DocumentCode :
2867526
Title :
A direct integration scheme for battery-supercapacitor hybrid energy storage systems with the use of grid side inverter
Author :
Jayasinghe, S.D.G. ; Vilathgamuwa, D.M. ; Madawala, U.K.
Author_Institution :
Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore, Singapore
fYear :
2011
fDate :
6-11 March 2011
Firstpage :
1388
Lastpage :
1393
Abstract :
Battery-supercapacitor hybrid energy storage systems are becoming popular in the renewable energy sector due to their improved power and energy performances. These hybrid systems require separate dc-dc converters, or at least one dc-dc converter for the supercapacitor bank, to connect them to the dc-link of the grid interfacing inverter. These additional dc-dc converters increase power losses, complexity and cost. Therefore, possibility of their direct connection is investigated in this paper. The inverter system used in this study is formed by cascading two 3-level inverters, named as the “main inverter” and the “auxiliary inverter”, through a coupling transformer. In the test system the main inverter is connected with the rectified output of a wind generator while the auxiliary inverter is directly attached to a battery and a supercapacitor bank. The major issues with this approach are the dynamic changes in dc-link voltages and inevitable imbalances in the auxiliary inverter voltages, which results in unevenly distributed space vectors. A modified SVM technique is proposed to solve this issue. A PWM based time sharing method is proposed for power sharing between the battery and the supercapacitor. Simulation results are presented to verify the efficacy of the proposed modulation and control techniques.
Keywords :
AC generators; DC-DC power convertors; PWM power convertors; battery storage plants; power grids; power transformers; supercapacitors; wind power plants; 3-level inverters; DC-DC converters; DC-link voltages; PWM based time sharing method; auxiliary inverter voltages; battery-supercapacitor hybrid energy storage systems; coupling transformer; direct integration scheme; distributed space vectors; grid side inverter; modified SVM technique; power losses; power sharing; renewable energy sector; Batteries; Converters; Inverters; Modulation; Supercapacitors; Voltage control;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Applied Power Electronics Conference and Exposition (APEC), 2011 Twenty-Sixth Annual IEEE
Conference_Location :
Fort Worth, TX
ISSN :
1048-2334
Print_ISBN :
978-1-4244-8084-5
Type :
conf
DOI :
10.1109/APEC.2011.5744773
Filename :
5744773
Link To Document :
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