19 results about "Stability margin" patented technology

This application belongs to the field of aero-engine design and presents a design method for high-altitude starting fuel supply patterns based on the low-altitude starting fuel supply patterns. It involves first conducting high-altitude bench tests on the starter to obtain the power reduction characteristics of the starter at different altitudes. Then, based on the power balance equation, the acceleration time of the starter from rotor standstill to idle speed is determined. Finally, based on the acceleration time of the starter from rotor standstill to idle speed, the time allocation of the three starting stages of the starting process—starter engagement, starter disengagement, and engine starting—is performed to obtain the high-altitude starting fuel supply pattern. This method enables rapid and accurate design of the high-altitude fuel supply pattern, taking into account the engine's stability margin design in high-altitude areas, starter power characteristics, and the attenuation characteristics of starter power with increasing altitude, thus avoiding abnormal phenomena such as engine cold suspension and overheating. Furthermore, it can be based on ground starting data statistics, achieving better design compatibility and reducing debugging work.

This application relates to the field of new energy technology, providing a control method, device, system, storage medium, and program product for an underwater compressed air energy storage system. It can employ a matching control strategy based on the actual operating conditions of the underwater compressed air energy storage system to ensure the reliability of its actual operation. This application involves obtaining the safety domain boundary of the underwater compressed air energy storage system; obtaining the current stability margin of the underwater compressed air energy storage system based on the distance between the current operating point of the system and the safety domain boundary; determining the current safety state of the underwater compressed air energy storage system from multiple preset safety states based on the current stability margin; and controlling the operation of components in the underwater compressed air energy storage system according to a control strategy matched to the current safety state.

This invention discloses a method and system for frequency oscillation transfer analysis under multi-machine islanding. The method includes: establishing a transfer function; substituting the operating parameters of each operating condition into the transfer function; if stable, determining whether it is stable; if stable, it indicates that the system on the second VSG side is stable; if unstable, jumping to S3.1 to determine the cause of frequency oscillations on the second VSG side and the first VSG side; if unstable, it indicates that the frequency oscillations on the second VSG side are caused by insufficient stability margin of the second VSG side itself. The advantage of this invention is that it more accurately explains the cause of low-frequency oscillations in the system, thereby guiding the design of virtual synchronous machine controller parameters.

The application relates to a rear wheel steering control method based on multi-source disturbance generalized stability margin and multi-target elastic constraint, which collects vehicle dynamics state data, driver operation behavior parameters and vehicle-road environment information; in a multi-source disturbance generalized stability margin calculation unit, a vehicle-road environment uncertainty multi-source disturbance excitation model and a driver expected steering characteristic model are fitted to obtain amplitude and phase generalized stability margin; in a limit stability influence law analysis unit, vehicle-road safety evaluation indexes, limit generalized stability analysis results and driver comfort evaluation indexes are calculated; in a multi-target elastic constraint optimization unit, a rear wheel steering vehicle multi-target elastic constraint model is established to obtain vehicle-road steering characteristic prediction results, man-machine front and rear steering cooperation instructions and critical stability domain widening control amounts; rear wheel steering angle control signals are output through a line control rear wheel steering high-order control unit. Compared with the prior art, the application has the advantages of high cooperation, safety and stability.

The present application relates to the technical field of wind turbine control, in particular to a control method and system of grid-connected double-fed wind turbine. In view of the problem that the stability margin of grid-connected double-fed wind turbine is different under different wind speeds, a rotor-side stability controller is arranged in the excitation control link of the rotor-side converter of the grid-connected double-fed wind turbine; according to the super-synchronous operating condition and the sub-synchronous operating condition of the actual operation of the grid-connected double-fed wind turbine, the rotor-side stability controller respectively adopts a low-pass filter or a high-pass filter. By adding the rotor-side stability controller, the present application effectively suppresses the oscillation caused by the rotor-side converter of the grid-connected double-fed wind turbine, improves the stability of the grid-connected double-fed wind turbine; at the same time, the stator side and the rotor side both show voltage source external characteristics, and the ability of the grid-connected double-fed wind turbine to actively support the power grid is enhanced.

