Control method for controllable rectifier transformer used in ultra-low frequency dielectric loss measurement device

Abstract

The invention belongs to the technical field of equipment control, and discloses a control method for a controllable rectifier transformer used in an ultra-low frequency dielectric loss measuring device; the method comprises: collecting voltage interference parameters in real time during the dielectric loss measuring process; extracting features of the collected voltage interference parameters to extract change characteristic data; calculating the voltage fluctuation degree according to the change characteristic data, and judging whether to generate an adjustment instruction; if an adjustment instruction is generated, formulating a voltage control strategy by adopting a fish optimization algorithm; calculating a voltage control signal according to the voltage control strategy in combination with a PID controller and a fuzzy controller, and adjusting voltage feedback data according to the voltage control signal by a rectifier transformer; the invention can effectively suppress the influence of external interference factors on the ultra-low frequency dielectric loss measuring accuracy, realize the fine control and stabilization of the output voltage of the rectifier transformer, and thus improve the performance and measurement quality of the dielectric loss measuring device.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment control, and more specifically, to a control method for a controllable rectifier transformer used in an ultra-low frequency dielectric loss measuring device. Background Art

[0002] Dielectric loss is the energy loss phenomenon caused by dielectric materials under the action of alternating electric fields; accurate measurement of dielectric loss is an important indicator for evaluating dielectric performance; in the ultra-low frequency range (such as 0.1-100Hz), the measurement of dielectric loss is of great significance for some special applications (such as power cables, high-voltage capacitors, etc.); common dielectric loss measurement methods include bridge measurement, Q value measurement, and resonant circuit measurement, all of which require the use of an adjustable AC voltage source to excite the measurement circuit;

[0003] Traditional adjustable AC power sources are usually implemented by controlled rectifier transformers or power amplifiers. Controllable rectifier transformers are a combination of controlled rectifiers and transformers that can output adjustable AC voltages. They have the advantages of small size, high efficiency, and low noise, and are very suitable for dielectric loss measurement devices. For example, Chinese patent publication number CN112505426A discloses a cable dielectric loss measurement device and a measurement method for a test voltage in an ultra-low frequency band. This invention uses a rectifier transformer when measuring the dielectric loss of a cable.

[0004] However, the output voltage of the controllable rectifier transformer is often affected by factors such as load changes and grid voltage fluctuations, making it difficult to achieve precise voltage control. Therefore, an intelligent control method is urgently needed to achieve precise regulation and stabilization of the output voltage of the controllable rectifier transformer.

[0005] In view of this, the present invention proposes a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device to solve the above problem. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art and achieve the above-mentioned purpose, the present invention provides the following technical solution: a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device, comprising:

[0007] S1: Real-time acquisition of voltage interference parameters during dielectric loss measurement;

[0008] S2: extracting features of the collected voltage interference parameters and extracting change characteristic data;

[0009] S3: Calculate the voltage fluctuation degree according to the change characteristic data, and determine whether to generate an adjustment instruction;

[0010] S4: If an adjustment instruction is generated, use The fish optimization algorithm formulates the voltage regulation strategy;

[0011] S5: According to the voltage control strategy, the voltage control signal is calculated by combining the PID controller and the fuzzy controller, and the rectifier transformer adjusts the voltage feedback data according to the voltage control signal.

[0012] Furthermore, the voltage interference parameters include electromagnetic field strength, grid voltage, ambient temperature and load impedance;

[0013] The method for obtaining the load impedance is: obtaining the sample voltage and the sample current, and obtaining the load impedance through the ratio of the sample voltage and the sample current;

[0014] The change characteristic data includes a change rate and a change amplitude; the change rate is the change rate of each parameter in the voltage interference parameter, and the change amplitude is the change amplitude of each parameter in the voltage interference parameter;

[0015] Methods for obtaining the change rate include:

[0016] Subtract the corresponding parameter in the voltage interference parameter collected last time from each parameter in the real-time collected voltage interference parameter to obtain the change amount of each parameter in the voltage interference parameter; divide the change amount of each parameter in the voltage interference parameter by the sampling frequency to obtain the change rate of each parameter in the voltage interference parameter;

[0017] Methods for obtaining the change range include:

[0018] When the measuring device measures the dielectric loss of the sample under test, the voltage interference parameter collected for the first time is marked as the first parameter; each parameter in the real-time collected voltage interference parameters is subtracted from the corresponding parameter in the first parameter to obtain the change amplitude of each parameter in the voltage interference parameters.

[0019] Furthermore, the method for calculating the voltage fluctuation degree includes:

[0020] Obtain the optimal voltage, which is the output voltage of the rectifier transformer when the dielectric loss measurement of the sample under test begins;

[0021] The change characteristic data and the optimal voltage are used as analysis data, and the analysis data are input into the trained stability analysis model to predict the corresponding voltage fluctuation degree;

[0022] The training process of the stability analysis model includes:

[0023] Collect a group of analysis data in advance, set corresponding voltage fluctuation degrees for the group of analysis data, a is an integer greater than 1, and convert the analysis data and the corresponding voltage fluctuation degrees into a corresponding set of feature vectors;

[0024] Each group of feature vectors is used as input of a stability analysis model. The stability analysis model uses a group of predicted voltage fluctuation degrees corresponding to each group of analysis data as output, and uses the actual voltage fluctuation degree corresponding to each group of analysis data as a prediction target, where the actual voltage fluctuation degree is the pre-collected voltage fluctuation degree corresponding to the analysis data; minimizing the sum of prediction errors of all analysis data is used as a training target; the stability analysis model is trained until the sum of prediction errors reaches convergence and the training is stopped; the stability analysis model is a deep neural network model;

[0025] The method for determining whether to generate an adjustment instruction includes:

[0026] A fluctuation degree threshold is preset, and the absolute value of the voltage fluctuation degree is compared with the fluctuation degree threshold;

[0027] If the absolute value of the voltage fluctuation degree is less than or equal to the fluctuation degree threshold, no adjustment instruction is generated;

[0028] If the absolute value of the voltage fluctuation degree is greater than the fluctuation degree threshold, an adjustment instruction is generated.

