US1819261A - Circuit interrupter - Google Patents

Description

Aug. 18, 1931. T s 1,819,261

CIRCUIT INTERRUPTER Filed April 12, 1928 ;2- Sheets-Sheet l INVENTOR John F. Peters MW ATTORNEY Au 18, 1931. F, PETER 1,819,261

CIRCUIT INTERRUPTER Filed April 12, 1928 2 Sheets-Sheet 2 4A lfA /4B I l2 [8 LE I55 I j I /5A' l 4A INVENTOR John F. Peters A'TTORNEY Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE JOHN F. PETERS, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA CIRCUIT INTERRUTPTER Application filed April 12,

denser type insulators, constituting the terminals of a circuit interrupter arranged to interconnect power systems energized from separate sources of alternating current, to furnish stepped-down voltages corresponding to those of the two systems to an automatic synchronizing devlce which controls the closure of said circuit breaker.

Other objects of my invention will be clearly apparent from the following description and from the drawings, in which:

Figure 1 is an elevational view in section of a circuit interrupter showing a particular embodimentof my invention,

Figs. 2, 3 and 4 are wiring diagrams of control systems embodying my invention.

My invention comprises, in general, a circuit interrupter 1 consisting of a tank 2 filled with an insulating fluid 3 in which a bridging member 4 for contact members 5 and 6 is suspended. The bridging member 4 is supported on a rod 7 suspended to an operating mechanism 8 that is connected to an actuating means, not shown. The tank 2 of the circuit interrupter 1 is enclosed by a cover member 9 that is the means of support for the operating mechanism 8 and for condenser- bushings 11 and 12 that constitute a feature of my invention now to be described in detail.

The condenser- bushings 11 and 12 comprise a conductor 13 upon which alternate layers of insulating and conducting material are wound forming a plurality of condensers. Such an insulatinglbushing is illustrated in Reynders Patent 0. 952,467. The ends of the conductors 13 immersed in the liquid 3 conductively support the contacts 5 and 6 and are connected at their upper ends to circuits 14 and 15. The outermost conducting layer 16 is employed to energize the circuits 17 and 18 in a manner that will now be described. A circuit 19 has one of its ends connected to the layer 16, and its other end is connected to ground.

A circuit 19 includes the primary winding 20 of a voltage transformer 21, the second- 1928. Serial No. 269,460.

ary winding 22 of which terminates in conductors 23 and 24. Usually, there is connected across the primary winding 20 a spark gap 25, or other well-known protective device, which breaks down upon occurrence of abnormally high voltage and immediately returns to a non-conductive condition when normal conditions are restored.

Connected across the conductors 23 and 24 it will usually be desirable to provide a suitable capacitance 26, such as a condenser, and included in one of said conductors 23 and'24 an inductance 27. The conductors 23 and 24 may be of any suitable length and are connected to the respective terminals of a suitable relay device that will be described hereinafter.

Preferably, the spark gap 25, the transformer 21, the condenser 26 and the inductance 27 are disposed within a metallic casing 28 secured to the wall of casing 1. Under such circumstance the conductors 23 and 24 extend thru the wall of casing 28.

Other methods of stepping down and controlling the potential desired from the circuits 17 and 18 may be employed, such as the use of condensers in place of the low-voltage transformers but the system above described is the preferred form. Y

By a proper adjustment of the magnitudes of capacitance 26 and inductance 27, which any skilled electrical engineer will be able to calculate, and which therefore need not be worked out in detail here, it is possible to arrange that thevoltage between conductors 23 and 24 is in phase with and a predetermined fraction of the voltage between line 14 and ground; or alternatively in phase with and a predetermined fraction of the voltage betwlegen line conductor 14A and line conductor 14 Referring particularly to Figure 1, an arrangement is shown in which the potential in the circuits 17 and 18 is employed to control a synchronizing device. In this arrangement the power circuit 14 is intended to be connected to the power circuit 15 and this, of course, is to be accomplished only when the alternating voltages of said circuit are in synchronism.

