Transient angular stability of three parallel connected synchronous generators with large load changes and control of active and reactive power

To study the angular stability in a network of parallel connected synchronous machines, all system components which effect on the transient behaviour of the whole system have to be taken into account. This article investigates the possibility of starting up of the loaded synchronous motor in case of using three parallel-connected salient-pole machines feeding the asynchronous motor. A detailed model for 30 MVA synchronous machines, with its electromechanical transient behaviour, is simulated. Other components which are assumed into the simulated model are: transient performance of non-rotating electrical components, the hydraulic systems of two different hydroelectric power plants (run-of-river power station and pumped-storage power station), and the influence of active and reactive power control where the network also contains four transformers and a 110 kV transmission line system of the whole length of 120 km. The calculated parameters are compared with the measured quantities.