The practice of ecological governance and reforestation was carried out by taking Pianyanzi fluctuation zone as the object, proposed the stone cage anti wall technology, stone cage plate slope protection technology, ecological bag slope protection technology, which provides the necessary soil matrix for plant growth and prevents the soil from being soaked by reservoir water and erosion. On this basis, more than a dozen species of water-resistant plants were screened, and different plant species were configured in different elevation areas. After a long period of inundation in one hydrological year, the overall survival rate of trees and shrubs was 54.9% and 35%, respectively. Among them, Taxodium ascendens Brongn, Ascendens mucronatum, Betula nigra, Myricaria laxiflora, and Salix variegata had better submergence tolerance and higher survival rates, which were 84%, 74.2%, 88.3%, 97%, and 95%. They could withstand long-term overtop submergence, and the effect of reforestation in the water-level zone was obvious.

Bidding is the main way for a hydraulic engineering contractor to obtain a project, and the level of the bid price directly affects whether the contractor can obtain its construction right. Before bidding, predicting the distribution of the bid price of the proposed hydraulic engineering can optimize the formulation of its own quotation. A global optimization Bayesian-MCMC algorithm was used to predict the Beta distribution parameters. Bidding behavior of contractor was simulated by numeric analysis. The algorithm does not need to consider the conjugate of the prior distribution and likelihood function in Bayesian estimation. The numerical simulation results show that the Bayesian-MCMC algorithm requires less data for simulation and has better prediction effect than the traditional moment estimation method.

Aiming at the nonlinearity and non-stationary of vibration signals of hydropower units and the timeliness of prediction, this paper proposed a vibration prediction model of hydropower units based on VMD-CIMFs-TCN. Firstly, the VMD algorithm was used to decompose the vibration signal to obtain the IMFs component with the minimum signal distortion, which realizes the accurate decomposition of the vibration signal. Secondly, by calculating the power spectrum entropy and the permutation entropy of each IMF component, the aggregation of the IMF components was realized to reduce the computational load of the prediction model. Finally, the TCN network was used to realize the accurate prediction of CIMFs, and the final vibration signal prediction results were obtained by adding them. The analysis shows that this method shortens the time required for prediction on the premise of ensuring the prediction accuracy, and meets the timeliness of the prediction model.

The influence of inlet blade setting angle valued in a large range was studied on the performance of residual energy recovery turbine. Firstly, the theoretical predicted model was established between the inlet setting angle and optimal unit speed, and the numerical simulation model was determined based on the characteristics of residual energy recovery turbine. Then, three runners with different inlet setting angle were gave for the residual energy recovery turbine in water distribution networks, and numerical simulations were carried out with the same conditions of flow rate, head and rotate speed. The flow field and performance of the runner were compared. The results show that the optimal unit speed of residual energy recovery turbine was negatively correlated with the inlet setting angle. The range of best numerical predicted efficiency is between 92.72% and 93.60% while the inlet setting angle is between 30° and 70°. The inlet setting angle and optimal efficiency was hardly correlated. However, the range with high efficiency was corresponded to a larger unit speed with the decrease of inlet setting angle. It is feasible for residual energy recovery turbine to increase working range by changing inlet setting angle. The conclusions could provide a reference for the design of residual energy recovery turbine.

The movable guide vane of domestic large hydropower units in early stage was mostly made by sand casting, which had the characteristics of large abnormal shape parts and they were located in the water wheel room of the units with narrow space. At present, the nondestructive testing of the area where the movable guide vane is hided in the shaft sleeve of large hydropower unit in service is generally carried out after the movable guide vane is lifted out during the unit overhaul period. This paper attempts to test it though phased array testing technology, modeling simulation and simulated test block test. This method is successfully applied in actual detection. Finally, the problem that coarse crystal, long sound path and abnormal shape of casting movable guide vane have serious attenuation, loss of sound energy, and difficulty in receiving defect echo is solved. The feasibility of nondestructive detection on the hided area of casting movable guide vane in completely assembling state of large hydropower units in service is verified.

