E-Mobility Engineering 014 l InoBat Auto dossier l In Conversation: Brandon Fisher l Battery monitoring focus l Supercapacitor applications insight l Green-G ecarry digest l Lithium-sulphur batteries insight l Cell-to-pack batteries focus

Module aimed at 900Vpowertrains NXP Semiconductors is working with Hitachi on a power module using 1200 V SiC transistors (writes Nick Flaherty). The collaboration combines NXP’s GD3160 isolated gate driver and Hitachi Energy’s RoadPak SiC half-bridge power modules for faster development of efficient, reliable and functionally safe EV powertrains using 900 V battery packs. The RoadPak uses 1200 V SiC MOSFETs, integrated cooling pin-fins and low-inductance connections in a form factor of 110 x 69 mm with a height of 17.35 mm, although the recommended clearance is 6.9 mm. Variants rated at 580, 780 and 980 A support applications from e-buses and electric passenger vehicles to high- performance Formula E racecars. The GD3160 is a single-channel high-voltage isolated gate driver that supports SiC MOSFETs up to 1700 V. It has ±15 A of gate current drive capability and a fast DeSat block, which can detect and react to short-circuits in the MOSFETs in less than 1 µs. The gate driver is programmable via the Serial Peripheral Interface (SPI), and adds protection and fault reporting features such as 2LTO, Soft Shutdown (SSD), DeSat Threshold, and over- temperature warning. It also includes power device temperature sensing and functional safety features such as analogue built-in self-test, and a comms watchdog circuit that continually checks the comms link to meet the requirements of ASIL-C or ASIL-D functional safety. A half-bridge evaluation kit is populated with two GD3160 single-channel IGBT/ SiC MOSFET gate drive devices, one to drive each RoadPak module. The kit includes the Freedom KL25Z microcontroller hardware for interfacing a PC installed with Flex GUI software for communicating with the SPI registers on the gate drive devices in daisy chain or standalone configurations. The GD3160 translator board is used to translate 3.3 V signals into 5.0 V signals between the microcontroller and MC33GD3160 gate drivers. “By pairing the GD3160 with Hitachi Energy’s RoadPak SiC module, we’ve delivered a solution that aims to reduce the transition time from the evaluation to the performance optimisation of SiC MOSFETs used in traction inverters,” said Robert Li, vice-president and general manager of NXP’s Drivers & Energy Systems product line. POWER TRANSISTORS Waxworkswell for conducting heat Researchers in the US and China have developed an economic but efficient battery thermal management strategy using paraffin wax (writes Nick Flaherty). The 3D, interconnected, thermally conductive boron nitride network greatly improves thermal conductivity compared with random distribution. “We designed a 3D network of boron nitride, and systematically studied its effect on the thermal management performance of power cells,” said Professor Bing Zhang of Zhejiang University in China. The sheets of hexagonal boron nitride (h-BN) were homogeneously dispersed in an aqueous solution of polyvinyl alcohol to form a suspension. The suspension was then poured into a square mould with a copper bottom surrounded by polymethyl methacrylate to achieve unidirectional growth by freezing the mixture using liquid nitrogen. The h-BN sheets were then squeezed by the growing ice crystals to form an ordered and interconnected network. After further freeze-drying to sublimate the ice, an h-BN aerogel with rich pores and a highly ordered structure was obtained where the connected h-BN sheets THERMAL MANAGEMENT The RoadPak module uses 1200 V SiC MOSFETs 7araffin wa_ can be cooled in a way that enables a + thermal management material to be created 10 Summer 2022 | E-Mobility Engineering