A new generation of power supplies for pulsed loads

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).