CONTROL METHOD FOR POWER CONVERTER, POWER CONVERTER EMPLOYING THE CONTROL METHOD AND ROLLING CONTROL SYSTEM

摘要

PURPOSE:To improve the stability of voltage and current control by a method wherein same signals are employed as the carrier signals of the pulse width modulation(PWM) control of a converter and inverter or reference signals equiva lent to the carrier signals. CONSTITUTION:A converter control circuit 7 and an inverter control circuit 8 perform PWM control by using the output of a same carrier output means 9 as the carrier signal of the PWM control. That is, a carrier which is the reference signal of the PWM control of the converter 3 is commonly used as a carrier which is the reference signal of the PWM control of the inverter 5. Therefore, the phase of the ripple current of the converter 3 can be matched with the phase of the ripple current of the inverter 5 and hence a current flowing into a smoothing capacitor 4 can be reduced. With this constitution, the ripple of the DC part voltage can be reduced, so that the stability of voltage and current control can be improved.