无刷直流电机无位置传感器转子位置闭环校正策略与实验研究

Study on Rotor Position Detection for Sensorless Control of a BLDC Motor

针对石油钻井用无刷直流电机无位置传感器换相误差问题,分析了逆变器高频PWM对无位置传感器检测电路参数设计的影响,构建了无位置传感器不同检测参数下电机换相延时的数学模型,结合换相前后电机相电流的变化,提出了一种基于相电流积分面积相等的无刷直流电机无位置传感器转子位置闭环校正策略。该控制策略以全转速范围内不切换换相表为前提,以换相前后相电流积分等值为控制目标,以电机相电流为检测量,通过PI控制器实时调制转子相位补偿角度,实现无刷直流电机高精度换相。实验表明,所提出的闭环校正策略在全转速范围内都能有效地补偿电机换相误差,减小电流波动,提高电机性能。

This paper analyzed the commutation error of Brushless DC （BLDC） motor for oil drilling, and the influence of inverter high frequency PWM on parameter design of position sensorless detection circuit was analyzed. The mathematical model of different detection parameters was structured, and a sensorless control strategy based on the integration area of phase current for BLDC motor was proposed. This method does need to switch the commutation table in the full speed range, the phase current integral equivalent of commutation phase was taken as the control target, and the motor phase current was taken as the detection quantity. The commutation error was modulated by the PI controller in real time to realize the high commutation accuracy of the BLDC motor. The experimental results show that the proposed methods can compensate motor commutation error in the full speed range, and improve the performance of the motor.