Patent GB-270788-A (GB)
Title: Improvements in or relating to the control of apparatus at an electric power substation from a central control office
IPC: H02J13/00
Filed: 1926-02-06
Abstract: 270,788. Automatic Telephone Manufacturing Co., Ltd., and Remington, C. Feb. 6, 1926. Addition to 252,231. Selective distant-control systems; tell-tale apparatus. - Relates to a modification of the system described in the parent Specification for supervising and controlling from a remote point, the conditions and operation of a number of apparatus units e.g. circuit-breakers at a substation wherein selection, a check on the selection, and the transmission of supervising signals are accomplished by characteristic impulse codes sent over two line wires and the operation of a selected unit is effected over a third wire. Instead of utilizing the third wire exclusively for controlling the units, it is now additionally used to carry the distinctive impulses which determine the apparatus to be selected or the supervising signal to be operated. This arrangement avoids the use of the polarized relays which were essential in the system described in the parent Specification. Figs 1 and 2 show the control station equipment and Figs. 3 and 4 the apparatus at the substation. The circuit breakers at one substation are selected by keys K<1>, K<2>, K<3> which are adapted to be moved upwardly or downwardly according to whether the circuit breaker is to be closed or opened and the selected units are operated by a common control key OK. When a selecting key is operated, a rotary switch RLS1 is rotated to transmit impulses over the lines 17A, 18A to operate rotary switches RLSA, RLSB, Fig. 4, at the substation. At a point in the cycle corresponding to a contact in the bank of wiper W1A which is marked by the operated selecting key, an impulse is transmitted over the lead 40 to transfer at the substation the impulsing, circuit from the switch RLSB to the switch RLSC. After the transmission of the complete train of impulses, the switch RLSA occupies its normal position and the switches RLSB, RLSC occupy positions which are complementary to each other. In this position, the switch RLSB effects the desired selection and together with the switch RLSC closes a circuit for operating a lamp such a; L1 associated with the operated selecting key to provide a check on the selection. An operating circuit, e.g. 215, 214, Fig. 4, for the selected unit may then be closed by the key OK, Fig. 1. When a circuit breaker is closed or opened the operation of rotary switches RLSD, RLS6 at the substation and control office is initiated. The circuit breakers are associated with the third, fifth, seventh &c. contacts respectively of the bank of contacts associated with the wiper D1 so that two impulses are transmitted for each unit. The first impulses are transmitted over the lines 17A, 18A to operate a relay QR8, Fig. 2, at the control station and thereby energize successively over the wiper W6B the relays R1A, R1B, R1C associated with the supervisory lamps. The second impulses are transmitted over the same lines or the lines 18A, 40 according to the position of the units. If, for example, a circuit breaker occupies its " in " position, the corresponding contact in the bank D1 is marked to cause an impulse to be sent at the appropriate point in the cycle over the lines 18A, 40 and energize a relay QR7 which completes a circuit over the wiper W6A to operate the corresponding relay R11, R12 or R13. This relay illuminates the red lamp, e.g. RL1 and locks up over the contacts of its associated relay R1A, R1B or R1C. Selection of a circuit breaker. When a key, e.g. K<1>, is operated a relav R1 or RA depending upon the nature of the operation to be effected is energized to mark a corresponding contact in the bank of the wiper W1A and a relay SR3 is energized to transmit an impulse over the wires 17A, 18A. The relay SR3 energizes the stepping magnet M1 of the switch RLS1 which is stepped forward when the relay SR3 is de-energized as a result of the operation of the key relay. After the first step the switch is automatically operated under the control of the wiper W1C and the interrupter contacts 23 and impulses are transmitted over the line wires 17A, 18A by the relay SR3. The impulses energize a line relay LR at the substation to operate the stepping magnets MA, MB of the rotary switch RLSA, RLSB. When the wiper W1A reaches the marked contact battery is connected over the contact 12 of the key relay and contacts OK1 of the key OK to the line 40 to energize a relay COR at the substation and thereby transfer the impulsing circuit from the stepping magnet MB to the magnet MC of the rotary switch RLSC. Further impulses transmitted over the lines 17A, 18A operate the switches RLSA, RLSC. Checking selection. At the end of the impulse train a series circuit is closed over the wipers B3, C3, which occupy complementary positions, for the relays HR, QR1 and the relay QR1 illuminates a lamp, such as L1, associated with the operated selecting key in order to provide a check on the selection. Operation of selected unit. If the selection is correctly performed the key OK is operated to connect battery at 'the contacts OK2 to the line 40 and energize a relay 01, Fig. 3, over the operating contacts 212 of the relay HR. The relay 01 closes the operating circuit, e.g. 214. 