Modeling, Simulation and Group Control of Distributed Static Series Compensators

This study investigates the new concept of Distributed Static Series Compensator (DSSC); a small, light weight cylinder that clamps directly onto the transmission line conductor and has the ability to alter the impedance of the power lines in order to increase power transfer capability and maximize economic value of the transmission system. A graphic-based simulation model of the DSSC is presented in PSCAD/EMTDC which takes into account the practical design considerations of such a device and can be considered as a starting point for extensive simulation studies. The performance and accuracy of the model is validated by simulation and comprehensive results are presented. Also a harmonic analysis of the electromagnetic model is carried out in order to investigate the amount of harmonic injection of each model and based on the results, different control strategies are applied to a group of DSSCs distributed along a transmission line. The effect of each control strategy on active power flow, THD injection and group response time is compared by simulations carried out in PSCAD/EMTDC and the most suitable control scheme for operating a group of DSSCs distributed along a typical 138 kV transmission line is presented both for capacitive and inductive compensating modes.