ISSUE 012 Winter 2021 Sigma Powertrain EMAX transmission dossier l In conversation: David Hudson l 48 V systems focus l 2021 Battery Show North America and Cenex-LCV reports l Everrati Porsche 911 digest l Switching insight l Motor laminations focus

speed control, current measurement of all three phases, 40 µs cycle time of the P1 controller, 28 kHz pulse width modulation (PWM), overcurrent protection for the hardware and software, and permanent boost from model-based component protection. For 48 V systems under load and with a reasonable state of charge, the voltage is normally at 42 V. The limits at low voltage and higher speed can now be increased by 55% for a short time through the positive effect of the field weakening. For enhanced component protection, the Gen2 e-booster’s PCB has three negative temperature coefficient sensors to measure coolant temperature in key areas along with the power electronics part of the PCB. A software model is used to measure these critical temperatures through the sensors. This allows intelligent derating of the e-booster to protect components based on the highest tolerable temperatures in critical areas. This temperature model will protect components from excessive thermal loads, even during heavy use. Calculated temperatures are transferred into a range of percentages that are used to develop a utilisation index, with the highest temperature setting the index percentage, which is conveyed to the electronic control unit through a CAN interface. Temperature warnings and an overtemperature alert can then be raised according to the index. The e-booster can also be used for commercial vehicles with engines up to 5 litres. The additional combustion air that can be added through this boosting technology now makes it possible for medium-duty engines to replace those that are 50-60% larger without losing power or torque, while maintaining and even improving transient behaviour. Battery pack monitoring Managing a 48 V lithium-ion battery pack is a critical task, as there is less design margin compared with high- voltage packs. The 48 V packs can have between four and 14 cells model-based software component protection for uninterrupted operation. Another important upgrade in the second generation is the use of sinusoidal commutation in place of a block commutation. Sinusoidal commutation provides a smoother transition and generates fewer ripples in the current compared with more rapid variations with a block commutation. Sinusoidal commutation also enables lower eddy-current losses in the electrical motor to deliver higher peak power and continuous operation of the e-booster. From the DC voltage, a three-phase commutation with variable frequency and amplitude is generated to drive the motor, and a sensorless FOC algorithm is used to generate signals for the switches of the three half-bridges of the power output stage. For operation points at very low voltage or at high speed with reduced torque requirements, FOC enables the motor to operate in a field-weakening area by splitting the phase currents into two vectors, a field generating current (I d ) and a torque generating current (I q ). This also supports faster current and Some suppliers of 48 V systems France Valeo +33 1 49 45 32 32 www.valeo.com Canada Dana +1 450 645 1444 www.danatm4.com Germany Avnet +49 8121 777 02 www.avnet.com CSM +49 711 779640 www.csm.de Elmos +49 231 75 49 0 www.elmos.com FEV +49 241 5689 0 www.fev.com In ineon +49 89 234 0 www.in ineon.com SEG Automotive +49 711 4009 8000 www.seg-automotive.com Vitesco +49 941 2031 0 www.vitesco-technologies.com The Netherlands NXP +31 40 272 9999 www.nxp.com Switzerland STMicroelectronics +41 22 929 2929 www.st.com Taiwan Yageo +886 2 6629 9999 www.yageo.com USA Eaton +1 269 342 3000 www.eaton.com Vicor +1 630 795 1417 www.vicor.com Focus | 48 V systems A 48 V e-compressor (Courtesy of BorgWarner) 36 Winter 2021 | E-Mobility Engineering