308results 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.

Fuel management system for operation of a spark ignition engine. The system includes a source of gasoline and a source of anti-knock fuel. A proportioning valve receives the gasoline and the anti-knock fuel to discharge a mixture having a controlled gasoline / anti-knock fuel ratio. A single high pressure pump receives the mixture and delivers the mixture to an injector. A fuel management control system controls the proportioning valve and the injector for injection of the mixture into a cylinder of the engine to control knock. A preferred anti-knock fuel is ethanol.

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.

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.

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.

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.

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.

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.

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.

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.