An optimal control strategy for power quality enhancement in a competitive environment

• Published in: International journal of electrical power & energy systems 2007-09, Vol.29 (7), p.514-525
• Main Authors: Griffo, A., Carpinelli, G., Lauria, D., Russo, A.
• Format: Article
• Language: English
• Subjects: Active filtering; Applied sciences; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; Kalman estimation; Miscellaneous; Operation. Load control. Reliability; Optimal control; Power electronics, power supplies; Power networks and lines; Power quality; Regulation and control
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2007.01.002

The new electric system restructuring requires more and more restrictive power quality requirements to be satisfied. The problem of disturbances compensation therefore becomes of noticeable importance, both in terms of device allocation and control strategy. The paper deals with active compensators, whose utilization is rapidly growing in modern power system, whereas power electronic devices play a fundamental role in controlling system behavior. An optimal control strategy for active compensators, particularly useful for distribution companies in a deregulated framework, is proposed with the aim of improving power quality. The proposed strategy is based upon a frequency domain approach for solving a linear quadratic regulator problem, without exceeding compensator rating. The proposed procedure is able to properly consider the buses sensitivity to different power quality disturbances. The methodology relies upon a Kalman filter based estimation technique, which enables an accurate tracking of relevant network state variables, as well as of harmonic disturbances injected into the power system. In the last part of the paper a numerical application with reference to a 18-busbar distribution network is presented, showing the feasibility and the effectiveness of the proposed methodology.