Research On Influence Of Stability Of Islanding Microgrid With Dynamic Load

With the rapid development of clean energy power generation, microgrid technology has attracted much attention. As an effective complement to the grid, a microgrid is able to give full play to the distributed power generation with high efficiency, economy and environmental protection, flexible maneuver, safe and reliable, and centralized power grid formed complementary use of energy, greatly improve the power system of power supply reliability and flexibility and provide a variety of high quality power supply heating service for the user.Study on the influence of dynamic load on the stability of microgrid, will further improve the microgrid technology and provide theoretical support for the engineering practice.By the scale and capacity constraints, the microgrid in islanding operation, due to the loss of high frequency and voltage support, microgrid voltage stability is facing a severe test.Induction motor dynamic load capacity, the type and parameters of the influence, its operating characteristic(including mechanical properties, turn difference characteristic, starting characteristic) will have a significant impact on the stable operation of microgrid. In this paper, the mathematical model of induction motor load, on the operating characteristics of inquiry and analysis, find out the key factors effecting the stability of the system, in order to study the influence stability of microgrid islanding operation provides a theoretical basis.For the dynamic load simulation analysis was established, including wind power,photovoltaic distributed power supply and storage aspects of the mathematical model, gives the model of link control mode, and design microgrids islanded operation overall topology model. In the AC microgrid, due to most of the distributed power supply with inverter as its final interface to access the microgrid. So we chose appropriate inverter control strategy of microgrid stability in an important guarantee for the supply side. After the inverter control strategy and control strategy of microgrid is studied, according to the microgrid topology model characteristics, select the in master-slave control for the overall control strategy,according to the characteristic of distributed power supply, select the corresponding invertercontrol strategy.From the simulation results, dynamic load for the given operation mode of microgrid islanding effect on the stability of different degree caused by the fluctuation of the output power of the DG, resulting in microgrid instability. In view of this situation, the microgrid stable operation of the premise, put forward several improvement measures, The rationality and effectiveness of the proposed improvement measures are verified by simulation comparison.