311results about How to "Improve transient performance" patented technology

A gas turbine engine, in particular a turboshaft engine, includes a spool having a turbine and a gas generator compressor mounted thereto, a source of heat positioned between the turbine and the compressor, a first shaft and a free turbine mounted to the first shaft, and a control system for transferring power between the spool and the shaft. The operating speed of the gas generator compressor is re-matched in order to improve the efficiency and surge margin of the gas generator compressor and to improve the transient performance of the gas turbine engine.

The invention relates to a quadrotor unmanned aerial vehicle attitude control system modeling and finite time attitude tracking control method, in particular to a quadrotor unmanned aerial vehicle finite time attitude tracking control method. Disturbance torque with which a quadrotor unmanned aerial vehicle is confronted is comprehensively analyzed, rotating inertia is unknown, output saturation and actuator failure and other factors are controlled, a passive fault-tolerant controller is designed on the basis of a parameter adaptive method, and the finite time stabilizing function is achieved. The method comprises the steps of 1 building a quadrotor unmanned aerial vehicle attitude tracking kinematic model, 2 building a quadrotor unmanned aerial vehicle attitude tracking kinetic model, 3 defining quadrotor unmanned aerial vehicle attitude smoothing errors, 4 designing a finite time integral sliding mode surface, and 5 designing a quadrotor unmanned aerial vehicle finite time attitude tracking controller. The method is used for the field of unmanned aerial vehicle flight control.

The invention discloses a predictive control method and system based on a multi-model generalized predictive controller. While process disturbance is inhibited, a preset desired output value is enabled to track the optimum set value track, and dynamic characteristics of a system are distinguished in parallel by adopting a plurality of fixed models and a plurality of adaptive models so that an actual output value and an optimum input control quantity of the system can be obtained. The invention also provides a predictive control system which is of a DRTO (Dynamic Real-Time Optimization) dual-layer structure, and adopts a multi-mode generalized predictive controller to replace an existing single-model generalized predictive controller. The predictive control method has the following beneficial effects of well matching the actual process characteristic in the production, reducing the system cost consumption, increasing the system economic benefit, improving the system transient state performance and the system regulating capacity when a system model parameter hops, being capable of effectively eliminating the interference of disturbance to system output, and reducing the influence of inconsistency of models of an optimization layer and a control layer in the DRTO dual-layer structure to the economic benefit.

An air conditioner using the cold of liquefied natural gas for automobile is composed of liquefied natural gas cylinder, coiled-tube beat exchanger arranged in said cylinder, sleeve-tube heat exchanger, finned heat exchanger, cold-accumulating ethanediol box, air cooling heat exchanger and liquid pump, which are communicated. The said fined heat exchanger is communicated with engine via low-pressure gas accumulator and condenser. The cooling water of engine is cooled by heat exchanger and then used to cool engine. Its advantages are better transient and steady-state performance and better cold balancing and regulating function.

The invention discloses an electronic voltage transformer using data fusion technology and an error calibration method thereof. The error calibration method comprises the following steps of: acquiring a secondary measured voltage by using a capacitive voltage divider and a sampling resistor R, accessing the voltage to a data acquisition processor for sampling, and tracing the frequency of the voltage; accessing a signal of a temperature sensor to the data acquisition processor, and computing the temperatures of measuring points; dynamically computing a divided voltage ratio of the capacitive voltage divider according to the temperature variation of the measuring points by using data acquisition device processing software so as to modify a transformation ratio error of the transformer; dynamically computing phase deviation according to signal frequency variation by using the data acquisition device processing software so as to modify a phase error; and outputting a digital sampling value through an optical fiber interface. The device is simple in structure, safe and practical; errors caused by manufacturing factors, temperature and signal acquisition circuits and the like can be effectively modified and restrained; and the measuring accuracy, temperature stability and transient performance of the electronic voltage transformer according to a capacitive voltage division principle are improved.

The invention provides a digital switch converter with fast transient response capability. The digital switch converter comprises a Buck type switch converter power level main topology structure, an A / D (analog-to-digital) sampling conversion unit, a prediction control unit, a fuzzy PID (proportion integration differentiation) control unit, a DPWM (digital pulse width modulation) unit and a driving unit, wherein the A / D sampling conversion unit respectively samples the analog output voltage value and the analog inductor current value of the sampling switch converter and converts analog signals into digital signals, the prediction control unit predicts the next switch period output voltage value according to the A / D sampling digital signal value combined with the Buck type switch converter main topology structure, the fuzzy PID control unit determines the switch period duty ratio according to the output voltage error value and the output voltage error deviation value, and the DPWM unit and the driving unit output the corresponding on-off state of a power tube of the PWM driving switch converter according to the duty ratio for regulating the output voltage value.