This invention relates to the field of aerodynamic design technology for multi-stage axial compressors, and discloses a design method and system for passive stability enhancement of a multi-stage axial compressor through self-circulation. By calculating the aerodynamic performance of the multi-stage axial compressor and evaluating engine stability, the method identifies operating conditions where the multi-stage axial compressor has insufficient stability margin. Unsteady flow field simulations are then conducted under these conditions to determine the first stage stall. For the first stage rotor tip stall, a self-circulating casing is used for passive stability enhancement of the multi-stage compressor. The self-circulating casing structure is derived from sensitivity analysis of its design parameters, selecting the optimal design parameters to ensure an increase in the stability margin of the multi-stage axial compressor across the entire speed range. This satisfies the stability margin requirements of multi-stage axial compressors and avoids the problem of insufficient stability margin in high-load multi-stage axial compressors across the entire operating speed range.

The application discloses a power system transient stability state and stability margin evaluation method and device based on Graphormer multi-task learning, equipment and medium, relates to the electric power technical field, including: the node characteristics corresponding to the bus and the edge characteristics related to the power transmission line and the transformer branch are standardized to obtain the standardized characteristics; determine the binary classification label based on the power angle difference between each generator after the fault occurs, determine the regression label based on the difference between the generator rotor angle trajectory and the inertia center trajectory, utilize the standardized characteristics, the binary classification label, the regression label and the initial Graphormer multi-task learning model, and determine the target Graphormer multi-task learning model in combination with the multi-task loss function; determine the transient stability state and the transient stability margin of the power system based on the real-time operation data and by utilizing the target Graphormer multi-task learning model. To improve the accuracy of transient stability evaluation.

The application discloses a kind of commercial vehicle multifunctional double motor coupling active steering system and its control method, comprising: the angle of collection vehicle steering wheel, torque signal;According to the signal calculated, vehicle stability margin is calculated, and the state of electromagnetic actuator is determined;Limiting the transmission ratio required under working condition is calculated;The angle value required by auxiliary motor is calculated, and control signal is sent to auxiliary motor;The assist torque value required by main motor is calculated, and control signal is sent to main motor;The torque distribution value of auxiliary motor and main motor under ordinary working condition is calculated, and is sent to auxiliary motor and main motor respectively;Output corresponding torque or angle, complete vehicle steering.The application can improve the lightness of steering at low speed under ordinary working condition by double motor assist coupling;Under limiting working condition, main motor is assisted alone, and auxiliary motor is compensated to driver steering angle by double-row planetary gear module, can realize stepless variable transmission ratio, realizes active rollover control.

The application discloses a kind of robust stability evaluation methods of phase-locked loop main leading isomeric multivariable converter power system, solve the problem of difficult robust stability analysis caused by isomeric converter phase-locked loop parameter coupling, parameter optimization has no reference.For: first, obtain system parameters, based on second-order phase-locked loop step-down model to construct uncertainty separation model;Then, combined with value set theory, whether the value set contains origin is judged to determine the robust stability of the system;Then calculate the multivariable stability margin K m , determine the dominant unstable oscillation frequency ω c ;Then analyze the moving trend of the value set of parameter change, determine the influence direction of parameter on system strength, introduce negative damping line under instability state to assist analysis;Finally, develop differentiated parameter optimization strategy, iterative optimization until the system meets the stability margin requirement.The application can quantitatively evaluate the robustness of the system, reveal the non-uniform parameter adjustment rule, provide accurate basis for parameter setting, effectively avoid small signal instability, and improve the robust stability of isomeric multivariable converter power system.

