US1759763A

US1759763A - Turbine-regulating means

Info

Publication number: US1759763A
Application number: US341918A
Authority: US
Inventors: Reginald G Standerwick
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1929-02-23
Filing date: 1929-02-23
Publication date: 1930-05-20
Anticipated expiration: 1947-05-20

Description

means other than its speed governor.

Patented May 20, 1930 REGINALD G,

PATENT OFFICE STANDERWICK, OF MARBLEHEAID, MASSACHUSETTS, ASSIGNOR TO GEN- ERAL ELECTRIQ COMPANY, A CORPORATION OF NEW YORK TURBINE-REGULATING MEANS Application filed February 23, 1929. Serial No. 341,918.

The present invention relates to elastic iiuid turbine `installations wherein there are provided amain turbine driven alternating current generator or generators which constitute the main Asource of powei` and which set the frequency of the system, and a secondary or auxiliary turbine driven alternating eurrent generator which is tied in with the main turbo-generator or generators whereby its speed is fixed, and which may be controlled -normally by an operating condition other thanthe load which it carries, that is, by a For example, the secondaryor auxiliary turbine may be an extraction turbine, a back pressure turbine, or a combination of the two and may be regulated normally in terms of extraction pressure or back pressure or both, turbines of this type being now well known in the art.

One object of my invention is to provide an improved construction and arrangement in a turbine installation of the type referred to wherein the secondary or auxiliary turbine, whicli is normally controlled by a means responsive to a condition other than its speed, will be changed over automatically to speed governor control in case the frequency of the system to which it is connected decrea es below apredetermined value,` whereby such turbine will function to help supply the load and thereby maintain the frequency of the system.

Afurther object of my invention is to proi vide an improved system whe-rein'the secondary or auxiliary turbo-.generator is connectedto secondary or auxiliary bus bars to which is connected a certain load, the secondary or auxiliary bus bars being connected to the nia-in bus bars of the main turbo-generator or generators, and wherein in case the frequency of the system decreases below a predetermined value, the secondary or auxiliary bus bars will be segregated from the main bus bars, the load on the secondary or auxiliary bus bars being then carried by the secondary or auxiliary turbine.

Other objects of my invention and the novel fea-tures thereof will be pointed out more fully hereinafter, and for a considerationv of what lbelieve to be novel and my invention attention is directed to the following specification and the claims appended thereto.

In the drawing, the figure is a diagrammatic view of a turbine installation or system embodying my invention.

Referring to the drawing, 1 indicates an elastic fluid turbine having an admission conduit 2 and an exhaust conduit Turbine 1 may be of any suitable type. in thepresent instance I have illustrated an impulse turbine of the type 'termed usually a back pressure turbine, this term being applied to the turbine because during normal operation it is controlled by the pressure of the exhaust elastic iiuid. 1t is to be understood, however, that this type of turbine is illustrated only by way of example and that my invention may be carried out in connection with turbines of other types suchv as, for example, turbines of the extraction-type.

The valve means for controlling the flow of elastic fluid to turbine 1 is indicated at 4. It is here shown diagrammatically and by way of example as comprising a sin glo valve member connected by a stem 5 to a lever 6 pivoted on a fulcruin 7', the free end of lever 6 being provided with a roller S which is engaged by a cam 9 carriedby a cam shaft 10. lt is to be understood that this valve structure is intended to represent any suitable turbine valve gear. On the end of cam shaft 10 is a pinionll which meshes with a rack 12 on the upper end of a rod 13. Rod 13 is connect-ed to a piston 14 located in a cylinder l5'. Piston 14 is biased toward the lower end of the cylinder b v a spring 16. Then piston 141e moves upward in the cylinder, cam shaft 10 is turned in a direction to open valve means t, while when the piston moves downward in cylinder 15, cam shaft l() is turned in a direction to permit valve means 41 to move toward closed position.

Turbine 1 is shown as-being directly connected to an alternating current generator 17 connected by lead wires 18 to bus bars 19, which maybe termed secondary or auxilary bus bars. The secondary or auxilary bus bars 19 are connected by lead wires 20 to main craters Turbo-generators 22 may be ain turbo-generators o' a power system and controlled to set the frequency of the s t" nections is a suitable circuit eem. l oreaker d in connections 2O is suitable circuit ort-,alter 24. Each oit these circuit conduit 28 which may lead to atmosphere or other suitable4 point. En conduit 28 is a pressure relier2 valve 29 which may be set to open ata desired pressure and which functions to prevent the pressure in conduit 3 from exceeding a predetermined high value. Any suitable form ot relief valve may be used.

