Flow Calculation And Multi-objective Optimization For Operation Of Microgrid With High Penetration

As the renewable energy-based distributed generation have many deficiencies, such as low power, high cost and difficulty of network operation control and so on. This leads to the microgrid concept. Microgrid is a small power supply for a series of links to the system integrated distributed generation, load, energy storage and the protection and control, which can solve the contradictions between the power system and distributed power, and overcome the shortcomings of distributed generation.With the research objectives of three-phase power flow and optimal operation, combining with micro-power steady-state mathematical model and backward distribution system power flow method, this paper has proposed a set of new research ideas and research methods to explore the microgrid three-phase power flow calculation method, with which it also has proposed multi-objective optimization program of the economic and security with the penetration constraint.Firstly, it has explained the definition of microgrid characteristics, basic structure, operation standards and research status, investigated the concept of the energy flow an permeability, with penetration of micro-simulation analysis of different power grid to run on the impact of power system stability, getting stable operation of the maximum allowable penetration of EPRI-36 bus system:λ=8.341%. Secondly, it has established a variety of DG and energy storage models, and according with backward power flow calculation, that handle the four node types of PQ,PV,PI and P-Q(V), derived three-phase power flow calculation equation of microgrid. Then, it derives static voltage stability index and the calculating formula for network loss, based on microgrid flow equations, and compares with the distributed power of the position, capacity and power factor's impact on the micro-grid voltage and the loss for concluding its regular which shows that seasonable allocation plays an important impact on the benefits of distributed power's play.Finally, considering both economy and security of microgrid, it has established the best microgrid voltage level, the least loss and the minimum cost of running economic model of multi-objective optimization, introduced the concept of self-adaptive proportion method and self-adaptive penalty function, proposed Self-adaptive genetic algorithm, and it solves multi-objective optimization problems into single objective ones. Then, using 30 bus microgrids to show that the optimization method is effective, which could get the best configuration of distributed power.