Modelling and simulation of a three-phase cycloconverter for input unbalance correction

Cycloconverters are converter structures capable of providing simultaneous voltage and frequency transformation without the need of intermediate stage reactive components. Consequently, they are well-suited for high-power density variable-frequency applications. Cycloconverters are designed to work under balanced input condition. The three phase power frequency input voltage of static converters may be unbalanced either in amplitude or in phase. This paper discusses a novel technique to produce the output of the converter balanced when the input is amplitude unbalanced. Analytically predicted results are verified by simulation.