永磁同步电机两种磁场定向控制策略的比较

简要分析了永磁同步电机(Permanent Magnet Synchronous Motor,简称PMSM)矢量控制和直接转矩控制的基本原理.矢量控制基于转子磁场定向,利用解耦思想将电机电流分解为转矩电流和励磁电流,并分别加以控制,从而获得高性能的控制效果.直接转矩控制基于定子磁场定向,以电机转矩为控制对象,通过实时观测电机转矩和定子磁链,利用滞环控制器和开关选择表控制逆变器功率器件的开关状态,输出合理的电压矢量,达到对转矩和定子磁链控制的目的.以TMS320LF2407A为控制芯片,并采用智能功率模块,搭建了实验平台,对这两种控制策略的初步实验测试结果表明,直接转矩控制的动态响应特性与矢量控制相差不大,但存在明显的电流和转矩波动.

Comparison of Two Kinds of Magnetic Field Oriented Control Strategies for Permanent Magnet Synchronous Motor

The theories of Field-Oriented Control(FOC) and Direct Torque Control(DTC) for permanent magnet synchronous motor(PMSM) are analyzed in brief.FOC is based on rotator field-oriented and the idea of decoupling.The motor current is decoupled into torque and magnetized current and dividually controlled for high performance.DTC is based on stator field-oriented and its controlling object is torque.The idea of DTC can be expressed as:observing torque and flux linkage,with Bang-Bang controller and switching table,controlling the state of power inverter,outputting proper voltage space vector,then realizing control of torque and flux linkage.An experimental system based on TMS320LF2407A and intelligent power module(IPM) is set up.Primary experiments are carried out for these two theories.The results of experiments showed that DTC has the same dynamic response as FOC,but the ripples of current and torque are so obvious.