297results about How to "Extended operating range" patented technology

The invention relates to a stable tracking control system for a satellite communication antenna for a motion carrier, comprising an embedded antenna controller, an attitude sensor, a high-frequency signal processor, a GPS receiver, a directional integrated driving and controlling motor, a pitching integrated driving and controlling motor, a rolling integrated driving and controlling motor, a mechanical transmission device and a satellite communication antenna. An output shaft of the designed integrated driving and controlling motor can directly drive the antenna so as to simplify the system structure and facilitate the mounting and the maintenance; various main parts of the system and user operation terminals are connected by a field bus mode so as to simplify the connection complexity and benefit the networking work of a plurality of antenna systems; and a novel switching control algorithm based on a switching control theory is designed to improve the control performance of the system. The invention can effectively ensure the indication stability and the tracking performance of the satellite communication antenna on the motion carrier.

The invention provides a weak magnetic speed regulating method for an induction motor, and belongs to the technical field of alternating current motors and control thereof. The method comprises the following steps of: determining actual given values of exciting current and torque current by using a current control algorithm based on current optimal working trajectory; acquiring space vector pulse width modulation (SVPWM) through a current loop, and obtaining calculation action time of two adjacent non-zero voltage vectors; determining actual action time of the two non-zero voltage vectors through a modulation algorithm so as to acquire a running voltage of the motor; and at the same time, determining a field current calculation given value of the next time through the calculation action time of the two adjacent non-zero voltage vectors. By the method, an operating range of speed constant power of the induction motor is enlarged, a utilization ratio of the voltage and the current of an inverter is increased, and the maximum output torque of the induction motor is improved.

The invention discloses a current prediction control method and apparatus for a permanent magnet synchronous motor (PMSM). The method comprises the steps: acquiring the motor stator current and stator voltage under two-phase rotating coordinates; constructing a current and perturbation sliding-mode observer, and predicting and obtaining the motor stator current and the parameter perturbation estimated value of the next moment; according to the principle that the practical current value of the next moment is equal to a current command value, obtaining a PMSM current prediction control expression; taking the current value, predicted by the observer, of the next beat, as current feedback, and obtaining the command voltage of a motor driver through calculation; and further adding the command voltage and the parameter perturbation estimated by the observer together, taking the sum as the final motor driver command voltage, and finally generating a pulse signal for controlling motion of a switch tube through an SVPWM device. The current prediction control method for a permanent magnet synchronous motor can predict the current of the next beat and estimate parameter perturbation at the same time, and can effectively restrain the current tracking static error and reduce the motor harmonic wave current and optimize the current control performance when a parameter mismatching problem exists.

The invention discloses an open winding permanent magnet synchronous motor series compensation vector control system which is composed of a direct-current power source, a main converter powered by the direct-current power source, an open winding permanent magnet synchronous motor, a compensation converter powered by a power supply capacitor, voltage sensors arranged at the two ends of the power supply capacitor, a current sensor arranged on the stator side of the open winding permanent magnet synchronous motor, a speed sensor arranged on a rotation shaft of the open winding permanent magnet synchronous motor, and a controller controlling the main converter and the compensation converter. According to the open winding permanent magnet synchronous motor series compensation vector control system, the compensation converter which is arranged at the stator tail end of the open winding permanent magnet synchronous motor and powered by the power supply capacitor is controlled to equivalently change stator winding impedance, so that the power factor of the main converter approaches to or reaches 1; through cooperation control over the main converter and the compensation converter, distribution of active power and reactive power is changed, performance of the motor is improved, a flux weakening control area of the permanent magnet synchronous motor is expanded, and the operation range is widened.

The invention discloses a method for controlling direct torsion/ flux linkage of a permanent magnet synchronous motor. The method comprises the steps of collecting three-phase stator voltage and currents of the motor, and obtaining voltage and currents under a two-phase static coordinate system through three-phase/two-phase static coordinate conversion; calculating actual feedback value of electromagnetism torsion and stator flux linkage according to the voltage and the currents under the two-phase static coordinate system; obtaining initial given value of the electromagnetism torsion through a PI controller according to difference between given rotating speed and feedback rotating speed; obtaining given value of the electromagnetism torsion and the stator flux linkage according to a given electromagnetism torsion and stator flux linkage calculating module; obtaining given voltage on an alpha beta shaft of the two-phase static coordinate system through a given voltage calculating module; generating switching signals of an inverter through space vector pulse width modulation, triggering a switching device of the inverter, and realizing direct torsion/flux linkage control of the permanent magnet synchronous motor. The method realizes low, medium and high speed wide range operation of the permanent magnet synchronous motor, does not need to rotate coordinate conversion, and has the advantages of being convenient to calculate, quick in dynamic response, strong in robustness, and the like.

The invention discloses a refrigerant control method of a parallel multi-split air-conditioner. The method comprises the steps of S1, in a heating mode, comparing the degree of superheat of each outdoor unit with the average degree of superheat of a plurality of outdoor units, S2, when the degree of superheat of the current outdoor unit is overhigh in contrast with the average degree of superheat, increasing the amount of the refrigerant going into the current outdoor unit, and S3, when the degree of superheat of the current outdoor unit is overlow in contrast with the average degree of superheat, reducing the amount of the refrigerant going into the current outdoor unit. In this way, the amount of the refrigerant going into each outdoor unit is decided by comparing the degree of superheat of the current outdoor unit and the average degree of superheat (system); the amount of the refrigerant going into each outdoor unit is adjusted from the overall aspect of the system so that the compressor can be enabled to be within an excellent running range, and therefore, the problems caused by overhigh or insufficient superheat of the compressor can be avoided and the reliability of the multi-split air-conditioner during operation is improved.