At the lower right hand portion of the drawing, 30 indicates the oil tank for the turbine, 31 indicates the oil pump which supplies oil under pressure for lubricating the turbine and also for supplying pressure to actuate the valve mechanisms, and 32 indicates the oil strainer for pum 31. lump 31 is provided with a vertical shaft, on the upper end of which is a worin wheel 33 driven by a Worm 34 on the end of turbine shaft 35. Also driven by the vertical pump sha'lit is a suitable speed governor 36.

rlhe parts just described are not shown in correct relative relation to turbine 1, but shown diagrammatically and as having een brought around into the plane of the paper. ',lhis is orthe purpose oi showing diagrammatically the connections of the parts of regulating mechanism to each oth er. jrs

be understood by those familiar with elastic fluid turbines, the parts will suite. ly arranged in combination with the turbine in a usual and convenient manner. will be understood, also, that the relative sizes ot the parts are not correctly shown, the size of some 01"' the parts being greatly exaggerated for purposes of illustration.

Speedrgovernor 3G has its weight arms 3T connected by a stem 38 to a pilot valve 39 provided with upper and lower valve heads 40 and 41. Stem 38 is preferably connected directly to pilot valve 39 so that the pilot valve rotates with the speed governor. vlllhen weights 37 ily outward, pilot valve 39 is pulled downward, while when t'hey'move inward,.

pilot valve 39 is moved upward.

Surround'ng pilot valve 39 is a pilot valve bushing 42 provided with annular grooves 43 and 44 controlled by valve heads 40 and 41, and with passages 45. Surrounding bushing 42 is pilot valve casing 46 vided with three spaced annular grooves with which and pf ly communicate. Eushin ly in lasing 46 but cannot held from turning by su shown). The upper annular g ing 46 is connected by pipe valve casino` 48; the iniidfllc unn to cvlin is connected bv a pipe il neath piston 1 andthe lewe connnunicates d ircctly with oil tau valve bushing 42 is connected by a ste: .SO to a lever 51 mounted on a 'iiulcruin Stem 50 is shown as being constructed in two parts united by a long nut 53 having threads in its bore and gear teeth on its outer surface. rlhe upper part ot stem 50 is pivotally connected to the upper end ot nut 53 and the lower part of stem 5() is threaded and engages with the threads ot nut lleshing with the gearl teeth on nut 53 is a gear wheel 54 connect-ed by `beveled gears 55 to a synchronizing motor 5G. ln these connections is a friction clutch 56aM ot suitable construetion, through which motor 5G drives nut 53. llhe total movement. of pilot valve bushing 42 is limited by a pinb which engages stops 56C. lll/'hen pin 56h engages a stop 56C, clutch 56a slips so as to avoid stalling the motor. lll/hen motero@ turns in one direction, nut 53 is turned to shorten the length ot stein 50, while when motor 56 turns in the opposite direction, nut 53 is turned to increase the length ot stein 50, thereby `aising and lowering pilot valve bushing 42. This diagrammatic showing of motor 5G in connectionwit-l'i stein 50 is intended to represent any suitable synchronizing arrangement. ln particular, l may use an arrangement such as that disclosed in the patent to Scott No. 1,583,610, patented lVlay 4, 1926.

flhe left hand end of lever 5l is connected by a link 5'4" to one end or a lever 58 pivoted on a tulcruin 59. The other end olf lever 58 is connected to rod 13.. ported by the plunger GO of an electromagnet, the winding or' which is indicated at 61. YW hen winding G1 is energized plunger tOis held against a stationary stop G1, whereby tulcrum `59-is held stationary.` lleneath the fulcrum of lever 58 is an adjustable stop 62 which limits downward movement of lever 58 when winding 61 is decnergized. Connected to lever 58 is a spring G3 lever v58 down into engagement with stop rlhe right hand end ol:l lever 51 is connected to one end of a lloatinglever 64. The other end or' floating lever 64 is connected by a stein 65 to a pilot valve (SG located in pilot valve casing 48. Pilot valve G6 has two valve heads 68 and (S9. Valve head 68 cooperates with an annular groove 70 in pilot valve casing 48 and valve head G9 cooperates with an annular groove 71 is the pilot valve casing. Connected to annular grooves 70 is a pipe-line 72 twhich communicates with Fulcrum 59 is supllO which tends to pull the turbine.

