US1680756A

US1680756A - Synchronizing device

Info

Publication number: US1680756A
Application number: US150869A
Authority: US
Inventors: Fred H Winter
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1926-11-26
Filing date: 1926-11-26
Publication date: 1928-08-14
Anticipated expiration: 1945-08-14

Description

Aug. 14, 1928.

F. H. WINTER SYNCHRONIZING DEVICE Original Filed Nov. 26, 1926 Fig.1.

- lnvefitbr; Zed H.Win ter; His Attorney.

nection is completed.

Patented Aug. 14, 1928.

UNITED STATES PATENT OFFICE.

FRED H. WINTER, F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK;

SYNGHRONIZING DEVICE.

Application filed November 26, 1926, Serial No. 150,869. Renewed April 21, 1928.

My invention relates to improvements in synchronizing devices, and has for an object to provide an improved synchronizing device for automatically controlling the operation of connecting two alternating current circuits whereby to provide for the time of the closing operation of the connecting means so that the connection can occur only when the electromotive'forces of the circuits are substantially alike in phase and frequency.

When two energized alternating current circuits or systems are to be connected, it is desirable that their electromotive forces be alike in phase and fre uency, when the conhe connecting opera- 7 tion should, therefore, be started sufliciently prior to the in-phase and in-frequency condition to allow for the time of operation of the switching means by which the circuits are to be connected; While this switching operation may be started over a considerable range in the phase difference when the difi'erence between the frequencies is less than a )redetermined value, as disclosed in United iatatesLetters Patent 1,563,120, issued to Oliver 0. Traver November 24, 1925, and assigned to the same assignee as this invention, I propose to use synchronizing apparatus comprising a light responsive means, in order to increase the sensitivity of. the synchronizing apparatus which, in order to reduce the chances of connecting the circuits when they are not in phase and in frequency, may be arranged further to limit the conditions under which the switching operation can be started to only a predetermined phase difi'erence when the difference between the frequencies is less than a predetermined value.

My invention will be better understood from the following description when considered in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

In the accompanying drawing, Fig. 1 illustrates diagrammatically an embodiment of my invention, and Fig. 2 is a detail of a part of my invention,

For purposes of illustration, I'have shown in Fig. 1 an embodiment of my invention as applied to a three-phase alternating current electric system comprising two alternating current circuits 1 and 2 which may be connected by any suitable circuit controlling or switching means 3. This switching means, as shown, is of the latched closed type, and comprises a closing coil 4 whose circuit is arranged to be energized from a suitable source 5 through the contacts 6 of a control relay 7'which, as shown, is of the instantaneous closing time delay opening type. This control relay 7 is arranged to be energized from a suitable source such as a control bus 20 and to be controlled through the contacts 8 of a substantially instantaneous relay 9 and the contacts 10 of a time limit relay 11 only when both of the relays are simultaneously in circuit controlling position.

In order to control the relays 8 and 10, and through them the switch 3, so that circuit closing operation thereof is started sufficiently prior to the in-phase and in-frequency condition of the electromotive forces of the circuits land 2 toallow for the time of the closin operation of the switch, I provide mova le means such as a disk 12 which is controlled in accordance with the difference between the frequencies of the electromotive forces. For this there may be used any suitable means, such as a dynamo-electric machine comprising a shaft 13 to which the disk is secured, a rotor winding 14 connected to be energized from the circuit 2 through any suitable means such as a potential transformer 15, and a stator winding 16 connected to be energized from the circuit 1 through any suitable means such as a potential transformer 17. The two rotating three-phase alternating magnetic fields produced by the windings 14 and 16, as is well known, cause movement of the rotor and, therefore, the disk 12 at an angular velocity dependent on the difference between the frequencies of the electromotive forces and-in a direction depending on which of the circuits has the greater frequency;

In order to employ the movement of the disk 12 without impairing its sensitivity by reason of having tov accelerate contacts, store energy in springs and the like, I provide light responsive means herein shown as comprising'photoelectric cells 18 and- 19 which are'arranged to be controlled in acpurpose cordance with the movement of the disk, and y control theenergization of the relays 9 and 11 whose windings are connected to a suitable source such as the control bus 20.

For controlling these photoelectric cells, I provide a suitable source -of light such as an incandescent lamp 21 which is mounted on the opposite side of the disk 12 from the cells. When the disk 12 is in predetermined positions, light passing portions. such as apertures or

transparent sections

22, 23, 24 and 25 permit light from the lamp 21 to reach

mirrors

26, 27, 28 and 29, respectively, the lamp being suitably shielded so that the light therefrom is not promiscuously distributed. Light from the lamp 21 passing through either the apertures 22 or 24 strikes the mirror 26 or 28 and is reflected therefrom to the light sensitive surface of the photoelectric cell 19. When the cell is thus energized, suflicient current is passed through the winding of the time limit relay 11 to start'the circuit controlling operation thereof. If the light from either of the apertures 22, 24 is reflected on the cell 19 for a time corresponding to the setting of the relay 11, it will close its contacts 10. The time durin which the cell 19 is energized is, of course, dependent on the angular velocity of the disk 12 and the angular extent or length of the apertures 22, 24. Since the angular velocity of the disk 12 is dependent on the frequency difference, the apertures 22,

