A method and device for measuring harmonic voltage, electronic equipment and storage medium

Abstract

The application discloses a kind of harmonic voltage measurement method, device, electronic equipment and storage medium.The method comprises: determining the secondary side voltage and primary side current of capacitive voltage transformer;According to the parameter information of the target equivalent element contained in the target equivalent circuit corresponding to the initial equivalent circuit of capacitive voltage transformer, intermediate parameter is determined, and transfer function and transfer function are constructed according to intermediate parameter;According to secondary side voltage, primary side current, transfer function and transfer function, determine target parameter, and determine the harmonic voltage to be measured according to target parameter, secondary side voltage and transfer function.The technical scheme of the present application determines the target parameter by measuring the secondary side voltage and primary side current of capacitive voltage transformer, and then determines the harmonic voltage to be measured by combining the transfer function and the transfer function.The voltage and current can be measured in real time, and the value of the target parameter can be updated in real time, so as to accurately determine the harmonic voltage to be measured.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electrical engineering technology, and in particular to a method, apparatus, electronic device and storage medium for measuring harmonic voltage. Background Technology

[0002] With the increasing number of nonlinear loads, the measurement of harmonic voltage has become an important requirement for the stable operation of the power industry, and the development of the situation has made the accurate measurement of harmonic voltage a focus of attention.

[0003] Currently, there are various methods for measuring harmonic voltage. For example, based on the traditional capacitive voltage transformer (CVT), a capacitive voltage divider is added to the low-voltage end as the measuring element for harmonic measurement to realize the analysis and measurement of harmonic voltage signals. A device is designed that includes harmonic generation, high voltage generation, accurate value output, output of the CVT under test, data processing, and result output. Through experiments on the harmonic transmission characteristics of various specific CVT devices, the harmonic measurement is corrected using the measured harmonic transmission characteristic curve.

[0004] However, the former requires modification of the CVT, and its manufacturing and design costs will no longer have the characteristics of a CVT. In addition, new components are added inside the CVT, making safety difficult to assess and predict. It has a complex structure, high cost, and potential reliability issues. The latter lacks dynamic tracking of the equivalent parameters of the CVT, and the measurement accuracy will drift with changes in the environment and time. Summary of the Invention

[0005] This invention provides a method, apparatus, electronic device, and storage medium for measuring harmonic voltage, so as to realize the measurement of harmonic voltage in the power grid.

[0006] According to one aspect of the present invention, a method for measuring harmonic voltage is provided, the method comprising:

[0007] Determine the secondary voltage and primary current of the capacitive voltage transformer;

[0008] The intermediate parameters are determined based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and the transfer function and transfer function are constructed based on the intermediate parameters.

[0009] The target parameters are determined based on the secondary side voltage, primary side current, transfer function, and transfer function. The harmonic voltage to be measured is then determined based on the target parameters, secondary side voltage, and transfer function.

[0010] Optionally, the method further includes determining a target equivalent circuit based on the initial equivalent circuit of the capacitive voltage transformer, wherein the initial equivalent circuit includes at least one initial calibration element and an initial equivalent element, and the target equivalent circuit includes at least one target equivalent element.

[0011] Optionally, determining the target equivalent circuit based on the initial equivalent circuit of the capacitive voltage transformer includes: determining the parameter information of the target equivalent elements contained in the target equivalent circuit based on the parameter information of the initial equivalent elements contained in the initial equivalent circuit.

[0012] Optionally, intermediate parameters are determined based on the parameter information of the equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and transfer functions and transfer functions are constructed based on the intermediate parameters, including: determining a first intermediate parameter based on the first and sixth parameter information of the target equivalent element; determining a second intermediate parameter based on the third and seventh parameter information of the target equivalent element; determining a third intermediate parameter based on the second and eighth parameter information of the target equivalent element; determining a fourth intermediate parameter based on the tenth parameter information of the target equivalent element; determining a fifth intermediate parameter based on the ninth parameter information of the target equivalent element; determining a sixth intermediate parameter based on the fourth and fifth parameter information of the target equivalent element; and constructing transfer functions and transfer functions based on the first, second, third, fourth, fifth, and sixth intermediate parameters, respectively.

[0013] Optionally, before determining the target parameters based on the secondary voltage, primary current, transfer function, and transfer function, the method may also include: determining the variability probability of the initial calibration element.

