Patent GB-235201-A (GB)
Title: Improvements relating to electrical signalling and controlling systems
IPC: H02J13/00
Filed: 1925-06-04
Abstract: 235,201. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of White, T. U.). June 6, 1924, [Convention date]. Selective distant control systems. - In a distant control and supervisory system for substation apparatus of the type wherein the apparatus units at the substation and the control keys and supervisory signals at the control station are associated with synchronously-driven relay chains at each station, the relay chains are driven by two pairs of control relays which are energized alternately in series over the line wire by alternating currents of different frequencies. The apparatus units and supervisory signals are also operated by currents of predetermined frequencies transmitted over the same line wire. The substation apparatus units may be operated automatically by the load conditions. Figs. 1 to 4 show the control station and Figs. 5 to 8 show the apparatus at the substation. The circuit of each apparatus unit, e.g. a circuit breaker C, Fig. 8, at the substation is prepared by a key K and a key K1 causes controlling relays at the control station and substation to associate groups of selecting relays 300 - - 309, 500 - - 509 at the control station and substation respectively with chains of counting relays 101 - - 124, 700 - - 723. The controlling relays are connected by a trunk line 490, the earth being used as a return. The selecting relays are closed and opened successively under the control of the counting relays, until the relay associated with the selected circuit breaker is operated to close the circuit prepared by the key K and operate the circuit breaker. When the unit operates, a circuit is also closed through its selecting relay at the control station to operate supervisory signal lamps, such as 231, 232, Fig. 2, and indicate the condition of the unit. The circuit breaker controlling and signalling circuits are closed over the trunk line 490. If the apparatus unit is not selected by the selecting relays 300 - - 309, 500 - - 509, further groups of relays are successively connected with the counting relays and the cycles of operation are repeated. The control circuit for the selecting relays is operated by alternate applications of alternating currents of different frequencies from generators G3, G5 at the control and substation respectively. The circuit breaker controlling circuit is supplied by one or other of the alternating current generators G1, G2, according to whether it is desired to " close " or " open " the breaker, and the supervisory signalling circuits are supplied by generators G6, G7. The operation of the selective equipment is initiated by opening the circuit of " start " relays which are normally energized over the line 490 by alternating current generator G4. All the generators have different frequencies and filters are included in series with the control, operating and signalling circuits in order to effect selection of the corresponding relays. Normal condition of the system. Normally the relays 222, Fig. 2, and 815, Fig. 8, are energized in series by the generator G4 over the line 490. The circuit includes filters 288, 861 which allow the passage of current having the frequency of the generator G4. Selection of circuit breaker C, Fig. 8. The key K1 is operated to energize the relay 213 which prepares the circuit of the relay 214. This latter relay is not operated so long as the energizing circuit of the relay 213 is maintained closed. The key K1 is then released and the relay 214 is energized to open, at the armature 270, the circuit of the relays 222, 815. When the relay 222 opens, the relay 410 is operated to establish one point in the control circuit at the armature 444 and the relay 216 is energized to operate the switching relay 310, Fig. 3, of the first group of selecting relays 300 - - 309 and connect these relays to the counting relays 101 - - 124. Similarly at the substation when the relay 815 opens, the first switching relay 518 is operated and the control circuit is completed by the relay 618. The control circuit, which now includes the line relays 205, 803 and filters 250, 836 is supplied from the generator G3. The line relays 205, 803 bring about the operation of the counting relays 112, 700 to complete the circuits of relays 111, 701 respectively. These relays, however, are short-circuited so long as the original energizing circuits of the relays 112, 700 are maintained. The relays 205, 803 also open the line circuit so that the short-circuits are removed and the relays 111, 701 are energized to operate the selecting relays 309, 500. The relays 111, 701 also prepare the circuit of the next counting relays 124, 712. In the apparatus shown, the circuit breaker C is associated with the relays 309, 500. Operation of circuit breaker. Before operating the key K1 to effect selection, the control key K is operated to prepare an operating circuit for the