scholarly journals Endurance of Polymeric Insulation Foil Exposed to DC-Biased Medium-Frequency Rectangular Pulse Voltage Stress

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 13 ◽  
Author(s):  
Raphael Färber ◽  
Thomas Guillod ◽  
Florian Krismer ◽  
Johann Kolar ◽  
Christian Franck
Keyword(s):  
Risk Factors ◽  
Degradation Process ◽  
Rectangular Pulse ◽  
Pulse Voltage ◽  
Switching Frequency ◽  
Time To Failure ◽  
Medium Frequency ◽  
Pulse Modulation ◽  
Peak Voltage ◽  
Voltage Stress

The endurance of polymeric insulation foil is investigated under a mixed medium-voltage stress (DC + medium-frequency rectangular pulse) by means of accelerated lifetime testing. A dedicated setup is used that allows us to selectively eliminate the known risk factors for premature insulation failure under medium-frequency pulse voltage stress: partial discharges (PDs) during pulse transitions, excessive dielectric heating, and systemic overvoltages. The obtained results on polyethylenterephtalat (PET) insulation foil suggest that the adequate consideration of these factors is sufficient for eliminating the adverse effects of the pulse modulation under the investigated conditions. Indeed, if all mentioned risk factors are eliminated, the time to failure observed under a pure DC stress is shorter than with a superimposed pulse (keeping the same peak voltage). There is then no indication of an additional detrimental “per pulse” degradation process (i.e., the time to failure is not dependent on pulse frequency). In contrast, when repetitive PDs are present, the lifetime under combined DC + rectangular pulse stress strongly decreases with increasing pulse switching frequency. PD erosion of the foil is quantified by means of confocal microscopy, and the applicability of the streamer criterion for predicting PD inception is discussed.

scholarly journals Asymmetrical ZVS-PWM Switched-Capacitor Based Half-Bridge DC-DC Converter With Switch Peak Voltage of Vin/2

2020 ◽  
Author(s):  
Angelica Paula Caus ◽  
Guilherme Martins Leandro ◽  
Ivo Barbi
Keyword(s):  
Theoretical Analysis ◽  
Power Converter ◽  
Maximum Efficiency ◽  
Switching Frequency ◽  
Switched Capacitor ◽  
Peak Voltage ◽  
Zero Voltage Switching ◽  
Power Switches ◽  
Converter Topology ◽  
Bus Voltage

This paper presents a new power converter topology<br>generated by the integration of the asymmetrical ZVS-PWM dcdc converter with a switched-capacitor ladder-type commutation<br>cell. Circuit operation and theoretical analysis with emphasis on<br>the soft-commutation process are included in the paper. The<br>main advantage of the proposed converter with respect to the<br>conventional asymmetrical half-bridge dc-dc converter is the<br>reduction of the voltage stress across the power switches to the<br>half of the input dc bus voltage, enabling the utilization of lower<br>voltage rating components. Experiments conducted on a<br>laboratory prototype with 1.4 kW power-rating, 800 V input<br>voltage, 48 V output voltage and 100 kHz switching frequency<br>are included, to verify the theoretical analysis and the design<br>methodology. The maximum efficiency of the experimental nonoptimized prototype was 93.6%.<br>Index Terms - Asymmetrical dc-dc converter, pulse-widthmodulation, switched-capacitor, zero voltage switching.<div><br><br></div>

scholarly journals A Dynamic Failure Time Degradation-Based Model

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1532
Author(s):  
Abdulhakim A. Albabtain ◽  
Mansour Shrahili ◽  
Lolwa Alshagrawi ◽  
Mohamed Kayid
Keyword(s):  
Hazard Rate ◽  
Failure Time ◽  
Degradation Process ◽  
Residual Lifetime ◽  
Time To Failure ◽  
Lifetime Distributions ◽  
Mean Residual Lifetime ◽  
Aging Properties ◽  
Degradation Models ◽  
Characterization Property

A novel methodology for modelling time to failure of systems under a degradation process is proposed. Considering the method degradation may have influenced the failure of the system under the setup of the model several implied lifetime distributions are outlined. Hazard rate and mean residual lifetime of the model are obtained and a numerical situation is delineated to calculate their amounts. The problem of modelling the amount of degradation at the failure time is also considered. Two monotonic aging properties of the model is secured and a characterization property of the symmetric degradation models is established.

