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A transmitter in a wireless power transfer network (WPTN) needs to deliver wireless power to a number of wireless power receiver. There can be diverse set of wireless power receivers, for example, Internet of Things devices, smart...
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A transmitter in a wireless power transfer network (WPTN) needs to deliver wireless power to a number of wireless power receiver. There can be diverse set of wireless power receivers, for example, Internet of Things devices, smart phones, laptops, etc. The wireless power requirements for receivers vary depending upon their type and state. Commercially deployed WPTNs may also have different subscription plans for users, hence each user’s device should receive wireless power transfer (WPT) service based on the subscribed plan. Usually, a transmitter has to provide service to a number of receivers. Hence, the transmitter needs to have a WPT scheduling method for WPT service delivery. The challenges associated with WPT delivery in a WPTN require a scheduling method that possess the following characteristics: a generalized scheduling method that can work in a setting comprising of heterogeneous receivers, and a scheduling method that can deliver prioritize WPT service, however at the same time it should avoid starvation of lower priority WPT requests. Here, a system and methods for WPT service scheduling are presented. The presented methods possess the above stated characteristics. One of the methods focuses on enhancing a WPT system’s throughput and the other focuses on a receiver device’s remaining charging time. Moreover, both methods avoid starvation of low-priority requests. The presented methods are compared with an existing method, and simulation results demonstrate effectiveness and usefulness of the presented methods.
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Capacitive power transfer (CPT) has been investigated as an alternative wireless power transfer technology based on electric field coupling. The coupling interface of CPT is formed by a pair of “capacitors” in series with the po...
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Capacitive power transfer (CPT) has been investigated as an alternative wireless power transfer technology based on electric field coupling. The coupling interface of CPT is formed by a pair of “capacitors” in series with the power source and load. The effective capacitance ranges from tens to a few hundreds of picofarads, yielding high impedance. Therefore, in most CPT systems, a tuning inductor is connected in series with the coupling interface for circuit compensation and power transfer capability enhancement. However, this compensation method suffers from high voltage spikes from the inductor if the secondary side load is removed suddenly causing electrical and health hazards. To address the issue, this paper proposes a CPT system based on a Z-impedance compensation network with inherent open-circuit and short-circuit immunity. It also has the voltage boost capability as a Z-source inverter. Its operating principle is described and a set of design equations are given. Both simulations and experimental results from a 5 W low power design have demonstrated that the proposed compensation method using the Z-impedance matching network exhibited open-circuit and short-circuit immunity, could boost up the output voltage by 50% with power efficiency exceeding 80%.
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In dynamic wireless charging applications, segmented transmitter coils transfer power to a moving receiver coil. This article proposes a method in which the field strength in coupled transmitter coils automatically adjusts based o...
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In dynamic wireless charging applications, segmented transmitter coils transfer power to a moving receiver coil. This article proposes a method in which the field strength in coupled transmitter coils automatically adjusts based on the position of the receiver. Specifically, a saturable inductor is applied to provide a high uncompensated inductive reactance in the uncoupled condition. By exploiting the reflected reactance as the system approaches the maximum coupled condition, the inductor saturates and the field strength in the coupled transmitter coils automatically increases. The field strength is at its peak when the transmitting and receiving coils reach their maximum coupling and sharply decreases when the receiver is decoupled from the transmitter. Consequently, the difference between the coupled and uncoupled currents in the transmitter coil is maximized, resulting in a near six-fold improvement in field containment performance compared to previously reported findings. This allows for system-level efficient power transfer and compliance with electromagnetic emission standards without complex shielding circuits and auxiliary active position detection approaches. We present the analysis, design criteria of the compensation network, and experimental validation for the proposed method.
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Recent research has shown an increasing interest in wireless power transfer (WPT) technology for drone batteries. The inconvenience of wired charging, especially for drones, is a huge obstacle. In this research project, a WPT plat...
