US1997657A - Regulating system - Google Patents

Description

April 16, 1935. o. SCHMUTZ REGULATING SYSTEM Filed May 11, 1953 a Y u E mm m Mm m m5 .A r M aY kB 5 Peyulated l/olzaye Z} Patented Apr. 16, 1935 UNITED STATES PATENT OFFICE REGULATIN G SYSTEM Oskar Schmutz,

Berlin-Siemensstadt, Germany,

Application May 11, 1933, Serial No. 670,497

Germany July 16, 1932 5 Claims.

My invention relates to electrical regulators and it has particular relation to regulators of the static-induction or transformer type utilized with alternating-current circuits for the control of voltage, current, or other electrical quantity thereof.

In the copending application, Serial No. 659,162 by E. R. Wolfert and E. C. Wentz, filed March 1, 1933, and assigned to the Westinghouse Electric & Manufacturing Company, there is disclosed and claimed a regulating system of the static-transformer type utilizing a transformer core assembly which carries, in addition to primary Winding means, two sections of secondary winding that are connected in opposition and arranged for adjustment of the relative magnitudes of the voltages induced therein. This ad- J'ustment is effected by shifting the division of total primary flux between the two sections which shift is attained by suitably controlling the reluctances of the portions of the magnetic circuit respectively associated with the two secondary winding sections.

In the preferred embodiment of that invention, the oppositely-connected secondary winding sections are associated with two separate magnetic core structures which are jointly infiuenced by the primary magnetizing force. In order to control the reluctance of the magnetic circuit, means is employed for controlling'the magnetic saturation of the two structures by direct-current excitation. The present invenvention is particularly directed to improved means for controlling the magnetic saturation of the two core structures in regulating systems of the type under consideration.

One object of my invention is to provide a regulating system employing two core structures and means for simultaneously varying the saturations thereof in opposite directions.

Another object of my invention is to provide means responsive to voltage changes for controlling the saturation of magnetic structures that are inherently sensitive to and capable of automatically controlling a characteristic of an alternating-current circuit which is being regulated.

Another object of my invention is to provide automatic control means for regulators of the above-described static-transformer type that shall be low in cost and effective in operation.

My invention will best be understood from the following description of specific embodiments thereof when taken in conjunction with the accompanying drawing, in which:

Figure 1 is a diagrammatic representation of a preferred embodiment of a static transformer type regulator comprising two separate corestructure assemblies, employing means for controlling the saturation of the core structure arranged in accordance with my invention.

Fig. 2 is a similar diagrammatic representation of a second embodiment of my invention employing rectifiers in the energizing circuits of the core structure;saturating windings, and which utilizes voltage change responsive means in the form of a circuit comprising a series connected capacitor and inductor; and

Fig. 3 is a diagram of curves illustrating certain characteristics of the voltage sources for the control circuits which form a part of the system of Fig. 2.

Referring to the drawing and particularly to Fig. 1 thereof, the static-transformer regulator there illustrated comprises two core structure assemblies I0 and I2, each of which is of a well known three-legged construction adapted for saturation control. The two structures, respectively, carry primary windings l4 and I5 which are connected in series and energized from the conductors l6 and ll of an alternating-current supply circuit having a voltage E5. The structure II! also carries secondary windings H, which are connected in voltage opposition with similar windings i8 carried by the structure l2, to complete a connection from the supply circuit conductor Hi to the conductor IQ of the circuit to be regulated, in which a voltage Ek exists.

Assuming that the magnetic characteristics of the transformer cores I8 and i2 are similar, the series connected primary windings l4 and i5 will eifect similar magnetizations thereof, so that balanced values of voltage E1 and E2 in the secondary winding sections l1 and iii of the two cores will result. Because of the opposition connection of these sections, the two balanced secondary voltages E1 and E2 neutralize each other, and cause the regulating component voltage E3 to be zero. However, increasing the saturation of one core and decreasing that of the other by respectively decreasing and increasing the magnetic reluctances thereof, causes a greater portion of the total flux produced by all of the primary winding sections to be circulated through the core having the lower reluctance than through the one having the higher reluctance. The result is a corresponding unbalance between the secondary voltages E1 and E2 which causes the corrective component E3 thus introduced into the regulated circuit to either buck or boost the supply voltage Es. 2

It will thus be apparent that, by proper control of the saturation of the two transformer cores, the direction of the regulating component E3 may be changed, and its magnitude adjusted throughout a wide range of values. To control this core saturation in an improved manner, the system of my invention is primarily directed.

In the system of Fig. 1, saturating windings ofthe two structures Ill and I2, respectively, to control the relative magneticreluctances of the assemblies. Supplementing windings 2| and 22 are additional windings 24 and 25, which are arranged for constant energization from any suitable source of uni-directional potential, such as a battery 21. The windings 2| and 22 are connected in parallel circuit relation and energized from a control circuit comprising the conductors 29 and 30., The relative polarities of the mag netizing forces thus set up are such that" the Winding 2| aids the winding 24 in saturating the core structure l0 and the winding 22 opposes the tendency of the winding 25 to saturate'the core structure l2 when the control circuit voltage is of one polarity, and vice versa when the control voltage is of the opposite polarity.

