PI control method based storage to control the microgrid in a state separated from the main network

A microgrid is a localized grouping of electricity generation energy storage and loads that normally connected to a main network micro grid generation resources can in clade some distributed generation utilities, wind turbines, photovoltaic systems (PV) diesel generator and fuel cell which are the electricity supplies and heat provider. One of the most important problems of micro grid. Is voltage control and frequency, in other words, the balance between generated power and consumed load, in the micro grid. In the network-connected modes the main network or macro grid establishes the power equilibrium. Since the unreproducible resources used in microgrid such as fuel cells and diesel generator act un satisfactory and in other hand, they cant use in the power balance, so in micro grids the rechargeable and energy storage resources like battery and flywheel more often used. These resources have high velocity and arable to create power equilibrium as soon as possible. In the research a tow-stag control strategy based on battery energy storage system is introduced for voltage control and micro grid frequency in the isolated mode. In the first stage energy storage system provide primary voltage and frequency control, then controllable resources act the role of power equilibrium in the micro grid. The aim of this processes that the energy saving system can fall down the output voltage and continuously the maximum capacity of energy saving would be available to establish power equilibrium in the micro grid. The simulation results on micro grids prove the efficiency of controller.