隔离式SEPIC三电平AC-AC变换器的研究

Research of Isolated SEPIC Three-level AC-AC Converter

电力电子装置已在电力系统中得到了越来越广泛的应用,代表之一就是交流调压稳压装置。但是目前的交流调压稳压器多数采用AC-DC-AC的变换方式,这种调压稳压器不仅体积大、噪音大,而且开关管的电压应力大、输出电压波形质量低。提出了一种新型的隔离式交-交变换器,它是在Sepic变换器(单端初级电感转换器)的基础上引入了推挽式变压器实现电气隔离。分析了工作原理,给出了控制策略,并通过仿真论证了变换器开关管电压应力小、输出电压波形质量高等特点。

Power electronics have been more widely used in power systems. One representative of power electronics is AC voltage regulator. But the AC - DC - AC conversion type is widely used for voltage regulator now. These AC voltage regulator not only have big bulk and high noise,but also with high power switch volt- age stress and low quality of output waveform. To solve these problems,an isolated three-level AC- AC direct converter was proposed. It joined the push-pull transformer to achieve electrical isolation based on sepic AC- AC converter. Its operation principle and control strategies of the converter were investigated. By modeling and simulation,the performances of the AC- AC converter were verified,such as low switch voltage stress, high quality of output waveform and so on.