CN-122019950-A - Lightning arrester configuration scheme determining method of bridge arm reactor and related equipment

CN122019950ACN 122019950 ACN122019950 ACN 122019950ACN-122019950-A

Abstract

The application discloses a method for determining a lightning arrester configuration scheme of a bridge arm reactor and related equipment, wherein the method takes total equivalent impedance of a pre-configured lightning arrester module as a variable and takes fault current of the pre-configured lightning arrester module as constraint that is smaller than the maximum value of short-circuit current as constraint, so as to construct a first equivalent impedance constraint function; the method comprises the steps of taking the upper limit of insulation voltage between ends of a bridge arm reactor, which is not higher than the protection level of a pre-configured arrester module, as constraint, taking the total column number, total equivalent impedance and curve fitting factor of the pre-configured arrester module as variables, constructing a second equivalent impedance constraint function, generating feasible solutions based on volt-ampere characteristic fitting coefficients of different arrester valve plate types, and selecting the optimal feasible solution from the feasible solutions as an arrester configuration scheme of a target MMC. Therefore, the method can be used for realizing the technical process of double constraint function construction, step solving, feasible solution screening and optimal solution determination, and has higher calculation efficiency and standardization and replicability.

Inventors

XIN QINGMING
LI YAN
WANG ZIYIN
XU DIZHEN
ZHAO XIAOBIN
ZHANG YINING
Huang Biyue
LU YUXIN

Assignees

南方电网科学研究院有限责任公司
中国南方电网有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (10)

1. The method for determining the configuration scheme of the lightning arrester of the bridge arm reactor is characterized by comprising the following steps of: Taking the total equivalent impedance of the pre-configured arrester module as a variable and taking the maximum value of fault current smaller than short-circuit current flowing through the pre-configured arrester module in a target MMC as a constraint, and constructing a first equivalent impedance constraint function; Constructing a second equivalent impedance constraint function by taking the upper limit of the insulation voltage between the ends of bridge arm reactors corresponding to the pre-configured lightning arrester module, the total column number of the pre-configured lightning arrester module, the total equivalent impedance and the curve fitting factor as variables; Solving the first equivalent impedance constraint function to obtain an equivalent impedance value range; Generating all feasible solutions of the second equivalent impedance constraint function based on the equivalent impedance value range and volt-ampere characteristic fitting coefficients of different lightning arrester valve plate types; and selecting the optimal feasible solution from the feasible solutions as a lightning arrester configuration scheme of the target MMC.
2. The method for determining the lightning arrester configuration scheme of the bridge arm reactor according to claim 1, wherein the constructing a first equivalent impedance constraint function with the total equivalent impedance of the pre-configured lightning arrester module as a variable and the fault current flowing through the pre-configured lightning arrester module in the target MMC being smaller than the maximum value of the short-circuit current as a constraint includes: Based on the equivalent impedance of the transformer in the target MMC, the reactance value of the bridge arm reactor and the alternating-current side fault voltage peak value, constructing a first current calculation function for calculating the alternating-current side fault current peak value by taking the total equivalent impedance as a variable; Generating a second current calculation function for calculating direct current capacitor fault current based on the module capacitance value, the capacitance number and the direct current voltage of the target MMC; and based on the first current calculation function and the second current calculation function, constructing a first equivalent impedance constraint function by taking the fact that the fault current flowing through the pre-configured lightning arrester module in the target MMC is smaller than the maximum value of the short-circuit current as constraint.
3. The method for determining the lightning arrester configuration scheme of the bridge arm reactor according to claim 2, wherein the constructing a first equivalent impedance constraint function based on the first current calculation function and the second current calculation function with a fault current flowing through a pre-configured lightning arrester module in a target MMC being less than a maximum value of a short-circuit current as a constraint includes: Integrating the first current calculation function and the second current calculation function to generate a fault current peak value calculation expression of a pre-configured lightning arrester module in a target MMC; And taking the product of the maximum turn-off current of the insulated gate bipolar transistor IGBT and the margin coefficient as a first equivalent impedance constraint function according to the fault current peak value calculation expression.
4. The lightning arrester configuration scheme determination method of the bridge arm reactor according to claim 3, wherein the first equivalent impedance constraint function is: In the formula, Is the fault voltage peak value of the alternating current side; Is angular frequency; Is a first intermediate variable; is a second intermediate variable; The capacitance value of the module; is the capacitance number; the reactance value of the bridge arm reactor; equivalent impedance of the transformer; is a direct current voltage; is a margin coefficient; maximum off current for the IGBT; Is the total equivalent impedance.
5. The method for determining the configuration scheme of the lightning arrester of the bridge arm reactor according to claim 1, wherein the constructing a second equivalent impedance constraint function with the upper limit of the insulation voltage between the bridge arm reactors corresponding to the pre-configured lightning arrester module, the total column number of the pre-configured lightning arrester module, the total equivalent impedance and the curve fitting factor as variables includes: generating a protection level calculation expression of the pre-configured arrester module based on the total column number of the pre-configured arrester module, the total equivalent impedance and a curve fitting factor; and taking the upper limit of the insulation voltage between the ends of the bridge arm reactors as a second equivalent impedance constraint function, wherein the protection level calculation expression is not more than the upper limit of the insulation voltage between the ends of the bridge arm reactors.
6. The lightning arrester configuration scheme determination method of the bridge arm reactor according to claim 5, wherein the second equivalent impedance constraint function is: In the formula, Is the total equivalent impedance; Is the total column number; Q is a curve fitting factor; Is the upper limit of the insulation voltage between the terminals.
7. The method for determining the lightning arrester configuration scheme of the bridge arm reactor according to claim 1, wherein the generating all feasible solutions of the second equivalent impedance constraint function based on the equivalent impedance value range and the volt-ampere characteristic fitting coefficients of different lightning arrester valve sheet types includes: substituting the volt-ampere characteristic fitting coefficient of each arrester valve plate type as the value of a curve fitting factor into the second equivalent impedance constraint function in sequence, and determining all column number feasible values which meet the equivalent impedance value range and belong to positive integers; And forming a feasible solution by using the type of the valve block of the lightning arrester corresponding to each volt-ampere characteristic fitting coefficient and one of the feasible column numbers corresponding to the type of the valve block of the lightning arrester.
8. The lightning arrester configuration scheme determining device of the bridge arm reactor is characterized by comprising the following components: the construction module is used for constructing a first equivalent impedance constraint function by taking the total equivalent impedance of the pre-configured arrester module as a variable and taking the maximum value of fault current which flows through the pre-configured arrester module in the target MMC as a constraint; The constraint module is used for constructing a second equivalent impedance constraint function by taking the upper limit of the insulation voltage between the ends of the bridge arm reactors corresponding to the pre-configured arrester module as constraint and taking the total column number of the pre-configured arrester module, the total equivalent impedance and the curve fitting factor as variables; The solving module is used for solving the first equivalent impedance constraint function to obtain an equivalent impedance value range; The generation module is used for generating all feasible solutions of the second equivalent impedance constraint function based on the equivalent impedance value range and volt-ampere characteristic fitting coefficients of different lightning arrester valve plate types; and the selecting module is used for selecting the optimal feasible solution from the feasible solutions as the lightning arrester configuration scheme of the target MMC.
9. The lightning arrester configuration scheme determining device of the bridge arm reactor is characterized by comprising a memory and a processor; The memory is used for storing programs; The processor is configured to execute the program to implement the steps of the lightning arrester configuration scheme determination method of the bridge arm reactor according to any one of claims 1 to 7.
10. A readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for determining the lightning arrester configuration scheme of the bridge arm reactor of any of claims 1-7.

