Bidirectional Wireless Research Articles

Li-Fi concept in terms of modulation techniques

Li-Fi (light fidelity) is a bidirectional wireless system that transmits data via LED or infrared light. Li-Fi technology only needs a light source with a chip to transmit an internet signal through light waves. The system has a receiver to pick up light signals and transmitter to send light signals back to the lamp using infrared light. The technology has high data rate as well as high spectral efficiency and also robust against inter symbol interference. Different forms of OFDM (a multicarrier modulation technique) are being used for Li-fi scheme. This paper reflects the theoretical study of various modulation techniques of Li-fi technology.

An Assessment of Shortest Prioritized Path-Based Bidirectional Wireless Charging Approach Toward Smart Agriculture

An Assessment of Shortest Prioritized Path-Based Bidirectional Wireless Charging Approach Toward Smart Agriculture

A multi-shift phase angle control strategy for bidirectional wireless power transmission system

Using the charging and discharging capability of battery-based loads and a two-way wireless energy transmission system, grid-load balancing can be achieved in both directions. The system can be applied to many locations by deploying power flow in real time. In the scenario of vehicle network interconnection, it realizes peak-shaving and valley-filling to optimize grid dispatching capability; in the scenario of modular satellite interconnection, it realizes load balancing and effectively improves energy utilization. Therefore, a suitable control strategy is needed to precisely change the output power flow and the output power magnitude. A method to coordinate multiple phase shifting angles in the system hierarchy to achieve power flow regulation is proposed for a bidirectional wireless power transmission system with a dual full-bridge topology. In this paper, we first model the bidirectional transmission system and analyze the relationship between each phase shift angle and active and reactive power. The traditional control strategy is optimized by reducing the number of control loop variables and using the system power factor angle instead of the difficult-to-control external phase shift angle, while ensuring the voltage gain for optimal system efficiency. Finally, only two control loops are used to control the direction and magnitude of the output power respectively, and the effectiveness and correctness of the control strategy are verified by using the corresponding simulation experiments to achieve smooth switching of the bidirectional electric power transmission power flow.

A Review of Compensation Topologies and Control Techniques of Bidirectional Wireless Power Transfer Systems for Electric Vehicle Applications

Owing to the constantly rising energy demand, Internal Combustion Engine (ICE)-equipped vehicles are being replaced by Electric Vehicles (EVs). The other advantage of using EVs is that the batteries can be utilised as an energy storage device to increase the penetration of renewable energy sources. Integrating EVs with the grid is one of the recent advancements in EVs using Vehicle-to-Grid (V2G) technology. A bidirectional technique enables power transfer between the grid and the EV batteries. Moreover, the Bidirectional Wireless Power Transfer (BWPT) method can support consumers in automating the power transfer process without human intervention. However, an effective BWPT requires a proper vehicle and grid coordination with reasonable control and compensation networks. Various compensation techniques have been proposed in the literature, both on the transmitter and receiver sides. Selecting suitable compensation techniques is a critical task affecting the various design parameters. In this study, the basic compensation topologies of the Series–Series (SS), Series–Parallel (SP), Parallel–Parallel (PP), Parallel–Series (SP), and hybrid compensation topology design requirements are investigated. In addition, the typical control techniques for bidirectional converters, such as Proportional–Integral–Derivative (PID), sliding mode, fuzzy logic control, model predictive, and digital control, are discussed. In addition, different switching modulation schemes, including Pulse-Width Modulation (PWM) control, PWM + Phase Shift control, Single-Phase Shift, Dual-Phase Shift, and Triple-Phase Shift methods, are discussed. The characteristics and control strategies of each are presented, concerning the typical applications. Based on the review analysis, the low-power (Level 1/Level 2) charging applications demand a simple SS compensation topology with a PID controller and a Single-Phase Shift switching method. However, for the medium- or high-power applications (Level 3/Level 4), the dual-side LCC compensation with an advanced controller and a Dual-Side Phase-Shift switching pattern is recommended.

Switchable function GaN power amplifier/rectifier

This letter proposes a switchable function power amplifier/rectifier using a GaN transistor. A dc single-pole double-throw switch is used to switch between the working mode of the circuit from power amplifier (PA) to rectifier and vice-versa, which greatly reduces the complexity of the circuit. A feedback network with an impedance close to infinity and the input port of the PA always terminated to 50 Ω are utilized to achieve consistent impedance conditions in both PA mode and rectifier mode. Class-F−1 operation is employed to design the PA/rectifier module. For validation, a PA/rectifier operating at 2.4 GHz is designed and fabricated using a CGH40010F GaN transistor. Measurements show that the implemented module can realize efficiency of over 70% regardless of operating in PA mode or in rectifier mode. Meanwhile, the application of the GaN transistor greatly increases the power capacity of the RF-DC rectifier mode, which is promising in bi-directional wireless high-power application scenarios such as enhanced drone airborne capability. To the best of the authors knowledge, this is the first realization of a switchable PA/rectifier module based on a GaN transistor.

