The HVAC (heating, ventilation, air conditioning) system in electric vehicles serves multiple functions related to heating and cooling processes. These processes ensure passenger comfort and optimal conditioning of the battery system and other electric components, either directly or indirectly. Several temperature and pressure sensors monitor the refrigerant cycle, which enables the control unit to regulate the entire system via different valves. Consequently, the HVAC system plays a significant role in the vehicle’s complex thermal management system. 

TDK solution

TDK offers reliable and robust sensor systems for various applications that monitor the refrigerant cycle. 

Suitable products

 Temperature Sensores 1  Temperature Sensores 2 Pressure-Temperature Sensors 

It is important to monitor ambient temperature conditions to provide essential information for controlling passenger comfort and achieving optimal battery thermal regulation. 

TDK solution

TDK offers robust, well-established sensor systems designed to accurately track outside temperature. These sensors can be integrated into vehicle bumpers or exterior mirrors.

Suitable products

To increase EV range, multiple heating and cooling applications must be efficiently combined to ensure passenger comfort. These applications use the vehicle battery as their only energy source. 

Therefore, the key to achieving both a long range and the best passenger comfort is to monitor and control the various applications within an optimized thermal management system. 

TDK solution

TDK offers a wide range of proven sensor systems designed to track the temperature of air flowing into vehicle interiors. In addition, the company provides temperature sensors for monitoring applications such as heated steering wheels, seat heating, and other dedicated heated surfaces in electric vehicles. 

Suitable products

PTC Heaters

Navigation software in electric vehicles estimates the car’s driving range by considering the speed limits along the route. Highways, especially those without speed limits, are excluded because air resistance increases with the square of velocity. To maximize the range without limiting the cruising speed, air resistance must be minimized. This can be achieved by mechanically closing the radiator openings, folding the mirrors, or extending the spoilers. 

TDK solution

TDK's HVC 5x family of Arm® Cortex® M3-based embedded motor controllers is designed for brushed DC (BDC), brushless DC (BLDC), and stepper motors used in applications such as radiator grill shutters, valves, flaps, and spoilers. The HVC 5x family enables complex motor control algorithms, including field-oriented control (FOC) and space vector modulation (SVM) for permanent magnet synchronous (PMS) motors. This helps design engineers achieve highly efficient motor operation while reducing acoustic noise and vibration. Additional features include six-step commutation with or without sensor feedback (sensorless), and various stepper algorithms with current limiting and stall detection. The GPIO application interface enables the integration of sensors for high-precision motor control. 

Suitable products

To maximize the range of electric vehicles (EVs), car manufacturers are focusing on two things: optimizing energy efficiency and increasing battery capacity. However, this presents new challenges for EV thermal management systems because the battery, charging system, power inverter, and motor have different ideal operating temperatures. Additionally, individual passengers have different preferred temperatures. 

TDK solution

Every location requires thermal sensors to measure local temperatures. Thermal valves are also necessary for routing and controlling the cooling and heating fluids. TDK has developed sensor and motor control solutions for these tasks, including temperature sensors, 3D position sensors that are robust against stray fields, and small, LIN-controlled motor actuators.

Suitable products

 Position Sensors Embedded Motor Controllers

Thermal valves for refrigerant distribution are becoming more common in hybrid-electric and fully electric vehicles because many high-power applications have different thermal needs at different times. These applications include cooling fast chargers when the vehicle is stationary, heating or cooling the interior while the vehicle is parked, cooling engine-control inverters and electric motors while driving, and maintaining a constant battery temperature during charging and driving. 

TDK solution

TDK has developed position sensors and motor controllers for thermal valve applications. The HVC 5x controls the positioning of motors in thermal needle valves and supports advanced motor control such as FOC, enabling smooth, precise, and silent operation. The HAL 39xy is a 3D HAL position sensor that accurately detects rotary and linear movements. The HVCs integrate the power supply, microcontroller, LIN transceiver, motor driver, and sensor interfaces into one single package by the HVCs, reducing system complexity and component count. High-voltage and high-current applications in EVs benefit from Hall-effect sensors that are immune to stray fields. 

Suitable products

 Position Sensors Embedded Motor Controllers

Properly monitoring the battery coolant temperature is essential for determining the operating condition of the battery and ensuring safe and efficient operation. Inadequate monitoring can result in wear and tear on system components, a reduced service life, or even component failure. In the worst case, severe overheating can cause the battery to catch fire. 

TDK solution

Pipe-mounted sensors, also known as “clip-on” sensors, measure the coolant temperature. Since they are attached to the outside of the pipes, they do not require additional sealing to prevent coolant leaks. This provides more flexibility in designing the piping system and installing the sensors than solutions that require a mounting hole. The sensors’ dimensions and electrical parameters can be customized to meet specific customer requirements. 

