Self-adaptive harmonic isolation method and device based on dynamic regulation and control of magnetic flux of transformer

Abstract

The invention relates to the technical field of power electronics, and discloses a self-adaptive harmonic isolation method and device based on dynamic regulation and control of magnetic flux of a transformer, and the method comprises the steps: calculating the total harmonic distortion rate of a power grid to analyze the harmonic pollution level of the power grid, and calculating the harmonic distortion rate of the power grid according to the harmonic pollution level; generating a target magnetic flux compensation instruction for suppressing the dominant subharmonic corresponding to the power grid; inputting the target magnetic flux compensation instruction into a power converter connected with an auxiliary compensation winding in a preset harmonic isolation transformer to generate compensation harmonic magnetic flux of the target magnetic flux compensation instruction; the compensation harmonic magnetic flux is injected into the transformer iron core, the dominant sub-harmonics are offset, offset net magnetic flux is obtained, and a target magnetic flux compensation instruction and a magnetic flux error of the offset net magnetic flux are calculated; and when the magnetic flux error accords with a preset magnetic flux error threshold value, sine wave back electromotive force is generated in a main winding in the harmonic isolation transformer by utilizing the offset net magnetic flux so as to execute harmonic isolation. The isolation effect of harmonic propagation can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of adaptive harmonic isolation method and device based on transformer magnetic flux dynamic regulation, belong to power electronics field. BACKGROUND

[0002] Adaptive harmonic isolation refers to the real-time monitoring of the harmonic characteristics of the power grid, intelligently generating a compensation magnetic field that accurately matches the harmonic characteristics, and directly canceling the harmonic magnetic flux in the magnetic circuit of magnetic devices such as transformers. Its core function is to build a "harmonic firewall" that actively prevents harmonic current from spreading to the power grid without affecting the normal transmission of fundamental current, thereby fundamentally protecting the power grid from pollution, reducing equipment loss and heating, and providing high-quality pure power for sensitive loads, achieving efficient, intelligent and robust harmonic control.

[0003] Traditional harmonic control technology is represented by active power filters, which inject compensation current equal in size and opposite in direction to harmonic current into the power grid to achieve harmonic suppression. This approach is limited to circuit compensation, and its control relies on external current feedback, with limited response speed and accuracy, resulting in poor harmonic propagation isolation effect. SUMMARY

[0004] The present application provides a kind of adaptive harmonic isolation method and device based on transformer magnetic flux dynamic regulation, which is mainly to improve the isolation effect of harmonic propagation.

[0005] To achieve the above purpose, the present application provides an adaptive harmonic isolation method based on transformer magnetic flux dynamic regulation, comprising: Collecting power grid current signals of the power grid to extract harmonic feature data sets of the power grid; Based on the harmonic feature data set, the total harmonic distortion of the power grid is calculated to analyze the harmonic pollution level of the power grid, and the target magnetic flux compensation instruction for suppressing the corresponding dominant harmonic of the power grid is generated through the harmonic pollution level; The target magnetic flux compensation instruction is input into the power converter connected to the auxiliary compensation winding of the preset harmonic isolation transformer to generate the compensation harmonic magnetic flux of the target magnetic flux compensation instruction; The auxiliary compensation winding is used to inject the compensation harmonic magnetic flux into the transformer core to cancel the dominant harmonic, obtain the net magnetic flux after cancellation, and calculate the magnetic flux error between the target magnetic flux compensation instruction and the net magnetic flux after cancellation; When the magnetic flux error meets the preset magnetic flux error threshold, the sinusoidal back electromotive force is generated in the main winding of the harmonic isolation transformer using the net magnetic flux after cancellation to perform harmonic isolation.

[0006] Optionally, calculating the total harmonic distortion of the power grid based on the harmonic feature dataset includes: Based on the harmonic characteristic dataset, analyze the fundamental amplitude and harmonic amplitude list of the power grid; Calculate the total effective value of harmonics of the power grid based on the fundamental amplitude and harmonic amplitude list; The THD percentage of the power grid is calculated using the fundamental amplitude and the total harmonics effective value. Calculate the effective THD coefficient of the THD percentage. When the effective THD coefficient meets the preset effective threshold, the THD percentage is taken as the total harmonic distortion of the power grid.

[0007] Optionally, the calculation of the THD percentage using the THD effective coefficient includes: Calculate the THD mean and THD standard deviation of the stated THD percentage over a historical window; Based on the mean THD and standard deviation of THD, the THD efficiency coefficient for the percentage of THD is calculated using the following formula:

[0008] in, Indicates the percentage of THD in The effective coefficient of THD at time t. Represents an exponential function. Represents the sensitivity coefficient. Indicates in The percentage of THD at any given time. Indicates in The average THD value corresponding to the historical window at that time. Indicates in The standard deviation of THD corresponding to the historical window at any given time. This represents the smoothing factor.

