61 results about "Power coefficient" patented technology

The invention relates to a stress calculation method, device, equipment and medium for a floating type draught fan foundation structure, and the method comprises the steps: carrying out the frequency domain potential flow water power analysis of a wet surface element model of a foundation floating body of a floating type draught fan, and obtaining the water power pressure distribution and a water power coefficient; boundary conditions are applied to the simulation model of the floating type wind turbine foundation structure, various working conditions are loaded, finite element analysis is carried out based on hydrodynamic pressure distribution, and various structural stress transfer functions are obtained; based on the hydrodynamic coefficient, performing linear processing on the fan aerodynamic force, the impeller pneumatic torque, the floating body hydrodynamic force and the mooring restoring force of the floating fan and the influence of a fan servo controller on the floating fan, and substituting a linearization result into a motion equation of the floating fan for calculation to obtain a plurality of dynamic response spectrums; and multiplying the structural stress transfer functions by the corresponding dynamic response spectrums, and adding a plurality of multiplied results to obtain a total stress spectrum. The method can improve the efficiency.

According to the doubly-fed wind turbine generator fault ride-through control method and system provided by the invention, a refined interval segmentation mechanism based on a voltage amplitude is introduced, reactive power coefficients under different falling or lifting depths are dynamically adjusted, and reactive power limits of the rotor-side converter and the grid-side converter are combined, so that the fault ride-through control of the doubly-fed wind turbine generator is realized. Reactive power optimal distribution of rotor side priority and network side auxiliary coordination is realized; furthermore, active feed-forward compensation is introduced to the grid side to quickly suppress DC bus voltage fluctuation, and a dynamic amplitude limiting strategy based on a current circle is adopted to the rotor side, so that the risks of rotor overcurrent and DC overvoltage are effectively suppressed while the power grid voltage recovery is supported in a full-force manner, and the reliability of the system is improved. Therefore, the ride-through capability and the operation safety of the doubly-fed wind turbine generator in the power grid fault period are remarkably improved, and reliable technical guarantee is provided for avoiding large-area off-grid of the generator.

The invention relates to the field of wind driven generators, and particularly discloses a floating type vertical axis wind turbine multi-partition variable pitch control strategy which comprises the steps that S1, basic parameters and operating condition parameters of a unit are obtained; s2, establishing an aerodynamic model based on a double-disk multi-flow management theory and a superposition wind speed method; s3, measuring parameters through a sensor, and calculating a theoretical attack angle of the blade; s4, establishing a multi-partition pitch angle change function based on the theoretical attack angle; s5, constructing an NSGA-II multi-target optimization model, and taking maximization of an average power coefficient and minimization of a blade thrust standard deviation as targets; s6, substituting a function to obtain an optimal variable pitch control factor and an optimal pitch angle; and S7, the optimal pitch angle is converted into a variable pitch actuator instruction. The problems that an existing strategy is limited in partition, the wind direction influence is ignored, and optimal parameters for working condition adaptation are lacked are solved, the wind energy capture efficiency is improved, the load fluctuation is reduced, and the variable pitch control accuracy is improved.

A fully-submerged multi-stage Horizontally-oriented Conical-helical Hydrokinetic Turbine that captures water stream flows (river, tidal, deep ocean currents) and funnels this kinetic-rich concentrated flow into a conical turbine system consisting of a rotating arrangement of helical hydrofoil blades wherein the internal stream is forced to exit out through the frustum turbine blade assembly. With a higher Capacity Factor and Power Coefficient than conventional renewables, this turbine is designed to be an environmentally friendly baseload electricity generator to meet the ever-increasing electricity demands.

The application discloses a wind power plant control method and device considering rotor speed dynamic constraint, and the method comprises the following steps: obtaining the operation parameters of synchronous units in a power grid; constructing an additional active control model of the wind power plant containing power optimization control; linearizing the power grid frequency and the synchronous unit output power according to the operation parameters and the additional active control model combined with the piecewise function principle to obtain a total power increment piecewise linear expression of the wind power plant; performing piecewise fitting according to the wind power coefficient and the rotor speed to obtain a first equation; obtaining a rotor speed piecewise expression according to the wind power plant rotor motion equation, the first equation and the total power increment piecewise linear expression; adjusting the control parameters of the wind power plant in each speed section according to the rotor speed piecewise expression; the control parameters at least include primary frequency modulation parameters; and controlling the wind power plant according to the control parameters.