[0014] Optionally, the target parameters are determined based on the secondary side voltage, primary side current, transfer function, and transfer function, including: constructing a target equation set based on the transfer function, transfer function, and the secondary side voltage and primary side current obtained multiple times; determining the fitness function of the target equation set, and determining the fitness and fitness gradient corresponding to the fitness function based on the mutation probability; if the fitness is less than or equal to a preset fitness threshold, then the target parameters are determined based on the current fitness function.

[0015] Optionally, if the fitness is greater than a preset fitness threshold, the mutation probability is updated according to the fitness gradient, and the fitness and fitness gradient corresponding to the fitness function based on the mutation probability are returned until the fitness is less than or equal to the preset fitness threshold.

[0016] According to another aspect of the present invention, a harmonic voltage measuring device is provided, the device comprising:

[0017] The acquisition module is used to determine the secondary voltage and primary current of the capacitive voltage transformer;

[0018] The determination module is used to determine intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and to construct the transfer function and the transfer function based on the intermediate parameters;

[0019] The measurement module is used to determine the target parameters based on the secondary side voltage, primary side current, transfer function, and transfer function, and to determine the harmonic voltage to be measured based on the target parameters, secondary side voltage, and transfer function.

[0020] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0021] At least one processor; and

[0022] A memory communicatively connected to the at least one processor; wherein,

[0023] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the harmonic voltage measurement method according to any embodiment of the present invention.

[0024] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the harmonic voltage measurement method according to any embodiment of the present invention.

[0025] The technical solution of this invention determines the secondary voltage and primary current of a capacitive voltage transformer; determines intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer; constructs a transfer function and a transfer function based on the intermediate parameters; determines target parameters based on the secondary voltage, primary current, transfer function, and transfer function; and determines the harmonic voltage to be measured based on the target parameters, secondary voltage, and transfer function. This invention determines the harmonic voltage to be measured by measuring the secondary voltage and primary current of the capacitive voltage transformer, then combining the transfer function and transfer function to determine the target parameters. The voltage and current can be measured in real time, and the value of the target parameters can be updated in real time, thereby accurately determining the harmonic voltage to be measured.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic flowchart of a method for measuring harmonic voltage provided in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of measuring the secondary voltage and primary current of a capacitive voltage transformer according to Embodiment 1 of the present invention;

[0030] Figure 3 This is a schematic diagram of the initial equivalent circuit of a capacitive voltage transformer provided in Embodiment 1 of the present invention;

[0031] Figure 4 This is a schematic diagram of the target equivalent circuit of a capacitive voltage transformer provided in Embodiment 1 of the present invention;

[0032] Figure 5 This is a two-port equivalent schematic diagram of a capacitive voltage transformer provided in Embodiment 1 of the present invention;

[0033] Figure 6(a) is a simulation diagram of the solution of the objective parameters;

[0034] Figure 6(b) is a simulation diagram of the solution of the target parameter provided in Embodiment 1 of the present invention;

[0035] Figure 7 This is a schematic diagram of the structure of a harmonic voltage measuring device provided in Embodiment 2 of the present invention;

[0036] Figure 8 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Example 1

[0040] Figure 1 This is a flowchart illustrating a method for measuring harmonic voltage according to Embodiment 1 of the present invention. This embodiment is applicable to the case of power grid harmonic voltage. The method can be executed by the harmonic voltage measuring device provided in this embodiment. This device can be implemented using software and / or hardware. In a specific embodiment, the device can be integrated into an electronic device. The following embodiments will illustrate this using the integration of the device into an electronic device as an example. (Refer to...) Figure 1 The method specifically includes the following steps:

[0041] S101. Determine the secondary voltage and primary current of the capacitive voltage transformer.

[0042] The secondary voltage and primary current of the capacitive voltage transformer change with the harmonic order of the harmonic voltage being measured. The secondary voltage and primary current of the capacitive voltage transformer can be measured by a voltage detector and a current detector, respectively.

[0043] Specifically, Figure 2 This is a schematic diagram of measuring the secondary voltage and primary current of a capacitive voltage transformer according to Embodiment 1 of the present invention. In the diagram, U1 represents the harmonic voltage to be measured, I1 represents the primary current of the capacitive voltage transformer, and U2 represents the secondary voltage of the capacitive voltage transformer. U2 and I1 can be measured by the voltage detector and current detector shown in the diagram, respectively.

