Energy awareness for supercapacitors using Kalman filter state-of-charge tracking
Energy awareness for supercapacitors using Kalman filter state-of-charge tracking
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DOI:
10.1016/j.jpowsour.2015.07.050
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发表时间:
2015-11-20
影响因子:
9.2
通讯作者:
Soyata, Tolga
中科院分区:
文献类型:
--
作者:
Nadeau, Andrew;Hassanalieragh, Moeen;Soyata, Tolga
Among energy buffering alternatives, supercapacitors can provide unmatched efficiency and durability. Additionally, the direct relation between a supercapacitor's terminal voltage and stored energy can improve energy awareness. However, a simple capacitive approximation cannot adequately represent the stored energy in a supercapacitor. It is shown that the three branch equivalent circuit model provides more accurate energy awareness. This equivalent circuit uses three capacitances and associated resistances to represent the supercapacitor's internal SOC (state-of-charge). However, the SOC cannot be determined from one observation of the terminal voltage, and must be tracked over time using inexact measurements. We present; 1) a Kalman filtering solution for tracking the SOC; 2) an on-line system identification procedure to efficiently estimate the equivalent circuit's parameters; and 3) experimental validation of both parameter estimation and SOC tracking for 5 F, 10 F, 50 F, and 350 F supercapacitors. Validation is done within the operating range of a solar powered application and the associated power variability due to energy harvesting. The proposed techniques are benchmarked against the simple capacitive model and prior parameter estimation techniques, and provide a 67% reduction in root-meansquare error for predicting usable buffered energy. (C) 2015 Elsevier B.V. All rights reserved.