用于小型断路器特性试验的能馈型电子负载设计

Design of energy feedback electronic load for characteristic test of miniature circuit breaker

为满足“双碳”目标下小型断路器特性试验需要,针对传统重复控制方法动态性能较差的问题,提出一种用于小型断路器测试的能馈型电子负载双模比例(proportional integral,PI)控制策略。该策略采用奇、偶次谐波内模相并联的结构作为改进型内模,并与PI控制器结合,既能有效抑制奇、偶次谐波,又能实现对指令电流的快速精确跟踪。搭建能馈型电子负载仿真模型,并研制装置样机。仿真与试验结果相吻合,验证了所提方法的有效性。结果表明,该能馈型电子负载能在启动后的3个基波周期内达到稳定的电流输出,并能在半个基波周期内完成电流切换。同时,在满载条件下输出电流畸变率、输出误差和能量回馈效率分别为2.98%,0.2%,92.4%,满足小型断路器特性试验要求。

In order to meet the needs of miniature circuit breaker characteristic test under the goal of“double carbon”,aiming at the poor dynamic performance of traditional repetitive control methods,a dual mode PI control strategy of energy feedback electronic load for miniature circuit breaker test was proposed.The structure of parallel connection of odd and even harmonic internal modes was adopted as the improved internal mode and combined with PI controller,which could not only effectively suppress odd and even har-monics,but also realized fast and accurate tracking of command current.The simulation model of energy feedback electronic load was built,and the device prototype was developed.The simulation results were con-sistent with the experimental results to verify the effectiveness of the proposed method.The results showed that the energy feedback electronic load could achieve stable current output in three fundamental wave cycles after startup,and could complete current switching in half fundamental wave cycle.At the same time,the output current distortion rate,output error,and energy feedback efficiency were 2.98%,0.2%,and 92.4%under full load conditions,which met the characteristic test requirements of miniature circuit breaker.