[0044] The advantage of this setup is that it allows for real-time acquisition of the secondary voltage and primary current of the capacitive voltage transformer, enabling the calculation of the measured harmonic voltage using the latest data, thereby improving the accuracy and success rate of harmonic voltage measurement.

[0045] S102. Determine intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and construct the transfer function and transfer function based on the intermediate parameters.

[0046] The initial equivalent circuit can be understood as the equivalent circuit corresponding to the working circuit of the CVT determined by electrical engineering principles; the target equivalent circuit can be understood as a simplified circuit of the initial equivalent circuit; the components included in the target equivalent circuit can be understood as target equivalent components; the intermediate parameters can be understood as the parameters used to solve the transfer function and the transfer function, determined based on the parameter information of the target equivalent components; the transfer function can be understood as the impedance function of the target equivalent circuit; and the transfer function can be understood as a characteristic function of the CVT, which can be used to solve the harmonic voltage to be measured.

[0047] Specifically, the target equivalent circuit of the capacitive voltage transformer is determined based on the initial equivalent circuit. For example, the target equivalent circuit corresponding to the initial equivalent circuit can be determined through methods such as star-delta transformation. The parameters of the target equivalent elements in the target equivalent circuit are determined based on the parameters of the elements in the initial equivalent circuit. The initial equivalent circuit includes at least one initial calibration element and one initial equivalent element, and the target equivalent circuit includes at least one target equivalent element.

[0048] The initial calibration element can be understood as a component whose parameter value can be determined by reading the nameplate data. For example, a component whose parameter value does not change during the process of converting the working circuit of a CVT into an initial equivalent circuit. The initial equivalent element can be understood as a component whose parameter value cannot be directly determined. That is, the parameter value of the initial equivalent element needs to be determined based on the parameter value of the initial calibration element and the relationship between the initial equivalent element and the initial calibration element.

[0049] For example, Figure 3 This is a schematic diagram of the initial equivalent circuit of a capacitive voltage transformer provided in Embodiment 1 of the present invention. Figure 3 In the diagram, U1 represents the harmonic voltage to be measured, and U2 represents the secondary voltage of the CVT. C1 and C2 represent the high-voltage capacitor and the medium-voltage capacitor, respectively. S R represents the inductance of the compensating reactor. S C represents the equivalent resistance of the compensating reactor. C R represents the equivalent stray capacitance of the compensating reactor. m L m R represents the magnetizing resistance and magnetizing inductance of the medium-voltage transformer T, respectively. T1 L T1 R represents the winding resistance and winding leakage inductance on the primary side of a medium-voltage transformer, respectively. T2 L T2 C represents the winding resistance and winding leakage inductance on the secondary side of a medium-voltage transformer, respectively.p1 C represents the stray capacitance of the primary winding to ground. p2 C represents the stray capacitance of the secondary winding to ground. p12 L represents the coupling capacitance between the primary and secondary windings. Z R Z L represents the equivalent inductance and resistance of the damper, respectively. b R b These represent the load inductance and resistance referred to the primary side, respectively.

[0050] C1 and C2 can be understood as initial calibration components. The values ​​of C1 and C2 can be determined based on the CVT nameplate data. The remaining components can be understood as initial equivalent components. The equivalent parameters of the compensation reactor can be calculated based on the values ​​of C1 and C2. Then, the parameters of the initial equivalent components such as the medium-voltage transformer, damper, and load can be calculated based on the CVT voltage level.

[0051] Specifically, C1 and C2 are initial calibration components, and their specific parameters are marked on the CVT nameplate. If, at the rated fundamental frequency, the sum of the reactance of the compensation reactor and the leakage reactance of the medium-voltage transformer is equal to the capacitive reactance of the voltage divider capacitor, the compensation reactor can keep the CVT's fundamental frequency transmission characteristics in a resonant state, ensuring that the voltage applied across the secondary load is the voltage divided by the primary side. From this, the theoretical inductance value L of the intermediate reactor can be calculated. S According to the inductance value L S Furthermore, the manufacturing process of the compensating reactor can be used to further calculate the resistance R of the compensating reactor. s The medium-voltage transformer and damping circuit are set according to conventional and rated operating parameters. The CVT can be set to no-load state when unloaded, and load parameters can be set according to real-time conditions when loaded. Parameters of all initial equivalent components, except for stray capacitance, can be obtained directly or indirectly. Stray capacitance exhibits capacitive characteristics, and its value depends on the dielectric constant of the dielectric, the shape of the equipment, and its relative position. Generally, the stray capacitance value of a CVT of the same model has only a relatively fixed range, and the value of stray capacitance varies with environmental changes.

