Method, system and electronic equipment for handling electromagnetic interference of photovoltaic power inverter

Abstract

The present invention relates to the field of inverter technology, and in particular to a method, system, and electronic equipment for handling electromagnetic interference of a photovoltaic power generation inverter. The method comprises the following steps: collecting power quality on both sides of the inverter, evaluating the power quality on both sides of the inverter with a set deviation standard, obtaining a degree of imbalance in power quality, extracting power quality imbalance factors by combining a specific transformation method with a time domain analysis algorithm, taking the power quality imbalance factors as input values, performing analysis based on historical optimization data, outputting a set of imbalance alternative optimization strategies, evaluating the degree of fit of each imbalance alternative optimization strategy in turn through a simulation analysis module and a voting method, obtaining multiple strategy fits, matching an optimal imbalance optimization strategy with the maximum value of the strategy fits, optimizing and controlling the power quality on both sides of the inverter with a corresponding module according to the optimal imbalance optimization strategy, and completing the handling of electromagnetic interference of the photovoltaic power generation inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of inverters, and in particular to a method, system and electronic equipment for dealing with electromagnetic interference of photovoltaic power generation inverters. Background Art

[0002] An inverter converts DC power into either constant-frequency and constant-voltage or variable-frequency and variable-voltage AC power. It consists of an inverter bridge, control logic, and filtering circuits. Energy-saving power supply is a current trend, and many factories are using photovoltaic panels installed on their rooftops to provide power. This can alleviate some of the factory's power load. However, in places like electrolysis plants, the strong magnetic field present in the electrolysis workshop can cause significant electromagnetic interference (EMI) to the rooftop PV inverters. This can cause the inverter to frequently start up, impacting its stable operation and lifespan. Therefore, a method to suppress EMI in PV inverters is urgently needed. Summary of the Invention

[0003] The purpose of the present invention is to provide a method, system and electronic equipment for dealing with electromagnetic interference of photovoltaic power generation inverters, which can suppress the electromagnetic interference of photovoltaic power generation inverters by optimizing and controlling the power quality of the inverter and controlling the magnetic field interference of the inverter based on the installation equipment outside the inverter.

[0004] The embodiments of the present invention are achieved through the following technical solutions:

[0005] A method for dealing with electromagnetic interference of a photovoltaic power generation inverter, the method comprising the steps of:

[0006] The power quality on both sides of the inverter is collected, and the power quality on both sides of the inverter is evaluated with a set deviation standard to obtain the imbalance of the power quality. The power quality imbalance factors are extracted by combining a specific transformation method with a time domain analysis algorithm. The power quality imbalance factors are used as input values, and the historical optimization data is used as the processing basis for analysis. A set of imbalance alternative optimization strategies is output. The fit of each imbalance alternative optimization strategy is evaluated in turn through a simulation analysis module and a voting method to obtain the fit of multiple strategies. The optimal imbalance optimization strategy is matched with the maximum value of the strategy fit. According to the optimal imbalance optimization strategy, the corresponding module is used to optimize and control the power quality on both sides of the inverter to complete the treatment of electromagnetic interference of the photovoltaic power generation inverter.

[0007] Optionally, a motor is fixedly provided on the outside of the inverter, and the rotating end of the motor is fixedly connected to the outside of the inverter. By detecting the external magnetic field interference source, the inverter is rotated by the motor based on the detection situation, so as to change the direction of the external magnetic field passing through the inverter to suppress the interference of the external magnetic field on the inverter.

[0008] Optionally, a hinge is fixedly provided at the connection between the rotating end of the motor and the outside of the inverter, and the rotating end of the motor and the outside of the inverter are connected through the hinge to perform multi-directional rotation of the inverter.

[0009] Optionally, a soft magnetic patch is attached to the outside of the inverter to form an attraction with the external magnetic field to suppress the interference of the external magnetic field on the inverter.

