Increase of Stability Margin in Embedded DC Electric Grid with Superconducting Stabilizer

Guan Bin Huang (1) , Bruno Douine (1) , Kévin Berger (1) , Gaëtan Didier (1) , Isabelle Schwenker (1) , Jean Lévêque (1)

1 GREEN - Groupe de Recherche en Electrotechnique et Electronique de Nancy

Embedded electric grids are constantly subject to problems of stability. Some responses can be done with the help of Resistive Superconducting Fault Current Limiters (RSFCL). In this paper, we propose a new system named Superconducting Stabilizer (SS) in order to stabilize DC grid. The SS uses the losses created by the AC and DC components of the current to increase the stability margin in DC electric grid. For DC electric grid, in stable state, only the DC current component exists. If the load increases beyond a threshold limit, the DC electric grid becomes unstable and the current contains AC + DC components. The SS has very low losses in superconducting state and they can be considered as negligible in comparison with other losses in DC grid. In case of unstable state, the AC component of the current induces losses in the SS. It will be theoretically shown that increasing of the losses in the SS can stabilize the DC grid with efficiency. In this paper, the measurements of the critical current Ic and the AC + DC losses of SS are reported. A comparison between a short length tape, and two superconducting non-inductive coils has been made. The tape used in the experiments is a DI-BSCCO tape. One non-inductive coil is wounded on an aluminium plate and the other one, on a wooden plate. In this latter, the turns are free to move and also, better cooled by liquid Nitrogen. Similar values of losses per meter have been measured for the three samples. The only and important observed difference is the maximal current which leads to the transition of the non-inductive coils. It can be explained by the cooling efficiency of the designed coils. These experimental results are useful to design SS in the future.

Mots clés: superconducting tape; superconducting stabilizer; DC electric grid; stability margin; losses

Domaines: Electromagnétisme; Supraconductivité [cond-mat.supr-con]; Energie électrique

Guan Bin Huang, Bruno Douine, Kévin Berger, Gaëtan Didier, Isabelle Schwenker, et al.. Increase of Stability Margin in Embedded DC Electric Grid with Superconducting Stabilizer. IEEE Transactions on Applied Superconductivity, 2016, 26 (4), pp.5000304. ⟨10.1109/TASC.2016.2543963⟩. ⟨hal-01290382⟩