[0052] Optionally, determining the target equivalent circuit based on the initial equivalent circuit of the capacitive voltage transformer includes: determining the parameter information of the target equivalent elements contained in the target equivalent circuit based on the parameter information of the initial equivalent elements contained in the initial equivalent circuit.

[0053] Specifically, Figure 4 This is a schematic diagram of the target equivalent circuit of a capacitive voltage transformer provided in Embodiment 1 of the present invention. Figure 4 In the diagram, U1 represents the harmonic voltage to be measured, U2 represents the secondary voltage of the CVT secondary side, and Z1, Z2, Z3, Z4, Z5, Z6 are the voltages of the CVT secondary side. a Z band Z c These represent the first, second, third, fourth, fifth, sixth, seventh, and eighth parameter information of the target equivalent element, respectively.

[0054] The process of solving for each parameter is as follows:

[0055]

[0056] Where Z1 represents the first parameter information, Z2 represents the second parameter information, Z3 represents the third parameter information, Z4 represents the fourth parameter information, Z5 represents the fifth parameter information, and Z... a This represents the sixth parameter information, Z. b This represents the seventh parameter information, Z. c This indicates the eighth parameter information. / / Indicates parallel connection, L S R represents the inductance of the compensating reactor. S C represents the equivalent resistance of the compensating reactor. C R represents the equivalent stray capacitance of the compensating reactor. m L m R represents the magnetizing resistance and magnetizing inductance of the medium-voltage transformer T, respectively. T1 L T1 R represents the winding resistance and winding leakage inductance on the primary side of a medium-voltage transformer, respectively. T2 L T2 C represents the winding resistance and winding leakage inductance on the secondary side of a medium-voltage transformer, respectively. p1 C represents the stray capacitance of the primary winding to ground. p2 C represents the stray capacitance of the secondary winding to ground. p12 L represents the coupling capacitance between the primary and secondary windings. Z R Z L represents the equivalent inductance and resistance of the damper, respectively. b R b These represent the load inductance and resistance referred to the primary side, respectively.

[0057] Optionally, intermediate parameters are determined based on the parameter information of the equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and transfer functions and transfer functions are constructed based on the intermediate parameters, including: determining a first intermediate parameter based on the first and sixth parameter information of the target equivalent element; determining a second intermediate parameter based on the third and seventh parameter information of the target equivalent element; determining a third intermediate parameter based on the second and eighth parameter information of the target equivalent element; determining a fourth intermediate parameter based on the tenth parameter information of the target equivalent element; determining a fifth intermediate parameter based on the ninth parameter information of the target equivalent element; determining a sixth intermediate parameter based on the fourth and fifth parameter information of the target equivalent element; and constructing transfer functions and transfer functions based on the first, second, third, fourth, fifth, and sixth intermediate parameters, respectively.

[0058] Specifically, the solution process for each intermediate parameter, transfer function, and transfer function is as follows:

[0059]

[0060] Where A represents the first intermediate parameter, B represents the second intermediate parameter, C represents the third intermediate parameter, D represents the fourth intermediate parameter, E represents the fifth intermediate parameter, and F represents the sixth intermediate parameter. / / Indicates parallel connection, Z1, Z2, Z3, Z4, Z5, Z a Z b and Z c These represent the first, second, third, fourth, fifth, sixth, seventh, and eighth parameter information, respectively. 1 / jωC2 represents the ninth parameter information, and 1 / jωC1 represents the tenth parameter information.

[0061] The ninth and tenth parameters are determined by the initial calibration elements in the initial equivalent circuit, i.e. Figure 4 The parameters of the target equivalent element represented by 1 / jωC2 in the figure are... Figure 3 The parameters of the initial calibration element C2 are consistent with those of the target equivalent element represented by 1 / jωC1. Figure 3 The parameters of the initial calibration element C1 are consistent.

[0062] The process of solving for the transfer function and the transition function is as follows:

[0063]

[0064] The product of the transfer function and the transfer function Where Z(jω) represents the transfer function, H(jω) represents the transfer function, and A, B, C, D, E and F represent the first intermediate parameter, the second intermediate parameter, the third intermediate parameter, the fourth intermediate parameter, the fifth intermediate parameter and the sixth intermediate parameter, respectively.

