Radio frequency (RF) energy transfer and harvesting techniques have recently become alternative methods to power the next-generation wireless networks As this emerging technology enables proactive energy replenishment of wireless devices, it is advantageous in supporting applications with quality-of-service requirements In this paper, we present a comprehensive literature review on the research progresses in wireless networks with RF energy harvesting capability, which is referred to as RF energy harvesting networks (RF-EHNs) First, we present an overview of the RF-EHNs including system architecture, RF energy harvesting techniques, and existing applications Then, we present the background in circuit design as well as the state-of-the-art circuitry implementations and review the communication protocols specially designed for RF-EHNs We also explore various key design issues in the development of RF-EHNs according to the network types, ie, single-hop networks, multiantenna networks, relay networks, and cognitive radio networks Finally, we envision some open research directions

Wireless Networks With RF Energy Harvesting: A Contemporary Survey

Emerging technologies for marine current turbines are mainly related to works that have been carried out on wind turbines and ship propellers. It is then obvious that many electric generator topologies could be used for marine current turbines. As in the wind turbine context, doubly-fed induction generators and permanent magnet generators seem to be attractive solutions for harnessing the tidal current energy. In this paper, a comparative study between these two generator types is presented and fully analyzed in terms of generated power, maintenance, and operation constraints. This comparison is done for the Raz de Sein site (Brittany, France) using a multiphysics modeling simulation tool. This tool integrates, in a modular environment, the resource model, the turbine hydrodynamic model, and generator models. Experiments have also been carried out to confirm the simulation results.

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Generator Systems for Marine Current Turbine Applications: A Comparative Study

In recent years a lot of research work was dedicated to energy efficiency in cellular networks. An emerging field of interest in that direction is the use of renewable energy sources such as wind and solar - a type of energy that is bound to increase and develop. In this paper we survey the existing works and present the fundamental principles and motivations necessary for a thorough understanding of the usage of renewable energy in cellular networks. Furthermore, we introduce a reference model for renewable energy base station (REBS) and provide analysis of its components. The synthesis of dedicated REBS algorithms, system architectures, deployment strategies and evaluation metrics provides comprehensive overview and helps identify the perspectives in this promising research field.

Renewable energy in cellular networks: A survey

Powering cellular base stations with renewable energy are one of the long-term strategies for achieving green networks and reducing their operational costs. As an energy provider, the power grid is evolving into a smarter one, which allows more energy-efficient cellular networks and enables cooperation and interaction with the smart grid. On one hand, cellular networks can use harvested renewable energy and on-site energy storage to reduce their energy costs. On the other hand, the price of electricity depends on the energy load, which will eventually contribute to decreasing the peak consumption and global energy cost. In this paper, we propose new integration architecture for renewable energy-powered cellular networks and the smart grid. The proposed architecture is designed based on the classification and the analysis of the existing proposals and the requirements of the smart grid, renewable energy systems, and cellular networks.

Integrating Cellular Networks, Smart Grid, and Renewable Energy: Analysis, Architecture, and Challenges

In this paper, the contemporary development in multiple input dc-dc converters are identified and examined. The quest to mitigate the difficulties associated with employing renewables in distribution systems and electric vehicles (EVs) has yielded many new converter topologies. These new topologies have easier control, lower parts count, are cheaper and are worthy alternatives to the typical series or parallel connection of converters. The converters are identified by three divisions that bother on the isolation between the respective ports. The electrically connected converters do not have isolation between the ports, and thus, a dc link connects the ports. Electromagnetically connected converters use a dc-link to connect input ports, but the input ports and output port are isolated. In magnetically connected converters, input ports are separated by multiple winding transformer, just as the output port is isolated from the input ports by the winding. The formation, structure, characteristics, operation, merits and demerits of the converters will be presented. Thereafter, comparisons will be done based on the distinct features of the converters. This review identifies that converter properties depend on the specific application requirement and thus, no converter fulfills all demands in the industry. Prospective future research trends are suggested. This work aims to update on research done during the time gap since the last comprehensive reviews.

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A review of multiple input DC-DC converter topologies linked with hybrid electric vehicles and renewable energy systems

In this paper, design procedure and characteristics of an RF energy harvesting circuit based on single-stage voltage multiplier rectifier have been discussed and analyzed. This circuit is capable to recycle RF energy at 2.45 GHz, and by connecting to a 2.45 GHz antenna, it is possible to form a complete rectenna device. The values of output dc voltage and power according to the received RF power have been measured and the best value of load resistance to harvest maximum output dc power has been selected by simulation.

