Winding open‐circuit fault‐tolerant operation of single DC‐link dual‐inverter fed three‐phase open‐end induction motor drive

Abstract

Abstract This study presents a winding open‐circuit fault‐tolerant control scheme for an open‐end induction motor drive with common DC bus for dual inverters. The proposed control scheme also permits balanced three‐phase operation of the same motor under healthy operation. It can suppress common mode current easily, yet permits maximum DC bus utilisation in both operating modes. It is mathematically established here that during fault‐tolerant operation, the magnetising current increases by a factor of √3. As a result, the airgap flux during fault‐tolerant operation is same as that during balanced three‐phase operation. An analytical relation is proposed for maximum torque capability of the machine during fault‐tolerant operation, taking into account the limit of winding current to its rated value and increase of magnetising current during such an operation. Extensive mathematical analysis is supported by simulation and experimental results to validate the performance of the proposed scheme during balanced three‐phase operation as well as winding open‐circuit fault‐tolerant operation.

Keywords

• Mathematical analysis
• Asynchronous machines
• DC‐AC power convertors (invertors)
• Drives