Patent GB-216085-A (GB)
Title: Improvements relating to electric substations
IPC: H02J13/00
Filed: 1923-10-09
Abstract: 216,085. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Wensley, R. J., and McCoy, J. L.). May 19, 1923, [Convention date]. Distant-control systems; tell-tale apparatus.- In a system for supervising and controlling from a remote point the operation and condition of a number of apparatus units at each of a number of substations of an electric supply system, in which a finder switch F1 at a sub-station, Figs. 2 and 5, hunts for an apparatus unit which changes its condition, a step-by-step switch CD1 moves from its normal position in two stages to contacts marked by the setting of the finder F1, and a connector switch H1 at the control station, Figs. 1, 6 and 7, moves in synchronism with the switch CD1, being controlled thereby over trunk conductors 590, 591. and controls through relay groups RG4, RG5, banks of supervisory lamps L, Fig. 7, provision is made for preventing a faulty supervisory signal being given in case the switches CD1, H1 gets out of synchronism. (Figs. 1 and 7 should be arranged with Figs. 1 - - 4 in order from left to right and with Figs. 7, 6, and 5 under Figs. 1, 2, and 3 respectively.) The apparatus at the control station comprises a number of keys K, one for each apparatus unit to be controlled, a finder switch F which hunts for the particular key operated and a switch CD which controls over two further trunk conductors 180, 181 a connector switch H, the switches CD, H acting in a manner similar to the switches CD1, H1, to mark group and unit relays RG, RG1, which effect, for ex- :ample, the closure of a relay 404 to start the machine shown at the bottom of Fig. 4. An audible alarm is given when any supervisory signal is being transmitted. Means are also provided for checking all existing supervisory signals and for indicating the load on the substation. In a modification, Fig. 9, a two-wire trunk is employed for simultaneously transmitting control and supervisory impulses in both directions. Another modification, Fig. 10, provides for a larger system employing more than one finder switch. Signalling starting of a machine. When a contact-maker 445, Fig. 4,. operates, it completes a circuit for relay 422 which in turn energizes relay 421. Relay 420 being already locked up, a circuit 427, 424, 462, 504, 540 is now completed for stepping magnet 504 which advances wipers 511 - - 514 of the finder FI in search of the bank contacts 515 - - 518 associated with the particular machine which has started. When these are reached, relay 528 operates over the circuit 464, 428, 463, 518, 514 to stop the wipers and to cause the operation of relays 527, 525, 526, 530, 532, 531. Relay 533 and impulse relay 501 energize in parallel circuits from battery at armature 552. Relay 501 energizes relay 607, Fig. 6, at the control station, at which circuits are also completed for relays 605, 604, .601 and stepping magnet 623. Relay 533 completes a circuit 506, 549, 551, 534, 557, 546 for magnet 534 which on operation, opens the circuit of relays 501, 533, the former transmitting an impulse over the trunk 590, 591 whilst the latter opens the .circuit of magnet 534 which on de-energizing advances its wipers 555 - - 558 one step. Impulse transmission thus goes on under the combined control of relay 533 and magnet 534 until wiper 556 reaches terminal 561 when relay 502 energizes over the circuit 556, 561, 517, 513, 462, 427 and opens the circuits of magnet 534 and of relay 532. After an interval, the relapse of relay 531 completes a new circuit for magnet 534 and the stepping movement of the wipers 555 - - 558 is resumed. The first set of impulses is repeated by relays 501, 607 to stepping magnet 623 which advances the wipers 630 - - 633 until wiper 630 engages terminal 640. At the first step, a circuit is completed for relay 606 which grounds lead 649, whereby relay 770 locks up over key K1, lights lamp 773 and sounds an audible alarm (not shown). Whilst the impulses are coming in, relay 604 is maintained energized over contacts 615, 620, but during the pause between the impulses due to the operation of relay 502, relay 604 releases its armatures and completes a circuit 616, 662, 708, 651, 630, 608, 617, for relay 708 which locks up to lead 650. The second stepping movement of wipers 555 - - 558 proceeds untii wiper 556 engages terminal 563 when relay 502 energizes again over the circuit 556, 563, 466, 430, 461, 516, 512, 462, 427 and' effects a pause in the operation as before. During this second stepping movement impulses are repeated to the stepping magnet 623 as before and a slow-release relay 603 is energized over wiper 631 in jets 12th-14th positions and maintained energized over back contact 620. At the end of the series, relay 603 relapses and completes a circuit 613, 661, 705, 657, 630, 608, 617 for relay 705 which locks up. After the second pause, the synchronous movement of switches CD1, H1 continues until