An Optimized Energy Management Strategy for Preheating Vehicle-Mounted Li-Ion Batteries at Subzero Temperatures

Abstract

This paper presents an optimized energy management strategy for Li-ion power batteries used on electric vehicles (EVs) at low temperatures. Under low-temperature environments, EVs suffer a sharp driving range loss resulted from the energy and power capability reduction of the battery. Simultaneously, because of Li plating, battery degradation becomes an increasing concern as temperature drops. All these factors could greatly increase the total vehicle operation cost. Prior to battery charging and vehicle operating, preheating battery to a battery-friendly temperature is an approach to promote energy utilization and reduce total cost. Based on the proposed LiFePO4 battery model, the total vehicle operation cost under certain driving cycles is quantified in the present paper. Then given a certain ambient temperature, a target temperature of preheating is optimized under the principle of minimizing total cost. As for the preheating method, a liquid heating system is also implemented on an electric bus. Simulation results show that the preheating process becomes increasingly necessary with a decreasing ambient temperature; however, the preheating demand declines as driving range grows. Vehicle tests verify that the preheating management strategy proposed in this paper is able to save total vehicle operation cost.

Sizing a battery-supercapacitor energy storage system with battery degradation consideration for high-performance electric vehicles

“…( 4), as varies, the trend of is different from that of (which is deduced in Section 3). The significance of exists in its implication for the financial losses due to degradation: the manufacturing price of battery is directly proportional to its energy capacity (e.g., battery unit price was imagined as 300 USD/kWh in 2017 [30]); thus, responses to the losses of battery price. Based on the above, the sub-objective contains two parallel functions: one is as a function of and , and the other is as a function of and , as Eq.…”

Investigation on the method of battery self-heating using motor pulse current

“…6 Zhang et al 7 studied the way of heating the battery by adding a heating film on the battery surface. Zhu et al 8 proposed to heat the coolant by controlling the thermal management system of the vehicle. When the coolant flows through the power battery, it will exchange heat with the power battery, so as to realize the purpose of battery heating.…”

Preheatingstrategy ofvariable‐frequencypulse for lithium battery in cold weather

“…Zhu et al 13 based on the LiFePO 4 battery model, optimized the target heating temperature under the principle of cost minimization, and heated the battery from −10 C to 2 C by liquid-heating method to reduce operating costs of electric bus. However, liquid heating caused a temperature gradient, which in turn caused uneven temperature distribution.…”