A method and system for analyzing overvoltage characteristics based on a multi-element power supply system

Abstract

The application provides a kind of overvoltage characteristic analysis method based on multi-element power supply system, including establishing the topology model of multi-element power supply system at least comprising load, reactive device and energy storage system, online energy storage system control protection model and reactive switching and energy storage power response transient interaction model, form overvoltage analysis model;Determine the simulation condition, and according to the size of load, and the collaborative switching situation and switching action between reactive device and energy storage system, overvoltage simulation calculation is carried out on overvoltage analysis model, obtain multiple overvoltage waveforms;Characteristic extraction is carried out on overvoltage waveform, and the characteristic value is extracted, and the characteristic value of each overvoltage waveform is introduced into the trained multi-class overvoltage analysis model, to obtain the corresponding overvoltage category. By implementing the application, the problems of unclear overvoltage mechanism, inaccurate feature extraction, conservative evaluation results or missed judgment in the existing method can be solved, thereby ensuring equipment insulation and power supply safety.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to an overvoltage characteristic analysis method and system based on a multi-source power supply system. Background Technology

[0002] With the advancement of new power system construction, diversified power supply systems have become the core power supply architecture for major event venues, industrial parks, data centers, rail transit, and microgrids in remote areas. This diversified power supply system consists of the main grid, distributed power sources, various types of reactive power regulation devices, and online energy storage systems, possessing high reliability, high flexibility, and high power quality power supply guarantee capabilities.

[0003] Currently, reactive power devices (such as capacitors, reactors, and static var generators, SVG) are used to maintain voltage stability and reduce grid losses; energy storage systems are used to smooth power fluctuations, peak shaving and valley filling, and emergency support. Frequent switching and coordinated operation of these two systems can trigger operational overvoltages, reignition overvoltages, resonant overvoltages, and feeder end-point overvoltages. These, combined with transient responses from power electronic interfaces, can easily lead to equipment insulation aging, protection malfunctions, and power outages.

[0004] However, current overvoltage analysis methods for multi-system power supply mainly focus on the switching of single devices, but have never considered the coupling characteristics of reactive power and energy storage coordinated switching of multi-systems. Therefore, this method is prone to problems such as unclear overvoltage mechanism, inaccurate feature extraction, conservative evaluation results or omissions, making it difficult to support safe switching strategies and insulation coordination design. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide an overvoltage feature analysis method and system based on a multi-element power supply system, which can solve the problems of unclear overvoltage mechanism, inaccurate feature extraction, conservative evaluation results or omissions in the existing methods, thereby ensuring the insulation and power supply safety of equipment.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide an overvoltage characteristic analysis method based on a multi-element power supply system, the method comprising the following steps: Establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices, and energy storage systems. This includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a reactive power switching and energy storage power response transient interaction model that incorporates switch reignition, current cutting, PWM harmonics, and control delay, in order to form an overvoltage analysis model for the multi-element power supply system. The simulation conditions are determined, and based on the load size set for each simulation condition, as well as the coordinated switching and switching actions between the reactive power device and the energy storage system set for each simulation condition, the overvoltage analysis model of the multi-element power supply system is subjected to overvoltage simulation calculation to obtain multiple overvoltage waveforms. Feature extraction is performed on the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform. The feature value of each overvoltage waveform is then imported into a pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs. The overvoltage types include switching overvoltage, reignition overvoltage, resonant overvoltage, and feeder end rise overvoltage.

[0007] The simulation conditions include normal conditions, coupled conditions, and extreme conditions; wherein, The reactive power device and energy storage system do not have a coordinated switching situation under normal operating conditions, and the two are switched independently under the simulation of the system's rated load operation. The reactive power device and the energy storage system under the coupled operating conditions have a coordinated switching situation, and the two are switched synchronously or in a chain under the simulation of the system's rated load operation. The reactive power device and the energy storage system do not have a coordinated switching situation under the extreme operating conditions, and the two are switched independently under the simulation of the system operating under light load or the energy storage system operating in an isolated state.

[0008] The switching actions of the reactive power device include connection, disconnection, rise, and fall; the switching actions of the energy storage system include grid connection, off-grid connection, and power step.

