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July 28, 1936. G. M. PESTARIN 2,049,388 ELECTROMECHANICAL POWER PLANT FOR WEHICLES Original Filed March 27, 1934 3. Sheets-Sheet l

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Patented July 28, 1936 2,049,388

UNITED STATES PATENT OFFICE 2,049,388 ELECTROMECHANCAL POWER PLANT FOR LOCOMOTIVE VEHICLES Giuseppe Massimo Pestarini, Sheffield, England . Application March 27, 1934, Serial No. 1,650. Renewed April 10, 1935. In Great Britain March 31, 1933 19 Claims. (C. 290-16) This invention relates to locomotive vehicles of two, usually diametrically opposite each other, the kind in which the motive power is furnished are used for the primary circuit and two others, by an internal combustion driving a dy which may be diametrically opposite each other namo , which supplies current in a different radial plane, are used for the sec to an or motors and a battery ondary circuit or circuits. The is rotated 5 which may be employed for starting the engine. at constant speed. The primary current flowing In order to reduce the size of the engine the bat in the rotor windings sets up a primary which tery may be of a capacity greater than that re is fixed in direction and may be said to be cut quired for starting the engine and be arranged by rotor conductors in which a is thereby () to supply to the motor or motors during induced and a constant secondary current can be 0 overloads. The battery may be recharged from drawn from the secondary circuit or circuits at the when the is at rest, and may variable voltage. The complete magnetic excita be also supplied with current by the motors. act tion of the is the combined magnetic ing as generators during braking periods. In effect of the primary and secondary currents. In s Some cases when only a small amount of energy order to obtain a balance of the primary 16 is required to drive the vehicle the battery may it is necessary that the machine produce an in be used to supply energy to the motor or motors duced primary voltage to oppose the constant for this purpose while the engine is stopped. voltage supplied to the primary brushes. To According to the present invention, in an equip accomplish this it is required that the magnetic 20 ment of the kind above indicated for fulfilling effect of the secondary circuit, that is, the sec- 20 certain or all of the requirements above men ondary turns, be maintained constant or, tioned a rotary or motor generator is in other words, that the secondary current remain employed the current in the secondary circuit of constant. Thus, if an external load is connected which is adapted to be regulated to a substantially in the secondary circuit, it is necessary that the constant value, and the primary circuit of which secondary voltage increase sufficiently to supply 25 rotary transformer or motor generator is connect this additional load and maintain the secondary ed with the battery. The dynamo driven by the current constant. A may be provided internal combustion engine and the electric motor which affords a return path of low magnetic or motors are connected in series in the secondary reluctance for the which are set up by the 30 circuit of the rotary transformer or motor gen rotor currents. The stator can be furnished with 30 erator. The motor or motors may be separately windings by which various magnetic fluxes can excited from an exciter which may be mounted be obtained, which combine with or modify the on or driven by the shaft of the rotary trans magnetic fluxes due to the primary and secondary former or motor generator. currents circulating in the rotor and thereby With the equipment according to the invention regulate the electro-mechanical performance of 35 if the internal combusticn engine, a for example, is running at a constant speed, being the machine. Such stator windings may in regulated by its , and the dynamo is ex clude a winding, known as a "variator' winding, cited through a field winding with constant am which is arranged to produce a flux co-axial with 0 the flux resulting from the secondary currents pere turns, the Diesel engine will supply constant flowing in the between the secondary 40 voltage. Consequently as the current in the dy brushes, so that by adjustment of the strength namo armature is constant the power output of of the field due to said variator winding, the Sec- . the dynamo will in this case also be constant. ondary current flowing from the trans The rotary transformer employed is convenient former to the consumption or load circuit may ly of the kind called a metadyne transformer. be adjusted. A second winding, known as a "reg 45 A metadyne transformer is a rotary apparatus ulator" winding, may be provided, acting mag which is designed to transform netically upon the currents flowing in the ar supplied to it at a fixed voltage and variable am ' mature, the energization of such regulator wind peres into electric power at constant and ing being operated by the aid of an auxiliary small variable voltage. The apparatus comprises in dynamo, called the regulator dynamo, in such a general a rotor provided with windings connected way as to produce an accelerating torque when to a somewhat similar to the arma the machin2-runs below a desired speed, and a re tuire of a dynamo electric ma tarding torque when the machine runs above the chine,whilst ordinarily four brushes are arranged desired speed. The elementary metadyne trans to make