一种割草机无刷电机高频注入启动策略研究

Research on a high-frequency injection starting strategyfor brushless motor of lawn mower

摘要:

针对割草机电机在启动过程中转子定位精度低,加速阶段稳定性差等问题,提出了一种手推式割草机的无感无刷电机高频方波注入启动策略。采用将割草机电机的启动分为低速和高速两个阶段的方法,在不同采样点提取αβ轴系下的高频响应电流,用于转子位置估计,该方法无需滤波器,降低了位置估计误差。论文还在正负脉冲注入的基础上,提出了一种在电机首次启动时d轴极性的判断方法。利用STM32F302芯片搭建硬件实验平台,实验结果表明：改进的脉冲注入转子极性判别方法,能够准确判断转子极性,利用优化后的综合电流处理策略能有效的进行转子位置估计,提高精准度,符合割草机电机启动的要求。

Abstract:

Aiming at the problems of low rotor positioning accuracy and poor stability during acceleration phase of the lawn mower motor during the start-up process, a high-frequency square wave injection start strategy for the hand-push lawn mower is proposed. The paper divides the start of the lawn mower motor into two stages, low speed and high speed, and extracts the high frequency response current under the αβ shaft system at different sampling points for rotor position estimation. This method does not require a filter and reduces the position estimation error. Based on the injection of positive and negative pulses, the paper proposes a method for judging the polarity of the d-axis when the motor is started for the first time. Using the STM32F302 chip to build a hardware experimental platform, the experimental results show that the improved pulse injection rotor polarity discrimination method can accurately determine the rotor polarity, and the optimized integrated current processing strategy can effectively estimate the rotor position, improve accuracy, and meet requirements for starting the lawn mower motor.