Tomorrow's energy challenges: a new approach to assessing and validating energy transition scenarios in the face of new technology integration using Digital Twins

Proffesor and researcher Eduardo Gómez Luna, one of the authors of the investigation. Credit: Édgar Bejarano, Communications Office, Faculty of Engineering.

As the search for environmentally friendly energy sources becomes imminent, electric power grids and systems are facing new challenges for their proper operation, derived from the addition of new energy sources, such as wind and solar. This is leading to an increasingly urgent update in the industries. This need is giving way to new mechanisms for the evaluation and validation of new technologies, which poses challenges at the time of their integration into conventional electrical systems in the coming years.  

Seeking to provide an efficient solution with a high degree of accuracy, Eduardo Gómez Luna, professor and researcher at the School of Electrical and Electronic Engineering and member of the GRALTA High Voltage Research Group, together with researchers Jorge de la Cruz and Juan C. Vásquez, from the Center of Research on Microgrids at the Aalborg University, Denmark, carried out a study based on a virtual model of digital twins, the results of which were recently published in the specialized magazine "Energies". It is an analysis destined to become a pioneer in this field, at local and national level. 

Lea el artículo en español aquí.

Ring configuration distribution power grids in the face of the integration of distributed energy resources: a challenge to be tackled   

In the midst of the change in the energy paradigm that the world is currently experiencing, the energy networks which have traditionally been used, have also been forced to decentralize, which means that they no longer only rely on energy flows produced through plants at a given point, but with the integration of other sources -technically called "distributed energy resources (DER)" - such as electric vehicles, storage, fuel cells, wind turbines and photovoltaic systems, among others.  

This new scenario poses challenges and impacts related to the protection systems of such power grids, due to the different flows of energies connected and the relationship between them. "When you have an electrical system, with its entire process from energy generation to consumption, there are different network configurations. I would say that the most complex to analyze are the distribution ones", explains professor and researcher Eduardo Gómez Luna, and adds that this complexity is mainly due to the fact that these networks, which are usually of mesh topology "or meshed", are unbalanced systems, which therefore require more complex evaluation processes, focused on the particularities of their failures.  

"When one does not have a good coordination of protections or a good adjustment of this protection equipment, there will be a loss of selectivity, or in the event of a fault, there may be rings which are left without energy supply", explains the professor and researcher. In addition to this, other failures to which these electrical systems are exposed have to do with short-circuit levels, bidirectional energy, loss of selectivity, false tripping or protections that are blind to the integration of distributed generation. According to the words of professor and researcher Eduardo Gómez Luna, the complexity of dealing with mesh topology systems means that the origin of a problem in these networks cannot be generalized, since multiple distributed energy sources can be connected at the same time, which makes it difficult to evaluate and increases response times.  

It was precisely for this purpose digital twins method was used: "What these tools do is allow analysis at a more detailed level, since they integrate the hardware (physical protection) with the software (model of the electrical network), and in a more precise way, of the different problems that are encountered, and much more so when distributed resources are integrated into the network", says the professor and researcher. 

Digital twins, the validation method of choice for analysis 

The research lasted about two years, and it had to do with the training trips that the professor and researcher Eduardo Gómez Luna made to Canada, where he could see firsthand the utilities of the digital twin method applied to large industries. "One saw how the Canadians put a control element and validated in the digital twin different failures and contingencies. Because going to the field was very expensive. It was more than a thousand kilometers to where they had to go to solve the problem. For them it was easier to evaluate in the laboratory, validate by means of the digital twin method, and when it was validated give the final solution. With this method, risks, costs and time are mitigated, which in my opinion are the three fundamental variables to manage with this type of technology," he recalls. 

Back in the country, professor and researcher Eduardo Gómez Luna was clear that his goal would be to put it to the service and application for this type of networks, since in the region there are difficulties in terms of security and climatic factors that hinder the transfer of equipment to solve the difficulties such networks present. "We started to use technologies such as these digital twins, which allow us to analyze this type of networks, which are complex and need to be analyzed in a different way to how it was being done with traditional tools," he explains, adding that what is sought with this technology is also "to have good commissioning practices, in the particular case of electrical protections for this type of networks, leads to have good results and analysis". 

The tests carried out throughout the research were based on standard models of electrical networks, available in electrical software such as Power Factory, ETAP and NEPLAN. This is due to the difficulty of working with real data from the productive sector, given the information reserves for each case.  

The models studied were those defined by the Institute of Electrical and Electronics Engineers (IEEE), as well as by the International Electrotechnical Commission (IEC), adjusting them to the needs and characteristics of each case to be examined. "Some classic test scenarios were chosen from the literature, in which a component was integrated, made mention of a fault and the reaction of these protections (in ring networks) in such scenarios was verified. We chose those cases which were already reported, and the objective was to validate how it worked with these new technologies, through the digital twins", explains professor and researcher Eduardo Gómez Luna. 

Given the results of the studies, the researcher mentions the need to guarantee the validation of the technologies, once they are acquired, to ensure that they fulfill the functions for which they were designed. "This method of digital twins allows me to verify that the technology is indeed fulfilling what was promised by the supplier," he says.  

Another conclusion of the study was the contribution these methods can provide, facing the behavior of new electricity networks, in a hypothetical future scenario, where new advances in these technologies will bring with them cases not yet recorded in the specialized literature, thus leaving them without a clear level of measurement. "Today you ask, without using the digital twin method, what could happen, and the uncertainty (in the industry) is around 50%, 60% for different validations and studies. With these technologies we can considerably reduce these uncertainties" opines the professor and researcher. 

Renewable energies, change in the electricity paradigm and challenges for the country  

For professor and researcher Eduardo Gómez Luna, although issues related to renewable and distributed energies are in their early stages in Colombia, the future projection of the country's role in this area will be key. "When this scenario comes to pass, and more than 30%, 40% of the national grid depends on distributed resources, we will necessarily have to use this type of technologies to be able to analyze and deliver much more accurate and detailed reports to the system operator. Because most likely this operator will have to deliver to potential users a report based on a digital twin. Today it is not being demanded, but in five or ten years it is what could happen with the integration of new technologies into the electric grid", he concludes.

If interested in being in touch with the researcher or any further information about the investigation, please write the Faculty of Engineering Communications Office: comunicaingenieria@correounivalle.edu.co.