[0009] Optionally, the extraction of the harmonic feature dataset of the power grid includes: The grid current signal corresponding to the grid is conditioned to obtain a conditioned current signal; The conditioning current signal is converted from analog to digital to obtain a digital current sequence; The current digital sequence is cached to obtain a cached current data window; The cached current data window is subjected to a fast Fourier transform to obtain the current spectrum information; Extract the current harmonic information from the current spectrum information to construct a harmonic feature dataset of the power grid.

[0010] Optionally, the generating the target flux compensation instruction of the target dominant harmonic by the harmonic pollution level comprises: identifying a target dominant harmonic whose harmonic pollution level exceeds a preset harmonic pollution standard in the dominant harmonics; extracting a dominant harmonic amplitude and a dominant harmonic phase of the target dominant harmonic; calculating a target flux amplitude of the target dominant harmonic based on the dominant harmonic amplitude; defining a compensation phase relationship of the target dominant harmonic; analyzing a target flux phase of the target dominant harmonic by the compensation phase relationship; and determining a target flux compensation instruction of the target dominant harmonic in combination with the target flux amplitude and the target flux phase.

[0011] Optionally, the generating the compensation harmonic flux of the target flux compensation instruction comprises: inputting the target flux compensation instruction into a power converter connected with a preset auxiliary compensation winding of a harmonic isolation transformer to output a target voltage parameter of the target flux compensation instruction; defining a sinusoidal reference wave of the target voltage parameter to generate a PWM control signal of the target flux compensation instruction; generating a sinusoidal wave compensation voltage of the PWM control signal by the power converter; applying the sinusoidal wave compensation voltage to the auxiliary compensation winding of the harmonic isolation transformer to generate a compensation harmonic flux of the target flux compensation instruction.

[0012] Optionally, the generating the sinusoidal wave compensation voltage of the PWM control signal by the power converter comprises: generating a reference sinusoidal wave sequence of the PWM control signal; measuring an actual voltage at an output end of the power converter to obtain a feedback voltage sequence of the PWM control signal; calculating an error of the reference sinusoidal wave sequence and the feedback voltage sequence; generating a sinusoidal wave compensation voltage of the PWM control signal based on the error.

[0013] Optionally, the calculating the flux error of the target flux compensation instruction and the net flux after cancellation comprises: analyzing an ideal reference flux of the target flux compensation instruction; identifying a residual harmonic component flux of the net flux after cancellation; Based on the residual harmonic component magnetic flux, the magnetic flux error of the ideal reference magnetic flux and the net magnetic flux after cancellation is calculated by using the following formula:

[0014] wherein, represents the magnetic flux error of the ideal reference magnetic flux and the net magnetic flux after cancellation, represents the magnetic flux amplitude tracking weight coefficient, represents the fundamental component amplitude of the net magnetic flux after cancellation, represents the ideal reference magnetic flux, represents the residual harmonic component magnetic flux, represents the harmonic suppression weight coefficient.

[0015] Optionally, the generating sinusoidal back electromotive force in the main winding of the harmonic isolation transformer by using the net magnetic flux after cancellation comprises: analyzing the steady state of the net magnetic flux after cancellation; when the steady state meets the preset steady state standard, electromagnetically coupling the net magnetic flux after cancellation with the main winding of the harmonic isolation transformer to generate sinusoidal back electromotive force in the main winding.

[0016] In order to solve the above problems, the application further provides an adaptive harmonic isolation device based on transformer magnetic flux dynamic regulation, which comprises: a harmonic feature extraction module, configured to collect power grid current signals of a power grid to extract a harmonic feature data set of the power grid; a compensation instruction generation module, configured to calculate a total harmonic distortion rate of the power grid based on the harmonic feature data set, analyze a harmonic pollution level of the power grid, and generate a target magnetic flux compensation instruction for suppressing a dominant harmonic of the power grid through the harmonic pollution level; a compensation harmonic magnetic flux calculation module, configured to input the target magnetic flux compensation instruction into a power converter connected with a preset auxiliary compensation winding of a harmonic isolation transformer to generate a compensation harmonic magnetic flux of the target magnetic flux compensation instruction; a magnetic flux error calculation module, configured to inject the compensation harmonic magnetic flux into a transformer core through the auxiliary compensation winding to cancel the dominant harmonic and obtain a net magnetic flux after cancellation, and calculate a magnetic flux error of the target magnetic flux compensation instruction and the net magnetic flux after cancellation; a power grid harmonic isolation module, configured to generate sinusoidal back electromotive force in a main winding of the harmonic isolation transformer by using the net magnetic flux after cancellation when the magnetic flux error meets a preset magnetic flux error threshold, so as to perform harmonic isolation.

