异步电机直接转矩控制系统降低转矩脉动方法的研究

发布时间：2018-01-15 12:30

本文关键词：异步电机直接转矩控制系统降低转矩脉动方法的研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：占空比控制(Duty Ratio Control,DRC)技术能够有效改善异步电机直接转矩控制(Direct Torque Control,DTC)系统运行过程中转矩脉动过大的现象,增强系统控制性能。传统的无差拍占空比控制(Deadbeat Duty Ratio Control,DB-DRC)技术存在优化效果不理想、不同的运行状态下脉动抑制作用不一致等问题。论文研究提高DB-DRC技术电磁转.矩变化率计算精度和转矩控制精度的改进策略。论文基于直接转矩控制理论,建立了电磁转矩与定子磁链幅值双滞环的异步电机直接转矩控制系统;同时详细分析了传统的基于转矩无差拍的DRC技术原理,分别根据控制周期中有效电压矢量和零电压矢量各自作用的时间段中定子磁链和转子磁链之间的相对运动对电磁转矩变化率进行分析与计算,进而确定有效电压矢量作用占空比。传统DRC技术的电磁转矩变化率计算中忽视了电机转速和负载转矩等运行状态的影响,导致计算结果不准确,改进的DRC方案基于定子磁链所在位置,综合考虑系统运行状态,有效提高电磁转矩变化率的计算精度;此外,为了进一步减小转矩脉动,确定有效电压矢量占空比时综合考虑控制周期结束时瞬时转矩与整个控制周期中电磁转矩曲线均方差。对改进型DRC技术进行建模仿真,通过对比仿真实验,验证了该方法的可行性与有效性。然后论文基于数字芯片MC56F8255对整个控制系统进行软、硬件系统设计并进行电机运行实验;实验结果表明,论文采用的基于改进型DRC技术的异步电机直接转矩控制系统运行稳定,性能良好。
[Abstract]:Duty ratio control (Duty Ratio Control, DRC) technology can effectively improve the asynchronous motor direct torque control (Direct Torque Control, DTC) system running big torque pulse phenomenon, enhance the performance of the control system. The traditional deadbeat control of duty ratio (Deadbeat Duty Ratio Control, DB-DRC) technology optimization effect the problem is not ideal, different operating conditions of pulse inhibition inconsistent. The study in this paper improve the DB-DRC technology. The change rate of the electromagnetic torque and torque control strategy to improve the calculation accuracy. The accuracy of the direct torque control system is established based on the theory of direct torque control system of induction motor electromagnetic torque and stator flux amplitude double hysteresis; at the same time, a detailed analysis of the traditional deadbeat torque based on the principle of DRC technology, respectively according to the effective voltage vector control period and zero voltage vector function of each time period The relative motion between the stator and rotor flux rate of the analysis and calculation of electromagnetic torque changes, and then determine the effective voltage vector duty ratio. The electromagnetic torque changes the traditional DRC technology affected the rate of calculation ignores the motor speed and load torque operation state, which leads to the inaccurate calculation result, the improved DRC scheme of stator flux based on the location, considering the running state of the system, effectively improve the calculation accuracy of electromagnetic torque change rate; in addition, in order to reduce the torque ripple, determine the effective voltage vector duty ratio when the control period is considered the end of comprehensive test electromagnetic torque curve and the instantaneous torque control cycle. The variance for modeling and Simulation of improved DRC technology and by comparing the simulation results to verify the feasibility and effectiveness of this method. Then the digital chip of the whole control system based on MC56F8255 The software and hardware system is designed, and the motor running experiment is carried out. The experimental results show that the asynchronous motor direct torque control system based on improved DRC technology is stable and has good performance.

【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM343;TP273

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