[0010] Optionally, silicon steel sheets are respectively provided at both ends of the inverter in the vertical direction, and the magnetic field shielding degree of the inverter in the vertical direction is tested. When the test result meets the expected value, the silicon steel sheet is used as a shielding cover to fully cover the inverter, and a shielding test of the external magnetic field is performed in combination with Permalloy material to suppress the interference of the external magnetic field on the inverter.

[0011] Optionally, the deviation standard includes a voltage deviation standard, a frequency deviation standard, a harmonic deviation standard, a fluctuation deviation standard and an imbalance deviation standard.

[0012] Optionally, an imbalance optimization tree model is constructed using power quality imbalance factors as node features, and historical optimization data is used as a processing basis to determine the type of imbalance optimization processing, and to summarize and output a set of imbalance alternative optimization strategies.

[0013] Optionally, a setting index is used to measure the impurity of the imbalanced optimization tree model. The calculation formula is as follows:

[0014]

[0015] Among them, Gini is the set index, p is the probability of the sample appearing, and i is the label of the sample.

[0016] The system for dealing with electromagnetic interference of photovoltaic power generation inverters is composed of a power quality optimization unit and a magnetic field optimization unit, wherein the power quality optimization unit includes: a power quality acquisition subunit for acquiring the power quality on both sides of the inverter, an imbalance assessment subunit for assessing the imbalance of the power quality on both sides of the inverter with a set deviation standard, an extraction subunit for extracting power quality imbalance factors, an imbalance optimization strategy generation subunit for acquiring alternative imbalance optimization strategies, a fit assessment subunit for assessing the fit of alternative imbalance optimization strategies and matching the optimal imbalance optimization strategy, and an optimization control subunit for optimizing and controlling the power quality on both sides of the inverter based on the optimal imbalance optimization strategy.

[0017] An electronic device, comprising:

[0018] memory for storing computer programs;

[0019] A processor is configured to implement the steps of any one of the above-mentioned methods for handling electromagnetic interference of a photovoltaic power generation inverter when executing the computer program.

[0020] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0021] This embodiment obtains the power quality of the inverter, and combines the power quality of the inverter to obtain its imbalance and the optimal control strategy of the inverter. The optimal control strategy is used to suppress the electrical interference of the inverter, and the magnetic field interference to the inverter is controlled based on the installation equipment outside the inverter. The combination of the two achieves the effect of suppressing the electromagnetic interference of the photovoltaic power generation inverter. Through this embodiment, it is possible to suppress the interference source, eliminate or weaken its coupling, and reduce the sensitivity of sensitive equipment to electromagnetic interference response. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a method for dealing with electromagnetic interference in a photovoltaic power generation inverter provided by the present invention;

[0023] Figure 2 Schematic diagram of the system framework for handling electromagnetic interference of photovoltaic power inverters provided by the present invention. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0025] Photovoltaic power generation is a technology that uses the photovoltaic effect at the interface of semiconductors to directly convert sunlight into electricity. It primarily consists of three main components: photovoltaic panels (modules), controllers, and inverters, with the majority of these components being electronic components. Solar cells are connected in series and then packaged and protected to form large-area modules. Combined with components such as controllers and inverters, these form photovoltaic power generation devices.

[0026] In photovoltaic power generation devices, inverters use maximum power point tracking (MPPT) technology to extract the maximum possible power from photovoltaic panels. Due to the complex relationship between solar irradiance, temperature, and the total resistance of the solar cells in a photovoltaic panel, the output power varies nonlinearly. The maximum power point is determined by sampling the output of the solar module under various conditions and generating a load resistance. Therefore, the safe and stable operation of the photovoltaic inverter has a significant impact on the economic benefits of photovoltaic power generation.

