Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

5233 results about "System stability" patented technology

System Stability. The system stability is “the finite output produced by a finite input of the system”. If the output of the system is infinite even when a finite input applied to a system, then this system is called “unstable system”, that is, stable system has bounded output when bounded input is applied to a system.

Method for islanding microgrid control and optimization based on rotating coordinate virtual impedance

The invention discloses a method for islanding microgrid control and optimization based on rotating coordinate virtual impedance. Aiming to a fact that the actual microgrids have complicated impedance characteristics, the method for islanding microgrid control and optimization based on the rotating coordinate virtual impedance includes utilizing the coordinate rotation orthogonal transformation to design the coordinate rotation virtual impedance, improving the impedance characteristics of the microgrid, compensating errors of power distribution and improving power decoupling performance; establishing a complete small-signal dynamic model of the microgrid, wherein the small-signal dynamic model comprises distributed energy sources, power converters, loads and power grids, and guiding the selection of an optimal value on the basis of the small-signal dynamic analytical method; and simultaneously, providing a theoretical basis for the optimization selection of islanding microgrid control parameters by using the small-signal dynamic analytical method, wherein the islanding microgrid control parameters comprise droop control coefficients of the power distribution, process identifier (PI) parameters of a voltage current feedback controller, feedforward control coefficients and the like. The microgrid after being subjected to optimization design in an islanded operational mode is capable of effectively achieving power decoupling and improving the accuracy of the power distribution, the stability of the system and the dynamic performances.
Owner:SHANDONG UNIV

Control system of offshore wind power flexible DC power transmission current transformer

The invention relates to a control system of a flexible wind power DC convertor on the sea, which pertains to the technical field of power transmission in wind power generation and comprises the doubly closed loop control structure of a sending end rectifier on the sea and the doubly closed loop control structure of a receiving end inverter on the coast; the doubly closed loop control structure of the sending end rectifier on the sea is used for controlling the active power of a flexible DC transmission system and the voltage stability of a wind power AC system; the doubly closed loop control structure of the receiving end inverter on the coast is used for controlling the constant voltage of the DC side of a receiving end convertor and the dynamic regulation of the reactive power of the main network accessing end of the receiving end convertor; two control structures are mutually independent and no data communication exists between the two control structures. The control system can fast and correctly control the active power of wind power transmission on the sea as well as promote the stability of the wind power AC system on the sea and the transmission efficiency and the power quality of the whole DC transmission system.
Owner:SHANGHAI JIAO TONG UNIV

Spacecraft attitude integral sliding mode fault tolerance control method taking consideration of performer fault

ActiveCN105843240AEasy to satisfy control torque limited constraintsSatisfy the control torque limited constraintCosmonautic vehiclesCosmonautic partsActive faultDynamic models
The invention relates to a spacecraft attitude integral sliding mode fault tolerance control method taking consideration of a performer fault and provides a robustness attitude active fault tolerance control method based on an integral sliding mode surface for problems of the performer fault, external disturbance and control moment amplitude limits in a spacecraft attitude control process. The method comprises steps that firstly, a spacecraft attitude dynamics model taking consideration of the performer fault and containing external disturbance is established; secondly, on the condition that a performer is not in fault, a designed nominal controller can guarantee system stability, and input saturation amplitude limits can be easily satisfied through adjusting controller parameters; lastly, the fault information is introduced to design an integral sliding mode controller, robustness of external disturbance and the performer fault can be effectively improved, system stability is analyzed on the basis of an Lyapunov method. The method is advantaged in that stability of the attitude control system is guaranteed when a spacecraft operating on orbit generates the performer fault, and relatively strong fault tolerance capability and external disturbance robustness are realized.
Owner:BEIHANG UNIV

Variable air volume air-conditioner control system with variable frequency fan and digital air valve for adjusting tail end air volume and implementation method

