According to the prototype characteristic curve of the pump set, there will be a deviation between the theoretical value and the actual value when guiding the actual scheduling of the pumping station, which will affect the accuracy of daily scheduling and energy consumption evaluation. Therefore, taking Liyuzhou pumping station as an example, this paper proposes a method combining the measured data of the pumping station and the law of similarity to correct the prototype characteristic curve of the pump set. The flow optimization distribution model is established in terms of the actual operating conditions, and the difference of optimal flow distribution scheme of pumping station between the characteristic curve of the pump set before and after the correction is analyzed. The results show that the deviation between the actual operating head and the theoretical head is mainly concentrated in 8%-11%, and the deviation between the actual operating efficiency and the theoretical efficiency is mainly concentrated in 6%-9% when the prototype characteristic curve of the pump set is used. When the flow optimization distribution scheme is selected through the corrected characteristic curve of the pump set, the results are more in line with the actual operation situation, which can effectively strengthen the guiding role of the flow optimization distribution scheme of the pumping station on the actual scheduling.

The number of long-distance, high drop, pressurized, and self-flowing water pipeline projects is increasing in the northwest region. Most of the pipelines show undulating shapes, and the hydraulic transition process of the entire pipeline system becomes very complex during operation and regulation. When the water hammer protection setting is unreasonable, it will lead to pipe explosion, seriously threatening the safety of people and property. In order to ensure the safe operation of the entire system, the characteristic line method and the HAMMER V8i water hammer analysis software were used to analyze the hydraulic transition process of a long and high drop inverted siphon in a water transmission project. By setting isolation and maintenance valves, submerged energy dissipation valves, and exhaust valves along the pipeline, and setting regulating valves at the end of the pipeline, the positive pressure of the pipeline system is effectively controlled during normal operation and valve closure. By simulating the hydraulic transition process of the pipeline system under different flow rates after pipe explosion, the installation of water hammer protection equipment minimizes the harm caused by pipe explosion. The flow rate of the pipeline system after complete pipe explosion is not continuous. The action time and operation rules of the water hammer protection equipment for long-distance and high drop inverted siphon lines play a crucial role in the safety of the entire system. The research results can provide reference for the similar projects.

Aqueducts are common water conveyance structures in water diversion projects, and accurate prediction of aqueduct deformation is crucial for ensuring the stable operation of water conservancy projects. For this purpose, taking the Liaohe Aqueduct in the South-to-North Water Diversion Project as an example, five different linear additive models, namely elastic net regression, multiple linear regression, stepwise regression, ridge regression and LASSO regression, were established based on the long-term deformation monitoring data of the aqueduct. The prediction results of the aqueduct's deformation behavior by the five different linear additive models were compared. The results indicate that as the prediction time increases, the prediction accuracy of different linear additive models gradually decreases. The LASSO model selects the optimal regularization parameter through cross-validation, achieving variable selection simplification and minimizing model complexity. Additionally, it is verified that the training length affects the prediction performance of multiple linear regression and stepwise regression. The findings of this study provide valuable references for selecting prediction model of aqueduct deformation.

Predicting risks in later diversion stages is essential for the scientific evaluation of initial impoundment schemes for hydropower stations. Considering the gradual development process from dam overtopping to the failure of the diversion system, taking the later diversion systems of the upstream existing and downstream under-construction power stations as the research objects, a later diversion risk model for cascade power stations based on level sets is established, and the risk is expressed in the form of interval numbers. Based on the prospect theory, the initial impoundment scheme of the cascade power stations is evaluated by taking risk loss, relative storage reservoir power generation benefits and storage duration as the indicators. Finally, taking two adjacent under-construction power stations in the upper reaches of the Jinsha River as an example, the results show that when the level sets change from 0 to 1, the equivalent recurrence interval corresponding to the later diversion risk interval of the original impoundment scheme meets the flood design standard with a high safety margin. The staged storage time can be advanced by 40 days, which provides a reference for the safety and economy of advanced impoundment.

In order to solve the problem that the response ability of a large mixed-flow hydropower unit is affected by the change of operating water head, a method based on the adaptive feedforward function is proposed for the application of the turbine's primary frequency regulation function. The 3D curve function library of turbine's water head, guide vane opening and power is introduced into the primary frequency regulation feedforward control of the turbine. According to the real-time water head and power and the position of guide vane, the power change corresponding to the frequency change is calculated through the 3D database to directly affect the output of the controller. Compared with the conventional control mode of primary frequency regulation, it is verified by field practice. The experimental results show that the feedforward function can not only satisfy the consistency of the next frequency regulation performance of different water heads, but also effectively avoid setting and switching multi-group PID control parameters. Thus, it provides a new way to realize the function of primary frequency regulation of hydraulic turbine units.

