US1657056A - Intermittently-operating electric regulator - Google Patents

Description

' 3,657 05 6 A. YTTERBERG ET AL INTERMITTE'NTLY OPERATING ELECTRIC REGULATOR Filed April 22. 1926 AR LE YTTE R BERG AAGE. GARDE \NVENTORS QL MM AT-TO R n EY,

Patented Jan. 24, 1928.

UNITED STATES PATENT OFFICE.

ABLE YT'IERBERG, OE LUDVIKA, A ND AAGE GARDE, OF VASTERAS, SWEDEN, AS-

SIGNORS TO ALLMKNNA. SVENSKA. ELEKTBISKA AKTIEBOIAGET, OI VASTERLS,

SWEDEN, A CORPORATION OF SWEDEN.

INTERMITTENTLY-OPERATING ELECTRIC REGULATOR Application filed.Apri1 22, 1926, Serial No. 103,695, andin Sweden April 3, 1925.

Our invention relates to regulators for dynamo-electric machinery and more particularly to the type where the regulating is effected by intermittently short-circuiting a portion of a circuit, for instance containing a field resistor. The regulating may be applied to voltage, current, speed, or any other quantity of the machinery capableof being regulated in an analogous manner.

One object of our invention is to provide a regulator which is Very light, handy and simple in construction.

Another object of our invention is to provide a regulator capable of directly (without the use of an intermediary relay) controlling larger currents than has been possible heretofore.

The intermittently acting regulators as heretofore constructed generally comprise an oscillating armature carrying a contact and another armature supporting the pivot of oscillation for the former. The latter armature is actuated by a coil energized according to the quantity to be kept constant (for instance the voltage of a main generator), while the former armature is actuated by a coil energized by a quantity controlling-the former (for instance the voltage of an ex-= citer). The latter quantity oscillates about a medium value which is, however, not constant but depends on certain factors (for instance the load on the main generator). For this reason, the medium position about which the first-named armature oscillates cannot be, constant, and therefore the pivot of oscillation must also be movable. All

these circumstances result in a rather com plicated construction and also in a rather hazardous operation of the contacts which makes it impossible for these to control comparatively large currents.

According to our present invention, a single movable member is employed which oscillates around a stationary axis and carries one of the contacts while the other contact is stationary. The said oscillatingmember is acted upon by the regulated quantity (e. g. main generator voltage) as well as by the quantity oscillating in value, but the action of the former, when normal, is compensated for instance by a spring, and the mean value of the latter is compensated by electrical means which shall be described hereinafter. In this way, the oscillating member can be tion ofthe main quantities determining the operation of the regulator, shown as a function of time, and Fig. 3 is a view showing a detail of construction.

Referring to Fig. 1, 11 is the armature winding and 12 the exciting winding of a main generator. The latter winding is fed from an exciting generator having an armature winding 61 and an exciting winding 62. A resistor 63 connected in series with the latter is intermittently short-circuited by the regulator, whereby the voltage is regulated in a manner known in principle.

The regulator proper comprises an oscillating member 41 actuated by two magnetic fields having cores 31, 51. One of the'fields is generated by a stationary winding 32 actuated by the voltage of the main generator.

As in the example shown the latter is supposed to be an alternating current generator, it is connected to the winding 32 over a voltage transformer 13. The field generated by the coil 32 acts on a coil 35 supported by the member 41, the said coil 35 being in series with the coil 32 and thus also actuated by a current proportional to the voltage of the main generator. The force acting upon the coil 35 will thus be substantially proportional to the square of the generator voltage, and the winding directions of the coils are preferably such as to make this force attractional..

The other field acting on the member 41 and having the core 51' is supposed to be constant and unidirectional and may for instance be generated by permanent magnetism. It acts on a coil'52 supported by the member 41 and fed in a manner characteristic to the invention which will be described later. The member 41 further supports a contact 44 performing the aforesaid intermittent short-circuiting of the resistor (53. It swings in a knife-ed e bearing 42, whlle the current is admitted y means of flexible conductors 47 and 48. The coils and 42 can be conveniently supported by the memher 41 as shown in Fig. 3, the frame of which member can serve as common return conductor for-said coils.

The coil 52 is actuated by the voltage of the exciting generator, however not directly but in such a manner that the constant portion of the said voltage is filtered away.

' a tertiary winding 56 connected to a condenser 57 for delivering itsv magnetizing current. .A corresponding winding with a condenser may be arranged also in any other suitable place, for instance on the core 31.

