Unified Power Quality Conditioners Based Different Structural Arrangements: A Comprehensive Review

Abstract

Mitigating power quality issues in distribution systems is of utmost importance to both electricity consumers and suppliers as it improves the distribution system's efficiency, reduces electricity costs, maintains continuous supply, and diminishes the requirement for frequent maintenance. Custom power devices were introduced to eliminate power quality issues like voltage sags, swells, transients, imbalances, and current harmonics arising in distribution systems. Unified power quality conditioner (UPQC) is one such frequently used custom power device that enhances the power quality of distribution systems. Various structural arrangements of UPQCs with improved performance capability were introduced within the last few decades. The main aim of this paper is to review the most frequently explored UPQC models in literature and to observe the impact of these UPQC structural configurations on their performance as well as that of the overall distribution system. Also, this study investigates the properties, applications, and control techniques used by these structural configurations of UPQCs to mitigate power quality issues.

Fuzzy Control Systems for Power Quality Improvement—A Systematic Review Exploring Their Efficacy and Efficiency

“…These works were subsequently used as the foundation for the research and selection process of the review's portfolio. Following the trends of literature reviews [10,54], a thorough examination of diverse databases was executed to obtain information on the content of the papers to make up the final set of papers. The Web of Science database was the primary source scrutinized to obtain the list of papers, considering the data found in the titles, keywords, and abstracts of papers.…”

“…The articles were classified based on the criteria outlined in Table 3. Additionally, taking into account the methodology from reference [10], the table includes detailed information about the criteria and their characteristics.…”

“…In the field of power systems, and particularly power quality (PQ) [7], one of the primary fuzzy logic applications used to control reactive power was produced in 1990. Later, more researchers presented FLCs in the literature dedicated to controlling PQ using filters and specialized devices [8][9][10]. Table 1 shows a historical sequence of 17 FLCs proposed for PQ improvement in the literature [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…The study concludes that a simple FLC with only one input can provide comparable results to a traditional PI (proportional-integral) controller, but it is easier to adjust. Another study [10] classified the different types of UPQCs, along with their corresponding control strategies, to eliminate or reduce PQ issues. The authors of this study mention that fuzzy logic controllers in association with other artificial intelligence techniques have the capability to improve PQ.…”

“…Similarly, in a review [51], voltage variation compensators are examined, and the authors conclude that employing fuzzy logic in the control of these compensators can improve PQ. Devices such as active power filters are also reviewed in [10,52,53], and different control methods are discussed. One significant conclusion from these studies is that a PI controller in association with fuzzy logic provides better results than a conventional PI controller in PQ improvement.…”