Optimal range of loading for operating a fixed-speed wind turbine using a self-excited induction generator

Abstract

In the present study, a new strategy of analysis was used to determine the optimal interval of a single-phase resistive load to operate a fixed-speed wind turbine. The essence of this optimal range is to enable the generator to have stable voltages and current balances, large power, and an acceptable frequency range, and also mitigate generator overheating. The generator windings and excitation capacitances were prepared according to the C-2C connection scheme with suitable values of excitation capacitances. The admittance matrix of the system was based on positive and negative sequence generator voltages and was calculated by symmetrical components theory. The generator performance was found through optimization of the determinant admittance matrix magnitude. Moreover, balanced position of the generator can be achieved near the maximum load power. Consequently, the best interval of resistive load of the generator (1.5 kW) was found around 2 % voltage unbalance factor. The appropriate optimal load was $\pm$ 6 % of the perfect balance resistive load value.