Investigation of the Impact of Active Short Circuit on Traction Inverter

Paper in proceeding, 2026

When faults occur in the drivetrain of an electric vehicle, the switches of the inverter can be turned on simultaneously to isolate the DC-link from the machine, which is referred to as active short circuit (ASC). However, the surge current during ASC may damage the inverter. This paper investigates the impact of ASC current on the inverter. A model describing the transient current under ASC for permanent magnet synchronous machine (PMSM) is presented. To evaluate the thermal stress, inverter loss and thermal models are introduced. Then, simulations of a PMSM and three-phase inverter system are conducted using PLECS. The worst rotor angle for ASC triggering is identified across the full operating range of the PMSM. Furthermore, different operating points are analyzed to determine the highest thermal stress due to ASC. Results show that the most critical condition occurs when the machine operates with base speed and rated torque.