US1361993A - System of control - Google Patents

Description

R. E. HELLMUND.

SYSTEM OF CONTROL.

APPLICATION FILED sen. z, 1917.

Patented Dec. 14, 1920.

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INVENTOR Rudolf E Hal/mund WITNESSES: 7/

ATTORNEY H. t. HtLLMuwu.

SYSTEM OF CONTROL.

APPLICATION mzo SEPT. 7. ISII.

Pamnted D60. 14, 1920.

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A'ILTORNEY UNITED STATES PATENT OFFICE.

RUDOLF E. HELLMUND, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR ,TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

SYSTEM OF CONTROL.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed September7, 1917. Serial No; 190,134.

7'0 all whom it may concern:

Be it known that I, RUDOLF E. HELLMUNO, a citizen of theGerman Empire, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have mvented a new and useful Improvement in Systems of Control. of which the following changeable, dependent upon operating conis a specification.

My invention relates to systems of control and especially to systems of the booster type wherein an auxiliary-machine armature is employed for the purpose of regulating the rain-machine operation in lieu of the customarily employed main-circuit resistors.

Curious systems of the above-indicated character have heretofore been proposed, but more or less difliculty has been encountered in their operation by reason of surges of current caused by supply-circuit voltage fluctuations or by flash-over conditions caused by the use of shunt-field windings in the booster machines.

The object of my present invention is to provide a relatively simple and reliable system of the above-indicated character where in flash-over conditions and the liability of heavy current surges are substantially obviated.

My invention may be best understood by reference to the accompanying drawings wherein Figure l is a diagrammatic View or the main circuits of a system of control cnihmlying the invention; Fig. 2 is a diagrammatic view of the auxiliary governing circuits for the system that is shown in Fig. 1; and Fig. 3 is a sequence chart, of well-known form, serving to indicate the preferred order of operation of the various switches during both acceleration and regeneration. Referring to Fig. 1 of the drawings, the system shown comprises supply-circuit conductors Trolley and Ground; a main dynanurelectric machine having a commutaor-type armature A1 and a field winding FL of the series type; a motor-generator set 155 of the booster type; a plurality of clectrically-controlled switches LS and 1 to 11, inclusive; a normal-voltage relay device 12; an over-voltage relay device 13; and a plurality of variable resistors R1 to R4, inclusive, that are associated with the various machine circuits, in a manner to be set forth.

The motor-generator set 15 comprises a driving or motor armature 16 which is mounted upon a shaft 17 carrying also an exciting armature 18 and a generator armature 19. The terms motor-armature and generator armature are chosen for purposes of distinction, although the character of action of such armature is interditions Field windings 20,21 and 22 are provided for the respective auxiliary armatures, such field windings being energized partially or wholly from the exciting armature 18, as subsequently traced in detail.

The shunt field winding 21 for the exciting armature 18 is connected in circuit with a variable resistor R4, whereby the exciting voltage may be initially adjusted to satisfactorily meet operating conditions. As hereinafter more fully described, the auxiliary motor armature 16 is connected in series relation with the main machine, while the auxiliary generator armature 19 is connected inparallel relation thereto.

The normal-voltage relay device 12 comprises an actuating coil 25 that is connected across the exciting armature 18 for the purpose of adjusting the position of the customary magnetizable core member, to which is attached a plurality of bridging contact members 26 and 27 for closing certain auxiliary circuits to be described in connection with Fig. 2. The relay device 12 is raised to its upper or circuit-closing position only when the voltage of the excitmg'armature 18 equals or exceeds a predetermined relatively high value.

The over-voltage relay 13 comprises an actuating coil 28 and a bridging contact member 29 which normally occupies its lower or circuit-closing position and is raised therefrom only under conditions of excessive combined voltages of the main armature and the auxiliary armature 16.

