CN-121981056-A - Modeling method and device for new energy converter

CN121981056ACN 121981056 ACN121981056 ACN 121981056ACN-121981056-A

Abstract

The invention relates to the technical field of simulation modeling of power electronics technology, and discloses a new energy converter modeling method and device, wherein the method comprises the steps of establishing a primary topological structure diagram of a converter in a mode of replacing the converter by a controlled voltage source; the method comprises the steps of constructing virtual DC bus voltage based on an energy balance relation of a soft DC converter, obtaining three-phase modulation waves by utilizing a closed-loop control mode based on electric parameters of a primary topological structure and the virtual DC bus voltage, and obtaining control signals of a controlled voltage source after delay control of the three-phase modulation waves. According to the modeling method of the new energy converter, a traditional switching device is replaced by a controlled voltage source, a model nonlinear link is removed, the simulation calculation amount is greatly reduced, the simulation step length can be increased, the simulation speed of a large-scale new energy station current collection system is remarkably increased, and the situation that the electric node accommodation limit of simulation software is exceeded is avoided. Meanwhile, the filter circuit is simplified into a three-phase inductance structure, so that an electric node is further simplified, and the system-level integrated simulation requirement is met.

Inventors

SONG YANG
GOU LIFENG
GAO WEI
CHEN MEIFU
WANG CE
LIAO ANRAN
WANG YIFAN
XUE YINGLIN
WANG YIN
GUO YONGQI
TANG BOJIN
CHANG YONG
LI XIAOTONG
LI ZONGSHANG

Assignees

中国长江三峡集团有限公司

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (11)

1. The new energy converter modeling method is characterized by comprising the following steps of: A primary topological structure diagram of the converter is built in a mode that a controlled voltage source replaces the converter; Constructing a virtual direct current bus voltage based on an energy balance relation of the soft direct current converter; Acquiring an electrical parameter of the primary topological structure; Based on the electrical parameters and the virtual DC bus voltage, a closed-loop control mode is utilized to obtain a three-phase modulation wave; And after the three-phase modulation wave is controlled in a time delay mode, a control signal of the controlled voltage source is obtained.
2. The modeling method of a new energy converter according to claim 1, wherein the primary topology structure of the converter comprises three controlled voltage sources and a filter circuit, wherein, A first end of each controlled voltage source is connected with a corresponding first side of the filter circuit, and a second end of each controlled voltage source is grounded; The second side of the filter circuit is used for grid connection.
3. The method of modeling a new energy converter according to claim 2, wherein the filter circuit comprises three filter inductors, wherein, The first end of each filter inductor is connected with the first end of one controlled voltage source, and the second end of each filter inductor is used for grid connection.
4. The modeling method of a new energy converter according to claim 1, wherein the process of obtaining the three-phase modulation wave by using a closed-loop control method comprises: Obtaining a d-axis current reference command and a q-axis current reference command by using a control outer ring; based on the d-axis current reference command, the q-axis current reference command, the d-axis current and the q-axis current, utilizing current closed-loop control to obtain d-axis modulation waves and q-axis modulation waves; And converting the d-axis modulation wave and the q-axis modulation wave into three-phase modulation waves.
5. The modeling method of a new energy converter according to claim 1, wherein the process of obtaining the d-axis current reference command and the q-axis current reference command by using the control outer loop includes: Converting the power grid voltage into d-axis voltage and q-axis voltage, converting the grid-connected current of the converter into d-axis current and q-axis current, and calculating real-time reactive power based on the power grid voltage and the grid-connected current; Based on the direct-current voltage reference instruction and the virtual direct-current bus voltage, a d-axis current reference instruction is obtained by using a PI regulator; And obtaining a q-axis current reference instruction by using the PI regulator based on the reactive power reference instruction and the real-time reactive power.
6. The method of modeling a new energy converter as claimed in claim 5, wherein the process of obtaining the virtual dc bus voltage includes: taking the ratio of the input power to the virtual DC bus voltage as an input current based on the input power of the primary topological structure; Taking the ratio of the output power to the virtual DC bus voltage as output current based on the output power of the primary topological structure; integrating the current difference value based on the difference value of the input current and the output current to obtain the charge variation of the virtual DC bus capacitor; and taking the ratio of the charge variation to the capacitance value of the virtual DC bus capacitor as the virtual DC bus voltage based on the charge variation of the virtual DC bus capacitor.
7. The modeling method of a new energy converter according to claim 4, wherein the process of obtaining the d-axis current reference command and the q-axis current reference command by using the control outer loop includes: Calculating real-time active power and real-time reactive power based on grid voltage and grid-connected current of the converter; based on the active power reference instruction and real-time active power, a d-axis current reference instruction is obtained by using a PI regulator; based on the reactive power reference instruction and the real-time reactive power, a q-axis current reference instruction is obtained by using a PI regulator; based on the d-axis current reference command, the q-axis current reference command, the d-axis current and the q-axis current, utilizing current closed-loop control to obtain d-axis modulation waves and q-axis modulation waves; And converting the d-axis modulation wave and the q-axis modulation wave into three-phase modulation waves.
8. The modeling device for the new energy converter is characterized in that after a primary topological structure diagram of the converter is established by replacing the converter with a controlled voltage source, the method comprises the following steps: The acquisition module is used for acquiring the electrical parameters of the primary topological structure; the virtual module is used for constructing virtual DC bus voltage based on the energy balance relation of the soft DC converter; The closed-loop control module is used for obtaining three-phase modulation waves by utilizing a closed-loop control mode based on the electric parameters and the virtual direct current bus voltage; And the driving module is used for obtaining the control signal of the controlled voltage source after the three-phase modulation wave is controlled in a time delay mode.
9. An electronic device, comprising: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the new energy converter modeling method of any of claims 1 to 7.
10. A computer-readable storage medium having stored thereon computer instructions for causing a computer to perform the new energy converter modeling method of any of claims 1 to 7.
11. A computer program product comprising computer instructions for causing a computer to perform the new energy converter modeling method of any of claims 1 to 7.

