Comparison of Control Algorithms for Shunt Active Filter for Harmonic Mitigation

ABSTRACT:

 Shunt Active Filter generates the reference current, that must be provided by the power filter to compensate harmonic currents demanded by the load. This paper presents different types of SRF methods for real time regeneration of compensating current for harmonic mitigation. The three techniques analyzed are the Synchronous Reference Frame Theory (SRF), SRF theory without synchronizing circuit like phase lock loop (PLL) also called instantaneous current component theory and finally modified SRF theory. The performance of Shunt Active Power Filter in terms of THD (Total Harmonic distortion) of voltage and current is achieved with in the IEEE 519 Standard. The comparison of all methods is based on the theoretical analysis and simulation results obtained with MATLAB/SIMULINK

KEYWORDS:

1.      Synchronous Reference Frame

2.      Instantaneous current component theory

3.      Modified SRF

4.      Active Filter

5.      Harmonics

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

CONCLUSION:

This paper presents the compensation performance of all the different SRF techniques under sinusoidal voltage source condition as shown in table-1. Results are similar with gained source THD under IEEE 519, but under various filter type the chebyshev type filter is having superior performance compare to Butterworth filter for all methods. The Synchronous Reference Frame method is one of the most common and performing methods for detection of harmonics in active filters. An Improved Synchronous Reference Frame Method for the control of active power filters was presented. It is called Filtered Modified Reference Frame Method (FMRF) and is based on the same principle as the Synchronous Reference Frame method. However, this new method explores the fact that the performance of the active filter to isolate harmonics depends on the speed of the system that determines the rotating reference frame, but doesn’t depend on its position. So, the delay introduced by the ac voltage filters, used for the detection of the reference frame, has no influence on the detection capability of the method. Compared with other methods, this new method presents some advantages due to its simplicity and its rudeness to perturbations on the ac network.

REFERENCES:

[1] M.J. Newman, D.N.Zmood, D.G.Holmes, “Stationary frame harmonic reference generation for active filter systems”, IEEE Trans. on Ind. App., Vol. 38, No. 6, pp. 1591 – 1599, 2002.

[2] V.Soares,P.Verdelho,G.D.Marques,“ An instantaneous active reactive current component method for active filters” IEEE Trans. Power Electronics, vol. 15, no. 4, July- 2000, pp. 660–669.

[3] G.D.Marques, V.Fernao Pires, Mariusz Mlinowski, and Marian Kazmierkowski, “An improved synchronous Reference Method for active filters,” the International conference on computer as a tool, EUROCON 2007, Warsaw, September - 2007, pp. 2564-2569.