The Research Of Optimal Operation In Microgrid Considering Randomness

Energy crisis is a hot topic since the new century. The development of new energy, new energy technology research and its effective utilization become an urgent problem. Renewable energy is more economic, more environmental, and more reliable than fossil energy as an alternative to fossil energy. In the microgrid, in order to give its full play and make good use of renewable energy units, the reasonable arrangement for power output of renewable energy units becomes essential to optimal operation of microgrid. The power output of renewable energy units is influenced by the randomness such as nature. This paper studied the optimal operation of microgrid considering the randomness in microgrid.Firstly, the power output model of wind turbine and photovoltaic is established based on the probability model of wind speed and light intensity. The power output model and the pollutant emissions model of diesel engine and microturbine are founded for they are the main sources of pollutant emissions in microgrid. Also, the steady-state output model of battery and fuel cell are established. Under the former models, the economic and environmental optimal operation model is built up.Secondly, the optimal operation model of the micro-grid is a multi-variable, multi-constraint, multi-objective, non-linear stochastic optimization model. The solution of the model involves two issues:dealing with the random variables and solving the model. To the previous question, point estimate method was used according to analyzing the advantages and disadvantages of current mathematical methods. On the latter issue, in terms of convergence and the ability to expand new solution of the intelligent algorithms, the artificial immune algorithm is selected. By means of adding chaos mutation, the ability to expand new solution of the artificial immune algorithm is enhanced. Multi-objective optimization result is a set of Pareto optimal solution, the Pareto solutions were ranked according to the multiple attribute decision making, which provides a useful reference for policy makers.Finally, a typical microgrid is selected and the optimization result is verified and analyzed. Four cases were modeled including minimizing the operating cost, minimizing the pollutants, deterministic model and probabilistic model. The results verified the effectiveness and validity of the form method and the algorithm.This paper modeled and simulated the economic and environmental operation of microgrid on the basis of considering the randomness. The advantage of microgrid and the impact of randomness to the microgrid scheduling were analyzed, which provides a valuable reference to the optimal operation and the engineering practice of microgrid. The results show that the microgrid have certain advantages over traditional power mode. The randomness increases the cost of optimal operation and the pollution emissions in microgrid.