Heretofore, in employing synchronizing indicating means on circuits of high-potential, it has been necessary to supply at each side of the circuit breaker a potential transformer that is expensive, bulky and that usually requires extensive high-voltage leads. My invention makes use of the insulators which must be provided for each circuit breaker terminal to avoid the necessity for such potential transformers. The arrangement disclosed in Fig. 1 comprises housings 28 of weather proof construction in which transformer 21, reactance 27 and condenser 26 are enclosed and which regulates the potential supplied to circuits 17 and 18 so that, in each, it is proportional to and in phase with that of the line 14 or 15 with which it is associated.

The circuits 17 and 18 are connected to actuating means 29 and 31 respectively of a synchronoscope 32 of any form well known in the art that records the phase relation of the voltages of the power circuits 14 and 15.

For many purposes, such as automatic synchronization, it is not necessary that the voltage between conductors 23 and 24 be in phase with the voltage between line 14 and ground; it is sufficient if it has the same phase relative thereto that the voltage between lines 23 and 24 has to the voltage between line 15 and ground. Under such conditions if bushings 11 and 12 are similar units the capacity 26 and inductance 27 may be dispensed with and windings 29 and 31 of the synchronizer 32 be connected directly across the terminals of transformer 21 or even directly between the respective layers 16 and the ground.

Figure 2 is a circuit diagram of a circuit interrupter employing a synchronoscope 32 connected in circuit in a manner similar to that shown in Fig. 1. The synchronoscope 32 in Fig. 2 is provided with contact members 33 and 34, that, are closed when'the voltages of lines 14 and 15 are in phase, thus completing a circuit through a relay 35. The relay 35 closes a switch 36 completing a circuit through a closing coil 37 of the circuit interrupter.

A switch 39, controlling the operation of the circuit interrupter, may be inserted in the circuit between the contacts 33 and 34 and the relay 35. When the circuit interrupter is to be closed, the switch 39 is closed connecting the relay 35 across the contacts 33 and 34, These will be closed in the manner already described when the voltages of the circuits 14 and 15 are in synchronism. The relay may be energized from an auxiliary source of energy such as the battery 38.

The contact 34 is adjustable and may be moved to an advanced position to advance the closing of relay 35 by a time interval equal to that required to complete the operation of the circuit interrupter. By this means the bridging member 4 will be brought into engagement with the contacts 5 and 6 at the exact time when the voltages of the power circuits 14 and 15 are in synchronism. This arrangement provides a system whereby one power circuit may be automatically connected to another when in exact synchronism by the mere closing of switch 39.

While one form of automatic synchronizer has been shown for controlling the relay 35, other suitable forms will be obvious to those skilled in the art.

My invention may also be employed as a means for tripping the circuit interrupters if desired. In Fig. 3, a separate secondary circuit 17 is energized by each phase of a three phase system in the above described manner. In ig. 3 the power circuit 14 is composed of three phases 14A, 14B and 14C,

connected to the bushing 11 of each circuit interrupters A, B and C respectively. Each circuit 17 is inductively connected to a bushing 11 and comprises two conductors 23 and 24. The conductors 23 are connected together by means of the conductor 41.

A relay 42 is connected in series with the circuits 24 of the circuit interrupters A and C. A relay 43 is connected in series with the conductors 24 of the circuit interrupters A and B. A relay 44 is provided in series with the circuit 24 of the circuit interrupters B and C.

As the circuit 17 will have the same potential characteristics, as the potential of the circuit 14, it will thus be seen that a change in the potential of the power circuit 14 will likewise change the potential in the circuit 17. Any change of line voltage conditions which could be made to control relay systems directly such as overvoltage or undervoltage can thus be made to actuate one or all of the relays 42, 43 and 44. The relays 42, 43 and 44 must necessarily be of a light burden type and can be employed to complete the circuit to a second relay that will thus be actuated to trip the circuit interrupters A, B and C.

Owing to the limitations of the light burden relays 42, 43 and 44, an arrangement is shown in Fig. 4 in which the burden of the relays may be double the amount of those shown in Fig. 3. In this arrangement, each of the condenser bushings 11 and 12 of the circuit interrupters A, B and C is provided with means for supplying the circuits 17 and 18 with a potential as above described. Thus in Figure 4 these circuits are shown connected in parallel to the relays 42, 43 and 44 and this arrangement provides twice as great a current to such relays as does the system shown in Fig. 3.

