The textbook "Power Quality Improvement Using UPQC" offers a comprehensive analysis and solution to the challenges of power quality arising from the use of power electronics. With the advent of modern semiconductor switching devices, such as thyristors and IGBTs, control over electrical energy has become possible. These devices are widely used in various applications, from adjustable drive systems to high-voltage direct current systems. The book addresses the issues of harmonic distortions and reactive power caused by nonlinear loads and presents innovative approaches to minimize these effects. By employing AI techniques and MATLAB/SIMULINK as tools for modeling, analysis, simulation, and optimization, it provides a practical perspective on improving power quality. It is aimed at researchers, industry representatives, and electrical engineering students who are active in this field or wish to further their education.