| 摘要 |
PROBLEM TO BE SOLVED: To make the adjusting width of reactive power wide so as to be finely adjustable and to reduce apparatus costs and an installation space in a control apparatus, for a power factor, in which a plurality of power-factor improvement capacitors are turned on sequentially so as to correspond to the reactive power and which improves the power factor. SOLUTION: Power-factor improvement capacitors are constituted of a plurality of kinds of capacitances. When a turning-on/ cutoff condition is established P1, a capacitance to be turned on is calculated on the basis of a capacitance which is turned on at present and on the basis of delay reactive power P2, and a combination of the power-factor improvement capacitors to be used as the capacitance is listed P3. In addition, on the basis of the combination, the number of devices in which a turning-on/ cutoff operation is changed over newly is calculated P4. While the number of times of input/output operations per day is being limited to the prescribed number of times or lower P5, P6, the combination in which the number of devices to be changed over is the smallest is selected P7. Thereby, the power-factor improvement capacitors which are composed of various large or small capacitances can be used so as to be combined to an optimum capaciatnce. |
