US1844909A - Transmission line - Google Patents

Description

9, 1932- J. SLEPIAN TRANSMISSION LINE Filed June 6, 1924 \NVENTOR Joseph Slepmn.

WITNESSES:

ATTORNEY 5 well known, commercial-frequency high-volt- Patented Feb. 9, 1932 UNITED STATES PATENT OFFICE I JOSEPH SLEPIAN, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELEC- TRIO AND MANUFACTURING COMPANY, A

CORPORATION OF PENNSYLVANIA TRANSMISSION LINE Application filed June 6, 1924. Serial No. 718,242.

My invention relates to transmission lines or structures and particularly to means for improving the operating characteristics of high-potential alternating-current transmission systems.

One object of my invention is to provide a means of the above indicated character that shall more or less perfectly compensate for the effects of inductance in a transmission line.

Another object of my invention is to improve the regulation of a high-potential alternating-current transmission system and to render the operation thereof more stable.

Another object of my invention is to provide a single means for supporting both a transmission line and a condenser, for operation in the line, whereby the use of high-potential leads for the condenser is avoided and the structure rendered compact.

A further object of my invention is to provide a transmission-line device, of the aboveindicated character, that shall be simple and I durable in construction, economical to manufacture and effective in its operation.

In high-voltage alternating-current trans mission systems, and particularly in those in which the lines extend for relatively great 7 distances, regulation is diflicult and stability of operation hard to obtain, by reason of the amount of inductance in the lines.

Lines which extend for relatively great distances, and in which regulation is difficult and stability hard to obtain, include, as is age power-transmission lines in which the total series inductance, including the transient reactances of the generators and receivers, the reactances of the step-up and stepn down transformers, and the reactance of the lines themselves, is such as to become a critical factor in the design of the transmission line or in the determination of the practical limit r of transmissible power, under the various practical operating conditions of the lines. Regulation is difiicult also in other lines, such, for instance, as a stub-end distributionfeeder connected to a line of higher voltage through a step-down transformer.

It is my aim to render the operation of the system more stable and effective by so nullifying the eflfects of inductance in the lines as to permit regulation of the system to be readily effected.

To accomplish the above-mentioned regulation, I provide electrostatic condensers, in series with the line, at intervals therealong and of such capacity as to annul or materially reduce the inductance.

In order to simplify the structure and to render the same more economical and effective, I propose to support the condensers by the insulators which support the transmission conductors, thereby avoiding the use of high-voltage terminals and other complicated and expensive structures, and rendering the device simple and compact.

My invention further contemplates the use of excess-voltage protective means for protecting the condensers against short-circuit, or other transient, high-voltage surges, so that the device is practicable and durable under all conditions of operation.

Figure 1 of the accompanying drawings, is a view of a portion of a high-potential transmission line embodying my invention, and

Fig. 2 is an enlarged side elevational view of one of the combined insulator and condenser devices shown in Fig. 1.

Referring to Fig. l, a higl1potential transmission line 1 is suspended from towers (not shown) by a plurality of spaced suspension insulator units 2, 3, l and 5. The units 3 and 4 may be of a usual and well-known type and are merely illustrative of any number of similar units that may be disposed between the units 2 and 5 which constitute composite insulator and condenser structures, as hereinafter set forth.

The line 1 comprises spaced sections 6, 7 and 8, of which the section 6 extends from the insulator unit 2 to the unit 5 and the sections 7 and 8 extend beyond the units 2 and 5, respectively. Thus, the line 1 is made up of spaced sections, each supported at its ends by a unit similar to one of the units 2 and 5 and at one or a plurality of intermediate points by ordinary insulator units, such as the units 3 and 4.

Each insulator unit 2 and 5 comprises, in general, a main insulator supporting section 10, auxiliary insulators 11, a static condenser or lumped capacitance 12 and an excessvoltage protective means symbolized by an arc-gap terminal device 14.

Referring to Fig. 2, the main insulator supporting section 10 or" the unit 2 is adapted for attachment, at its upper end, to a supporting transmission-tower structure 14a and comprises aflexible string of series-connected insulator units 15, here shown as or" a usual cap-and-pin type but which may be of the link type, similar to the auxiliary insulators 11.

