87 results about "Stability margin" patented technology

Belongs to the technical field of motion control of foot-type robots, and particularly relates to an anti-interference whole-body control method and system for a quadruped robot based on stability margin perception. The expected joint position, speed and foot end contact force are obtained through nonlinear model predictive control NMPC; a whole body controller WBC based on hierarchical quadratic programming calculates a joint driving torque according to the task priority; according to the joint position, the speed and the torque fed back by the driver and a robot dynamic model, estimating the foot end contact force; calculating resultant force which causes instability of the robot relative to each support polygon side line of the robot; projecting the resultant force, and calculating an included angle between the projection force and the vertical direction; calculating a compensation acceleration through a PI controller; and the compensation acceleration is used as a part of a fuselage linear acceleration task in the WBC, so that the anti-interference capability of the robot is improved. The method is used for solving the problems that in the prior art, the stable state of the quadruped robot cannot be effectively sensed, and an anti-interference control strategy cannot be rapidly generated according to the stable state.

The invention relates to the technical field of aero-engines, and discloses an aero-gas turbine engine complete machine stability margin evaluation method, which comprises the following steps of: analyzing physical characteristics and working principles of all parts of a gas turbine engine to construct an engine complete machine model, and constructing an engine experiment table to carry out an experiment; judging whether the compressor enters a surge state and recording experimental data, carrying out numerical simulation based on the constructed engine complete machine model and recording simulation data, comparing the simulation data with the experimental data, verifying the accuracy of the model, if so, constructing a surge boundary, and if not, optimizing the model. The method comprises the following steps: judging whether an engine has a stall hysteresis phenomenon or not in real time, generating a normal operation signal or a stall hysteresis signal, if the stall hysteresis signal is generated, updating a surge boundary, calculating a stability margin value of the engine based on the surge boundary, and evaluating the stability margin of the whole engine.

The invention discloses an electric power system transient stability state and stability margin evaluation method, device and equipment based on Grapher multitask learning and a medium, and relates to the technical field of electric power, and the method comprises the steps: carrying out the standardization of node features corresponding to a bus and edge features related to a power transmission line and a transformer branch, and obtaining standardized features; determining a dichotomy label based on a power angle difference between the generators after a fault occurs, determining a regression label based on a difference between a generator rotor angle trajectory and an inertia center trajectory, and determining a target Grapher multi-task learning model by using the standardized features, the dichotomy label, the regression label and an initial Grapher multi-task learning model in combination with a multi-task loss function; and determining a transient stability state and a transient stability margin of the power system based on the real-time operation data and by using the target Grapher multi-task learning model. Therefore, the accuracy of transient stability evaluation is improved.

The invention relates to a stability margin measuring method based on data driving, which adopts a small gain theorem to ensure the stability of a closed loop of a system and defines the stability margin of the system based on the stability margin. The defined gain margin and the time delay margin can be obtained through a data-driven experimental measurement method. According to the method, a class of gain margins and time-delay margins for the multiple-input multiple-output linear system are established through the small gain theorem, so that the defect that the small gain theorem is only suitable for amplitude margin analysis is overcome. And a frequency sweeping method is established to obtain the gain margin and the time delay margin through an experimental method, so that the uncertainty and unmodeled dynamics in practice can be considered, and the obtained stability margin is closer to the stability margin of an actual system.

The invention relates to the technical field of floating fans, in particular to a parameter tuning method suitable for a multi-tuned mass damper of a floating fan, which sequentially comprises the following steps of: establishing a system dynamics model; defining an optimization variable and a constraint range; constructing a comprehensive fitness function; initializing a grey wolf population and algorithm parameters; executing a grey wolf position optimization updating mechanism; setting convergence judgment conditions; and outputting the optimal TMD parameter combination. According to the method, structural dynamic characteristics and an intelligent algorithm strategy are fully fused, particularly, spatial arrangement coordinates of the TMD are brought into an optimization variable domain, collaborative design of tuning parameters and arrangement space is achieved, the method is different from a single-parameter or fixed-point optimization mode, the limitation of artificial experience layout is avoided, overall suppression of structural multi-order modal response is achieved, and the method is suitable for large-scale popularization and application. The damping capacity and the stability margin of the fan structure under wind wave flow coupling excitation are improved, cross-modal and multi-source vibration cooperative treatment is achieved on the system response coordination and control strategy level, and the method has the adaptability to offshore wind power scenes.