The present application belongs to the field of wind power generation, and specifically discloses a wind deviation quantitative evaluation method, system, device and medium, comprising: obtaining sampling data, performing standardization processing, cleaning unit operation data, excluding the influence of factors such as control difference, turbulence intensity difference and blade damage after eliminating abnormal data, and taking the screened unit as an evaluation object; taking the power coefficient CP expected value as a characteristic parameter to reduce the influence of power fluctuation and randomness on wind deviation evaluation; calculating the effective wind speed interval of wind deviation, and selecting the constant CP control wind speed interval of the unit to reduce the data amount requirement; calculating the expected CP under each wind deviation angle and performing normalization processing, and finally performing wind deviation curve fitting to further weaken the fluctuation influence; deriving the fitted curve and calculating the inflection point, comparing with the set early warning judgment rule, issuing an alarm and giving a quantitative evaluation conclusion, and guiding the wind deviation correction.

A display system for imaging fish beating data of an electric winder is used for monitoring take-up or take-out of the electric winder, the electric winder comprises a machine body and a wire wheel, the wire wheel is rotatably arranged in the machine body and connected to a connecting piece penetrating through a side frame of the machine body, the connecting piece is connected with a driving assembly, the driving assembly drives the wire wheel to rotate, and the driving assembly drives the wire wheel to rotate. A winding motor is used for assisting the wire wheel to rotate; the display system judges the take-up and take-out linear speeds of the fishing line through a rotating speed detection unit, detects the current value and the voltage value of the system through a current detection unit and a voltage detection unit respectively, stores a rotating speed relation table and a power relation table through a memory unit, calculates a linear speed coefficient and a power coefficient through a coefficient calculation unit, and outputs the linear speed coefficient and the power coefficient to the display system. And the fish beating data calculation unit calculates fish beating data and integrates the calculated fish beating data into an imaging result to be displayed on the display device, so that a fisherman can intuitively know the fighting power of the fish, the visual stimulation is increased, and the fishing activity is more interesting.

Systems and methods for controlling a variable-pitch propeller of an aircraft are provided. A method for controlling the variable-pitch propeller includes using a feedback controller, operating the variable-pitch propeller at a current operating condition including a current rotational speed, determining a speed error between the current rotational speed of the variable-pitch propeller and a set point rotational speed for the variable-pitch propeller, determining a gain for the feedback controller based on a power coefficient and an advance ratio of the variable-pitch propeller. Using the feedback controller, a propeller pitch command is determined based on the speed error and using the gain. The pitch of the variable-pitch propeller is adjusted according to the propeller pitch command to reduce the speed error.

The application discloses a pitch angle control method considering fast active power regulation of a wind driven generator, which can reduce pitch angle fluctuation of all PMSGs during fast active power control, minimize fatigue damage of the wind driven generator, prolong the service life of the wind driven generator and reduce maintenance cost. P ; S2, a wake effect model of the wind farm containing mathematical models of the plurality of PMSGs is constructed to determine a plurality of pitch angles beta from the power coefficient c P ; and S3, a fast active power control model of the wind farm is constructed to satisfy minimum pitch angle beta fluctuation of the PMSGs.

Embodiments of the present application provide a rotating speed control method and device, a vertical axis wind turbine and a storage medium, and relate to the technical field of wind turbine control. The method adjusts the motor side load voltage which is inversely related to the rotating speed of the vertical axis wind turbine, according to the operating stage of the vertical axis wind turbine, the real-time tip speed ratio, the real-time rotating speed, and the preset parameters obtained from the corresponding tip speed ratio-power coefficient curve of the vertical axis wind turbine, to control the rotating speed of the vertical axis wind turbine in each operating stage, so as to take the tip speed ratio and the real-time rotating speed as the control variables, integrate all operating stages such as real-time calibration, dead zone identification, resonance avoidance, power tracking and safe shutdown into the same control framework, and enable the vertical axis wind turbine to have the intelligent operating ability of "acting according to the wind and adjusting the rotating speed according to the demand" like a wind turbine with variable pitch.