the discharge side of pump 31. 73 is a suitable non-return valve arranged in this pipeline and 7e' is a pressurereliet1 valve which may be set to ielieve the pressure on the discharge side of pump 31 whenever it exceeds a predetermined high` value. 74 indicates the conduit through which oil is supplied from an auxiliary source for use in starting Annular groove 71 may communicate with any suitable discharge region. Lever 64 is connected by a link 75 to one end ot a lever 76. The right hand end of lever '76 is pivotally connected to a stein 77 which at its lowerend carries a piston 78 which moves in a cylinder 79. On stein 77 is a threaded portion 80 on which is an adjustable bushing 81. Mounted on bushing 81 in a, manner such that the bushing may turn in it is a spring clamp 82 which is attached'to one end ot a spring 83, the other end of the spring being attached to a 'spring ,clamp 84 fixed to the top of cylinder 79. Spring 83 serves tooppose upward movement ot piston 78 and may be adjusted to load the piston to ;-l the desired extent.- Connected to stem 77 is an arm 85 to which is connecteda contact 80 adapted to bridge a paii of contacts 87 carried by insulating housing 88.

Lever 7G is pivotally mounted on a l'ulcruiii 89 connected to the plunger 90 of an electromagnet, the winding of which is indicated at 91. W'hen winding 91 is energized, plunger 90 is held against a stationary abutment 92. Connected to lever 70 is a spring 93 which,

- when winding 91 is deenergized,'serves to litt lever 76, turning it on the upper end of stem 77 as a Jfulcrum. Windings 91 and 61 are connected iii series with a suitable source of electrical energy 941. rl`he circuit may be traced as follows:

Upper lead line 94, conductor 95, solenoid winding 91, conductor 92a, solenoid winding G1, conductor 93a, contacts 9-1 and bridge piece 9,ot acontact-making frequency-responsive instrument (described hereinafter), conductor 96, contacts and contact blade of circuit breaker 24, conductor 97, hand switch 98, contacts 20 and contact blade ot circuit breaker 23, conductor 99, and fuse 100 to the lower lead line 94. lVhen windings 61 oi' 91 are energized, the corresponding plungers, having been moved to the positions shown in the drawing, will be held thereby the windings. Then the windings are (ileenergized, however, and the springs 03 and 93 have moved levers 58 and 7G, i'n the one case into engagement with stop 62 and in the other case to the limit ot the movenient otl pilot valveGG, neither will bc moved back to its prior position when windings 01 and 91 are again energized.

They must be moved back manually in order to restore them to their to'riner positions. The pull ot the windings 61 and 91, when energized, while suiiicient to hold the plungers in the position shown in the drawing, is not sufficient to move them to such positions after they have been moved away by springs 63 and 93.

101 indicates a contact making ammeter having a movable contact arm 102 adapted to engage either of two pairs ot contacts 1023 and 104, or to stand in a position interinodiate between such contacts. 105 indicates the winding ot contact making an'iineter-101. This winding is connected by conductors 102l to line wires'l8 of generator 17, the connection being made through a suitable current transformer 10G. lith this arrangement, the current flowing through ammeter winding 105 proportional to the load oii generator 17. In conductors 102 is a load adjusting shunt connected resistance 107.

108 and 109 indicate the two tield windings ot synchronizing motor 5F lVinding 108, when energized, operates motor 56 in a direction tolower bushing 42; and windin g 109, when energized, operates motor in a direction to raise bushing L12. One side ot winding 108 is connected by a conductor 108l to one ot the contacts 109, the other contact 103 being` connected by a conductor 110 to one otl the contacts 87. One side ot winding 109 is connected by a conductor r111 to one ot the contacts 104, the other contact 101 being connected by a conductor 112 to the upper line of energy source 9-1. The other terminals of windings 108 and 109 are connected through the armature ot motor 56 to the lower line of source ot energy 9'1by a conductor 118. The other terminal 87 is connected by a conductor 114 to conductor 112. 115 is a hand switch connected Jfo'conductor 112 and adaptcd to be moved into engagement with either Contact button 110 or contact button 117.

Trip coil 27 ot circuit breaker 2stA is connected to source ot energy 91 by conductors 118 and 119, the conductor 119 including a pair of contacts 120 adapted to be bridged by bridge piece 121, and a tuse 121% The lower end ot cylinder 79 is connected by a pipe-line 122 to exhaust conduit 3 ot turbine 1, whereby piston 78 is subjected to the pressure ot the exhaust elastic'fluid of turbine 1.' lVhen the exhaust pressure inconduit 9 increases piston '7 8 will be moved upward against the action of spring 83, while when the exhaust pressure in conduit 3 decreases, spring 83'will move piston 7 8 downward.

