162 results about "Closed-loop transfer function" patented technology

A fast and reliable technique for tuning multivariable model predictive controllers (MPCs) that accounts for performance and robustness is provided. Specifically, the technique automatically yields tuning weights for the MPC based on performance and robustness requirements. The tuning weights are parameters of closed-loop transfer functions which are directly linked to performance and robustness requirements. Automatically searching the tuning parameters in their proper ranges assures that the controller is optimal and robust. This technique will deliver the traditional requirements of stability, performance and robustness, while at the same time enabling users to design their closed-loop behavior in terms of the physical domain. The method permits the user to favor one measurement over another, or to use one actuator more than another.

An automated tuning method of a large-scale multivariable model predictive controller for multiple array papermaking machine cross-directional (CD) processes can significantly improve the performance of the controller over traditional controllers. Paper machine CD processes are large-scale spatially-distributed dynamical systems. Due to these systems' (almost) spatially invariant nature, the closed-loop transfer functions are approximated by transfer matrices with rectangular circulant matrix blocks, whose input and output singular vectors are the Fourier components of dimension equivalent to either number of actuators or number of measurements. This approximation enables the model predictive controller for these systems to be tuned by a numerical search over optimization weights in order to shape the closed-loop transfer functions in the two-dimensional frequency domain for performance and robustness. A novel scaling method is used for scaling the inputs and outputs of the multivariable system in the spatial frequency domain.

The invention discloses a method for determining the equivalent aeroservoelasticity (ASE) robust stability of a statically unstable aircraft through a flight test, which is used for solving the technical problem of large modeling errors of the conventional flight test determination method. The technical scheme is that: a closed loop transfer function frequency characteristic matrix of a multi-loop system of the statically unstable aircraft can be obtained through a sweep frequency flight test; a relational expression between a closed loop transfer function and ASE stability is established according to a corresponding relation between the closed loop transfer function and an open loop transfer function; and the closed loop transfer function frequency characteristic matrix of the system is subjected to characteristic decomposition, and a multi-loop stability margin analysis scalar equation is obtained according to the critical stability condition of the system, so that the ASE stability of the whole loop is calculated, and problem difficulty is greatly simplified.

A mass flow controller having a feedback controller gain, comprises: a sensor configured so as to sense the flow of fluid through controller; a valve arranged so as to adjust the flow of fluid through the controller; and a processor configured so as to controlling the valve as a function of the flow of fluid sensed by the sensor. The sensor and valve are arranged within a feedback system, and the processor updates the feedback controller gain in real time based on the ratio of at least one calibration gas parameter to at least one operating gas parameter, such that the closed loop transfer function of the feedback system remains substantially constant regardless of operating conditions so as to have a consistent control performance at different operation conditions from the calibration condition.

The invention relates to a power system stabilizer (PSS) configuration method in coordination with a low-excitation limiting function. The method is characterized by comprising steps: a generator typical leading phase operation working condition point set based on a low-excitation limiting boundary line is set; an open-loop transfer function G<X>(s) for electromagnetic torque increment signals generated by the traditional power system stabilizer PSS1 through an excitation link when low-excitation limiting does not act in relative to PSS1 input signals is determined; an open-loop transfer function G'<X>(s) for electromagnetic torque increment signals generated by the newly-added power system stabilizer PSS2 through an excitation link when low-excitation limiting acts in relative to PSS2 input signals is determined; and by using the transfer function G<X>(s) and the transfer function G'<X>(s), an optimal mathematical model for a lead-lag link time constant of the PSS2 is built and solved. The configuration method of the invention has the advantages that comprehensive factors are considered; the operation is simple and convenient; the practicability is strong; and the deteriorated dynamic stability of the power system caused as the low-excitation limiting acts can be effectively solved.

The invention discloses a wind power station subsynchronous resonance suppression method and system, the wind power station at least comprises: a plurality of wind turbines, a plurality of transformers and wind power station lines, the wind power station is characterized in that: acquiring voltage signals and current signals of wind power station lines, resistance and inductance of the plurality of wind turbines, resistance and inductance of the plurality of transformers, resistance and inductance of the wind power station lines and current signals actually outputted from the subsynchronous suppression system to a power grid; performing filtering processing on voltage signals and current signals of the wind power station lines, obtaining subsynchronous frequency signals, according to the subsynchronous frequency signals, the resistance and the inductance of the plurality of wind turbines, the resistance and the inductance of the plurality of transformers and the resistance and the inductance of the wind power station lines, obtaining wind power station closed loop transfer functions, and according to the current signals actually outputted from the subsynchronous suppression system to a power grid, optimizing the attenuation rate of the closed loop transfer functions under different zero points through optimizing parameters. According to the invention, the stability of the wind power station can be effectively improved.

A mass flow controller having a feedback controller gain, comprises: a sensor configured so as to sense the flow of fluid through controller; a valve arranged so as to adjust the flow of fluid through the controller; and a processor configured so as to control the valve as a function of the flow of fluid sensed by the sensor. The sensor and valve are arranged within a feedback system, and the processor updates the feedback controller gain in real time based on the ratio of at least one calibration gas parameter to at least one operating gas parameter, such that the closed loop transfer function of the feedback system remains substantially constant regardless of operating conditions so as to have a consistent control performance at different operation conditions from the calibration condition.