Feed-forward compensation method and apparatus for pwm converter in a cascaded multilevel inverter

An apparatus and a method for controlling a PWM(Pulse Width Modulation) converter of a cascaded multilevel topology are provided to prevent an over-voltage or a low voltage by uniformly maintaining a DC link voltage of each module. An apparatus for controlling a PWM(Pulse Width Modulation) converter of a cascaded multilevel topology includes a PWM converter, a PWM converter controller, an inverter module, and a DC link. The PWM converter converts an AC input power into a DC power by a PWM. The PWM converter controller controls the PWM converter, and is sequentially coupled to a voltage controller(34), a current controller(36), and a PWM generator(38). The inverter module inverts the DC power outputted from the PWM converter to an AC power, and drives an induction motor. The DC link is located between the PWM converter and the inverter module. The voltage of the DC link is compared with a reference voltage value, and is feed-backed to an input of the voltage controller. A current command value calculated from an output power of the inverter module is feed-forwarded to an input of the current controller with an output of the voltage controller.