Patent ID: 8190387
Filing Date: 2012-05-29
Classification: G01R

Abstract:
1. A frequency measurement apparatus configured to protect a power system using a breaker, comprising: a reception unit configured to receive analog time-series data of an alternating current (AC) voltage signal; a converter configured to convert the analog time-series data to digital time-series data of the AC voltage signal; a calculating unit configured to calculate at least: a transmitter configured to transmit a breaker trip command, responsive to the calculated dynamic frequency exceeding a second threshold value, to trip the breaker wherein the calculating unit is configured to calculate the dynamic frequency based on introducing a variable acceleration coefficient having a value that changes in accordance with the frequency change rate and, in an event that the frequency change rate is higher than or equal to the predetermined threshold value, the calculating unit is configured to determine the frequency change rate to be voltage fluctuation data, and latch the current frequency while, in an event that the frequency change rate is lower than the predetermined threshold value, reduces the variable acceleration coefficient at an initial cycle of an acceleration or a deceleration.