How to heat the permanent magnet motor of new energy vehicle?

With the promotion of national policies and the enhancement of people’s awareness of environmental protection, the popularity of new energy vehicles is gradually deepening. Of course, this situation is inseparable from the progress of new energy vehicle technology, one of which is new energy vehicle cooling technology.
The cooling unit of new energy vehicle mainly includes power battery, driving permanent magnet motor and electronic control system. From the traditional engine cooling technology and the practical application effect of new energy vehicle cooling, water cooling and air cooling are the two main ways of new energy vehicle cooling.

As the drive of pure electric new energy vehicles, permanent magnet motor can achieve very low or zero emissions. In the process of driving and energy recovery of pure electric vehicle, the stator core and stator winding of permanent magnet motor will produce losses in the process of movement. These losses radiate outward in the form of heat. Therefore, effective cooling medium and cooling method are needed to take away the heat, so as to ensure the safe and reliable operation of permanent magnet motor in a stable ventilation system with heat and cold circulation balance . The design of permanent magnet motor cooling system will directly affect the safe operation and service life of permanent magnet motor.

The permanent magnet motor with air cooling is equipped with coaxial fan to form internal or external air circulation. The fan generates enough air volume to take away the heat generated by the motor. The medium is the air around the permanent magnet motor. The air is directly sent into the permanent magnet motor, and the heat is absorbed and then discharged to the surrounding environment. The characteristics of air cooling are relatively simple structure, low cooling cost of permanent magnet motor, but the cooling effect and efficiency are not very good, the working reliability is poor, and the requirements of weather and environment are relatively high.
The permanent magnet motor with water cooling will introduce the coolant into the stator or rotor hollow conductor through pipes and channels, and the heat generated by the rotor and stator of the permanent magnet motor will be taken away through the continuous flow of circulating coolant, so as to achieve the purpose of cooling the permanent magnet motor. Although the cost of water cooling is slightly higher than that of air cooling, its cooling effect is more significant than that of air cooling, with uniform heat dissipation, high efficiency, strong reliability and less noise. As long as the whole device can have good mechanical sealing, it can be used in various environments.

Comparison of water cooling and air cooling for new energy vehicles

Principle of water cooling and heat dissipation for new energy vehicles:

Water pipeline is reserved in the design of power battery and driving permanent magnet motor system. When the permanent magnet motor is driven to work, the heat is generated, and the coolant flows through the water jacket to take away the heat and enter the radiator of the water tank. The radiator is integrated with the electronic fan. The electronic fan accelerates the heat dissipation of the water tank and cools the coolant to reach the normal working temperature required for driving the permanent magnet motor. The cooling liquid after heat dissipation flows through the driving permanent magnet motor again and circularly.

New energy vehicle water cooling system components:

• 1. Water tank radiator, the main function is to cool the coolant into the chip. From the material, it is divided into copper water tank and aluminum water tank. From the internal structure, it can be divided into plate fin type, tube belt type and segment type.
• 2. Electronic fan. Different engine cooling systems and cooling fans of new energy vehicles all use electronic fans for heat dissipation. Different cooling systems have different electronic fans. Yili technology ATS permanent magnet motor cooling system can match one fan version and two fan versions according to the power of driving permanent magnet motor. In general, the heat dissipation capacity of the two electronic fans is enough to meet all the common pure electric vehicles on the market. Hybrid electric vehicles need more electronic fans, generally no more than 6, because they also have engines and turbochargers.
• 3. Electronic control system. The electronic control system mainly includes fan controller, wiring harness, sensor, display, etc. Yili technology ATS includes electronic control system, but from the market as a whole, not all new energy vehicle cooling systems have electronic control system. With the help of electronic control system, Yili technology ATS can intelligently control the heat dissipation of new energy vehicles, which is not as rigid as the traditional engine cooling system.
• 4. Electric water pump. Water pump is an indispensable component, the main function is to provide the power of coolant circulation. The circulation of coolant between driving permanent magnet motor and electric control and radiator needs electric water pump. Yili technology ATS has its own electric water pump components, but some customers will choose the pump brand separately. In terms of the overall stability of the system, we do not recommend this.

Source: China Permanent Magnet Manufacturer – www.rizinia.com