The invention provides a wind driven generator control method and system adapting to high-power disturbance at random wind speed, and relates to the technical field of wind power generation control. Calculating a first power instruction by combining the frequency variation, the unit adjustment power coefficient and the output power at the previous moment; calculating a second power instruction based on the rotor speed and the optimal gain; and selecting the smaller one of the two as the current active power instruction output. According to the method, by dynamically limiting the output power not to exceed the maximum available mechanical power at the current rotating speed, the technical problems that an existing wind driven generator frequency modulation control method is poor in adaptability and low in safety are solved, and the frequency modulation adaptability and operation safety of a wind power generation system under the complex wind condition are effectively improved.

The invention belongs to the technical field of wind power generation, and relates to a wind turbine generator blade icing identification method, system and device and a storage medium. Comprising the following steps that operation data of a wind turbine generator are obtained, and the operation data comprise the wind speed, the generator power and the environment temperature; calculating an actual power coefficient of the wind turbine generator according to the wind speed and the power of the generator; obtaining a unit theoretical power coefficient corresponding to the wind speed; calculating a deviation value between the actual power coefficient and the theoretical power coefficient; and when the deviation value exceeds a first preset threshold value and the environment temperature is lower than a second preset threshold value, it is judged that the blades of the wind turbine generator set are frozen. According to the invention, accurate and reliable identification of the icing state of the blade is realized.

The invention discloses an offshore wind turbine generator power curve test method and related device, and the method comprises the steps: collecting the operation data of an offshore wind turbine generator, and carrying out the preprocessing of the operation data, and obtaining the data only containing the wind turbine generator in a non-fault state; creating a cabin wind speed transfer function NTF based on the data of the wind turbine generator in the non-fault state; correcting the cabin wind speed based on the cabin wind speed transfer function NTF to obtain error-free wind speed data; and drawing a power curve and a power coefficient by using error-free wind speed data in combination with power output data of the wind turbine generator, and comparing the power curve and the power coefficient with a guaranteed power curve to finish the test. According to the method, various operation data are collected and preprocessed, abnormal data caused by faults, manual shutdown, instrument faults and environmental factors (such as influences of obstacles and wake flow) are eliminated, it is ensured that data used for follow-up analysis are all data in the non-fault state of the wind turbine generator, and therefore the accuracy and reliability of the data are improved.

The invention discloses a high-voltage disturbance-oriented direct-drive fan dynamic reactive power support method and system, and relates to the technical field of power systems and automatic control, and the method comprises the steps: when high-voltage disturbance occurs, judging the triggering condition of a high-voltage ride-through state, and adjusting the reactive current injection amount according to the disturbance amplitude; based on the triggering condition of the high-voltage ride-through state, during the voltage rising period, according to a preset reactive high-voltage ride-through current coefficient, the injection duration and quit time of reactive current are controlled, and the injection amplitude and duration of the reactive current are adjusted in real time; based on the triggering condition of the high voltage ride through state, after the voltage is recovered to a stable value, the reactive current exit rate is adjusted according to the voltage difference between the power grid side and the generator terminal, and the active power output is adjusted based on the active high voltage ride through power coefficient; according to the method, reactive current injection and quit are dynamically adjusted, the stability of the draught fan under high-voltage disturbance is optimized, and the coordination and adaptability in the power grid voltage recovery process are improved.

The present invention discloses a power optimization method for a wind turbine generator set, which relates to the technical field of wind turbine generator sets. The dynamic adjustment and optimization of the tip speed ratio further improves the conversion efficiency of wind energy. By calculating the tip speed ratio under different wind speed conditions and combining the variation range of the rotor angular velocity, the relatively optimal interval of the tip speed ratio is accurately obtained, and the mechanical energy conversion efficiency of the wind wheel is monitored and evaluated, and the wind wheel power coefficient under different wind speed conditions is calculated to ensure that better power output can be achieved under various wind speed conditions. Finally, the feedback adjustment of the rotor angular velocity further smoothes the output power. After obtaining the standard conversion conditions, the system can trace and adjust the angular velocity of the rotor, so that the wind turbine generator set can adapt to different wind speed changes and achieve smooth power output.

