The output characteristics of automobile generators can tell which engines output power?

The engine power and torque marked on the nameplate of an automobile are the maximum values measured under specific conditions, indicating the highest performance of the engine, also known as the external characteristics of the engine, which will not appear in daily driving. We only use part of the performance of the engine in daily driving, for example, the model with power above 100 kW can only use dozens or even dozens of kilowatts in actual use.

So what is more meaningful to us is the performance of the engine at medium and low speeds, that is, some characteristics of the engine. Let's talk briefly about how the power of the engine is measured, the relationship between the power of the car and the power of the engine, and how much power is consumed in daily driving.

At present, the test of automobile engine power is generally carried out on the engine test bench, and the equipment used is hydraulic dynamometer or eddy current dynamometer, the latter is mostly. The specific conditions of the test are: the engine is in good technical condition (generally just adjusted accurately), the engine water temperature is within the normal working range (80 ~ 90℃), the lubrication is good, and the climatic conditions are under standard conditions (20℃, one standard atmospheric pressure).

Then, under this condition, the torque output by the engine at full throttle (full load), half throttle and quarter throttle (partial load) is tested, and then the engine power is calculated according to the relationship between engine power, torque and speed. If the climatic conditions are not standard conditions, they need to be multiplied by a certain correction coefficient.

There are actually two ways to mark the engine power, one is to mark the rated power, and the other is to mark the maximum net power.

Rated power refers to the maximum power measured by the engine in the most ideal state. At this time, the test method is that the engine has no accessories, such as air conditioning compressor, steering pump, generator, fan and so on, except the parts necessary for maintaining operation. Obviously, although this test method can get more data, it is of little practical significance and can only explain the performance of the engine.

Another method is to mark the maximum net power of the engine. At this time, the test method is that all engine accessories are in the loading state, including air conditioning compressor, steering pump, generator, fan and so on. Obviously, the engine at this time consumes some power to drive these accessories, so the maximum net power of the engine is less than the rated power of the engine, generally around 5 kW. The maximum net power of the engine shows the highest performance of the engine in actual use, so it is more practical for us.

In China's automobile technical standards, there is no clear regulation on engine power labeling, so some manufacturers label rated power and some manufacturers label maximum net power. Obviously, if it is a car of the same class with similar weight and technology, one is rated power and the other is maximum net power. The parameters of the two may be the same, but in fact, the power is very different, which is why. Therefore, it is meaningless to just look at the engine power when we buy a car.

The greater the power of the engine, the better the power of the car;

This statement is correct for the same model. Generally, the engines of high, medium and low models are different, and the engines of high models have higher power and stronger performance, so the power of the car is naturally good. But for different models, it is meaningless to simply compare engine power. The engine power labeling and adjustment of different models are different.