This invention discloses a stability assessment and control method for grid-connected converters during fault recovery based on the hybrid potential function theory. First, the grid-connected system parameters of the grid-connected converter are obtained, and its equivalent model in a synchronous rotating coordinate system is established. Second, the hybrid potential function of the system is constructed to extract the current potential and voltage potential. Then, an analytical stability criterion is derived as an evaluation index for quantifying the transient stability of the system. Finally, the peak value of transient overvoltage is substituted into the evaluation index to assess the system stability. Based on the evaluation index, the system parameters during fault recovery are adjusted to improve the system's stability margin, suppress voltage divergence and power oscillation at the moment of fault clearing, and ensure the converter's continuous synchronous support capability. This invention reveals the mechanism of transient overvoltage leading to the contraction of the system's stable domain at an analytical level, which can avoid the instability risk caused by overvoltage and provide a reliable quantitative basis for the safe operation of grid-connected converters.

This invention discloses an intelligent collaborative control method and system for industrial equipment based on the Internet, belonging to the technical field of intelligent control. The method includes the following steps: Step S1, determining whether the control time deviation of the equipment is fixed; Step S2, setting a first cooling priority, setting open-loop control parameters for the valve opening time, and controlling the equipment according to the open-loop control parameters; Step S3, setting closed-loop control parameters for the valve opening time, and compensating the equipment according to the closed-loop control parameters. This invention adopts an open-loop control mode, pre-calculating the duty cycle sequence based on a feedforward compensation mechanism, improving the system's response speed and reducing the real-time calculation burden. When the control time deviation is not fixed, a control mode combining open-loop and closed-loop control is adopted, enhancing the system's robustness to parameter drift and external disturbances. The Nyquist stability criterion is introduced to verify the closed-loop control parameters online, achieving a balanced optimization of control performance and stability margin.

This invention discloses a stability margin testing method for a distributed fly-by-wire flight control system, relating to the field of flight control system testing technology. The stability margin testing system for this distributed fly-by-wire flight control system includes a flight control computer, actuator control electronics, actuator servo controllers, actuators, control surfaces, a digital-to-analog converter module, and a frequency response analyzer. The stability margin testing method for this distributed fly-by-wire flight control system achieves the conversion and output of digital and analog signals by adding or retrieving digital-to-analog converter modules and analog-to-digital converter modules. It also acquires flight control commands and excitation signals from the frequency response analyzer, modifies the calculation logic of the actuator servo controller to superimpose the excitation signals and flight control commands, transmits the superimposed commands to the actuators, and simultaneously returns them to the digital-to-analog converter module. The digital-to-analog converter module converts the digital signals into analog signals and transmits them to the frequency response analyzer to calculate the stability margin.

This application proposes an off-road path planning method for unmanned ground vehicles based on a stability margin field. The method includes: constructing a normalized 3D failure envelope proxy model library, which includes proxy models for 3D failure envelopes corresponding to various environmental parameters; calculating the normalized demand force vector required for contact components to maintain their motion state based on the terrain features and preset motion state of the area to be planned; retrieving the corresponding proxy model from the proxy model library according to the environmental parameters of the area to be planned, calculating the minimum geometric distance from the normalized demand force vector to the 3D failure envelope, and defining a 3D stability margin based on the minimum geometric distance; constructing a comprehensive cost map based on the 3D stability margin; and searching for the optimal path within the comprehensive cost map. This method can plan off-road paths for unmanned ground vehicles while considering the interaction mechanics between the unmanned ground vehicle and the ground and anticipating instability risks.

This application discloses a method, apparatus, system, and storage medium for preventing rollover after a tire blowout. The method includes: monitoring tire pressure changes in real time using high-dynamic tire pressure monitoring units deployed on each wheel to identify a tire blowout event; in response to identifying a blowout, calculating and evaluating the vehicle's current stability margin based on the vehicle's real-time dynamic state information to predict its instability trend; generating corresponding coordinated control commands based on the stability margin evaluation results and the number and type of multiple existing execution systems on the vehicle; and issuing the coordinated control commands to the corresponding execution systems to apply corrective torques to the vehicle and adjust its attitude. This solution reduces vehicle development costs while optimizing rollover prevention.

