International OPEN ACCESS Journal Of Modern Engineering Research (IJMER) | IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss.9| Sept. 2014 | 75| Novel Direct Switching Power Control Method of UPFC by Using Matrix Converter Based On SVPWM Techniques B. Venkateswarlu 1 , D. Jagan 2 , A. Karunakar 3 , CH. Renuka 4 . 1,2,3, Assistant Professor/ 4, PG Student /Sri Sai Educational Society’s Group of Institutions/JNTUH/T.S/ INDIA. I. Introduction In the last few years, electricity market deregulation, together with growing economic, environmental, and social concerns, has increased the difficulty to burn fossil fuels, and to obtain new licenses to build transmission lines (rights-of-way) and high-power facilities. This situation started the growth of decentralized electricity generation (using renewable energy resources). Unified Power-Flow Controllers (UPFC) enable the operation of power transmission networks near their maximum ratings, by enforcing power flow through well-defined lines. These days, UPFCs are one of the most versatile and powerful flexible ac transmission systems (FACTS) devices. The UPFC results from the combination of a static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC) that shares a common dc capacitor link. The existence of a dc capacitor bank originates additional losses, decreases the converter lifetime, and increases its weight, cost, and volume. These converters are capable of performing the same ac/ac conversion, allowing bidirectional power flow, guaranteeing near sinusoidal input and output currents, voltages with variable amplitude, and adjustable power factor. These minimum energy storage ac/ac converters have the capability to allow independent reactive control on the UPFC shunt and series converter sides, while guaranteeing that the active power exchanged on the UPFC series connection is always supplied/absorbed by the shunt connection. Recent nonlinear approaches enabled better tuning of PI controller parameters. Still, there is room to further improve the dynamic response of UPFCs, using nonlinear robust controllers. In the last few years, direct power control techniques have been used in many power applications, due to their simplicity and good performance. In this project, a matrix converter- based UPFC is proposed, using a direct Switching power control approach (DSPC-MC) based on an MC-UPFC dynamic model (Section II). In order to design UPFCs, presenting robust behavior to parameter variations and to disturbances, the proposed DSPC-MC control method, in Section III, is based on sliding mode-control techniques, allowing the real-time selection of adequate matrix vectors to control input and output electrical power. Sliding mode-based DSPC-MC controllers can guarantee zero steady-state errors and no overshoots, good tracking performance, and fast dynamic responses, while being simpler to implement and requiring less processing power, when compared to proportional-integral (PI) linear controllers obtained from linear active and reactive power models of UPFC using a modified Aventurine high-frequency PWM modulator. Abstract: This paper presents a direct Switching power control for three-phase matrix converters operating as unified power flow controllers (UPFCs). Matrix converters (MCs) allow the direct ac/ac power conversion without dc energy storage links; therefore, the MC-based UPFC (MC-UPFC) has reduced volume and cost, reduced capacitor power losses, together with higher reliability. Theoretical principles of direct Switching power control based on sliding mode control techniques are established for an MC-UPFC dynamic model including the input filter. As a result, line active and reactive power, together with ac supply reactive power, can be directly controlled by selecting an appropriate matrix converter switching state guaranteeing good steady-state and dynamic responses. Experimental results of DSPC controllers for MC-UPFC show decoupled active and reactive power control, zero steady-state tracking error, and fast response times. Compared to an MC-UPFC using active and reactive power linear controllers based on a modified Venturing high-frequency PWM modulator, the experimental results of the advanced DSPC-MC guarantee faster responses without overshoot and no steady state error, presenting no cross-coupling in dynamic and steady-state responses. Index Terms: Direct Switching Power Control, matrix converter (MC), unified power-flow controller (UPFC).