Title: Power sharing control strategy of parallel inverters in AC microgrid using improved reverse droop control

Authors: Chethan Raj D; Dattatraya N. Gaonkar; Josep M. Guerrero

Addresses: Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka, Surathkal, Karnataka, 575025, India; Department of Energy Technology, Aalborg University, Aalborg, Denmark ' Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka, Surathkal, Karnataka, 575025, India; Department of Energy Technology, Aalborg University, Aalborg, Denmark ' Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka, Surathkal, Karnataka, 575025, India; Department of Energy Technology, Aalborg University, Aalborg, Denmark

Abstract: Microgrid structure is developed on the basis of distributed generation units. Microgrid distributed generation units and energy storage devices are connected through inverters interface to the point of common coupling. Microgrid system with multiple inverters, the use of conventional direct and reverse droop control method will cause uneven distribution of power, which is due to the difference between the output impedance and the line impedance of the inverter. In this paper, the traditional reverse droop control method is introduced, the power distribution of inverter output impedance is analysed, and the defects of traditional reverse droop control are pointed out. Adding virtual resistor in the control loop of reverse droop control improves the power sharing and stability of operation, but also leads to the voltage drop in microgrid. To compensate the output voltage deviation, secondary control is proposed. Simulation results show the correctness and effectiveness of the proposed control strategy.

Keywords: droop control; reverse droop control; distributed generation; inverters; microgrid; output impedance; secondary control; virtual resistors.

DOI: 10.1504/IJPELEC.2020.103953

International Journal of Power Electronics, 2020 Vol.11 No.1, pp.116 - 137

Received: 09 Jul 2017
Accepted: 14 Aug 2017

Published online: 02 Dec 2019 *

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