Continental has developed new sensor technology for permanently excited synchronous motors in electric vehicles (EVs). This technology measures temperature directly on the rotor for the first time.
The e-Motor Rotor Temperature Sensor (eRTS) provides more precise results than current software-based temperature simulations, according to Continental. It reduces the tolerance range from 15°C to only 3°C.
This precision allows vehicle manufacturers to reduce rare earth usage in motor magnets. It also helps improve potential motor performance and enhances sustainability.
The E-Mobility Sensors (EMS) product center developed eRTS and other EV sensor technologies.
Lower Costs and Resource Use Through Precision
“With less resource consumption and lower costs, eRTS sensor technology is advantageous to current solutions,” says Bin Huo.
Huo is head of the Passive Safety and Sensorics (PSS) segment in Continental Automotive.
“This innovation shows that investing resources and focusing expertise in our product center were the right decision. We will continue to successively expand our EV sensor portfolio,” Huo adds.
EV rotors face extreme conditions, reaching temperatures up to 150°C. Therefore, engineers must monitor and control EV motor temperature development. Currently, systems do not measure heat directly.
They estimate it using stator temperature sensors, phase current and environmental variables. This method results in a tolerance range up to 15°C.
Material Savings and Design Freedom to Reduce Rare Earth Usage
Manufacturers use rare earth elements to prevent magnets from demagnetizing due to high temperature. These materials ensure magnets remain heat-resistant within the wide tolerance range.
By reducing the tolerance range to 3°C, eRTS increases measurement accuracy. This allows manufacturers to reduce rare earth usage while maintaining safety and reliability. They gain more design freedom in EV motor development, and reduce material cost and complexity in magnet production.
They can also explore higher performance by safely pushing motor temperature limits.
Enabling Sustainability Across the EV Supply Chain
“Our E-Mobility Sensors product center aims to increase efficiency and sustainability in electric vehicles,” says Christoph Busch, who leads the E-Mobility Sensors product center.
“The eRTS technology is a good example of this: reducing the use of rare earths contributes to a more sustainable supply chain, especially given that the number of EVs is expected to greatly increase in the coming years and decades. In combination with other sensor technologies, such as the e-Motor Rotor Position Sensor, it can even act as a system solution to create synergies that can save car manufacturers money and effort,” Busch adds.
