Research And Application Of Grid Connection Scheme For Photovoltaic Power Station

With the rapid development of the economy and society,energy demand is also constantly improving.Compared with the application of non-renewable resources such as coal and petroleum,the development of new energy has become an important trend.Green,clean and renewable have become important development goals and requirements.As an important part of new energy application fields,photovoltaic power generation can not only alleviate China’s energy crisis but also reduce China’s environmental pollution.It has broad application prospects.The Dandong area studied in this paper is located in an area with abundant solar energy resources.Through the construction of photovoltaic power stations,the reliability of power supply in Dandong area can be effectively improved and the power supply pressure in China can be alleviated.In the research process of the thesis,firstly,the basic principle of photovoltaic power generation is deeply studied.By establishing the mathematical model of photovoltaic cells,the output characteristics of photovoltaic cells under different temperatures and illumination intensity,and the commonly used maximum power tracking point algorithm.(MPPT,Maximum power point tracking)is carried out,and an improved method is proposed for the deficiencies in the MPPT algorithm.At the same time,the effectiveness of the proposed algorithm is verified by MATLAB simulation.Secondly,the control strategy of photovoltaic grid-connected network is studied in detail.The mathematical model of three-phase grid-connected inverter in rotating coordinate system is obtained through mathematical calculation and analysis.On the basis of this model,the decoupling control link of current is added.The system is guaranteed to be dynamic and stable,and the corresponding simulation model is established to verify the correctness of the control strategy.Then,the grid-connected scheme of the photovoltaic power generation system is designed,and the current project overview is analyzed at the design time.Based on this,the grid-connected scheme is designed to select the optimal access scheme and the system can be stabilized.Operation,calculate the short-circuit current after the PV station is connected to the grid,and then select the appropriate equipment to ensure the safe operation of the system.Finally,the secondary side of the photovoltaic power station is designed,and the communication scheme,relay protection configuration and dispatching automation system in the station are designed to ensure the safety of the system operation and improve the automation of the station operation.