46results about How to "Suppression of resonance phenomena" patented technology

A power regenerative converter includes: a power conversion unit configured to convert AC power supplied from an AC power supply into DC power and convert DC power into AC power to be supplied as regenerative electric power to the AC power supply supply; an LCL filter including a reactor unit having a plurality of reactors connected in series between the power conversion unit and the AC power supply, and capacitors each having one end connected to a series connection point of the reactors in the reactor unit; a drive control unit for controlling the power conversion unit based on an AC voltage command; and a voltage command compensation unit for calculating a compensation value in accordance with a capacitor voltage being a voltage at the series connection point of the reactors and adding the compensation value to the AC voltage command input to the drive control unit.

The invention provides a parameter design method for a high-voltage high-capacity VSC (voltage source converter). The VSC is connected with an electric grid through an LCL (lower control limit) filter, the LCL filter comprises an electric grid side electric reactor, a valve side reactor and a filter capacitor, and the filter capacitor is connected in parallel between the valve side reactor and the electric grid side electric reactor. The problems for filtering out harmonic waves filled into the electric grid by the VSC and inhibiting the converter main loop resonance led in by the LCL filter are solved through setting the parameters of the LCL filter and a controller of the VSC. Compared with the simple experience algorithm and the complicated calculating method of the existing LCL filter, the method has the advantages that the parameter of the filter is designed according to the operation characteristics of the VSC and the frequency-domain characteristics of the LCL filter, simplicity is realized, the implementation is easy, the engineering construction can be realized, the theoretical basis is full, the harmonic pollution to the electric grid is low, and the grid-connected electric energy quality requirement of the national standard on the VSC can be met.

The present invention discloses a voltage detection device that suppresses the resonance phenomenon in a closed circuit including the capacitance between an intermediate electrode and a grounded metal container, and a capacitor for voltage detection, and prevents overshoots from occurring in each part of the closed circuit. Voltage. Its structure is made: a first capacitor composed of a grounded metal container (1) separated from the bus bar (2) by a predetermined distance and coaxially formed into a cylindrical intermediate electrode (3) and the grounded metal container (1); A voltage sensor (12) is applied to a voltage sensor (12) to detect the voltage of the bus (2) by applying the divided voltage between the second capacitor (10) for voltage detection. And the resistance (21) is arranged in the closed circuit (1) including the capacitance between the intermediate electrode (3) and the grounded metal container (1) and the second capacitor, and suppresses the resonance phenomenon in the closed circuit (1).

The invention belongs to the field of fluid machines and relates to an axial flow type fluid driving device. The axial flow type fluid driving device comprises a hub, fan blades and a fairing which rotate together, wherein the fan blades are of radial fan blade structures and are arranged between the hub and the fairing. The axial flow type fluid driving device is characterized in that suspension blades are arranged on the axial flow type fluid driving device; the inner end of the suspension blades are of a cantilever structure; and the outer end of the suspension blades are in fastening connection with the fairing or are integrally formed with the fairing. Due to the adoption of the suspension blade structure, at least part of fan blades and the hub are not connected to yield part of axial inlet channel area, further the passing flow of a working medium can be increased and the conveying efficiency of the device is increased. The weight and the rotary inertia are reduced, so that the possibility of fatigue damage of a driving shaft of the device is reduced; the lengths of the blades are inconsistent, so that the action rules of the blades for the working medium or the action rules of the working medium for the blades are inconsistent, the noises can be reduced by suppressing the resonance phenomenon and the work reliability of the device is improved.

A regulator circuit includes an operational amplifier, a buffer, a power transistor, a first feedback circuit, a current sensor, and second feedback circuit. The operational amplifier drives a first node with a first voltage generated by amplifying a difference between an input voltage and a feedback voltage. The buffer drives a second node with a second voltage generated by buffering the first voltage. The power transistor has a drain receiving a supply voltage, a gate connected to the second node, and a source connected to a third node. The current sensor generates a first sensing current based on the second voltage. The second feedback circuit generates a plurality of feedback currents corresponding to a ripple of the output voltage and enhances a speed at which the ripple is reduced by providing at least one of the plurality of feedback currents to the third node.