[0017] Firstly, its core advantage lies in realizing accurate harmonic isolation from the source. The traditional active filter injects a compensation current at the grid side, and through directly injecting a compensation harmonic magnetic flux with equal amplitude and opposite phase in the transformer core, the original harmonic magnetic flux is accurately cancelled out, this magnetic flux to magnetic flux cancellation method can fundamentally block the transmission path of the harmonic magnetic flux, prevent it from being coupled to the secondary side load through electromagnetic induction, and realize the effect of nearly perfect harmonic isolation, providing truly pure electric energy for sensitive equipment. Secondly, the application adopts a closed-loop adaptive control strategy, ensuring high precision and strong robustness of the system. The system can dynamically adapt to the changes of the grid harmonics by calculating the magnetic flux error between the target magnetic flux compensation instruction and the net magnetic flux after cancellation in real time, and taking it as the control core. No matter how the load fluctuates or the harmonic characteristics evolve, the system can automatically adjust the compensation strength until the magnetic flux error is below the preset threshold. This closed-loop feedback mechanism overcomes the problem of insufficient or over-compensation caused by parameter drift or model mismatch in open-loop control, ensuring optimal harmonic suppression performance under various complex working conditions. Thirdly, the application realizes dual optimization of power quality and system efficiency. When the magnetic flux error meets the standard, the magnetic field in the core returns to a pure sinusoidal state, which not only makes the voltage waveform output by the main winding a high-quality sinusoidal wave, greatly reducing the total harmonic distortion rate and protecting downstream equipment, but also eliminates the additional iron loss and eddy current loss caused by harmonic magnetic flux in the core, significantly improving the operating efficiency of the transformer, reducing the temperature rise, and prolonging the service life of the equipment. Therefore, the application can improve the temperature control precision of industrial integrated circuit manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The flowchart of the adaptive harmonic isolation method based on transformer magnetic flux dynamic regulation provided by an embodiment of the application is shown. Figure 2 The module diagram of the adaptive harmonic isolation method based on transformer magnetic flux dynamic regulation provided by an embodiment of the application is shown.

[0019] The purpose of the application, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the application and do not limit the application.

[0021] This application provides an adaptive harmonic isolation method based on dynamic transformer flux control. The executing entity of this adaptive harmonic isolation method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the adaptive harmonic isolation method based on dynamic transformer flux control can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0022] Reference Figure 1 The diagram shown is a flowchart illustrating an adaptive harmonic isolation method based on dynamic transformer flux control according to an embodiment of the present invention. In this embodiment, the adaptive harmonic isolation method based on dynamic transformer flux control includes: S1. Collect the power grid current signal to extract the harmonic characteristic dataset of the power grid.

[0023] It should be explained that the grid current signal refers to the total current flowing through the main winding of the harmonic isolation transformer and from the grid side to the load side, and the load node voltage signal refers to the voltage applied to the load at the output terminal on the load side of the harmonic isolation transformer.

[0024] This invention extracts the harmonic feature dataset of the power grid to provide data support for subsequent harmonic feature analysis.

[0025] Specifically, the extraction of the harmonic feature dataset of the power grid includes: The grid current signal corresponding to the grid is conditioned to obtain a conditioned current signal; The conditioning current signal is converted from analog to digital to obtain a digital current sequence; The current digital sequence is cached to obtain a cached current data window; The cached current data window is subjected to a fast Fourier transform to obtain the current spectrum information; The harmonic information of the current spectrum is extracted to construct the harmonic feature dataset of the power grid.

[0026] The conditioning current signal refers to the grid current signal after being processed by the signal conditioning circuit. The current digital sequence refers to the set of discrete data points obtained after the conditioning current signal is converted from analog to digital. The buffered current data window refers to a fixed-length segment of data extracted from the continuous current digital sequence. The current spectrum information refers to the original result obtained after performing a fast Fourier transform on the buffered current data window. The current harmonic information refers to harmonic parameters with clear physical meaning extracted and calculated from the current spectrum information, such as the amplitude and phase of the fundamental current. The harmonic feature dataset refers to a complete dataset that integrates the current harmonic information to describe the current grid harmonic state.

[0027] Optionally, the conditioning of the grid current signal corresponding to the grid to obtain the conditioned current signal and the conditioned voltage signal can be achieved by an operational amplifier circuit.

[0028] Optionally, the analog-to-digital conversion of the conditioning current signal can be achieved by sampling the two signals using an ADC at a set sampling frequency.

[0029] S2. Based on the harmonic feature dataset, calculate the total harmonic distortion rate of the power grid to analyze the harmonic pollution level of the power grid, and generate a target flux compensation command to suppress the corresponding dominant subharmonic of the power grid based on the harmonic pollution level.