A voltage regulator includes an adjuster to provide an adjust signal according to its load current to adjust at least one of the feedback signal, the reference signal, the error signal, and the ripple signal of the voltage regulator, to automatically adjust the output voltage. The output voltage increases when the load current increases, and decreases when the load current decreases. Preferably, a CCR voltage regulator according to the present invention will have its PWM frequency varying with its output voltage and thus have better transient performance.

An apparatus for generating a high frequency audio signal that includes an analyzer for analyzing an input signal to determine a transient information adaptively. Additionally a spectral converter is provided for converting the input signal into an input spectral representation. A spectral processor processes the input spectral representation to generate a processed spectral representation including values for higher frequencies than the input spectral representation. A time converter is configured for converting the processed spectral representation to a time representation, wherein the spectral converter or the time converter are controllable to perform a frequency domain oversampling for the first portion of the input signal having the transient information associated and to not perform the frequency domain oversampling for the second portion of the input signal not having the associated transient information.

An automotive air blower, in particular a supercharger, comprises an air pump, such as an air impeller (2) connected to the output shaft (4) of a transmission system, the input shaft of which is connected, in use, to the engine of a motor vehicle. The input and output shafts (6, 4) are connected to respective branches of a three-branch epicyclic differential gearset. The third branch of the gearset and the input shaft (6) are connected to the rotor (20, 22) of respective electrical machines, the electrical connections of the stators (24, 26) of which machines are connected together via a controller (27) arranged to control the flow of electric power between them.

A flow rate ratio control device having: a main channel (RM); branch channels (R1, R2) branching from the end of the main channel (RM); control valves (31, 32) respectively provided in the branch channels (R1, R2); flow rate measurement means for measuring the flow rate of the main channel (RM) and the flow rate of each of the branch channels (R1, R2); a valve control section (5) for controlling the a control valve (31) provided in one branch channel (R2) so that the pressure on the upstream side of the control valve (31) is a given target pressure and, only when the upstream-side pressure is near or not less than the target pressure, starting control of the other control valve (32) so that the flow rate ratios of the branch channels (R1, R2) are predetermined ratios; and a target pressure setting section (6) for setting the target pressure such that the smaller the flow volume is in the main channel (RM), the lower is the target pressure.

The invention provides a multi-model generalized predictive control system and a performance evaluation method thereof. A plurality of fixed models and two self-adaptation models are adopted to parallelly identify dynamic characteristics of a system, optimal partial models are switched at each sampling instant to serve as current models based on performance indexes, optimal controllers are designed to control, and a minimum variance standard performance evaluation method is adopted to conduct performance evaluation on the multi-model switched generalized predictive control system. Compared with the traditional single-model generalized predictive control system, the multi-model switched generalized predictive control is adopted in a system for treating procedure parameter hopping, transient state performance of the system is improved, transient state errors are removed, and stability of the system is guaranteed.

The invention discloses a finite time robust fault diagnosis design method for a leader-follower multi-agent system. The method includes the steps: firstly, building a multi-agent system connection diagram with a leader and showing the multi-agent system connection diagram by a directed graph to obtain a Laplacian matrix L of a follower and an adjacent matrix G of the leader; building a state equation and an output equation of each node flight control system and augmenting a state vector and a fault vector into new vectors; constructing a distributed error equation and a global error equation based on the directed graph for each node according to the built directed graph, constructing a finite time fault diagnosis observer of a flight control system based on finite time robust control, and performing finite time fault diagnosis for faults of a multi-agent executor based on the directed graph. Faults of an optional node of the control system or simultaneously occurring faults of a plurality of nodes are effectively and accurately diagnosed and estimated on line in finite time.

