CIRCUIT BREAKING METHOD FROM OVER COUNTER ELECTROMOTIVE FORCE OF DRIVING MOTER FOR FUEL CELL VEHICLE

摘要

A method for preventing an inflow of excessive counter electromotive force a drive motor for fuel cell powered vehicle is prevent a breakdown and damage of a fuel cell powered vehicle system by switching off a relay for connecting a drive motor with a fuel cell stack. A determination process is performed to determine an operating state of a drive motor for receiving power from a fuel cell stack of a fuel cell powered vehicle by an inverter(S1). Counter electromotive force is detected in the operating state of the drive motor(S2). Three-phase power is applied to the drive motor in order to generate torque(S3). The detected counter electromotive force of the drive motor is compared with a maximum input voltage of the drive motor(S4). A close circuit is formed between the inverter and the drive motor by controlling a switch of the inverter when the counter electromotive force is larger than the maximum input voltage. A counting process is performed to count a time for forming the close circuit(S6). A redetection process is performed to redetect the counter electromotive force of the drive motor(S7). The redetected counter electromotive force of the drive motor is the maximum input voltage of the drive motor(S8).