In this paper, to optimize vibration of the fractional slot concentrated winding interior permanent magnet (FSCW-IPM) motor for electric vehicles (EVs) without sacrificing any torque performance, modifications of iron-core structures are proposed. First, the effects of basic stator/rotor auxiliary slots on torque, cogging torque, torque ripple, and 2 ^nd order spatial harmonic of radial force are investigated by finite element analysis (FEA). The combinations of stator/rotor auxiliary slots, which can optimize vibration with maintained torque, are analyzed. To improve torque and optimize vibration, uneven airgap rotor is proposed. With variation of the uneven air-gap rotor, torque improvement and vibration reduction do not contradict each other. The vibration levels of FSCW-IPM motors are calculated by magnetic-mechanical coupling models, while the peak vibrations are optimized with the proposed methods. Inductance, torque, and vibration experiments of the FSCW-IPM motor with the uneven airgap rotor are performed. The theoretical and experimental results both validate effectiveness of the proposed methods for torque improvement and vibration optimization.

Dual three-phase permanent magnet synchronous motors (DTPMSM) are used in the steer-by-wire system of electric vehicles that require high reliability. Multiple faults should be considered for the steering system, such as open-circuit faults and speed sensor faults. However, the current speed sensorless control methods of the dual three-phase motor are mainly derived from the promotion of the three-phase motor. They fail when an open-circuit fault occurs, leading to the failure of fault-tolerant control. Researchers have noticed this problem and proposed many methods, but they are very complicated and computationally intensive. This paper proposes one type of improved model reference adaptive system (MRAS). By adding certain fault-related restraints to the output of the adjustable model, speed sensorless control can automatically fit the open-circuit fault and estimate accurately even if an open-circuit fault occurs, which makes sure the whole system continues to operate. Simulation results are presented that contain normal operation, open-circuit fault operation, fault-tolerant control operation, and the whole process from start to fault-tolerant operation. The results show that no matter what period the motor is in, the improved speed sensor can accurately estimate the motor speed and position. The improved model reference adaptive system is significant for improving the reliability of the motor steering system and ensuring the safety of people and property.

This paper proposes a voltage sense circuit and a current sense circuit for extracting the fundamental AC voltage and current in variable-frequency inductive power transfer (IPT) systems. Particularly, the proposed circuits are designed for an EV wireless charger. A current source is generated via a high resistance and a current transformer in these two sense circuits, respectively. The main part of both sense circuits uses the “double resonance” and “critical damping” principles to gain a stable voltage gain and a linear phase response in the operating frequency band. The AC output voltage is processed by a rectifier for amplitude measurement and by a comparator for phase detection. Meanwhile, the harmonic components are effectively filtered due to the band-pass property of the sense circuits, hence their impact on the AC output voltage is negligible. The operating principle, parameter design method and parameter sensitivity analysis are discussed in detail. The feasibility of the proposed sense circuits is verified by calculations and experiments.

Due to the frequently changing working conditions and complex operating environment of electric vehicle permanent magnet synchronous motor(PMSM), the motor parameters change dramatically. However, the performance of the PI current regulator, which is the most widely used, is sensitive to motor parameters and has weak robustness, which will lead to the deterioration of motor control system performance. To address this problem, active disturbance rejection control (ADRC) technology is applied to the PMSM current loop control. Firstly, the traditional ADRC current regulator is designed, and the performance and parameter tuning laws of the extended state observer are analyzed by the method of frequency domain analysis. Then, the traditional ADRC algorithm is improved in three aspects: observation error compensation, utilization of model information and anti-windup. After that, simulations and bench test validation are performed. The simulation results show that the improved ADRC current regulator is more robust in the face of parameter changes. The torque step test results show that the improved ADRC current regulator has fast dynamic response without overshoot and has high robustness when the motor parameters change. The dynamic test results show that the improved ADRC current regulator has high robustness when the load, speed and motor parameters change, and the anti-windup measures designed can effectively overcome the integral saturation phenomenon.

In the context of informatization and intelligent manufacturing systems, digital twin technology provides new technical ideas for intelligent decision-making. Aiming at instruments with high cost and low output, this paper develops low-cost high-efficiency fault diagnosis system to realize rapid feedback and fault of fault diagnosis results. The system includes three layers: data layer, control layer and output layer. In the data layer, this uses MEMS sensors and Zigbee wireless transmission network to construct a data link the physical end and the virtual model. In the control layer, this paper stores the collected twin data through cloud technology, extracts and calls relevant data according to the function module and then maps it to the output layer. In the output layer, this paper constructs a characteristics interpretation system, which divides the test set and training set through the dynamic database, to complete the classifier and results output. The results are fed back to the judgment framework and control layer to evaluate the effects of fault diagnosis and prediction, which provides a new method for model optimization.

During the working of an electric vehicle wireless charging transfer system, if the vehicle is transversely offset from the charging area, a greater leakage magnetic field (LMF) will be generated. Shielding LMF can significantly reduce the hazards to the human body. Therefore, this article proposes a dual active suppression coil (ASC) high degree-of-freedom LMF active shielding method based on an independent inverter drive and proposes a corresponding control strategy by analyzing the ASC current control method, the LMF synthesis mechanism, and the LMF minimization condition. On this basis, the effectiveness of the control strategy was verified by simulation, and the control parameters of the ASC inverter are optimized to ensure the system transmission efficiency while reducing the LMF as much as possible. The experimental results show that the LMF shielding rates of the passive shielding method and the active method were 61.71% and 94.57% at zero coil offset and 44.55% and 66.55% at 100 mm coil offset, respectively.