APPARATUS AND METHOD FOR DIAGNOSING SWITCH TROUBLE OF BI-DIRECTIONAL MULTI-PHASES DC-DC CONVERTER

摘要

Provided are an apparatus and a method to diagnose a switch failure using existing devices prepared in a bi-directional multi-phase DC-DC converter without the necessity of expensive voltage sensor or current sensor. A control unit according to an embodiment of the present invention to perform boost mode and buck mode bi-directional voltage conversion between high-voltage power supply and low-voltage power supply is connected to a DC-DC converter including a plurality of DC-DC converter units connected in parallel one another and forming multi-phase, wherein the DC-DC converter unit comprises: a buck switch for the buck mode; a boost switch for the boost mode; an inductor connected to the buck switch and the boost switch; and a current sensor to sense a current passing through the inductor. The control unit further comprises: a switching control unit to connect a first phase in which a buck switch of a diagnosis target exists and a second phase which is different from the first phase to the high-voltage power supply and turn on a boost switch existing in the second phase; and a failure diagnosis unit to determine that the buck switch of a diagnosis target is out of order if a short-circuit current is sensed by the current sensor.