Magnetically levitated (ML) systems that incorporate PCB coils represent a growing trend in precision machining, valued for their controllable current flow and high fill factor. The size of modern power devices is decreasing to enhance power density, minimize parasitic inductance, and reduce power losses. However, due to the high resistance of PCB coils, managing heat generation has become a significant area of study. This paper seeks to optimize PCB coil design to minimize power loss and control peak temperatures in ML systems, using a numerical model. An improved magnetic node model is employed to construct the magnetic fields of an ML system. The proposed optimization method considers the interdependencies among parameters to reduce overall power loss from coil resistance and switching losses in the H-bridge circuit, while enhancing heat dissipation efficiency in steady-state operation. A heuristic multi-objective optimization algorithm is employed to optimize the design of the ML actuator. The optimization process initially focuses on the PCB coils, with the magnet size held constant. Once the optimal coil parameters are identified, the magnet volume is optimized. By integrating a theoretical analysis with simulation, this approach effectively addresses the optimization challenges and achieves the desired performance for the ML actuator. Coils and magnets are constructed based on the optimized design and tested by the magnetic field simulation software Radia, confirming the feasibility of the approach. The method was also applied to a different type of ML system for comparison, demonstrating the universality of the proposed strategy. In this optimization effort, the maximum temperature reduction reached an impressive 50 °C

Metal detectors detect hidden metal objects through electromagnetic induction. Significant research has focused on improving the detector sensitivity by redesigning the structure of differential receiving coils. Higher sensitivity allows the detector to identify smaller metal objects or detect objects at greater depths. This is significant in applications such as security screening and industrial quality control, where precision is essential. This paper introduces a novel receiving PCB coil prototype for a high-sensitivity metal detector and presents a numerical modeling method to optimize the coil size. The strip coils distributed around the emitting coil are employed in the differential receiving coils, thereby strengthening the induced voltages caused by the electromagnetic field excited from the detected metal objects. The balance state of the differential receiving coils is analyzed using a numerical model based on the Biot-Savart law, solving the total magnetic flux from the emitting windings. An optimization problem is constructed from the numerical model, and the optimal design parameters of the receiving coil are determined via a heuristic algorithm. Experimental results indicate that the newly designed prototype exhibits superior sensitivity compared to commercial differential detectors of comparable size. Specifically, the sensitivity of the novel detector is twice that of the advanced commercial counterpart.

This paper presents a novel spatial-structure optimization method for the coils of moving-coil magnetically levitated planar motors (MLPMs) to address the coupled challenges of power consumption and spatial constraints. The proposed framework systematically determines the optimal coil geometry and arrangement to minimize power consumption under a required force output and a strictly confined mover volume. A harmonic-based electromagnetic force model is employed to guide a compact coil layout by defining the number, length, and spacing of coils. These parameters are subsequently incorporated into a power-minimization model to determine the coil and beam widths. A final trade-off optimization is performed to balance high-order harmonic suppression and manufacturing tolerance, resulting in a comprehensive design strategy. Experimental results validate the superiority of the proposed method: under identical motor dimensions and magnetic pole pitch, the optimized design achieves more than a 40% increase in thrust-to-weight ratio (TWR) while reducing thrust fluctuation to below 15%. Furthermore, at a constant levitation height, the proposed design reduces power consumption by 10% to 25% compared with conventional systems. These findings demonstrate significant improvements in system stability and force efficiency, offering a generalized and practical design guideline for high-performance moving-coil MLPM.