US1833428A - Electrical remote control system - Google Patents

Description

Nov. 24, 1931. B. H. LEESON ELECTRICAL REMOTE CONTROL SYSTEM Filed June 16, 1927 3 Sheets-Sheet 1 v w 'm L l G n W IIT.

l p L- NOV. 24, 1931. LEESQN 1,833,428

ELECTRICAL REMOTE CONTROL SYSTEM Filed June 16, 1927 5 Sheets-Sheet 2 FEEDE1R\N 2 FEE ER N03 FEEDER N 4 FEEDER N 5 F'EEDEQ N e;

0 w .nvwsw T07? Nov. 24, 1931. B. H. LEES ON ELECTRICAL REMOTE CONTROL SYSTEM Filed June 16, 1927 s Sheets-Sheet 3 NORMAL/ UT JAM/54v Tow 2 y ZBM Patented Nov. 24, 1931.

' UNITED STATES PATENT OFFICE BRUCE mm LEESON, OI TYNEKOUTH, ENGLAND, ASSIGNOR TO A. REYROLLE & COE- PANY, LIMITED, 01 EEBBURN-ON-TYNTE, ENGLAND, COMPANY OF GREAT BRITAHQ' ELECTEICAL mOTE CONTROL SYSTEM Application fled-Jane 1 0, 1927, Serial No. 199,346, and in Great Britain July 29, 1926.-

. This invention relates to an electrical system for the remote control of a numberof switches or other apparatus and is more especially applicable to the'remote control of electric power substations from a central station. Thus for example there may be a number of feeders leading from a'substation each controlled by a. circuit-breakerand the system according to the invention may be used for the selective control of such circuitbreakers. Or again the system may be employed for controlling a. sequence of operations, such as would be re uired 1n startmgup semi-automatic substation apparatus and connecting it to a load circuit.

Generally speaking, the invention has for its object to provide a simple system wherem an operator at a central station can obtain immediate information as to the condition of 0 apparatus at a substation and can operate such apparatus at w' In the remote con rol system according to the invention a; selector device at the substation is caused by currents transmitted from the central station to select an individual switch or other apparatus and to give an indication at the central station of the condition thereof, and means are provided whereby the selecting movement of the selector device causes circuits to be left free for the immediate transmission of current from the central station for the operation of the selected switch or other apparatus. I

Preferably a step-by-step movement is imparted to the selector device to cause the successive completion of circuits associated respectively with the individual switches or other apparatus. These circuits may be such that after each movement of the selector de-- vice an indication is given at the central station of the condition of an individual switch, .whils't current for operating such switch (if desired) can be immediately transmitted from the central station. Means are also preferably provided whereby, if such operating current is transmitted, a further indication is given at the central station immediately the operation of the selected switch is completed.

A further feature of the'invention relates to the apparatus employed for giving the desired selective indication of the condition of the substation switches. this further featureiof the invention corresponding movements are imparted to two devices, one of which at the substation constitutes a selector device acting to cause the successive completion of indicating circuits associated reslpectively with the individual switches or ot whilst the other er apparatus, constitutes a selection-indicating device disposed at the central station for the purpose of giving an indication as to which of the indicating circuits has been completed by the selector device, a second indicating device being provided at the central station which is operated by the indicating circuits to give vices are preferably each of the rotary type,

and the selector-device may have a step-byoperating current. it may in some cases be desirable to provide means for ensuring correct and simultaneous rotation of the two devices. To this end the first movement of the plunger of each solenoid may be arranged to short-circuit a resistance in the common controlling circuit or otherwise to increase the magnitude of the controlling current; Thus as soon as one plunger begins to move the controlling current will be automatically increased, thereby ensuring that the other solenoid will also respond, and

as soon as the second plunger begins to move there will be a further increase in the con trolling current which will ensure that both According to a an indication of the condition of the selected "switch. The two correspondingly moved deplungers will complete their movement and operate their ratchet wheels.

It will generally be desirable to provide means whereby, when a change takes place in the condition of any of the controlled switches or other apparatus (other than as a result of operation from the central station), an alarm is given at the central station. This may be effected by means of an alarm relay in the substation which is energized when such a change occurs and acts to complete a circuit to an indicating or alarm device in the central station, such device preferably being that which gives an indication of the condition of' a selected switch. This alarm relay is preferably rendered inefl'ective during operation of the selector device, and means may be provided whereby an alarm which should have been given during such operation is stored up until the operation is completed.

The transmission of currents for the operation of the selector device and for the operation of a selected switch or other apparatus is preferably controlled by means of two hand-switches at the central station.

The invention may be carriedinto practice in various ways but one convenient arrangement according theretois illustrated by way of example in the accompanying drawings.