The invention provides a trajectory online planning method for an air-breathing hypersonic aircraft with an unstarted air inlet, and the method comprises the steps: constructing a mechanism model of the air-breathing hypersonic aircraft, and correcting the mechanism model according to the output of a neural network and in combination with an air inlet / isolation section pressure sensor array; and in the flight process, stability margin prediction is carried out based on the corrected mechanism model, and when the air inlet non-starting margin is lower than a warning value in the future, the trajectory optimization model is called to carry out online trajectory planning. The output error of the corrected mechanism model is obviously reduced, and more accurate dynamic characteristic data supports reduction of the error between the control effect and the preset index; the accuracy of the mechanism model is obviously improved; once it is found that the non-starting margin of the air inlet channel is lower than the warning value in the future, the track optimization model is called to conduct online track planning, and therefore the situation that the air inlet channel is not started is avoided; the method has remarkable effectiveness and robustness in the aspects of trajectory optimization and air inlet non-starting protection.

The invention discloses a transient stability control method and system for a power system with equilibrium point continuation after disturbance, and the method comprises the steps: firstly building a steady-state mathematical expression of each dynamic element, and constructing a solving model of a system equilibrium point in combination with a power network equation; then, a homotopy method is introduced, homotopy parameter values at saddle node bifurcation points are solved, and whether balance points still exist in the system or not is judged; and for the condition of system instability, further deriving the sensitivity of the fault parameter of the homotopy curve at the saddle node bifurcation point to each control variable, and optimizing the adjustment strategy of the adjustable parameter in combination with the sensitivity and the control cost. Through a systematic search method, the optimal control scheme with the lowest cost is determined on the premise that the stability margin is met, and therefore the economical efficiency and effectiveness of control measures are improved. The optimization adjustment direction of each adjustable parameter can be accurately identified, the effectiveness of a control scheme is ensured, and accurate operation is provided for stability recovery of a power system.

The invention provides a stability margin calculation method of a new energy station grid-connected system, a terminal and a storage medium. The method comprises the following steps: acquiring inverter output impedance and power grid side equivalent impedance of an initial new energy station grid-connected system under multiple working conditions; taking the ratio of the output impedance of the inverter to the equivalent impedance of the power grid side under the same working condition as an open-loop transfer function, and determining a gain margin and a phase margin of the new energy station grid-connected system under each working condition based on the open-loop transfer function under each working condition; determining the weakest working condition of the new energy station grid-connected system based on the gain margin and the phase margin of the new energy station grid-connected system under each working condition; and under the weakest working condition, based on the gain margin and the phase margin of the new energy station grid-connected system under different numbers of inverters connected in parallel, the maximum capacity expansion number is determined. According to the method, accurate quantification of the capacity expansion limit is realized, the system stability is ensured, and the capacity expansion potential of the station is fully excavated.

The invention discloses a new energy base maximum bearing degree evaluation method considering a system stability margin. The method comprises the following steps: firstly, carrying out admittance modeling on the new energy multi-infeed system, and deducing a calculation method of a power grid strength index in a large-scale new energy access scene and a linear equation of a critical stability index of the system about a steady-state equilibrium point; then, taking maximization of the sum of active output of the new energy equipment as a target function, and establishing a new energy base maximum bearing degree evaluation optimization model considering the power grid intensity; and finally, obtaining a final new energy base maximum bearing degree evaluation result based on semi-definite programming and a sub-optimization problem iteration method. The method can accurately analyze the optimal configuration problem of the active power output of the new energy equipment under various complex operation conditions such as an unrated condition and a non-unity power factor condition, and has practical engineering significance.

The invention relates to the technical field of power system control, and discloses a method for determining power angle stability control sensitive points of a power system and related equipment, and the method comprises the steps: obtaining the power angle stability margin improvement amount under different control measures based on a generated system power angle stability margin evaluation model under the occurrence of a power angle instability phenomenon; calculating sensitivity screening effective control points through the power angle stability margin lifting amount, determining control sensitive points according to a sensitivity sorting result, and completing the determination work of the power angle stability control sensitive points of the electric power system. According to the method, the power angle stability margin lifting amount under different control measures is calculated, the effective control points are screened through the sensitivity, and finally the control sensitive points are determined. According to the method, the control point which has the greatest influence on the stability of the power system can be accurately identified, so that control measures are specifically applied, and the control efficiency is improved.

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.

The invention discloses a posture adjustment and turnover control method and system of an adjustable platform. The method comprises the following steps: firstly, collecting mounting positions and the like of a plurality of supporting units of a platform, calculating effective supporting length and determining a current platform posture and a supporting polygon; calculating a centroid projection trajectory within a predetermined overturning angle range by using the overturning shaft and the centroid position of the workpiece, forming stability margin distribution according to the minimum distance of the centroid projection to the boundary of the support polygon, determining a target platform attitude meeting a stability threshold, and reversely solving the target telescopic length of each support unit; establishing a corresponding relation between the overturning angle and the telescopic length of the driving mechanism according to the installation geometric parameters of the overturning driving mechanism, and generating an overturning angle track; in the overturning process, the current overturning angle is determined by measuring the telescopic length of the driving mechanism, and a corresponding control section is selected to generate an overturning control instruction. According to the invention, the coordination control of the platform posture adjustment and the overturning process is realized, and the stability and the safety of the overturning operation are improved.