Bridge pieces 95au and 121 are carried by a stem 123 which is moved by a suitable type ot instrument responsive to the frequency ofi the system to which the alternating current generators 22 are connected. Any suitable type ot frequency responsive instrument may be utilized, the essential thing being that. when the frequency decreases below the desired value, in the tirst instance the circuit including contacts 94: will be opened, and when the frequency decreases still further bridge piece 121 connects together contacts 120. In the Cil uinent of the type disc application `Serial lilo. 314,31i',iiled of even e herewith. llllie instrument comprises a chionous motor connected te bus bars Y conductors 125. The shalt oiinotoi' projects into a casing 126 and is supported i;-v suitable bearings 127 therein. @n the shai't is a worm which meshes with a worin wlvieel'128 mounted on a shaft 129 carried in a suitable bearing 130. Connected to the lower end of shaft 129 is a positive displacement pump 131 which in Athe present instance is shown as being a pump of the gear type. rl`he suction opening ot the pump is indicatedat 132 and the discharge opening at ing 126 is adapted to contain oil or other suite able liquid to'avlevel such as that indicated, whereby the pump is submerged in the liquid. Connected to the upper end ot shaft 129 is a fly ball speed governor 134, the weights ot which are indicated at 135. The weights are pivoted at 136 and are provided with arms 137 which' are connected to a pilot valve 133 which forms apart of a pilot valve structure. Pilot vvalve 138 rotates with the speed governor and is provided with heads 139 and 140 which control discharge and inlet ports 141 and 142 respectively in a sleeve 143 which surrounds the pilot valve. Pilot valve 138 and sleeve 143 are located in a pilot ,valve casing 144 which is connected by ports 145 and a passage 146 to the lower end of a cylinder 147. 1n cylinder 147 is a piston 148 which is connected by a piston rod 149 to a lever 150 pivoted at its outer 'end on a tulcruin 151 carried on the up `)er end of a rod 152. llod 152 is pivoted ai its lower end on a fulcruin 153. Filet vabe sleeve 143 is pivotally connected to lever 150 vby a rod 154. 1n cylinder 147 is onenin in oilot valve casinfr 143 which admission opening cbmmunicates with ports 142. Connected to pipe-line 15'? is a by-pass pipe-line 158 which leads back to tank 126. ln by-pass pipe-line 153 is a pressure relief valve 159 of any suitable construction. For example, it may be an adjustable, siringpressed relief valve of known type, which may be set to maintain the desired pressure in pipe-line 157.

Stem 123 which carries bridge pieces 95 and 121 is connected to the tree end of lever 150. Also, carried by stem 123 is a bridge piece 160 adapted to bridge a pair ,of contacts 161 in circuit with. which is a signal 132 such as a lamp, a bell, er the like Vliet valve 159 is ad l l, being connecte ,to

a speed correspond- Pry,

tra line. as a result, sp f be driven by motor speed corresponding to that of the and 1 (l shut ofi erts 141 and142.' 131 r ill supp d continuously to ipeline los and maintain tl erein dei'inite pressure fixed by the pressure for which rejusted. There will have been built up beneath piston 143 a pressure oll a 'alue sutlicient to raise piston 148 against the action of spring 156`and bring it to the position wherein ports 141 and 142 are covered by valve heads 139 and 140. rllhere thus exists a condition et equilibrium wherein piston 143 and lever arm 150 occupy certain predetermined positions. F or normal frequency on the line this may be the positions indicated in the drawing.

'1f the ltrequency decreases, thespeed of motor 124`decreases a corresponding amount. ils a result, governor weights 135 will move inward a deiinite amount, thus raising pilot valve 133` a corresponding amount and Inoving head 140 so that it uncovers admission ports 142. Fluid is thus admitted from pipeline 15T through ports 142, ports 1457 and passage 14ol to the underside of piston 148, moving it upward and raising lever 150 until sleeve 143 assumes a new and lhigher position such that ports 142 are again closed by head 140. 11i the frequency increases, an action siiuilail to that described, except in the opposite direction, takes place. rElie arrangementv is lsuch that when the 'frequency decreases by a certain predetermined amount,\le'ver 150 will move upward sulliciently to bring bridge piece 160 into engagement with contacts 161, thus operating signal 162. the frequency decreases further by a predetermined amount, bridge pie n5 meres from engage- 94, thus opening the circe n nient with contacts cuit through solenoid windings 61 and 91. li the frequency decreases by a further predetermined amount bridge piece 121 is brought into engagement with contacts 120, thus closing the circuit through tripv coil 27 to eli'ect the opening of circuit breaker 24 so as to disconnect the auxiliary bus bars 119 from the main bus bars 21. r1`he operation is as follows:

