Research On Modeling And Simulation Of Wind/PV/ ES Hybrid Micro-grid System

With the vigorously development of smart grid worldwide, as a vital part of the development process, the research on micro-grid also attracted the attention of domestic and foreign experts. With the appearance of micro-grid, it is easy to overcome a series of problems caused by the presence of distributed generation in power grid, the development of distributed generation is no longer restricted and has a broader field. As a complete stand-alone system, micro-grid is very important to the traditional power grid because of its self-sufficiency and complementarily. Considering the advantages of micro-grid, this paper has carried out a research on the modeling and simulation of Wind/PV/ES hybrid micro-grid system. The main contents are as follows:(1)According to the definition of micro-grid system, a detailed analysis of the mathematical principles of wind power, photovoltaic power generation and energy storage devices in micro-grid system is carried out to build a simulation model. Through simulation examples for the model characteristic simulation analysis, validate the correctness of the model, and laid a solid foundation for the following research. Through the characteristic analysis of specific simulation examples, it can prove the validity of the model and lay a foundation for the following research.(2) In view of the islanding problems due to the large-scale and high-power run of grid-connected PV systems, this paper first introduces the relevant standards of islanding detection at home and abroad; secondly expounds the detection principle; then, makes a detailed introduction of several common methods and summarizes their advantages, disadvantages, applicable scope; finally, adopts an islanding detection method based on frequency-reactive current feedback and through a simulation example to verify the correctness and effectiveness.(3) According to the characteristics of micro-grid system, this paper carries out the research on Under Frequency Load Shedding(UFLS) and Under Voltage Load Shedding(UVLS) of micro-grid system in two modes, and designs a set of device with reference to the traditional principle of UVLS and UFLS; Through a specific simulation example, it can prove the validity of the device and the results show that the device designed in this paper is suitable and effective for ensuring the safe and stable operation of micro-grid system.