基于三电平SVM技术的船舶电力推进DTC研究

Research on ship electric propulsion DTC system based on three-level inverter of SVM algorithm

介绍二极管钳位型三电平在中高压大中容量的船舶电力推进直接转矩控制(DTC)技术中的应用。针对船舶在低速运行时,控制系统存在低速时性能差以及二极管钳位型三电平固有的直流侧中点电压不平衡的问题,在u-i磁链观测器模型基础上,引入一种带定子电阻补偿的磁链观测器。研究基于双PI调节的电压空间矢量调剂技术(SVM)在系统中的应用。仿真结果表明,系统具有转矩响应快速、磁链观测准确性好、转矩脉动低等优点,能有效抑制三电平的直流侧中点电压不平衡,限制输出电压变化率并降低开关损耗。

The applications of neutral-point-champed three-level inverter in ship electric propulsion DTC with middle-high voltage and big capacity has been introduced in this paper. According to the poor performance at low speed in ship electric propulsion, a new flux observer with stator resistance compensation was presented based on U-I flux observation model. At the same time, SVM algorithm based on double PI regulator has been used in this system. The simulation results show that the low speed performance and dynamic performance can be improved significantly and it has good accuracy of flux observation, also it can effectively control the neutral point voltage.