With the development of electric driving systems, the synchronization control system of multiple motors has been used widely in many industry fields recently. The research on the synchronized control technique of multiple motors is getting more and more important. This paper focuses on the synchronization control strategy of multi-motor control system based on PROFIBUS fieldbus. In this paper, the development of the synchronization control technique of multi-motor system is summarized. The model structure of synchronization control system of multi-motor based on PROFIBUS-DP fieldbus is proposed. MS (master-slave) communication mode is adopted. Specially, the synchronization control strategy based on this network control system is analyzed and described. It includes four parts. The first, in order to assign intelligently the given speed of each motor which in the slave station, a BP neural network arithmetic controller is set up in the DP master station. The next, in order to realize high precision control to the single motor, an adaptive double mode fuzzy PID arithmetic is adopted in the intelligent slave station. The third, the sync/freeze control method in virtue of PLC system function is adopted when the DP master transfers its command of synchronization execution to its distributed intelligent slave stations. The last, a short step control method of output frequency is adopted for the converter in the process of start and stop of motor to reduce the ill influence of some factors of equipments. It is the trend of development for the synchronization control of multiple motors to combine the technology of fieldbus with the technology of motor driving control. The analysis result of this paper can offer effective reference for the control of congener equipments. It is quite useful for actual application.

The magnetic coupling problem is discussed for the six topologies of compound-structure permanent-magnet (PM) synchronous machine (CS-PMSM), and the radial-radial flux CS-PMSM is investigated as example. Taking Toyota Prius hybrid system as reference, a radial-radial flux CS-PMSM is designed. Owing to mechanical reason, the thicknesses of the PMs on the outer and inner sides of the outer rotor are quite different, which induces more coupling problem. The magnetic system of CS-PMSM is researched in two aspects: the combination of thicknesses of PM and outer rotor yoke and the effect due to armature reaction. It is concluded that the magnetic coupling problem can be solved by designing an appropriate outer rotor thickness. In order to evaluate the magnetic structure, a downsized radial-radial flux CS-PMSM prototype was designed and manufactured. Back electromotive force (BEMF), relations between torque and current, and efficiency of the prototype were measured, and the experimental results are in good accordance with the calculated results.

In order to improve the performance of multipole Galatea traps, this paper proposes an optimized method for the design of coil parameters. Based on an accurate magnetic field model, key parameters describing the multipole Galatea magnetic trap configuration were analyzed to establish an optimization model using the axial electromagnetic force, weak magnetic field area, and average magnetic mirror ratio as the optimization goals with the coil current as the design variable. Applying the improved multiple population genetic algorithm (MPGA), which has a strong searching ability and a fast convergence speed, enables production of optimization results following selection of the appropriate weight coefficients. Results confirm that optimization design results from MPGA are consistent with the design goals for different weight coefficients. In addition, the performance of multipole Galatea magnetic traps with optimization coil parameters was improved. Finally, the results from finite-element simulation software proved the validity and feasibility of the proposed method.

To address the complexities, inflexibility, and security concerns in traditional data sharing models of the Industrial Internet of Things (IIoT), we propose a blockchain-based data sharing and privacy protection (BBDSPP) scheme for IIoT. Initially, we characterize and assign values to attributes, and employ a weighted threshold secret sharing scheme to refine the data sharing approach. This enables flexible combinations of permissions, ensuring the adaptability of data sharing. Subsequently, based on non-interactive zero-knowledge proof technology, we design a lightweight identity proof protocol using attribute values. This protocol pre-verifies the identity of data accessors, ensuring that only legitimate terminal members can access data within the system, while also protecting the privacy of the members. Finally, we utilize the InterPlanetary File System (IPFS) to store encrypted shared resources, effectively addressing the issue of low storage efficiency in traditional blockchain systems. Theoretical analysis and testing of the computational overhead of our scheme demonstrate that, while ensuring performance, our scheme has the smallest total computational load compared to the other five schemes. Experimental results indicate that our scheme effectively addresses the shortcomings of existing solutions in areas such as identity authentication, privacy protection, and flexible combination of permissions, demonstrating a good performance and strong feasibility.

Equilibrium reconstruction is an important basic work for the design and operation of a multipole Galatea magnetic trap device, and it is also a fundamental theoretical work for plasma equilibrium control. Based on the static equilibrium model of the multipole Galatea magnetic trap, an equilibrium reconstruction scheme based on solving the Grad-Shafranov equilibrium equation is proposed. In the proposed scheme, a plasma current density distribution model is established, and the combination of the Green function and the finite difference method is investigated to realize the fast solution to the Grad-Shafranov equilibrium equation. At the same time, the least-squares fitting method is employed, along with the magnetic probe measurement data, which realizes correction and iteration of the parameters of the plasma current density distribution model. Through simulation, the magnetic field distribution, plasma current density distribution, and plasma pressure distribution of multipole Galatea magnetic trap can be obtained, which confirms the effectiveness of the equilibrium reconstruction when compares with other experimental results. At the end of this paper, the influence of the magnetic field produced by the solenoid coil on the equilibrium configuration of plasma is studied.