Fault diagnosis for multiple current sensors in grid‐connected inverter based on average modulation voltage

Abstract

Grid‐connected inverters are the core equipment in the renewable power system. There are multiple current sensors which may affect the driving module of the switch in inverter. In multiple current sensor fault diagnosis, the coupling between fault components makes fault diagnosis difficult. This paper presents an offset fault diagnosis method of multiple current sensors based on the average modulation voltage model. Based on the influence of current sensor offset fault in the system, the average modulation voltage model is established in three‐phase stationary coordinates. The difference between the measured value of the current and the actual value is estimated through the model when the offset fault occurs. And then the fault is located. Experimental results show that the fault can be located accurately and fault tolerant control can be performed by this method when there are offset faults in multiple sensors simultaneously.

Open-Circuit Fault Diagnosis of T-Type Three-Level Inverter Based on Knowledge Reduction

“…A discrete wavelet transform-based fault feature extraction strategy for microgrid inverters was proposed by the authors in [7]. The authors in [8] propose a fault-diagnosis method based on the average modulation voltage model for multi-current sensor disordered grid-connected inverters, which establishes the average modulation voltage model of three-phase steadystate coordinates and estimates the difference between the measured value and the actual value of the current by the model. Then, the fault is found.…”