[0029] Furthermore, the use of The steps of the fish optimization algorithm to formulate voltage regulation strategy include:

[0030] Step 1: Construct m voltage sets, set different labels for different voltage sets, and mark them as voltage labels; preset the population size Z and the number threshold T;

[0031] Step 2: Initialize the population. The fish positions are defined in a one-dimensional search space, The positions of the fish correspond one-to-one to the voltage labels, and the number of iterations t corresponding to the initialization population is 0;

[0032] Step 3: Determine the fitness function;

[0033] Step 4: Select each Fish parasite hosts;

[0034] Step 5: Update each The location of the fish;

[0035] Step 6: Calculate each The fitness of the fish's updated position corresponds to the fish's updated position, and determines whether to switch hosts;

[0036] Step 7: Switch host The fish updates its position again;

[0037] Step 8: Each The fish enter the foraging stage and update each The location of the fish;

[0038] Step 9: If the number of iterations t is less than the number threshold T, return to step 4, and the number of iterations t=t+1; if the number of iterations t is greater than or equal to the number threshold T, proceed to step 10;

[0039] Step 10: Calculate each The fitness corresponding to the position of the fish, sort all the fitness from large to small, and get the fitness corresponding to the first one Fish location, based on the obtained The fish position obtains the voltage set corresponding to the corresponding voltage label.

[0040] Furthermore, in the step 1, a range of voltage feedback data is obtained, the voltage feedback data includes a rectifier trigger angle, a transformer tap position and an excitation current, and the range of the voltage feedback data includes a range of each data in the voltage feedback data; a value is randomly selected from the range of each data in the voltage feedback data, and a voltage set is constructed, and a total of m voltage sets are constructed, where m is an integer greater than 1;

[0041] In step 2, the population S is initialized 0 ={X 1 ,X 2 ,...,X Z}, including Z bar Fish, X Z For Article Z fish; the voltage label range is [1,m], that is, the range of the one-dimensional search space is [1,m]; each The expression for the fish position is: In the formula, For the i-th The initial position of the fish, D i is a random number between [0,1], i∈[1,Z].

[0042] Furthermore, in step 3, the fitness function is expressed as: In the formula, f is the fitness, U is the voltage difference; the method for obtaining the voltage difference is: The voltage set corresponding to the voltage label corresponding to the fish position is used as the test data, and the test data is input into the trained difference analysis model to predict the corresponding voltage difference. The training process of the difference analysis model is consistent with the training process of the stability analysis model, and both are deep neural network models.

[0043] In step 4, the hosts include swordfish and whales; each The random number D corresponding to the fish i And round up, if the rounded random number is 0, then The host of the fish parasite is a whale. If the rounded random number is 1, then The host of the fish parasite is swordfish.

[0044] Furthermore, in step 5, each The fitness corresponding to the position of the fish, the fitness with the largest value Fish positions are marked

[0045] If the host is a whale, then after the update The calculation method of fish position includes:

[0046]

[0047] In the formula, is the updated article i The location of the fish, For the i-th article before the update The position of the fish, α is the search range adjustment coefficient, and C′ is a random number between [0,1];

[0048] If the host is a swordfish, then after the update The calculation method of fish position includes:

[0049]

[0050] In the formula, A random one before the update Fish location.

[0051] Further, in step 6, When the fish is parasitic on the host, according to the previous iteration The final position of the fish The fish makes a tentative move at its current position; calculates The position of the fish after the tentative move, and calculate the corresponding fitness, marked as the tentative fitness; The fitness corresponding to the current position of the fish is marked as the current fitness; the test fitness is compared with the current fitness; if the test fitness is greater than or equal to the current fitness, the host is not switched; if the test fitness is less than the current fitness, the host is switched;

[0052] In step 7, the host is switched The method for updating the fish position again is the same as that for updating each The method of fish location is consistent;

[0053] In step 8, The methods for updating the fish's position when it enters the foraging phase include:

[0054]

[0055]

[0056] B i =2V i C″-V i ;

[0057]

[0058] In the formula, For the i-th The updated position of the fish after the foraging phase, For the i-th The updated position of the fish after switching hosts, A i For the i-th The distance fish travel during the foraging phase, B i For the i-th The volume of the host the fish is parasitizing, for Fish Factor, V i For the i-th The volume of the fish, C″ is a random number between [0,1].

[0059] Further, the voltage control signal includes a rectifier trigger angle control signal, a transformer tap position control signal and an excitation current control signal;

[0060] The calculation method of the rectifier trigger angle control signal includes:

[0061] Collecting the rectifier trigger angle; subtracting the collected rectifier trigger angle from the rectifier trigger angle in the voltage set to obtain an angle error;

[0062] The angle error is used as the input of the fuzzy controller and the PID parameter control signal is used as the output;

[0063] Design fuzzy control rules based on the relationship between the change of PID parameters and the angle error. PID parameters include proportional gain, integral gain and differential gain. Fuzzy control rules are expressed in IF-THEN form.

[0064] The angle error is converted into a fuzzy set through fuzzification technology;

[0065] According to the fuzzified angle error and the fuzzy control rule, the fuzzy output is obtained;

[0066] Use defuzzification technology to convert fuzzy output into PID parameter control signal;

[0067] The PID controller calculates the rectifier trigger angle control signal and adjusts the PID parameters according to the PID parameter control signal;

[0068]

[0069] Where ZL(t′) is the rectifier trigger angle control signal, WC(t′) is the angle error, BL is the proportional gain, JF is the integral gain, WF is the differential gain, and t′ is the current moment;

[0070] The calculation method of the transformer tap position control signal and the excitation current control signal is consistent with the rectifier trigger angle control signal.

[0071] Further, obtain Z in the population The voltage difference of the voltage set corresponding to the position of the fish, n excellent sets are screened out according to the voltage difference, the adjustment coefficient of each excellent set is calculated, and the best set is screened out from the n excellent sets, where n is an integer greater than or equal to 1;

[0072] The excellent set is a voltage set whose absolute value of voltage difference is less than or equal to the fluctuation degree threshold;

[0073] If n is 1, the best set is the superior set;

[0074] If n is greater than 1, the corresponding data in the voltage feedback data collected in real time is subtracted from the data in each excellent set to obtain the adjustment amount corresponding to each excellent set, and the adjustment amount includes the rectifier trigger angle adjustment amount, the transformer tap position adjustment amount and the excitation current adjustment amount;

[0075] The adjustment amount corresponding to each excellent set is weightedly summed to calculate the adjustment coefficient corresponding to each excellent set; the adjustment coefficients corresponding to each excellent set are sorted from small to large, and the excellent set corresponding to the adjustment coefficient ranked first is taken as the best set.

