Active Short Circuit and Safe Discharge Mechanisms in Multi-Phase Inverters During Critical Failures

Abstract

The multi-phase inverter has become more complicated, particularly in an Electric Vehicle (EV)'s power train, which requires a robust fault protection system. The proposed active short circuit and safe discharge mechanisms are also included in this work, dedicated to multi-phase converters in failure conditions. With silicon carbide (SiC) power modules increasingly used in high efficiency and high-power applications, the reliability under fault conditions is an extremely important factor. Cascading failures and permanent damage will occur in multi phase inverter systems if short circuit faults are not prevented. The proposed method combines one centralized short circuit detection, active phase shorting and controlled discharge to make these structures more robust. The on chip active short circuit mechanism isolates the affected phases quickly preventing faults from spreading to other areas of the inverter and the safe discharge mechanism controls energy discharged in fault scenarios, which reduces the thermal stress placed on essential components. The experimental results show that the proposed mechanisms can effectively enhance a fault detection performance, system response during faults, and the operation as whole at faults over the several existing methods. These mechanisms are demonstrated to be very important for enhancing the safety and reliability of multiphase inverters, especially for critical applications of such inverters as EV where high operational security is required.