contact with the commutator of which former above indicated may be modified and SS 2 2,049,888 M2, M3, M4 and M5, whilst the metadyne trans elaborated in many ways under the same general former is indicated at MT. As shown in the theory of operation. figure, the dynamo DY, motors Mi to M5 and For a fuller description of metadyne trans the secondary brushes S and S2 of the meta formers reference is directed to the specification dyne MT are connected electrically in Series with 5 of French Patents No. 647,855, dated February one another as hereinbefore set forth. The Stor 25, 1922, No. 623,438, dated January 27, 1926, and age battery is indicated at 2 and is connected No. 637,946, dated November 25, 1926. A descrip across the primary brushes P, P2 of the meta tion of the general construction and operation of dyne M.T. In Fig. 1 the metadyne machine is metadyne , generators and motors O treated mathematically in considerable detail will illustrated as comprising besides the metadyne 0 also be found in a paper entitled "Esquisse Sur la transformer itself the usual regulator machine Metadyne' by G. M. Pestarini in the Bulletin RG and an exciter EX, the three being Scientifique A.I. M. No. 4 April 1931 of L'Associa mounted upon a common shaft. Said exciter is tion des Ingénieurs Electriciens, published by the connected with the field windings ff to f5 of the Institut Electrotechnique Montefiore, Liége. motors Mf to M5 respectively and is provided 15 When a metadyne transformer is employed the with field winding B energized in any desired electromotive forces induced in the armature of manner, as by a battery 37. The dynamo DY is the dynamo and in the secondary circuit of the illustrated as provided with a field winding A metadyne transformer are in Series and are op which may be excited at a constant value, aS 20 posed by the counter of the hereinbefore set forth as by a battery 38. 20 motorS. When the counter electromotive force The operation of the above described embodi of the motors is equal to the voltage Supplied by ment of the invention will be clear from the fore the dynamo the secondary voltage of the meta going description. dyne transformer will be zero and the battery will In the example of the invention illustrated in 25 therefore supply substantially no current to the Fig. 1 the motors M and M2 are connected on primary set of brushes. When more power is re one side of the metadyne transformer MT whilst quired to drive the train, as when it is desired to the remaining motors M3, M4 and M5 are con operate the train at a higher speed, other condi nected on the other side of said metadyne trans tions, such as grade, remaining constant, the former, whereby the maximum voltage reached motors will require a higher voltage than the in the secondary circuit, namely, the circuit Con- 30 30 electromotive force of the dynamo. That is, prising dynamo DY, motors. M to M5 and the when the power required by the motors for pro metadyne transformer MT, which circuit is for pelling the vehicle is greater than that which is Convenience hereinafter termed the power cir Supplied by the engine, the metadyne transformer cuit, will be only a part of the maximum will supply additional regulating electromotive voltage required by said motors. Furthermore 35 force from its secondary set of brushes, the en the mid-point 3 of the storage battery 2 may be ergy being obtained from the battery through the connected to earth as shown at G whereby the primary brushes. Under these conditions cur voltage between any point of the secondary cir rent will flow from the battery to the primary cuit and earth will be lowered. 40 windings of the metadyne transformer. This Referring now to Fig. 2 which is a graph in 40 sets up a primary flux which will be cut by the which the power required by the motors M to M5 armature conductors and induces therein a volt is plotted against the time t during an assumed tage between the secondary set, in such a cycle of operation of the locomotive, the line E. direction as to produce a rise in voltage between represents the power required by said motors and 45 them, as required by the increase in motor load. shows the variation of this power with time 45 If the motors, on the other hand, require less elec through the cycle. The broken line AB represents tromotive force than that given by the dynamo the constant power supplied by the internal con the secondary electromotive force of the meta bustion engine at the optimum speed and the dyne transformer will be negative and current chain line CD represents the maximum output of 50 will be supplied to charge the battery. This will the engine at its maximum speed. 50 also occur when the motors are regenerating and Fig. 3 which is a diagram similar to Fig. 2 results in a substantially constant power output shows how, with the arrangement shown in Fig. 1, from the engine, which normally operates at a and assuming that the electrical circuits have constant Speed. an eficiency of 100 per cent. the energy will be In order that the invention may be clearly distributed between the Diesel engine DY and the 55 understood several embodiments thereof will now storage battery 2, the line F representing the be described by way of example with reference rate at which the battery is charged or discharged. to the accompanying drawings, in which:- Under these conditions the dynamo DY will sup ply a constant power throughout the cycle of op 60 Figure 1 is an electrical diagram showing the eration represented by the straight line AB whilst 60 arrangement of the electrical apparatus in One embodiment of the invention. during the first part of the cycle the storage bat Figs. 2 and 3 are diagrams used for explaining tery .. 