Input- Output Linearization Control of SSSC for Power Flow Enhancement in a Power System Network

Fast growing power system network requires highly precise control on system parameters. Nowadays, Flexible AC Transmission Systems (FACTS) has got vital importance for attaining this goal. The series FACTS controllers can improve power flow and effectively damp out the oscillations in an interconnected system. Static Synchronous Series Compensators (SSSC) consists of a three phase Voltage Source Converter (VSC) coupled to a DC link capacitor. The SSSC is maintaining overall transmission line impedance by injecting a voltage phase shifted by 90° with the line current. The dynamic equations governing VSC operation is nonlinear in nature. So nonlinear control techniques are best suited for wider operating conditions. Input-Output Feedback Linearizaton (IOFL) technique is a proficient nonlinear controller can feasibly work with a nonlinear model of SSSC. The IEEE 5 bus system is selected as the test system for proving the relevancy of the control algorithm under steady state and dynamic conditions. The power flow improvement has been observed in IEEE 5 bus system with SSSC. The results also imply that the unique robust nature of IOFL control when compared with PI controller for procuring the desired performance indices.