[0009] The characteristic values ​​of each overvoltage waveform are obtained by wavelet packet transform, Hilbert-Huang transform and mode decomposition, and include amplitude, duration, rate of rise, oscillation frequency, energy density and spatiotemporal distribution.

[0010] The method further includes: Based on the characteristic values ​​of each overvoltage waveform, a three-level evaluation system is established; wherein, the three-level evaluation system includes an amplitude over-limit evaluation system, an insulation stress evaluation system, and a system risk evaluation system; The amplitude over-limit assessment system assesses whether the amplitude of the overvoltage waveform exceeds the preset overvoltage protection setting value to evaluate switch tripping or equipment disconnection from the grid; if so, it is determined that the switch has tripped or the equipment has a risk of being disconnected from the grid, and an early warning is issued; if not, it is safe and no early warning is issued. The insulation stress assessment system evaluates the equipment insulation withstand capability based on whether the cumulative stress of the amplitude and duration of the overvoltage waveform exceeds a preset stress threshold. If so, the equipment insulation withstand capability is considered poor, and an early warning is issued. If not, the equipment insulation is considered safe, and no early warning is issued. The system risk assessment system is based on whether the circuit breaker tripping or equipment disconnection from the grid in the amplitude over-limit assessment system leads to system instability risk; if so, there is a risk and an early warning is issued; if not, it is safe and no early warning is issued.

[0011] The method further includes: When at least one of the three-level assessment systems is found to have a risk, an appropriate overvoltage optimization strategy is selected and output based on the assessment system with the detected risk; wherein, the overvoltage optimization strategy includes switching timing adjustment strategy, phase selection control strategy, damping activation strategy and online energy storage system power limiting strategy.

[0012] This invention also provides an overvoltage characteristic analysis system based on a multi-element power supply system, comprising: The large model building unit is used to establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices, and energy storage systems. It includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a reactive power switching and energy storage power response transient interaction model that incorporates switch reignition, current cutting, PWM harmonics, and control delay, in order to form an overvoltage analysis model for the multi-element power supply system. The waveform simulation unit is used to determine the simulation conditions and, based on the load size set for each simulation condition, as well as the coordinated switching and switching actions between the reactive power device and the energy storage system set for each simulation condition, performs overvoltage simulation calculations on the overvoltage analysis model of the multi-element power supply system to obtain multiple overvoltage waveforms. The feature analysis unit is used to extract features from the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform, and to import the feature value of each overvoltage waveform into a pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs; wherein, the overvoltage type includes switching overvoltage, reignition overvoltage, resonant overvoltage, and feeder end rise overvoltage.

[0013] The simulation conditions include normal conditions, coupled conditions, and extreme conditions; wherein, The reactive power device and energy storage system do not have a coordinated switching situation under normal operating conditions, and the two are switched independently under the simulation of the system's rated load operation. The reactive power device and the energy storage system under the coupled operating conditions have a coordinated switching situation, and the two are switched synchronously or in a chain under the simulation of the system's rated load operation. The reactive power device and the energy storage system do not have a coordinated switching situation under the extreme operating conditions, and the two are switched independently under the simulation of the system operating under light load or the energy storage system operating in an isolated state.

[0014] The switching actions of the reactive power device include connection, disconnection, rise, and fall; the switching actions of the energy storage system include grid connection, off-grid connection, and power step.

[0015] The characteristic values ​​of each overvoltage waveform are obtained by wavelet packet transform, Hilbert-Huang transform and mode decomposition, and include amplitude, duration, rate of rise, oscillation frequency, energy density and spatiotemporal distribution.

