In optical metrology, state of the art algorithms for background and noise removal fringe patterns are based on space-frequency analysis. this Letter, an approach variational image decomposition is proposed to remove from a pattern simultaneously. method, directly decomposed into three components: first one containing background, second fringes, third noise, which described in different function spaces solved by minimization functional. A simple technical process involved algorithm improves...

The deicing process and its status characteristics of dual-side pulsed surface dielectric barrier discharge (SDBD) are studied via electro-optical diagnostics, thermal properties, numerical simulation. Experimental results show that the SDBD can remove glaze ice compared to traditional under applied pulse voltage 8 kV a frequency 1 kHz. maximal temperature reaches 39.5 °C time 800 s, while is still below point about −7.8 °C. Surface temperatures demonstrate with gap mm possesses prospects in...

To develop high-voltage-pulsed power switches with better performances, a multi-gap laser-triggered vacuum switch is proposed in this study. Based on established test prototype for double-gap switch, closing processes of are discussed combined laser-produced plasma. Closing performances under different gap polarity configurations, operating voltages, laser energies and split ratios investigated. time delay characteristics single-gap compared later. The results prove that, affected by the...

In this paper, we are concerned with denoising in experimentally obtained electronic speckle pattern interferometry (ESPI) fringe patterns poor quality. We extend the application of two existing oriented partial differential equation (PDE) filters, including second-order single PDE filter and double filter, to ESPI very quality, compare them other efficient filtering methods, adaptive weighted improved nonlinear complex diffusion PDE, windowed Fourier transform method. All five filters have...

Grading capacitors are required to balance the voltage distribution of double-break vacuum circuit breaker. However, large grading increase magnitude and duration reignition current. To reduce capacitors, a synthetic with double breaks was set up study effects arcing time on distribution. The upper break decreases from 61% 52% times two decreasing 6.6 3.4 ms synchronously. experimental results demonstrate that reducing can during transient recovery (TRV) rising phase. unbalance TRV be...

Surface flashover triggered vacuum switch (STVS) working performance mainly depends on the electrical characteristics of trigger pulse. This article presents an experimental investigation process. The influence properties pulse is focused. Based self-developed high-performance STVS product, test platform was established. results show that a shorter delay time can be obtained by heightening voltage. However, effect voltage jitter not obvious. slight increase in current has evident time. It...

Working performances of laser-triggered vacuum switch (LTVS) mainly rely on the interactions laser with target materials. Influences from configuration, which is one key factors in interactions, are neglected so far. The trigger LTVS different configurations studied this paper. Relevant influence about discussed briefly based theoretical analysis process. test prototype established detachable chamber. characteristics structures, depths, and focal positions compared. relationships between...

This paper investigates the dynamic dielectric recovery synergy (DDRS) of hybrid circuit breakers (HCBs) with CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas and vacuum gaps in series. The interaction between arc is simulated by continuous transient model Mayr model. simulation results indicate that extra methods, for example, dividing capacitors, are needed to obtain optimal DDRS HCB. prototype HCB test established. influence...

Electronic speckle pattern interferometry fringe patterns usually have poor contrast so it is important to enhance for the extraction of phase from a single pattern. We present new enhancement methods based on differential equations (called DE methods) electronic fringes. The transform image processing solve equations. With proposed methods, visibility correlation can be improved significantly. tested computer-simulated fringes and experimentally obtained fringes, we compared method with...

The electrode configurations have an important effect on the interruption performances of laser triggered vacuum switch (LTVS), but few works pay attention to it so far. objective this article is study capacity LTVS with different configurations. 3-D simulation models axial magnetic field (AMF) and transverse (TMF) are built up, distributions calculated compared. test platform set up based a detachable chamber. structures, spacings, polarity studied analyzed. results prove that, compared AMF...

Vacuum gap saturation of single break can be solved by multiple breaks in series. In different breaking processes, the unbalanced energy and charges injected into lead to voltage distribution. The purpose this paper was compare distribution under regulation magnetic field opening process. fields with 3 ms width were applied at point before current through zero. Comparing no axial field, unbalances deceased both synchronous asynchronous processes. Under condition that arcing time high-voltage...

During the operation of high voltage (HV) motors, end-winding surface can be contaminated by oil or dust, resulting in a type intense discharge: tracking, which gradually develops into phase-to-phase phase-to-ground faults. To improve our understanding development process and characteristics tracking on end-winding, an accelerated aging test was performed 10-kV stator coils to induce under electrical contamination stresses. understand evolution partial discharge (PD) collected corresponding...

CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas is a possible substitute for SF xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> in circuit breaker with relatively superior arc interruption performance. To enhance the capacity of which employs as its dielectric, principle hybrid composed vacuum interrupter and studied. Based on black-box models built ATP-EMTP, interactions characteristics transient recovery voltage distribution...

To develop high voltage pulsed power closing switch utilizing the advantages of vacuum gap, a laser triggered multi-stage (LTMVS) is proposed in this paper. Trigger processes triple-gap LTMVS are analyzed based on detachable chamber. Closing and time-delay characteristics different sections studied later. The results convey that, trigger process can be separated to two periods, gap cascade breakdown series connected gaps. Breakdown sequences gaps unstable, its delay time mainly depends...

A coplanar-volume coupled discharge utilizing a capillary coplanar dielectric barrier (CDBD) as pre-ionization source and employing negative direct current (DC) voltage to prompt plasma propagation from the surface air gap is proposed experimentally investigated. Optical-electrical properties, spatial-temporal evolution of plasma, active species generation are systematically studied provide in-depth insights into characteristics based on pre-ionization. Compared traditional discharge, this...

Laser triggered vacuum switch (LTVS) is one of the pulsed power switches with superior working performances compared to other switches. Previous works about LTVS illustrated that time-delay characteristics and life are affected by its target apparently. However, except for influences from various physicochemical properties materials, there also configurations. And effects configurations on delay time mainly involve structures. To study different structures LTVS, electric field distribution...

Based on the working principle of laser triggered multi-stage gas switch and previous work multi-break vacuum switch, a (LTMVS) composed gap self-breakdown gaps is proposed in this paper. LTMVS shows highly developing potential to be substitute for switches pulse power facilities. And simplified prototype established with detachable chamber short gap. theoretical analysis about tested closing process test prototype, can equally divided into two periods, trigger gap; thus, delay time contains...