Title :
A Novel Droop-Based Average Voltage Sharing Control Strategy for DC Microgrids
Author :
Po-Hsu Huang ; Po-Chun Liu ; Weidong Xiao ; El Moursi, Mohamed Shawky
Author_Institution :
Electr. Eng. & Comput. Sci. Dept., Masdar Inst. of Sci. & Technol., Abu Dhabi, United Arab Emirates
Abstract :
This paper introduced a decentralized voltage control strategy for dc microgrids that is based on the droop method. The proposed distributed secondary voltage control utilizes an average voltage sharing scheme to compensate the voltage deviation caused by the droop control. Through nonexplicit communication, the proposed control strategy can perform precise terminal voltage regulation and enhance the system reliability against system failures. The distributed voltage compensators that resemble a centralized secondary voltage controller are implemented with the bi-proper anti-wind-up design method to solve the integration issues that necessarily lead to the saturation of the controller output efforts. The proposed concept of pilot bus voltage regulation shows the possibility of managing the terminal voltage without centralized structure. Moreover, the network dynamics are illustrated with a focus on cable resonance mode based on the eigenvalue analysis and small-signal modeling; analytical explanations with the development of equivalent circuits give a clear picture regarding how the controller parameters and droop gains affect the system damping performance. The proposed derivative droop control has been demonstrated to damp the oscillation and to improve the system stability during transients. Finally, the effectiveness and feasibility of the proposed control strategy are validated by both simulation and experimental evaluation.
Keywords :
damping; decentralised control; distributed power generation; eigenvalues and eigenfunctions; power generation faults; power generation reliability; power system transient stability; voltage control; DC microgrid; average voltage sharing control strategy; biproper antiwind-up design method; cable resonance mode; decentralized voltage control strategy; derivative droop control; distributed secondary voltage control; distributed voltage deviation compensation; eigenvalue analysis; equivalent circuit development; integration issues; network dynamics; nonexplicit communication; oscillation damping; pilot bus voltage regulation; power system failures; power system reliability enhancement; power system stability transient improvement; small-signal modeling; system damping performance; terminal voltage management; terminal voltage regulation; Eigenvalues and eigenfunctions; Equivalent circuits; Indexes; Microgrids; Reliability; Resistance; Voltage control; Decentralized control; droop method; hierarchical control; microgrids (MGs); parallel load sharing;
Journal_Title :
Smart Grid, IEEE Transactions on
DOI :
10.1109/TSG.2014.2357179