Real time implementation and optimal design of autonomous microgrids

• The autonomous microgrid stability enhancement problem is addressed in this work.
• PI controllers and power sharing coefficients have been optimally tuned.
• The proposed controllers have been examined under different disturbances.
• Experimental implementation has been carried out RTDS.
• The effectiveness of the proposed control schemes have been demonstrated and verified experimentally.

In this paper, an autonomous microgrid including current, voltage and power controllers, inverter-based distributed generation (DG) units, coupling inductance, LC filter, lines, and loads has been developed and implemented on real time digital simulator (RTDS). The optimal settings of the PI controllers and power sharing coefficients to enhance the autonomous microgrid stability have been also implemented. Nonlinear time domain simulation is carried out to minimize the error in the measured power to improve the damping characteristics and to assess the effectiveness of the proposed controllers under overloading condition, fault and step change disturbances. The results show satisfactory performance with efficient damping characteristics of the considered autonomous microgrid equipped with the proposed controllers. The considered autonomous microgrid with its controllers has been examined in real time using RTDS. The performance of three inverter-based DGs of the considered autonomous microgrid with the proposed controllers has been verified on RTDS. The experimental results confirm the effectiveness of the proposed controllers to enhance the stability of the microgrid considered.