The book "Performance of D-STATCOM for Voltage Sag and Swell Mitigation" offers a comprehensive analysis of improving power quality through the use of Distribution Static Synchronous Compensator (DSTATCOM). It addresses the challenges posed by voltage sags and swells and examines how DSTATCOM can be employed to mitigate these issues. The author, Miska Prasad, explains various theoretical approaches, including the Synchronous Reference Frame (SRF) theory, the Instantaneous Active and Reactive Current (IARC) theory, and the Proportional-Integral (PI) controller. These concepts are used to generate reference signals and control the operation of the DSTATCOM, with the aim of enhancing power quality. The results of MATLAB/Simulink simulations conducted under various load conditions demonstrate the effectiveness of the presented control techniques and provide valuable insights into the practical application of DSTATCOM.