The recently launched BMW ActiveHybrid 7 (earlier post) uses a new lightweight electric AC compressor from Visteon Corporation. Visteon designed an integrated solution that meets the demands of hybrid and electric vehicles while maintaining the performance levels of traditional belt-driven compressors.
Air conditioning compressors are used to pump refrigerant through the climate system, cooling and dehumidifying the air for vehicle occupants. In conventional vehicles, the compressor is driven by the engine with a belt; therefore it can operate only when the engine is running. An electric compressor in a hybrid vehicle can operate independently, thus enabling the cabin to be cooled when the engine is off.
The electric compressor’s compact design fits the traditional belt-driven compressor package space, minimizing vehicle complexity in platforms that also offer hybrid-electric model variants. Visteon’s product includes the compressor, electric motor and inverter in an integrated, compact set of housings. This modular approach allows the same basic packaging dimensions for the electric motor and power electronics to be designed for either 120V DC or 288V DC applications.
Electric compressors also enhance passenger comfort. The cabin can be pre-conditioned before passengers enter, and can be cooled faster because of the independent operation from the combustion engine rpm. Also, cabin comfort can be maintained when the engine is idling or off.