Description

Modeling method and device for new energy converter Technical Field The invention relates to the technical field of simulation modeling of power electronics technology, in particular to a new energy converter modeling method and device. Background The simulation modeling of the current new energy converter is mainly divided into two types, namely, detailed modeling based on Simulink, PSCAD and other software, and the method can accurately reflect the topological structure and the electrical characteristics of equipment by constructing a complete electrical element model and a control loop model and even adding modules such as a photovoltaic cell, a fan, a variable pitch yaw and the like, but the method has the problems of complex model and more electrical nodes, the nonlinear characteristics of a switching element have higher requirements on simulation precision, the simulation step length is required to be reduced, the simulation speed is seriously dragged in a large-scale station modeling scene, even the node bearing limit of a simulation platform is exceeded, and a large number of current collecting system nodes are omitted by adopting a multiplication mode integration model, so that the influence of key node characteristics and current collecting circuit segments on the transient electrical characteristics cannot be estimated; the other type is small-signal modeling in system-level simplified modeling, and although model simplification can be realized to adapt to system-level simulation, the obtained pure mathematical model is difficult to integrate with an electric model of a current collecting system, and the multi-characteristic impedance and frequency domain characteristics are unfavorable for electric transient characteristic evaluation. Disclosure of Invention The invention provides a new energy converter modeling method and device, which are used for solving the problem of how to model a new energy converter in a simulation manner. The invention provides a new energy converter modeling method, which comprises the steps of establishing a primary topological structure diagram of a converter in a mode of replacing the converter by a controlled voltage source, establishing virtual direct current bus voltage based on an energy balance relation of a soft direct current converter, obtaining electric parameters of the primary topological structure and the virtual direct current bus voltage, obtaining three-phase modulation waves in a closed-loop control mode based on the electric parameters, and obtaining control signals of the controlled voltage source after the three-phase modulation waves are controlled in a delayed mode. In an alternative embodiment, the primary topological structure diagram of the converter comprises three controlled voltage sources and a filter circuit, wherein a first end of each controlled voltage source is connected with a corresponding first side of the filter circuit, a second end of each controlled voltage source is grounded, and a second side of the filter circuit is used for grid connection. In an alternative embodiment, the filter circuit comprises three filter inductors, wherein a first end of each filter inductor is connected to a first end of one controlled voltage source, and a second end of each filter inductor is used for grid connection. In an alternative implementation mode, the process of obtaining the three-phase modulation wave by utilizing a closed-loop control mode comprises the steps of obtaining a d-axis current reference command and a q-axis current reference command by utilizing a control outer ring, obtaining the d-axis modulation wave and the q-axis modulation wave by utilizing current closed-loop control based on the d-axis current reference command, the q-axis current reference command, the d-axis current and the q-axis current, and converting the d-axis modulation wave and the q-axis modulation wave into the three-phase modulation wave. In an alternative implementation mode, the process of obtaining the d-axis current reference command and the q-axis current reference command by utilizing the control outer ring comprises the steps of converting grid voltage into d-axis voltage and q-axis voltage, converting grid-connected current of a converter into d-axis current and q-axis current, calculating real-time reactive power based on the grid voltage and the grid-connected current, obtaining the d-axis current reference command by utilizing a PI regulator based on the direct-current voltage reference command and the virtual direct-current bus voltage, and obtaining the q-axis current reference command by utilizing the PI regulator based on the reactive power reference command and the real-time reactive power. In an alternative implementation mode, the process of obtaining the virtual direct current voltage comprises the steps of taking the ratio of input power to virtual direct current bus voltage as input current based on input power of a primary topologi