融合连续过渡模型与Helmer模型的真空断路器开断模型研究OA北大核心CSTPCD

Widely used in medium-voltage power grids,the vacuum circuit breaker(VCB)is prone to occur the high-frequency overvoltage in frequent operation scenarios.The post-arc transient process of the VCB directly determines the characteristics of the breaker interruption and the system overvoltage.To solve the problem that the current electromagnetic transient model of VCB is difficult to simulate its post-arc transient process and high-frequency characteristics at the same time,this paper establishes a new model of VCB based on the continuous transition model and the Helmer model and obtains its simulation parameters through tests and calculation.Taking the VCB breaks 35kV system shunt reactors as an example,the difference between the results of the integrated model and those of the continuous transition model and the Helmer model are compared.The results show that the integrated model considers both the restriking process of the cold gap and the dielectric recovery stage.The calculation of the post arc parameters is basically consistent with that of the continuous transition model,and its high frequency breaking characteristics are close to those of the Helmer model.By analyzing the sheath growth and restriking stage,the main reasons for the restrikes of the VCB are obtained.These simulation results verify the feasibility and necessity of the proposed simulation model for the VCB,which provides a reference for the analysis of f sheath growth and the determination of the causes of the restrikes of the VCB under the condition of high-frequency breaking.