[0076] The technical effects and advantages of the controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device of the present invention are as follows:

[0077] 1. Real-time judgment and monitoring of the output voltage of the rectifier transformer can be achieved by monitoring the voltage interference parameters in real time and establishing a deep learning model to evaluate the voltage fluctuation degree; The fish optimization algorithm takes into account the influence of multiple voltage variables, dynamically formulates voltage control strategies, and combines PID controllers and fuzzy controllers to accurately implement voltage regulation. It can effectively suppress the influence of external interference factors on the measurement accuracy of ultra-low frequency dielectric loss, and achieve fine control and stabilization of the output voltage of the rectifier transformer to meet the accuracy requirements of ultra-low frequency dielectric loss testing, ensure the reliability of test results, and thus improve the performance and measurement quality of the dielectric loss measurement device.

[0078] 2. By screening multiple voltage sets and using the differences in the adjustment rates of each data in the voltage feedback data, the weight coefficient of each data in the adjustment amount is set, the adjustment coefficient is calculated more accurately, and the voltage set with the smallest adjustment coefficient and the voltage difference that meets the requirements is selected; that is, when formulating the voltage control strategy, not only the voltage set with the greatest fitness is considered, but also the suboptimal solution. While ensuring the measurement accuracy, the adjustment amplitude and adjustment time of the rectifier transformer are minimized as much as possible, the interference to the entire dielectric loss measurement device is reduced, and the robustness of the control strategy and the stability of voltage control are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 This is a flow chart of a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device according to Embodiment 1 of the present invention;

[0080] Figure 2 This is a flow chart of a method for calculating a rectifier trigger angle control signal according to Embodiment 1 of the present invention;

[0081] Figure 3 This is a flow chart of a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device according to Embodiment 2 of the present invention;

[0082] Figure 4 This is a schematic diagram of an electronic device according to Embodiment 3 of the present invention;

[0083] Figure 5 This is a schematic diagram of a storage medium according to Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0084] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0085] Example 1

[0086] See also Figure 1 As shown, the controllable rectifier transformer control method for the ultra-low frequency dielectric loss measurement device described in this embodiment includes:

[0087] S1: Real-time acquisition of voltage interference parameters during dielectric loss measurement.

[0088] Voltage interference parameters include electromagnetic field strength, grid voltage, ambient temperature and load impedance;

[0089] The electromagnetic field strength is the electromagnetic field strength of the environment in which the measuring device is located, and the measuring device is an ultra-low frequency dielectric loss measuring device; the grid voltage is the voltage of the grid AC power supply connected to the measuring device; the ambient temperature is the temperature of the environment in which the measuring device is located; the electromagnetic field strength is obtained by the electromagnetic field strength sensor integrated in the measuring device, the grid voltage is obtained by the AC voltage sensor integrated in the input end of the rectifier transformer in the measuring device, and the ambient temperature is obtained by the temperature sensor integrated in the measuring device;

[0090] The load impedance is a complex impedance composed of the resistance and capacitance characteristics of the sample under test; the method for obtaining the load impedance is: obtaining the sample voltage and the sample current, and obtaining the load impedance through the ratio of the sample voltage and the sample current; the sample voltage is the voltage of the sample under test, and the sample current is the current of the sample under test, and the sample voltage and the sample current are obtained through voltage-current sensors installed at both ends of the sample under test;

[0091] Strong electromagnetic fields will interfere with the magnetic components of the rectifier transformer, causing changes in the magnetic flux, thereby affecting the output voltage of the rectifier transformer; the input voltage of the rectifier transformer comes from the AC voltage of the power grid. If the power grid voltage fluctuates, it will directly affect the output voltage of the rectifier transformer; changes in ambient temperature will cause changes in the rectifier transformer parameters, such as the magnetic properties of the core, winding resistance, etc., causing the output voltage of the rectifier transformer to drift; changes in load impedance will affect changes in load current, and the output current of the rectifier transformer will also change, causing the rectifier transformer core magnetic flux to saturate, thereby affecting the output voltage of the rectifier transformer, and when the load impedance changes, the power transfer efficiency of the rectifier transformer will also change, thereby affecting the output voltage of the rectifier transformer.

[0092] The voltage interference parameter is collected according to a preset sampling frequency, and the sampling frequency is preset by a person skilled in the art according to an actual variation rule of the voltage interference parameter.

[0093] S2: Extract features of the collected voltage interference parameters and extract change characteristic data.

[0094] The change characteristic data includes a change rate and a change amplitude; the change rate is the change rate of each parameter in the voltage interference parameter, and the change amplitude is the change amplitude of each parameter in the voltage interference parameter.

[0095] Methods for obtaining the change rate include:

[0096] Subtract the corresponding parameter in the voltage interference parameter collected last time from each parameter in the real-time collected voltage interference parameter to obtain the change amount of each parameter in the voltage interference parameter; divide the change amount of each parameter in the voltage interference parameter by the sampling frequency to obtain the change rate of each parameter in the voltage interference parameter.

[0097] Methods for obtaining the change range include:

[0098] When the measuring device measures the dielectric loss of the sample under test, the voltage interference parameter collected for the first time is marked as the first parameter; each parameter in the real-time collected voltage interference parameters is subtracted from the corresponding parameter in the first parameter to obtain the change amplitude of each parameter in the voltage interference parameters.

[0099] It should be noted that the purpose of extracting the change characteristic data is to be able to understand the changes in the voltage interference parameters and to promptly discover the abnormal changes in the voltage interference parameters, so as to facilitate the subsequent accurate judgment of the impact of the fluctuation on the output voltage of the rectifier transformer according to the changes, and to provide a basis for formulating the output voltage control strategy, thereby improving the stability and reliability of the output voltage of the rectifier transformer.

[0100] S3: Calculate the voltage fluctuation degree according to the change characteristic data, and determine whether to generate an adjustment instruction.