[0027] Reference Figure 1 As shown, the present invention provides a first embodiment based on the safe and stable operation of photovoltaic power generation inverters in parts of the plant such as electrolysis plants: a method for dealing with electromagnetic interference of photovoltaic power generation inverters, the method comprising the following steps:

[0028] The power quality on both sides of the inverter is collected, and the power quality on both sides of the inverter is evaluated with a set deviation standard to obtain the imbalance of the power quality. The power quality imbalance factors are extracted by combining a specific transformation method with a time domain analysis algorithm. The power quality imbalance factors are used as input values, and the historical optimization data is used as the processing basis for analysis. A set of imbalance alternative optimization strategies is output. The fit of each imbalance alternative optimization strategy is evaluated in turn through a simulation analysis module and a voting method to obtain the fit of multiple strategies. The optimal imbalance optimization strategy is matched with the maximum value of the strategy fit. According to the optimal imbalance optimization strategy, the corresponding module is used to optimize and control the power quality on both sides of the inverter to complete the treatment of electromagnetic interference of the photovoltaic power generation inverter.

[0029] During the implementation of the above-mentioned embodiment, the specific transformation in this embodiment can use the S-transform algorithm. The S-transform algorithm can be derived from the wavelet transform and can automatically adapt to transformations of various resolutions. This embodiment extracts the power quality imbalance by combining the S-transform algorithm with the time-domain analysis algorithm. Feature data related to the power quality imbalance is extracted from the amplitude matrix and time-domain analysis of the S-transform algorithm to form the power quality imbalance factor. The S-transform algorithm has excellent noise immunity and can also avoid certain errors. This embodiment can also use a variant of the fast S-transform algorithm. Compared with the S-transform algorithm, the time used for extracting the power quality imbalance factor is shorter and the real-time extraction of the power quality imbalance factor will not be affected by some interference factors.

[0030] The derivation formula of the S-transform algorithm is:

[0031]

[0032]

[0033]

[0034] in, is the mother wavelet function, b is the scale factor of the wavelet transform, and in this embodiment, b=σ, e -2jπfτ is the phase correction factor, σ is the width, After the amplitude is modified, the width

[0035] In this embodiment, the deviation target includes a voltage deviation target, a frequency deviation target, a harmonic deviation target, a fluctuation deviation target, and an unbalance deviation target.

[0036] In the above implementation process, the voltage deviation standard is the relative value of the deviation of the actual operating voltage of the inverter to the standard voltage, and its calculation formula is:

[0037]

[0038] Among them, ζU is the voltage deviation standard, U s is the actual voltage, U N The voltage is the standard voltage. In this embodiment, the voltage deviation is used as one of the imbalance evaluation criteria. This is because the voltage deviation in power quality can easily affect the service life of the inverter and reduce the operating efficiency and performance of the inverter.

[0039] In the above implementation process, the frequency deviation standard is specifically the deviation value between the actual frequency value of the inverter and the frequency standard value, and its calculation formula is:

[0040] Δf=f τ -f N

[0041] Where Δf is the frequency deviation standard, f τ is the actual value of the inverter frequency, f N In this embodiment, the frequency deviation standard can be obtained by using the Kalman filter algorithm.

[0042] In the above implementation, the harmonic deviation standard is specifically the frequency obtained after Fourier transform of the periodic AC quantity. The fluctuation deviation standard is specifically a series of changes or continuous changes in the RMS voltage value. The imbalance deviation standard is specifically the voltage imbalance caused by faults such as single-phase grounding and two-phase disconnection, or asymmetry. Using the voltage deviation standard, frequency deviation standard, harmonic deviation standard, fluctuation deviation standard, and imbalance deviation standard as a basis, the imbalance degree of the inverter power quality can be better determined, and the subsequent solution process can be carried out based on the imbalance degree.

[0043] In this embodiment, the imbalance optimization tree model is constructed with the power quality imbalance factor as the node feature, and the historical optimization data is used as the processing basis to determine the imbalance optimization processing type, summarize and output the imbalance alternative optimization strategy set.

