A new conduction angle controller for Unified Power Flow Controller

This paper presents the modeling and design of Unified Power Flow Controller (UPFC) using novel control technique in the inverter. The proposed control technique implements the 150 degree conduction mode of individual IGBTs in the inverter. The UPFC can be operated using PWM controllers to enhance the reactive power compensating and regulating the line voltage and also reduces the harmonic in the transmission line current and voltage. The 150 degree inverter is advantageous and increases the RMS values of output voltages, when compared to 120° mode, and 180° mode. Total required VA rating of the inverters is reduced greatly over wide load conditions. The operating performance of UPFC is demonstrated on Single Machine Infinite Bus (SMIB) system for different case studies. The proposed model considerably improves the system stability by improving the reactive power requirement of the load variations.