VF-Input AC-AC Converter - Evaluation at High-Frequencies and Characteristics of Power Interfacing

A compact three-phase VF-input AC-to-AC power converter, capable of operating a wide range of input frequencies, 360 - 700 Hz, is reported, which is desirable for some applications of vehicular power systems, e.g. series-hybrid. This capability of one-stage VF-VF power conversion can eliminate a mechanic speed regulation stage associated with the conventional generating systems for series-hybrid vehicular or distributed renewable energy/power systems, thus improving the efficiency. Digital control using a low-cost DSP is presented. Extensive experimental tests and evaluations are conducted and reported giving desirable operating characteristics at both input and output side, including the EMI characteristics and line harmonics.