The Importance of Thermal Management in Electric Vehicles

Key Takeaways

• The importance of battery thermal management in electric vehicles.

• The importance of power electronic system thermal management in electric vehicles.

• The importance of electric motors thermal management in electric vehicles.

Electric vehicles are taking over combustion engine vehicles. However, when electric vehicles first came out, there was a lot of confusion regarding their systems and maintenance. Today, the current trend in the automotive market shows that these doubts are lessening. Now, the most concerning problem that persists is the thermal management of electric vehicles. 

In conventional vehicles, thermal management is required to cool down the internal combustion engine. The thermostat, coolant, and radiator system remove heat from the engine. In electric vehicles, thermal management involves the cooling of batteries, power electronic systems, and the motor.  Let’s take a closer look at why thermal management in electric vehicles is so critical.

Thermal Management in Electric Vehicles 

The thermal management in electric vehicles powered by batteries is important in that it affects the performance, reliability, and robustness of these vehicles. Electric vehicles need optimal temperatures (neither warm nor cold) to run efficiently. The optimum temperature is essential for the proper working of the battery pack, power electronic systems, and motor in the electric vehicle. When maintained at an optimal temperature, the battery charge, health, and capacity are preserved. Power electronic systems and motors showcase their best working profile under optimal temperatures.

Let’s take a look at a few reasons why thermal management is so critical for electric vehicles. 

Battery Thermal Management

The performance, service life, and cost of the battery packs and electric vehicles have a direct dependency. The availability of discharge power for starting and acceleration, charge acceptance during regenerative braking, and the health of the battery are at their best at optimal temperatures. As the temperature increases, the battery life, electric vehicle driveability, and fuel economy degrade. Considering the overall thermal effect of the battery on electric vehicles, battery thermal management is critical. 

Thermal Management of Power Electronic Systems

Power electronic systems are responsible for controlling electric motors. Power electronic systems operate in line with the electric vehicle control system and drive the electric motor according to the control instructions. DC-DC converters, inverters, and control circuits in the power electronic system are vulnerable to thermal effects. While working, the power electronic circuits generate heat loss, and proper thermal management is essential to release the heat from the circuit and associated systems. If the thermal management is improper, it can result in control glitches, component failures, and vehicular mal-operations. Usually, the power electronic system is connected to the electric vehicle’s cooling system to maintain optimal temperatures. 

Thermal Management of Electric Motors

Since the wheel movement of electric vehicles is motor-driven, the working temperature of the electric motor is critical to the performance of the vehicle. With increasing load, the motor draws more power from the battery and heats up. The cooling of the motor is necessary for its full performance in electric vehicles.

Cooling Loop in Electric Vehicles

For a high level of efficiency in electric vehicles, optimal temperature maintenance is essential. The optimal temperature is regulated by the cooling system of the electric vehicle. Usually, the cooling system regulates the vehicle temperature, which includes the battery pack temperature, power electronic-based drive temperature, and motor temperature. In the cooling loop, a coolant is circulated using an electric pump to cool the batteries, electronics, motor, and related systems. In electric vehicles, radiators are used in the cooling loop to release heat to the ambient air. The air conditioning system is used in electric vehicles to cool down the systems within the cooling loop and evaporators are incorporated to remove heat from the cooling loop.

The thermal management in electric vehicles adapts to external-internal temperature conditions and regulates optimal temperatures in battery packs, power electronics drives, and electric motors. Thermal management is crucial, as it impacts an electric vehicle’s driveability and safety. Cadence offers processors that can address the most critical automotive problems and safety requirements. And, to see what Cadence’s Celsius Thermal Solver can do, please check out the video below.

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