Patent GB-227114-A (GB)
Title: Improvements relating to electrical control systems
IPC: H02J13/00
Filed: 1924-12-30
Abstract: 227,114. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Wensley, R. J., and Gardner, J. E.). Jan. 2, 1924, [Convention date]. Selective distant control systems; tell-tale apparatus.-In a control and supervisory signalling system for power substations having a distant control station of the type described in Specification 225,542, wherein chains of relays at the stations are operated synchronously through a complete cycle by impulses transmitted over the line wires upon the operation of a key at the control station or an automatic change of condition of an apparatus unit at the substation, the impulses are of alternate polarity in order to minimize the risk of synchronous operation due to inductive interference. Figs. 1 and 2 show 'the control apparatus and Figs. 3 and 4 show the apparatus at the substafion. The chains of relays at each station are divided into three groups: (1) transmitting and receiving chains 110 - - 114, 400 - - 404 for selecting one or more of a number of apparatus units such as circuit breakers, (2) transmitting and receiving chains 405 - - 409, 105 - - 109 for selecting supervisory signal lamps such as 121, 122 at the control station, and (3) auxiliary chains 115 - - 120, 412 - - 417 which operate in conjunction with both of the other groups and determine the nature of the operation, viz. " opening " or " closing " of the circuit breakers and also the appropriate signal lamp corresponding to this condition. The control station is provided with a key such as K for preparing the operating circuit of each apparatus unit, such as the circuit breaker C, Fig. 4. Each key is associated with a relay in the chain 110 - - 114, and the contacts of the relays in the chain 400 - - 404 are connected to relays such as 410, 411 for preparing the circuits of the operating coils of the circuit breakers. The contacts such as 136<a> - - 138 corresponding to the two positions of all the control keys &c. are multipled respectively on back contacts of relays 116, 118 in the auxiliary group 115 - - 150 and the contacts of the corresponding relays in the auxiliary group at the substation are connected to relays 313, 314, Fig. 3, respectively, which when operated complete a circuit over the contacts of the appropriate relay in the main group at the substation for operating one or other of two relays 410, 411 and thereby prepare the circuit of the corresponding operating coil of the circuit breaker. The chains of relays at each station are operated synchronously by polarized relays 207, 302 which are operated by impulses of alternate polarity derived from batteries B<1>, B<2>, Fig. 3, transmitted over the lines 280, 281. When a key is operated, the lines 280, 281 are connected to the relay 207 and an impulse is sent over the lines 281, 282 from the battery B to connect the relay 302 to the lines. The main groups are impulsed by the relay 302 in the sequence 114, 113 ..., 400, 401, until the relays corresponding to the operated key are operated. The relay 113, say, at the control station causes the transference of the impulsing circuit to the auxiliary group and sends a second impulse from the battery B to effect a similar transference at the substation. The auxiliary groups are then impulsed synchronously until one or other of the relays 118, 116 depending upon the position of the key is energized, whereupon a further impulse is sent over the lines 281, 282 to energize the corresponding relay 410, 411. The auxiliary chains continue to operate until the relays 115, 417 are energized to re-connect the impulsing circuit to the main group of relays at the control station and send a further impulse from the battery B to effect a similar operation at the substation. The remaining relays in the main groups are then operated successively until upon operation of the last relays another impulse is sent from the battery B to operate the selected actuating coil of the circuit breaker. When the circuit breaker is operated, the chains of relays 405 - - 409, 109 - - 105 together with the auxiliary groups are operated in a similar manner to actuate the corresponding supervisory signal lamp such as 121 or 122. During this operation, however, the impulses for transferring the impulsing circuit, and selecting and operating the appropriate supervisory signal are derived from the battery. B' at the substation. When a circuit breaker is operated automatically by varying load conditions, the supervisory signals are operated in a similar manner, the relay chains bemg operated in the sequence 114, 113, 112 ..., 400, 401, 403 . . ., until a relay in the chain 405 - - 409, corresponding to the operated circuit breaker is reached and a transfer of the impulsing circuit to the auxiliary groups is effected. Relays 203, 300 at the control and substation respectively are energized at each operation of corresponding relays in the chains to open the impulsing circuit over the lines 280, 281 and thereby further minimize the risk of asynchronous operation. Selection and operation of circuit breaker C, Fig. 4. Assuming the circuit breaker is closed and it is desired to trip it, the key K is operated so as to complete a circuit at the contact 125 and energize a relay 104. The relay 104 illuminates a lamp 123 to signify the initiation of the operation, operates a relay 202 to associate a line relay 207 with the lines 280. 