USRE18740E

USRE18740E - breisky

Info

Publication number: USRE18740E
Authority: US
Publication date: 1933-02-14

Description

\ J. VJBREISKY 7 Feb. 14, PRO SYSTEM Rea Original Fild July 27. 1926 INVENTOR Jbim 1 Brez'siiy ORNEY Reissued Feb. 14, 1933 JOHN V. BREISKY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA PROTECTIVE SYSTEM Original No. 1,764,385, dated June 17, 1930, Serial No. 125,144, filed July 27, 1926. Application for reissue filed January 15, 1931.

circuit-interrupter having an operating coil and means for energizing the coil from the circuit under predetermined conditions, said means including an eleotro-ionic tube and a contact device associated therewith for rectifying and controlling the magnitude of the current through the operating coil of the interrupter.

Another object of my invention is to provide, in connection with a relay-controlled automatic circuit-interrupter, means for controlling the operating current for the circuitinterrupter and for limiting the current traversing the realy contact members.

A further object of my invention is to provide, in connection with a relay-controlled automatic circuit-interrupter, im-

proved means for securing a definite time delay in the operation of the interrupter.

For a better understanding of my invention, reference should be had to the accompanying drawing, in which:

Figure 1 is a diagrammatic view of a pro tective system including an over-current relay and circuit-interrupter embodying my invention; and i Fig. 2 is a similar view. of a polyphase circuit-interrupter responsive to different electrical-conditions embodying my invention.

Referring to Fig. 1, an electrical circuit 1 is shown having a circuitinterrupter 2 therein adapted to be controlled by a tripping coil 3 upon the occurrence of predetermined electrical conditions in the circuit. In accordance with my invent-ion, the energization of the tripping coil 3 is controlled by the current transformer 4, and electromagnetic relay 5 and an electro-ionic device 6 connected to the relay 5 through an auxiliary transformer 30 and the tripping coil 3.

The electromagnetic relay 5 is provided with an actuating winding 7 connected to the terminals of the secondary winding of the current transformer; 4 and with cooperating contact members 8 controlled by the actuating winding 7 An auxiliary relay 9 is connected t0 the contact members 8 of the relay Serial No. 509,041.

5 and is adapted, when operated, to close a i it shunt circuit around the contact members 8.

The electro-ionic tube 6 may be of the thermionic or heated-cathode type as shown, and comprises an envelope in which'the filamentary cathode 10- and anodes 11 are disposed. The envelope may be exhausted or may be filled with-an inert gas, such as neon or argon. Furthermore, the filamentary cathode shown may be replaced by other forms of electron-emitting cathodes, which are wellknown, or the device 6 may be replaced by other electro-ionic current-controlling devices having similar characteristics.

An auxiliary transformer is interposed between the current transformer 4 and the cathode and anode circuits of the electroionic tube 6. The transformer 30 comprises three legs on which

windings

31, 32 and .33 are disposed. The winding 31 is connected across the current transformer 4 in series with the contact members 8 of the relay 5. The winding 32 is connected in series with the tripping coil 3 of the circuit-interrupter 2 and the anodes and cathode of the electroionic device 6. As shown, the device 6 comprises two anodes 11 arranged to provide full-wave rectification of the current through the tripping coil 3. The winding 33 is connected to the cathode 10 of the electro-ionic device 6 and may be restricted in cross section in order to limit the cathode-heating current to a safe value.

If the circuit 1 is traversed by an excessive current, the over-current relay 7 is. operatively energized and closes its contact members 8, thereby closing the circuit of the cathode 10 of the electro-ionic tube 6. After a definite time delay, which is required for the cathode 10 to reach the electron-emitting temperature, a current is established in the anode circuit of the electro-ionic tube 6 and the tripping coil 3 is operatively energized to open the circuit-interrupter 2.

The time delay may be made small or even substantially eliminated if desired by reducing the mass of the cathode or increasing the filament current.

In some cases, a definite time delay in the operation of a circuit-interrupter is desired irrespective of the magnitude of the overload or other abnormal condition to which the cir-' cuit-interrupter responds, while in other cases, the circuit-interrupter should open practically instantaneously even upon a relatively small overload. If the relay 5 is of the induction type, the desired time element may be obtained. by the adjustment of the relay. If the electro-ionic tube is arranged to introduce a time delay in the operation of the circuit-interrupter, an additional. time element is obtained or the relay 5 may be an instantaneous relay, such as the solenoid type. r

If the relay 5 is an instantaneous relay and the electro-ionic tube is instantaneously operative, as would be the case if the cathode 10 is of small mass or normally at or near the electron-emitting temperature, there is no time element in the operation of the circuitinterrupter.

When the contact members 8 of the relay 5- engage, the relay 9 becomes energized and closes a shunt circuit around the contact members 8 until the circuit-interrupter 2 operates. The operation of the circuit-interrupter is therefore independent of chattering of the contact members 8 and the contact members are not required to interrupt the heating current" of the cathode 10. The'electro-ionic device 6' serves not only to provide a definite minimum time delay, where a time delay is desirable, in the operation of the circuit-interrupter 2' but also rectifies the current through the trippin coil 3 so that an ordinary direct-current trlpping coil may be used.