Bit Error Rate Analysis of Physical Layer Network Coding Spatially Modulated Full-Duplex Nodes Based Bidirectional Wireless Relay Network

In this paper, Physical Layer Network coding (PLNC)-Spatially Modulated Full-Duplex (SMFD) nodes based two-way/bidirectional cooperative wireless relay network is proposed. The PLNC-SMFD-based system is a viable technology in the field of next-generation wireless networks to enhance spectral efficiency. In the proposed system model, both the source nodes and relay nodes are employed with 2 × 2 antenna configurations where 2 bits of information are exchanged between the source nodes through a relay node. Transmit antenna selection at the source nodes is based on the incoming bitstreams. For instance, the transmit antenna is selected at PLNC-SMFD nodes based on the data symbols of the Most Significant Bit (MSB). Whereas the selected transmit antenna sends the Least Significant Bit (LSB) bit of data symbol at any time instance. Further, the self-interference at the transmitting and receiving nodes is modeled as Gaussian with the thermal noise power as a variance. The Bit Error Rate (BER) analytical expressions for both the upper and lower bound are derived in a Rayleigh Fading channel background. It has been graphically shown that the BER performance of the proposed system analyzes the effect of self-interference.

Neural probe system for behavioral neuropharmacology by bi-directional wireless drug delivery and electrophysiology in socially interacting mice

Assessing the neurological and behavioral effects of drugs is important in developing pharmacological treatments, as well as understanding the mechanisms associated with neurological disorders. Herein, we present a miniaturized, wireless neural probe system with the capability of delivering drugs for the real-time investigation of the effects of the drugs on both behavioral and neural activities in socially interacting mice. We demonstrate wireless drug delivery and simultaneous monitoring of the resulting neural, behavioral changes, as well as the dose-dependent and repeatable responses to drugs. Furthermore, in pairs of mice, we use a food competition assay in which social interaction was modulated by the delivery of the drug, and the resulting changes in their neural activities are analyzed. During modulated food competition by drug injection, we observe changes in neural activity in mPFC region of a participating mouse over time. Our system may provide new opportunities for the development of studying the effects of drugs on behaviour and neural activity.

Review on Power Flow Evaluation of Grid Connected Bidirectional Wireless Power Transfer for EV System

Wireless Power Transfer (WPT) for Electric Vehicle (EV) battery charging application is one of the key upcoming technologies. The possibility of using EVs to transfer power back to the grid, utilizing the concept of Bidirectional Wireless Power Transfer (BD-WPT) is extensively being explored. The effect of integration of EV on grid is also of concern. This paper presents analysis of complete grid integrated BD-WPT system for controlling power transfer between grid and EV battery, along-with ensuring Unity Power Factor (UPF) at grid side. Mathematical model of each component in the system is presented which is then used to design vehicle and grid side controllers for achieving desired output. Concepts stated analytically are validated by simulation in MATLAB (Simulink).

Front cover: Bidirectional wireless power/data transfer via magnetic field

The Journal of EngineeringVolume 2022, Issue 7 p. i-i FRONT COVEROpen Access Front cover: Bidirectional wireless power/data transfer via magnetic field First published: 02 July 2022 https://doi.org/10.1049/tje2.12165AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract The cover image is based on the Research Article Bidirectional wireless power/data transfer via magnetic field by Jia-Jing Kao et al., https://doi.org/10.1049/tje2.12150 Volume2022, Issue7July 2022Pages i-i RelatedInformation

An Optimization Method of Dual-Side LCC Compensation Networks Simultaneously Considering Output Power and Transmission Efficiency in Two Directions for BWPT Systems

This article presents an optimization method of dual-side <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> compensation networks for bidirectional wireless power transfer systems, which aims to simultaneously realize the rated forward and reverse output power directly through compensation network designing. In addition, due to that the optimization results of compensation networks are close to the values that meet the condition of the maximum transmission efficiency, good system efficiency in the two directions can be simultaneously obtained under the rated condition. Firstly, an equivalent circuit of bidirectional power converter (BPC) working in rectification mode is established, which includes the parasitic and external parallel capacitance of metal oxide semiconductor (MOS) devices. Also, its equivalent impedance is calculated. Then, considering the reactance part of the BPC equivalent impedance, the optimization method of the dual-side <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> compensation networks is analyzed. Finally, a 3.3 kW BWPT prototype is developed to verify the proposed method. The simulation and experiment results showed that the effect of the parasitic and parallel capacitance of MOS devices, on the reactance part of BPC equivalent impedance is more obvious; the proposed optimization method can simultaneously realize the rated forward and reverse output power, and both forward and reverse transmission efficiency are greater than 94% under the rated condition.

