No abstract available

[en] The characteristics of a pulse power system using a homopolar generator (HPG) and single-shot, explosive circuit breaker are described. The breaker conducts for several seconds while the self-excited HPG energizes a 1.5 mH inductor. The opening breaker then commutates the 20-kA current into load resistance of less than 0.6 /OMEGA/ within tens of microseconds with an energy transfer efficiency of 99%. When larger load resistance is used, current commutation is assisted by a parallel fuse. The open breaker withstands the voltage pulse of 40-kV peak and 750-/mu/s decay obtained from a 2-/OMEGA/ load. These experiments demonstrate the feasibility of using inertial current sources for inductive generation of terawatt output pulses. 10 refs

[en] A fast circuit breaker operated by an electromagnetic command has been realized. It can open very high currents in times in order of a few microseconds. By means of electromagnetic forces, a conductor is sent against rods and thus cut. The current is then transferred onto a fuse placed in parallel. The explosion of the fuse opens the circuit. A simplified set up has permitted to test some performances of the switch. A 240kA current has been opened in 6μs and a 5kV peak voltage simultaneously generated (half-width : 3μs). The transfer of a 130kA current has been realized in a time as small as 2μs

[en] This paper reports that the basic function of the power circuit breaker is a switching action consisting of opening and closing an electric circuit, that is, making and breaking the current under any conceivable circuit conditions. In that sense, it can be described as a circuit element whose function is intrinsically similar to that of the switches routinely met in daily life. However, major differences are that the current or circuit voltage used in a power transmission system are considerably large and the switching time must be very short, which raises technical problems. Thus circuit-breaker development constitutes one of the fields where the most advanced techniques are required

[en] This paper reports that a DS-416 low-voltage air circuit breaker manufactured by Westinghouse is mechanically cycled to identify age-related degradation in the various breaker subcomponents, specifically in the power-operated mechanism. This accelerated aging test is performed on one breaker unit for over 36 000 cycles. Three separate pole shafts, one with a 60-deg weld, one with a 120-deg weld, and one with a 180-deg weld in the third pole lever, are used to characterize cracking in the welds. In addition, during the testing, three different operating mechanisms and several other parts are replaced as they become inoperable. Among the seven welds on the pole shaft, welds 1 and 3 are found to be critical ones whose fracture can result in misalignment of the pole levers. This can lead to problems with the operating mechanism, including the burning of coils, excessive wear in certain parts, and overstressed linkages. Furthermore, the limiting service life of a number of subcomponents of the power-operated mechanism, including the operating mechanism itself, is assessed

[en] Reasons are examined for failures of gas-insulated circuit breakers on lines with shunt reactors that provide a level of line compensation close to 100%. It is shown that using a TCSR as a linear reactor makes it possible to eliminate the reason leading to failure of the circuit breaker in line testing.

[en] The Joule heating of an inhomogeneous, temperature dependent resistivity conductor is studied numerically when a time-varying current flows through it. The bidimensionnel numerical model computes the temperature and current distributions at each time step consistently. A simple experimental verification is presented, together with one example showing how the model may be exploited

No abstract available

[en] Brief discussions are given for the following research topics: (1) HVDC interrupter tests, (2) 300-kJ test facilities, (3) superconducting wire development, (4) coil development program, (5) SFTR prototype METS system, (6) SFTR conceptual design study, (7) dielectric strength and voltage tracking studies, and (8) EPRI homopolar study contract

[en] A 10 MJ inductive energy storage system is described in which the storage coil is also the excitation coil of a homopolar generator. Energy is stored initially in two counter-rotating rotors, and transferred to the coil when the generator is connected in a self-excited mode. The circuit is interrupted by a large SF₆ circuit breaker working in conjunction with a fuse, and delivers energy to a resistive load in approximately 10^-3 sec. The system contains a number of novel features, including very high-speed rotors and carbon-fiber brushes. It is intended as a prototype module for large energy storage systems