[0044] In this embodiment, the setting index is used to measure the impurity of the imbalanced optimization tree model, and its calculation formula is as follows:

[0045]

[0046] Among them, Gini is the set index, p is the probability of the sample appearing, and i is the label of the sample.

[0047] In this embodiment, a motor is fixedly provided on the outside of the inverter, and the rotating end of the motor is fixedly connected to the outside of the inverter. By detecting the external magnetic field interference source, the inverter is rotated by the motor based on the detection situation, so as to change the direction of the external magnetic field passing through the inverter to suppress the interference of the external magnetic field on the inverter.

[0048] In the above implementation process, this embodiment changes the installation orientation of the inverter, changes the direction of the magnetic field passing through the inverter, detects the source of magnetic field interference, and uses the motor to actively rotate the orientation of the inverter main panel to switch the direction of magnetic field interference and reduce interference.

[0049] In this embodiment, a hinge is fixedly provided at the connection between the rotating end of the motor and the outside of the inverter. The rotating end of the motor and the outside of the inverter are connected through the hinge to perform multi-directional rotation of the inverter.

[0050] In this embodiment, a soft magnetic patch is attached to the outside of the inverter to form an attraction with the external magnetic field to suppress the interference of the external magnetic field on the inverter.

[0051] In the above implementation process, this embodiment uses soft magnetic patches to be attached to the outside of the inverter to form an attraction with the on-site magnetic field, thereby reducing the interference of the external magnetic field on the internal components of the device.

[0052] In this embodiment, silicon steel sheets are provided at both ends of the inverter in the vertical direction, and the magnetic field shielding degree of the inverter in the vertical direction is tested. When the test results meet the expected values, the silicon steel sheets and the added EMC shielding structure are used as a shielding cover to fully cover the inverter, and a shielding test is performed on the external magnetic field in combination with the Permalloy material to suppress the interference of the external magnetic field on the inverter.

[0053] In the above implementation process, this embodiment uses specially made silicon steel sheet materials, which are placed at the bottom and top of the inverter to test the vertical magnetic field shielding effect; the silicon steel sheets are made into a shielding cover to fully cover the inverter, and the magnetic field shielding test is performed in combination with Permalloy material, adding an EMC shielding structure to shield the equipment from interference caused by the magnetic environment.

[0054] In a specific application of this embodiment, an electronic device is also provided, including: a memory for storing a computer program; and a processor for implementing the steps of the method for handling electromagnetic interference of a photovoltaic power generation inverter as described in this embodiment when executing the computer program.

[0055] In the above implementation process, the electronic device can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the method for handling electromagnetic interference in photovoltaic inverters of the first embodiment.

[0056] In addition, if Figure 2 As shown, in combination with the method proposed in the first embodiment, the present invention also provides a second embodiment: a system for handling electromagnetic interference of a photovoltaic power generation inverter, composed of a power quality optimization unit and a magnetic field optimization unit, wherein the power quality optimization unit includes: a power quality acquisition subunit, used to obtain the power quality on both sides of the inverter, an imbalance assessment subunit, used to assess the imbalance of the power quality on both sides of the inverter with a set deviation standard, an extraction subunit, used to extract power quality imbalance factors, an imbalance optimization strategy generation subunit, used to obtain an imbalance alternative optimization strategy, a fit assessment subunit, used to evaluate the fit of the imbalance alternative optimization strategy and match the optimal imbalance optimization strategy, and an optimization control subunit, used to optimize and control the power quality on both sides of the inverter based on the optimal imbalance optimization strategy.

