A new energy grid-connected resonance overvoltage suppression method, device and equipment

Abstract

The application provides a new energy grid-connected resonance overvoltage suppression method, device and equipment, relates to the power grid technical field, and the method comprises the following steps: receiving a zero starting voltage boosting completion signal, sequentially connecting a photovoltaic system and a wind turbine generator of a wind farm of a photovoltaic power station into a power grid to obtain a grid-connected point; based on electromagnetic transient simulation, acquiring voltage harmonic components of the grid-connected point in real time to generate second monitoring data; dynamically adjusting grid-connected timing and converter control parameters to reduce the resonance overvoltage amplitude in the second monitoring data to within a safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably operated, a new energy grid-connected completion signal is output; according to the new energy grid-connected completion signal, a substation switch is closed to access a preset load, and when load operating parameters continuously reach a stable state, the black start mode is exited and switched to a normal operation mode. The scheme improves the safety and reliability of the black start process in the high-proportion new energy access scenario.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid, in particular to a new energy grid-connected resonance overvoltage suppression method, device and equipment. BACKGROUND

[0002] At present, with the transformation of energy structure, the proportion of new energy power generation represented by photovoltaic and wind power in the power system continues to rise. After a large area of power grid outage, fast and reliable power restoration (i.e. "black start") is the key link to ensure the resilience and safety of the power grid. Grid-forming (GFM) energy storage system has become an ideal choice to support regional power grid black start because of its ability to independently establish and support grid voltage and frequency, especially for new power systems dominated by new energy. In the process of black start using grid-forming energy storage, a key step is to gradually integrate large photovoltaic power stations and wind farms in the recovery area into the "microgrid" preliminarily established by energy storage. However, this grid-connection process faces serious technical challenges, especially the problem of resonance overvoltage. At present, the common suppression ideas for resonance overvoltage in the process of black start mainly include: installing passive filters (such as single-tuned, high-pass filters) at key nodes to absorb harmonics of specific frequencies; trying to optimize the control parameters of new energy converters (such as improving the phase-locked loop damping and adjusting the current loop bandwidth) to improve their stability in weak grids. However, the main shortcomings of the existing technology are that it cannot effectively combine real-time voltage monitoring data (especially resonance components) in the black start process for dynamic decision-making, and it cannot close-loop coordinated control the stages of grid-forming energy storage voltage stabilization, step-by-step grid-connection of new energy stations, resonance suppression, and load access as an organic whole. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a new energy grid-connected resonance overvoltage suppression method, device and equipment to improve the safety and reliability of the black start process in the scenario of high proportion of new energy access.

[0004] To solve the above technical problems, the technical solutions of the present application are as follows:

[0005] The present application provides a new energy grid-connected resonance overvoltage suppression method applied to an energy storage system, which comprises:

[0006] Real-time acquisition of power frequency voltage of energy storage system bus, photovoltaic power station bus and wind farm bus to obtain first monitoring data;

[0007] According to the first monitoring data, when all bus voltages are stable in the preset range and there is no resonance phenomenon, output a zero step-up completion signal;

[0008] receive the zero-voltage rise completion signal, in turn, the photovoltaic system and the wind turbine of the wind farm connected to the transformer of the photovoltaic power station are connected to the power grid, and the grid-connected point is obtained;

[0009] Based on the electromagnetic transient simulation, the voltage harmonic component of the grid-connected point is obtained in real time, and the second monitoring data is generated;

[0010] The grid-connected timing and converter control parameters are dynamically adjusted to reduce the resonance overvoltage amplitude in the second monitoring data to within the safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably operated, the new energy grid-connected completion signal is output;

[0011] According to the new energy grid-connected completion signal, the switch of the transformer substation is closed to access the preset load, and when the load operating parameters continuously reach a stable state, the black start mode is exited and switched to a normal operation mode.

[0012] Optionally, the first monitoring data includes: the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind farm bus, the voltage fluctuation waveform and the voltage fluctuation waveform.

[0013] Optionally, according to the first monitoring data, when all bus voltages are stable in the preset range and there is no resonance phenomenon, the zero-voltage rise completion signal is output, including:

[0014] Real-time acquisition of the first monitoring data includes: the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind farm bus, the voltage fluctuation waveform and the voltage fluctuation waveform;

[0015] Judge whether the power frequency voltage of all buses is continuously in the standard specified preset range, and whether there is a resonance phenomenon based on the voltage fluctuation waveform;

[0016] When all bus voltages are continuously stable in the preset range for a preset period of time, and the voltage fluctuation waveform has no resonance characteristics, the zero-voltage rise completion signal is output.

[0017] Optionally, receiving the zero-voltage rise completion signal, in turn, the photovoltaic system and the wind turbine of the wind farm connected to the transformer of the photovoltaic power station are connected to the power grid, and the grid-connected point is obtained, including:

[0018] According to the zero-voltage rise completion signal, the photovoltaic system grid-connected instruction is generated and sent to the transformer of the photovoltaic power station, so that the transformer of the photovoltaic power station performs closing operation according to the grid-connected instruction, and the connected photovoltaic system is connected to the power grid. Real-time monitoring of the voltage and current transient response of the grid-connected point;

[0019] When the transient response of the photovoltaic system after grid connection is continuously stable for a first preset time, the wind turbine grid-connected instruction is generated and sent to the wind farm, so that the wind farm performs wind turbine grid-connected operation according to the wind turbine grid-connected instruction, and the position parameters of the grid-connected point are recorded synchronously, and the new energy grid connection is completed.

[0020] Optionally, the voltage harmonic components of the grid-connected point are obtained in real time based on electromagnetic transient simulation to generate second monitoring data, including:

[0021] An electromagnetic transient simulation model is established based on the grid-connected point position parameters to obtain initial simulation parameters;

[0022] Based on the initial simulation parameters, real-time simulation calculation is performed on the grid-connected point voltage to extract fundamental wave components and harmonic components to form original harmonic data;

[0023] The original harmonic data is analyzed in time domain and frequency domain to determine the dominant harmonic order of the resonance overvoltage and its dynamic amplitude variation characteristics;

[0024] According to the dominant harmonic order and the dynamic amplitude variation characteristics, second monitoring data containing harmonic components, amplitude fluctuation range and time evolution law are generated.