2 will supply the amount of power re the action of said embodiment of the invention, quired by the motors over and above that at Fig. 4 is an electrical diagram showing a modi which the engine f operates, namely the differ 65 fled embodiment of the invention, ence between the Ordinates of the line EE and Figs. 5, 7 and 10 show respectively certain mod the line AB of Fig. 2. In the latter part of ified arrangements of details in systems accord said cycle however the power required by the ing to the invention, and motors M to MS is less than the regulated Output Figs. 6, 8, 9 and 1 are diagrams used for ex of the engine and the excess of energy produced plaining the action of said modifications. by the dynamo DY under these conditions is uti 70 Referring first to Fig. 1 of the drawings, the lized to charge the storage battery 2 as is indicat Diesel engine or other internal combustion engine is illustrated generally at f being coupled mechan ed in Fig. 3 by that part of the line F below the ically with the generator DY. A plurality of axisWith of the graph.arrangement illustrated in Fig. 1 the 7 is traction motors are indicated respectively at M,

8,049,888 3 storage battery 2 is arranged to provide for the ance with the direction of running to which the whole of the peaks of power as determined by controller C is actuated. The amount of the re the amount by which the output of the engine sistor B which is inserted in the above described is above or below the power required by the elec series circuit will.depend upon which one of its tric motors. In order to reduce the necessary size operative positions f, 2 or 3 the controller is ac- 5 of said storage battery the system may be ar tuated the arrangement being such that said re ranged so that only the extreme peaks of power sistance f is cut out as the controller is actuat are supplied to or from the battery. In one meth ed from the of position 0 to the "full on' posi od of obtaining such operation, the dynamo DY is tion 3 (F) or 3 (R). Actuation of the controller C O arranged to be excited proportionally to the volt to an operative position also causes through the 10 age required at any moment by the notors M to contact fingers h, , and k and the correspond MS whilst at the same time the Diesel engine is ing contact segments the connection of the field governed so that its power output, is responsive to . winding fl of the exciter. EX across the motors the power taken by said motors. M, M2 and M3. The arrangement of the con 5 One such arrangement is illustrated in Fig. 4, troller is such that the connection of said wind in which three motors M, M2 and M3 are shown ing f and the connections of the winding 3 connected in: series with the metadyne trans are reversed when the controller C is actuated former MIT and dynamo DY. The relay device from a forward running to a reverse running posi for governing the power output of the internal tion. The generator DY may be provided with a 20 combustion engine (which is not shown in Fig. 4) differential winding S. 20 is indicated diagrammatically at GR and may With this arrangement the relay GR acts up conveniently be of the wattmeter type having one on the governor of the internal combustion coll 4 connected across a shunt 5 in circuit with engine so that said engine being arranged to 25 the dynamo DY and motors M, M2 and M3 and run at a variable speed, the power supplied with a second coil 6 which is connected in series thereby will be approximately proportional to 25 with the main field winding A of the dynamo DY, the power required by the propelling motors Mf, a variator winding 7 on the metadyne transform M2 and M3. The battery 2 will thus intervene er MT, and with a drum type controller C which only when said motors require more power than is indicated in the conventional manner. The said is available from the internal combustion en 30 controller is arranged to connect the above de gine, the speed of the latter and therefore the 30 fined series circuit in series with a winding 3 voltage supplied by the generator DY having provided on the exciter EX, across the positive then risen to the value at which said engine de and negative conductors 8 and 9 of the storage velops its maximum power. If the Diesel engine 35 battery 2 in a manner to be hereinafter de is arranged to run at constant speed whilst de scribed in detail. Switches 0 and f are provid veloping a variable torque then the relay such as 35 ed as shown for connecting the battery with said GR is arranged to act upon the of the conductors 8 and 9 and starting arrangements for generator DY, to increase the power generated the metadyne transformer are illustrated as thereby as the load presented by the motors comprising a series resistance 2 which is ar M?, M2, M3 increases in any suitable manner. 