Open AccessSecondary voltage controls of virtual‐droop‐controlled bidirectional DC/DC converters in hybrid energy storage system
Author(s) -
Cheng Long,
Zhang Zehua,
Zhang Fanghua
Publication year - 2020
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2019.1566
Subject(s) - voltage droop , settling time , control theory (sociology) , controller (irrigation) , voltage , capacitance , battery (electricity) , converters , output impedance , computer science , capacitor , state of charge , energy storage , voltage source , engineering , electronic engineering , power (physics) , electrical engineering , control (management) , control engineering , step response , physics , quantum mechanics , agronomy , chemistry , electrode , artificial intelligence , biology
For a hybrid energy storage system consisting of battery and super‐capacitor (SC) in More Electric Aircraft, a decentralised control strategy, which is based on the virtual impedance droop control, can implement the frequency domain allocation of load power avoiding communication delay and a single point of failure. Although the output voltage deviation and state‐of‐charge (SoC) limitation are solved by existing methods, it still suffers from settling time extending. Secondary voltage controls (SVCs) of virtual‐droop‐controlled for battery and SC are proposed to solve the issue. SVC for the output voltage is designed to compensate for the output voltage deviation in the battery converter based on virtual resistance droop control. SC converter, which is controlled by the SVC for input voltage in virtual capacitance droop control, enforces SC SoC back to the initial value and maintains consistent settling time. In this study, a set of detailed design methods for the controller parameters of SVC are developed not only to regulate the output voltage and SoC recovery but also to keep the same settling time. The results of the simulation and experiment validate the effectiveness of the proposed SVC and design method.