US1387741A - Electric generating system - Google Patents

Description

C. F. STRONG.

ELECTRIC GENERAHNG SYSTEM.

APPLICATION FILED MAR,31,1920.

1,387,? {11, Patented Aug. 16,1921.

A TR) 578 UNITED STATES CHESTER F. STRONG,

PATENT OFFICE.

OF NEW YORK, N. Y.

EEEcrEIo GENERATING SYSTEM.

Application filed March 31, 1920. Serial No. 370,064.

suitable prime mover and proper mecha-.

nism for changing the speed of the engine and changing the generator characteristics accordingly with variations of the load on the line, so as tomaintain voltage on the line substantially equal to that of the storage battery.

It further has for its object the bettering the fuel economy of the engine by permitting it'to operate at low speeds when the line load is light and at increased speeds as the load on the line becomes heavier, thus, running the engine at Very nearly its full torque capacity for the varying loads.

It further has for its object to provide such a system in which the engine shall be started automatically and stops automatically.

The following is a description of an em:

bodiment of my invention, reference being had to the accompanying drawing which diagrammatically shows an engine generator and circuits embodying my system in which Figure 1 shows the complete system and Fig. 2 shows a modification of one feature thereof.

Referring more particularly to the drawings 1 is a prime mover, such for instance as an internal combustion engine, although other prime movers can be substituted there- 'for. 2 is the armature of a generator having the field coil 3 and brushes 1 and 5. These brushes are connected by conductors 6 and solenoid 7, conductor 8 and solenoid 9 to the main 10, to which are connected translating devices 11, whose other terminals are connected to a main 12 connected to the brush 4 through a switch 13. The solenoid 9 is responsive to any load while the solenoid 7 is responsive only to a load which is beyond the torque capacity of the motor at first speed. 14: is a secondary battery having one terminal connected to the main 12 and the other terminal connected to the brush 5. 15

is a switch-arm actuated by the solenoid 9,-

adapted to close contacts in a circuit 15 in series with solenoid 17, the switch-arm 18, of which is adapted toconnect the contacts 19 in series with the main 12 so as to place vthe battery in parallel with the generator. 20 1s a resistance adapted to be cut in and out of series with the field coil 3. This resistance 20 has its terminals connected to contacts 21, adapted to be closed and opened by an arm 22, controlled by the solenoid 7 Specification of Letters Patent. Patented Aug, 16 1921.

23 is a spring connected to the core of the solenoid 7 and having its lower end connected to a lever 24:, whose opposite end is connected to the plunger of a valve 25 controlling the fuel supply of the engine. This lever is fulcrumed at 26 and has an arm whose lower end engages a groove 27 in a governor sleeve, which is moved to and fro by the centrifugal weights 28 and the spring 29 connected thereto.

Where the prime mover is an internal combustion engine of the electrical ignition explosive type, I provide means for controlling the ignition circuit, said means consisting of a switch-arm 30 actuated by the solenoid l7 and adapted to close and open contacts in series with a rimary coil 31, which is in series with a t1mer 32. 33 is a secondary which is connected to the spark plug 341. The base of the engine is grounded so as to be connected to the other terminal 35 of the secondary battery. 36 is a reverse current time limit relay, acting to open the circuit through the solenoid 17 in case the engine fails to start firing after a predetermined time.

In the modification shown in Fig. 2 the resistance is subdivided as shown at 20 being cut out gradually by the arm 22 moving over contacts 21 as the current on the mains increases.

The operation of the system is as follows: When there is no load upon the mains the switch arm 15 is open. When, however, a translating device is put in circuit, a load comes on, being supplied from the battery 14. i The current passing through the translating device passes through the solenoid 9', closing the switch-arm 15, which closes the circuit through the solenoid 17, which acts to close the arm 18, so as to connect the battery 14 in a series with the armature of the generator and to close the ignition circuit. Current from the battery acts tomove the generator and in so doing starts the engine, the action of the coil 17 having closed the switch-arm 30 so as to supply the necessary spark. The engine then supplies power to drive the generator 2, which supplies current for the load, the governor of the engine acting to maintain its speed substantially normal for that particular load which is on the line, and for consider able variationsthereof. Should, however, the load increase beyond a predetermined point, and the magnetization of the generator remain substantially constant, the engine would not be able to develop the required power at the speed to which it would be confined by the action of the mechanical governor.

In order to increase the engine speed, I therefore supply the solenoid 7, which acts upon the governor and in opposition thereto and also upon the throttle valve 25, so as to tend to open the throttle as the load increases. The increase in the speed due to the action of the solenoid 7, however, would tend to increase the voltage upon the line to an objectional extent; and to prevent that the resistance 20 is provided, which, as the core of the solenoid 7 is raised, is cut into series with the field coil 3 by reason of the disengagement of the switch-arm 22 with the contacts 21, so that the magnetization of the field is decreased. This decrease in the magnetization permits the engine to speed up so as to develop more power without increasing the voltage on the line. Furthermore, the cutting down of the magnetization of the generator enables the motor to speed up more quickly than it otherwise would.

During the interval of change from one speed to another, the battery 14 supplies current to the mains, and also supplies current which flowing through the generator helps the speeding of the engine to the speed which is determined by the action of the mechanical portion of the governor and the new field strength in the generator.

