US1251446A - Regulator. - Google Patents

Description

L. W. THOMPSON.

REGULATOR.

APPLIIjATIOIl ,FILED Ill. 22. l9l3. RENEWED API. 29. ISIS.

1,251,446. Patented Dec. 25,1917.

WITNESSES:

Lou/3 W Thom won INVENTOR UNITED STATES PATENT OFFICE.

LOUIS w. THOMPSON, OF WILKINSBUBG, PENNSYLVANIA, ASSIGNOB TO GENERAL ELECTRIC COMTANY, A CORPORATION OF NEW YORK.

REGULATOR.

Specification of Letters Patent.

Patented Dec. e5, 1917.

Application fled latch 22, 1913, Serial No. 756,068. Renewed April 29, 1916, Serial No. 94,518.

To all whom it may concern:

Be it known that I LomsW. Tuoarrson,

My invention relates to regulators thatare adaptedto be employed in connection with dynamo electric machines for automatically regulating the effect of a resistance by intermittently short-circuiting the same. It has lators of the v1 rating type which efiect'the regulation ofgenerator voltage by controlling the field strength of the erators. Llectric regulators of the vibrating have long been used for controlling the e d current of dynamo-electric machines for the pur se of controllin their operation as reaar s speed, voltage, oad, power factor, etc. ne of thecnief difliculties encountered in the use of this type of regulator is an excessive sparking at the contacts, which ultimately so in ures these contacts that their operation is imperfect and unsatisfactory. Large contacts cannot be satisfactorily used because of the increase in weight. This difficulty is commonly overcome by using a.

plurality of synchronously operated relays, each of which short-circuits only a portion of the whole resistor, so that the potential difference across each pair of ;contacts is reduced. Further difiiculty has been oncountered-in so arrangin the moving contacts that the surges technically known as hunting are prevented.

My invention comprises a regulator of the vibrating type in which sparking at the contacts is prevented, while the use of a plurality of relays is avoided. To this end I short circuit a resistor by means of alternative, or transfer, circuits, each of which comprises a periodic circuit interrupter of rugged construction in series with vibratory contacts. The vibration of said contacts is effected and controlled jointly by the quantity to be regulated, and b the periodic circuit interrupter. These evices are s o arranged that said alternative, or transfer, circuits arealrways' broken by the periodic circuit' interrupter.

A further object of my invention is to provide a novel and improved arrangement articular reference to regufor the prevention of hunting. For this purpose I provide, in connection with the combination of vibrating contacts a periodic circuit interrupter, a resilient member tending, when stremed, to open the vibrating contacts and a device for stressing said resilient member which is set in action upon the closing of the circuit throu h said device and put out of action by t e opening of the periodic circuit interrupter.

The single figure-of the drawings is a diagrammatic view of circuits and apparatus showing my invention asapplied to the regulation of the voltage of an alternating current generator through regulating the field current of its exciter.

Referring to the drawings, an electrical circuit, the voltage of which it is desired to maintain substantially constant,,comprises line conductors 1 and 2, and is supplied from an alternating current generator 3. The field winding 4 of the generator is energized by an exciter 5 which is here indicated as a direct current shunt wound generator.

The exciter 5 is provided with a shunt field windin 6 and a field resistor 7 in series therewit The main circuit of the exciter comprisesa variable resistor 8 which may be adjusted to control the current in the circuit.

M regulator, as shown, comprises means for intermittently short ircuiting the field resistor for varying len hs of time, depending upon an electric condition of the circult including tl conductors 1, 2. Said means comprise relatively 'm'ovable contacts which may have any one of a variety of forms, but, as illustrated, comprise resilient switch members 9 and 10, the extremities of which are provided with contact members which coact respectivel tact members 11, 12 an 13, 14. The switch members 9 and 10 are actuated by movable members 15 and lfi respectively, and are adapted, due to their yielding character, to permit some movement of the members 15 and 16 after engagement of the contact members carried thereby with the contact members 11, 12 and 13, 14 respectively. The core members are each provided with two coils 17 and 18.

The coils 17 are in series with each other and with the secondary winding 19 of :1 voltage transformer 20, the primary winding 21 of which is connected across the line of the alternator 3. The coils 18 are connected in series with each other and with the' secondary winding 22 of a current transformer 23. the primary winding 24 of which is in series with the line conductor 1. The transformers 2O and-23 are'made without cores or with.

