Intelligent control method and device for electromagnetic interference suppression in photovoltaic energy storage system

Abstract

The invention relates to the technical field of electromagnetic interference suppression, and discloses an intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system, and the method comprises the steps: obtaining an electromagnetic transient pulse flow signal of an electric field sensor in the photovoltaic energy storage system; carrying out electromagnetic transient pulse interference signal suppression by adopting a self-adaptive time-varying filter and recording suppression time; performing electric field change detection on the distribution transformer by adopting an electric field sensor to judge whether the electric field change is detected or not; if yes, performing steady-state electromagnetic interference suppression on the distribution transformer; and if not, performing cyclic detection according to the time length from the current time to the suppression time. According to the method, a transient pulse interference signal automatic suppression mode based on the adaptive time-varying filter is adopted, the measurement precision of the electric field around the distribution transformer is improved, steady-state electromagnetic interference suppression is performed on the distribution transformer, the influence of electromagnetic interference on the electric field sensor and the distribution transformer can be effectively suppressed, and the measurement accuracy is improved. And the operation stability of the photovoltaic energy storage system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic interference suppression, and in particular to an intelligent control method and device for electromagnetic interference suppression in a photovoltaic energy storage system. Background Art

[0002] In modern energy management, photovoltaic (PV) energy storage systems, as a key component of renewable energy, are becoming an integral part of the global energy transition. This system not only improves the efficiency of solar energy utilization but also plays a key role in achieving sustainable development. Distribution transformers play a crucial role in PV energy storage systems. Because PV power generation is a distributed power source, it can have some adverse effects on distribution transformers within the distribution system. Large amounts of DC power are injected into the ground through grounding electrodes, creating a constant DC electric field near the poles. Within the distribution system, a current is input from the ground, and a potential difference is output by another transformer (the transformer's neutral conductor). Because the rated operating point of a distribution transformer is located at the saturation point of the core magnetization curve, passing DC current through the transformer coils can cause the operating point of the transformer core magnetic field to deviate from the designed value, resulting in a DC offset. In severe cases, this can damage the transformer.

[0003] At the same time, the electric field sensor used to measure the electric field around the distribution transformer operates based on the capacitance principle. It measures the electric field strength by measuring the capacitance between electrodes based on the potential difference formed by the interaction between charges. During use, inductive sensors are susceptible to interference from various electromagnetic interference sources, including equipment switching, transient overvoltages, transient electromagnetic interference, transient current interference, external electromagnetic sources, and transient current interference generated by inductive components when current or voltage changes suddenly. The electromagnetic pulse signals generated by these interference sources are characterized by short duration, wide frequency range, and high energy density. These pulse interference signals can form pulse interference signals that can seriously disrupt the normal operation of the electric field sensor, causing deviations or anomalies in the electric field strength data measured by the sensor, and thus abnormal monitoring of the distribution transformer.

[0004] Therefore, how to effectively suppress the impact of electromagnetic interference on electric field sensors and distribution transformers is the key to ensuring the normal operation of the power system. Summary of the Invention

[0005] The present invention provides an intelligent control method and device for suppressing electromagnetic interference in a photovoltaic energy storage system. The method adopts an automatic suppression method for transient pulse interference signals of an electric field sensor based on an adaptive time-varying filter to improve the measurement accuracy of the electric field sensor for the electric field around the distribution transformer, and thereby suppresses steady-state electromagnetic interference of the distribution transformer. This method can effectively suppress the impact of electromagnetic interference on the electric field sensor and the distribution transformer, and improve the operational stability of the photovoltaic energy storage system.

[0006] The present invention provides an intelligent control method for suppressing electromagnetic interference in a photovoltaic energy storage system, comprising:

[0007] The electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system is obtained by undersampling;

[0008] According to the electromagnetic transient pulse flow signal, an adaptive time-varying filter is used to suppress the electromagnetic transient pulse interference signal of the electric field sensor, and the suppression time is recorded;

[0009] Use electric field sensors to detect electric field changes in the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected;

[0010] If an electric field change caused by electromagnetic interference is detected, steady-state electromagnetic interference suppression is performed on the distribution transformer;

[0011] If no electric field change caused by electromagnetic interference is detected, determining whether the time length from the current time to the suppression time reaches the set time length;

[0012] If the set time length is not reached, the process returns to the step of using an electric field sensor to detect electric field changes on the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected;

[0013] If the set time length is reached, the process returns to the step of obtaining the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling.

[0014] Furthermore, the step of suppressing the electromagnetic transient pulse interference signal of the electric field sensor using an adaptive time-varying filter according to the electromagnetic transient pulse flow signal and recording the suppression time includes:

[0015] Based on the generalized S transform, the electromagnetic transient pulse flow signal of the electric field sensor is processed to obtain a signal time-frequency diagram, and the time-frequency diagram is transformed and segmented;

[0016] An adaptive time-frequency filter is used to perform time-frequency filtering processing to separate the interference signal from the electromagnetic transient pulse flow signal and complete the suppression of the electromagnetic transient pulse interference signal of the electric field sensor.

[0017] Furthermore, the steps of processing the electromagnetic transient pulse flow signal of the electric field sensor based on the generalized S transform, obtaining a signal time-frequency diagram, and converting and segmenting the time-frequency diagram include:

[0018] The generalized S-transform result of the electromagnetic transient pulse flow signal of the electric field sensor is expressed by g(τ, f, λ), and its calculation formula is:

[0019]

[0020] Where x(t) represents the electromagnetic transient pulse flow signal of the electric field sensor, τ and t both represent time, f represents frequency, λ represents the adjustment factor, and ξ(·) represents the Gaussian window function;

[0021] In the application process, if the discrete signal of x(t) is represented by x(n), τ = iT, where T and N represent the sampling period and the total amount of data x(n), respectively. The generalized S-transform formula of x(n) is:

[0022]

[0023] Among them, m, n, and i are all variables;

[0024] Perform time-frequency transformation of x(n) using the above formula to obtain a two-dimensional time-frequency negative matrix, and perform modulo processing on the matrix to obtain the time-frequency spectrum of x(n);

[0025] During the application of the generalized S transform, the corresponding adjustment parameters are introduced into the Gaussian window function ξ(·), so that the function can adjust the parameters according to the changes in the aggregation of the signal time-frequency. The improved ξ(·) calculation formula is:

[0026]

[0027] Among them, a, b, c, and d are adjustment parameters used to control the algorithm window properties, including the window size and the width of the basis function;

[0028] During the adjustment process, the standard deviation affecting the Gaussian window function is constrained, and its calculation formula is:

[0029]

[0030] Using time-frequency concentration measurement value ρ CM As the objective function of window parameter optimization, the generalized S transform formula of the signal is:

[0031]

[0032] Within the window standard deviation constraint, according to ρ CM The results of the adaptive optimization of parameters are defined by ρ CM The processed time-frequency is an adaptive S-transform, which improves the resolution of the time-frequency diagram after the algorithm transforms the pulse stream signal.

