Development of a Wireless Power Transfer System using Resonant Inductive Coupling

Access to power is a fundamental requirement for the effective functioning of any electrical/electronic circuit. The conduit of transfer of power can be either physical (wires, cables etc.) of non-physical (i.e. wireless). Wireless power transfer is a broad term used to describe any means used to transmit power to electricity dependent systems and devices. In this paper, a wireless power transfer system is developed to provide an alternative to using power cords for electrical/electronic devices. With this technology, challenges like damaged or tangled power cords, sparking hazards and the extensive use of plastic and copper used in cord production are resolved and also the need for batteries in non-mobile devices is eliminated. In this system, electromagnetic energy is transmitted from a power source (transmitter) to an electrical load (receiver) via resonant inductive coupling. The performance achieved is a good indication that power can still be transmitted over a medium range. In addition, possible ways of improving the efficiency of the system are discussed

A comparison of analytical models for resonant inductive coupling wireless power transfer

Recent research in wireless power transfer (WPT) using resonant inductive coupling has demonstrated very high e±ciencies (above 40%) at large distances compared to the antenna dimensions, which has exponentially increased the number of potential applications of WPT. Since resonant inductive coupling is a very multidisciplinary ¯eld, di®erent approaches have been proposed to predict the behaviour of these systems from physical theory of resonators, reflected load theory and the circuit point of view. However, the relation between these methods is still obscure. In this article, we compare the results of these models to find the effciency of a Resonant Inductive Coupling WPT system under Steady-State sonditions and to analyze the relation between the optimal load values obtained from this perspectives and the ones obtained using impedance matching techniques.Peer ReviewedPostprint (published version

Resonant coils analysis for inductively coupled wireless power transfer applications

This paper proposes Wireless Power Transfer (WPT) system, consisting of transmitter-receiver coils along with some conditioning and stabilizing circuits. The transmitter circuit is designed with a simple H bridge circuit to supply the pulses to source coil. The efficiency variation or performance with respect to the coil size has been demonstrated in this paper, which is not well demonstrated experimentally in the past. It is about an inductive link efficiency calculation as a function of the geometrical dimensions. The efficiency has been derived analytically, and analytical results are validated experimentally. From the results observed the effect of geometrical dimensions (area, distance, shape, and size) is explored. The performance analysis evaluated analytically against experimentally, infers that the inductive coupling with same sized coil has achieved maximum power transfer wirelessly, for a shorter distance with applied input voltage of 24 V at resonance frequency of 180 kHz. This proposed system is practically tested for applications such as charging of devices or providing wireless sensor networks with energy supplied. The results have got useful utility for Electric Vehicles automobile industry. © 2016 IEEE

Load monitoring and output power control of a wireless power transfer system without any wireless communication feedback

For mid-range wireless power applications, the load is normally far away from the power source. In this project, a new method is proposed to determine the load impedance and load power without using any direct output feedback. Based only on the information of the input voltage and current, the load impedance and load power can be monitored and controlled without using any wired or wireless feedback from the load. This new method can therefore eliminate the need for any directly measured output feedback, which was previously thought to be essential. It also makes the power control of a wireless power transfer very simple. The concept is verified by the comparison between the computed results and practical results of an 8-ring domino wireless power transfer system. A good degree of accuracy has been achieved in the verification. 2013 IEEE.published_or_final_versio

Energy-security-based contactless battery charging system for roadway-powered electric vehicles

This paper proposes an encrypted contactless charging system for roadway-powered electric vehicles (EVs), where the energy can be specifically transferred from the electric supply to authorized EVs. The key of the proposed energy encryption scheme is to utilize the random-like Gaussian map as the security key to chaotically regulate the charging circuit of the electric supply. In such way, the energy can be wirelessly transferred to authorized EVs, while unauthorized EVs cannot illegally acquire the electric energy without knowledge of the security key. Hence, the proposed energy encryption scheme can significantly improve the secure performance of the roadway EV charging system. In this paper, the simulated and experimental results are both provided to illustrate the effectiveness of the proposed the encrypted contactless charging system for multiple roadway-powered EVs. © 2015 IEEE.published_or_final_versio

