Narasimhan, S. (2017). Dynamic Response of a Separately Excited DC Motor using Parameter Identification. Unc Charlotte Electronic Theses And Dissertations.
DC machines are prone to oscillations or swings in angular speed and armaturecurrent due to dynamic changes in the operating conditions, such as excitation andmechanical transients from load or speed variations. In this thesis, a sensitivityanalysis-based parameter optimization is applied to a separately excited DC motor tomitigate the swings. A gradient-based criterion minimization method is employed tominimize the gradient of the performance index of the angular velocity and armaturecurrent. The optimization is performed on the modeled system and the optimal gainvalues are fed to the actual system for improved dynamic performance. The angularspeed (!) and armature current (Ia)-based control approach converges faster reachingoptimal gain values compared to the existing ! only-based control approach. Theeffectiveness of the proposed approach is quantified by comparing the integral squarederror of the performance index with that of the existing -based control approach. Theproposed approach results in a smaller time constant and reduced oscillation dampingtime, and improves the response of both ! and Ia. The approach promises an efficientswing mitigation in the actual physical system during excitation, speed variations andmechanical transients.