In Fig. 4 the power circuit 14 is connected to the load circuit 15 in a manner such that the load side 15 will be deenergized upon the opening of the circuit interrupters A, B and C. It is found desirable to provide a switch 45 between each of the circuits 17 and i operate and to install as the energy in the 18 so connected to the operating mechanism of the circuit interrupters that it is opened when the circuit interrupter opens. The

opening of the switch prevents any feed- 5 back of power through the power circuit 14, the secondary circuits 17 and 18 to the load circuit 15.-

The. circuit interrupter A in Figure 4 can also be employed for synchronizing when connecting two proper circuits 14 and 15 shown in Figs. 1 and 2 if it is provided with the same control circuits these figures show.

It will thus be seen that I have provided a source of control "for the operation of a circuit interrupter that is very economical to circuit is provided from equipment already in the field, that is, from the condenser bushing of circuit interrupters. My system is also novel in providing a circuit for actuating a synchronoscope that automatically actuates a circuit to energize the closing means of a circuit interrupter when the two power circuits are in synchronism.

My method is further novel in employing the induced potential from a condenser bushing of a circuit interrupter to operate meters to indicate the potential characteristics of the main circuit and to operate relays for the control of the said circuit interrupter.

It is to be understood that such changes in the form arrangements and connections of the component parts of my invention may be made as shall fall'within the scope of the appended claims.

I claim as my invention:

1. Apparatus for connecting together two separately-energized sections of a high-tension alternating-current line when they are in synchronism, consisting of a switch for connecting the sections having two terminals each connected with a separate one of said line-sections, a low-potential terminal associated with each switch terminal and deriving potential therefrom, and a synchronismresponsive device connected with bothof said low-potential terminals to indicate when the sections are in synchronism and the switch can be closed.

2. An electric switch for connecting together two high tension line-sections when they are in synchronism with each other, saidswitch having two insulated stationary terminals each adapted for connection with a separate one of the two line sections, and a movable switch member for connecting said terminals, each of said stationary terminals constituting a condenser having an insulated low-potential terminal, both of said low-potential terminals adapted for connection with synchronism-responsive a paratus.

3. An electric switch or connecting to- 'gether two high-tension line-sections when they are in synchronism with each other, said 3 switch having section terminals, and a movable member for bridging said terminals, and also having low-potential terminals, the potential of each of which is a function of the potential of a separate one of the section terminals.

4:. An electric switch for connecting together two high-tension line-sections when they are in synchronism with each other, said switch having two insulated switch terminals each connected with a separate one of the line sections, both insulated terminals constitutcasing for said switch having high-tensionterminals thereon for connection to said lines, respectively, means for deriving a potential from each of said high-tension terminals proportional to, and substantially in phase with, the voltage of the respective alternating-current lines, a synchronism-responsive device,

and electrical connections for energizing said detl'ice in accordance with'said derived potentia s.

6. Apparatus for connecting together two separately-energized sections of a high-tension alternating-current line when they are in synchronism, consisting of a switch for connecting the sections having two terminals each connected with a separate one of said line-sections, means including a low-potential terminal associated with each switch terminal for deriving potentials proportional to, and substantially in phase with, the potentials of the respective line-sections, a synchronism-responsive device and means for energizing said device in accordance with said derived potentials.

7. In combination with the terminals of two separately-energized high-tension alternating-current lines, a synchronism-responsive device associated with said terminals, and means for energizing saiddevice from said terminals including a low-tension terminal associated with each high-tension terminal for energization capacitatively therefrom, electrical circuits operatively connecting said low-tension terminals and said synchronism-responsive device and means in each of said circuits for establishing a condition of substantial resonance With respect to the frequency of the power traversing the respective high-tension lines.

In testimony whereof I have hereunto subscribed my name this 11th day of April, 1928.

JOHN F. PETERS.

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