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

“By the International Annealed Copper Standard conductivity measure, pure copper with a low residual phosphorous content is the most conductive, at 100%, but least strong in terms of MPa, with most manufacturers of electro-deposited foils quoting around 300 MPa,” Thorben Beckman said. “Schlenk offers Cu HCP deoxidised oxygen-free copper, also called SE-Cu, for which we quote a strength of more than 360 MPa.” Schlenk’s high-tensile foils split the difference with strengths from 500 to 750 MPa and conductivities from 86% down to about 60%. They are available as thin as 0.010 mm, or thinner on request. Further alloys with new features are in r&d to optimise the conductivity and thermal stability for special coatings with elevated process temperatures. They can also be supplied in the company’s battery sample kit along with pure copper and pure nickel foils with different surface degreasing and passivation, all in 100 m-long rolls for testing in new battery designs. The HV Breakout Module 1.2 is inserted directly in series with the power cables between the battery and the inverter to measure current and voltage at a 1 MHz data rate. The HV Breakout Module 3.3 is inserted in the same manner into the AC cables between the inverter and the motor to measure the three-phase current and voltage at a rate of 2 MHz per variable. These new, ‘C’ variants introduced at the show have PowerLok connectors enabling quick connect and disconnect for efficient changeover in test benches or vehicle instrumentation. The HV Breakout Module 3.3 acquires and synchronises data from EtherCAT and CAN bus modules, and carries out Precision Time Protocol (PTP) synchronisation. “At the same time, the CAN-based HV PTMM2 or HV THMM4 modules measure temperatures in the inverter and motors, and CNT4 evo can include data from speed and torque sensors at the motor shaft,” explained Tom Doerr. “Thus the efficiencies of the powertrain can be analysed with minimal instrumentation.” To expand the Vector CSM e-mobility measurement system, data from the ECU is recorded and synchronised via PTP using a Vector VX1000 interface. This enables the Vector CANape or vMeasure exp software to carry out the real-time efficiency analysis, drawing on the included eMobilityAnalyser function library, evaluating onboard three-phase AC chargers, determining power, energy and ripple on DC voltage and current and DC efficiency, as well as mechanical power and efficiency. Reliable battery performance requires accuracy and consistency in manufacturing, which demands continuous measurement of electrode material thickness during production of the electrode roll. This is the function of Honeywell’s showcased lithium-ion battery optical caliper sensor, which uses a chromatic confocal displacement sensing system to measure the material’s total thickness during the coating and pressing steps. The thickness and weight of the coating on both sides have a major impact on the pore structure and, consequently, the battery’s electrochemical performance. With an accuracy to within 1 micron, the sensor’s head features temperature control and air purging to maximise measurement stability, while a 10 mm head gap eases product threading and a 7 mm measurement range enables it to cope with fluctuations in line tension and to measure thicker material. Schlenk presented its latest high- tensile rolled copper alloy foils offered as current collectors for high-power batteries that use anode coatings with a significant silicon content, the expansion of which can impose higher mechanical stresses inside the battery. The greater strength helps improve the stability of advanced battery coatings and helps avoid microcracking in the copper substrate. Schlenk pointed out that there is an inverse relationship between strength and electrical conductivity in copper alloys. ShowReport | Battery Show North America 2021 Honeywell’s lithium-ion battery optical caliper sensor Chart showing the relationship between strength and conductivity in copper alloys 44 Winter 2021 | E-Mobility Engineering