In many instances it is desirable to vary the time adjustmentof the circuit-interrupter in order tosecure the selective operation of several circuit-interrupters connected in se ries or for some other purpose. In such systems, the disconnection of only the faulty section is obtained by increasing the time element of the circuit-interrupter nearest the station. This: is accomplished in the system which I have described as indicated above by either changing the time adjustment of the over-current relay 5, by increasing the thermal lag of the cathode 10, as by increasing its mass or by delaying the increase of anode orcathode potential to the operating value.

It will be apparent that the system which I have described has-several advantages over prior" systems. A sensitive auxiliary relay may be employed in connection with the electro-ionic tube and the tube limitsthe current through the-contact members of the relay'to prevent injuringthesame. Furthermore, the

.electro-ibnic tube not only provides a definite out altering the cathode potential.

'traversing'the' cathode 10 and the -members 28 of the relay 7 When the positive phase-sequence compo- The principles of my invention may be applied to polyphase circuits and to other forms of contact devices or protective relays. For example, in Fig. 2 I have shown a threephase circuit l5 -ha-ving a circuit-interrupter 16 therein provided with a tripping coil 17.

The energization of the tripping coil 17 ber 24 on the three legs of which the Wind'-

ings

25,26 and 2? are disposed.

The winding 0f the auxiliary transformer is connected to the current transformers 18 and-19 The winding 26 is'c'onnected inseries with the cathode 10 of the electro-ionic device 21 and the contact members 28 of" the relay 20'. The winding 27 is connected in series with the tripping coil 17 in the anode circuit ofthe electro-ionic device 21*. This arrangement permits the anode potential to be selected independently of the potential applied to the cathode and to be changed with- The leg of the transformer 23 on which the winding 26 is disposed, may be so restricted in crosssecti'on, as indicated, as to become magnetically saturated in order to limit the current contact nent of currentin thecircuit 15 exceeds a predetermined value, the relay 20 is operatively energized and closes the-circuitof thecathode 10 of the electro-ionic device 21.v After a time delay required to heat the cathode 10 to the electron-emittingtemperature, a current traverses'the anode circuit of the electroionic device 21 and the tripping coil 17 of the circuit-interrupter 16 is operatively energized, thereby openin the circuit.

' I have" shown di erent modifications of my invention in order to illustrate the princi ples thereof more clearly. Various other modifications within the scope 0t my invention will occur to those: skilled in the art and therefore Idesire that my invention shall not be limited in scope except as indicated in therefor, a thermionic device having an anode and acathode, a transformer core having a winding thereon. for energlzatlon 1n accordwith an electrical condition in said circuit, a second winding on said core for energizing said cathode and means for limiting the energization thereof, and a third winding 011 said core for energizin the actuating Winding of said interrupter t rough a circuit including the anode and cathode of said thermionic device.

2. In an electrical circuit having a circuit interrupter therein and an actuating winding therefor, a thermionic device having an anode and a cathode, a triple-leg transformer core having a winding on one of the legs thereof for energization in accordance with an electrical condition on said circuit, a winding on another leg of said core for energizing said cathode and means embodied in said leg for limiting the energization of said cathode, and a winding on the third leg of said core for energizing the actuating winding of said interrupter through a circuit including said anode and cathode in series relation.

3. In an electrical circuit having a circuit interrupter therein and an actuating winding therefor, a thermionic device having an anode and a cathode, a transformer core having a winding thereon for energization in accordance with an electrical condition in said circuit, a second winding on said core for energizing said cathode, means for limiting the energization thereof, and a third winding on said core for energizing the actuating winding of said interrupter through a circuit including the anode and cathode of said thermionic device, and means operable in response to a predetermined condition on said circuit for controlling the operation of said thermionic device.

4. In a polyphase electric circuit having a circuit interrupter and an actuating winding therefor, a thermionic device having a cathode and an anode, a transformer core having a winding thereon and means for energizing said windings in accordance with the current traversing said circuit, a second winding on said core for energizing said cathode, a third winding on said core for energizing the actuating Winding of said interrupter through a circuit including said anode and cathode in series relation, and means responsive to the phase-sequence characteristics of said circuit for controlling the energization of said thermionic device.

5. In protective apparatus for an alternating-current circuit, a circuit interrupter, a thermionic device having a cathode and an anode, transforming means comprising a primary winding energized from said circuit, a magnetic core element energized by said primary winding, said core element having parallel branches of different reluctance characteristics such that the flux which can be induced in one of said branches is of substantially limited maximum value and a winding interlinked with said last-mentioned branch for supplying heating current to said cathode, means for applying an anode voltage to said device, and means responsive to the anode current of said device for operating said interrupter.

6. In protective apparatus for an alternating-current circuit, a circuit interrupter, a thermionic device having a cathode and an anode, transforming means comprising a primary winding energized from said circuit, a magnetic core element having a first branch interlinked with said primary winding and having second and third branches of different reluctance characteristics such that the flux which can be induced in said second branch is of substantially limited maximum value, a winding interlinked with said second branch for supplying heating current to said cathode and a winding interlinked with said third branch for applying an anode voltage to said device, and means responsive to the anode current of said device for operating said interrupter.

In testimony whereof, I have hereunto subscribed my name this 13th day of J anuary, 1931.

JOHN V. BREISKY.