A 20-ampere, 4-quadrant power supply for magnets

Modern particle accelerators, in particular “Ultra-Low-Emittance Light Sources”, often adopt small and compact electromagnets, with low current levels for minimizing losses. Compact power supply systems are required, as well, and characterized by high efficiency and high output current stability. These are the key features on which we have developed the A2720 Power Supply System described in the paper. The A2720 System can host one to four independent current-controlled bipolar DC-DC modules, each capable of delivering up to ±20 A and ±50 V in DC-operation, in a single 19-inch, 3U standard crate. Each module implements a fully digital control loop (PID regulation) with high-resolution PWM pattern generation that makes the system versatile and easy to “tune” to any load condition. The A2720 System is composed by the crate of the power supplies and up to 4 AC/DC “bulk” power supplies, connected electrically by a proprietary backplane. Remote communication is guaranteed by means of a 10/100 Mbps Ethernet autosensing socket present on each A2720 module front panel.