The Evaluation Method Of Hydropower Unit Start-Up State Based On Order Analysis

With the continuous promotion of low-carbon and clean energy structure transformation in China,the high-quality development of renewable energy to meet the power demand has become the core of China’s energy development.Due to its characteristics of quick start and stop and convenient load adjustment,hydropower takes on many tasks such as peak load regulation and frequency regulation in the power grid,which plays an important role in absorbing wind power and solar power and promoting the utilization of various types of power generation equipment.As the key equipment of hydropower resources development,hydropower units are developing towards the direction of giant,high specific speed,high efficiency and intelligence.During the start-up process of hydropower units,the guide vane opening,rotating speed,excitation current and other complex changes need to be experienced.At this stage,the unit’s oscillating pendulum signal contains rich information of the unit,and also shows strong nonlinear and non-stationary characteristics,making it difficult to evaluate the unit’s state based on the starting process data.Existing system with most state evaluation method based on the stable condition data,the current evaluation standards of vibration also did not consider transient process such as boot,boot and based on the state of the data evaluation are mostly based on the working condition of simple parameters,based on the evaluation of stability parameter exists problem of selecting evaluation index,evaluation method,need to be researched.In this paper,the evaluation index and index curve similarity evaluation method are studied from two directions.Firstly,the frequency characteristics of the signal are analyzed from the generation mechanism of common vibration faults of the unit.In order to obtain the characteristic order tracking spectrum representing the unit state,this paper introduces the order analysis method,and based on the order tracking,transforms the unstable signal in the time domain into the stationary signal in the Angle domain,so as to analyze the signal in the Angle domain.In this paper,the variation of characteristic order spectrum is compared to compare the starting process state of the unit.Therefore,correlation distance and Euclidean distance are introduced to evaluate the curve similarity based on its sensitivity to curve shape and numerical difference.On the basis of the above work,combining with the feature order extraction method and the curve similarity evaluation method,the paper proposes the power-on state evaluation method of hydropower units based on the order analysis.Through the data analysis of the actual starting process of the power station,the abnormal conditions of the starting state of the unit were found,which verified the feasibility of the method and the significance of engineering guidance.Finally,the author sorts out the results of the paper and points out the possible research direction of the proposed method in the future.