采用主从开关表的矩阵变换器电机系统直接转矩控制策略

Direct torque control for matrix convert-fed motor system using master and slave switching table

本文提出一种采用主从开关表的矩阵变换器电机系统直接转矩控制策略。该策略仅使用6个旋转矢量来驱动电机,达到消除共模电压的目的。为了克服相邻旋转矢量之间的角度不断变化的困难,将旋转矢量分为逆时针旋转和顺时针旋转两组,同组的相邻矢量之间具有固定的夹角。将逆时针旋转矢量用于建立主开关表,顺时针旋转矢量用于建立从开关表,根据定子磁链相对于各组中旋转矢量的夹角查找相应开关表。实验结果表明,与使用有效矢量的传统直接转矩控制相比,本文方法可充分实现共模电压的抑制,并且满足控制系统动、静态性能的基本要求。

A direct torque control(DTC)strategy using master and slave switching tables is proposed for matrix converter(MC)fed motor system.Rotating vectors were employed to achieve minimization of common-mode voltage.As the angle between adjacent rotating vectors were changing continuously,which is an obstacle to establish a switching table,two groups of rotating vectors were obtained according to the principle of common rotating direction.In this way,vectors in the same group exhibit constant adjacent vector angle.The counterclockwise rotating vector group were taken to establish the master switching table,and the clockwise ones for the slave switching table.Each table is looked up according to the angle of stator flux referenced to a rotating vector in that group.Experiment results show that common-mode voltage is considerably reduced by the proposed method compared with the active vector-based MC-DTC,and dynamic performance is adequately maintained.