Inductive Power Research Articles

Wireless Power Transfer of Electric Vehicle Battery Charging

Abstract: Wireless power transfer (WPT) is a cutting-edge technology that utilizes magnetic resonance to eliminate the need for cumbersome wires. WPT builds upon the principles of inductive power transfer and has been rapidly advancing in recent years. At power levels of kilowatts, the transfer distance can range from a few millimeters to several hundred meters, achieving an efficiency of over 90%. This progress has made WPT an attractive option for electric vehicle (EV) charging, both in stationary and dynamic settings. This study examines the latest developments in WPT as it pertains to wireless charging for EVs. By integrating WPT into EVs, challenges such as charging time, range, and cost can be effectively addressed. Battery technology is no longer a limiting factor in widespread adoption, and it is hoped that researchers will be inspired by recent advancements to further enhance WPT and expand the use of EVs.

Advancing V2G Technology: Design of an Adaptive Bi-directional Three Phase AFE Converter for High-Power Applications

The grid-connected active front end (AFE) converter is an essential component of the Vehicle-to-Grid (V2G) system. In the current scenario, only a battery charger with unidirectional power capability for various power levels is being developed, which improves the grid’s power quality in compliance with the standard. A bi-directional battery charger with a high-power rating for V2G applications is a challenging task that is the focus of the current research. This paper presents a three-phase bi-directional grid-connected AFE converter for a 15 kW charging system. The novelty of this paper is to design and implement an adaptive synchronous reference frame (SRF) model-based controller for bi-directional power flow between the electric vehicle (EV) and grid. It uses an adaptive constant current/constant voltage (CC/CV) mode while integrating a bi-directional DC/DC converter to the proposed AFE system. The significant advantages of the proposed AFE system are high power quality at the grid side, along with suitable total harmonics distortion (THD) and ripple-free DC output voltage. Moreover, the bi-directional offboard charger responds to inductive and capacitive reactive power requests in less than three grid cycles, demonstrating a rapid reaction to grid commands. This paper achieves a fast transient response with a less peak overshoot to improve the steady-state performance. The performance of AFE is further analyzed using simulations, and it has finally been verified using a 15 kVA AFE converter on the laboratory set-up.

WIRELESS CHARGING FOR ELECTRICAL VEHICLES

Nowadays Wireless power transmission (WPT) is popular and gaining technology finding its application in various fields. The power is transferred from a source to an electrical load without the need of interconnections. Wireless power Transmission (WPT) is useful to power electrical devices where physical wiring is not possible or inconvenient. The technology uses the principle of mutual inductance. One of the best future applications finds in automotive sector especially in Electrical Vehicles. This project deals with research and development of wireless charging systems for Electric Vehicles using Wireless transmission. The main goal is to transmit power using resonance coupling and to build charging systems. The System deals with AC source, transmission coil, reception coil, converter and electric load which are battery. As Electric Vehicles (EVs) continue to gain popularity as a sustainable transportation solution, the need for efficient charging infrastructure becomes increasingly critical. Wireless charging technology presents a promising solution to address the limitations of traditional plug-in charging systems, offering convenience and flexibility to EV users. This Project explores the concept of wireless EV charging while the vehicle is in motion, also known as dynamic wirelesscharging (DWC). By integrating inductive power transfer (IPT) technology with dynamic charging infrastructure embedded in roadways or dedicated lanes, vehicles can replenish their batteries continuously while in motion, extending their range and reducing the need for frequent stops. Furthermore, DWC has the potential to enhance the feasibility and adoption of EVs in various sectors, including public transportation, logistics, and personal mobility. This abstract provides a comprehensive overview of the emerging field of wireless EV charging while the vehicle is inmotion, highlighting its benefits, challenges, and future prospects.

Design & Simulation of an Intelligent Energy Management System for Electric Vehicle Charging Stations

The transition towards electric vehicles (EVs) necessitates the development of efficient and reliable charging infrastructure. This paper presents the design and simulation of an EV charging station using MATLAB/Simulink. The proposed charging station incorporates both wired and wireless charging capabilities, aiming to provide a comprehensive solution that meets the diverse needs of EV users. The design process involves creating detailed models of the charging station components, including the power electronics for AC/DC conversion, wireless power transfer modules, and control systems for charge management. The MATLAB/Simulink environment offers robust tools for modeling and simulating these components, allowing for thorough analysis and optimization. Simulation results demonstrate the effectiveness of the charging station design in terms of efficiency, power management, and user convenience. The wired charging system is modeled to ensure compliance with standard charging protocols, optimizing the power flow to achieve minimal charging times while maintaining safety and reliability. The wireless charging system, based on inductive power transfer principles, is evaluated for its alignment sensitivity, power transfer efficiency, and interoperability with different vehicle models. Key performance metrics such as charging efficiency, power quality, and thermal performance are analyzed under various operating conditions. The simulation results indicate that the proposed design can achieve high efficiency and reliable operation, with wireless charging efficiencies exceeding 90% under optimal alignment conditions. Keywords: METLAB, Simulink, AC-DC, Simulation, Wireless Charging etc.