ssun'ie that the parts are in the positions shown in the drawing, the valve means 4 for turbine 1 being open a predetermined amount so that turbine 1` is carrying a certain load, the amount ot elastic fluid admitted to the turbine being such that the pressure in the exhaust conduit 3 is at a desired predetermined value. ln this connection, it will be understood that the elastic fluid exhausting from turbine 1 is used for industriali purports 43 in pilot valve sleeve 42. Pilot valve 66v occupies a position 'wherein head 68 covers annular groove O, thereby preventing flow of oil from pipe-line 72. lf now the exhaust pressure in conduit 3 increases, indicating too great a supply of exhaust elasticfluid, the pressure in cylinder 79 beneath piston 78 increases, thereby raising the piston. This will raise the right hand end of lever 76 and lower the lefthand end, the leverturningon its fulcrum 89. The lowering of the left hand end of lever 76 lowers the right hand end of lever 64, thus lo ering pilot valve 66 and movinghead 69 do vnward, permitting escape of 'oil from beneath piston 14 by way of pipe 49, ports 45, ports 43 in 42, pipe 47 and annular groove 71. Spring 16 now forces piston 14 downward, thereby moving the valve means 4 toward closed position and decreasing the supply of elastic fluid to turbine 1. lVhen piston 14 moves downward it carries with it the left hand end of lever 58 and raises the right hand end, the lever turning on'its fulcruni 59. Raising the right hand end of lever 58 raises link 57 and lifts the left hand end of lever 51. This lowers the right hand end of lever 51 and at the same time the left hand end of lever 64.` Lowering` the left hand end of lever 64 raises its right hand end and restores pilot valve 66 to its former position wherein head 69 covers annular groove 71 to prevent further escape of liquid from beneath piston 14. The parts thus assume a new position corresponding to the new posi-A tion of piston 78 and valve means 4. The lowering of ,the right harfdend of lever 51 lowers somewhat pilot valve sleeve 42 but this has no effect on the governing mechanism. If the pressure in conduit 3 decreases,

indicating an increased demand for exhaust elasticv Huid, piston 78 moves downward in cylinder 7 9 and effects an opening movement of valve means 4 after the manner just described except that the various parts are moved in theopposite sense. The operation of the mechanism as so far described is that of a. known back pressure regulating means. Under normal operating conditions, they-frequency of the system remaining substantially constant, the mechanism will continue to operate as described, the turbine 1 functioning as what is known as a back pressure regulated turbine. L

If for any reason, the frequency on'the main bus bars 21 decreases by a predetermined amount, bridge piece 16() engages contacts 161, thus operating signal 162 to bring the matter to the attention of the operator. lf, however, the frequency continues to decrease, then when it reaches a 'va-lue a predetermined amount lower, bridge piece 95' will move from engagement with contacts 94a, thus opening the circuit through sole noid windings 61 and 91. l/Vhen this occurs, spring 93 will lift the left hand ,end of lever 76, the lever turning on the upper end of stem 77 as a fulcrum, and will move pilot valve 66 to the upper end of pilot valve casing 67, whereby valve head 68 is moved to uncover annular groove 70. Liquid will be thus admitted from pipe 72 through pipe 47, the pilot valve structure, and pipe 49 to the underside of piston 14, thus tending to move piston 14 upward and tending to open wide valve means 4. At the same time, however, lever 58 .will be moved downward by spring 63 in engagement with stop 62, thus lowering the left hand end of lever 51 and raising the right hand end, whereby pilot valve sleeve 42 is moved upward, tending to bring ports 43 to a position wherein they will be covered by pilot valve head 40. Stop 62 is set so that the movement of the pilot valve sleeve 42 up` ward will be sufficient to set the opening of the valve means 4 relative to the position of the speed governor 36 so that full elastic fluid admission at the existing frequency is obtained. The increase in electrical energythus obtained will tend to restore the fre'- quency of the system tothe original value, but as this is accomplished the speed gov ernor may slightly close the valve means 4 until a balance of frequency against electrical demand is obtained. lf it is able to do this, then the system will continue to operate with turbine 1 under control of the speed governor 36, the back pressure regulator being now entirely out of control of the turbine. y

In connection with the operation just de-l scribed, it will be seen that the release of ful Crum 89 serves to render inoperative the pressure control piston 78 and that at the same time the movement of fulcrum 59 into engagement with stop 62 serves to chan;Tc the setting of speed governor 36, the changing of the position of fulcrum 59 being in effect the equivalent of adjusting the length of rod 50.

If, in spite of the efforts of turbine 1, the 'frequency of the systemv still continues to fall, then when it reaches a predetermined lower value, bridge piece 121 is brought into. engagement with contacts 120, thus energizing trip coil 27 and effecting the opening of circuit breaker 24, thus disconnecting the auxiliary bus bars 19 from the main bus bars 21. Turbine 1 will then continue to operate and maintain the desired frequency on bus bars 19 which have now been segregated from the main system. Bus bars 19 may carry a station load and inr addition may carry other load connected to them; or the load connected to bus bars 19 maybe any desired load which it is desired especially to maintain.

l/Vhile the baclr pressure governor' is out of action, the excess of exhaust elastic fluid will be discharged past relief valve 29.