24 will have a length correspondmg to somepredetermined frequency difference which it is undesirable to exceed when the switch closing operation is to be started. The time and, therefore, the predetermined value of the frequenc' difference may be varied by changing eit er the angular extent of the apertures 22, 24 or the time setting of the relay 11. V I

In order to make it possible to start the closing operation of the switch 3, whether the frequency of one of the circuits is greater or less than the frequency of the other, the two sets of

apertures

22, 23 and 24, 25 and their res ectively associated mirrors are provided. Sthe'rwise, only one setmay be emplozed. Thus, if the frequency difference is suc that rotation of the disk 12 is in the direction indicated by the arrow 30, the aperture 22 will function to control the relay 11. If the rotation is in the opposite direction, the aperture 24 functions. Where both apertures 22 and 24 are employed, it is preferable in order to prevent any possibility of completing the circuit controlling o eration of the time limit relay 11 when the sk 12 is rotating at a velocity such. as in effect to ,combinethe lengths of the twoapertures 22 and 24, to arrange them on radii of different lengths. This makes it impossible for the timing operation of both of the apertures 22 and 24 to become cumulative. Adjacent the trailing ends, the lower ends as seen in Fig.

1, of the apertures 22 and 24 are the cooperating apertures 23 and 25. These are relatively short apertures through which light. from the lamp 21 passes to the mirrors 2? and 29, respectively. From these mirrors the light is reflected to the light sensitive surface of the cell 18 to control the energization of the instantaneous relay 9. The trailing ends of the apertures 22,24 and the apertures 23, 25 are angularly so located on the disk 12 as to permit the contacts 8 and 10 to be in circuit closing positions at a predetermined phase difference between the electromotive forces of the circuits 1 and 2.

For varying the phase difference at which the switch closing operation can be started, the angular positions of theapertures in the disk 12 may be varied in any suitable manner. One way of doing this is shown in Fig. 2, wherein as shown by the dotted lines the angular extent of the apertures in the disk 12 is considerably increased and. wherein movable members such as sectors 31 and 32 are provided with apertures 22', 23', 24 and 25, corresponding, for example, in angular extent to those in the disk 12 of Fig. 1. These sectors, as shown, are arranged for movement about the axis of rotation of the disk 12, and permit a definite angular extent of opening in the apertures in the disk, so that the angular disposition of the apertures can be varied as desired to change the phase relation at which operation of the switch 3 is started.

In explaining the operation of the illustrated embodiment of m invention, it will be assumed that the diflerence between the frequencies of the electromotive forces of the circuits 1 and 2 is such as to cause rotation of the disk 12 in the direction indicated by the arrow 30. .Thcn when the upper or leading end of the aperture 22 has moved suflicientl to permit light from the lamp 21 to reach t c mirror 26, the photoelectric cell 19 is energized and starts the'time limit relay 11 operating. If the frequencydifference is below the predetermined value for which the timing of the relay is set, then the contacts 10 Will be closed by the time the aperture 23 has moved to a position which permits light from the lamp 21 to reach the mirror 27 and thus to effect the energization of the photoelectric cell 18. The instantaneous relay 9 is thus energized to close its contacts 8 at a predetermined phase difference between the electromotive. forces of the circuits 1 and 2. Whenboth of the contacts 8 and 10 are closed, the control relay 6 is energized. This relay completes the circuit of the closin coil 4 of the switch 3 sufiiciently prior to t e inhase and infrequency condition to allow or the time of the closing operation of the switch. Although in Fig. 1, the disk 12 is shown in the instantaneous position corresponding to the phase relation at which the instantaneous relay 9 is energized to start the closing operation, the switch 3 is shown in the closed position since the time dimension, that is, the time to close the switch after the control relay is energized, cannot be illustrated simply in a drawing.

Considering again rotation of the disk 12 in the direction indicated by the arrow 30, it is obvious that, as the aperture 24 is moved into an angular position such that light can strike the mirror 27, the cell 18 may effect operation of the instantaneous relay 9. This, however, cannot effect incorrect closing of the switch 3 since, although the aperture 25 may be moved into an angular position such that light can strike the mirror 26, the cell 19 will not be energized for a time sufficient to causecircuit closing operation of the time limit relay 11. In other words, although one of the relays 9, 11 may be actuated to close its contacts, the other will not be in circuit closing position at the same instant except when predetermined conditions, such that it is safe to start the switch closing operation, prevail.

It will be understood that, if desirable, I may provide an additional control operative in response to the relative values of the electromotive forces of the circuits 1 and 2. Examples of such means are Well known in the art, one suitable means being disclosed in Letters Patent 1,563,120 heretofore referred to. Such additional control, which may comprise further contacts in the control circuit, is desirable where the circuits are to be connected only when their electromotive forces are nearly equal in value.

lVhile I have shown and described only one embodiment of my invention, I do not desire to be limited to the exact arrangement shown and described, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope o my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a plurality of alternating current circuits, means for connecting said circuits and means comprising a light responsive device for starting the closing operation of the connecting means at a-predetermined phase difference of the electromotive forces of the circuits when the difference between the frequencies of the electromotive forces is less than a predetermined value for a predetermined time.