[0033] Furthermore, the step of using an adaptive time-frequency filter to perform time-frequency filtering processing to separate the interference signal from the electromagnetic transient pulse flow signal and complete the step of suppressing the electromagnetic transient pulse interference signal of the electric field sensor includes:

[0034] The processed electromagnetic transient pulse flow signal x(t) of the electric field sensor is expressed as y(t), and its expression formula is:

[0035]

[0036] in, and Represent the transient functions of the rising and falling edges of a single pulse, and The rise time and fall time of the mth pulse respectively;

[0037] Input y(t) into the filter and perform low-pass filtering on it. The function calculation formula is:

[0038] f p (t) = H -1 {H[y(t)],f p (ω)}

[0039] Among them, H ―1 and H[y(t)] represent the inverse Fourier transform and the Fourier transform, respectively. p (ω) represents the low-pass filter function;

[0040] like and The time difference between them is represented by ΔT, then the single pulse function The calculation formula is:

[0041]

[0042] Based on the above formula, the adaptive filter function f p The calculation formula for (t) is:

[0043]

[0044] Among them, F p represents the output function after filtering;

[0045] According to the above Fourier transform, the two-dimensional distribution of signal time and frequency can be obtained, F p Multiply it by the two-dimensional distribution result to retain the effective pulse signal, complete the effective separation between the signal and the interference, and effectively suppress the interference of the pulse signal outside the pass domain.

[0046] Furthermore, if an electric field change caused by electromagnetic interference is detected, the step of suppressing steady-state electromagnetic interference on the distribution transformer includes:

[0047] If an electric field change caused by electromagnetic interference is detected, the transformer parameters of the distribution transformer are improved; wherein the transformer parameters include core magnetic flux density, magnetostriction, and overlap area of the inclined seam area;

[0048] An interference suppression device is constructed according to the transformer parameters, and the interference suppression device is used in combination with logic operations to suppress electromagnetic interference.

[0049] Furthermore, if the electric field change caused by electromagnetic interference is detected, the step of improving the transformer parameters of the distribution transformer includes:

[0050] Improvement of core flux density:

[0051] The rated working magnetic flux density of the core is related to the noise. The noise impact caused by the change of working magnetic flux density is expressed by the following formula:

[0052]

[0053] Among them, φ0 and φ′ represent the rated working magnetic flux density parameters of the core before and after the change respectively; g Fe0 , g′ Fe Represents the weight of the core before and after the change in magnetic flux density. In order to keep the total magnetic flux unchanged, the cross-sectional area of the core is increased to compensate for the magnetic flux loss caused by the decrease in magnetic density. When the magnetic flux density and weight of the core increase, the noise also becomes larger. The noise is suppressed by controlling the magnetic flux density and weight.

[0054] Improvement of magnetostriction:

[0055] The formula for the change of magnetostriction can be expressed as:

[0056]

[0057] Where ΔL represents the increment of silicon steel sheet length during excitation, and L0 represents the initial length of silicon steel sheet. Since the silicon steel sheet magnetostricts twice for each current change in the distribution transformer, the number of magnetostrictions should be reduced to avoid the generation of high harmonic components.

[0058] Improvements to the overlap area of mitered joints:

[0059] The noise change caused by the change in the overlapping area of the bevel joint can be expressed as follows:

[0060]

[0061] Wherein, S represents the overlapping area of the bevel joint area. In order to suppress noise, the overlapping area of the bevel joint area is reduced to achieve the purpose of reducing noise.

[0062] Furthermore, the step of constructing an interference suppression device according to the transformer parameters and using the interference suppression device in combination with logic operations to suppress electromagnetic interference includes:

[0063] Construct an interference suppression device by connecting a capacitor in series between the neutral point of the transformer and the system ground, and achieve DC isolation through the capacitor's AC blocking and DC isolation functions. Specifically, the device includes:

[0064] One end of the inductor L1 is connected to one end of the switch K2 and one end of the switch K1, the other end of the switch K1 is grounded, the other end of the switch K2 is connected to one end of the resistor R, one end of the blocking capacitor, one end of the coupling transformer, one end of the switch K3, and one end of the switch K4, the other end of the resistor R is connected to one end of the capacitor C, the other end of the capacitor C is connected to one end of the inductor L2, the other end of the inductor L2 is connected to the other end of the blocking capacitor, the other end of the switch K3, the other end of the switch K4, and the current transformer, the current transformer is connected to the other end of the coupling transformer and is grounded;

[0065] During the operation of the interference suppression device, if a single-phase grounding fault occurs and the capacitor voltage rises, the large-capacity fast switch K2 of the zinc oxide valve plate is used to provide double protection for the DC insulation capacitor. The bypass fast switches K3 and K4 are immediately closed after receiving the signal and the neutral point is directly grounded to effectively protect the zinc oxide, that is, to suppress the DC current to zero;

[0066] According to the interference suppression device, signals with a common busbar adjacent relationship are detected and marked with serial numbers. The device is subjected to an exclusive OR logic operation in a one-way forward loop, and then all operations are processed in an AND logic operation. The specific interference suppression is based on:

[0067] I B =(I i ⊕I i+1 )&(I i+1 ⊕I i+2 )&…&(I i+j―1 ⊕I i )

[0068] Among them, i and j represent the minimum number and the number of transformer buses in the detection processing point, respectively. ⊕ represents the exclusive OR operator, & represents the AND operator. B It represents the comparison result of the transient current polarity measured on all buses. The judgment formula for whether electromagnetic interference occurs on the bus is:

[0069]

[0070] When I B =1, the following interference suppression is performed:

[0071] Compare the filtered distribution transformer operating curve with the curve subjected to electromagnetic interference to obtain the relationship between the two. The operating mode in this state can be expressed as:

[0072]

[0073] Among them, R t 、R t′ They represent the state values after filtering at time t and time t' respectively. After filtering, the signal after electromagnetic interference is filtered out is concentrated in the range of 50-250Hz. The filtered signal is converted from a digital signal to an analog signal after A / D conversion. The analog signal is sent by the driving speaker of the audio amplifier to prevent interference from other high-frequency devices and achieve the purpose of suppressing electromagnetic interference.

