Optimal adaptive droop control for effective load sharing in AC microgrids

During the past few years, microgrids (MGs) have been becoming more attractive as effective means to integrate different distributed energy resources (DERs). To coordinate active and reactive power sharing among DERs, conventional droop control method is widely used as a decentralized control scheme. However, sharing powers among the sources based on the units’ rated capacities is not an optimal solution in terms of economy and efficiency. In this paper, a new adaptive droopbased control strategy is proposed for AC MGs to optimally share MG load between corresponding units. The mentioned control strategy is developed in two levels. The upper control level is a mixed-objective optimization algorithm that provides optimal set-points for power generations considering system’s constraints and goals, while the lower control level is responsible for tracking the reference signals coming from the upper level. To demonstrate the effectiveness of the proposed control strategy under different operating scenarios, simulation results in a benchmark MG are also presented.

[1]  Josep M. Guerrero,et al.  Mode Adaptive Droop Control With Virtual Output Impedances for an Inverter-Based Flexible AC Microgrid , 2011, IEEE Transactions on Power Electronics.

[2]  R. Adapa,et al.  Control of parallel connected inverters in stand-alone AC supply systems , 1991, Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting.

[3]  P. Kundur,et al.  Power system stability and control , 1994 .

[4]  Yun Wei Li,et al.  Analysis, Design, and Implementation of Virtual Impedance for Power Electronics Interfaced Distributed Generation , 2011, IEEE Transactions on Industry Applications.

[5]  E.F. El-Saadany,et al.  Adaptive Decentralized Droop Controller to Preserve Power Sharing Stability of Paralleled Inverters in Distributed Generation Microgrids , 2008, IEEE Transactions on Power Electronics.

[6]  J.A.P. Lopes,et al.  Defining control strategies for MicroGrids islanded operation , 2006, IEEE Transactions on Power Systems.

[7]  Mahesh K. Mishra,et al.  Adaptive Droop Control Strategy for Load Sharing and Circulating Current Minimization in Low-Voltage Standalone DC Microgrid , 2015, IEEE Transactions on Sustainable Energy.

[8]  Josep M. Guerrero,et al.  Advanced Control Architectures for Intelligent Microgrids—Part I: Decentralized and Hierarchical Control , 2013, IEEE Transactions on Industrial Electronics.

[9]  Oriol Gomis-Bellmunt,et al.  Trends in Microgrid Control , 2014, IEEE Transactions on Smart Grid.

[10]  Taher Niknam,et al.  Multi-operation management of a typical micro-grids using Particle Swarm Optimization: A comparative study , 2012 .

[11]  Frank L. Lewis,et al.  Team-oriented adaptive droop control for autonomous AC microgrids , 2014, IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society.

[12]  R. Iravani,et al.  Microgrids management , 2008, IEEE Power and Energy Magazine.

[13]  Florian Dörfler,et al.  Voltage stabilization in microgrids via quadratic droop control , 2013, 52nd IEEE Conference on Decision and Control.

[14]  Juan C. Vasquez,et al.  Control Strategy for Flexible Microgrid Based on Parallel Line-Interactive UPS Systems , 2009, IEEE Transactions on Industrial Electronics.

[15]  Juan C. Vasquez,et al.  Distributed Secondary Control for Islanded Microgrids—A Novel Approach , 2014, IEEE Transactions on Power Electronics.