Patent ID: 6486632
Filing Date: 2002-11-26
Classification: B60L,H02M,H02P,Y02T

Abstract:
A control device for motor/generators comprising:a first inverter connected to a direct-current (DC) power source through DC bus lines, the first inverter applying a control current to a first motor/generator which is used mainly as a motor; a second inverter connected to the direct-current power source through the DC bus lines, the second inverter applying a control current to a second motor/generator which is used mainly as a generator; the second inverter having the same configuration of switching elements as the first inverter; a first PWM signal generating circuit comparing a first carrier signal limiting the operational frequency of the first inverter with a first voltage command signal for establishing a desired control current of the first motor/generator, the first PWM signal generating circuit generating pulse width modulation (PWM) signals each operating one of the switching elements of the first inverter; and a second PWM signal generating circuit for comparing a second carrier signal with a second voltage command signal and generating pulse width modulation (PWM) signals each operating one of switching elements of the second inverter; the second carrier signal having the same period as the first carrier signal and limiting the operational frequency of the second inverter, the second voltage command signal establishing a desired control current of the second motor/generator; the first PWM signal generating circuit and the second PWM signal generating circuit controlling the first inverter and the second inverter respectively so that the operation of the first inverter is synchronized with the operation of the second inverter and so that the current of the first inverter which flows in the DC bus lines flows in an opposite direction to the current of the second inverter which flows in the DC bus line.