Hardware-in-Loop-Based Reliability Improvement of Power Converter for Critical Electrical Drive Applications

Drive system is an assembly of various components such as source, power converter, machine, sensors and controller. Power converters of any drive system are one of the most vulnerable and important failure causes. The reliability of power converters plays a significant role in the uninterrupted operation of drives, especially in critical electrical drive applications. Since the solid-state switches are the most sensitive component in power converters, a reliable fault detection method is essential to provide uninterrupted service for any critical drive systems. This chapter assesses various fault identification methods and focuses on a method to detect the fault. When the fault is detected, the redundant switch is interposed to a power converter for improving the reliability of critical electrical drive applications. Redundancy has been widely employed in many safety-critical electrical drive applications such as space machines, aerospace, defense, electric vehicle and many other industrial applications. The type of source (AC/DC), machine model (IM, SRM, BLDC, PMSM) and converter configurations (AC–DC, DC–DC, DC–AC and AC–AC) are selected by the desired application. This chapter focuses on high-frequency signal-based fault diagnosis strategy for open-circuit (OCFs) and short-circuits fault (SCFs) identification on two-level three-phase voltage source power converter-based PMSM drive system. High-frequency current may cause temperature rise in the power converter circuits due to overheating. Hence, this chapter also focuses on identifying the switches with suitable materials and methods of cooling the parts which are prone to be melted and cause an electric fire. Materials that work under extreme temperatures, pressures and humid conditions are proposed for crucial components to ensure performance with high reliability under different operating conditions. In place of the conventional techniques that use extra sensors, the chapter focused diagnostic strategy identifies the faults from the high-frequency current components by inserting a high-frequency voltage signal into PWM signal of the inverter circuit. A reconfigurable two-level inverter presented for the reliability improvement of PMSM drives with control strategies. Both open-circuit (OCFs) and short-circuit faults (SCFs) are analyzed for different fault condition like single fault or hybrid fault for different drive speeds. Thus, any fault that occurs in the inverter circuit will not affect the performance of the electrical drive application, drive continuously runs with the same torque and speed even after fault. This developed system is implemented and validated in Typhoon Hardware-in-Loop environment.