Automatic droop control for a low voltage DC microgrid

作者：Khorsandi Amir^*; Ashourloo Mojtaba; Mokhtari Hossein; Iravani Reza

来源：IET Generation Transmission & Distribution, 2016, 10(1): 41-47.

DOI：10.1049/iet-gtd.2014.1228

• distributed power generation
• power generation control
• power grids
• decentralised control
• adaptive control
• voltage control
• linearisation techniques
• power system stability
• automatic droop control
• DC microgrid
• energy storage unit
• decentralised control
• DC-MG
• adaptive control method
• voltage regulation
• loading condition
• current sharing process
• equivalent droop gain
• linearised model
• digital time-domain simulation
• stability

A DC microgrid (DC-MG) provides an effective mean to integrate various sources, energy storage units and loads at a common dc-side. The droop-based, in the context of a decentralised control, has been widely used for the control of the DC-MG. However, the conventional droop control cannot achieve both accurate current sharing and desired voltage regulation. This study proposes a new adaptive control method for DC-MG applications which satisfies both accurate current sharing and acceptable voltage regulation depending on the loading condition. At light load conditions where the output currents of the DG units are well below the maximum limits, the accuracy of the current sharing process is not an issue. As the load increases, the output currents of the DG units increase and under heavy load conditions accurate current sharing is necessary. The proposed control method increases the equivalent droop gains as the load level increases and achieves accurate current sharing. This study evaluates the performance and stability of the proposed method based on a linearised model and verifies the results by digital time-domain simulation and hardware-based experiments.

• 出版日期2016-1-7