INSTANTANEOUS VOLTAGE DROP COMPENSATION DEVICE AND INSTANTANEOUS VOLTAGE DROP COMPENSATION METHOD

摘要

PROBLEM TO BE SOLVED: To reduce a voltage difference when switching to normal power feeding after restoration from an instantaneous voltage drop.;SOLUTION: This instantaneous voltage drop compensation device maintains a voltage of a load side at a prescribed voltage by compensating a voltage of a capacitor to a load via an inverter when a voltage of a power system side instantaneously drops. The instantaneous voltage drop compensation device determines the relationship of magnitudes of an upper limit value obtained by multiplying a prescribed percentage to an average value of the prescribed number of voltages in the past nearest to the present in a voltage storage part that successively stores voltages at the power system side detected in the past and/or at the load side, and a newly detected voltage. When the newly detected voltage is determined to be higher than the upper limit value, the device repeats an average and determination by making the voltage storage part store the newly detected voltage as the nearest past voltage. When the newly detected voltage is determined to be lower than the upper limit value, the prescribed voltage at the load side is made to be the average value that corresponds to the upper limit value.;COPYRIGHT: (C)2006,JPO&NCIPI