[0057] In the above implementation process, the magnetic field optimization unit in this embodiment is installed outside the inverter as a peripheral device of the inverter, including the motor, soft magnet magnetic patch and special silicon steel sheet material mentioned in the first embodiment, to suppress the influence of magnetic field interference on the inverter.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for dealing with electromagnetic interference of photovoltaic inverters, characterized in that: The steps of the method include: The power quality on both sides of the inverter is collected, and the power quality on both sides of the inverter is evaluated with a set deviation standard to obtain the imbalance of the power quality. The power quality imbalance factor is extracted by combining a specific transformation method with a time domain analysis algorithm. The power quality imbalance factor is used as the input value, and the historical optimization data is used as the processing basis for analysis. A set of imbalance alternative optimization strategies is output. The fit of each imbalance alternative optimization strategy is evaluated in turn through a simulation analysis module and a voting method to obtain the fit of multiple strategies. The optimal imbalance optimization strategy is matched with the maximum value of the strategy fit. According to the optimal imbalance optimization strategy, the corresponding module is used to optimize and control the power quality on both sides of the inverter to complete the treatment of electromagnetic interference of the photovoltaic power generation inverter. Among them, the specific transformation method is specifically the S transformation algorithm; A motor is fixedly provided on the outside of the inverter, and a rotating end of the motor is fixedly connected to the outside of the inverter. By detecting the external magnetic field interference source, the motor rotates the inverter based on the detection situation, so as to change the direction of the external magnetic field passing through the inverter, thereby suppressing the interference of the external magnetic field on the inverter; A soft magnetic patch is also attached to the outside of the inverter to form an attraction with the external magnetic field to suppress the interference of the external magnetic field on the inverter; An imbalance optimization tree model is constructed using power quality imbalance factors as node features. Historical optimization data is used as a processing basis to determine the type of imbalance optimization processing, and a set of imbalance alternative optimization strategies is summarized and output. The set index is used as a measure of the impurity of the imbalanced optimization tree model, and its calculation formula is as follows: in, To set the index, is the probability of the sample appearing, is the label of the sample.

2. The method for dealing with electromagnetic interference of photovoltaic inverter according to claim 1, characterized in that: A hinge is fixedly provided at the connection between the rotating end of the motor and the outside of the inverter. The rotating end of the motor and the outside of the inverter are connected through the hinge to perform multi-directional rotation of the inverter.

3. The method for dealing with electromagnetic interference of photovoltaic inverter according to claim 1, characterized in that: Set silicon steel sheets are respectively set at both ends of the inverter in the vertical direction, and the magnetic field shielding degree of the inverter in the vertical direction is tested. When the test result meets the expected value, the silicon steel sheet is used as a shielding cover to fully cover the inverter, and a shielding test of the external magnetic field is performed in combination with the permalloy material to suppress the interference of the external magnetic field on the inverter.

4. The method for dealing with electromagnetic interference of photovoltaic inverters according to claim 1, characterized in that: Deviation targets include voltage deviation target, frequency deviation target, harmonic deviation target, fluctuation deviation target and imbalance deviation target.

5. A system for handling electromagnetic interference of photovoltaic power generation inverters, which is applied to the method for handling electromagnetic interference of photovoltaic power generation inverters according to any one of claims 1 to 4, characterized in that: It consists of a power quality optimization unit and a magnetic field optimization unit, wherein the power quality optimization unit includes: a power quality acquisition subunit, used to obtain the power quality on both sides of the inverter, an imbalance assessment subunit, used to assess the imbalance of the power quality on both sides of the inverter with a set deviation standard, an extraction subunit, used to extract power quality imbalance factors, an imbalance optimization strategy generation subunit, used to obtain imbalance alternative optimization strategies, a fit assessment subunit, used to evaluate the fit of the imbalance alternative optimization strategies and match the optimal imbalance optimization strategy, and an optimization control subunit, used to optimize and control the power quality on both sides of the inverter based on the optimal imbalance optimization strategy.

6. An electronic device, characterized in that: include: Memory for storing computer programs; A processor is configured to implement the steps of the method for handling electromagnetic interference of a photovoltaic power generation inverter as described in any one of claims 1 to 4 when executing the computer program.

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