The invention relates to a parameter identification based multi-motor servo system synchronization and tracking control method. The parameter identification based multi-motor servo system synchronization and tracking control method comprises the steps that 1, a multi-motor driven servo system containing unknown parameters is analyzed, and a mathematic model of the multi-motor driven servo system containing unknown parameters is established according to a motor structure and a physical law; 2, a load model established in the step 1 is analyzed, and unknown parameters in the load are estimated by utilizing a variable-gain self-adaptive parameter identification method; 3, synchronization and tracking control is conducted on the multi-motor driven servo system by utilizing neural network integral sliding-mode control algorithm according to a parameter identification result obtained in the step 2. The control method can ensure the steady-state accuracy of synchronization and tracking, effectively ensure transient-state and steady-state performance of parameter estimation, decrease the complexity and calculated quantity of algorithm design and effectively improves the response speed and robustness of the multi-motor driven servo system.

The invention discloses a frequency stabilization control method for an alternating-current / direct-current series-parallel system, which comprises the steps of designing an under-frequency load shedding optimization model considering emergency power generation control and high-voltage direct current power support, providing an objective function giving consideration to the frequency recovery performance and the load shedding amount, selecting the action frequency of an under-frequency load shedding program and the load shedding amount of each turn as control variables, carrying out optimization on a scheme by using a cloud adaptive particle swarm algorithm containing a dimension mutation operator, and realizing intelligent control for the frequency of the alternating-current / direct-current series-parallel system. The control method disclosed by the invention solves a problem of coordination and optimization between the system instability possibly caused by frequency oscillation after the alternating-current / direct-current series-parallel system breaks down and the economy of system frequency recovery; an under-frequency load shedding scheme is optimized, an optimal setting scheme is searched intelligently, the frequency recovery performance is considered, the load shedding amount is minimized, and the transient-state performance and the steady-state performance of the alternating-current / direct-current series-parallel system are improved.

A multi-model generalized predictive control system based on dynamic optimization comprises a dynamic optimization layer, an MPC layer and a basic control layer. The dynamic optimization layer is located in the upper layer and calculates the optimization value of a critical control variable as the optimal set value of the MPC layer; the MPC layer is located in the lower layer and adjusts a to-be-optimized variable based on a rolling optimization prediction algorithm on the condition that the to-be-optimized variable satisfies a model dynamic behavior, thereby tracking the optimal set value obtained in the S1; the basic control layer is located in the bottom layer and transmits the final optimization value of the to-be-optimized variable to an actuating mechanism. According to the present invention, the cost consumption of the system is reduced, the economic benefit of the system is improved, the transient performance and the model parameter jump adjusting capability of the system can be improved, at the same time, the interference of disturbance on the output of the system can be eliminated effectively.

The invention relates to a real-time monitoring method for short-circuit current of a near zone of a transformer, and the real-time monitoring method is characterized in that three non-inductive resistors connected in series onto three current transformators at the secondary side of the transformer are used for sending acquired analog signals to an analog / digital (A / D) sampling unit through an isolation amplifier, a low-pass filter, an absolute converting unit and a range self-adaption unit; the A / D sampling unit is used for continuously acquiring the analog signals; a first processor is used for computing read current sampled data, screening to obtain a wavelike current effective value and the fault instantaneous value of break-variable of current and caching fault data at the fault occurrence moment to a dual ported memory; a second processor is used for receiving the fault data of the dual ported memory and communicates with an upper computer through a network interface to draw an oscillogram, and simultaneously, the second processor is used for performing statistics on the received fault data and storing to a large-capacity memory. According to the real-time monitoring method for the short-circuit current of the near zone of the transformer, acquisition, recording and analysis are performed on the short-circuit impact current at the secondary side of the transformer, and an accurate basis can be provided for the running state analysis and the maintenance of the transformer.

The invention discloses a fuzzy control method for a lifting bridge crane system with persistent disturbances. The fuzzy control method comprises the following steps that Step one, when a load is subjected to an external persistent disturbance force, a mathematical model of the lifting bridge crane system with the persistent disturbances is established by introducing coordinate transformation; Step two, based on the mathematical model of the lifting bridge crane system in the step one, a fuzzy disturbance observer is established, and accurate evaluation on the external disturbances is realized; and Step three, an energy-based fuzzy controller is established by introducing a generalized signal gathering trolley motion and load swing. According to the fuzzy control method, the external disturbances are completely compensated, and the fuzzy control method has very important theoretical significance in analyzing the robustness of a rope length variable crane system.

