Research On Uncertainty Optimal Dispatch Of Microgrids Considering Renewable Energy Sources

Nowadays, considering the requirement and environment protection, microgrids is getting more and more attention, which can make full use of renewable energy sources as well as traditional sources efficiently. However, those increasing various renewable energy sources are uncontrollable to be dispatched to system operators. If the proportion of stochastic energy sources reach a high level for microgrids, that is high permeability, it become s harder for operators to achieve the requirements of power balance and reliable operation. The traditional deterministic operation scheduling is not applicable to microgrids with random renewable energy sources. Then considering the influence of the uncertainty of renewable energy sources, it has a great significance to propose an indeterminate optimal dispatch model for microgrids. Thus, aiming at the uncertainty in microgrids, the corresponding optimal dispatching models with uncertainty considered are proposed on the aspect of chance constrained programming and robust optimization, respectively. The main work of this paper is as follows:1 The probabilistic models of PV and wind power are discussed respect to the probabilistic models of wind speed and intensity of illumination. The serialization of wind power, PV power and load is modelled based on the sequence operation theory. Then the output of association system including wind power, PV power and load is modelled according to their joint probability sequence.2 The predicting method is proposed based on Markov chain, and an optimal dispatching model based on chance constrained programming with the fault probability considered is constructed. With the objectives of economy, reliability, environmental benefits and stability, this model takes into account the constraints including power balance, output limits and so on. The chance constraints are transformed into the deterministic constraints and an improved particle swarm optimization algorithm is proposed. Last, the validity is verified by case study.3 First, cassette sets considering the uncertainty of renewable energy sources and load are proposed in this part. The power fluctuation is balanced by schedulable units, energy storage and the exchanged power form the main grid. Considering that the spinning reserve is enough to deal with the worst scene of the power fluctuation within the uncertainty sets, it is aim to optimize the economic operation cost of the microgrid. Last, the validity is verified by case study.