THE STATE OF CHARGE ESTIMATION FOR LI-ION BATTERY PACK BY THE SINGLE BATTERY EQUIVALENT CIRCUIT-BASED MODEL AND THE FUZZY C-REGRESSION MODEL

• Main Authors: Wei-Siang Liao, 廖緯祥
• Other Authors: Chung-Chun Kung
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/27065884270794737678

碩士 === 大同大學 === 電機工程學系(所) === 100 === In this thesis, the fuzzy c-regression model of the equivalent circuit-based model (ECM) shown in Fig 2.2 and series battery pack model shown in Fig. 2.3 are adopted to estimate the state of charge (SOC) of the battery. The ECM has been built by the electric circuit parameters, but it can be possible to express as mathematical formulas. Then, the one set of RC circuit can model the polarization effect that will provide us to simulate about the internal chemical variation of the battery to estimate the SOC in detail. In order to obtaining the parameters such as V_OC, R_t, R_p, and C_p are not known in the ECM, we set the rated capacity, the open circuit voltage test, and the direct current internal resistance test to calculate the parameters with terminal voltage. Fallowing that, the parameters of ECM are known as with the function of SOC. Since the data line of those parameters varying with the SOC is nonlinear and piecewise continue, the fuzzy c-regression model (FCRM) will be used to formulate the test data with the function of SOC. The all test data is measured by the battery testing system, Gwinstek GBT-2211 and Maccor 4300, and test in room temperature with 4 batteries, Molicel ICR 18650H, with similar characteristics. We will do the test with each 4 batteries and also with 4 series battery pack. Then, the all parameters will be obtained by mention method, and we can use it to estimate the SOC of the battery. Finally, the proposed method will be proved it is work by simulation result to estimate the SOC of the ECM of single battery and battery pack.