[0016] Implementing the embodiments of the present invention has the following beneficial effects: 1. This invention establishes an overvoltage analysis model for a multi-element power supply system, comprising a topology model of the multi-element power supply system, a control and protection model of the online energy storage system, and a transient interaction model of reactive power switching and energy storage power response. Combining simulation conditions and corresponding load sizes, the coordinated switching status and actions between the reactive power device and the energy storage system, overvoltage simulation waveforms are obtained. Furthermore, features of the overvoltage waveforms are extracted and imported into pre-trained multi-type overvoltage analysis models to output the types of overvoltages. This addresses the problems of unclear overvoltage mechanisms and inaccurate feature extraction in existing methods. 2. This invention analyzes the characteristic values ​​of each overvoltage waveform through a three-level evaluation system to assess the related risks caused by overvoltage, thereby solving the problems of conservative evaluation results or omissions in existing methods, and thus ensuring the safety of equipment insulation and power supply. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0018] Figure 1 A flowchart illustrating an overvoltage characteristic analysis method based on a multi-element power supply system provided in this embodiment of the invention; Figure 2 This is a schematic diagram of an overvoltage characteristic analysis system based on a multi-element power supply system, provided as an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0020] like Figure 1As shown in the figure, an overvoltage characteristic analysis method based on a multi-element power supply system is proposed in an embodiment of the present invention. The method includes the following steps: Step S1: Establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices, and energy storage systems. This includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a transient interaction model of reactive power switching and energy storage power response that incorporates switch reignition, current cutting, PWM harmonics, and control delay, in order to form an overvoltage analysis model for the multi-element power supply system. Step S2: Determine the simulation conditions, and based on the load size set for each simulation condition, as well as the coordinated switching situation and switching action between the reactive power device and the energy storage system set for each simulation condition, perform overvoltage simulation calculations on the overvoltage analysis model of the multi-element power supply system to obtain multiple overvoltage waveforms. Step S3: Extract features from the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform, and import the feature value of each overvoltage waveform into the pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs; wherein, the overvoltage type includes switching overvoltage, reignition overvoltage, resonance overvoltage and feeder end rise overvoltage.

[0021] The specific process is as follows: In step S1, firstly, using PSCAD electromagnetic transient simulation software, a multi-element power supply system topology model is built, including at least the main grid, feeders, transformers, reactive power devices (capacitors, reactors, SVG), energy storage system, and loads; secondly, considering the energy storage system control and protection strategy, an online energy storage system control and protection model is built, including fast transfer switch (ATS) delay setting and anti-islanding protection; nextly, considering the reactive power-energy storage synergistic coupling effect, factors such as switch reignition, current cutting, PWM harmonics, and control delay are introduced to build a transient interaction model of reactive power switching and energy storage power response; finally, the above-mentioned multi-element power supply system topology model, online energy storage system control and protection model, and reactive power switching and energy storage power response transient interaction model are combined to form a multi-element power supply system overvoltage analysis model.

[0022] In step S2, firstly, a simulation case library is constructed in the PSCAD electromagnetic transient simulation software, including normal cases, coupled cases, and extreme cases. Under normal cases, the reactive power device and the energy storage system do not have coordinated switching, and they are switched independently under the simulation of the system operating at rated load. Under coupled cases, the reactive power device and the energy storage system have coordinated switching, and they are switched synchronously or interlocked under the simulation of the system operating at rated load. Under extreme cases, the reactive power device and the energy storage system do not have coordinated switching, and they are switched independently under the simulation of the system operating at light load or the energy storage system operating in islanded mode.

[0023] Understandably, normal operating conditions, coupled operating conditions, and extreme operating conditions can all be further subdivided into two types of operating conditions: normal and fault conditions, thus enabling the overvoltage analysis model of the multi-factor power supply system to achieve accurate analysis across all operating conditions.

[0024] Secondly, in the overvoltage analysis model of the multi-source power supply system, different load parameters (such as 5MW, 10MW, 20MW, etc.) are set for each simulation condition, as well as the coordinated switching situation and switching action between reactive power devices and energy storage systems under various load parameters.

[0025] At this time, the switching actions of reactive power devices include connecting, disconnecting, increasing, and decreasing; for example, the switching actions of capacitors and reactants are connecting or disconnecting; and the switching actions of SVG are increasing or decreasing the capacitive reactance. The switching actions of energy storage systems include grid connection, off-grid connection, and power step.

[0026] In one example, the simulation is set as a normal operating condition, which is under the condition of an asymmetrical grounding fault in the multi-source power supply system; the reactive power device is set to connect capacitors or reactors when the switch is closed (or disconnect capacitors or reactors when the switch is opened); the energy storage system is set to connect the energy storage system when the switch is closed (or disconnect the energy storage system when the switch is opened), etc.