40 ranged to be short-circuited by a contactor C With the arrangement illustrated in Fig. 4 40 which contactor is provided with interlock the excitation of the generator DY is under the contacts Clk arranged in the series circuit control of the controller C and said quantities comprising the variator winding 7 of the meta Gre increased as the controller is actuated from dyne transformer, the winding A of the dynamo the off position 0 to an operative position 3 (F) 45 DY and the relay winding 6, so that said windings or 3(R). The connection of the field winding 45 cannot be energized until said contactor C is 4 across the motors M, M2 and M3 has the re closed. The exciter EX is provided with a second sult that as the speed of said motors M, M2 and field winding 4 adapted to be connected through M3 rises the excitation thereof is reduced, the the controller C across the motors M, M2 and M3 winding 4 being arranged so as normally to 50 and is preferably arranged to be magnetically oppose the winding 13. The torque produced by 50 saturated. the motors will thus be reduced as the speed The controller C is arranged in a manner which thereof rises so that a convenient balancing will be clear to those skilled in the art so as to speed of the locomotive if obtained namely the have an of position O and three positions, 2 and Speed to which the locomotive will be accelerated 55 3 (F) for forward running with three further po before the motor torque is balanced by the re- 55 sitions , 2, and 3 (R) for reverse running. Said sistance to traction will be a convenient speed. controller is arranged so that when moved from Obviously the fields of the motors may be re the of position to one of its operative positions duced in other ways, such as for example by 60 (F) or f (R) a circuit will be completed from rangedmeans ofto aoppose shunt a windingfurther fieldon each winding motor, which ar the conductor 8, comprising a conductor 5, fixed produces the main field of said motor, or the contacts a and b and corresponding segments of first said winding may be fed from an exciter the master controller, the two sections of a re which is excited in accordance with the motor sistor 6, the contactfingers d and e or f and cor voltage. re 65 responding contact segments of the controller ac As the controller C is actuated through the ' cording to whether the controller is actuated to a positions , 2, 3 the energization of the variator forward or a reverse position, field winding f winding of the metadyne transformer is pro of the exciter X through conductors f and 8, gressively increased so as to reduce the arma contact fingers for e and g and corresponding ture current of the motors. MIf, M2, M3 and contact segments of the controller, conductor 9, thereby to maintain good commutation of said O relay winding 6, field winding A of the dynamo motors even under the reduced field conditions DY, interlock contact C k. and variator winding The reduction of armature current through the 7 of the metadyne transformer to the conductor motors will also provide a further reduction of . As will be seen, the winding f will be ener 75 tised in one direction or the other in accord motorthe torque Armature of said current motor. doesSuch not reduction result inof thethe

4. 2,049,888 of variations in the armature current of the gen power output of the generator DY being re erator DY. As will be appreciated any other duced since the excitation of said generator by known means of controlling the generator field the winding A is increased as the excitation of in such a way as to give a voltage approximately the variator winding T is increased. The ar or exactly inversely proportional to the armature is rangement of the system shown in Fig. 4 is such current of the generator may be adopted. The that during running of the locomotive in One said generator may be provided with a differential direction actuation of the controller C to a series winding or the arrangement illustrated in position corresponding to running in the Op Fig. 5 may be employed in which the generator posite direction will result in regenerative brak DY is provided with a separately excited winding 10 0. ing of the locomotive being obtained. 22 which is connected in Series with the armature The Diesel engine may be started up by means 23 of an exciter and with a source of constant of operation of the dynamo DY as a motor en voltage at C, the exciter 2 being elgized through the metadyne transformer MT excited by means of a winding 24 inserted in from the storage battery 2. During such start Series with the armature DY of the generator. In l5. 5 ing up operation the motors Mil, M2 and M3 order to improve the response of the exciter 28, may be a short-circuited by means of a switch said exciter may be provided with a shunt wind 20. As hereinbefore set forth the locomotive ing indicated at 25 in broken lines. The opera may at certain times be Supplied with power tion of this arrangement will be clear from Fig. 6 entirely from the battery 2 and during these in which the voltage provided by the constant 20 20 periods the dynamo DY may be short-circuited by means of a switch 2. potential supply source at C is indicated by the Various modifications of the above described line c whilst the voltage produced by the exciter embodiments of the invention may be made. armature 23 with varying current A in the arma For example reduction of the torque produced ture DY is indicated by the line e said voltage 25 by the propelling motors as the speed thereof being subtracted from that of the supply source 25 rises, may be obtained in any convenient or de at C with the result that the generator DY pro Sired manner. In caSSes where Such reduction duces a voltage W which varies with the current A in the manner shown by the line a. of motor torque is obtained by the reduction of Referring