[0074] The present invention also provides an intelligent control device for suppressing electromagnetic interference in a photovoltaic energy storage system, comprising:

[0075] An acquisition module is used to acquire electromagnetic transient pulse flow signals of electric field sensors in photovoltaic energy storage systems by undersampling;

[0076] a first suppression module, configured to suppress the electromagnetic transient pulse interference signal of the electric field sensor using an adaptive time-varying filter according to the electromagnetic transient pulse flow signal, and record the suppression time;

[0077] A detection module is used to detect electric field changes in the distribution transformer of the photovoltaic energy storage system using an electric field sensor to determine whether electric field changes caused by electromagnetic interference are detected;

[0078] a second suppression module, configured to suppress steady-state electromagnetic interference on the distribution transformer when a change in the electric field caused by electromagnetic interference is detected;

[0079] A judgment module, configured to judge whether the time length from the current time to the suppression time reaches a set time length when no electric field change caused by electromagnetic interference is detected;

[0080] A first return module is configured to return to the step of using an electric field sensor to detect electric field changes on a distribution transformer in the photovoltaic energy storage system to determine whether an electric field change caused by electromagnetic interference is detected if the set time length has not been reached;

[0081] The second returning module is used to return to the step of obtaining the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling when the set time length is reached.

[0082] The present invention also provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0083] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0084] The beneficial effects of the present invention are:

[0085] The present invention obtains the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system, and adopts an adaptive time-varying filter to suppress the electromagnetic transient pulse interference signal of the electric field sensor. It can reliably complete signal conversion, and realize effective separation of interference signals based on the converted results, retain effective signals, improve the suppression effect, and ensure the measurement accuracy of the electric field sensor; then, the electric field sensor is used to detect the electric field change of the distribution transformer to suppress the steady-state electromagnetic interference of the distribution transformer according to the electric field change, and perform electromagnetic interference cyclic detection and suppression according to the electric field change detected by the electric field sensor and the suppression time of the electric field sensor, which can effectively suppress the influence of electromagnetic interference on the electric field sensor and the distribution transformer, and improve the operation stability of the photovoltaic energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 Schematic diagram of a method flow according to an embodiment of the present invention.

[0087] Figure 2 Schematic diagram of the structure of the interference suppression device in the present invention.

[0088] Figure 3 FIG. 1 is a schematic diagram of the device structure according to an embodiment of the present invention.

[0089] Figure 4 Schematic diagram of the internal structure of a computer device according to an embodiment of the present invention.

[0090] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0091] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0092] like Figure 1 As shown, the present invention provides an intelligent control method for suppressing electromagnetic interference in a photovoltaic energy storage system, comprising:

[0093] S1. Obtain the electromagnetic transient pulse flow signal x(t) of the electric field sensor in the photovoltaic energy storage system through undersampling.

[0094] The characteristics of electromagnetic transient pulse interference signals in electric field sensors involve multiple aspects, primarily influenced by the interference source, propagation path, and the performance of the electric field sensor itself. These interference sources can originate from within or outside the electronic device. When an electronic device switches on or off, changes in current or voltage can generate pulse interference. Similarly, when a power supply line experiences a surge of high current or voltage, it triggers transient overvoltage, which in turn generates pulse interference. Furthermore, external electromagnetic sources, such as lightning and radio equipment, can also cause transient electromagnetic interference in electric field sensors. Within electronic devices, capacitors and inductors can also generate transient current interference when current or voltage changes suddenly. These pulse signals can interfere with the electric field sensor, reducing its measurement accuracy.

[0095] Based on the principle structure of electric field sensors and the causes of electromagnetic transient pulse interference signals, the pulse width and amplitude of transient pulse interference signals will vary depending on the interference source. They may be extremely short pulses or relatively long pulse sequences. The repetition frequency of these pulses will also vary depending on the characteristics of the interference source. The spectrum distribution of transient pulse interference signals can be very wide, covering multiple frequency bands from low to high frequencies, so the interference may affect the performance of electric field sensors in different frequency bands.

[0096] x(t) is used to represent the electromagnetic transient pulse flow of the electric field sensor, and its calculation formula is:

[0097]

[0098] Among them, η k represents the amplitude of the pulse flow, t k represents the time delay parameter of the pulse stream function, and h(t) represents the pulse stream basis function. The pulse stream signal x(t) can be obtained by undersampling. During the sampling process, to ensure the sampling effect, it is completed in a low-speed sampling mode.

[0099] S2. According to the electromagnetic transient pulse flow signal, an adaptive time-varying filter is used to suppress the electromagnetic transient pulse interference signal of the electric field sensor, and the suppression time is recorded.

[0100] According to the characteristics of the electromagnetic transient pulse interference signal of the electric field sensor, in order to achieve the interference suppression of the signal, the electromagnetic transient pulse flow signal x(t) of the electric field sensor is processed based on the generalized S transform to obtain the signal time-frequency diagram; and after the time-frequency diagram is transformed and segmented, the adaptive time-frequency filter is used to perform time-frequency filtering to achieve the separation of the interference signal in the electromagnetic transient pulse flow signal x(t) of the electric field sensor, and complete the suppression of the electromagnetic transient pulse interference signal of the electric field sensor. In the entire interference suppression process, the main purpose of introducing grayscale transformation and threshold segmentation into the method is to more deeply distinguish the background in the signal time-frequency diagram, more accurately determine the interference signal, and ensure the suppression effect of the electromagnetic transient pulse interference signal of the electric field sensor. Specifically including:

[0101] S201 . Based on the generalized S transform, the electromagnetic transient pulse flow signal of the electric field sensor is processed to obtain a signal time-frequency diagram, and the time-frequency diagram is converted and segmented.

[0102] To effectively suppress electromagnetic transient pulse interference signals from electric field sensors, a time-frequency analysis is first performed on the pulse stream signal. This analysis captures changes in signal amplitude, width, and frequency, enabling better interference signal suppression. To ensure effective processing of the pulse stream signal, the electromagnetic transient pulse stream signal x(t) from the electric field sensor is transformed based on an adaptive generalized S-transform algorithm to obtain its time-frequency diagram. The generalized S-transform result of the electromagnetic transient pulse stream signal x(t) from the electric field sensor is represented by g(τ, f, λ), and its calculation formula is:

[0103]

[0104] Where x(t) represents the electromagnetic transient pulse flow signal of the electric field sensor, τ and t both represent time, f represents frequency, λ represents the adjustment factor, and ξ(·) represents the Gaussian window function. According to the above formula, the width of the window function is proportional to the analysis frequency. Therefore, the generalized S transform can obtain better frequency resolution in the low-frequency region and better time resolution in the high-frequency region, ensuring the analysis results of the pulse flow signal.

