Design of Separately Windings Control System of Series/Compound DC Traction Motors

Abstract

This paper focuses on the problem of the control system of Series/Compound DC motor in both areas of speed adjustment. Traditional field weakening is achieved by means of resistances and contactors wich inserting and/or shunting in field circuits. It is characterized by shock currents, torque and speed as well as by increased energy consumption. To eliminate these disavantages paper proposes separate control of armature, series and shunt windings of Series/Compound DC motor and supply their own power converters. Keeping hyperbolic mechanical characteristic of these motors requires setting the series field current equal to or less than armature current. Developed control system is equipped with a single loop for series field and two loops for armature with a current and speed controllers. Imposing series excitation current required is achieved through a special computer based on actual values of current and rotor speed. Control system design was made based on a mathematical model and use of default instrument of Matlab-Simulink for tuning of PID controllers. Simulation results demonstrate the system's ability to control separate windings for continuous speed adjustment in both areas, strictly limiting the rotor current, reducing energy consumption and ensuring the imposed performance indicators. The proposed control method is recommended for use in electric traction systems with Series/Compound DC Motors.