US Patent 7851866 Electric power conversion device

An object of the present invention is to provide an electric power converter including means for accurately detecting a principal current of IGBT. An electric power conversion device according to the present invention includes principal current estimation means for estimating a principal current by using: an output of temperature measuring means whose diode is disposed in the same semiconductor substrate as an IGBT including an emitter having flowing therethrough the principal current and a sense emitter having flowing therethrough a sense current proportional to the principal current; the sense current; and the information, preliminarily stored in memory means, on the relationship among the semiconductor substrate temperature, the principal current and the sense currant.