Microgrid optimal dispatch considering random characteristics of solar and wind

Study on microgrid optimal dispatch has always been one of the most essential issues for microgrid operation and management. The paper fully considers the random characteristics of the photovoltaic power and wind turbine power output, as well as the charging/discharging characteristics of the energy storage unit in the microgrid in order to illuminate the intermittent uncertainty of power generation output, load consumption and the system equipment which will have an influence on the microgrid, and further to achieve optimal power dispatch within the microgrid. Aside from this, various levels of electricity prices of the main power grid, which are divided into crest, peak, level and valley prices according to different time periods when the microgrid is connected to the main power grid, along with the cogeneration of combined heat and electric power from a gas turbine which depends on the heat load condition when the microgrid is off-grid are both carefully taken into consideration at the same time. Furthermore, differential optimal dispatch strategies are drawn up, and a microgrid economical dispatch model with the optimization target of minimizing the operational cost considering uncertainty factors under the condition of system constraints is established. In the last part, a typical microgrid system is given as an example, which then is calculated and analyzed. The calculation results of the example have shown that the aforementioned strategies are very reasonable and much more economical than the strategies without considering these two factors.