[0101] Methods for calculating the degree of voltage fluctuation include:

[0102] Obtaining the optimum voltage, which is the output voltage of the rectifier transformer when the dielectric loss measurement of the sample under test begins; the optimum voltage is obtained by a voltage sensor integrated at the output end of the rectifier transformer in the measuring device;

[0103] The variation characteristic data and the optimum voltage are used as analysis data, and the analysis data are input into the trained stability analysis model to predict the corresponding voltage fluctuation degree.

[0104] The training process of the stability analysis model includes:

[0105] Collect a group of analysis data in advance, set corresponding voltage fluctuation degrees for the group of analysis data, a is an integer greater than 1, and convert the analysis data and the corresponding voltage fluctuation degrees into a corresponding set of feature vectors; the voltage fluctuation degrees corresponding to the analysis data are collected by technicians in the historical dielectric loss measurement process, a group of analysis data is collected, under the condition of each group of analysis data, the output voltage of the rectifier transformer after the voltage interference parameter is changed is collected and marked as a changed voltage, and the optimal voltage in the corresponding analysis data is subtracted from each changed voltage to obtain the voltage fluctuation degree corresponding to each group of analysis data; the corresponding voltage fluctuation degrees are set for the group of analysis data in turn;

[0106] Each set of feature vectors is used as the input of the stability analysis model. The stability analysis model uses a set of predicted voltage fluctuation degrees corresponding to each set of analysis data as output, and uses the actual voltage fluctuation degree corresponding to each set of analysis data as the prediction target. The actual voltage fluctuation degree is the voltage fluctuation degree corresponding to the analysis data collected in advance. The training target is to minimize the sum of the prediction errors of all analysis data. The calculation formula of the prediction error is ηK =(β K -ε K ) 2 , where η K is the prediction error, K is the group number of the eigenvector corresponding to the analyzed data, β K is the predicted voltage fluctuation degree corresponding to the Kth group of analysis data, ε K is the actual voltage fluctuation degree corresponding to the Kth group of analysis data; the stability analysis model is trained until the sum of the prediction errors reaches convergence and the training is stopped.

[0107] The above-mentioned stable analysis model is specifically a deep neural network model; it includes an input layer, a hidden layer and an output layer; each hidden layer includes multiple neurons, each neuron is connected to the neurons in the next layer, and the connection contains weights, which determine the importance and influence of data transmission in the neural network; an activation function is applied to each neuron between the hidden layer and the output layer, and the activation function reflects nonlinearity, allowing the network to learn more complex patterns and features.

[0108] The method for determining whether to generate an adjustment instruction includes:

[0109] A fluctuation degree threshold is preset. The fluctuation degree threshold is determined by a technician in this field during the historical dielectric loss measurement process. The technicians collect analysis data c times, and collect b groups of analysis data each time, where c and b are both integers greater than 1. Under the condition of collecting b groups of analysis data once, the measured dielectric loss value is subtracted from the actual dielectric loss value of the measured sample to obtain the corresponding dielectric loss error value. The analysis data with a dielectric loss error value less than or equal to the preset accuracy requirement is marked as normal data. The absolute values ​​of the voltage fluctuation degrees corresponding to each group of normal data are compared to obtain the absolute value of the voltage fluctuation degree with the largest value, and marked as the maximum degree. The maximum degree corresponding to each collection of analysis data is obtained by analogy, and the average of multiple maximum degrees is used as the fluctuation degree threshold. The accuracy requirement is preset by a technician in this field according to the actual dielectric loss measurement accuracy requirement.

[0110] Compare the absolute value of the voltage fluctuation degree with the fluctuation degree threshold;

[0111] If the absolute value of the voltage fluctuation degree is less than or equal to the fluctuation degree threshold, no adjustment instruction is generated; this indicates that the fluctuation of the output voltage of the rectifier transformer is small and will not affect the measurement accuracy of the dielectric loss, and there is no need to adjust the output voltage;

[0112] If the absolute value of the voltage fluctuation degree is greater than the fluctuation degree threshold, an adjustment instruction is generated; this indicates that the output voltage of the rectifier transformer fluctuates greatly, which will affect the measurement accuracy of the dielectric loss, so the output voltage needs to be adjusted.

[0113] S4: If an adjustment instruction is generated, use The voltage regulation strategy is formulated using the fish optimization algorithm.

[0114] use The steps of the fish optimization algorithm to formulate voltage regulation strategy include:

[0115] Step 1: Construct m voltage sets, set different labels for different voltage sets, and mark them as voltage labels; preset the population size Z and the number threshold T.

[0116] Step 2: Initialize the population. The fish positions are defined in a one-dimensional search space, The positions of the fish correspond one-to-one to the voltage labels, and the number of iterations t corresponding to the initialization population is 0.

[0117] Step 3: Determine the fitness function.

[0118] Step 4: Select each Fish parasite hosts.

[0119] Step 5: Update each Fish location.

[0120] Step 6: Calculate each The fitness of the fish's updated position corresponds to the fish's updated position, and determines whether to switch hosts.

[0121] Step 7: Switch host The fish updates its position again.

[0122] Step 8: Each The fish enter the foraging stage and update each Fish location.

[0123] Step 9: If the number of iterations t is less than the number threshold T, return to step 4, and the number of iterations t=t+1, that is, the value of the number of iterations is increased by one and then assigned to the number of iterations; if the number of iterations t is greater than or equal to the number threshold T, go to step 10.

[0124] Step 10: Calculate each The fitness corresponding to the position of the fish, sort all the fitness from large to small, and get the fitness corresponding to the first one Fish location, based on the obtained The fish position obtains the voltage set corresponding to the corresponding voltage label.

[0125] In the above step 1, the range of voltage feedback data is obtained, the voltage feedback data includes the rectifier trigger angle, the transformer tap position and the excitation current, and the range of voltage feedback data includes the range of each data in the voltage feedback data; a value is randomly selected from the range of each data in the voltage feedback data, and a voltage set is constructed, and a total of m voltage sets are constructed, where m is an integer greater than 1; the range of voltage feedback data is obtained through the technical specifications of the rectifier transformer.

