Optimal Configuration Of Distributed Generations And Economic Dispatch For Microgrid

In recent years, distributed generation(DG) springs up, and microgrid(MG)integrating the distributed generations, energy storage devices and controllableloads in a more effective way has become an important part of the smart gridfor its advantages: easy to access for renewable energy, improved energyefficiency and integration of emerging technologies. Optimal configuration ofdistributed generations is the core of planning and designing for MG, and howto achieve optimal distribution of energy resources is closely related to the safe,reliable, economical and environmental operation of MG. Therefore, study onthe optimal configuration of distributed generations and economic dispatch forMG has important practical significance.This paper analyses the current research status and emphasis point in thefield of optimal configuration of distributed generations and economic dispatchfor MG. On this basis, first of all, steady-state output and cost models of windpower system, photovoltaic, fuel cell, diesel generator and energy storagesystem are established. Some suggestions on the selection and cut-in way ofeach distributed generation are also given. Aiming at a hybrid solar-windindependent MG, the optimal sizing model is built, and a hybrid quantumgenetic algorithm based solving method is proposed. In the study case, thesuperior performance of the proposed algorithm on convergence speed andglobal convergence are verified by being compared with typical quantumgenetic algorithm and genetic algorithm. From the perspective of loadcontrollability, loads can be divided into three categories: critical loads,adjustable loads and shiftable loads. Then, the model of shiftable loads whichare the strongest controllable ones and the strategy for load shifting are presented. Finally, combined with energy distribution and load management,the problem of optimal economic dispatch for MG considering shiftable loadsis considered, what’s more, dynamic economic dispatch features are also beentaken into account. The economic dispatch problem is regarded as a multi-stagedecision problem and its dynamic programming principle is modeled.According to the particularity of the problem: the objective function is aquadratic function and the constraints are all linear constraints, dynamicprogramming is converted to sequential quadratic programming and thepredictor-corrector interior-point algorithm is adopted to solve it. The results ofsimulation and analysis show that load shifting plays a notable role in theoperation of MG, as an efficient way to reduce peak and fill valley, to increaseoperation economics and to alleviate solar and wind curtailment.