An Anti‐Offset Electric Vehicles Wireless Charging System Based on Four Decoupled Receiver Coils

The large dv/dt and di/dt outputs of power devices in wireless charging system (WCS) in electric vehicles (EVs) always introduce conducted electromagnetic interference (EMI) emissions. This paper proposes a mitigation conducted emission strategy based on transfer function from a direct current fed (DC-fed) WCS for EVs. A complete test for the DC-fed WCS is set up to measure the conducted emission of DC power cables in a frequency range of 150 kHz–108 MHz. An equivalent circuit with high-frequency parasitic parameters for WCS for EV is built based on measurement results to obtain the characteristics of conducted emission from WCS. The transfer functions of differential mode (DM) interference and common mode (CM) interference were established. A judgment method of using transfer functions to determine the dominated interference mode responsible for EMI is proposed. From the comparison of simulation results between CM or DM and CM+DM interference, it can be seen that the CM interference is the dominated interference mode which causes the conducted EMI in WCS in EVs. A strategy of giving priority to the dominated interference mode is proposed for designing the CM interference filter. Finally, the conducted voltage experiment is performed to verify the mitigation conducted emission strategy. The conducted voltage of simulation and experiment is decreased respectively by 21.17 and 21.4 dBμV at resonance frequency 30 MHz. The conduced voltage at frequency range of 150 kHz–108 MHz can be mitigated to below the limit level-3 of CISPR25 standard (GB/T 18655-2010) by adding the CM interference filters.

Wired charging of electric vehicles comes with certain challenges and difficulties, such as handling bulky cables, risk of damage and compromised safety due to harsh climatic conditions such as heavy rain, wind or snow, and even vandalism. Wireless charging of electric vehicles is gaining prominence because it can mitigate the aforementioned challenges and difficulties and can also operate at the same power transfer efficiency as wired methods today. To design and optimize magnetically coupled coils of a wireless charging system for electric vehicles, numerous simulations utilizing the finite element method (FEM) need to be performed for the estimation of several parameters. This process is time-consuming and computational resource- intensive. In this paper, a real-time approach for obtaining quick estimated results for coupled coil parameters in an 11-kW wireless charging system for electric vehicles is presented. The proposed hybrid approach utilizes fitted curves obtained from the results of a single three-dimensional (3D) FEM simulation for a set of parameters and combines them with polynomial equations in order to estimate the values of the self-inductances of the coupled coils, their mutual inductance, the coupling coefficient and the power transfer efficiency of the wireless charging system. An experimental verification is conducted to compare the coupling coefficient values obtained from the real-time estimator with the measured coupling coefficients of an 11-kW wireless charging system laboratory prototype. The measured values of the coupling coefficient closely correlate with those predicted by the real-time estimator with a median error of 2.133%. Thus, the proposed approach opens up a new way for real-time estimation of parameters for coupled coils, which can save time during the initial developmental stage of an 11-kW wireless charging system for electric vehicles.

This paper presents a comprehensive review of the intelligent algorithms (IAs) based optimization of electric vehicle (EV) wireless charging. First, a general overview of EV wireless charging system is introduced in terms of the compensation circuit, coupling coils, and control strategies, followed by the potential application of IAs. Then, the optimization target, parameter optimization, and structure design of the compensation topologies based on IAs are elaborately expounded by citing current research findings. Subsequently, the IAs are deeply explored for optimizing the systematic parameters, structural geometries, and coupling coils. Then, the IA-based research on the control strategies in the wireless charging system is discussed in detail from three aspects, including power controlling, efficiency optimizing, and parameter tracking. Finally, the prospects for the application of IAs to the EV wireless charging system are summarized and delineated. This paper will be highly beneficial to research entities as a ready reference for the wireless charging system of EVs, with information on IA-based system design.

Compensation networks play the role of reactive power compensation, impedance matching and constant voltage/current conversion in wireless electric vehicle charging systems. With the development of technology, there are more and more types of compensation topologies. In the process of standardization, two topologies, double-sided LCC (DSLCC) topology recommended by Chinese national standard and the tunable matching network (TMN) recommended by the international standard SAE J2954, emerge. In this paper, the above two compensation topologies are modeled and analyzed, including the impact of load and mutual inductance on the output voltage/current. Then, the parameters of DSLCC topology and TMN are investigated aiming at the load-independent output characteristics. Furthermore, the output power and zero phase angle (ZPA) conditions when the DSLCC topology interoperates with TMN are derived considering the system input impedance. Finally, the output characteristics of DSLCC topology and TMN with different parameters are simulated, and the interoperability between them is verified.KeywordsWireless chargingInteroperabilityCompensation topologyElectric vehicle