[0126] The rectifier trigger angle is the phase angle of the trigger signal required for the control element (such as a thyristor or a thyristor) in a rectifier (such as a silicon rectifier) ​​to go from the on state to the off state; the rectifier trigger angle range is generally between 0° and 180°. The rectifier trigger angle will directly affect the output voltage of the rectifier transformer. A smaller trigger angle will result in a higher output voltage, while a larger trigger angle will reduce the output voltage; the transformer tap position is a pre-set connection point on the transformer winding. The connection point is switched mechanically or electronically to change the turns ratio of the transformer, thereby changing the output voltage of the rectifier transformer; the excitation current is the current applied to the transformer excitation winding. Changes in the excitation current will affect the flux density of the transformer core, thereby affecting the flux of the transformer. The flux of the transformer is proportional to the output voltage, so it will also affect the output voltage of the rectifier transformer.

[0127] The population size Z is set by a technician in the field during the historical dielectric loss measurement process under multiple sets of different analysis data conditions for the same analysis data, and is repeated multiple times. The fish optimization algorithm obtains the corresponding voltage label after the same number of iterations, and takes the population size corresponding to the voltage label closest to the actual voltage label as the population size corresponding to the group of analysis data. The actual voltage label is the voltage label that best matches the group of analysis data, and the actual voltage label is obtained by technical personnel in this field based on actual experience; and so on, the population size corresponding to each group of analysis data is obtained, and the average of multiple population sizes is taken as the preset population size Z.

[0128] The number threshold T is determined by a person skilled in the art in the art during the historical dielectric loss measurement process by performing multiple analysis on the same analysis data under multiple different analysis data conditions. Fish optimization algorithm, obtain multiple voltage labels, each of which The number of iterations of the fish optimization algorithm is different, and the population size is the same and is Z; the number of iterations that corresponds closest to the voltage label and the actual voltage label is taken as the number of iterations corresponding to the group of analysis data; and the number of iterations corresponding to each group of analysis data is obtained by analogy, and the average of multiple iterations is taken as the number threshold T.

[0129] It should be understood that the population size Z determines the breadth of the search. A larger population size can explore more solution spaces, while the number threshold T determines the termination condition of the algorithm and can control the speed at which the algorithm converges.

[0130] In step 2 above, the population S is initialized 0 ={X 1 ,X 2 ,...,X Z}, including Z bar Fish, X Z For Article Z fish; the voltage label range is [1,m], that is, the range of the one-dimensional search space is [1,m]; each The expression for the fish position is: In the formula, For the i-th The initial position of the fish, D i is a random number between [0,1], i∈[1,Z].

[0131] In the above step 3, the expression of the fitness function is: In the formula, f is the fitness, U is the voltage difference; the method for obtaining the voltage difference is: The fish position corresponds to the voltage set corresponding to the voltage label. The voltage set and the analysis data are used as test data. The test data is input into the trained difference analysis model to predict the corresponding voltage difference. The training process of the difference analysis model is consistent with the training process of the stability analysis model, and both are deep neural network models.

[0132] It should be noted that the voltage difference of the test data is obtained by technical personnel in this field during the historical dielectric loss measurement process. D groups of test data are collected, where d is an integer greater than 1. Under the conditions of each group of test data, the rectifier transformer affected by the voltage interference parameters in the test data is adjusted using the voltage set in the corresponding test data, and the output voltage of the rectifier transformer after adjustment is collected and marked as the adjusted voltage; the optimal voltage in the corresponding test data is subtracted from each adjusted voltage to obtain the voltage difference corresponding to each test data.

[0133] In step 4 above, the hosts include sailfish and whales; obtain each The random number D corresponding to the fish i And round up, if the rounded random number is 0, then The host of the fish parasite is a whale. If the rounded random number is 1, then The host of the fish parasite is the swordfish; Fish parasitize hosts to effectively guide their search direction.

[0134] In step 5 above, calculate each The fitness corresponding to the position of the fish, the fitness with the largest value Fish positions are marked

[0135] If the host is a whale, then after the update The calculation method of fish position includes:

[0136]

[0137] In the formula, is the updated article i The location of the fish, For the i-th article before the update The position of the fish, α is the search range adjustment coefficient, and C′ is a random number between [0,1].

[0138] If the host is a swordfish, then after the update The calculation method of fish position includes:

[0139]

[0140] In the formula, A random one before the update Fish location.

[0141] In step 6 above, When a fish parasitizes a host, it will The final position of the fish The fish makes a tentative move at its current position; calculates The position of the fish after the tentative move, and calculate the corresponding fitness, marked as the tentative fitness; The fitness corresponding to the current position of the fish is marked as the current fitness; the trial fitness is compared with the current fitness; if the trial fitness is greater than or equal to the current fitness, the host is not switched; if the trial fitness is less than the current fitness, the host is switched.

[0142] It should be noted that the purpose of switching hosts is to test the fitness to be less than the current fitness. After the fish moves in a small range around the host, the fitness of the new position is low, that is, the current host position may be close to the local optimum, and continuing to explore around the host may not bring significant improvements. Therefore, by switching hosts, Fish can jump out of the current local area and explore a wider solution space, increasing the chance of finding the global optimal solution. It can also avoid all individuals gathering in the same area, increasing the diversity of the population, and making the algorithm more adaptable and robust.

[0143] In step 7 above, the host is switched The method for updating the fish position again is the same as that for updating each The method of fish positioning is consistent.

[0144] In step 8 above, The methods for updating the fish's position when it enters the foraging phase include:

[0145]

[0146] B i =2V i C″-V i ;

[0147]

[0148] In the formula, For the i-th The updated position of the fish after the foraging phase, For the i-th The updated position of the fish after switching hosts, A i For the i-th The distance fish travel during the foraging phase, B i For the i-th The volume of the host the fish is parasitizing, for Fish factor, used to limit The location of the fish, V i For the i-th The volume of the fish, C″ is a random number between [0,1].

[0149] It should be noted that the use of The reason why the fish optimization algorithm formulates the voltage regulation strategy is that The fish optimization algorithm is highly flexible and adaptable. It can define the fitness function according to the specific voltage regulation requirements and flexibly deal with different voltage regulation problems. It also has excellent global search capabilities. The fish parasitic host constantly updates its position and is able to explore in a wide search space, increasing the probability of finding the global optimal solution. At the same time, mechanisms such as host switching and foraging are also adopted to effectively overcome the problem of local optimality and accelerate the convergence of the algorithm. In addition, it has low requirements for computing resources, the results are highly interpretable, and it has a wide range of applications.

[0150] S5: According to the voltage control strategy, the voltage control signal is calculated by combining the PID controller and the fuzzy controller, and the rectifier transformer adjusts the voltage feedback data according to the voltage control signal.

