A fast reactive power sharing strategy for islanded microgrid based on feeder current sensing

To solve the reactive power sharing issue in droop control, many improved methods have been developed. However, existing methods can't provide both accurate and fast performance in reactive power sharing, no matter wireless or communication methods. In fact, rapidity is an important indicator for reactive power sharing control, especially when load changes frequently. In this paper, a fast reactive power sharing strategy that employs feeder current sensing and feeder voltage drop compensation is proposed for islanded microgrid. The proposed strategy introduces feeder current sensing based on the conventional droop control method. With the instant information of feeder current, the mismatched feeder voltage drops that cause reactive power sharing errors in microgrid are calculated and compensated in real time. The proposed strategy can not only reach the same accuracy as communication based solutions, but also provide faster response to load change. Moreover, it is more convenient to be applied due to its wireless manner. Matlab simulation and experimental results are used to validate the feasibility of this strategy.

[1]  Mehdi Savaghebi,et al.  Modeling, Analysis, and Design of Stationary-Reference-Frame Droop-Controlled Parallel Three-Phase Voltage Source Inverters , 2013, IEEE Transactions on Industrial Electronics.

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

[3]  Juan C. Vasquez,et al.  Hierarchical Control of Droop-Controlled AC and DC Microgrids—A General Approach Toward Standardization , 2009, IEEE Transactions on Industrial Electronics.

[4]  Tarlochan S. Sidhu,et al.  Investigations Into the Control and Protection of an Existing Distribution Network to Operate as a Microgrid: A Case Study , 2014, IEEE Transactions on Industrial Electronics.

[5]  Fang Zhuo,et al.  Accurate power sharing strategy for complex microgrid based on droop control method , 2013, 2013 IEEE ECCE Asia Downunder.

[6]  Qing-Chang Zhong,et al.  Robust Droop Controller for Accurate Proportional Load Sharing Among Inverters Operated in Parallel , 2013, IEEE Transactions on Industrial Electronics.

[7]  Josep M. Guerrero,et al.  Line-Interactive UPS for Microgrids , 2014, IEEE Transactions on Industrial Electronics.

[8]  Jin Jiang,et al.  Accurate Reactive Power Sharing in an Islanded Microgrid Using Adaptive Virtual Impedances , 2015, IEEE Transactions on Power Electronics.

[9]  Balarko Chaudhuri,et al.  Hardware and Control Implementation of Electric Springs for Stabilizing Future Smart Grid With Intermittent Renewable Energy Sources , 2013, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[10]  J.M. Guerrero,et al.  Hierarchical control of droop-controlled DC and AC microgrids — a general approach towards standardization , 2009, 2009 35th Annual Conference of IEEE Industrial Electronics.

[11]  Yun Wei Li,et al.  An Enhanced Microgrid Load Demand Sharing Strategy , 2012, IEEE Transactions on Power Electronics.

[12]  Josep M. Guerrero,et al.  An Improved Droop Control Strategy for Reactive Power Sharing in Islanded Microgrid , 2015, IEEE Transactions on Power Electronics.

[13]  T. L. Vandoorn,et al.  Communication-based secondary control in microgrids with voltage-based droop control , 2012, PES T&D 2012.

[14]  J. Miret,et al.  Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output Impedance , 2005, IEEE Transactions on Industrial Electronics.

[15]  Yan Li,et al.  Power Management of Inverter Interfaced Autonomous Microgrid Based on Virtual Frequency-Voltage Frame , 2011, IEEE Transactions on Smart Grid.

[16]  Josep M. Guerrero,et al.  Output impedance design of parallel-connected UPS inverters with wireless load-sharing control , 2005, IEEE Transactions on Industrial Electronics.

[17]  A. Keyhani,et al.  Control of distributed generation systems - Part II: Load sharing control , 2004, IEEE Transactions on Power Electronics.

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

[19]  Josep M. Guerrero,et al.  Design and Analysis of the Droop Control Method for Parallel Inverters Considering the Impact of the Complex Impedance on the Power Sharing , 2011, IEEE Transactions on Industrial Electronics.

[20]  Fang Zhuo,et al.  An enhanced load power sharing strategy for low-voltage microgrids based on inverse-droop control method , 2014, 2014 International Power Electronics Conference (IPEC-Hiroshima 2014 - ECCE ASIA).

[21]  Mehdi Savaghebi,et al.  Secondary Control Scheme for Voltage Unbalance Compensation in an Islanded Droop-Controlled Microgrid , 2012, IEEE Transactions on Smart Grid.

[22]  Timothy G. Moore,et al.  Implementing the virtual output impedance concept in a three phase system utilising cascaded PI controllers in the dq rotating reference frame for microgrid inverter control , 2013, 2013 15th European Conference on Power Electronics and Applications (EPE).

[23]  Mehdi Savaghebi,et al.  Secondary Control for Voltage Quality Enhancement in Microgrids , 2012, IEEE Transactions on Smart Grid.