Hospital beds to learn from electric cars and feed power back into the battery

When you lift your foot off the accelerator in an electric car, the motor slows the vehicle down and feeds electricity back into the battery. This technology—known as regenerative braking—is now set to be deployed in offices and hospitals around the world.

In a new project, the University of Southern Denmark (SDU) will, together with industrial companies LINAK and Secop, develop a new generation of motor control systems. Guided by the principle that many small savings add up, the goal is to address the massive energy waste found in the millions of small motors that adjust our desks, beds, and industrial machines every day.

- Efficiency also means that the motor can brake and feed energy back into the battery when a load is lowered. This is well known from electric vehicles, but there are more and more applications where it is desirable to do the same with smaller motors, says Peter Gravesen, Chief Technology Officer at LINAK.

Putting an end to oversizing

The key to significant energy savings lies in the system's design. Today, companies often purchase motors and control systems separately, leading to inefficient solutions that are unnecessarily large and heavy.

- We optimise the system as a whole instead of optimising each component individually. This allows us to significantly reduce our CO₂ footprint by avoiding oversizing equipment. We use exactly the materials that are needed—no more, no less, explains Associate Professor Ramkrishan Maheshwari from the Centre for Industrial Electronics at SDU.

He also points out that the project will use new materials in power electronics, including wide-bandgap technologies such as silicon carbide (SiC) and gallium nitride (GaN). These materials have far lower energy losses than traditional electronics, enabling the construction of control systems that are both smaller and more efficient.

A competitive advantage for the Danish industry

Although the energy required to raise a desk may seem insignificant in the bigger picture, the technology has enormous potential when scaled up to industrial robots and battery-powered equipment.

- Customers are increasingly talking about energy efficiency as a competitive parameter. Especially in battery-powered systems and mobile robots, we must make optimal use of every single watt, so batteries last longer, and equipment doesn't overheat, says Peter Gravesen.

The new technology is expected to reduce energy losses in motors by up to 50 per cent compared to current solutions.