According to past experience, we are used to using the battery capacity given by the government and the energy consumption data of the Ministry of Industry and Information Technology to calculate the cruising range, so this time I used the energy consumption data and cruising range of the Ministry of Industry and Information Technology to calculate the battery capacity in turn.
Battery energy = comprehensive energy consumption ×NEDC cruising range
The data brought in is13.9× 594/100 = 82.566 kwh. But my colleague told me that he remembered that the Y-shaped battery pack did not exceed 80kWh, and then he sent me a Y-shaped vehicle nameplate. ..
Battery energy = system voltage × battery capacity
The alternative data is 355.2× 216.2/1000 = 76.79 kwh. So far, I have confirmed that the battery capacity of Model Y is 76.79kWh. So, what was the previous calculation of 82.566kWh? Is the power consumption of the Ministry of Industry and Information Technology not allowed?
Is the problem of inaccurate electricity consumption an example? I also found the imported Audi e-tron and AION LX of GAC to calculate the fuel consumption of 100 kilometers.
Power consumption per 100 kilometers = battery pack energy /NEDC cruising range
Import data to obtain:
We found that the calculated data of the three cars are inconsistent with the data of the Ministry of Industry and Information Technology. Is there a problem with MIIT? Don't worry, let's keep looking down.
Let's take a look at how NEDC's battery life is obtained. According to GB/T 18386-20 17 "Electric vehicles? Energy consumption rate and driving range? Test method ",interested partners can refer to this standard. First of all, this test is carried out under laboratory conditions, not on the actual road. Now I will briefly describe the test process: first, fully charge the vehicle, and ensure that the experiment is carried out within 12 hours after full charge, and ensure that the laboratory temperature is controlled at 20 ~ 30℃. Put the vehicle on the test bench, turn on the blower in front of the vehicle, and simulate the wind impact when the vehicle is driving normally.
Start the vehicle, turn off the vehicle air conditioner, and start the cycle experiment according to the speed change shown below. This cycle experiment is 19 minutes, including? The theoretical mileage of a cycle is11.022km. Run one cycle, and then enter the next cycle.
When the vehicle can't meet the speed change in the cycle, the experiment ends, and the mileage is the NEDC mileage of the vehicle. I'll explain it here again. In fact, at this time, the vehicle still has electricity, and there is no "squatting" situation, but the power provided by the battery is not enough to meet the high-power requirements. In fact, this is not the ultimate endurance test. At this time, the vehicle can still continue driving for a certain mileage at a low speed.
Now that we know the cruising range of NEDC, can't we directly get the power consumption of 100 kilometers by using the capacity and mileage of the battery pack? Actually, it's not like this. When testing the NEDC endurance experiment, the vehicle did not "squat down" and the battery pack still had electricity, so the capacity of the battery pack could not be directly used to participate in the calculation. Therefore, we need to know the actual power consumption of the battery pack. So, how to get the actual power consumption?
Everyone knows the electricity meter at home, right? It's the same here We need to connect the vehicle that has completed NEDC to the charging pile within two hours, record the reading of the electric meter until the vehicle is fully charged, and then get the power consumption.
At present, we already know the actual NEDC endurance values of these three cars and the power consumption of vehicles for 100 kilometers. Therefore, we can get the actual power consumption of the meter when these three vehicles are tested by calculation.
At this time, we will find a wonderful thing: the energy output from the actual power grid is a little larger than the capacity of the battery pack.
Why is this?
In fact, the loss here comes from the charging system of the vehicle. We know that every step of energy transfer and conversion will lose energy. The heat of battery, charger and wire will all cause the loss of electric energy, so not all the energy on the power grid will enter the battery pack of the vehicle.
Based on the NEDC cruising range and the energy consumed by the power grid, according to GB/T 18386-20 17 "Electric Vehicles? Energy consumption rate and driving range? Test method We can calculate the power consumption of the vehicle 100 km.
Power consumption per 100 kilometers = actual power grid energy consumption ÷NEDC cruising range
abstract
Now do you understand what is wrong with the formula of the article title? Because the battery capacity of the vehicle is not used in the calculation of the Ministry of Industry and Information Technology, it is inaccurate to use the rated capacity of the battery to participate in any calculation.
There is another interesting point here. You can look at the actual power grid energy consumption of Audi's e-tron, which is similar to the battery pack. Does Audi have any technology that goes against the sky to make the charging efficiency far superior to other models? No, this actually shows that Audi's model does not use its battery pack to the limit, and its battery pack utilization rate is far less than that of the other two models. This involves another topic of new energy vehicle battery pack-the difference between rated capacity and available capacity of battery pack. I will talk about this problem in the next article. If you like, please continue to follow me and bring more content later. (Some pictures are from the Internet)