Patent GB-319813-A (GB)
Title: Improvements relating to electrical power distribution systems
IPC: H02J3/46
Filed: 1928-06-26
Abstract: 319,813. Pearce, H., and Associated Electrical Industries, Ltd. June 26, 1928. Transmission conductor arrangements; boosting by transformers; boosting by dynamo-clutch machines. -In an a.c. distribution system in which power may be transferred from generators on one set of bus-bars through one or more current limiting reactances to another set of bus-bars, bv means of low tension synchronizing bus-bars or high tension interconnecting or tie feeders, for example, undesired diferences of voltage or of phase between the sets of bus-bars is prevented by means which are adjusted to supply a voltage of the necessary magnitude or phase or both to achieve this object. Such means may be tapped transformers, booster auto-transformers with arrangements for tap changing under load, double potential regulators of the kind described in Specification 319,877, [Class 38 (ii), Electric currents, Converting &c.], for example, which are adapted to provide both voltage and phase adjustment independently, or a synchronous booster in which the relative core angle position of the two stators mav be adjusted. Fig. 1 shows a system, to which the invention is applicable. Groups of generators 1, 2. 3 and associated transformers supply high tension bus-bars 5, 6, 7 in power stations I, II. The generators in each station are interconnected through low tension equalizing or synchronizing bus-bars 9 and reactances 8. The bus-bars supply through reactances 11 feeders 10 which may lead to substation bus-bars 14, 15. 16 and are interconnected through ties or feeders 12 having reactances 13 larger than the reactances 8 and 11. Load transference between generators is effected by the usual means of governor adjustment, and to permit this to take place in such a system without giving rise to undesirable phase or voltage differences, double induction regulators may, for example, be introduced where indicated at 22 in Fig. 2 and transformers 4 with switches 21 for tap changing under load may connect the generators with the high tension bus-bars. Fig. 5 shows a modification in which a double potential regulator 23 of the kind above referred to supplies the primary of a boosting transformer 24 in a high tension tie 12. Fig. 7 shows star connected auto-transformer windings 112 associated with the high tension interconnector between two systems 110, 111. Tap changing switches supply respectively, from these windings, the primary windings of two sets of booster transformers 134, 135 connected to give respectively a voltage in phase with and in quadrature with the interconnector voltage. Adjustment of the tappings is made to supply the required voltage or phase displacement or both. Fig. 11 shows a further modification in which tapped transformer windings 213, 214, 215, which may comprise some or all of the current limiting reactance, are connected in series with the interconnectors between the systems 110, 111. Variable points on each winding are connected to delta connected transformer windings 219, 220, 221 associated respectively with the windings 213, 214, 215, and adjustments of the points of connection of the delta and of the system 111 to the latter windings effect the required correction of voltage and phase.