[0065] S103. Determine the target parameters based on the secondary side voltage, primary side current, transfer function, and transfer function, and determine the harmonic voltage to be measured based on the target parameters, secondary side voltage, and transfer function.

[0066] The target parameter can be understood as the parameter to be determined.

[0067] Specifically, capacitor parameters are easily affected by environmental factors; therefore, parameters involving capacitance in the transfer function and transfer function are set as target parameters. As frequency increases, the permeability of the core components decreases, leading to a reduction in the excitation characteristics of the components; therefore, parameters involving inductance in the transfer function and transfer function are also set as target parameters. To ensure CVT accuracy, the impedance of the CVT damping device is close to infinite during normal operation, and the load is usually unloaded, so its impact on the CVT circuit can be ignored.

[0068] In summary, the target parameters are C2 and L. s C c C p1 C p12 and L m .

[0069] Specifically, the harmonic voltage to be measured has a corresponding relationship with the target parameters, the secondary side voltage, and the transfer function. Once the target parameters are determined, the harmonic voltage to be measured can be determined by combining the secondary side voltage and the transfer function.

[0070] Figure 5 This is a two-port equivalent schematic diagram of a capacitive voltage transformer provided in Embodiment 1 of the present invention. Since the input impedance of voltage measuring instruments is usually approximately infinite, the secondary side of the capacitive voltage transformer can be approximated as an open circuit. According to the circuit principle:

[0071]

[0072]

[0073] Where U1 represents the harmonic voltage to be measured, I1 represents the primary current of the capacitive voltage transformer, U2 represents the secondary voltage of the capacitive voltage transformer, and Z... 11 Z represents the open-circuit input impedance. 21 H represents the open-circuit transfer impedance. 11 H 12 H 21 H 22These represent the first, second, third, and fourth transfer parameters, respectively. Since the CVT is a linear system, H... 21 =-H 12 Therefore, Where, ΔH=H 11 H 22 -H 12 H 21 .

[0074] According to circuit principles, Based on this, combine and It can be seen that, Therefore, the transfer impedance of the CVT primary and secondary sides is

[0075] Optionally, before determining the target parameters based on the secondary voltage, primary current, transfer function, and transfer function, the method may also include: determining the variability probability of the initial calibration element.

[0076] Specifically, when using the heritage algorithm to solve for the target parameters, it is necessary to set the mutation probability of the initial calibration element. The mutation probability of the initial calibration element is generally 0.1 times the mutation probability of the stray capacitance. During the solution process, the mutation probability of the initial calibration element can be dynamically adjusted according to the solution requirements, thereby accelerating the solution process and improving computational efficiency.

[0077] Optionally, the target parameters are determined based on the secondary side voltage, primary side current, transfer function, and transfer function, including: constructing a target equation set based on the transfer function, transfer function, and the secondary side voltage and primary side current obtained multiple times; determining the fitness function of the target equation set, and determining the fitness and fitness gradient corresponding to the fitness function based on the mutation probability; if the fitness is less than or equal to a preset fitness threshold, then the target parameters are determined based on the current fitness function.

[0078] The objective equation, which includes the target parameters, can be determined based on the transfer function, the secondary voltage, and the primary current. The objective equation is: Where X1 represents C2, and X2 represents L s X3 represents C c X4 represents C p1 X5 represents C p12 X6 represents L m .pass Figure 2The measuring device shown can detect the secondary voltage and primary current in real time. It performs spectral analysis on I1 and U2 respectively to obtain the amplitude and phase of the harmonic current I1(jw) and harmonic voltage U2(jw). Substituting these values ​​into the objective equation yields the objective equation set for the objective parameters x1, x2, x3, x4, x5, and x6. The objective equation set is as follows:

[0079]

[0080] The objective parameters are solved based on a genetic algorithm, which is a type of randomized search algorithm that draws on the mechanisms of natural selection and natural inheritance in the biological world. In the solution process, a population of fixed size is set up, and each individual in the population represents a possible solution to the problem. The degree to which an individual adapts to the environment is judged by a fitness function. Individuals with poor fitness are eliminated, while individuals with good fitness continue to reproduce. In the process of reproduction, selection, crossover, and mutation may be carried out to form a new population. This process is repeated until more and better solutions are obtained.

