| 摘要 |
PROBLEM TO BE SOLVED: To reduce the outflow amount of harmonic current generated from load to an external system, and prevent a trouble due to harmonic overcurrent by controlling inputting and opening of a group(s) of phase advance capacitors according to the magnitude of reactive power and/or the harmonic current per number of the groups of the phase advance capacitors. SOLUTION: A reactive power detector 1 outputs a signal if the magnitude of detected reactive power is in excess of preset magnitude on the phase lag side, and stops the signal if it is in excess on the phase advance side. A harmonic current detector 3 outputs a signal if the magnitude of detected harmonic current is in excess of a preset one, and stops the signal if it is below the prescribed one to some degree. A phase advance capacitor input signal generator 4 receives the signals of the reactive power detector 1 and the harmonic current detector 3. If the signal of either of the reactive power detector 1 or the harmonic current detector 3 is ON, an input signal is given to the switch 13 of a phase advance capacitor installation 21, and if both of the reactive power detector 1 and the harmonic current detector 3 are OFF, an open signal is outputted to the switch 13. |
