State space modeling of parallel self-excited induction generators for wind farm simulation

Self-excited induction generators (SEIG) offer many advantages as variable speed generators in renewable energy systems. Small hydro and wind generating systems have constraints on the size of individual machines and several induction generators must be paralleled in order to fully access the potential of the site. SEIGs connected in parallel may lose excitation momentarily due to large transient currents caused by differences in individual instantaneous voltages and frequency. This phenomenon cannot be easily simulated using the conventional models due such a fast transient nature. This work presents an innovative and automatic numerical solution for steady-state and transient analysis of any number of SEIGs operating in parallel. Experimental results confirm the accuracy of the proposed model opening new possibilities to incorporate advanced control to monitor and optimize a parallel installation of SEIGs. The proposed SEIG model is applied to a two-turbine case, which can be extended to any number to simulate a wind generating system.