[0030] Based on the aforementioned harmonic feature dataset, this invention calculates the total harmonic distortion of the power grid as the basis for subsequent harmonic pollution analysis.

[0031] Specifically, calculating the total harmonic distortion of the power grid based on the harmonic feature dataset includes: Based on the harmonic characteristic dataset, analyze the fundamental amplitude and harmonic amplitude list of the power grid; Calculate the total effective value of harmonics of the power grid based on the fundamental amplitude and harmonic amplitude list; The THD percentage of the power grid is calculated using the fundamental amplitude and the total harmonics effective value. Calculate the effective THD coefficient of the THD percentage. When the effective THD coefficient meets the preset effective threshold, the THD percentage is taken as the total harmonic distortion of the power grid.

[0032] Wherein, the fundamental amplitude refers to the peak value of the current or voltage waveform with the power frequency in the power grid; the harmonic amplitude list refers to the amplitude of all harmonic components from the second harmonic up to the highest analysis order set by the system; the total harmonic effective value refers to the equivalent effective value after all harmonic components are superimposed; the THD percentage refers to the degree of pollution of harmonics relative to the fundamental frequency; the THD effective coefficient refers to the quality index used to evaluate whether the THD percentage calculation result is reliable; the effective threshold refers to the judgment standard used to decide whether to adopt the THD percentage calculated this time; and the total harmonic distortion refers to the THD percentage that is finally confirmed and adopted by the system after effectiveness verification and used for subsequent control decisions.

[0033] Optionally, the calculation of the total effective value of harmonics of the power grid based on the fundamental amplitude and harmonic amplitude list can be obtained by square root calculation.

[0034] Optionally, the calculation of the THD percentage of the power grid using the fundamental amplitude and the total harmonic effective value is obtained by (total harmonic effective value / fundamental amplitude) × 100%.

[0035] Further, the calculation of the THD percentage using the THD effective coefficient includes: Calculate the THD mean and THD standard deviation of the stated THD percentage over a historical window; The effective coefficient of the THD percentage is calculated based on the mean THD and the standard deviation of THD.

[0036] Furthermore, as another embodiment of the present invention, the THD effectiveness coefficient is calculated using the following formula:

[0037] in, Indicates the percentage of THD in The effective coefficient of THD at time t. Represents an exponential function. Represents the sensitivity coefficient. Indicates in The percentage of THD at any given time. Indicates in The average THD value corresponding to the historical window at that time. Indicates in The standard deviation of THD corresponding to the historical window at any given time. This represents the smoothing factor.

[0038] Wherein, the historical window refers to a fixed-length sliding time window used to store historical THD calculation results, the THD average value refers to the arithmetic mean of all THD percentages within the historical window, the THD standard deviation refers to the sample standard deviation of all THD percentages within the historical window, the sensitivity coefficient refers to a positive real constant used to adjust the sensitivity of the weights to changes in THD, and the smoothing factor refers to a very small positive number to prevent the denominator from being zero.

[0039] This invention analyzes the harmonic pollution level of the power grid, assessing not only the current state of the grid but also integrating the assessment results with the system's automatic control capabilities, thus achieving intelligent and automated management of power grid harmonic pollution. The harmonic pollution level refers to a standardized assessment system used to qualitatively classify and identify the severity of power grid harmonic pollution, including excellent, good, moderate, severe, and extremely severe.

[0040] This invention generates target flux compensation commands to suppress the dominant subharmonics of the power grid based on the harmonic pollution level. It makes strategic decisions based on the pollution level and concentrates efforts to precisely target the dominant subharmonics with the greatest impact, thereby achieving efficient and reliable power quality management.

[0041] Specifically, generating a target flux compensation command to suppress the corresponding dominant subharmonic of the power grid based on the harmonic pollution level includes: Identify the target dominant subharmonics whose harmonic pollution level exceeds a preset harmonic pollution standard; Extract the dominant subharmonic amplitude and dominant subharmonic phase of the target dominant subharmonic; Based on the amplitude of the dominant subharmonic, the target magnetic flux amplitude of the target dominant subharmonic is calculated; Define the compensation phase relationship of the target dominant subharmonic; And by using the compensated phase relationship, the target flux phase of the target dominant subharmonic is analyzed; By combining the target magnetic flux amplitude and the target magnetic flux phase, the target magnetic flux compensation command for the target dominant subharmonic is determined.

