**ABSTRACT:**

The problem of quality electrical energy provided to the users has arisen. This is due to the increasing presence in network of nonlinear loads.They constitute a harmonic pollution source of the network, which generate many disturbances, and disturb the optimal operation of electrical equipments. This work, proposed a solution to eliminate the harmonics introduced by the nonlinear loads. It presents the analysis and simulation using Matlab Simulink of a active power filter (APF) compensating the harmonics and reactive power created by nonlinear loads in steady and in transients. The usefulness of the simulation approach to APF is demonstrated , have a better power quality insight using Matlab Simulink in order to develop new fuzzy logic controller based active power filter.

** ****KEYWORDS:**

- Active Power Filters
- Harmonics
- Fuzzy Logic Controller
- MATLAB

** ****SOFTWARE:** MATLAB/SIMULINK

** ****BLOCK DIAGRAM:**

Figure 1 Block diagram of Basic Active Power Filter

**EXPECTED SIMULATION RESULTS:**

** **

** **Fig. 2 Three phase voltage and current waveform with non linear load

** **Fig.3 THD analysis of three phase voltage waveform with nonlinear load

** **Fig.4 Three phase voltages and current waveform with shunt active power filter with connected fuzzy logic controller

** **Fig.5 THD analysis of voltages with shunt active power filter using fuzzy logic controller

** ****CONCLUSION:**

** **The paper presents the application of the fuzzy logic controller to control the compensating voltage. The Mamdani max-min approach is used for the fuzzy inference and the defuzzification method, respectively. The design of input and output membership for the fuzzy logic controller is very important for the system performance. The simulation results show that the fuzzy logic controller provides a good performance to control the compensating voltage of shunt active power filter. The %THD of the voltages at PCC point can be followed the IEEE Std. 519-1992.

** ****REFERENCES:**

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[2] Wilson E. Kazibwe and Mucoke H. Senduala : “*Electric Power Quality Control Techniques”. *New York: Van Nostrand Reinhold, 1993

[3] N. Mohan, “A Novel Approach to Minimize Line- Current Harmonics in Interfacing Power Electronics Equipment with 3-Phase Utility Systems”, IEEE Trans on Power Delivery, Vol. 8, July. 1993, pp 1395-1401.

[4] Elias M. Stein, Timonthy S. Murphy : “*Harmonic Analysis: Real-Variable Methods, Orthogonality and Oscillatory Integrals*.”, Princeton, N.J.: Princeton University Press, 1993

[5] J.S. Lai and T.S. Key, “*Effectiveness of harmonic mitigation equipment for commercial office buildings,*” IEEE Transactions on Industry Applications, vol.33, no.4, sep 1997, pp. 1065-1110