FEED-FORWARD COMPENSATION METHOD AND APPARATUS FOR PWM CONVERTER IN A CASCADED MULTILEVEL INVERTER

摘要

One device and a kind of method, PWM (Pulse Width Modulation) converter for controlling cascade connection multi-level topology are arranged to prevent an overvoltage or a low-voltage by maintaining evenly a DC link voltage of each module. One device, for controlling PWM (Pulse Width Modulation) converter of cascade connection multi-level topology, including a pulse width modulated inverter, a pulse width modulated inverter controller, an inverter module and a DC link. One exchange input power is converted to a DC power supply by a PWM by pulse width modulated inverter. Pulse width modulated inverter controller responds pulse width modulated inverter, is to be sequentially coupled to a voltage controller (34), a current controller (36) and a PWM generators (38). Inverter module is inverted DC power output from pulse width modulated inverter to an AC power source, drives a squirrel-cage motor. DC link is between pulse width modulated inverter and inverter module. The voltage of DC link is the feedback of the input to voltage controller compared with a reference voltage value. By the feedforward that the current command value that an output power of inverter module calculates is with the input to current controller of the output of voltage controller.