A Flexible Asynchronous AC Link for Two Area Power System Networks

The flow of electric power between the two power system networks needs an interconnection. This interconnection should be simple, cost-effective, reliable, and secure for electric power supply. In this paper, a flexible asynchronous ac link (FASAL) is presented for interconnecting two asynchronous independent power system networks. The FASAL system consists of a doubly fed induction machine (DFIM) operating as an ac link wherein two separate power system networks are connected to its stator and rotor. The electrical power is transmitted between the two networks by magnetic coupling through the air gap of the DFIM. It controls the power transmission between these power system networks, which are asynchronous under different operating conditions. The direction and the magnitude of power flow are controlled by controlling voltage and frequency. The performance and effectiveness of the FASAL system during steady-state and the fault conditions are evaluated and validated using PSCAD/EMTDC software. It is also compared with conventional back-to-back line-commutated converter-based high-voltage direct current (BTB LCC-HVDC) system, and it exhibits better performance under blackout and severe fault conditions. The FASAL system is also verified experimentally for two asynchronous power sources.