The invention relates to controlling a wind turbine. A predefined power coefficient data structure and a predefined thrust coefficient data structure respectively comprise values of a power coefficient and a thrust coefficient as functions of blade pitch angle and tip speed ratio. The invention includes using an iterative search algorithm to determine values of pitch angle and tip speed ratio that maximise the power coefficient value in the predefined power coefficient data structure subject to a constraint that the thrust coefficient value in the predefined thrust coefficient data structure is no greater than a maximum threshold thrust coefficient value. A rotor speed reference is determined based on the determined tip speed ratio value and on a received wind speed. The determined pitch angle value is set as a pitch angle reference. The wind turbine is controlled in accordance with the pitch angle and tip speed ration references.

The invention discloses a method and system for calculating the cold end power gain of a unit online, and belongs to the technical field of power generation. The method comprises the following steps: firstly, according to different loads and exhaust steam pressures of a cycle unit, obtaining a correction curve of the exhaust steam pressure and the load change rate through thermal performance test fitting; then, according to the condenser backpressure and the correction curve of the unit, calculating a micro-increasing power coefficient in a segmented manner; then, the turbine micro-increasing power under the current unit load is calculated based on the micro-increasing power coefficient, and the power income is further determined; and finally, the backpressure of the condenser and the operation mode of the circulating pump are dynamically adjusted, so that the power benefit is maximized. Through real-time curve correction and dynamic back pressure regulation and control, the limitation of traditional static calculation is solved, the accuracy of power income evaluation is remarkably improved, energy conservation and consumption reduction can be achieved without additional hardware investment, and the method has the advantages of being short in construction period and quick in effect and is suitable for optimized operation of the cold end system of the power plant.

This invention discloses a voltage recovery control method and system for grid-connected wind farms after faults based on variable reactive power coefficients. The method includes: acquiring parameters of the grid-connected wind turbine generators and their operational requirements; determining the feasible region of reactive power output for the grid-connected wind turbine generators based on these parameters and operational requirements, combined with voltage-reactive power droop control constraints, and evaluating the maximum reactive power support and dynamic voltage support capabilities of the grid-connected wind turbine generators to obtain evaluation results; establishing an integrated model for voltage recovery control after faults involving the wind turbine generators, the wind farm, and the power grid, transforming the feasible region of reactive power output and the evaluation results into control constraints, and calculating the optimal reference value for the reactive power coefficient of the wind turbine generators to regulate each wind turbine generator. This invention aims to ensure the stability of node voltages in grid-connected wind farms under strong disturbances, maximize reactive power support and dynamic voltage support capabilities, and improve the voltage recovery control capability after wind farm faults.

The invention relates to the technical field of aerodynamic performance prediction, in particular to an aerodynamic performance correction method for an H-shaped vertical wind turbine and a related device. The method comprises the following steps: determining an induction factor value of a current round, and determining a flow parameter; determining a lift coefficient and a resistance coefficient based on the corrected attack angle and a preset aerodynamic force lookup table; determining a first corrected lift coefficient after correction and a corrected resistance coefficient after first correction; determining a normal force coefficient and a tangential force coefficient; determining a corrected normal force coefficient after correction and a corrected tangential force coefficient after correction; determining the power coefficient loss of the H-shaped vertical wind turbine based on the geometrical parameters of the supporting structure of the H-shaped vertical wind turbine; and determining aerodynamic performance parameters based on the corrected normal force coefficient, the corrected tangential force coefficient and the power coefficient loss of the H-shaped vertical wind turbine. According to the method, the prediction accuracy of the aerodynamic performance of the H-type vertical wind turbine can be improved through correction of various parameters.

The invention belongs to the technical field of aerodynamic design and verification of helicopters, and particularly relates to a method for designing a safe course control instruction of a helicopter. Comprising the steps that S1, a relation curve of heading control and tail rotor torque is obtained through a tail rotor table test, the slope relation between a power coefficient Cp and heading control Lat is determined, and the power coefficient Cp corresponds to the tail rotor torque; s2, according to a course control limit value and the slope relationship between the power coefficient Cp and the course control Lat, determining the slope relationship between the power coefficient Cp and the course control Lat corresponding to the course control limit value; and S3, obtaining actually-measured course control, actually-measured tail rotor power and tail rotor power limitation, and calculating safe course control according to a slope relation between a power coefficient Cp corresponding to a course control limitation value and course control Lat.