[0105] In the application process, if the discrete signal of x(t) is represented by x(n), τ = iT, where T and N represent the sampling period and the total amount of data x(n), respectively. The generalized S-transform formula of x(n) is:

[0106]

[0107] Among them, m, n, and i are all variables;

[0108] Perform time-frequency transformation of x(n) using the above formula to obtain a two-dimensional time-frequency negative matrix, and perform modulo processing on the matrix to obtain the time-frequency spectrum of x(n);

[0109] In the application process of generalized S transform, the Gaussian window function ξ(·) has a direct impact on the application performance of the algorithm. In order to improve the transformation effect of generalized S transform on pulse stream signal x(t), ξ(·) is optimized and the corresponding adjustment parameters are introduced into the function so that the function can adjust the parameters according to the aggregation change of signal time-frequency. The improved ξ(·) calculation formula is:

[0110]

[0111] Among them, a, b, c, and d are adjustment parameters used to control the algorithm window properties, including the window size and the width of the basis function;

[0112] During the adjustment process, in order to avoid over-adjustment, the standard deviation affecting the Gaussian window function is constrained, and its calculation formula is:

[0113]

[0114] After completing the constraints according to the above formula, in order to further improve the high-frequency analysis resolution of the algorithm, the time-frequency concentration measurement value ρ is used CM As the objective function of window parameter optimization, the generalized S transform formula of the signal is:

[0115]

[0116] Within the window standard deviation constraint, according to ρ CM The results of the adaptive optimization of parameters are defined by ρ CM The processed time-frequency is an adaptive S-transform, which improves the resolution of the time-frequency diagram after the algorithm transforms the pulse stream signal.

[0117] S202 , performing time-frequency filtering processing using an adaptive time-frequency filter to separate interference signals from the electromagnetic transient pulse flow signal, thereby completing electromagnetic transient pulse interference signal suppression of the electric field sensor.

[0118] After completing the processing of the electromagnetic transient pulse flow signal x(t) of the electric field sensor, interference signal suppression is performed. Since the pulse interference signal changes in real time, in order to ensure the suppression effect, an adaptive time-varying filter is selected to complete it. This filter is formed based on the improvement of the traditional bandpass filter. Its center frequency can change with the change of the pulse signal frequency, and it can effectively suppress multi-component signals. The filter performs grayscale transformation and threshold segmentation on the acquired time-frequency graph, and then suppresses the electromagnetic transient pulse interference signal of the electric field sensor. The processed electromagnetic transient pulse flow signal x(t) of the electric field sensor is expressed by y(t), and its expression formula is:

[0119]

[0120] in, and Represent the transient functions of the rising and falling edges of a single pulse, and The rise time and fall time of the mth pulse respectively;

[0121] Input y(t) into the filter and perform low-pass filtering on it. The function calculation formula is:

[0122] f p (t) = H ―1 {H[y(t)],f p (ω)}

[0123] Among them, H ―1 and H[y(t)] represent the inverse Fourier transform and the Fourier transform, respectively. p (ω) represents the low-pass filter function;

[0124] like and The time difference between them is represented by ΔT, then the single pulse function The calculation formula is:

[0125]

[0126] Based on the above formula, the adaptive filter function f p The calculation formula for (t) is:

[0127]

[0128] Among them, F p represents the output function after filtering;

[0129] According to the above Fourier transform, the two-dimensional distribution of signal time and frequency can be obtained, F pMultiply it by the two-dimensional distribution result to retain the effective pulse signal, complete the effective separation between the signal and the interference, and effectively suppress the interference of the pulse signal outside the pass domain.

[0130] S3. Use an electric field sensor to detect electric field changes in the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected.

[0131] When a distribution transformer is subject to electromagnetic interference, electric field sensors can be used to detect it in the following ways. Typically, the sensors are installed near the transformer's casing, as close as possible to areas where electromagnetic interference may occur, such as the windings and core. This allows for more accurate detection of electric field changes caused by electromagnetic interference. Alternatively, sensors can be installed on the walls of the transformer room or in a cable trench near the transformer to monitor the electric field distribution in the space surrounding the transformer.

[0132] The electric field sensor works based on the principle of capacitive induction. It has a sensitive electrode inside. When there is a changing electric field around it, charges will be induced on the sensitive electrode, thereby generating an electrical signal that is proportional to the electric field strength.

[0133] When a distribution transformer operates normally, a stable electric field distribution exists around it, and the electric field signals detected by the electric field sensor are also relatively stable. However, when subjected to electromagnetic interference, such as when nearby high-frequency equipment starts up or when a power line fault creates an arc, the electric field around the transformer becomes distorted. The electric field sensor promptly detects these changes and converts them into an electrical signal for output. The output signal is amplified and filtered by the signal conditioning circuit to remove noise and interference before being transmitted to the data acquisition system. By analyzing the collected electric field signals, such as using spectrum analysis or time domain analysis, the presence of electromagnetic interference and its characteristics, such as frequency and intensity, can be determined. For example, if spectrum analysis reveals an abnormal high-frequency component that matches the frequency of a known interference source, it can be determined that the distribution transformer is experiencing electromagnetic interference.

[0134] S4. If an electric field change caused by electromagnetic interference is detected, steady-state electromagnetic interference suppression is performed on the distribution transformer.

[0135] Step S4 specifically includes:

[0136] S401. If an electric field change caused by electromagnetic interference is detected, the transformer parameters of the distribution transformer are improved; wherein the transformer parameters include core magnetic flux density, magnetostriction, and overlap area of the inclined seam region.

[0137] (1) Improvement of core magnetic flux density:

[0138] The rated working magnetic flux density of the core is related to the noise. The noise impact caused by the change of working magnetic flux density is expressed by the following formula:

[0139]

[0140] Among them, φ0 and φ′ represent the rated working magnetic flux density parameters of the core before and after the change respectively; g Fe0 , g′ Fe They represent the weight of the core before and after the change in magnetic flux density. In order to keep the total magnetic flux unchanged, the cross-sectional area of the core is increased to compensate for the magnetic flux loss caused by the decrease in magnetic density. When the magnetic density and weight of the core increase, the noise also becomes larger. The noise is suppressed by controlling the magnetic flux density and weight.

