Open AccessControl strategy of clustered micro‐grids for grid voltage unbalance compensation without communications
Author(s) -
Liu Baoquan,
Zhao Xuguang,
Liu Yan,
Zhu Yixin,
Chen Jingwen
Publication year - 2020
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2020.0421
Subject(s) - voltage droop , grid , voltage , computer science , matlab , compensation (psychology) , spare part , electronic engineering , engineering , electrical engineering , voltage regulator , psychology , psychoanalysis , mechanical engineering , geometry , mathematics , operating system
Grid‐connected converters are expected to provide ancillary service utilising their spare capacities during operation. This study proposes a novel control strategy for clustered micro‐grids to compensate voltage‐unbalance of the power grid at the point of common coupling. Every micro‐grid are interfaced to the power grid through a micro‐grid inverter (MGI). All MGIs are designed independently with positive‐sequence (PS) and negative‐sequence (NS) control loops. Every micro‐grid autonomously performs grid synchronisation and mode switching. After grid‐connecting, a dynamic capacity allocation method is proposed for the MGIs to optimise its PS and NS capacity according to the grid voltage unbalance factor. Furthermore, a V–I droop control of the NS control loops is developed, with which each MGI can regulate its NS current according to the NS voltage in a droop manner. With the proposed method, all micro‐grids participate in grid voltage unbalance compensation according to their own potential capacities without communications. Finally, a micro‐grid cluster model with three micro‐grids is built on Matlab/Simulink to validate the proposed control strategy.