2. In combination, a plurality of alternating current circuits, means for connecting said circuits, and means controlled in accordance with the difference between the frequencies of the electromotive forces of the circuits and comprising a light responsive device for starting the closing operation of the connecting means at a predetermined phase difference of the electromotive forces when said frequency difference is less than a predetermined value for a predetermined time.

3. In combination, a plurality of alternating current circuits, means for connecting said circuits and, means comprising a light responsive device for starting the closing operation of the connecting means when the difference between the frequencies of the electromotive forces of the circuits is less than a predetermined value for a predetermined time.

4. In combination, a plurality of alternating current circuits, means for connecting said circuits, and means controlled in accordance with the difference between the frequencies of the electromotive forces of the circuits and comprising a light responsive device for starting the closing operation of the connecting means at a predetermined phase difference of the electromotive'forces when the frequency difference is less than a predetermined value.

5. In combination, a plurality ofalternating current circuits, means for connecting said circuits, means comprising a light responsive devicearranged to be controlled in accordance with the difference between the frequencies of the electromotive forces of the circuits for controlling the closing operation of the connecting means.

6. In combination, a plurality of alternating current circuits, means for connecting the circuits, and means for controlling the closing operation of the connecting means comprising a movable member arranged to be actuated at a velocity dependent on the difference between the frequencies of the electromotive forces of the circuits and light responsive means comprising a photoelectric cell arranged to-be controlled by said memher.

7. A synchronizing device comprising a rotatable member adapted to be rotated at a velocity dependent on the difference between the frequencies of two alternating electromotive forces and light responsive means ar ranged to be controlled in accordance with the angular velocity and position of the member.

8. A synchronizing device comprising a substantially instantaneous relay, a time limit relay and controlling means therefor comprising a member adapted to be rotated at a-velocity dependent on the difference between ;the frequencies of two alternating electromotive forces and light responsive means arranged to be controlled by said member to effect the circuit controlling op- .eration of said instantaneous and time limit relays in accordance with the angular posi tion and velocity respectively of said member.

9. In combination, a plurality of alternating current circuits, means for connecting said circuits, means for controlling the clos ing of said connecting means comprising a time limit relay and means for controlling the circuit closing operation of said relay comprising a movable member arranged to be actuated in accordance with the difference between the frequencies of the electromotive forces of said circuits and light responsive means comprising a photoelectric cell controlled in accordance with the velocity of said member for effecting the circuit closing operation of said relay when the velocity of the member is less than a predetermined value. v

10. In combination, a plurality of alternating current circuits, means for connecting said circuits, means for starting the closing operation of said connecting means comprising a substantially instantaneous relay and a time limit relay, means for controlling the circuit closing operation of said relays comprising a movable member arranged to be actuated in accordance with the difference between the frequencies of the electromotive forces of said circuits, and light responsive means controlled in accordance with the velocity of said member for effecting the circuit closing operation of the time limit relay .when the velocity of the member is less than a predetermined value and the circuit closing operation of the instantaneous relay when the member is in a predetermined position.

11. A synchronizing device comprising a member adapted to be rotated at a velocity dependent on the difference between the frequencies of two electromotive forces, a source of light, a plurality of light sensitive means, and means associated with said member for permitting light from said source to sensitize one of said means for a time dependent on the angular velocity of the member and another of said light sensitive means substantially instantaneously when the disk is in a predetermined position.

12. A synchronizing device comprising a member adapted to be rotated at a velocity dependent on the difference between the frequencies of two electromotive forces, 'a source of light, light sensitive means, and means associated with said member for permitting light from said source to sensitize said means when the velocity of the member is less than a predetermined value during a predetermined movement and the member is in a predetermined position.

18. A synchronizing device comprising a member adapted to be rotated at a velocity dependent on the difference between the frequencies of two electromotive forces and having light passing portions of relatively small and large extent, a source of light on one side of. said member and light sensitive means on the other side of said member arranged to receive light from'said source when the smaller portion is in a predetermined position and while the other portion is moving through a predetermined angle.

let. A synchronizing device comprising a member adapted to be rotated at a velocity dependent on the difference between the frequencies of two electromotive forces and having light passing portions of relatively small and large extent, a source of light on one side of said member, light reflecting means on the other side of said member arranged to receive light from said source when the smaller portion is in a predetermined position and while the other portion is moving through a predetermined angle, light sensitive means arranged to receive light reflected from said light reflecting means, and means comprising a control circuit arranged to be controlled by said light sensitive means and to lie-completed when the angular velocity of the member is less than a predetermined value during a predetermined movement of the member and the member is in a predetermined position.

In witness whereof, I have hereunto set my hand this 24th day of November, 1926.

FRED H. WINTER.