一种改善矩阵变换器-DTC系统输入电流的策略

Strategy to Improve Inlet Current for Matrix Converter-DTC System

简述了矩阵变换器—异步电机直接转矩控制系统的优点,将矩阵变换器与异步电机直接转矩控制系统相结合。为了得到满足直接转矩控制要求的电压矢量,通过合成两个幅值变化的电压矢量以得到幅值固定的电压矢量;为了改善此控制系统输入端电流波形,在使用电压矢量的同时,引入电流矢量对系统输入电流进行正弦化控制,并且提出了一种电压矢量和电流矢量的协调控制策略。它既保证了直接转矩控制系统的转矩稳定的优点,又改善了矩阵变换器输入端的电流波形。通过仿真实验验证了此控制策略的性能优良,输出转矩脉动小,输入电流正弦度良好。将此控制策略应用于实际电机系统中,可实现高性能转矩控制和能量双向流通,并且减小了对电网造成的谐波危害。

In this paper, the virtue of the DTC system with matrix converter is presented simply, and Matrix converter is combined withDTC system. Two amplitude variable voltage vectors are combined to get one voltage vector with fixed amplitude to fulfill the requirement of DTC system. To improve the current of matrix converter-DTC system, current vector is added to make the inlet current of this system to be sinusoidal, and one coordination control method of voltage vector and current vector is proposed to keep the virtue of the DTC system, and at the same time the inlet current of the matrix converter is improved. Simulation results show this method has good performance： low torque ripple and good sine performance of the inlet current of the matrix converter. And this strategy can get high quality DTC system and make two-way flow of power, and decrease the harmonic for energy grids.