ELECTRIC POWER CONVERSION DEVICE FOR DRIVING MOTOR

摘要

An electric power conversion device is provided with a voltage measurement device (21) for measuring the induced voltage of a motor (M); an inverter (10) for supplying electric power with a variable frequency to the motor (M); a vector control unit (30) for controlling the output electric power of the inverter (10); and a synchronous start control unit (50) for determining the phase and rotational speed of the electric motor (M) from the induced voltage. When the induced voltage is lower than or equal to a predetermined value, the synchronous start control unit (50) discards the determined phase and rotational speed of the motor (M), and when the induced voltage is higher than the predetermined value, the synchronous start control unit (50) sends the determined phase and rotational speed of the motor (M) to the vector control unit (30).