| 摘要 |
PURPOSE:To reduce harmonic components of a power source current by detecting a load current with a first resistor, detecting a differentiated value of the power source current via a second resistor and a reactor, adding the outputs to be used as a base of a compensating current command. CONSTITUTION:A load current is detected by a current transformer 11, and a load current detection voltage VL is output to the both ends of a resistor 112 connected to a load current detector 111. Further, an active filter current is detected by a current transformer 12. A parallel circuit of a resistor 122 and a reactor 123 for differentiating a power source current is connected to an active filter current detector 121, and a power source current detection voltage VC is outputted to both ends of the parallel circuit. The added value of the voltages VL and VC is applied to input terminals A', B' for a compensation command. Thus, the harmonic current to the high frequency current of the resistor can be widely suppressed. |