[0025] Optionally, the grid-connected timing and converter control parameters are dynamically adjusted to reduce the resonance overvoltage amplitude in the second monitoring data to within a safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably running, a new energy grid-connected completion signal is output, including:

[0026] The dominant harmonic order and the dynamic amplitude variation characteristics in the second monitoring data are analyzed to generate a resonance overvoltage suppression strategy, including a converter parameter adjustment scheme and a grid-connected timing optimization scheme;

[0027] According to the converter parameter adjustment scheme, impedance adjustment instructions and phase compensation instructions are sent to the photovoltaic power station and wind farm converter, and converter feedback parameters are synchronously collected;

[0028] Based on the grid-connected timing optimization scheme and the converter feedback parameters, the final grid-connected time window of the to-be-grid-connected unit is recalculated to generate a grid-connected timing control instruction;

[0029] The grid-connected timing control instruction is executed to complete the grid-connected operation of the remaining units within the final grid-connected time window, while monitoring the grid-connected point voltage harmonic components and the energy storage system output power;

[0030] When the resonance overvoltage amplitude is continuously monitored for three sampling periods below the safety threshold, and the energy storage system output power fluctuation rate is maintained within a preset range, a new energy grid-connected completion signal is generated.

[0031] Optionally, according to the new energy grid-connected completion signal, a substation switch is closed to access a preset load, and when the load operating parameters continuously reach a stable state, the black start mode is exited and switched to normal operation, including:

[0032] Receive new energy grid-connected completion signal, generate load hierarchical access instruction and send to substation switch controller;

[0033] According to the load hierarchical access instruction, the low-voltage side bus coupler switch and the high-voltage side incoming line switch are closed in a predetermined order, and the preset load capacity is realized by stage-by-stage input;

[0034] In the load input process, the load active power, reactive power, power factor and power grid frequency deviation data are collected in real time to form a load dynamic response data set;

[0035] The load dynamic response data set is stably evaluated, and a stability confirmation signal is generated;

[0036] In response to the stability confirmation signal, the energy storage system is disconnected from the black start control link and switched to the power grid dispatching master station control mode, and the mode switching time parameter is recorded.

[0037] The embodiment of the application also provides a new energy grid-connected resonance overvoltage suppression device, comprising:

[0038] The acquisition module is used for collecting the power frequency voltage of the energy storage system bus, the photovoltaic power station bus and the wind farm bus in real time to obtain first monitoring data;

[0039] The confirmation module is used for outputting a zero voltage rise completion signal when all bus voltages are stably in a preset range and there is no resonance phenomenon according to the first monitoring data;

[0040] The grid-connected module is used for receiving the zero voltage rise completion signal, sequentially connecting the photovoltaic system connected to the photovoltaic power station transformer and the wind turbine generator connected to the wind farm transformer to the power grid to obtain a grid-connected point; the voltage harmonic component of the grid-connected point is obtained in real time based on electromagnetic transient simulation to generate second monitoring data;

[0041] The adjustment module is used for dynamically adjusting the grid-connected timing and the converter control parameter, so that the resonance overvoltage amplitude in the second monitoring data is reduced to within a safety threshold; and when it is confirmed that the energy storage system is stably operated according to the second monitoring data, a new energy grid-connected completion signal is outputted;

[0042] The processing module is used for closing the substation switch to access the preset load according to the new energy grid-connected completion signal, and when the load operation parameter continuously reaches a stable state, the black start mode is exited and switched to a normal operation mode.

[0043] The embodiment of the application also provides a computing device, which comprises a processor and a memory storing a computer program, and the computer program is executed by the processor to perform the above-mentioned method.

[0044] The embodiment of the present application also provides a computer readable storage medium, comprising: storage instructions, when the instructions are run on a computer, the computer executes the method.

[0045] The above scheme of the present application at least has the following beneficial effects:

[0046] The new energy grid-connected resonance overvoltage suppression method provided by the present application comprises the following steps: collecting the power frequency voltage of a bus of an energy storage system, a bus of a photovoltaic power station and a bus of a wind power field in real time to obtain first monitoring data; when all bus voltages are stable in a preset range and no resonance phenomenon occurs, outputting a zero voltage rise completion signal according to the first monitoring data; receiving the zero voltage rise completion signal, sequentially connecting photovoltaic systems connected to a transformer substation of the photovoltaic power station and wind turbine generators of the wind power field to the power grid to obtain a grid-connected point; obtaining voltage harmonic components of the grid-connected point based on electromagnetic transient simulation to generate second monitoring data; dynamically adjusting grid-connected timing and converter control parameters to reduce the resonance overvoltage amplitude in the second monitoring data to within a safety threshold; outputting a new energy grid-connected completion signal when it is confirmed that the energy storage system is stably operated according to the second monitoring data; and closing a substation switch to access a preset load according to the new energy grid-connected completion signal, and exiting a black start mode and switching to a normal operation mode when load operation parameters continuously reach a stable state. Through a multi-dimensional collaborative control mechanism, the safety and reliability of the black start process in a high-proportion new energy access scenario are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 Fig. 1 is a flowchart of a new energy grid-connected resonance overvoltage suppression method according to the present application.

[0048] Figure 2 Fig. 2 is a module diagram of a new energy grid-connected resonance overvoltage suppression device according to the present application. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0050] As shown in Figure 1 Fig. 1, an embodiment of the present application provides a new energy grid-connected resonance overvoltage suppression method, applied to an energy storage system, which comprises the following steps:

[0051] Step 11, collect the power frequency voltage of the energy storage system bus, the photovoltaic power station bus and the wind farm bus in real time to obtain first monitoring data, the first monitoring data including: the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind farm bus, the voltage fluctuation waveform and the boost time parameter;

[0052] Step 12, according to the first monitoring data, when all bus voltages are stable in the preset range and there is no resonance phenomenon, output a zero-voltage boost completion signal;

[0053] Step 13, receiving the zero-voltage boost completion signal, sequentially connecting the photovoltaic system and the wind turbine generator of the wind farm connected to the photovoltaic station transformer to the power grid to obtain a grid-connected point;

[0054] Step 14, based on the electromagnetic transient simulation, real-time acquisition of the voltage harmonic component of the grid-connected point to generate second monitoring data;

[0055] Step 15, dynamically adjusting the grid-connected timing and the converter control parameter to reduce the resonance overvoltage amplitude in the second monitoring data to within the safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably running, output a new energy grid-connected completion signal;

[0056] Step 16, according to the new energy grid-connected completion signal, closing the substation switch to access the preset load, and when the load operation parameter continuously reaches a stable state, exiting the black start mode and switching to a normal operation mode.

