Stability analysis and reactive power compensation issue in a microgrid with a DFIG based WECS

• Small signal modelling of DFIG based microgrid has been developed.
• Designed ANFIS based UPFC controller for reactive power compensation.
• Studied comparative analysis of PI and ANFIS controllers for transient stability.
• Stability analysis using Bode plot, Nyquist and Popov criterion studied.
• Stability analysis using eigen values and participation factors also carried out.

This paper presents a novel methodology for compensating reactive power in a microgrid, having a DFIG based wind–diesel system, to enhance the voltage stability of the hybrid system. UPFC as a FACTS device is proposed in order to improve the control of reactive power mismatch and the stability of the system. A small signal model of the wind–diesel system, DFIG based wind turbine system, UPFC and the controllers are designed for the stability analysis. Further, the voltage variation and reactive power compensation is analysed with the incorporation of proposed ANFIS based UPFC controller. Simulations are performed in MATLAB environment for transient stability analysis in a wind–diesel based microgrid with different wind power input and 2% step increase in load demand. Simulation results illustrate the efficiency and effectiveness of the proposed approach and its impact upon transient behaviour of the microgrid.