Electric vehicles (EVs) have gained significant adoption due to their advantages over conventional vehicles. The Photovoltaic Inductive Wireless Power Transfer (PV-IWPT) system combines wireless charging technology with photovoltaic panels to provide clean, solar-powered EV charging. However, varying distances between the ground and EV chassis create inconsistent coupling coefficients, causing fluctuating optimal load conditions for the IWPT converter and making it challenging to maintain peak efficiency without manual recalibration. This paper introduces a Ground-to-Chassis distance adaptive control approach for PV-IWPT systems that simultaneously achieve Maximum Power Point Tracking (MPPT) for solar harvesting and Maximum Efficiency Point Tracking (MEPT) for power transfer across different ground-to-chassis distances. The system automatically adapts to positional variations without requiring hardware adjustments. We validate our approach through theoretical analysis and experimental verification using a 500-W test platform under multiple distance configurations and solar shading conditions, demonstrating its practical viability for real-world applications.

Conventional wireless power transfer (WPT) systems struggle to maintain constant voltage output under wide input voltage variations, such as battery-powered devices and renewable energy systems where voltages fluctuate due to load changes and environmental conditions. This paper addresses the challenge of maintaining constant voltage output under a tenfold input voltage range. The proposed adaptive full-bridge/half-bridge (FB/HB) dynamic modulation switching topology with asymmetric PWM (APWM). Comparing dynamic table lookup control (LUC) with the proposed method shows superior output voltage stability with reduced overshoot. The system achieves constant voltage regulation through single-stage modulation across the entire ten-fold input range that enables robust wireless power delivery.

In electric vehicle wireless power transfer systems, misalignment between primary and secondary coils commonly occurs, resulting in mutual inductance fluctuations that decrease transfer efficiency. To overcome this problem, this paper proposed a novel misalignment-tolerant coil design combining quadrupolar trapezoidal coils with unipolar square coils on the secondary side. These two sets of coils are connected in series through a diode rectifier, making the equivalent mutual inductance equal to the sum of their absolute mutual inductance values. When perfectly aligned, the unipolar square coils maintain good coupling with the transmitter coil while the quadrupolar trapezoidal coils remain decoupled. During misalignment, as the mutual inductance between unipolar coils and the transmitter decreases, the mutual inductance between quadrupolar coils and the transmitter increases. This complementary relationship maintains a nearly constant total equivalent mutual inductance, providing exceptional misalignment tolerance and stable system output. Simulation results show mutual inductance fluctuation of only 2.60%, with experimental verification demonstrating 3.11%. The output voltage fluctuation in simulation is just 2.51%, while the system achieves a peak efficiency of 95.52%.

The use of unmanned surface vehicles (USVs) in oceanography research is widespread due to their ability to provide real-time data. Due to the limited battery size, recharging operations including plugging and unplugging decrease the overall utilization of the USV. To address this issue, wireless power transfer (WPT) can be implemented by installing coils at the dock and inside the USV. In this paper, a three-coil WPT system is designed for offshore USV wireless charging applications. The proposed three-coil structure is designed to ensure adequate coupling and achieve high transfer efficiency. Aiming to meet practical battery charging specifications, LCC-S-S compensation topology is analyzed with detailed parameter design to provide constant current output. Finally, simulations are conducted to verify the coupling and output characteristics of the system.

The wireless power transfer (WPT) technology has gained significant attention in recent years due to its potential to provide a convenient and efficient method to charging electronic devices without the need for physical connections. In wireless charging, the inductive coils are significantly important as they are the component that power transfer takes place. In this context, Multi-Objective Particle Swarm Optimization (MOPSO) has emerged as a promising technique for designing WPT coils with improved performance. Aiming to verify the performance of the designed coil, LCC-S compensation topology was utilized as it can provide practical battery charging specifications.

Compared with the conventional constant current-constant voltage (CC-CV) charging profile of Li-ion battery, multi-stage constant current (MSCC) charging profile that composed of different constant current stages can improve the charging rate. This paper proposes a MSCC charging profile for an inductive power transfer (IPT) converter with LCC-S compensation topology. However, the wide load range variation during charging process impacts the transfer efficiency of the IPT converter. Thus, aiming to improve the transfer efficiency throughout the whole MSCC charging process, a bivariate operation approach is proposed with a variable inductance to achieve different constant current stages, while the voltage-controlled semi-active rectifier (VCSAR) is controlled to ensure the converter’s efficiency optimization. Finally, simulation study is conducted based on PSIM software simulation to verify the validity and effectiveness of the bivariate control strategy and MSCC charging for the LCC-S compensated IPT converter.

In lithium-ion (li-ion) battery charging process, multistage constant-current (MSCC) charging can effectively increase the charging capacity with less charging time compared with the conventional constant current-to-constant voltage (CC-to-CV) charging in wired charging. This paper proposes and designs a MSCC charging strategy for the wireless power transfer system. By using the LCC-S compensation topology for the inductive power transfer (IPT) converter, the current gain is designed with mathematical derivation to achieve load-independent current output with zero phase angle (ZPA) according to the MSCC charging pattern. Phase-shift modulation (PSM) is adopted to control the input DC-link of the WPT system to achieve different current outputs according to different CC stages. Finally, the charging system is simulated to verify the correctness of the design and the feasibility of the proposed WPT system with MSCC charging. The maximum efficiency of the system is 92.4% and the time-averaged efficiency is 91.3%.