[0151] The voltage control signal includes a rectifier trigger angle control signal, a transformer tap position control signal and an excitation current control signal.

[0152] like Figure 2 As shown, the calculation method of the rectifier trigger angle control signal includes:

[0153] The rectifier trigger angle is collected. The rectifier trigger angle is obtained by a dedicated IC chip integrated in the rectifier transformer in the measuring device. The chip integrates functions such as voltage detection and current detection, and can directly output the rectifier trigger angle; the rectifier trigger angle in the voltage set is subtracted from the collected rectifier trigger angle to obtain the angle error.

[0154] The angle error is taken as the input of the fuzzy controller and the PID parameter control signal is taken as the output.

[0155] Fuzzy control rules are designed according to the relationship between the change of PID parameters and the angle error. PID parameters include proportional gain, integral gain and differential gain. The fuzzy control rules are expressed in IF-THEN form, for example: IF the angle error increases THEN the PID parameter increases; the relationship between the change of PID parameters and the angle error is obtained by technical personnel in this field through actual experiments.

[0156] The angle error is converted into a fuzzy set through fuzzification technology; fuzzification is the process of converting precise numerical values ​​into fuzzy sets, and fuzzification technologies include triangular membership function, trapezoidal membership function, etc.; fuzzy sets are mathematical tools used to represent fuzzy concepts and can be described by membership functions.

[0157] According to the fuzzified angle error and the fuzzy control rules, the fuzzy output is obtained.

[0158] Use defuzzification technology to convert fuzzy output into PID parameter control signal; defuzzification is the process of converting fuzzy output into precise numerical value. Defuzzification techniques include centroid method, median method, maximum membership method, etc.

[0159] The PID controller calculates the rectifier trigger angle control signal and adjusts the PID parameters according to the PID parameter control signal;

[0160]

[0161] Where ZL(t′) is the rectifier trigger angle control signal, WC(t′) is the angle error, BL is the proportional gain, JF is the integral gain, WF is the differential gain, and t′ is the current moment.

[0162] The method for obtaining the current time t′ includes: installing a time sensor inside the measuring device, when the measuring device starts working, the time sensor also starts to collect time, when the PID controller calculates the rectifier trigger angle control signal, the current time t′ is obtained from the time sensor, when the measuring device stops working, the time sensor also stops collecting time.

[0163] The calculation method of the transformer tap position control signal and the excitation current control signal is consistent with the rectifier trigger angle control signal.

[0164] It should be noted that by combining the PID controller and the fuzzy controller to calculate the voltage control signal, the PID control can quickly and accurately eliminate the voltage deviation and keep the output voltage near the target value, while the fuzzy control can adapt to nonlinear parameter changes and further improve the control accuracy; thereby improving the stability and accuracy of the rectifier transformer output voltage, enhancing the anti-interference ability, and optimizing the response characteristics.

[0165] This embodiment monitors voltage interference parameters in real time and establishes a deep learning model to evaluate the voltage fluctuation degree, thereby achieving real-time judgment and monitoring of the output voltage of the rectifier transformer. The fish optimization algorithm takes into account the influence of multiple voltage variables, dynamically formulates voltage control strategies, and combines PID controllers and fuzzy controllers to accurately implement voltage regulation. It can effectively suppress the influence of external interference factors on the measurement accuracy of ultra-low frequency dielectric loss, and achieve fine control and stabilization of the output voltage of the rectifier transformer to meet the accuracy requirements of ultra-low frequency dielectric loss testing, ensure the reliability of test results, and thus improve the performance and measurement quality of the dielectric loss measurement device.

[0166] Example 2

[0167] See also Figure 3 As shown, this embodiment further improves the design based on the embodiment 1. When formulating the voltage control strategy, the voltage set selected is the one with the largest fitness. The voltage set corresponding to the fish position; however, in actual situations, simply selecting the voltage set with the largest fitness may not be the best choice; the reason is that, although the fitness of the multiple voltage sets arranged at the back is lower, the adjustment amount of the voltage feedback data is smaller, and the voltage difference still meets the requirements, so it can also be used as an optional set; that is, when formulating the control strategy, it is necessary not only to consider the voltage set with the largest fitness, but also to evaluate the suboptimal solution and select the voltage set with a smaller adjustment amount and a voltage difference within the requirements; under the premise of ensuring the measurement accuracy, the adjustment amplitude is reduced as much as possible, the interference to the entire dielectric loss measurement device is reduced, and the robustness of the control strategy is improved; therefore, this embodiment provides a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device, which also includes:

[0168] S6: Get Z entries in the population The voltage difference of the voltage set corresponding to the position of the fish is obtained, n excellent sets are screened out according to the voltage difference, the adjustment coefficient of each excellent set is calculated, and the best set is screened out from the n excellent sets, where n is an integer greater than or equal to 1.

[0169] The excellent set is a voltage set whose absolute value of voltage difference is less than or equal to the fluctuation degree threshold;

[0170] If n is 1, the best set is the superior set;

[0171] If n is greater than 1, the corresponding data in the voltage feedback data collected in real time is subtracted from the data in each excellent set to obtain the adjustment amount corresponding to each excellent set, and the adjustment amount includes the rectifier trigger angle adjustment amount, the transformer tap position adjustment amount and the excitation current adjustment amount;

[0172] The adjustment amount corresponding to each excellent set is weightedly summed to calculate the adjustment coefficient corresponding to each excellent set; the adjustment coefficients corresponding to each excellent set are sorted from small to large, and the excellent set corresponding to the adjustment coefficient ranked first is taken as the best set.

[0173] It should be noted that the sum of the weight coefficients corresponding to each data in the adjustment amount is 1; the weight coefficient corresponding to each data in the adjustment amount is set according to the actual situation, and the weight coefficient reflects the adjustment rate of each data in the voltage feedback data. Technical personnel in this field can preset the corresponding weight coefficient for each data in the adjustment amount according to the actual adjustment rate of each data in the voltage feedback data to accurately evaluate the adjustment coefficient of each excellent set; the adjustment rate is the completion time of the adjustment of each data in the voltage feedback data when the adjustment amount is the same.

