POWER LOAD IMBALANCE DETECTION DEVICE AND POWER LOAD IMBALANCE DETECTION METHOD

摘要

First through third phase voltage level determiners (30-32) output signals , respectively, when any of the first through third phase impedance values fall below a reference value among the three phase voltages representing transmission grid voltages. When an output signal is received from all of the determiners, a grid fault detecting AND circuit (33) outputs a grid fault detection signal indicating that a major grid fault has occurred among the various types of grid faults that may occur. A rate-of-change detector (19) outputs a rate-of-change detection signal when the change in the value of a generator end current (18) exceeds a given set value. A logic circuit (46), which includes an OR circuit (23) and an AND circuit (24), outputs inflowing steam flow-rate reduction signals (26) based on grid fault detection signals or rate-of-change detection signals.