| 摘要 |
PROBLEM TO BE SOLVED: To obtain an in-plant bus voltage controller capable of compensating for an in-plant bus's voltage that drops at the time of a motor's start-up and securely controlling steady load capacity origin voltage fluctuations.SOLUTION: A voltage compensation value calculation unit 111 calculates a required voltage compensation value corresponding to a voltage fluctuation value generated in an in-plant bus 2, from a voltage signal from a potential transformer 8 and a current signal from a current transformer 9. When a start signal SS of a motor 4 has been output, a number-of-capacitor insertion stages calculation unit 112 calculates the number of capacitor insertion stages required for obtaining the voltage compensation value. A capacitor opening/closing instruction unit 115 outputs an insertion instruction to a capacitor block required to be inserted of capacitor blocks 6a to 6c. Thereby, phase-advanced reactive power is controlled; an in-plant bus voltage Vh is controlled. In the case that the in-plant bus voltage Vh has been out of a target voltage specified value range even when all of the capacitor blocks 6a to 6c have been inserted, a tap position of an in-plant transformer 21 is switched to adjust the in-plant bus 2's voltage.SELECTED DRAWING: Figure 1 |
