MODELING AND CONTROL OF INTERLINE POWER FLOW CONTROLLER FOR POWER SYSTEM STABILITY ENHANCEMENT

Mitigation of power system oscillations is the problem of concern in the power
industry as these oscillations, when exhibiting poor damping; affect the transmission
line power transfer capability and power system stability. These oscillations greatly
restrict power system operations and, in some cases, can also lead to widespread
system disturbances. In this context, the Flexible AC Transmission System (FACTS)
device, Interline Power Flow Controller (IPFC) employed to improve the transmission
capability can be additionally utilized for damping control of power system
oscillations.
IPFC based damping controller design for power system stability requires proper
and adequate mathematical representation of power system incorporating the FACTS
device. This thesis reports the investigation on the development of steady state model,
the dynamic nonlinear mathematical model of the power system installed with the
IPFC for stability studies and the linearized extended Phillips Heffron model for the
design of control techniques to enhance the damping of the lightly damped
oscillations modes.
In this context, the mathematical models of the single machine infinite bus
(SMIB) power system and multi-machine power system incorporated with IPFC are
established. The controllers for the IPFC are designed for enhancing the power system
stability. The eigenvalue analysis and nonlinear simulation studies of the
investigations conducted on the SMIB and Multi-machine power systems installed
with IPFC demonstrate that the control designs are effective in damping the power
system oscillations. The results presented in this thesis would provide useful
information to electric power utilities engaged in scheduling and operating with the
FACTS device, IPFC.