| The adjustment of energy structure has promoted the research and development of microgrid technology.Compared with AC microgrid,DC microgrid has less power electronic devices and less electrical parameters to be controlled,and higher energy efficiency.Therefore,DC microgrid has higher potential application value in the future complex load environment.The distributed power supply system composed of wind turbine and photovoltaic cell can realize complementary characteristics,so it is widely used in microgrid.The energy storage system configuration composed of battery and supercapacitor,which integrates the characteristics of power-type energy storage device and energy-type energy storage device,plays the role of peak clipping and valley filling and stabilizing the system in microgrid.In some remote mountainous areas,islands and other areas where the cost of power line erecting is too high,isolated microgrid can provide a practical power supply scheme.In isolated microgrid planning,Configuration planning lays the foundation for the economical and reliable operation of microgrid,so it has become an important field of microgrid related research.In this paper,the isolated wind-solar storage DC microgrid consisting of wind turbines,photovoltaic cells,lead-acid batteries,supercapacitors and other equipment is discussed and studied,and the configuration optimization method of the microgrid is analyzed and studiedFirst of all,the object of the study-isolated wind-solar storage DC microgrid is systematically explained in this paper.Wind turbines,photovoltaic cells,lead-acid batteries and supercapacitors are selected and introduced,and their working principles,mathematical models and input-output relationships are analyzed.At the same time,the life degradation mode of lead-acid battery discussed in this paper is explained and analyzed,and the related mathematical model is established.Secondly,the method of microgrid configuration optimization is explained.The economic evaluation model based on the average annual construction cost,maintenance cost and power failure penalty and the reliability evaluation model based on the power loss rate of load are established.The constraints were established according to the power balance of the microgrid,the working characteristics of each device,and the occupied area of the microgrid,and the economic model and constraints were modified based on the lead acid battery model.Based on this,a microgrid scheduling strategy considering the incomplete charging and complete charging of the lead acid battery was proposed.Then,the Spider Monkey Optimization Algorithm,which has outstanding performance in the field of swarm intelligence algorithms in recent years,is improved.Aiming at the defects of Spider Monkey Optimization Algorithm in solving multi-objective problems,an algorithm improvement strategy is proposed,and the feasibility of the algorithm improvement is verified by ZDT test function combined with the convergence and distribution evaluation indexes,which provides a kind of improvement idea for other researchers of swarm intelligence algorithm.Finally,based on the annual timing environment and load data of the example,the configuration optimization results are obtained through simulation with MATLAB.Through comparison in many aspects,the influence mode and importance of the nonlinear battery model on the configuration optimization research of the microgrid are verified and explored. |