Description

Lightning arrester configuration scheme determining method of bridge arm reactor and related equipment Technical Field The application relates to the technical field of modularized multi-level flexible direct current systems, in particular to a lightning arrester configuration scheme determining method of a bridge arm reactor and related equipment. Background At present, a modular multilevel flexible direct current system MMC has become a first-choice topological structure for ultra-long-distance transmission of large-scale new energy. Bridge arm reactors are typically configured in MMCs, which mainly function to limit bridge arm circulation while limiting fault current at system faults. Because the turn-off process of the insulated gate bipolar transistor IGBT is extremely short, the characteristic of quick turn-off of the insulated gate bipolar transistor IGBT is easy to cause higher overvoltage, the overvoltage is particularly remarkable at the two ends of the bridge arm reactor, and therefore, in engineering, lightning arresters are usually required to be arranged at the two ends of the bridge arm reactor so as to effectively inhibit the overvoltage level. However, when the lightning arrester is arranged at two ends of the reactor, after a fault occurs, the capacity of limiting short-circuit current of the reactor is greatly reduced due to the fact that a large current flows after the lightning arrester acts. Based on this, the arrester parameters are designed as an integral part of the MMC configuration process. In the prior art, electromagnetic transient simulation is generally adopted, and a mode of repeated iterative computation is adopted to determine final lightning arrester parameters, but the mode is complex in iterative computation process, and has large iterative computation workload, so that rapid selection of the lightning arrester parameters is difficult to realize, and the high-efficiency requirements of engineering design cannot be met. Disclosure of Invention In view of the above, the application provides a method for determining a configuration scheme of a bridge arm reactor and related equipment, which are used for solving the defect of low speed in the existing parameter design scheme of the lightning arrester. In order to achieve the above object, the following solutions have been proposed: A lightning arrester configuration scheme determining method of bridge arm reactors comprises the following steps: Taking the total equivalent impedance of the pre-configured arrester module as a variable and taking the maximum value of fault current smaller than short-circuit current flowing through the pre-configured arrester module in a target MMC as a constraint, and constructing a first equivalent impedance constraint function; Constructing a second equivalent impedance constraint function by taking the upper limit of the insulation voltage between the ends of bridge arm reactors corresponding to the pre-configured lightning arrester module, the total column number of the pre-configured lightning arrester module, the total equivalent impedance and the curve fitting factor as variables; Solving the first equivalent impedance constraint function to obtain an equivalent impedance value range; Generating all feasible solutions of the second equivalent impedance constraint function based on the equivalent impedance value range and volt-ampere characteristic fitting coefficients of different lightning arrester valve plate types; and selecting the optimal feasible solution from the feasible solutions as a lightning arrester configuration scheme of the target MMC. Optionally, the constructing a first equivalent impedance constraint function with the total equivalent impedance of the pre-configured arrester module as a variable and with the fault current flowing through the pre-configured arrester module in the target MMC being smaller than the maximum value of the short-circuit current as a constraint includes: Based on the equivalent impedance of the transformer in the target MMC, the reactance value of the bridge arm reactor and the alternating-current side fault voltage peak value, constructing a first current calculation function for calculating the alternating-current side fault current peak value by taking the total equivalent impedance as a variable; Generating a second current calculation function for calculating direct current capacitor fault current based on the module capacitance value, the capacitance number and the direct current voltage of the target MMC; and based on the first current calculation function and the second current calculation function, constructing a first equivalent impedance constraint function by taking the fact that the fault current flowing through the pre-configured lightning arrester module in the target MMC is smaller than the maximum value of the short-circuit current as constraint. Optionally, the constructing a first equivalent impedance constraint function bas