both reach their 25th positions when wiper 555 disconnects relays 527, 525 and energizes relay 529. Relay 527 has a vibrating armature which maintains relays 525, 526 energized for an interval and is adjusted to release relay 525 first. When this relay relapses, relay 503 energizes and connects ground to conductor 460, thereby short-circuiting relays 420, 421 which release. When switch H1 reaches its 25th position, relay 602 is disconnected at wiper 633 and, on its release, completes a circuit 610, 660, 726, 720, 712 which short-circuits relay 700 so that lamp 715 is extinguished and lamp 717 lit to signal the starting of the machine. The final release of relay 526 de-energizes relay 530 which on releasing completes a circuit 548, 534, 547, 558, 552 for magnet. 534 which advances wipers 555 - - 558 into their normal position. Relays 529, 503 are now de-energized and relay 422 being still operated, relay 421 energizes again and locks up. The disconnection of relay 501 causes the release of relays 607, 605, and magnet 623 energizes over the circuit 618, 624, 632 and advances switch HI to its normal position. Since the operation of the lamp group L is dependent upon switches CD1, H1 both reaching their 25th positions at the same time, a faulty supervisory signal is prevented in case the switches get out of synchronism and, in such a case, the whole operation commences again. Signalling load on substation. A Kelvin balance ammeter A, Fig. 4, of known type responds to a change in load in the bus-bar 440 and closes a circuit 433, 435 for a relay 450 which in conjunction with relays 451, 452 controls the finder F1 and switch CD1 in a similar manner to the relays 420 - - 422. As a result, relays 711, 706, Fig. 7, are selected in the manner already described and a relay 738, energized over the circuit 659, 609 unlocks whichever of the relays 735 - - 737 is then energized and extinguishes the corresponding lamp. When switch H1 reaches its 25th position, relay 735 energizes over circuit 775, 660, 610 and lights lamp 750. In a similar manner, in response to further changes in load, the contact member 433 closes circuits for other relays similar to relay 450. Control of substation apparatus by control operator. In order to start up the machine controlled by contact-maker 445. the operator throws a corresponding key K, Fig. 1, to the right, thereby completing a circuit 103, 109, 120 in which stepping-magnet 109 operates and rotates the finder F. When the terminals 127 - - 130 corresponding to the operated key are reached, relay 113 energizes over wiper 126 and contact 101 in series with relay 108 and stops the finder. Relay 113 also causes the operation of relays 111, 110, 140, 141, 142. whilst relav 143 and impulse relay 144 energize in parallel circuits from battery at armature 152. Belay 144 energizes relay 200, Fig. 2, at the substation at which the circuits of the switch H are similar to those of switch H1 already described. Relay 143 completes a circuit 155, 151, 153, 146, 162, 148 for magnet 146 which, on operating, opens the circuits of relays 144, 143, the. former transmitting an impulse oyer the trunk 180, 181 whilst the latter opens the circuit of magnet 146 which on de-energizing advances the wipers 160 - - 163 one step. Impulse transmission thus goes on until wiper 161 engages terminal 165 when relay 145 energizes over the circuit 161, 165, 129, 125, 102 and acts in a similar manner to relay 502 to effect a pause in the impulse transmission. Further impulses are then transmitted until wiper 161 engages terminal 166 when relay 145 again energizes over contacts 166, 128, 124, 119, 102 and effects a further pause. The two series of impulses thus transmitted over the trunk 180, 181 effect the locking up of relays 306, 303 respectively. Switches CD, H then move forward synchronously to their 25th positions in which the release of relay 205 completes a circuit 220, 269, 372, 404, 371, 319, 323 for relay 404 which energizes to complete a circuit for contact-maker .445. The closure of contact 446 transmits an answer-back signal in the manner previously described. Relay 404 also completes a circuit for relay 420, 421 to ensure an answer-back signal in case the contact-maker 445 is already operated. The short-circuiting of relay 700 in addition to lighting lamp 717 also energizes magnet 105 to release the operated key K. If, however, any error occurs in the transmission key K will not be released and the whole cycle of operations will take place again. In' the 25th position of switch CD, relay 111 is disconnected and relay 112 operated so that when, after an interval, relay 110 relapses, the stepping-magnet 109 is again energized to advance the wipers 123 - 126 a few steps so as to prevent the finder F'from being held up indefinitely by the repetition of a faulty transmission. The relapse of relay 110 also de-energizes relay 140 which completes a circuit 147, 146, 149, 163, 152 for driving switch CD into its 1st (normal) position. In ord