281 and prepares a circuit over the contact 189 of the counting relay 113. The relay 202 also operates momentarily the relay 214 which transmits an impulse from the battery B to the relay 308 at the substation over lines 281. 282. When the relay 308 is operated. the lower winding of the relay 301 is energized and the circuit of the line relay 302 is closed at the armatures 320, 321. The line relays 207, 302 are thus energized in series by the battery B<2> and the right-hand sides of their armatures are attracted. A slow-acting relay 304, which was previously energized by the operation of the relay 308, is maintained energized by the relav 302 and prepares the circuit of the lower winding of the first counting relay 400. When the line relays 207, 302 are operated, a relay 303 is energized to insert a battery B<1> in series with the relays in the place of the battery B<2>. A reverse current is thus sent over the lines 280, 281 and the armatures of the line relays are operated in the opposite direction. The relay 207 energizes the lower winding of the first counting relay 114 and the relay 203. The relay 203 opens the line circuit and is de-energized to again close the line circuit when the armatures of the relay 114 are attracted. Similarly, the relay 302 at the substation energizes the lower winding of the counting relay 400 and the relay 300 which functions in a manner similar to the relay 203. The relays 203, 300 thus open the line circuit upon the transmission of each impulse and thereby ensure synchronous operation of the relay chains. When the lower windings of the relays 114, 400 are energized, circuits for the upper windings are completed but are not effective since they are short-circuited while the impulsing circuit is maintained. The operation of the line relay 302 again inserts the battery B<2> into the line circuit and the line relays operate in the opposite direction to remove the short-circuits and allow the complete operation of the counting relays 114, 400 to prepare the circuits of the lower windings of the next counting relays 113, 401. Two subsequent operations of the line relays 207, 302 cause the complete energization of the relays 113, 401. The relay 113 operates the relay 205 over the back contact which is associated with the kev K and transfers the impulsing circuit to the group of counting relays 115 - - 120. The relay 205 also energizes the relay 214 which operates the relay 308 at the substation. The relay 308 energizes the lower winding of the relay 310. The slow-acting relay 204 retracts its armature after an interval, due to the operation of the relay 205, and opens the circuit of the relay 214 which deenergizes the relay 308 and causes the relay 310. the upper winding of which is short-circuited while the relay 308 is energized, to prepare the circuit of the relay 311 and connect the impulsing circuit to the auxiliary relay group. The line relays 207, 302 continue to operate again under the control of the relay 302 and the synchronizing relays 208, 300 and the lower windings of the counting relays 120, 412 are energized to prepare their upper windings. Upon the next operation of the line relays, the next relays 119, 413 are operated. This operation is repeated until the. counting relays 116, 416, which correspond to the " tripping " operation that it is desired to effect, are energized. The relay 116 operates the relay 208, the circuit of which has been prepared by the counting relay 113 corresponding to the key K and prepares the circuit, for the next counting relay 115. The relav 208 energizes the slow-acting relay 204 and the relay 214. The relay 214 operates the relay 308 which energizes the lower winding of the relay 311 and the relay 313, the circuit of which has been prepared by the counting relay 416. The relay 313 prepares the circuit of the relay 410 over the operated contacts of the relay 401. The relay 308 de-energizes after an interval under the action of the relay 204 and the circuit of the relay 312 is prepared. Upon the next operation of the line relays, the counting relays 115, 417 are operated. The relay 115 opens the locking circuits of the relay 205 and the relays 116 - - 120 and energizes the, relay 214 which again operates the relay 308 to energize the lower winding of the relay 312 and operate the relay 410. The circuit of the relay 208 is also opened by the relay 115 and the relay 308 is de-energized to remove the short-circuit from the relay 312 and allow it to operate completely.. The relay