考虑电池老化的电动汽车中长期充电负荷预测方法

Medium-and Long-term Charging Load Forecasting Method for Electric Vehicles Considering Battery Aging

随着电动汽车市场份额逐年上升,受限于区域内动力电池容量大小的电动汽车充电负荷占总用电负荷的比例不断提高。为此,提出一种考虑电池老化的电动汽车中长期充电负荷预测方法。首先,构建考虑电池老化的区域电动汽车电池总容量预测模型,预测电池老化带来的总容量衰减以及更换新电池和车辆数目增长带来的总容量上升。其次,构建考虑温度变化的动力电池老化特性估计模型,预估每次充电后电池最大容量、可充电量和续航电量,当电池最大容量不足以保证车辆安全运行时,对车辆更换新电池。最后,构建考虑充电成本的车辆行为仿真模型,模拟车辆出行和充电过程;借助模糊C均值法对不同种类电动汽车充电负荷进行划分,通过蒙特卡洛模拟与线性加权确定区域内电动汽车中长期负荷。仿真结果表明,随着车辆使用时间的增加,年负荷曲线波动程度不断变大;相较于新车,电池老化后单位车辆周均用电负荷峰值出现的时间会提前,且负荷峰谷差也会增大。

As the market share of electric vehicles continues to grow annually,the proportion of electric vehicle charging load limited by the capacity of power battery in the region to the total electricity load continues to increase.To this end,this paper proposes a medium-and long-term charging load forecasting method for electric vehicles considering battery aging.First,a total capacity forecasting model for electric vehicle batteries in the rigion considering battery aging is constructed to forecast the total capacity attenuation caused by battery aging,as well as the total capacity increase caused by the replacement with new batteries and the growth in the number of the vehicles.Then,an estimation model for the aging characteristics of power batteries considering temperature changes is constructed to estimate the maximum capacity,rechargeable capacity and driving range of the battery after each charging cycle.When the maximum capacity of the battery is insufficient to ensure the safe operation of the vehicle,it is replaced with a new one.Finally,a vehicle behavior simulation model considering charging costs is constructed to simulate both vehicle travel and charging processes.By using the fuzzy C-means method to partition different kinds of charging loads of electric vehicles,the medium-and long-term loads of electric vehicles in the region are determined through Monte Carlo simulation and linear weighting.The simulation results show that as the vehicle usage time increases,the fluctuation degree of the annual load curve continues to increase.Compared with new vehicles,after battery aging,the peak time of weekly electricity load of single vehicle will be earlier,and the peak-to-valley differences of loads will also increase.