The invention discloses a resonance suppressing device for a multi-inverter grid-connected system. The resonance suppressing device for the multi-inverter grid-connected system comprises a resonance information extraction device and a centralized passive resonance suppressing device, wherein the input end of the resonance information extraction device is connected with a common point of the multi-inverter grid-connected system, the output end of the resonance information extraction device is connected with the input end of the centralized passive resonance suppressing device, and the output end of the centralized passive resonance suppressing device is connected with the common point of the multi-inverter grid-connected system. According to the resonance suppressing device for the multi-inverter grid-connected system, the damping of the multi-inverter grid-connected system is improved through the centralized passive resonance suppressing device, the purpose that the system resonance phenomenon generated in the process of grid connection of a plurality of inverters is effectively suppressed is achieved, the system stability margin is improved, and therefore the situation that the multi-inverter grid-connected system works safely and stably is guaranteed.

The invention provides a resonance suppression method of a permanent magnet synchronous motor air-conditioner driving system without an electrolytic capacitor and relates to a resonance suppression method of a permanent magnet synchronous motor driving system. The invention is to solve the problem of resonance in the system after the electrolytic capacitor in an existing air-conditioner driving system is replaced by a thin-film capacitor. The method comprises the following steps: 1) calculating total input impedance of the permanent magnet synchronous motor driving system and conditions required for stability of the motor driving system; 2) processing bus voltage signals, extracting bus voltage fluctuation components, and multiplying the extracted bus voltage fluctuation components by a coefficient to obtain a system damping regulation signal; 3) selecting values of regulation parameters according to the calculated minimum input impedance meeting stability of the motor driving system; and 4) carrying out inverse park transformation on the damping regulating signals to enable dq axis damping regulating signals to be converted into alpha beta axis signals and superimposed on the alpha axis voltage and beta axis voltage portions. The method is used for the technical field of motor control.

The invention relates to a voltage feed-forward control method suitable for parallel connection of a plurality of stationary synchronous compensators. The method includes the following steps of (1) determination of number of the stationary synchronous compensators: the number N of the stationary synchronous compensators in operation is determined by detecting the reactive component Iq of a system; (2) net-side impedance detection: the net-side impedance Zg is detected by means of an active injection harmonic method; and (3) feed-forward signal generation: the final feed-forward voltage Uff of the stationary synchronous compensators is obtained based on the net-side impedance Zg detected in the step (2), compensation point voltage Upcc, and current Ipcc. Compared with the prior art, the voltage feed-forward control method has the advantages of wide application, good robustness, and low loss.

The invention relates to a short pitch mixing tank radial type leaky coaxial cable which is mutually crisscross and has non-uniform spacing. The structure of the cable is formed by enveloping and sheathing an inner conductor of the leaky coaxial cable, an insulated foam material layer, an outer conductor of the leaky coaxial cable and an insulated outer sheath from inside to outside in sequence; the leaky coaxial cable is characterized in that periodical radiation notches are manufactured on the outer conductor of the leaky coaxial cable, the notch has a 'U' shape and an 'L' shape, and every repeated cycle includes two groups; six radiation notches are available, the shapes of the two 'U' shaped radiation notches in each group are the same as each other, but reverse alternately, and the shapes of the 'L' shaped radiation notches between the groups are the same as each other, but reverse alternately; central axes of the radiation notches in each group are mutually staggered at a certain distance. In the same group, the center to center spacing of the 'U' shaped radiation notches in same group is that A is equal to 40mm; the center to center spacing of the 'L' shaped radiation notches between different group is that B is equal to 120mm; the staggered distance among the central axes is that C is equal to 3mm.

