Decouple and Control Strategy for Variable Speed Variable Pitch Wind Energy Conversion System

University of Minnesota M.S.E.E. thesis.March 2018. Major: Electrical Engineering. Advisor: Subbaram Naidu Desineni. 1 computer file (PDF); vii, 110 pages.With the rapid growth of wind energy usage, the complexity of control systems used in the wind energy conversion systems (WECS) is also growing. As the nature of the wind is indeterminate, control systems must be able to deal with the stochastic nature of the wind and must be able to give the desired results. Thus, consideration of different types of advanced controllers for the WECS becomes important. One of the promising divide (decouple) and conquer (control) strategy using singular perturbations and time scales (SPaTS) for WECS has been used earlier for variable speed and constant pitch (VS-CP) wind model and using the linearization of the nonlinear model. In this project, the model of the variable speed and variable pitch (VS-VP) turbine wind energy system is considered for study. The designing and integrating the model of the VS-VP system is a bit more complicated and challenging than that of the VS-CP model. Further, the VS-VP system contains both mechanical and electrical components giving rise to the slow and fast dynamics, respectively and hence exhibiting the time scales. Briefly, the SPaTS technique helps in expressing the system with low-order, outer (slow) dynamics and inner (fast) dynamics. The inner dynamics is also called boundary layer correction. In this project we consider VS-VP WECS model for the decoupling process to obtain low-order slow and fast subsystems. Next, using the advanced optimal control methods, two low-order, closed-loop, optimal, slow and fast sub-controllers are obtained. A composite optimal controller is constructed using the two slow and fast sub-controllers and applied to the original nonlinear wind energy system. Comparisons are made between the results of the system using the full-order, optimal controller and the low-order, optimal sub-controllers to validate the SPaTS strategy.Finally, some conclusions and future work are included

Estimation and control of non-linear and hybrid systems with applications to air-to-air guidance

Issued as Progress report, and Final report, Project no. E-21-67

Advanced Strategies for Robot Manipulators

Amongst the robotic systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. Modern manipulators are designed complicatedly and need to do more precise, crucial and critical tasks. So, the simple traditional control methods cannot be efficient, and advanced control strategies with considering special constraints are needed to establish. In spite of the fact that groundbreaking researches have been carried out in this realm until now, there are still many novel aspects which have to be explored