Simulation Study On Modeling And Energy Management For Isolated Micro-grid System

The fossil energy such as oil and coal is facing a serious problem of depletion in today's world. Wind and solar are deemed as new clean and inexhaustible energies, and also they are friendly and non-pollute to the environment. Developing new energy sources has become a trend in the world. As an important form to accept renewable energy, micro-grid can be used as a useful supplement to the large power grid, and it is a good solution to the problem of power supply in remote mountainous areas, pastoral areas and islands. Simulation study on modeling and energy management for the wind/PV/battery Micro-grid has important practical significance.The whole topological structure of the isolated micro-grid based on wind/PV/storage is presented in this paper, and wind power system, photovoltaic power generation system and energy storage system are introduced in detail. Based on researching the characteristics of wind/PV/storage micro-grid, wind turbine, direct-drive permanent magnet synchronous generator, AC/DC rectifier, DC/DC booster each are established in the wind power generation system model. Photovoltaic power generation system model is set up based on the photovoltaic cell, DC/DC booster; Energy storage system is set up based on battery and super capacitor. At the same time, PWM control module modeling is built. Based on the model of each subsystem, the simulation model of micro-grid is built, and the simulation research is carried out to simulate the operation, control and energy management of micro-grid.In this paper, the maximum power tracking technology(MPPT) of wind power generation system and photovoltaic power generation system is described in detail.Simulation research of maximum power tracking strategy is implemented using the simulation model. The inverter control strategy is described explicitly. According to the characteristics of PID controller and with the advantages of neural network, the BP-PID compound control strategy is proposed. The control strategy is compared with the conventional PID control strategy. When the nonlinear load is used, the system can run normally and stably. At last, based on the model, the energy flow of the system is analyzed, and the different energy management strategies are proposed according to the DC bus voltage.