| 摘要 |
PROBLEM TO BE SOLVED: To increase the input power factor of a cycloconverter and at the same time reduce the amount of harmonics to be generated, by calculating an evaluation function value from the evaluation result of a generated reactive power and generated harmonics, and determining the output voltage of each phase so that the evaluation function value can be minimized. SOLUTION: In the control device of a cycloconverter for performing asymmetrical control, a voltage instruction circuit 30 inputs a torque axis voltage signal Vq and a magnetic flux axis voltage signal Vd from current control circuits 15 and 16, a slide angle frequency signal Ws from a vector operation circuit 13, and a speed feedback signal Wr from a speed detector 6. The voltage instruction circuit 30 is provided with a circuit for evaluating generated reactive power and harmonics, calculates the generated reactive power and at the same time evaluates generated harmonics, and calculates an evaluation function value from the generated reactive power and the generated harmonics evaluation value. Then, the output voltage of each phase is determined so that the evaluation function value can be minimized and output voltage instruction values V'u, V'v, and V'w are outputted.
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