Research On Optimal Operation And Maintenance Technology Of Photovoltaic Power Station

With the increasing of PV generation station scale and quantity year by year,more and more PV power stations are facing the difficult problems during operation and maintenance process.The existing operation and maintenance system can analyze some equipment problems,but can't satisfy the acquisition and processing requirements of large data,can't evaluate comprehensively the operation status of PV power station.In this thesis,it is focused on the operation and maintenance problems,and special considerations are paid on operation performance evaluation,fault diagnosis,system design and development,etc.(1)The performance index of PV power station is set up,including component efficiency,PV array efficiency,PV inverter efficiency,AC grid efficiency,AC side maximum output power,theoretical generation time,full time number,PV system's long time generation capacity,PR value,PVUSA power level,system energy efficiency ratio and so on.Combined with the long-term monitoring of the power generation data of a PV power station in Northwest China,the overall efficiency of the PV system and the efficiency of each key link are analyzed.The target of the key components of the power station is determined,the efficiency model parameters of the key parts and important links of the PV power station are extracted,and the generation reliability is considered for the PV power station during the evaluation of medium and long term power generation performance for PV power station.(2)The common failure types and influencing factors of PV power station are analyzed,including PV array failure,controller failure,inverter fault,transformer fault and so on.The common fault diagnosis methods of PV power station are summarized,including fault diagnosis based on infrared image analysis,fault diagnosis of TDR,fault diagnosis based on neural network,fault diagnosis based on extension theory,etc.Taking the fault diagnosis of PV array as an example,the applicability and effectiveness of neural network and extension theory are verified.(3)The intelligent operation and maintenance system of PV power generation is designed from the aspects of logic architecture,network architecture,data storage,basic function,application function and so on,and the intelligent operation and maintenance system of PV power station is developed.The system is applied to a 30MW PV power station in North China.Because of the low construction quality and operation and maintenance level,the power generation efficiency is lower than the same type of power station in the same area.After the trial operation of the power station in June 2017,the power efficiency of the power generation is raised by 0.5%?1.5%.