To analyze the causes of turbine segmented shutdown device miloperation for a hydropower station in Central Asia, the structure of mechanical hydraulic control system of governor and its principle were described, and oil line of mechanical hydraulic control system was analyzed. It found that after the operation of the emergency pressure distribution valve, the pressure oil velocity in pipe was too fast, so the pressure of the control chamber of the segment closing device was reduced and the hydro-generator speed was too high because of the long closing time of the servomotor. The oil intake port of the control pressure oil of the stage closing device can be moved from the main pressure oil supply pipe of the emergency pressure distribution valve to the energy storage tank of the governor system. The feasibility of the scheme was verified by test.

In order to accurately grasp the actual operation of the governor of hydropower units, this paper proposed a multi-dimensional verification method of the governor operation data of hydropower units based on correlation analysis. The multi-dimensional correlation verification architecture was constructed to process the multi-dimensional operation data of the unit governor. The correlation analysis method was used to calculate the correlation degree between the multi-dimensional operation data change sequences, and the anomaly identification of the multi-dimensional operation data was completed by judging the range of the correlation degree. Based on the characteristics of the identified abnormal data, abnormal data reconstruction was completed from three dimensions of single point, multi-point and continuous abnormal data respectively to achieve multi-dimensional verification of governor operation data of hydropower units. The experiment shows that the method can effectively identify the abnormal data, reconstruct the missing data, reduce the abnormal rate of data through verification, and improve the availability of the governor operation data of hydropower units.

In order to shorten the start-up time of the hydroelectric generating set and improve the stability of the generating set 's start-up process and non-loading, a start-up optimization strategy of hydropower unit based on improved grey wolf search coupling cuckoo algorithm was proposed. This fitness function weighs the two index values of the unit ' s start-up frequency ITAE index and the unit 's start-up time and standardizes them. Two penalty functions of unit frequency overshoot and unit frequency steady-state error are introduced to effectively improve the start-up performance evaluation index of the hydroelectric generating set. An improved grey wolf search coupled cuckoo algorithm (IGWSCSA) based on good point set theory to improve the initial population is proposed to optimize the start-up parameters of the generating set. Based on the simulation experiment of the refined model of the speed control system, the optimal parameters are obtained to shorten the start-up adjustment time of the generating set, and the overshoot is reduced from 0.235 to 0.004, which greatly optimizes the start-up speed and frequency fluctuation of the hydroelectric generating set.

When the magnetoelectric velocity sensor is used to test the vibration of the top cover, distortion is easy to occur due to the inherent characteristics of the sensor and the test conditions, and the data can not truly and effectively reflect the operation state of the water turbine top cover. The correlation among excitation force, vibration and strain was clarified through vibration theoretical analysis and stress calculation of top cover structure. Using finite element structural analysis to determine the weak position of the rigidity and strength of the top cover, the dynamic strain value based on this position was proposed as an indicator parameter for evaluating the operation status of the hydraulic turbine top cover. Based on the vibration value and dynamic strain value in the stable operation area, a mapping relationship between strain and vibration was established to solve the problem of inaccurate vibration measurement of the top cover. Taking a power plant unit as an example, the feasibility of the proposed method was verified.

In order to solve the frequency safety problem caused by the large-scale access of renewable energy, adjustable-speed pumped storage unit (ASPSU) was involved in frequency regulation of new power system. Firstly, the AGC frequency regulation stability of ASPSU was analyzed through the root locus method. Then, the evaluation scheme of unit power command response performance was designed to measure the rapidity and accuracy of output of ASPSU. And on this basis, the active power dynamic optimization allocation strategy based on the rate of change of frequency (ROCOF) was proposed. The new energy disturbance was simulated in the LFC model of a two-area interconnected power system to verify the effectiveness of proposed strategy. The results show that the proposed active power dynamic optimization allocation strategy can give full play to the frequency regulation advantage of ASPSU, effectively prevent frequency exceedance and maintain the frequency stability of power system.