After the frequency is restored on the main bus bars 21, the turbo-generator set may be then again phased in onto the system through tie switch 24 and the valve gear for turbine 1 may be then reset manually, restoring the parts to the positions for pressure control.

ylhe function 'or the contact making ammeter 101 is to protect generator 17 trom an overload in current. rThis overload may be caused by an excessive power output of the turbine generator set in terms of steam demand from the turbine 1 into the exhaust conduit 3, or it may be produced by the incorrect adjustment ozt the ield ot the. alternator 17 whereby, due to this incorrect field adjustment, a leading or lagging current in excess of. the full load current permitted by the design of the generator 17 may be produced. 1t the current from the generator increases beyond a predetermined maximum, coil 105 ot the Contact making amnieter lirst draws contact arm 102 away trom the contacts 103. 112 now, the current increases still further, coil 105 draws contact arm 102 over until contacts 104 are bridged by contact arm 102, thus permitting current to flow Yfrom the upper supply line `94 through conductor 112, contacts 104, conductor 111, ield winding 109, armature of the synchronizing motor 56, and conductor 113 to lower supply line .94. rlhis will cause the armature of synchronizing motor 56 to run in a direction to raise'bushing 42,

"' and when groove `44 rises above pilot valve head 41, oil will be permitted to' escape from beneath piston 14 thereby ei'lecting movement'of valve means 4 toward closed position, thus reducingl the supply of elastic fluid to the turbine and hence the current output of the generator. Thiswill continue until the current has been reduced to such a value that'v the reduced force oi" the coil 105 allows the contact arm 102 to rise from the conbridge the contacts 103.

However, after the V 'While this has been taking place, the iiow of elastic luid through the valve means 4 may have been curtailed to an extent such that it does not meet the demand ttor exhaust elastic fluid in conduit 3, with the result that the pressure of the exhaust elastic fluid in conduit 3 will be lower than the desired normal. 1f the pressure in conduit 3 decreases below a certain value, piston 78 will'move to its lowest position and arm 85 will be lowered to an eXtent such that bridge 86 engages contacts 88. Upon the bridging of these contacts, current may be applied from the upper supply line 94 through conductors 112 and 114, contacts 88, conductor 110, contacts 103,` (these having been bridged now by contact arm 102) conductors 108g, the iield coil 108 and the armature of the synchronizing motor, and conductor 113` to the lower supply line 94. Motor 56 now will be operated in a direction to lower pilot valve sleeve 42 to move annular groove 43 below head 40, thereby admitting oil pressure under piston 14 and el'ecting opening movement of valve means 4. Ars the valve -means 4 is.opened, the increase in llow of elastic iluid through turbine 1 will gradually increase the fluid pressure in conduit 3 until the piston 78 rises, opening contacts 88. Further operation of motor 56 will then cease. The pressure, however, may continue to rise because the rise in pressure indicates an increase in the supply oi elastic fluid through the valve means 4 beyond that which is demanded by the conduit 3. However, the opening of contacts 88 restores. the system to its 'former operating conditions and the back pressure governor will take control and operate after the'manner already described to regulate turbine 1.

It, during what may be termed normal back pressure operation, the back pressure ygovernor loads generator 17 to the maximum value of current permitted, then contact arm 102 will be moved from engagement with contacts 10,3 and stand between contacts 103-and contacts 104. lt now the demand "tor exhaust elastic fluid continues the pressure in conduit 3 will decrease, and may bring bridge 86 into engagement with contacts 88. However, thls will not now serve to ellect adjustment of the governing mechanism after the4 manner just described because the circuit is open at contacts 103, these contacts being in series with contacts 88. lt this condition should obtain, the load responsive device 105 would function to maintain the turbine fully loaded by operating the synchronizing motor through engagement with contacts 104 and 103. However, as will be clear, it would not be possible for it to adjust the valve means to an extent such that generator 17 would be over loaded.

Hand switch 15 may be utilized to eect operation of the synchronizing motor 56 manually, being moved into engagement with contact 11T to effect operation of motor 56 in a directimi to move sleeve 42 upward, and so ctfect movement of valve means 4- toward closcdposition, and being moved in engagement with contact 1.16 to effect operation of motor 56 in a direction to move sleeve lf3 downward and so effect movement of valve means 4 toward open position. In this con; nection, it will be note-d thatcontacts 103 are in series with contact. 11() so that in case generator 17 is already fully loaded valve means 4 cannot be opened further by means of the hand switchbecause contact arm 102 will not be in engagement with contacts 103. In other words, the hand switch can be utilized to cffect opening movement of the valve means only when contact arm 102 bridges contact 103. -On the other hand, itmay be used to efect closing movement of the valve means at any time.

