An Innovative Method for Short Circuit Protection of a Three-Phase MOSFET Power Inverter

An innovative mechanism for short circuit protection (VDS-monitoring of each power switch) of a three-phase MOSFET power inverter system driving an electric motor is presented. This method features a novel filter which is added to the VDS-monitoring circuit of the state-of-the-art inverter. Its application drastically reduces manufacturing costs and complexity. It has been implemented in hardware and tested successfully in the field on inverter/motor combinations on forklifts and other electric vehicles. The method has been patented at German Patent and Trade Mark Office [8].