准 Z 源逆变器中IGBT 开路故障诊断

针对三相准 Z 源逆变器的安全可靠运行问题，提出一种快速、实用的准 Z 源逆变器 IGBT 开路故障诊断 方法。新型 IGBT 开路故障诊断基于 Z 源逆变器自身特性实现，通过在开关周期内观察故障前后直通状态的变化 对系统变量的影响来辨识故障，实施时分为两个连续阶段，一是 IGBT 开路故障检测和定位，二是激活冗余桥臂， 完成故障容错运行。利用三相准 Z 源逆变器低压样机进行测试，实验结果验证，所设计的 IGBT 开路故障诊断方 案可快速检测出 IGBT 故障，并能在 0.5 ms 内完成系统重构，实现故障容错运行。在轨道交通系统中采用所提出 的 Z 源逆变器 IGBT 开路故障诊断方案，可以保证供电系统的可靠运行。

Fault Diagnosis of an IGBT with an Open-Circuit in the Quasi-Z-Source Inverter

A fast and practical IGBT open-circuit fault diagnosis method for quasi-Z-source inverters is proposed to ensure safe and reliable operation of three-phase quasi-Z-source inverters. A new IGBT open-circuit fault diagnosis was realized based on the characteristics of the Z-source inverter. The primary method was to observe the influence of the change in the shoot-through state on the system variables before and after the fault during the switching period to identify the fault. The implementation is divided into two consecutive stages: IGBT open-circuit fault detection and location, and activation of the redundant bridge arm to complete the fault-tolerant operation. The tests were performed using a low-voltage three-phase quasi-Z-source inverter prototype. The experimental results verified that the designed IGBT open-circuit fault diagnosis scheme can quickly detect IGBT faults and complete the system reconstruction within 0.5 ms to achieve fault-tolerant operation. The use of the proposed Z-source inverter IGBT open-circuit fault diagnosis scheme in a rail transit system can ensure reliable operation of the power supply system.