This book presents the nine switch converter based UPQC is simulated using MAT LAB/SIMULINK. It effectively reduces the current and voltage harmonics. The nine-switch converter is more suitable for replacing back- to-back converter in "series-shunt" systems. As a further performance booster, a modified space vector modulation and 120 degree modulation scheme is presented for reducing the overall commutation count by 33%. It is also compensated for voltage sags, total harmonic distortion with proper series and shunt controls. Since the number of switches required is less compared to conventional converter, the switching losses are less.