[0174] This embodiment screens multiple voltage sets, and uses the difference in regulation rate of each data in the voltage feedback data to set the weight coefficient of each data in the regulation amount, so as to more accurately calculate the regulation coefficient and select the voltage set with the smallest regulation coefficient and voltage difference that meets the requirements; that is, when formulating the voltage control strategy, not only the voltage set with the greatest fitness is considered, but also the suboptimal solution. While ensuring the measurement accuracy, the regulation amplitude and regulation time of the rectifier transformer are reduced as much as possible, the interference effect on the entire dielectric loss measurement device is reduced, and the robustness of the control strategy and the stability of voltage control are improved.

[0175] Example 3

[0176] See also Figure 4As shown, the present application also provides an electronic device 500. The electronic device 500 may include one or more processors and one or more memories. The memories store computer readable codes, and when the computer readable codes are run by one or more processors, the controllable rectifier transformer control method for the ultra-low frequency dielectric loss measurement device as described above may be executed.

[0177] The method or system according to the embodiment of the present application can also be used by Figure 4 The electronic device architecture shown in FIG. Figure 4 As shown, the electronic device 500 may include a bus 501, one or more CPUs 502, ROM 503, RAM 504, a communication port 505 connected to a network, an input / output 506, a hard disk 507, etc. The storage device in the electronic device 500, such as ROM 503 or hard disk 507, may store the controllable rectifier transformer control method for the ultra-low frequency dielectric loss measurement device provided by the present application. Furthermore, the electronic device 500 may also include a user interface 508. Of course, Figure 4 The architecture shown is only exemplary and can be omitted according to actual needs when implementing different devices. Figure 4 One or more components of an electronic device are shown.

[0178] Example 4

[0179] See also Figure 5 As shown, one embodiment of the present application discloses a computer-readable storage medium 600. Computer-readable instructions are stored on the computer-readable storage medium 600. When the computer-readable instructions are executed by the processor, the controllable rectifier transformer control method for the ultra-low frequency dielectric loss measurement device according to the embodiment of the present application described with reference to the above figures can be executed. The storage medium 600 includes, but is not limited to, for example, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and cache memory (cache), etc. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0180] In addition, according to the implementation of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the present application provides a non-transitory machine-readable storage medium, which stores machine-readable instructions, and the machine-readable instructions can be executed by a processor to execute instructions corresponding to the method steps provided by the present application, for example: a controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device. When the computer program is executed by a central processing unit (CPU), the above functions defined in the method of the present application are executed.

[0181] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0182] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A controllable rectifier transformer control method for an ultra-low frequency dielectric loss measurement device, characterized in that: include: S1: Real-time acquisition of voltage interference parameters during dielectric loss measurement; S2: extracting features of the collected voltage interference parameters and extracting change characteristic data; The change characteristic data includes a change rate and a change amplitude; the change rate is the change rate of each parameter in the voltage interference parameter, and the change amplitude is the change amplitude of each parameter in the voltage interference parameter; Methods for obtaining the change rate include: Subtract the corresponding parameter in the voltage interference parameter collected last time from each parameter in the real-time collected voltage interference parameter to obtain the change amount of each parameter in the voltage interference parameter; divide the change amount of each parameter in the voltage interference parameter by the sampling frequency to obtain the change rate of each parameter in the voltage interference parameter; Methods for obtaining the change range include: When the measuring device performs dielectric loss measurement on the measured sample, the voltage interference parameter collected for the first time is marked as the first parameter; each parameter in the voltage interference parameter collected in real time is respectively subtracted from the corresponding parameter in the first parameter to obtain the variation amplitude of each parameter in the voltage interference parameter; S3: Calculate the voltage fluctuation degree according to the change characteristic data, and determine whether to generate an adjustment instruction; S4: If an adjustment instruction is generated, use The fish optimization algorithm formulates the voltage regulation strategy; S5: According to the voltage control strategy, the voltage control signal is calculated by combining the PID controller and the fuzzy controller, and the rectifier transformer adjusts the voltage feedback data according to the voltage control signal.

2. The controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device according to claim 1, characterized in that: The voltage interference parameters include electromagnetic field strength, grid voltage, ambient temperature and load impedance; The method for obtaining the load impedance is: obtaining the sample voltage and the sample current, and obtaining the load impedance through the ratio of the sample voltage to the sample current.

3. The controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device according to claim 2, characterized in that: The method for calculating the voltage fluctuation degree comprises: Obtain the optimal voltage, which is the output voltage of the rectifier transformer when the dielectric loss measurement of the sample under test begins; The change characteristic data and the optimal voltage are used as analysis data, and the analysis data are input into the trained stability analysis model to predict the corresponding voltage fluctuation degree; The training process of the stability analysis model includes: Collect a group of analysis data in advance, set corresponding voltage fluctuation degrees for the group of analysis data, a is an integer greater than 1, and convert the analysis data and the corresponding voltage fluctuation degrees into a corresponding set of feature vectors; Each group of feature vectors is used as input of a stability analysis model. The stability analysis model uses a group of predicted voltage fluctuation degrees corresponding to each group of analysis data as output, and uses the actual voltage fluctuation degree corresponding to each group of analysis data as a prediction target, where the actual voltage fluctuation degree is the pre-collected voltage fluctuation degree corresponding to the analysis data; minimizing the sum of prediction errors of all analysis data is used as a training target; the stability analysis model is trained until the sum of prediction errors reaches convergence and the training is stopped; the stability analysis model is a deep neural network model; The method for determining whether to generate an adjustment instruction includes: A fluctuation degree threshold is preset, and the absolute value of the voltage fluctuation degree is compared with the fluctuation degree threshold; If the absolute value of the voltage fluctuation degree is less than or equal to the fluctuation degree threshold, no adjustment instruction is generated; If the absolute value of the voltage fluctuation degree is greater than the fluctuation degree threshold, an adjustment instruction is generated.

