带式输送机多机变频驱动功率平衡控制研究

针对多机驱动带式输送机在负荷变化、加减速过程中极易出现因功率不平衡而造成电动机过载甚至损坏等问题,依据转矩分配原则推导出电动机转矩分配公式;采用变频驱动的主从控制方法,主机为速度、磁链闭环的矢量控制,从机为速度级联下的转矩控制,主、从机在转矩分配给定情况下进行转矩闭环控制;建立了功率平衡控制系统模型,并给出了双电动机拖动功率平衡控制系统结构。Matlab仿真结果表明,在负荷变化、加减速过程中各电动机输出转矩可实现按比例分配,证明了功率平衡控制系统的有效性。

Research of power balance control for multi-motor frequency-conversion drive of belt conveyor

For problems of motor overload and even damaged caused by power unbalance which easily appears in processes of load changing,acceleration and deceleration of multi-motor drive for belt conveyor,a torque distribution formula of motor was deduced according to torque distribution principle.Master-slave control method of frequency-conversion drive was adopted,namely vector control with closed loop of speed and magnetic chain was used for the master motor and speed cascade torque control was used for the slave motor,so torque closed-loop control was done under the case that torque distribution of the master and slave motor were given.Model of power balance control system was established and the structure of dual-motor drive power balance control system was given.The result of Matlab simulation shows that output torques of the motors can achieve proportional distribution in processes of load changing,acceleration and deceleration,which proves effectiveness of the power balance control system.