Digital Simulation and Analysis of Sliding Mode Controller for DC-DC Converter using Simulink

The switching converters convert one level of electrical voltage into another level by switching action. They are popular because of their smaller size and efficiency compared to the linear regulators. These are used extensively in personal computers, computer peripherals, and adapters of consumer electronic devices to provide dc voltages. The wide variety of circuit topology ranges from single transistor buck, boost and buck-boost converters to complex configurations comprising two or four devices and employing soft-switching or resonant techniques to control the switching losses. There are some different methods of classifying dc-dc converters. One of them depends on the isolation property of the primary and secondary portion. The isolation is usually made by a transformer, which has a primary portion at input side and a secondary at output side. Feedback of the control loop is made by another smaller transformer or optically by optocoupler. Therefore, output is electrically isolated from input. This type includes Fly-back dc-dc converters and PC power supply with an additional ac-dc bridge rectifier in front. The dc-dc buck converter is the simplest power converter circuit used for many power management and voltage regulator applications. Hence, in this paper the analysis and design of the control structure is done using simulink for the buck converter circuit.