1 period of the frequency change amount measurement equipment, the frequency rate of change measurement equipment and

摘要

PROBLEM TO BE SOLVED: To provide a frequency change part and change rate measuring device capable of measuring a stable frequency change part and change rate with high accuracy without being affected by a sudden change of phase appearing in real time in an electric power system.;SOLUTION: A voltage amplitude and its moving average value computing means 4 computes amplitude values of a voltage rotation vector by an integrating method and determines its moving average. A chord length and its moving average value computing means 5 computes chord length between adjacent voltage rotation vector tips by an integrating method and determines its moving average. A rotational phase angle and its moving average value computing means 6 obtains a rotational phase angle from a voltage amplitude average value and a chord length average value and determines its moving average. A frequency computing means 7 computes static frequency not affected by the sudden change of phase using the rotational phase angle average value. A frequency change part average value computing means 9 determines the moving average of change part instantaneous values between frequencies separate for a fixed period computed by the frequency change part instantaneous value computing means 8. A frequency change rate average value computing means 10 computes a frequency change rate average value by dividing the frequency change part average value by the fixed period.;COPYRIGHT: (C)2009,JPO&INPIT