[0042] Wherein, the preset harmonic pollution standard refers to the set of maximum permissible limits for each harmonic component pre-set in the system; the target dominant harmonic refers to the specific harmonic among all harmonic components that simultaneously satisfies the conditions of "maximum amplitude" and "exceeds the preset standard"; the dominant harmonic amplitude refers to the peak current of the target dominant harmonic; the dominant harmonic phase refers to the angular offset of the waveform of the target dominant harmonic relative to the fundamental waveform; the target magnetic flux amplitude refers to the intensity of the compensation magnetic flux that the magnetic flux compensation device needs to generate to completely counteract the influence of the target dominant harmonic; the compensation phase relationship refers to the phase difference rule that must be satisfied between the compensation magnetic flux and the original harmonic magnetic flux to achieve harmonic suppression; the target magnetic flux phase refers to the precise phase angle of the magnetic flux that the compensation device actually needs to generate, calculated according to the compensation phase relationship; and the target magnetic flux compensation command refers to the structured digital command used to directly drive the magnetic flux compensation device to perform precise harmonic suppression operations.

[0043] Optionally, the compensation phase relationship of the target dominant subharmonic is defined as a phase difference of 180°.

[0044] S3. Input the target magnetic flux compensation command into a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer to generate the compensation harmonic magnetic flux of the target magnetic flux compensation command.

[0045] This invention inputs the target magnetic flux compensation command into a power converter connected to the auxiliary compensation winding of a preset harmonic isolation transformer, so as to generate the compensation harmonic magnetic flux of the target magnetic flux compensation command to obtain a pure voltage waveform that does not contain the dominant harmonic, thereby achieving high-precision harmonic isolation and control.

[0046] Specifically, the compensation harmonic flux for generating the target flux compensation command includes: The target magnetic flux compensation command is input to a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer to output the target voltage parameter of the target magnetic flux compensation command. Define a sinusoidal reference wave for the target voltage parameter to generate a PWM control signal for the target flux compensation command; The power converter is used to generate a sinusoidal compensation voltage for the PWM control signal; The sinusoidal compensation voltage is applied to the auxiliary compensation winding in the harmonic isolation transformer to generate the compensation harmonic flux of the target flux compensation command.

[0047] The harmonic isolation transformer refers to a specially designed power transformer that integrates harmonic isolation and active compensation functions. The auxiliary compensation winding refers to an independent winding on the core of the harmonic isolation transformer, used to receive compensation power and generate a magnetic field to cancel harmonics. The power converter refers to a power conversion circuit based on power electronic switching devices (such as IGBTs and MOSFETs), which can be a voltage source inverter. The target voltage parameter refers to the quantitative index of the voltage that the power converter needs to generate after the target magnetic flux compensation command is converted by physical laws. The PWM control signal refers to a digital pulse sequence used to precisely control the on and off times of the switching devices in the power converter. The sinusoidal compensation voltage refers to the high-power, high-quality sinusoidal AC voltage that the power converter ultimately outputs according to the PWM control signal. The compensation harmonic magnetic flux refers to the magnetic field generated in the core of the harmonic isolation transformer after the sinusoidal compensation voltage is applied to the auxiliary compensation winding, used to cancel the target dominant secondary harmonics.

[0048] Optionally, the PWM control signal that generates the target flux compensation command can be implemented using sinusoidal pulse width modulation.

[0049] Further, the step of generating a sinusoidal compensation voltage for the PWM control signal using the power converter includes: Generate a reference sine wave sequence for the PWM control signal; Measure the actual voltage at the output terminal of the power converter to obtain the feedback voltage sequence of the PWM control signal; Calculate the error between the reference sine wave sequence and the feedback voltage sequence; Based on the error, a sinusoidal compensation voltage for the PWM control signal is generated.

[0050] The reference sine wave sequence refers to a set of discrete, time-ordered digital data points generated by a software algorithm within the digital controller. The actual output voltage refers to a continuously changing analog voltage signal directly measured by a high-precision voltage sensor at the physical output port of the power converter. The feedback voltage sequence refers to a set of discrete, time-ordered digital data points obtained by sampling and quantizing the analog signal of the "actual output voltage" through an analog-to-digital converter at a fixed sampling period. The error refers to the difference signal obtained by subtracting the current value in the reference sine wave sequence from the current value in the feedback voltage sequence in each control cycle.

[0051] S4. Using the auxiliary compensation winding, the compensation harmonic flux is injected into the transformer core to cancel the dominant second harmonic, resulting in a net flux after cancellation. The flux error between the target flux compensation command and the net flux after cancellation is calculated.

[0052] By injecting the compensating harmonic flux into the transformer core using the auxiliary compensation winding, the dominant harmonics are canceled, resulting in a net flux after cancellation. This perfectly combines the precision of digital control with the deterministic nature of electromagnetic physics, achieving effective cancellation of harmonic pollution from the power grid. The transformer core refers to the high-permeability magnetic material entity shared by the primary winding, secondary winding, and auxiliary compensation winding in a harmonic isolation transformer. The net flux after cancellation refers to the composite flux remaining after the original dominant harmonic flux and the injected compensating harmonic flux are vector-superimposed in the transformer core. The net flux after cancellation includes the fundamental flux and residual harmonic flux.