• Clip-on design
• Serviceability
• Fast and reliable mounting and dismounting
• No leakage issue 

Suitable products

High-voltage batteries operate most efficiently within specific temperature ranges. Reliable monitoring and control of the battery temperature prevents overheating, extending the battery’s service life and increasing safety. To accomplish this, the temperature of the battery must be measured at multiple points to detect localized overheating. 

TDK solution

TDK has developed temperature sensors that ensure optimal thermal contact with the battery surface. A ring tongue made of a battery-compatible material allows for easy attachment. In the spring load series, an external spiral spring, flat spring, or plastic hook presses down on the battery surface. This intelligent mounting solution compensates for interface tolerances, ensuring excellent thermal contact throughout the product's lifetime. 

• Ring-tongue, spring-load, and temperature-sensor design
• HV strength and humidity resistance
• Smart mounting concept for temperature offset reduction  

The PTC SMD temperature limit sensors are designed for SMD sizes 0402, 0603, and 0805. They are a reliable and space-saving solution that can be used for automated production lines. 

• Small dimensions
• Fast and reliable response
• Reflow soldering possible
• Suitable Products

Suitable products

 Temperature Sensors SMD NTC Sensors PTC Sensors PTC Heaters

Efficient battery management is essential for hybrid and electric vehicles (xEVs). The most important function of battery monitoring is to accurately determine the battery's status at all times. To maximize the range, charging and discharging currents must be measured precisely and reliably. High-voltage (400 V/800 V) batteries in xEVs require galvanic isolation for current sensing and a very high level of safety integration. 

TDK solution

TDK has developed a current sensor solution for battery management in xEVs. Its Tunnel Magneto Resistance (TMR) technology enables contactless current sensing and provides galvanic isolation from the high-voltage battery supply. The coreless system design reduces the module’s weight and size. The CUR 423x is designed for precise current sensing in safety-critical applications. 

Suitable products

Electric motors operate most efficiently at temperatures around +100 °C. At higher temperatures, however, motor performance deteriorates rapidly. Therefore, temperature sensors are used to regulate electric motors. These sensors also protect the stator winding from overheating and prevent damage to the motor insulation. Such sensors must respond quickly to temperature changes, withstand demanding mechanical and environmental conditions, and offer a mounting concept that reduces integration efforts. 

TDK solution

TDK temperature sensors feature a simple, smart clip-and-interlock system that ensures fast sensor integration. No additional gluing or fixing is necessary. These sensors are resistant to ATF oil and offer high dielectric strength and excellent thermal conductivity. TDK also offers alternative sensor encapsulation materials, such as hard or soft housings, to simplify integration for customers. 

• Easy mounting and dismounting
• Robust locking system
• Excellent thermal conductivity
• High dielectric strength
• ATF resistance
• Suitable products 

Suitable products

Inverters operating in high-voltage systems are subject to high loads. These increased loads can lead to overheating, which can degrade the system’s overall performance. To ensure optimal performance, inverters must be temperature-controlled and actively cooled. Protecting sensitive power electronics from overheating is also essential for maximizing the service life of the inverter.

TDK solution

The TDK portfolio includes a series of NTC temperature sensors with ring tongues for controlling the inverter temperature. The way the sensor is mounted ensures good thermal coupling and a low temperature offset. Additionally, TDK sensors are validated to operate under high-voltage conditions. 

• Easy and flexible mounting
• High dielectric strength
• Good thermal coupling
• Fast response time
• Compatible with different surfaces

Suitable products

Vehicle inlet connectors are exposed to high temperatures during the charging process. To ensure reliable temperature monitoring and prevent overheating, the International Electrotechnical Commission (IEC) stipulates that temperature sensors used in connector systems must meet the minimum requirements of IEC TS 62196-3-1. For this reason, a reliable measuring accuracy with a narrow temperature tolerance is an essential requirement for temperature sensors. 

TDK solution

The K862 series features a miniaturized design. The small ceramic housing of the sensor enables optimal connection to the connector pins’ surface and ensures excellent thermal contact. The sensors are also designed for a high AC voltage of up to 4 kV. 

• Miniaturized design
• High dielectric strength
• Excellent thermal conductivity 

PTC SMD limit temperature sensors have been developed in the following SMD sizes: 0402, 0603, and 0805. These reliable and space-saving sensors can be used for automated production lines. 

• Small dimensions
• Fast and reliable response
• Reflow soldering possible
• Suitable products 

Suitable products

 Temperature Sensors SMD NTC Sensors SMD PTC Sensors