最少拍电流控制在海口动车牵引系统中的应用

在动车牵引系统中，逆变器输入电压较高（1800 V），为了降低功率模块开关损耗和减少散热，牵引逆变器的开关频率通常较低，只有几百赫兹，而动车牵引异步电机的调速范围较宽，输出频率可达200 Hz，转速较高时的载波比较低。在这种情况下，由于每个电周期内的电流调节次数减少，常规电流PI控制器性能变差，无法达到系统要求。为此，将异步电机电压、电流等方程进行复矢量处理，建立了包含延时影响的离散数学模型，在此基础上，设计无差拍电流控制器。通过Simulink仿真及在海口动车线装车进行试验，试验结果表明基于复矢量的最少拍电流控制器在动车牵引异步电机运行过程中具有较好的动态及稳态性能，转矩/励磁反馈电流均能较好地跟随转矩/励磁给定电流。并且在牵引/制动过程中，电压和电流变化平稳，无明显振荡。

Application of Deadbeat Current Control in Haikou EMU Traction System

In EMU traction system, the inverter input voltage is high (1800 V). In order to reduce the power module switching loss and reduce heat dissipation, the switching frequency of the traction inverter is usually low, only a few hundred hertz. But the speed range of the traction asynchronous motor is wide, and the output frequency can reach 200 Hz. When the speed is high, the carrier ratio is relatively low. Due to the reduction of current regulation times within each electric cycle, the performance of the conventional current PI controller deteriorates, which fails to meet the requirements of the system. To solve this problem, the asynchronous motor voltage, current and other equations are processed by complex vector, and the discrete mathematical model containing the influence of delay is established. On this basis, the deadbeat current controller is designed. By Simulink simulation and test in Haikou EMU vehicle linear loading, the test results show that the deadbeat current controller based on complex vector has better dynamic and steady-state performance in the running process of the traction asynchronous motor, and the torque/excitation feedback current can follow the torque/excitation given current well. In the traction/braking process, the voltage and current change smoothly, without obvious oscillation.