now to Fig. 7, the embodiment of the the field strength of the motors as hereinbefore invention therein shown is arranged so that the 30: described, means may be provided whereby the output of the generator is maintained substan armature current is automatically reduced as tially constant and so that the battery 2 supplies the motors increase in speed so that the com only the extreme peaks of power required by the Inutation of the motors is not affected by the motors Mi and M2 above the average power and reduced fields thereof and any convenient ar in which furthermore the armature current of 35: rangement may be adopted for this purpose. said motors may be arranged to fall with increase For example an arrangement Such as set forth of speed of said motors. With this arrangement in my prior application for Letters Patent Serial the internal combustion engine (not shown) is No. 677,523 filed June 24, 1933 may be applied to assumed to operate at a constant Speed. The the metadyne transformer. As hereinbefore de generator DY is so designed as to be Saturated 40 Scribed, in the arrangement which has been de for values of field excitation exceeding a given Scribed above with reference to Fig. 4, a reduc value and so that such is introduced tion of the armature current through the mo as suddenly as possible after said limit is exceeded tors Mi, M2 and M3 is obtained as the controller so that above this limit the flux remains Substan is actuated to the "full on' position due to the tially constant. The generator is excited largely 45 45 action of the variator field 7 of the metadyne transformer MT. or wholly by the voltage across the load, and as It will be appreciated that in arrangements shown in Fig. 7 has a field winding A which is where the motor armature current is reduced as connected across the motors, shown as being two the motor Speed rises then if the field of the in number, M and M2. The arrangement is generator DY is maintained constant the load further such that below the Saturation point of 50 On Said generator will be reduced, assuming that the generator the latter produces a voltage which the Diesel or other internal combustion engine is rather greater than the voltage across the operates at a constant speed. It is thus desir motors Mf and M2 in a predetermined proportion. able in Such arrangements to provide also for an Thus, until saturation is reached the Diesel en increase in the shunt excitation of the generator gine will supply power somewhat in excess of the 55 55 DY in inverse proportionality to the armature load presented by the motors M, M2, and Current of Said generator so that the load on the the battery will be charged at a rate dependent Eator DY is maintained approximately con upon said load, as shown in Fig. 8, in which the Stant. voltage of the generator DY is plotted as ordi The above requirements may be fulfilled by nates against the load voltage, that is, the volt 60 exciting the generator DY at least in part by the age across the motors M and M2. The straight voltage across the load so that the generator volt line lirepresents the voltage required by the motors age is increased in accordance with increase of MI and M2 Whilst the line d represents the Wolt the voltage across the load. Alternatively the age produced by the generator DY. The differ 65 field of the generator DY may be produced by a ence between these two lines represents the volt field winding which is connected with a shunt age which has to be provided by the storage bat wound exciter, the critical speed of which is to tery 2 acting through the metadyne transformer coincide with the desired speed of operation of MT. Thus, when the lined lies above the line ! the internal combustion engine. With this ar the battery 2 will be charged, whilst when said 70 railgement the torque of the generator will ad lined lies below the line l said battery will supply just itself under control of the speed o the en gine to the output of the latter as determined by energy to the motors M and M2. Thus when the the fuel supply thereto, so that assuming said load voltage reaches the value V, the output of fuel supply to be constant the power output of the generator DY is limited due to the saturation the generator also will be constant irrespective thereof as above referred to, and above this value 75

2,049,888 5 energy is discharged from the storage battery to ence to Fig. 11 in which the load voltage and the notors, excitation of the winding 29 is plotted on the The distribution of power with the arrange abscissae, and the voltage of the generator DY ment shown in Fig. 7 is illustrated by the diagram is plotted on the ordinates. The excitation pro shown in Fig. 9 which is of a similar nature to the duced on the generator DY by the winding 3 is diagram in Figs. 2 and 3 but for a different cycle is constant and is indicated in Fig. 11 by the of operation of the load. In Fig. 9 the load re horizontal line p whilst the excitation produced quired by the motors M and M2 is indicated by On the exciter 28 by the winding 30 is indicated the line L-L and the power developed by the by the vertical line q. The voltage produced at 10. Diesel engine is represented by the line E-E. the brushes of the generator DY as the load 10 The power provided by the storage battery 2 is varies will thus be represented by the line r of the difference between said two powers and the Fig. 11 and by adjustment of the field strength resultant energy