4. The controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device according to claim 3, characterized in that: The adoption The steps of the fish optimization algorithm to formulate voltage regulation strategy include: Step 1: Construct m voltage sets, set different labels for different voltage sets, and mark them as voltage labels; preset the population size Z and the number threshold T; Step 2: Initialize the population. The fish's position is defined in a one-dimensional search space, The positions of the fish correspond one-to-one to the voltage labels, and the number of iterations t corresponding to the initialization population is 0; Step 3: Determine the fitness function; Step 4: Select each Fish parasite hosts; Step 5: Update each The location of the fish; Step 6: Calculate each The fitness of the fish's updated position corresponds to the fish's updated position, and determines whether to switch hosts; Step 7: Switch host The fish updates its position again; Step 8: Each The fish enter the foraging stage and update each The location of the fish; Step 9: If the number of iterations t is less than the number threshold T, return to step 4, and the number of iterations t=t+1; if the number of iterations t is greater than or equal to the number threshold T, proceed to step 10; Step 10: Calculate each The fitness corresponding to the position of the fish, sort all the fitness from large to small, and get the fitness corresponding to the first one Fish location, based on the obtained The fish position obtains the voltage set corresponding to the corresponding voltage label.

5. The controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device according to claim 4, characterized in that: In the step 1, a range of voltage feedback data is obtained, the voltage feedback data includes a rectifier trigger angle, a transformer tap position and an excitation current, and the range of the voltage feedback data includes a range of each data in the voltage feedback data; a value is randomly selected from the range of each data in the voltage feedback data, and a voltage set is constructed, and a total of m voltage sets are constructed, where m is an integer greater than 1; In step 2, the population S0 is initialized to {X1, X2, ..., X Z }, including Z bar Fish, X Z For Article Z fish; the voltage label range is [1,m], that is, the range of the one-dimensional search space is [1,m]; each The expression for the fish position is: In the formula, For the i-th The initial position of the fish, D i is a random number between [0,1], i∈[1,Z].

6. The control method for controlling a controllable rectifier transformer for an ultra-low frequency dielectric loss measurement device according to claim 5, characterized in that: In step 3, the expression of the fitness function is: In the formula, f is the fitness, U is the voltage difference; the method for obtaining the voltage difference is: The voltage set corresponding to the voltage label corresponding to the fish position is used as the test data, and the test data is input into the trained difference analysis model to predict the corresponding voltage difference. The training process of the difference analysis model is consistent with the training process of the stability analysis model, and both are deep neural network models. In step 4, the hosts include swordfish and whales; each The random number D corresponding to the fish i And round up, if the rounded random number is 0, then The host of the fish parasite is a whale. If the rounded random number is 1, then The host of the fish parasite is swordfish.

7. The control method for controlling a controllable rectifier transformer for an ultra-low frequency dielectric loss measurement device according to claim 6, characterized in that: In step 5, calculate each The fitness corresponding to the position of the fish, the fitness with the largest value Fish positions are marked If the host is a whale, then after the update The calculation method of fish position includes: In the formula, is the updated article i The location of the fish, For the i-th article before the update The position of the fish, α is the search range adjustment coefficient, and C′ is a random number between [0,1]; If the host is a swordfish, then after the update The calculation method of fish position includes: In the formula, A random one before the update Fish location.

8. The control method for controlling a controllable rectifier transformer for an ultra-low frequency dielectric loss measurement device according to claim 7, characterized in that: In step 6, When the fish is parasitic on the host, according to the previous iteration The final position of the fish The fish makes a tentative move at its current position; calculates The position of the fish after the tentative move, and calculate the corresponding fitness, marked as the tentative fitness; The fitness corresponding to the current position of the fish is marked as the current fitness; the test fitness is compared with the current fitness; if the test fitness is greater than or equal to the current fitness, the host is not switched; if the test fitness is less than the current fitness, the host is switched; In step 7, the host is switched The method for updating the fish position again is the same as that for updating each The method of fish location is consistent; In step 8, The methods used to update the fish's position when it enters the foraging phase include: B i =2V i C″-V i ; In the formula, For the i-th The updated position of the fish after the foraging phase, For the i-th The updated position of the fish after switching hosts, A i For the i-th The distance fish travel during the foraging phase, B i For the i-th The volume of the host the fish is parasitizing, for Fish Factor, V i For the i-th The volume of the fish, C″ is a random number between [0,1].

9. The control method for controlling a controllable rectifier transformer for an ultra-low frequency dielectric loss measurement device according to claim 8, characterized in that: The voltage control signal includes a rectifier trigger angle control signal, a transformer tap position control signal and an excitation current control signal; The calculation method of the rectifier trigger angle control signal includes: Collecting the rectifier trigger angle; subtracting the collected rectifier trigger angle from the rectifier trigger angle in the voltage set to obtain an angle error; The angle error is used as the input of the fuzzy controller and the PID parameter control signal is used as the output; Design fuzzy control rules based on the relationship between the change of PID parameters and the angle error. PID parameters include proportional gain, integral gain and differential gain. Fuzzy control rules are expressed in IF-THEN form. The angle error is converted into a fuzzy set through fuzzification technology; According to the fuzzified angle error and the fuzzy control rule, the fuzzy output is obtained; Use defuzzification technology to convert fuzzy output into PID parameter control signal; The PID controller calculates the rectifier trigger angle control signal and adjusts the PID parameters according to the PID parameter control signal; Where ZL(t′) is the rectifier trigger angle control signal, WC(t′) is the angle error, BL is the proportional gain, JF is the integral gain, WF is the differential gain, and t′ is the current moment; The calculation method of the transformer tap position control signal and the excitation current control signal is consistent with the rectifier trigger angle control signal.

10. The controllable rectifier transformer control method for ultra-low frequency dielectric loss measurement device according to claim 9, characterized in that: Get Z entries in the population The voltage difference of the voltage set corresponding to the position of the fish, n excellent sets are screened out according to the voltage difference, the adjustment coefficient of each excellent set is calculated, and the best set is screened out from the n excellent sets, where n is an integer greater than or equal to 1; The excellent set is a voltage set whose absolute value of the voltage difference is less than or equal to the fluctuation degree threshold; If n is 1, the best set is the superior set; If n is greater than 1, the corresponding data in the voltage feedback data collected in real time is subtracted from the data in each excellent set to obtain the adjustment amount corresponding to each excellent set, and the adjustment amount includes the rectifier trigger angle adjustment amount, the transformer tap position adjustment amount and the excitation current adjustment amount; The adjustment amount corresponding to each excellent set is weightedly summed to calculate the adjustment coefficient corresponding to each excellent set; the adjustment coefficients corresponding to each excellent set are sorted from small to large, and the excellent set corresponding to the adjustment coefficient ranked first is taken as the best set.

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