El Economista is one of the main economy newspapers in Spain and they informed about the validation trials performed by Mondragon University in an article in April. The piece is written in Spanish, you can it read here, and we leave you a translation to English.
New technology for wind turbines in weak networks
The validation trials of the technology will start in May in Mondragon University within the FasTaP project, led by Siemens Gamesa.
In the end of March, the University of Mondragon inaugurated the new medium-voltage laboratory at their facilities located in Arrasate-Mondragon (Guipúzcoa, Spain), which will become a landmark in Europe for the transformation and improvement of the wind sector.
The new equipment installed is rising the laboratory’s capacity, compared to the lab started by the university back in 2006, and will allow different trials to enlarge the wind turbines market installation in areas with weaker networks. This equipment will be able to test rotating machines up to 8MW of rated power and to validate codes medium-voltage network codes of 20kV.
The set-up of the new machinery is being performed within the EU-funded project FasTaP, fostered by Mondragon University; the Spanish wind turbines manufacturer Siemens Gamesa; the German semiconductors manufacturer Infineon; and the German transformers manufacturer SGB-SMIT. The main goal is to optimise the electric capacities of the wind turbines with technologies which would raise up to 5% the annual energy production as well as reduce by 5,5% the leverage costs of win energy. In addition, CO2 emissions would be lowered too.
Fernando Santodomingo, chief of R&D projects at Siemens Gamesa and FasTaP coordinator, stated: “Everything started in 2016. Back then, we must validate a machine, the 2,5MW from Gamesa, which could overcome the power peaks required by Mexican and Brazilian network codes, and which could operate in both countries. Surge requirements were very high, and we needed to be able to keep injecting power, no matter how much the tension would rise”.
“This circumstance coincided with the tests that the Mondragon laboratory was carrying out with thyristors in an 850kW machine’s transformer from Gamesa. It was then that we saw the possibility of integrating the thyristors in a transformer, and to regulate the tension, so we prepared a team who could replicate the power peaks demanded in Mexico and Brazil”.
Everything worked so well, that in 2018 they started to assess the possibility to set in motion a project to standardise the inclusion of this technology in all their wind turbines. “Thanks to this technology it is possible to reduce the investment costs in the parks and to maintain or raise the performance in weaker networks to, therefore, the weaker the network, the greater the saving”, explained Fernando Santodomingo.
During 2020, they were awarded with a European grant, which would allow them to rise the technology readiness level (TRL) from TRL5 to TRL8, which is the commercial level. They currently have 6 patents of this technology: four of them belong to Siemens Gamesa, and the other two are a property by 50% of Siemens Gamesa and Infineon.
Infineon’s contribution to the project us the thyristors technology activated with light (LTT) for medium-voltage- The use of thyristors instead of mechanic switches reduces the maintenance effort and allows a faster commutation. Besides, additional electric isolation is not necessary, as LTT activate through light transmitted with optic fibre. Their hermetically sealed casing, unlike most thyristors, can also be installed in transformers submerged in oil.
SGB is contributing with a dry cast resin transformer with a 7,4MVA power during the trials, approximately 19t of weight and 4x2x3 metres dimension. The transformer can adjust to several main tension levels (30/20/15kV) to simulate different medium-voltage networks, though in its main levels, a more precise regulation can be performed to simulate the behaviour and mistakes of the network. SGB is also providing the prototypes of the FasTaP transformer, which will be installed in the SGRE validation wind turbines for the 4.X platforms (dry transformers) and 5.X (isolation in oil transformers).
The project ends in April 2024
The new laboratory has 700 squared metres and counts on two independent trial areas. “On one side, the low tension/low power area with 100m2,divided into two areas: one for destructive trial and another one for conventional trials. The second area, 600m2, is destined for medium-voltage/high power, and is divided into four areas: two for independent testing, with 10MVA and 4MVA, where rotative machine tests are carried out up to these power levels and network codes are validated; a container area, with enough space to install client’s equipment or rented to third parties for the validations; and a transformers room”, explains Manex Barrenetxea, laboratory responsible.
FasTaP project es currently on a lab-scale technology validation stage to, afterwards, validate it in the wind turbines. “We will start the trials at Mondragon’s laboratory between May and June of this year in a prototype of dry transformer. In July, the plan is to integrate it in the prototype at Siemens Gamesa 4.X platform that we have in the Wind Experimental Park of CENER in Sierra de Alaiz (Navarra) to start the tests in August. Then, between August and December, a certification campaign is planned”, says Santodomingo.
Additionally, “we also count on a prototype for a transformer in oil for the Siemens Gamesa 5.X platform, with bench testing planned for September. During November, we will take it to Alaiz to have it installed before Christmas, where it will stay until March 2024. The project will end in April 2024, after obtaining all the certification papers. From that moment, the commercial stage will begin”, concludes a Siemens Gamesa representative.
The medium-voltage laboratory will be available for companies not linked to the project to run tests and trials of their equipment and to validate photovoltaic generation systems, storage systems, etc.