The Research On The Control Technology Of The Super-capacitor Management System

With the rapid development of social economy and technology, we are facing an increasingly serious energy crisis. Therefore, the development of new energy technologies and new energy storage technologies is imperative. Super-capacitor has large capacity, long working life and rapid charge and discharge, compared with the traditional storage carrier. But the monomer voltage is low, some super-capacitors are used to consist of capacitor bank with series and parallel to meet the requirement of the voltage and power of the energy storage system. The voltage difference exists between monomers in the process of charging and discharging because of the difference of supercapacitors'performance parameters. It will impact the service life and the energy storage efficiency of super-capacitor seriously. So the study of the rational design of super-capacitor management system is important.The core technology of super-capacitor management system contains SOC estimation, voltage equalization technique and status parameters detection. Firstly, paper researches on the above issues, in terms of SOC estimation, uses the method of the combination of integral an open-circuit voltage and introduces four correction parameters. They are current equivalent coefficient ki, capacitor health correction coefficient, temperature compensation coefficient and the initial value SOC(to) to reduce the accumulated errors. In terms of voltage equalization, selecting the active control scheme to achieve the two-way and non-dissipative equalization control of any monomer capacitor within the capacitor bank. In terms of status parameters detection, the system mainly monitors monomer voltage, the total voltage of the capacitor bank, charge and discharge current and temperature.Secondly, designing the hardware circuit and the software of system. The DSPIC30F6014A microcontroller is used as control core of the system. Designing the voltage detecting circuit based on LTC6804. Constructing the current and temperature detection circuit with Hall element and thermistor. Designing the voltage equalization circuit based on LTC3300 to achieve the control of super-capacitors. The design of software includes the main program of system, the initialization subroutine of system and chips, A/D conversion subroutine and SOC estimation algorithm.Finally, build experimental platform, charge super-capacitors with constant current, measure super-capacitors state parameters, verify the validity of the voltage equalization circuit. Discharge super-capacitors with constant current, measure and draw SOC estimation curve by changing discharge current. Verify the validity of the management system by the above experiments.