The member 41 is also actuated by a spring 43 counteracting the force between 86 the coils 32 and 35. This force being supposed to be constant, as the regulator is intended to regulate upon constant voltage,

the member can normally be considered to be actuated only by the oscillating force set up by the coil 52 in the constant magnetic field, by the unbalanced spring force caused under oscillation (when the spring is alternately stretched and contracted), and in some cases, if it is not counterbalanced with respect to its axis, by gravity. All these orces are more or less accurately harmonic 1n nature and thus will cause a harmonicswinging of the member 41. What has a tendency to disturb this harmonic swinging is practically only the contact pressure, but y arranging the movable contact in some suitable manner also this disturbing action ,may be considerably reduced. A suitable arrangement of the movable contact has been found to be to suspend it in a hinge 46 practically coaxial with the knife-edge hearing 42 by a comparatively rigid member 45 and connect the latter to the member 41 by one or more weak springs 49. In this way, it is possible to avoid any sliding at the contacts which is objectionable in this apparatus. If the member 41 is balanced around its axis, two contacts balancing each other are also preferably employed.

The general manner of operation of the apparatus shall now-be described, reference being bad particularly to Fig. 2 of the drawing. The curve 8 represents the path of the member 41 and the curve 2) its velocity, both as functions of time. As long as the voltage of the main generator is constant, these will be practically sine-shaped. By reason of i the decidedly elastic'connection between the member 41 and the movable contact or contacts, the latter will rest against the corresponding stationary contact or contacts during practically one half of each cycle of oscillation of the member 41. The semicycles corresponding to closed contacts are marked by full-drawn, the semi-cycles cortransformer itself free from magnetic leak-' age, the current through the'coil '52 would follow practically the same curve as the voltage E, but on account of the inductance the real current I becomes more or less displaced in phase from the voltage-and in the same time its curve obtains a more rounded shape. At any rate, it obtains a'component inphase with the velocity '0, such a component being just required for compensating the damping by friction and the like which is always more or less proportional to the velocity. The mechanical characteristics of the member 41 should preferably be such that it will swing practically in resonance with the electric impulses. When the voltage of the main generator is changed .by some reason, for instance a change in load, the above-described quasistationary conditions are disturbed. The force betwen the coils 32, 35' and that exerted by the spring 43 no longer keep each other in equilibrium, but either of these (depending on whether the voltage is raised or lowered) becomes predominant. As the member 41 is very light compared with these forces, it will instantlystop its motion and come to rest in one of its end positions, corresponding to open or closed contacts. The voltage of the exciter generator will then be 'very rapidly lowered or raised, until the voltage of the main generatoris restored to its normal value, when the member 41 resumes its. harmonic oscillation. It is to be noted, that the time intervals corresponding to open and closed contacts will still be equal, this condition corresponding to constant (high or low) value of the exciter voltage (as long as the machine operates on the straight portion of its magnetizin curve), while difi'erent intervals of close and open contacts would correspond to a time variation of the exciter voltage. The

only difference caused in Fig. 2 when the 139 ing about ried by said member and responsive to the emons exciter voltage is made higher or lower, is that the branches of the curve E will be higher and steeper and the amplitude of the curve I correspondingly larger.

Instead of using a separate transformer between the exciter and the coil 52, the latter may be connected to an extra winding on the field of the exciter. Instead of directly short-circuiting the resistor 63 by means of the contacts 44 the said short-circuiting may be efi'ected by an intermediary relay.

We claim as our invention:

1. In regulating systems for dynamo-electric machinery, an oscillating member carrying electromagnetic means responsive to the action of the quantity to be regulated, contact means carried by said oscillating member and adapted to short-circuit a portion of an electric circuit, electromagnetic means carried by said oscillating member and responsive to the action of an electric quantity altered by said short-circuiting and means for compensating the action, upon said oscillating member, of a certain portion of the quantity to be regulated and of the quantity altered by said short-circuiting.

' 2. In regulating systems for dynamo-electric machinery, a member capable of oscillat:

an axis, electromagnetic means caraction of the quantity to be regulated, a spring connected to said oscillating member and normally compensating the action of said electromagnetic means, contact means carried by 'said oscillating member and adapted to short-circuit a portion of an electric circuit, electromagnetic means carried by said oscillating member and responsive to the action of an electric quantity altered by said short-circuiting, and means for compensating the action, upon said oscillating member, of the mean value of said last-mentioned electric quantity, v

3. In regulating systems for dynamo-electric machiner a member capable of oscillat ing about an exciter,

axis, electromagnetic means tities of said circuit to aifect said oscillating member.

4. In regulating systems for dynamo-electric machinery, a main generator, an exciter therefor, a resistor in the field circuit of said an oscillating regulator member, contacts controlled by said member ,and adapted to intermittently short-circuit said resistor, electromagnetic means carried by said oscillating member and responsive to an electrical characteristic of said main generator, a transformer connected on its primary side to the terminals of said exciter and electromagnetic means carried by said oscillating member, responsive to the secondary current of said transformer.

5. In electric regulators adapted to operate by intermittently short-circuiting a portion of an electric circuit, an oscillatory member, contact means for said short-circuitin carried thereby, two coils adapted to be ed by different circuits carried by said oscillatory member, stationary magnet cores adjacent to each oi the paths of said coils, and means for maintaining, in one of said cores, a constant field, and in the other core a field proportional to the current traversing the coil moving adjacent thereto,

In testimony whereof we have signed our names to this specification.

ABLE r'rrnnnnns. AAGE sense.

Images