[0057] In the embodiment, the new energy grid-connected resonance overvoltage suppression method significantly improves the safety and reliability of the black start process in the high-proportion new energy access scenario through a multi-dimensional collaborative control mechanism; the voltage harmonic real-time monitoring and dynamic adjustment mechanism based on electromagnetic transient simulation breaks through the limitations of traditional passive protection, realizes rapid and accurate identification and adaptive suppression of resonance overvoltage, and effectively avoids the risk of equipment insulation damage and protection misoperation; by dynamically adjusting the new energy grid-connected timing and the converter control parameter, the control interaction conflict problem when multiple units are connected to a weak power grid is solved, and the resonance amplification effect caused by improper timing or parameter mismatch is significantly reduced; a three-level safety verification mechanism of "zero-voltage boost-new energy grid connection-load access" is constructed, voltage stability and resonance state criteria are set at key nodes to ensure that the grid-forming energy storage system always acts as a stable voltage source support and prevent system collapse;

[0058] In the embodiment, the new energy grid-connected resonance overvoltage suppression method combines real-time monitoring data dynamic optimization control strategy, overcomes the influence of grid topology change and impedance characteristic fluctuation in the black start process, does not need to rely on fixed parameter model, significantly enhances the anti-disturbance ability under complex working conditions, fully utilizes the controllability and monitoring system of the existing converter, realizes resonance suppression through the algorithm layer, avoids additional installation of filter devices or compensation equipment, reduces the system transformation cost, under the premise of ensuring safety, shortens the new energy grid-connected time window through resonance rapid suppression, and exits the black start mode in time based on the load stability criterion, and speeds up the global grid recovery process.

[0059] In an optional embodiment of the present application, step 12, according to the first monitoring data, when all bus voltages are stable in the preset range and there is no resonance phenomenon, a zero start voltage boosting completion signal is output, including:

[0060] Step 121, real-time acquisition of the energy storage system bus power frequency voltage, photovoltaic power station bus power frequency voltage, wind farm bus power frequency voltage, voltage fluctuation waveform and voltage fluctuation waveform in the first monitoring data;

[0061] Step 122, judge whether the power frequency voltage of all buses is continuously in the preset range of the standard regulation, and whether there is resonance phenomenon based on the voltage fluctuation waveform analysis;

[0062] Step 123, when all bus voltages are continuously stable in the preset range for a preset period of time, and the voltage fluctuation waveform has no resonance characteristics, a zero start voltage boosting completion signal is output.

[0063] In this embodiment, step 121 is specifically: extracting key information from the first monitoring data in real time, continuously collecting the power frequency voltage of the energy storage system bus, the photovoltaic power station bus and the wind farm bus, and recording the voltage value of each collection; at the same time, the time parameters in the boosting process are recorded synchronously, including the boosting start time, the time point corresponding to each time, etc., in addition, the voltage fluctuation waveform of each bus is captured uninterruptedly, the change of these waveforms is stored in the form of data sequence, and a complete first monitoring data set is formed; step 122 is specifically: for the power frequency voltage of all buses, the real-time collected voltage value is compared with the preset range specified by the standard; the voltage value at each time is continuously tracked to determine whether it is in the qualified interval, and the duration that the voltage is in the preset range is counted, for the voltage fluctuation waveform, the resonance phenomenon is analyzed by observing the morphological characteristics of the waveform, whether the waveform has periodic sharp changes in amplitude, oscillation and other resonance characteristics is checked, if the waveform presents regular and large amplitude fluctuations, it is judged that there may be resonance phenomenon; on the contrary, if the waveform is smooth and has no obvious abnormal fluctuations, it is judged that there is no resonance phenomenon; step 123 is specifically: first, a preset period is set, for example, 5 seconds, all bus voltages are continuously monitored, when the time that all bus voltages continuously reach the preset range reaches the preset period, the condition of voltage stability is met, at the same time, combined with the analysis result of the voltage fluctuation waveform in step 122, it is confirmed that there is no resonance characteristic, only when the two conditions are met at the same time, the system will output the zero-rise boosting completion signal.

[0064] Through the determined judgment standard and method, whether the bus voltage is in the preset range and whether the resonance phenomenon exists can be found in time, and scientific judgment basis for whether the zero-rise boosting is completed is provided; step 123 sets double conditions and a preset period, so that the accuracy and rigor of the output of the zero-rise boosting completion signal are guaranteed, the signal error output caused by instantaneous stability or misjudgment is avoided, and therefore the stability and safety of the zero-rise boosting stage in the black start process are ensured.

[0065] In an optional embodiment of the present application, step 13 receives the zero-rise boosting completion signal, and sequentially connects the photovoltaic system connected to the photovoltaic station transformer and the wind turbine generator of the wind farm to the power grid to obtain a grid-connected point, including:

[0066] Step 131 generates a photovoltaic system grid-connected instruction according to the zero-rise boosting completion signal and sends it to the photovoltaic station transformer, so that the photovoltaic station transformer performs closing operation according to the grid-connected instruction, connects the connected photovoltaic system to the power grid, and monitors the voltage and current transient response of the grid-connected point in real time;

[0067] Step 132, when the transient response of the grid-connected photovoltaic system is stable for a first preset time length, a wind turbine generator grid-connection instruction is generated and sent to the wind farm, so that the wind farm performs wind turbine generator grid-connection operation according to the wind turbine generator grid-connection instruction, the position parameters of the grid-connection point are recorded synchronously, and the new energy grid-connection is completed.

