Study on the Output Voltage Characteristics of the Unbalanced Input Voltage Three-Level Inverter

Abstract

An unbalanced input voltage three-level inverter can be applied to boost the input voltage by employing energy storage devices, such as the electric double layer capacitor (EDLC), in order to enhance the motor output performance. However, the unbalanced input DC voltage limits the output power and generates particular voltage harmonics. In this paper, the harmonic characteristics, a method to change the power distribution and the limit of the power distribution when the ratio of the DC source voltage to the EDLC voltage is changed are discussed.