Automatic voltage control by load side converter of DFIG in wind-biomass isolated hybrid power system

This paper presents a novel small signal model of the doubly fed induction generator (DFIG) used for wind generator. A new mathematical model is developed using reactive power equations for small deviations in the operating conditions of the system. An isolated wind-biomass hybrid power system is designed using DFIG for wind and synchronous generator (SG) for biomass source. A small reactive power load change, is applied and the change in system voltage is observed at the load bus. The voltage is controlled by the load side converter (LSC) connected in the rotor of the DFIG. The LSC works as STATCOM and supplies necessary reactive power for the change in load demand. The system is simulated in MATLAB/Simulink environment and the PI control is used to damp out the voltage deviations in the system. The results demonstrate the appropriate voltage control capability of converters in entire speed range of the DFIG.