Design of a low power 2.45 GHz RF energy harvesting circuit for rectenna

This These Mobile operators of Bangladesh are experiencing a fast growth of consumer market which has made it one of the highest growing areas of business Power failure is a serious problem which the mobile operators are facing frequently and Diesel Generators (DG) are the common mean to tackle this problem But constant increase of fuel price is a big concern for optimum operation of telecom Base Transceiver Stations (BTS) Therefore mobile operators are finding this system very cost ineffective and difficult to rely upon Environmental issue is another major concern as burning diesel fuel increases emission of Carbon-Di-Oxide (CO2) and other harmful Greenhouse Gas (GHG) Renewable energy ie solar energy based solutions has the capability to overcome these aforesaid complications in context of Bangladesh This paper gives emphasis on grid connected BTS sites powered by Solar PV (SPV) arrays along with DG's The simulation of feasibility study and optimization analysis of proposed model has been performed using HOMER software From the results of the simulation it is evident that SPV-Battery based systems are really cost-effective although requires a huge initial investment and at the same time they are much more environment friendly than the existing system

Feasibility study of solar PV arrays in grid connected cellular BTS sites

In conventional photovoltaic (PV)-battery systems, a centralized battery storage system (BSS) is typically connected through a separate bidirectional converter at the common dc link to support the PV system. It is known that a bidirectional converter typically requires more switches than a unidirectional converter, and hence, a complete PV-battery power interface will result in a high-cost system and will suffer high power losses. This paper proposed an integrated battery storage interface with soft-switching capability for module-integrated PV systems. In the proposed system, a multi-input converter (MIC) structure that consists of an integrated soft-switched quasi-resonant (QR) Cuk- and flyback-based circuit is presented. In this approach, the battery charging circuit is integrated with the input side of the PV power optimizer while the battery discharging circuit of the proposed system shares the output filter of the PV power optimizer, resulting in a compact and efficient system. The proposed converter is capable of tracking the maximum power point (MPP) and following the charging profile (constant voltage and constant current) of the battery. Moreover, all the switches in the proposed converter are able to achieve soft-switched turn on and turn off for different operating conditions. The operating principles and the theoretical analysis of the proposed system are presented. Experimental results on a 175-W proof-of-concept prototype are presented to demonstrate the features of the proposed converter.

A Soft-Switched Power Module With Integrated Battery Interface for Photovoltaic-Battery Power Architecture

The energy consumption of the information technology (IT) data centers and servers have been increasing rapidly for the past decade. In order to reduce global warming and conserve depleting sources of fossil fuel, hybrid wind-solar energy systems can be an attractive alternative energy source to supply clean and sustainable energy for powering the IT data centers and servers. To minimize the cost and power losses in individual power converter of the conventional hybrid renewable energy system, multi-input converters (MICs) are an attractive solution. This paper proposed a new quasi-resonant soft-switched MIC with integrated power factor correction (PFC) for hybrid wind-solar energy systems. The proposed MIC topology requires only one switch in each input module and all the switches are able to achieve zero voltage switching (ZVS) turn-on and zero current switching (ZCS) turn-off for individual and simultaneous operation for different operating conditions. The operating principles of the proposed circuit are provided. Results are given on a hybrid wind-solar energy system with 48V-output to highlight the performance of the proposed circuit.

A novel multi-input converter using soft-switched single-switch input modules with integrated power factor correction capability for hybrid renewable energy systems

This paper introduces the design and development of a novel axial-flux permanent magnet generator (PMG) using a printed circuit board (PCB) stator winding. This design has the mechanical rigidity, high efficiency and zero cogging torque required for a low speed water current turbine. The PCB stator has simplified the design and construction and avoids any slip rings. The flexible PCB winding represents an ultra thin electromagnetic exciting source where coils are wound in a wedge shape. The proposed multi-poles generator can be used for various low speed applications especially in small marine current energy conversion systems.

Sanjida Moury

Papers

Design of a low power 2.45 GHz RF energy harvesting circuit for rectenna

Feasibility study of solar PV arrays in grid connected cellular BTS sites

A Soft-Switched Power Module With Integrated Battery Interface for Photovoltaic-Battery Power Architecture

A novel multi-input converter using soft-switched single-switch input modules with integrated power factor correction capability for hybrid renewable energy systems

A permanent magnet generator with PCB stator for low speed marine current applications