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Recent research has shown an increasing interest in wireless power transfer (WPT) technology for drone batteries. The inconvenience of wired charging, especially for drones, is a huge obstacle. In this research project, a WPT platform was proposed by applying four transmitting coils and a single receiving coil. To meet the industrial standards required for transmitter Tx and receiver Rx, a calculation of the parameters was implemented. An H-bridge MOSFET was used as a DC–AC inverter, a bridge diode was used as an AC–DC rectifier, and a Pi low pass filter was added to the receiver circuit design to filter the high-frequency noise. Experimental investigations were conducted to study the maximum power and power efficiency of the coil’s alignment. The focus of this article was to design and fabricate workable multiple-transmitter coils and a single-receiver coil for a wireless power transfer system, in order to charge a 3S LiPo drone’s battery. It not only covers an overview of wireless power transfer but also includes the method for charging a 3S LiPo drone’s battery, a misalignment study on the X and Y axes of the wireless charging system, and a stable charging of the battery that does not exceed the maximum current of 1.26 A for healthy charging. An efficiency of 58.29% was achieved at a power of 14.924 W and the minimum value was found to be 0.008 W. The efficiency of the typical coil design and the proposed coil design were 55.04% and 12.06%, respectively. The charging current obtained was 1.27 A, which gives an estimated charging time of 3.31 h based on the calculation. The actual charging time of the 3s 4200 mAh 11.1 V LiPo battery was 2 h.
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This brief presents a pulse phase modulation scheme for simultaneous wireless power and downlink data transfer system through the same inductive link. It is proved that the impact of data transfer on power transfer can be minimize...
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This brief presents a pulse phase modulation scheme for simultaneous wireless power and downlink data transfer system through the same inductive link. It is proved that the impact of data transfer on power transfer can be minimized when using the proposed pulse phase modulation. A prototype is built up with 1-MHz resonant frequency for power transfer. It shows that the data can be successfully transferred while achieving a data rate of 125 kb/s, which is 1/8 of carrier frequency, and a bit error rate (BER) of 4.5x10(-6). Furthermore, compared with the case without data transfer, the input powers and the output powers are almost unchanged, respectively.
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As an important application of the fifth generation (5G) mobile communication systems, Internet of Things (IoT) has attracted worldwide research interests. Since most of the communication devices in IoT are powered by batteries, t...
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As an important application of the fifth generation (5G) mobile communication systems, Internet of Things (IoT) has attracted worldwide research interests. Since most of the communication devices in IoT are powered by batteries, these devices always have limited operation time. Wireless power transfer (WFT) technology, which can transfer power over a wireless medium (without any wires), can avoid the need to manually replace or recharge the batteries of the wireless devices in IoT. For electromagnetic (EM) radiation-based WPT, since radio-frequency (RF) signals that transport energy can at the same time be used for wireless communications, integrated wireless communications and WPT becomes a new research area which has attracted great research interests. In this paper, we first introduce two main research paradigms for integrated wireless communications and WFT, i.e., simultaneous wireless information and power transfer (SWIPT) and wireless-powered communication network (WPCN). Then we provide an overview of the state-of-the-art of both SWIPT and WPCN, respectively. Finally, we point out the new and challenging future research direction.
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Seit der immer gr??er werdenden Verbreitung von Wireless Power Transfer in der Consumer Elektronik, wie z.B. Smartphone Ladestationen, richtet sich auch der Blick der Industrie- und Medizintechnik immer mehr auf diese Technologie ...
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Seit der immer gr??er werdenden Verbreitung von Wireless Power Transfer in der Consumer Elektronik, wie z.B. Smartphone Ladestationen, richtet sich auch der Blick der Industrie- und Medizintechnik immer mehr auf diese Technologie und der daraus resultierenden Vorteile. Ziel dieses Artikels ist es, dem Entwickler aufzuzeigen, dass es für eine kontaktlose Energieübertragung, für 100 Watt und mehr, durchaus einfach zu realisierende L?sungen im Bereich der Schaltungstechnik gibt, welche auch ohne Software und Controller aus-kommen.
