GB416974A - Improvements in or relating to bridge or remote electric control arrangements for electric ship propulsion systems - Google Patents

Abstract

416,974. Systems for transmitting mechanical power. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and COATES, H. J., c/o General Electric Co., Witton, Birmingham. Dec. 23, 1932, No. 36457. [Class 38 (iv).] A bridge or remote electric control arrangement for an electric ship propulsion system having motors which are respectively coupled to port and starboard propellers, and are arranged to be fed from the same generator, comprises port and starboard controllers 55, 56 arranged with ahead and astern positions, speed control being effected by regulation of the output of the generator and effected by one of the controllers depending upon which is in the lower speed position. The invention is described in application to a Diesel-electric ship employing D.C. motors and generators connected according to the Ward Leonard system. With each motor supplied from its own generator, operation of the port and starboard controllers 55, 56, causes ahead or astern contactors 107 and 220, on 115, 212, for the port and starboard motors to close and controllers 131, 237, to be operated by pilot motors 133, 239, to positions corresponding to the positions of the respective controllers 55, 56. The follow-up system comprises potentiometers 62, 58 regulated by the controllers 55, 56, potentiometers 152, 259, regulated by the pilot motors 133, 239, and respective polarized relays 157, 264, which control " raise " and " lower " contactors 176, 179, and 274, 278 for the split field pilot motors, and clutch contactors 187, 287 for clutches 132, 238. The controllers 131, 237, regulate the amount of resistance 105, 210 in the field 4, 3, of the starboard and port generators. If one of the controllers 55, 56 is moved from an ahead to a reverse position the corresponding generator field controller 131, or 237 is returned to the " off " position, the corresponding motor field reversed, and the generator field controller moved to the new astern setting of the controller. If the port and starboard motors are both connected by means of change over switches to the starboard generator, a switch 262 is opened to put the port follow-up gear out of action and a switch 302 closed to connect selecting potentiometers 63, 59, regulated respectively by the starboard and port controllers 56, 55, together through a coil 172 of a relay 164. If the controllers 56, 55 are in different positions, the relay 164 connects the port and starboard polarized relays 157, 264 to that one of the transmitter potentiometers 62, 58 which is in the lowest speed position, so that the starboard generator field controller 131 is controlled by that one of the bridge controllers 55, 56 which is in the lowest speed position. If both controllers 55, 56, are in an " ahead position and the starboard controller 56 is moved to an " astern " position the pilot motor of the starboard generator field regulator is returned to an " off " position, the starboard motor " ahead " contactor then opens, the starboard motor astern contactor then closes, the starboard lower " contactor opens and the starboard raise contactor closes until the pilot motor moves the starboard generator field regulator to a position corresponding to the position of that of the controllers 55, 56, which is in the lowest speed position. Similar corresponding control is obtained when both motors are fed from the port generator. The invention is stated to be applicable to an A.C. propulsion system employing speed control of the engine driving the generator, e.g., the system described in Specification 352,615.