TWha-t i claim as new and desire to secure by Letters lDatcnt of the United States is-:-

l. ln combination, an elastic fluid turbine, an valtermnting current generator driven thereby, bus bars to which the alternating current generator isY connected, means other than said generator for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that atnormal frequency on the bus bars it is not operative to control the. turbine, a frequency responsive device, and means controlled by the frequency responsive device for rendering the speed governor operative to control the turbine in case the frequency on the bus bars decreases below a predetermined low value. l

2. ln combination, an elastic fluid turbine, an alternating current generator driven thereby, bus bars .to which the alternating current, generator is connected, means other than said generator for iixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control theturbine, means responsive to a condition of operation other than the speed of the turbine for nor- `mallv controlling the admission of elastic fluid to the turbine, andmeans for transferring` the control of the turbine from said last named means to the speed governor in case the frequency on the bus bars decreases below a predetermined low value.

3. In combination, an elastic fluid turbine, an alternating current generator driven thereby, auxiliary bus bars to which the alternating current generator is connected, main bus bars, means connecting the auxiliary bus bars to the main bus bars, means connected tothe main bus bars for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control the turbine, a frequency responsive device, and means controlled by the frequency responsivc device for segregating'the auxiliary bus bars from the main bus bars in case the frequency on the main bus bars decreases bclow a predetermined low value.

'-1. ln combination, an elastic fluid turbine, an alternating current generator driven thereby, auxiliary bus bars to which the alternating current generator is connected, main bus bars` means-connectino` thc auxiliary bus bars to the main bus 2bars, means connected to the main bus bars for fixing the frequency of the current on said bus bars, a

speed governor for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control the turbine, means for varying` the setting of the speed governor when the frequency on the bus bars decreases below a predetermined value whereby the. turbine tends to talie on full load, and means for segregating the auxiliary bus bars from the main' bus bars in case the frequency decreases to a still lower value.

ln combination, an elastic fluid turbine, an .alternating` current generator driven thereby, auxiliary bus bars to which the alternating current generator is connected, main bus bars, means connecting the auxiliary bus bars to the. main bus bars, means'connected to the main bus bars for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the bus barsvit is not operative to control the turbine, means for varying the setting of tl ae speed governor when the frequency on the bus bars 'decreases below a predetermined value whereby the turbine tends to take on full load, and means responsive tothe currentflowing from said generator for limiting the current load which can be placed on the 'generator by the turbine.

6. ln combination, an elastic fluid turbine, an alternating current generator driven thereby, bus bars to which the alternating current generator is connected, means other than said generator for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the turbine it is not operative to control the turbine, means responsive to a condition of operation other than the speed of the turbine for normally controlling the admission of elastic fluid to the turbine, and means for automatically rendering the speed governor operative to control the turbine and for changing Ithe setting of the speed governor in case the frequency on the bus bars decreases below a predetermined low value.

'l'. In combination, an elastic fluid turbine, an alternating current generator driven thereby, bus bars to which the alternating current generator is connected, means other than said generator for fixing the frequency of the current on said bus bars, a speed governor for tlie turbine, said governor being set so that at normal frequency on the turbine it is notoperative to cont-rol the turbine, means responsive to a condition of operation other than the speed of the turbine for normally controlling the admission of elastic fluid to the turbine, and means for automatically changing the setting of the speed governor and transferring the control of the tuibine from said last named means to the speed governor incase the frequency on the bus bars decreases below a predetermined low value. ,A 8. ln combination, an elastic fluid turbine, an alternating current generator driven thereby, auxiliary bus bars to which the alggtternating current generator is connected,

main bus bars, means connecting the auxiliary bus bars to the main bus bars, means connected to the main bus bars for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control the turbine, means responsive to a condition of operation other than the speed of the turbine for normally controlling the admission of .elmtic fluid to the turbine, means for automatically changing the setting of the speed governor and transferring the control of the turbine from said last named means to the N. UD

speed governor in case the frequency on bus bars decreases below a predetermined low value, and means for segregating the auxiliary bus bars from the main bus bars in case the frequency decreases to a still lower value.

9. ln combination, an elastic fluid turbine, an alternating' current generator driven thereby, bus bars to which the alternating current generator is connected, means other than said generator for fixing the frequency of the current on said bus bars, a speed governor for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control the turbine, means includingl a lever through which the governor effects changes in the amount of elastic fluid supplied to the turbine, and means for changing the position of-tlie ful- "cruni of said lever to vary the setting of the speed governor when the 'frequency on the bus bars decreases below a predetermined low value.