A stacking machine‐learning based method for accelerating magnetic coupler design with ferrite cores in inductive power transfer applications

AbstractThis paper presents a magnetic coupler design method for WPT systems based on stacking machine‐learning algorithms. A synthetic dataset generated by ANSYS Maxwell is used for training and evaluating machine‐learning models. Stacking technology effectively combines the results from multiple models and make best predictions. The designed model allows us to obtain the optimal values of the coil inner radius and number of turns , when other coil design parameters such as the coil outer radius , the wire diameter , and the coil inductance , are given based on the application environment. The proposed method provides practical solutions meeting design requirements quickly, easily accommodating magnetic couplers with ferrite cores, and showing advantages in designing magnetic couplers with optimal power transfer efficiency.

Optimal deployment of dynamic wireless charging infrastructure for battery electric buses – a case study in Auckland, New Zealand

ABSTRACT Inductive power transfer (IPT) systems offer a promising solution to multiple major hurdles associated with electric vehicles, such as the lack of widespread charging infrastructure, driving range anxiety, and significant charging time. With the aid of IPT systems, dynamic wireless charging enables electric vehicles to be charged when running over the IPT power pads. The objective of this study is to minimise the overall cost of charging infrastructure by optimising the deployment of IPT transmitters and the battery size required to support charging for electric buses. A mixed-integer linear programming model is proposed and solved using the commercial solver Gurobi. Bus route information and the characteristics of electric buses, such as weight, drag coefficient and frontal area, are used as input to run the traffic simulation in SUMO to get time-varying velocity and acceleration data during bus operations. A bus route in Auckland, New Zealand, is used as a case study in the presented numerical experiments. A strong correlation between the velocity of the bus and the state of charge is identified. The largest cost component is the charging pad, followed by the battery.

Design and Performance Investigation of a Series Compensated Inductive Wireless Power Transfer System for Supplying a Low Power DC Load

In this study, a series compensated WPT system is presented for low power DC load applications. Series LC resonant circuits are applied for both transmitter and receiver sides of WPT system to reduce the impedance at a specified operation frequency, and thus, ensure low power losses. The operation frequency is chosen as 109 kHz for the series compensated WPT system. Then, the series resonant LC filter is designed according to the operation frequency and WPT rating values. In addition, the power electronics systems with their controller and operation principle are demonstrated in depth. To investigate the performance of the proposed system, a 100 W series compensated WPT model is designed and constructed in Matlab/Simulink enviroment. Different simulation results are provided to illustrate the performance of the proposed WPT model. The simulation results show the stable operation of the proposed system under the designed system parameters.

Wireless Power Transfer for Unmanned Underwater Vehicles: Technologies, Challenges and Applications

Unmanned underwater vehicles (UUVs) are key technologies to conduct preventive inspection and maintenance tasks in offshore renewable energy plants. Making such vehicles autonomous would lead to benefits such as improved availability, cost reduction and carbon emission minimization. However, some technological aspects, including the powering of these devices, remain with a long way to go. In this context, underwater wireless power transfer (UWPT) solutions have potential to overcome UUV powering drawbacks. Considering the relevance of this topic for offshore renewable plants, this work aims to provide a comprehensive summary of the state of the art regarding UPWT technologies. A technology intelligence study is conducted by means of a bibliographical survey. Regarding underwater wireless power transfer, the main methods are reviewed, and it is concluded that inductive wireless power transfer (IWPT) technologies have the most potential. These inductive systems are described, and their challenges in underwater environments are presented. A review of the underwater IWPT experiments and applications is conducted, and innovative solutions are listed. Achieving efficient and reliable UWPT technologies is not trivial, but significant progress is identified. Generally, the latest solutions exhibit efficiencies between 88% and 93% in laboratory settings, with power ratings reaching up to 1–3 kW. Based on the assessment, a power transfer within the range of 1 kW appears to be feasible and may be sufficient to operate small UUVs. However, work-class UUVs require at least a tenfold power increase. Thus, although UPWT has advanced significantly, further research is required to industrially establish these technologies.

