US1266607A - Control system. - Google Patents

Description

P. L. Mums CONTROL svsnzu.

Patented m 21, 1918.

3 SHEETS-SHEET I INVENTOR Paa/L. Ward/3.

WITNESSES fl ATTORNEY P. L. MARDIS.

CONTROL SYSTEM.

APPLICATION FILED IIAY 3, 1915.

1,266,607. Patented May 21,1918.

3 SHEETS-SHEET 2. 5 7 /0 wfinsssss: 4 INVENTOR W Pau/L/Vard/b".

P. L. MARDIS.

CONTROL SYSTEM.

APPLICAHON mEo MAY 3. 1915.

1,266,607. Patented May 21,1918.

3 SHEETS-SHEET 3.

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M/ 9 M4 m, 0 m m "I- 2 0A0) I; n t! In "In 0 u 0 m I WITNESSES INVENTOR S Paa/LMard/J:

l ATTORNEY PAUL L. MARDIS, OF ALTOONA, PENNSYLV ANIA, ASSIGNOR TO WESTINGHOUSE ELEC- TRIO AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

common svs'rmir.

Specification of Letters Patent.

Patented May 21, 1918.

Application filed May S, 1915. Serial No. 25,496.

To all whom it may concern:

Be it known that I, PAUL L. MARDIS, a citizen of the United States, and a resident of Alloona, in the county of Blair and State of Pennsylvania, have invented a new and useful'lmprovement in Control Systems, of which the following is a specification.

My invention relates to control systems for dynamo-electric machines, and it has special reference to four motor equipments of the series-parallel type such as are commonly employed upon electric railway vehic es. One of the objects of my invention is to provide an improvedmethod and means for controlling the operation of a plurality of motors constituting a portion of a system of the above-indicated character, and to provide a simple mode of successively arranging the circuit connections of the motors for series, series-parallel and parallel-circuit operation, whilenmaintaining a unidirectional flow of current through the motors during the circuit changes.

Another object of my invention is to provide a method and means for controlling a four-motor equipment of the general class referred to which shall be adapted to disconnect each of the respective motors from the system during the several steps by which the motors are accelerated to their full-speed operation, whereby each of the motors is permitted to remain idle for a portion of.

the accelerating period.

Another object of my invention is to provide a method nd means for changing the several motors from series-parallel groups into full-parallel-circuit relation through an intermediate step in which a single motor is connected in parallel with two motors that are connected in series-circuit relation, and, moreover, for effecting these changes in circuit connections without reversing the current in any of the motors.

In the prior art'yit has heretofore been proposed to provide a system and mode of control of somewhat similar characteristics, but, in all such systems with which 1 am familiar, the desired circuit changes are effected at the expense of reversing the direction of flow of the current in certain of the motors, and the motors are not worked uniformly during the acceleration period, cer- I tain of the motors being actively in circuit throughout the entire acceleration, while other motors are permitted to be idle to some extent.

According to my invention, I propose to Improve and simplify the systems of the prior art, to overcome the difficulties and deficiencies incident to other systems and to secure'the advantages and benefits hereinbefore enumerated.

My invention is illustrated in the accompanying drawings in which Figure 1 is a diagrammatic view of the main circuit connections and main control apparatus of a s stem of control embodying my invention;

i'g. 2 is a sequence chart indicating the positions of the several switches in different steps of the controller; Fig. 3 is a diagrammatic view of the auxiliary control circuit connections and the auxiliary control circuit apparatus which is employed for governing the operation of the main circuit apparatus shown in Fig. 1; Fig. simplified view of the main rcuit connections of the motors that are stablished in certain steps of the controller; and Figs. 5 and 6 are, respectively, views corresponding to Figs. 2 and 4 of a. modified form of control s stem embodying my invention.

Re erring to Fig. 1, a plurality of series motors M1, M2, M3 and M4 are adapted to receive energy IIOID'JL'SUPPIY circuit, one member of which comprises a trolley condoctor 1 and the other, a ground G, throu h a resistor R and a plurality of electricafiy operated motor-circuit switches a, b, c, d, e, f, g, h, i, j, and k, which are adapted to arrange the circuit connections of the several motors for series, series-parallel and full-parallel operation. v

The several unit switches maybe of any well-known construction and each comprises an energizing coil 3, a movable magnetlzable core 4, a movable switch member 5 and a plurality of stationary contact terminals 6 which are adapted for cooperative engagement, while some of the unit switches referred to are provided with interlock switches 7 by means of which certain of the control circuits are interlocked and a predetermined sequence of operation is obtained. The unit switches may be, and preferably are, of the well-known electro-pneumatic type.

