Research on Application of Dynamic Resistors Based on IGBT in Tyre Cranes

Diesel-electric tyre cranes are popularly applied in the port logistics, whose lifting and luffing mechanisms adopt series plus separately excited DC motors, and slewing mechanisms adopt DC motors with full series excitation. Traditional method with stepwise resistors is very complex in calculation and control, therefore this paper presents a new approach with dynamic resistor based on IGBT to start DC motors. By means of analysis and comparison of start-up process with stepwise resistors, it expounds the principle, selection and control method of dynamic resistor. Compared with the traditional method, calculation and control of dynamic resistor are very simple, and motor can be started up linearly and work smoothly. Examples prove that the dynamic resistors are perfectly practicable in tyre cranes for their small size, simple control method and suitability for different DC motors.