交流斩波器输出电压瞬时值重复控制研究

介绍了一种在输出电压平均值控制基础上引入瞬时值重复控制的交流斩波器。该交流斩波器输出电压采用均值闭环控制,以使输出电压有效值保持稳定。为了克服由于电网电压瞬变或负载突变造成的输出电压瞬时变化,在均值闭环控制环的前向通道上引入基于重复控制思想的瞬时值前馈补偿控制,从而使输出电压波形无瞬变。搭建了交流斩波器的实验平台验证所采用的控制方法,控制部分采用ATmega128单片机作为核心,均值PID调节器、重复控制的前馈补偿控制器等均在该单片机中数字实现。实验结果表明,所采用的控制方法能有效地抑制输入电压变化、输出负载变化等扰动,使输出电压波形稳定。

Research on Repetitive Control of Instantaneous Voltage for AC Chopper

An AC chopper controlled with the method of the repetitive control theory based on the output voltage mean value control is introduced.The AC chopper is controlled with an output voltage rms value feed-back control loop to keep the amplitude of the output voltage stable.In order to overcome the output voltage transient variation caused by the power grid voltage transient change or by the load sudden change,an instantaneous compensation con-trol which based on the repetitive control theory is introduced into the forward path of the mean value closed control loop so that there is little voltage sag or surge on the output voltage waveform.An laboratory AC chopper prototype is built to verify the control method.An MCU ATmega128 is adopted as the core of the system control in which the mean value PID regulator,the forward compensation repetitive controller are all implemented digitally.Experimental re-sults show that the proposed forward compensation repetitive control method can effectively suppress the disturbance of the load or grid sudden changes,leading to a stable output voltage waveform.