| 摘要 |
PROBLEM TO BE SOLVED: To control a power active filter for every number of order without requiring circuits for all number of orders. SOLUTION: A load current from a current detector CTL is subjected to Fourier analysis through a fast Fourier transform operation circuit 3. A digital filter operating circuit 5 determines the amplitude and phase data of harmonics in the load current, based on the data of Fourier analysis. Subsequently, each order harmonic systhesis circuit 9 creates a compensation current command value IL* based on the amplitude and phase data of harmonics and controls an inverter 2 to supply a compensation current to the power supply S side. The amplitude and phase information of each order component can be separated perfectly through Fourier analysis and digital filter operation. The component of required number of order can be compensated through synthesis of data of perfectly separated component of required number of order. |
