Sensitivity of Torsional Modes and Torques to Uncertainty in Shaft Mechanical Parameters

Time enlargement law for gas pulse breakdown

“…(1) placing the test two-electrode system inside the gas chamber, (2) multi-stage vacuuming of the chamber and introduction of the work gas (SF 6 ) (i.e. rinsing the chamber to remove the residual air) (3) setting the desired pressure of the work gas in the chamber (adjusted to the temperature of 0 • C), (4) conditioning the electrode system with 100 consecutive pulse breakdowns, (5) measuring 20 consecutive dc breakdown voltages, with a 30 s pause between each two sequential breakdowns, (6) measuring 1000 successive values of the pulse breakdown voltage along with the corresponding breakdown times (i.e. time intervals between the moment when the pulse voltage equals the dc breakdown voltage and the moment of breakdown itself), using 250/2500 ms commutational voltage (there was again a 30 s pause between each two sequential breakdowns), while gradually decreasing the pulse amplitude so that breakdown can occur either at the leading or at the trailing edge of the pulse or even not occur at all (such measurements were rejected and repeated), (7) ending the measuring procedure after the pulse amplitude becomes so low that 100 successive pulses produce no breakdown, (8) conducting measurements described under (6) using voltage pulses with one of the aforementioned slopes of the leading edge, and with an amplitude which assured that breakdown always occurred at the leading edge of the pulse, and (9) setting the generator to the next value of the pulse leading edge slope and repeating point (8).…”

“…. ), corresponding to the adopted values for the xth and yth quantiles (limiting breakdown probabilities), were calculated using expression (6), based on the determined statistical distribution of the breakdown time random variable and the mean value of the basic system's breakdown time.…”

“…However, when time constants of voltage change and elementary gas discharge processes are of the same or approximately the same order, the value of breakdown voltage becomes distinctly stochastic (experimental determination of such a breakdown voltage must include both A and B types of measurement uncertainty [4]). The stochastic nature of the breakdown voltage appears in the case of pulse voltage load [5][6][7].…”

Designing of Drive Systems in the Aspect of the Desired Spectrum of Operation

“…At the same time, these tests allow to conduct an analysis of emergency states and to shorten the time of design processes. Therefore, having an appropriate model of the machine, it is possible to take into account various factors that have a significant impact on its technical parameters, already at the designing stage [23,24]. At the same time, the quality of the model used by the designer, understood as the precision of recreating important phenomena occurring in the real system, has a fundamental impact on the accuracy of decisions made at the designing stage, related to a selection of the optimal solution or the appropriate design form of the machine.…”

Mechanism of electrical breakdown of gases for pressures from 10−9to 1 bar and inter-electrode gaps from 0.1 to 0.5 mm

“…This instability develops further, until sufficient density of anode material vapor is established so that the Townsend condition for gas breakdown is met. On the macroscopic scale the time of anode vacuum breakdown initiation is longer than 10 µs, while the rise in the breakdown voltage with the increase in the inter-electrode gap is slower than linear [28][29][30][31]. The micro-particle breakdown is caused by microparticles, generally present on the electrodes, loosely bound to their surface or free.…”