37results about How to "Reduce the risk of resonance" patented technology

The invention is a seismic acquisition vibroseis pseudo random scanning signal generating method in geophysical exploration. The method comprises the following steps: a Gold sequence code is generated according to the length of to-be-generated Num groups of vibroseis pseudo random scanning signals to obtain a target amplitude spectrum; windowing processing is performed on cross-correlation and autocorrelation of the Num groups of amplitude spectrum shaping signals in a time domain to obtain Num groups of pressed reconstruction signals; the maximum value of cross-correlation between each Num group of high-cut filter signals on the same time point position is divided by the minimum value of autocorrelation of each group of signals at the time zero to obtain the maximum relative cross-correlation value of the Num groups of high-cut filter signals; and iterative modification is performed to generate the final Num groups of vibroseis pseudo random scanning signals. The method of the invention enables the cross-correlation effect between the groups of pseudo random signals to be weak, thereby inhibiting adjacent gun interference in the efficient acquisition process, and improving the separation quality of shot records. The instantaneous frequency energy does not vary monotonically with time, which can greatly reduce the risk of resonance of surrounding buildings in the vibroseis construction process.

The invention discloses an optimization method for the wind-generation-set gear-case elastic support span. The optimization method includes the steps that 1, according to the initial parameter of a target wind generation set, a wind-generation-set transmission chain model containing a gear case model is set based on the many-body dynamics, and the initial parameter comprises an initial value of the span of a gear-case elastic support; 2, the value of the span in the wind-generation-set transmission chain model is continuously adjusted, and is subjected to modal and time domain analysis during adjusting every time, the potential resonant frequency obtained by modal and time domain analysis can be avoided after adjustment, and the adjusted wind-generation-set transmission chain model is output; 3, the value of the span in the adjusted wind-generation-set transmission chain model is continuously subjected to fine tuning optimization, the operating characteristic of a transmission chain in the wind-generation-set transmission chain model is best accordingly, and the best span value is obtained and output. By means of the optimization method, the resonance risk of the transmission chain can be avoided, and meanwhile the movement performance is best; the optimization method has the advantages of being simple in achieving method, reasonable in span design and high in optimization efficiency.

The invention relates to a compound energy-saving type medical molecular sieve central oxygen generation and medical air compression integrated device, comprising a main air supply source, auxiliary air supply sources, and a standby air supply source for continuing to supply oxygen when the main air source and the auxiliary air sources stop at the same time, wherein the main air supply source, the auxiliary air supply sources and the standby air supply source share one air balance tank, one oxygen balance tank and one oxygen division pot with a voltage-sharing and flow-equalizing function, the auxiliary air supply sources are arranged beside the main air supply source side by side and perform auxiliary supplement air supply for the main air supply source, and the standby air supply source continues to supply oxygen when the main air supply source and the auxiliary air supply sources stop at the same.

The invention discloses a flexible direct-current high-frequency resonance suppression method, system and equipment. The method comprises the steps of enabling the input quantity and output quantity of a virtual power grid adaptive filter to be completely isolated physically under a normal condition, enabling the harmonic waves of an actual electrical quantity not to be reflected on the virtual electrical quantity, and achieving an effect of suppressing the harmonic waves. When the effective value of the actually input actual alternating-current voltage is reduced to meet the preset conditionfrom the normal value, the virtual electrical quantity is enabled to be completely equal to the actual electrical quantity, the complete real-time tracking of the actual electrical quantity is realized, and the dynamic characteristic of the power system at the fault moment is improved; and after completely tracking for a period of time, if the effective value of the actual alternating-current voltage is smaller than a preset threshold value, adaptive tracking is carried out until the actual electrical quantity is recovered to a stable value. According to the method, the risk of high-frequencyresonance of the flexible direct current can be reduced, deterioration of dynamic characteristics of the flexible direct current under the fault working condition is avoided, damage to devices or equipment due to overstress is avoided, and the safety of flexible direct current fault ride-through is improved.

The invention relates to a cast shell type EGR cooler. An air inlet connector is connected with a telescopic structure with a corrugated pipe and a sleeve, the outer circumference of the telescopic structure is fixedly connected with an input end flange cover, and the input end flange cover is in bolted connection with one end of a cast pipe shell through an input end sealing gasket. The other endof the pipe shell is in bolted connection with a fixing structure and an output end flange cover with an output pipe connector through an output end sealing ring. The telescopic structure is welded to and connected with a pipe plate at one end of a pipe bundle, and a pipe plate at the other end of the pipe bundle is welded to and connected with the fixing structure. According to the cast shell type ERG cooler, the fixing structure is arranged at one end of the pipe bundle, the telescopic structure is arranged at the other end of the pipe bundle, the problem of dislocation between the pipe shell and the pipe bundle due to thermal expansion and cold contraction is solved, axial displacement compensation is conducted on a heat exchange core through a flexible structure of a double-layer corrugated pipe in the telescopic structure, the influence of thermal expansion and cold contraction on the heat exchange core is reduced, the double-layer corrugated pipe is placed at an air inlet end and combined with a shell water inlet structure, the water flow space is increased, and water flow uniformity is guaranteed.