The invention discloses a variable air volume air-conditioner control system with a variable frequency fan and a digital air valve for adjusting tail end air volume and an implementation method, belonging to the technical field of the control of a variable air volume air-conditioner system. The variable air volume air-conditioner control system structurally comprises a master station DDC (direct digital control) controller, a tail end temperature controller, a filed bus, a tail end variable air volume box (VAV-BOX) and an air valve driver, comprises mater station DDC control and tail end temperature controller control in control types, and adopts a strategy of collective processing at first and decentralized control later. Through a method for adjusting the tail end air volume by the variable frequency fan and the digital air valve, the variable air volume air-conditioner system eliminates throttle energy loss of the air valve without a device for measuring the air volume, has simple control type and no influence on the operation of the whole variable air volume system, and has the advantages of good system stability and obvious energy-saving effect; and the fault on the variable air volume tail end device of certain node has no influence on the normal operation of other variable air volume tail end devices.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS +1

Enhanced data right protection method based on block chain and smart contract

InactiveCN107507091ACannot be deletedCan not be modifiedFinanceDigital data authenticationData PropertySystem stability
The present invention belongs to the data safety technology field, especially to an enhanced data right protection method based on a block chain and a smart contract. The method comprises the steps: a data owner submits data attributes and strategy attributes to a smart contract at a block chain for data publishing; other users are taken as data assignees to allow the circulation attributes of the data assignee to take as parameters to call the smart contract to perform circulation application, after the smart contract automatically determines whether the application is valid or not according to the strategy attributes of the data, an application result is returned back; if the circulation attributes of the data assignees are valid, a circulation license authorized and generated by the smart contract is obtained; or else, the smart contract determines that the application is failed. The enhanced data right protection method based on the block chain and the smart contract applies the block chain technology to protect data owner right and justly accept the applications of each data assignee; and moreover, the enhanced data right protection method based on the block chain and the smart contract improves the system stability, remove the dependence on a third-party authority in the data right protection process and provide a just, transparent and trusted execution environment for the data circulation process.
Owner:FUDAN UNIV

Efficient direct-expansion solar heat pump and water source heat pump coupled heat supplying system

The invention discloses an efficient direct-expansion solar heat pump and water source heat pump coupled heat supplying system. The system is characterized in that the angle of a solar heat collector is adjusted in real time through a full-automatic solar tracking device, therefore, sunlight vertically irradiates the solar heat collector, and maximum solar radiation energy is achieved; by arranging a phase change heat storage device on a direct-expansion solar heat pump system, the evaporating temperature of a refrigerating agent is kept within a certain range, and then influences of changes of the solar radiation intensity to the system stability are greatly reduced; solar energy is stored through a heat storage water tank, intermediate water is preheated through the heat storage water tank, therefore, heat obtained through the direct-expansion solar heat pump system is effectively transmitted to a user, and then effective coupling of a solar heat collection and heat storage technology and a water source heat pump is completed. The efficient direct-expansion solar heat pump and water source heat pump coupled heat supplying system has the advantages that the problems of intermittency and unstability of solar energy sources are effectively solved, it is guaranteed that the system can stably supply energy, the system performance is significantly improved, and high efficiency and environmental friendliness are achieved.
Owner:大连葆光节能空调有限公司

Improved active-disturbance-rejection position controller for direct current (DC) motor, and design method of improved active-disturbance-rejection position controller

The invention discloses a structure and a design method of an improved active-disturbance-rejection position controller for a direct current (DC) motor; the DC motor is taken as a controlled object, and an output position signal is taken as a controlled variable; the controller mainly consists of four parts, i.e., a tracking differentiator, a nonlinear state error feedback part, an extended state observer and a disturbance compensation part. The improved active-disturbance-rejection position controller is mainly used to improve a fal function in a nonlinear function in the extended state observer, and the fal function is used to determine the tracking performance of the extended state observer and the controller; the concrete improvement measure is adding a linear feedback area into non-linear feedback; therefore, the problem that in the traditional method, timely control cannot be realized when the system error is too large and the gain is too low can be solved on the basis of guaranteeing system stability. By comparing simulation lines obtained before and after the improvement for the controller, the structure and the design method which are provided by the invention are proved to accelerate the output signal response speed under the condition that the position error of the DC motor is larger, thus improving the integral control performance of a system.
Owner:NANJING UNIV OF POSTS & TELECOMM