smallcores to reduce the. inductance and thereby decrease the time required for an impulse to be transmitted by the transformers which serve as butters and also to impart an upward movement to'said mres when the windings 25 are subsequently dei nergized. A pair of periodic circuit interrupting devices 27 com rises rotatable drums '28 provided with a tomato sections of oonducting material 29 and insulating material 30. .\s here shown, four sections of each material are used, the oppositb sections of conducting material being cross-connected in order that oppositel arranged brushes 31 may be con: nected w ten sections of conducting material are engaged by the respective brushts. The

conductor sections are arranged to project from thewheel in order that, as the drmns rotate, a quick break may lie-obtained at the brushespwhich may be yieldingly purist-d inst the drums 28 by any suitable means. T e drums are arran to be rotated by any suitable source wlnch'may be connected to a rotating part of the system or may be independent as desired. It will be noted the drums are arranged to rotate 45 degrees apart in order that one pair of brushes will be in engagement. with a pair of contacts on one :lrum when the other pair of brushes is out of engagement with the contacts on the other drum, the conditions alternating as the drums rotate. The circuit interruptcrs 27 control the energization of the. windings 25 and prevent the disbngagemcnt of the contacts carried by the switch members 9 and 10 from contacts 11, 12 and 13, 1-1 respecmay, while current is passing therethrongh, and any equivalent construction may, of course, e'employed.

'lhe'ope-ra-tlon ofmy invention, as at present understood, is as follows: Assume for purposes of explanation that it is desired to maintain the voltage of the. circuit 1, 2 at. a predetermined value and that the various elements of the system are adjusted for this value. Also disregard for lho moment the effect of the compensating windings 18, 18,

the exciter, the voltage of the circuit 1, 2

will be less than the desired value, whereas, .if a short circuit be continually maintained around said resistance 7, the voltage of the circuit 1, 2 will have a value greater than that desired. If the voltage of the circuit 1, 2 he. sulliciently high. the cores 15 and 16 will be raised to a position in, which the contacts carried by the switch members 9 and 10, secured thereto. will be maintained out of contact with the contacts 11. .12 and 13, 14. The resistance. 'i' will accordingly be rendered effective and hence the voltage of the circuit 1:2 will decrease. \Vhcn a certain decrease in voltage has occurred, the core members 15 and 16 will lower so that the contacts carried by the switch members J and 10 will engage with the contacts 11, 1:2 and 13. 14. During the period of such eugagement. the resistance 7 will be short circuited through alternative circuits, one of which comprises, the. conductor 32. contact 12. switch nu-mber 9. contact 11, lefthand whaling 25. and the left-hand interrupter 27. and the other of which comprises the conductor 32. contact 13. switch member 10, c 'mtact l-t. right-hand winding Q5. and the right-hand interrupter :27. The field current of the exciter will thus be transferred from the circuit comprising one. interrupter totlucircuit comprising the other interrupter. \Vhcn the circuitis closed through a. winding :25. the core member associated therewith will be drawndown so that it; will compress the-spring :26 associated there with and will also flex the switch member 9 or 10, asthe. case may be. causing the contacts carried by the. same to firmly engage with the. contacts 11. 12 or .13. H. On the drawing, the switch member 9 is shown flexed in the manner described. since the circuit through the -lcfthnnd winding 25 is closed. If now, the voltage of the circuit 1, .2 rise to. or above. the desired value. the increased energization'otthe windings 17. 17

will tend to raise the cores l3 and 16 and lift the. contacts carried b the switch members 9 and 10 out of engagement with the contacts ll, 12 and l3. l4. ll the iuterrupters. at the. moment. the. circuit voltage reaches this value. are. in the position shown. the. con

their coiiperating Stationary contacts, the ref sistance 7 will become efi'ective and the voltage ofthe circuit 1, 2- will consequently decrease. The cores 15 and 16 will there .fore lower and a circuit in shunt to the resistance 7 will be completed through that interrupter, which at the instant has a pair. of contacts 29 in engagement'with a pair of brushes 31, and the winding "25 in circuit with suchinterru ter. Assume that, at this instant, the rightand interrupter has a pair of contacts 29 in engagement with the brushes 31. 1 The shunt circuit will therefore be completed through such ri hthand in: terrupter,'the ri' ht-hand win ing 25, the contact '14, switc member 10, contact 13, and the lead 32. The resistance 7 being short circuited the voltage of'the 'circuit 1,

- 2 will increase. The right-hand winding 25 being energized, the s ring 26 will be comand the switc member 10 will be exed in the manner previously described. In this waythe core members 15 and 16 are caused to vibrate vertically, and if 'the voltage of the circuit 1, 2 is below the desired value, the riod, at each vibration, during which a ort circuit around the resistahce 7 exists is greater than the period during which'such a short circuit exists when the voltage of the circuit 1, 2 has the desired value and, on the other hand, if the voltage of the circuit 1, 2 be above the desired value the riod during which a short circuit around t e resistance 7 exists is less than the period during which such short circuit exists when the voltage of the circuit 1, 2 has the desired-value. It is also evident that the switch members 9 and 10 can never be opened until afterthe respective circuits in which they are included are opened by the interrupter. Thus sparking between the switch members 9 and 10 and their respective contacts is wholly eliminated.