4 is a diagrammatic the several unit switches will be referred to, as a whole, by their reference characters and no attempt will be made to designate the component parts of each switch with separate reference characters.

It will, of course, be understood that each of the switches is adapted to occupy two positions, an in position, in which the switch is energized and closed, and an out" position, in which it is de'cinergizedaml opened. The interlock switches associated with the several unit switches will be denoted by means of the reference character of the unit switch with which it is associated, followed by the word in or out, which indicates the position in which the interlock switch is closed. For instance, interlock switch i--out indicates that the interlock switch associated with the unit switch i is closed when said unit switch occupies its open or out position.

Referring now to Fig. 3, a master controller MO is shown, which comprises a movableicontact member 10 of peculiar configuration and a plurality of stationary contact terminals 13+, (1,, b, c, (l, c, f, g, k,

i, j and is that are adapted to be engagedoy the movable contact member 10 along the position-indicating lines 1, 2, 3, 4, 5, 6, 7 and 8 for the purpose of establishing suitable circuits from a battery B, or other source of energy, through the energizing coils of the several unit switches a to is, inclusive.

Assumin the apparatus and circuit connections to be as shown, the operation of the system is as follows: The master controller BIC is first moved into its osition 1 in which a circuit is established rom the positive side of the battery B which includes stationary contact terminal B+ and movable conductin segment 10 of the master controller M where the circuit divides, one branch including contact terminal a and energizing coil. of switch a and thence to a conductor B which connects to the negative side of the battery; another circuit traverses contact terminal bf, energizing coil of switch 6, and interlock switch z'out to the B conductor; another circuit traverses stationary contact terminals 0', energizing coil of switch 0, and interlock switch 7out to the B- conductor, and a fourth branch includes contact terminal d, energizing coil of switch d, and interlock switch k-out to the B- conductor.

Having established the circuits just traced, the several unit switches a, b, c, and cl are energized and closed. Thus, energy is supplied from thesupply-circuit conductor Z through trolley T, switch a, resistor R, motor M1, switch 12, motor M2, switch 0, inotor M3, switch (1, and motor M4 to the return circuit G. The'several motors M1, M2, M3, and M4 and resistor R are thus connected in sr -ies-circuit relation, as shown in step 1. in Fig. 4, and, being supplied with energy, are started into operation at slow speed.

When the master controller MC is moved to its position 2, another circuit is established from the movable contact member 10 throu h contact terminal e and energizing coil 0? switch 1: to the conductor B. The switch e isftherefore, energized and closed to short'circuit the accelerating resistor R,

thereby causing the motors to increase in speed, the circuit connections being as shown in step 2 of Fig. 4.

During the next step of the controller MC, circuits are established from conducting member 10 through contact terminal h and energizing coil of switch it to conduc tor B, and through contact terminal i, and energizing coil of switch 2' to the interlock switch b-out. The switch it is thus energized and closed, although switch '11 is not energized, inasmuch as its circuit is broken by the interlock switch bout, switch 6 being still held in its in or closed position. Immediately subsequent to this action, the stationary contact terminals b and d become disengaged from the movable conducting member 10 and, therefore, the corresponding switches b and (l are denergized and permitted to open. As soon as' the-switch 6 drops into its out position, its interlock switch bout completes the energizing circuit of the switch i, and said switch immediately is closed.

The main circuit through the motors is then as follows: from trolley T through, switch a, switch e, motor M1, switch i, switch 0, switch it and motor M4 to the ground G, as shown in step 3 of Fi 4. Motors M2 and M3 are disconnected rom active circuit and are permitted to remain idle.

As the master controller is moved into position 4, circuits are established from contact member 10 through contact terminal f and energizing coil of switch f to conductor B,- and through contact terminal energizing coil of switch is and interlock switch dout to the B- conductor. Switches f and here thus energized and closed, thereby connecting the several motors M1, M2, M3 and M4 in series-parallel groups, as indicatedin step 4 of Fig. 4.

