中文摘要：

根据无刷直流电机的特点,在其直接转矩控制中,可以省去磁链观测环节。分析了无磁链观测条件下无刷直流电机电压矢量和电机转矩之间的关系,根据二者之间的关系得到最优电压矢量的选择依据,选择最优电压矢量直接控制转矩。根据无磁链观测条件下电机转矩和电流的关系,通过对转矩的控制实现对电流的限制。仿真和实验验证了最优电压矢量选择依据的正确性和电流限制方法的有效性,实现了无磁链观测条件下电机转矩的直接控制,为提高无刷直流电机直接转矩控制系统的性能提供了理论依据。

英文摘要：

According to the characteristics of brushless DC motor（BLDC）,the observation of stator flux linkage can be eliminated.The relationship between the voltage vectors and torque is analyzed in this paper and the optimal voltage vector selection rule is gained based on the relationship.The current limiting is achieved by the control of motor torque.The analysis is validated by the simulation and experiment results and it provides the theoretical basis to improve the performance of direct torque control of BLDC.