| Energy storage system of micro-grid consisting of lithium iron phosphate batteries become a key point in the research of micro-grid technology. It provides short-term power supply, energy buffer, and improves power quality and other important support. In this paper, the micro-grid and its energy storage and power battery and its charging and discharging technology research status were summarized according to the geographical and time sequence in the world. Surrounding the micro-grid energy storage system controller development and application, the main jobs of the thesis are as the following.Firstly, a summary of control strategies and control modes of micro-grids are given. The control strategies of the inverter can be summarized as follows, P/Q control, V/f control and droop control. Based on the energy management system (EMS) of the micro-grid, three control modes summarized as follows, master slave control, peer-to-peer control and multi-larger agent control.Secondly, a lithium iron phosphate batteries energy storage system of micro-grid is designed and implemented. The bidirectional DC/DC converter, DC/AC converter and their controllers are the key of the system. An energy storage system of micro-grid has been modeled and simulated using the Simulink in the MATLAB. The simulation results show that the main circuit and its controller of the system can maintain stable operation under the proposed control schemes, and provide a theoretical basis for the hardware development of controllers.Again, a bi-directional DC/DC controller is designed by the dSP ACE 1104 controller development system. For hardware circuit design and components selection, including power circuit, drive circuit and sample circuit. An experimental platform of micro-grid is set up. To control system software development, including the collection and the signal processing unit, main control unit, software protection unit and PWM control signal generating unit. The quality of the controller is verified by experiments under the environment of low voltage. Results show that the main circuit and its controller of the system can maintain stable operation under the proposed control schemes.Finally, bidirectional DC/DC converter and its controller are used in the charging and swapping electrical system of electrical vehicle (EV) in the Hybrid AC/DC micro-grid. How to improve the charging efficiency of power system of EV has become a research focus in the whole world. A charging and swapping electrical energy management system is necessary to improve the charging efficiency of EV, which can be combined with the charging and swapping electrical devices. The energy storage, the hybrid AC/DC micro-grid, and the total system structure are designed in the paper. The simulation results show that the system meets IEEE 1547TM power quality standard, and it is not only effective on peak load leveling, energy saving, emission and cost reducing, but also useful to promote the EV technology. |
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