六边形磁链轨迹的无刷直流电机直接自控制

The Direct Self Control of Brushless DC Motor Based on the Hexagon Locus of Stator Flux Linkage

按照定子磁链运动轨迹的不同,直接转矩可分为2大流派,圆形轨迹称为直接转矩控制,六边形轨迹称为直接自控制。近来国外尝试将直接转矩控制应用到无刷直流电机上,但受关断相电压不确定的影响,定子磁链与给定磁链均呈现周期性变化,在一个周期内其幅值逐渐增大,计算复杂。为此,该文将基本直接自控制引入无刷直流电机,将定子磁链的3个投影与1个常数比较,以更简单的结构实现了无刷直流电机地高性能控制。仿真与实验证明:常见的无刷直流电机三三导通方式可以看作是直接自控制的特例,对应直接自控制在全速运行;转矩动态响应时间不超过1ms。

The direct torque control should be classified into two styles according to the locus of stator flux-linkage： one was well known as DTC with circular locus , the other was known as DSC with hexagon locus. Recently, DTC had been applied on brusbless DC motor. As the result of uncertainty of voltage across the off-phase, the stator flux-linkage changed its value periodically every sixty electric degree, and which value gradually increased in one period. The basic DSC strategy for BLDC solved these problems, just as this paper presented. Three projections of the stator flux-linkage reference were compared with a constant. The control structure was more simple while the performance was exciting. Both the simulation and experiment were carried on and the results showed： the generally used three-phased conduction of brushless DC motor should be regarded as a special case for DSC, corresponding to the highest speed running of DSC. The simple structure of DSC for BLDC produced excellent torque dynamic response within 1ms.