The invention relates to an auxiliary energy-saving type medical molecular sieve central oxygen generating device, comprising a main air supply source and auxiliary air supply sources, wherein the main air supply source and the auxiliary air supply sources share one air balance tank, one oxygen balance tank and one oxygen division pot with a voltage-sharing and flow-equalizing function, and the auxiliary air supply sources are arranged beside the main air supply source side by side and perform auxiliary supplement air supply for the main air supply source.

The invention relates to the technical field of shear beam anti-seismic structures, in particular to an anti-seismic structure for a shear beam and the shear beam. The anti-seismic structure for the shear beam comprises a beam body, and an anti-seismic frequency modulation mechanism is arranged on the upper surface of the beam body; the anti-seismic frequency modulation mechanism comprises a shellwhich is internally provided with a balance chamber and at least one damping chamber, and all the damping chambers are communicated with the balance chamber through power pumps; the anti-seismic frequency modulation mechanism further comprises a central controller and a vibration frequency sensor; the vibration frequency sensor and the central controller are fixed to a shell, all the power pumpsand the vibration frequency sensor are electrically connected with the central controller. According to the anti-seismic structure for the shear beam and the shear beam, by arranging the anti-seismicfrequency modulation mechanism, the vibration frequency of the beam body can be adaptively adjusted, the resonance risk is lowered, and the anti-seismic property of the beam body is effectively improved.

The invention discloses a design method for rail transit electronic product vibration reliability. The design method comprises the following steps: acquiring vibration excitation frequency informationof the rail transit electronic product in an actual operation environment; acquiring inherent frequency information of the product based on an initial design scheme of the rail transit electronic product; carrying out matching analysis on the inherent frequency information and the vibration excitation frequency information, and when the matching condition that the inherent frequency avoids the vibration excitation frequency is met, determining an initial design scheme as a vibration reliability design scheme; otherwise, adjusting the quality and/or rigidity of the product in the initial design scheme to optimize the scheme until the vibration reliability design scheme is determined. According to the design method provided by the invention, a design scheme meeting the vibration reliabilitycan be provided, the resonance risk of the product in the operation process can be reduced to the maximum extent, and the operation reliability of the rail transit electronic product is improved.

The invention relates to the technical field of electro-acoustic conversion, in particular to a double-sided ultrathin loudspeaker, which is characterized in that a first loudspeaker individual and asecond loudspeaker individual are arranged in a cavity of a basin frame; the first loudspeaker individual is arranged on the upper end surface of the basin frame; and the second loudspeaker individualis arranged on the lower end surface of the basin frame. When the low-frequency effect needs to be enhanced, a second vibration system is not powered on while the normal sounding first vibration system is powered on to work, and a voice diaphragm part is used as a back plate for enhancing the bass part; the voice coils of the first vibration system and the second vibration system are electrified,when the two voice diaphragm parts vibrate, a good damping effect is achieved, and the resonance risk of the whole machine is greatly reduced; a nine-magnet design is used, the loudspeaker is made tobe thin, a high sound effect of the loudspeaker can be achieved, first side edge magnetic steel in the first magnetic circuit system and second center magnetic steel in the second magnetic circuit system are the same part, and a magnetic bowl of the first magnetic circuit system and a second center polar plate in the second magnetic circuit system are the same part. Therefore, the size of the loudspeaker is greatly reduced.

The invention relates to a virtual power grid adaptive control strategy optimization method and device and terminal equipment, which are applied to a flexible direct current power transmission system. According to the virtual power grid adaptive control strategy optimization method and the device and the terminal equipment, a virtual power grid adaptive control strategy is controlled to be switched among a first link, a second link and a third link according to the actual alternating current voltage of an alternating current side of a flexible direct current converter of the flexible direct current power transmission system, the risk of resonance of the flexible direct current power transmission system can be reduced, so that the flexible direct current power transmission system can obtain better dynamic characteristics at the moment of fault and in the fault recovery process, damage to a load (a device or equipment) caused by overstress generated by the flexible direct current power transmission system is avoided, and the DC fault ride-through safety of the flexible DC power transmission system is improved; and the problem that when an existing virtual power grid self-adaptive controller is adopted to suppress high-frequency resonance of a flexible direct-current power transmission line, the dynamic characteristic is poor in the alternating-current fault recovery process is solved.

The invention provides a vortex reducer assembly which is used for an aero-engine air compressor. A vortex reducing pipe comprises a fixing end and a free end, the vortex reducing pipe is fixed through the fixing end, and a damping pipe is connected with the free end of the vortex reducing pipe through a threaded pair. The invention further provides the aero-engine air compressor which comprises the vortex reducer assembly. The provided vortex reducer assembly can replace an existing vortex reducer assembly and is convenient to machine or assemble.

