The virtual voltage vector based fault-tolerant control has been widely concerned, but suffering from the increased switching frequency and the reduced bus voltage utilization at the faulty operation. Also, the harmonic space is uncontrollable. This article proposes a conditional-extreme-point based fault-tolerant model predictive control for a five-phase permanent magnet synchronous motor. The conditional extreme point is used to predict the optimal reference voltage vector. First, to suppress the harmonics, dual control sets are established without the sacrifice of bus voltage utilization. Then, the unconditional extreme point and y-axis voltage are predicted to select the appropriate control set, and two adjacent vectors are preselected for generating the optimal reference voltage vector. Subsequently, the conditional extreme point of the cost function is calculated to obtain the optimal reference voltage vector. Due to the unemployment of the null vector, the switching frequency is greatly reduced. Finally, the experimental results are presented to verify the proposed control scheme.

The conventional virtual voltage vector (VV) based model predictive control for dual three-phase permanent magnet motor is a harmonic subspace open-loop scheme. This paper proposes a remedy method to realize a closed-loop predictive control both in fundamental and harmonic subspace. The harmonic-free VVs are synthesized in the fundamental subspace while the torque-free VVs are synthesized in the harmonic subspace. The optimal VVs are selected in respective subspaces using the predefined cost functions. Then, the duty cycle of the optimal harmonic-free VV is calculated according to the deadbeat principle of dq-axes current. The remaining duty cycle is proportionally allocated to the optimal torque-free VV. In this case, both fundamental and harmonic subspace can be controlled in a closed-loop scheme. Therefore, the harmonic currents and torque ripple can be further suppressed. The simulation and experiments results show that the proposed method can significantly improve the operational performance of the motor.

Permanent magnet (PM) excited vernier machines capable of high torque density have good potential for electric vehicles while requiring high rare earth PM consumption. To achieve a high torque density at a reasonable material cost, hybrid PM excited vernier machines incorporating both expensive rare earth and low-cost ferrite magnets are investigated in this paper. Various combinations of PM arrangements for the hybrid permanent magnet excited vernier machine are investigated to acquire low cost and superior torque density. The best solution obtained is that the PM on the stator adopts rare earth material while the rotor uses ferrite. Furthermore, the PMs on the stator are arranged in an iron-cored Halbach array, which can reduce leakage flux and enhance flux density effectively and the ferrite PMs are used in the rotor, therefore, high-temperature demagnetization is avoided. Then, the reluctance torque and the cogging torque can offset each other effectively, which is beneficial to reducing the torque ripple and smoothing the electromagnetic torque. Finally, a prototype is manufactured and tested to verify the correctness of the theoretical analysis.

This paper presents a triple three-phase permanent magnet synchronous motor (PMSM) with shaped magnets for low vibration applications. Firstly, the features of the designed PMSM are investigated from three aspects, including triple three-phase windings, shaped magnets, and multi-layered housing. Then, the armature reaction, magnetomotive force, torque performance, and fault tolerance ability of the designed PMSM are investigated. Subsequently, the radial force of the designed PMSM with shaped magnets is studied, in which the radial force modulation effect is considered. In addition, the radial force and vibration reduction principle is elaborated in detail. The modal simulation and experiment are carried out, and the vibration reduction effect of the designed PMSM is verified by the multiphysics vibration predicted model. The result shows that the vibration can be effectively reduced by the shaped magnets and multi-layered housing design, and the output torque of the designed PMSM has been reduced insignificantly thanks to the triple three-phase windings.

疫情期间,根据教育部提出的"停课不停学"要求,全国高校利用各类网络平台开展形式多样的在线学习.基于虚拟仿真实验教学资源的建设情况,文章提出"虚实结合"实验教学新模式,讨论了以虚拟仿真实验教学资源作为线上课程、"虚实结合"开展实验教学的思路及方法;介绍了江苏大学在疫情期间如何指导开展实验教学的案例,探讨该"虚实结合"实验教学模式的实际意义;在新常态下,能及时改变、积极应变,以期在教育信息化建设中更好地实现实践育人,为实验教学信息化改革提供参考.

为引导学生了解电动汽车电机基本设计方法,掌握电机关键参数对电机转矩、效率等性能的影响,提出并建设电动汽车电机设计与转矩性能评估虚拟仿真实验项目.该虚拟仿真实验项目克服了电机设计制造周期长,实验测试操作风险大,实体实验难以实现等不足,完整再现了电机设计、台架测试、道路测试等全过程,并将课程知识点巧妙融入到虚拟仿真实验中.该实验项目内容前沿、新颖,实验考核评价客观、公正,经过在线平台的开放共享,取得了良好的实施效果.

