Voltage control through reactive power support for WECS based hybrid power system

• Developed small signal model of DFIG based on reactive power equations.
• Used reactive power capability of LSC for voltage control.
• PI gains are optimized using ISE method for LSC controller.
• Reduced the requirement of converters using ’front end inverter’.

This paper presents a novel technique for voltage and reactive power control a multi wind generator based hybrid power system. The proposed configuration consists of wind energy conversion system (WECS) comprising number of wind turbines each having doubly fed induction generator (DFIG), and power generation from biomass source using synchronous generator (SG). The dynamics of the system is analyzed with the step change in inputs applied in both reactive load demand and wind speed. The analysis is focused on the voltage and reactive power control of the hybrid power system using reactive capability of the load side converter (LSC) of DFIG. When the reactive load and thereby the terminal voltage deviates by a small amount, the LSC works as a reactive power generator. A PI control is used in LSC and it provides the effective control of system voltage.