[0068] In the embodiment, step 131 specifically comprises: after the system receives the zero-voltage rise completion signal, an photovoltaic system grid-connection instruction generation mechanism is first triggered, which determines the initial conditions of the photovoltaic system grid-connection in combination with the power grid state parameters at the time of zero-voltage rise completion, such as the stable values of each bus voltage; then, the generated grid-connection instruction is sent to the photovoltaic power station transformer substation, the transformer substation executes the closing operation after receiving the instruction, and gradually connects the photovoltaic system connected thereto to the power grid; in the grid-connection process, the voltage and current data of the grid-connection point are monitored in real time, and the transient value, change rate of the voltage, and transient peak value, fluctuation range of the current and other transient response parameters are recorded continuously; by comparing these parameters with the preset transient allowable range, it is determined whether the transient response of the photovoltaic system after grid-connection is in a controllable state; step 132 specifically comprises: after the transient response of the photovoltaic system after grid-connection is monitored in step 131 for a first preset time length (for example, 30 seconds), the system automatically generates a wind turbine generator grid-connection instruction, which determines the initial parameters of the wind turbine generator grid-connection according to the real-time data of the current power grid load, voltage stability and the like; after the instruction is sent to the wind farm, the wind farm performs the wind turbine generator grid-connection operation according to the instruction; when each unit is grid-connected, the specific position information of the grid-connection point is recorded synchronously, including the corresponding line number, connection node and other position parameters, to form a complete grid-connection point position record; after all wind turbine generators are grid-connected, all grid-connection point information is integrated, and it is confirmed that the new energy grid-connection operation is completed.

[0069] The present application can timely discover abnormal conditions in the grid-connection process by monitoring the transient response of the photovoltaic system during grid-connection in real time, ensure the safe access of the photovoltaic system to the power grid, and avoid disturbance to the power grid caused by excessive transient impact; step 132 sets a stable judgment condition of the first preset time length to ensure the stable state of the power grid after the photovoltaic system is grid-connected, and then integrates the wind turbine generators, which can effectively avoid the mutual interference caused by the simultaneous grid-connection of multiple types of new energy, and record the position parameters of the grid-connection point, thereby improving the orderliness and controllability of the new energy grid-connection process.

[0070] In an optional embodiment of the present application, step 14, the voltage harmonic components of the grid-connection point are obtained in real time based on electromagnetic transient simulation to generate second monitoring data, which comprises:

[0071] Step 141, an electromagnetic transient simulation model is established based on the position parameters of the grid-connection point to obtain initial simulation parameters;

[0072] Step 142, according to the initial simulation parameters, real-time simulation calculation is performed on the grid-connected point voltage, and the fundamental component and each harmonic component are extracted to form original harmonic data;

[0073] Step 143, time-domain and frequency-domain joint analysis is performed on the original harmonic data to determine the dominant harmonic order of the resonance overvoltage and its dynamic amplitude variation characteristic;

[0074] Step 144, according to the dominant harmonic order and dynamic amplitude variation characteristic, second monitoring data containing harmonic component, amplitude fluctuation range and time evolution law are generated.

[0075] In this embodiment, step 141 specifically comprises: collecting the grid-connected point position parameters recorded in step 132, including the line number, connection node, and electrical distance from the surrounding equipment corresponding to the grid-connected point; according to these position parameters, the corresponding power grid topology structure is built in the electromagnetic transient simulation platform, and the position of the grid-connected point is accurately mapped to the simulation model; then, the parameters of the related equipment around the grid-connected point are recorded, such as the converter parameters of the photovoltaic system and the wind turbine generator, the impedance parameters of the line, the capacity and transformation ratio of the transformer, etc.; by integrating and initializing these parameters, an electromagnetic transient simulation model consistent with the actual power grid structure and parameters is constructed, thereby obtaining the initial simulation parameters; step 142 specifically comprises: based on the initial simulation parameters obtained in step 141, starting the electromagnetic transient simulation calculation program to perform real-time simulation on the voltage of the grid-connected point; during the simulation process, the voltage instantaneous value of the grid-connected point is collected at a set time interval (such as every millisecond); then, the collected voltage instantaneous value is processed to separate the fundamental component and each harmonic component; for example, by analyzing the period characteristics of the voltage waveform, the frequency and amplitude of the fundamental wave are determined, and by comparing the difference between the actual waveform and the fundamental waveform, the amplitude and phase information of each harmonic such as 2nd, 3rd, 5th, etc. are extracted, and these data are arranged to form original harmonic data.

[0076] In this embodiment, step 143 specifically comprises: time-domain analysis is performed on the original harmonic data obtained in step 142 to observe the amplitude variation of each harmonic at different times, and the time point and duration of the amplitude peak value are recorded; at the same time, frequency-domain analysis is performed to determine the energy proportion of the harmonic at different frequencies by analyzing the frequency distribution of each harmonic. The time-domain and frequency-domain analysis results are combined to find out the harmonic components with large amplitude, long duration and significant influence on the power grid, determine the corresponding harmonic order, i.e. the dominant harmonic order of the resonance overvoltage, and further analyze the amplitude variation trend of these dominant harmonics with time to summarize the dynamic amplitude variation characteristic, such as amplitude rise rate, fluctuation period, etc.

[0077] In this embodiment, step 144 is specifically: according to the dominant harmonic order determined in step 143, combing all harmonic components that should be included in the second monitoring data, including the dominant harmonic and other secondary harmonics; for each harmonic component, the amplitude fluctuation range in different time periods is counted to determine the maximum value, minimum value and average fluctuation amplitude. At the same time, combined with the time axis, the amplitude evolution of each harmonic component with time is recorded, and the time evolution law is summarized, such as the change trend of harmonic amplitude in different stages after grid connection. These harmonic components, amplitude fluctuation ranges and time evolution laws are integrated to generate complete second monitoring data.

[0078] The step 141 of the present application establishes an accurate electromagnetic transient simulation model by combining the grid connection point position parameters, provides a reliable basis for subsequent harmonic analysis, and ensures that the simulation results can truly reflect the actual power grid situation; the step 142 can master the voltage harmonic condition of the grid connection point in time by real-time simulation calculation and extraction of fundamental wave and harmonic components, and provides original data support for identifying resonance overvoltage; the step 143 adopts time-domain-frequency-domain joint analysis, which can accurately determine the dominant harmonic order and its dynamic characteristics, and is helpful to deeply understand the generation and development law of resonance overvoltage, and the second monitoring data generated by the step 144 comprehensively reflects the key information of the harmonic, thereby effectively suppressing the resonance overvoltage.

