A Battery Charge Controller for a Flyback Converter With Digital Primary Side Regulation

Author(s):  
Paul C.-P. Chao ◽  
W. D. Chen ◽  
R. H. Wu

The market of electronic products such as mobile phones and portable devices grows rapidly while the demand of lithium battery for fast charge, long duration, and long life cycle increases significantly as well. There are several charge methods for lithium battery, such as constant current (CC)/constant voltage (CV) charge [1], pulse charge [2] and reflex charge [3], etc. In general, a flyback converter has been widely adopted as the front-end converter of battery charger due to its low-cost, wide power range, and galvanic isolation between input and output stage. The battery charge controller with flyback converter has been developed in digital control with opto-coupler feedback [4]–[6]. The conventional flyback converter with CC or CV applications always requires two sensed ADC channels for regulating [7]–[9]. An improved control method is proposed in this study to achieve CC/CV by only one ADC channel. This study presents a battery charge mechanism with a flyback converter and associated trickle charge method for the temperature compensation. The PSR is adopted for switching the charge modes within trickle current (TC), constant current (CC) and constant voltage (CV). The TC charging method is used to avoid the rapid increase in the temperature of the battery which is based on the characteristics of the internal resistance of the battery [10]. The proposed system circuit contains two stages in topology. The first stage is a front-end flyback converter which operates in DC-DC discontinuous current mode (DCM) by using PSR to sense the output voltage from auxiliary winding. It is adopted to replace the opto-coupler for avoiding temperature limitation for operations and reducing cost. The software Powersim is used to simulate the proposed flyback converter and PSR method. The second stage is the digital feedback loop, which processes the controlled signal by a digital processor (DSP) TMS320F2812. The experimental results were compared with general CC/CV method. The results show favorable performance of the propose charging method.

2020 ◽  
Vol 10 (3) ◽  
pp. 895 ◽  
Author(s):  
Judy M. Amanor-Boadu ◽  
Anthony Guiseppi-Elie

Pulse charging of lithium-ion polymer batteries (LiPo), when properly implemented, offers increased battery charge and energy efficiencies and improved safety for electronic device consumers. Investigations of the combined impact of pulse charge duty cycle and frequency of the pulse charge current on the performance of lithium-ion polymer (LiPo) batteries used the Taguchi orthogonal arrays (OA) to identify optimal and robust pulse charging parameters that maximize battery charge and energy efficiencies while decreasing charge time. These were confirmed by direct comparison with the commonly applied benchmark constant current-constant voltage (CC–CV) charging method. The operation of a pulse charger using identified optimal parameters resulted in charge time reduction by 49% and increased charge and energy efficiencies of 2% and 12% respectively. Furthermore, when pulse charge current factors, such as frequency and duty cycle were considered, it was found that the duty cycle of the pulse charge current had the most impact on the cycle life of the LiPo battery and that the cycle life could be increased by as much as 100 cycles. Finally, the charging temperature was found to have the most statistically significant impact on the temporarily evolving LiPo battery impedance, a measure of its degradation.


2016 ◽  
Vol 6 (1) ◽  
pp. 35
Author(s):  
Daniel Fajar Puspita ◽  
Susanto Sigit Rahardi

Penelitian  mengenai  stabilisasi  produksi  baterai  ion  litium  berdasarkan  parameter  kapasitas  pengisian, kapasitas pelepasan  dan  efisiensi  pengisian-pelepasan  telah  dilakukan. Tujuan  dari penelitian  ini adalah  untuk mengetahui apakah prosedur pembuatan baterai ion litium ini dapat menghasilkan produk yang homogen. Pada penelitian material selanjutnya hal ini berguna untuk meyakinkan bahwa perubahan kualitas   dari produk baterai yang dihasilkan merupakan pengaruh dari material, bukan karena variabel proses perakitan. Pada penelitian ini dipakai lembaran elektroda siap pakai untuk meniadakan pengaruh variasi bahan baku terhadap kualitas sel baterai yang dihasilkan. Sel baterai dibuat di laboratorium riset baterai B4T. Baterai dibuat sebanyak 3 batch dengan jumlah baterai 8 buah setiap batch. Baterai yang dihasilkan diuji dengan alat battery analyzer merek Berkeley buatan USA dengan arus 0,5 C pada saat constant-current charging dan voltase 4,2 V sewaktu constant-voltage charging selama 10 siklus pada saat uji kinerja  dan arus 0,1 C pada saat pengisian  awal.  Hasil yang didapat adalah  batch C menghasilkan sel-sel baterai yang lebih homogen yang ditandai dengan nilai varians dan simpangan baku yang paling kecil dibandingkan batch lainnya.  Selain itu pada saat uji pengisian-pelepasan  10 siklus, batch C juga memperlihatkan kinerja yang lebih tinggi. Hal ini menunjukkan bahwa proses yang dipakai pada batch C dapat menghasilkan sel baterai ion litium berkinerja baik dan homogen.Kata kunci: stabilisasi produksi, ion litium, kapasitas, efisiensi


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