The connected and autonomous vehicle (CAV) is promised to ease congestion in the future with the rapid development of related technologies in recent years. To explore the characteristics of mixed-traffic flow and the dynamic transmission mechanism, this paper firstly detailed the car-following model of different vehicle types, establishing the fundamental diagram of the mixed-traffic flow through considering the different penetration rates and fleet size of CAV. Secondly, this paper constructed the lane-changing judgment mechanism based on the random utility theory. Finally, the paper proposed a lane-level dynamic cell transmission process, combined with a lane-changing strategy and cell transmission model. The effectiveness and feasibility of the model are verified using simulation analysis. This model makes a systematic, theoretical analysis from the perspective of the internal operation mechanism of traffic flow, and the lane-level traffic strategy provides a theoretical basis for balancing urban lane distribution and intelligent traffic management and control.

Since the racetrack excitation windings of the superconducting synchronous motor are in the cylindrical air gap, during the preliminary design, the magnetic field analysis model of the motor can be simplified to solve the magnetic field generated by the current-carrying conductor within a single or two circular ferromagnetic boundaries. Because the magnetic field analysis method based on Laplace equation and Poisson equation is difficult to calculate the flux density on the excitation windings, an analytical model of the superconducting excitation field based on the mirror method is proposed in this paper. The calculation results show that the proposed model has high accuracy and computational efficiency for the superconducting synchronous motors, so it is suitable for the preliminary design and optimization of the superconducting synchronous motors. Considering the saturation of the rotor core, a calculation method of the equivalent image current on the rotor core is presented, which can effectively reduce the error of the analytical model in the saturated case. In addition, to make the critical current calculation results of 2D model more reliable, a margin factor is added when applied to the preliminary design of superconducting motors.

When researching and designing high-temperature superconducting (HTS) excitation motors, it is crucial to account for the impact of ferromagnetic structures on the critical current and losses in superconducting windings. The finite element methods based on the T-A formulation, H formulation, and other formulations are viable options. However, since the finite element method has to calculate the huge air domain, its computational efficiency is lower than the J-model, which only calculates the superconducting winding domain. Ferromagnetic structures in HTS excitation motors are circular, and the J-model has not been applied in such application. Therefore, to increase the efficiency of the research and design for superconducting windings in HTS motors, this article combines the J-model with the mirror image method and realizes the calculation of critical current density and losses in the superconducting winding of HTS motors. The accuracy of the improved J-model is increased by using current density instead of concentrated current. To further enhance the efficiency of the improved J-model, an adjustment method for calculation step-size is designed to ensure fast convergence and rapid calculations. A two-pole HTS excitation motor model is set up to verify the reliability of the improved J-model. The results demonstrate that the improved J-model achieves high accuracy in calculating critical current density and losses. Meanwhile, the improved J-model also has very high computational efficiency and strong convergence. Therefore, the improved J-model significantly increases the efficiency of research, design and optimization of HTS windings in HTS excitation motors. Moreover, it offers a valuable reference for calculating critical current density and losses based on the J-model in superconducting windings of other superconducting applications involving ferromagnetic structures.

This paper proposes the application of high-voltage stator-cable windings in superconducting machines, based on the characteristics of strong magnetic fiel

The expense of superconductors is crucial in determining the feasibility of large-capacity superconducting machines and ambitious projects. Various superconducting coil (SC) arrangements, including stepped-shape field windings, have been optimized by finite-element analysis (FEA) to minimize material usage. In this paper, for precise design and optimization, the H homogenization technique is first implemented in the modeling of a high-temperature superconducting (HTS) aircraft propulsion machine with the stepped-shape field winding. Consequently, numerical model suffers from large execution time and computation burden, especially for optimization of structural parameters of large equipment. Then, an efficient method for superconducting machines with multiple groups of field coils stacked design optimization is proposed to achieve optimal performances as indicated by the high fundamental magnetic field, low total harmonic distortion, and minimizing the price of the HTS winding. In addition, this paper proposes enhancing bottom SC utilization in stacked superconducting machines by independently adjusting currents. The proposed machine is optimized and compared by the optimization method proposed in this paper. Ultimately, the optimized superconducting machine exhibits excellent electromagnetic performance, notably reducing SC usage.

The high-frequency electromagnetic noise caused by a frequency converter power supply has become the main composition of the vibration and noise of frequency-converter-driven PMSMs. Determining how to reduce this kind of noise is very important to improve motor performance. This paper analyzes the frequency characteristics of the high-frequency noise generated by an inverter, using the magnetic circuit analysis and Maxwell tensor methods. The switching frequency and the natural frequencies of the main modes are optimized according to the modal characteristics of the motor in order to reduce the vibration and noise of the motor. The results show that the high-frequency electromagnetic vibration and noise generated by the inverter is mainly caused by the high-frequency switching harmonic current. The frequencies of the vibration and noise are related to the switching frequency and the modulation wave frequency. At the same time, the simulation calculation of the natural frequencies of the main modes and the noise spectrum obtained from the experiment provide direction for the optimization of the vibration noise near the switching frequency. The switching frequency optimization and the natural frequency optimization based on the main modes of the motor can effectively reduce vibration and noise. This work has certain reference significance for the design of low-noise PMSMs.