[0053] The present invention calculates the flux error of the target flux compensation command and the net flux after cancellation to evaluate the effect of the harmonic suppression system in real time, and uses it as input to an advanced adaptive control algorithm to achieve optimal power quality control.

[0054] In detail, the calculation of the flux error between the target flux compensation command and the net flux after cancellation includes: Analyze the ideal reference flux of the target flux compensation command; Identify the residual harmonic component magnetic flux of the net magnetic flux after cancellation; Based on the residual harmonic component magnetic flux, the flux error between the ideal reference magnetic flux and the net magnetic flux after cancellation is calculated.

[0055] Furthermore, as another embodiment of the present invention, the magnetic flux error is calculated using the following formula:

[0056] in, The flux error represents the ideal reference flux and the net flux after cancellation. This represents the magnetic flux amplitude tracking weighting coefficient. This represents the amplitude of the fundamental component of the net magnetic flux after cancellation. Represents the ideal reference flux. Represents the residual harmonic component magnetic flux. This represents the harmonic suppression weighting coefficient.

[0057] Wherein, the fundamental component amplitude refers to the peak value of the sine wave corresponding to the fundamental frequency component of the power supply in the final remaining net magnetic flux waveform after the target magnetic flux compensation command is applied; the ideal reference magnetic flux refers to the pure fundamental magnetic flux without any harmonic pollution that is expected to be finally achieved in the transformer core in the harmonic compensation system; the residual harmonic component magnetic flux refers to the target dominant secondary harmonic magnetic flux that still exists in the net magnetic flux after harmonic compensation and has not been completely eliminated; the magnetic flux error refers to the degree to which the actual net magnetic flux after cancellation deviates from the ideal reference magnetic flux; the magnetic flux amplitude tracking weight coefficient refers to the proportion of the overall tracking error when calculating the comprehensive magnetic flux error; and the residual harmonic component magnetic flux refers to the proportion of the specific harmonic residual error when calculating the comprehensive magnetic flux error.

[0058] S5. When the magnetic flux error meets the preset magnetic flux error threshold, the net magnetic flux after cancellation is used to generate a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer to perform harmonic isolation.

[0059] In this invention, when the flux error meets a preset flux error threshold, the net flux after cancellation generates a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer to achieve harmonic isolation. Specifically, the flux error threshold is a critical value used to determine whether the harmonic compensation effect meets the expected standard. When the flux error does not meet the preset flux error threshold, the target flux compensation command is optimized to obtain an optimized flux compensation command. This optimized command is then used to cancel the dominant second harmonic until the flux error of the net flux after cancellation meets the preset flux error threshold.

[0060] In detail, the method of generating a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer using the net magnetic flux after cancellation includes: Analyze the steady state of the net magnetic flux after cancellation; When the stable state meets the preset stable state standard, the net magnetic flux after cancellation is electromagnetically coupled with the main winding of the harmonic isolation transformer to generate a sinusoidal back electromotive force in the main winding.

[0061] The stable state refers to a dynamic equilibrium and high-quality operating state achieved by the net magnetic flux after cancellation in the core of the harmonic isolation transformer. The stable state standard refers to a preset threshold used to quantitatively determine whether the net magnetic flux after cancellation has reached the stable state. The main winding refers to the core winding in the harmonic isolation transformer used to transmit electrical energy to the load. The sinusoidal back electromotive force refers to the high-quality sinusoidal voltage induced at both ends of the main winding according to Faraday's law of electromagnetic induction when the stable net magnetic flux after cancellation passes through the main winding.

[0062] First, its core advantage lies in achieving precise harmonic isolation at the source. Traditional active power filters inject compensation current on the grid side, directly injecting a compensation harmonic flux of equal amplitude and opposite phase into the transformer core to precisely cancel the original harmonic flux. This flux-on-flux cancellation method fundamentally blocks the transmission path of harmonic flux, preventing it from coupling to the secondary load through electromagnetic induction, achieving near-perfect harmonic isolation and providing truly clean power to sensitive equipment. Second, this invention employs a closed-loop adaptive control strategy, ensuring high system precision and robustness. By calculating the flux error between the target flux compensation command and the net flux after cancellation in real time and using this error as the control core, the system can dynamically adapt to changes in grid harmonics, regardless of load fluctuations or harmonic characteristics. As the magnetic flux error evolves, the system automatically adjusts the compensation intensity until it drops below a preset threshold. This closed-loop feedback mechanism overcomes the problems of insufficient or overcompensated compensation caused by parameter drift or model mismatch in open-loop control, ensuring optimal harmonic suppression performance under various complex operating conditions. Furthermore, this invention achieves dual optimization of power quality and system efficiency. When the magnetic flux error reaches the target, the magnetic field in the core returns to a pure sine wave state. This not only makes the voltage waveform output by the main winding a high-quality sine wave, significantly reducing the total harmonic distortion rate and protecting downstream equipment, but also significantly improves the transformer's operating efficiency, reduces temperature rise, and extends equipment lifespan by eliminating the additional iron loss and eddy current loss caused by harmonic magnetic flux in the core. Therefore, this invention can improve the temperature control accuracy in industrial integrated circuit manufacturing.