The equipment shown in Fig. 1 is disposed to automatically maintain the voltage Ek of the regulated circuit |9|1 at a constant value regardless of fluctuations in the supply circuit voltage Es. To efiect this result a direct-current potential E4, which is directly proportional to the regulated circuit voltage Ek, is impressed across a resistor 32. The potential E4 is com pared with that of a uni-directional potential of constant magnitude, such as that produced by a battery 34, which is connected in voltage opposition to the resistor 32, the differential voltages of which supply energizing current to the two saturation control windings 2| and 22. The resistor 32 is connected to the output terminals of a full-wave rectifier 36, the input terminals of which are energized through a potential transformer 31 from the conductors I! and I9. As the magnitude of the voltage E: varies the potential E4, supplied by the rectifier to the resistor 32 correspondingly changes.

In the operation of the complete regulating system shown in Fig. 1, when the supply voltage E. is of the value at which it is desired to maintain the regulated circuit voltage Ek, the potential E4 appearing across resistor 32 is equal to that of the standard potential source 34, in which case there is no voltage impressed across the circuit conductors 29 and 30, and the two saturation control windings 2| and 22 remain unenergized. The saturating windings 24 and 25, being similarly energized, produce similar saturation conditions of the core structures l0 and I2 with the result that the secondary voltages E1 and E2 are equal to and exactly cancel each other.

A decrease in the magnitude of the supply .voltage Es effects a reduction in the potential E4 appearing across resistor 32 with the result that its value falls below that of the standard source 34, and thereby allows the conductor 30 to become positive with respect to the conductor 29. This voltage circulates energizing current through the control windings 2| and 22 causing the winding 2| to oppose the constantly energized winding 24 and oppose the saturation of the core structure l0, thereby lowering the magnetic reluctance of 7 rent change.

that structure, and causes the winding 22 to assist the constantly energized winding 25 in its saturation of the core structure l2 with the result that the degree of saturation and the magnetic reluctance of that structure are increased.

A greater portion of the total primary winding magnetizing ,force is accordingly shifted to structure H! with the result that secondary voltage E1 increases in magnitude and voltage E2 decreases. The excess of voltage E1 accordingly ap- 2| and 22 are provided on the central core legs pears'as a component E3, additive to supply voltage Es, which raises the voltage E1; of the regulated'circuit back to the desired value.

, In a similar manner, in the event that the supply voltage Es rises, the potential E4 appearing across the resistor 32 correspondingly increases and, by overbalancing the voltage of the standard potential source 34, makes the conductor 29 positive with respect to the conductor 30. This potential so energizes the control windings 2| and 22 that the winding 2| aids the constantly energized winding 24 in saturating core structure Ill, and the Winding 22 opposes the winding 25 in its effort to saturate the structure l2. The reluctance of the structure I2 is accordingly reduced below that of the structure l0, and the magnitude of the secondary voltage E2 is. correspondingly raised, while that of voltage E1 is lowered. The direction of the regulating voltage component E3 is now reversed so that it subtracts from the supply voltage Es and reduces the voltage Ex to the desired value.

The embodiment of my invention shown in Fig. 2 is illustrated in conjunction with a statictransformer regulator which is in general, similar to that already described in connection with Fig. .1. The constantly energized windings 24 and 25 of the system of Fig. 1 are in Fig. 2 replaced by closed-circuited windings 40 and 4|, which are for the purpose of preventing the alternating flux pulsations in the outer portions of the core structure from influencing the saturation control windings 2| and 22. Likewise, the energizing circuit for these control windings comprises conductors 29 and 30'. The supply source for this circuit is modified in the manner to be pointed out. i

In combination with the resistor 32, across which is disposed to appear the direct-current potential E4 proportional to the regulated-circuit voltage Ek, I utilize a second resistor 43 energized from a rectifier 45 which derives energization through a series connection of an iron core reactor 41 and a capacitor 48 from the regulated circuit conductors I9 and H.

The direct-current voltage impressed upon the resistor 43 is at all times proportional to the current in the rectifier energizing circuit comprising the capacitor 48 and the reactor 41. By proper selection of the constants of this circuit the current therein may be caused to change at a rate which is higher than that of the change of regulated voltage'Ek which produces the our- The reactance of the capacitor 48 may be of such value as to substantially neutralize or be in resonance with the inductive reactance of the reactor 4'1, thereby causing the total impedance of the circuit to be relatively low. The degree of saturation of the iron core of the reactor 41 and the ohmic resistance of the reactor winding are then made such that, when the regulated voltage Ek is of the desired value, there will be a relatively great change in the current in the energizing circuit upon the occurrence of only a small variation in the voltage Ek.

The behavior of the energizing circuit, when the series connected capacitor and reactor are properly proportioned, is graphically illustrated in Fig. 3, in which the two curves show the variat ons in direct-current potentials E4 and E5, re spectively, impressed upon the two resistors 32 and 43 when changes in the magnitude of the regulated circuit voltage El; take place. As Fig. 3 illustrates, the voltage E5 increases or decreases very greatly upon variations in the voltage E1; in the neighborhood of the desired value thereof because of the design and constants of the energizing circuit for rectifier 45.

