Patent ID: 8159840

Claim:
A multilevel inverter, comprising: a converter unit configured for converting an input alternating current (AC) power source to a direct current (DC) power source; a film capacitor configured for rectifying the DC power source; an inverter unit configured for: 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 configured for detecting the current output from the inverter unit; a power cell main controller configured for generating a voltage instruction and a frequency instruction using the current detected by the current detector; a PWM controller configured for generating the PWM control signal using the voltage instruction and frequency instruction; and a phase shift transformer configured for outputting power to the input AC power source, wherein the phase shift transformer has a predetermined inductance value, and wherein a relation between the predetermined inductance value of the phase shift transformer and a capacitance value of the film capacitor is 1:3.