Voltage balancing of a 320-V, 12-F electric double-layer capacitor bank combined with a 10-kW bidirectional isolated DC-DC converter

• Main Authors: Tan N.M.L., Inoue S., Kobayashi A., Akagi H.
• Other Authors: 24537965000
• Format: Article
• Published: 2023
• Subjects: Bidirectional isolated dc-dc converter; Electric double-layer capacitor (EDLC); Voltage balancing; Automobiles; Capacitance; Capacitors; Control system stability; DC-DC converters; Dielectric devices; Electric automobiles; Electric discharges; Electric network analysis; Electric vehicles; HVDC power transmission; Hybrid systems; Industrial applications; Life cycle; Power converters; A centers; Charge/discharge; Dc converters; Double-layer capacitors; Energy-storage systems; Environmental friendliness; Experimental verifications; High power densities; Hybrid electric vehicles; Long lives; Low ripples; Rated voltages; Renewable energy systems; Self-starting; Static energies; Storage devices; Voltage-balancing circuits; Renewable energy resources

double-layer capacitors (EDLCs) have attributes that feature high power density, quick charge/discharge time, long life cycle, and environmental friendliness. These attributes accord for increased appeal in employing the EDLCs as energy-storage devices in renewable energy systems, industrial applications, and hybrid electric vehicles as compared to other mature static energy-storage devices. This paper describes the construction of a 320-V, 12-F EDLC energy-storage bank connected to a bidirectional isolated dc--dc converter. Two types of EDLC bank configurations are considered with emphasis on their voltage-balancing circuits. Subsequently, this paper proposes a voltage-balancing circuit based on a center-tapped transformer, and includes its experimental verifications. It also discusses the charge--discharge and self-starting operation of the EDLC energy-storage system. During the charge--discharge operation, a low ripple current flowing in the EDLC bank is observed, leading to a theoretical analysis. The EDLC bank is also successfully charged to its rated voltage without any external dc charging circuit. � 2008 IEEE.