35results about How to "Increased stability range" patented technology

A premix burner has a mixing section (3) for a heat generator, sectional conical shells (5) which complement one another to form a swirl body, enclose a conically widening swirl space (6), and mutually define tangential air-inlet slots (7), along which feeds (8) for gaseous fuel are provided in a distributed manner, having at least one fuel feed (11) for liquid fuel, this fuel feed (11) being arranged along a burner axis (A) passing centrally through the swirl space (6), and having a mixing tube (4) adjoining the swirl body downstream via a transition piece (2). At least one additional fuel feed (13) for liquid fuel is provided in the region of the swirl body, the transition piece (2), and/or the mixing tube (4).

Novel platform mesogens, intermediates, and polymerizable mesogens made therefrom.

System for providing sealing between a rotor and a turbine casing in a hydraulic turbomachine includes a sealing ring arranged in a peripheral region of the rotor. The sealing ring forms at least one hydrostatic bearing with respect to at least one of the rotor and the turbine casing. The at least one hydrostatic bearing includes at least two bearing surfaces which face one another. At least one of the at least two bearing surfaces is arranged on the sealing ring. At least another of the at least two bearing surfaces is arranged on at least one of the rotor and the turbine casing. At least one groove is formed on at least one of the at least two bearing surfaces. At least one pressure-liquid line is coupled to each of the at least one groove and a pressure-liquid supply. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

A gas turbine is operated using a varying blend of a first fuel, preferably natural gas, and a second fuel that is hydrogen. The hydrogen concentration is varied depending on operating conditions in order to reduce emissions of CO and NOx, and/or to mitigate LBO. The fuel mixture is varied using a controller based on a combination of factors in a modular operation concept to address different issues according to relevant load limitations. A method of operating a gas turbine according to this modular operational concept is also provided.

A five-level feed-back digital-to-analog converter (DAC) in a switched capacitor sigma-delta analog-to-digital converter has an improved switching sequence that boosts from two to five the number of quantization levels of the feed-back DAC. Switching sequences are used to obtain five equally distributed charge levels C*VREF, C*VREF/2, 0, −C*VREF/2 and −C*VREF. When summed with an input voltage, VIN, the five-level feed-back DAC produces five equally distributed output voltages of A*VIN+VREF, A*VIN+VREF/2, A*VIN+0, A*VIN−VREF/2 and A*VIN−VREF, where A is gain, VIN is the input voltage, and VREF is the reference voltage.

The invention provides an astigmatism self-compensation solid laser, which comprises a pump source, a resonant cavity and a gain medium, wherein the gain medium has thermal lens astigmatism; the resonant cavity is an astigmatic cavity; and the gain medium is arranged in the resonant cavity in a way that the direction, with relatively poorer thermal effects, of the gain medium is in the meridian plane of the resonant cavity and the direction with relatively better thermal effects is in the sagittal plane of the resonant cavity. The solid laser can be obtained by compensating the astigmatism of the resonant cavity and the thermal lens astigmatism without inserting an additional astigmatism compensation element, and is high in output power, conversion efficiency, beam quality and stability, simple, convenient and reliable.

The invention aims at providing an observer-based stability analysis method for a time-delay haptic interface system. The method comprises: step one, establishing a mathematical model of each part ofa single-degree-of-freedom haptic interface system; step two, combining a haptic device with a retaining device, a sampling switch, and a time-delay characteristic and carrying out discretizing processing to obtain a discretized state space model of the haptic device with input delay; step three, designing a discrete state observer to estimate the state of the discrete haptic interface device andcalculating a feedback force according to a virtual environment model by using the estimated state as an input signal of a virtual environment; and step four, establishing a Lyapunov-Kolasovsky L-K function by using a time-delay segmentation idea, providing a time-delay-dependent asymptotic stability condition of the haptic interface system based on linear matrix inequality (LMI), acquiring a gainmatrix Ld of the observer and a parameter matrix Kd of a virtual wall as well as an allowable maximum time lag taum based on the stability condition.