Referring to Fig. 2, the auxiliary governing system shown comprises the actuating 0011s of the several switches that are shown in Fig. 1 and the bridging contact members of the relay devices 12 and 13, together with a master controller MC having a plu rality of operative positions a to f, inclusive, corresponding to acceleration, and a to f, inclusive, corresponding to regeneration; and a battery B or other suitable source of cnerg 1 for the auxiliary system.

Assuming that it is desired to effect acceleration of the main machine, the master controller MC is actuated to its initial accelerating positionia, whereby a circuit is established from the positive terminal of the battery B through conductor 40; control fingers 41 and 42, which are bridged by fingers 54 and 55; and conductors 56 and 57,

to the actuating coils of the switches 11 and 2, respectively,, whereby such switches are initially closed topartially short-circuit the resistor R1 and thereby provide the maximum excitation for the auxiliary series-reiated armature 16, under starting conditions of the main motor, for a purpose to be pointed out. Onthe other hand, the switches 4 and 5 initially remain open to suitably weaken the field excitation for the auxiliary parallel-related generator armature 19.

A further circuit is initially established from the contact segment 43 through control finger 58, conductor 59 and the actuating coil ofthe switch 7 to the negative conductor 47 I The three auxiliary machines are thus initially connected inseries relation across the supply circuit, andthe booster set is gradually brought up to speed, the field windings 20 and 22 bein thus series-excited to produce the desired initial Volta e of theexciting armature 18 by means 0 the shunt-excited field winding 21.

When such initial voltage has been attained, a further auxiliary circuit is completed from the contact segment 43 through control finger 48, conductor 49, bridging contact member 26 of the normal-voltage relay device 12, which now occupies its upper position, conductor 50, and the actuating coil of the switch 3 to the ne ativc conductor 47. A similar circuit is continued from the contact segment43 through control fin er 51, conductor 52, bridging contact mem er 27 of the relay 12, in its upper position, and

conductor 53, to the actuating coil ofthe switch 6. The field windings 20 and 22 for the auxiliary armatures 16 and 19 are thus energized from the exciting armature 18. in accordance with circuits about to be traced.

After the booster set attains its full operating condition, the main machine is gradually accelerated, either as a straight series motor, by leaving the switch 11 in its illustrated open condition, or by closing the switch 11 to provide additional excitation' for the main field windin F1. Such initial closure of the switch 11, if desired, may ha readily accomplished by manually closing switch 60 (Fig. 2) which connects the positively energized conductor .44 to'the actuating coil of the switch 11.

he various main'circuits that have been completed in the previously described manner may be set forth as follows:

The-main machine circuit, indicated by solid arrows, is established from the lrollcy through conductor 65, line switch LS, conductor 66, auxiliary driving armature 1(3, junction-point 67,conductor 68, switches 1. and 2, which partially short-circuit the rcsistor R1,"switch 3, conductors 69, and 71, main-field winding F1, junction-point 72, mainnrrhature A1, and conductors 73 and 74, to the negative supply-circuit conductor Ground.

One of the exciting circuits, indicated by the dotted arrows, is established from the positive terminal of the exciting armature 18, through conductors 75, 76, 70 and (3.). switches 3, 2 and 1, conductors 8 and 7?, auxiliary field winding 20, switch 7, and conductor 78, to a junctionpoint 79 A socond exciting circuit is completed from the conductor 69 through conductor 80, auxiliary field winding 22, conductors 81 and 82, switch 6, resistor R2, and conductor 83 to the junction-point 79, whence a common circuit is completed through conductor 84 to the negative terminal of the exciting armw ture 18.

Another circuit is established from the positive terminal of the generator armature 19, through conductors 85 and 82 to the previously-mcntioned junction-point 79, where the circuit may divide, dependent upon the closed or open condition of the switch 1.1. lVith the switch closed, the circuit traverses the resistor R3 and the switch 11 to the junc tion-point 72. \Vith the switch open, the circuit is continued through conductor 84-, exciting armature 18, conductors 75, 76 and 71, main field winding F1 and junctionpoint 72, whence circuit is completed through main armatureril, and conductors 73, 86 and 87, to the negative terminal oi the generator armature 19.

