Study on speed sensorless system of permanent magnet synchronous motor based on improved direct torque control

Author(s):  
Xiaoxin Hou ◽  
Mingqian Wang ◽  
Guodong You ◽  
Jinming Pan ◽  
Xiating Xu ◽  
...  

The traditional direct torque control system of permanent magnet synchronous motor has many problems, such as large torque ripple and variable switching frequency. In order to improve the dynamic and static performance of the control system, a new torque control idea and speed sensorless control scheme are proposed in this paper. First, by deriving the equation of torque change rate, an improved torque controller is designed to replace the torque hysteresis controller of the traditional direct torque control. The improved direct torque control strategy can significantly reduce the torque ripple and keep the switching frequency constant. Then, based on the improved direct torque control and considering the sensitivity of the stator resistance to temperature change, a speed estimator based on the model reference adaptive method is designed. This method realizes the stator resistance on-line identification and further improves the control precision of the system. The performance of the traditional direct torque control and the improved direct torque control are compared by simulation and experiment under different operating conditions. The simulation and experimental results are presented to support the validity and effectiveness of the proposed method.

2013 ◽  
Vol 655-657 ◽  
pp. 1510-1514
Author(s):  
Shan Qiao ◽  
Jian Ying Xu ◽  
Bing Han

This paper reports results of further investigation of the direct torque control to a permanent magnet synchronous motor drive. A variable parameters speed controller is proposed from the point of view of speed control to accelerate the dynamic response and increase the control precision and decrease the torque ripple of the system. It is presented that a reference flux vector calculation direct torque control system with a speed controller using different proportional and integral coefficients, and a novel torque-limiting method is recommended. The simulation results show that the control system can improve its performances and limit torque ripple effectively.


2013 ◽  
Vol 712-715 ◽  
pp. 2757-2760
Author(s):  
Jun Li Zhang ◽  
Yu Ren Li ◽  
Long Fei Fu ◽  
Fan Gao

In order to deeply understand the characteristics of the permanent magnet synchronous motor direct torque control method, its mathematical models were established in the two-phase stationary coordinate system, the two-phase synchronous rotating coordinate system, and x-y stator synchronous rotating coordinate system. The implementation process of direct torque control method in varied stator winding connection was analyzed in detail. In order to improve the speed and torque performance of the permanent magnet synchronous motor, the direct torque control block diagram and the space voltage vector selection table were given. Finally, the summary and outlook of reducing torque ripple in the permanent magnet synchronous motor direct torque control methods.


2021 ◽  
Vol 54 (2) ◽  
pp. 345-354
Author(s):  
Fayçal Mehedi ◽  
Habib Benbouhenni ◽  
Lazhari Nezli ◽  
Djamel Boudana

In this work, the direct torque control (DTC) is applied to the five-phase permanent magnet synchronous motor (FP-PMSM). The DTC method based on classical space vector pulse width modulation (SVPWM) is a common solution used to overcome traditional problems; such as stator flux ripple, electromagnetic torque ripple and gives more total harmonic distortion (THD) of the stator current. The actual paper is based on improving the performance of DTC-SVPWM by using the feedforward neural networks (FNNs) instead of the proportional-integral (PI) regulators and hysteresis comparators (HCs) of the conventional SVPWM strategy. This algorithm can solve the traditional PI regulators and HCs problems which are represented in responses dynamic and reduce the torque ripple, flux ripple, and the THD of stator current of FP-PMSM drives. The proposed strategy was tested in different tests with simulation using Matlab software.


Author(s):  
Tibor Vajsz ◽  
László Számel ◽  
György Rácz

Direct torque control with space vector modulation (DTC-SVM) is one of the most promising alternatives of field-oriented control in the case of permanent magnet synchronous motor drives. This method controls the electromagnetic torque of the motor with excellent dynamics which makes it an attractive choice in the case of servo drives. In this article DTC-SVM is investigated with Matlab-Simulink simulation and it is proven that DTC-SVM has severe instability-issues during overloading and its overload-capabilities are heavily dependent on the speed. Therefore, a novel modified DTC-SVM method is proposed which is stable during overloading and its overload-capabilities are practically independent of the speed. Also, the overload-capability of the new method is superior to that of classical DTC-SVM, while the two methods are practically identical from the point of view of the torque-control dynamics and the torque-ripple generated.


2013 ◽  
Vol 341-342 ◽  
pp. 1013-1017
Author(s):  
Yi Ming Li ◽  
Wei Huang ◽  
Peng Jin ◽  
Jun Rong

According to the analysis of mathematical model for permanent magnet synchronous motor (PMSM), direct torque control(DTC) technology is introduced to the control system of PMSM. The paper builds dual-closed loop control system of PMSM, and the outer loop is speed loop, the inner loop is flux and torque loop, at the same time, the paper makes simulation in Matlab/Simulink. The simulation results show that the DTC technology significantly improves the dynamic performances of PMSM, and the control system is no overshoot, and has small flux response comparing with the conventional control methods of PMSM. So the application of DTC technology in PMSM provides a new thoughtful way for PMSM control system designing and debugging in actual application.


Sign in / Sign up

Export Citation Format

Share Document