Patent GB-333172-A (GB)
Title: Improvements in or relating to electric selective remote control systems
IPC: H02J13/00
Filed: 1929-05-02
Abstract: 333,172. Reyrolle & Co., Ltd., A., Leeson, B. H., and Lambert, D. E. May 2, 1929. Selective distant control systems.-An electric selective remote control system for circuitbreakers or other apparatus at a power station employs four pilot wires for carrying the remote control currents, and the currents passing over either of two'of these wires are such that the two wires can be temporarily disconnected without causing incorrect operation of the remote control apparatus, and whenever these wires are connected together at either end through remote control apparatus, such apparatus will remain inoperative if temporarily energized from a source of current external to the remote control system, whereby the two pilot wires can be temporarily borrowed from the remote control system for other purposes, without harmful interference with the system. In the construction shown, the remote control system employing four pilot wires A<1> - - A<4> is combined with a protective system of the kind described in Specification 314,778, [Class 38 (v), Electric switches &c.]. A power feeder B connecting the control station and substation is provided at the substation with a group of tripping relays indicated at C and a group of stabilizing relays indicated at D. The relays D are directional so that one or other operates on the occurrence of a fault provided that the current at the adjacent end of the feeder is flowing outwards from the feeder, while the operation of the relays C is independent of the direction of current flow. Auxiliary relays E, F are adapted to be operated by relays D, C respectively. Similar relays and groups of relays are provided at the control station. Normally the pilot wires A', A<2> are connected to their remote control circuits through contacts F<1>, F<2>, f<1>, f<2>. If a fault occurs on the network external to the feeder B a current in one direction flows through the feeder, causing operation of the tripping relays F, f at both ends, and at one end, for example, the substation end, causing operation of the stabilizing relay E. At this end the wires A', A<2> will therefore be connected to a local battery H and at the control station end to a lock-out relay g. The relay g operates to prevent operation of a time-lay relay j controlling a tripping circuit k for a circuit-breaker l. The relay E at the substation by its contacts E<3> prevents operation of the time-lay relay J. The feeder B therefore remains in circuit at both ends. When the fault is cleared the tripping and stabilizing auxiliary relays re-set and return the wires A<1>, A<2> to their normal circuits. If the fault occurs in the feeder itself and fault current is supplied from both ends of the feeder the relays F, f operate, but relays E, e are inoperative so that the time-lay relays. J, j act. to cut out the feeder at both ends, the relays F, f then resetting to restore the wires A<1> A<2> to normal. When the fault current is supplied from one end on]y, the relay F or f at the supply end operates so that the wires A'. A<2> are disconnected from the remote control circuits at one end only and are connected up again when the feeder is cut out at the supply end. To avoid any harmful effect on the operation of the protective system. in the event of the relays at the two ends operating rot quite simultaneously, the protective and remote control batteries at each end may be connected to the two pilot wires with opposite polarities, the lock-out relays being polarized to respond only to current from the protective batteries. General nature of the remote control system. The substation is provided with a rotary selector 20, the step-by-step movement of which corresponds with that of a rotary selector 220 at the control system, the arrangement being that described in Specification 307,379, wherein during each selecting movement the selector 220 makes two half-notch movements for one fullnotch movement of the substation selector 20. Completion of the selecting movement causes a supervisory current to be transmitted to the control station to indicate the condition of the selected substation apparatus. In any selected position an executive hand-push or a meter switch may be operated for effecting, respectively, an operation on the substation apparatus, or the establishment of a metering circuit. The normal zero portion of the selectors, shown in the drawing, is reserved for special purposes such as telephonic communication, and the transmission of a general alarm current associated with means for causing a complete selecting and indicating cycle to be performed to indicate the condition of all substation apparatus. Selection of apparatus. Operation of the selector push 270 closes contact 274 to complete a circuit to the first motion solenoid 221, which drives the selector 220 to its first half-notch position and closes contacts 242, 245, 246. The control