矿井皮带机用感应电机无传感器控制研究

Research on Sensorless Control of Induction Motor for Mine Belt Conveyor

针对大功率矿井皮带机用感应电机无速度传感器系统带负载启动困难的问题,提出一种无速度控制工程实用方法,电机起动采用电流单闭环I/F控制,进入低频运行后应用自适应状态切换策略调节转矩电流,当系统满足设定的切换条件时投入磁链、速度闭环矢量控制,实现速度及转矩的平滑状态切换,满足矿井皮带机在各种负载工况下的启动及全速度范围正常运行。以一种混合磁链模型作为MRAS转速估计器的参考模型,电机低频运行阶段能得到较精确的转速估计值,可以较早使系统切换到矢量控制模式,在交流对拖样机平台进行了带负载起动及中高速运行实验,电机可以顺利起动并在3Hz时满足切换条件,平滑切换到矢量控制模式,电机转速响应快,动态特性较好,实验结果表明了该方法的正确性和有效性。

A practical engineering method without speed control is proposed to solve the problem of difficulty in starting the induction motor without speed sensor system for high-power mine belt conveyor under load.The motor starts using a current single closed-loop I/F control,and after entering low-frequency operation,an adaptive state switching strategy is applied to adjust the torque current.When the system meets the set switching conditions,magnetic flux and speed closed-loop vector control are applied to achieve smooth state switching of speed and torque,meeting the starting and normal operation of the mine belt conveyor under various load conditions and the full speed range.Using a hybrid magnetic flux model as the reference model for the MRAS speed estimator,the motor can obtain more accurate speed estimation values during the low-frequency operation stage,which can enable the system to switch to vector control mode earlier.Load start and medium to high speed operation experiments are conducted on the AC drag prototype platform.The motor can start smoothly and meet the switching conditions at 3 Hz,smoothly switching to vector control mode.The motor speed response is fast,and the dynamic characteristics are good.The experimental results indicate the correctness and effectiveness of this method.