discharging the battery is indi of the winding 30 the load at which the engine cated in Fig. 9 by the dotted areas whilst the cross supplies zero power may be adjusted, whilst re 5 hatched areas indicate the energy charging the sistance 32 and 33 enable the upper and lower 15 battery. limits of the demands on the engine to be ad The variation of the armattire current of the justed. notors M and M2 and of the motor field strength In order to reduce the wear and tear on the may be obtained in any desired manner and the engine and to improve the efficiency of the sys 20 arrangement shown in Fig. 7 will still ensure tem the speed of said engine may be varied ac- 20 that when the voltage across the motors M and cording to the power required therefrom and, M2 is below, a predetermined value the Diesel for instance, in the above described arrangement engine will supply a certain excess of power to in which a critically excited shunt machine feed charge the battery 2, whilst when the voltage ing a field winding on the generator driven by 25 across the motors is greater than said predeter the engine is employed, any desired reduction of 25 mined value the battery 2 will supply substan speed may be obtained by variation of the re tially the whole of the additional power required sistance in the field of the critically excited reg by the motors M and M2 above that produced ulator exciter. by the generator DY. It is to be understood that many modifica 30 In Fig. 7 a relay 26 is illustrated the coil of tions may be made without departing from the 30 which is connected across the load M, M2 scope of the invention, for example in addition through a 27 and the contacts of which to the arrangements above described the power are arranged to break the circuit of the field developed by the Diesel or other internal com winding A when said coil 26 is energized whereby bustion engine may be adjusted independently by 35 the field of the dynamo DY is removed when variation of the fuel supply and such operation 35 the motors M and M2 operate regeneratively, may be obtained for example by electrical con the voltage across said motors being of course trol of the feel supply means in any suitable reversed under such regenerative operation, Ob name. viously any other convenient or desired polarized claim as my invention:- 40 switch device may be employed in place of the 1. A power system including an engine and a 40 relay 26 and rectifier 27. generator driven thereby, an Con In certain cases it may be desirable that the nected to said generator, and means including a Diesel engine should supply the whole of the metadyne transformer connected in series with power between certain upper and lower limits, said electrical load and said generator for main 45 whilst the storage battery 2 supplies or absorbs taining substantially constant load on said engine. 45, the excess of energy outside said limits. One ar 2. A power system including an engine and a rangement in accordance with the invention for generator driven thereby, an electrical load con obtaining such operation is illustrated in Fig. 10, nected to said generator, a metadyne trans In this arrangement the generator DY is pro former having a primary brush set and a sec 50 vided with an exciter 28 the armature of which ondary brush set electrically displaced from said 50 is connected across a field winding A of said primary brush set, and means connecting said generator DY. The exciter 28 is itself excited generator and said electrical load in series across by means of a field winding 29 connected across. said secondary brush set for maintaining Sub the motors M and M2 and by means of a sep stantially constant load on said engine. - arately excited field winding 30. The generator 3. A power system including an engine and a 55 DY is also provided with a separately excited generator driven thereby, an electrical load con field winding 3. The field windings 29 and 30 nected to said generator, a metadyne transformer are arranged to oppose one another. The opera having a primary brush set and a secondary brush tion of this arrangement will thus be such that set electrically displaced from said primary brush when the voltage across the motors Mi and M2 set, an electrical source of constant potential 80 reaches a predetermined value the field winding , means for connecting said primary 29 will predominate over the field winding 30 to brush set across said electrical source of power such an extent that the exciter 28 becomes satu supply, and means connecting said generator and rated, whilst when the said voltage is below. an said electrical load in series across said secondary 65 other predetermined value less than the first brush set for maintaining substantially constant 65 said predetermined value the winding 30 will pre load on said engine. dominate. Over the winding 29 to such an extent 4. A power system including a constant speed that the voltage produced by the exciter 28 will and a generator driven thereby, be in the reverse direction and the exciter will means including a field exciting winding for sup again be Saturated. The voltage produced by the plying a constant excitation for said generator, exciter is applied to the field winding A and an electrical load connected to said generator, thus added or subtracted from the excitation pro and means including a metadyne transformer duced by the field winding 3 of the generator connected in a series circuit with said electical DY. The above described operation of the ex load and said generator for maintaining constant 75 citation arrangements will be clear from refer current in said series circuit. 