Automatic reactive power control of isolated wind-diesel hybrid power systems for variable wind speed/slip

In this article, automatic reactive power control of an isolated wind-diesel hybrid power system having an induction generator coupled with wind turbine for power generation is presented. The mathematical model of the system using reactive power flow equations is developed. The dynamic voltage stability evaluation is based on small signal analysis considering a typical static VAR compensator (SVC) and IEEE type-I excitation system. It is shown that a variable reactive power source, like SVC, is a must to meet the varying demand of reactive power by induction generator and load and to obtain a very good voltage regulation of the system with minimum fluctuations. Integral square error (ISE) criterion is used to evaluate the optimum setting of gain parameters. Finally, the dynamic responses of the sample power system considered with optimum gain setting are also presented.