GB582384A - Improvements in and relating to electric generating equipments - Google Patents

Abstract

582,384. Electricity supply; selfcontained supply systems. PARTING- TON, W., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Oct. 2, 1944, No. 18796. [Class 38 (iv)] In an axle-driven generating equipment for railway locomotives, or other vehicles, the armature winding 1 of an alternator is connected through a rectifier 7 to a battery 3 supplying an auxiliary load 4. The alternator field winding 2 is also connected across the battery through a voltage.relay 14 and a switch 12. The contacts of relay 14 are normally closed, but are opened in response to the battery voltage attaining its fully-charged value, whereupon a resistance 10 is inserted in the field circuit. The switch 12 is adapted to be closed by means of a reciprocating lever 21 connected to the regulator 22 of the locomotive so that only when the regulator is moved to start the locomotive, will switch 12 close and the alternator generate current. A substantially constant-current output is obtained from the alternator by designing it so that except at low speeds the battery voltage and hence the alternator output is a small proportion of the internal reactive drop in the. latter, so that over a wide range of normal running speeds the alternator output current is substantially equal to its short-circuit current. The switch. 12 may be operated by a piston working in a cylinder connected with the main steam pipe between the regulator 22 and the cylinders of the locomotive, or any means responsive directly or indirectly to the condition of a control member governing the application of driving power to the locomotive. A swamping resistance 23 may be connected in the alternator field circuit to reduce variations in excitation with temperature changes.