the low quality factor circuit has a wider bandwidth. The feedback network is adjusted according to the quality factor to reversely reduce the bandwidth by controlling the gain of the operational amplifier, namely, the gain is improved, so that the feedback network is calibrated, the calibrated feedback network can adjust the control parameters of the self-adaptive calibration capacitor and the inductance according to the accurate gain of the operational amplifier, thereby realizing the accurate control effect on the output parameters of each element of the series circuit, greatly improving the frequency response capability of the selected resonance point identified by the series resonance circuit, avoiding the phenomena of missing and misjudgment of the resonance point, and further improving the resonance stability of the power frequency series resonance device.

Further, in a preferred embodiment of the present invention, the negative feedback network after calibration outputs a new inductance-inductance parameter and a new capacitance-capacitance parameter to precisely control the power frequency series resonance device, if the calibration scanned resonance point distribution diagram still has a phenomenon of missing an accurate resonance point, an adjusted feedback loop compensation network is constructed to improve the control precision of the operational amplifier, so as to obtain a second intelligent control scheme, as shown in fig. 3, and specifically includes the following steps:

S302: outputting new inductance-inductance parameters and new capacitance-capacitance parameters through the calibrated negative feedback network, accurately controlling the power frequency series resonance device to rescan a preset frequency range, and obtaining a resonant point distribution diagram after calibration scanning;

s304: if the calibration scanned resonance point distribution diagram still has the phenomenon of missing accurate resonance points compared with the accurate resonance point distribution diagram, model specifications for controlling all operational amplifiers in the series resonance circuit are obtained, and the preset gain bandwidth products of all the operational amplifiers are obtained in a large data network search based on the model specifications;

S306: acquiring accurate resonance points in a current peak value and a voltage peak value in an accurate resonance point distribution diagram, defining the accurate resonance points as peak resonance points, extracting a target frequency response value of a negative feedback network of an operational amplifier in response to the peak resonance points, and determining a preset feedback coefficient of a feedback loop compensation network according to the target frequency response value and a preset gain bandwidth product;

S308: a pole analysis algorithm is introduced to analyze the pole position change of the series resonant circuit in the power frequency series resonant device when the preset frequency range is scanned, so as to determine the pole position change and the corresponding phase margin of the series resonant circuit under the scanning frequency range change, and the actual frequency response value of the scanning peak resonant point of the series resonant circuit in the power frequency series resonant device is calculated according to the pole position change and the corresponding phase margin;

S310: acquiring a series resonance knowledge graph based on a big data network, importing the model specification of an operational amplifier into the series resonance knowledge graph for identification, determining a feedback loop compensation network architecture, and initializing the feedback loop compensation network architecture through a preset feedback coefficient;

S312: adjusting phase delay existing between the actual frequency response value and the target frequency response value in the initialized feedback loop compensation network architecture until a feedback coefficient in the output voltage topological graph of the series resonant circuit reaches a preset feedback coefficient, thereby obtaining an adjusted feedback loop compensation network;

S314: and uploading the adjusted feedback loop compensation network to a series resonance circuit control terminal of the power frequency series resonance device to improve the frequency response performance of the amplifier in different frequency ranges of the adjustment inductance and the capacitance scanning, so as to obtain a second intelligent control scheme.

