Journal of Electrical and Electronic Engineering 2013; 1(4): 90-94 Published online November 10, 2013 (http://www.sciencepublishinggroup.com/j/jeee) doi: 10.11648/j.jeee.20130104.15 Power quality analysis in a distribution network of a quarry processing plant Joseph Cudjoe Attachie * , Christian Kwaku Amuzuvi Department of Electrical and Electronic Engineering, University of Mines and Technology, Tarkwa, Ghana Email address: jattachie@yahoo.com(J. C. Attachie), jcattachie@umat.edu.gh(J. C. Attachie) To cite this article: Joseph Cudjoe Attachie, Christian Kwaku Amuzuvi. Power Quality Analysis in a Distribution Network of a Quarry Processing Plant. Journal of Electrical and Electronic Engineering. Vol. 1, No. 4, 2013, pp. 90-94. doi: 10.11648/j.jeee.20130104.15 Abstract: Power quality problems encompass a wide range of different phenomena. Each of these phenomena may have a variety of different causes and different solutions that can be used to improve upon the power quality and equipment per- formance. This paper analyses the malfunctioning of a capacitor bank at a quarry processing company (QPC) in the Western Region of Ghana. The QPC had held the Electricity Company of Ghana (ECG) responsible for the damage. According to QPC, the damage was due to frequent power fluctuations and outages experienced from the ECG distribution network. The paper presents and discusses techniques used to investigate the cause of the problem. The result of the analysis of the damage was conducted using the electromagnetic transient programme (EMTP) and relates the damage to harmonic resonance pro- duced from the QPC power distribution network. It is recommended that, for reliable, safe and economic operation of ca- pacitor banks, the harmonic content of an electrical installation is measured and analyzed before installation. Keywords: Power Quality, Capacitor Bank, Harmonic Resonance, Resonant Frequency, Distribution Network 1. Introduction Power quality encompasses voltage, frequency and waveform distortions that result in failure of customer equipment. From a theoretical point of view, good power quality can be taken to mean that: the voltage supplied by the utility at the customer’s service entrance is steady and within the prescribed range; that the ac frequency is steady and very close to its nominal value (within a fraction of a percent); and that the waveform or shape of the voltage curve versus time very much resembles the smooth sine wave (a condition also described as the absence of har- monic distortion). In practice, however, it makes more sense to consider power quality as the compatibility be- tween what comes out of an electric outlet and the load that is plugged into it. Over recent years, there has been a significant increase in the installation and use of power electronic equipment in electrical power distribution systems. The operation of this equipment has in many cases significantly affected the electrical power quality to such an extent that measures have to be implemented in order to minimise the resultant adverse effects on the electrical plant and equipment [1]. Distortion of sinusoidal voltage and current waveforms caused by harmonics is one of the major power quality concerns in the electric power industry. Considerable ef- forts have been made in recent years to improve the man- agement of harmonic distortions in power systems. Stan- dards for harmonic control have been established. Instru- ments for harmonic measurements are widely available. The area of power system harmonic analysis has also expe- rienced significant advancement [2-3]. During the process of power quality measurement, the electric utility providers use class A (Medium Voltage (MV) bus) and class B (Low Voltage (LV) bus) equipment. Power quality parameters include: voltage frequency, RMS vol- tage values, voltage flicker, imbalance in the voltage three phase system and voltage harmonic distortion. Furthermore, the electric utility suppliers measure the magnitude of all voltage dips or sags that occur in the net- works, as well as swells and interruptions both in number and duration. Power quality is ultimately a consum- er-driven issue, and the end user’s point of reference takes precedence. The objective of this paper is to investigate the frequent failure of a capacitor bank at a QPC in the Western Region of Ghana. The company blamed the ECG for damaging its power factor correction capacitor bank. According to the company, the cause of the damage was due to frequent power fluctuations and outages experienced from the ECG