A modified droop-based decentralized control strategy for accurate power sharing in a PV-based islanded AC microgrid

Area of Science:

• Electrical Engineering
• Renewable Energy Systems
• Control Systems

Background:

• Islanded AC microgrids face challenges in precise power sharing among parallel inverters.
• Conventional droop control (P-f/Q-V) suffers from voltage/frequency deviations and power-sharing inaccuracies due to line impedance variations.

Purpose of the Study:

• To develop and validate a novel droop-based decentralized control scheme for enhanced power sharing in PV-fed islanded AC microgrids.
• To overcome limitations of conventional droop control by integrating virtual impedance concepts.

Main Methods:

• A novel control scheme combining conventional (P-f/Q-V) droop control with an enhanced virtual impedance loop was developed.
• The proposed strategy was simulated and validated using real-time simulations on the OPAL-RT OP4510 platform within MATLAB/Simulink.

Main Results:

• The enhanced virtual impedance control effectively addressed power-sharing inaccuracies.
• Precise distribution of active and reactive power among parallel inverters was achieved.
• Stable voltage and frequency profiles were maintained throughout the system operation.

Conclusions:

• The proposed droop-based decentralized control scheme with enhanced virtual impedance offers an efficient solution for power-sharing challenges in islanded AC microgrids.
• Real-time simulation results confirm the strategy's effectiveness in ensuring accurate power distribution and system stability.