The invention relates to a cascade 2-mu m solid laser of double-wavelength mixed pumping, which belongs to the technical field of laser. Pumping light output by a double-wavelength mixed pumping source is focused on 2-mu m laser crystals, the 2-mu m laser crystals absorb the pumping light with different wavelengths lambda 1 and lambda 2 and obtain gains, the two 2-mu m laser crystals are cascaded to realize laser oscillation in a laser resonator comprising a laser totally reflecting mirror, a laser reflecting mirror of 45 degrees and a laser output mirror, and 2-mu m laser is output from the laser output mirror. The invention has the advantages that the absorption of the 2-mu m laser crystals to the pumping light can be increased, the thermal lens effect of the 2-mu m laser crystals is decreased, and the quality of the light beam of the 2-mu m output light is improved, thereby obtaining the output of the 2-mu m laser with high power and high efficiency.

The invention discloses a three-phase-single-phase power electronic converter system and a rectifier fault tolerance method thereof. On the basis of a traditional three-phase-single-phase power electronic converter, an isolation switch group is added, the risk that rear-end equipment is damaged due to faults of a three-phase three-level rectifier to cause output instability of a traction network is reduced, the robustness of a single-phase three-level cascaded inverter is improved, and stable output of the traction network is guaranteed. During fault tolerance, the problems of override jump ofa switching pulse sequence SSi and unbalanced charging and discharging time of a direct current capacitor in a direct current link are fully considered. Fault-tolerant operation after a system faultis realized by utilizing charging and discharging of a direct-current capacitor to the greatest extent. The reliability of system operation is enhanced, the stability range of the system after fault tolerance is broadened, even if an extremely severe fault state occurs, i.e., after the three-phase three-level rectifier of a certain module completely quits operation due to a fault, the normal and stable operation of the system can still be ensured, and the network voltage of the traction network is not influenced by the fault.

The invention provides a middle-low speed maglev train cross track seam control system based on image processing. An image acquisition module acquires a suspension gap image and a track image through a binocular camera, and an image processing module and a gap calculation module process the images and calculate a suspension gap value d and a track-crossing joint distance L of an electromagnet; a suspension control module compares the received d value with a target suspension gap value, obtains a current value without a track gap through PID adjustment, carries out gap correction on the current value without the track gap through L and d, finally compares the current value with the current current value of an electromagnet to obtain a current deviation, and changes the duty ratio of a suspension chopper through the deviation so as to change the current of the suspension electromagnet, and stable suspension is kept. The dynamic rigidity of the system is improved, and the system has the characteristics of high anti-interference capability, high suspension stability and the like.

The invention provides a motor control method and circuit for stable operation of an AC motor in a full frequency band, the low-speed and high-speed control switching is smooth, the stable range is widened, the speed regulation range is wide, and the application is wide. The method includes the steps of performing deviation processing on a given current Idref generated according to a set frequencyand a feedback current Idfed generated by collecting a current of an AC motor; performing PID control on the obtained deviation to generate an initial given direct-axis voltage; performing amplitudelimiting on the initial given direct-axis voltage according to an operating direction of the AC motor to obtain a given direct-axis voltage Udref; obtaining the corresponding set rotational speed according to the set frequency and obtaining a given quadrature-axis voltage Uqref from the set rotational speed; and synthesizing the given direct-axis voltage Udref with the quadrature-axis voltage Uqref to output the value and angle of the control voltage of the AC motor.

The invention discloses an ecological electrode, an electric energy storage device and a preparation method thereof. The present invention relates to a composite electrode for a device for storing electrical energy wherein the electrode comprises an electrode body and an electrode housing wherein the body comprises at least one water-soluble polymer and at least a portion of the housing comprises a housing comprising at least one organic or organometallic material. The invention also relates to a device for storing electrical energy comprising the composite electrode and a method for preparing the composite electrode.