Converter with a plurality of indirect voltage link a.c. converter units

摘要

The present invention relates to a multilevel inverter comprising: a converter unit converting an inputted AC power source to a direct current (DC) power source; a film capacitor (120) rectifying the DC power source converted by the converter unit; an inverter unit (130) converting the rectified DC power source to a three-phase current in response to a pulse width modulation (PWM) control signal and outputting the current; a current detector (140) detecting a current outputted from the inverter unit; a power cell main controller (150) generating a voltage instruction (v*) and a voltage instruction using the detected current; and a PWM controller (160) generating the pulse width modulation (PWM) control signal using the voltage instruction (v*) and frequency instruction (f*).