A study on voltage equilibration circuit of EDLC using self-oscillation circuit

Abstract

This study proposes a voltage equilibration circuit with a self-oscillation circuit for application to electric double layer capacitors (EDLCs). In typical monitoring circuits, multiple EDLCs are connected in series and the circuits are connected to a power supply. In contrast, the proposed circuits uses a self-oscillation technique, and its voltage is supplied by the EDLC, greatly simplifying the circuit structure. In particular, the circuit comprises only 15 electrical components and self-oscillates without a dead-time control circuit. Moreover, the circuit prevents the flow of the short-circuit current into the drains of the FETs. which causes overcurrent circuit damage. Further, the circuit can be constructed into a module of two serially connected EDLCs. The characteristics and usability of the proposed circuit are evaluated in a simulation and experiment.