Controlling of Distribution Voltage for DC Micro-grids Using MRAS, Fuzzy Control and Gain-Scheduling Technique
نویسندگان
چکیده
---------------------------------------------------------------------***--------------------------------------------------------------------Abstract Micro-grid is a novel conceptual power system for smooth installation of many Distributed Generators which is used for distributing the power in order to provide high quality. The most of micro-grids adopt ac distribution as well as conventional power systems, in these days dc micro-grids have gained more popularity because DC output type sources such as photovoltaic (PV) system, fuel cell and energy storages can be interconnected to distribution system without any converters. So the conversion losses are reduced from source to load which leads increase system efficiency and high-quality power can be supplied continuously even though voltage sags or blackouts occur in utility grids. Low-voltage bipolar type DC micro-grid is used with one energy storage unit with a converter to maintain the DC bus voltage. Gain scheduling control technique adopted as droop controller for adding energy storage units for sharing output powers. If the DC micro-grid has two or more energy storage units and those converters can be operated in parallel, it contributes to the voltage regulation and system redundancy. If the converters connect to energy storage units, the controller should consider not only the output power balance, but also the stored energy. If gain scheduling control technique is adopted to share the storage unit outputs, the storage energy would become unbalanced. The energy storage units are selected by fuzzy controller for stored energy balance to carry out the operation of grid under an unbalanced condition of the stored energy. In general, the droop controller detects the output power or current as a feedback parameter, and the deviation of DC voltage is controlled in proportion to the output power. This paper presents a new control that combines MRAS, Fuzzy control with gain scheduling to accomplish both power sharing and energy management by using current as feedback parameter.
منابع مشابه
A New Concept on Intelligent Distribution Voltage Control for Dc Micro Grids Using Fuzzy Control and Gain-Scheduling Technique
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