In this paper, a dual-stator permanent-magnet Vernier linear machine is proposed, which is suitable for long-distance application. The stator is only a salient pole structure, while the PM and windings are all placed on the mover. So the cost can be greatly reduced when it is used in a long-distance application. The topology and the operation principle of the proposed machine are introduced. Due to the appropriate dual-side structure, the magnetic flux leakage of the proposed machine can be effectively reduced. Moreover, the magnetic fields produced by PM between the two stators are connected in series. This means that the utilization of magnetic field can be enhanced. Therefore, the thrust force density and power factor will be improved. Finally, the electromagnetic performances are analyzed for verification by using finite element method.

Fractional-slot concentrated-winding (FSCW) permanent magnet (PM) machines have been widely studied in recent years. This is mainly due to the several advantages, including high power density, high efficiency, short end turns, high fill factor, low cogging torque, good flux-weakening and fault-tolerant performance. However, the key challenges of utilizing FSCW-PM machines are the abundant stator magnetomotive force (MMF) harmonics. In this paper, the multiphase star–delta hybrid connection (SDHC) windings configuration that can eliminate some stator MMF harmonics is systematically studied. First, the general relationship between the number of slots and phases which are appropriate for the SDHC windings configuration is derived. In addition, the particular principle of the MMF harmonics elimination by the SDHC windings configuration is researched. In order to verify the analysis results, four three-phase SDHC FSCW-PM machines with different slot–pole combinations are built and calculated by the finite-element method. Finally, experiments on a prototype three-phase 12-slot ten-pole FSCW-PM machine are carried out for validation.

This paper proposes a novel modular linear primary permanent-magnet vernier (LPPMV) machine. With PMs and windings placed on the primary side, this machine possesses a simple secondary side, suitable for long stroke applications such as urban rail transit. Owing to its appropriate primary structure and the Halbach PM arrays, the proposed LPPMV machine offers higher force density, higher back-EMF and lower harmonic compared to the existing one. Its performance is predicted for verification by using finite-element method.

The linear vernier permanent-magnet (LVPM) motor incorporates the merits of high efficiency and low cost, which is very suitable for long stroke applications. This paper proposed a new direct thrust force control for dual inverter fed open-end winding LVPM motor to reduce force ripple. First, the topology and structural characteristics of the LVPM motor are briefly presented. Second, the mathematic model of the LVPM motor is derived. Then, a new direct thrust force control based on dual inverter fed open-end winding technique is proposed. The open-end winding drive is obtained by connecting six windings terminal of the LVPM motor to dual inverter respectively, which provides greater numbers of voltage vector and higher classes of output voltage to improve control performance. An improved space vector pulse width modulation based on dual inverter is configured to minimize force and flux ripples, which results constant switching frequency of operation. Finally, the simulation results are given to verify well steady-state and dynamic performances of the proposed control strategy.

Linear primary permanent magnet vernier (LPPMV) motor incorporates the merits of high efficiency and low cost because its long stator can be designed as simple iron core only with salient poles. In this paper, a new double-sided linear primary permanent magnet vernier (LPPMV) motor is proposed, which artfully adopts appropriate halbach PM arrays. Compared with the existing single-sided LPPMV motor, the proposed motor has over twice thrust force. Also, the proposed motor exhibits relatively enhanced force performance with various optimized structure elements, which is more suitable for long stoke applications.

To solve the problems of the existing vehicle suspensions,an electromagnetic active suspension system was proposed,in which a linear fault-tolerant flux-switching permanent-magnet( LFT-FSPM) motor was adopted. The proposed LFT-FSPM motor incorporated the merits of high efficiency,simple and robust mover structure,and good thermal dissipation conditions. For the purpose of high reliability operation of the active vehicle suspension system,the concept of fault-tolerant teeth was employed to provide the desired decoupling among phases. Two LFT-FSPM motors,namely 6 /10-pole and 6 /11-pole ones,were designed. The finite-element method was employed to analyze and compare their electromagnetic performances,verifying the effectiveness of the theoretical analysis.

Two-motor drive system is a multi-variable, nonlinear and strongly coupled system. A new synchronous control strategy for two-motor system is proposed based on radial basis function (RBF) neural network inverse with particle swarm optimization. To enhance the system performance, the particle swarm optimization is adopted to optimize the RBF nerve center, an optimized RBF neural network inverse and a two-motor system is connected in series to form composite pseudo-linear system. This two-motor synchronous system can be decoupled into two independent linear subsystems for speed and tension. Then, the decoupled control is implemented by designing a linear closed-loop adjustor. The experimental results verify that the two-motor synchronous system can be decoupled well for speed and tension based on the proposed neural network inverse system. Also, the proposed system can deal with external disturbances with strong robustness.