Assessment of heat transfer mechanisms of a novel high-frequency inductive power transfer system and coupled simulation using FEA

The calculation of the temperature fields in solid state transformers is a critical step of the design process in order to ensure the stable and efficient operation of the device. Transformers operating in high frequencies can develop increased temperatures that potentially may result in the failure of the components due to the associated thermal stresses. This paper investigates the heat transfer mechanisms of a novel inductive power transfer (IPT) system submerged in a dielectric oil and operating at 50 kHz, in the context of SSTAR, a Horizon Europe project. The commercial software ANSYS is employed to implement a one-way coupled electromagnetic-thermal finite element simulation model in order to calculate the temperature field of the IPT components based on the electromagnetic losses. To cross-validate the model, the results obtained from ANSYS are benchmarked against the COMSOL software, revealing accepted temperature deviations between the two software. A comprehensive parametric analysis explores the impact of rated power, operating frequency, and dielectric gap on generated heat, highlighting their direct correlation with temperature increase. The findings underscore increased temperature levels, approximately reaching 224 °C under nominal operating conditions, with the temperature distribution concentrated around the transformer's windings.

Improvement of Power Factor in Wireless Electric Vehicle Charging Using Inductive Power Transfer Topology

The EV requires energy supplied to its motors to function properly. This required energy either can be transmitted by a physical wired connection or by wireless power transfer firstly to the battery using charging of the EV system and then battery discharges to supply to the vehicle. This paper deals with the wireless transfer of power using the induction method for charging battery of the vehicle using electric energy for its functioning as it is the most suitable and fast mode to charge the batteries of many vehicles altogether at charging station. The challenges recently faced by EV’s includes the movement of energy from the energy supply point to the destination i.e., EV’s without the direct interaction of battery and energy source. Many topologies have been introduced in this regard and several simulation models are built.

Evaluation of Additive Manufacturing for Wireless Power Transfer Applications

Additive Manufacturing (AM) has emerged as an economical and feasible technology for creating industrial components. This paper evaluates the use of AM for inductive Wireless Power Transfer (WPT) systems. In particular, the innovative use of metal 3D printing is proposed as a manufacturing process for the coils. For this reason, the recent improvement of metal AM is proposed as a suitable solution to increase design opportunities, reduce costs and production time while improving transmission efficiency. In fact, the WPT coil current distribution can be preliminarily studied through Finite Element Analysis (FEA) to optimize its cross-section and geometry. In this work, a general design procedure for WPT coils using metal AM is presented and this technology is compared with traditional solutions (i.e. hollow and litz wire) through extensive experimental measurements. The analysis shows that AM allows to reduce the parasitic resistance, costs and weight while increasing the transmission efficiency. Thus, the obtained results confirm the potential of AM for producing WPT coils, nominating this technology as a flexible, sustainable, and rapid solution for custom WPT coils production.

Memristor Equivalent Model of an Inductive Wireless Power Transfer System Based on the Sigmoid Function

Memristor Equivalent Model of an Inductive Wireless Power Transfer System Based on the Sigmoid Function

A Comparative Review on Acoustic and Inductive Power Transfer

Wireless Power Transmission (WPT) has emerged as a prominent player in numerous industries recently. It is already established in wireless charging for electric cars and electronic gadgets. However, it has promising applications in medical implants and imaging as well. Among several proposals, Inductive Power Transfer (IPT) and Acoustic Power Transfer (APT) have shown a major impact on this area of interest. This paper presents a comparison between IPT and APT for wireless power transmission (WPT). Most recent proposals are reported, and several key parameters are considered to evaluate the proposals. That includes operating frequencies, separations gaps, powers and power transmission efficiencies and experimental validity. It is found from the review that; a maximum 818 kW of power is transmitted using IPT for electric vehicles. However, APT can transmit 1.068 kW and 5.4 W through wall and in-body medium (implants). Over 90% efficiencies are found for both APT and IPT. In fact, power transfer with 95.66% efficiency over a 6 cm distance of 23.4 W is achieved for APT and 95.6% with 20 cm separation gaps is achieved for IPT for 20 kW power. A wide range of frequencies are applied for both APT and IPT. However, lower frequencies are mostly suitable for high power, more specifically less than MHz ranges. Naturally, lower frequencies are preferable for low power high efficiencies.

