SPWM逆变器单极性控制方式的实现

A Unipolar Method is Applied in SPWM Inverter

逆变电源因其变换效率高、体积小、重量轻而得到广泛的应用,介绍了一种基于SG3525控制芯片、工作于单极性SP-WM(Sinusoidal Pulse Width Modulation)调制方式的单相电压型逆变器,利用SG3525芯片及其外围辅助电路产生四路SPWM脉冲,控制逆变桥在输出电压的前半周期桥臂1工作于高频状态,桥臂2工作于低频状态;而在后半周期内逆变器的桥臂1工作于低频状态,桥臂2工作于高频状态。采用这种控制方式相对简单,同时可以减少器件的开关次数,降低器件开关损耗,提高逆变的效率。仿真分析和实验结果验证了理论分析与设计的正确性。

The inverter has been used widely because of his high efficiency, lower bulk and lower weight and so on.His main disadvantage is their complex control method.In this paper, a novel single-phase inverter is proposed which works in the unipolar SP-WM, based on SG3525.We use SG3525 chip and peripheral circuits to produce four SPWM pulses ,so that arm-1 of the inverter bridge works in a high frequency, arm-2 works in a low-frequency in the first half cycle of the output voltage, while in the latter half cycle of the output voltage, arm-1 of the inverter bridge works in a low-frequency, arm-2 works in a high frequency.This control method can reduce the switching losses, improving the efficiency of the inverter.The simulation and experimental results show the validity of the proposed method.