This arrangementwill, for convenience, be described with reference to the remote control from a central station of a number of circuit-breakers each controlling a feeder leading from the substation, although it will be appreciated that the system is applicable to the control of other apparatus and is of such a nature as to render it particularly suitable also for the control of a sequence of operations such as is required for the starting-up and throwing on to load of semiautomatic substation apparatus.

In the accompanying drawings,

Figure 1 is a diagram showing the arrangement of the electrical circuits,

Figures 2 and 3 are respectively end and front elevations of the selection-indicating device at the central station,

Figures 4 and 5 show the device at the central station for indicating the condition of a selected circuit-breaker, and

Figures 6 and 7 illustrate the substation selector device.

In this arrangement the central station apparatus (which is indicated in the lower half of Figure 1) is connected to the substation apparatus (indicated in the upper half of Figure 1) by. means of three pilot wires A A A, one of which A is employed mainly for selective and indicating purposes and may be referred to asthe selective pilot, whilst the second A the execution pilot, is used for transmitting currents for operating a selected circuit-breaker, and the third A is a common return circuit.

The apparatus at the central station comprises broadly a selection-indicator, an alarm indicator and two hand-operated switches of the push-button type, the first for selective and indicating control and the second for execution control.

The selection-indicator (see Figures 1, 2 and 3) consists of a polygonal drum B bearing indications on its various faces corresponding to the circuit-breakers to be controlled, such indications being visible through a slot indicated at B in the control panel. The drum B is mounted on a shaft B carrying at one end a ratchet wheel C, having the Same number of teeth as the drum B has faces. Cooperating with the ratchet wheel C is a pawl C carried by a lever C freely mounted on the shaft B this lever being pivoted at its end to a rod C driven by the plunger of a solenoid D. The shaft B also carries a locking wheel E having recesses E in which engages a roller E carried on the end of a pivoted arm E the roller E being held in the recesses E by a spring E for the purpose of ensuring that the indications on the drum are properly disposed with relation to the slot 13. v

The solenoid D is connected on one side to the selective pilot A, and on the other side through aresistance 1) (part of which is short-circuited by means of contacts D as soon as the solenoid plunger begins to move) to the normally open contacts F of the selective hand-switch F. The other side of the contacts F is connected tothe operating coil G of the alarm indicator the other side of this coil being connected to the return pilot A The hand-switch F is also provided with normally closed contacts F which make direct connection through resistances F 3 between the selective pilot A and the alarm coil Gr. Thus normally the alarm coil G is connected between the selective and return pilots through the resistances F but when the selective hand-switch F is depressed, the resistances F are cutout and the solenoid i) and its resistance D are substituted there- The alarm indicator (see Figures 1, 4 and 5) consists of a pivoted armature G operated by the coil G and carrying at its ends two 1ndicating surfaces G 3 respectively bearing the legends Normal and Out, the arrangement being such that when the coil G is operated the armature G will lift and expose the surface G through a slotindicated at G in the control panel in place of the normally exposed surface G". The coil G also operates contacts G controlling the circuit of an alarm bell Gr energized from a battery G.

The execution hand-switch H, when depressed, closes normally open contacts H and thus makes a direct connection between The selector (see Figures 1, 6 and 7) com-- prises a rotary contact drum J which may 10 be of any convenient construction but as.

shown is in the form of a cylinder of insulating'materialbearing on its surface conducting segments each of which in the appropriate drum position bridges the gap between a i pair of spring contact arms J J The drum J is mountedon a shaft J a which is driven by Y mechanism similar to that employed for driv-' ing the selection-indicator at the central station. Thus a ratchet wheel K mounted on the shaft J 3 cooperates with a pawl K carried by a lever K which is driven-through a rod K by the plunger of a solenoid L, and the shaft J also carries a locking wheel M having recesses M engaged by a roller M 'on the end of a spring-controlled arm M The solenoid L is connected on one side to the selective pilot A and on the other side to a resistance L part of which is shortcircuited by the contacts L immediately the 0 solenoid plunger begins to move. The solenoid L is also provided with change-over-contacts-L referred to later. The other side of the resistance L is connected to the control busbar V which together with the control busbar V is illustrated'as energized from a source 'of current V. The return pilot A is directly connected to the busbar V There is thus normally a complete circuit containing the solenoid L and resistance L, the se- 40 lective pilot A, the resistances F the alarm indicator coil G and the return pilot A but the magnitude of the current flowing in this circuit is insuflicient to operate either the solenoid L orithe alarm indicator. When however the selective hand-switch F is depressed, the solenoid D and its resistance D are inserted in this circuit in place of the resistances F and the current is now large enough to operate the solenoids D and L, but is still insufficient to operate the alarm indicator even after the contacts D andL have closed to decrease the resistance in the circuit.