The impact of Nodes Distance on Wireless Energy Transfer System

Wireless energy transfer (WET) reemerges as the method for transmitting electric power without the necessity to deal with cable losses and an aesthetically pleasing environment. The problem with WET is how to maintain magnetic induction as the distance gets further. This paper investigates the impact of nodes distance on the WET system. The experimental results show that the most effective distance among transmitter, nodes, and receiver are 4 cm. The measurement is taken with and without load. The without load application give that for node 1; the results are 6 V, 110 mA, and 2.85 mT for voltage, current, and magnetic flux, respectively. At the application of 2 nodes, the voltage is 6.8 V, the current is 0.124 mA, and the magnetic flux is 3.83 mT, and at three nodes installation, it is 7 V, 134 mA, and 3.83 mT. During the application of 3-Watt and 5-Watt lamp, at 4 cm distance, the power received is 1.66 W and 3.66 W at 3-Watt and 5-Watt lamp for one node, 1.84 W, and 3.84 for two nodes, and 1.93 W and 3.93 for three nodes. The experimental results show that the transmitted signal can be prolonged by installing nodes. Even though this study shows that 4 cm is the most effective, it is possible to increase up to 20 cm to power a 3-Watt lamp and 5-Watt lamp

Design and simulation of high frequency colpitts oscillator based on BJT amplifier

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectively. This result is seen to be very encouraging

Recent progress in mid-range wireless power transfer

This is a review paper describing recent progress of mid-range applications of wireless power transfer. Starting from Tesla's principles of wireless power transfer a century ago, it outlines magneto-inductive research activities in the last decade on wireless power transfer with the transmission distance in the order of or greater than the coil dimension. It covers the basic characteristics of 2-coil systems, 4-coil systems, systems with relay resonators and the wireless domino-resonator systems. © 2012 IEEE.published_or_final_versio

Magnetic characterization of interfering objects in resonant inductive coupling wireless power transfer

Resonant Inductive Coupling (RIC) Wireless Power Transfer is a key technology to provide an efficient and harmless wireless energy channel to consumer electronics, biomedical implants and wireless sensor networks. However, there are two factors that are limiting the applicability of this technology: the effects of distance variation between transmitter and receiver and the effects of interfering objects. While distance variation in WPT has been thoroughly studied, the effects of conductive interfering objects in resonant inductive coupling links are still unclear. When a conductive element is in the vicinity of a RIC link, both the transmitter and the receiver can experiment a change on their resonant frequencies as well as their impedances. This can greatly affect the efficiency of such WPT link causing it to a) make the transmitter and/or receiver act as a pass-band filter and b) loose part of the transmitter magnetic field through coupling to the interfering object. Depending on the natural resonant frequency of the object and the distances between this object and the transmitter and receiver antennas, this can affect significantly the RIC wireless power transfer link. In this article, we characterize the Magnetic behavior of a resonant inductive coupled link in the presence of a conductive interfering object using a Finite Element Field Solver (FEKO). Several distances between interference and transmitter/receiver are analyzed providing a design space exploration and applicability study of this link.Peer ReviewedPostprint (published version

Investigation of magnetic resonance coupling circuit topologies for wireless power transmission

© 2019 Wiley Periodicals, Inc. Magnetic resonance coupling circuits have four general topologies; however, there is a lack of comprehensive theoretical analysis with experimental verification for each of these topologies regarding their attractiveness for wireless power transfer (WPT). This article provides this for each of the four topologies to fully understand their differences and allow the selection of the most appropriate type based on system requirements. In addition, a problem associated with the resonance coupling method is the phenomenon of frequency splitting, which can lead to a high-power transfer efficiency but low-load power at the resonant frequency. Reasons for frequency splitting and methods of circumventing the problem will be illustrated in this article. Of the four topologies, the series-parallel (SP) (input-output) circuit configuration is the most efficient for the realization of a WPT system with a large load impedance, in terms of achieving both a high power transfer efficiency and high-load power