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 invention discloses a parameter estimation and adaptive control method, device, medium and product of a high-performance aircraft pitch angular velocity control system with stability margin self-configuration, and relates to the field of aircraft control, the method comprises the following steps: collecting the pitch angular velocity of an aircraft and the deflection angle of an elevator in real time, and calculating a tracking error; constructing a relation equation of system parameters and stability margin based on a PI controller, and performing approximate simplification by adopting a numerical approximation method; estimating system parameters and time delay on line by adopting an approximate nonlinear least square algorithm; and substituting the target stability margin, the system parameter estimation value and the time delay estimation value into a system frequency domain characteristic equation for solving to obtain a proportional gain and an integral time constant of a PI controller, and adjusting an elevator deflection angle of the aircraft in combination with a tracking error so as to control the pitch angular velocity of the aircraft. According to the invention, the autonomous configuration of the stability margin is realized, and the stability, robustness and dynamic adaptation capability of the control system are improved.

The application discloses a grid-construction converter parallel system transient stability evaluation and enhancement method, and belongs to the technical field of power system transient stability evaluation; the evaluation method comprises the following steps: a differential-algebraic model of a hybrid system is established and is converted into a state space form, time variables are eliminated by performing quotient operation on equations to establish a time domain separation reduced-order model; a multivariable alternating iteration algorithm is used to solve implicit space trajectory integral equation groups, and a generalized transient kinetic energy is used to find a farthest point of a phase orbit, so that instantaneous generalized acceleration torque at the point is calculated to quantitatively evaluate transient stability margin of the system. The enhancement method comprises the following steps: a frequency deviation signal of a local phase-locked loop of the grid-construction converter is collected, and an active current reference value is dynamically reduced by a feedback controller to adjust output current. The application breaks through the order limitation of a traditional equal-area criterion, realizes accurate evaluation of a high-order hybrid system, and the control strategy can spontaneously reduce acceleration torque without station communication, thereby improving system synchronous stability.

The application discloses an active damper control method based on oscillation risk assessment, and relates to the technical field of new energy power generation systems.The control method comprises four parts: an inverter conventional control part, an oscillation risk assessment part, a stability margin improvement part and an oscillation monitoring and instability recovery control part.The inverter conventional control part is the basis of the active damper control and runs through the whole control stage, and the other three control parts cyclically act in sequence to ensure the stable operation of the inverter system, assess the oscillation risk of the system through current relation, and thus do not need voltage information, thereby reducing the calculation burden of the controller, improving the stability margin of the system before the system is unstable, and improving the stability margin to a set value.

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 belongs to the field of engine design technology, and specifically relates to a method for determining the flight envelope of an aircraft turbofan engine. The method mainly includes: step S1, obtaining the load spectrum of the power extraction of aircraft accessories within the full envelope range and the comprehensive distortion index allowed by the engine inlet; step S2, determining the speed of the compression component of the turbofan engine when the engine stability margin is weakest; step S3, determining the stable working boundary of the engine after power extraction based on the speed of the compression component when the engine stability margin is weakest. The present application obtains the speed of the critical distortion index of the engine under different altitudes and different speed conditions through pressure distortion tests, thereby determining the flight envelope of the engine under the influence of actual power extraction, greatly improving the engine aerodynamic stability evaluation method, thereby giving the power extraction limit within the envelope range, and avoiding problems such as engine surge.

The application provides a method and system for evaluating the stability margin of a long-distance retrograde orbit spacecraft. First, the current orbit state information of the target spacecraft is obtained. Then, based on the evaluation allowed time range, evaluation time interval, speed error size range and speed error size interval, an error parameter combination set is constructed. Next, based on the current orbit state information and the error parameter combination set, the stability evaluation parameters and the eclipse evaluation parameters corresponding to the error parameter combination are determined through a high-precision ephemeris model. Second, based on the stability evaluation parameters and the eclipse evaluation parameters, the target error parameter combination is determined. Finally, the stability margin is determined based on the target error parameter combination. This method combines the characteristics of long-distance retrograde orbits, engineering application requirements and the influence of eclipses, and selects parameters through the error parameter combination set to determine the stability margin. In this way, the efficiency and accuracy of determining the stability margin of the spacecraft can be effectively improved.