Data buffering system with load balancing function

The invention provides a data buffering system comprising a data buffering manager, a data buffering library and a load balancing processor, wherein the data buffering manager receives a data acquiring request from outside, and responds to the data acquiring request to send a data acquiring command to the data buffering library to judge if the data buffering library preserves corresponding data, if the data buffering library preserves the corresponding data, the data buffering manager gets the corresponding data back, and if the data buffering library does not preserve the corresponding data, the data buffering manager sends a database server acquiring request to the load balancing processor; the data buffering library responds to a data storage command to store data which need to be buffered in blocks and pages and also responds to the data acquiring command to send the corresponding data to the data buffering manager; the load balancing processor responds to the database server acquiring request to provide a database server which processes fewest request to the data buffering manager, and the load balancing processor acquires data and returns the data to be stored into the data buffering library according to the information of the database server. The invention enhances the memory utilization factor, reduces the interactive communication capacity, decreases the using inquiry times and the magnetic disc access times and enhances the system stability and the system operation efficiency.
Owner:YONYOU NETWORK TECH

Comprehensive video monitoring system of intelligent traffic

The invention provides a comprehensive video monitoring system of intelligent traffic, belonging to the field of intelligent traffic and electronic police. The monitoring system comprises at least one high-definition digital web camera, a video-monitoring industrial control host, a loop vehicle detector and / or a radar device and a high-definition intelligent traffic behavior monitoring unit. The intelligent system is capable of integrating various intelligent traffic monitoring behaviors as a whole, that is, fulfilling the functions of multilane illegal activity monitoring, license number recognition and traffic data acquisition on a single machine at the same time, and conducting detection, analysis and evidence collection on various illegal activities by using the Linux-based embedded technology in combination with the watchdog technology and the network management function. The monitoring system based on the invention has the advantages of high stability, low mistaking and missing rate and high anti-interference capacity, and the monitoring system can effectively filter the interference caused by bicycles, passersby and light; and the monitoring system has flexible, customized monitoring modes, thereby meeting the monitoring requirements under complex environment.
Owner:DERUISHI BEIJING TECH DEV

Intelligent parking lot management method

The invention discloses an intelligent parking lot management method, and belongs to the technical field of parking lot management. The intelligent parking lot management method is characterized by comprising the following steps: dividing the physical space of a parking lot into a plurality of parking areas, and sequentially performing serial numbering on all the parking areas with Arabic numerals, and arranging a parking spot display screen; driving cars to enter the parking areas by drivers according to the green ray prompt of the parking spot display screen and a direction guide display screen, inputting license numbers on a reverse car searching terminal, performing information matching by a management server, feeding pictures of cars and the information of the parking areas where the cars are placed back to the reverse car searching terminal after the matching is completed, and generating the indicating diagrams of the routes from departure points to the packing areas. According to the invention, the systematic framework is greatly simplified, the system construction cost is reduced, the system stability is improved, the rapid parking and reverse car searching are realized, and the method has the characteristics of being high in reverse car searching accuracy, and rapid and convenient in parking.
Owner:LESHAN NORMAL UNIV

Dual-redundancy attitude control system and debug method of coaxial unmanned helicopter

The invention discloses a dual-redundancy attitude control system of a coaxial unmanned helicopter, which consists of a serial communication module, a PCM (Pulse-Code Modulation) decoding module, an AD acquisition module, a PWM (Pulse-Width Modulation) output module and a CPU control module. The serial communication module, the PCM decoding module and the AD acquisition module are used as system input, the CUP control module carries out improved digital PID control, and the PWM output module carries out output in the form of PWM pulses, and thus, the control of a backward-stage high power valve is realized. A debug method comprises the following fives steps of: firstly, connecting a defined I/O port to a high or low-level end according to a parameter debug object; secondly, adjusting a potentiometer to provide initial parameters for Kp and Kd and controlling the backward-stage high power valve; thirdly, keeping a neutral position of Futaba unchangeable, adjusting the potentiometer so that a steering engine achieves a critical state of self-excitation vibration; fourthly, operating the Futaba to output a signal exceeding a pulse threshold; and fifthly, operating the Futaba to return to a central position. The method realizes the debug and the storage of relevant parameters, decreases interference and improves the system stability and the response speed.
Owner:BEIHANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products