Oil Circuit Breakers Research Articles

Discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the South Midland Centre, at Birmingham, 2nd December, 1946

Discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the South Midland Centre, at Birmingham, 2nd December, 1946

Discussion on “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the East Midland Centre, at Loughborough, 26th November, 1946

Discussion on “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the East Midland Centre, at Loughborough, 26th November, 1946

The authors' reply to the discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

The authors' reply to the discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

Discussion on “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the North-Western Centre, at Manchester, 7th January, 1947

Discussion on “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the North-Western Centre, at Manchester, 7th January, 1947

The authors' reply to the discussions on “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

The authors' reply to the discussions on “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

The performance of high-voltage oil circuit-breakers incorporating resistance switching

The performance of high-voltage oil circuit-breakers incorporating resistance switching

The performance of high-voltage oil circuit-breakers incorporating resistance switching

The paper reviews the improvement obtained in the performance of side-vented explosion pots when they are shunted by resistors.First, it is shown that the rating of explosion pots is determined by two critical regions, one of which determines the maximum voltage rating, whilst the other determines the maximum breaking-current rating. The effect of resistors on these critical regions is first described and then illustrated by actual test results.Secondly, it is shown that the resistors shunting the pots can also be used to give even voltage-distribution over several pots in series.The application of resistors in practice is illustrated by the description of a 132-kV oil circuit-breaker rated at 2,500 MVA.The effect of the resistors when breaking small currents in inductive and capacitive circuits is discussed in detail.A discussion follows on the validity of testing separately one pole of a 3-phase separate-tank breaker, having two breaks per pole, by applying the full 3-phase output of the test plant, the third Jerminal being obtained by bringing out through the tank wall a connection from the moving cross-bar.In conclusion, actual performances are illustrated by test results obtained on one pole of a 3-phase, 132-kV, 2,500-MVA breaker.

Discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the Institution, 7th November, 1946

Discussion on “The extinction of arcs in air-blast circuit-breakers” and “The performance of high-voltage oil circuit-breakers incorporating resistance switching” before the Institution, 7th November, 1946

The authors' replies to the discussion on “The extinction of arcs in air-blast circuit-breakers”and “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

The authors' replies to the discussion on “The extinction of arcs in air-blast circuit-breakers”and “The performance of high-voltage oil circuit-breakers incorporating resistance switching”

The Interruption of Charging Current at High Voltage

The switching of high-voltage transmission lines and underground cables occasionally produces overvoltage surges on electric power systems. While operating experience generally has been satisfactory voltages of 66 kv and below, there have been transient disturbances of considerable magnitude at the higher voltages. The length of many of the transmission lines and the importance of maintaining continuity of service on heavily loaded interconnections have stimulated a critical analysis of the problem. However, in contrast to the extreme overvoltages predicted by theoretical studies, a review of several hundred field tests over the past ten years, including many tests with voltage records by cathode ray oscillographs, discloses practically no cases of line or bus surge voltages on solidly grounded systems reaching transient peaks as high as 2? times normal line-to-ground crest voltage. This paper attempts to evaluate the effect of both the circuit constants and the characteristics of the various types of interrupters used in modern high voltage oil circuit breakers on the magnitude of switching surges. Particular attention is given to the advantages and disadvantages of such oil flow pistons or low ohmic value resistors in parallel with the main arc extinguishing devices.

4,370,000-Kva Short-Circuit Tests on Grand Coulee 230-Kv Bus

The unusually large concentration of generating capacity Coulee Dam makes possible short-circuit power on the 230-kv bus considerably in excess of the rupturing capacity of circuit breakers now available at that voltage. Methods of sectionalizing the bus and segregating the transmission lines to limit the maximum short circuit to less than 3,500,000 kva are described in this paper. A group of fault tests on one of the 230-kv 3-cycle 3,500,000-kva steel tank oil circuit breakers was made with a maximum of six generators connected. Three-phase faults close to the breaker rating and single phase-to-ground short-circuit currents equivalent to 4,370,-000-kva 3-phase were cleared with no apparent effort by the breaker. These are believed to be the heaviest short circuits ever interrupted on any power system in the world.