The invention belongs to the field of airborne power system design, and particularly relates to a stability constraint method for an MEA variable-frequency alternating-current power system. The method comprises the following steps: firstly, establishing a port impedance / admittance model of each device in a system; secondly, analyzing the stability of each subsystem, and redesigning if the stability margin does not meet the requirement; then, on the premise that all subsystems are stable, the overall stability of the system is analyzed according to a generalized Nyquist stability criterion; if the whole system is unstable or underdamped, quantitatively identifying a high-influence negative subsystem with the maximum stability deterioration degree in a mode of setting admittance of a load-side subsystem to be zero; and finally, the stability margin of the high-influence negative subsystem is improved by redesigning the high-influence negative subsystem. The MEA variable-frequency alternating-current power system is ensured to have enough stability margin in the design stage, so that the stability problem is avoided.

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 invention discloses a power system fault control method and device for a stability boundary, and belongs to the field of power systems, and the method comprises the steps: obtaining a current composite stability margin index of a power system in real time; when the index is greater than or equal to a preset threshold value, collecting a current operation scene sample set, and obtaining a current fault operation scene and an anticipated disturbance set in combination with the offline stable scene knowledge base; according to the fault operation scene and the anticipated disturbance set, adopting fast time domain simulation to obtain a dynamic response track, and performing power flow identification to obtain a power flow section and an influence node set; establishing a state space according to the composite stability margin index, the power flow section and the influence node set, training in a reinforcement learning environment in combination with a reward function, and outputting a fault control scheme; and performing fault control on the power system according to the scheme. Therefore, by implementing the method and the device, the problem that the accuracy of fault control is difficult to improve while the fault identification efficiency is difficult to guarantee in the prior art can be solved.

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 invention provides a stability margin maintaining method for a high-pressure compressor of an aero-engine, and belongs to the technical field of aerodynamic stability of compressors, and the stability margin maintaining method comprises the steps that a corresponding relation graph of the relative conversion rotating speed of the compressor and the axial speed coefficient of an inlet of the compressor is obtained; actual flight data are obtained, and a Reynolds number index corresponding to the actual relative conversion rotating speed of the gas compressor is obtained in combination with the corresponding relation graph; a gas compressor part test is carried out, and the first gas compressor stability margin, the second gas compressor stability margin and the third gas compressor stability margin are obtained; based on the first gas compressor stability margin and the second gas compressor stability margin, a first characteristic relation is established; based on the first gas compressor stability margin and the third gas compressor stability margin, a second characteristic relation is established; and according to the actual relative conversion rotating speed of the gas compressor, the corresponding Reynolds number index, the first characteristic relation and the second characteristic relation, the actual gas compressor guide vane correction amount is obtained and corrected. According to the treatment scheme, the working stability of the gas compressor is improved.

The invention provides an automobile stability hierarchical control method based on motor energy consumption optimization and a fault state, which comprises the following steps of: firstly, calculating energy consumption loss through motor loss power integration; secondly, an upper-layer control algorithm takes a linear two-degree-of-freedom vehicle model as a reference, a sequential quadratic programming (SQP) algorithm is adopted to calculate required total driving torque and additional yawing torque, and effective tracking of the vehicle to an expected motion state is achieved; and finally, distributing the total driving torque and the additional yawing torque to each wheel by a lower-layer control algorithm, and solving a motor torque control law by adopting a gradient descent method by taking tire stability margin maximization as a target when a wheel side motor has no fault. When the motor breaks down, torque correction distribution is carried out on the remaining normal motors according to the fault state, and it is ensured that the output driving torque and the additional yawing torque meet the requirement of an upper-layer control algorithm. According to the method, energy consumption optimization, stability control and fault tolerance are fused into automobile hierarchical control, and the method has the advantages of being high in optimization precision and high in adaptability.

The application belongs to the technical field of engine control, and particularly relates to a deceleration control method and device for improving fan stability margin. The method comprises the following steps: S1, obtaining an engine deceleration start time, a low-pressure conversion speed after deceleration and a nozzle throat area; S2, discretizing a low-pressure conversion speed change interval into a plurality of low-pressure conversion speed control amounts; S3, superimposing a nozzle throat area increase amount on the basis of an initial value of the nozzle throat area to form a first nozzle throat area, and simultaneously determining a second nozzle throat area for maintaining stable operation of the fan; S4, selecting a minimum value from the two nozzle throat areas and a maximum value of the nozzle throat area to form a nozzle throat area adjustment amount corresponding to the low-pressure conversion speed control amount; and S5, adjusting the nozzle throat area according to the corresponding relationship between the low-pressure conversion speed control amount and the nozzle throat area adjustment amount. The application can ensure that the deceleration time meets the index requirement and improve the aircraft maneuvering performance.