High-power integrated traction inverters must, like all automotive components, combine excellent performance with being as tiny and light as possible in order to convert DC into AC and gather energy for the automobile. In the cutthroat EV industry, distance and charging speed are essential factors. Compared to a traditional C-core sensor, the new HSTDR current sensor from LEM is significantly smaller and lighter, measuring only 29 mm by 21 mm by 12 mm and weighing only 27g. As a result, integrating it into inverter boxes with limited space is made significantly easier. The sensor makes it possible for traction inverters to operate as efficiently as possible by combining high accuracy, affordability, and the capacity to function in difficult settings. The sensor can withstand vibrations of up to 10G and has an operating temperature range of -40°C to +125°C. In order to provide more precise torque control, the HSTDR offers strong immunity to external field and cross talk as well as consistent behavior throughout frequency with minimal part-to-part phase shift dispersion. Open loop Hall effect technology and a cutting-edge magnetic core design enable this.
In addition to being 50% lighter, having a 50% better measurement range, and being 42% smaller than its predecessor (LEM’s HSNDR), the sensor offers best-in-class accuracy with a global error over temperature and lifetime of less than 3.5%. The sensor is suitable for 800V battery systems and ensures galvanic separation between the primary circuit (high power) and the secondary circuit (electronic circuit). It allows EV manufacturers the choice of having different current measuring ranges — from 300 A to 1500 A — in the same container. The only sensor for EV traction inverters, DC link, and 3-phase current measurement to incorporate an integrated busbar, starting with the previous HSNDR, fitting exactly into the smallest core aperture, was one way LEM’s designers were able to minimize the footprint of the HSTDR. EV producers and designers of automotive components will now have the freedom to drastically reduce the time it takes for their products to reach the market thanks to access to a fully calibrated package comprising core, busbar, and sensing element.