A signal processing module for power system applications

This paper presents a unified power signal processor (PSP) for use in various applications in power systems. The introduced PSP is capable of providing a large number of signals and pieces of information which are frequently required for control, protection, status evaluation, and power quality monitoring of power systems. The PSP receives a set of locally measured three-phase voltage and current signals and provides their fundamental components, amplitudes, phase angles, frequency, harmonics, instantaneous and stationary symmetrical components, active and reactive currents and powers, power factor, and the total harmonic distortion. Simplicity and integrity of its structure as well as its robustness with respect to internal parameters and external disturbances and noise render the proposed scheme very attractive for practical implementations.

I. Introduction

Signal processing tools are used for control, protection, status evaluation, and power quality monitoring of power systems [1]–[10]. In power systems, an ideal voltage or current signal is a pure sinusoidal waveform. However, a typical voltage or current signal is usually distorted by harmonics, subharmonics, dc component, transient signal, and noise. It may also contain uncertainties or nonstationary behavior of parameters such as changes in the central frequency.