74; 6 2,049,388 gine, and means responsive to an electrical char 5. A power system including an engine and a acteristic of said motor and including a field generator driven thereby, an electrical load con exciting winding on said generator for varying nected to said generator, a metadyne transformer the voltage of said generator. having a primary brush set and a secondary brush 11. A power system including a constant speed 5 set electrically displaced from said primary brush prime mover and a generator driven thereby, set, an electrical source of substantially constant means including a field exciting winding for Sup potential power supply, means for connecting Said plying a constant excitation for said generator, primary brush set across said electrical source an electrical load connected to said generator, of power supply, means connecting Said gener a metadyne transformer having a primary brush l0 0 ator and said electrical load in series across said set and a secondary brush set electrically dis secondary brush set for maintaining substantially placed from said primary brush set, an electrical constant load on said engine, and means for source of constant potential power supply, means causing said metadyne to operate at constant for connecting said primary brush set across said speed. electrical source of power supply, means connect- lS 5 6. A power system including an engine and a generator driven thereby, a motor connected to ing said generator and said electrical load in said generator, a field exciting winding for said series across said secondary brush set for main motor, means responsive to an electrical charac taining substantially constant load on Said en teristic of said motor for varying the excitation gine, and means for varying the voltage of said of said motor field exciting winding, and means generator inversely with respect to the current in 20 said series circuit. including a metadyne transformer connected in 12. A power system including an engine and a series with said motor and said generator for generator driven thereby, an electrical load con maintaining substantially constant load on said nected to said generator, a metadyne transformer engine. having a primary brush set and a secondary 25 7. A power system including an engine and a brush set electrically displaced from said primary generator driven thereby, a motor connected to brush set, an electrical source of constant poten said generator, a field exciting winding for Said tial power supply, means for connecting said pri motor, means responsive to an electrical charac mary brush set across said electrical source of teristic of said motor for varying the excitation power supply, means connecting said generator 30 30 of said motor field exciting winding in inverse relation to the speed of said motor, and means and said electrical load in series across said sec including a metadyne transformer connected in Ondary brush set for maintaining substantially series with said motor and said generator for constant load on said engine, and means for vary maintaining Substantially constant load on Said ing the voltage of Said generator in accordance 35 engine. with the voltage across said electrical load for 35 8. A power system including an engine and a a portion of the range of variation and for vary generator driven thereby, a motor connected to ing the voltage of said generator at a different said generator, a metadyne transformer having rate beyond said portion of said range of variation. a primary brush set and a secondary brush set. 13. A power system including an engine and electrically displaced from said primary brush a generator driven thereby, a motor connected 40 40 Set, an electrical source of substantially constant to Said generator, a metadyne transformer nav potential power supply, means for connecting said ing a primary brush set and a secondary brush primary brush set across said electrical source Set electrically displaced from said primary brush of power Supply, means connecting said gener Set, an electrical source of power supply, means ator and motor in series across said secondary for connecting said primary brush set across 45 brush set for maintaining substantially constant said electrical Source of power supply, means load. On Said engine, and means responsive to the connecting said generator and motor in series Speed of said motor for varying the voltage of across said secondary brush set for maintaining Said generator. Substantially constant load on said engine, and 50 9. A power system including an engine and a means responsive to the control of an electrical generator driven thereby, an electrical load con characteristic of the circuit including said gen nected to Said generator, a metadyne transformer erator, motor, and transformer for varying the having a primary brush set and a secondary Speed of the engine, brush set electrically displaced from said primary 14. A power system including an engine and a brush set, an electrical source of power supply, generator having an armature driven thereby, an 55 means for connecting said primary brush set electrical load, means for connecting said gen across said electrical source of power supply, erator armature and said electrical load in series means connecting Said generator