电动汽车不同测试工况下的经济性差异分析

Analysis of Economic Differences in Electric Vehicles under Different Test Cycles

为了探讨不同测试工况对电动汽车经济性产生的影响,根据欧洲工况WLTP、通用阿特拉斯循环CADC、德国高速工况BAB 3种测试循环以及不同空调温度、挡位、驾驶模式、环境温度设计了15个不同的测试工况,共进行了12次常温试验和3次非常温试验,对15个测试工况下的电机能量消耗量、制动回收能量、瞬时制动能量回收功率、DCDC能量消耗量、车辆座舱温度、充电效率进行了测试,并对测试结果进行了分析。结果表明,在WLTC、CADC和BAB 130的常温测试中,不同挡位、驾驶模式、空调设置、试验顺序对电机能量消耗量的影响不是很大;在WLTC高温测试中,电机能量消耗量稍有减少;在-7℃的WLTC低温测试中,电机能量消耗量明显增大。在WLTC-2循环中,车辆在B挡、运动模式、-7℃低温测试下的回收能量分别比WLTC标准测试多4.1%、少4%、少11.5%;在CADC-2循环中,B挡的回收能量比D挡的回收能量最多多8.7%。在高SOC状态,低温下,制动能量回收功率被限制在5 k W以内;常温下,制动能量回收功率最多为17.5 kW。车辆的DCDC基本功率需求在300 W上下浮动;在室温下开启HVAC系统,风速为极弱时,DCDC最低功率比基本功率高了约100 W;在低温环境下,车辆加热增大了功率需求,DCDC功率最高。大部分测试工况,车辆座舱内温度与HVAC的设定温度都存在一定程度的偏离;在常温低风速测试中,座舱内的平均温度比HVAC的设定温度高出2℃;在常温中等风速的WLTC和BAB 130测试中,座舱内温度均较高;在车辆驾驶模式为运动模式时,座舱内温度比HVAC的设定温度约高2.5℃;在高温测试中,座舱内温度比HVAC的设定温度高3.7℃;在5℃和-7℃低温测中,座舱内温度分别比HVAC的设定温度高3.5℃和6℃。电网到电池的效率和电网到车轮的效率分别为93.01%和88.42%,说明车辆在各种模式下耗电后,充电效率稳定。

In order to explore the influence of different test conditions on the economy of electric vehicles,15 different test conditions were designed based on three test cycles,namely,the European test condition WLTP,the General Atlas cycle CADC,and the German high-speed test condition BAB,as well as different air conditioning temperatures,gears,driving modes,and ambient temperatures.A total of 12 WLTC tests and 3 non-WLTC tests were conducted to test the motor energy consumption,brake recovery energy,instantaneous brake energy recovery power,DCDC energy consumption,vehicle cabin temperature,and charging efficiency under the 15 test conditions,and the test results were analyzed.The results show that the effects of different gears,driving modes,air conditioning settings,and test sequences on the motor energy consumption are not very significant in the ambient temperature tests of WLTC,CADC,and BAB 130;In the high-temperature test of WLTC,the motor energy consumption decreases slightly;and in the low-temperature test of WLTC at-7°C,the motor energy consumption increases significantly.In the WLTC-2 cycle,the recovered energy of the vehicle in B gear,sport mode,and-7°C low-temperature test is 4.1%more,4%less,and 11.5%less than that of the WLTC standard test,respectively;and in the CADC-2 cycle,the recovered energy in B gear is up to 8.7%more than that in D gear.In the high SOC state,the braking energy recovery power is limited to 5kW at low temperature,while the braking energy recovery power is up to 17.5kW at ambient temperature.The vehicle's basic DCDC power requirement fluctuates around 300W;When the HVAC system is turned on at room temperature and the wind speed is very weak,the minimum DCDC power is about 100W higher than the basic power;At low temperatures,the vehicle heating increases the power requirement,and the DCDC power is the highest;For most of the test conditions,the temperature in the vehicle cockpit deviates from the HVAC set temperature to a certain extent.In the room-temperature low-wind test,the brake energy recovery power of high-speed segment 2 is not much different from that of high-speed segment 2 at high SOC conditions.In room temperature low wind speed test,the average temperature in the cockpit was 2°C higher than the set temperature of HVAC;In the room temperature medium wind speed test of WLTC and BAB130 test,the temperature in the cockpit was higher;when the vehicle driving mode was in sport mode,the temperature in the cockpit was about 2.5°C higher than the set temperature of HVAC.In the high temperature test,the temperature in the cockpit was 3.7°C higher than the set temperature of HVAC;In the 5°C and-7°C low-temperature tests,the in-cockpit temperature was 3.5°C and 6°C higher than the HVAC's set temperature,respectively.The grid-to-battery and grid-to-wheel efficiencies were 93.01%and 88.42%,respectively,indicating that the charging efficiency of the vehicle was stable after power consumption in all modes.