摘要
The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders＇ thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany （IESCO）, Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.
The performance of complementary feeders,running in parallel,can be significantly improved by installing static transfer switches(STSs) at critical locations. We develop the STS control logic,which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders' thyristor,thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently pro-posed time delay technique for STS operation. Two different feeders,namely New Exchange,the preferred feeder,and Sector I-10/2,the alternate feeder of Islamabad Electric Supply COmpany(IESCO),Pakistan,have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.