Switched reluctance(SR) motors incorporate the merits of simple structure and fault tolerance,having a bright future in the mining applications.To improve torque performance of SR motors,its torque ripple is analyzed,thus proposing an optimal control strategy of SR motor in the angle position control mode.A finite-element analysis model is developed for a SR motor,and it is used to predict the torque performance of motor.Thus,the validation and the accuracy of the proposed control s trategies are verified.The research results lay a foundation for design and optimal control of SR motor drive.

The flux-switching permanent magnet (FSPM) motors are a new class of moving-iron machines, offering high power density, simple and robust rotor structure, and good thermal dissipation conditions. This paper proposes a new tubular fault-tolerant FSPM (TFT-FSPM) motor for high reliability operation of the active vehicle suspension system. The key is that the new motor topology incorporates the concept of fault-tolerant teeth to provide the desired decoupling among phases. Two TFT-FSPM motors, viz., the existing and the proposed ones, are designed based on the size constraints of the vehicle suspension. They are compared in terms of their flux linkages, back-EMFs, self and mutual inductances as well as cogging and thrust forces. The finite element analysis results show that the proposed TFT-FSPM motor not only retains the merits of high power density, strong mechanical integrity, good immunity from thermal problem and high thrust force capability, but also offers higher performances and lower cost than the existing one.

As a multi-variable,nonlinear and strongly coupled research object,a two-motor synchronous control system was investigated in this paper.A new synchronous control strategy for two-motor system was proposed based on RBF neural network inverse with genetic algorithm.To enhance the system performance,the genetic algorithm was adopted to optimize the RBF nerve center,an optimized RBF neural network inverse and a two-motor system was connected in series to form composite preudo-linear system.This two-motor synchronous system can be decoupled into two independent linear subsystems,e.g.,speed and tention types.Moreover,a linear closed-loop adjustor was designed to control each subsystem.The experimental results show that the two-motor synchronous system can be decoupled well for speed and tension based on a GA-RBF neural network inverse system.Also,the proposed system can deal with external disturbances with strong robustness.

两电机变频调速系统是一个多输入多输出(multi-inputmulti-output,MIMO)非线性强耦合的控制系统.神经网络广义逆摔制方法不但可以实现MIMO系统的线性化与解耦,而且通过合理地调节广义逆系统的参数,可以使解耦后的单输入单输出(single-input single-output,SISO)系统具有开环稳定的特性,从而有利于系统的综合.论文对变频器工作在矢量控制方式下的系统数学模犁进行广义逆存在性分析,进而导出系统的广义逆数学表达式.进一步构造神经网络广义逆系统串联在两电机系统之前,组成基于广义逆的伪线性复合系统.基于S7-300PLC试验平台,分别研究伪线性复合系统的开环特性和闭环特性,试验结果表明神经网络广义逆控制方法不但可以实现系统的解耦,而且可以使伪线性化后的子系统开环稳定,附加闭环控制器的问题就迎刃而解.

Multi-motor variable frequency speed-regulating system is a MIMO, nonlinear, and high coupling control system. Being rightly designed, the generalized inverse can transform the MIMO nonlinear system into a number of SISO linear subsystems with open-loop stability, and then benefits the integration of this tension control system. The generalized reversibility of this multi-motor system working on vector control mode was testified. Consequently, a pseudo-linear system was completed by constructing a neural network generalized inverse system and combining it with two-motor system. Both the open-loop and the closed-loop characteristics of this pseudo-linear system were studied based on S7-300 PLC experiment platform. The experiment results demonstrate that decoupling control with open-loop stability can be reached by neural network generalized inverse (NNGI) control method.

The variable frequency speed-regulating system which consists of an induction motor and a general inverter, and controlled by PLC is widely used in industrial field. However, for the multivariable, nonlinear and strongly coupled induction motor, the control performance is not good enough to meet the needs of speed-regulating. The mathematic model of the variable frequency speed-regulating system in vector control mode is presented and its reversibility has been proved. By constructing a neural network inverse system and combining it with the variable frequency speed-regulating system, a pseudo-linear system is completed, and then a linear close-loop adjustor is designed to get high performance. Using PLC, a neural network inverse system can be realized in actural system. The results of experiments have shown that the performances of variable frequency speed-regulating system can be improved greatly and the practicability of neural network inverse control was testified.