Overheating protection system of switching module

摘要

An overheating protection system for a switching module prevents thermal breakdown of switching devices for passing currents through a load, for example an electric motor, while making it possible for the switching module to provide as much required current to the load as possible. The system comprises a temperature detector for detecting the temperature of a switching module, a temperature estimator for calculating a temperature change rate of a switching device inside the switching module corresponding to a current passed through the load and calculating an estimated value of the internal temperature of the switching module on the basis of the calculated temperature change rate and the detected temperature and a current limiter for on the basis of the estimated value correcting a target current value of a current controller controlling a current passed by the switching device.