[0081] Fitness function of the objective equation system Where X = {x1, x2, ..., x6}. A smaller G value indicates a higher fitness for the individual. The fitness and fitness gradient corresponding to the fitness function are determined based on the mutation probability. If the fitness is less than or equal to a preset fitness threshold, it proves that the fitness of the target parameter in the fitness function is high, and the solution can be considered complete. The parameter to be solved for the current fitness function is directly determined as the target parameter. If the fitness is greater than the preset fitness threshold, it is determined that the current fitness function needs further training. The relationship between the fitness gradient corresponding to the fitness function and the preset fitness gradient is judged. When the fitness gradient is greater than or equal to the preset fitness gradient, the mutation probability of the initial calibration element is reduced; when the fitness gradient is less than the preset fitness gradient, the mutation probability of the initial calibration element is increased. The mutation probability is updated according to the fitness gradient, and the process returns to determine the fitness and fitness gradient corresponding to the fitness function based on the mutation probability.

[0082] The permeability of the iron core decreases with increasing frequency, reducing the core's excitation characteristics and increasing leakage inductance. Therefore, the equivalent inductance parameters of a CVT differ at different frequencies, with greater frequency differences resulting in greater parameter variations. To improve accuracy and convergence speed, this invention categorizes the target parameters into two types: frequency-affected inductance parameters (x2 and x6) and frequency-independent capacitance parameters (x1, x3, x4, and x5). Currently, the iron core material is typically cold-rolled silicon steel sheets, whose permeability remains relatively constant below 400Hz, gradually decreasing with increasing frequency. Therefore, this application first determines the capacitance parameters of the CVT at low frequencies, while at high frequencies, the capacitance parameters are treated as constants, and the inductance parameters x2 and x6 are calculated for each frequency band.

[0083] The mutation stage in a genetic algorithm is to give the algorithm global search capabilities. The gene mutation probability p... m The settings directly affect the algorithm's running efficiency and accuracy. m If the value is too small, the algorithm's global search capability is weak, making it prone to getting trapped in local optima. Conversely, a large value will reduce the algorithm's efficiency and may even prevent convergence. The capacitance parameter is the most environmentally sensitive parameter in the CVT equivalent parameters. The initial calibration components are designed with the effect of temperature changes on the capacitance value in mind, and their structure typically uses a film-paper combination. Because the polypropylene film has a negative capacitance temperature coefficient, while the capacitor paper has a positive one, their temperature characteristics cancel each other out during temperature changes, resulting in a smaller overall capacitance temperature coefficient. For example, in a two-film, three-paper structure, the temperature coefficient of the main capacitor is -7*10⁻⁷. -5 / K, which is basically negligible. Stray capacitance is affected by the shape, size, relative position of the conductor system, and the dielectric between the conductors. Environmental factors affect it in two ways: firstly, the dielectric constant of the insulating oil varies due to temperature and degradation; secondly, the physical properties of the CVT change under temperature, leading to variations in stray capacitance parameters. Therefore, stray capacitance parameters are more significantly affected by the environment than those of other components.

[0084] To ensure both algorithm accuracy and convergence speed, this application employs a dynamic adjustment strategy for gene mutation probabilities. Based on actual conditions, the mutation probability of the initial CVT calibration element is set much lower than that of the stray capacitance parameter. Then, the mutation probability is adjusted by evaluating the overall fitness of the population. For example, when the population fitness gradient is small, the mutation probability of the initial calibration element is gradually increased; otherwise, the mutation rate of the initial calibration element is maintained at 0.1 times the stray capacitance mutation probability.

[0085] Real-time measurement has the advantage of uninterrupted measurement. During normal operation, the environmental influence on the CVT equivalent parameters is slow, meaning that when the calculation interval is small, the final solution will not change significantly. Therefore, using the previous calculation result as the initial value for the current calculation is beneficial to improving the algorithm's calculation speed.

[0086] Figure 6(a) is a simulation diagram of solving the target parameters, and Figure 6(b) is a simulation diagram of solving the target parameters according to Embodiment 1 of the present invention. Specifically, Figure 6(a) shows the target parameters solved using a traditional genetic algorithm. Comparing the two simulation results, it can be seen that the method used in this embodiment of the present invention requires no more than 110 iterations to solve the target parameters, while the traditional genetic algorithm requires far more than 200 iterations. Furthermore, the optimal fitness of the population is 1.59 when using the traditional genetic algorithm to solve the target parameters, while the optimal fitness of the population is 5.8 * 10⁻⁹ when using the method of this application. The method provided in this embodiment of the present invention effectively improves the solution speed and computation speed.

