Efficient Fast Charging Using Simultaneous Search of Optimal Frequency and Optimal Duty Cycle in Pulse Charging Method

Abstract

The demand of charging a battery in shorter time leads to the development of fast charging strategies. The aim of fast charging is to inject higher amount of currents in such a way that the battery can reach to its full capacity in the shortest possible time. Battery impedance and polarization voltage needed to be taken into account to do so. CC-CV method, pulse charging method, boost charging etc. are some of the commonly known fast charging methods but among them, CC-CV method is the most used. However, its inability to charge the battery fast enough and also heating the battery have made this method inefficient and dangerous. To overcome these issues pulse charging method can be used where pulses of current are sent into the battery. There are various strategies to do pulse charging. Searching optimal frequency and optimal duty cycle simultaneously and charging with them results in faster charging time and lower battery temperature. The results of the strategy can be found in both hardware implementation and through simulation. Studies have been made with variable frequency and variable duty cycle but the simultaneous use of these two strategies along with the temperature changes was not done, nor the comparison of the simulated result and hardware implementation. Here, both are compared in order to determine which one is the most efficient where we have found out the charging time of the battery to be improved significantly when we have used delay between the pulses. However, an increased charging time have been seen when the delay was not present.