CN-122021485-A - Electromagnetic transient rapid representation method and system of energy storage equipment in power simulation

CN122021485ACN 122021485 ACN122021485 ACN 122021485ACN-122021485-A

Abstract

The invention relates to the technical field of power system simulation, in particular to a method and a system for rapidly representing electromagnetic transient state of energy storage equipment in power simulation. The method comprises the steps of obtaining topology and boundary information of energy storage equipment, enabling an internal high-frequency switching process to be equivalent to a controlled source, achieving topology simplification, mapping a high-dimensional state space to a low-dimensional subspace to obtain a dimension reduction state description, forming a simultaneous equation through a correlation port variable and a power grid node variable, solving the simultaneous equation, obtaining a port time domain response, and carrying out dynamic correction based on a state error. The invention obviously reduces the calculation complexity of electromagnetic transient simulation of the energy storage equipment on the premise of ensuring the simulation precision.

Inventors

ZHANG YAXU
Kuang binqiang
XU JING
HAN QIAOMEI
SONG HENGJIA
HU ZHIFENG
ZHENG DIE
TIAN WENLI
CHEN XIAOJUN
LIU QIDUAN
ZHOU FENG
HAN YUNYUN

Assignees

博智安全科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The electromagnetic transient rapid representation method of the energy storage equipment in the electric power simulation is characterized by comprising the following steps of: Obtaining topological structure information and boundary interface information of energy storage equipment, wherein the topological structure information represents an electrical connection relation between an internal power converter of the energy storage equipment and an energy storage device, and the boundary interface information represents voltage and current constraint between the energy storage equipment and an external power grid; Based on the topological structure information and the boundary interface information, performing equivalent simplification on an electromagnetic transient process in the energy storage equipment, and mapping high-frequency switching characteristics of the power converter and the energy storage device into equivalent controlled source expression to obtain simplified topological characterization; Mapping an original high-dimensional state space to a low-dimensional subspace according to the boundary interface information and the coupling relation between each equivalent controlled source in the simplified topological representation to obtain a dimension-reduction state description; according to the network relation between the dimension reduction state description and an external power grid, a simultaneous solving expression is obtained by correlating a port variable in the dimension reduction state description with a voltage and current variable of an external power grid node; Solving the simultaneous solving expression to obtain a voltage-current time domain response at an energy storage device port, and dynamically correcting the dimension reduction state description based on a state variable error in the voltage-current time domain response.
2. The method of claim 1, wherein equivalently simplifying the electromagnetic transient process inside the energy storage device based on the topology information and the boundary interface information, mapping the high frequency switching characteristics of the power converter and the energy storage device to an equivalently controlled source representation, resulting in simplified topology characterization, comprises: Extracting a switching state conversion sequence of the power converter and a charging and discharging state conversion sequence of an energy storage device in the topological structure information, and obtaining an equivalent periodic time window based on periodic repeated characteristics in the switching state conversion sequence and the charging and discharging state conversion sequence; in the equivalent period time window, performing time average processing on the high-frequency switching action of the power converter, and converting discrete switching states into continuous equivalent duty ratio representation; Determining a correlation between a source voltage magnitude and a source current magnitude in an equivalent controlled source representation based on the equivalent duty cycle representation and a voltage-current constraint in the boundary interface information; converting the charge-discharge state conversion sequence of the energy storage device into an energy transmission direction identification, wherein the energy transmission direction identification indicates that energy flows from a power grid to an energy storage device or flows from the energy storage device to the power grid; And determining the simplified topological characterization according to the equivalent duty ratio representation, the association between the source voltage amplitude and the source current amplitude and the energy transmission direction distinguishing mark, wherein the coupling relation between the equivalent controlled sources in the simplified topological characterization is constrained by the energy transmission direction distinguishing mark.
3. The method of claim 1, wherein mapping the original high-dimensional state space to the low-dimensional subspace according to the coupling relationship between the boundary interface information and each equivalent controlled source in the simplified topology representation to obtain the reduced-dimensional state description comprises: Determining port response frequency distribution characteristics of each equivalent controlled source in the simplified topological characterization based on the voltage and current constraint in the boundary interface information, and dividing the port response frequency distribution characteristics into a dominant frequency band and a non-dominant frequency band; Decomposing a coupling relation among all equivalent controlled sources in the simplified topological characterization, extracting a state variable corresponding to the dominant frequency band in the coupling relation as a dominant state variable, and extracting a state variable corresponding to the non-dominant frequency band in the coupling relation as a non-dominant state variable; calculating contribution degrees of the dominant state variable and the nondominant state variable to the port response frequency distribution characteristics respectively, and screening based on the contribution degrees to obtain a state variable set after dimension reduction; Based on the state variable set after dimension reduction, adjusting the coupling relation among all equivalent controlled sources in the simplified topological characterization to obtain state variable evolution expression in a low-dimension subspace; And correlating the state variable evolution expression with the voltage and current constraint in the boundary interface information, and determining the dimension reduction state description.
4. A method according to claim 3, wherein determining the port response frequency distribution characteristics of each equivalent controlled source in the simplified topological characterization based on the voltage-current constraints in the boundary interface information, and dividing the port response frequency distribution characteristics into dominant and non-dominant bands comprises: performing frequency domain transformation on the voltage and current constraint in the boundary interface information, and calculating the power spectrum density distribution of the boundary interface; Associating an output port of each equivalent controlled source in the simplified topology characterization with the boundary interface, and extracting voltage response and current response of each equivalent controlled source at the output port; Performing frequency domain transformation on the voltage response and the current response, calculating port response frequency distribution characteristics, and calculating frequency domain correlation between the port response frequency distribution characteristics and power spectrum density distribution of the boundary interface; Taking a frequency interval, in which the frequency domain coupling degree of the power spectrum density distribution of the port response frequency distribution characteristic and the boundary interface exceeds a preset coupling threshold, as a candidate dominant frequency interval; and respectively carrying out energy integration on the port response frequency distribution characteristics in the candidate dominant frequency interval and outside the candidate dominant frequency interval, and dividing the candidate dominant frequency interval into a dominant frequency band and a non-dominant frequency band based on the ratio of the accumulated energy in the candidate dominant frequency interval to the total energy of the port response frequency distribution characteristics.