A rotor parameter sensor can be used for electric drives. A rotor of an electric engine or motor is monitored by a sensor sensing one or more physical observables or operation parameters. Furthermore, a method and system can be used for monitoring an electric engine or motor for use in electric or hybrid vehicles.

The invention disclose a serial compensation direct torque control method for a winding permanent magnetic synchronous motor. Through cooperation control of a main converter and a compensation converter, the main converter bears most active power and necessary reactive power; and the compensation converter bears most reactive power and necessary active power, and the power factor of the main converter is enabled to be close to one or reach one. By using a direct torque control method, during a weak magnetic control process, the actual situations that the main converter simultaneously bears a part of reactive power and DC bus voltages and capacitance voltages may change are taken into consideration, and a weak magnetic control method of voltage feedback of the main converter is employed during the weak magnetic control process, such that the weak magnetic work area of a motor is effectively expanded, and the operation scope of the motor is enlarged.

The invention relates to logistic equipment, in particular to an automatic finished-tire separation device which is arranged on a loading platform of a stacker for movable equipment and used cooperatively with a finished-tire storehouse. The automatic finished-tire separation device comprises a temporary tire storage box, a tire release mechanism, a finished-tire storehouse exit gate lifting mechanism and an exit gate mechanism, wherein the tire release mechanism is arranged on the temporary tire storage box, and the exit gate mechanism is arranged on a finished-tire storehouse exit. The movable equipment is controlled according to the command sent by control software of a control system, thus the finished tires can be separated automatically when being stored in and taken out of the storehouse. The automatic finished-tire separation device is used cooperatively with the stacker and the finished-tire storehouse, thus the structures of the equipment are simplified, the equipment cost is lowered, and the one-time investment and recurrent expenses of users are saved. The automatic finished-tire separation device is simple in structure, large in range of operation, flexible to operate and convenient to maintain, and the work efficiency and the economic benefit are greatly improved.

The invention discloses a method for controlling diluent or lean mixed gas burning and ignition through high-flammability fuel micro ignition. The method comprises the steps that gasoline is ignited through spontaneous burning of a small amount of layered high-flammability fuel, and stable flame propagation is formed; the temperature inside a cylinder is increased through energy released by flame propagation and piston upward compression, meanwhile, multiple spontaneous burning points are formed in unburnt diluent or lean mixed gas under the assistance of a small amount of pilot injection high-flammability fuel, and then stable and rapid burning or multi-point spontaneous burning is formed. When an engine encounters knock or the largest explosion pressure exceeds limits, the burning process can be converted into rapid flame propagation type burning by introducing cooled burnt waste gas or excess air. When the heat state in the cylinder is not enough to form stable flame propagation or spontaneous burning heat release, the heat state in the cylinder is improved by introducing internal residual waste gas. The control problem in the ignition and burning process of premixed diluent or lean mixed gas can be solved.

The invention discloses a voltage cutting method based weak magnet control method for a low-switch-loss open-winding permanent synchronizing motor system. The method is that the voltage cutting method and the optimal zero vector selecting method are combined to use; a main inverter is controlled by the manner of combining single effective voltage vector and zero vector to output voltage vector under the limited power condition; the switch loss can be reduced while the active power is outputted as system requirement; the capacitive voltage stability is maintained; compared with the SVPWM switch loss, 1/3 of the loss is reduced, and thus the system efficiency can be greatly to the maximum; the inverter is controlled and adjusted to provide reactive powder and can compensate the harmonic wave caused by low switching frequency of the main inverter; therefore, high-efficiency and high-performance control of an open-winding motor can be achieved; meanwhile, the method is applied to the weak magnet control based on the effective voltage vector action time feedback, and the operation range of the motor can be expanded.

The invention discloses a centrifugal compressor model. The centrifugal compressor technology in China still need be improved continuously so that the operation stability and efficiency of a compressor can be enhanced. The centrifugal compressor model comprises an impeller, a blade diffuser, a bent way and a backflow unit. The blade diffuser is arranged at an outlet of the impeller. Diffuser blades of the blade diffuser are skewed blades, that is, the sides, close to a diffuser wheel cover, of outlets of the diffuser blades are bent to form outlet flow stabilizing blades. An outlet of the blade diffuser is communicated with the bent way. Circular grooves are formed in the outer wall of the bent way. Resistance reduction grooves are formed in blade pressure faces and suction faces of backflow unit blades of the backflow unit, and rectangular channels are formed in blade outlets of the backflow unit blades. According to the centrifugal compressor model, structures of diffusers, bent ways and backflow units of prior centrifugal compressor models are improved, enhancement of operation efficiency and enhancement of operation stability of the centrifugal compressor model are guaranteed, and a computational formula of energy gradient function values in the diffuser is raised.

The invention relates to a last-stage front half section adjustable stator blade for an axial-flow compressor and a working method thereof and belongs to the technical field of impeller machinery. The last-stage stator blade comprises an adjustable front half section blade (8) and a nonadjustable rear half section blade (10), wherein the adjustable front half section blade (8) is arranged on the nonadjustable rear half section blade (10) through a rotating shaft (9); the rotating shaft (9) is positioned at the position with the largest thickness of the last-stage stator blade; the nonadjustable rear half section blade (10) is fixedly arranged on an outer cartridge receiver of the axial-flow compressor. The blade has the advantages of (1) the operation pressure ratio and the flow rate range of the compressor are expanded; (2) the efficiency of the compressor in the whole working range is improved.