circuit breaker. If it is desired to " close " the breaker, the key K is operated in the appropriate direction and the key K1 is again operated so that when the relays 309, 500 are operated a circuit is closed from the generator G1, key K1, key K, conductor 12, contacts 334 of relay 309, filter 395, conductor 489, line 490, conductor 670, filter 531, to relay 511, Fig. 5. The relay 511 operates the relay 810 which energizes the " closing " coil 812 and operates the circuit breaker. The circuit breaker may be opened by operating the key K in the opposite direction and thereby causing the transmission of alternating current from the generator G2 to the corresponding relay 513 which energizes the " tripping " coil of the circuit breaker. Signalling condition of circuit breaker. On closing, the circuit breaker C operates a relay 811 which connects the generator Go to a circuit including an alternating current relay 895, conductor 560, contacts 522 of relay 500, filter 595, - conductor 670, line 490, conductor 489, filter 361, and relay 318. The relay 318 establishes a circuit from earth through armature 357 of relay 316, contacts 333 for relay 309, line 14 to relay 201 which lights the supervisory signal lamp 232 and extinguishes the lamp 231. The relay 811 and the supervisory lamp relay 201 also transfer the control circuit to line relays 208, 806 in place of the relays 205, 803. Signals indicative of the opening of a circuit breaker are transmitted from the generator G7. Completing the cycles of operations and checking the conditions of apparatus units. The control circuit including the line relays 208, 806 and the corresponding filters 252, 838 is spplied from the generator G5. Relays 208, 806 are thus energized and the counting relays 124, 712 open the selecting relays 309, 500. The relays 124, 712 also prepare the relays 123, 713 which are operated to energize the next selecting relays 308, 501. The unit associated with the relays 308, 501 may thus be operated if desired. If, however, the key is not operated, the control circuit is again transferred to the relays 205, 803. In this manner the selecting relays are energized successively by the counting relays until finally the line relays 205, 803 cause the counting relays 102, 710 to open the selecting relays 300, 509. Upon the next operation of the control relays the relays 101, 711 de-energize the switching relays 310, 518 to disconnect the selecting relays from the counting relays and complete the control circuit from the generator G5 over the relays 208, 806. The counting relays 114, 722 are operated to energize the switching relays 311, 517 and connect the second group of selecting relays with the counting chain. The relays 113, 723 are finally operated to bring about the operation of relays 126, 724 which open the circuits of the counting relays. The relays 126, 724 also deenergize the relays 410, 618 and a circuit is completed from the generator G4 through the relay 222, line 490, to relay 815. The relays 222, 815 are thus energized in series and the relays 213, .823 are energized to open the series circuit and thereby re-initiate the operation of the counting relays to operate the second group of selecting relays in sequence. When finally, the last -counting relays are operated, the switching relays 311, 517 are de-energized to disconnect - the second group of selecting relays from the counting chain and the relays 312, 516 are operated to associate the third group of selecting relays with the counting relays. The circuit of the relays 222, 815 is also completed and the control circuit again functions to successively operate the third group of selecting relays. The last counting relays, when separated, again restore the system to normal after the cycle is completed, and the selective equipment is reoperated in order to check the positions of all the apparatus units. Signalling position of circuit breaker when operated automatically by load conditions. When the circuit breaker C is operated automatically, a relay 825 is closed to initiate the operation of the selective equipment. The relays 309, 500 associated with the breaker are energized and the generator G6 operates the supervisory lamps 231, 232 in the manner described previously. Should the selective equipment be operating when a circuit breaker is automatically operated, the relay 825 operates a relay 819 which, at the end of the cycle of operations, causes the energization of the relay 823 and the re-operation of the selecting equipment to signal the changed condition of the circuit breaker. A testing key K2 is provided at the control station for operating the selecting apparatus without causing the operation of the substation units. The system shown may be enlarged by providing additional switching relays and groups of selecting relays or by providing three additional switching relays with three groups of selecting relays so that one counting relay controls two apparatus units and two supervisory signals. Specification 225,542 is