[0063] like Figure 2 The diagram shown is a functional block diagram of an adaptive harmonic isolation device based on dynamic control of transformer magnetic flux according to the present invention.

[0064] The adaptive harmonic isolation device 200 based on dynamic transformer flux control described in this invention can be installed in electronic devices. Depending on the functions implemented, the adaptive harmonic isolation device based on dynamic transformer flux control may include a harmonic feature extraction module 201, a compensation instruction generation module 202, a compensation harmonic flux calculation module 203, a flux error calculation module 204, and a power grid harmonic isolation module 205. The module described in this invention can also be called a unit, referring to a series of computer program segments that can be executed by the processor of an electronic device and perform a fixed function, stored in the memory of the electronic device.

[0065] In this embodiment of the invention, the functions of each module / unit are as follows: The harmonic feature extraction module 201 is used to collect the power grid current signal of the power grid in order to extract the harmonic feature dataset of the power grid. The compensation instruction generation module 202 is used to calculate the total harmonic distortion rate of the power grid based on the harmonic feature dataset, so as to analyze the harmonic pollution level of the power grid, and generate a target magnetic flux compensation instruction to suppress the corresponding dominant subharmonic of the power grid based on the harmonic pollution level. The compensation harmonic flux calculation module 203 is used to input the target flux compensation command into a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer, so as to generate the compensation harmonic flux of the target flux compensation command. The flux error calculation module 204 is used to inject the compensation harmonic flux into the transformer core using the auxiliary compensation winding, cancel the dominant second harmonic, obtain the net flux after cancellation, and calculate the flux error of the target flux compensation command and the net flux after cancellation. The power grid harmonic isolation module 205 is used to generate a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer by using the net magnetic flux after cancellation when the magnetic flux error meets the preset magnetic flux error threshold, so as to perform harmonic isolation.

[0066] In detail, the modules in the adaptive harmonic isolation device 200 based on transformer flux dynamic control described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The method used here is the same as the adaptive harmonic isolation method based on dynamic control of transformer magnetic flux, and can produce the same technical effect, so it will not be repeated here.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0068] Finally, it should be noted that in the above embodiments, each embodiment can be combined with each other or independent. Deleting any one of them will not affect the technical implementation of other embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An adaptive harmonic isolation method based on dynamic control of transformer flux, characterized in that, The method includes: Collect the grid current signal of the power grid to extract the harmonic characteristic dataset of the power grid; Based on the harmonic feature dataset, the total harmonic distortion rate of the power grid is calculated to analyze the harmonic pollution level of the power grid, and a target flux compensation command to suppress the corresponding dominant subharmonic of the power grid is generated based on the harmonic pollution level. The target magnetic flux compensation command is input into a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer to generate the compensation harmonic magnetic flux of the target magnetic flux compensation command. The auxiliary compensation winding is used to inject the compensation harmonic flux into the transformer core to cancel the dominant second harmonic, and the net flux after cancellation is obtained. The flux error of the target flux compensation command and the net flux after cancellation is calculated. When the magnetic flux error meets the preset magnetic flux error threshold, the net magnetic flux after cancellation is used to generate a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer to perform harmonic isolation.

2. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 1, characterized in that, The calculation of the total harmonic distortion of the power grid based on the harmonic feature dataset includes: Based on the harmonic characteristic dataset, analyze the fundamental amplitude and harmonic amplitude list of the power grid; Calculate the total effective value of harmonics of the power grid based on the fundamental amplitude and harmonic amplitude list; The THD percentage of the power grid is calculated using the fundamental amplitude and the total harmonics effective value. Calculate the effective THD coefficient of the THD percentage. When the effective THD coefficient meets the preset effective threshold, the THD percentage is taken as the total harmonic distortion of the power grid.

3. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 2, characterized in that, The calculation of the THD percentage using the THD effective coefficient includes: Calculate the THD mean and THD standard deviation of the stated THD percentage over a historical window; Based on the mean THD and standard deviation of THD, the THD efficiency coefficient for the percentage of THD is calculated using the following formula: in, Indicates the percentage of THD in The effective coefficient of THD at time t. Represents an exponential function. Represents the sensitivity coefficient. Indicates in The percentage of THD at any given time. Indicates in The average THD value corresponding to the historical window at that time. Indicates in The standard deviation of THD corresponding to the historical window at any given time. This represents the smoothing factor.

4. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 1, characterized in that, The extraction of the harmonic feature dataset of the power grid includes: The grid current signal corresponding to the grid is conditioned to obtain a conditioned current signal; The conditioning current signal is converted from analog to digital to obtain a digital current sequence; The current digital sequence is cached to obtain a cached current data window; The cached current data window is subjected to a fast Fourier transform to obtain the current spectrum information; The harmonic information of the current spectrum is extracted to construct the harmonic feature dataset of the power grid.

5. The adaptive harmonic isolation method based on dynamic control of transformer flux as described in claim 1, characterized in that, The step of generating a target flux compensation command to suppress the corresponding dominant subharmonic of the power grid based on the harmonic pollution level includes: Identify the target dominant subharmonics whose harmonic pollution level exceeds a preset harmonic pollution standard; Extract the dominant subharmonic amplitude and dominant subharmonic phase of the target dominant subharmonic; Based on the amplitude of the dominant subharmonic, the target magnetic flux amplitude of the target dominant subharmonic is calculated; Define the compensation phase relationship of the target dominant subharmonic; And by using the compensated phase relationship, the target flux phase of the target dominant subharmonic is analyzed; By combining the target magnetic flux amplitude and the target magnetic flux phase, the target magnetic flux compensation command for the target dominant subharmonic is determined.

6. The adaptive harmonic isolation method based on dynamic control of transformer flux as described in claim 1, characterized in that, The compensation harmonic flux for generating the target flux compensation command includes: The target magnetic flux compensation command is input to a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer to output the target voltage parameter of the target magnetic flux compensation command. Define a sinusoidal reference wave for the target voltage parameter to generate a PWM control signal for the target flux compensation command; The power converter is used to generate a sinusoidal compensation voltage for the PWM control signal; The sinusoidal compensation voltage is applied to the auxiliary compensation winding in the harmonic isolation transformer to generate the compensation harmonic flux of the target flux compensation command.

7. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 6, characterized in that, The step of generating a sinusoidal compensation voltage for the PWM control signal using the power converter includes: Generate a reference sine wave sequence for the PWM control signal; Measure the actual voltage at the output terminal of the power converter to obtain the feedback voltage sequence of the PWM control signal; Calculate the error between the reference sine wave sequence and the feedback voltage sequence; Based on the error, a sinusoidal compensation voltage for the PWM control signal is generated.

8. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 1, characterized in that, The calculation of the flux error between the target flux compensation command and the net flux after cancellation includes: Analyze the ideal reference flux of the target flux compensation command; Identify the residual harmonic component magnetic flux of the net magnetic flux after cancellation; Based on the residual harmonic component magnetic flux, the flux error between the ideal reference magnetic flux and the net flux after cancellation is calculated using the following formula: in, The flux error represents the ideal reference flux and the net flux after cancellation. This represents the magnetic flux amplitude tracking weighting coefficient. This represents the amplitude of the fundamental component of the net magnetic flux after cancellation. Represents the ideal reference flux. Represents the residual harmonic component magnetic flux. This represents the harmonic suppression weighting coefficient.

9. The adaptive harmonic isolation method based on dynamic control of transformer magnetic flux as described in claim 1, characterized in that, The method of generating a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer using the net magnetic flux after cancellation includes: Analyze the steady state of the net magnetic flux after cancellation; When the stable state meets the preset stable state standard, the net magnetic flux after cancellation is electromagnetically coupled with the main winding of the harmonic isolation transformer to generate a sinusoidal back electromotive force in the main winding.

10. An adaptive harmonic isolation device based on dynamic control of transformer flux, characterized in that, The device includes: The harmonic feature extraction module is used to collect the grid current signal of the power grid in order to extract the harmonic feature dataset of the power grid. The compensation instruction generation module is used to calculate the total harmonic distortion rate of the power grid based on the harmonic feature dataset, to analyze the harmonic pollution level of the power grid, and to generate a target magnetic flux compensation instruction to suppress the corresponding dominant subharmonic of the power grid based on the harmonic pollution level. The harmonic flux compensation module is used to input the target flux compensation command into a power converter connected to the auxiliary compensation winding in a preset harmonic isolation transformer, so as to generate the compensation harmonic flux of the target flux compensation command. The flux error calculation module is used to inject the compensation harmonic flux into the transformer core using the auxiliary compensation winding, cancel the dominant second harmonic, obtain the net flux after cancellation, and calculate the flux error of the target flux compensation command and the net flux after cancellation. The power grid harmonic isolation module is used to generate a sinusoidal back electromotive force in the main winding of the harmonic isolation transformer by using the net magnetic flux after cancellation when the magnetic flux error meets the preset magnetic flux error threshold, so as to perform harmonic isolation.

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