The use of power converters for real life applications is continuously increasing. Technological requirements include high precision levels and very good performances at the same time, where DC-DC converters have always played an important role in energy conversion-based systems. Our interest, throughout this thesis, is to analyze modeling and control law synthesis approaches in order to provide efficient control laws that are stable within the operating range, in response to certain specifications and also taking into account the problem of being industrially applicable. The aim of our research is hence to propose control law synthesis based on formalized {modeling + control} approaches, and adaptable to the operating point change. The exploited principles deal with Sliding Mode Observation and Control on one hand, and with the Passivity theory for control law synthesis coupled with the Immersion and Invariance principle for synthesizing {observers + load estimators} on the other. Also, the ease of implementing and validating the control law structures with common hardware available in the industry has always been a main issue throughout our study. In the view of illustrating the efficacy of the proposed methods, their experimental validation has been carried out on the SEPIC. This type of converter has many advantages compared to other converters. However, despite its advantages, it is still not well-exploited due to the difficulty in obtaining control laws capable of stabilizing its output voltage within a wide operating range.