This invention discloses a method for optimizing the propulsion performance of a biomimetic flapping wing under multiple operating conditions, relating to the fields of biomimetic fluid mechanics and propulsion technology. The method includes steps such as selecting the airfoil of the biomimetic flapping wing, setting the distance between the pitch axis and leading edge of the biomimetic flapping wing, setting the motion mode of the biomimetic flapping wing, adjusting the phase difference and pitch amplitude to match the motion mode of the biomimetic flapping wing under different operating conditions, setting the pitch frequency to be equal to the heave frequency, adjusting the pitch motion mode according to the pitch amplitude, and calculating the propulsion power coefficient and propulsion efficiency of the biomimetic flapping wing. This invention achieves precise control of different propulsion directions by optimizing the phase difference under different operating conditions; it determines the optimal frequency matching relationship to avoid propulsion performance degradation caused by frequency mismatch, ensuring stable and efficient operation of the flapping wing under all operating conditions; and it optimizes non-harmonic motion parameters for large pitch amplitudes, increasing propulsion efficiency to 24.10%, a 71% improvement compared to harmonic motion, significantly reducing energy loss.

The present invention provides a method for evaluating damage monitoring of nuclear power plant fuel assemblies. The method comprises: determining whether a fuel assembly has been damaged based on the measured Xe-133 activity in the reactor coolant under stable pressurized water reactor (PWR) operation, correcting for the contribution of core sparse matter and power, and normalizing the Xe-133 activity value to a 100% linear power coefficient. The method is widely applicable to PWR fuel assembly damage assessment, and is particularly suitable for damage cases characterized by xenon growth alone without iodine growth.

A horizontal axis wind turbine, HAT wind turbine (151), for a bulk production of electricity from wind, comprising a tower (5), a nacelle (6), a generator, a rotor (152), and a blade (154), the rotor being rotatable about a rotor axis by the wind and having at least two blades, the rotor having a rotor solidity SOLrotor of maximally 0.05, the rotor configured to have a design tip speed ratio λdesign of at least 4, and an electric power coefficient CPE of at least 0.30, the rotor having a radius R and a diameter D which is at least 50m, the rotor further having an average radial solidity avgsol.25R in the radial range from 0.2R to 0.3R, and an average radial solidity avgsol.75R in the radial range from 0.7R to 0.8R, wherein the ratio between the average radial solidities avgsol.25R / avgsol.75R is one of: less than 2.00; less than 1.75; less than 1.50; less than 1.25; less than 1.00; less than 0.90; less than 0.75; less than 0.50; and less than 0.25.

The embodiment of the invention relates to the technical field of new energy vehicles, in particular to a generated power control method of a hydrogen electric power vehicle, the vehicle, computer equipment and a computer readable storage medium. The method mainly comprises the steps that a target power coefficient is adopted to adjust the smaller value of the maximum output power and the battery pack demand power, first generated power is obtained, the target generated power is determined according to the smaller value of the whole vehicle consumption power and the first generated power, and the target generated power is output according to the target generated power. And the hydrogen supply fuel cell supplies power to the hydrogen-electricity power vehicle according to the target generated power. The target generated power determined by the method can adapt to the power demand of the passenger car.

The application discloses a design method of a diesel-electric hybrid propulsion system test bench, computer maximum power, according to the propeller power coefficient obtained by the propeller absorption power and the propeller rotating speed, the diesel engine is selected in combination with the given diesel engine maximum continuous power area, according to the use area of the diesel engine and the working characteristic curve of the diesel engine, the power range in the diesel-electric hybrid power PTH mode, the PTO mode and the PTI mode is divided, the control logic of the gear box clutch is designed according to the diesel engine mode, the PTO mode, the PTI mode and the PTH mode of the diesel-electric hybrid propulsion system, and the main transmission ratio, the PTH transmission ratio and the PTO transmission ratio are calculated; the diesel-electric hybrid power system PTH, PTO, PTI and other operation modes can be realized, the fault simulation experiment of a typical fault is designed, and the influence of different fault modes on the performance and monitoring parameters in each operation mode can be provided.

