基于状态空间的PWM逆变器数字PI双环控制技术研究

Research on the state space based digital PI dual loop control for PWM inverters

主要研究了数字控制的实际应用情况以及脉宽调制(PWM)正弦波逆变器的特点,包括电流内环电压外环的双闭环控制。在建立逆变器控制系统状态空间模型的基础上,详细分析了外环为输出电压,内环为电感电流加负载电流前馈控制对应的控制策略的稳定性和动态响应。先对控制系统直接离散化,再利用极点配置的方法进行系统参数设计。从响应速度、外特性、稳定性方面进行了具体分析,结果说明在离散域里双环控制逆变器具有较好的动态响应速度和输出外特性。最后通过实验验证和仿真波形分析,证明这种双环控制技术能满足各项性能指标要求。

The practical application of digital control,including dual loop digital control technique with instantaneous voltage and current feedback,as well as the feature of sinusoidal wave pulse width modulation（ PWM） inverters,were mainly studied. Based on the establishment of state space model for the inverter control system,a dual loop digital control strategy（ the inner loop is for inductor current and the out loop is for output voltage） was proposed with output feed forward. After direct discretization,the control system＇s parameters were calculated by a pole assignment method. The simulation waveforms under various conditions were presented. Both the simulations and the experiments showed that the proposed technique was simple and feasible,which can meet all the performance requirements of the inverter power source perfectly.