Patent ID: 11038438

Abstract:
An inverter system is described. The inverter system includes a DC power source such as a plurality of photovoltaic (PV) panels, an inverter and a controller. The inverter includes a plurality of semiconductor devices (e.g., controllable semiconductor switches such as IGBTs and anti-parallel connected diodes) arranged in a suitable inverter topology. The inverter includes DC input terminals connected to the PV panels by means of a DC link and at least one AC output terminal. When starting the inverter, the controller is configured to enable a short circuit state of the inverter by controlling the semiconductor switches to create a short circuit between the DC input terminals such that the inverter carries a current substantially equal to the short circuit current of the PV panels. This short circuit current may be used to pre-heat the semiconductor devices of the inverter to reduce failure rates caused by cosmic radiation when the semiconductor devices subsequently experience high blocking voltages during normal operation of the inverter.