一种脉冲电流工况下晶闸管缓冲电路的优化方法

对脉冲工况下超导磁体失超保护系统的晶闸管阀组缓冲回路参数进行设计和优化。基于晶闸管反向恢复电流的指数衰减模型建立了晶闸管关断时刻的电流数学模型。通过测试实验获得关键参数之间的关系并结合晶闸管性能及系统要求在Matlab中建立晶闸管电流反向恢复模型。考虑关断时刻电流下降率、反向恢复电压峰值等性能指标要求及回路研制费用，提出了一种脉冲工况下晶闸管缓冲回路的参数设计及优化方法。在Matlab中搭建失超保护系统模型，对比优化前后缓冲回路对系统在晶闸管关断时刻电气性能的影响，仿真结果显示，相比于原参数，最优参数下，反向恢复电压峰值降低了11%，反向恢复电压变化率峰值降低了43%。同时，回路制造成本降低为原先的1/7。

A parameter optimization method of snubber circuit of thyristor under pulse current working condition

As thyristor valve is the core equipment of quench protection system of large fusion device,the design and optimization of its snubber circuit parameters are related to the safety and reliability of the valve and even the whole quench protection system.So far,most of the design and optimization of snubber circuit parameters are based on DC steady-state conditions.However,there are few literatures on parameter optimization under impulse conditions.In this paper,the buffer circuit parameters of thyristor valve are designed and optimized under the pulse condition of superconducting magnet quench protection system.Based on the exponential model of thyristor reverse recovery current,the current mathematical model at the turn-off time is established.The relationship between the key parameters is obtained through experiments,and the reverse recovery model of thyristor current is established in Matlab according to thyristor performance and system requirements.Considering the performance requirements such as current drop rate at turn-off time,peak reverse recovery voltage and the cost,a parameter design and optimization method of thyristor snubber circuit under pulse condition is proposed.The model of quench protection system is built in Matlab,the simulation results show that compared with the original parameters,the optimal parameters reduce 11%of the peak reverse recovery voltage and 43%of the peak reverse recovery voltage change rate.At the same time,the manufacturing cost of the circuit is reduced to 1/7 of the original one.