单相级联中点箝位整流器IGBT和传感器的统一故障诊断方法

电力电子牵引变压器(PETT)含有大量易故障的绝缘栅双极型晶体管(IGBT)以及传感器,导致系统可靠性和稳定性降低.以PETT前端的输入级——单相级联中点箝位整流器(SPCNPCR)为对象,研究了一种IGBT与传感器故障的统一故障诊断方法.首先,建立SPCNPCR的混合逻辑动态模型,并通过此模型估计得到网侧输入电流和输...

Unified fault diagnosis method for IGBT and current sensor in single-phase cascaded NPC rectifier

A large number of fault-prone IGBTs(Insulated Gate Bipolar Transistors) and sensors are contained in the PETT(Power Electronic Traction Transformer),which reduces the reliability and stability of the system. A unified fault diagnosis method for IGBT and current sensor is studied for the input stage of PETT, i. e. SPCNPCR(Single-Phase Cascaded Neutral Point Clamped Rectifier). Firstly, the hybrid logic dynamic model of SPCNPCR is established, and the grid-side input current and input voltage are estimated through the model. Then, the residuals and the change rates of residual are obtained by comparing the actual and estimated values of the input current and voltage. Furthermore, the voltage residual is used to detect the faulty rectifier cell with open circuit faulty IGBT, and the current residual is used to identify the specific faulty IGBT and the faulty sensor in the faulty cell. The proposed diagnosis method can detect the faulty rectifier cell and achieve the open circuit fault location of single IGBT or multiple IGBTs, and can also effectively distinguish the gain fault, offset fault and drift fault of the grid-side current sensor. Finally, the effectiveness of the proposed diagnosis method is verified by the hardware-in-the-loop test system.