Modular/Compact Hybrid Electric Drive and Permanent Magnet Motor for FFX-II

DRS has developed a Variable-Frequency Drive (VFD) and Permanent Magnet (PM) Electric Propulsion Motor (EPM) for a 1.7MW Hybrid Electric Drive system currently commissioned on the Frigate FFX-II of the Republic of Korean Navy. The EPM utilizes a “bearingless” design, allowing for more compact equipment and shafting arrangements. The machine is mounted directly on the shaft, permitting operation of the HED system without main gear engagement. The VFD employs a modular, power-dense, 3-Level Neutral Point Clamped, Power Electronics Module used as an Active Front End and Inverter that enables superior current distortion performance, thereby enabling input electrical interface compliance to MIL-STD-1399 Sec. 300B and output performance that enables compliance of the motor to MIL-STD- 740-2 structure borne noise, which supports Anti-Submarine Warfare vessel operations. The HED system provides superior fuel economy, offering significant life-cycle cost savings over the life of the ship from fuel savings and reduced maintenance costs.