In Fig. 3, the desired value of regulated voltage is designated at 50, which corresponds to a condition in which voltages E4 and E5 are equal. These two voltages act in opposition to each other, so that at this desired value condition the voltage E5 impressed upon circuit 29'30 is zero. Because of the differential connection just described, this voltage is of one polarity in case the regulated voltage circuit Ek is too high, and of the opposite polarity in case voltage ER is too low, the magnitude being determined by the amount of opening between the two curves shown in Fig. 3.

In order that control winding 2| of core structure I may be energized only when it is desired to effect the saturation of structure I0, and control winding 22 only when it is desired to effect the saturation of core I2, rectifying devices 52 and 53 are disposed in the energizing circuits of these two windings in the manner shown. Device 52 permits current to be passed through winding 2| only when circuit conductor 30' is positive with respect to conductor 29, and device 53 similarly permits current to pass through winding 22 only when conductor 29' is positive with respect to conductor 30.

Thus in the operation of the complete system shown in Fig. 2, when the voltage Ek rises above the desired value, conductor 30 is made positive with respect to conductor 29, as has been explained in connection with the curves of Fig. 3, and winding 2| is accordingly energized to effect the magnetic saturation of core structure In. This saturation raises the reluctance of and shifts a greater portion of the total primary winding fiux to core structure |2. This reduces additive secondary voltage E1 and raises the voltageof subtractive voltage E2 with the result that the component E3 is of a value which subtracts from the supply voltage E5 to appropriately reduce the regulated voltage Ek.

In a similar manner, when voltage Er falls below the desired value, the differential connection of resistors 32 and 43 supplies a saturating winding energizing voltage which makes conductor 29' positive with respect to conductor 30'. For this condition, control winding 22 only will be energized, and will accordinglyeffect a saturation of core structure |2 to reduce the value of secondary voltage E2 and raise that of additive voltage E1. This causes the regulating component E3 to add to the supply voltage Es and appropriately raise the regulated voltage Bk back to the desired value.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are fully possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the scope of the appended claims.

I claim as my invention:

1. The combination with an alternating current circuit, a regulating transformer therefor, and a control circuit for said transformer, of a rectifier energized by the voltage acting in said alternating-current circuit to provide a direct current potential proportional to said voltage, a second rectifier, acapacitor, a saturated core reactor connected in series with said capacitor, a circuit including said series connection for energizing said second rectifier from said alternating current voltage, the characteristics of said capacitor and reactor being so proportioned that the current supplied therethrough to the rectifier changes at a more rapid rate than does the alternating current circuit voltage, and means for impressing upon said control circuit the difference between the output potentials of said two rectifiers.

2. The combination with an alternating current circuit, a regulating transformer therefor, and a control circuit for said transformer, of a rectifier energized by the voltage acting in said alternating-current circuit to provide a direct current potential proportional to said voltage, a second rectifier, a capacitor, a saturated core reactor connected in series with said capacitor, a circuit including said series connection for energizing said second rectifier from said alternating current voltage, the characteristics of said capacitor and reactor being so proportioned that the current supplied therethrough to the rectifier changes at a more rapid rate than does the alternating current circuit voltage, and means for impressing upon said control circuit the difference between the output potentials of said two rectifiers, the energizing circuits of said two rectifiers being so related that the two rectifier output potentials are equal when the alternating-current circuit voltage is of a given desired value.

3. In combination with a regulating transformer comprising a pair of reluctance-control windings, means, comprising a common circuit for supplying unidirectional energizing current to said two windings, a rectifier disposed intermediate the circuit and one of the windings in such manner that only acircuit potential of given polarity can circulate current through that winding, a second rectifier disposed intermediate the circuit and the other of said windings in such manner that only a circuit potential of the opposite polarity can circulate current through that winding.

4. In combination with a regulating transformer comprising a pair of reluctance control windings, means, comprising a common circuit for supplying unidirectional energizing current to said two windings, a rectifier disposed intermediate the circuit and one of the windings in such manner that only a circuit potential of given polarity can circulate current through that winding, a second rectifier disposed intermediate the circuit and the other winding in a manner that only a circuit potential of the opposite polarity can circulate current through that winding, and means for controlling the direction and magnitude of the potential which acts in said circuit.

5. A regulating system for an alternating current circuit comprising, in combination, a regulating transformer having a pair of magnetic-core members each of which carries a secondary winding and a saturating winding, primary-winding means, energized by the voltage of said circuit, disposed to circulate fiux through both core members, means for introducing into said circuit, to adjust a characteristic thereof, the difference in the voltages induced in the secondary windings of said two members, means, comprising a control circuit, for supplying unidirectional energizing currents to said saturating windings, a rectifier posed intermediate the control circuit and the other saturating winding in a manner that only a circuit potential of the opposite polarity can circulate current therethrough, and means, re-

sponsive to changes in the said characteristic ofthe alternating current circuit, for determining the direction and magnitude of the unidirectional potential which acts in said control circuit.

OSKAR scm/m'rz.

Images