It should be noted that, the calibrated negative feedback network outputs new inductance-inductance parameters and new capacitance-capacitance parameters to accurately and stably control the bandwidth limit of the series resonant circuit in the power frequency series resonant device, but when the resonant point distribution diagram after being regulated and scanned by the calibrated negative feedback network still has the condition of missing accurate resonant points, it is proved that the actual frequency response requirements of the inductance and capacitance in the current series resonant circuit are still difficult to be met after the accurate regulation of the calibrated negative feedback network, which proves that the calibrated negative feedback network may have a certain applicability defect for the operational amplifier in the current series resonant circuit, and reduces the adaptation degree of the series resonant circuit with different frequency response requirements regulated by the negative feedback network. According to the method, the actual frequency response and the phase margin of the series resonant circuit in the current power frequency series resonant device when scanning the peak resonance point are analyzed, so that whether the series resonant circuit has enough phase margin in the target working frequency range is evaluated, and oscillation and instability phenomena are avoided; the method comprises the steps of scanning a peak resonance point of a series circuit, and adjusting phase delay existing between an actual frequency response value and a target frequency response value of the peak resonance point until a feedback coefficient reaches a preset feedback coefficient, wherein the feedback coefficient determines the influence degree of a feedback loop on the gain of an operational amplifier, and the lower feedback coefficient can improve the frequency response and reduce nonlinear distortion; therefore, a feedback loop compensation network for compensating the shortages and the changes of the operational amplifier in different frequency response demands can be constructed, the frequency response performance of the amplifier for adjusting inductance and capacitance to scan different frequency ranges is improved, the adaptation degree of the negative feedback network for adjusting the series resonant circuit with different frequency response demands is further optimized, the reliability of bandwidth control is maintained, and the resonance stability of the power frequency series resonant device is improved.

When the power frequency series resonance device is used for carrying out partial discharge test on the electrical equipment, when the voltage output by the power frequency series resonance device exceeds the withstand voltage limit of the electrical equipment, the partial discharge in the power frequency series resonance device can possibly generate an electric breakdown phenomenon on the electrical equipment, and the continuous electric breakdown phenomenon has certain danger and can possibly cause a certain degree of damage to the nearby testers and the electrical equipment, so that the circuit of the power frequency series resonance device needs to be cut off in time to eliminate the continuous electric breakdown phenomenon. When an electric breakdown phenomenon occurs, a partial discharge in the electric equipment is a dendritic discharge phenomenon, which is a precursor of the electric breakdown phenomenon. The method comprises the steps of constructing a tree-shaped discharge dynamic model based on uniform time sequence test intervals according to actual partial discharge test data of the power equipment to be tested, and predicting partial discharge trend of future time sequence test intervals, namely actual partial discharge amplitude values according to the tree-shaped discharge dynamic model; if the actual partial discharge amplitude exceeds the minimum partial discharge amplitude required by the breakdown critical value, the fact that partial discharge at a future time sequence test interval can generate an electric breakdown phenomenon is indicated, at the moment, an early warning mechanism of the power frequency series resonance device can be controlled to send out an alarm signal in advance so as to warn a nearby tester to keep away from and make corresponding defending measures, an instantaneous protection control signal is generated according to the amplitude deviation rate to cut off the power supply operation of the power frequency series resonance device, the electric breakdown phenomenon is prevented from damaging the tester and electrical equipment, the safety coefficient of the power frequency series resonance device during the withstand voltage test is improved, meanwhile, the fault phenomenon caused by the overhigh operation voltage or current of the power frequency series resonance device is prevented, the service life is ensured, and the safety and reliability are high.

In addition, the intelligent control method of the power frequency series resonance device further comprises the following steps:

Acquiring a frequency modulation strategy of the power frequency series resonance device, and extracting resonance steady-state values of the power frequency series resonance device on a plurality of preset time nodes based on the frequency modulation strategy to obtain a plurality of resonance steady-state values;

Calculating the resonant frequency matching rate of the power frequency series resonant device on a resonant point according to the plurality of resonant steady-state values, and if the resonant frequency matching rate is lower than a preset resonant frequency matching rate, acquiring an actual frequency modulation error rate of the power frequency series resonant device;

Acquiring corresponding operation parameters of each control mechanism in the power frequency series resonance device under different preset frequency modulation error rates through a big data network, and calculating the association degree between the actual frequency modulation error rate and the different preset frequency modulation error rates through the Spi-son correlation coefficient to obtain a plurality of association degrees;

extracting a preset frequency modulation error rate corresponding to the maximum association degree from the plurality of association degrees, and determining actual operation parameters corresponding to each control mechanism of the power frequency series resonance device under the actual frequency modulation error rate according to the preset frequency modulation error rate corresponding to the maximum association degree;

And obtaining the reference operation parameters of each control mechanism, correspondingly calculating the deviation between the actual operation parameters corresponding to each control mechanism and the reference operation parameters corresponding to each control mechanism, obtaining the deviation value of each control mechanism, and regulating and controlling the frequency modulation strategy of the power frequency series resonance device based on the deviation value of each control mechanism so as to eliminate the frequency modulation error of the power frequency series resonance device.

