DSP控制的能量回馈型交流电子负载设计

摘要

AC electronic load is a kind ol power electronic equipment used to simulate real impedance load fixed or variable. An energy-feedback-type AC electronic load is designed with two-stage PWM converter for testing AC power supply. The working principle of AC / DC / AC converter is analyzed and a decoupling control strategy is put forward for it:the single HCC(Hysteresis Current Control) is applied for the first stage PWM converter to simulate the load characteristics and the voltage-current dual closed-loop control is applied for the second stage PWM converter to feed energy back. The modified software-hardware combined phase locked tracking is proposed to improve its accuracy. The experimental results show that,the designed HCC simulates the electronic load as specified impedance and feeds the test energy back with unity power factor at input port effectively and accurately.%交流电子负载是可以模拟传统真实阻抗负载的电力电子装置,它能模拟一个固定或变化的负载.采用2级PWM变换器设计了一种适用于各种交流电源试验的能量回馈型交流电子负载,根据主电路的2级AC/DC/AC变换结构,分析了其工作原理,并提出了将2级PWM变换器分开控制的方案,前级PWM变换器采用单电流滞环控制实现负载特性模拟功能,后级PWM变换器采用电压、电流双闭环控制实现能量回馈功能.在锁相跟踪控制中,提出了一种软硬件相结合的改进方法.实验结果表明,所设计的滞环电流控制方法是有效的,输入端能准确地模拟设定阻抗值且实验能量以单位功率因数回馈电网.