Torque Control of a Separate-Winding Excitation DC Motor for a Dynamometer

In this thesis, the theory behind a separate-winding excitation direct current (DC) motor and profile of the motor’s torque versus rotor speed is studied. The torque versus rotor speed profile results are predictably linear at a given armature voltage. Output torque of a separate-winding excitation DC motor is proportional to the armature current. From this theory, a program was written in Simulink with Xilinx embedded software to enable a user to command the DC motor torque through a Graphical User Interface (GUI). The command is then converted to control armature current through a Field Programmable Gate Array (FPGA) to the DC motor. The armature current level is maintained through a programmed Proportional Integral (PI) Controller to keep output torque constant regardless of armature voltage and rotor speed. This result is a way to command constant output torque to a DC motor.