Design and experimental analysis for a high-power wireless charging system design for electric vehicles

This paper presents the design, simulation, and experimental validation of a constant current–constant voltage (CC–CV) wireless electric vehicle (EV) charging system utilizing Power Balance Control (PBC) in both primary-side (PS) and secondary-side (SS) converter configurations. The system was tested using a step-resistance load and a typical 72 V, 50 Ah lithium-ion NMC battery to assess control precision, dynamic behavior, and charging efficiency of the system. Experimental results demonstrate that both PS and SS converters employing PBC successfully achieve stable CC–CV operation. The SS converter achieved a peak efficiency of 82%, outperforming 77% from the PS converter. Regarding transient performance, the PBC significantly enhanced settling times over the conventional proportional–integral (PI) controller. Specifically, the settling time was reduced from 600 ms to 100 ms in the PS converter and from 400 ms to 200 ms in the SS converter, with minimal voltage overshoot. Power loss analysis indicated that the highest losses occurred in CC mode, particularly in the inductive power transfer (IPT) coils and high-frequency inverters. The SS control effectively minimized these losses by dynamically adjusting its input resistance to match the optimal load resistance. Overall, the proposed PBC approach, especially in the SS converter, demonstrates efficiency, faster dynamic response, and robust power regulation for next-generation wireless EV charging systems.

Wireless charging schemes aim to counter some drawbacks of electric vehicles’ wired charging, such as the fact that it does not encourage mobility, leads to safety issues regarding high voltage cables, power adapters high cost, and has more battery waste by companies. In this paper, a comparative study of wireless power transfer multiple coil geometries is performed to analyze the efficiency, coupling coefficient, mutual inductance, and magnetic flux density production for each geometry. Results show that coil geometry, current excitation, and shielding techniques within the Wireless Electric Vehicle Charging (WEVC) system substantially influence magnetic flux leakage. In addition, the paper proposes an analytical framework for a WEVC scheme via electromagnetic resonance coupling. Safety considerations of the WEVC system, including the effects on humans, are investigated in several scenarios based on the relative location of the human while EV charging is conducted as the leading paper’s goal. The exposure measurements are performed across various radial distances from the coils using 3-D FEA ANSYS Maxwell Software (American technology company, Pennsylvania, United States). The analysis shows that WEVC systems can achieve high power transfer, resulting in increased magnetic flux leakage around the coils. The safe distance for humans and animals during the charging sequence is attained from research results. For instance, in the 120 mm spiral coil, 120 mm square coil, and 600 mm spiral coil operating at 1 A, excitation, the SAR levels are under the threshold of 700 mm away from the coils. For the 600 mm spiral coil excited at 8 A, the SAR levels fall under the threshold at 900 mm away from the coils. When shielding is utilized, the safe distance is improved by up to 350 mm. Considering the regulations of the Non-Ionizing Radiation Protection (ICNIRP) standards, 600 mm is a safe distance away from the coils, and, vertically, anywhere past 300 mm is safe for humans.

The paper proposes a bipolar coil arrangement method (BCAM) to identify a new anti‐misalignment positioning of overlapping (OV) coils in a bipolar pad (BP) for achieving high‐power transmission in a wireless electric vehicle (EV) charging system. Six different magnetic couplers with identical geometric dimensions, such as circular pad (CP), rectangular pad (RP), double‐D pad (DDP), DD quadrature pad (DDQP), BP, and four‐coil pad, are compared to identify a better performance charging pad. The performance evaluation for all charging pads is done by considering a vertical airgap (Δ Z ) of 60–100 mm between the transmitter and receiver with and without ferrite (Fe) core and aluminum (Al) shield using ANSYS Maxwell software. In addition, the lateral misalignment (LTM) distance (Δ Y ) of 40–60 mm is also examined in all charging pads. The measurable quantities, such as coupling coefficient ( k ), the magnetic field strength ( B ), and mutual inductance ( M ), are evaluated for the above‐mentioned charging pads with different misalignment conditions. The proposed coil arrangement in the BP provides better mutual inductance by facilitating omnidirectional flux distribution with Δ Y of −60 to 60 mm. It also achieved the maximum DC–DC efficiency of 94.5% at Δ Z of 100 mm between charging pads by incorporating the inductor–capacitor–capacitor‐series (LCC‐S) compensation circuit for a 4.75 kW inductive power transfer (IPT) charging system. Finally, a small‐scale laboratory‐based prototype is designed for all charging pads to verify the feasibility of the proposed method. Both simulation and experimental validation ensure the improvement of DC–DC efficiency irrespective of LTMs of the proposed inward OV BP coil position.

