电力电子变压器直流端口传感器位置选取方法

为了保证电力电子变压器端口故障切除快速响应,在直流端口侧会配有直流固态开关。而当电力电子变压器直流端口电压已经建立,在固态开关闭合瞬间,电力电子变压器直流端口的电容会对固态开关内电容进行充电,在考虑线路阻抗特性情况下,直流端口传统位置的电流传感器会由于线路阻抗和固态开关中电容产生振荡,严重会引发过流保护整机闭锁。文中对电力电子变压器直流端口进行建模分析,简化成RLC电路串联响应特性,对电力电子变压器直流侧的电流振荡波形展开分析,并提出了电流互感器测点优化选取原则,仿真和试验验证了所提理论的正确性。

Selection of DC port sensor position for power electronic transformer

In order to ensure fast response of power electronic transformer port fault removal, DC solid-state switches are usually equipped on the DC port side. When the DC port voltage of power electronic transformer has been established, the capacitance of DC port of power electronic transformer will charge the capacitance of solid-state switch at the moment of solid-state switch closing. Considering the line impedance characteristics, the current sensor at the traditional position of DC port will oscillate due to the line impedance and capacitance in solid-state switch, which will cause serious over-current protection rectification. The machine is locked. In this paper, the DC port of power electronic transformer is modeled and analyzed, which is simplified to the series response characteristics of RLC circuit. The current oscillation waveform on the DC side of power electronic transformer is analyzed, and the principle of optimal selection of measuring points of current transformer is proposed. The correctness of the theory is verified by simulation and experiment.