Research On Voltage Balance Of Supercapacitor Storage Energy System

Supercapacitor can provide very high power and has long life as a new device with high energy density. It has both capacitor and battery characteristics, which has great potential for applications on electric vehicles, pulsed power systems and emergency power supply. In order to meet the voltage levels for high power energy storage system, numbers of supercapacitors should be connected in series and parallel. But the dispersion of the capacitors used in series and parallel is the main factor that restrains their life and reliability. So the voltage balance of the capacitor stacks is of great important.This paper is to design a voltage balance system based on DSP, which uses one electrolytic capacitor, after analyzing the existing equalization technology. The system is consisted of parameter acquisition, PWM output and switch network. A DSP is used as the control core of the system and an electrolytic capacitor is used for transferring energy. Signals collected by monitoring system are sent to DSP through A/D converter. After processing by DSP, the PWM signal is put out depending on an enacted equalization strategy to drive the switch net, As a result, energy will be transferred between capacitor cells and the voltage differences will be reduced. Finally, the simulation and experimental data are analyzed. A conclusion can be draw that this method achieve a good balance result through comparing the data.The system is used on charge or discharge of supercapacitor stacks, it can achieve static and dynamic balance. Compared with other methods, it has a higher balance speed and better effect.