The invention discloses a method for erecting a shock-absorbing ground pump guide pipe of a high-rise building penetrating through a flue hole and relates to the technical field of constructional engineering. According to the method for erecting the shock-absorbing ground pump guide pipe of the high-rise building penetrating through the flue hole, a flue hole periphery pump pipe fixing and bearing system and a shock-absorbing pull rod system are included. According to the method for erecting the shock-absorbing ground pump guide pipe of the high-rise building penetrating through the flue hole, risks of cracking and water seepage of a pump pipe penetrating through the periphery of an interlayer hole structural plate in an existing scheme are fully reduced; vibration reduction suspenders are formed by turn buckles and vibration reduction springs and used for supporting the pump pipe, the vibration reduction suspenders with different elastic coefficients are combined and matched with one another, the overall natural vibration frequency of a pump pipe erecting system is adjusted, and the risk of resonance in the concrete pumping process is reduced. compared with the prior art, the method is advantaged in that in the pump pipe erecting process, assembly and disassembly procedures are simple, permanent and temporary combination is fully embodied, a large amount of disassembly and recovery work in the later period is avoided, and the method better fits the field reality and is safe, economical and efficient.

The invention discloses a resonance suppression method, module and device of a converter. The method comprises the following steps: acquiring a capacitive current component of an alternating current side of the converter; after the capacitance current component is adjusted through a first gain link and a first phase compensation link, obtaining a first control action quantity; and superimposing the first control action into a controller output of the converter to form a final control action. According to the invention, the phase compensator is introduced into the capacitor current feed-forward control branch, the problem that the resonance damping capability is limited due to the delay of a digital control system in the existing resonance suppression method is avoided on the basis of not increasing the system cost, the resonance risk of the converter operating under wide-range power grid impedance is reduced, and the stable operation capability under power grids with different intensities is enhanced.

The invention relates to an offshore wind plant current collection topology analysis method capable of avoiding a resonance area, and discloses a resonance risk assessment and current collection system topological structure optimization method for a whole offshore wind farm through an alternating current submarine cable sending-out system (a current collection system, an offshore wind turbine generator considering dynamic characteristics of a variable current control system, a power transformation system, a power transmission system and a grid-connected system). The method comprises the following steps: deducing an impedance model of the current collection system for an offshore wind power plant through the alternating current submarine cable sending-out system, and combining the impedance model with a deduced impedance model of an offshore wind turbine generator, a deduced impedance model of the power transformation system, a deduced impedance model of the power transmission system and a deduced impedance model of the grid-connected system; constructing to obtain an admittance network model of the whole system sent by the offshore wind plant through an alternating current submarine cable; performing singular value calculation and analysis on the basis of the constructed admittance model of the whole system of the offshore wind plant through the alternating current submarine cable sending-out system, drawing a frequency-singular value curve, and judging a resonant frequency point in the system according to amplitude-frequency characteristics of singular values; and changing the topological structure of the current collection system, and changing the frequency point corresponding to the singular value or reducing the amplitude of the singular value.

The invention discloses a flexible DC power transmission system fault ride-through method and a control system, and the system mostly employs a method for delaying a 1/4 fundamental frequency period to obtain positive and negative sequence voltage and current components, and then suppresses the negative sequence current at a fault moment through a negative sequence current inner loop control method. Due to the inherent characteristics of a 1/4 fundamental frequency period delay positive and negative sequence decomposition method, the periodic fluctuation of the impedance of the flexible direct current power transmission system is caused, especially at the high frequency, the risk that the impedance of the flexible direct current power transmission system exceeds 90 degrees is increased, and the possibility of instability exists when the flexible direct current power transmission system is connected with other systems. According to the method, the inner-loop total-sequence current control is adopted, periodic fluctuation of the flexible direct-current power transmission system is avoided in a steady state, the risk that flexible direct-current impedance exceeds 90 degrees is reduced, meanwhile, negative-sequence current control is overlaid in a fault period, and alternating-current fault ride-through of the flexible direct-current power transmission system is achieved.

The invention relates to a roll winding device, which is used for winding a sheet of material, particularly a paper web or a cardboard web to at least a roll on at least a winding core and a preferably winding cylinder, during winding, at least a roller supported on a rolling bearing is attached to the roll, and at least a moveable rolling bearing is connected with a support part via a damping unit. The damping unit comprises a cylinder and a piston movably arranged in the cylinder. In order to improve a winding structure and particularly stabilize relationship in winding scope, a frictionless sealing is provided between the cylinder and the piston. An independent claim is also included for a beneficial method for winding a sheet of material.

The embodiment of the invention provides a rotating speed control method and device of a wind generating set, equipment and a medium. The method comprises the steps that the given rotating speed and the torque of the wind generating set are obtained; when the given rotating speed is equal to the lower limit value of a first rotating speed interval and the torque is larger than a first preset torque threshold value, the given rotating speed is adjusted to be increased, and the first rotating speed interval is the rotating speed interval corresponding to the resonant frequency range between the rotating frequency of the wind generating set and inherent components of the wind generating set; and under the condition that the given rotating speed is equal to the upper limit value of the first rotating speed interval and the torque is smaller than a second preset torque threshold value, the given rotating speed is adjusted to be reduced, and the actual rotating speed of the wind generating set is controlled through the adjusted given rotating speed. According to the embodiment of the invention, the safety of the wind generating set can be improved.