In recent years, there is a growing concern about the use of switched reluctance motor. Robustness, high efficiency, low cost, high speed, simple structure, easy to maintain, high controllability, high torque to inertia ratio, simple power converter circuits with reduced number of switches and smaller dimension of the motor, are unique features of this machine. However, high torque ripple and acoustic noise are most disadvantages of the motor and torque ripple minimization of switched reluctance motor drives is a major subject based on these drives’ extensive use in the industry In this thesis, first a nonlinear adaptive sliding mode speed control of switched reluctance motor in the presence of parameter variations, load uncertainty and external disturbances for the purpose of torque ripple reduction and steady state characteristic improvement is presented. To achieve this goal, theoretical analyses of mathematical modeling and computer simulations with MATLAB/Simulink have been performed. Simulation of the drive system requires models for the SRM drive subsystems and their interconnections. The magnetization characteristics of this machine are achieved. In this model, currents produced by the nonlinear function which is implemented as a lookup table. The electromagnetic torques produced by the stator phases are provided by the nonlinear function implemented as a lookup table. The torques produced by all stator phases are then summed up to provide the total torque on the rotor shaft. These characteristics data of the 4kw, 8/6 switched reluctance motor for a finite set of currents and rotor position are implemented in the lookup tables of model. In the method mentioned above, for the control strategies of the switched reluctance motor it is assumed that its parameters are known exactly or the unknown parameters can be identified by the adaptive technique. However the parameters of the SRM are not exactly known and always vary with current and position. Actually, control is difficult to implement owing to its complex algorithm when considering the structural information of switched reluctance motor in design. Improving the applicability of the SRM on the basis of the simplified model and taking the structural characteristics into account is a significant step in designing the controller of the switched reluctance motor. Hence, by using a well known cascaded torque control structure and taking the machine physical structure characteristics into account, the proposed composite passivity-based adaptive sliding algorithm derived from the view point of energy dissipation, control stability and algorithm robustness. A nonlinear dynamic model is developed and decompos.. Keywords: Switched Reluctance Motor (SRM), Torque Ripple Minimization, Passivity-based control, Feedback Dissipative Hamiltonian Realization