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Abstract To optimize railway car routing based on balanced station‐line capacities, thereby improving railway freight traffic organization efficiency, and reducing transportation costs, a railway car routing optimization model based on the coordinated utilization of station‐line capacities was developed. Based on the theory of the membership function in fuzzy mathematics, the level of railway station‐line coordination based on capacity utilization was presented. The occupancy of a railway line by each car was taken as a binary decision variable. Using a set of deviation constraints, the deviation between the station‐line flow of the railway network and the utilization of a certain level was expressed in the form of decision variables that were then penalized to different degrees in the objective function. The total transportation cost and the penalty cost were taken as the objective function for minimization. Based on the characteristics of the fuzzy membership degree, the relationship between the penalty for capacity deviation and the membership function in the optimization model was analyzed, and the calculation method of the penalty for the capacity deviation considering the membership function was presented. An adaptive large‐scale neighbourhood search (ALNS) algorithm was designed to solve the model, and its effectiveness was verified. An actual 36‐station railway network was used to validate the proposed railway car routing optimization model through comparison with existing models. The optimization results showed that, at the expense of increasing the transportation cost by 1.05%, the coordination penalty cost was reduced by 11.24%, the overall cost was reduced by 3.21%, and most of the situation with 90% utilization rate of stations and lines in the railway network was eliminated. The model proposed in this paper can help reduce the pressure on lines and stations with tight capacity in the network, improve the utilization of virtual lines and stations and coordination of station‐line capacities.

The three-phase voltage type Pulse Width Modulation (PWM) rectifier is widely used in the front-end power factor of electric vehicle wireless charging systems due to its simple control structure and easy implementation. The system often adopts a double closed-loop PI control method based on voltage and current, which inevitably leads to a significant starting current surge and poses significant risks to the safe operation of the equipment. On the basis of establishing a mathematical model for PWM rectifiers, this article analyzes in detail the causes of starting over-current and designs a starting strategy with a voltage outer proportional and integral separated active current directly given. Simulation experiments show that this method can reduce the starting over-current of PWM rectifiers and the excessive DC voltage surge towards normal operation during the starting process. [ABSTRACT FROM AUTHOR]

This work uses the Hamiltonian function approach to investigate the observer-based finite-time robust control problem of a broad nonlinear system and presents various new results. To begin, the Hamiltonian technique is used to convert the original system to its equivalent form, and then the observer system is designed. Afterward, utilizing the technology and the Lyapunov method, we investigate the finite-time control issue and give several finite-time stabilization results based on the observer method. Finally, a real unmanned vehicle is used to verify the performance of the observer-based finite-time robust stabilization controller. Different from the existing literature on the Hamiltonian method, the Hamiltonian function in this article has different powers, which implies that the results developed in this article have a wider range of application. [ABSTRACT FROM AUTHOR]

In order to improve wireless charging power and reduce heating problems, the optimal design of the high-current wireless charging coil has always been the research focus of wireless charging system research. This paper proposes a multi-branch and multi-capacitance current sharing method for series–series (SS) receiving coils. Firstly, the current sharing model with n branches that are connected parallel to multiple compensation capacitors is established. The current sharing situation of parallel coils with three branches and three capacitors with independently resonant compensation is analyzed. Then, the wireless charging system with the parallel coils of 48 V/100 A receiving coils is simulated. The results show that when one capacitor is used for compensation, the three-coil currents highly differ; when three capacitors are compensated independently, the three-coil currents are basically equal. The simulation results show that the current sharing method can effectively improve the charging power of the system and reduce the maximum temperature of the receiving coil, which proves the effectiveness of this method. Finally, through the experimental comparison, it is verified that the current sharing measure can make the current of each wire basically equal. [ABSTRACT FROM AUTHOR]