[0079] In an optional embodiment of the present application, step 15, the grid connection time and the converter control parameters are dynamically adjusted, so that the resonance overvoltage amplitude in the second monitoring data is reduced to within the safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably operated, a new energy grid connection completion signal is output, including:

[0080] Step 151, analyze the dominant harmonic order and dynamic amplitude variation characteristics in the second monitoring data to generate a resonance overvoltage suppression strategy, wherein the suppression strategy includes a converter parameter adjustment scheme and a grid connection time optimization scheme;

[0081] Step 152, according to the converter parameter adjustment scheme, send impedance adjustment instructions and phase compensation instructions to the photovoltaic power station and wind farm converter, and synchronously collect converter feedback parameters;

[0082] Step 153, based on the grid connection time optimization scheme and the converter feedback parameters, recalculate the final grid connection time window of the to-be-connected unit, and generate a grid connection time control instruction;

[0083] Step 154, execute the grid connection time control instruction to complete the remaining unit grid connection operation in the final grid connection time window, and monitor the voltage harmonic component of the grid connection point and the output power of the energy storage system;

[0084] Step 155, when the resonant overvoltage amplitude is monitored for three consecutive sampling periods below the safety threshold, and the energy storage system output power fluctuation rate is maintained within the preset range, a new energy grid-connected completion signal is generated.

[0085] In this embodiment, step 151 specifically comprises: deeply analyzing the second monitoring data, and focusing on extracting the dominant harmonic order and the change characteristics of its dynamic amplitude, such as the peak value of the amplitude, the frequency of occurrence, the duration, etc. According to these information, the causes and influence degree of the resonant overvoltage are analyzed; combined with the operation state of the power grid, a converter parameter adjustment scheme is developed, for example, the type of parameters that need to be adjusted and the approximate adjustment direction and range are determined; at the same time, according to the characteristics of each unit and the carrying capacity of the current power grid, a grid-connection timing optimization scheme is developed, and the grid-connection sequence adjustment suggestion and the approximate range of time interval of different units are determined, so as to form a complete resonant overvoltage suppression strategy.

[0086] In this embodiment, step 152 specifically comprises: according to the converter parameter adjustment scheme generated in step 151, combined with the current operating parameters of the converter, the specific values of impedance adjustment and the specific angles of phase compensation are determined; then these specific values and angles are converted into impedance adjustment instructions and phase compensation instructions, which are sent to the converters of the photovoltaic power station and the wind farm; after sending the instructions, the feedback parameters of the converter are collected in real time, such as the actual impedance value after adjustment, the phase compensation effect, the output current and voltage, etc., to evaluate the execution of the instructions and the preliminary effect of the parameter adjustment.

[0087] In this embodiment, step 153 specifically comprises: based on the grid-connection timing optimization scheme obtained in step 151 and the converter feedback parameters collected in step 152, the current power grid's acceptance ability for newly connected units is analyzed; considering the operating state of the already connected units, the load level of the power grid, the voltage stability and other factors, the final grid-connection time window of the units to be connected is recalculated, and when calculating, it needs to ensure that the newly connected units will not cause the resonant overvoltage amplitude to exceed the safety threshold within the time window, and finally the grid-connection timing control instructions that determine the specific grid-connection time of each unit to be connected are generated.

[0088] In this embodiment, step 154 specifically comprises: according to the grid-connection timing control instructions generated in step 153, the remaining units are sequentially arranged to perform grid-connection operation within the corresponding final grid-connection time window; during the grid-connection process, the voltage harmonic components of the grid-connection point are continuously monitored, including the amplitude, frequency, etc. of each harmonic; at the same time, the output power of the energy storage system is monitored in real time, and the instantaneous value and change of the power are recorded, through these monitoring data, the influence of the grid-connection operation on the power grid and the resonant overvoltage, as well as the operating state of the energy storage system are timely grasped.

[0089] In this embodiment, step 155 is specifically setting a safety threshold and a preset range of fluctuation rate of the energy storage system output power; continuously sampling the resonance overvoltage amplitude of the grid-connected point, and when the amplitude is lower than the safety threshold in three consecutive sampling periods, the voltage stability condition is met; at the same time, the change of the energy storage system output power is observed, and when the power fluctuation rate continuously maintains in the preset range, it indicates that the energy storage system is stable, and only when the two conditions are met at the same time, the new energy grid-connected completion signal is generated.

[0090] The step 151 of the present application improves the pertinence and effectiveness of the resonance overvoltage suppression by accurately analyzing the monitoring data and formulating targeted suppression strategies; the step 152 realizes accurate adjustment of the converter parameters by sending specific instructions and collecting feedback parameters, and at the same time can timely grasp the adjustment effect, providing basis for further optimization; the step 153 re-calculates the grid-connected time window in combination with various factors, ensuring the safety of the remaining units during grid connection and reducing the resonance risk caused by improper grid-connected timing; the step 154 monitors key parameters in real time during grid connection, can timely discover problems and take measures, and ensures the smooth operation of the grid connection operation; the step 155 ensures the stable operation of the system after the new energy is connected to the grid through the judgment of the double stability conditions, lays a solid foundation for subsequent load connection, and improves the reliability of the entire black start process.

[0091] In an optional embodiment of the present application, step 16, according to the new energy grid-connected completion signal, the substation switch is closed to access the preset load, and when the load operation parameters continuously reach a stable state, the black start mode is exited and switched to a normal operation mode, which includes:

[0092] Step 161, receiving the new energy grid-connected completion signal, generating a load staged access instruction and sending it to the substation switch controller;

[0093] Step 162, according to the load staged access instruction, sequentially closing the low-voltage side bus tie switch and the high-voltage side incoming line switch in a predetermined order to realize staged input of the preset load capacity;

[0094] Step 163, in the process of load input, real-time collection of load active power, reactive power, power factor and grid frequency deviation data to form a load dynamic response data set;

[0095] Step 164, stability evaluation of the load dynamic response data set to generate a stability confirmation signal;

[0096] Step 165, in response to the stability confirmation signal, controlling the energy storage system to disconnect the black start control link and switch to the grid dispatching master station control mode, and recording the mode switching time parameter.