It will be seen that the auxiliary driving armature 16 is thus connected in series relation with the main machine to perform a function similar to that of the familiar accelerating resistors, while the generator armature 19 is connected in parallel relation to the main machine to furnish a portion of the accelerating current therefor, the field windings for the two auxiliary arma tures 16 and 19 being energized by the exciting armature 18.

To further accelerate the main machine, the master controller may be actuated to its second position b, whereupon the contact segment 43 engages control finger 90, whence circuit is continued through conductor 91 lull lll l ill:

and the actuating coil of the switch 4, to the negative conductor 47. A section of the resistor R2 is thus short-circuited to correspondingly increase the voltage of the generator armature 19 and thus further raise the voltage impressed upon the main armature A1.

By actuating the master controller to its position 0, the contact segment 43 first becomes disengaged from the control finger 55 to eflect the opening of the switch 2 and then makes contact with control finger 92 to complete a circuit therefrom through conductor 93 and the actuating coil of the switch 5. A portion of the resistor R1 is thus included in circuit by the opening of the switch 2 to weaken the excitation of the auxiliary field winding 20, thereby de creasing the voltage of the auxiliary armature 16 and correspondingly increasing the portion of supply-circuit voltage that is delivered to the main armature A1, and, secondly, short-circuitin the remainin scction of the resistor 1 1 2 to correspondingly strengthen the field excitation for the g6l1 erator armature 19 and thus impress a larger voltage upon the main machine. In position d of the master controller, the switch 1 is opened by reason of the disengagement of contact segment 43 and control finger 54 to further weaken the excitation of the auxiliary driving armature 16 and efi ect another QCCBlGIatIDg step of the main machine.

In transition position 6, the auxiliary driving armature 16 is excluded from circuit by effecting the disengagement of the contact segment 43 and control finger 58, thus opening the switch 7. In position f, a new circuit is established from the contact segment 43 through control finger 94, conductor 95, and the actuating coil of the switch 8, thereby directly connecting maincircuit conductors 66 and 70. The booster set is then driven from the supply circuit by the generator armature 19, now acting as a motor, the armature 16 remaining inactive to reduce the operating losses of the system, while the full supply-circuit voltage is impressed upon the mam machine.

The inherent regulating features of my system, whereby surges of accelerating current are prevented, will now be set forth. From the previous descri tion, it will be observed that the resistor 2 carries, in the same direction, the currents of both the enerator armature 19 and of the excitingeld winding 22. Consequently, any incipient increase in either of these currents, caused by an upward fluctuation of supply-circuit voltage, for example, to increase the speed of the booster set, will correspondingly increase the voltage .drop across the resistor R2 and thus weaken the excitation of the field winding 22 which is connected in series-circuit relation therewith. The voltage of the generator armature 19 is thus reduced to impress a decreased voltage upon the main machine and thereby counteract the incipient rise of accelerating current.

Furthermore, current from the auxiliary driving armature l6 traverses the resistor R1 in a direction opposite to the current that flows through the resistor from the exciting armature 18. Consequently, any increase of accelerating current in the auxiliary driving armature 16 will decrease the voltage drop across the resistor R1 by reason of the differential relation of the currents just mentioned and thus increase the excitation of the auxiliary field winding 20.

Such action will correspondingly augment the counter-electromotive force of the driving armature 16 and thus again counteract the imgending increase of accelerating current. t will be understood that the con verse actions inherently occur in the auxiliary armatures 16 and 19 upon an incipient decrease of accelerating current. In this way, heavy surges of main-machine current during the accelerating period are inherently prevented.

To efl'ect regenerative operation of the main machine under suitable speed conditions thereof, the master controller may be actuated from its intermediate ofi' position to the initial regenerative position a. Switches LS, 3, 4, 5, 6 and 8 are closed in accordance with the previously described circuits, a contact segment 96 of the master controller being substituted for the previously mentioned contact segment 43 during the regenerative period.

