Patent GB-414444-A (GB)
Title: Improvements in or relating to regulating means for electrical powersystems
IPC: H02J3/46
Filed: 1933-02-20
Abstract: 414,444. Supply systems. WESTING- HOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, Pennsylvania, U.S.A.- (Assignees of Camp, R. de ; 305, Atlantic Avenue, Wilkinsburg, Pennsylvania, U.S.A.) Feb. 20, 1933, No. 5234. Convention date, March 2, 1932. [Class 38 (iv).] Running generators in parallel.-The load distribution in a system comprising a number of generators A, B, C operating in parallel is made dependent on and variable with the total load in a predetermined manner by the provision of separate output regulating means 25, 26, 27 on each generator, each controlled by means 92, 133, 134 having graded response characteristics, acted upon by load-responsive or measuring-means 150, 151, 152, 36 responsive to the total power output of all the generating units. The generating units A, B, C are parallel-connected to a distribution system 18, and have their individual outputs controlled each by a regulator 25, 26, 27 respectively acting on a reversible motor 63, 116, 117, which adjusts the tension of a spring 58 on the arm 54 of the centrifugal regulator 53, 113, or 114 respectively, controlling the input fuel or motive fluid valve 51, 52, 56 of the prime mover 14, 15, 16. The regulators 25, 26, 27 are each acted on, in opposition, by the power output of the respective generator and by the current in windings 84, 218, 219 respectively, which are controlled by rheostats 86, 142, 143 respectively operated by reversible motors 92, 133, 134 actuated by regulators 30, 31, 32 which are each acted on, in opposition, by current in coils 101, 215 and 216 respectively and current in coils 102, 145 and 146. The current in the respective coils 101, 215 and 216 is adjustable by rheostats 90, 139 and 140 respectively, which are operated by the motors 92, 133 and 134 respectively, whilst the coils 102, 145 and 146 are in series with each other and the current in these coils is controlled by a rheostat 184 controlled by a reversible motor 178 which is energized by the operation of a regulator comprising three Kelvin balance systems 150, 151, 152 responsive to the output of the units C, B and A respectively to move a regulator arm 170 in opposition to force exerted by a coil 172 which is in series with coils 102, 145, 146 and the rheostat 184. Current in coil 172 is controlled by the regulator contacts 174, 175, 176, reversible motor 178 and rheostat 184, and is therefore responsive to the total power output of the three units and hence each of the regulators 30, 31, 32 responds to the total output and adjusts the rheostats 86, 142, 143 correspondingly. These rheostats are calibrated so that the forces exerted by the coils 84, 218, 219 and hence the outputs of the individual units are varied in a predetermined manner according to the total output of the units. They may be calibrated so that each complete unit works at its maximum overall efficiency for all loads, the efficiency-load characteristics of the separate units being co-related in order to obtain this desideratum. In a modification the rheostats 86, 142, 143 are replaced by cam or template surfaces movable by the motors 92, 133 and 134 and acting on rollers connected to spring controlled rods which exert varying pull on the regulators 25, 26, 27, thus replacing the coils 84, 218, 219 and associated rheostats. The surfaces of the cams or templates correspond to the predetermined load per generator against total load characteristic of each unit. The regulator 36 responsive to total load may be replaced by individual single power devices of a similar nature on each unit which act in parallel with each other on each of the regulators 30, 31, 32. In a further modification, the means operating the calibrated rheostats 86, 142, 143 or, alternatively, the templates or cams, may be ganged and operated directly from the motor 178 on the load totalising regulator 36, thus dispensing with the regulators 30, 31, 32, motors 92, 133 and 134 and rheostats 90, 139, 140.