Research On High Elasticity Of Microgrid System In Highway Service Area

In order to actively respond to the national"dual carbon"strategic goal,the Ministry of Science and Technology proposed that the establishment of a micro-power grid system that is compatible with natural endowments with the natural endowment of the highway road network system to achieve the green development of transportation energy.However,my country’s highway network is widely distributed,with different climatic conditions,and in recent years,the extreme natural disasters of"small probability and high damage"in my country have been frequent.Severe destruction and economic losses are extremely serious to the micro-grid system.In order to express the operating status of the grid in the face of the extreme natural disaster of"small probability and high damage",the concept of scholars at home and abroad proposed the concept of"elastic grid"to describe the performance of the grid in the face of extreme natural disasters,that is,the resistance of the power grid’s resistance Ability and self-recovery ability.In this article,the concept of elastic grid is applied to the microscopic grid.With the funding of the National Key R&D Plan Project（2021YFB1600202）,related research on the elasticity assessment of the micro-grid system and how to improve its elasticity.The main research content includes:（1）To build a mathematical model of extreme natural disasters,for wind load,use the collective wind speed,extreme disaster center position,movement speed,and mobile direction angle of weather to obtain the wind load function model L_{WIN D}（x _i,y _i,t）about time;Weather data such as extreme disaster center position,movement speed and disaster duration can be obtained by the ice-covered load function modelL_ICE（x _i,y _i,t）of time points;for the phenomenon of flashing,according to the height of the line distance,the thickness of the insulator,the real-time voltage of the insulators and the transmission lines on both sides Parameters and other data can build a light-lined voltage numerical model;combined with actual engineering experience,the weight of the three influence factors to cause damage to the transmission lines is divided into_Wa=0.10,a_I=0.80,a_f=0.10the proportion of the transmission line.That is the line failure model.In the calculation example,Monte Carlo is simulated,combined with historical weather data and actual line parameters to build extreme weather models and line failure rate models,and obtain the corresponding component fragile curve model.（2）According to the relevant national standards,the load level of the highway service area is divided,and the elastic assessment of the micro grid is conducted according to the load level.Under the influence of the extreme Blizzard disaster,the four micro-grids were proposed from the three time dimensions before the accident,during the accident,and after the accident.Elasticity evaluation indicators:Average defense durationM_ADTM,average power off timeM_{AT PM},elastic recovery coefficient M_ERCM,and average statistical length used for complete recoveryM_ATCM.And propose the concept of elastic comprehensive evaluation indicatorsM_ECEM between the microcontrollers systems with different composition structures,comprehensively analyzes the importance of four elastic assessment indicators,and the proportion of the above four indicators in the weight comprehensive evaluation indicators accounted for the proportion of the elastic comprehensive evaluation indicators,respectively It is defined as 0.10,0.25,0.50,0.15,and comprehensively evaluates the elastic properties of the entire micro-grid system based on four elastic evaluation indicators.（3）By configured a hybrid energy storage system（HESS）containing supercapacitors and batteries to reduce the loss of micro-grid caused by extreme natural disasters,against the backdrop of extreme blizzards and use the improved multi-target dual group taboo hereditary white shark algorithm（MODTGW）.The target function is to require HESS investment And the sum of operational maintenance costs to minimize multi-target functions to solve the optimal HESS capacity configuration.It is proposed to use the effects of the intensity of various impact factor in extreme blizzards weather scenes such as wind speed,ice covering,flashing,etc.to perform clustering analysis,and to divide the centers from 3 to 15 aspects,combine K-combined with K-Means cluster algorithm reduces the clustering of extreme weather scenes;uses Monte Carlo simulation to compare the elastic recovery coefficient indicatorM_ERCM of HESS and traditional single battery energy storage coefficients in each typical scenario,respectively,and verify the superiority of HESS.Combined with example analysis,compared with the traditional single battery energy storage,the elastic recovery coefficient of HESS has increased by 6%,and the power outage rate of the entire micro grid system also reaches 0.41%.Because the power generation of renewable natural resources is volatile and unstable,the electrical energy issued contains high-frequency electricity power and low-frequency power.Proposed the combination of HESS and complementary collections of empirical modulus（CEEMD）algorithm（CEEMD）algorithm is optimized The distribution between the battery can further improve the service life of HESS and indirectly improve the elasticity of the micro-grid system.（4）Established the pre-disaster and post-disaster scheduling model of mobile power vehicles.Before extreme natural disasters,the most vulnerable and damaged transmission line in the transmission line was obtained through historical statistics.The mobile power vehicle was arranged in advance.The minimum loss rate of the power grid is the target function,with the standard deviation coefficient of the target function as a convergence judgment,combined with the historical weather data and road parameters of extreme Blizzard disaster,in the Monte Carlo simulation Seeking the solution to sampling and solving,and statistics get the optimal access point of mobile power vehicles.Combined with example analysis,compared with the unchanged model of the mobile power vehicle access position of the post-disaster after the disaster,the pre-arrangement of the mobile power vehicle pre-arrangement and the post-disaster mobile scheduling model increased the proportion of the load of power supply in the microcontroller by 12%,and further increased the further increase.The elasticity of the entire micro grid.Finally,the physical reinforcement and material replacement of the hardware infrastructure was introduced to improve the defense capacity before the micro-grid disaster.