Constant-Voltage and Constant-Current Controls of the Inductive Power Transfer System for Electric Vehicles Based on Full-Bridge Synchronous Rectification

When an inductive power transfer (IPT) system conducts wireless charging for electric cars, the coupling coefficient between the coils is easily affected by fluctuations in the external environment. With frequent changes in the battery load impedance, it is difficult for the IPT system to achieve constant-voltage and constant-current (CVCC) controls. A CVCC control method is proposed for the IPT system that has a double-sided LCC compensation structure based on full-bridge synchronous rectification. The proposed method achieved good dynamic stability and was able to effectively switch between the output current and voltage of the system by adjusting only the duty cycle of the switch on the secondary side of the rectification bridge. As a result, the system efficiency was improved. The output characteristics of the double-sided LCC compensation structure was derived and the conduction condition with zero voltage was analyzed by using four switches through two conduction time series of the rectifier circuit. Then, the output voltage of the synchronized rectifier was derived. The hardware implementation of the full-bridge controllable rectifier was described in detail. Finally, a MATLAB/Simulink 2018a simulation model was developed and applied to an 11 kW prototype to analyze and validate the design. The results showed that the designed system had good CVCC output characteristics and could maintain constant output under certain coupling offsets. Compared with semi synchronous rectification methods, the proposed method had a higher efficiency, which was 95.6% at the rated load.

Deposition of a‐C:H:SiOx Coatings Using Low‐Frequency Inductively Coupled Plasma

This article investigates the plasma‐enhanced chemical vapor deposition of a‐C:H:SiOx coatings in a non‐self‐sustaining arc discharge plasma with a hot cathode in combination with a low‐frequency (200 kHz) inductively coupled plasma. It is shown that increasing the inductor power from 0 to 600 W leads to a twofold increase in the ion current density on the substrate. An increase in ion bombardment intensity results in a 1.3‐fold reduction in the coating's growth rate due to the resputtering phenomenon, a 1.5‐fold reduction in surface roughness, and an improvement in the mechanical properties of the coatings. The hardness of the coating is increased by 9–11%, the plasticity index by 10–17%, and the resistance to plastic deformation by 32–49%.

Telemetry System to Monitor Elastic Torque on Rolling Stand Spindles

This article outlines the relevance of building online telemetry systems for online monitoring of the technical conditions of rolling mill equipment. Electromechanical systems of the horizontal stand of the plate Mill 5000 are described, when operating in harsh conditions caused by the shock loading when workpieces enter the stand. It is noted that dynamic torque overloads, exceeding the rated motor torque by many-fold, cause the fatigue failure of spindle joints and breakage of rolls. In this regard, the development and implementation of systems for monitoring the elastic torque on spindles are extremely urgent. This issue has long been studied, but the references provide no information on the building principles and hardware composition of such systems. The use of strain gauges connected according to a balanced bridge circuit to measure the elastic torque is justified. This paper’s contribution is the proposed modular principle for building a telemetry monitoring system based on the analysis of known techniques for measuring and transmitting diagnostic data. The developed system structure is provided and the concept of data transfer and processing are explained. This article suggests the inductive power supply of a measuring unit mounted on a shaft without the use of batteries. A hardware structure was developed to be applied in a system for measuring, transmitting, and visualizing signals proportional to the elastic torque, manufactured on the basis of data measuring instruments by leading companies. The specifics of placement and connection of strain gauges are considered. The hardware providing a wireless power supply to the signal encoder and digital data transfer between the transmitter and receiver is described. The results of implementing the system on Mill 5000 are provided. The installation of a telemetry ring and a receiving head for the inductive power supply and data reception is shown. An experimental assessment of the elastic torques occurring when workpieces enter the cage was obtained by implementing a drive control algorithm which provided biting in the drive acceleration mode. The reliability of measuring the elastic torque with an error not exceeding ±5% and the reduction of dynamic loads on the spindle by 1.3–1.5 times due to the elimination of impacts from closing angular gaps in spindle joints was confirmed. This increases the service life of mechanical equipment and reduces the cost of eliminating the accident aftermath. The prospect of modifying the developed system into a cyber-physical system for monitoring the rolling mill’s mechatronic equipment conditions is shown.

Modeling and Control of an Inductive Power Transmitter Based on Buck–Half Bridge–Resonant Tank

In this paper, a previously proposed converter to be used for inductive wireless power transmission is modeled and a control strategy is proposed. The converter topology combines into a single stage, two buck converters and a half-bridge converter to feed a resonant stage. This simple and symmetrical topology is straightforward to design; only a buck converter and a parallel resonant tank must be specified. It would be desirable for the converter to feed a wide range of loads and be robust under input voltage variations. These objectives can not be attained with a linear model and control. For this reason, in this paper, a nonlinear converter model is derived step by step and controller strategy is developed without relying on system linearization. The proposed controller does not measure the output but only its peak value. This can be conducted because it takes advantage of the square current pulse fed into a resonant tank; it outputs an approximately sinusoidal signal. The control strategy is completed with a scheme to build the required pulse at the input of the resonant tank. The resulting nonlinear controller has a fast closed-loop performance; furthermore, it is robust under parameter uncertainty, and load and input voltage variations. Despite its features, the controller is fairly simple to implement.

