Research On Low-Complexity Model Predictive Torque Control Of Permanent Magnet Synchronous Motor

As a novel motor drive control method,Model Predictive Torque Control(MPTC)has been widely used in the field of Permanent Magnet Synchronous Motor(PMSM)control due to its fast dynamic response,easy handling of nonlinear constraints and multi-objective controls.However,the conventional MPTC scheme has some drawbacks,such as large torque ripple,complex voltage vector selection and variable switching frequency.In view of the above drawbacks in the control system of PMSM based on MPTC,several modified MPTC schemes are proposed in this paper.The main research contents of this article are as follows:The basic principle of MPTC scheme of PMSM is introduced in detail.The conventional MPTC,Duty-MPTC and double-vector-based MPTC are studied.The above three MPTC schemes are modeled and simulated in Simulink.Two low-complexity multi-vector-based MPTC schemes are proposed to address the drawbacks of complex selection of voltage vectors,poor steady-state performance and large computation in Duty-MPTC.The proposed MPTC schemes are implemented in the α-βstationary frame without additional coordinate transformation.To reduce the calculation effort,an active voltage vector pre-selection method based on stator flux vector error is proposed,which can effectively reduce the number of candidate voltage vectors.Meanwhile,a simple and effective method for calculating the duty cycle of active voltage vectors is proposed to reduce the computational effort and the sensitivity to parameters.Furthermore,to further improve the steady-state performance of PMSM,a low complexity three-vector-based MPTC with voltage vector pre-selection is proposed.In this scheme,three voltage vectors are applied in one control cycle to further improve the control performance.A novel three-vector-based MPTC scheme based on a new switching table is proposed to solve the problem of complicated selection of voltage vectors in double-vector-based MPTC.In order to reduce the complexity of the control algorithm,a new switching table which only consider the sign of torque error.And then a novel method of accurately selecting the active voltage vectors by using predicted torque error is proposed.Two active voltage vectors will be selected directly from the switching table,which eliminates the process of optimization based on cost function enumeration.In order to obtain better steady-state performance,a duty cycle calculation method based on torque and stator flux difference parameters is proposed to realize the deadbeat control of torque and stator flux.A PMSM control experiment platform based on d SPACE1103 is built.The hardware circuit of DSPACE1103 control system is designed and the motor drive platform is built.The proposed MPTC control 4.schemes are verified and analyzed experimentally.