station equipment is then locked until the reception of a release current from the substation. Closing of contacts 245, 246 prepares a circuit for release relay 223. Closing of contact 242 completes a circuit for a selecting current through pilot wires A<3>, A<4> and polarized relay 100, which closes contacts 101 to energize selector relay 90. The relay operates selector solenoid 21 to drive the substation selector 20 to its new position. The armature of the solenoid closes contacts 22, 24 to complete a release circuit through polarized relay 223 and also through contact 273, so that the second motion solenoid is energized to prepare ratchet and pawl mechanism for driving the selector 220 through its second half-notch movement. The armature of the solenoid 222 opens contact 242, whereby eventually the solenoid is de-energized and the second half-notch movement of the selector 220 is effected. For express selection the push 270 instead of being depressed and released is depressed and rotated to close contact 272, which bridges contact 273. Indicating circuit. Assuming that the selectors are in the second position corresponding to the open circuit-breaker 10 shown, an indicating circuit is closed through pilot wires A<2>, A<4> and polarized relay 200, the latter closing its contacts 202 to energize a coil 215. The coil acts on an armature adapted to operate indicating mechanism which may take one or other of the forms described in Specifications 307,381 and 307,383. Operation of circuit-breaker. Depression of close push 290 or trip push 280 to effect closing or opening, respectively, of the selected circuitbreaker opens the indicating circuit and closes a circuit through the wires A<3>, A<4> and the control station battery 250. The polarized relay 100 is thereby energized to close contacts 102 and energize executive relay 80. The latter locks up and at contact 84 closes a circuit for trip relay 140 or close relay 145. Trip relay 140 has a contact 141 adapted to control the energization of the circuit-breaker trip coil 12. Close relay 145 at contact 146 closes a circuit through closing coil 11. Transmission of meter readings. The estab. lishment of a metering circuit in any selected position is initiated by rotation of a meter switch 300, which when rotated through 180‹ completes a circuit from one side of the metering source through bus-bar 77, pilot wire A<3>, bus-bar 262, the selected meter 265, bus-bar 260, pilot wire A<4>, bus-bar 78 to the other side of the metering source 19. Further rotation of the meter switch causes disconnection of the meter 265, and energization of the release meter relay 150, whereby normal conditions in the substation are re-established, except for the de-energization of the relay 135. This relay is de-energized and normal conditions restored at the control station when the switch 300 has completed a revolution. According to the Provisional Specification, the metering circuit is over the second and fourth pilot wires. Telephone communication. The control station operator, on lifting the telephone instrument, operates a dummy push 320. This first breaks the circuits of the wires A<2>, A<4> at contacts 322, 326 and momentarily closes contacts 324, 325 to transmit an executive current which energizes relay 100 to close its contacts 102 and energize relay 80. Contact 83 closes to cause the operation of relay 120 which locks up and releases relay 100 at contact 127. Contact 121 prepares the circuit for telephonic communication, and contact 122 closes a circuit to the substation call bell 162 through the hook switch 161, which when lifted breaks the calling circuit. The speaking circuit is complete through the substation telephone 160, pilot wires A<3>, A<4>, and the control station telephone 330. Replacement of the instrument at the control station releases the dummy push, whereby the system returns to its normal zero position. The substation operator to call the control station depresses telephone push 165, closing through contacts 166 a circuit through polarized relay 200. This relay closes contacts 201 and energizes coil 210, thereby closing at contact 212 a circuit to buzzer 331. The telephone push 165 is locked in all selected positions other than zero position by an electromagnetic locking device 169 energized over a circuit closed in all positions except the zero position. General alarm arrangements. When a change of condition of one of the substation apparatus such as a circuit-breaker occurs while the system is at rest in the zero position, a flick switch 16 closes momentarily to cause energization of substation general alarm relay 150, which locks up and at contact 153 closes a circuit for a definite time-limit relay 156. Contact 152 closes to complete a circuit through, relays 130 and 200. Relay 200 closes contacts 202 to energize coil 215 and thereby close contact 218. As the relay .130 closes contacts 132 a circuit is now complete through pilot wires A', A<2>, polarized relay 200, and general alarm relay 350