作者: Yu Ying Gao, Ming Ji Liu, De Ping Kong, Yun Gao Li

摘要: Direct torque control (DTC) has been widely used due to its advantages of less parameter dependence and faster torque response. However, in conventional DTC, there are obvious torque and flux ripples. This paper studies the influence of zero space voltage vectors on DTC system of permanent magnet synchronous motor (PMSM). The control model is established with Matlab/Simulink software. The simulation results show that the ripple torque can be reduced significantly when zero space voltage vectors are used. Meanwhile, the use of zero space voltage vectors can evidently decrease the switching frequency of the power switches as well as the switching loss. The achievements in this paper can provide a reference to improve DTC performance of PMSM.

2628

作者: Jun Zhu, Xu Dong Wang, Bao Yu Xu, Hai Chao Feng

摘要: In order to improve the dynamic servo performance of PMLSM, a classical direct torque control (DTC) scheme based on bang-bang control is proposed in the paper. The proposed control method uses the bang-bang hysteresis controller formed a dual-closed loop control system, it contains torque loop and flux loop. The DTC control model was established and the simulation experiment was made. The simulation experiment results show that the DTC can improve the dynamic performance of PMLSM. It can reduce the ripples of speed and torque, so that it can provide more precision and accuracy servo performance.

350

作者: Li Ping Liu, Zhi Qiang Du, Jing Tao Yin

摘要: This paper presents a current orientation of the rotor doubly-fed motor speed control system of the simple vector control method, mainly through the detection of rotor current to control the rotor voltage and rotor current phase or reversed. When the double-fed speed, if the rotor and the rotor voltage vector vector always super-synchronous operation or sub-synchronous operation, we can guarantee the rotor side of the power factor is 1, which can reduce the capacity of the rotor side converter, reducing system costs. This paper introduces the basic principles of the system and composition, and finally gives the system simulation and experimental results

385

作者: Wen Xiang Wei, Xiao Ping Zhang

摘要: A flux observer based on the extended state observer (ESO) is proposed for rotor flux estimation and speed identification of indirect field oriented induction motor drives system. The uncertain component including rotor resistance and speed in the stator current equation is extended to a new state, the ESO is then constructed. By the current estimate error, the uncertain component convergences to its actual value and the accurate rotor flux, speed and the rotor time constant are obtained. The accuracy of the ESO independent the rotor resistance and load torque variations, simulations under high and low speed show that the proposed method achieves prefect robust, and the validity and practicability is verified by simulation results.

414

作者: Yue Dou Pan, Ze Ping Chen, Hua De Li

摘要: This paper proposes a stator flux estimation method for induction motor based on Prescribed Convergence Law algorithm. A stator flux observer is designed and applied for direct torque control (DTC) of induction motor. The observer tracks stator current and its differential with Prescribed Convergence Law algorithm of second order sliding mode in order to estimate rotor flux, and then estimate stator flux using the relationship between stator flux and rotor flux. This paper takes the differential of estimated flux error as disturbance and divides the MIMO (Multiple Input Multiple Output) observer model into two separate SISO (single input single output) systems, which simplifies the stability analysis. The observer is applied to DTC of induction motor and achieves a good control effect. Simulation experiment results validate the proposed method.

461