【作者】 王德明；

【导师】 鞠平；

【作者基本信息】 河海大学 ， 电力系统及其自动化， 2005， 博士

【摘要】 本文在异步电动机直接转矩控制系统无速度传感器的设计、定子磁链的观测、低速性能的提高以及系统高性能数字控制的实现等方面进行了广泛而深入的研究，采用TMS320LF2407DSP实现了无速度传感器的异步电动机直接转矩控制系统。 论文针对传统磁链观测方法的局限性，提出了一种新的定子磁链自适应磁链观测器，该观测器在观测定子磁链的同时也辨识了随温度变化的定、转子电阻，并观测出转子速度。通过数字仿真，其鲁棒性和观测效果得到充分的证实。在磁链观测器的基础上，依据波波夫稳定性理论和李雅普诺夫理论推导出自适应收敛率，设计出三种不同的自适应速度观测器，对这三种观测器进行对比研究，最后将一种简单实用的速度估计器与磁链观测器结合在一起应用于直接转矩控制系统中，并进行了仿真和实验研究。 在分析传统DTC的固有缺陷的基础上，提出了基于SVM矢量细分的直接转矩控制策略，提高了DTC的低速性能。将离散空间电压矢量调制技术应用到直接转矩控制中，每个周期分三个时间段，用三个电压矢量合成来增加电压矢量的数目，进而减少了转矩脉动。在此基础上，使用磁链五层和转矩双层滞环控制方案，进一步改进和优化开关表，扩大了调速范围，并且提高了控制性能。仿真和实验结果表明新的自适应速度观测器与磁链观测器结合在一起应用于直接转矩控制系统中，并将离散空间矢量调制技术(DSVM)加入直接转矩控制策略后，在保留传统DTC动态性能的情况下，提高了电机的低速转矩，并减小了转矩脉动和电磁噪声。该方案简单可靠，观测精度高。 最后，在控制系统的数字化实现以及实时软件的编制方面，进行了大量的理论与实践研究。采用C语言／汇编语言混合编程的方法，成功地完成了DSP实时控制软件的研制工作，实现了无速度传感器的异步电动机直接转矩控制系统的高性能控制。更多还原

【Abstract】 In this thesis the author made a profound and broad study on the design of speed observer and stator flux observer, the improvement of low speed performance and the digital realization of system. Speed sensorless asynchronous motor system of direct torque control has been introduced by high performance digital signal processor (DSP) of TMS320LF2407.Because of the limitation of the classical observer method of stator flux, the observing precision of the stator flux observer must be high, a new adaptive stator flux observer is proposed. With this observer, the stator flux , the stator resistance and rotor resistance which vary with motor temperature, are identified simultaneously and the speed can be also observed. The robustness to parameter variations and good performance are fully verified by the simulations. Based on the full order flux observer, according to the Lyapunov’ theory and Popov’s theory, three kinds of adaptive schemes of speed observer are designed successfully. Comparing the three schemes, at last, the author applied a simple speed estimator combined with the flux observer in the direct torque control system.The defect of the classical DTC is researched deeply, a new tactic of Vector Subdivision Direct Torque Control based on space vector modulation is proposed. Low performance of DTC system is improved. An improvement can be obtained adding a new DTC algorithm based on the application of the discrete space vector modulation(DSVM) to DTC. At each sampling period, the voltage vector is synthesized by three voltage space vectors, each one applied for one third of the sampling. By this means ,a high number of voltage vectors can be generated, and the torque ripple is reduced. At the same time, the classic switching table is replaced with a two-level hysteresis band for the flux, and a five-level hysteresis band for the torque, which widens the speed range of drive system and improves the control performance. Simulation and experiment results show that these methods above-mentioned can hold dynamic performance of the basic DTC, improve the torque at low speed and weaken the torque ripple and electromagnetic noise greatly. Furthermore, the methods are very easy to realize and have improved accuracy ofthe observation.The test prototype system is implemented on a Digital Signal Processor (DSP TMS320LF2407). The real-time controller software is written by C mixed with assemble language, and the research of digital realization and the software design are carried out deeply. Many performances of the Speed sensorless asynchronous motor system of direct torque control have attained the most advanced level in domestic.更多还原