A Four-Port DC-DC Converter for a Hybrid Wind/Solar Energy System

With the increasing demand for clean and hybrid energy in the last decades, more and more attentions are paid to the renewable energy, e.g., wind and solar energy. According to the International Energy Agency, solar power was growing-fastest source in the world. In a hybrid wind/solar system, power converters play an important role in in power management and the voltage regulation. Gradually, power systems have undergone a paradigm shift from centralized generation to distributed generation. Smart grid, which is a combination of power systems and communication networks, was proposed to allow power systems to fit the future system challenge. However, Due to their intermittence characteristics, energy storage such as battery is used together with renewable energy sources. Generally, there are two ways to integrate these distributed energy sources, one is to use several individual converters for each source; the other is to use an integrated multiple ports converter. The later iv solution is preferable because some component can be shared and has lower cost and higher efficiency than that using several individual converters. In this thesis, a new four-port DC-DC converter is proposed for a hybrid wind/solar energy system. The operation principle is analyzed and different controllers are designed to regulating the DC-link and source voltage, power management for the battery and maximum power point tracking (MPPT) for the renewable energy sources. The effectiveness of the hardware design and controllers are validated by a developed prototype which interfaces wind turbine generator, photovoltaic (PV) panel, battery, and the load