A DSP Based Optimal Algorithm for Shunt Active Filter Under Nonsinusoidal Supply and Unbalanced Load Conditions

• Published in: IEEE transactions on power electronics Vol. 22; no. 2; pp. 593 - 601
• Main Authors: George, S., Agarwal, V.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active filters; Algorithms; Applied sciences; Capacitors. Resistors. Filters; Circuit properties; Circuits; Current imbalance; Digital signal processing; Distortion; Electric currents; Electric potential; Electric power; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electricity; Electronic circuits; Electronics; Exact sciences and technology; Frequency filters; harmonics; Integrated circuits; Integrated circuits by function (including memories and processors); nonsinusoidal voltage; Optimization; Power electronics; Power electronics, power supplies; Power factor; Power systems; Power transmission lines; Reactive power; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; shunt active filter (SAF); Transformers; Transmission line theory; Various equipment and components; Voltage; Waveforms; Performance evaluation; Non sinusoidal conditions; shunt active filter (SAF); Voltage fall; Power system harmonics; Unbalanced conditions; Power system stability; Harmonic analysis; Electronic circuit; Power supply; Transmission line; harmonics; optimization; Active filter; Voltage stability; Current imbalance; Energy quality; Harmonic distortion; Power factor; Stream line; Shunt; Optimal algorithm; Power circuit; Power electronics; Power transformer; Electrical network; Integrated circuit; nonsinusoidal voltage; Impedance; Digital signal processor; Service quality; Signal distortion
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2006.890001

The use of power electronic circuits in a wide range of applications has resulted in distorted current waveforms in the power system. This results in nonsinusoidal voltage drops across the transformers and transmission line impedances, resulting in a nonsinusoidal voltage supply at the point of common coupling. Asymmetrical distribution of large, 1-phi loads further complicates the issue by causing imbalance in the line currents of the 3-phi system. Not only should this imbalance be compensated, other parameters, such as the current total harmonic distortion and the power factor should also be maintained as per the norms. However, the requirements of harmonic free current waveforms and good power factor, under nonsinusoidal voltage conditions, are contradictory to each other. Under these conditions, an optimum performance is the best one can achieve. This paper proposes a new scheme for balancing the currents and obtaining the best compromise between the power factor and current distortion under nonsinusoidal voltage conditions. The technique does not use p-q theory and does not require sequence transformation for power calculations, even though the current is unbalanced. All the details of this work are presented