The integration of solar panels with wireless Electric Vehicle (EV) charging systems presents a promising solution for sustainable and autonomous energy transfer in electric mobility. By harnessing solar energy, these systems can generate clean, renewable power to charge EVs wirelessly, reducing dependency on the grid and promoting eco-friendly transportation. Solar-powered wireless EV charging systems typically combine photovoltaic (PV) technology with inductive power transfer (IPT) for energy delivery, offering a cleaner alternative to conventional charging methods. This technology enables the deployment of charging stations that not only provide energy to EVs but also contribute to reducing carbon footprints by utilizing renewable energy. Key challenges include optimizing solar energy conversion efficiency, ensuring effective energy storage, and addressing variability in solar power generation due to weather conditions

The efficiency of inductive power transfer (IPT) system is highly related to the conditions of load and the compensation network. Combined with lithium battery charging characteristic, the transfer efficiency exhibits sharply decreasing in constant voltage (CV) mode in wireless electric vehicle (EV) charging system. This paper compares the light-load efficiency between LCC-Series (LCC-S) and LCC-Parallel (LCC-P) compensation networks under constant voltage (CV) charging mode. An efficiency optimization method is proposed for the LCC-P compensated wireless EV charging system, which is more suitable for the load variation during the constant voltage (CV) charging phase of the lithium battery. After the theoretical analysis is conduced, the MATLAB simulation and experiment were completed to prove the accuracy of the analysis result.

Due to the inherent misalignment variations in wireless electric vehicle (EV) charging systems, particularly in dynamic charging modes, it is essential to acknowledge the misalignment performance in the design and optimization of the coupling coils and the shielding layers. In this work, a heuristic inductive link design approach is presented, in which the coupling performance of rectangular RIPT coils is evaluated over a range of lateral misalignments for different coil parameters and shielding layer thickness. Accordingly, recommendations are made on the inductive link design that provides good coupling behavior, sufficiently high power transfer efficiency and effective shielding performance over a wide range of lateral misalignments.

The inevitable coils misalignment of the loosely coupled transformer (LCT) and load variations in a wireless EV (electric vehicle) charging system can dramatically affect the output and input characteristics. In this paper, a resonant method is investigated for a closed-loop LCC-series compensated inductive power transfer (IPT) system. With the proposed method, coupling- and load-independents voltage transfer characteristic and zero phase angle (ZPA) operation are achieved simultaneously. A laboratory prototype is implemented and the validity of proposed LCC-series compensated IPT system is verified.

Electric vehicles (EVs) wireless charging is enabled by inductive power transfer (IPT) technology, which eliminates the need for physical connections between the vehicle and the charging station, allowing power to be transmitted without the use of cables. However, in the present wireless charging equipment, the power transfer still needs to be improved. In this work, we present a power transfer structure using a unique “DD circular (DDC) power pad”, which mitigates the two major obstacles of wireless EV charging, due to the mitigating power of electromagnetic field (EMF) leakage emissions and the increase in misalignment tolerance. We present a DDC power pad structure, which integrates features from both double D(DD) and circular power pads. We first build a three-dimensional electromagnetic model based on the DDC structure. A detailed analysis is performed of the electromagnetic characteristics, and the device parameters regarding the power transfer efficiency, coupling coefficient, and mutual inductance are also presented to evaluate the overall performance. Then, we examine the performance of the DDC power pad under various horizontal and vertical misalignment circumstances. The coupling coefficients and mutual inductance, as two essential factors for effective power transmission under dynamic circumstances, are investigated. The findings of misalignment effects on coupling efficiency indicate that the misalignment does not compromise the DDC pad’s robust performance. Therefore, our DDC power pad structure has a better electromagnetic characteristic and a higher misalignment tolerance than conventional circular and DD pads. In general, the DDC structure we present makes it a promising solution for wireless EV charging systems and has good application prospects.