Bidirectional wireless power/data transfer via magnetic field

Recently, inductive power transfer (IPT) system has been used for wireless charging of electric vehicles (EVs). However, most of them only treat the issue of single directional wireless power transfer (WPT). This research proposes a novel bi-directional IPT (BD-IPT) scheme EVs, which can simultaneously transmit power/data via magnetic field when the mutual inductance changes. For power transmission, resonant inverters with phase-shift pulse width modulation (PSPWM) are used to generate carrier waves and alternating current. As for data transmission, a dedicated communication method with the accompanied protocol is proposed. Binary phase shift keying (BPSK) is used to simulate the two-quadrature amplitude modulation (QAM), which generates digital signals for data transmission without the need of extra communication links. Hamming codes are combined with single-error correction and double-error detection (SECDED) to ensure communication quality.

Drone Operated Bidirectional Wireless Charging System for Energy Constrained Devices in Smart Farming Applications

The new age of technology has revolutionized the way the agriculture sector functions. Smart machines are gradually captivating primitive farming techniques and aid in increasing the quality and yield of crops. The implementation of Energy Constrained Devices (ECDs) into the agricultural sector has grabbed the curiosity of many researchers and has opened up opportunities for autonomous monitoring of soil-crop’s health. This research benefits the agricultural sector in providing top quality yield at minimal human resources and uses smart machinery, such as drones to monitor the progress on the field. This study aids in implementing the use of ECDs for collecting field data, such as moisture content, temperature, mineral requirements, etc. at a given area. The key challenge in this research is to identify the ECDs that needs to be charged and to find the shortest path between the home position and the ECDs for the drone to fly and charge the required ECDs. The proposed algorithm modifies the Dijkstra’s algorithm and prioritizes the ECDs in the order to be charged and plan a path accordingly.

Optimal pricing for bidirectional wireless charging lanes in coupled transportation and power networks

As electric vehicles (EVs) become more prevalent, there is growing concern regarding their impact on transportation and power networks. Using vehicle-to-grid (V2G) technology, EVs can operate as additional energy storage sources that make the power grid more efficient and reliable. With their onboard battery, EVs can relocate energy supply spatially and temporally. In this study, we envision that the future deployment of bidirectional charging lanes is capable of transferring power wirelessly and bidirectionally in regional road networks. Additionally, in this study, these futuristic bidirectional charging lanes are controlled by a government agency that manages both transportation and power systems. The government agency attempts to minimize total system costs by using an electricity pricing scheme to buy energy from and sell energy to EVs, which can be modeled as a bi-level optimization problem. In this study, we developed a new user equilibrium (UE) model to depict the equilibrium conditions in a road network in which bidirectional charging lanes are deployed. When traveling between their origin and destination, EV drivers are assumed to select routes and decide on battery charging/discharging plans to minimize their trip costs while ensuring the completion of their trips without running out of range. Trip costs consist of trip travel time and the purchase price of electricity minus the benefits of discharging energy to the power grid. Having established UE conditions, we next formulated the equilibrium conditions of a transportation network coupled with an electricity network as a non-linear complementarity system, which formed our lower-level problem. In such a network, the agency tries to provide energy to both networks with the objective of minimizing total system costs. To formulate the agency’s decision-making process, an additional layer of optimization is added on top of the coupled networks, which is our upper-level problem. This layer minimizes the total travel time and the price of electricity paid to EVs and generators. Next, to efficiently solve the model, a meta-heuristic solution algorithm based on gray wolf optimizer and manifold sub-optimization was developed. The model and the solution algorithm were evaluated based on three different numerical examples. Numerical results demonstrate that bidirectional charging lanes have significant potential to reduce peak load and charging costs associated with EVs.

