WAMS-based transfer capacity assessment in multi-machine systems

The implementation of Wide Area Measurement Systems (WAMS) makes real-time rotor angle and voltage angle measurements accessible. Since transfer capacity constraints are more related to the angle difference, new constraints based on the rotor or voltage angles can be applied to real system in order to increase transfer capacity in the transmission corridors. This paper reveals the fact that more power through transmission corridor can be delivered using static extended equal area criterion if the transfer capacity limits are defined on angle difference rather than conventional active power constraints. An inverse extended equal area criterion method is established. This method aims to find out the maximum steady-state transfer capacity in transmission corridors of a multi-machine system with real operational clearing time. A computational algorithm is developed for the calculation of assigning incremental mechanical power to existing generators. Two-area four-machine system is used for simulation to illustrate the benefit of this angle constraints.