[0027] Finally, based on the above simulation conditions and the states of the reactive power device and energy storage system after switching on and off under different load conditions, overvoltage simulation calculations were performed on the overvoltage analysis model of the multi-element power supply system to obtain multiple overvoltage waveforms.

[0028] In step S3, firstly, multiple overvoltage analysis models are constructed, and the characteristic values ​​of historical overvoltage waveforms are used to train and test these models to obtain well-trained multiple overvoltage analysis models. It should be noted that the construction, training, and testing of the multiple overvoltage analysis models are all implemented using conventional techniques in this field, and will not be elaborated upon here.

[0029] Secondly, for the overvoltage waveforms in step S2, the corresponding characteristic values ​​are obtained through wavelet packet transform, Hilbert-Huang transform, and mode decomposition. Among them, the overvoltage waveform of each overvoltage includes amplitude, duration, rate of rise, oscillation frequency, energy density, and spatiotemporal distribution.

[0030] It should be noted that the overvoltage waveform from which the feature values ​​are extracted can also be obtained by actually acquiring the switching transient waveform through an electronic current transformer or an edge waveform recording device, or it can be a fusion of the actual transient waveform and the overvoltage waveform simulated in step S2.

[0031] Finally, the feature values ​​of each overvoltage waveform obtained above are imported into the pre-trained multi-type overvoltage analysis model to obtain the overvoltage type of each overvoltage waveform, thereby realizing the automatic classification and identification of switching / re-ignition / resonance / feeder overvoltages.

[0032] In this embodiment of the invention, a risk quantification assessment and early warning system is established. Therefore, the method further includes: establishing a three-level assessment system based on the characteristic values ​​of each overvoltage waveform; wherein, the three-level assessment system includes an amplitude over-limit assessment system, an insulation stress assessment system, and a system risk assessment system; the amplitude over-limit assessment system assesses whether the amplitude of the overvoltage waveform exceeds the preset overvoltage protection setting value to evaluate switch tripping or equipment disconnection; if so, it is determined that the switch has tripped or the equipment has a risk of disconnection, and an early warning is issued; if not, it is safe and no early warning is issued; the insulation stress assessment system assesses the insulation withstand capability of the equipment based on whether the cumulative stress of the amplitude and duration of the overvoltage waveform exceeds a preset stress threshold; if so, it is determined that the equipment insulation withstand capability is poor, and an early warning is issued; if not, the equipment insulation is safe and no early warning is issued; the system risk assessment system assesses whether the switch tripping or equipment disconnection in the amplitude over-limit assessment system leads to system instability risk; if so, there is a risk and an early warning is issued; if not, it is safe and no early warning is issued.

[0033] In this embodiment of the invention, for the overvoltage risk output optimization strategy, the method further includes: when at least one of the three-level assessment systems is detected to have a risk, selecting and outputting the corresponding overvoltage optimization strategy according to the assessment system with the detected risk; wherein, the overvoltage optimization strategy includes a switching timing adjustment strategy, a phase selection control strategy, a damping activation strategy, and an online energy storage system power limiting strategy.

[0034] It is understandable that overvoltage optimization strategies can be flexibly designed according to actual conditions, and will not be elaborated here.

[0035] like Figure 2 As shown in the figure, an overvoltage characteristic analysis system based on a multi-element power supply system is provided in an embodiment of the present invention, comprising: Large model building unit 110 is used to establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices and energy storage systems. It includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a reactive power switching and energy storage power response transient interaction model that incorporates switch reignition, current cutting, PWM harmonics and control delay, in order to form a multi-element power supply system overvoltage analysis model. The waveform simulation unit 120 is used to determine the simulation conditions and, based on the load size set for each simulation condition, as well as the coordinated switching and switching actions between the reactive power device and the energy storage system set for each simulation condition, performs overvoltage simulation calculations on the overvoltage analysis model of the multi-element power supply system to obtain multiple overvoltage waveforms. The feature analysis unit 130 is used to extract features from the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform, and to import the feature value of each overvoltage waveform into a pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs; wherein, the overvoltage type includes switching overvoltage, reignition overvoltage, resonance overvoltage and feeder end rise overvoltage.

