Modelling and analysis of voltage balancing topology for series-connected supercapacitor energy storage system

ABSTRACT

This paper proposes a forward conversion topology using a multi-winding transformer known as global modular balancing (GMB) for multiple supercapacitor cells connected in a series of high-voltage applications. The proposed topology can easily be modularized and is not limited to the number of supercapacitors existing in the modules. Moreover, the proposed GMB needs merely one MOSFET switch for each supercapacitor, and a one Pulse width modulation circuit that can control all the switches in the modules. Furthermore, the proposed topology is employed to achieve voltage balancing in a supercapacitor string. The proposed topology balancing performance is validated through MATLAB/Simulink Software.

KEYWORDS:

• Hybrid electric vehicles (HEVs)
• supercapacitors
• forward conversion
• voltage balancing
• global modular balancing
• multi-winding transformer

Nomenclature

D	=	Duty cycle
T	=	Switching period
Pi	=	Transformer iron loss
VDS1	=	Voltage stress on diode
Pc	=	Transformer copper loss
NR	=	Turns ratio of transformer
VTP1	=	primary voltage of module 1
VTP2	=	primary voltage of module 2
VTPjk	=	Transformer primary voltage
VQDS	=	Voltage stress on MOSFETs
${\mathrm{P}}_{\mathrm{R}}$	=	power delivered by Module I
${\mathrm{P}}_{\mathrm{D}}$	=	power delivered by Module II
VTS1	=	Secondary voltage of module 1
VTS2	=	Secondary voltage of module 2
NP	=	Number of primary winding turns
NS	=	Number of secondary winding turns
Leqjk	=	Primary winding leakage inductance
Reqjk	=	Primary winding equivalent resistance
iSCjk	=	balancing current of the supercapacitor
${\eta }_{\mathrm{e}}$	=	Total balancing efficiency among cells
iLm1, iLm2	=	Magnetizing currents of the transformer
iSC1, iSC2	=	Module I and II supercapacitors currents
${\eta }_{\mathrm{S}}$	=	Balancing Efficiency between two modules
Lm1, Lm2	=	Magnetizing inductances of Modules I and II
VP	=	Total Module voltage of supercapacitor strings
iTS1	=	Balancing current from the secondary side of transformer
VM1, VM2	=	Total voltages of each module i.e. (Module I and Module II)
LeqS1(1) ${\mathrm{V}}_{\mathrm{T}\mathrm{P}\mathrm{j}\mathrm{k}}={\mathrm{V}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}+{\mathrm{L}}_{\mathrm{e}\mathrm{q}\mathrm{j}\mathrm{k}}.\frac{\mathrm{d}{\mathrm{i}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}}{\mathrm{d}\mathrm{t}}+{\mathrm{R}}_{\mathrm{e}\mathrm{q}\mathrm{j}\mathrm{k}}.{\mathrm{i}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}$(1) , LeqS2	=	Leakage inductances on the secondary windings of transformers I and II.
ReqS1(1) ${\mathrm{V}}_{\mathrm{T}\mathrm{P}\mathrm{j}\mathrm{k}}={\mathrm{V}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}+{\mathrm{L}}_{\mathrm{e}\mathrm{q}\mathrm{j}\mathrm{k}}.\frac{\mathrm{d}{\mathrm{i}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}}{\mathrm{d}\mathrm{t}}+{\mathrm{R}}_{\mathrm{e}\mathrm{q}\mathrm{j}\mathrm{k}}.{\mathrm{i}}_{\mathrm{S}\mathrm{C}\mathrm{j}\mathrm{k}}$(1) , ReqS2	=	Parasitic resistances on the secondary windings of transformers I and II

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

No funding was received for conducting this study.

Notes on contributors

Arigela Satya Veerendra

Arigela Satya Veerendra is with Manipal Institute of Technology, is a constituent engineering college of the Manipal academy of higher education in Manipal, Karnataka. Currently, he is working as an Assistant Professor in the department of Electrical and Electronics Engineering ([email protected]). He received his bachelor’s degree in 2012 from Jawaharlal Nehru Technological University, Hyderabad. He received his Master’s degree in 2015 from Jawaharlal Nehru Technological University, Kakinada, India and Ph.D. degree in 2022 from Universiti Malaysia Pahang, Malaysia. His research interests include modelling and control of fuel cell electric vehicles and energy storage systems, power electronic converters topology and control.

Mohd Rusllim Mohamed

Mohd Rusllim Mohamed is with Universiti Malaysia Pahang as an Associate Professor in the department of Electrical and Electronics Engineering ([email protected]). He received his bachelor’s degree in 2001 from University of Warwick, U.K. He received his Master’s degree in 2004 from Universiti Teknologi Tun Hussien Onn (UTHM), Malaysia and Ph.D. degree in 2013 from Universiti Malaysia Pahang, Malaysia. His research interests include energy storage, electric vehicles, power electronics and drives systems, renewable energy, control systems and engineering education.

Chavali Punya Sekhar

Chavali Punya Sekhar is with Acharya Nagarjuna University, department of Electrical and Electronics Engineering ([email protected]). He received his bachelor’s degree in 2008 from Jawaharlal Nehru Technological University, Hyderabad. He received his Master’s degree in 2011 from Jawaharlal Nehru Technological University, Hyderabad, India and Ph.D. degree in 2020 from Jawaharlal Nehru Technological University, Kakinada. His fields of interests are multilevel inverter, modeling and control of power electronics converters and its applications.