In this article, a dual-loop active shielding coil directly connected in series with the primary coil is proposed to reduce the leakage magnetic field while eliminating the additional coupling between the shielding coil and the receiving coil of a wireless electric vehicle (EV) charging system. Parameter design strategy featuring system efficiency improvement and shielding coil cost reduction using multi-objective optimization algorithm is proposed. Finally, a 1.5 kW with 19 cm air gap prototype is fabricated to verify the analytical results and investigate the influence of the shielding coil over the system parameters. The results prove that the proposed active shielding coil shows its advantage on the system transmission performance and the shielding effectiveness on the target surface comparing to conventional aluminum shielding.

Inductive power transfer (IPT) has found application prospect in dynamic wireless electric vehicle (EV) charging as it can avoid the constraints of physical connection. With the commonly-used LCC compensation, the ground-assembled transmitter coil is always excited by a fixed standby current even if there is no receiver coil coverage. As for dynamic wireless power transfer (DWPT) systems, even without EV charging, the underground transmitter coils typically remain activated at full power output to wait for the receivers in most cases, resulting in huge standby current and magnetic exposure safety concerns. In this paper, we proposed a method for automatic containment of field exposure caused by standby current in the transmitter coil of wireless chargers, which applies LCC compensation networks requiring only primary-side control with the elimination of wireless feedback communication and extra detection. The wireless chargers can be automatically deactivated once EVs depart, as well as automatically activated once detecting the presence of EVs. Also, its excellent interoperability for different loads and types of compensation topology has been well analyzed and then verified. Moreover, experiments demonstrate that the magnetic field exposure is merely 11.66% of the ICNIRP 2010 standard exposure limit with proposed modulation, which is suppressed by 94.64% than before.

Wireless Electric Vehicle Charging (WEVC) systems have become a game-changing remedy aimed at enhancing the convenience, safety, and efficiency of electric vehicle (EV) charging. Unlike traditional plug-in systems, with WEVC, physical connectors are no longer necessary by utilizing wireless energy transfer technologies, such as resonant electromagnetic techniques, capacitive coupling, and inductive coupling. These technologies enable seamless power delivery from charging pads to onboard vehicle receivers, allowing EVs to be charged either in stationary or dynamic conditions without manual intervention. This review provides a comprehensive examination of recent advancements in WEVC systems, focusing on improvements in energy efficiency, power transfer capabilities, and adaptability with existing transportation infrastructure. Key innovations in coil design, alignment mechanisms, and power electronics have significantly improved the reliability and performance of these systems. Despite these advancements, several technical and economic challenges persist, including misalignment losses, electromagnetic interference, high implementation costs, and limitations in standardization and interoperability. The review further discusses the regulatory and safety factors that need to be taken into account in order to guarantee the secure implementation of WEVC technology, especially in urban and high-traffic environments. Additionally, the integration of WEVC with smart grid systems and renewable energy sources holds great promise for enhancing grid resilience and enabling energy-efficient transportation networks. The synergy between wireless charging and intelligent traffic management could further promote the development of sustainable, connected, and automated mobility solutions. By evaluating the current state of research and deployment, this review emphasizes the transformative potential of WEVC in supporting environmentally friendly transportation and contributing to the development of smart cities. Future research directions are proposed to overcome existing limitations and accelerate the widespread adoption of this innovative technology.

