Accurate Active and Reactive Power Sharing Based on a Modified Droop Control Method for Islanded Microgrids

Area of Science:

• Electrical Engineering
• Power Systems Engineering
• Control Systems

Background:

• Conventional droop control in islanded microgrids struggles with accurate power sharing due to mismatched feeder impedance.
• Distributed generation (DG) units require precise power sharing for stable microgrid operation.

Purpose of the Study:

• To develop a modified droop control strategy for accurate active and reactive power sharing among DG units in islanded microgrids.
• To address the limitations of conventional droop control in the presence of mismatched feeder impedance.

Main Methods:

• A small AC signal (SACS)-injection-based modified droop control method is proposed.
• The control strategy adjusts DG voltage amplitude via injected AC signals to create a reactive power control loop.
• The method relies solely on local information, eliminating the need for communication links or feeder impedance parameters.

Main Results:

• The proposed control scheme achieves accurate active and reactive power sharing among DG units.
• Simulation and experimental results validate the effectiveness of the SACS-injection method.
• The strategy successfully overcomes challenges posed by mismatched feeder impedance.

Conclusions:

• The SACS-injection-based modified droop control offers an effective solution for precise power sharing in islanded microgrids.
• This approach enhances microgrid stability and efficiency by ensuring equitable power distribution among DG units.
• The method's reliance on local information simplifies implementation and reduces reliance on external communication infrastructure.