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The implementation of a novel bidirectional medium voltage AC-DC converter based on 10kV SiC MOSFET is presented in this paper. The improved topology allows the removal of the reverse blocking silicon diode in medium voltage SiC MOSFET module. Shoot-through problems and avalanche of the integrated silicon diode in traditional medium voltage bridge-type AC-DC converters are solved, allowing zero dead-time...
With the sinusoidal charging scheme, the large dc link capacitance of the on-board battery charger can be reduced significantly. However, the variable charging current together with the wide battery voltage range imposes serious challenge to maintain high efficiency throughout the whole charging procedure. This paper proposes a LLC dc-dc transformer (DCX) battery charger solution to improve the efficiency...
Thanks to their comparatively low system complexity, SSTs based on an isolated front end (IFE) approach are suitable for space and weight-constrained medium voltage (MV) AC to low voltage (LV) DC power supply applications, e.g., in future traction, naval, subsea or aerospace systems. The IFE approach connects series resonant isolation stages operating in the half-cycle discontinuous-conduction-mode...
A flexible neural network adaptive controller based on particle swarm optimization algorithm is proposed for the trajectory tracking control of manipulator robots with model errors and uncertain disturbances. The flexible neural network with adjustable nonlinear degree by parameter variation is used as controller. The particle swarm algorithm is used to optimize the initial weights and thresholds...
Endovascular surgery is becoming a widespread procedure to treat cardiovascular diseases (CVDs) such as abdominal aortic aneurysm and peripheral artery disease. The guide-wire is a crucial surgical instrument inserted into vessels to offer guidance to physicians during the surgery. There are some approaches for tracking the guide-wire, most algorithms consist of two phases, namely, the initialization...
This paper firstly discusses about the impacts of voltage sags on electricity users. Combined with economic survey methods of power quality in domestic and foreign countries and the actual situation of electricity users suffered of voltage sags, a calculation method of the losses due to voltage sags by questionnaires and face-to-face interviews is described. Then, cost-benefit analysis of voltage...
Voltage sag and short interruption are increasingly hot spots of power quality concerns. This paper presents the application of more than a thousand voltage-sag protection equipment by Golden Cooperate in China, over ten years in petrochemical, coal chemical, chemical fiber and semiconductor industries and in power plants. With the original data from on-site equipment, main causes of voltage sags...
This article researches on node importance ranking of multiplex network. Existing node importance ranking methods are amost monoplex network using only single relationship. However, in real life a person often has various relationships, so how to rank nodes of multiplex network is more realistic and meaningful. In this article, we propose a multiplex network node ranking method based on weighted aggregation...
Voltage sags are inevitable phenomenon in power system operation. Firstly impacts of voltage sags on sensitive loads in thermal power plants, petrochemical and coal chemical industry, chemical fiber industry and semiconductor industry are discussed. Then, treatment measures of voltage sag are discussed from power supply side and user side, including reducing the occurrence of line faults, reducing...
The electrical shock fault signal is very important to the protection and control of power system. However, in practical cases, the signal is usually corrupted by artifacts through the recording process. Thus, denoising of this type of electric shock fault signals seems necessary. In this paper, a novel method for denoising electriccal shock fault signals is proposed based on Empirical mode Decomposition-Thresholding...
The aperture integral equation (AIE) and method of moment (MoM) technique is proposed for analyzing the electromagnetic scattering properties of a finite perfectly conducting cone loaded with a slot. The solution allows us to deal accurately with slots of any shape. Two kinds of slots representing for electrical large and electrical small structure respectively, are considered in this paper. Bi-static...
The tensor type data acquired by the triaxial induction tool enables the determination of not only resistivity, but also resistivity anisotropy of reservoir. The most popular anisotropic model for triaxial data interpretation is a horizontally layered formation with transversely isotropic (TI) resistivity anisotropy in each bed. When there is invasion developed in a permeable reservoir, the invasion...
An essential objective of collecting measurements in the oil and gas industry is to detect, locate and quantify the amount of oil and gas in the Earth subsurface. Electromagnetic measurements either at DC, induction, propagation, and dielectric frequencies play a central role because electromagnetic properties of hydrocarbon and water are very different. These electromagnetic measurements can be collected...
Electromagnetic Gradient Surface (EGS) has attracted considerable attention due to its unusual physical characteristics, showing great potential in radar cross section (RCS) reduction. In this paper, we provide a new approach to reduce radar cross section at boresight and present a design example of a novel hybrid electromagnetic gradient metasurface, which appears as a single sandwiched structure...
The extraordinary transmission has been a much-discussed topic in recent years. It can be realized from optical frequency to microwave range based on several kind of mechanism. The article presents the analysis of the extraordinary transmission of EM (electromagnetic) wave through periodic subwavelength apertures smaller than classical diffraction limit by using connected ring resonators (CRRs). At...
We proposed an ultra-thin absorber, which consists of a two dimensional metallic Jerusalem cross array and a metallic ground plane separated by a dielectric layer, with its thickness is about λ/44 at the lowest resonant frequency. The simulated results indicate that this structure can perform absorbing peaks at dual resonant frequencies 3.25 GHz and 6.77 GHz with the absorption of 99% and 96%, respectively...
In the cooperative spectrum sensing, if too many nodes take part in the cooperative data fusion, it would weigh the channel overhead and energy loss lot but improve the spectrum sensing performance little. This paper focuses on the channel overhead of cooperative spectrum sensing and the lifecycle of cognitive networks, and proposes a novel cooperative spectrum sensing algorithm. In the algorithm,...
Flash Translation Layer (FTL) is a key technology in a Solid–State Disk (SSD) system to manage the data transfer. Different mapping granularity in FTL will cause a change in the read/write performance and the size of mapping table. For the scenario that big capacity storage needs to hold high performance, on the basis of former mapping algorithms, this paper design a mapping method based on grouping...
We constructed a new secure searchable encryption scheme aided by a computationally powerful but untrusted cloud server. Our scheme allows a client to provide a single search token to the server, but still allows the server to search for that token's word over all the documents he can access that encrypted with different keys. We achieved the scheme using multikey fully homomorphic encryption (MFHE)...
Cooperative jamming is a promising technology for improving information secrecy at the physical layer. The increase of secrecy capacity heavily depends on the participation of the jammer and its geographical locations. However, the jammer's geographical location might not be known to others such as the source node due to privacy, and the asymmetric information will lead to inefficiency in jamming...
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