US2137068A - Contactless regulator - Google Patents

Description

Nov 15, 1938. c. E, VALENTINE ET AL 2,137,068

C ONTAC TLES S REGULATOR Filed Jan. 29. 1958 43 INVENTORS Vincent E. Thar bwg 2 V mm Patented Nov. 15, 1938 UNITED STATES CONTACTIEBS REGULATOR Oarroll E. Valentine, Forest mils, and Vincent E. Thornburg, Pittsburgh, Pa assignors to Westinghouse Electric 4: Manufacturing Com-- pany, East Pittsburgh, 2a., a corporation Pennsylvania Application January 29, 1938, Serial No. 187,692

10 Claims.

Our invention relates to electrical regulator systems and particularly to regulating systems in which a primary regulating control element is employed that does not require movable contact members or wearing parts.

In mechanical type regulators for controlling the value of electrical quantities, it has been common practice to use contact members that are subject to wear for controlling a variable resistor or similar element. The contact operating mechanism also employs movable parts such as pivot pins that are subject to wear and which, therefore, periodically or ultimately require readjustment or replacement. In a number of such applications, if periodic servicing and readjustment of the parts is not properly made, improper operation of the mechanism results.

It is an object of our invention to provide an electrical regulator without contacts and essentially without parts subject to wear or deterioration, thus avoiding the necessity for servicing at frequent intervals.

It is a further object of our invention to provide a regulator of the above-indicated character having a control element consisting of a spring mounted movable member actuated by an electromagnet and restrained by a spring.

Qther objects and advantages of our invention will be apparent from the following description of a preferred embodiment thereof taken together with the accompanying drawing, in which:

Figure 1 is a diagrammatic view of circuits and apparatus illustrating a preferred embodiment of the invention;

Figs. 2 and 3 are plan and elevational views, respectively, of a preferred embodiment of the primary control element; and,

Figs. 4 and 5 are diagrammatic views of modifled portions of the circuits shown in Fig. l.

Referring particularly to Figs. 2 and 3, the operating mechanism of the primary regulator control element employed corresponds to that described and claimed in application Serial No. 118,554 of C. R. Hanna for Voltage regulator, filed December 31, 1936, and assigned to the same assignee as this application.

In the above-named application, the primary element employs a movable armature to operate contact members to control a variable resistor, while in the present construction, the primary element is employed for actuating a vane of magnetic material in an air gap. The primary element comprises a supporting panel I upon which is suitably mounted a core structure 2 (Cl. 1'l1119) having two outer winding legs 4 and 5 which terminate with an air gap between each other and also between a central leg 3. The outer winding legs 4 and 8 support windings l and 8, respectively, that are connected in series with each other to a source of alternating-current supply. A movable vane 3 is provided and positioned to move in the air gap between the end of the central leg 3 of the core structure and the ends of the winding legs 4 and 5 to vary the reluctance of the magnetic circuits associated with the windings l and 3. Means is provided for actuating the vane 8 comprising a core structure 3 of magnetic material having a winding leg for accommodating an energizing winding H and providing a space in the magnetic circuit for accommodating an armature i2 attached to a lever i3 that is pivotally mounted to the core structure to form a pivot line indicated at i4 and deter mined by the line of intersection of fiat vertical and horizontal spring members and I6 extending between a block i'l carried by the lever l3 and the upper portion of the core structure 9. One end of a spring II is attached to a stud l9 carried by the lever i 3, the other end of the spring being attached to a stud 2| carried by the supporting bracket 22 mounted on the panel i.

The arrangement oithe apparatus and the circuits connecting the various parts thereof is best shown in Fig.1, in which an alternatingcurrent generator 25 is illustrated as supplying circuit conductors 23, the voltage of which it is desired to maintain at some desired value. The generator 25 is provided with a field winding 21 connected to be supplied with energy from an exciter generator having an armature 28 connected to the field winding 21 through an adjusting resistor 29 and conductors 32 and 33. An exciter field winding 34 is provided for controlling the excitation of the armature 28, and consequently the output voltage thereof. This field winding is supplied with energy from three separate sources consisting of the armature 28 as a self-exciting source, a corrective rectifier 35, and a compounding rectifier 36. The self-exciting circuit or the exciter extends from the positive terminal of the armature 23 through an adjustable resistor a blocking rectifier 33, conductor 33, a saturating winding 42 on a multiple-legged reactor 43. conductor 44, through the field winding 34 to the negative terminal of the exciter armature 23. The alternating-current side of the corrective rectifier 35 is connected to the secondary winding of a potential transformer 45 through a circuit extending through conductor 46,'the rectifier l6, alternating-current windings 41 and 48 of the multiple-legged reactor 46, conductor 46 to the opposite terminal of the secondary winding of the transformer 46. The output circuit from the corrective rectifier 66 extends through conductor 62, field winding 64 and conductor 53 to the negative terminal of the rectifier. The alternating-current side of the compounding rectifier I6 is connected to a current transformer 54 that is responsive to the output current from the generator 26 and therefore the rectifier 36 supplies direct current that is a measure of the generator current from the positive terminal of the rectifier 36 through conductor 56, conductor 36, saturating winding 42, conductor 44, field winding 34 to the negative terminal of the rectifier 86.

