FPGA Based Speed Control of a Separately Excited DC Motor

An armature voltage control is used to control the supplied voltage of an armature of a 2 kW separately excited DC motor. A buck regulator is used to vary the supplied voltage of the motor. A pulse width modulation (PWM) generator is implemented to supply the signal to the gate of the switch of the buck regulator. A series or cascade compensator is placed to control the duty cycle of the (PWM) generator in the closed loop control system. Both cascade compensator and (PWM) generator are designed by adopting the very high speed integrated circuit hardware description language (VHDL) and the Xilinx Spartan-3E field programmable gate array (FPGA). The results obtained are in close resemblance with those got from a MATLAB model for the same system.