The usage of a PWM rectifier to improve three-phase induction motor drive performance under fault conditions

Reliability and power quality are two aspects of motor drives which have been gaining the attention of the industry. In fact, as the processes increased in number and complexity, the criticality of each component also increased. This paper proposes the usage of a PWM rectifier to accomplish a fault-tolerant motor drive with optimal performance and power quality. The system uses a hardware reconfiguration, which requires no additional hardware components, to isolate any inverter semiconductor fault. Additionally, in order to guarantee system full performance, under faulty operating conditions, a PWM rectifier is used to adjust de DC link voltage. The detection and location of the fault is obtained by using a new diagnostic technique based on the average current Park´s vector approach, which can be readily integrated in the drive control system. The strategy guarantees uninterruptible functioning of the drive and full system performance during a fault situation as well as optimal power quality.