Real-Time Prognostic and Dynamic Maintenance Window Scheme for Reconfigurable Manufacturing Systems

2019 ◽  
Author(s):  
Yifan Dong ◽  
Tangbin Xia ◽  
Lei Xiao ◽  
Ershun Pan ◽  
Lifeng Xi
Keyword(s):  
Real Time ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Degradation Process ◽  
Maintenance Cost ◽  
Time To Failure ◽  
Reconfigurable Manufacturing Systems ◽  
Reconfigurable Manufacturing ◽  
Reconfigurable Manufacturing System ◽  
Dynamic Maintenance

Abstract Real-time condition acquisition and accurate time-to-failure (TTF) prognostic of machines are both crucial in the condition based maintenance (CBM) scheme for a manufacturing system. Most of previous researches considered the degradation process as a population-specific reliability characteristics and ignored the hidden differences among the degradation process of individual machines. Moreover, existing maintenance scheme are mostly focus on the manufacturing system with fixed structure. These proposed maintenance scheme could not be applied for the reconfigurable manufacturing system, which is quite adjustable to the various product order and customer demands in the current market. In this paper, we develop a systematic predictive maintenance (PM) framework including real-time prognostic and dynamic maintenance window (DMW) scheme for reconfigurable manufacturing systems to fill these gaps. We propose a real-time Bayesian updating prognostic model using sensor-based condition information for computing each individual machine’s TTFs, and a dynamic maintenance window scheme for the maintenance work scheduling of a reconfigurable manufacturing system. This enables the real-time prognosis updating, the rapid decision making for reconfigurable manufacturing systems, and the notable maintenance cost reduction.

Creeping Discharge Characteristics under Rectangular Pulse Voltage inSF6Gas

1996 ◽  
Vol 35 (Part 1, No. 7) ◽  
pp. 4079-4080 ◽  
Author(s):  
Hiroshi Nakayama ◽  
Mitsuyoshi Onoda ◽  
Tsuyoshi Nishida ◽  
Takehumi Kubota ◽  
Humihiro Kamatani ◽  
...  
Keyword(s):  
Rectangular Pulse ◽  
Pulse Voltage ◽  
Discharge Characteristics ◽  
Creeping Discharge

scholarly journals Asymmetrical ZVS-PWM Switched-Capacitor Based Half-Bridge DC-DC Converter With Switch Peak Voltage of Vin/2

2020 ◽  
Author(s):  
Angelica Paula Caus
Keyword(s):  
Theoretical Analysis ◽  
Power Converter ◽  
Maximum Efficiency ◽  
Switching Frequency ◽  
Switched Capacitor ◽  
Peak Voltage ◽  
Zero Voltage Switching ◽  
Power Switches ◽  
Converter Topology ◽  
Bus Voltage

This paper presents a new power converter topology<br>generated by the integration of the asymmetrical ZVS-PWM dcdc converter with a switched-capacitor ladder-type commutation<br>cell. Circuit operation and theoretical analysis with emphasis on<br>the soft-commutation process are included in the paper. The<br>main advantage of the proposed converter with respect to the<br>conventional asymmetrical half-bridge dc-dc converter is the<br>reduction of the voltage stress across the power switches to the<br>half of the input dc bus voltage, enabling the utilization of lower<br>voltage rating components. Experiments conducted on a<br>laboratory prototype with 1.4 kW power-rating, 800 V input<br>voltage, 48 V output voltage and 100 kHz switching frequency<br>are included, to verify the theoretical analysis and the design<br>methodology. The maximum efficiency of the experimental nonoptimized prototype was 93.6%.<br>Index Terms - Asymmetrical dc-dc converter, pulse-widthmodulation, switched-capacitor, zero voltage switching.<div><br><br></div>

scholarly journals Effect of DC Bias Voltage upon Treeing Breakdown in Epoxy Resin under Rectangular Pulse Voltage

1977 ◽  
Vol 97 (3) ◽  
pp. 156-162
Author(s):  
Hiroshi Nakayama ◽  
Shigeyuki Nagata ◽  
Toshihiko Yoshida ◽  
Yoshio Inuishi
Keyword(s):  
Epoxy Resin ◽  
Bias Voltage ◽  
Rectangular Pulse ◽  
Pulse Voltage ◽  
Dc Bias
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