V The insulators 11 are linked by connectors 16 that are connected to the bottom main in sulator unit 15 as by a common connecting member 18. The insulators 11 are also linked by connectors'19 that support members 20 for the reception ofthe ends of the adjacent lineconduc'tor sections 6 and 7. As shown in the drawings, the conductor sections 6 and 7 are linked through eyelet portions of the members 20 and are bent back upon themselves, for clamping by clamps 22, although this construction is merely illustrative of any one of various structures which may be employed,

The condenser 12, which may be of any suitable construction, is connected between the conductor sections 6 and 7 in series therewith, by any suitable means, such as brackets 23, here shown as constituting portions of the clamps 22. w 7 p v The arc-gap terminal device 14, is shown, for illustrative purposes, as comprising two conducting spheres 24 that are mounted at the ends of screws 25, although more complicated excess-voltage, protective devices may obviously be employed for the better protection of the condenser, within the spirit or" my invention. The screws 25 may be adjustably mounted in projections 26 of the brackets 23 and are adapted to be held in position by nuts 27.

"While the auxiliary insulators 11 are required to resist only. the potential drop across the condenser 12, they may be so chosen as to more nearly equalize the potential drops across the individual units 15. In usual transmission-line practice, where the bottom unit is connected directly to the line, the potential drops across the several units are not equal but are higher across the unit next to the line. Thus, by a proper selection of the auxiliary insulators 11, thelatter may serve not only as insulator supports between the condenser terminals but, also, as means for reducing the inequality of the potential drops across the main insulator units 15. i

The excess-voltage protective device 24 is so adjusted that a short-circuit, or other transient-voltage wave, which may develop by reason of any abnormal condition of reso-v nance with the line inductance, will be by passed in the protective device before the condenser dielectric is damaged by high voltage and thus shunt each condenser and destroy any possible resonance with the line inductance.

By my invention, the regulation of high ductively connectedin series with the line,

it is obvious that the condensers may be connected thereto through series or current transformers, which might be mounted either in the condenser tanks or in separate units, and while I have shown my condensers applied to a single-conductor line, it is obvious that my condensers might be applied to each phase-conductor of a polyphase line.

Since the foregoing and other modifications and changes may be made without departing from the spirit and scope of the invention, 1 desire that only such limitations shall be placed thereon as are imposed by the prior art.

I claim as my invention: v

1. A transmission-line device comprising a main supporting structure, insulating means disposed between said structure and the line, and means for compensating for the efiects of line inductance supported by said insulating means.

2. A transmission-line device comprising a main supporting structure, insulating means for supporting the line to said struce ture and having a portion between spaced sections of the line, and means for compensating for the effects of line inductance supported by said structure and connected between said sections.

3. A transmission-line device comprising a main supporting structure, insulating means for supporting the line to said structure and having a portion between spaced sections of the line, and means for compensating for the effects of line inductance including a condenser and a discharge device supported by said structure and connected between said section.

4. A transmissionline device comprising a main supporting structure, an insulator including portions connected between spaced sections of the line and a portion intermediate said portions connected to said structure, and means for compensating line inductance supported by the insulator and connected between said sections. 7 v

5. A transmission-line device comprising a main supporting structure, a suspension insulator including flexibly-connected insulator units depending from said structure for sup- 5 porting and separatin spaced line sections and means supported y said insulator and connected between said sections for compensating for line inductance.

6. A transmission-line device comprising a 10 main supporting structure, a suspension insulator dependin therefrom and including fleXibly-connecte insulator units arranged in substantially inverted Y-shape, and means including a condenser and a discharge device 1 connected across the diverging lower ends of said insulator for compensating for line inductance.

7. A transmission-line device comprising a main supporting structure, an insulator sup- 20 ported thereby and includin insulator units arranged in substantially V- iape, and means for compensating for line inductance supported by the insulator and connected across the diverging arms of the V formed by said 25 units.

In testimony whereof, I have hereunto subscribed my name this 27th day of May, 1924- JOSEPH SLEPIAN.

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