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Pulsed power supply systems are employed in many fusion projects and in other scientific applications. A novel power supply approach and a first prototype unit were specifically developed to feed pulsed loads (low duty cycle), as the resistive or superconducting coils used to produce high magnetic fields for some seconds or longer. Thanks to the integrated energy storage, the high pulsed power required for the load is not drawn directly from the electrical grid. In fact, a huge amount of energy can be stored at low power (even through a single-phase 10 A plug, as normally used for household appliance). A significant fraction of the energy stored in the load can be recovered for successive operations. Without such energy storage, all the power supply devices and the upstream chain must be oversized and installed only in locations provided with adequate power. The first power supply unit (2 kA) was able to replace a previous system with comparable performances, but the old system occupies an extremely larger volume and needs a 20-kV connection at the input. Moreover, a specific solution was implemented to achieve a very fast (600 kW) energization of the magnets. The energy storage capability is intrinsically scalable: the setup can be rearranged and the storable energy can be updated even after the installation (for example, to increase the pulse duration). [ABSTRACT FROM AUTHOR]

The Divertor Tokamak Test (DTT) facility will be the link between ITER and DEMO as regards the study of the power exhaust in the divertor structure. In order to accomplish this goal, the Italian DTT will be a complete superconducting tokamak with 45 MW of additional power coupled to the plasma. According to the last requirements, the DTT coil power supplies are designed to achieve a toroidal field of 6 T and a 5.5 MA plasma in single-null configuration, but also to achieve double-null (with plasma at 5.5 MA), snow-flake (4.5 MA), super-X (3 MA) and other advanced configurations. This paper presents the conceptual design of the DTT power supply and electrical systems, including the site layout, the distribution networks, the expected scenarios and the mechanisms for breakdown and emergency discharge. In particular, the main rationales for the selection of the power supply topology are summarized. The power demand from the grid, presented in the various design options, can reach values above 300 MVA, including the contribution of the additional heating and current drive systems and of the auxiliary services. [ABSTRACT FROM AUTHOR]

In many relevant cases requiring a net energy comparable with that of a household appliance, the power supplies (PSs) and the electrical systems must be oversized to sustain short peak demands. The same equivalent energy could be achieved by storing and distributing the power over the time. These considerations lead to a new PS concept based on the exploitation of the energy stored between the actual operations. The new compact ($60\,\,\text {cm} \times 120\,\,\text {cm} \times 190$ cm) PS is able to generate arbitrary currents up to 2 kA by an integrated energy storage system based on supercapacitors. The delivered output power (approximately 200 kW) is obtained from a very low and tunable input power (<1 kW). Furthermore, a portion of the injected power can be recovered in the storage system. Even though the system was designed for a specific project (the PROTO-SPHERA spherical tokamak), the presented approach can be applied to general-purpose PSs, and there are encouraging prospects to extend it to large facilities with higher currents and voltages. [ABSTRACT FROM AUTHOR]