Modelling of power systems for dynamics stabilisation studies

In general, when building a model for power system dynamics studies, the following requirements and aspects should be considered: (1) active dynamics of the equipment: power system models are often conveniently defined in terms of the major subsystems of equipment. Only these dynamics of the equipment which are active in determining the system performance need to be considered. Generally speaking, the following components are important to the dynamic study: the synchronous machines, the excitation systems, the prime movers and governors, HVDC systems, FACTS devices and power system loads. For each of them, several basic models are recommended by professional societies. (2) Linearised differential equation representation: we are interested here in modelling of the power system for the study of small-disturbance performance. This means that the system is described by a set of differential equations which can be linearised around its operating condition. The most common method is to simulate each component by its transfer function. The various transfer function blocks are connected to represent the system under study. Or the state space model can be used. (3) Stability analysis or controller design: depending on the purpose of the study, the models required will be different. A general treatment of typical system equipment modelling is presented