基于IMC多机传动系统的控制策略研究

针对传统交直交变换器多机传动系统中间直流环节存在大电感或大电容而使其体积大,笨重等的问题,采用了一种新颖的基于间接矩阵变换器IMC的多机传动系统电路拓扑。其结构紧凑,体积小,重量轻;整流级采用两段式PWM调制策略,可获得单位功率因数的正弦输入电流,多个逆变级均采用空间矢量调制,实现各个逆变级的独立控制,获得不同频率和幅值的正弦电压。在这种调制策略的基础上,分析了零矢量重叠PWM分布方式对输入输出性能的影响,它可以实现整流级电路的零电流换流,减少了逆变级的开关次数,极大地降低了开关损耗,提高了变换器的效率。仿真结果表明:采用零矢量重叠的调制策略可以减少输出电压电流的谐波含量,能够有效改善传动系统的动态和稳态性能。

Research of Control Strategy of Multi-drive System Based on Indirect Matrix Converter

The problems of the traditional AC-DC-AC converters are large volume and heavy because of large inductor and capacitor.In order to overcome these problems,a new topology of multi-drive system based on indirect matrix converter(IMC) for driving two motors were introduced.It has compact structure,small volume and light weight.Rectifier use two-stage pulse wide modulation(PWM) strategy which can get sinusoidal PWM input current with unity input power factor.Voltage space vector modulation in inverters can realize independent control of each inverter and get sinusoidal output voltage with different frequency and amplitude.Basing on this modulation strategy,the influence of zero-vector overlapping PWM switching pattern to the output and input performance was researched.Zero current commutation in the rectifier side can be realized,and the switching frequency in the inverter can be reduced,greatly reduce the switch loss,improve the efficiency of the converter.The simulation results demonstrate that the output voltage and current harmonic can be reduced effectively when applying zero-vector overlapping PWM switching pattern,and steady and dynamic performance of drive system is well improved.