AN ELECTRIC MACHINE ASSEMBLY

摘要

The present invention relates to an electric machine assembly comprising an electric DC or AC machine having a plurality of power terminals for supply of a DC or AC generator voltage and receipt of a DC or AC input drive voltage. A motor control unit is operatively coupled to the electric machine and comprises a bi-directional AC/DC power converter which is configured to operate in a first conversion mode for conversion of the DC or AC generator voltage into a rectified DC voltage at first and second battery connections of the motor control unit and a second conversion mode for conversion of a DC battery voltage applied at the first and second battery connections into the DC or AC input drive voltage. A controller of the motor control unit is coupled to the bi-directional AC/DC power converter for selection of one of the first and second conversion modes. The motor control unit comprises an overvoltage protection circuit operatively coupled between the first and second battery connections. The overvoltage protection circuit comprises a first controllable semiconductor device configured to selectively electrically connect or disconnect the first and second battery connections in accordance with a first trigger signal applied to a control terminal of the controllable semiconductor device. A trigger voltage generator coupled to the first and second battery connections is configured to generate the first trigger signal in response to the rectified DC voltage exceeding a predetermined trigger voltage level.