Open AccessPower sharing control strategies for a three‐phase microgrid in different operating condition with droop control and damping factor investigation
Author(s) -
Souza Wanderson Ferreira,
SeveroMendes Marcos Antônio,
Lopes Luiz A.C.
Publication year - 2015
Publication title -
iet renewable power generation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 76
eISSN - 1752-1424
pISSN - 1752-1416
DOI - 10.1049/iet-rpg.2014.0250
Subject(s) - voltage droop , microgrid , control theory (sociology) , output impedance , ac power , power factor , voltage source , electrical impedance , resistive touchscreen , engineering , damping factor , equivalent impedance transforms , voltage , electronic engineering , computer science , input impedance , electrical engineering , control (management) , artificial intelligence
In this study, a microgrid with two voltage source inverters (VSIs), operating in islanded or grid‐connected mode is analysed. The active power control by droop coefficients and reference frequencies is demonstrated. In addition, the inductive and resistive droop strategies are compared by considering the complex line impedance. By measuring the line impedance in the prototype, it was found that, even for the low‐voltage microgrid, the line impedance was not predominantly resistive, but complex. For this line impedance condition, an investigation to determine the best droop control law considering the partial derivatives. Observing the partial derivatives and the experimental results obtained it is demonstrated that inductive droop control is better to control the active power for complex line impedance. For a scenario with resistive unbalanced loads and different power sharing between the inverters, the proposed control, implemented in the a–b–c reference frame, was validated. A novel absolute damping factor is developed to improve the transient response and reduce the reactive power flow. The VSIs are connected to the grid without transformers to reduce the connection costs. Simulation and experimental results are presented to confirm the improvements achieved using the implemented control method.