A new circuit is established from the contact segment 96, through control finger 97 and conductor 98, to the actuating coil of the switch 11, whereby an auxiliary excitation circuit is established from the positive terminal of the exciting armature 18, through conductors 75, 76 and 71, main field winding F1, junction-point 72, switch 11, resistor R3, junction-point 79, and conductor 84 to the negative terminal of the exciting armature. Themain machine is thus initially connected to the supply circuit through the switches 8 and LS.

By moving the master controller to position I), one new circuit is established from the contact segment 96, through control finger 100 and conductor 102, to the actuating coil of the switch 9, and a second circuit is subsequently completed from the contact segment 96, through control finger 103 and conductor 104, to the actuating coil of the switch 10. The resistor R3 is thus partially short-circuited to increase the main field excitation.

In position 0, the contact segment 96 first is disengaged from the control finger 94, to open the switch 8, and then makes contact with the control finger 58 to close the, switch 7 and complete the series connection of the auxiliary drivin armature 16 with the main machine. l ithout tracin in detail, the various main follows the opposite direction from that indicated by the solid arrows. t

In the present instance, however, .switches 1 and 2 are initially open to excite a relatively small voltage in the auxiliary armature 16, while the switches 4. and 5 are closed to produce a relatively high voltage in the generator armature 19, thus producing the opposite effect from that initially attained during acceleration.

To compensate for the gradual, decrease of vehicle speed during the retardation period, the master controller may be moved to its position d to energize the control, finger 54 and thereby close the switch 1 to short-circuit a section of the resistor R1 and correspondingly increase the voltage of the series-related auxiliary armature 16, which thus absorbs a greater portion of the supply-circuit voltage and permits the main machine to regenerate at a voltage lower than that of the supply circuit.

In position e, the control finger 55 is like wise energized to close the switch 2 for a similar purpose, tact segment 96 becomes disengaged from the control finger 92 to effect the openin of the switch 5 and thus correspondingly ecrease the excitation of the parallel-related auxili-. ary armature 19. In the final position f, a similar action occurs with respect to the switch 4, whereby the entire resistor R2 is included in circuit during the lowest speed range of the regenerating main machine.

\Vithout a detailed description, it will be understood that the inherent action of the resistors B1 and R2, during the regenerative period, serves to prevent sudden vari-- ations of main-machine current, although the currents from the auxiliary armatures 16 and 19 traverse the allied resistors R1 and R2 in the opposite direction from that taken during acceleration; that is, the exciting current from the auxiliary armature 18 and the current from the auxiliary driving armature 16 traverse the resistor R1 in the same direction, while the currents from the exciting armature 18 and the generator armature 19 traverse the resistor R2 in opposite directions.

Furthermore, the active portion of the resistor R3 effects an inherent regulating action of a similar nature. Since the mainarmature current and the main-field-winding current traverse the resistor R3 in the same direction during regeneration, an incipient increase of regenerated current correspondingly increases the voltage drop circuits, itwill be understood that the regenerative current and, in addition, the consisters R1 and.

'rangements, such as p a relatively simple system i for inherently preventing sudden variations of main-machine current during either acceleration or regeneration, and furthermore, flash-over difficulties are obviated bv, reason of ithewelimination of shunt fiel windings from the auxiliary drivingarmature and the generator armature 16 and 1 9, respectively. z i

It will be appreciatedthat, by suitable design and arrangement of parts, any desired degree of compounding may be imposed upon the main armature; that is, any desired degree of shunt operating characteristic may be provided. Furthermore, in lieu of the single main machine that I have illustrated, for purposes of simplicity and elearness, two or more main machines may be utilized, and series-parallel control thereof may be employed, as set forth, for example, in my coending application Serial No. 71,198, filed l anuary 10, 1916.

