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Wireless charging of electric vehicles (EV) are inevitable for user convenience of EV charging when the EVs are parked in the charging stations. A new set of triangular DQ transmitting (Tx) coils for wireless EV chargers is newly proposed in this article for large longitudinal, lateral, and diagonal displacement tolerances. The proposed coil set consists of two layers, i.e., D-Tx and Q-Tx, where each Tx layer has two triangular coils of the same magnetic polarity diagonally, facing each other to generate a more uniform coupling coefficient between Tx and Rx w.r.t. the misalignments. In practice, diagonal misalignment tolerance is an important design criterion to deliver load power to EV because the worst scenario of misalignment is when longitudinal and lateral misalignments occur at the same time, i.e., diagonal misalignment. To solve these misalignment issues, the DQ transmitters were optimally designed to obtain uniformed output voltage against wide range of the diagonal misalignment situations. A prototype of an inductive power transfer (IPT) system having the proposed triangular DQ Tx coils for 3.5 kW wireless EV chargers was fabricated and experimentally verified with a switching frequency of 85 kHz, which can satisfy J2954 WPT1 class in the society of automotive engineers (SAE). As a result, it is found that 8.62 of the diagonal misalignment tolerance γd has been achieved, and this value is superior to the other Tx coils.

A reliable dc magnetic field generator (DFG), which utilizes residual magnetic field in ferromagnetic material for uniformly distributed wide-range dc magnetic generation, is newly proposed in this article for motion measurement applications. Contrary to the conventional optical sensors for motion measurement applications, the inertial measurement units (IMUs) sensors are the most viable solution by virtue of high resolution and no sensor shadow issue although the sensors are closed together. In conventional IMU sensors, a geomagnetic field is used for the terrestrial magnetism sensors as a reference to calibrate the absolute positions. However, the geomagnetic field inside buildings, factories, or houses may be severely distorted and, therefore, is unreliable as an absolute reference for precise motion measurements. Thus, uniformly distributed dc magnetic generation is strongly required for reliable IMU sensor measurements. To provide convenient motion measurement environments, a U-shaped magnetic core is applied so that the users can easily access the measurement environments while the uniformed and reliable magnetic field is built. To enhance the uniformity of the magnetic field generation, the residual magnetic field is utilized so that the resultant magnetic vector is finally uniformed in the $y$ -axis, i.e., $B_{\text {t}} \approx B_{y}$ in this article. All the detailed design procedure of the DFG for uniformly magnetic field generation and the appropriate coil shape selection are provided in this article. The experimental results verified by a $30\times 30\times30$ cm small-scaled prototype, and a $1.5\times 1.5\times1.5$ m real-scaled prototype of the DFG showed that the dc magnetic field uniformity $\theta _{\mathrm {t}}$ is below 10.0° over 92% of the total volume.