Pulse-Based Fast Battery IoT Charger Using Dynamic Frequency and Duty Control Techniques Based on Multi-Sensing of Polarization Curve

Abstract

Abstract:The pulse-based charging method for battery cells has been recognized as a fast and efficient way to overcome the shortcoming of a slow charging time in distributed battery cells, which is regarded as a connection of cells such as the Internet of Things (IoT). The pulse frequency for controlling the battery charge duration is dynamically controlled within a certain range in order to inject the maximum charge current into the battery cells. The optimal frequency is determined in order to minimize battery impedance. The adaptation of the proposed pulse duty and frequency decreases the concentration of the polarization by sensing the runtime characteristics of battery cells so that it guarantees a certain level of safety in charging the distributed battery cells within the operating temperature range of 5-45 • C. The sensed terminal voltage and temperature of battery cells are dynamically monitored while the battery is charging so as to adjust the frequency and duty of the proposed charging pulse method, thereby preventing battery degradation. The evaluation results show that a newly designed charging algorithm for the implemented charger system is about 18.6% faster than the conventional constant-current (CC) charging method with the temperature rise within a reasonable range. The implemented charger system, which is based on the proposed dynamic frequency and duty control by considering the cell polarization, charges to about 80% of its maximum capacity in less than 56 min and involves a 13 • C maximum temperature rise without damaging the battery.

Add-On Type Pulse Charger for Quick Charging Li-Ion Batteries

“…In this case, the charging speed of the battery increases, but the cost of the charging system increases. This is because a higher charging system is required for the battery capacity [12].Pulse charging, which charges the battery by controlling the charging current, improves fast charging time and battery charging efficiency without significantly increasing costs [13][14][15]. However, to achieve the pulse charging effect, the duty and frequency of the pulse current must be appropriately selected [14].…”

“…Pulse charging, which charges the battery by controlling the charging current, improves fast charging time and battery charging efficiency without significantly increasing costs [13][14][15]. However, to achieve the pulse charging effect, the duty and frequency of the pulse current must be appropriately selected [14].…”

The Impact of Pulse Charging Parameters on the Life Cycle of Lithium-Ion Polymer Batteries

“…Pulse charging does not have this drawback. The use of pulse charging has been shown to increase battery charge and energy efficiencies and to also reduce charge time [9,17,18]. It also has the added benefit of improved safety, since the relaxation times in between charge current pulses allows time for the Li + to successfully intercalate and helps to prevent dendrite formation [14].…”

“…Though battery runtime can be improved by using various hardware and software techniques [6][7][8], these desirable Energies 2018, 11, 2162 2 of 15 characteristics are impacted by the type of charging algorithm used, and as such, many charging algorithms have been proposed to achieve desirable and optimal output performance metrics. Of these charging algorithms, pulse charging is the most propitious [9][10][11][12][13]. Pulse charging is the application of carefully controlled charge current pulses into the battery.…”

“…Of these charging algorithms, pulse charging is the most propitious [9][10][11][12][13]. Pulse charging is the application of carefully controlled charge current pulses into the battery.…”