[0087] The technical solution of this embodiment determines the secondary voltage and primary current of a capacitive voltage transformer; determines intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer; constructs a transfer function and a transfer function based on the intermediate parameters; determines target parameters based on the secondary voltage, primary current, transfer function, and transfer function; and determines the harmonic voltage to be measured based on the target parameters, secondary voltage, and transfer function. The technical solution of this invention determines the harmonic voltage to be measured by measuring the secondary voltage and primary current of a capacitive voltage transformer, then combining the transfer function and transfer function to determine the target parameters. Voltage and current can be measured in real time, and the value of the target parameters can be updated in real time, thereby accurately determining the harmonic voltage to be measured.

[0088] Example 2

[0089] The harmonic voltage measuring device provided in Embodiment 2 of the present invention can execute the harmonic voltage measuring method provided in any of the embodiments above, and has the corresponding functional modules and beneficial effects of the method.

[0090] Figure 7 This is a schematic diagram of the structure of a harmonic voltage measuring device provided in Embodiment 3 of the present invention, as shown below. Figure 7 As shown, it includes: an acquisition module 701, a determination module 702, and a measurement module 703.

[0091] The acquisition module 701 is used to determine the secondary voltage and primary current of the capacitive voltage transformer.

[0092] The determination module 702 is used to determine intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and to construct the transfer function and the transfer function based on the intermediate parameters.

[0093] The measurement module 703 is used to determine the target parameters based on the secondary side voltage, primary side current, transfer function and transfer function, and to determine the harmonic voltage to be measured based on the target parameters, secondary side voltage and transfer function.

[0094] The harmonic voltage measuring device provided in this embodiment is to implement the harmonic voltage measuring method in the above embodiment. The implementation principle and technical effect of the harmonic voltage measuring device provided in this embodiment are similar to those in the above embodiment, and will not be repeated here.

[0095] Optionally, the determining module 702 is further configured to determine a target equivalent circuit based on the initial equivalent circuit of the capacitive voltage transformer, wherein the initial equivalent circuit includes at least one initial calibration element and an initial equivalent element, and the target equivalent circuit includes at least one target equivalent element.

[0096] Optionally, the determining module 702 is specifically used to determine the parameter information of the target equivalent element contained in the target equivalent circuit based on the parameter information of the initial equivalent element contained in the initial equivalent circuit.

[0097] Optionally, the determining module 702 is specifically used to determine the first intermediate parameter based on the first and sixth parameter information of the target equivalent element; determine the second intermediate parameter based on the third and seventh parameter information of the target equivalent element; determine the third intermediate parameter based on the second and eighth parameter information of the target equivalent element; determine the fourth intermediate parameter based on the tenth parameter information of the target equivalent element; determine the fifth intermediate parameter based on the ninth parameter information of the target equivalent element; determine the sixth intermediate parameter based on the fourth and fifth parameter information of the target equivalent element; and construct the transfer function and the transfer function based on the first, second, third, fourth, fifth, and sixth intermediate parameters, respectively.

[0098] Optionally, the determination module 702 is also used to determine the mutation probability of the initial calibration element.

[0099] Optionally, the measurement module 703 is specifically used to construct a target equation set based on the transfer function, the transfer function, and the secondary side voltage and primary side current obtained multiple times; determine the fitness function of the target equation set, and determine the fitness and fitness gradient corresponding to the fitness function based on the mutation probability; if the fitness is less than or equal to the preset fitness threshold, then determine the target parameters based on the current fitness function.

[0100] Optionally, the measurement module 703 is further configured to update the mutation probability according to the fitness gradient if the fitness is greater than a preset fitness threshold, and return to execute the fitness and fitness gradient corresponding to the fitness function based on the mutation probability until the fitness is less than or equal to the preset fitness threshold.

[0101] Example 3

[0102] Figure 8 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0103] like Figure 8 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0104] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0105] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as methods for measuring harmonic voltages.

[0106] In some embodiments, the harmonic voltage measurement method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the harmonic voltage measurement method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured for the harmonic voltage measurement method by any other suitable means (e.g., by means of firmware).