The new motor circuit established by the closure of the switches 'ust referred to, supplies ener to motors 1 and M4 through a circuit mm the trolley through switch f, motor M2, switch a, motor M3 and switch is to ound G.

etween positions or steps 4 and 5 of the master controller MC, there are a plurality of transition notches 4a, 4b, 4c and 4d, as

indicated in the chart shown in Fi 2, for the purpose of effecting the transition of motor-clrcuit connections from the. seriesparallel relation lished in position step or position 5 of the motor current. suitable transition connections may be ployed between steps 4 of the motors, as estab 4, to the next operative without the interruption Inasmuch as any and 5, so long as the motor circuits are not interrupted and a unidirectional flow of current through the motors is maintained, I do not deem it necessary to trace the circuit connections of the various transition notches.

Therefore,

a description of the transition connections will be omitted and the connections established in the next running position 5 will be considered.

In this position, the movable conducting member 10 is in engagement with the following stationary contact tcrminals B|, a,

b e, g, j and k and, therefore, the responding switches a, b, c, g, j, and is closed to establish the arrangement of tors indicated in step 5 of Fig. 4. The circuit connections are as follows: from trolley T through switch the circuit divides In the step 6 of the controller MC,sta

contact terminal h and its cormtiona spending switch understood.

a a h is energmed, as Wll a, and switche, where one branch including the motor M1,'sw1tch 6, motor M2, an

ther and lbe The switch h, therefore, is

closed and connects the motor M4 in parallel with the motor M3, both of which ar ein multiple-circuit relation with the motors M1 and M2 The arrangement of circuit connections motors is shown in step 6 of Fig. 4.

In moving the master controller to its sition 7, contact terminal b which are in series with each other.

and

becomes disengaged from the movable conducting member 10 and, hence, the switch 6 and opened. Concurrently,

is denergized therewith, howi ever, contact terminal f becomes energized and its corresponding switch f closed. Thus,

the motor M1 is disconnected from the tem and is idle, while motor M2 is conne in parallel lel-connected motors M3 and M4. The

syscted relation with the other two paralcircuit connections are then as shown in step 7 of Fi ."4.

Ast its last is closed to conncct the motor M1 in par with the other motors M2,

M3 and e master controller MC is moved into position 8, contact terminal 2 becomes disengaged and its corresponding switch a allel M4,

whereby the full-parallel arrangement of the motors is established.

Throughout the operation, set forth, it is manifest that, reversal in the direction of through any of the motors cfi'ected, but a unidirectional flow thereof is mainta at no time,

as hereinbefore isa flow of current that ined nections for fnl Moreover, each one of the sevat all times.

motors is disconnected from the era! driving system and permitted to be idle for a certain Reference may now be had to Figs. 5 and p a modified form of my invention in which the sequence of the switches shown in Fig. 1 is so fixed as to effect the changes in circuit connections from seriescireuit relation to full-parallel relation while maintaining a unidirectional flow 0 current through said motors throughout the circuit changes.

In step 1, switches a, b, c, and rl are closed and the motors M1, M2, M3 and M4 and the starting resistor R are connected in seriescircuit relation. as shown in step 1 of Fig. 6.

In step 2,switch c is also closed to shortcircuit the resistor R and exclude it from the motor circuit.

In step 3, switch G is closed and switch 0 opened, thereby disconnecting the motors M1 and M2 and connecting motors M3 and M4 in series circuit directly across the source of ener;

Switch J is closed in position 4 to connect the negative side of the motors M1 and M2 ttrground, thereby establishing a seriesparallel grouping of the'motors.

In the next or transition position, switch I) is opened and switch f closed. Thus, the motor M1 is disconnected from circuit and motor M2 is connected in parallel-circuit relation to motors M3 and M4 which are connected in series circuit with each other.

ln step 5, switch c is opened and switch 2' closed, thereby temporarily inserting the resistor R and connecting the motor M1 in parallel with the motor M2, said motors being arranged in n'lultiple-circuit relation 6 which disclose with the series-connected motors M3 and M4.

In step 6, switch 0 is again closed to incl ude the resistor R, the other circuit connections remaining unchanged.

