Research on Motor Soft-Starting Based on IGBT in Port of Wheel Cranes

Port of wheel cranes are popularly applied in the logistics, and their lifting, luffing and slewing mechanisms generally adopt DC motors. Traditional method with stepwise resistors to start motors was very complex in calculation and control, but poor performance. Considering specific conditions of wheel cranes, a composited excited system and a new approach with dynamic resistors based on IGBT to start DC motors are presented. By expounding the principle, selection and control method, it illustrates the dynamic resistors could be simple in calculation and control, and could make motors linearly start and smoothly run. Examples prove that the dynamic resistors are perfectly practicable in port of wheel cranes for their small size, simple control method, excellent property and suitability for different DC motors.