[0107] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0108] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0109] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0110] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0111] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0112] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0113] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0114] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for measuring harmonic voltage, characterized in that, include: Determine the secondary voltage and primary current of the capacitive voltage transformer; The intermediate parameters are determined based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and the transfer function and transfer function are constructed based on the intermediate parameters. A genetic algorithm based on dynamic mutation probability strategy and frequency band parameter processing determines target parameters according to the secondary side voltage, the primary side current, the transfer function and the transfer function, and determines the harmonic voltage to be measured according to the target parameters, the secondary side voltage and the transfer function. The genetic algorithm based on the dynamic mutation probability strategy includes: setting the mutation probability of the initial calibration element to be lower than the mutation probability of the stray capacitance parameter, and dynamically adjusting the mutation probability of the initial calibration element according to the population fitness gradient. The frequency band parameter processing includes: determining the capacitance parameters of the capacitive voltage transformer at low frequencies, treating the capacitance parameters as constants at high frequencies, and obtaining the inductance parameters by frequency band.

2. The method according to claim 1, characterized in that, Also includes: The target equivalent circuit is determined based on the initial equivalent circuit of the capacitive voltage transformer. The initial equivalent circuit includes at least one initial calibration element and one initial equivalent element. The target equivalent circuit includes at least one target equivalent element.

3. The method according to claim 2, characterized in that, Determining the target equivalent circuit based on the initial equivalent circuit of the capacitive voltage transformer includes: Based on the parameter information of the initial equivalent elements contained in the initial equivalent circuit, the parameter information of the target equivalent elements contained in the target equivalent circuit is determined.

4. The method according to claim 3, characterized in that, The step of determining intermediate parameters based on the parameter information of the equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and constructing a transfer function and a transfer function based on the intermediate parameters, includes: The first intermediate parameter is determined based on the first parameter information and the sixth parameter information of the target equivalent element; The second intermediate parameter is determined based on the third and seventh parameter information of the target equivalent element; The third intermediate parameter is determined based on the second parameter information and the eighth parameter information of the target equivalent element; Based on the tenth parameter information of the target equivalent element, determine the fourth intermediate parameter; Based on the ninth parameter information of the target equivalent element, determine the fifth intermediate parameter; Based on the fourth and fifth parameter information of the target equivalent element, the sixth intermediate parameter is determined; The transfer function and the transmission function are constructed based on the first intermediate parameter, the second intermediate parameter, the third intermediate parameter, the fourth intermediate parameter, the fifth intermediate parameter, and the sixth intermediate parameter, respectively.

5. The method according to claim 4, characterized in that, Before determining the target parameter based on the secondary side voltage, the primary side current, the transfer function, and the transfer function, the method further includes: Determine the mutation probability of the initial calibration element.

6. The method according to claim 5, characterized in that, Determining the target parameter based on the secondary voltage, the primary current, the transfer function, and the transfer function includes: Based on the transfer function, the transfer function, and the secondary side voltage and primary side current obtained multiple times, construct the target equation system; Determine the fitness function of the target equation system, and determine the fitness and fitness gradient corresponding to the fitness function based on the mutation probability; If the fitness is less than or equal to a preset fitness threshold, the target parameter is determined based on the current fitness function.

7. The method according to claim 6, characterized in that, Also includes: If the fitness is greater than the preset fitness threshold, the mutation probability is updated according to the fitness gradient, and the process returns to determine the fitness and fitness gradient corresponding to the fitness function based on the mutation probability, until the fitness is less than or equal to the preset fitness threshold.

8. A device for measuring harmonic voltage, controlled by the method for measuring harmonic voltage as described in any one of claims 1-7, characterized in that, include: The acquisition module is used to determine the secondary voltage and primary current of the capacitive voltage transformer; The determination module is used to determine intermediate parameters based on the parameter information of the target equivalent elements contained in the target equivalent circuit corresponding to the initial equivalent circuit of the capacitive voltage transformer, and to construct a transfer function and a transfer function based on the intermediate parameters. The measurement module is used to determine target parameters based on the secondary side voltage, the primary side current, the transfer function, and the transfer function, and to determine the harmonic voltage to be measured based on the target parameters, the secondary side voltage, and the transfer function.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the method for measuring harmonic voltage as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method for measuring harmonic voltage as described in any one of claims 1 to 7.

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