Study of a Universal Power SMES Compensator for LV Distribution Grid

The design of an interface device for interconnecting a SMES (Superconducting Magnetic Energy Storage) to a LV distribution grid is carried out, in order to demonstrate the feasibility of a SMES for achieving, with the same device, power quality and critical load protection functions. The work is developed inside a three-year research project, called DRYSMES4GRID, funded by the Italian Minister of Economic Development and sees the cooperation of five partners (companies, universities, and research institutes). The aim of the project is to demonstrate the feasibility of the SMES (500 kJ/200 kW) in the short/medium term at competitive cost based on Magnesium Diboride (MgB2). In particular, in this article, after a brief state of art of the SMES applications for the grid, the design and the control logics of the DC/DC chopper for the power modulation of the energy stored in the SMES and of the threephase AC/DC inverter are shown. The activities are mainly based on digital simulations to evaluate the performances of this device in a LV distribution grid in presence of linear and non-linear loads, considering in particular the peak shaving function, while the device is connected to the mains, and the islanding operation condition after the detection of a voltage dip.