Research On Grid Connection And Key Problems Of 10kV Photovoltaic Power Stations In Dalian

Energy is indispensable to human development,and traditional petrochemical energy will eventually be exhausted.Therefore,the development and utilization of renewable energy is the guarantee of sustainable development of future society.Solar energy is inexhaustible and easy to get.So it is the most ideal renewable energy.At present,the research and design of PV grid-connected system is more focused on the design of grid-connected controller.They have not done grid-connected research for special photovoltaic power station level systems.Therefore,there are still some gaps in the actual construction of photovoltaic grid-connected power plants.This paper mainly studies the construction of grid-connected system of 10 kV photovoltaic power station.The construction of the system takes Dalian Dingdi 10 kV photovoltaic power station as the background.It mainly discusses the design of electrical part and grid-connected control system of 10 kV photovoltaic power station.The paper is divided into three parts.First,the electrical system design of 10 kV photovoltaic power station.It is the electrical basis of transmission and distribution of photovoltaic power station.It should be designed according to the grade requirements of 10 kV photovoltaic power station and the specific distribution network environment.This paper focuses on the primary and secondary design of the electrical part of Dalian Dingdi 10 kV photovoltaic power station.It discusses the calculation of short-circuit current and chooses the corresponding equipment according to the calculation results.Secondly,it studies the design of photovoltaic grid-connected control system.It is the core of grid-connected control of photovoltaic power station.On the basis of analyzing the demand of 10 kV photovoltaic grid-connected control system,it completes the overall design of the system.According to the requirement of grid-connected control,it chooses the TMS320F28335 processor as the control core.Based on the overall design of the grid-connected controller,the detailed design of the hardware circuit of the 10 kV grid-connected control unit is analyzed.It discusses the general function block diagram of grid-connected control system and the structure block diagram of voltage conversion unit of photovoltaic grid-connected control system.On this basis,it studies the design of analog signal acquisition and processing circuit,full bridge inverter circuit,wireless data transmission circuit and time synchronization circuit.It gives the corresponding circuit schematic design.The third part is the simulation and performance test of photovoltaic grid-connected control system.The control circuit is the basic circuit to complete the control.The software design and algorithm simulation of the system are the soul to complete the grid-connected control.In the research,the maximum power point tracking control method and parameters are determined by using MATLAB tool to simulate and design the maximum power point tracking.The control flow of grid-connected photovoltaic system is discussed,and the closed-loop control flow of inverter based on PID algorithm is discussed.After the hardware and software design is completed,the system is tested in this paper.It is realized by testing and verifying the functions of each unit of the system,and has stable performance.Through the model trial operation,it is found that the photovoltaic power plant has good operation effect and can meet the requirements of use.The construction of the power station will serve as a demonstration project for 10 kV photovoltaic substation in Dalian.It will provide templates and references for the construction of other similar power stations.