Nonlinear Dynamics of a Current Controlled D.C. Drive with PID Controller

This paper describes a closed loop model of a current controlled PMDC motor drive with PID Controller. The output speed of the PMDC motor is compared with a preset reference speed. The differences between these two signals are fed as an error signal to the PID controller of the system. The output of the speed controller is the actuating signal that controls the duty cycle of converter and hence controls the converter output. Through this controlled converter output, required voltage gets injected into the motor to bring it back to its desired speed. As a small change in the input voltage can cause a large change in the motor current and lead to a particular drive control feature.