The invention discloses a multi-inverter system resonance restraining device and a controlling method thereof. The multi-inverter system resonance restraining device is connected to a point of common coupling (PCC) of a multi-inverter system. According to the multi-inverter system resonance restraining device, only PCC voltage needs to be sampled, PCC current signals do not need to be sampled, and software and hardware configuration of each inverter in a multi-inverter system does not need to be modified; and the controlling method of the multi-inverter system resonance restraining device has the basic principle that the multi-inverter system resonance restraining device is virtualized into one resistor working at all resonance frequency bands to restrain the resonance phenomenon of the multi-inverter system, and the method is simple, effective and feasible.

The invention relates to a method for restraining 4-order Boost converter resonance. A compound-control closed loop topological structure is adopted; on a basis of conventional dual-closed-loop feedback control, current in a front-stage LC filter circuit is subjected to high-pass filtering, and acts on a system control terminal at certain proportional gain; a feedforward compensation technology for the 4-order Boost converter based on high frequency current at the resonant frequency of an input filter is designed; according to the compensation technology based on the high frequency current signals at the resonant frequency of the input filter provided by the invention, the stable output power range is expanded, and the system stability is reinforced under the premise of not changing the original system structure; the resonance phenomenon of the system can be effectively restrained and the circuit can be protected; and in addition, the compensation technology based on the high frequency current signals at the resonant frequency of the input filter provided by the invention can be widely applied to the fields of independent power supplies and transportation, such as pure electric vehicles, ships, submarines and the like, and is expected to be widely applied to the future electric power systems.

A disk drive device that can prevent warping deformation in upward and downward directions of a disk tray and can prevent vibration in a warping deformation mode without producing a rattle vibration is provided. A disk drive device has a casing and a disk tray on which the spindle motor and the pickup are mounted; and a pair of parallel first and second guide mechanisms that slidably supports the disk tray so as to eject the disk tray from the casing to the outside. In the disk drive device, in a center part in a width direction along the disk mount surface of an introduction side distal end part of the disk tray, an introduction side abutment part having a groove section or a protruding portion is formed, and an inner part abutment part formed on an elastic member is installed on an inner side inner wall part.

The invention discloses a suspending swing arm assembly, and belongs to the technical field of auto spare parts. The suspending swing arm assembly comprises a ball pin, internal and external ball seats and a housing which are sequentially arranged in match from inside to outside; a dustproof cover is arranged between the external wall of the ball pin and the housing, and the external wall of the ball pin is extended out of the housing; the internal ball seat is made of resin; the ball pin, the external ball seat and the housing are all manufactured by forging aluminum-silicon-magnesium alloy; and concave grooves are formed in the internal wall of the internal ball seat. The suspending swing arm assembly has the advantages of capability of automatically compensating the abrasion loss, high strength of extension and capability of achieving self-lubricating effect; and with the adoption of the suspending swing arm assembly, relatively high safety and relatively high riding comfort can be kept when a vehicle runs in various road conditions.

In a laminated piezoelectric element, a plurality of piezoelectric layers and a plurality of metal layers are alternately laminated. The metal layers include a plurality of high resistance metal layers having an electrical resistance higher than electrical resistances of the adjacent metal layers on the both sides. The high resistance metal layers are regularly arranged by sandwiching a plurality of metal layers other than the high resistance metal layers. In another laminated piezoelectric element, a plurality of piezoelectric layers and a plurality of metal layers are alternately laminated, and at least one layer of the metal layers is composed of a plurality of partial metal layers arranged between the piezoelectric layers.

Integral track bed track structure for medium and low speed maglev transportation to accurately realize height adjustment, distance adjustment and longitudinal telescopic adjustment at each fastener node. It includes: support adjustment units arranged at intervals along the extension direction of the track beam, each support adjustment unit includes a left reinforced concrete connector, a right reinforced concrete connector, and a steel truss and a long steel bar connecting them as a whole; the integral track The bed slab is integrated with the track beam through the connecting structure; the angle steel member and the supporting steel plate are detachably installed on the outer side of the left reinforced concrete connector and the right reinforced concrete connector through the high-strength bolts fixed at both ends of the full-length steel bar , the F-shaped rail is fixedly installed on the top plate of the angle steel member through a fastener system; the side plate of the angle steel member is provided with a side plate oblong hole corresponding to the position of the full-length steel bar, and the side plate oblong hole extends vertically. The top plate of the angle steel member The top plate is separated with long round holes, and the top plate long holes extend along the line direction.

