OEM & Lieferant - Ausgabe 1/2021

74 Innovations Supports electrification of the powertrain Increasingly, OEMs employ electrification methods such as 48-volt electrical systems in order to improve engine efficiency and meet emissions targets. BorgWarner´s new eBooster supports them in attaining these goals and also provides optimized transient re- sponse as well as a significant torque increase at low speed. Combined with the eBooster, which improves charging at engine partial load, the turbo- charger can be designed specifically for full load operation. This leads to improved gas exchange, lower backpressure in the exhaust manifold and improved engine performance. Launch of the second generation of the eBooster Since being introduced in 2017, the eBooster has been enhanced continually. The second generation distinguishes itself by a significant increase in performance and improved operat- ing efficiency. While the first generation of the electrically driven 48V compressor allowed a transient boost of only 5 kW max. for 20 sec- onds per minute, the Gen 2 eBooster now en- ables both higher peak performance of 7 kW and continuous usage with 2.5 kW. Series production for the second generation eBooster began in early 2020 and the new product features a number of further improve- ments; including a connection between power electronics and stator with reduced resistance for better efficiency and a rigid rotor designed for higher speeds. An advanced compressor with reduced inertia provides improved tran- sient behavior, the new EMC filter is designed for less power losses and an enhanced filter effect. Uninterrupted operation is ensured by model-based software component protection and a microcontroller with added computing capacity for Field Oriented Control (FOC). Both generations utilize a permanently ex- cited synchronous motor (PMS), which already provided benefits for the first generation such as significantly improved NVH and engine re- sponse along with higher torque density and optimized efficiency. The PMS also allowed to considerably reduce the energy requirement during acceleration compared to a traditional reluctance motor. In its latest generation of the eBooster model BorgWarner has improved the performance even further by reducing the moment of inertia of the rotor and compressor which allows for lower power usage and faster spool-up. In a detailed comparison figure and table illustrate similarities and differences be- tween Gen1 and Gen2. Sinusoidal commutation provides more power In order to increase the performance of the second generation electrically driven com- pressor for continuous operation, BorgWarner relies on sinusoidal commutation. Compared to block commutation it reduces eddy current losses in the electric engine and also offers a smoother transition with less ripple, whereas block commutation produces faster variations. Permanent boost from model-based compo- nent protection, faster current and speed con- trol, over-current protection for the hardware and software as well as current measurement BorgWarner Introduces Next Generation of the Electrically Driven Compressor eBooster By Dr.-Ing. Hermann Breitbach, Vice President Fuel Injection System Engineering, Dr.-Ing. Ralf Christmann, Director Product Development PC Turbochargers, Dipl.-Ing. Dietmar Metz, Technical Specialist eProducts, Borg Warner BorgWarner´s eBooster has undergone crucial development stages. Due to its compact size, the robust compressor is suitable for smaller engines. In addition, it features improved NVH behavior, higher efficiency as well as optimized performance. S H A R E Graphics: © BorgWarner Gen1 vs. Gen2 eBooster cross sections