Distributed Grid-connected Photovoltaic Research On The Harmonic Influence Of Power Grid And Countermeasures In Lincheng Area

With the rapid development of power industry,fossil fuels has been rampant mining use,leading to a sharp decline in non renewable energy reserves,in order to solve the problem of scarcity of fossil fuels,the state vigorously advocated the use of new clean energy,including wind,solar and other.At present,the wind energy,solar as distributed power and in the power grid were combined to the grid,in the domestic solar energy without pollution,high reserves characteristics of the photovoltaic power generation in the power grid can be widely applied.However,with the increasing number of distributed photovoltaic grid,it can also have serious impact on the quality of electric power grid.In order not to affect the reliability of power supply,inverter and other harmonic components have nonlinear elements should meet the national standards.In this paper the trend for photovoltaic grid connected power generation,according to the actual status and power grid photovoltaic power generation access,give full consideration to the future photovoltaic power generation access capacity and the way,development of photovoltaic grid connected generation on distribution network effects and the countermeasure research.In this paper,the concept of the concept,harm and calculation methods of harmonic were carried out.The equivalent model of power distribution network is built by using current injection method,and the harmonic resonance mechanism and the low pass filtering control strategy and the notch control strategy are studied.According to the established model,the expression formula of harmonic voltage distortion rate is derived,and the harmonic characteristics of the grid connected inverter are analyzed.Using MATLAB software and the selection of distribution network simulation model is built and the photovoltaic grid capacity,photovoltaic access locations and PV output active power change and grid node voltage and current harmonic distortion rate.Theoretical analysis and simulation results show that the method is reasonable and effective,only to solve specific grid of large-scale grid connected photovoltaic provides specific and feasible technical measures and the principle of research results with universal applicability and practical application of a certain.