Design of an advanced high power density 1U intelligent rectifier

This paper details both the challenges involved and the solutions proposed in the design of a very compact 2800 Watt intelligent telecom rectifier with a power density twice that of existing units (greater than 7.5 W per cubic inch or 0.46 W cm^-3). The unit is 1U high and designed to fit in a 400 mm deep cabinet allowing high density power blocks producing up to 2000 amps at 54 V to be constructed in a single 2 m high 19´´ cabinet. To meet cost and performance targets a single PCB is used with a combination of planar and foil wound magnetics. A corrected input stage is used to attenuate mains harmonics and allow high power factor operation. The main inverter power conversion stage uses high frequency resonant power conversion techniques with zero voltage switching (ZVS) and a current doubler output stage. This combination optimises the sizes of the magnetics while achieving high efficiency. To further reduce board area extensive use is made of surface mount technology. The built in intelligence allows both `plug and play´ capabilities and connection, via a two wire serial bus, to the system controller thus reducing system inter-wiring. It also enables extensive self protection features to be employed. This, combined with a wide universal voltage input range gives a flexible and very robust unit suitable for worldwide application