Abstract—This article presents two methods for the compensation of harmonics generated by a nonlinear load. The first is the classic method P-Q. The second is the controller by modern method of artificial intelligence specifically fuzzy logic. Both methods are applied to a shunt Active Power Filter (sAPF) based on a three-phase voltage converter at five levels NPC topology. In calculating the harmonic currents of reference, we use the algorithm P-Q and pulse generation, we use the intersective PWM. For flexibility and dynamics, we use fuzzy logic. The results give us clear that the rate of Harmonic Distortion issued by fuzzy logic is better than P-Q. Keywords—Fuzzy logic controller, P-Q method, Pulse Width Modulation (PWM), shunt Active Power Filter (sAPF), Total Harmonic Distortion (THD). I. INTRODUCTION HE increasing use of control systems based on power electronics in industry involves more and more disturbance problems in the level of the electrical power supply networks [1], [2]. Non-linear electronic components such as diode/thyristor rectifiers, switched mode power supplies, arc furnaces, incandescent lighting and motor drives are widely used in industrial and commercial applications. These non-linear loads create harmonic or distortion current problems in the transmission and distribution network. The harmonics induce malfunctions in sensitive equipment, over voltage by resonance and harmonic voltage drop across the network impedance that affect power quality [3]. Researchers around the world are developing a shunt Active Power Filter (sAPF) to improve the power quality without the disadvantages of passive filters described in [4], [5]. The power switching devices is driven with specific control strategy to produce current that is able to compensate for harmonic and poor power factor load. In this work, we took the inverter supplied with four identical continuous sources that can replace by other sources like solar photovoltaic energy. A. Morsli, A. Tlemçani and N. Ould Cherchali are with the Research Laboratory on Electrical Engineering and Automatic, University Dr. Yahia Fares of Medea, Algeria (e-mail: morsli_aek2006@yahoo.fr, h_tlemcani@yahoo.fr, nocherchali@yahoo.fr). M. S. Boucherit is with the Laboratory of Process Control, National Polytechnic School (ENP), Algiers, Algeria (e-mail: ms_boucherit@yahoo.fr). II. SHUNT ACTIVE POWER FILTER (SAPF) Shunt Active Power Filter (sAPF) is a power electronics device based on the use of power electronics inverters (Fig.1). The shunt active power filter is connected in a common point connection between the source of power system and the load system which present the source of the polluting currents circulating in the power system lines. This insertion is realized via low pass filter such as, L, LC or LCL filters [6]. Fig. 1 Shunt Active Power Filter Principle Schematics The most important objective of the APF is to compensate the harmonic currents due to the non-linear load. Exactly to sense the load currents and extracts the harmonic component of the load current to produce a reference current as shown in Fig. 2, The reference current consists of the harmonic components of the load current which the active filter must supply [7], [8]. sAPF is controlled to supply/extract compensating current to/from the utility Point Common Coupling (PCC). III. MULTILEVEL INVERTER ILLUSTRATION A. Modeling of Three-Phase Inverter a Five-Level NPC Topology The topology modeled in this study is the voltage inverter three phase five-level topology NPC (Neutral Point Clamp) [9], [10]. Fig. 3 shows the voltage three-phase five-level NPC topology inverter. The symmetry of three-phase five-level inverters can model them by leg [11]-[13]. Comparative Study between Classical P-Q Method and Modern Fuzzy Controller Method to Improve the Power Quality of an Electrical Network A. Morsli, A.Tlemçani, N. OuldCherchali, M. S. Boucherit T Non-Linear Load Source is iL if 3Ph ∼ Current quality Improvement Source Current Load Current Filter Current shunt Active Power Filter (sAPF) World Academy of Science, Engineering and Technology International Journal of Electrical and Computer Engineering Vol:9, No:5, 2015 1316 International Scholarly and Scientific Research & Innovation 9(5) 2015 scholar.waset.org/1307-6892/10001562 International Science Index, Electrical and Computer Engineering Vol:9, No:5, 2015 waset.org/Publication/10001562