METHOD AND APPARATUS FOR CONTROLLING ELECTRIC MOTOR

摘要

PURPOSE: A method and a device for controlling an electric motor are provided to suppress an excessive surge voltage. CONSTITUTION: A converting device(12) includes a converter circuit(16) and a capacitor(20) which is connected to an input unit of the converter circuit. A temperature detector detects a temperature of a region except for the capacitor. A capacitor temperature calculator calculates the temperature of the capacitor based on the temperature detected by the temperature detector. A memory unit(23) stores a map or mark which shows a relation between a maximally receivable motor current value and the temperature of the capacitor. A rotor position determining unit determines the rotation position of a rotor of the electric motor. A converting device(11) controller controls the converter circuit to supply the smaller direct current than the maximally receivable motor current to an electric motor(10).