Three-Phase Shunt Active Power Filter for Power Improvement Quality using Sliding Mode Controller


In this paper, experimental study of Sliding Mode Controller (SMC) DC bus voltage of three phase shunt active power filter (APF), to improve power quality by compensating harmonics and reactive power required by nonlinear load is proposed. The algorithm used to identify the reference currents is based on the Self Tuning Filter (STF). For generation of the pulse switching of the IGBTs inverter the hysteresis current controller is used, implemented into an analogue card. Finally, various experimental results are presented under steady state and transient conditions.


  1. Shunt Active Power Filter (APF)
  2. Total Harmonic Distortion (THD)
  3. Sliding Mode Controller (SMC)
  4. Self Tuning Filter (STF)




Fig. 1: The basic compensation principle of the shunt APF.




Fig. 2. Experimental APF results: load current iL (A), filter current iF (A)

and source current iS (A). Ch1 to Ch4 scale: 5 A/div. Time scale: 20 ms/div.


Fig. 3. Experimental APF results: load current iL (A), filter current iF (A),

source current iS (A) and source voltage Vs (V). Ch1 and Ch3 scale: 5 A/div;

Ch2 scale: 100 V/div;Ch4 scale: 80 V/div; Time scale: 10 ms/div.

Figure 4. Experimental APF results : load current iL(A), filter current iF(A) ,

source current iS(A) and DC voltage Vdc(V). Ch1,Ch3 and Ch4 scale: 10

A/div. Ch2 scale: 100 V/div. Time scale: 20 ms/div.

Figure 5. Experimental APF results: DC voltage Vdc (V) and DC reference

voltage V*dc (V). Ch1 and Ch2 scale: 100 V/div. Time scale: 1s/div


The control of the shunt Active Power Filter was divided in three parts, the first one realized by the dSPACE system to generate the reference currents, the second one achieved by an analogue card for the switching pattern generation, implementing a hysteresis current controller and the third party use a sliding mode controller SMC. A SMC controlled shunt active power filter has been studied to improve the power quality by compensating both harmonics and reactive power requirement of the nonlinear load. The performance of the SMC controller has been developed in real time process and successfully tested in the laboratory The results of experiment study of APF control technique presented in this paper are found quite satisfactory to eliminate harmonics and reactive power components from utility current. The shunt APF presented in this paper for the compensation of harmonic current components in non-linear load was effective for harmonic isolation and keeping the utility supply line current sinusoidal. The validity of this technique was proved on the basis of experiment results. The APF is found effective to meet IEEE- 519-1992 standard recommendations on harmonics levels.


[1] Chaoui; J.P.Gaubert; F.Krim; G.Champenois, “PI Controlled Threephase Shunt Active Power Filter for Power Quality Improvement” A. “Electric Power Components and Systems, 1532-5016, Volume 35, Issue 12, 2007, Pages 1331 – 1344.

[2] D. Benatous, R. Abdessemed, “Digital voltage control of AC/DC PWM Converter with improved power factor and supply current ”, Journal of electric machines and power systems, Taylor and francis, 2000.

[3] G. A. Capolino, A. Golea, H. Henao, “Système de réduction des perturbations réseau pour commande vectorielle ”, Proc. Colloque SEE Perturbations Réciproques des Convertisseurs et des Réseaux, Nantes, 6 juillet 1992.

[4] M. Abdusalam, P. Poure and S. Saadate,’’ A New control scheme of hybrid active filter using Self-Tuning Filter,’’ POWERENG, International Conference on Power Engineering , Energy and Electrical Drives, Setubal Portugal,12-14 April (2007).

[5] M. Abdusalam, P. Poure and S. Saadate, « Study and experimental +6validation of harmonic isolation based on Self-Tuning-Filter for threephase active filter ». ISIE, IEEE International Symposium on Industrial Electronics, Cambridge, UK, (2008).


Three-Phase For-Wire Shunt Active Filter With Unbalanced loads



The electrical power quality at low voltage alternative networks became a serious concern because of the increased use of nonlinearloads and pollutants. This work is to improve the quality of electric current in such networks. Four-Wire Shunt Active Filter is studied; deferent loads (balanced and unbalanced) are discussed. We propose to identify harmonic and reactive currents at the base of Self-Tuning-Filters, which proved very good filtering performance, either in transient or steady state. The simulations demonstrate the importance of this work in harmonic filtering and reactive power compensation.


  1. Shunt Active Filter (SAF)
  2. Total Harmonic Distortion(THD)
  3. Self-Tuning-Filter (STF)
  4. Unbalanced loads




 Fig. 1. Block diagram of the APF



 Fig.2 Simulation results of STFs under three balanced loads:

(a) Supply and loads currents, (b) 1st phase filter current, (c) Neutral currents,

(d) Harmonic current spectre of 1st phase load, (e) Harmonic current spectre of 1st phase of supply


 Fig.3 Simulation results under three unbalanced loads:

(a) Source and loads currents, (b) Neutral currents, (c) Filter currents,(d) Harmonic currentspectres of loads,(e) Harmonic current spectres of supply


Fig.4 Supply voltage and current (phase 1)


In this paper we have presented a new tree-phase for-wire active power filter based on STF extraction, to identifyharmonic current and reactive power. The objective was to improve the dynamic of identification method and also selectivity. The advantages of this filter are: STFs don’t introduce any displacement between input and output, at the fundamental pulsation. Good dynamic,and high selection of fundamental signal. Their selectivity is improved by reducing K. They can filtrate the voltages that are used to calculate instantaneous powers, to identify perturbation, and so PLL is not used. This method reduces the complexity of the control scheme and consequently facilitates the digital implementation of the control system. Those results demonstrate the good performances of the proposed control.


[l] M. Abdusalam, P. Poure,S. Saadate, “Hardware Implementation of a Three-PhaseActive Filter System with HarmonicIsolationBased on Self-Tuning-Filter”, IEEE. Power Electronics Specialists Conference, Aug. 2008, pp. 2276-2278.

[2] M. Abdusalam, P. Poure, S. Saadate, “A New Control Method of Hybrid Active Filter to Eliminate the 5th and 7th Harmonic Frequency Using Self-Tuning-Filter in the Feedforward Loop”. IREE, International Review of Electrical Engineering, Feb. 2008, pp. 65-72.

[3] A Ghamri, M.T Benchouia, A.Golea.,Sliding-mode Control Based Three-phase Shunt Active Power Filter: Simulation and Experimentation; Electric Power Components and Systems Journal, 2012, 40( 4): 383-398.

[4] M. Abdusalam, P. Poure, S. Saadate, “A New ControlScheme of Hybrid Active Filter Using Self-Tuning Filter”, POWERENG, International Conference on Power Engineering , Energy and Electrical Drives, Setubal Portugal,April. 2007, pp. 12-14.

[5] M.C. Benhabib, S. Saadate, “ New Control Approach for Four-Wire Active Power FilterBasedon the Use of Synchronous Reference Frame”,Elsevier B.V. Electric Power Systems Research 73,Nov. 2004, pp. 353–362. .