The paper proposes a reactive power control system for the circurating current type cycloconverter. Reactive power compensation is provided by circurating current control, with properly sized capacitors at the input line of the cycloconverter, For a balanced three-phase output cycloconverter, the presence of the characteristic cycloconverter harmonics (
fi±6
nf0) in the input line is based on the fact that the reactive component of the fundamental input current varies with the frequencies 6
nf0. Consequently, when the reactive power is controlled successfully by using circulating current control, the characteristic harmonics will not appear. In order to improve the reactive power control response, feed forward control is introduced in addition to feedback control. According to the proposed control system, input current harmonics with frequencies
fi±6
nf0 are reduced to zero approximately. Another topics are consideration on high output frequency operation. Authors suggest that the reactive power controlled cycloconverter has possibility in practical use, of high output frequency operation over input frequency.
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