Increasing efficiency of ecological vehicles by integrating auxiliary units directly to the driven shaft

Kurzfassung

The climatisation requirements of Electric Vehicles (EVs) largely depend on its usage location. For example, EVs operated in European countries require heating only during the winter season. Meanwhile, EVs operated in equatorial regions face cooling load throughout the year. To date, the low range for a given battery charge remains the single-most important factor that hinders the widespread acceptance of EVs. The high-power electrical loads as a result of the traction, heating systems and air-conditioning compressor motors results in rapid battery drainage leading to poor performance. This study addresses the issue by integrating the traction and air-conditioning compressor motors into a single unit. The integrated unit is expected to operate close to 100 % efficiency during recuperation mode. This is attained by direct mechanical coupling between the traction motor and the air conditioning compressor during breaking events. The mechanical configuration of the unit is such that it provides the flexibility to independently control the torque and speed characteristics of the compressor and traction at other operating modes. In addition to improved efficiency, the integrated unit will have numerous other advantages such as increased reliability, compact design and weight saving. The reduction of the parts is an important factor to introduce electric vehicles into the market and could be reached by integrating more functions into the drive motor.