US2324822A - Electrical regulator - Google Patents

Description

J y 20, 1943- F. J. CHAMPLIN 2,324,322

ELECTRICAL REGULATOR Filed Sept. 12, 1942 Inventor: Franklin J. Champlin,

b W JWAM y His Attovney.

ratented July 20, 1943 ELECTRICAL REGULATOR Franklin J. Champlin,

General Electric Co New York Dalton, Mass., assignor to mpany, a corporation of Application September 12, 1942, Serial No. 458,067

Claims.

This invention relates to electrical regulators and more particularly to improvements in control circuits for variable ratio transformer type voltage regulators of the vernier variety.

By vernier variety is meant a dual regulator in which one part provides relatively coarse steps of voltage correction and another part provides relatively fine steps or even smooth correction, the latter part having a maximum range of operation which is of the order of one of the coarse steps of the first part. A typical example of such a regulator is a so-called step induction voltage regulator. In that regulator a load-ratiocontrol power 'or distribution transformer or a step voltage regulator (usually an auto-transformer) is combined with an induction voltage regulator, the two regulators having acommon driving means which operates them in such a manner that the induction voltage regulator provides an infinite number of intermediate voltages between the tap voltages or steps of the main regulator. In such a regulator the induction regulator corresponds to the vernier regulator. When the main regulator is provided with an auxiliar low voltage winding which is used to excite the vernier regulator and the vernier regulator in turn excites a series transformer in the output circuit of the combined regulator, I have found that it is possible to eliminate the usual potential transformer used in the automatic control circuits of such regulators and thereby materially improve their reliability and reduce their cost.

An object of the invention is to provide a new and improved regulator system.

Another object of the invention is to provide an improved energizing circuit for the control of variable ratio transformer type voltage regulators.

A further object of the invention is to eliminate the usual potential transformer in the control circuit of automatic step induction type regulators.

The invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Referring now to the single figure of the drawing, I have shown therein diagrammatically a preferred embodiment of the invention in the form of a step induction voltage regulator I. This regulator comprises a three-winding transformer 2 having a multi-tapped primary winding 3, a relatively high voltage secondary winding 4, and a relatively low voltage auxiliary winding 5.

tained from a An input circuit 5 of the regulator is connected across various portions of the winding 3 by means of a ratio adjusting switch 7 which selectively makes connection to the tape of the primary winding. A load or output circuit 8 of the regulator is connected across the relatively high voltage secondary winding 4.

Smooth control of the voltage of the output circuit 8 is obtained by means of a vernier regulator shown as an induction voltage regulator 9. This regulator has a primary winding l8 connected across the auxiliary winding 5 and a secondary winding II connected across the primary or exciting winding it of a series transformer whose secondary winding I3 is connected in the output circuit 8.

The induction regulator 9 is constructed in the usual manner whereby its two windings are relatively rotatable so as to vary the coupling between them. In this manner the voltage induced in the secondary winding I i may be varied from a maximum to zero in a smooth manner and as the voltage of this winding is applied across the series transformer a similarly variable voltage will be inserted in the load circuit in series with the high voltage secondary winding 4 of the main regulating transformer. Consequently, the voltage of the circuit 8 may be varied smoothly throughout the entire tap range of the main transformer by properly operating the induction regulator over its range for all the various positions of the ratio adjusting switch 1'.

The ratio adjusting switch 1 and the regulator 8 are mechanically connected together by suitable driving means shown schematically as II. This means is operated by any suitable well-known control elements indicated generally by the control cabinet l5. Such control cabinets contain a primary electroresponsive device, such as a voltage regulating relay or contact-making voltmeter which is actuated in accordance with the voltage to be regulated or maintained constant by the regulator. Usually this energization is obpotential transformer connected across the output circuit of the regulator.

However, in accordance with the present invention the necessary control voltage is obtained from a circuit I 6. One side of this circuit I8 is connected directly to a point on the auxiliary winding 5 and the other side of the circuit I6 is connecteddirectly to a point on the exciting winding H of the series transformer. The circult is completed through a direct interconnection [1 between the two windings l0 and H of the induction regulator 9.

