The Application Of Photovoltaic Power Generation System In Railway Lines

As a clean and renewable energy,solar energy has been widely used in various fields of economic life.With the rapid development of railway construction,railway line across the vast land of China.In the western region,the land resources are relatively rich,solar resources are also very rich,which is the ideal area to the Building-Integrated-Photovoltaic.Generally,the city center in the eastern coastal areas,always have to face to the stress of the electrical.The application of Building-Integrated-Photovoltaic system of the railway station that not only be the important geographical location,but also have a huge area,can effectively alleviate the pressure on electricity.Building-Integrated-Photovoltaic technology can not only meet the general load demand,but also can be used as a standby power supply of "one primary & one standby" two input power supply,which there are following advantages:(1)Saving the construction cost of power line.(2)Saving standby power supply operating costs;(3)When normal conditions in the day-time,it can also feed the power system,selling excess electricity,to recover the cost of inputs.In this paper,the equivalent circuit of photovoltaic cell array as a constant voltage source is analyzed firstly.According to the different light intensity and temperature conditions,a mathematical model is established to obtain the I-V and P-V characteristic curves of the photovoltaic cell array.Based on MATLAB,the output characteristics simulation diagram of photovoltaic cell array has been done.Compare with the simulation curves of three different conditions,the I-V output characteristic curve and P-V output characteristic curve of photovoltaic cell array under different light intensity and temperature conditions are obtained.Secondly,this paper proposes the circuit topology structure of 500 kW photovoltaic grid connected inverter by using IGBT as the core component of the controller,which can realizes the functions of signal acquisition,monitoring,control,communication,heat dissipation,and integrate the islanding detection function on the grid side.By using the method of disturb the active current periodically,observe public node voltage is beyond the threshold or not,and design the flow chart and simulation diagram of islanding detection.Comparethe diagram of voltage and current with the traditional islanding detection,and put forward the conclusion.Then,according to the 8.9MW photovoltaic power generation project of a railway station,the overall design scheme is put forward.Including :(1)The selection scheme of three major equipments,photovoltaic cell,inverter and transformer.(2)The specific scheme of battery array placement.(3)The configuration scheme of electromechanical part and the selection scheme of electrical equipment for the grid.(4)The generating capacity of the project,harmonic detection and power quality of parallel point.Finally,this paper summarizes the 8.9MW photovoltaic power generation project of the railway station,and puts forward some future development directions of the research and application of the photovoltaic building integration.