光伏发电变换器的功率管故障检测与定位研究

Research on Power Tube Fault Detection and Location of Photovoltaic Converter

光伏发电变换器容易因为功率器件发生开路故障或短路故障造成系统停机,在并网状态下还会对公共电网造成瞬间冲击。为了有效识别光伏发电变换器存在的功率管故障,提出一种低成本的光伏串联谐振变换器的功率管故障检测与定位策略,可以在变换器输入侧功率管发生短路故障和输出侧功率管发生开路故障时快速实现对故障的精确检测与定位,使系统能够快速检测到故障并及时地应对故障。对于输入侧功率管的短路故障,利用基于光伏组件电压测量的方法来检测短路故障;输出侧的功率管开路故障则通过检测与直流母线共用同一个地的2个底部开关的电压来发现。搭建一台300 W的实验样机对所提方案进行验证,实验结果表明本文方案可以快速精准地识别2种功率管故障,并在检测到故障后及时控制系统使其恢复到可接受的工作状态。

The photovoltaic converter is easy to shut down the system because of the open circuit fault or short circuit fault of the power device,and it may also cause an instant impact on the public grid in the grid-connected state.In order to effectively identify the power tube fault existing in photovolatic converter,a low-cost power tube fault detection and location strategy for photovolatic series resonant converter is proposed.The method can quickly and accurately detect and locate the fault when the power tube on the input side of the converter is short-circuited and the power tube on the output side is open.This enables the system to quickly detect the existence of the fault and deal with the fault in time.For the short-circuited fault of the input side power tube,the short-circuited fault of the input side power tube is detected based on the photovoltaic module voltage measure-ment method,and the open-circuited fault of the output side power tube is detected by detecting the voltage of the two bottom switches that share the same ground with the DC bus.Finally,a 30o W experimental prototype is built to verify the proposed scheme.The experimental results show that the proposed scheme can quickly and accurately identify the two kinds of power tube faults,and timely control the system to restore it to an acceptable working state after the faults are detected.