Method for performing electromagnetic transient-state simulation to large power system

Abstract

The invention discloses a method for performing electromagnetic transient-state simulation to a large power system. Firstly, equivalence is performed to an external system and specifically comprises the steps of sequentially obtaining sub-admittance rational functional expressions according to the sequence form an Mth sub external passive network to a first sub external passive network and finally obtaining a sub-admittance rational functional expression of the first sub external passive network to serve as a port admittance rational functional expression of the external system. An equivalent circuit of the external system is obtained through the port admittance rational functional expression of the external system. An external power supply is processed through the equivalent circuit of the external system to obtain an equivalent power source. After an equivalent system of an actual system is obtained, the electromagnetic transient-state simulation is performed to the equivalent system, harmonic waves and electromagnetic transient-state characteristics of a device and elements are detected through simulation results so as to judge whether the harmonic waves and transient-state components of the device, the elements and a local network are reasonable or not, if not, the electrical device is replaced, reasonable parameters are adjusted and corresponding measures are adopted, and if so, the process is finished.

Description

technical field [0001] The invention relates to the field of electromagnetic transients in power systems, in particular to a method for simulating electromagnetic transients in large-scale power systems. Background technique [0002] The electromagnetic transient simulation of the actual power system is to study whether the transient overvoltage and overcurrent that may occur after power system failure or operation meet the requirements, and whether the harmonics and electromagnetic transient components of the corresponding power components, equipment and local networks are reasonable , so that more suitable equipment and parameters can be selected and adjusted, and corresponding preventive measures can be taken, which is a basic and important work content of power system planning, design, operation, analysis and control. It often takes a long time to conduct a comprehensive electromagnetic transient simulation analysis on the actual power system. The transient analysis of ...

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Problems solved by technology

[0006] The traditional method has the problem of insufficient equivalent precision, while the VF equivalent method needs to sample the frequency of the external system, and use the least square method to solve the overdetermined linear equations whose coefficient matrix is ​​a dense matrix to obtain the corresponding coefficients of the rational function formula. and the obtained poles may appear unstable poles, and in order to improve the stability of the poles, this method often needs to adopt other measures to stabilize the equivalent system [15-19]

Therefore, although the VF method has greatly improved the accuracy compared with the traditional equivalent method, it costs a lot of time to solve the equivalent circuit, which makes the solution time of the equivalent circuit longer, and it is not convenient to perform electromagnetic simulation on the entire system, so that it cannot be quickly To accurately verify whether the harmonic and transient components of the equipment in the power system are reasonable, which will cause unnecessary economic losses

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