Published 5 August 2021

Sheffield-based SME Magnomatics has partnered with ORE Catapult to develop its state of the art in wind turbine generator technology by reducing the cost of the turbine and increasing the efficiency of the generator to reduce the cost of energy.

The Compact High Efficiency Generator (CHEG)

The Compact High-Efficiency Generator (CHEG) project was established in 2018 and delivered a 500kW pseudo direct drive (PDD) generator based around Magnomatics’ innovative magnetic gear technology. The PDD technology replaces the traditional turbine generator and gearbox with a single, magnetically-geared permanent magnet generator. As gearboxes are one of the most common sources of component failure in offshore wind, PDD technology could have significant advantages in terms of reliability and lower maintenance costs when scaled up to the size of current offshore wind turbines.

The Catapult’s research team has played a key role in the development, specification and concept model review of the generator, while our testing team are developing a rigorous programme to prove and demonstrate the prototype’s feasibility in our 3MW powertrain test facility. The project team has established a potential 2.9% reduction in the cost of energy through using the highly efficient system – which, along with lower maintenance costs, makes the switch to PDD generators an attractive prospect.

WIND Electric Revolution (WINDER) project

As part of the UK Research and Innovation (UKRI) Driving the Electric Revolution Challenge, Magnomatics returned to partner with ORE Catapult to complete further trials of its 500kW compact, high-efficiency generator, whilst exploring more efficient scale-up concepts and the potential for developing a long-term UK supply chain for full scale generators.

The novel component in this technology is a pole piece rotor (PPR), a cylindrical structure comprising multiple axial steel pole pieces within a non-magnetic composite structure. In operation these pole pieces are subject to significant forces and complex cyclical loads. The 500kW generator currently incorporates the largest PPR to date at 2m diameter, however, the construction techniques used for this can be expensive and labour intensive.

The WIND Electrical Revolution (WINDER) project takes this concept further by introducing new instrumentation installed in the generator and then extensively dynamometer testing to better understand the behaviour of the PPR under wind turbine loads and cycles. Using its 1MW drivetrain test rig, ORE Catapult both performed the test and validated the data, with further product validation set to be performed on concept designs, ensuring the PPR achieves the expected product lifetime of 25+ years.

The University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) – part of the High Value Manufacturing Catapult – is also providing Design for Manufacture input and support to Magnomatics for production of pole-piece rotors in much larger 20MW generators to further reduce the Levelised Cost of Energy.

ROBOMAG project

AMRC also worked with Magnomatics on the ROBOMAG project to explore how robotic technologies can optimise the manufacturing process and drive big productivity improvements for its wind turbine generators, which form part of its Pseudo Direct Drive (PDD) generator technology.

A labour-intensive process to position powerful permanent magnets onto large generators for offshore wind has been made 60 times faster by automation experts at the AMRC, cutting down the cycle time from one hour to just 55 seconds for each magnet. It is also the one of the first ever supply chain improvement projects to be funded by the Offshore Wind Growth Partnership (OWGP) and a great example of the UK’s innovative supply chain in action to be cost-competitive through advanced manufacturing techniques, and a key step in anchoring offshore wind manufacturing activity in the UK.

Attracting Investment and Scaling Up

As the UK gets set to quadruple its offshore wind capacity by 2030, PDD designs can potentially offer a reduction in the levelised cost of energy of between 2% and 3% compared to mechanical geared or direct drive generators. This means that testing and demonstrating the PDD design with ORE Catapult was critical for Magnomatics, which has since been able to attract significant investment in its innovation, supporting the company’s huge scale-up ambitions.

“The facility here is unique in the country, and as a result of demonstrating the technology with ORE Catapult, we’ve had a global engineering company take an exclusive option to use our technology for offshore wind. The support the Catapult has provided has been enormous for us, and I don’t think we could have done it without them.” said David Latimer, CEO of Magnomatics

David continued: “This is a UK invention that has global significance in the climate change challenge, and we hold the IP and design expertise here in the UK. As we scale up the technology, we are looking to engage our UK partners in manufacturing support and technology.”