State space modelling of distortion compensation in a realistic power network

A power system, constituting generators, a distribution system and non-linear consumer loads with hybrid power compensators, is a complex system characterised by changing line impedances and load and generator conditions.The use of sophisticated control techniques in these systems is becoming very important, necessitating the need for accurate system modelling, that is software compatible with controller design programs. The time domain transient behaviour of the system is of particular importance to facilitate time domain control investigations. The use of the state space modelling technique is motivated and a comprehensive state space model developed to serve as a time domain analysis platform for hybrid power filter control investigations. A typical scenario comprising 2 generators, 4 transformer substations and 3 consumers with interconnecting lines, is modelled. Each consumer has a hybrid power compensator constituting a static VAR compensator and a dynamic compensator associated with it. The stability and accuracy of the discrete state space model is also analysed. Results from the model are compared to actual measurements on distorted conditions in industrial networks, and shown to correspond extremely well, also for hybrid power compensator operation.