In current days electric vehicles (EVs) are being promoted on significant scale through various government initiative as a zero-emission means of transport. However the major hurdle for wider customer acceptance of EVs are being comparatively expensive, lack of charging station infrastructure and ambient based limited driving range. It is known that Heating Ventilation and Air Conditioning (HVAC) system is major contributor in overall power consumption of electric vehicles. The HVAC system architecture and working logics in EVs are different from the one in fuel based vehicle. This calls for the different control strategy and logics such that HVAC system will work in manner which provides passengers thermal comfort as well as able to manage the overall power consumptions
Our work discusses above the operation and working logics of various HVAC components which ensures occupant thermal comfort at various ambient conditions with minimum stress on power consumption and thus optimizing the range at various ambient conditions. The control strategies on electric compressor are on the basis of optimum cooling capacity and power consumption over the range of operating speeds. Compressor operation is integrated with the Fully Automatic Temperature Control (FATC) system and battery cooling request to main control unit which ensures sufficient cooling and durable life.
Other components of HVAC system like PTC heater and solenoid valves are activated and deactivated through various individual strategies to ensure its operations only when there is optimum requirement. There is control strategy for condenser fans for operating it at different speeds based on the heat rejection requirements across the condenser. Thus instead of under-performing the whole HVAC system to reduce the power consumption, a complex matrix of various strategies on each component level would ensure optimizing the range of vehicle, providing sufficient cooling performance and durability of all components. This paper describes various aspects which influences the overall climate control strategies for electric vehicles and their impact on HVAC system performance.