Design of High Efficiency Wireless Power Thansfer System With Nonlinear Resonator

Wireless power transfer technology (WPT) has been rapidly developed in recent years. The primary benefit of WPT is that it replaces the traditional wire charging with a cordless charging method. WPT technology has been applied in many fields, such as bio-implants, electric vehicles, and wirelessly charging systems. According to the different energy transmission mechanism, WPT technology can be divided into magnetic field coupling (includes magnetically coupled inductive and magnetically-coupled resonant), microwave radiation, laser emission, electrical-field coupling, and ultrasonic transmission type. Among these technologies, the magnetic resonance coupling method has a better promise because of its long transfer distance and high efficiency. However, there are some questions that need to be resolved, among which the most prominent is that the technology has a low tolerance to the variations of the coupling factor because of the frequency splitting phenomenon, which would lead to transmission efficiency degradation of magnetic resonance coupling WPT systems. Hence, based on reviewing the research status and trend of WPT technology, this paper analyses the frequency splitting phenomenon of the wireless power transfer system, discusses the duffing resonator circuit and its properties, and designs a kind of high-efficiency wireless power transfer inductive system with both non-linear inductors and non-linear capacitors. The main research works of this paper are as follows: Firstly, aiming at the frequency splitting problem during magnetic coupled resonance wireless power transmission, the frequency splitting phenomenon for the wireless power transfer system is studied by an electric circuit model method. The expression of the relationship between the load voltage, transmission efficiency, and coupling factor was derived, and the law of frequency splitting is discussed. Furtherly, an analysis of frequency splitting based on simulation also presented. Finally, the frequency splitting suppression method is proposed. The above research work provides a theoretical basis for solving the problem of frequency splitting and designing a kind of high-efficiency WPT system. Subsequently, a duffing resonator circuit with a nonlinear capacitor, which can eliminate the frequency splitting and keep the high transmission efficiency and power delivered to the load is developed. With the help MATLAB software, the properties of the duffing resonance circuit are discussed furtherly. The results show that the duffing resonance circuit has significantly wider bandwidth than the conventional linear resonance circuit while achieving a similar amplitude level. Finally, the high efficiency non-linear wireless power transfer system based on non-linear inductors with ferromagnetic thin film core and non-linear capacitors with ferroelectric thin film dielectrics is designed. Moreover, the system\u27s performance is improved, the range of coupling factors significantly extended while both load power and high PTE were maintained. The reason for the high efficiency of the system is furtherly discussed, and the research result shows that non-linear inductor with ferromagnetic thin film core has variable inductance which can be synchronously changed along with the current through the inductor in the circuit. The non-linear capacitor with ferroelectric thin film dielectrics can also have variable capacitance, which can be synchronously changed along with the voltage applied to the capacitor. However, the voltage across the capacitor and current through the inductors are different initially, high power transmission efficiency can be achieved by self-tuning capability of inductance and capacitance from the film based non-linear resonators. Research results of this paper can lay the solid foundations for the application of WPT technology in the fields of bio-implants, electric vehicles, wirelessly charging systems, etc

Supporting Transportation System Management and Operations Using Internet of Things Technology

Low power wide-area network (LPWAN) technology aims to provide long range and low power wireless communication. It can serve as an alternative technology for data transmissions in many application scenarios (e.g., parking monitoring and remote flood sensing). In order to explore its feasibility in transportation systems, this project conducted a review of relevant literature to understand the current status of LPWAN applications. An online survey that targeted professionals concerned with transportation was also developed to elicit input about their experiences in using LPWAN technology for their projects. The literature review and survey results showed that LPWAN’s application in the U.S. is still in an early stage. Many agencies were not familiar with LPWAN technology, and only a few off-the-shelf LPWAN products are currently available that may be directly used for transportation systems. To conceptually explore data transmission, a set of lab tests, using a primary LPWAN technology, namely LoRa, were performed on a university campus area as well as in a rural area. The lab tests showed that several key factors, such as the mounting heights of devices, distance between the gateway and sensor nodes, and brands of devices affected the LPWAN’s performance. Building upon these efforts, the research team proposed a high-level field test plan for facilitating a potential Phase 2 study that will address primary technical issues concerning the feasibility of transmitting data of different sizes, data transmission frequency, and transmission rate, deployment requirements, etc

Development of Wireless Techniques in Data and Power Transmission - Application for Particle Physics Detectors

Wireless techniques have developed extremely fast over the last decade and using them for data and power transmission in particle physics detectors is not science- fiction any more. During the last years several research groups have independently thought of making it a reality. Wireless techniques became a mature field for research and new developments might have impact on future particle physics experiments. The Instrumentation Frontier was set up as a part of the SnowMass 2013 Community Summer Study [1] to examine the instrumentation R&D for the particle physics research over the coming decades: {\guillemotleft} To succeed we need to make technical and scientific innovation a priority in the field {\guillemotright}. Wireless data transmission was identified as one of the innovations that could revolutionize the transmission of data out of the detector. Power delivery was another challenge mentioned in the same report. We propose a collaboration to identify the specific needs of different projects that might benefit from wireless techniques. The objective is to provide a common platform for research and development in order to optimize effectiveness and cost, with the aim of designing and testing wireless demonstrators for large instrumentation systems

A novel multipath-transmission supported software defined wireless network architecture

The inflexible management and operation of today\u27s wireless access networks cannot meet the increasingly growing specific requirements, such as high mobility and throughput, service differentiation, and high-level programmability. In this paper, we put forward a novel multipath-transmission supported software-defined wireless network architecture (MP-SDWN), with the aim of achieving seamless handover, throughput enhancement, and flow-level wireless transmission control as well as programmable interfaces. In particular, this research addresses the following issues: 1) for high mobility and throughput, multi-connection virtual access point is proposed to enable multiple transmission paths simultaneously over a set of access points for users and 2) wireless flow transmission rules and programmable interfaces are implemented into mac80211 subsystem to enable service differentiation and flow-level wireless transmission control. Moreover, the efficiency and flexibility of MP-SDWN are demonstrated in the performance evaluations conducted on a 802.11 based-testbed, and the experimental results show that compared to regular WiFi, our proposed MP-SDWN architecture achieves seamless handover and multifold throughput improvement, and supports flow-level wireless transmission control for different applications