Research Of Voltage Equalization System For Supercapacitor

Supercapacitor is a new kind of energy-storage component, which has advantages of high power density, high capacitance, long life cycles, and quick charging speed. But restricted by its internal factors, a single supercapacitor has a low voltage, which is about 2.5 volt. Supercapacitors are always been in series-parallel connected as an energy storage module in practical application. When charged in series, the supercapacitors will have different voltages because of their difference in capacitance and equivalent resistance. The problem will affect the supercapacitor's life and energy utilization ratio. Therefore, it is very necessary to design a voltage equalization system.In this paper, the supercapacitor's development, application, features and some voltage equalization methods were introduced firstly. Then a voltage equalization system has been designed. It is based on a nondissipasive method and suit for charge with a large constant current. The design is include hardware and software. The hardware part contains a voltage acquisition circuit, a PIC MCU, a current control circuit, a LCD and a button control circuit. Then the hardware and software were described. At last the system's effectivity was proved through experiments. Compare with other equalization systems, this system has the features of low dissipation energy, fast voltage equalization speed and uncomplicated circuit.