Design and fractional sliding mode control of Z-source DC-DC converter

Within the scope of this thesis, fractional-order control of the Z-source DC-DC converter circuit has been performed. Firstly, the circuit was analyzed and mathematical equations were obtained according to the open and closed positions of the switch in the circuit. Based on these equations, the transfer function was found. Then, general circuit equations were derived. Control signals were obtained by using these equations. The circuit was controlled by three different methods in Matlab/Simulink simulation program. These are PI control, sliding mode control and fractional sliding mode control. The reason for using methods other than fractional sliding mode control is to make comparisons in the results. There are many controller coefficients in the control signals of controllers that affect the performance of the system. Determining the optimal value of these coefficients can be difficult and time-consuming. In this study, the Particle Swarm Optimization algorithm, which is one of the heuristic algorithms, was used to find the optimal coefficients. In order to compare the performance of the three different methods mentioned, the load resistance was gradually reduced, and its effect on the output voltage was examined. The input voltage was changed while keeping the load resistance constant and the effect of the controllers on the output voltage has been investigated. Looking at the output voltages, it was observed that the fractional sliding mode controller responded best to changes in the load resistance and input voltage. As a result, it has been determined that the fractional sliding mode control method is more robust than the PI control and sliding mode control methods.