级联H桥光伏逆变器开关管开路故障诊断

DIAGNOSIS OF OPEN-CIRCUIT FAULT OF SWITCH TUBE OF CASCADED H-BRIDGE PHOTOVOLTAIC INVERTER

多电平逆变器包含大量的半导体开关,以级联H桥光伏逆变器为例,针对开关管开路故障提出一种快速故障诊断和处理方法。在载波的顶端或底端采样每个H桥模块的输出电压,将其作为判断开关管开路故障的判据。诊断完成后,采取相应的措施降低故障程度。该方法可在一个载波周期内完成故障开关管的精确定位。实验结果验证了该方法的有效性。

Multilevel inverters contain a large number of semiconductor switches.Taking cascaded H-bridge photovoltaic inverters as an example,a rapid fault diagnosis and treatment method for open-circuit fault of switch tubes is proposed.The output voltage of each H-bridge module is sampled at the top or bottom of the carrier and used as the criterion to judge the open-circuit fault of the switch tube.After the diagnosis is completed,the corresponding measures should be taken to reduce the degree of fault.This method can accurately locate the fault switch tube in one carrier cycle.Experimental results demonstrate the effectiveness of this method.