Next-Generation Smart Solid-State Transformers (S3T)

For better power grids that also integrate green energy

A new UOW research project funded by the Australian Research Council (ARC) aims to design, develop and implement a next-generation smart solid-state transformer (S3T) that will greatly contribute to Australia’s energy infrastructure.

The proposed S3T has the potential to revolutionise the power grid by replacing the traditional transformer with a new highly flexible, compact and light-weight device made of solid-state power modules providing an elevated level of control of power system networks. 

With integrated sensing and communications to cope with intermittent renewable energy resources and the growing need for intelligence and monitoring in the power grids, the S3T will become the backbone of future power grids that will allow control of bidirectional power flows. 

It will provide improved adaptabilities in energy distribution, such as:

  • faster and better voltage regulation,
  • renewables and storage integration,
  • reactive power compensation,
  • power-flow optimisation and management,
  • power quality improvement with seamless conversion between AC and DC, and
  • automatic control and protection.

"Solid-state transformer is an emerging technology set to make big changes in the electrical power and energy sector. We think our research into a new type of solid-state transformer will provide unimaginable flexibility”, according to Prof Kashem Muttaqi, one of the chief investigators on the grant. 

The outcomes of this project, entitled “A Next-Generation Smart Solid-State Transformer for Power Grid Applications” address an important national goal – to develop an electricity grid that can readily integrate green energy technologies. 

“Our design will have multiple inputs for the integration of multiple energy sources, so it will be possible to easily add renewable energy resources (such as solar PV or wind farms) to the grid.” 

“The street level distribution transformer that you can see in the suburbs, or pole-mounted distribution transformer that you can see on the poles, will be able to be replaced by the proposed smart solid-state transformer (S3T) in the future.” 

“Not only will the new technology will have a great potential to improve the performance of our national grid, but it will greatly strengthen the competitiveness of the Australian power industries in the world market, providing significant economic, social and environmental benefits.” 

The research builds on previous work by the team from three years ago, where they were investigating developing medium-voltage converters for step-up transformerless direct grid integration of renewable energy generation. 

“We were curious to know how the off-shore low-voltage wind farms and remote solar PV plants can be connected to the medium-voltage grid without using heavy and bulky step-up transformers.” Said Prof. Muttaqi. 

This led the team to develop a new technology to replace the traditional distribution transformer to address many of the existing issues. 

“That is how our idea of a new and advanced solid-state transformer began.” 

The UOW researchers leading the ARC Discovery project, Professor Kashem Muttaqi, Dr Rabiul Islam and Professor Danny Sutanto, will be working with Professor Josep Pou from Nanyang Technological University in Singapore and Professor Frede Blaabjerg, from Aalborg University in Denmark. 

Such an international collaboration will ensure the new S3T technology will be at a world-class level that can meet the requirements of all three technologically developed countries, with a potential to dominate the global power and energy markets.