Sliding Mode Control of AC/DC Bridgeless Converter using Piezoelectric Energy Harvesting System

In this paper, a sliding mode controller has been applied to control AC/DC bridgeless converter which is widely used in many low voltage renewable energy applications. This promising technology has been perfectly applied to many low output AC voltage sources as in Piezoelectric harvesting energy, heat transfer transducers, and small wind turbine panels. Designing stabilized controllers to increase the efficiency and reliability of these converters has been an area of intense research interest in designing the required circuits of renewable energy development. A well-known bridge rectifier is generally used in most types of conventional AC/DC converters in order to convert the AC voltage from the source to a full wave DC rectified signal. However, these converters are not conductive for millivolt output level of renewable sources. The proposed approach consists of both Boost and Buck-Boost converters with two controllers in order to maximize the useful output energy from the source. In this work, the traditional PI controllers are used as a first approach. Then the Sliding Mode Controller (SMC) technique has been integrated with PI in order to stabilize the converter and improve its efficiency. Here, a comparative study using simulations in MATLAB is presented to insure the effectiveness and robustness of the proposed SMCPI controller under some external disturbances.