CONTROL METHOD FOR ELECTRIC VEHICLE DRIVE MOTOR

摘要

PURPOSE:To make the generated torque of a motor approximately constant in spite of the change of temperature, to prevent the variation of the vehicle performance and the generation of unfamiliar driving feeling, and to make stable torque correction possible over the whole speed range. CONSTITUTION:The quantity of torque correction DELTAK is operated by estimating the quantity of magnetic flux at the current temperature of permanent magnets constituting the rotor of a motor, and finding the rate of change of this estimated value with the quantity of magnetic flux at a reference temperature by an induced voltage correcting part 45 or a temperature correcting part 46. A command value Iq* of a torque current component is corrected by reflecting the quantity of torque correction DELTAK on Iq* through a quantity of correction adding part 48 and torque-current converting part 43, and given to an inverter control part 44. The rate of change of the quantity or the magnetic flux of the permanent magnets is found by directly operating induced voltage by the induced voltage correcting part 45 at the time of moddle- and high-speed rotation, or by operating it by the temperature correcting part 46 at the time of stopping or low-speed rotation.