摘要
针对传统的异步电机直接转矩控制系统低速转矩脉动大、磁链轨迹内陷、电流畸变严重以及开关频率不固定等缺点,基于离散空间电压矢量调制(DSVM)技术和模糊控制技术提出一种改善异步电动机直接转矩控制系统低速运行性能的控制策略。将一个控制周期细分为m个时间片,每个时间片输出1个电压矢量,可以合成多个等效的空间电压矢量,供控制策略选择,优化了开关选择表。采用模糊控制器选择电压工作矢量,取代传统的滞环比较控制器。仿真结果表明,改进的DSVM控制策略及模糊控制算法的应用,有效改善了直接转矩控制的低速运行性能。在开关频率恒定的前提下,低速时磁链轨迹趋于圆形,电流谐波分量明显减少,平均转矩脉动降低为3.1%。
To solve the problems of large torque ripples, current distortion, flux depression and unstable switching frequency in low speed range in conventional direct torque control system of induction motor, a modified strategy was proposed based on the technology of discrete space vector modulation （DSVM） and fuzzy control. Controlling period was divided into m time slices, in which a voltage vector outputs forming space voltage vector. And then switching stable was optimized by new space voltage vector. The fuzzy logic controller was used to select the voltage vector instead of the conventional hysteresis controllers. Simulation results prove that the application of the improved DSVM-DTC and the fuzzy DSVM-DTC strategy improves the low speed performance of direct torque control effectively. While maintaining the switching frequency constant, flux depression and current harmonious decomposition are overcome remarkably, and the average of torque ripple reduces to 3.1%.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第1期166-171,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(60574030)
关键词
直接转矩控制
模糊控制
离散空间矢量调制
低速性能
direct torque control （DTC）
fuzzy control
discrete space vector modulation
low speed performance