It should be noted that, because the power frequency series resonance device operates for a long time under different environmental conditions, the control mechanism inside the power frequency series resonance device generates certain aging, abrasion or poor contact and other fault phenomena, so that a frequency modulation error occurs when the power frequency series resonance device executes a frequency modulation strategy in the actual test process, and the error rate of the final test result is caused, which is not beneficial to the efficient and accurate test of the power frequency series resonance device. The method can accurately regulate and control the operation parameter errors generated when each control mechanism in the power frequency series resonance device executes the frequency modulation strategy one by one, thereby eliminating the frequency modulation errors of the power frequency series resonance device, improving the accuracy and reliability of the withstand voltage test result and ensuring the test control quality of the power frequency series resonance device.

The second aspect of the present invention provides an intelligent control system for a power frequency series resonance device, where the intelligent control system for a power frequency series resonance device includes a memory 41 and a processor 42, where the memory 41 stores an intelligent control method program for a power frequency series resonance device, and when the intelligent control method program for a power frequency series resonance device is executed by the processor 42, as shown in fig. 4, the following steps are implemented:

The foregoing is merely illustrative embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present invention, and the invention should be covered. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. An intelligent control method of a power frequency series resonance device is characterized by comprising the following steps:

2. The intelligent control method of a power frequency series resonance device according to claim 1, wherein the obtaining of the historical partial discharge test data of the power frequency series resonance device on the power equipment to be tested, analyzing the historical partial discharge test data to construct a series resonance circuit output voltage topological graph, calculating a transition probability matrix of voltage mutation points generated during series resonance circuit testing according to the series resonance circuit output voltage topological graph, and obtaining mutation probability of the voltage mutation points in the series resonance circuit output voltage topological graph, specifically comprises the following steps:

3. The intelligent control method of a power frequency series resonance device according to claim 1, wherein if the topology node with the mutation probability larger than the preset mutation probability is not in the topology node area where the voltage mutation point is in the output voltage topology diagram of the series resonance circuit, the frequency signal of the resonance frequency point is obtained, and the frequency drift generated when the adjustment frequency strategy is adjusted to the frequency signal is adjusted, so as to obtain a first intelligent control scheme, which specifically comprises the following steps:

4. The intelligent control method of a power frequency series resonance device according to claim 1, wherein if the topology node with the mutation probability larger than the preset mutation probability is located in the topology node area where the voltage mutation point is located in the output voltage topology diagram of the series resonance circuit, the gain control of the operational amplifier by the feedback network is calibrated according to the gain difference between the actual resonance point distribution diagram and the accurate resonance point distribution diagram, and the calibrated negative feedback network is secondarily optimized, so as to obtain a second intelligent control scheme, which specifically comprises the following steps:

5. The intelligent control method of a power frequency series resonance device according to claim 4, wherein the negative feedback network after calibration outputs new inductance-inductance parameters and new capacitance-capacitance parameters to precisely control the power frequency series resonance device, and if the calibration scanned resonance point distribution diagram still has the phenomenon of missing accurate resonance points, an adjusted feedback loop compensation network is constructed to improve the control precision of the operational amplifier, so as to obtain a second intelligent control scheme, and the intelligent control method specifically comprises the following steps:

6. The intelligent control method of the power frequency series resonance device according to claim 1, wherein after the first intelligent control scheme or the second intelligent control scheme is operated, actual partial discharge test data of the power equipment to be tested is obtained, a tree-shaped discharge dynamic model is constructed according to the actual partial discharge test data, partial discharge amplitude is predicted and analyzed based on the tree-shaped discharge dynamic model, and an early warning signal and an instantaneous protection control signal cut-off circuit are generated to improve the withstand voltage test safety of the power frequency series resonance device, and specifically comprises the following steps:

7. The intelligent control system of the power frequency series resonance device is characterized by comprising a memory and a processor, wherein the memory stores an intelligent control method program of the power frequency series resonance device, and when the intelligent control method program of the power frequency series resonance device is executed by the processor, the following steps are realized: