Tram endurance standards are different, which is more appropriate, mainstream endurance test analysis

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NEDC endurance, CLTC endurance, WLTP endurance, we can see their figures in a variety of new car conferences or tram endurance related information, the same car in these different endurance conditions tested out of the endurance are different, in the actual car experience is more so, especially pure electric models, watching the endurance display 400 kilometers, may actually travel after a fold.

This is already a pure tram has a battery life anxiety for consumers who dare not easily believe the manufacturer's data, then in these standards, which will be closer to the reality, more worthy of reference, the following we will briefly understand and compare the current mainstream three tests.

First, NEDC

The NEDC endurance standard, full name New European Driving Cycle, translates to the new European driving cycle, also known as the "new standard European cycle test". The NEDC endurance test consisted of five conditions: 4 urban cycles and 1 simulated suburban cycle. The test method is to put the vehicle on the roller bench, and the roller driving motor in contact with the tire is used to simulate the resistance under different working conditions, and at the same time, the blower is used at the front of the car to simulate the air flow and increase the wind resistance, so as to obtain the endurance data of the vehicle.

NeDC test time is 1180s, 780 seconds before simulating the urban working conditions, urban cycle test speed does not exceed 50km/h, average speed of 18.5km/h, acceleration, maintenance speed, deceleration, stop during the test, repeated four times. After 780 seconds, the simulation test of suburban circulating conditions was carried out, with a maximum speed of 120 km/h and an average speed of about 62 km/h.

In NEDC's cycle test, application loads such as air conditioners, headlights, and heated seats are turned off, which is different from the actual scene. At the same time, in the overall test process, whether it is the simulation of urban circulation or suburban circulation, there is still a big difference from the actual working conditions now, which is why the NEDC battery life will be quite different from the actual battery life.

2. WLTP

WLTP, full name World Light Vehicle Test Procedure, translates as the World Light Vehicle Test Procedure. The WLTP test cycle lasted for 1800s, with a cumulative drive of 23.3km, and the vehicle's top speed was increased to 131km/h, with an average speed of 47km/h.

The WLTP test cycle is divided into four parts: low speed, medium speed, high speed and ultra-high speed, and the corresponding duration of each stage is 589s, 433s, 455s, and 323s, and the corresponding maximum speeds are 56.5km/h, 76.6km/h, 97.4km/h and 131.3km/h, respectively.

Compared with NEDC, WLTP simulates the daily car situation as much as possible, simulating the rolling resistance, gear and load of the vehicle, while the speed change is irregular. Therefore, the mileage of the WLTP test is closer to the real road conditions than the NEDC, and the reference significance is greater.

3. CLTC

CLTC, the full name of China light-duty vehicle test cycle, includes light passenger vehicle conditions (CLTC-P) and light commercial vehicle conditions (CLTC-C). Compared with THECD, CLTC adds a wider range of road condition information: urban conditions, suburban conditions and high-speed conditions, with a cycle time of 1800 seconds.

CLTC used a large number of Chinese cars on the road data, the maximum speed, average speed and the current high-speed regulations and traffic GIS collected big data is more matched, this standard is based on 41 cities, 3832 vehicles, accumulated 32.78 million kilometers, 2 billion GIS traffic low-frequency dynamic big data (the average speed of the road every five minutes) definition of the standard working conditions.

China's traffic congestion is more serious, the idle speed ratio is high, the average speed is low, the vehicle mainly runs in the middle and low speed range, and the acceleration and deceleration are frequent. CLTC will consider these aspects more, so it will be more suitable for the driving conditions of cars on the mainland.

But CLTC is still not perfect, compared to WLTP, CLTC lacks the working conditions of the ultra-high-speed section, and the maximum speed, the average speed is the lowest of the three, while the CLTC test under the electric vehicle in the parking condition energy consumption of 0, in the driving can also be kinetic energy recovery, so may cause CLTC mileage will be longer than NEDC.

In the actual use process, although kinetic energy recovery can increase some endurance, the ambient temperature and the use of air conditioning systems have a greater impact on the cruising range, and the test is not considered. Therefore, although the CLTC is tailored for the mainland, there are still many aspects that need to be optimized as a whole.

According to the planning of the Ministry of Industry and Information Technology, by 2025, all new energy vehicles will use the CLTC standard to determine the mileage. Therefore, this set of standards must be constantly updated and optimized, and then a set of reasonable and comprehensive endurance test standards that are fully applicable to the mainland will be obtained.

summary:

Although most models currently use NEDC battery life, it is of little reference significance; at the same time, CLTC's temporary comprehensive test will get a longer battery life, and many car companies will also use it; but in the current situation, WLTP will be more referenced. However, with the continuous improvement of CLTC, its test situation is the standard answer to the endurance of new energy vehicles in mainland China.