If the new load is entirely taken off the mains, the switch-arm 15 opens resulting in the opening of the switch-arm 18, disconnecting one terminal of the battery 14 from the generator.

The switch-arm opens its contacts simultaneously with the opening of switch-arm 18, and by so doing interrupts the ignition circuit of the engine so that the engine cannot continue to run after the load on the main is discontinued.

In the modification shown in Fig. 2 the resistance in series with the field winding is shown at 20 and is divided so as to be introduced in sections, the switch-arm being vshown as a lever 22' connected to the circuit so as to short circuit the resistance at no load and gradually cut it out by passing over the contacts 21 under the action of its solenoid 7 While I have shown my invention in connection with an internal combustion engine of the electrical ignition type, various other forms of prime movers can be employed.

As will be evident to those skilled in the art my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

What I claim is:

1. In an electric generating and distributing system, the combination of mains and translating devices thereon, an electrical generator having a field winding, a prime mover therefor, a storage battery in parallel with the translating devices on the mains, means controlled by the load for placing said battery in parallel with the generator, and means controlled by the load for speeding up the prime mover by increasing the fuel charge and correspondingly increasing the resistance of the field winding of the generator, said first means being responsive to small load and said second means being responsive to a load beyond the torque capacity of the engine on its first speed.

2. 11 an electric generating and distributing system, the combination of mains and translating devices thereon, an electrical generator having a field winding, a prime mover therefor, a storage battery in parallel with the translating devices on the mains, means controlled by the load for placing said battery in parallel with the generator, means controlled by the load for speeding up the prime mover by increasing the fuel charge and correspondingly increasing the resistance of the field winding of the generator, said first means being responsive to a small load and said second means being responsive to a load beyond the torque capacity of the engine on its first speed, said.

motor being an internal combustion engine of the electrical ignition type, and an ignition circuit controlled by the action of said first means.

3. In a system for generating and distributing electricity, the combination of mains and translating devices thereon, a prime mover, a mechanical governor therefor controlling the supply of energy, a generator having a shunt field winding, translating devices supplied thereby, a storage battery in multiple with said translating de vices, circuit closing means controlled by the current supplied from said storage battery to said devices for placing said battery in parallel with said generator, and a solenoid in series with said translating devicesact- 'ing as the current increases to increase the resistance in the field circuit and increase the flow of energy from the prime mover.

4. In a system for enerating and distributing electricity, t e combination of mains and translating devices thereon, a

,prime mover, a mechanical governor therefor controlling the supply of energy, a generator having a shunt field winding, translating devices supplied thereby, a storage battery in multiple with said translating devices, circuit closing means controlled by the current supplied from said storage battery to said devices for placing said battery in parallel with said generator, a solenoid in series with said translating devices acting as the current increases to increase the re sistance in the field circuit and increase the flow of energy from the prime mover, and a reverse current time limit relay in series with said storage battery and generator and acting to disconnect said generator and battery after a predetermined time.

5. In a system for generating and distributing electricity, the combination of mains and translating devices thereon, a prime mover, a mechanical governor therefor controlling the supply of energy, a generator having a shunt field winding,.translating devices supplied thereby, a storage battery in multiple with said translating devices, circuit closing means controlled by the current supplied from said storage battery to said devices for placing said battery in parallel with said generator, and a solenoid in series with said translating devices acting as the current increases to increase the re sistance in the field circuit and increase the flow of energy from the prime moyer, said prime mover being an electric ignition internal combustion engine having an ignition circuit controlled by said circuit closing so as to be closed when said battery is in parallel with said generator.

6. In a system for generating and distributing electricity, the combination of mains and translating devices thereon, a prime mover, a mechanical governor therefor controlling the supply of energy, a generator having a shunt field winding, translating devices supplied thereby, a storage battery in multiple with said translat ing devices, circuit closing means controlled by the current supplied from said storage battery to said devices for placing said battery in parallel with said generator, a solenoid in series with said translating devices acting as the current increases to increase the resistance in the field circuit and increase the flow of energy from the prime mover, and a reverse current time limit relay in series with said storage battery and generator and acting to disconnect said generator and battery, said prime mover being an electric ignition internal combustion engine having an ignition circuit controlled by said circuit closing means so as to be closed when said battery is in parallel with said generator.

7. In a system for generating and distributing electricity, the combination of mains and translating devices thereon, an internal combustion engine having a fuel supply and a governor tending to reduce the supply as the speed increases, a generator having a shunt winding and driven by said engine, translating devices supplied thereby, a storage battery in parallel with said translating devices, means controlled by current supplied from said battery to said translating devices for placing said storage battery in parallel with said generator, and a solenoid in series with said generator and trans lating devices acting to cut resistance into the field winding of said generator and oppose the fuel reducing action of said governor.

8. In an electric generating and distributing system, the combination of mains and translating devices thereon, an electric generator, an internal combustion engine, a governor for said engine adapted to maintain the speed approximately constant for any given adjustment thereof, a storage battery in parallel with the translating devices, means for connectingsaid battery in parallel with said generator, and means responsive to the load for controlling the excitation of said generator and also controlling the action of said engine-governor in such manner as to permit an increased or decreased output substantially in accordance with the resulting change of speed.

CHESTER F. STRONG.

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