[0036] The simulation conditions include normal conditions, coupled conditions, and extreme conditions; wherein, The reactive power device and energy storage system do not have a coordinated switching situation under normal operating conditions, and the two are switched independently under the simulation of the system's rated load operation. The reactive power device and the energy storage system under the coupled operating conditions have a coordinated switching situation, and the two are switched synchronously or in a chain under the simulation of the system's rated load operation. The reactive power device and the energy storage system do not have a coordinated switching situation under the extreme operating conditions, and the two are switched independently under the simulation of the system operating under light load or the energy storage system operating in an isolated state.

[0037] The switching actions of the reactive power device include connection, disconnection, rise, and fall; the switching actions of the energy storage system include grid connection, off-grid connection, and power step.

[0038] The characteristic values ​​of each overvoltage waveform are obtained by wavelet packet transform, Hilbert-Huang transform and mode decomposition, and include amplitude, duration, rate of rise, oscillation frequency, energy density and spatiotemporal distribution.

[0039] Implementing the embodiments of the present invention has the following beneficial effects: 1. This invention establishes an overvoltage analysis model for a multi-element power supply system, comprising a topology model of the multi-element power supply system, a control and protection model of the online energy storage system, and a transient interaction model of reactive power switching and energy storage power response. Combining simulation conditions and corresponding load sizes, the coordinated switching status and actions between the reactive power device and the energy storage system, overvoltage simulation waveforms are obtained. Furthermore, features of the overvoltage waveforms are extracted and imported into pre-trained multi-type overvoltage analysis models to output the types of overvoltages. This addresses the problems of unclear overvoltage mechanisms and inaccurate feature extraction in existing methods. 2. This invention analyzes the characteristic values ​​of each overvoltage waveform through a three-level evaluation system to assess the related risks caused by overvoltage, thereby solving the problems of conservative evaluation results or omissions in existing methods, and thus ensuring the safety of equipment insulation and power supply.

[0040] It is worth noting that the various system modules included in the above system embodiments are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional module are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0041] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, optical disk, etc.

[0042] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for analyzing overvoltage characteristics based on a multi-element power supply system, characterized in that, The method includes the following steps: Establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices, and energy storage systems. This includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a transient interaction model of reactive power switching and energy storage power response that incorporates switch reignition, current cutting, PWM harmonics, and control delay, in order to form an overvoltage analysis model for the multi-element power supply system. The simulation conditions are determined, and based on the load size set for each simulation condition, as well as the coordinated switching and switching actions between the reactive power device and the energy storage system set for each simulation condition, the overvoltage analysis model of the multi-element power supply system is subjected to overvoltage simulation calculation to obtain multiple overvoltage waveforms. Feature extraction is performed on the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform. The feature value of each overvoltage waveform is then imported into a pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs. The overvoltage types include switching overvoltage, reignition overvoltage, resonant overvoltage, and feeder end rise overvoltage.

2. The overvoltage characteristic analysis method based on a multi-element power supply system as described in claim 1, characterized in that, The simulation conditions include normal conditions, coupled conditions, and extreme conditions; among them... The reactive power device and energy storage system do not have a coordinated switching situation under normal operating conditions, and the two are switched independently under the simulation of the system's rated load operation. The reactive power device and the energy storage system under the coupled operating conditions have a coordinated switching situation, and the two are switched synchronously or in a chain under the simulation of the system's rated load operation. The reactive power device and the energy storage system do not have a coordinated switching situation under the extreme operating conditions, and the two are switched independently under the simulation of the system operating under light load or the energy storage system operating in an isolated state.

3. The overvoltage characteristic analysis method based on a multi-element power supply system as described in claim 1, characterized in that, The switching actions of the reactive power device include connection, disconnection, increase, and decrease; the switching actions of the energy storage system include grid connection, off-grid connection, and power step.

4. The overvoltage characteristic analysis method based on a multi-element power supply system as described in claim 1, characterized in that, The characteristic values ​​of each overvoltage waveform are obtained by wavelet packet transform, Hilbert-Huang transform and mode decomposition, and include amplitude, duration, rate of rise, oscillation frequency, energy density and spatiotemporal distribution.