This invention relates to a method and system for fast retrieval of the sequence components from phase, frequency and amplitude varying signals and synchronization therewith, and the concept of a system on a chip for power signal processing. More specifically, it relates to a method and system where the sequence components of a three-phase power signal are extracted and filtered in real time using a multirate phase-locked loop and a dual infinite impulse response filter with fault detection and reinitialization.

The invention relates to an electromagnetic sensing heating device and a method thereof. The electromagnetic sensing heating device comprises a microprocessor, a modulation circuit, a driving circuit, an insulated gate bipolar transistor (IGBT) half-bridge circuit, a main oscillation circuit and a synchronizer circuit, wherein the input end of the modulation circuit is connected with an input / output (I / O) port of the output end of the microprocessor, and the output end of the modulation circuit is connected with the driving circuit; the output end of the driving circuit is connected with the control end of the IGBT half-bridge circuit; the output end of the IGBT half-bridge circuit is connected with the control end of the main oscillation circuit; and the input end of the synchronizer circuit is connected with the main oscillation circuit in serial, and the output end of the synchronizer circuit is connected with the driving circuit. The heating efficiency of the heating device is higher than that of a traditional half-bridge circuit. The improved half-bridge circuit is connected with an inversion circuit in serial, so the cost of a full-bridge circuit is greatly reduced. A control strategy combining a constant-power temperature control method and a temperature control method is adopted, so good transient-state performance and good stable performance can be realized, and higher precision and higher reaction sensitivity can be realized.

The invention relates to a Rogowski coil-based integrator circuit for an electronic current transformer. The integrator circuit consists of a Rogowski coil, a low-frequency gain planarization analog integrator and a signal processing circuit, wherein the Rogowski coil is used for outputting a transient signal to the low-frequency gain planarization analog integrator and outputting a steady-state signal to the signal processing circuit; the low-frequency gain planarization analog integrator is used for processing the transient signal output by the Rogowski coil and is connected with the Rogowski coil and the signal processing circuit; and the signal processing circuit is used for processing an output signal of the low-frequency gain planarization analog integrator and performing digital integration on the steady-state signal output by the Rogowski coil, and then the processed signal is transmitted to a protecting channel and a metering channel through an output interface circuit. The integrator circuit has the advantages of measuring the steady-state signal with high precision, quickly responding to the transient signal, and providing measurement data of the protecting channel and the metering channel at the same time through one Rogowski coil, along with high temperature stability and vibration resistance.

Provided is a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function. For the dynamic system of a four-rotor aircraft, an integralsliding mode obstacle Lyapunov function is selected, and a four-rotor aircraft output-limited backstepping control method based on the integral sliding mode obstacle Lyapunov function is designed. Theintegral sliding mode obstacle Lyapunov function is designed in order to ensure that the output of the system is limited within a certain range, avoid too large overshoot and reduce the time of arrival. Therefore, the dynamic response performance of the four-rotor aircraft system is improved. The invention provides a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function, which enables the system to have a good dynamic response process.

An adaptive control method for a robotic arm servo system based on a time-varying asymmetric obstacle Lyapunov function comprises the following steps of step 1, establishing a mathematical model of the robotic arm servo system, and designing the time-varying asymmetric obstacle Lyapunov function; step 2, designing an adaptive controller by using the time-varying asymmetric obstacle Lyapunov function and combining an inversion method; and step 3, analyzing stability. By setting the parameter value of a constraint boundary function, the adaptive control method provided by the invention can effectively solve the system output constraint problem and ensure the steady-state performance and transient performance of the system. In addition, the uncertain part of a neural network approximation model and the derivative of the virtual control quantity are used to effectively simplify the design of the controller, improve the robustness of the system to a certain extent, and enable the robotic arm servo system to achieve accurate and fast tracking control.

A flow ratio controller having: a main channel; branch channels branching from the end of the main channel; control valves respectively provided in the branch channels; a plurality of flow rate meters for measuring the flow rate of the main channel and the flow rate of each of the branch channels; a valve control section for controlling the control valve provided in one branch channel so that the pressure on the upstream side of the control valve is a given target pressure and, only when the upstream-side pressure is near or not less than the target pressure, starting control of the other control valve so that the flow rate ratios of the branch channels are predetermined ratios; and a target pressure setting section for setting the target pressure such that the smaller the flow volume is in the main channel, the lower is the target pressure.