The step-by-step movement of the selector causes the successive closing of groups of contacts (similar to J J of Figure7), each group being associated with one of the circuit-breakers. In Figure l of the drawings two circuit-breakers N and 0 only are shown,

but it will be seen from Figures 27 that the apparatus illustrated is capable of dealing with nine circuit-breakers. Thus the first operation of the selective hand-switch F causes the selector to step round to the first position and close the three contacts P Q} R (Figures 1 and 7) associated with the first circuit-breaker N. The second operation of the hand-switch F causes the selector to break these contacts P Q R and to close the con.- tacts I? Q R associated with the second circuit-breaker O, and so on until the last operation brings the circuits back to'their original condition, the selector having made one complete revolution. The first movement of the selector-from its zero position also closes a contact and opens acontact Q, these contacts being common to all the circuit-breakers and not returning to their original positions until the cycle is completed.

The first contacts P P of each group cooperate with auxiliary switches N O on the circuit-breakers to control indicating circuits containing resistances N 0 The auxiliary switch- N or O is closed when its circuit-breaker N or O is open, and the arrangement is such that, when the selector moves to its first position, (assuming that the first circuit-breaker N is open) the resistance N is connected across the solenoid L and its resistance L thus increasing the current flowing through the selective pilot to such an extent as to operate thealarm indicator at the central station. The reduction in current 1n the circuit of the solenoid L due to the connecting up of the resistance N? is not, however, such as to prevent energizatlon of the solenoid when the selective switch F is agaln depressed. The second contacts Q} Q of' each group on the selector are in series respectively. with the trip coils N O of the circuit-breakers and the third contacts R R are in series with the closing coils N 0*. These tripping and closing circuits are also controlled'by a change-over auxiliary switch N or O on the circuit-breaker, and on the other side of the selector contacts by the change-over contacts L of the solenoid L and the contacts S of the execution relay S. The execution relay S is connected on one side to the execution pilot A and on the other side through a resistance, S to the control busbar V Thus depression of the execution hand-switch H energizes the execution relay S which closes its contacts S Assuming now that the circuits are in the condition shown in Figure 1 with the circuitbreaker N open and the circuit-breaker 0 closed, depression of the selective handswitch F will cause the selector to move to its first position and close its contacts P Q R the selection-indicator simultaneously moving to display Feeder 1 through the slot B in place of the normally exposed'legend Alarm. Since the switch N is closed, the indication circuit will now be complete and the alarm indicator G will operate to show Out through the slot G. If now the operator wishes to close the circuit-breaker N, he must release the selective switch F (thus allowing the-contact L to return to the lower position) and depress the execution hand-switch H. The execution relay contacts S will close and thus (since the auxiliary switch N is in its right-hand position) complete the circuit to the closing coil N, which will close the circuit-breaker N. At the same time the auxiliary switch N will open and will deenergize the alarm indicator G, which will thus display Normal, through the slot G to give the desired indication that the circuit-breaker N has closed. It should be'mentioned that the values of the various resistances are such that the release of the selective switch I? to cause the contact L to drop does not reduce the current sufficiently to de-energize the alarm indicator G. In this connectlon, it is to be noted that, during the above mentioned operation of closing the circuit breaker N by releasing the selective switch F, the solenoid L and its resistance L are shunted by the resistance N Whereas in the normally complete circuit previously referred to containing the solenoid L and the resistance L, the selective pilot A, the resistances F, the alarm indicator coil G, and the return pilot A the solenoid L and its resistanceL are not shunted by the resistance N. The execution handswitch H having been released, the selective hand-switch F is again depressed to move the selector and selection-indicator to the second position. Since the circuit-breaker O is closed, the indicating circuit is broken by the auxiliary switch 0 and the alarm indicator shows Normal. If now it is desired to trip the circuit-breaker O, the selective handswitch F is locked in its depressed position (to maintain the contact L in its upper position) and the execution hand-switch H is do:

pressed. This completes the circuit to the trip coil 0 which trips the circuit-breaker: O, the alarm indicator G thus being operated to show Out. 'By completing the cycle an indication is obtained of the condition of alt the circuit-breakers and an opportunity is atforded of operating any of them, should it be so desired, the circuits finally returning to the condition shown.

