Patent GB-452453-A (GB)
Title: Improvements in electrical power systems for driving auxiliary apparatus in boiler houses and the like
IPC: H02P5/68
Filed: 1935-02-22
Abstract: 452,453. Control of several D.C. motors. EASTWOOD, F. A., 46A, Poplar Grove, Brooklands, Cheshire, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Feb. 22, 1935, No. 5802. [Class 38 (iii)] An electric power system for the auxiliary apparatus associated with a plurality of boilers comprises a set of electric motors for each boiler, a, plurality of generators for supplying the sets of motors respectively, a common source of excitation for all the generators, with means for varying the voltage applied from said source to the several excitation circuits of the boilers, one or more sets of bus-bars with means for energizing them, and switching means for connecting the motors associated with each boiler selectively with one of the generators and said set or sets of bus-bars. Motors 1-7 driving the auxiliary apparatus for one boiler are normally supplied from a generator 28 having its field winding energized from conductors 43, 45, common to the equipment of all boilers, the conductors 43, 45 being in turn energized from excitation bus-bars 43, 44, supplied from exciters such as that shown at 34, each driven with a generator 28. The groups of motors for other boilers are normally supplied from similar generators connected in the same way as the generator 28. The connection between the bus-bar 44 and the conductor 45 includes a booster machine 50 which reduces the voltage. The booster 50 which in the event of its failing may be short-circuited by a switch 53, is controlled by a field regulator 51 whereby the several groups of motors for the several boilers may be collectively controlled. A regulating resistance may be used in place of the machine 50. Each group of motors may be connected to its generator 28, or alternatively to "hospital" bus-bars 41 by means of a series of switches such as that shown at 37. The bus-bars 41 may be supplied as shown through switches 40 from one or more of the generators 28. Alternatively, a separate generator or a battery may be provided for this purpose. Two or more sets of bus-bars may be provided, some of which may be energized from one or more of the generators 28 or from a separate generator and the others from a battery. Where a battery is employed for the energization of the bus-bars, the circuit may include a series booster for controlling the voltage. The generator fields 32 may alternatively be supplied from a battery supplying a set of bus-bars in series with a controlling booster. A generator 54 driven with the booster 50 may permanently energize the bus-bars 41. The motor fields 15-21 and armatures 1-7 are shown grouped and controlled by circuit-breakers 10-14 and rheostats 24-27 as described in Specification 452,452. Switching means may be provided for interchanging the connections between the various generators and motors. One or more motors of a group may have a field regulator coupled with the excitation controller 33 of the generator supplying that set or alternatively some of the motors of a group may be shunt-wound and the others compound-wound so that the characteristics of the several motors may differ as desired. The motors 29 driving the generators 28 may be supplied from one or other of two independent sources 31, 31a. Specification 441,078 also is referred to.