The invention relates to a method and a system for controlling a battery energy storage power station for primary frequency modulation of a power grid. The method comprises the steps of determining the frequency modulation requirement of the power grid according to the frequency deviation change rate of the power grid; determining the energy demand of the battery energy storage power station according to the battery charge information of the battery energy storage power station; and adjusting the frequency modulation power of the battery energy storage power station based on the power grid frequency modulation requirement and the energy demand of the battery energy storage power station. According to the method, the rapid response characteristic of the battery energy storage power stationis utilized, and fast response and rapid recovery are carried out on the frequency change of the power grid, so that the steady-state performance of primary frequency modulation is improved; and meanwhile, the battery energy state of the battery energy storage power station is optimized, so that the battery energy storage power station has the capability of primary frequency modulation for a longtime, and the transient performance of primary frequency modulation is improved.

The invention discloses an excitation state analysis-based low-voltage ride-through control method of a virtual synchronous power generator. The method comprises the steps of improving designs of droop characteristic, a reactive power ring and an active power ring by means of a reactive power adjustment principle of the synchronous power generator and a power grid which are connected in parallel,and the problems of excessive large reactive power increment, difficulty in preventing impact current and loop coupling reinforcement are effectively dealt with; and on the basis of no change on characteristic of the state analysis-based low-voltage ride-through control method of virtual synchronous power generator (VSG) system, an additional current ring is designed again, the under-excitation state running of an auxiliary system can be assisted during power grid fault period, an output current is adjusted, and a reactive power support is given out. A new directional method is employed, the transient process is accelerated, a control algorithm is not needed to be switched during the power grid fault period, a smooth switching strategy among states is also not needed to be added, and the low-voltage ride-through problem and the asymmetric drop of the power grid can be simultaneously dealt with.

A control circuit and method for a PWM voltage regulator combine a high frequency feedback technique with a constant on-time or constant off-time topology to improve the transient performance of the PWM voltage regulator. The PWM voltage regulator generates a constant on-time or constant off-time depending on a current for generating a PWM signal, and dynamically adjusts the current according to the droop-voltage at its output during a transient period. Therefore, the PWM voltage regulator boosts its transient response without any threshold for load step detection.

A four-rotor aircraft output limited backstepping control method based on an asymmetric time-varying obstacle Liapunov function; the invention aims at the four-rotor aircraft dynamics system, selectsthe asymmetric time-varying obstacle Liapunov function, and designs the four-rotor aircraft output limited backstepping control method based on the asymmetric time-varying obstacle Liapunov function;the asymmetric time-varying obstacle Liapunov function ensures the system output to be limited in a certain scope, can prevent overlarge overstrikes, and can reduce the arrival time, thus improving the four-rotor aircraft system dynamic response performance; the four-rotor aircraft output limited backstepping control method based on the asymmetric time-varying obstacle Liapunov function enables the system to have a good dynamic response process.

The invention discloses an optical current sensor based on the Faraday magneto-optic effect. The optical current sensor comprises a laser generator which is used to generate polarized laser of a set wavelength, an integrated probe which comprises a magneto-optical medium, a photodetector which is used to convert an optical signal into an electrical signal, and a data analyzing and processing device which filters out noise through the combination of hardware filtering and software filtering to acquire a good response effect. A polarizer and an analyzer are arranged on two ends of the magneto-optical medium respectively, and are insulatedly packaged on both ends of the magneto-optical medium respectively. The laser generator and the polarizer are connected through an optical fiber path, andthe photodetector and the analyzer are connected through an optical fiber path. The invention further discloses a current measurement method of the optical current sensor based on the Faraday magneto-optic effect.

A four-rotor aircraft output limited backstepping control method based on an asymmetric time-invariant obstacle Liapunov function; the invention aims at the four-rotor aircraft dynamics system, selects the asymmetric time-invariant obstacle Liapunov function, and designs the four-rotor aircraft output limited backstepping control method based on the asymmetric time-invariant obstacle Liapunov function; the asymmetric time-invariant obstacle Liapunov function ensures the system output to be limited in a certain scope, can prevent overlarge overstrikes, and can reduce the arrival time, thus improving the four-rotor aircraft system dynamic response performance; the four-rotor aircraft output limited backstepping control method based on the asymmetric time-invariant obstacle Liapunov functionenables the system to have a good dynamic response process.