5. The overvoltage characteristic analysis method based on a multi-element power supply system as described in claim 4, characterized in that, The method further includes: Based on the characteristic values ​​of each overvoltage waveform, a three-level evaluation system is established; wherein, the three-level evaluation system includes an amplitude over-limit evaluation system, an insulation stress evaluation system, and a system risk evaluation system; The amplitude over-limit assessment system assesses whether the amplitude of the overvoltage waveform exceeds the preset overvoltage protection setting value to evaluate switch tripping or equipment disconnection from the grid; if so, it is determined that the switch has tripped or the equipment has a risk of being disconnected from the grid, and an early warning is issued; if not, it is safe and no early warning is issued. The insulation stress assessment system evaluates the equipment insulation withstand capability based on whether the cumulative stress of the amplitude and duration of the overvoltage waveform exceeds a preset stress threshold. If so, the equipment insulation withstand capability is considered poor, and an early warning is issued. If not, the equipment insulation is considered safe, and no early warning is issued. The system risk assessment system is based on whether the circuit breaker tripping or equipment disconnection from the grid in the amplitude over-limit assessment system leads to system instability risk; if so, there is a risk and an early warning is issued; if not, it is safe and no early warning is issued.

6. The overvoltage characteristic analysis method based on a multi-element power supply system as described in claim 5, characterized in that, The method further includes: When at least one of the three-level assessment systems is found to have a risk, an appropriate overvoltage optimization strategy is selected and output based on the assessment system with the detected risk; wherein, the overvoltage optimization strategy includes switching timing adjustment strategy, phase selection control strategy, damping activation strategy and online energy storage system power limiting strategy.

7. An overvoltage characteristic analysis system based on a multi-element power supply system, characterized in that, include: The large model building unit is used to establish a multi-element power supply system topology model that includes at least the main grid, feeders, transformers, loads, reactive power devices, and energy storage systems. It includes an online energy storage system control and protection model with fast transfer switch (ATS) delay setting and anti-islanding protection, as well as a reactive power switching and energy storage power response transient interaction model that incorporates switch reignition, current cutting, PWM harmonics, and control delay, in order to form an overvoltage analysis model for the multi-element power supply system. The waveform simulation unit is used to determine the simulation conditions and, based on the load size set for each simulation condition, as well as the coordinated switching and switching actions between the reactive power device and the energy storage system set for each simulation condition, performs overvoltage simulation calculations on the overvoltage analysis model of the multi-element power supply system to obtain multiple overvoltage waveforms. The feature analysis unit is used to extract features from the obtained multiple overvoltage waveforms to obtain the feature value of each overvoltage waveform, and to import the feature value of each overvoltage waveform into a pre-trained multi-type overvoltage analysis model to obtain the overvoltage type to which each overvoltage waveform belongs; wherein, the overvoltage type includes switching overvoltage, reignition overvoltage, resonant overvoltage, and feeder end rise overvoltage.

8. The overvoltage characteristic analysis system based on a multi-element power supply system as described in claim 7, characterized in that, The simulation conditions include normal conditions, coupled conditions, and extreme conditions; among them... The reactive power device and energy storage system do not have a coordinated switching situation under normal operating conditions, and the two are switched independently under the simulation of the system's rated load operation. The reactive power device and the energy storage system under the coupled operating conditions have a coordinated switching situation, and the two are switched synchronously or in a chain under the simulation of the system's rated load operation. The reactive power device and the energy storage system do not have a coordinated switching situation under the extreme operating conditions, and the two are switched independently under the simulation of the system operating under light load or the energy storage system operating in an isolated state.

9. The overvoltage characteristic analysis system based on a multi-element power supply system as described in claim 7, characterized in that, The switching actions of the reactive power device include connection, disconnection, increase, and decrease; the switching actions of the energy storage system include grid connection, off-grid connection, and power step.

10. The overvoltage characteristic analysis system based on a multi-element power supply system as described in claim 7, characterized in that, The characteristic values ​​of each overvoltage waveform are obtained by wavelet packet transform, Hilbert-Huang transform and mode decomposition, and include amplitude, duration, rate of rise, oscillation frequency, energy density and spatiotemporal distribution.

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