BASIC TOPOLOGY

POLARIS converter family continues to be built with the same basic fundament brick as its predecessors APOLO and SIRIUS. Topology consists of a line power transformer for voltage adaptation and galvanic isolation, a diode rectifier followed by a DC-link, the H-bride converter with output high-frequency filter serving as the magnet power supply and protection circuitry including earth fault detection network and crowbar for magnet energy dissipation whenever converter is triggered to stop operation.

Unlike SIRIUS converters having a boost regulator in DC-link or APOLO converters equipped with a braking chopper, new POLARIS has a 2Q converter installed in DC link which is identified as the enabling topology for the energy management in the slow extraction applications such as in case of the North Area Fixed Target Physics Complex. POLARIS converter brings together the advantages of both past topologies, possibility of the electrical grid loading during ramp-up and flat-top as in APOLO and reactive energy exchange between the energy storage and the magnet as in SIRIUS.

POLARIS TEAM

WP Responsables - Production & Validation & Operation: I. Josifovic - F. Daligault

Hardware and Software Design: D. Xystras - O. Michels - S. Reignier - D. Brethoux

POLARIS MODULAR APPROACH

The converter integration is done in two standard 19-inch racks. One rack is the Main brick and it houses the output filter capacitors, high precision current measurement DCCTs, the Function Generation Controller (FGC) crate and the cooling distribution equipment. Another rack is the Power brick and it houses the semiconductor power stack with transformer, magnetics and energy storage capacitors. Each converter type has one Main brick and different converter types can be created by adding different number of power bricks: single (POLARIS S), two (POLARIS 2P or POLARIS 2S) and four (POLARIS 4P or POLARIS 2P-2S).

POLARIS S

POLARIS 2P

POLARIS 2S

POLARIS 4P

POLARIS 2P-2S