Distribution power loss mitigation of parallel-connected distributed energy resources in low-voltage DC microgrids using a lagrange multiplier-based adaptive droop control

• Main Authors: Jiang, Yajie, Yang, Yun, Tan, Siew-Chong, Hui, Ron Shu-Yuen
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Electrical and electronic engineering; Adaptive Droop Control; Lagrange Multiplier Method
• Online Access: https://hdl.handle.net/10356/160761
• Institution: Nanyang Technological University

This article presents a Lagrange multiplier-based adaptive droop control to mitigate distribution power loss of parallel-connected distributed energy resource (DER) systems in dc microgrids. The distribution power loss comprising line loss and converter loss can be modeled as a quadratic function of the output currents of the DER systems, which can be optimized by the tertiary-layer Lagrange multiplier method to obtain the optimal output current references for the secondary-layer adaptive droop control. The output currents are compensated by the adaptive droop control to provide output voltage references for the primary-layer local dual-loop control, which is a conventional local control scheme for the regulations of grid-connected dc-dc converters. Both simulation and experimental results validate that the proposed control strategy can reduce the distribution power loss of parallel-connected DER systems in 48 V dc microgrids as compared to the conventional control strategy by only optimizing the line loss in different cases.