Wireless electric vehicle (EV) charging is an important operation for valuable EV options in modern life. Inductive wireless EV charging needs constant current and voltage (CC–CV) charge controllers. This paper presents 750 W variable frequency CC–CV inductive wireless charging for an e-golf cart 50 Ah 72 V Li-ion battery. Due to this system’s low power, the system’s efficiency may be weak; the secondary-side (SS) maximum efficiency-controlled (MEC) converter was validated. The golf cart’s battery characteristics were evaluated to design and experiment with inductive wireless power transfer (IPT) coils and an integration system for a 42 kHz resonant frequency. The CC–CV charged control is an infrastructural part of the H-bridge inverter at varied frequencies from 50 kHz to 56 kHz when the DC input voltage is 310 V, and in the range of 44 kHz to 46 kHz at the 155 V input. The results found the charging of 9 A CC, 82 V CV and 730 W. The 310 V input voltage system without the SS MEC converter’s efficiencies was 62% to 72% and it was improved to 65% to 81% using the SS MEC converter. Finally, the best cases were validated at the 155 V DC input voltage and the system with the SS MEC converter had 76% to 86% efficiency.

Although inductive power transfer (IPT) systems dominate the wireless power transfer (WPT) technologies, recently capacitive power transfer (CPT) systems also have received significant attention due to their outstanding benefits such as negligible eddy- current loss, higher reliability, better misalignment performance, lower cost, lightweight, and lower EMI . The CPT technology has many application areas in wireless charging concept. The first example that comes to mind for large transfer distance applications is the wireless electric vehicle (EV) charging . In addition, the effects of dielectric materials on capacitive coupler structures have great importance for increasing the power transfer capability and electric field strength . here three or four metal plate is proposed for EV charging applications . Herein, the chassis of a vehicle and earth ground are high- lighted to substitute for three or four plates used in conventional six plate structures. In addition, a three or four plate capacitive coupler structure provides a decreased number of plates and cost reduction in CPT applications. Then, three or four plate coupler structure to provide less electric field emission for large transfer distance applications. Nevertheless, the number of coupling capacitances to realize the equivalent circuit and increased cost with six metal plates are the drawbacks. the last conventional capacitive coupler structure called as an electric field repeater to enhance the transfer distance in CPT systems. However, the low system efficiency is the disadvantage of the coupler.

Although inductive power transfer (IPT) systems dominate the wireless power transfer (WPT) technologies, recently capacitive power transfer (CPT) systems also have received significant attention due to their outstanding benefits such as negligible eddy- current loss, higher reliability, better misalignment performance, lower cost, lightweight, and lower EMI . The CPT technology has many application areas in wireless charging concept. The first example that comes to mind for large transfer distance applications is the wireless electric vehicle (EV) charging . In addition, the effects of dielectric materials on capacitive coupler structures have great importance for increasing the power transfer capability and electric field strength . here three or four metal plate is proposed for EV charging applications . Herein, the chassis of a vehicle and earth ground are high- lighted to substitute for three or four plates used in conventional six plate structures. In addition, a three or four plate capacitive coupler structure provides a decreased number of plates and cost reduction in CPT applications. Then, three or four plate coupler structure to provide less electric field emission for large transfer distance applications. Nevertheless, the number of coupling capacitances to realize the equivalent circuit and increased cost with six metal plates are the drawbacks. the last conventional capacitive coupler structure called as an electric field repeater to enhance the transfer distance in CPT systems. However, the low system efficiency is the disadvantage of the coupler.

The growing demand for sustainable transportation and renewable energy has led to the development of innovative charging solutions for electric vehicles (EVs). This project presents a Solar Wireless Electric Vehicle Charging System that combines solar energy generation with inductive wireless power transfer (WPT) technology. The system harnesses solar energy through photovoltaic (PV) panels, which convert sunlight into electrical energy. This energy is then conditioned and transmitted wirelessly from a transmitter coil embedded in the ground to a receiver coil installed beneath the vehicle. The proposed system eliminates the need for physical charging cables, enhancing convenience, safety, and efficiency while promoting clean and renewable energy usage. The design integrates power electronics circuits, such as DC–DC converters and resonant inverters, to maintain stable power transfer and improve charging efficiency. The project aims to demonstrate the feasibility of integrating solar power and wireless charging for electric vehicles, offering a sustainable and user-friendly alternative to conventional plug-in charging systems