单元级联型多电平逆变电源研究与实现

Research and Realization of Units Cascaded Multilevel Inverter Power Supply

单元箱H桥级联型多电平逆变器因输出电压谐波含量低以及电压变化率d u/d t小等优点,在高压逆变器中得到广泛的运用。首先分析了3种不同结构的级联型拓扑的优缺点,选用H桥级联型多电平拓扑方案作为所设计的中频逆变电源拓扑;然后分析了几种常用H桥级联型多电平调制算法的优缺点,选用载波移相调制算法作为SPWM波形输出的调制算法;最后根据所选方案和分析结论,设计和研制出一台实际9个H桥单元级联并且额定输出电压为2400 V_(AC),输出频率为100 Hz的中频逆变电源进行试验,验证了所提方案的可行性,并且该逆变电源在感应加热应用性能十分优越。

The unit box H-bridge cascaded multilevel inverter possesses many advantages such as low output voltage harmonics and low rate of voltage change d u/d t,which makes it widely applied in high-voltage inverters.Firstly,the advantages and disadvantages of three different types of cascaded topologies are discussed,and the H-bridge cascaded multilevel topology proposal is selected as the IF inverter topology designed in this paper.Secondly,the advantages and disadvantages of several commonly used H-bridge cascaded multi-level modulation algorithms are analyzed,and the carrier phase-shift modulation algorithm is selected as the modulation algorithm for waveform output of SPWM.Finally,according to the selected scheme and analysis conclusion,a real 9 H-bridge cascade with rated output voltage of 2400 V_(AC) and output frequency of 100 Hz is designed and developed for test.The feasibility of the proposed scheme is verified,and the performance of the inverter in induction heating application is excellent.