What does PTC mean? On the bus? How to use PTC button in electric vehicle

The PTC of electric vehicle is actually the heat source of air conditioning, and the heat source of air conditioning of traditional internal combustion engine vehicle is the cooling water of engine. Because the electric car has no internal combustion engine, PTC is used to generate heat. PTC is the abbreviation of positive temperature coefficient, which means positive temperature coefficient, and generally refers to semiconductor materials or components with large temperature coefficient. Usually, the PTC we refer to is a thermistor used to correct the temperature coefficient, which is called PTC thermistor for short. Ceramic PTC is a semiconductor ceramic with barium titanate (or strontium and lead) as the main component, supplemented by a small amount of donors (Y, Nb, Bi, Sb), acceptors (Mn, Fe) and glass (silica, alumina) as additives, and its manufacturing cost is relatively low. PTC thermistor is a typical semiconductor resistor with temperature sensitivity. When it exceeds a certain temperature (Curie temperature), its resistance increases step by step with the increase of temperature. Above Curie temperature, the resistance increases by 65,438+0,000 times to 1 million times. According to the characteristics of PTC materials, we can easily see the advantages of PTC air conditioner: fast heating, simple structure and low manufacturing cost, but the disadvantage of PTC is also "fatal", that is, high energy consumption. If the heat pump air conditioner is an LED bulb, then the PTC air conditioner is a tungsten bulb. To reach the same temperature, heat pump air conditioner may only need 0.8 kWh, while PTC air conditioner may need 2 kWh. If the air conditioner consumes high power, then the battery life must be discounted. And we can't ignore the reality: when will the hot air conditioner be used? Oh! It is winter that will naturally give a discount on battery life! ! On the other hand, the advantages and disadvantages of PTC and heat pump are actually complementary, so some cars will adopt PTC+ heat pump. When the hot air conditioner is started, PTC will be responsible for rapid heating, so that the temperature in the car will rise rapidly, and then switch to a more energy-saving heat pump air conditioner, which not only ensures the heating effect of the air conditioner, but also reduces the weakening of the cruising range by the hot air conditioner. It is worth mentioning that the cooling water of electric vehicle control unit and power battery will also provide a certain role for heating in the car, but this proportion is not large, but it can more or less reduce the dependence on PTC and heat pump and avoid excessive consumption of battery life.