H桥级联多电平逆变器旁路方法研究与应用

Research and Application of H-bridge Cascaded Multilevel Inverter Bypass Method

单元级联H桥逆变器因具有良好的输出电压和电流性能,在中高压变频器中逐渐得到广泛的应用,然而可靠的H桥功率单元故障旁路方法是级联H桥逆变器长期稳定运行的保证。当前逆变器应用现场要求具有高平均无故障时间(MTBF)需求,首先对级联H桥功率单元箱多电平逆变器传统旁路方法的优缺点进行分析;接着根据传统旁路方法的缺陷提出一种有着高可靠性级联H桥多电平逆变器的双重旁路方法;最后详细设计了满足双重旁路方法功能的电路并对该方法进行试验验证。试验结果表明此处所提方法能够实现级联H桥多电平逆变器的双重旁路,具有非常巨大的工程实际应用价值和意义。

The unit cascaded H-bridge inverter has good output voltage and current performance,it is gradually widely used in medium and high voltage frequency converter.However,a reliable H-bridge power unit fault bypass method is a guarantee for the long-term stable operation of cascaded H-bridge inverters.Current inverter application sites require high mean time between failure(MTBF)requirements,firstly,the advantages and disadvantages of the traditional by-pass method of cascaded H-bridge power unit box mulilevel inverter are analyzed.Then,according to the defects of the traditional bypass method,a double bypass method with high reliability cascaded H-bridge multilevel inverter is proposed.Finally,the circuit that meets the function of the double bypass method is designed in detail and the method is verified by tests.The test results show that the proposed method can realize the double bypass of cascaded H-bridge multilevel inverter,it has great practical application value and significance in engineering.