Comparative study of Unified Power Quality Conditioner (UPQC) with different injecting devices for voltage injection

The FACTS technology has proven its versatility due to its collection of controllers which are applied individually or in co-ordination, according to the need. The FACTS technology along with the FACTS Controllers is essential to alleviate the power quality issues in the transmission system and thus enhances the reliability of the grid. Out of the available FACTS controllers, the series - shunt compensators are used for power quality issues. Thus the installation of Unified Power Quality Conditioner (UPQC) in the distribution side has been proven to be a very effective solution for the power quality issues. The UPQC is constituted of two VSCs connected via a power link. The series compensator is connected to the line in series and injects voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for the current related issues, and is connected in shunt to the line. The voltage injection to the line uses an injection transformer. Here in this the conventional injection transformer is replaced with an injection capacitor. A comparative study of both the systems are done here to check the efficiency and reliability of the proposed controller using MATLAB/SIMULINK.