New AC switching technology set to revolutionise the manufacturing industry

Sprint Electric

The challenge

Sprint Electric is a world leading manufacturer of drives for industrial motor control. Founded in 1987, the firm has traditionally specialised in the design and manufacture of direct current (DC) motor controllers.

Sprint Electric was looking to expand its market reach by diversifying into the alternating current (AC) market – in particular, AC drives using a unique switching technology to provide four quadrant control. A huge advantage of this new switching technology over other AC motor drives is the ability to regenerate energy enabling power flow either transiently or continuously from the motor to the supply and at the same time producing no harmonic distortion in the supply current. This technology allows AC-AC power conversion with no requirement for an intermediate DC bus as used in traditional AC Drives. The result is a much more compact and reliable AC regenerative drive.

The aim of the project was to develop this patented AC drive switching technology to be suitable for high reliability applications. This is a significant technical challenge because although electrolytic capacitors inherently make inverters less reliable, they do allow them to tolerate high levels of supply voltage instability.

Our experience with KTPs has been a wholly positive one. Not only has it quickly and effectively embedded understanding of a complex technology in our business but it has also established a relationship with the PEMC group that I am confident will continue to deliver benefits to both parties in years to come. Sprint’s determination to launch a range of products with this unique switching technology has strengthened over the course of the KTP. This KTP and the other projects that preceded it have made a fundamental contribution to changing the company’s strategy. Put simply, by embedding this technology, Sprint is able to set some very exciting growth plans. This is because we are introducing a new technology, with outstanding energy saving credentials, into the large and growing AC drives market.
Mark Gardiner, Director, Sprint Electric

What we did

Knowledge Transfer Partnerships (KTPs) are a three-way collaboration between a UK-based business or charity, a research organisation, and a qualified graduate known as a KTP Associate who has the capability to lead a strategic business project. 

Building on the success of a previous KTP with the University of Nottingham, Sprint Electric were partnered with power electronics engineer and KTP Associate, Azlia Abdul Rahman. Azlia was guided by the academic expertise of Professor Pat Wheeler and Associate Professor Liliana de Lillo, with support from researchers from the Power Electronics, Machines and Control (PEMC) Research Group in the Faculty of Engineering.

With world-renowned expertise in AC drive switching technology, the PEMC Research Group had a detailed understanding of the challenges facing Sprint Electric. Fully embracing the collaborative opportunity, the company opted to establish a base at the PEMC Centre on Nottingham’s Jubilee Campus.

With the support of Associate Professor Liliana de Lillo and the team at the PEMC Research Group, Azlia created a low voltage simulation model of an AC drive using bi-directional switching technology for AC-AC power conversion to gain a better understanding of the underlying principles. She also devised a set of design recommendations, for both hardware and software, to improve the robustness of this technology against supply disturbances. Working alongside engineers at the company the team created a 22kW prototype converter, designed to work at 400V, which they put through a series of rigorous trials.


The collaboration resulted in the creation of the Generis AC regeneration drive. Designed to not only lower running costs, benefits also include reduced heat generation, motor control accuracy and improved system efficiency.

The company launched the Generis at the Smart Production Solutions (SPS) exhibition in Nuremberg in November 2023. They went on to secure funding from Innovate UK’s Investor Partnerships programme, enabling it to accelerate the development of the Generis range to power outputs from 22kW to 200kW.

Finally, the collaboration has encouraged Sprint Electric to apply more structured design methods within the business, including greater rigour in the specification process and use of Failure Mode and Effects Analysis (FMEA) in the design process to control risk. The benefits accruing from these improved working practices have led to Sprint Electric appointing a Quality Manager who will be responsible for formally documenting the processes and training staff in their use.