Patent GB-422206-A (GB)
Title: Improvements in and relating to electric selective supervisory control systems
IPC: H02J13/00
Filed: 1933-07-10
Abstract: 422,206. Electric signalling and distant-control systems. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Oliver, J. H. ; 15, Ridley Avenue, Aldan, Pennsylvania, U.S.A.) July 10, 1933, No. 19494. Convention date, July 8, 1932. [Class 40 (i)] In an electric supervisory control system wherein apparatus units at a station are selectively associated with corresponding control members and signalling devices at the control station by synchronously-driven switches, the stepping of the switches and controlling and signalling are accomplished over a single pair of line wires. Fig. 1 shows the equipment at the control office and Fig. 2 that at a substation provided with a plurality of circuit breakers AU1-AU23, only two of which are shown. The line circuit is normally closed to provide a check on continuity or short-circuit. When it is desired to operate a particular circuit breaker the corresponding key in the office is operated and the switches A, A<1> are driven synchronously by relays SSR, SSR<1> responsive to impulses of alternate polarity until they reach positions corresponding to the depressed key. Operation of a common control key then transmits a current over the line wires to cause the desired operation of the circuit breaker. A signal of characteristic frequency is reverted to the office to indicate the position of the unit. Normal circuit conditions and fault-checking arrangements. Under normal conditions the line relay SSR operates relays X, D at the office and line relay SSR<1> energizes relay C<1>, B<1> at the substation. The normal check circuit of the system includes positive of battery BAT<1>, relay E<1>, Fig. 2, wiper S<1>, relay SSR<1>, line L<1>, relay SSR, wiper S, relays S1, E, key ERK to negative of battery BAT, contact of relay P, and line L<2> to neutral point of battery BAT<1>. This circuit includes portions of the batteries in series and the normal current is sufficient to produce operation of relay S1 only so as to operate relay H and thereby cause illumination of lamp STL. Relay H also locks up relay K which controls an audible alarm AL. In the event of an open circuit in the line circuit, relay H is released to extinguish lamp STK and release K to effect operation of alarm AL. If the alarm key AK is in position shown, the relay K is re-energized and the alarm stopped. If the key AK is opened, a continuous alarm is given in the event of a fault. A short-circuit across the line circuit increases the current flow in the check circuit and causes operation of relay E which deenergizes H to give the alarm signals. A relay All, Fig. 2, is connected across the substation battery so that in the event that that battery fails the line circuit is opened to cause operation of the alarms. Selection of apparatus unit. To select a particular unit, the corresponding key SK1 .. SK23 is operated. The "start" key STK also is depressed to operate relay P in a circuit including wiper T. Relay 8 disconnects line wire L<2> from the neutral point of battery BAT and connects it to the positive pole, and shortcircuits relays S1, E. This operation increases the line current, and energizes relay E<1> which operates F<1> to shunt E<1> and again increase the line current to a value sufficient to operate the line relays SSR, SSR<1>. These relays operate the stepping magnets m, m<1> of the switches A, A<1> over wipers N, N<1>. The switches A, A<1> are thereby advanced one step and in the new positions connect opposite poles of the battery over wipers S, S to the line wires so as to cause reverse operation of the line relays and cause further stepping. The line relay SSR holds up relay C during stepping and line relay SSR<1> impulses a slow relay C<1> so as to control the speed of operation of the selectors. Stepping of the selectors continues in the manner described until the switch A engages the contact and corresponding to the depressed key. In this position relay A<1> also connected to line L<1> is no longer short-circuited and a circuit is established over relay A<1> and line wires L<1>, L<2>, the relay A<1> pulling up and operating relay B which illuminates an amber light AM1 corresponding to the selected unit. Control of selected unit. Common control key OK is depressed to operate relay F which disconnects the line wires from the line relay SSR and connects them to the wipers of banks C, C<1> corresponding contacts in which banks are connected to opposite battery poles. The operation of relay F therefore applies full battery potential to the line wires in opposition to half battery potential at the other station and thereby causes the transmission of reversed current to operate relay MOR<1> in the appropriate direction. Relay MOR<1> operates one or other of the relays M<1>, K<1> which operates a relay, e.g. CR 1 over wiper C to effect operation of the associated circuit breaker. The selected breaker may be opened and closed as many times as desired by operation of the key OK by the transmission of corresponding impulses of like polarity over the line. Supervisory signalling. The position of a relay P<1> is controlled over wiper I<1> by auxiliary contacts on the circuit breakers in accordance with the position of the breaker. The relay P<1> switches one or other of the alternators AC<1>1, AC'2 of different frequency across the line wires to operate relay M1R in one or other direction. The relay M1R operates the appropriate supervisory relay, e.g. IR1 over wiper 1 of switch to switch on the lamp R1 or G1 corresponding to the position of the circuit breaker. If disagreement exists between a check key CK and the relay 1R a white lamp W also is lit. Restoration to normal of equipment. When the operated selecting key is restored relay A<1> is short-circuited and the current in the line circuit is increased to cause operation of the relays SSR, SSR<1> which cause stepping of the switches to normal position. In these positions the above-described check circuit is reestablished. Signalling automatic operation of circuit breakers. When a circuit breaker is automatically tripped, an indication relay 1A is operated to energize a " start " relay D<1> which operates P<1> to connect alternator AC<1>1 across the line wires. An alternating current signal is thus transmitted to the office, the relay MIR operating relay P over wiper 1 in the normal position and contacts of the start key STK. Operation of P initiates the operation of the switches A, A<1> which during their rotation cause operation of the signalling devices associated with the affected circuit breaker. Correcting out-of-synchronous operation. In the event that the switches become out of synchronism, a key ERK is operated to shortcircuit the line wires between the stations. Local circuits are thereby closed for the line relays SSR, SSR<1> and independent stepping occurs until both switches come to rest in their normal positions. The Specification as open to inspection under Sect. 91 refers to Specification 307,469, [Class 40 (i)]. This reference does not appear in the Specification as accepted.