215 over the selected contact associated with the wiper B<1>. After the desired operation is effected, the selecting key is restored to normal and the relay HR is de-energized to close the circuit of a relay BR over the wipers C5, B5 of the switches RLSC, RLSB. The relay BA closes the circuit of the stepping magnets MB, MC over the wipers B2, C2 and the switches RLSB, RLSC are stepped into their normal positions. Supervisory signalling. When a circuit breaker changes i'ts position automatically or under the control of the operator at the control station, a relay RSR1 is energized over contacts 222, 223 by an arm rotated by the circuit breaker. The relay RSR1 energizes relays SARI, LLR, C01. The relay C01 transfers the line wires from the selecting apparatus to the supervisory signal transmitting apparatus at the substation. The relav SARI energizes the stepping magnet MD of the switch RLSD and a. slow-acting relay SAR2. The relay LLR transmits an impulse over the lines 18A, 40 to energize a relay QR7, Fig. 2. The, relay QR7 operates the relay SR7 which switches the line wires 17A, 18A on to the relay QR8 and actuates an alarm CBA which is maintained until nullified by the key 79. The magnet M6 of the switch RLS6 is also energized ready for the first stepping operation of the switch. When the relay SAR2 at the substation is energized, the circuit of the relay SAR1 is opened and the magnet MD is de-energized to step forward the switch RLSD. Movement of the wiper D1opens the circuit of the relay LLR and in consequence the circuit over the lines 18A, 40 is opened to cause operation of the switch RLS6. After the switch RLSD is moved one step, the wiper D5 closes a. circuit which causes the alternate energization of the relays SARI, SAR2 to operate automatically the switch RLSD step-by-step and simultaneously transmit impulses over the lines 17A, 18A to energize the relay QR8 and thereby operate the switch RLS6. When a circuit breaker occupies its closed position, a corresponding contact in the bank associated with the wiper D1 is marked and when the wiper D1 makes contact therewith the relay LLR is again energized to transmit an impulse over the lines 18A, 40 to energize the relay QR7 and complete a circuit over the wiper W6A for the corresponding relay R11, R12, &c., which illuminates its red lamp such as RL1 and locks up over the back contact of a second relay such as R1A. If a circuit breaker which has been " in ' occupies its '' out " position, battery is removed from the corresponding contact of the switch RLSD and an impulse is sent over the lines 17A, 18A to energize the relay QR8 which closes a circuit over the wiper W6B for the corresponding relay R1A, R1B, &c. This relay opens the locking circuit of its associated relay R11, R12, &c. and thereby alters the indication. In order to prevent the transmission of incorrect signals in the event of a circuit breaker " closing " and then " opening " immediately, means are provided to ensure the transmission of both signals. When the circuit breaker is " closed " a circuit is completed over the contacts 222, 241, wiper C1, Fig. 4, wiper D2, Fig. 3, and contact 243 of relay 01, which is energized by the control key OK, for the relay X. The relay X locks up and prepares relay Y which is energized over contacts, such as 222, 223, when the circuit breaker drops out. The relay Y locks up and energizes the relay RSR1 which, initiates the transmission of a " closed " signal in the manner previously described except that the corresponding contact in the bank wiper D1 is marked over a circuit including contact 244 of relay X, and wiper C1. Upon the first step of switch RLSD the relay RSR1 is deenergized but is again energized over the contact 248 of relay Y. When the wiper D2 reaches its last contact the relay X is released and the relay BR is energized over the contact 218 to restore the switches RLSB, RLSC to normal. Energization of the relay RSR<1> initiates a second impulse train to signal the " open " position of the circuit breaker.