Improvements in Electric Accumulator Substations Fed from Alternating Current Systems.

摘要

2147. Taylor, A. M. Jan. 29. [Cognate Applications 2335 and 5623.] Systems for conversion employing rotary converters &c.-The sub-station of an alternating-current distribution system is provided with a rotary-converter unit arranged for the lagging effect due to inductive loads, a second rotary unit to compensate for the reactance of the line itself, and one or more rotary units arranged to compensate for the momentary variations of the load. Each of the rotary units is connected to a battery as described in Specification No. 22,581, A.D. 1907, or they may all be connected to one battery, while during the peak of the load all the units may be arranged in parallel two relieve the main generator. The high-tension lines A, Fig. 1, are connected to the distributionfeeders D and sub-station bus-bars E through a step-down transformer B. The rotary converter a1, arranged to compensate for inductive loads, is connected on the alternating- current side to the bus-bars E through a transformer c1, and on the direct-current side to a battery b'. The field g1 of the converter a1 is fed from an excitor j1, the field k1 of which is controlled by a regulator o', the current coil m1 of which is fed from a transformer p and a voltage coil n1 fed from the transformer @r. The ratio of the transformer p may be varied by a switch q. To compensate for the reactance of the distributing line D, the field g2 of a rotary converter a2 is fed from an exciter j2, the field k2 of which is controlled by a regulator o2 having a potential coil m2 fed by the transformer r, and a current coil n2 fed by the transformer s. The load on the main generator is equalized, during momentary variations, by means of rotary converters a', a4 connected to batteries b3, b4; while their fields g3, y4 are fed by exciters j3, j4, the fields of which are controlled by a regulator o3 having a potential coil m3 and a current coil n3. When the variations of load are gradual, the regulators may be replaced by indicators, the machines being handcontrolled by means of the regulators h', h2, h3, h4. The rotary converters may be replaced by motor converters, induction motor generators, or synchronous motor generators, but in all cases the machines connected to the batteries b1, b2 must be of the synchronous type. In the arrangement shown in Fig. 5 when a large converting unit is employed with a set of batteries b', b1, one pole of the battery is connected to one brush of the machine a1 while the other pole is connected to the neutral point of the transformer c1, and when a second set of batteries b1 b1, b' b1 is added, the free end of the set is connected to the second brush of the machine. To compensate for the reactance in the incoming or outgoing lines, transformers H, J, Fig. 6, are inserted in series in the leads C, the secondaries of these transformers being connected to a rotary converter a3 by means of a switch S. The transformers may be short-circuited by switches L. Current transformers O are inserted in the outgoing lines D, and are arranged to be connected to the converter a' by means of a double-pole switch Q, while a second switch R is arranged to connect the converter a' to its transformer c1. The primary winding of a transformer K, placed in parallel with the primary windings of the transformers H, J has its secondary winding in series with the secondary winding of a transformer G, the primary winding of which is in parallel with a choking-coil F in the high-tension line A. The winding m3 of the regulator o3 is supplied by these two transformers, the regulator operating upon the field of the exciter j3 to energize the field winding g3 of the converter a3, which compensates for the reactance of the incoming line. The reactance of the outgoing line D is compensated for by means of a similar arrangement of transformers P, N which control the excitation of the converter a1.