The Design For An Independent Micro-grid System

Micro-grid has an effective integration of distributed generations (DGs). Micro-grid can work in grid connected mode or islanded mode. An islanded mode micro-grid system provide a power supply possible for the island, border post and remote mountainous areas. This thesis bases on the basic situation of an actual investigation of a border post. Design of an islanded mode micro-grid system based on hybrid energy storage system, including system design, energy management policy design. Use the hardware-in-the-loop experimental platform for experiments to verify the control strategy of DC/DC converter in the system. This thesis mainly launches the research from the following three aspects.Firstly, make a selection of architecture forms and the main unit of capacity of the island mode micro-grid system. The basic situation of the border post is investigated. This thesis analyzes several basic forms of architecture in micro-grid. The AC-DC hybrid micro-grid architecture form is chosen in this thesis. The storage characteristics of several storage batteries are comparative analyzed. The lithium iron phosphate battery and the lithium titanate battery are chosen as a unit of the hybrid energy storage system. With weather conditions and load conditions, consider its own characteristics of the hybrid energy storage system, this thesis complete capacity options of the photovoltaic cell panels, lithium iron phosphate and lithium titanate.Secondly, research the single control method and coordination control strategy of bidirectional DC/DC converter and DC/DC converter. This thesis describes the working principle of DC/DC converter and DC/DC converter. This thesis describes the control method for a single DC/DC converter of voltage and current double-loop control and single current loop control. This thesis also describes the control method for a single DC/AC converter of two-loop control and the PQ control. Master-slave control and peer-to-peer control of multiple DC/DC converters and DC/AC converters are studied. A simulation system is built using Matlab which consists of three DC/DCs and a DC/AC. And the two system control method is tested in the simulation. The hardware-in-the-loop experimental platform is built with the using of dSPACE1104and DC/DCs. Experiments show the effectiveness of the control strategy.Finally, this thesis researches the energy management policy of the islanded mode micro-grid system with the hybrid energy storage system. This thesis also researches the overall structure of energy management system. The energy management policy which is divided into power assignment and SOC adjustment of high power density battery. The simulation model of the system is built in Matlab. The simulation simulates24hours situations, and the results verify the energy management policy.