Design and Performance of a 20 Kva Ground Support Static Frequency Changer

This paper describes a static frequency changer which accepts a variable voltage and frequency input, and produces regulated 3-phase 400 cps at 20 kva. An important feature allows connection of any number of frequency changers in parallel, load division being automatically controlled. Auxiliary functions are provided including short-circuit current limiting, output voltage transient suppression, and protection. Both electrical and mechanical characteristics of production equipment demonstrate the inherent advantages of this power conversion approach.