Drives & Controls September 2022

n TECHNOLOGY September 2022 www.drivesncontrols.com 18 BECKHOFF HAS developed a software tool that makes it possible to use linear motors for precision applications such as milling or laser- cutting machines. The software uses machine learning to compensate for the uneven cogging forces that have previously limited the use of linear motors in these applications. The unwanted cogging forces are caused by the magnetic attraction between the iron core in the motor’s primary and the permanent magnets in the secondary. The new software takes into account not only these magnetic effects, but also those of energy chains and the application’s mechanical design. As a result, it expands the range of potential applications for iron-core linear motors “significantly”, says Beckhoff. The compensation tool is based on the automated application of machine learning in Beckhoff’s TwinCat software and is designed to be used with the company’s AL8000 linear servomotors. The software records the cogging data in an application during a reference run over the entire length of the motor’s magnetic track. Using this data, it trains a neural network, which is integrated with the control system for current pre- control. By adapting the current pre-control in this way, the lag error can be reduced by a factor of up to seven, while the synchronisation of the machine is increased up to five-fold without needing any hardware changes to the linear motor. www.beckhoff.com/en-gb Machine learning tool compensates for cogging in linear motors p Toshiba Electronic Devices & Storage has launched a third generation of silicon carbide (SiC) Mosfet power devices that it says will raise the efficiencies of electronic equipment such as power supplies and inverters. The TWxxNxxxC devices reduce on-resistance per unit area by about 43%, cutting switching losses by about 20% and lowering on-resistance. There are ten versions so far: five rated at 1200V and five at 650V. Toshiba plans to expand the line-up and enhance its production facilities. https://toshiba.semicon-storage.com/ ap-en/top p igus has launched a high-performance plastic for use in its igubal food contact joint system that it claims is three times more wear- resistant than its predecessor, 25% cheaper, solvent-free, maintenance-free, hygienic and FDA and EU 10/2011 compliant. The iglidur A181 material is intended for use in spherical balls that improve the hygiene of food industry machines. It is up to 85% cheaper than stainless-steel alternatives and, because it incorporates a solid lubricant, it avoids the need for external lubricants that can bind with dirt to form sticky coatings and create a contamination risk. www.igus.co.uk p The German machine vision developer, SVS- Vistek , has launched what it claims is the highest resolution camera with a global shutter. Even on high-speed conveyors, the 127- megapixel CMOS global shutter sensor in the shr661 camera ensures distortion-free inspection of complex objects such as solar panels, PCBs and semiconductor wafers. It is available with a CoaXPress-12 interface that transmits 17 frames/second at full resolution (13,392 x 9,528 pixels), or a 10GigE interface for up to 6.5 fps. Other ultra-high resolution cameras rely on rolling shutter sensors that can distort moving objects. www.svs-vistek.com p A German EV systems specialist, hofer powertrain , is developing an inverter based on a gallium nitride chip technology from VisIC Technologies that is claimed to be more efficient that silicon or silicon carbide designs. The inverter is said to offer higher switching speeds in a smaller, lighter package, cutting system costs. The aim is to feed 100A rms sinsusoidal currents through inductive loads. hofer is planning “real-world” tests involving permanent magnet synchronous motors. www.hoferpowertrain.com p Two Swedish companies, the electric car- maker Polestar and the electric boat developer Candela , have signed an agreement under which Polestar will supply batteries and charging systems for Candela’s hydrofoil boats. The deal will allow Candela to scale up production, bringing mass-market electric boats closer to reality. The aim is to overcome two hurdles: the high cost of marine batteries; and the high energy consumption of conventional hulls that Candela claims to have tackled with its hydrofoil technology that cuts energy use by up to 80% while “flying” above the water at 30 knots. The companies are planning a broader partnership TECHNOLOGY BRIEFS Beckhoff’s machine-learning tool compensates for cogging forces in precision linear motor applications SKF HAS DEVELOPED a low-friction, deep- groove ball-bearing for electric motors that supports high rotational speeds and enables higher power densities, leading to higher power outputs from the same-size motor. The hybrid bearing is aimed at applications such as electric machines and drives, as well as traction motors. A two-piece polymer cage pushes the bearing to new limits and gives more flexibility in the design choices. By allowing higher rotational speeds, it is said to operate more quietly and efficiently than bearings with conventional cages. The lightweight cage can boost the limiting speed by at least 60% compared to traditional brass designs, and twice as much as single-piece polyamide cages, according to SKF. The cage also helps to reduce friction, leading to quieter operation and higher power densities. “Our new cage design helps our customers to get more power from electric motors, which enables downsizing,” explains SKF business and project engineer, Andreas Pichler. By improving the efficiency of electric machines, the new bearing can cut energy consumption, increase reliability and cut the total cost of ownership. Its two-piece cage is 80% lighter than a brass cage. As well as running quietly, the bearing operates at lower temperatures, prolonging grease life and extending lubrication intervals. SKF has three pilot customers for the new bearings, all of them OEMs. www.skf.com Hybrid ball-bearing extracts more power from smaller motors