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A common problem for most strongly coupled magnetic resonance (SCMR) wireless power transfer (WPT) systems is the dramatic efficiency drops by surrounding high-dielectric objects, e.g., people, caused by the narrow bandwidth of th...
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A common problem for most strongly coupled magnetic resonance (SCMR) wireless power transfer (WPT) systems is the dramatic efficiency drops by surrounding high-dielectric objects, e.g., people, caused by the narrow bandwidth of the systems due to a high quality factor (Q). In this paper, a compact broadband planar double-spiral resonator with a via is proposed to obtain a robust SCMR system with a stable efficiency where interference from high-dielectric surrounding objects is mitigated. The increased bandwidth is obtained without compromising power transfer efficiency by introducing coupling enhancement to the structure while Q is reduced. The bandwidth of the system is increased by over 15% compared to a conventional system with single-sided resonators, and the efficiency is comparable. In this paper, it is found that the location of the via affects both the efficiency and bandwidth of the SCMR system. Meanwhile, this paper reports an experiment with human hand phantom and a simulation study with multi-layered tissue model, both of which mimic a real human involved environment, and successfully demonstrate the stability and high efficiency of power transfer of the proposed broadband resonators in a WPT system. Moreover, the proposed structure is tested to be less sensitive to misalignment between the transmitter and the receiver, and the proposed method is compared to the systems proposed for similar human-involved environments. This proposed viaed double-spiral resonator is a promising candidate for a robust WPT system for human-involved environments.
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Aim of this work is to study the energy transfer wirelessly using a pair of transmitter and receiver coil. The system aims to generate magnetic coupling resonance between two coils. Wireless power transfer system can eliminate wir...
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Aim of this work is to study the energy transfer wirelessly using a pair of transmitter and receiver coil. The system aims to generate magnetic coupling resonance between two coils. Wireless power transfer system can eliminate wire connection during energy transmission. Many researchers show great interest on wireless power transfer technique for biomedical devices. This technique is important to be applied and integrated into biomedical devices such as pacemakers, defibrillators, Left Ventricular Assist Devices (LVAD) to ease the transfer system. Basically, there are two ways to power up the biomedical devices such as external power cord and batteries. However, batteries had its limited capacity and external power cord limit patient's freedom and might lead to infection. Therefore in this study, two coil wireless transfer system was designed in order to solve the problem. Two 30 cm diameter coils transmitter and receiver pairs had been designed to provide 72.7% of efficiency up to 37 cm of transmission distance. It can be concluded that this system is suitable for long range power transmission with good efficiency.
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This paper proposes a wireless power transfer (WPT) system with two parallel opposed coils for powering capsule robot (CR) or other implantable medical devices, where the power cable is inconvenient. The novel WPT system can obvio...
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This paper proposes a wireless power transfer (WPT) system with two parallel opposed coils for powering capsule robot (CR) or other implantable medical devices, where the power cable is inconvenient. The novel WPT system can obviously improve the low power transfer efficiency (PTE) and poor power transfer stability (PTS), which are the key limitations of WPT system in this application conventionally. The transmitting coils (TC) of the proposed WPT system are arranged up and down, and the magnetic cores are embedded inside the coils for the first time. In addition, benefiting from the up-down structure of the TCs, the coil spacing can be adjusted according to the patients? body size. As a result, the PTS and PTE are significantly improved. In this paper, the theoretical model of the proposed WPT system is established and analyzed by finite element simulation. To verify the effectiveness of the proposed design, we conducted experimental tests on PTE and PTS, and an in-vitro experiments for prototype of the WPT system with CR was carried out. The experimental results demonstrate that the proposed WPT system achieves PTE of 8.68 % and PTS of 94.24 %, which is a notable improvement in the WPT system for CR. ? 2020 Elsevier B.V. All rights reserved.
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