Electric Power Systems Research 116 (2014) 128–135 Contents lists available at ScienceDirect Electric Power Systems Research j o ur nal ho me page: www.elsevier.com/lo cate/epsr Parameter estimation procedure for the equivalent circuit model of compact fluorescent lamps Julio Molina a , Juan José Mesas b , Luis Sainz b,∗ a Department of Power, School of Electrical Engineering – UCV, Los Chaguaramos 1040, Caracas, Venezuela b Department of Electrical Engineering, ETSEIB-UPC, Av. Diagonal 647, 08028 Barcelona, Spain a r t i c l e i n f o Article history: Received 13 November 2013 Received in revised form 26 March 2014 Accepted 17 May 2014 Available online 17 June 2014 Keywords: Compact fluorescent lamps Estimation procedures Non-linear load modeling Power system harmonics a b s t r a c t The spreading use of compact fluorescent lamps (CFLs) in utility distribution systems is leading to increased concerns over power quality because CFLs consume highly distorted currents, which may account for significant power consumption of distribution feeders. For this reason, CFL models and estimation procedures of CFL model parameters must be studied in order to predict CFL harmonic cur- rent emissions into networks. This paper describes estimation procedures of CFL model parameters and presents estimation algorithms based on least-square techniques and actual measurements. The estimation procedures are validated with extensive laboratory measurements. © 2014 Elsevier B.V. All rights reserved. 1. Introduction CFLs are small-power, energy-efficient lighting devices increas- ingly used in residential and commercial installations due to their low energy consumption and long useful life in comparison with incandescent lamps. CFLs consume highly distorted current waveforms, which can pose a harmonic issue because CFL power consumption of all residential and commercial customers in a power distribution system may be of the order of mW, causing unacceptable voltage distortion in distribution feeders [1–3]. For the above reason, CFL modeling is currently studied in the literature in order to assess CFL harmonic current injection and predict its impact on power quality [1,2,4–6]. In [1], supply voltage harmonic interaction in CFL harmonic currents is modeled using the concept of tensor analysis with phase dependence. In [2], CFL harmonic currents are introduced in power flow calculation with Norton equivalent circuits. In [4], CFL study is based on the CFL equivalent circuit without considering its ac equivalent resistance because it can lead to unrealistic infinite slopes in the ac current rising edge. In [5], the CFL equivalent circuit is improved by consid- ering the ac equivalent resistance because it enhances the accuracy of the model at the expense of a slight increase in model complexity. In [6], CFL external behavior is modeled using a double-exponential function to characterize ac current waveform dependence on the supply voltage without considering the internal electric circuit. CFL ∗ Corresponding author. Tel.: +34 93 4011759; fax: +34 93 4017433. E-mail address: sainz@ee.upc.es (L. Sainz). parameter estimation procedures are also necessary to allow use of the previous models in harmonic studies but they have not been studied as extensively as CFL modeling. Little detailed informa- tion about CFL parameter values is available and only a few works deal with parameter estimation of the CFL equivalent circuit model [1,4,5,7]. In [1], typical dc capacitor values of either 4.7 F or 10 F are suggested for CFL modeling. In [4], a simple procedure for deter- mining the parameters of the 120 V, 60 Hz CFL equivalent circuit model from limited information is described. In [5], a straight- forward method for CFL parameter estimation using experimental measurements of the CFL supply voltage and ac consumed current is proposed. In [7], a range of typical values for estimation of CFL equivalent circuit components is presented. Among these works, only the study in [5] provides an accurate estimation of CFL equiv- alent circuit parameters, although these results can be improved with least-square algorithms. These algorithms are used in [8] for estimating the parameters of the CFL double-exponential model in [6]. Other studies deal with the estimation of other non-linear loads using least-square algorithms [9–11]. In particular, [9,10] investi- gate parameter estimation of single-phase rectifiers by analyzing several non-linear sets of equations. This paper examines CFL parameter estimation by non-linear least-square procedures based on actual measurements and the CFL equivalent circuit model in [5]. These procedures are experi- mentally validated with two laboratory tests performed on 12 CFLs of different power ratings and trade names. From this study, a non- linear least-square procedure based on the minimization of the square error between the temporal samples of the CFL measured and simulated ac currents is finally proposed. http://dx.doi.org/10.1016/j.epsr.2014.05.009 0378-7796/© 2014 Elsevier B.V. All rights reserved.