When this is done cuit, a load-ratio-control regulator connected therein, said regulator having a high voltage winding with a fixed number of effective turns connected across said circuit on the output side of said regulator, a low voltage auxiliary winding.

on said regulator, a series transformer having its secondary winding connected in series with said will be of the order of 120 to 240 volts which is a suitable regulator control voltage. Consequently, the circuit It will ordinarily include all of the winding 5. Usually, however, it will only include a small fraction of the winding i2 because the maximum voltage of the winding l3 will ordinarily be of the order of of the voltage of the winding 4 so that the maximum voltage of the winding i2 which is included in the control circuit I6 will be of the order of 10% of the voltage of the entire winding H.

The two regulating transformers and the series transformer may all be mounted in the same tank or casing if desired.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention and, therefore, it is aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

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

1. In combination, an alternating-current circuit, a variable ratio transformer type voltage regulator, said regulator having a high voltage winding with a fixed number of effective turns connected across said circuit on the output side of said regulator, a low voltage auxiliary winding on said regulator, a series transformer having its secondary winding connected in series with said high voltage winding, adjustable means for variably exciting the other winding of said series transformer from said auxiliary winding, said means including a direct interconnection between said auxiliary winding and said other winding, and a control circuit for said regulator and adjustable means connected across predetermined portions of said auxiliary winding and said other winding in series through said direct interconnection.

2. In combination, an alternating-current circuit, a variable ratio transformer type voltage regulator connected therein, said regulator comprising a, main step-by-step regulator and a vernier regulator, said main step-by-step regulator having an auxiliary winding for exciting said vernier regulator, and an automatic control circuit for said regulator connected to be energized in accordance with the voltage of said auxiliary winding and a portion of the exciting voltage of said vernier regulator, the ratio of said two voltages being the same as the ratio of the regulating voltages of said main regulating transformer and said vernier regulator.

3. In combination, an alternating-current cirhigh voltage winding, adjustable means for variably exciting the other winding of saidseries transformer from said auxiliary winding, said means including a direct interconnection between said auxiliary winding and said other winding, and a control circuit for said regulator and adjustable means connected across predetermined portions of said auxiliary winding and said other winding in series through' said .direct'interconnection, the ratio of the voltages of said predetermined portions being the same as the ratio of the voltages of said high voltage winding and said secondary winding.

4. In combination, an alternating-current circuit, a variable ratio transformer type voltage regulator connected therein, said regulator having a high voltage winding with a fixed number.

of effective turns connected across said circuit on the output side of said regulator, a low voltage auxiliary winding on said regulator, a series transformer having its secondary winding connected in series with said high voltage winding, an induction voltage regulator connected between said auxiliary Winding and the other winding of said series transformer, a direct interconnection between the windings'of said induction voltage regulator, and a control circuit for both of said regulators connected across predetermined portions of said auxiliary winding and said other winding of the series transformer in series through said direct interconnection, the ratio of the voltages of said predetermined portions being the same as the ratio of the voltages of said high voltage winding and the secondary winding of said series transformer.

5. In combination, a step-induction voltage regulator comprising, in combination, a loadratio-control regulating transformer, an induction voltage regulator, said load-ratio-control transformer having a main relatively high voltage secondary winding and an auxiliary relatively low voltage winding, a series transformer having its secondary winding connected in series with said high voltage winding said series transformer having a primary winding connected to be excited from said auxiliary winding through said induction voltage regulator, a direct interconnection between said auxiliary winding and the primary winding of said series transformer, and a control circuit for said regulator connected across predetermined portions of said auxiliary winding and the primary winding of said series transformer in series through said direct interconnection, the ratio of the voltages of said portions of the auxiliary winding and the primary winding of the series transformer being the same as the ratio of the voltages of said high voltage winding and the secondary winding of said series transformer.

FRANKLIN J. CHAMPLIN.

Images