Dynamic simulation and analysis of parallel self-excited induction generators for islanded wind farm systems

In this paper, a dynamic mathematical model to describe the transient behavior of a system of self-excited induction generators (SEIGs) operating in parallel and supplying a common load is proposed. Wind turbines with SEIGs are increasingly being used to generate clean renewable energy in rural areas owing to many economical advantages. Parallel operation of SEIGs is required where the size of the machine is a constraint. SEIGs connected in parallel experience various transient conditions such as generator/load/capacitor switching that are not easy to simulate using conventional models. An automatic numerical solution to predict the steady-state and transient behavior of any number of SEIGs connected in parallel is proposed in this paper. The generators can be of different ratings and can have different prime mover speeds. The performance of the proposed model when subjected to various dynamic scenarios is compared with experimental results. The simulation results are in good agreement with the experimental results, confirming the validity of the proposed model. An aggregated model of a small wind power system is also proposed. This model was applied to a two-wind turbine case, which can be extended to simulate a complete wind generating system.