[0097] In this embodiment, step 161 is specifically: when receiving the new energy grid-connected completion signal, the system will first obtain the total capacity, type and importance of each load of the preset load and other information. According to these information, the load is divided into different levels, such as first-level load, second-level load, etc., and different levels correspond to different access priorities and access capacities; then, based on the load level, the specific access sequence and the load amount of each access are formulated, the load hierarchical access instruction is generated, and then the instruction is sent to the substation switch controller.

[0098] In this embodiment, step 162 is specifically: after the substation switch controller receives the load hierarchical access instruction, it starts operating according to the predetermined order in the instruction. First, the current state of the low-voltage side bus coupler switch is confirmed, and in the case of meeting the safety conditions, the low-voltage side bus coupler switch is closed to access the first-level preset load. After access, the operation state of the power grid is monitored, such as whether the voltage and frequency are stable. When the first-level load runs stably, the same process is followed to close the high-voltage side incoming line switch in turn, and the subsequent level of preset load is put into operation in stages to ensure that the power grid can remain relatively stable after each load is put into operation.

[0099] In this embodiment, step 163 is specifically: during the entire process of load input, the monitoring equipment in the power grid is used to collect various load operation parameters in real time. For active power of the load, its instantaneous value and change trend are recorded. For reactive power, its value change is also tracked. At the same time, the real-time value of power factor is calculated, and the deviation data of power grid frequency and rated frequency are monitored. These collected data are sorted in chronological order to form a complete load dynamic response data set, which intuitively reflects the change of each parameter in the load access process.

[0100] In this embodiment, step 164 is specifically: analyzing and evaluating each parameter in the load dynamic response data set; setting the stable range of active power and reactive power to determine whether they fluctuate within the range; determining the qualified threshold of power factor to check whether it meets the requirements; setting the allowed value of power grid frequency deviation to check whether the frequency deviation is within the allowed range. When all load operation parameters are within the corresponding stable interval for continuous multiple sampling periods and no obvious fluctuations or abnormalities occur, it is determined that the load operation parameters reach a stable state, and a stable confirmation signal is generated.

[0101] In this embodiment, step 165 is specifically: after receiving the stability confirmation signal, the system starts the black start mode exit procedure; first, the control energy storage system disconnects the control link related to black start, stops the special control strategy in the black start mode; then, the control authority of the energy storage system is switched to the grid dispatching master station, so that it is included in the unified dispatching management of the power grid and enters the control mode of normal operation. During the mode switching process, the switching start time, completion time and other time parameters are accurately recorded to facilitate subsequent tracing and analysis of the entire process.

[0102] The step 161 of the present application realizes the orderly access of the load by generating the load hierarchical access instruction, avoids the impact on the power grid caused by the one-time access of a large amount of load, and guarantees the stable operation of the power grid; the step 162 closes the switch according to the predetermined order to stage the load, further reduces the disturbance of the load access to the power grid, and improves the safety of the load access process; the step 163 collects the load dynamic response data in real time, which facilitates the timely discovery of potential problems, the step 164 ensures that the load operation parameters truly reach the stable state through strict stability evaluation, and provides a reliable judgment standard for mode switching; the step 165 realizes the smooth switching from the black start mode to the normal operation mode, records the switching parameters for subsequent analysis and optimization, and guarantees the smoothness and reliability of the power grid recovery to the normal operation.

[0103] As shown in Figure 2 The embodiment of the present application also provides a new energy grid-connected resonance overvoltage suppression device 20, which comprises:

[0104] The acquisition module 21 is used for collecting the power frequency voltage of the energy storage system bus, the photovoltaic power station bus and the wind power plant bus in real time to obtain first monitoring data;

[0105] The confirmation module 22 is used for outputting a zero voltage rise completion signal when all bus voltages are stable in a preset range and there is no resonance phenomenon according to the first monitoring data;

[0106] The grid connection module 23 is used for receiving the zero voltage rise completion signal, sequentially connecting the photovoltaic system connected to the photovoltaic power station transformer and the wind power generator set to the power grid to obtain a grid connection point; and generating second monitoring data based on the voltage harmonic component of the grid connection point obtained in real time through electromagnetic transient simulation;

[0107] The adjustment module 24 is used for dynamically adjusting the grid connection timing and the converter control parameter, so that the resonance overvoltage amplitude in the second monitoring data is reduced to within a safety threshold; and outputting a new energy grid connection completion signal when it is confirmed that the energy storage system is stably operated according to the second monitoring data;

[0108] The processing module 25 is configured to close the substation switch to access the preset load according to the new energy grid-connected completion signal, and exit the black start mode and switch to the normal operation mode when the load operation parameter continuously reaches a stable state.

[0109] Optionally, the first monitoring data comprises: a power frequency voltage of the energy storage system bus, a power frequency voltage of the photovoltaic power station bus, a power frequency voltage of the wind power field bus, a voltage fluctuation waveform, and a voltage rise time parameter.

[0110] Optionally, according to the first monitoring data, when all the bus voltages are stable in a preset range and there is no resonance phenomenon, a zero-voltage rise completion signal is output, comprising:

[0111] The first monitoring data is acquired in real time, including the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind power field bus, the voltage fluctuation waveform, and the voltage rise time parameter;

[0112] It is determined whether the power frequency voltages of all the buses are continuously in a standard specified preset range, and whether there is a resonance phenomenon based on the voltage fluctuation waveform;

[0113] When all the bus voltages are continuously stable in the preset range for a preset period of time, and the voltage fluctuation waveform has no resonance characteristics, a zero-voltage rise completion signal is output.

[0114] Optionally, the zero-voltage rise completion signal is received, and the photovoltaic system connected to the photovoltaic power station transformer and the wind turbine generator of the wind power field are sequentially connected to the power grid to obtain a grid-connected point, comprising:

[0115] According to the zero-voltage rise completion signal, a photovoltaic system grid-connected instruction is generated and sent to the photovoltaic power station transformer, so that the photovoltaic power station transformer performs a closing operation according to the grid-connected instruction to connect the connected photovoltaic system to the power grid, and the voltage and current transient responses of the grid-connected point are monitored in real time;

[0116] When the transient response of the photovoltaic system after grid connection is continuously stable for a first preset time length, a wind turbine generator grid-connected instruction is generated and sent to the wind power field, so that the wind power field performs a wind turbine generator grid-connected operation according to the wind turbine generator grid-connected instruction, and the position parameters of the grid-connected point are recorded synchronously, and the new energy grid connection is completed.