Each circuit-breaker is provided with a further auxiliary, switch N or O which is so arranged that it momentarily makes and breaks a circuit when the circuit-breaker trips, but remains inefi'ective when the circuit-breaker closes. This switch comprises a pair of spring contacts N and N arranged so that they are momentarily bridged by the conducting bar N .as the circuit-breaker opens orcloses. In order to render 1 such bridging ineffective when the circuit-breaker closes an insulated block N or N is arranged on one side of each of the contacts N and N so that the bar N engages with such insulated blocks when it moves past the contacts during the closing movement of the circuitbreaker but electrically connects N and N when it moves past the contacts during the opening movement of the circuit-breaker.

.The circuit momentarily completed by the switch N 6 extends from the control busbar V through a resistance T the operating coil T of the general alarm rel'ay, contact N bar N, contact N to the control busbar V Thus if a circuit-breaker trips automatically, the general alarm relay Twill close its contact T and (if the selector is in its zero position with the common contact Q, closed) will thus complete a circuit for holding the relay T energized and for actuating the alarm indicator G in the central station. This circuit may be traced from the control busbar V through the resistance T the relay T, the contact T the contact Q, the pilot wire A, the resistance F the contact F the resistance F, the alarm indicator G, and the pilot wire 2 to the control busbar V This alarm indic tor thus shows Out and rings the alarm bell G and it is then necessary for the operator at the central station to operate the selector in order to determine which circuitbreaker h is tripped, and, if desired, to close it again. It should be mentioned that, if the closing of a circuit-breaker is immediately followed by its automatic tripping out again, the alarm indicator G will first indicate the closing and. then the tripping so that the operator will have an immediate indication that there is some fault in the circuit concerned.

If now a circuit-breaker trips out automatically during the performance of a selecting cycle, the general alarm relay contacts T will be cut off from the alarm indicator Gr owing to the fact that the contact Q is open. But the other common contact P is now closed and consequently the storing relay U is connected in parallel with the general alarm relay T between the spring contact N and the control busbar V Thus the momentary operation of the auxiliary switch N or 0 will energize both the relays T and U, and the consequent closing of contact U will complete a holding circuit for both relays, this circuit being trace clfrom the control busbar V through the contact U and thence either through the relay U and the contact P or through the relay T and the re- 115 sistance T to the control busbar V Nothing further will happen in this circuit until the cycle is completed, when the closing of the contact Q ,will complete the alarm circuit and givethe desired alarm at the central station. 120

"It will be appreciated that the arrangements more'particularly described have been given by way of examplepnly, and ,that the system can be modified in many ways without departing from the scope of the inven- 1 tion.

What I claim as my invention and desire to secure by Letters Patent is 1. In an electrical control system, the combination of two step-by-step devices, an elec- 130 tromagnetic device having a movable member for operating each step-by-step device,-

means for simultaneously energizing the two to which corresponding stepped movements are to be imparted, two electromagnetic devices having movable members serving respectively to actuate the two step-by-step devices, a pilot circuit in which the two electromagnetic devices are connected in series means for causing repeated energization and de-energization'6f the two electromagnetic devices whereby corresponding stepped movements are imparted to the two step-bystep devices, and means whereby on energization of the two electromagnetic devices the first movement of the movable member of each electromagnetic device acts to increase the magnitude of the current in the pilot circuit. v

3. In an electrical remote control system,

the combination of two step-by-step devices to which corresponding stepped movements are to be imparted, two solenoids havingplungers serving respectively to actuate the H two devices, a pilot circuit in which the two solenoids are connected in series, means for causing repeated energization and de-ener-.

gization of the two solenoids whereby corresponding stepped movements are imparted to the two devices, a resistance connected inseries with each solenoid, and means whereby on energization of the two solenoids the first movement of the plunger of each solenoid acts to short-circuit art of the associ ated resistance and thereby to increase the magnitude of the current in the pilot circuit.

4. In anelectrical control system, the combination of two rdtarystep-by-step devices, a ratchet mechanism through which step-bystep movements are imparted to each device, a solenoid having a plunger actuating each ratchet mechanism, means for simultaneously energizing the two operating solenoids for the performance of eachIstepped movement of the two devices, and means whereby the first movement of the plunger of either solenoid acts to increase the magnitude of the series, means for causing the repeated energization and de-energization of the two solenoids whereby corresponding stepped movements are imparted to the two devices, a resistance connected in series with each solenoid, and means whereby on energization of the two solenoids the first movement of the plunger of each solenoid acts to short-circuit part of the associated resistance and thereby to increase the magnitude of the current in the pilot circuit.

In testimony whereof I have signed my' name to this specification.

BRUCE HAMER LEESON.

energizing current supplied to the other solenoid. i

5. In an electrical remote control system, thepombinati'on of two rotary step-by-step devices, a ratchet mechanism through which -step-by-step movements are imparted to each device, a solenoid having 'a plunger actuatmg each ratchet mechanism, a pilot circuit in which the two solenoids are-connected in

Images