Unsteady friction plays a very complex role in the water hammer phenomenon within pipeline systems. For hydropower station with super-long headrace tunnel (SLHT), it is crucial to consider the effects of unsteady friction adequately. This paper conducts a study on the nonlinear transient response characteristics of hydropower station with SLHT based on unsteady friction. Firstly, a system model of hydropower station with SLHT is established using the method of characteristics, incorporating unsteady friction based on instantaneous acceleration. Then, simulations of this model are performed under load and frequency disturbances. Finally, the stability of the model under frequency disturbances is evaluated using the Bode plot method, and the impact of unsteady friction parameters on system stability is investigated in conjunction with the energy equation. The results show that the unsteady friction in the pipeline primarily affects the rapid response phase of the water turbine in the hydropower station with SLHT. When the impact coefficients of local acceleration (k_t) and convective acceleration (k_l) increase, the system stability deteriorates. Moreover, changes in k_t and k_l make the system more sensitive to high-frequency disturbances.

The pumped storage power station has the characteristics of frequent unit start-up and shutdown and working condition switching, which has great influence on the safe operation of the power station. At present, the on-site monitoring data of the vibration response of the underground powerhouse structure of pumped storage power station under the vibration load of the unit are few, especially the vibration monitoring of the unit under the transient conditions such as unit start-up and shutdown and load rejection. This paper takes the underground powerhouse of a pumped storage power station as the research object, and carries out the dynamic characteristics monitoring analysis under the transient conditions of power generation, pumping switch and different output load rejection. The results show that the peak vibration response of each typical part of the powerhouse structure under transient condition is obviously greater than that under steady condition, and the vibration response under power generation on and off condition is greater than that under pump pumping condition, but the vibration displacement and acceleration can basically meet the recommended limits of the current vibration standard. Under 100% load rejection conditions, the vibration response of the powerhouse structure is the strongest, and the maximum vibration acceleration can reach more than 30 m/s², which is easy to cause impact damage to the powerhouse structure. It is recommended to avoid 100% load rejection conditions during daily operation and maintenance of the power station. In case of occurrence, it is necessary to timely detect the key structural parts of the powerhouse to eliminate safety risks.

The pumped storage power stations are critical infrastructure for achieving carbon neutrality goals. Based on the three-dimensional computational fluid dynamics method, the head loss characteristics in the combined diversion shaft-surge chamber arrangement are investigated. Firstly, the three-dimensional model from the upstream inlet to the inlet of the unit is established. Then, the hydraulic characteristics under different arrangement types are analyzed. Finally, the influence of the diameter of the turning section and the impedance holes on the head loss is explored under the combination arrangement. The results indicate that the pressure distributions are similar in combined and uncombined arrangements. The hydrodynamic characteristics are not deteriorated and reflective water hammer is more effective in combined arrangements. Under the combined arrangement, the larger the diameter of the turning section and the impedance hole, the smaller the head loss coefficient is. This study can provide theoretical references for the design of new structures for pumped storage power stations.

With the increasing proportion of new energy, the inertia support, voltage support, and frequency regulation ability are obviously weakened in current power system. The development of energy storage system with synchronous condenser and flywheel (ESSSCF) is of great significance to improve the regulation capability of new energy power generation and enhance the stability of new power systems. This article briefly describes the principle and different operation states of the magnetic-geared speed regulator (MGSR) for ESSSCF, and focuses on the design optimization of its electromagnetic structure. The electromagnetic finite element model of the MGSR is established. The shape of the flux barrier is selected for the inner rotor with V-shaped permanent magnet by calculating and analyzing the no-load leakage flux factor. The geometric parameters of the V-shaped permanent magnets and stator slots and the pole-arc coefficient of the modulating ring are optimized for multiple objectives, respectively, using genetic algorithm, under the conditions of a constant amount of permanent magnet and a constant area of stator slot. In addition, the correlation of the target performances with the geometric parameters is analyzed. The results of the design optimization and correlation analysis can direct the structural design of the magnetic-geared speed regulator for improvement of the torque and efficiency performances.

To address the issue of reduced detection accuracy under complex working conditions due to the fixed threshold of the isolation forest algorithm, an anomaly detection method for ship lock miter gate monitoring data based on singular spectrum analysis (SSA) and an improved isolation forest (KMIF) is proposed. The SSA is employed to decompose and reconstruct the monitoring data, and separate the trend and noise components. The isolation forest algorithm is improved by incorporating K-Means++ clustering to dynamically set anomaly thresholds for different monitoring datasets. The noise component is then fed into the improved isolation forest algorithm for training and anomaly detection. Taking the stress and vibration data from multiple measuring points of the lower lock miter gate in Jiangsu ship gate project as an example for validation, the results show that the proposed SSA-KMIF method performs excellently in terms of false positive rate, precision, recall ratio, and accuracy. It demonstrates high accuracy and flexibility, which provides a reliable technical support for health monitoring of ship lock miter gates.