| Pumped storage power station is an important part of modern power system.It has important functions,such as peak filling and grain filling,frequency modulation and phase adjustment,accident reserve,and so on.It can greatly improve the quality of mains supply and the flexibility and reliability of the power grid,and its running state directly affects the safety and stability of the power system.As the main hydraulic mechanical energy conversion device in the pumped storage unit,the pump turbine has the ability of reversible operation in the two directions of water turbine and water pump,which realizes the circulation flow between the upper and lower reservoirs of the pumped storage power station,and can switch flexibly under the two working modes of pumping and generating electricity.Due to the importance of the pump turbine in the pumped storage unit,it is of great significance to make a reasonable maintenance plan for the pump turbine to ensure the stable operation of the unit and the power quality of the power grid.The traditional planned maintenance is routine maintenance of the unit according to a certain period of time,not fully considering the current comprehensive state of the unit,increasing the unnecessary maintenance cost,and improving the operation cost of the power station.In order to realize the pre-known maintenance of the unit,and to promote the unit maintenance strategy from the planned overhaul to the state maintenance,it is necessary to carry out the research work on the comprehensive state evaluation of the pump turbine.Aiming at the problem that the comprehensive state evaluation index system of water pump turbine is incomplete and the algorithm model is not accurate enough,this paper systematically studies the index system and algorithm model,combines the two,constructs the comprehensive state evaluation model of the pump turbine,and applies the research results to the engineering practice in the form of software system.The main research contents and innovative achievements of this article are as follows:(1)In view of the problem that the current water pump turbine comprehensive state evaluation index system is not comprehensive and the actual feasibility is not high,through the study of the structural characteristics and typical failures of the pump turbine,the structure index system of the pump turbine and the typical fault index system of the pump turbine are established respectively.Combined with the actual operation of the power station monitoring system,a multiple index system of pump turbine running state for real-time state evaluation is constructed.(2)In view of the deviation of the underlying indicators of the multi-index system of pump turbine operating conditions,a degradation degree model was introduced,and an evaluation model of the underlying indicators of comprehensive evaluation of the pump turbine was established using the membership function.At present,the evaluation of hydraulic generating units depends on the experts’ direct judgment or the simple application of the analytic hierarchy process,and the evaluation algorithm model is not objectively reliable.To this end,the objective evaluation method-entropy weight method was introduced and the comprehensive weight algorithm model was established in combination with the analytic hierarchy process.The consistency weights of the comprehensive weights were tested using the Kendall harmony coefficient.On this basis,the underlying indicator evaluation model and the integrated weights algorithm model were combined using a fuzzy comprehensive assessment process to establish an algorithm model for the comprehensive assessment of the pump turbine.(3)Based on the actual data of the power plant monitoring system,the model of the integrated state assessment algorithm of the pump turbine was used to evaluate the operation status of the pump turbine and verify the effectiveness of the model.Finally,the pump-turbine integrated condition assessment model was applied to the actual situation,and a software system for comprehensive condition assessment of pumped-storage unit with friendly user interface and friendly interface was developed. |