A New Bidirectional Wireless Power Transfer Topology

There is a growing demand in the marketplace for wirelessly powered consumer applications. Some of these low-power applications require wireless power transfer with bi-directional power flow. For such consumer applications, this paper proposes a new bi-directional wireless power transfer (BD-WPT) topology that facilitates wireless power transfers in both directions using fewer components. The paper describes the operating principles of the topology in detail and presents a mathematical model to predict and investigate its performance. Besides, the the control method is proposed for this topology including the power transfer control and synchronization. Simulations and theoretical results are presented in comparison to the measured results of a 60W prototype BD-WPT to demonstrate the viability of the proposed converter topology. Results are convincing and indicate that the proposed converter is suitable for low power applications being low cost, reliable, and efficient.

A fully implantable wireless bidirectional neuromodulation system for mice

Novel research in the field of bioelectronic medicine requires neuromodulation systems that pair high-performance neurostimulation and bio-signal acquisition hardware with advanced signal processing and control algorithms. Although mice are the most commonly used animal in medical research, the size, weight, and power requirements of such bioelectronic systems either preclude use in mice or impose significant constraints on experimental design. Here, a fully-implantable recording and stimulation neuromodulation system suitable for use in mice is presented, measuring 2.2 cm3 and weighing 2.8 g. The bidirectional wireless interface allows simultaneous readout of multiple physiological signals and complete control over stimulation parameters, and a wirelessly rechargeable battery provides a lifetime of up to 5 days on a single charge. The device was implanted to deliver vagus nerve stimulation (n = 12 animals) and a functional neural interface (capable of inducing acute bradycardia) was demonstrated with lifetimes exceeding three weeks. The design utilizes only commercially-available electrical components and 3D-printed packaging, with the goal of facilitating widespread adoption and accelerating discovery and translation of future bioelectronic therapeutics.

Bidirectional LCC–LCC-Compensated 20-kW Wireless Power Transfer System for Medium-Duty Vehicle Charging

This article presents the design and demonstration of a bidirectional 20-kW wireless charging system (WCS) with a significantly large air gap (11 in) and asymmetrical input-output voltage levels. Analytical and experimental sensitivity analyses of the WCS resonant tank were conducted to verify the optimal operating region under the load and frequency variation. The inverter and rectifier were designed with switching components, the charging pads were designed with double-D (DD) coils, and the tuning networks were designed with an LCC - LCC tuning circuit. The grid and vehicle side tuning circuits were designed separately to achieve a ~1:2 gain for the asymmetrical input (800 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> ) and output (350 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> ) voltages. The proposed WCS was designed, simulated, and tested to verify the efficiency, power transfer capacity, and sensitivity under load variation. The experimental results show that, at 20-kW output power, the achieved grid-to-vehicle dc - dc efficiency was 96.1%, and the vehicle-to-grid dc - dc efficiency was 96.2%. The proposed system is the largest-air gap bidirectional WCS with the highest efficiency and power density.

Review on Control Techniques for EV Bidirectional Wireless Chargers

Due to their flexibility, Electric Vehicles (EVs) constitute an important asset for the integration of renewable energy sources in the Smart Grid. In particular, they should have a dual role: as a controllable load and as a mobile generator with a low inertia. To perform these tasks, chargers must provide the electronics with a power flow from the grid to the vehicle and vice versa. This bidirectionality can also be implemented in wireless chargers. The power converters, the compensation networks and the coil misalignment must be considered when designing the control of these systems. This paper presents a review about the proposed algorithms to control the active and the reactive power flow in a bidirectional wireless charger.

Design of a Bidirectional Wireless Power Transfer System for Vehicle-to-Home Applications

Energy storage plays a fundamental role in balancing the power fluctuations induced by the distributed generation of renewable energy sources. In this scenario, electric vehicles can strongly contribute to exchange power with the grid through their on-board batteries. When the vehicle is parked, the battery can be discharged, injecting active power into the grid, provided that its state of charge will be restored before vehicle utilization. This paper presents a comprehensive step-by-step design of a wireless charger for a Vehicle-to-Home application. The design procedure begins from the constraints disposed by the Italian reference technical rules for Low Voltage utilities and by the standard SAE J2954 for Wireless Power Transfer for electric vehicles. The selection of the output power of the battery is followed by the power sizing of each stage of the bidirectional wireless charger.

Structure and Circuit Solution of a Bidirectional Wireless Power Transmission System in Applied Robotics

Structure and Circuit Solution of a Bidirectional Wireless Power Transmission System in Applied Robotics

Eigenvalue Based Relay Selection for XOR-Physical Layer Network Coding in Bi-Directional Wireless Relaying Networks

Eigenvalue Based Relay Selection for XOR-Physical Layer Network Coding in Bi-Directional Wireless Relaying Networks