该文主要研究脉宽调制(pulse width modulation,PWM)逆变电源电流内环电压外环数字双环控制技术,基于极点配置方法,设计双环控制器参数;在数字控制中,为了克服数字处理器采样、计算延时造成的占空比受限问题,引入状态观测器和扰动观测器。由于直流电压波动、死区效应等建模误差和模型误差影响,状态观测器输出存在较大预测误差。提出一种重复补偿器以减小状态观测器预测误差。仿真分析和试验结果均证明带重复补偿的状态观测器能较好预测系统状态。实验结果表明该控制系统既有较好的稳态性能,又有较快的响应速度。
This paper focuses on the dual-loop digital control technique for pulse width modulation (PWM) inverters. A method based on the pole assignment approach was proposed to tuning the control parameters. To avoid one-timestep delay caused by time consumption in sampling and calculating of digital processors, design of state observer and disturbance observer were brought in. Due to the ripples in DC voltage and dead time effect, there an un-neglected prediction error of state observer, To overcome the prediction error, a repetitive compensator was proposed, and its nice performance was proved by both simulation and experimental results. The experimental results show that the control system has good steady-state performances and fast transient response.