POWER-FACTOR PREDICTION METHOD AND POWER-FACTOR CONTROL APPARATUS OF POWER CONSUMPTION INSTALLATION

摘要

PURPOSE: To control a power factor properly by predicting a change in the power factor with good accuracy. ;CONSTITUTION: Capacitors 31 to 2m for power-factor improvement are installed at large loads 11 to 1m so as to correspond to each other, and they are changed over individually so as to be turned on or cut off by means of switches 41 to 4m. In principle, the large loads 11 to 1m and the capacitors 31 to 3m for power-factor improvement are turned on or cut off simultaneously. When a part of the large loads 11 to 1m is cut off, a power factor is lowered due to the power consumption of small loads 51 to 5n. In a power-factor prediction apparatus 70, a final power factor is predicted on the basis of an actual result up to the halfway part of a constant period in which a power factor is to be controlled, and it computes the number of days in which the capacitors 31 to 3m, for power-factor improvement, whose corresponding large loads 11 to 1m have been cut off are turned on singly according to the relationship, between the condition and the power factor of a load, which has been learned in advance in a learning table 71. A power-factor control apparatus 73 controls the switches 41 to 4m according to a computed result.;COPYRIGHT: (C)1996,JPO