Moreover, it will be evident that the rel 12 may readily be connected m circuit to carry the sum or the difierence of certain combinations of auxiliary-armature and auxiliary-field winding currents other than those illustrated; that is, the aux iliary-driving-machine and auxiliary-generating-machine armature and field-winding circuits may be interconnected in various ways.

I desire it to be understood that, by the statement in the accompanying claims, an auxiliary armature winding connected in parallel-circuit relation to the main machine, I do not restrict myself to a direct shunt connection of such auxiliary armature across the main machine, but equivalent arconnection of the auxiliary armature across the suppl circuit, are also intended to be covered. Ciinsequentl I do not desire to be restricted to the speci c circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of the invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

claim as my invention:

1. Ina system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectivel connected in series-circuit relation with, an in parallel-circuit relation to said main machine, means for exciting said auxiliary armatures, and a translating device connected in circuit to carry a combination of the auxiliary arn'iature currents and the auxiliary exciting currents.

2. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectively connected n 'i *s-rircuit rela tion with, and in parallet .1: nit relation to said main machine, means for exciting said auxiliary armatures, and a plurality of translating LlCVl es connected in circuit to respectively carry the sum and the difference of certain of the auxiliary-armature currents and auxiliary exciting currents.

3. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectively connected in series-circuit relation with, and in parallel-circuit relation to said main machine, a plurality of field windings for said auxiliary armatures, a source of energy for exciting said field windings, and a plurality of resistors res iectiveiy connected in circuits common to the auxiliary armatures and the auxiliary field windings.

l. In a system of control. the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectively connected in series-circuit relation with, and in parallel-circuit relation to said main machine, a plurality of field windings for said auxiliary armatures, a source of energy for exciting said field windings, a resistor connected in rircuit with the seriesrelated auxiliary machine to carry the difference of the corresponding ari'nature and field-winding currents, and a second resistor connected in rircuit with the parallehr lated auxiliary machine to carry the sum of the corresponding armature and field-winding currents.

5. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectively connected in series-circuit relation with, and in parallel-circuit relation to said main machine, means for exciting said auxiliary armatures, and means associated with the respective auxiliary machines for inherently counteracting variations of the portion of main-machine current that tra erscs each auxiliary machine.

6. In a system of control, the combination with a main dynamo-electric machine and a supply circuit therefor, of a plurality of auxiliary armature windings respectively connected in series-circuit relation with, and in parallel-circuit relation to said main machine, a low-voltage source of energ and a single field winding for each of said auxiliary armatures excited from said source.

7. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings respectively connected in series-circuit relation With, and in parallel-circuit relation to said main machine, a source of energy, and a single field winding for each auxiliary armature dependent for effective excitation partially upon said source and partially upon the corresponding armature currents.

8. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings one of which is connected in series-circuit relation with said main machine, means for exciting said auxiliary armatures, and a translating device connected in circuit to carry a combination of the auxiliary armature currents and the auxiliary exciting currents.

9. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature windings one of which is connected in series-circuit relation with said main machine, means for exciting said auxiliary armatures, and a plurality of translating devices connected in circuit to respectively carry the sum and the difference of certain of the auxiliary-armature currents and auxiliary exciting currents.

10. In a system of control, the combination with a main dynamo-electric machine, of a plurality of auxiliary armature wind ings one of which is connected in seric. circuit relation with said main machine, an auxiliary source of energy independent of said series-circuit, and a single field winding for at least one of the auxiliary armatures dependent for effective excitation partially upon said auxiliary source and par tially upon the corresponding armature current.

11. In a system of control, the combination with a main dynamo-electric machine. of a plurality of auxiliary armature Wind ings, one of which is connected in seriescircuit relation with said main machine, an auxiliary source of energy independent of said series circuit, and a single field wind ing for at least one of the auxiliary armatures dependent for effective excitation partially upon said auxiliary source and partially upon the load of the system.

In testimony whereof, I have hereunto subscribed my name this 23rd day of Am gust, 1917.

RUDOLF E. HELLMU N D.

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