The deadbeat control is one of the widely concerned control methods for the permanent-magnet synchronous motor (PMSM) due to its fast dynamic performance. However, its control performance relies heavily on the accuracy of the PMSM model parameters, which may vary with the operation cases. In this article, a novel online parameter identification algorithm is proposed for the PMSM deadbeat control. First, an identification model is established to estimate the parameter errors from the offsets of the deadbeat control, in which the nonlinearity of the voltage source inverter is fully concerned. Then, a novel “parameter perturbation method” is proposed for gathering the essential data to solve the rank deficient problem in the parameter identification process. It does not need to inject additional instructions in the control, resulting in no impact on the normal operation of the PMSM. The Adaline neural network is employed to achieve the online acquisition of parameter identification results. Finally, the effectiveness and superiority of the proposed algorithm are verified by experimental results on a PMSM platform.

SiC mosfet s allow a higher frequency, lighter weight inverter over their Si counterparts for electric vehicle (EV) applications. However, using SiC-based EV traction inverters is likely to increase the shaft voltage in an ac motor drive system, which significantly affects the reliability of the system. This paper investigates the impact of high-speed switching of SiC devices and high switching frequency of SiC-based inverter on the common-mode voltage (CMV) and the shaft voltage. It is theoretically illustrated and experimentally demonstrated that the high switching frequency increases the amplitude of the shaft voltage, while the fast switching speed has limited influence on both CMV and the shaft voltage. Afterward, active zero state pulsewidth modulation (AZSPWM) and common-mode chokes are employed to mitigate the shaft voltage. The experimental results show that either the AZSPWM modulation scheme or common-mode chokes have the capability to minimize the shaft voltage. Better performance can be achieved by utilizing both techniques simultaneously. It is also observed that the high switching frequency enabled by the fast-speed SiC device is able to be helpful to the use of reduced shaft voltage technologies.

This paper presents a novel open-loop gate control of the turn-on transient for SiC MOSFETs in hard switching conditions. The gate control could reduce the SiC MOSFETs turn-on gate voltage overshoot and control turn-on di/dt and dv/dt independently. Because of the high turn-on speed, SiC MOSFETs bring serious electromagnetic interference (EMI) in the half-bridge topology. A conventional gate driver decreases EMI by increasing the gate resistor, but clearly increasing the turn-on loss. To address this tradeoff and optimize SiC MOSFETs turn-on transition, the drain current slope and the drain-source voltage slope are controlled independently by controlling the gate-source voltage profile during the current rise phase and the gate current during the voltage falling phase. In addition, gate voltage overshoot is considered and discussed. By adding a considerably higher gate resistance during the on-state operation stage, gate voltage overshoot is almost non-existent while maintaining low turn-on loss. Experimental verifications of the proposed approach are finally conducted, and the advantages of proposed driver are analyzed and discussed.

Zero voltage switching(ZVS) is of great importance for high efficiency DC/DC converters. In the dual active bridge (DAB) converter with the extended phase shift (EPS) control, however, due to the junction capacitance of switches, the ZVS region splits into two separated parts according to its load degree. It has been found that applying the variable frequency modulation (VFM) simply to the EPS can move rather than fill the gap between the ZVS areas. In this paper, a partition VFM is proposed, which increases the switching frequency at heavy loads and decrease it at light loads. The partition VFM extends the ZVS regions of EPS towards each other and connect them finally. A hybrid control law combining the partition VFM and EPS has been developed. The minimum RMS current optimization is carried out to determine the relation between duty cycle and phase shift. Some frequency-dependent characteristics are analyzed to establish loss model. Minimum switching frequency is calculated to obtain high efficiency while ensuring ZVS. Finally, the effectiveness of the proposed control method is experimentally verified on a 100-300kHz, 1kW DAB prototype.

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.

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.