Application of structure preserving energy margin sensitivity to determine the effectiveness of shunt and series FACTS devices

This paper presents a structure preserving energy margin sensitivity based analysis to determine the effectiveness of FACTS devices to improve transient stability of a power system. A structure preserving energy model, which retains the topology of the network is used to derive simple analytical expressions for improvement in energy margin due to series or shunt compensation. The expressions are in terms of current magnitude through a line for series compensation and voltage magnitude at a bus for shunt compensation. Therefore, these expressions are easy to interpret in the context of applying compensation at strategic locations. The proposed method is applied to a four-machine, ten-bus system and a ten-machine, 39-bus New England system, and its validity is demonstrated through time domain simulations both for a classical and detailed model with AVR for generators.