Conference Agenda

This paper proposes a method for reducing harmonic noise in wireless power transfer (WPT) systems using reflected impedance. In a conventional WPT system, DC power is supplied to the transmitting coil through an inverter, generating a time-varying magnetic field that induces voltage in the receiving coil. However, due to the operation of the inverter and rectifier, a square wave voltage is generated, which contains not only the fundamental frequency component but also multiple harmonic components. These harmonic voltage components can cause unwanted harmonic noise, leading to electromagnetic interference (EMI) issues. Therefore, a method is required to effectively suppress harmonic components while maintaining the fundamental frequency characteristics. In this study, a harmonic noise reduction technique utilizing reflected impedance is proposed for an SS topology-based WPT system. Additional inductance (L) and capacitance (C) are introduced to adjust the impedance characteristics at both the operating and harmonic frequencies. The proposed method is theoretically analyzed, and its effectiveness is validated through simulations. The results demonstrate that the system's power transfer efficiency (PTE) is increased by 0.2%, and harmonic current components are significantly reduced.

In this work, the goal is to characterize PCB-based passive resonators, fabricated to work in a 4×4 array with the aim of mitigating the magnetic leakage in dynamic wireless electric vehicle (EV) charging systems. The array of resonators is configured in a 2D layout, and it consists of spirals having rectangular shape which will be activated through inductive coupling with the nearby dynamic wireless power transfer (DWPT) system. Current research for low-frequency magnetic shielding in this area is limited. The solution proposed in this research is lightweight, cost-efficient and adjustable with magnetic shielding purposes. Hence, since the system is narrowband, the tuning capacitance values play a crucial role in the DWPT system. Consequently, this work concerns measuring the performance of the single resonator’s resonance frequency, which for magnetic shielding purposes needs to be as accurate as possible.

This study analyzes the high-frequency characterization of Dynamic Wireless Power Transfer (DWPT) coils for electric vehicles (EVs), focusing on frequency dependent resistance, inductance, and parasitic capacitance. Using FEM simulations and experimental measurements by an LCR meter, key parameters such as AC resistance of a Litz wire coil and inter-winding and ground capacitances are extracted to model coil behavior. The Vector Fitting (VF) method is applied to develop an accurate equivalent circuit with time constant parameters over a wide frequency range.

This paper investigates the impact of resonant reactive shielding on both, the magnetic field emissions and efficiency of a wireless power transfer (WPT) system for electric vehicles. The shield coil is designed, built, and analyzed through CST simulations and experimental validation in a semi-anechoic chamber using an SAE J2954-compliant test setup at 3.7 kW. The influence of the shield coil position on max. attenuation is determined, showing that an optimal attenuation of nearly 15 dB occurs at a specific height, with good qualitative agreement between simulation and measurement with respect to the required resonance capacitance and the shield coil height. The shielding effect is most pronounced in the x- and z-directions. The best field attenuation reduces the efficiency of the WPT system by approximately 4%. Additionally, it is shown that the shield coil does not necessarily need to be mounted on the vehicle, which would cause higher weights and require expensive space. Max. shielding effectiveness can also be achieved, when the shielding coils are embedded into the ground assembly (GA).