Researchers design hybrid electricity system

An AC-DC hybrid distribution system could reduce electricity prices by more than 5% and improve service reliability.

AC-only distribution systems are currently used worldwide, meaning DC-powered electronic devices, such as computers, televisions and smartphones, and electric vehicles must include AC-DC converters. The new system, designed by researchers at the University of Waterloo, delivers both kinds of current to customers, minimising conversions and making it easier to integrate growing green technologies.

“Minimising power conversion requirements creates a simpler system with greater efficiency and less loss,” explained Haytham Ahmed, a postdoctoral fellow who led the research. “As you reduce the number of converters, you also reduce the chances of service interruptions due to breakdowns.”

Existing power networks carry AC because of the utilisation of power transformers to increase voltage for greater long-distance transmission efficiency and reduce voltage for distribution purposes. Therefore, the distribution systems that deliver electricity from local substations to end users also carry AC.

The hybrid system introduces AC-DC converters at strategic points in the distribution system itself, instead of only at end points where customers access it. Converters would no longer be required to feed electricity into the grid from green generation sources, including solar panels and fuel cells, or for electronic devices and electric vehicles, meaning they would be cheaper to make and use less electricity.

Compared to an AC-only system, the researchers estimated the hybrid system could offer savings of over 5% due to reduced energy loss and infrastructure costs. “When you feel heat coming off the charger for your laptop, that is lost energy,” Ahmed said. “We can eliminate those losses so we consume less power.”

Researchers expect it to have the greatest potential in new residential and commercial areas, or when existing systems are being expanded with additional substations.

The latest in a series of papers on their research, ‘A reliability-based stochastic planning framework for AC-DC hybrid smart distribution systems’, is published in the International Journal of Electrical Power and Energy Systems.

Image credit: ©stock.adobe.com/au/bizio_ti