The reactor 43 is shown as having three winding legs, the two outer legs accommodating the alternating-current windings 41 and 46, and the inner leg accommodating the aforenamed saturating winding 42 and two additional saturating windings 56 and 61. The winding 66 is connected by conductors 56 and 66 to the output terminals of a full-wave rectifier L, and the saturating winding 61 is connected by conductors 62 and 63 to the output terminals of a full-waverectifier R. The rectifiers are so connected to the windings 56 and 51 that the magnetomotive force produced by the winding 64 opposes the magnetomotive force produced by the winding 42, and the magnetomotive force produced by the winding 5! adds to that produced by the winding 42. The alternating- current terminals 64 and 66 of the rectifier L are connected to the terminals of the winding 1 so that the voltage applied to the rectifier L is a measure of the voltage drop across the winding 1, and the alternating-current terminal 66 and 61 of the rectifier R are connected to the terminals of the winding 6 so that the voltage applied thereto is a measure of the voltage drop across the winding 6. The windings I and 6 are connected in series circuit relation with each other to the secondary winding of the voltage transformer 45 through conductors 49 and 66.

The energizing winding i i of the primary control element is energized in accordance with the voltage of the generator 25 through a voltage transformer 45, the primary winding of which is connected to the conductors 26, and thesesondary winding of which is connected to supply alternating current to the terminals 14 and 15 of the control rectifier 13. The output circuit of the rectifier supplies undirectional current through conductors 69 and 12 to the winding II. The sources for energizing the circuit including the series connected windings 'l and 6 and also the source for energizing the corrective rectifier 35 and including the windings 41 and 46 may be any suitable alternating-current source other than the transformer 45, if desired.

A feed-back transformer 16 is provided having a secondary winding 11 connected in conductor 69 between the rectifier l3 and the energizing winding II, and a primary winding 16 connected by conductors 53 and 19 to be energized in accordance with the voltage of the exciter armature 28. The feed-back transformer 16 acts as an anti-hunting or stabilizing transformer to prevent over-shooting of the regulated voltage beyond the desired value.

It will be noted that, in tracing the circuits from the three sources, namely, the armature winding 28, the corrective rectifier 66, and the compounding rectifier 66, through the field winding 34, all three circuits provide for the now of current in the same direction through the field winding 34. The circuits are initially so adjusted that the field current supplied to the winding I4 from the exciter armature 26, together with the field current supplied from the corrective rectifier II, when the magnetomotive force produced by the windings 66 and 61 are of equal intensity and neutralize each other, and the current supplied from the rectifier I6 is substantially zero, is just enough to supply the minimum excitation required for the generator 16. In this condition of the system, the reactor 43 is partially saturated by the current fiowing through the winding 42, thereby decreasing the voltage drop across the alternating-current windings 41 and 46 and increasing the voltage supplied to the corrective rectifier 36 above the minimum value that would be supplied if the core were completely unsaturated.

The tension of the spring I6 is so adjusted that when the value of the regulated voltage between conductors 26 is at its desired value, the pull of the core 9 on the armature I2 is just balanced by the tension of the spring l6, so that the vane 6 is held in substantially its mid-position, and the reluctance of the two magnetic paths through the core legs 3 and 4 and the core legs 3 and 6, respectively, is substantially the same. Under these conditions the voltage drops across the windings I and 6 are substantially equal and the undirectional potentials supplied from the rectifiers L and R to the windings 66 and 51, respectively, are substantially equal and neutralize each other, since they are applied to the saturating leg of the reactor 43 in magnetic opposition.