Wireless Solar Charging Stations for Electric Vehicles

The automotive industry is quickly transitioning from IC engine vehicles to electric vehicles as we enter a new era of automobiles. The growing demand for electric vehicles is also driving up the number of charging stations. In this idea, the automobile is charged wirelessly through inductive coupling using a wireless charging system. All we have to do is pull the automobile into the charging station. Wireless Power Transmission is the process of sending electrical energy from a source to a load over a distance without the need of cables or other conducting wires. Nikola Tesla’s greatest invention was the idea of wireless power transfer. There is no need for human contact with this technology. One technology that may be a step towards the future is wireless power transmission. With the help of this project, wireless charging may become more practical for everyday usage. Magnetic resonance-based wireless power transfer (WPT) is a technology that has the potential to free people from obtrusive wires. Actually, the WPT uses the same fundamental theory known as inductive power transfer that has been studied for at least thirty years. WPT technology has advanced quickly in the last many years. With a load efficiency above 90%, the power transfer distance grows from several millimeters to several hundred millimeters at the mill watts to kilowatts power level. Electric vehicle (EV) charging applications find the WPT highly appealing due to its advancements, as it can be used in both stationary and dynamic charging settings. The WPT technologies that are relevant to EV wireless charging are represented in this presentation. The challenges of charging time, range, and cost can be readily reduced by implementing WPT in EVs. With the widespread adoption of EVs, battery technology is no longer significant. It is believed that the cutting-edge accomplishments would inspire researchers to further both the spread of EV and the continued development of WPT.

Self-Oscillating Converter Based on Phase Tracking Closed Loop for a Dynamic IPT System

The coupling of converters with resonant networks poses significant challenges for frequency tracking and power control in inductive power transfer (IPT) systems. This paper presents an implementation method that addresses these issues by dividing the system’s operation into two distinct states: self-oscillating and power-injecting. Based on these states, a phase-closed loop is constructed. Within this closed loop, the phase tracking unit detects and tracks frequency drift, while the power regulating unit incorporates an integrator and adopts a control variable to adjust the output power by modifying the duration of the power injecting state. Meanwhile, the oscillating unit operates in the self-oscillating state. Operating in this manner, the system achieves self-oscillation and demonstrates the capability to effectively track and compensate for system variations within a single cycle. A verification prototype has been constructed, and it demonstrates that the converter within it completely decoupled from the resonant network. Experimental results validate that altering the control variable solely affects the duration of the power-injecting state, allowing for independent control of the output power. When the control variable changes from 2.0 V to 3.5 V, the output power changes from 178 W to 519 W while the self-oscillating state remains unchanged. Furthermore, the system accurately tracks frequency changes, even under significant variations in the coupling coefficient or load, without compromising the power injection state. When the air gap changes from 3 cm to 12 cm, the duration of the self-oscillating state changes from 22.1 μs to 26.3 μs, while the power injecting state remains unchanged. This approach exhibits a robust performance, particularly suitable for dynamic IPT systems sensitive to parameter variations.

A Control Strategy for Achieving Constant Voltage Output with an Extensive ZVS Operating Range in Bidirectional Wireless EV Charging Systems

Variations in the coupling coefficient of loosely coupled transformers and dynamic loads have a significant impact on the overall performance of bidirectional inductive power transfer (BIPT) systems. However, a wide range of load and coupling coefficient variations are common in the actual charging process, which may cause the converter on both sides to operate in a hard switching state, resulting in switching noise, reduced efficiency, and potential safety concerns. In this paper, a triple-phase-shift control (TPSC) strategy is proposed to study the zero-voltage switching (ZVS) operating range and constant-voltage output (CVO) characteristics of the double-side-LCC (DS-LCC) topology. To ensure a CVO over the wide range of coupling coefficient variations, a dual-phase-shift control is introduced for AC voltage matching. Based on this, the third phase-shift angle control between the converters on both sides is introduced to ensure the ZVS realization. Meanwhile, the time-domain model is developed to analyze the rationality of the proposed third phase-shift angle and the ZVS operating range. Finally, the effectiveness of the proposed TPSC strategy is validated through a 1.5 kW experimental prototype with an air gap of 100–150 mm.