Dynamic Interaction of Electrical Power Plants, Loads and Transmission Network

Abstract

A comprehensive nonlinear dynamic power system model will be presented describing the interaction of an interconnected system with its individual components such as prime mover and generator including their controllers, frequency-and voltage-dependent loads as well as the transmission lines.The model consists of a µ-nodes transmission network with up to nG power plants and nL loads per node.With the dynamic power system model described, the following problems are presently considered:-How does a power system react to a tripping of a power station in respect to the frequency behaviour and the power exchange between the part networks?-How will the load flow situation and the voltage level change after tripping of a power plant or an important transmission line? Do regional transients or static overloadings occur which exceed protection devices and therefore lead to sequence disturbances?-Where and when do low frequency and power oscillations appear in a power system? And how can they be damped?The power system model has been tested with the aid of extensive measurements carried out in a 1000 MW part system of the West European Interconnected system. In this system - consisting of a 43 node 220/110 KV transmission network and three power stations with in all 5 generator units - real and reactive power stepswere carried out by disconnections from the interconnected West European power system.The good agreement of measured and simulated curves will be shown in this paper.