As the global electric vehicle (EV) market grows rapidly, so does the call for improved and efficient thermal management systems in those vehicles. The heat produced by the battery must be controlled and dissipated while also ensuring protection from external conditions. Controlling heat dissipation in electric vehicles increases battery performance and life, prevents thermal runaway, and ensures more range and comfort. Let’s take a closer look at the various aspects of an efficient thermal management system in electric vehicles.
The Ideal Thermal Management System in Electric Vehicles
As per a recent study by the American Automobile Association, ambient temperature affects the overall range of a battery electric vehicle (BEV). Adverse weather conditions pose a challenge for electronic components in terms of optimal performance. In this regard, an intelligent thermal management system must adequately direct heat or cold to exactly where they are needed inside the system. This is achieved by creating a perfect interplay between the refrigerant and coolant systems of the vehicle.
Here is a typical block diagram of the Bosch thermal management system featured in hybrid electric vehicles today:
This very basic model offers enough scope for customization given the placement flexibility of the circuit elements.
To paint a broader picture of their significance, here’s how engineers optimize thermal management systems in EVs under various weather conditions and operating situations:
In winter, sufficient heat is required by the vehicle’s interior and battery. To meet the former requirement, engineers use heat pumps and further improve heating efficiency through a waste heat recovery system. Failing to properly utilize the wasted heat puts more pressure on the heat pump, draining the battery in the process.
On the flip side, vehicle interiors and batteries require cooling during the summer. A refrigerant circuit keeps the interior cool and further chills the battery via a chiller. The electric drive and other high-voltage hybrid systems attain the desired temperature through radiators separate from the battery. This ensures unlimited cooling and energy efficiency.
Fall and Spring
In moderate temperatures, the cooling circuit keeps the battery and hybrid drive cool by dissipating the extra heat generated out into the environment. As a result, the system draws less energy for thermal management which directly influences the efficiency and range of the vehicle.
In a normal charging environment like home or at work, a vehicle makes use of an alternating current to charge its battery. The battery and the charger that converts the alternating current to a direct current are cooled by the cooling circuit and module.
Fast charging in harsh weather conditions can also cause the system temperature to rise. The ideal thermal management system transfers the air conditioner’s full cooling power to the battery refrigerant circuit via the chiller.
PCBA Manufacturing for Extreme Environments - Part 1
Necessary Components of an Intelligent Thermal Management System
A coolant pump is a centrifugal pump designed to circulate and regulate coolant throughout the battery or engine block. Its goal is to provide enough coolant supply for the respective cooling situation. An integrated electronic motor circuit helps the motor regulate speed by offering diagnostic capability and controllability.
Coolant switch valves offer excellent flow distribution in the powertrain and vehicle interior to optimize temperature and increase comfort. The design requirement may recommend any of the two types of coolant valves—solenoid or air-operated. Moreover, the advanced version comes with a flexible placement option to meet any specific design requirement.
Brushless electric communicated (EC) motors efficiently drive heat out of the housing to optimize battery consumption and CO2 emissions. The EC drive also protects the motor from false triggers such as overvoltages and short circuit currents. As the aim is to optimize the thermal management system, motor materials must offer high resistance to environmental influences.
Electronic Expansion Valve (EEV)
EEVs guide the flow of refrigerants in the evaporator and make the thermal management system in electric vehicles work under optimized conditions. They are designed to offer energy-saving temperature controls for both heating and cooling modes.
Model Predictive Control (MPC)
Model Predictive Control (MPC) is an advanced process control algorithm that better addresses thermal comfort criteria in electric vehicles. The thermal management system in electric vehicles involves many components, and each one may have several operating modes. The MPC software decides their ideal functionalities via predictive algorithms. It can be used to control different, independent modules such as waste heat management or battery preconditioning to reduce charging times.
|Tempo‘s Custom Vehicle Electrification PCB Manufacturing Service
Choosing the right materials is instrumental for an efficient thermal management system in electric vehicles. An ideal strategy involves understanding the operating environment, modeling your system’s thermal behavior during design, and choosing the right materials accordingly. At Tempo Automation, our DFM feedback helps you select the right heat dissipation components for designing compatible PCBA systems for various driving cycles and conditions.
Tempo employs a white-box turnkey PCBA manufacturing process that promotes collaboration and transparency between engineers and CMs. This allows us to quickly deliver high-quality boards for both standard and non-standard designs that meet automotive industry criteria for prototyping and on-demand production. We also provide downloadable DRC files in Altium Designer, Cadence Allegro, Mentor Pads, other CAD formats, and Excel.