Patent GB-225542-A (GB)
Title: Improvements relating to electrical control systems
IPC: H02J13/00
Filed: 1924-11-21
Abstract: 225,542. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Wensley, R. J.). Nov. 28, 1923, [Convention date]. Selective distant-control systems; tell-tale apparatus.-In a supervisory control system for a substation having a distant control office relay chains at the substation and control office are adapted to be operated synchronously through a complete, cycle when a key at the control office corresponding to an apparatus unit at the substation is operated. A pause is introduced at a point in the cycle of operation corresponding to the actuated key to allow for the selection of the apparatus unit and actuation of the unit is effected when the cycle is completed. Relay chains, operating in a similar manner, are also provided for operating supervisory lamps at the control office. The substation apparatus units may be operated manually or automatically at the substation according to load conditions. Figs. 1 and 3 show the apparatus at the control office, and Figs. 2 and 4 show a substation having circuit breakers C, C', C<2>, which are operated from the control office by keys K<2>, K<1>, K respectively. The keys are of the " double throw " type and each controls two relays such as 106, 105 which correspond with the " open " and " closed " positions of the circuit breakers. When one or more of the relays 101 - - 106 are operated, counting relays 115 - - 108, 206 - - 200 at the control office and substation respectively are operated synchronously. The relavs 206 - - 201 effect the selection of relays in the chain 213 - - 208, which correspond to the selected relays of the chain 101 - - 106, and thereby prepare the circuits of the corresponding actuating coils such as 412 of the circuit breakers. When finally the cycle is completed and the relay 207 is operated, the circuits of the. selected actuating coils are closed at the armature 239 and the circuit breakers are operated. When the circuit breakers are operated the groups of counting relays 401 - - 407, Fig. 4, and 300 - - 307, Fig. 3, are operated in a similar manner to effect the selection of the supervisory signal lamps 323 - - 328 at the control office. The relay 118 is operated by each counting relay in the chain 108 - - 115, and impulses are sent over the lines 265, 266 to the relay 214, which operates the counting chain 206 - - 200. Similarly, the relay 316, Fig. 3, is operated by the relay 408, Fig. 4, over the lines 380, 381 to effect the operation of the counting chain 302 - - 307. Selection of a circuit breaker. In order to effect the selection of any particular circuitbreaker a pause in the cycle. of operation of the relays 115 - - 108 takes place at the relay which corresponds to the selected relay in the group 101 - - 106. This pause is introduced by the action of slow-release, relays 116, 117 which, by means of circuits prepared by the appropriate relay in the group 101 - - 106, delay the operation of the counting relay until the relays 116, 117 retract their armatures. During this pause, the relays 118, 214 are maintained energized and the armature 254 of a slow-release relay 215 operates the particular relay in the group 208 - - 213 which corresponds to the selected relay in the group 101 - - 106. After this relay is operated to prepare the circuit of the circuit-breaker actuating coil, the remaining relays of the counting chains operate, without delay since the slow-release relays 116, 117 are effective only at the counting relay associated with the operated keys. Finally the relay 207, Fig. 2, is operated to complete, at the armature 239, the circuit of the operating coil of the selected circuit-breaker. The relay 107, Fig. 1, also opens the locking-circuits of the counting relays 108 - - 115, and actuates, through a relay 90, slow-release relay 93 which ensures that the sending operation does not recur before the slow-release relay 216 opens the locking circuits of the relays 200 - - 213. The relay 90 has a weighted armature which upon de-energization of the relay, vibrates for an interval of time, during which the relay 93 is maintained energized. Supervisory signalling. When the circuitbreakers are all in the " open " position a relay 400, Fig. 4, is energized. When, however, any particular circuit-breaker is closed, the locking circuit of the relay 400 is opened by a switch, such as 416, on the circuit-breaker and the relay starts the cycle of operations of the counting chain 407 - - 402. Each circuit-breaker is associated with a pair of relays in this chain, and each counting relay is operated to energize and de-energize the line relay 408. Impulses are thus sent over the line 380, 381 to a line relay 316, Fig. 3, at the control office to effect the successive operation of the counting relays 307 - - 302 and the selection of the appropriate relay in the group 308. 304, 310. Selection is effected in a manner similar to that described for selecting a circuit-breaker, the pauses being introduced by slow-release relays 409, 410. During these pauses the line relay 316 is maintained energized for a time sufficiently long to permit the retraction of the armature, 370 of a slow-release relav 315 and thereby cause the operation of the selected relay in the group 308, 309, 310 and the preparation of the circuit of the corresponding supervisory lamp relay in the group 311, 312, 313. The rslays 303. 309, 310 are operated only when the circuitbreakers occupy their " closed " positions. The open " positions are indicated normally when the relays are de-energized. When finally the relay 300, Fig. 3, is operated by the action of the relay 401, Fig. 4, a further pause is introduced to allow the armature of the relay 315 to retract and close the circuits of the selected relays in the group 311, 312, 313 and thereby illuminate the appropriate supervisory lamps. When these relays are operated the locking circuits of the operated relays in the group 101 - - 106 are opened and the sending operation is terminated. This makes it impossible to secure a false operation, inasmuch as the sending operation is continued in the manner described above, until a proper answer-back signal is given. The relay 401 causes the operation of the relay 400 to open the locking circuits of all the counting relays 401 - - 407. The relay 400 also opens the circuit of the relay 470, which is of similar construction to that of the relay 90, Fig. 1. The action of the relay 470 introduces a pause in the cycle of operation of sufficient time to permit the slow-release relay 314 to de-energize and open the circuits of the relays 300 - - 306 and 308 - - 310 to restore the apparatus to normal.