10. ln combination. an elastic fluid turbine, an alternating current generator driven thereby, bus bars to which the alternating current generator is connected, means other than said generator for fixing t'lie frequency of the current on 'said bus bars` a speed. goveriior for the turbine, said governor being set so that at normal frequency on the bus bars it is not operative to control the turbine, means including a lever through which the governor effects changes in the amount of elastic liuid supplied to the turbine, a inagneticallv controlled fulcruni for said lever, and means for changing the position of said fulcrum to vary the setting of the speed governor wlien the frequency on the bus bars decreases below a predetermined low value.

ll. The combination with an elastic fluid turbine having valve means foi; controlling the flow of elastic fluid thereto, of control means for positioning said valve means cornprising a speed responsive governor and a governor responsive to the pressure of elastic Huid flowing from the turbine, means for adjusting the set-ting of the speed governor, and means controlled by said pressure'responsive governor for adjusting the speed governor setting means to effect opening of the valve means when the pressure of the elastic fluid flowing from the turbine is below a certain low value.

l2. rEhe combination with an elastic fluid turbine having valve meansfor controlling 'the flow of elastic vfluid thereto, of'control means for positioning said valve means comprising a speed responsive governor and a governor responsive to the pressure or" elastic fluid flowing from the turbine, means for adjusting the setting of the speed governor, means controlled by said pressure responsive governor for adjusting the speed governor setting means to effect opening of the valve means when the pressure of the lelastic iiuid flowing from the turbine is below a certain low value, and means for rendering last said means inoperative when turbine is fully loaded.

13. rllie combination with an elastic fluid turbine having valve means for controlling tlie flow of elastic fluid thereto, and an alternating current generator driven by said turbine, ot control means for positioning said valve means comprising a speed responsive governor and a governor responsive to the pressure of elastic fluid derving from the turbine, means for adjusting the setting of the 1 speed governor, means controlled by said pressure responsive governor for adjusting tlie speed governor setting means to effect opening of the valve means when the pressureof the elastic fluid flowing from the turbine..

is below a certain low value, and means responsive to the current delivered by the generator for rendering said last named means inoperative when such current exceeds a predetermined higli value. c

le. rilie combination with an elastic fluid turbine having valve means for controlling tlie flow of elastic fluid thereto, and an alter- -nating current generator driven by said turbine, ot control means for positioning said valve means Vcomprising a speed responsive governor and a governor responsive to the iis i' pressure of elastic fluid iiowing from the t11r bine, means for adjusting the setting of the speed governor, means responsive to the current load on the generator for adjusting the speed governor setting means in a direction to eect closing of said valve means when the current load exceeds a predetermined high value, means controlled by said pressure responsive governor for adjusting the speed governor setting means to eii'ect opening of the valve means vvlien the pressure of the elastic duid flowing from the turbine is be A low a certain low value, and means responsive to the current delivered by the generator' for rendering said last named means ino erative when such current exceeds a pre etermined high value. l

l5. The combination with a turbine driven set comprising an elastic fluid turbine liaving valve means for controlling the flow of elastic Huid thereto, of a speed governor for the turbine, meansfor adjusting the setting of the speed governor, a second overning means for the turbine, said secon governing means normally controlling the supply of elastic fluid to the turbine, and means responsive to an abnormal operating condition of said set for rendering inoperative said second governing means and adjusting the setting of the speed governor,

1d, The combination with an elastic fluid turbine, a dynamo-electric machine con-- nected to the turbine, and alternating cur,

rent bus bars to which the dynamo electric machine is connected and which serve normaliy to iin the speed of the turbine of a speed governor for the turbine, said governor being set normally for a speed higher than Gmimwm @E @@RRECNN,

www im. 3,75%:?@3 i I y Gmmedmay ze, w30, w

Mmmm@ STANDERWECK.

v is hereby certiee mat error appeals in the printed specicatior of the above numbeeed paient requiring @affection as follows: Page 2, line 128, Afor the word "is" read "n"; page 3, im@ 54, for "efeby" mad "there by"; page 4Li line 3, im "Sera No., Sl-,Qwread "Sera NQ. SLQIIT; and that fihe said Lettes Paemf swud he fread wim thes cmrecons @mein-that the same may confoml t@ the fammi -o the @ase in @ne Patemf,

Signed and Seaed mi@ 22nd day Juy, A. D. i939.

* Wm. A. Kirman, (Seal) Acing Commissioner o Patents.