Research On Calculation Of Sensitivity Of Microgrids Based On Generalized Tellegen's Theorem

As a kind of functional index,sensitivity has been widely used in the power system safety and stability analysis,control,evaluation,planning etc.In recent years,with the use of green renewable energy,micro-grid has been vigorously developed as an effective way to consume new energy.However,the intermittency,volatility and uncontrollability of micro sources have adverse effects on the power supply quality and stability control of the micro-grid,such as frequency,voltage and stability problems.Whether sensitivity index and sensitivity analysis method can be used for integrated evaluation of the micro-grid,the stability analysis and the control are the current research direction in this field,and accurate sensitivity acquisition is the core.Therefore,this thesis aims at the research object of the photovoltaic source micro-grid based on the generalized Tellegen's theorem,which has practical significance and theoretical value.When building the micro-grid sensitivity calculation of steady-state model,based on typical physical framework and mathematical models of components such as the photovoltaic source,energy storage,interface and load in the micro-grid,considering micro-grid operation control strategy,the classification block of micro-grid comprehensive steady state model and a simplified and practical model are established.On the basis of the formula method,perturbation method and adjoint network method in depth comparison and analysis of calculation sensitivity,and based on Tellegen's theorem,the mathematical expression of sensitivity calculation of micro-grid with universal significance is derived in combination with integrated steady state model of the partitioned micro-grid.Micro-grid computing based on generalized Tellegen's theorem are given the sensitivity of simple practical method,and this method is applied to the IEEE14 testing system and micro-grid system for sensitivity of simulation calculation,and calculated the volatility of light,temperature and load on system voltage sensitivity,and with real data of micro-grid,the results show that the feasibility of the model and sensitivity calculation method is simple and practical.In order to further analyze the static voltage stability problem of micro-grid,the factors affecting the stability of source,net,charge,storage in micro-grid are deeply analyzed,and the method of analyzing the static voltage stability of micro-grid based on sensitivity is studied.Sensitivity calculated by using the generalized Tellegen's theorem has the characteristics of flexibility,solving as to determine the stability of the system impedance model sensitivity index,by calculating the critical impedance model sensitivity trends,the method can give a quick static voltage stability weak link,the example analysis shows that the proposed method is effective.