4,370,000-Kva short-circuit tests on grand coulee 230-kv bus

The unusually large concentration of generating capacity at Coulee Dam makes possible short-circuit power on the 230-kv bus considerably in excess of the rupturing capacity of circuit breakers now available at that voltage. Methods of sectionalizing the bus and segregating the transmission lines to limit the maximum short circuit to less than 3,500,000 kva are described in this paper. A group of fault tests on one of the 230-kv 3-cycle 3,500,000-kva steel tank oil circuit breakers was made with a maximum of six generators connected. Three-phase faults close to the breaker rating and single phase-to-ground short-circuit currents equivalent to 4,370,-000-kva 3-phase were cleared with no apparent effort by the breaker. These are believed to be the heaviest short circuits ever interrupted on any power system in the world.

Field tests of interrupting capacity of 138-kv oil circuit breakers

Field tests of interrupting capacity of 138-kv oil circuit breakers

A new line of high-voltage outdoor tank-type oil circuit breakers

A new line of high-voltage outdoor tank-type oil circuit breakers

Field tests of interrupting capacity of 138-kv oil circuit breakers

The preliminary planning necessary to estimate the amount of current to be interrupted on a large network for staged tests under short-circuit conditions is outlined, also the precautions necessary to keep the applied fault from developing into a total system interruption. The circuit breakers under test are identified, various quantities required for record, and the means of obtaining the same are discussed. The results of a number of tests are given as well as a general discussion as to the conditions of the tests and of results obtained.

A new line of high-voltage outdoor tank-type oil circuit breakers

THE TREND of the past few years and studies of future trends indicate an oncoming demand for higher interrupting capacities and decreased interrupting and reclosing times. Today there may be relatively few applications which justify these more severe requirements, but there is every indication that as time passes they will become more and more universal.

Field Tests of Interrupting Capacity of 138-Kv Oil Circuit Breakers

The preliminary planning necessary to estimate the amount of current to be interrupted on a large network for staged tests under short-circuit conditions is outlined, also the precautions necessary to keep the applied fault from developing into a total system interruption. The circuit breakers under test are identified, various quantities required for record, and the means of obtaining the same are discussed. The results of a number of tests are given as well as a general discussion as to the conditions of the tests and of results obtained.

A New Line of High-Voltage Outdoor Tank-Type Oil Circuit Breakers

THE TREND of the past few years and studies of future trends indicate an oncoming demand for higher interrupting capacities and decreased interrupting and reclosing times. Today there may be relatively few applications which justify these more severe requirements, but there is every indication that as time passes they will become more and more universal.

Field Tests and Performance of Heavy-Duty High-Speed 138-Kv Circuit Breakers-Oil and Air-Blast

The heavy expansion brought about on the Central System of the American Gas and Electric Company in response to demands for power during the defense and war periods has produced a requirement for circuit-breaker rupturing duties close to 3,500 megavolt-amperes. In order to test the interrupting performance and reliability of two types of 138-kv 3,500-megavolt-ampere circuit breakers, the first an oil, the second an air-blast design, and also to explore faster reclosing cycles than now offered by the most improved oil circuit breakers, high-capacity, field tests were carried out at the Philo Plant of The Ohio Power Company. In these tests, involving 20 interruptions on each breaker, there has been accomplished for the first time successful interruption of a full three-phase short circuit of 3,500 megavolt-amperes with three-cycle interruption and with 13-cycle reclosure. The results of these tests, it is believed, indicate that a goal of 5,000 megavolt-amperes with 12-cycle reclosure definitely is attainable.

A high-capacity high-voltage three-cycle oil circuit breaker

A high-capacity high-voltage three-cycle oil circuit breaker