Results 61 to 70 of about 395,154 (260)

Study on the Unipolar Impulse Aging Characteristics of ZnO Varistors and Their Condition Monitoring Methods

open access: yesApplied Sciences
Metal-oxide surge arresters (MOSAs) are critical devices for overvoltage protection in power systems, and the aging characteristics of their zinc oxide (ZnO) varistors under impulse and power-frequency voltages exhibit significant differences.
Yongqiang Fan   +7 more
doaj   +1 more source

Mechanism and suppression of breaking overvoltage of DC circuit breakers

open access: yesHigh Voltage, Volume 10, Issue 1, Page 32-46, February 2025.
Abstract The occurrence of breaking overvoltage in a DC circuit breaker (DCCB) poses a potential threat to the safe operation of a DC grid. Based on the structure of the ±10 kV three‐terminal DC distribution network, this paper sets up the medium‐voltage DCCB and formulates a fault protection strategy.
Lu Qu   +7 more
wiley   +1 more source

Research on influence of double energy absorptions on dynamic volt‐ampere characteristics of metal oxide varistors

open access: yesHigh Voltage, Volume 10, Issue 1, Page 78-87, February 2025.
Abstract Metal oxide varistors (MOVs) are extensively employed in DC circuit breakers (DCCBs) to suppress overvoltage, dissipate energy and build up voltage after interruption. Despite their widespread use, the performance of MOVs under short‐time, double energy absorption conditions is not well understood, posing a challenge to their application in ...
Chen Long   +5 more
wiley   +1 more source

Stability of microprocessor relay protection and automation systems against intentional destructive electromagnetic impacts. Part 2 [PDF]

open access: yes, 2011
Problems of impact of the electromagnetic high-power pulses generated at nuclear explosion or by means of the special equipment, intended specially for damage of the electronic equipment, in particular digital protective relays and automatic systems ...
Gurevich, V. I.
core   +3 more sources

Preparation of zinc-oxide and zinc-sulfide powders by controlled precipitation from aqueous-solution [PDF]

open access: yes, 1994
Resumo não disponível..
Jesus, Júlio D. Pedrosa de   +2 more
core   +2 more sources

Influence of Y–Bi–Co oxide doping on electrical performance of ZnO varistors based on simulation analysis

open access: yesInternational Journal of Ceramic Engineering &Science, Volume 7, Issue 1, January 2025.
Simulation methods were used to help reveal the effect mechanism of Y, Bi, and Co dopants on ZnO varistors. It provides an important theoretical basis for the development of high‐performance varistor. Abstract ZnO varistors doped with Y2O3${\rm Y}_2{\rm O}_3$, Bi2O3${\rm Bi}_2{\rm O}_3$, and Co2O3${\rm Co}_2{\rm O}_3$ were analyzed for electrical ...
Zhengzheng Fu   +7 more
wiley   +1 more source

High‐Current Cryogenic DC Solid‐State Circuit Breaker for Electric Aircraft

open access: yesIET Electric Power Applications, Volume 19, Issue 1, January/December 2025.
Cryogenic and superconducting technologies have great potential to significantly enhance the power density and efficiency of electric propulsion aircraft. This paper presents the design of a 300 V/1700 A DC solid‐state circuit breaker (SSCB) operating at cryogenic temperatures.
Zhongying Wang   +8 more
wiley   +1 more source

Optical and Thermal Characterization of Zinc Oxide-Based Ceramic Using Pyroelectric and Photopyroelectric Techniques [PDF]

open access: yes, 2009
The advantage of wide electrical band-gap of zinc oxide (ZnO) semiconductor has been used in many applications particularly as varistors, which are ceramic devices with highly non-linear current-voltage characteristics. For ZnO-based varistor system, one
Mohd Shapee, Sabrina
core  

High Dielectric Permittivity in AFe$_{1 / 2}$B$_{1 / 2}$O$_{3}$ Nonferroelectric Perovskite Ceramics (A - Ba, Sr, Ca; B - Nb, Ta, Sb)

open access: yes, 2002
AFe$_{1 / 2}$B$_{1 / 2}$O$_{3}$(A- Ba, Sr, Ca; B-Nb, Ta, Sb) ceramics were synthesized and temperature dependencies of the dielectric permittivity were measured at different frequencies.
A. S. Bogatin   +19 more
core   +1 more source

Cryogenic DC Circuit Breaker Based on High‐Power Press‐Pack IGBT

open access: yesIET Electric Power Applications, Volume 19, Issue 1, January/December 2025.
This paper presents the performance of cryogenically compatible 3.3 kV/1.5 kA PP‐IGBTs as the main circuit breaker in a hybrid circuit breaker. The 3.3 kV/1.5 kA press‐pack IGBT can interrupt currents exceeding 5.1 kA when immersed in a liquid nitrogen bath. PP‐IGBTs are promising candidates for high‐power circuit breakers in cryogenically cooled power
Zhongying Wang   +9 more
wiley   +1 more source

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