The converter that reduces energy losses by a factor of ten
Researchers at Electrical Energy Conversion have developed an energy converter with an efficiency close to 100 percent. The converter will, among other things, make our electric cars, hybrid cars, electric trains and cross-border electricity grids more energy and cost efficient.
Cooling systems are the reason why today’s energy converters cost as much as they do. Most converters are made of silicon, a semiconductor material which can only withstand temperatures of up to 125 degrees. Now Professor Hans-Peter Nee, PhD student Dimosthenis Pefthitsis and guest researcher Jacek Rabkowski have built and tested a converter made of silicon carbide with an efficiency of 99.7 per cent – as opposed to today’s 97 percent. The advantage of silicon carbide is that it can tolerate temperatures of up to 250 degrees.
“We have reduced the energy losses to about one tenth, i.e. 0.3 per cent! Thanks to silicon carbide, which reduces energy losses, we can reduce the need for cooling to one tenth. As a result, you don’t need any liquid or fan cooling. In many instances, naturally flowing air can often be sufficient”, Hans-Peter Nee, Professor and Head of the Department for Electrical Energy Conversion, explains.
This will of course have a major impact on diverse areas of society. Similar converters will be found in hybrid cars, electric trains and subways. When the big converters reach the market, they can be used for high voltage direct current transmission (HVDC); for example in the smart electric grids that connect two countries’ power grids together.
“Regulating the speed of electric motors in hybrid cars is one area of use. Cooling water for the combustion engine is too hot for silicon electronics, but with silicon carbide, it is perfect”, says Hans-Peter Nee.
Reviewers of the researchers’ own work could not believe their eyes when they saw the results on paper. It has therefore been important to demonstrate that the test process really does work. With conventional measuring methods, it is difficult to know that you have such a good level of efficiency. "Researchers have found an ingenious way of measuring the losses, i.e. the amount of heat generated," Hans-Peter Nee explains.
“First we take known cases of losses and look at the temperature of the converter. We measure many different values. Then we run the converter for real and measure the temperature. In this way, we know that we have measured correctly”, Hans-Peter Nee explains.
“You can save a lot of energy with the silicon carbide converter. But we cannot say how much as of today. It is not going to disrupt things too much in terms of energy usage, but you will be seeing these converters being used for so much more”, says Hans-Peter Nee.
For more information, contact Hans-Peter Nee, +46-70-6953470, firstname.lastname@example.org.