The invention discloses a resonance control system of an inverter grid-connected system. The voltages uapcc, ubpcc and ucpcc of a common connection point (PCC) of a multi-inverter grid-connected system are sampled, and a resonance information extraction unit is used for obtaining the sampled voltage resonance frequency omega<r> at the PCC point, so a centralized passive resonance suppression device composed of a high-pass filter is reasonably configured at a PCC point of a multi-inverter grid-connected system according to the obtained voltage resonance frequency information, thereby increasingthe damping of the multi-inverter grid-connected system at the resonant frequency, and improving the operation stability margin of the system; meanwhile, the centralized passive resonance suppressiondevice only needs to be operated at the PCC, the hardware and software of all grid-connected inverters do not need to be changed, and the system is high in reliability, easy to configure, suitable for on-site large-scale application and the like.

The invention provides a resonance-restrained washing machine, which comprises a shell. The middle part and the bottom part of the shell are respectively provided with a barrel and a drive motor, wherein the barrel is provided with dewatering holes; a thumb wheel at the bottom part of the barrel is driven by the drive motor or the barrel is directly driven by the drive motor; the barrel is enclosed in a water cavity; a thin-walled cylindrical cavity is formed between the inner wall of the water cavity and the outer wall of the barrel; a drain pipe extends upwards at the bottom part of the thin-walled cylindrical cavity; and the drain pipe extends straightly to the lower end of the exterior of the shell after passing through the middle-upper part of the water cavity. Resonance can be restrained during the dewatering process of the washing machine, and therefore, the washing machine is more stable and quiet when in use.

A disk drive device that can prevent warping deformation in upward and downward directions of a disk tray and can prevent vibration in a warping deformation mode without producing a rattle vibration is provided. A disk drive device has a casing and a disk tray on which the spindle motor and the pickup are mounted; and a pair of parallel first and second guide mechanisms that slidably supports the disk tray so as to eject the disk tray from the casing to the outside. In the disk drive device, in a center part in a width direction along the disk mount surface of an introduction side distal end part of the disk tray, an introduction side abutment part having a groove section or a protruding portion is formed, and an inner part abutment part formed on an elastic member is installed on an inner side inner wall part.

Disclosed is a filter capable of inhibiting resonance. The filter comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a switch and a controller. The first end of the first inductor is connected with the voltage output end of a power source, the first end of the first inductor is also grounded through the first capacitor, the first end of the first inductor is also connected with the first end of the second inductor through the first end and the second of the switch, the second end of the second inductor is connected with the second end of the first capacitor, the second end of the first inductor is connected with the control end of the switch through the controller, the second end of the first inductor is also grounded through the second capacitor, and the second end of the first inductor is also connected with a load. The filter provided by the invention changes the resonant frequency point of the filter by use of the second inductor when the resonance is generated so as to inhibit the resonance.

The invention discloses an anaesthesia machine and an APL valve thereof. The anaesthesia machine comprises a breathing circuit, a fresh gas branch, a manual driving gas branch, a discharge branch and the APL valve, and the APL valve is installed on the manual driving gas branch to limit the gas pressure in the manual driving gas branch. The APL valve comprises a valve seat assembly, a pressure adjusting assembly, a valve plate assembly and an elastic piece; the valve seat assembly is provided with an gas inlet and an gas outlet, the gas inlet is communicated with the manual driving gas branch, the gas outlet is communicated with the discharging branch, and the pressure adjusting assembly is movably installed on the valve seat assembly. The valve plate assembly is in sliding connection with the pressure adjusting assembly, an gas cavity is defined by the valve plate assembly and the pressure adjusting assembly, the valve plate assembly is used for controlling connection and disconnection between the gas inlet and the gas outlet, the elastic piece is arranged in the gas cavity, the first end of the elastic piece abuts against the pressure adjusting assembly, the second end of the elastic piece abuts against the valve plate assembly, and the APL valve is further provided with a damping hole communicating the gas cavity with the outside. The damping hole is used for discharging and sucking gas in the gas cavity so as to restrain resonance of the valve plate assembly.