5. The method according to claim 1, wherein obtaining the simultaneous solution expression by correlating the port variable in the dimension reduction state description with the voltage-current variable of the external grid node according to the network relationship between the dimension reduction state description and the external grid comprises: extracting a port variable from the dimension reduction state description, wherein the port variable represents the electrical state of the dimension reduction state description at a boundary interface; determining a constraint relation between a port voltage variable and a port current variable in the port variable according to the state variable evolution expression in the dimension reduction state description; According to the connection position of the boundary interface described by the network topology structure of the external power grid and the dimension reduction state, determining a target node directly connected with the boundary interface in the external power grid, and determining a voltage mapping relation between a node voltage variable of the target node and the port voltage variable and a current mapping relation between a node current variable of the target node and the port current variable; And combining the constraint relation between the port voltage variable and the port current variable, the voltage mapping relation and the current mapping relation to obtain the simultaneous solution expression, wherein the simultaneous solution expression comprises all node voltage and current variables of the port variable and an external power grid in the dimension reduction state description.
6. The method of claim 5, wherein determining a target node in the external power grid directly connected to the boundary interface according to a connection location of a network topology of the external power grid and the boundary interface described by the dimension reduction state, and determining a voltage mapping relationship between a node voltage variable of the target node and the port voltage variable and a current mapping relationship between a node current variable of the target node and the port current variable, comprises: Extracting node connection information and branch connection information from a network topology structure of an external power grid, wherein the node connection information represents a spatial distribution relation of each node in the external power grid, and the branch connection information represents a connection topology of each branch in the external power grid; According to the connection position of the boundary interface described by the dimension reduction state, matching nodes which are overlapped with the connection position of the boundary interface in space in the node connection information, and determining the nodes overlapped in space as the target nodes; Determining node voltage variables and node current variables of the target node in a network topology structure of an external power grid, and determining port voltage variables and port current variables at boundary interfaces of the dimension reduction state description; According to the spatial coincidence relation of the connection positions of the target node and the boundary interface, determining the constraint that the numerical values of the node voltage variable and the port voltage variable of the target node are equal to each other as the voltage mapping relation, and determining the constraint that the node current variable of the target node and the inflow and outflow directions of the port current variable are consistent as the current mapping relation.
7. The method of claim 1, wherein solving the simultaneous solution expression to obtain a voltage-current time domain response at an energy storage device port and dynamically correcting the reduced-dimension state description based on a state variable error in the voltage-current time domain response comprises: Performing numerical solution on the simultaneous solution expression to obtain a port voltage time domain response and a port current time domain response at the port of the energy storage device; determining the voltage-current time-domain response based on the port voltage time-domain response and the port current time-domain response; Extracting an actual state variable at an energy storage device port from the voltage-current time domain response, extracting a predicted state variable corresponding to the actual state variable from the dimension-reduction state description, and calculating the deviation between the actual state variable and the predicted state variable as the state variable error; when the state variable error exceeds a preset error threshold, generating a state variable correction amount according to the amplitude and sign of the state variable error; And adding the state variable correction amount to a predicted state variable in the dimension reduction state description, and updating a state variable evolution expression in the dimension reduction state description to obtain the dimension reduction state description subjected to dynamic correction.
8. An electromagnetic transient rapid representation system of an energy storage device in a power simulation, for implementing the method of any one of claims 1-7, comprising: the information acquisition unit is used for acquiring topological structure information and boundary interface information of the energy storage equipment, wherein the topological structure information represents an electrical connection relation between an internal power converter of the energy storage equipment and the energy storage device, and the boundary interface information represents voltage and current constraint between the energy storage equipment and an external power grid; The topology simplification unit is used for equivalently simplifying an electromagnetic transient process in the energy storage equipment based on the topology structure information and the boundary interface information, mapping the high-frequency switching characteristics of the power converter and the energy storage device into equivalent controlled source expression, and obtaining simplified topology characterization; The state dimension reduction unit is used for mapping an original high-dimension state space to a low-dimension subspace according to the boundary interface information and the coupling relation between the equivalent controlled sources in the simplified topological characterization to obtain dimension reduction state description; the network association unit is used for obtaining a simultaneous solution expression by associating a port variable in the dimension reduction state description with a voltage and current variable of an external power grid node according to the network relation between the dimension reduction state description and the external power grid; The solving and correcting unit is used for solving the simultaneous solving expression, obtaining a voltage-current time domain response at the energy storage device port, and dynamically correcting the dimension reduction state description based on a state variable error in the voltage-current time domain response.
9. An electronic device, comprising: A processor; A memory for storing processor-executable instructions; Wherein the processor is configured to invoke the instructions stored in the memory to perform the method of any of claims 1 to 7.
10. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the method of any of claims 1 to 7.