The present invention relates to the field of power grids and provides a method and related device for collaboratively supporting the voltage and frequency of a wind farm at a grid connection point. A discretized grid frequency response model during a grid fault is constructed based on the inertia time constant, damping time constant, mechanical power proportional coefficient, governor droop coefficient, high-voltage cylinder power coefficient, and reheater time constant of synchronous generators within the grid. A collaborative support model for the voltage and frequency of the wind farm at the grid connection point during a grid fault is constructed based on the grid frequency response model and the grid equivalent circuit during the grid fault. Based on the collaborative support model, current commands for each generator in the wind farm are calculated and generated, and each generator is controlled to operate according to its respective current command to collaboratively support the frequency and voltage of the grid connection point. The present invention actively supports the recovery of grid frequency and voltage based on the parameters of the generators, avoids abnormal grid frequency and voltage caused by the fault, and improves grid stability during the fault.

The present invention relates to the technical field of power system safety and stability control, and specifically refers to a method for estimating a power system disturbance value based on a dynamic admittance matrix, comprising: obtaining voltage data and current data of each node at each sampling moment within a preset period after the disturbance occurs, calculating the power system dynamic admittance matrix, the synchronous power coefficient between each generator node and each disturbance node, and the initial value of the power system disturbance power; adding the frequency-based system load power deviation and the voltage-based system load power deviation at each sampling moment to obtain the power system load power change at each sampling moment; adding the power system disturbance power initial value and the power system load power change at each sampling moment to obtain the power system disturbance estimation value at each sampling moment, and then using a post-disturbance system frequency prediction model to predict the minimum value of the post-disturbance system frequency. The present invention improves the safety and stability of the power system.

The invention provides an electric-thermal integrated energy system dynamic energy flow calculation semi-analytical method and system, and belongs to the technical field of integrated energy system calculation and analysis. The method comprises the following steps: constructing a semi-analytical model of a power network and thermoelectric coupling equipment through one-dimensional generalized differential transformation; constructing a semi-analytical model of the heat supply network through two-dimensional generalized differential transformation; calculating a power series coefficient of the semi-analytical model by adopting a linear recursive non-iterative dynamic energy flow algorithm EFC, and performing hydraulic coefficient recursion, thermal coefficient recursion, thermoelectric coupling calculation and power coefficient recursion; according to the power series coefficient, a time continuous expression of thermoelectric state variables is generated, the thermoelectric state variables comprise bus voltage, electric power, pipeline temperature, mass flow of water in the pipeline and temperature, and dynamic energy flow calculation of the electric-thermal comprehensive energy system is carried out. According to the method, the problems of precision-efficiency selection and multi-time step length matching in dynamic energy flow calculation of the electric-thermal integrated energy system are relieved.

The invention is suitable for the technical field of fan design, and provides a fan airfoil optimization method and system based on a Kriging proxy model and a genetic algorithm, and the method comprises the following steps: carrying out the parameterized expression of an airfoil curve based on a classification function and shape function transformation method, and obtaining the expression of the airfoil curve; selecting sample points, calculating a power coefficient of each sample point, and constructing sample point data; based on the sample point data, constructing and training a Kriging agent model; power coefficient maximization is used as a target function, parameters and installation angles in an expression of an airfoil curve are used as design variables, constraint conditions are set, and global optimization is carried out on the basis of a Kriging agent model based on a multi-island genetic algorithm; and based on an optimization result, through comprehensive evaluation, selecting an optimal airfoil profile. According to the optimized airfoil profile, the power coefficient of the fan is remarkably improved, a systematic theoretical basis is provided for the design of the airfoil profile of the fan, and meanwhile, an effective technical support is provided for improving the aerodynamic performance of the fan.

The invention discloses a control method and system for dynamic advanced pitch change of a large-megawatt wind generating set. The method comprises the steps that S1, the wind speed, the wind wheel rotating speed, the generator power and the current pitch angle Pitch of the set in the running process of the wind generating set are obtained; s2, based on the wind speed and the wind wheel rotating speed, the current blade tip speed ratio Lambda of the unit is calculated; calculating a current power coefficient Cp * according to the wind speed, the generator power and the air density; s3, according to the tip speed ratio Lambda and the power coefficient Cp *, an ideal steady-state pitch angle Pitch * is obtained; s4, calculating the deviation E between the current pitch angle Pitch and the ideal steady-state pitch angle Pitch * of the unit, and adjusting an advanced variable pitch value according to the deviation E; wherein the larger the deviation E is, the larger the advance variable pitch value is. The method has the advantages of improving the generating capacity of the unit, improving the safety of the unit and being low in cost.