Abstract :
The main frequency is an important parameter of an electrical power system. The frequency can change over a small range due to generation-load mismatches. Some power system protection and control applications, e,g, frequency relay for load shedding, load-frequency controller, require accurate and fast estimation of the frequency. Most digital algorithms for measuring frequency have acceptable accuracy if voltage waveforms are not distorted. However, due to nonlinear devices, e,g, semiconductor rectifiers, electric arc furnaces, the voltage waveforms can include higher harmonics. The paper presents a new method of measurement of power system frequency, based on digital filtering and Prony´s estimation method. Simulation results confirm, that the proposed method is more accurate than others, e,g, than the method based on the measurement of angular velocity of the rotating voltage phasor
Keywords :
FIR filters; discrete Fourier transforms; frequency estimation; frequency measurement; power engineering computing; power system measurement; power system protection; Prony´s estimation method; digital algorithms; digital filtering; discrete Fourier transforms; electric arc furnaces; frequency relay; generation-load mismatches; load shedding; load-frequency controller; measurement of angular velocity; nonlinear devices; parameter estimation; power system control; power system frequency; power system protection; rotating voltage phasor; semiconductor rectifiers; simulation; voltage waveforms; Control systems; Distortion measurement; Frequency estimation; Frequency measurement; Power system measurements; Power system protection; Power system relaying; Power systems; Real time systems; Voltage;