Description

Electromagnetic transient rapid representation method and system of energy storage equipment in power simulation Technical Field The invention relates to the technical field of power system simulation, in particular to a method and a system for rapidly representing electromagnetic transient state of energy storage equipment in power simulation. Background The energy storage device is taken as a key component in a modern power system, and the accuracy and the calculation efficiency of electromagnetic transient simulation are important to system stability analysis and control strategy verification. In the prior art, when electromagnetic transient modeling of energy storage devices comprising power converters and energy storage means, it is common practice to build detailed switching stage models thereof. Such models are typically based on actual physical topology, and perform high-precision, high-resolution mathematical descriptions of the switching actions of the power semiconductor device, the filter dynamics, and the internal electrical characteristics of the energy storage unit, so as to directly solve a detailed differential algebraic equation set in the time domain. This modeling approach aims to reproduce the electromagnetic transients inside the device as truly as possible in order to obtain accurate port electrical characteristics. However, the conventional detailed switching model described above exposes significant limitations in engineering practice. Because the model needs to accurately simulate the high-frequency switch action and the rapid electromagnetic transient caused by the high-frequency switch action, the state space dimension is high, the differential equation rigidity is high, the calculated amount in the numerical solution process is huge, and the simulation step length is extremely short. This directly results in large-scale power system simulations, especially in scenarios involving multiple such energy storage devices, where the overall simulation speed is extremely slow, and it is difficult to meet the requirements of real-time or super-real-time simulations, as well as long-term dynamic process analysis. Furthermore, high fidelity detailed models often involve manufacturer core parameters and control logic, complicating model acquisition and integration. Therefore, how to significantly improve the calculation efficiency of the energy storage device including the complex power electronic interface in the system-level electromagnetic transient simulation on the premise of ensuring the critical dynamic characteristic characterization precision has become a technical problem to be solved in the field. Disclosure of Invention The embodiment of the invention provides a method and a system for rapidly representing electromagnetic transient state of energy storage equipment in power simulation, which can solve the problems in the prior art. In a first aspect of the embodiment of the present invention, a method for rapidly representing an electromagnetic transient state of an energy storage device in power simulation is provided, including: Obtaining topological structure information and boundary interface information of energy storage equipment, wherein the topological structure information represents an electrical connection relation between an internal power converter of the energy storage equipment and an energy storage device, and the boundary interface information represents voltage and current constraint between the energy storage equipment and an external power grid; Based on the topological structure information and the boundary interface information, performing equivalent simplification on an electromagnetic transient process in the energy storage equipment, and mapping high-frequency switching characteristics of the power converter and the energy storage device into equivalent controlled source expression to obtain simplified topological characterization; Mapping an original high-dimensional state space to a low-dimensional subspace according to the boundary interface information and the coupling relation between each equivalent controlled source in the simplified topological representation to obtain a dimension-reduction state description; according to the network relation between the dimension reduction state description and an external power grid, a simultaneous solving expression is obtained by correlating a port variable in the dimension reduction state description with a voltage and current variable of an external power grid node; Solving the simultaneous solving expression to obtain a voltage-current time domain response at an energy storage device port, and dynamically correcting the dimension reduction state description based on a state variable error in the voltage-current time domain response. Based on the topology structure information and the boundary interface information, performing equivalent simplification on an electromagnetic transient process in the energy s