The usage of electric vehicles will contribute to a decrease in greenhouse gas emissions and rising fuel costs. To promote acceptance of electrified mobility, a variety of charging networks must be established in an approachable setting. A prospective substitute solution for charging electric vehicles (EVs) without any plug-in issues is wireless electric vehicle charging systems (WEVCS). This paper presents the surface of the wireless charging system flow from the start until the end of the line. The discussions take the consideration from the grid side until to the battery of the EVs including the battery management system (BMS). So, the application of WEVCS also is driven into the impact on the electric power grid. Then, the author also predicts the future of WEVCS based on potential technical advancements and already in effect policies, followed by some conclusions.

In this paper, an optimized core structure is proposed for the double-D (DD) power pad to reduce its core loss in a wireless charging system for Electric and Plug-in Hybrid Electric Vehicle (EV/PHEV) application. At around 85 kHz operating frequency, the core loss is found to be one of the most significant loss in typical wireless charging system of high power application. The core loss in power ferrite mainly depends on the operating frequency and magnetic field density in the core. The frequency is usaully fixed for certain appication, therefore, the magnetic field density in the core is be to optimized to reduce the loss. The magnetic field density in core of a double-D (DD) pad has very different pattern compared to unpolar pad; therefore traditional bar or plate core does not provide the optimum performance considering core loss. In this paper, an optimized core structure is proposed to make the flux density uniform in the core and minimize its loss. The proposed optimized model is simulated in finite element analysis (FEA), and compared with traditional flat type core. Finally, the proposed model is verified through a 3.2kW wireless Double-D (DD) type wireless charging pad.

This paper comparatively analyses the four fundamental compensation topologies (series-series (SS), series-parallel (SP), parallel-series (PS), parallel-parallel (PP)) for wireless power transfer (WPT) systems applied to electric vehicle (EV) charging, evaluating by MATLAB/Simulink the energy efficiency, voltage/current constraints and misalignment tolerance. The results show that: SS topology achieves the best efficiency with stable voltage regulation but increased sensitivity to coupling variations; SP has the advantage of reducing stress on switches while increasing circuit complexity; while PS and PP configurations demonstrate better output current stability but higher losses under misalignment conditions. The analysis provides clear recommendations for the choice of topologies according to target applications, highlighting the trade-offs between energy performance, robustness and implementation complexity in wireless charging systems for electric vehicles (EVs).

Wireless charging system for electric vehicles is a hot research issue in the world today. Since the existing research on wireless charging is mostly forward-looking aimed at low-power appliances like household appliances, while electric vehicles need a high-power, high-efficiency, and strong coupling wireless charging system. In this paper, we have specifically designed a 6.6 KW wireless charging system for electric vehicles and have proposed a control strategy suitable for electric vehicles according to its power charging characteristics and existing common wired charging protocol. Firstly, the influence of the equivalent load and frequency bifurcation on a wireless charging system is analyzed in this paper. Secondly, an adaptive load control strategy matching the characteristics of the battery, and the charging pile is put forward to meet the constant current and constant voltage charging requirements to improve the system efficiency. In addition, the frequency adjustment control strategy is designed to realize the real-time dynamic optimization of the entire system. It utilizes the improved methods of rapid judgment, variable step length matching and frequency splitting recognition, which are not adopted in early related researches. Finally, the results of 6.6 kW test show that the control strategy works perfectly since system response time can be reduced to less than 1 s, and the overall efficiency of the wireless charging system and the grid power supply module can reach up to 91%.

This paper presents a study of the influencing factors on magnetic leakage field of a 7 kW wireless electric vehicle charging (WEVC) system. The leakage field was measured in different test configurations and environments which afterwards were used to validate simulation models. The impact on magnetic leakage field distribution when varying the test environment and the test setup is presented in this paper. These results will be used to support discussion and recommendation in standards bodies related to the measurement of the magnetic leakage field of WEVC systems.

Wireless Power Transfer (WPT) is a popular technology with applications in many fields.Power is transmitted from source to source without connection.WPT can be used to handle physically unavailable or unsuitable electronic devices.This method uses the principle of mutual inductance.One of the applications of the future is the automotive sector, especially electric vehicles.This project includes the research and development of a wireless charging system for electric vehicles using wireless transmission.The main purpose is to transfer energy and create a compensation using resonance coupling.The system includes electrical equipment such as AC power supply, transmit coils, receive coils, transducers and batteries.

