How Can Range Be Improved in Cold Weather?
We’ve all read about how some EVs can lose a significant amount of range in the winter. Unlike gasoline vehicles, which can use waste heat from the engine to heat the vehicle’s cabin, electric cars are so efficient that they have to generate their own heat. Plus, EV batteries need to be at the right temperature to deliver their peak performance. That’s why temperature control for an electric car – both for the cabin and its motive components – is an essential factor in vehicle range.
An electric car relies on a thermal management system to ensure that the cabin is pleasantly cool in summer and warm in winter for its occupants. An EV also uses thermal management to ensure that the motors, power electronics, and battery are at the right temperature to deliver their best. Recently, industry supplier ZF showed an integrated thermal management system that uses a central unit to control all thermal process for both the cabin and the drivetrain.
Propane-Based EV Thermal Management
Using a propane-based 800-volt heat pump, ZF’s TherMaS central thermal management system was shown in a modified Porsche Taycan. Its integrated design significantly reduces both the weight of the thermal management hardware as well as the space required compared to previous heating and cooling systems for electric cars – meaning it can be easily integrated into a number of vehicle sizes and formats. The propane-based heat pump also requires significantly less energy than previous solutions, leading to improved efficiency and range.
The TherMaS concept integrates three separate heating and cooling components. At the center of it all is a tiny refrigerant unit that is pre-filled and hermetically sealed; that mean’s it’s maintenance free. There are also no interfaces to other vehicle components like the interior, making installation and service simple. Propane, which is fluorine-free, is used as the refrigerant. It’s efficient and only half as much is needed as prior refrigerants, even though cooling capacity is twice that of other systems.
The central refrigerant circuit serves two separately-controllable cooling circuits I which frost-protected water flows, like in conventional heating and cooling systems. The first circuit is used for the comparatively high temperatures of the EV motor, while the second is used to regulate the temperature of the charging and power electronics. Intelligent control software manages the cooling capacity.
Up to a Third More Range and Performance
ZF claims that thanks to the significantly improved efficiency of its integrated approach, it could improve the range of an electric car by up to a third, especially when operating in winter. The TherMaS system also has significantly better cooling performance, which simultaneously makes it possible for electric motors to deliver higher continuous output and improved performance.