If the voltage between the conductors 26 drops the energization of the winding ll correspondingly drops, thus decreasing the pull on the armature I2 and permitting the spring it to move the vane 6 slightly toward the right, as viewed in each other of the figures of the drawing, thereby decreasing the reluctance of the path through the core legs 5 and 3 and increasing the reluctance of the path through the core legs 4 and 3. The voltage drop acrossthe winding 6 is thereby increased and the voltage drop across the winding 1 is thereby decreased, thus increasing the energization of the saturating winding 61 and decreasing the energization of the saturating winding 56 so that the reactor 43 is further saturated, and the voltage drop across the windings 41 and 48 decreased to correspondingly increase the altemating-curreni voltage at the potentials of the rectifier 35, and the unidirectional output therefrom through the field winding 34 to increase the excitation thereof, and correspondingly increase the output voltage of the exciter gengrs'ator armature 28, and of the main generator As the output voltage of the armature 26 increases, the current fiowing in the primary winding 16 of the feed-back transformer 16 increases correspondingly and induces a transient electromotive force in the secondary winding 11 to increase the energization of the winding Ii sooner than it would be increased by the change in the potential across conductors 26 alone, thereby moving the vane 6 towards its mid-position before the increase in excitation of the generator 25 has been fully realized by a corresponding increase in the voltage between conductors 26.

In a similar manner, if the voltage between conductors 28 increases above the desired value, the energization of the winding ii is correspondingly increased, thus moving the armature l2 toward the right, as viewed in Figs. 1 and 3, and moving the vane 8. toward the left, as viewed in each of the three figures, to decrease the reluctance of the magnetic circuit including the core parts 8 and 4, and to increase the reluctanceof the magnetic circuit including the core parts 5 and 8, correspondingly increasing the voltage drop across winding I and decreasing the voltage drop across the winding 8 to increase the energization of the saturating winding 88 and decrease the energization of the saturating winding 81. Thus the total saturating efifect is decreased, since the magnetomotive force from the winding 88 opposes the magnetomotive force from the winding 42, and the magnetomotive force from the winding 51 adds to the magnetomotive force from the winding 42. The voltage drop across-windings 41 and 48 is thus increased so that the alternating voltage impressed on the rectifier 35 is decreased and the unidirectional output voltage therefrom is correspondingly decreased to decrease the total energization of the exciter generator field winding 84, and correspondingly decreases the voltage of the exciter generator armature 28 and of the main generator 25. During the changing voltage of the exciter generator armature 28, any feed-back current supplied into the circuit of the winding Ii by means of the transformer 16 is in a direction to decrease the energization of the winding II and return the armature i2 and the vane 6 towards their normal or mid-position prior to a completion in the correction of the voltage between conductors 26 to thus stabilize the regulator system. I

If the generator load changes, a corresponding change in the excitation thereof is required to maintain a-constant terminal voltage. The com pounding rectifier 36 is caused to increase its unidirectional output current which fiows through the saturating winding 42 of the reactor 43 and through the field winding 34 to give a normal increase in excitation of the generator 25 apart from that effected by the primary element that controls the rectifiers L and R in response to the line circuit voltage, thus decreasing the range of activity required by the primary element to maintain the desired voltage. I

In Fig. 4 a modification of a portion of the circuits shown in Fig. 1 is illustrated in which the reactor windings I and 8 are connected in parallel intead of in series circuit relation. With this circuit arrangement condensers 82 and 83 may be connected in shunt to windings 1 and 8 respectively and tuned to give sharp voltage output changes from the rectifiers L and R upon slight movement of the vane 6. The circuits are otherwise as shown in Fig. 1.

In Fig. 5 another modification of the circuit shown in Fig. l is illustrated, in which the rectifiers L and R are connected through insulating transformers 84 and 85 respectively to the secondary winding of the transformer 45. In this modification of the circuit resistors 88 and 81 are connected across the output terminals of rectifiers L and R respectively, and a single saturating winding 82 is substituted for the two windings 58 and 51 shown in Fig. 1. The winding 92 is connected between the positive terminals of the rectifiers L and R by conductors 89 and 98, the negative terminals being connected together by conductor 88. The winding 92 is energized in either direction depending upon the differential values of the output voltage from the rectifiers L and R.

It will be apparent to those skilled in the art that many modifications may be made in the circuits and apparatus illustrated and described without departing from the spirit of our invention, and we do not wish to be limited otherwise than by the scope of the appended claims.

We claim as our invention:

1. In a regular system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation of said field winding, said reactor having two saturating windings connected in magnetic opposition, separate rectifiers for supplying current to said saturating windings, and means for oppositely varying the alternating voltage supplied to said rectifiers comprising a core having two magnetic circuits with a variable air gap in each circuit, windings provided about portions of each of said magnetic circuits and connected to a source of alternating current, and means controlled by the regulated quantity for oppositely varying said air gaps.

2. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation of said field winding, said reactor having two saturating windings connected in magnetic opposition, separate rectifiers for supplying current to said saturating windings, and means for oppositely varying the alternating voltage supplied to said rectifiers comprising a core structure providing two magnetic circuits each having an air gap, a vane of magnetic material movably mounted to oppositely vary said air gaps, separate windings about the cores of the two magnetic circuits, and means controlled by the regulated quantity for moving said vane.

3. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation of said field winding, said reactor having three saturating windings, one of said saturating windings being connected in series between said field winding and a source of unidirectional energy therefor, alternating current rectifiers connected to the other two saturating windings for supplying unidirectional current thereto in magnetic opposition, means for supplying alternating current to said rectifiers comprising a circuit including a pair of reactor windings connected in series circuit relation, and means controlled by the regulated quantity for oppositely varying the reactances oi said reactor windings.

4. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation oi said field winding, said reactor having three saturating windings, one of said saturating windings being connected in series between said field winding and a source of unidirectional energy therefor, alternating current rectifiers connected to supply unidirectional current to the other two saturating windings in magnetic opposition, means for supplying alternating current to said rectifiers comprising a circuit including a pair of reactor windings connected in series circuit relation, a separate magnetic circuit associated with each of said reactor windings, and means including a movable armature for oppositely varying the reluctances of said two magnetic circuits in accordance with variations in the regulated quantity.

5. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation of said field winding, said reactor having three saturating windings, one of said saturating windings being connected in series between said field winding and a source of unidirectional energy therefor, alternating current rectifiers connected to supply unidirectional current to the other two saturating windings in magnetic opposition, means for supplying alternating current to said rectifiers comprising a circuit including a pair of reactor windings connected in series circuit relation, a separate magnetic circuit associated with each of said reactor windings and each provided with a variable air gap, means movable for oppositely varying the said air gaps, and an armature actuated in accordance with variations in the regulated quantity for actuating said last named means.

6. In a regulator system, a quantity to be regulated, means for governing said quantity including a multiple leg reactor having two saturating windings thereon connected in magnetic opposition, two rectifiers for supplying unidirectional current to said two windings, respectively, said two rectifiers being connected, respectively, across two series connected windings wound on separate magnetic circuit cores and each having an air gap, said cores being provided with means for oppositely varying the air gaps in the two core circuits, an armature for actuating said means, and means energized in accordance with the regulated quantity for actuating said armature.

7. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a regulated characteristic of said machine, means for governing the excitation of said field winding including a multiple leg reactor having alternating current windings thereon and saturating windings thereon, a field energizing rectifier supplied by a circuit including said alternating current windings, two separate rectifiers for supplying unidirectional current to two of said saturating windings connected in magnetic opposition, said two rectifiers being connected across two series connected windings wound on separate magnetic circuit cores each having an air gap, said cores being provided with means for oppositely varying the air gaps in the two core circuits, an arms--- ture for actuating said means, an energizing winding and circuit energized in accordance with the regulated quantity, and a feed back transformer having a winding included in said energizing circuit and a winding subject to the voltage of said field winding for introducing a stabilizing influence into the control circuit.

8. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation of said field winding, said reactor having a plurality of saturating winding means, one of said saturating windings being connected in series between said field winding and a source of unidirectional energy, means for supplying unidirectional current to the remaining saturating winding, means comprising two alternating current rectifiers and means for supplying alternating current to said rectifiers comprising a pair of reactor windings, a separate magnetic circuit associated with each of said reactor windings, and means including a movable armature for oppositely varying the reluctances of said two magnetic circuits in accordance with variations in the regulated quantity.

9. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling the excitation of said field winding including a saturable reactor, an alternating current winding on said reactor and a rectifier having its alternating current side connected in series circuit relation with said reactor for supplying unidirectional current to control the excitation oi said field winding, said reactor having three saturating windings, one of said saturating windings being connected in series between said field winding and a source of unidirectional energy therefor, alternating current rectifiers connected to supply unidirectional current to the other two saturating windings in magnetic opposition, means for supplying alternating current to said rectifiers comprising a pair of reactor windings connected in parallel circuit relation to an alternating current source and tuned to magnify voltage output with critical changes in the conditions of the magnetic circuits, as separate magnetic circuit associated with each of said reactor windings, and means including a movable armature for oppositely varying the reluctance of said two magnetic circuits in accordance with variations in the regulated quantity.

10. In a regulator system, an electric circuit, a dynamo-electric machine having a field winding and connected for controlling a desired characteristic of the circuit, means for controlling one or the other direction to the other saturating winding, means for supplying alternating current to said rectifiers comprising two reactor windings, a separate magnetic circuit associated with each of said reactor windings, and means including a movable armature for oppositely varying the reluctances of said two magnetic circuits in accordance with variations in the regulated quantity.

CARROLL E. VALENTINE.

VINCENT E. THORNBURG.

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