[0141] (2) Improvement of magnetostriction:

[0142] Magnetostriction refers to the rotation of silicon steel grains in a magnetic field. The transformer core is made of stacked silicon steel plates. When the high-voltage coil's excitation current is excited by the core, the size of the core's silicon steel plates changes due to the rotation of the plates under the action of the AC magnetic field. This change in size due to electromagnetic interference is magnetostriction. The formula for the change in magnetostriction can be expressed as:

[0143]

[0144] Among them, ΔL represents the increment of silicon steel sheet length during excitation, and L0 represents the initial length of silicon steel sheet. Since the silicon steel sheet magnetostricts twice for each current change in the distribution transformer, the number of magnetostrictions is reduced to avoid the generation of high harmonic components.

[0145] (3) Improvement of the overlap area of the bevel joint area:

[0146] The overlap area of the bevel joint area also affects the noise of the transformer. Although the iron core increases the overlap area of the silicon steel sheets and increases the friction between the silicon steel sheets, it also increases the noise in the direction of the magnetic flux of the silicon steel sheets. The change in noise caused by the change in the overlap area of the bevel joint area can be expressed as:

[0147]

[0148] Wherein, S represents the overlapping area of the bevel joint area. In order to suppress noise, the overlapping area of the bevel joint area is reduced to achieve the purpose of reducing noise.

[0149] S402: construct an interference suppression device according to the transformer parameters, and utilize the interference suppression device in combination with logic operations to suppress electromagnetic interference.

[0150] The interference suppression device is designed by comprehensively improving the core magnetic flux density, magnetostriction coefficient, and overlap area of the inclined seam. The steady-state electromagnetic interference suppression device of the distribution transformer is to connect a suitable capacitor in series between the neutral point of the transformer and the system ground, and achieve DC isolation through the capacitor's AC and DC isolation function, which can effectively suppress the DC current at the neutral point to zero. The suppression device structure is as follows: Figure 2 As shown, specifically including:

[0151] One end of the inductor L1 is connected to one end of the switch K2 and one end of the switch K1, the other end of the switch K1 is grounded, the other end of the switch K2 is connected to one end of the resistor R, one end of the blocking capacitor, one end of the coupling transformer, one end of the switch K3, and one end of the switch K4, the other end of the resistor R is connected to one end of the capacitor C, the other end of the capacitor C is connected to one end of the inductor L2, the other end of the inductor L2 is connected to the other end of the blocking capacitor, the other end of the switch K3, the other end of the switch K4, and the current transformer, the current transformer is connected to the other end of the coupling transformer and is grounded;

[0152] During operation of the interference suppression device, if a single-phase ground fault occurs and the capacitor voltage rises, the zinc oxide valve's high-capacity, fast-acting switch K2 provides dual protection for the DC isolation capacitors. The zinc oxide valve features excellent nonlinear performance and a fast response. The suppressor's high-capacity, fast opening and closing times are less than 15ms. It accurately predicts the current zero crossing and closes at zero, with no rebound or cold welding. When the voltage reaches the zinc oxide operating state, the zinc oxide is opened, preventing the voltage from exceeding the capacitor's tolerance limit. Upon receiving the signal, the bypass fast switches K1 and K2 immediately close, directly grounding the neutral point. The bypass switch's fast switching function effectively protects the zinc oxide, suppressing the DC current to zero.

[0153] According to the interference suppression device, signals with a common busbar adjacent relationship are detected and marked with serial numbers. The device is subjected to an exclusive OR logic operation in a one-way forward loop, and then all operations are processed in an AND logic operation. The specific interference suppression is based on:

[0154] I B =(I i ⊕I i+1 )&(I i+1 ⊕I i+2 )&…&(I i+j―1 ⊕I i )

[0155] Among them, i and j represent the minimum number and the number of transformer buses in the detection processing point, respectively. ⊕ represents the exclusive OR operator, & represents the AND operator. B It represents the comparison result of the transient current polarity measured on all buses. The judgment formula for whether electromagnetic interference occurs on the bus is:

[0156]

[0157] When I B =1, the following interference suppression is performed:

[0158] Compare the filtered distribution transformer operating curve with the curve subjected to electromagnetic interference to obtain the relationship between the two. The operating mode in this state can be expressed as:

[0159]

[0160] Among them, R t 、R t′ They represent the state values after filtering at time t and time t' respectively. After filtering, the signal after electromagnetic interference is filtered out is concentrated in the range of 50-250Hz. The filtered signal is converted from a digital signal to an analog signal after A / D conversion. The analog signal is sent by the driving speaker of the audio amplifier to prevent interference from other high-frequency devices and achieve the purpose of suppressing electromagnetic interference.

[0161] S5. If no electric field change caused by electromagnetic interference is detected, determine whether the time length from the current time to the suppression time reaches the set time length.

[0162] S6. If the set time length is not reached, return to the step of using an electric field sensor to detect electric field changes on the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected.

[0163] S7. If the set time length is reached, return to the step of obtaining the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling.

[0164] The present invention obtains the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system, and adopts an adaptive time-varying filter to suppress the electromagnetic transient pulse interference signal of the electric field sensor. It can reliably complete signal conversion, and realize effective separation of interference signals based on the converted results, retain effective signals, improve the suppression effect, and ensure the measurement accuracy of the electric field sensor; then, the electric field sensor is used to detect the electric field change of the distribution transformer to suppress the steady-state electromagnetic interference of the distribution transformer according to the electric field change, and perform electromagnetic interference cyclic detection and suppression according to the electric field change detected by the electric field sensor and the suppression time of the electric field sensor, which can effectively suppress the influence of electromagnetic interference on the electric field sensor and the distribution transformer, and improve the operation stability of the photovoltaic energy storage system.

[0165] like Figure 3As shown, the present invention also provides an intelligent control device for suppressing electromagnetic interference in a photovoltaic energy storage system, comprising:

[0166] Acquisition module 1, used to acquire electromagnetic transient pulse flow signals of electric field sensors in photovoltaic energy storage systems by undersampling;

[0167] A first suppression module 2 is configured to suppress the electromagnetic transient pulse interference signal of the electric field sensor using an adaptive time-varying filter according to the electromagnetic transient pulse flow signal, and record the suppression time;

[0168] Detection module 3, used to detect electric field changes in the distribution transformer in the photovoltaic energy storage system using an electric field sensor to determine whether electric field changes caused by electromagnetic interference are detected;

[0169] A second suppression module 4 is configured to suppress steady-state electromagnetic interference on the distribution transformer when an electric field change caused by electromagnetic interference is detected;

[0170] A judgment module 5 is used to judge whether the time length from the current time to the suppression time reaches the set time length when no electric field change caused by electromagnetic interference is detected;

[0171] A first return module 6 is configured to return to the step of using an electric field sensor to detect electric field changes on the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected when the set time length has not been reached;

[0172] The second returning module 7 is configured to return to the step of acquiring the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling when the set time length is reached.

