Weighing-sensor-free starting torque control method of elevator permanent magnet dragging system

The invention relates to a weighing-sensor-free starting torque control method of an elevator permanent magnet dragging system, and belongs to the technical field of motor and elevator dragging control. According to the starting torque control method, the problems that under the condition that only position information of a common resolution ratio incremental encoder is used in the elevator permanent magnet dragging system to serve as control system feedbacks, the method of obtaining elevator load weight information through a weight sensor is adopted for maintaining balance before the elevator system operates, the reliability of the elevator system is accordingly reduced, and the cost of the elevator system is accordingly increased are solved. The starting torque control method includes the steps of firstly obtaining a current permanent magnet synchronous motor rotor position value theta through calculation; obtaining the current motor inversed slipping distance deltas and the current motor angular speed omega through calculation; controlling the starting torque of a permanent magnet synchronous motor according to the current motor inversed slipping distance deltas and the current motor angular speed omega to restrain inversed slipping of the permanent magnet synchronous motor in the zero servo period. The weighing-sensor-free starting torque control method is used for the elevator permanent magnet dragging system.