The invention relates to the technical field of sound box parts, in particular to an anti-distortion high-tone-quality sound box diaphragm. The diaphragm comprises a diaphragm body, a composition mechanism is arranged in the diaphragm body, a suppression mechanism and an expansion mechanism are arranged on the diaphragm body, and an abutting mechanism is connected between the expansion mechanism and the suppression mechanism; through the arrangement of the composition mechanism, various materials can be combined together to be pressed into the vibrating diaphragm, the bucket effect is avoided by utilizing the complementary advantages of the various materials, and the sounding effect of the loudspeaker box under high and low frequencies is improved; the damping effect can be provided for the vibrating diaphragm through the suppression mechanism, the resonance of the vibrating diaphragm is suppressed, and the tone quality is improved, and the expansion mechanism drives the suppression mechanism through the abutting mechanism, so that the damping strength of the suppression mechanism can be adjusted, the vibrating diaphragm can be adjusted more conveniently, and the vibrating diaphragm is more excellent in the use process.

The invention relates to a voltage feed-forward control method suitable for parallel connection of a plurality of stationary synchronous compensators. The method includes the following steps of (1) determination of number of the stationary synchronous compensators: the number N of the stationary synchronous compensators in operation is determined by detecting the reactive component Iq of a system; (2) net-side impedance detection: the net-side impedance Zg is detected by means of an active injection harmonic method; and (3) feed-forward signal generation: the final feed-forward voltage Uff of the stationary synchronous compensators is obtained based on the net-side impedance Zg detected in the step (2), compensation point voltage Upcc, and current Ipcc. Compared with the prior art, the voltage feed-forward control method has the advantages of wide application, good robustness, and low loss.

The present invention provides a motor driving system capable of suppressing vibration of a resonance phenomenon independent of special control. The resonance phenomenon is characterized in that: shaft twisting vibration occurs on a generator shaft, the vibration becomes generator terminal voltage variation to be transmitted towards an inverter for driving the motor, so that the generator terminal voltage varies and the motor shaft vibrates, and the vibration further enables the generator shaft to vibrate. The motor driving system has a prime motor, a generator for generating electricity through driving of the prime motor, a converter for converting the electric power generated by the generator into the electric power with an expected frequency, a motor driven through the electric power supplied from the converter, and a driven device driven by the motor; wherein, a shaft resonant frequency of the generator shaft for transmitting a driving force of the prime motor towards the generator is different from a shaft resonant frequency of the motor shaft for transmitting a driving force of the motor towards the driven device.

The invention discloses a resonance suppression device used for a banknote code printing machine. The device comprises a wall plate and side wall plates parallel to the wall plate; a first roller shaft head and a second roller shaft head which are parallel are arranged between the wall plate and the side wall plates, the first roller shaft head is sleeved with a pressing roller, the second rollershaft head is sleeved with multiple lower number rollers, each lower number roller is provided with a fluorescent printing plate clamping ring, the two ends of the second roller shaft head are each sleeved with a vibration-prevention clamping ring, the fluorescent printing plate clamping rings are located between the two vibration-prevention clamping rings, the radius of the vibration-prevention clamping rings is equal to that of the fluorescent printing plate clamping rings, and the face, making contact with the pressing roller, of the vibration-prevention clamping rings is of an arc structure. The problems of fluorescent blackening and breezing during fluorescent printing can be solved, production efficiency is improved, and cost is reduced; and the invention further discloses the banknote code printing machine adopting the resonance suppression device.