[0173] In one embodiment, the first suppression module 2 includes:

[0174] a first processing unit, configured to process the electromagnetic transient pulse flow signal of the electric field sensor based on a generalized S transform, obtain a signal time-frequency graph, and perform conversion and segmentation processing on the time-frequency graph;

[0175] The second processing unit is used to perform time-frequency filtering processing using an adaptive time-frequency filter to separate the interference signal from the electromagnetic transient pulse flow signal and complete the suppression of the electromagnetic transient pulse interference signal of the electric field sensor.

[0176] In one embodiment, the first processing unit includes:

[0177] The generalized S-transform result of the electromagnetic transient pulse flow signal of the electric field sensor is expressed by g(τ, f, λ), and its calculation formula is:

[0178]

[0179] Where x(t) represents the electromagnetic transient pulse flow signal of the electric field sensor, τ and t both represent time, f represents frequency, λ represents the adjustment factor, and ξ(·) represents the Gaussian window function;

[0180] In the application process, if the discrete signal of x(t) is represented by x(n), τ = iT, where T and N represent the sampling period and the total amount of data x(n), respectively. The generalized S-transform formula of x(n) is:

[0181]

[0182] Among them, m, n, and i are all variables;

[0183] Perform time-frequency transformation of x(n) using the above formula to obtain a two-dimensional time-frequency negative matrix, and perform modulo processing on the matrix to obtain the time-frequency spectrum of x(n);

[0184] During the application of the generalized S transform, the corresponding adjustment parameters are introduced into the Gaussian window function ξ(·), so that the function can adjust the parameters according to the changes in the aggregation of the signal time-frequency. The improved ξ(·) calculation formula is:

[0185]

[0186] Among them, a, b, c, and d are adjustment parameters used to control the algorithm window properties, including the window size and the width of the basis function;

[0187] During the adjustment process, the standard deviation affecting the Gaussian window function is constrained, and its calculation formula is:

[0188]

[0189] Using time-frequency concentration measurement value ρ CM As the objective function of window parameter optimization, the generalized S transform formula of the signal is:

[0190]

[0191] Within the window standard deviation constraint, according to ρ CM The results of the adaptive optimization of parameters are defined by ρ CM The processed time-frequency is an adaptive S-transform, which improves the resolution of the time-frequency diagram after the algorithm transforms the pulse stream signal.

[0192] In one embodiment, the second processing unit includes:

[0193] The processed electromagnetic transient pulse flow signal x(t) of the electric field sensor is expressed as y(t), and its expression formula is:

[0194]

[0195] in, and Represent the transient functions of the rising and falling edges of a single pulse, and The rise time and fall time of the mth pulse respectively;

[0196] Input y(t) into the filter and perform low-pass filtering on it. The function calculation formula is:

[0197] f p (t) = H ―1 {H[y(t)],f p (ω)}

[0198] Among them, H ―1 and H[y(t)] represent the inverse Fourier transform and the Fourier transform, respectively. p (ω) represents the low-pass filter function;

[0199] like and The time difference between them is represented by ΔT, then the single pulse function The calculation formula is:

[0200]

[0201] Based on the above formula, the adaptive filter function f p The calculation formula for (t) is:

[0202]

[0203] Among them, F p represents the output function after filtering;

[0204] According to the above Fourier transform, the two-dimensional distribution of signal time and frequency can be obtained, F p Multiply it by the two-dimensional distribution result to retain the effective pulse signal, complete the effective separation between the signal and the interference, and effectively suppress the interference of the pulse signal outside the pass domain.

[0205] In one embodiment, the second suppression module 4 includes:

[0206] An improvement unit, configured to improve transformer parameters of the distribution transformer when an electric field change caused by electromagnetic interference is detected; wherein the transformer parameters include core magnetic flux density, magnetostriction, and overlap area of the bevel joint region;

[0207] The suppression unit is used to construct an interference suppression device according to the transformer parameters, and utilize the interference suppression device in combination with logic operations to suppress electromagnetic interference.

[0208] In one embodiment, the improvement unit includes:

[0209] Improvement of core flux density:

[0210] The rated working magnetic flux density of the core is related to the noise. The noise impact caused by the change of working magnetic flux density is expressed by the following formula:

[0211]

[0212] Among them, φ0 and φ′ represent the rated working magnetic flux density parameters of the core before and after the change respectively; g Fe0 , g′ Fe Represents the weight of the core before and after the change in magnetic flux density. In order to keep the total magnetic flux unchanged, the cross-sectional area of the core is increased to compensate for the magnetic flux loss caused by the decrease in magnetic density. When the magnetic flux density and weight of the core increase, the noise also becomes larger. The noise is suppressed by controlling the magnetic flux density and weight.

[0213] Improvement of magnetostriction:

[0214] The formula for the change of magnetostriction can be expressed as:

[0215]

[0216] Where ΔL represents the increment of silicon steel sheet length during excitation, and L0 represents the initial length of silicon steel sheet. Since the silicon steel sheet magnetostricts twice for each current change in the distribution transformer, the number of magnetostrictions should be reduced to avoid the generation of high harmonic components.

[0217] Improvements to the overlap area of mitered joints:

[0218] The noise change caused by the change in the overlapping area of the bevel joint can be expressed as follows:

[0219]

[0220] Wherein, S represents the overlapping area of the bevel joint area. In order to suppress noise, the overlapping area of the bevel joint area is reduced to achieve the purpose of reducing noise.

