Patent GB-295331-A (GB)
Title: Improvements in or relating to electrical signalling and/or controlling systems
IPC: H02J13/00
Filed: 1928-08-09
Abstract: 295,331. Associated Electrical Industries, Ltd., (formerly Metropolitan- Vickers Electrical Co.., Ltd.), (Assignees of Moreau, A. L.). Aug. 9, 1927, [Convention date]. Selective distant control systems; tell-tale apparatus.-In a system for the supervising control of. apparatus at a distant station of the type wherein the apparatus e.g. circuit breakers and the corresponding control keys and supervising signals are associated with control and supervising line wires by chains of synchronously driven relays which are driven over a third line wire, auxiliary relays are provided at each station to check the synchronous operation of the relay chains. In the event of faulty operation the checking relays fail to operate and thereby prevent closure of the operating circuit of the apparatus unit which is being selected. Furthermore synchronous operation of the relay chains is preserved by altering the polarity and the circuit of the driving and checking impulses as the cycle of operations proceeds. Faulty operation may still further be prevented by transmitting a code of impulses to cause operations of the unit after selection. Figs. 1, and 2 show the control station apparatus and Figs. 3, and 4 show the equipment at the substation. Circuit breakers 420, 430 (two only being shown) and their selecting keys 150, 156 and supervisory lamps 152, 153, 158, 159 are associated with a corresponding number of selecting relays in the chains 211 - - 220, 311 - - 320 at the control station and substation respectively. To effect a particular selection, the appropriate selecting and " stop " keys are operated to cause the relay chains to operate synchronously until the associated relays at each station are energized. Upon selection and the operation of a master key a code of impulses depending upon the operation to be effected e.g. " opening or " closing " a circuit breaker, is transmitted. When the apparatus unit changes its position a supervisory impulse is transmitted over the line s to operate the appropriate lamp. The relay chains are driven by relays 225, Fig. 2, and 327, Fig. 3, which are energized in series over the line wire d and the operation of each selecting relay is checked by relays 227, 325-which are operated in seriesover one or other of the lines c, s. The code of impulses for operating a selected unit comprises impulses transmitted over the line c and reverted over line wire s. The polarity and the circuit of the driving and checking impulses are altered at predetermined points in the cycle of operations in order that the operating code for each relay in the selecting chain may differ. The possible number of selections may be increased by further extending the use of the line wires for additional selecting relays. The control and supervisory operations are effected while the driving circuit is energized in order that non-synchronous conditions may be detected without the need of further line wires. Normal condition of system. The relays 222 Fig. 2, and 330, Fig. 3 are normally energized in series over the line c. The relay 222 operates a lamp 168, Fig. 1. Normal operation of selecting equipment. In order to effect the sequential operation of the relay chains, a " start " key 169, Fig. 1, is depressed to energize relay 230 which opens the normally closed holding circuit to de-energize relays 222, 330, and prepares the circuits over the lines c, s, d. Release of relay 222 illuminates a lamp 170 to signify that the equipment, is in operation, and de-energization of relay 330 causes operation of relay 322 which also prepares the line circuits. A circuit is now closed over the drive line d and relays 225, 327 in series. These relays operate the first selecting relays 211, 320 in the relay chains, the selecting relays locking up and closing a circuit over the checking relays 227, and the supervisory line wire s. This circuit is closed only provided the corresponding selecting relays at the stations operate simultaneously. Relays 227, 325 respectively cause the operation of relays 229, 323 which, in the event that the position of the selected apparatus unit differs from that of its key, transmits a supervisory indication. Normally, however, the key and its apparatus unit occupy corresponding positions and no signal is transmitted owing to a battery to battery or earth to earth connection over the supervisory line s. The relay 229 switches the line wires c, s, from their checking connections to contacts in the operating circuits and operates a relay 223 over the stop key 151 corresponding to the first selecting relays and the contact of the selecting relay 211, to open the driving circuit over the line d. In the event that operation of the apparatus unit associated with the first selecting relays is desired the stop key 151 is opened to prevent operation of the relay 223 and in consequence to maintain the drive line closed. In this manner the sequential operation of the relay chains is stopped and the connection to the selected apparatus unit is maintained to facilitate its operation. When the driving circuit is opened, line relays 225, 327 are de-energized. Relay 225, de-energizes 229 to restore lines c, s to the checking contacts and operates relay 201 while relay 327 simultaneously operates relay 310. Relays 201. 