The application belongs to the technical field of milling processing, and particularly relates to a high-precision numerical control milling processing method for a high-temperature alloy thin-wall machine case support plate, which comprises the following steps: collecting material characteristics and machine case support plate structure characteristic data, combining support plate rigidity distribution and machining allowance distribution, formulating basic milling process parameters; adopting a layered rigidity milling method, calculating milling deformation regulation and control parameters according to cutting load distribution and tool path planning, adjusting the basic process parameters to obtain layered milling control parameters; collecting cutting vibration response data of the support plate in the milling process, obtaining a flutter stability margin through a frequency domain flutter evaluation method, and judging whether the flutter stability margin meets the standard or not; if the flutter stability margin does not meet the standard, the control parameters are optimized; extracting cutting force fluctuation characteristics from the vibration response data, obtaining regulation and control influence indexes through parameter sensitivity analysis, adjusting the milling deformation regulation and control parameters, and obtaining milling correction parameters; and the application can significantly improve the processing precision, effectively prevent and control milling flutter, improve the processing efficiency, and enhance the process stability.

The invention discloses a grid-connected inverter stability control method based on an improved phase-locked loop, and belongs to the technical field of new energy grid-connected control, and the method comprises the steps: firstly building a grid-connected inverter impedance model, and revealing a mechanism that the phase-locked loop introduces negative damping and reduces stability margin under a weak power grid; based on an impedance model, a composite control strategy fusing dynamic feed-forward compensation and an improved Kalman observer is designed, the former actively counteracts the negative impedance effect of a phase-locked loop, and the latter improves dynamic response through state reconstruction and advanced prediction. Finally, an improved cascade delay signal elimination phase-locked loop with a selective conduction harmonic filtering function is provided, and the improved cascade delay signal elimination phase-locked loop is deeply integrated with the control strategy and a multi-harmonic feedback link, so that high-precision phase locking and active harmonic suppression are realized. According to the method, the operation stability, the dynamic performance and the electric energy quality of the grid-connected system under the conditions of high background harmonic waves and weak power grids are remarkably improved.

The application relates to a vehicle intelligent control method and device based on tire pressure anomaly grading and a storage medium, and belongs to the technical field of tire pressure monitoring. The method comprises the following steps: determining a tire pressure anomaly grade based on vehicle tire pressure sensor data and wheel speed monitoring data; determining a deviation torque based on the tire pressure anomaly grade and an abnormal wheel position; determining a stability margin grade based on the deviation between an expected yaw rate under the deviation torque and a measured yaw rate, a current vehicle speed and a road adhesion coefficient; and cooperatively controlling an electric power steering system, a braking system and a driving system of the vehicle based on the tire pressure anomaly grade and the stability margin grade. The vehicle intelligent control method based on tire pressure anomaly grading provided by the application upgrades passive alarm of tire pressure anomaly to active intervention, different control strategies can be adopted according to different anomaly severities, and the driving stability of the vehicle under various tire pressure anomaly working conditions is ensured.

This invention discloses a perception consistency diagnosis and control method based on the vehicle dynamics feasible domain, including a vehicle state acquisition module, a dynamics dynamic feasible domain construction module, a perception consistency diagnosis module, and a control strategy adaptive adjustment module. The vehicle state acquisition module collects the vehicle's longitudinal and lateral motion parameters and constructs dynamic state variables; the dynamics dynamic feasible domain construction module establishes a state feasible domain model based on vehicle dynamics constraints; the perception consistency diagnosis module constructs a consistency evaluation index by fusing state deviation, feasible domain violation, and stability margin to determine the reliability of the perception results; the control adaptive adjustment module dynamically allocates traction and braking forces based on the consistency evaluation results, enhancing control intervention when perception anomalies occur or near-limit conditions, thereby improving the stability and robustness of the vehicle control system.