Decentralised congestion management of interconnected power systems

Abstract

A method for the decentralised solution of the congestion management problem in large interconnected power systems is presented. The multi-area congestion management is achieved through crossborder co-ordinated redispatching by regional transmission system operators. The co- ordination is performed through a pricing mechanism inspired by Lagrangian relaxation. The prices used for the co-ordination of the regional subproblem solutions are the prices of electricity exchanges between adjacent areas. Test results from the application of the method to the three-area RTS96 are reported. unit index, identical to bus index; for simplicity of notation it will be assumed that only one unit is connected to each bus line from bus i to bus ; index; also used for tie-lines number of buses, identical to number of units number of areas number of tie-lines cost of congestion relief associated with unit i, here a quadratic function unit active power output vector bus active power demand vector bus voltage phase angle vector reference bus voltage phase angle network admittance matrix admittance of line ij power flow on line ij area (region) index