310 de-energize selecting relays 211. 320 and prepare the circuits of the next selecting relays 212, 319. Relay 201 also operates a relay 103 which operates a buzzer 163 to indicate, that the equipment is in operation. The buzzer can only be stopped by depression of a key 162. De-energization of selecting relay 211 offers the circuit of relay 223 which again closes the driving circuit over the line relays 225, 327. The line relays then operate the selecting relays 212, 319 which complete the checking circuit over the line s and relays 227, 325 but the polarity of the checking impulse is reversed. The checking relays operate in the manner previously described to open the driving circuit and allow the sequential operation of the relays to proceed. The third and fourth checking impulses transmitted after the operation of the relays 213, 214 at the control station and the relays 318, 317 at the substation are however impulses of opposite polarity transmitted over line wire c. Arrangements are also made for altering the polarity of the driving impulses after the operating of the fourth selecting relays at each station. When the corresponding relays 204, 307 are energized after the operation of the selecting relays 214, 307 relays 225, 328 are operated to reverse the battery polarity over the driving line d at each station. This polarity is maintained throughout the operation of the next four selecting relays after which relays 208, 303 operate relays 231, 321 to switch line s into the driving circuit and to adapt the original driving line d as the supervisory and checking line. This condition is maintained during operation of the last two selecting relays. In this manner each pair of corresponding selecting relays is operated and checked by a different combination of driving and checking impulses in order to ensure synchronous operation. Lamps such as 155, 161 are operated by the corresponding selection of relays to indicate the position of the selecting equipment at any moment. Operation in the event of non-synchronous working. If corresponding selecting relays are not operated synchronously the relays 227, 325 remain de-energized. Normally at each operation of relay 227 a lamp 171 is illuminated and in consequence non-synchronous operation is notified bv the absence of intermittent illumination of the lamp. Depression of key 172 operates relay 234 which disconnects battery from the operated relays and causes release at the control station. Absence of impulsing at the substation allows a slow-release relay 333 to operate a relay 332 which disconnects battery to cause release in a similar manner. If two neighbouring selecting relays are energized simultaneously a marginal relay 228 is operated to open the checking circuit. A relay 324 is provided at the substation for a similar purpose. Operation of circuit breaker. Assuming it is desired to operate circuit breaker 420 the corresponding selecting key 150 and stop key 151 are operated. Operation of the stop key prevents the energization of relay 223 and thereby maintains the driving circuit closed to prevent further stopping after the corresponding selecting relays 211, 320 are operated. The master key 167 is then depressed to transmit one or other of two codes depending upon whether it is desired to " open " or " close " the circuit breaker. The apparatusshown is adapted to transmit five impulses for " closing " or three for " tripping " according to which of the relays 107, 105 is energized. If it is desired to " close " the circuit breaker relay 107 is energized over the contacts of keys 167, 150 and the selecting relay 211. The first impulse is transmitted over the control line c and contacts of selecting relays, and stop and master keys upon energization of relay 226 subsequent to operation of the selecting relay 211. This impulse operates relay 406, Fig. 4, which through a relay 402 reverts a second impulse back to the control station to operate a relav 108. Relay 108 operates relay 109 over a circuit prepared by relay 107 to open the original impulse circuit over line c, and de-energize relay 406 to terminate the reverted impulse over line s. Release of relay 108 causes operation of relay 110 to transmit a third impulse over line c. The transmission and reversion of impulses continues until the fifth impulse causes operation of relay 409 and the energization of the circuit breaker operating relays 414, 417, 419. If it is desired to " open " the circuit breaker, relay 415 is operated upon energization of relay 403 by the third impulse. Supervisory signalling. When the circuit breaker is operated relays 413, 412 are energi