[0221] In one embodiment, the suppression unit comprises:

[0222] Construct an interference suppression device by connecting a capacitor in series between the neutral point of the transformer and the system ground, and achieve DC isolation through the capacitor's AC blocking and DC isolation functions. Specifically, the device includes:

[0223] One end of the inductor L1 is connected to one end of the switch K2 and one end of the switch K1, the other end of the switch K1 is grounded, the other end of the switch K2 is connected to one end of the resistor R, one end of the blocking capacitor, one end of the coupling transformer, one end of the switch K3, and one end of the switch K4, the other end of the resistor R is connected to one end of the capacitor C, the other end of the capacitor C is connected to one end of the inductor L2, the other end of the inductor L2 is connected to the other end of the blocking capacitor, the other end of the switch K3, the other end of the switch K4, and the current transformer, the current transformer is connected to the other end of the coupling transformer and is grounded;

[0224] During the operation of the interference suppression device, if a single-phase grounding fault occurs and the capacitor voltage rises, the large-capacity fast switch K2 of the zinc oxide valve plate is used to provide double protection for the DC insulation capacitor. The bypass fast switches K3 and K4 are immediately closed after receiving the signal and the neutral point is directly grounded to effectively protect the zinc oxide, that is, to suppress the DC current to zero;

[0225] According to the interference suppression device, signals with a common busbar adjacent relationship are detected and marked with serial numbers. The device is subjected to an exclusive OR logic operation in a one-way forward loop, and then all operations are processed in an AND logic operation. The specific interference suppression is based on:

[0226] I B =(I i ⊕I i+1 )&(I i+1 ⊕I i+2 )&…&(I i+j―1 ⊕I i )

[0227] Among them, i and j represent the minimum number and the number of transformer buses in the detection processing point, respectively. ⊕ represents the exclusive OR operator, & represents the AND operator. B It represents the comparison result of the transient current polarity measured on all buses. The judgment formula for whether electromagnetic interference occurs on the bus is:

[0228]

[0229] When I B =1, the following interference suppression is performed:

[0230] Compare the filtered distribution transformer operating curve with the curve subjected to electromagnetic interference to obtain the relationship between the two. The operating mode in this state can be expressed as:

[0231]

[0232] Among them, R t 、R t′They represent the state values after filtering at time t and time t' respectively. After filtering, the signal after electromagnetic interference is filtered out is concentrated in the range of 50-250Hz. The filtered signal is converted from a digital signal to an analog signal after A / D conversion. The analog signal is sent by the driving speaker of the audio amplifier to prevent interference from other high-frequency devices and achieve the purpose of suppressing electromagnetic interference.

[0233] The above modules and units are used to execute the corresponding steps in the intelligent control method for suppressing electromagnetic interference in the photovoltaic energy storage system. The specific implementation method thereof is described in the above method embodiment and will not be repeated here.

[0234] like Figure 4 As shown, the present invention also provides a computer device, which can be a server, and its internal structure can be as follows Figure 4 As shown. The computer device includes a processor, a memory, a network interface and a database connected via a system bus. The processor of the computer design is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store all data required for the process of the intelligent control method for suppressing electromagnetic interference in a photovoltaic energy storage system. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, the intelligent control method for suppressing electromagnetic interference in a photovoltaic energy storage system is implemented.

[0235] Those skilled in the art will understand that Figure 4 The structure shown in is merely a block diagram of a portion of the structure related to the present application solution and does not constitute a limitation on the computer device to which the present application solution is applied.

[0236] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, any of the above-mentioned intelligent control methods for suppressing electromagnetic interference in a photovoltaic energy storage system is implemented.

[0237] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0238] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, apparatus, article, or method comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, apparatus, article, or method. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, apparatus, article, or method comprising the element.

[0239] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An intelligent control method for suppressing electromagnetic interference in a photovoltaic energy storage system, characterized in that: include: The electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system is obtained by undersampling; According to the electromagnetic transient pulse flow signal, an adaptive time-varying filter is used to suppress the electromagnetic transient pulse interference signal of the electric field sensor, and the suppression time is recorded; Use electric field sensors to detect electric field changes in the distribution transformers in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected; If an electric field change caused by electromagnetic interference is detected, steady-state electromagnetic interference suppression is performed on the distribution transformer; If no electric field change caused by electromagnetic interference is detected, determining whether the time length from the current time to the suppression time reaches the set time length; If the set time length is not reached, the process returns to the step of using an electric field sensor to detect electric field changes on the distribution transformer in the photovoltaic energy storage system to determine whether electric field changes caused by electromagnetic interference are detected; If the set time length is reached, the process returns to the step of obtaining the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling.

2. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 1, characterized in that: The step of using an adaptive time-varying filter to suppress the electromagnetic transient pulse interference signal of the electric field sensor according to the electromagnetic transient pulse flow signal and recording the suppression time includes: Based on the generalized S transform, the electromagnetic transient pulse flow signal of the electric field sensor is processed to obtain a signal time-frequency diagram, and the time-frequency diagram is transformed and segmented; An adaptive time-frequency filter is used to perform time-frequency filtering processing to achieve separation of interference signals from the electromagnetic transient pulse flow signal and complete suppression of electromagnetic transient pulse interference signals of the electric field sensor.

3. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 2, characterized in that: The steps of processing the electromagnetic transient pulse flow signal of the electric field sensor based on the generalized S transform, obtaining a signal time-frequency diagram, and converting and segmenting the time-frequency diagram include: The generalized S-transform result of the electromagnetic transient pulse flow signal of the electric field sensor is expressed by g(τ, f, λ), and its calculation formula is: Where x(t) represents the electromagnetic transient pulse flow signal of the electric field sensor, τ and t both represent time, f represents frequency, λ represents the adjustment factor, and ξ(·) represents the Gaussian window function; In the application process, if the discrete signal of x(t) is represented by x(n), τ = iT, where T and N represent the sampling period and the total amount of data x(n), respectively. The generalized S-transform formula of x(n) is: Among them, m, n, and i are all variables; Perform time-frequency transformation of x(n) using the above formula to obtain a two-dimensional time-frequency negative matrix, and perform modulo processing on the matrix to obtain the time-frequency spectrum of x(n); During the application of the generalized S transform, the corresponding adjustment parameters are introduced into the Gaussian window function ξ(·), so that the function can adjust the parameters according to the changes in the aggregation of the signal time-frequency. The improved ξ(·) calculation formula is: Among them, a, b, c, and d are adjustment parameters used to control the algorithm window properties, including the window size and the width of the basis function; During the adjustment process, the standard deviation affecting the Gaussian window function is constrained, and its calculation formula is: Using time-frequency concentration measurement value ρ CM As the objective function of window parameter optimization, the generalized S transform formula of the signal is: Within the window standard deviation constraint, according to ρ CM The results of the adaptive optimization of parameters are defined by ρ CM The processed time-frequency is an adaptive S-transform, which improves the resolution of the time-frequency diagram after the algorithm transforms the pulse stream signal.

4. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 3, characterized in that: The step of using an adaptive time-frequency filter to perform time-frequency filtering to separate the interference signal from the electromagnetic transient pulse flow signal and complete the step of suppressing the electromagnetic transient pulse interference signal of the electric field sensor includes: The processed electromagnetic transient pulse flow signal x(t) of the electric field sensor is expressed as y(t), and its expression formula is: in, and Represent the transient functions of the rising and falling edges of a single pulse, and The rise time and fall time of the mth pulse respectively; Input y(t) into the filter and perform low-pass filtering on it. The function calculation formula is: f p (t)=H ―1 {H[y(t)],f p (ω)} Among them, H ―1 and H[y(t)] represent the inverse Fourier transform and the Fourier transform, respectively. p (ω) represents the low-pass filter function; like and The time difference between them is represented by ΔT, then the single pulse function The calculation formula is: Based on the above formula, the adaptive filter function f p The calculation formula for (t) is: Among them, F p represents the output function after filtering; According to the above Fourier transform, the two-dimensional distribution of signal time and frequency can be obtained, F p Multiply it by the two-dimensional distribution result to retain the effective pulse signal, complete the effective separation between the signal and the interference, and effectively suppress the interference of the pulse signal outside the pass domain.

5. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 1, characterized in that: The step of suppressing steady-state electromagnetic interference on the distribution transformer if an electric field change caused by electromagnetic interference is detected comprises: If an electric field change caused by electromagnetic interference is detected, the transformer parameters of the distribution transformer are improved; wherein the transformer parameters include core magnetic flux density, magnetostriction, and overlap area of the inclined seam area; An interference suppression device is constructed according to the transformer parameters, and the interference suppression device is used in combination with logic operations to suppress electromagnetic interference.

6. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 5, characterized in that: The step of improving transformer parameters of the distribution transformer if an electric field change caused by electromagnetic interference is detected comprises: Improvement of core flux density: The rated working magnetic flux density of the core is related to the noise. The noise impact caused by the change of working magnetic flux density is expressed by the following formula: Among them, φ0 and φ′ represent the rated working magnetic flux density parameters of the core before and after the change respectively; gF e0 , g′ Fe Represents the weight of the core before and after the change in magnetic flux density. In order to keep the total magnetic flux unchanged, the cross-sectional area of the core is increased to compensate for the magnetic flux loss caused by the decrease in magnetic density. When the magnetic flux density and weight of the core increase, the noise also becomes larger. The noise is suppressed by controlling the magnetic flux density and weight. Improvement of magnetostriction: The formula for the change of magnetostriction can be expressed as: Where ΔL represents the increment of silicon steel sheet length during excitation, and L0 represents the initial length of silicon steel sheet. Since the silicon steel sheet magnetostricts twice for each current change in the distribution transformer, the number of magnetostrictions should be reduced to avoid the generation of high harmonic components. Improvements to the overlap area of mitered joints: The noise change caused by the change in the overlapping area of the bevel joint can be expressed as follows: Wherein, S represents the overlapping area of the bevel joint area. In order to suppress noise, the overlapping area of the bevel joint area is reduced to achieve the purpose of reducing noise.

7. The intelligent control method for electromagnetic interference suppression in a photovoltaic energy storage system according to claim 6, characterized in that: The step of constructing an interference suppression device according to the transformer parameters and utilizing the interference suppression device in combination with logic operations to suppress electromagnetic interference includes: Construct an interference suppression device by connecting a capacitor in series between the neutral point of the transformer and the system ground, and achieve DC isolation through the capacitor's AC blocking and DC isolation functions. Specifically, the device includes: One end of the inductor L1 is connected to one end of the switch K2 and one end of the switch K1, the other end of the switch K1 is grounded, the other end of the switch K2 is connected to one end of the resistor R, one end of the blocking capacitor, one end of the coupling transformer, one end of the switch K3, and one end of the switch K4, the other end of the resistor R is connected to one end of the capacitor C, the other end of the capacitor C is connected to one end of the inductor L2, the other end of the inductor L2 is connected to the other end of the blocking capacitor, the other end of the switch K3, the other end of the switch K4, and the current transformer, the current transformer is connected to the other end of the coupling transformer and is grounded; During the operation of the interference suppression device, if a single-phase grounding fault occurs and the capacitor voltage rises, the large-capacity fast switch K2 of the zinc oxide valve plate is used to provide double protection for the DC insulation capacitor. The bypass fast switches K3 and K4 are immediately closed after receiving the signal and the neutral point is directly grounded to effectively protect the zinc oxide, that is, to suppress the DC current to zero; According to the interference suppression device, signals with a common busbar adjacent relationship are detected and marked with serial numbers. The device is subjected to an exclusive OR logic operation in a one-way forward loop, and then all operations are processed in an AND logic operation. The specific interference suppression is based on: Among them, i and j represent the minimum number and number of transformer buses corresponding to the detection processing point, respectively. Indicates the same or logical operator, & indicates the logical and operator, I B It represents the comparison result of the transient current polarity measured on all buses. The judgment formula for whether electromagnetic interference occurs on the bus is: When I B =1, the following interference suppression is performed: Compare the filtered distribution transformer operating curve with the curve subjected to electromagnetic interference to obtain the relationship between the two. The operating mode in this state can be expressed as: Among them, R t 、R t′ They represent the state values after filtering at time t and time t' respectively. After filtering, the signal after electromagnetic interference is filtered out is concentrated in the range of 50-250Hz. The filtered signal is converted from a digital signal to an analog signal after A / D conversion. The analog signal is sent by the driving speaker of the audio amplifier to prevent interference from other high-frequency devices and achieve the purpose of suppressing electromagnetic interference.

8. An intelligent control device for suppressing electromagnetic interference in a photovoltaic energy storage system, characterized in that: include: An acquisition module is used to acquire electromagnetic transient pulse flow signals of electric field sensors in photovoltaic energy storage systems by undersampling; a first suppression module, configured to suppress the electromagnetic transient pulse interference signal of the electric field sensor using an adaptive time-varying filter according to the electromagnetic transient pulse flow signal, and record the suppression time; A detection module is used to detect electric field changes in the distribution transformer of the photovoltaic energy storage system using an electric field sensor to determine whether electric field changes caused by electromagnetic interference are detected; a second suppression module, configured to suppress steady-state electromagnetic interference on the distribution transformer when a change in the electric field caused by electromagnetic interference is detected; A judgment module, configured to judge whether the time length from the current time to the suppression time reaches a set time length when no electric field change caused by electromagnetic interference is detected; A first return module is configured to return to the step of using an electric field sensor to detect electric field changes on a distribution transformer in the photovoltaic energy storage system to determine whether an electric field change caused by electromagnetic interference is detected if the set time length has not been reached; The second returning module is used to return to the step of obtaining the electromagnetic transient pulse flow signal of the electric field sensor in the photovoltaic energy storage system by undersampling when the set time length is reached.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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