CONTROL METHOD FOR REACTIVE-POWER COMPENSATING APPARATUS

摘要

PURPOSE:To remove the phase delay of the frequency component lower than the commercial frequency caused by the load change in an arc furnace because the phase delay is the cause of miscontrol in the detection of fluctuation amount DELTAQ of reactive power when the steep, random fluctuation of the reactive power as in the arc furnace or the like is detected and the control is performed with an SVC. CONSTITUTION:The fluctuation of reactive power is detected with DELTAQ detector 3. At the same time, the frequency component lower than the commercial frequency is detected with a frequency detector 42. In response to the detected frequency, the cut-off frequency of a high-pass filter 41, through which the detected signal DELTAQ passes, is switched in conformity with the low frequency. A control signal DELTAQ' is obtained at the output side of the high-pass filter 41.