Detection of generated and measured transient power quality events using Teager Energy Operator Abdulhamit Subasi a , A. Serdar Yilmaz b,⇑ , Kadir Tufan c a Department of Information Technologies, International Burch University, 71000 Sarajevo, Bosnia and Herzegovina b Department of Electrical and Electronics Eng., Kahramanmaras ß Sutcu Imam University, 46100 Kahramanmaras ß, Turkey c Department of Computer Engineering, Fatih University, 34500 Büyükçekmece, _ Istanbul, Turkey article info Article history: Received 3 November 2009 Received in revised form 9 November 2010 Accepted 21 November 2010 Available online 8 January 2011 Keywords: Power quality (PQ) Power system disturbances Power system transients Teager Energy Operator (TEO) Threshold algorithm abstract In this paper, a novel algorithm, based on the Teager Energy Operator (TEO) of a sinusoidal waveform, proposed to detect and analyze the voltage disturbances. Most common power quality (PQ) disturbances at the distribution level such as voltage sags, notches, and capacitor switching are presented. These examples provide the basis for further characterization of other power quality events. Magnitudes of transient PQ events are located in the width of the signal. Furthermore, meaningful components of tran- sients are analyzed. The whole method is implemented and tested over a sample representing recorded disturbances. Simulation and experimental results of different PQ disturbances show that the proposed method is fast and robust in detecting voltage disturbances and requires only a few samples to calculate the energy of a signal. Crown Copyright Ó 2010 Published by Elsevier Ltd. All rights reserved. 1. Introduction The remarkable increase in the amount of activity in the power quality area has been observed from literature since 1990s. Due to increasing usage of devices which are more sensitive to voltage/ current disturbances and high frequency transients, consumers are affected and exposed to the unexpected mis-operation and out- age [1]. Power quality problems can be described as any variation in the electrical power supply such as voltage sags/swell, flickers, interruptions, notches, and harmonics. Also, The International Electrotechnical Commission (IEC) defined the power quality in IEC 61000-4-30 [2] as: ‘‘ Characteristics of the electricity at a given point on an electrical system, evaluated against a set of reference tech- nical parameters’’. This definition is related to the possibility of mea- suring and quantifying the performance of the power system. Another standardized power quality definition is given by IEEE standard 1100 [3] as: ‘‘The concept of powering and grounding sensi- tive equipment in a matter that suitable to the operation of that equipment’’. Power quality affects the cost of manufacturing nega- tively in industrial plants. It deals with not only voltage quality but also current quality. Actually it is a combination of current and voltage quality. Disturbances in voltage/current waveform have negative influence on the operation of sensitive loads and equipments. These disturbances and rapid transients occur in industrial electric networks frequently because of some operational phenomena such as load/capacitor switching and faults. In general, power quality studies cover the countermeasure of effects and post processing of power quality signals for several aims. During past decade, investigations on post processing of power quality signals have increased due to the fact that the determination and definition of power quality events are required. Detection of power quality events can be defined as catching the disturbances in sinusoidal voltage/current waveforms and notify the abnormal operations. Nowadays, several methods have been applied to detect power quality (PQ) disturbances. Most of these methods are the well- known signal processing methods and have presented satisfactory results. Since, most of power quality events is time varying and non-linear, classical Fourier transform cannot be adequate in the analysis of non-stationary signals such as transient oscillations [4,5]. Short Time Fourier Transform (STFT) is used for time– frequency analysis of non-stationary signals, but, transient signals including both low and high frequency components cannot be suc- cessfully analyzed by STFT method [4,6,7]. The wavelet transform (WT) was proposed in several studies to overcome the limitations of STFT and used to detect power quality disturbances transients, sag/swell [8], flicker [9] and harmonics [8,10]. Since wavelet trans- form has a wide application area in power quality disturbances and the other applications in power systems, it was applied to several power system problems such as fault classifications [11,12], high impedance fault detection [13], and power system relaying [14]. 0196-8904/$ - see front matter Crown Copyright Ó 2010 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.enconman.2010.11.006 ⇑ Corresponding author. Tel.: +90 344 2191254; fax: +90 344 2191052. E-mail addresses: asyilmaz@ksu.edu.tr, a.s.yilmaz@gmail.com (A.S. Yilmaz). Energy Conversion and Management 52 (2011) 1959–1967 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman