Reliability Assessment Of Typical Wiring In Active Distribution Networks In Mountainous Area Of Northen Guangdong Province

In recent years,the new energy technology developed rapidly,the household photovoltaic power generation spread everywhere,the access of the wind farm increased obviously,and the small hydropower in the mountain area scattered everywhere.The access of low-power distributed generation(DG)into the grid of 10 k V and below,brings the influence to the power quality and power supply reliability of the traditional distribution network.The termination of traditional distribution is only a load,without the DG.The output of wind farm,the hydropower and the photovoltaic power is greatly dependent on the climatic conditions,extremely unstable with time,and changed rapidly.First of all,the paper introduces the present situation of medium voltage distribution network of northen Guangdong Province from the aspects of power supply,load,line,station area and distribution automation.Secondly,the reliability calculation model is established from the two dimensions of load point reliability and system reliability.Throuth the failure modes simulation and analysis of a typical 10 k V feeder,this thesis evaluates the load point reliability and system reliability with different access location,permeability and support time by matrix calculation,and compared with the traditional distribution network.Thirdly,the paper analyzed the typical connection modes of traditional distribution network,calculated the index of power supply reliability and the average user outage time,explored the influence of DG to the reliability of traditional typical connection modes.A number of typical feeders are selected to calculate the improvement of power supply reliability after DG access.Through the research and calculation,this thesis evaluate the influence of DG on power supply reliability in different typical connection mode,different access location,different permeability,different support time.The research results can offer directive opinions for the upgrade of distribution network,will provide advisements for the DG access,especially hydropower and photovoltaic power,provide theoretical support for the scientific planning of distribution network in mountainous areas.