and said elec circuit relation, and means including a dynamo trical load in Series across said secondary brush connected in series with said set for maintaining substantially constant load generator armature and said electrical load for 00 80 on Said engine, and means responsive to the volt producing a regulating electromotive force in age across Said electrical load and including a said series circuit and for inherently maintain field exciting winding on said generator for vary ing substantially constant load on said engine, ing the voltage of said generator. said dynamo-electric machine being mechanical 65 10. A power System including an engine and a ly independent of said generator. generator driven thereby, a motor connected to 15. A power System including a constant speed Said generator, a metadyne transformer having a prime mover and a generator driven thereby, primary brush set and a secondary brush set elec means including a field exciting winding for trically displaced from said primary brush set, an Supplying a constant excitation to said generator, electrical Source of constant potential power sup an electrical load connected to said generator, 70 70 ply, means for connecting said primary brush set a Source of electrical power supply, and means across Said electrical source of power supply, including a dynamo-electric machine connected means connecting said generator and motor in in series with said generator and said electrical Series across said secondary brush set for main load and adapted to transfer electrical power be taining Substantially constant load on said en tween said generator and said source of electrical 75 2,049,888 7 power supply for maintaining substantially con for energizing said generator field exciting wind stant current in said series circuit and for main ing, means for varying the energization of said taining substantially constant load on said en field exciting winding in response to speed varia gine, said dynamo-electric machine being ar tions of Said generator, an electrical load, a ranged to produce a regulating electrical po metadyne transformer having a primary brush 5 tential in said series circuit and being mechanical set and a secondary brush set electrically dis ly independent of said generator. placed from said primary brush set, a source of 16. A power system including an engine and electrical power supply, means for connecting a generator driven thereby, an electrical load, said primary brush set to said source of elec O means for connecting said generator and said trical power supply, means for connecting said O electrical load in series circuit relation, a source generator and said electrical load in series across of electrical power supply, and means including said secondary brush set, and means dependent a dynamo-electric machine connected in series upon an electrical charcteristic of said series With said generator and Said electrical load and circuit for maintaining a substantially constant 5 adapted to transfer electrical power between said load on said engine. 5 generator and said source of electrical power 19. A power System including an engine, a gen supply for maintaining substantially constant erator driven by Said engine, an electrical load load on said engine, said dynamo-electric ma Connected to said generator, a field exciting chine being arranged to produce a regulating winding for said generator, means including an 20 electrical potential in said series circuit and be exciter for energizing said generator field ex 20 ing mechanically independent of said generator. citing Winding, means including a field exciting 17. A power system including an engine and a winding for providing a constant component of generator driven thereby, an electrical load, excitation to said exciter, means dependent upon means for connecting said generator and said the voltage across said electrical load and includ 25 electrical load in series circuit relation, a source ing a second field exciting winding for supplying 25 of electrical power supply, a dynamo-electric ma a component of excitation to said exciter in op chine, means for connecting Said dynamo-electric position to said first mentioned exciter field ex machine in series with said generator and said citing winding, means for varying the excitation electrical load and to said Source of electrical of said exciter between predetermined limits in 30 power Supply, and means including said dynamo accordance with the voltage across said electrical 8 electric machine and adapted to transfer elec load, a metadyne transformer having a primary trical power between said generator and said brush set and a secondary brush set electrically source of electrical power supply for maintaining displaced from said primary brush Set, a source substantially constant load on said engine, said of electrical power supply, means for connecting 35 dynamo-electric machine being arranged to pro said primary brush set to said source of electrical duce a regulating. electrical potential in said se power supply, and means for connecting Said gen ries circuit and being mechanically independent erator and said electrical load in series across of said generator. said secondary brush set for maintaining a Sub 18. A power system including an engine and stantially constant load on said engine. 40 a generator driven thereby, a field exciting wind 40 ing for said generator, means including an exciter GUSEPPE MASSIMO PESTARINI.