Transient Stability Investigations of the Wind-Diesel Hybrid Power Systems

This paper presents automatic reactive power control of the isolated wind-diesel hybrid power systems. The synchronous generator (SG) is used for power generation from diesel and the induction generator (IG) is used for electric power generation from wind turbine. To minimize the gap between reactive power generation and demand, the variable sources of reactive power is used such as static synchronous compensator (STATCOM). The mathematical model of the STATCOM based on reactive power flow equations is developed with the wind-diesel hybrid power system. The examples of the wind-diesel hybrid power systems considered in the paper are multi-wind/single diesel, and single wind/multidiesel. The study is based on small signal analysis by considering IEEE type-1 excitation system for the synchronous generator. The paper also shows the dynamic performance of the hybrid system for 1% step change in reactive power load without any change in input wind power i. e. constant slip, and for 1% step change in reactive power load with 1% step increase in input wind power i. e. variable slip.