[0117] Optionally, the voltage harmonic components of the grid-connected point are acquired in real time based on electromagnetic transient simulation to generate second monitoring data, comprising:

[0118] An electromagnetic transient simulation model is established based on the position parameters of the grid-connected point to obtain initial simulation parameters;

[0119] According to the initial simulation parameters, real-time simulation calculation is performed on the voltage of the grid-connected point, the fundamental component and each harmonic component are extracted, and original harmonic data are formed;

[0120] Performing time-domain and frequency-domain joint analysis on the original harmonic data to determine the dominant harmonic order of the resonance overvoltage and its dynamic amplitude variation characteristics;

[0121] According to the dominant harmonic order and the dynamic amplitude variation characteristics, the second monitoring data containing harmonic components, amplitude fluctuation range and time evolution law are generated.

[0122] Optionally, the grid-connected timing and the converter control parameters are dynamically adjusted to reduce the resonance overvoltage amplitude in the second monitoring data to within a safety threshold; according to the second monitoring data, when it is confirmed that the energy storage system is stably running, a new energy grid-connected completion signal is output, including:

[0123] Analyzing the dominant harmonic order and the dynamic amplitude variation characteristics in the second monitoring data to generate a resonance overvoltage suppression strategy, the suppression strategy including a converter parameter adjustment scheme and a grid-connected timing optimization scheme;

[0124] According to the converter parameter adjustment scheme, impedance adjustment instructions and phase compensation instructions are sent to the photovoltaic power station and wind farm converter, and converter feedback parameters are synchronously collected;

[0125] Based on the grid-connected timing optimization scheme and the converter feedback parameters, the final grid-connected time window of the to-be-connected unit is recalculated, and a grid-connected timing control instruction is generated;

[0126] Executing the grid-connected timing control instruction to complete the remaining unit grid-connected operation within the final grid-connected time window, while monitoring the harmonic component of the grid-connected point voltage and the energy storage system output power;

[0127] When the resonance overvoltage amplitude is continuously monitored for three sampling periods below the safety threshold, and the energy storage system output power fluctuation rate is maintained within a preset range, a new energy grid-connected completion signal is generated.

[0128] Optionally, according to the new energy grid-connected completion signal, the substation switch is closed to access the preset load, and when the load operating parameters continuously reach a stable state, the black start mode is exited and switched to normal operation, including:

[0129] Receiving the new energy grid-connected completion signal, generating a load staged access instruction and sending it to the substation switch controller;

[0130] According to the load staged access instruction, the low-voltage side bus tie switch and the high-voltage side incoming line switch are closed in a predetermined order to realize phased input of the preset load capacity;

[0131] In the process of loading, the load active power, reactive power, power factor and grid frequency deviation data are collected in real time to form a load dynamic response data set;

[0132] Performing stability evaluation on the load dynamic response data set to generate a stability confirmation signal;

[0133] In response to the stability confirmation signal, controlling the energy storage system to disconnect the black start control link and switch to a grid dispatch master station control mode, and recording a mode switching time parameter.

[0134] It should be noted that the device corresponds to the above method, and all implementation manners in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0135] Embodiments of the present application also provide a computing device, comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, and the program or instruction is executed by the processor to implement the steps of the method described above.

[0136] Embodiments of the present application also provide a computer-readable storage medium comprising instructions, which, when executed on a computer, cause the computer to perform the method described above. All implementation manners in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0137] Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0138] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0139] In the embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented by other ways. For example, the device embodiments described above are only schematic, and the division of the units is only a logical function division, and there can be another division way in actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0140] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0141] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit.

[0142] If the functions are realized in the form of software functional units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk, and various program code storage media.

[0143] In addition, it should be noted that in the device and method of the present application, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombination should be considered as equivalent solutions of the present application. Moreover, the steps of executing the above series of processes can naturally be executed in time sequence according to the order of description, but do not necessarily have to be executed in time sequence, and some steps can be executed in parallel or independently of each other. It can be understood by those skilled in the art that all or any steps or components of the method and device of the present application can be realized in any computing device (including processor, storage medium, etc.) or network of computing devices in hardware, firmware, software or their combination, which can be realized by those skilled in the art using their basic programming skills after reading the description of the present application.

[0144] Therefore, the object of the present application can also be achieved by running a program or a set of programs on any computing device. The computing device can be a commonly known general purpose device. Therefore, the object of the present application can also be achieved by merely providing a program product containing program code for implementing the method or device. That is, such a program product also constitutes the present application, and a storage medium storing such a program product also constitutes the present application. Obviously, the storage medium can be any commonly known storage medium or any storage medium developed in the future. It should also be pointed out that in the device and method of the present application, obviously, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present application. Furthermore, the steps of performing the above series of processes can naturally be executed in time sequence according to the order of description, but do not necessarily have to be executed in time sequence. Some steps can be executed in parallel or independently of each other.

[0145] The above is the preferred embodiment of the present application. It should be pointed out that for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for suppressing resonant overvoltage in grid-connected new energy sources, characterized in that, Applied to energy storage systems, the method includes: The power frequency voltage of the busbars of the energy storage system, photovoltaic power station, and wind farm is collected in real time to obtain the first monitoring data; Based on the first monitoring data, when all bus voltages are stable within the preset range and there is no resonance phenomenon, a zero-start boost completion signal is output. Upon receiving the zero-start voltage boost completion signal, the photovoltaic system connected to the photovoltaic power station transformer and the wind turbine generator of the wind farm are sequentially connected to the power grid to obtain the grid connection point; The voltage harmonic components at the grid connection point are acquired in real time based on electromagnetic transient simulation to generate second monitoring data. The grid connection timing and converter control parameters are dynamically adjusted to reduce the resonance overvoltage amplitude in the second monitoring data to within the safe threshold. Based on the second monitoring data, when the stable operation of the energy storage system is confirmed, a new energy grid connection completion signal is output. Based on the new energy grid connection completion signal, the substation switch is closed to connect the preset load. When the load operating parameters continue to reach a stable state, the black start mode is exited and the system switches to normal operation mode.

2. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, The first monitoring data includes: the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind farm bus, the boost time parameters, and the voltage fluctuation waveform.

3. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, Based on the first monitoring data, when all bus voltages are stable within the preset range and there is no resonance phenomenon, a zero-start boost completion signal is output, including: Real-time acquisition of the power frequency voltage of the energy storage system bus, the power frequency voltage of the photovoltaic power station bus, the power frequency voltage of the wind farm bus, the boost time parameters, and the voltage fluctuation waveform from the first monitoring data; Determine whether the power frequency voltage of all busbars is continuously within the preset range specified in the standard, and analyze whether there is a resonance phenomenon based on the voltage fluctuation waveform; When all bus voltages are continuously and stably within a preset range for a preset time period, and the voltage fluctuation waveform has no resonance characteristics, a zero-start boost completion signal is output.

4. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, Upon receiving the zero-start voltage boost completion signal, the photovoltaic system connected to the photovoltaic power station transformer and the wind turbine generators of the wind farm are sequentially connected to the power grid to obtain the grid connection point, including: Based on the zero-start voltage boost completion signal, a photovoltaic system grid connection command is generated and sent to the photovoltaic power station transformer box, so that the photovoltaic power station transformer box performs a closing operation according to the grid connection command, connecting the connected photovoltaic system into the grid, and monitoring the voltage and current transient response at the grid connection point in real time. When the transient response of the photovoltaic system after grid connection remains stable for a first preset duration, a wind turbine grid connection command is generated and sent to the wind farm, enabling the wind farm to execute the wind turbine grid connection operation according to the wind turbine grid connection command, and simultaneously record the grid connection point location parameters to complete the new energy grid connection.

5. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, Based on electromagnetic transient simulation, the voltage harmonic components at the grid connection point are acquired in real time to generate second monitoring data, including: An electromagnetic transient simulation model was established based on the grid connection point location parameters to obtain the initial simulation parameters. Based on the initial simulation parameters, the grid connection point voltage is simulated and calculated in real time, and the fundamental component and each harmonic component are extracted to form the original harmonic data. The original harmonic data were subjected to time-domain and frequency-domain joint analysis to determine the dominant harmonic order of the resonant overvoltage and its dynamic amplitude variation characteristics. Based on the dominant harmonic order and dynamic amplitude variation characteristics, a second monitoring data set is generated that includes harmonic components, amplitude fluctuation range, and time evolution patterns.

6. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, The grid connection timing and converter control parameters are dynamically adjusted to reduce the amplitude of the resonant overvoltage in the second monitoring data to within the safe threshold. Based on the second monitoring data, when the stable operation of the energy storage system is confirmed, a signal indicating completion of grid connection of the new energy source is output, including: The dominant harmonic order and dynamic amplitude variation characteristics in the second monitoring data are analyzed to generate a resonant overvoltage suppression strategy, which includes a converter parameter adjustment scheme and a grid connection timing optimization scheme. According to the converter parameter adjustment scheme, impedance adjustment commands and phase compensation commands are sent to the converters of photovoltaic power plants and wind farms, and converter feedback parameters are collected simultaneously. Based on the grid connection timing optimization scheme and converter feedback parameters, the final grid connection time window of the unit to be connected to the grid is recalculated, and grid connection timing control instructions are generated. The grid connection timing control command is executed to complete the grid connection operation of the remaining units within the final grid connection time window, while monitoring the voltage harmonic components at the grid connection point and the output power of the energy storage system. When the amplitude of the resonant overvoltage is detected to be below the safety threshold for three consecutive sampling cycles, and the output power fluctuation rate of the energy storage system remains within the preset range, a signal indicating that the new energy grid connection is complete is generated.

7. The method for suppressing resonant overvoltage in new energy grid connection according to claim 1, characterized in that, Based on the new energy grid connection completion signal, the substation switch is closed to connect the preset load. Once the load operating parameters have reached a stable state, the black start mode is exited and the system switches to normal operation, including: Receive the signal indicating that the new energy grid connection is complete, generate a load hierarchical access instruction and send it to the substation switch controller; According to the load grading access command, the low-voltage side bus tie switch and the high-voltage side incoming line switch are closed in a predetermined order to realize the phased input of the preset load capacity. During the load input process, the active power, reactive power, power factor and grid frequency deviation data of the load are collected in real time to form a load dynamic response dataset; The stability of the load dynamic response dataset is evaluated, and a stability confirmation signal is generated. In response to the stability confirmation signal, the energy storage system is controlled to disconnect the black start control link and switch to the grid dispatch master station control mode, while the mode switching time parameter is recorded.

8. A new energy grid-connected resonant overvoltage suppression device, characterized in that, include: The data acquisition module is used to acquire the power frequency voltage of the busbars of the energy storage system, photovoltaic power station, and wind farm in real time to obtain the first monitoring data; The confirmation module is used to output a zero-start boost completion signal based on the first monitoring data, when all bus voltages are stable within the preset range and there is no resonance phenomenon. The grid connection module is used to receive the zero-start voltage boost completion signal, and sequentially connect the photovoltaic system connected to the photovoltaic power station transformer and the wind turbine of the wind farm to the power grid to obtain the grid connection point; based on electromagnetic transient simulation, the voltage harmonic components of the grid connection point are obtained in real time to generate the second monitoring data; The adjustment module is used to dynamically adjust the grid connection timing and converter control parameters to reduce the amplitude of the resonant overvoltage in the second monitoring data to within the safe threshold. Based on the second monitoring data, when it is confirmed that the energy storage system is operating stably, a signal indicating that the new energy grid connection is complete is output. The processing module is used to close the substation switch to connect the preset load according to the new energy grid connection completion signal. When the load operating parameters continue to reach a stable state, it exits the black start mode and switches to normal operation mode.

9. A computing device, characterized in that, include: A processor, a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A storage instruction that, when executed on a computer, causes the computer to perform the method as described in any one of claims 1 to 7.

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