Periodic Reporting for period 1 - R2D2-NET (RELIABLE, RECONFIGURABLE DC DISTRIBUTION NETWORKS)
Reporting period: 2018-10-02 to 2020-10-01
The MSCA Action investigated the potential of reconfigurable Direct Current (DC) electricity distribution networks to contribute towards the reliable delivery of electrical power to low voltage consumers. Traditional Alternating Current (AC) electricity distribution networks are fixed systems that have been gradually deployed and upgraded over several decades. Reconfiguring an electricity network involves a lengthy planning process that cannot be done in real time. However, in situations such as equipment overloading or unconventional power flows, network reconfiguration can reduce the probability of a fault developing. Hence, reconfiguration has recently been proposed as a methodology for increasing electrical network reliability.
Network reconfiguration can be performed with devices and installations that are enabling a connection where previously there was none. These are called Soft Open Points (SOP). Such devices exist for AC networks, but not for DC networks. This project set out to create an equivalent of this reconfiguration device for DC networks, the DCSOP.
In addition, the project set out to assess the possible impact of DC network reconfiguration on the reliability of the network. Assessment of reliability in DC networks is more difficult than their AC counterparts, since there are no precedents or definitions of calculation methods. In this project, an AC network has been converted to a DC network and a reliability assessment methodology has been adapted and tested, using different reconfiguration combinations.
Finally, in future Smart Grids, it is necessary to control and co-ordinate devices such as generators, demand, batteries and other network equipment. This can be done with local autonomous control devices based on Artificial Intelligence concepts. The final objective of this project was to develop a concept that can control and co-ordinate the reconfiguration devices for the safer operation of the DC electricity network. This would be especially useful in local microgrids, which can be more difficult to regulate.
The above work is very important for the safer operation of electricity distribution networks, and will provide an efficient alternative to AC networks. This will help ensure security of energy supply to electricity consumers, and would contribute towards more resilient electricity networks that can handle more intermittent renewable energy. Hence, there are environmental benefits as well.
Network reconfiguration can be performed with devices and installations that are enabling a connection where previously there was none. These are called Soft Open Points (SOP). Such devices exist for AC networks, but not for DC networks. This project set out to create an equivalent of this reconfiguration device for DC networks, the DCSOP.
In addition, the project set out to assess the possible impact of DC network reconfiguration on the reliability of the network. Assessment of reliability in DC networks is more difficult than their AC counterparts, since there are no precedents or definitions of calculation methods. In this project, an AC network has been converted to a DC network and a reliability assessment methodology has been adapted and tested, using different reconfiguration combinations.
Finally, in future Smart Grids, it is necessary to control and co-ordinate devices such as generators, demand, batteries and other network equipment. This can be done with local autonomous control devices based on Artificial Intelligence concepts. The final objective of this project was to develop a concept that can control and co-ordinate the reconfiguration devices for the safer operation of the DC electricity network. This would be especially useful in local microgrids, which can be more difficult to regulate.
The above work is very important for the safer operation of electricity distribution networks, and will provide an efficient alternative to AC networks. This will help ensure security of energy supply to electricity consumers, and would contribute towards more resilient electricity networks that can handle more intermittent renewable energy. Hence, there are environmental benefits as well.
The work performed under this project falls mainly under three categories, as per the organisation of the project.
(1) The device referred to as the DC Soft Open Point (DCSOP) has been designed and characterised. A number of computer simulations have been performed in order to stress-test it, by subjecting it to adverse scenarios. In addition, a realistic local network (microgrid) was designed in the simulated environment, and the device was found to be reconfiguring it successfully.
(2) The impact of DC network reconfiguration on the reliability of DC networks had to be established. For this purpose, a methodology that calculates certain reliability metrics based on the structure of the network has been employed. The same local microgrid as above has been used with different reconfiguration scenarios, which altered the structure of the network. It has been found that the reliability metrics of the reconfigured DC network were improved.
(3) Finally, there was a need to develop a method to coordinate the reconfiguration devices, so that they can improve the operation of the network. This method involved using local control software that were able to act autonomously based on a certain logic, but also co-ordinate between them. It was tested in the local microgrid and was found to be effective in improving the operation of the network. In particular, a local network has comparatively large variations in voltage, which can be problematic. This methodology managed to reduce these variations, as shown in the attached graph.
(1) The device referred to as the DC Soft Open Point (DCSOP) has been designed and characterised. A number of computer simulations have been performed in order to stress-test it, by subjecting it to adverse scenarios. In addition, a realistic local network (microgrid) was designed in the simulated environment, and the device was found to be reconfiguring it successfully.
(2) The impact of DC network reconfiguration on the reliability of DC networks had to be established. For this purpose, a methodology that calculates certain reliability metrics based on the structure of the network has been employed. The same local microgrid as above has been used with different reconfiguration scenarios, which altered the structure of the network. It has been found that the reliability metrics of the reconfigured DC network were improved.
(3) Finally, there was a need to develop a method to coordinate the reconfiguration devices, so that they can improve the operation of the network. This method involved using local control software that were able to act autonomously based on a certain logic, but also co-ordinate between them. It was tested in the local microgrid and was found to be effective in improving the operation of the network. In particular, a local network has comparatively large variations in voltage, which can be problematic. This methodology managed to reduce these variations, as shown in the attached graph.
The project’s results provided an important argument towards considering DC electricity networks as an alternative to existing AC networks. The DCSOP device concept that has been developed is a key tool that can be used for reconfiguring the DC network and this did not exist in the literature, to the team’s knowledge. The reliability impact of DC network reconfiguration also confirmed its usefulness. The control and co-ordination method using artificial intelligence has not been applied to this particular problem, and is opening up great possibilities for reconfigurable DC networks.
The project was also expected to enhance the Fellow’s career by enabling him to undertake leading research in the field, and introducing him to key contacts in the academia and industry, which was fully realised. The impacts on the European society and economy are long-term, and this project contributed to the promotion of resilient and reconfigurable DC microgrids, which can play an important role in the future of security of energy supply. The impacts on the University of Sussex were also realised, and included participation in a prestige research project, and publications that could potentially enhance the School’s research visibility.
The project was also expected to enhance the Fellow’s career by enabling him to undertake leading research in the field, and introducing him to key contacts in the academia and industry, which was fully realised. The impacts on the European society and economy are long-term, and this project contributed to the promotion of resilient and reconfigurable DC microgrids, which can play an important role in the future of security of energy supply. The impacts on the University of Sussex were also realised, and included participation in a prestige research project, and publications that could potentially enhance the School’s research visibility.