In step 7. switch rl is opened and switch 1.: closed. Thus, the motors M1, M2 and M3 are connected in multiple relation and motor M4 is disconnected from the system.

In the last step, step 8, switch It is closed to connect the motor M4 in parallel with the other motors, thereby establishing con- -parallel operation.

By reason of the fact that a master controller and auxiliary-control-ciicuit connections have been fully set forth in connection with the system first described, and also, inasmuchas it is believed that no difliculty will be experienced by those skilled in the art in understandingthe mode of operation and circuit connections of the modified form of my invention just described, I have deemed it unnecessary to illustrate a master controller for the purpose of governing the several switches to secure a sequence of operation thereof in accordance with the chart shown in Fig. 5, whereby the circuit connections shown in Fig. 6 are established.

It is manifest, of course, that various modifications in the arrangement of circuit connections and mode of operation may be effected without departing from the spirit and scope of my invention, and such modifications are intended to be covered by the appended claims.

I claim as my invention:

1. The method of controlling four electric motors which consists in connecting said motors in series relation, disconnecting two of the motors from circuit, connecting the motors in series-parallel groups, connecting two of the motors in series-circuit and in parallel relation to a single motor and connecting the motors in full-parallel relation, while maintaining a unidirectional flow of current during the changes.

2. In a system of control, thecombination with four motors, of control apparatus associated therewith for arranging the circuit connections of the several motors to change the motors from series to parallel relations and to eflect the changes by successively establishing as many parallel paths throng the motors as there are motors, while maintaining the flow of current through each of the active motors unchanged, said changes including one transition step wherein two series-connected motors are in multiple circu with a single motor.

3. In a system of control, the combination with a plurality of motors, of means comprising control apparatus and circuit connections for connecting the motors in series, in series-parallel and in arallel relation, and means for disconnectrn each of said motors from circuit during t e acceleration from series to parallel relation and for maintaining at least two of said motors in circuit throughout the changes.

4. The method of chan ing four electric motors from series-paralle relation to fullparallel relation, which consists in first cutting-out one of the said motors, leaving one motor in parallel with the two which are in series, then reconnecting the motor which is cut-out in parallel with the remaining motors, then cuttin -out one of the two motors in series, an finally connecting the last motor cut-out in parallel with the others, while maintaining a unidirectional flow. of current through the respective m'otors.

5. In a control system, the combination with a plurality of motors, of control apparatus for first connecting all of the motors in series relation, then connecting them in series-parallel groups, and finally all in parallel relation, said control apparatus comprising rclafively movable contact members and circuit connections arranged to disconnect the motors one after another from circuit, while effecting the motor circuit changes and to maintain a unidirectional flow of current through the respective motors.

6. In a system of control, the combination with a plurality of electric motors, of control apparatus comprising contact members and circuit connections for changing the motors from series-parallel relation to fullparallel relation, said contact members and connections being adapted to successively disconnect the motors, one after another, form circuit, and to maintain .a unidirectional flow of current tln-nugh the active motors duri ng the circuit changes.

7. The method of control of four electric motors, which consists in connecting all of said motors in series-parallel groups, then connecting two series-connected motors in multiple circuit with a single-motor, and then connecting all of the motors in parallelcircuit relation, while maintaining a uni-.

directional flow of current through said motors during the operation.

S. The method of controlling four electric motors, which consists in successively fionnet-ting the motors in series-circuit relation, in seriesparallel groups and in full-pan ,allcl-circuit relation, while idling all of said motors at. different times during the changes in connections.

9. The method of controlling four electric inotors, which consists in successively connecting said motors in series-circuit relation and then in full-parallel-circut relation, while disconnectin all of the motors from circuit and idling t e same at different times during the changes in connections.

10. In a system of control, the combination with a plurality of electric motors, of control apparatus and circuit connections for successively connecting the motors in series-circuit relation, in serics-parallel groups and in full-parallel-circuit relation, while disconnecting all of the motors from the system at different tilnesand allowing them to remain idle; during the circuit changes.

In testimony whereof, I hays hereunto subscribed my name this 27th day of April,

PAUL L. MARDIS. Witnesses:

ALEX Warn, PERRY H. WEDGE.

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