The effect of the compensating coils 18 will now he explained. When a heavy load i thrown on the supply circuit, there will be an increase in the drop in potential due to line resistance. It is usually desirable to maintain a substantially constant voltage at the points of current supply and inorder to efi'ect this result; the generator voltage must be increased to compensate for the line drop. The compensating coils 18 are arranged to provide for the necessary modifications of the effects produced by the coils 17. An incrcase'in the flow of current in the line conductor 1 will cause a corresponding insultant effect may be either the sum or dif- 'of a resilient member, means responsive to crease in the secondary winding 22 of the transformer 23 and in the energization of the coils 18. The coils 18 are so wound that an increase in current has the effect of opposing the upward movement of the core members and, as before explained, the relativel longer period of closure of the switch mem ers 9 and 10 will cause an increase in the generator voltage. When the current decreases, this effect is diminished and when no load is on the line, the compensating coils have no effect. Thus, it will be understood that the'coils 17 and 18 have independent effects-upon the core members but the reference of the independent efi'ects according to line conditions.

It will be understood that many changes will occur to one skilled in the art. Such changes as fall within the limits of the appended claims may be made without de--. parting from the spirit of my invention.

I claim as my invention:

1 An electric regulator comprising a re-v sistor, relatively movable contacts responsive to the quantity to be regulated, means for holding said contacts in engagement, a pcriodic circuit interrupter and a'circuit for shunting said resistor comprising said contacts, holding means, and circuit interrupter.

2. 'An electric regulator comprising a resister, relatively movable contacts responsive to the quantity to be regulated, 'means for holding said contacts in engagement, resilient means put under tension by the action of said holding means, a periodic circuit interrupter, and a circuit for shunting said resistor ,comprising said contacts, holding means, and circuit interrupter.

3.-An electrical regulator comprising a 1,5 resistor, relatively movable contacts responsive to the quantity to be regulated, one of said contactsbeing resiliently mounted, means for holding said contacts in engagement and putting said resilient mount ng under tension, a 'periodic circuit interrupter, and a circuit for shunting said resistor comprising said contacts, holding means, and circuit interrupter.

4. An electric regulator comprisin a rc- 116 sistor, two sets of relatively movab e contacts, each of which is responsive to the quantity to be regulated, at periodic circuit interrupter in series with each set of contacts, said circuit interrupters being ar- 129 ranged so that one will be open when the other is closed and alternative circuits for shunting said resistor, each of which comprises a periodic circuit interrupter and a pair of contacts.

5. An electrical regulator comprising a resistor, a pair of relatively fixed contacts, a pair of movable contacts associated therewith and electrically connected by means the quantity to be regulated associated with said resilient member intermediate said contacts, a coil in series withsaid contacts arranged, when energized, to hold said con;- tncts in en gement and put said resilient member un er tension, rupter, and a circuit or shunting said resistor comprising said contacts, series coil, and circuit interru ter.

6; The combination with a main electrical circuit-comprising a generator, of a field winding therefor, meansfor controlling the excitation of said winding comprisin a circuit, said circuit including a-peri ic circuit interiilpter and a switch membervthat is res xmsive to the current and the voltage values of said main circuit and to conditions in the circuit'of said field winding.

7. The combination with a crater, of a field winding therefor xneans'i ii controlling the excitation of: windingioomprising a circuit including a periodic circuit interrupter and a switch member responsive to an electrical condition'of said generator and conditions in the circuit of saidfield 8. The combinationwith a generator having a field magnetwinding and a resistor iii circuit therewith, 'of means for,shunting said resistor comlf a periodic circuit interrupter, a co in circuit 'with said circuit interrupter, and a inovable core member by saidcoil.

riodic circuit intcr- 9. An electric regulator comprising a resistor, a plurality of periodic clrcuit interrupters, a plurality, of vibratory members,

and a plurality of transfer circuits in shunt to' said resistor and adapted to be jointly controlled by mid circuit interrupters and said vibratory members.

10. An electric regulator comprising a rcsister, a pair of circuits in shunt to said resistor, a pair of periodic circuitinterrupters adapted to alternately open said circuits, and a. pair of vibratory members adapted to be controlled both b the quantity to be regulated and by sai interru ters for controlling the continuity of sai circuits.

11. An electric regulator comprising a resistor, a pair of circuits in shunt to said resistor, a pair of periodic circuit interrupters adapted to alternately open said circuits, and a vibratory device, associated with each of said circuits,comprising a winding and vibratory contacts, in series therewith, and a winding adapted to be energized in response to the quantity to be lated.

In testimony whereof, -I have hereunto subscribed my name this 20th day of March,

LOUIS w. THOMPSON.

wanes-es? J. R. Laxomr, B. B. Hrnrs.

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