Study On Equalization Technology For Supercapacitor Stacks In Series Connection And Module Structural Parameters Design

Supercapacitor, which possesses the features of high specific power, fast charging and discharge rate and long cycle life and so on, is becoming to be an important power storage equipment in recent years. However, supercapacitor cell can not meet the requirement of the load for voltage, power and time of discharge. The voltage rating of supercapacitors is typically less than 4V. When higher voltage ratings are required, many supercapacitors are connected in series to form a string of cells. The inconsistency of the series supercapacitor stacks is the main factor that restrains their service life and causes high failure rate. For this reason, an active or passive voltage balancing circuit is employed to regulate the cell voltage. At the same time, supercapacitors connected in series will reduce the equivalent capacity of supercapacitor module, and increase the equivalent internal resistance.Therefore, capacitors should be combined in parallel to make up for the decline of charging and discharging performance caused by capacitors in series. So the research on supercapacitor energy management system is of great significance.This dissertation studies on the supercapcitor voltage balance technology in detail. For different load, the supercapacitor modules are designed. The main achievements are as follows:1.Analyze the Series Supercapacitors constant voltage and constant current charging charge process with the voltage direct parallel resistance balanced. And through simulations and experiments obtain the impact of the resistance option on balance speed and balance level; Established the principle of the selection of resistance.2. Analysis the switch capacitor energy transfer method and the supercapacitor series balanced process , establish the principles of the main components parameters. Implement a series of two supercapacitor module simulations and experiments. The experimental results were analyzed. According to the experimental results, the equalization speed and equalization level were analyzed.3. Through the supercapacitors switch inductance balanced simulation, determine the parameters of the main circuit power components. Given the parts of the system software and hardware design and implementation process. And the results of the balanced method were evaluated.4. For different load, design the supercapacitor module and give the case analysis.