New Energy Vehicle Air Conditioning Compressor
An electric compressor consists of an inverter, a motor, and a compressor. The inverter converts DC power from the high-voltage battery into three-phase AC power, which is then fed to the motor to drive it. The compressor is a scroll type, directly connected to the motor, which directly controls its operation. Since the inverter and motor generate high temperatures during operation, the compressor uses the refrigerant it draws in to cool it.
The electric compressor system consists of multiple precision components. The motor serves as the power source, driving the rotor inside the compressor, which in turn compresses the refrigerant. A high-voltage plug and interlock ensure a secure and reliable connection to the high-voltage power supply (typically 350V DC), essential for the proper operation of the electric compressor. The system also features a low-voltage plug, providing a stable 12V power supply to the control module and a 0V ground connection, ensuring circuit stability and safety.
New Energy Vehicle electric compressors commonly use electric scroll compressors, primarily consisting of a housing, an electronic control unit, a motor stator and rotor, an orbiting scroll, and a stationary scroll (as shown in the figure below). Among them, the rotating groups of the dynamic and static scrolls form several pairs of crescent-shaped cavities, which respectively form the suction chamber, compression chamber, and exhaust chamber of the scroll compressor. In addition, for the electric scroll compressor with three pairs of crescent-shaped cavities, there is a pair of suction ports, a pair of suction chambers, a pair of compression chambers, an exhaust port, and an exhaust chamber in each cycle.
Advantages
1) High efficiency and energy saving, high reliability. Suction, compression, and exhaust are carried out continuously in one direction; there is no gas leakage during piston compression, and the shaft seal adopts a flexible mechanism with low friction.
2) Simple structure, small size, and light weight. The volume is 40% of that of the plunger compressor, and the mass is 85% of that of the plunger compressor.
3) High volumetric efficiency. Because there is no suction valve, the gas is continuously compressed in multiple chambers, so the volumetric efficiency is high, which is particularly suitable for variable frequency speed control motors.
4) Small starting torque, low noise, and low vibration. The multiple crescent-shaped spaces within a pair of scrolls can simultaneously compress, creating a multi-chamber continuous compression system. Several working cycles with different phases operate simultaneously, with the peaks of the preceding wave coinciding with the troughs of the following wave. This minimizes drive torque variations and ensures smooth compressor operation. Because exhaust is continuous, mechanical impact on the exhaust valve and airflow pulsation are virtually nonexistent, resulting in noise levels 3-5dB lower than those of other compressor types. The moving parts perform circular motion in a very small radius, resulting in minimal inertia and vibration.