For electric vehicle wireless charging (EVWC) systems, the foreign metal objects in the charging area will be heated, and it carries danger to the system because of the induced eddy current. Existing foreign object detection (FOD) methods focus on the same detection area as the transmitter. However, the foreign objects in the edge area of the transmitter may also be heated and cannot be detected. This paper proposes a method that can determine the area of FOD based on the temperature rise. Firstly, the loss model and the temperature variation of the foreign object is established. Secondly, the threshold of the flux density exposed to the foreign object is calculated according to the temperature rise. Then, the reasonable area of FOD can be determined by the threshold. Finally, an 11 kW EVWC prototype is set up. The experimental results prove that for a transmitter with an area of $650mm\times 510mm$, the foreign objects in the detection area of $726mm\times 596mm$ will be heated to the dangerous temperature so the detection area needs to be extended.

This project introduces a solar-based wireless charging system for electric vehicles (EVs), designed to provide a contactless, automated, and sustainable energy transfer method using inductive coupling technology.The primary objective is to eliminate the need for physical connectors, reduce human intervention, and enable environmentally friendly EV charging using renewable energy sources.The system harnesses solar energy via a 12V, 10W polycrystalline solar panel, which charges a Li-Ion battery through a solar charge controller.The stored energy is then used to power a high-frequency wireless transmitter coil.When an EV is detected at the station using an IR sensor, the system automatically activates a servo motor that aligns the transmitter coil to maintain an optimal 10mm distance from the vehicle's receiver coil, ensuring maximum energy transfer efficiency.The receiver side of the EV includes a coil that captures the magnetic field, a rectifier to convert the received AC into DC, a 7805 voltage regulator, and a charging module for safe battery management.The energy is then stored in the EV's onboard battery and used to drive a DC motor, simulating EV movement.A voltage sensor continuously monitors the battery, and the status is displayed on a 16x2 I2C LCD screen, indicating states such as "Full", "Half", or "Not Charging".This system not only demonstrates wireless power transmission but also integrates automation, IoT-based monitoring potential, and renewable energy for a fully self-sustaining setup.Its compact and modular design makes it ideal for small-scale applications like autonomous delivery robots or prototype electric cars and opens the door to future scalability for full-size EVs.By eliminating wear-prone connectors and supporting real-time battery monitoring, the project addresses key challenges in modern EV charging.Furthermore, the implementation of smart alignment using servo motors, and the potential to extend the system with IoT platforms like Firebase/Blynk, makes it a next-generation charging model.

This paper presents a performance analysis of the power inverter and switching devices for wireless charging systems (WCS) applied in Electric Vehicles (EV). The purpose of this analysis was to determinate the switching devices impact and effects on the WCS efficiency under EV chargers conditions. Besides, to show a perspective on the trend and use of new power semiconductor technologies and the way for choosing the adequate devices. The study was developed through the power and total losses evaluation on the devices, considering the EV chargers requirements such as power levels and operation frequency. The analysis showed that not only the power transmission stage is so important in the WCS design for achieving high-performance chargers but else the electronic components of the power inverter. In addition, the investigation showed that the use of new technologies is necessary for the new WCS requirements, as well as additional considerations in the design of WCS with the proposed standards.

Wireless charging is an attractive option of energy replenishment for electric vehicles (EVs) as it does not require direct electrical contact to the EVs. However, the radiated magnetic field from the EV wireless charging system can be an electromagnetic compatibility (EMC) concern nearby electrical and electronic devices. This paper investigates the influence of the power level, the clearance, and offset between coils on the radiated magnetic field emitted from the wireless charging system. The experimental study shows that these variable parameters can affect the radiated magnetic field level and the field distribution, which provides valuable input for standardization of the test setup and working condition of the EV wireless charging system.

The paper overviews novel technique for wireless charging system of electric vehicle in which verifies the developed theory using battery charger application of electric vehicle. In electric vehicle charging of battery through charger and wire is inconvenient, hazardous and expensive. The existing gasoline and petrol engine technology vehicles are responsible for air, noise pollution as well as for greenhouse gases. The implemented wireless charging system of battery for Electric vehicle by inductive coupling method has been presented in this paper. The driving circuit is used between the transmitter coil & receiver coil where MOSFET is used for switching operation. The transmitter coil circuit is turn ON and OFF whenever the vehicle is present and absent respectively. The system is achieves 67% efficiency level while providing safety, reliability, low maintenance and long product life.