40results about How to "With damping" patented technology

The invention relates to a high-energy consumption self-decoupling magnetorheological damper with damping force decoupling property and failure self-protection function. The damper not only has high energy consumption and output, but also can effectively prevent subsidence of magnetorheological fluid, therefore, the invention is suitable for civil engineering structures. The damper mainly comprises a master cylinder body (6), an auxiliary cylinder body (13), a main piston (8), two auxiliary pistons (23), a piston rod (25), and novel composite-structure energy accumulators (14 and 15). Permanent magnets (9) arranged in the main piston (8) and the two auxiliary pistons (23) can effectively prevent subsidence of magnetorheological fluid, and can still provide corresponding damping force under the condition of power supply failure to enhance the safety of the structure. Magnetic circuit guiding components improve the utilization factor of the magnetic field. A mechanical spring self-decoupling device is mainly operated on the condition that the damper is under low-frequency driving, thereby overcoming the disadvantage of low output of the damper under low-frequency driving.

The invention discloses a photovoltaic power generation system virtual synchronous machine control method, a control device, a converter and a system. The present invention connects the energy storage device and the energy storage converter on the DC side where the photovoltaic inverter is connected to the photovoltaic module; collects the voltage and current of the photovoltaic module and executes the maximum power point tracking algorithm to obtain the target value of the DC voltage, according to the The DC voltage target value controls the energy storage converter to operate in a constant output DC voltage mode; the DC power output by the photovoltaic module is multiplied by the conversion efficiency of the photovoltaic inverter, and the SOC of the superimposed energy storage device is optimized to adjust the power component as the photovoltaic inverter. The active power command is used to control the photovoltaic inverter to operate in a virtual synchronous machine mode according to the active power command. The invention only needs a small battery capacity to meet the application requirements, ensures the maximum power generation of the photovoltaic panel, optimizes the availability and life of the battery, and provides power support for the grid.

The invention provides a foundation structure of pile-raft composite seismic-isolation groove under strong earthquake, which comprises multiple pile foundations and multiple seismic-isolation bearings, and a plurality of matrix-arranged pile foundations are arranged in the foundation soil, and the pile top of each pile foundation is fixed The shock-isolation support is installed, and also includes the shock-isolation groove, the shock-isolation groove is installed on the vibration-isolation seat, the inner wall of the shock-isolation groove is laid with a hot-melt rubber layer, and the shock-isolation groove is laid sequentially from bottom to top. Rubber mats, pebble cushions, geogrids, rubber gravel mats, composite geomembranes, epoxy pours, asphalt sand mats and rafts. The invention can effectively attenuate or eliminate earthquake energy, avoid shaking and vibration of superstructures, and reduce disasters caused by earthquakes. The anti-seismic effect is outstanding, the construction is simple, the construction period is short, and the cost is reduced.

The invention discloses a material for a diaphragm of a loudspeaker and a preparation method thereof, belonging to the technical field of electroacoustic products. The material for the diaphragm is prepared by using electrospinning technique; fibroin and carbon nanotubes are blended to form the loudspeaker diaphragm with a micro-nano fibrous net structure; and in post-treatment, an ethanol solution is used for dipping and a polyurethane, polyacrylate or polyvinyl chloride coating is used for finishing, so the diaphragm has certain mechanical strength. According to the invention, supply of raw materials is sufficient; the preparation method is simple and has low energy consumption; the ultra-thin loudspeaker diaphragm is prepared while the strength of the diaphragm is guaranteed; the prepared diaphragm has high specific elasticity, good damping vibration attenuation performance and the characteristics of good sound effect and high fidelity; and the fibroin protein loudspeaker diaphragm has biodegradability, which is beneficial for environmental protection.

The invention relates to the technical field of medical devices, and specifically discloses a disposable safety blood collection needle, which at least includes a housing, a needle core, a needle cap, an inner sleeve, a driving spring and a retracting spring. The inner sleeve has a first position and the second position, the driving spring is located between the needle core and the housing and has a first pre-tightened state; the needle core is provided with a pair of opposite first steps facing the side of the needle cap, and the inner sleeve A pair of oppositely disposed first elastic arms are provided, and a second step for abutting against the first step is provided on the first elastic arms; a separation mechanism is provided in the housing. The driving spring of the present invention has multiple functions. In the process of compressing the inner sleeve, due to the need to overcome the elastic force of the driving spring and compress the driving spring, the force required to trigger the ejection of the needle core is greater, which can prevent unconsciousness due to small The excessive force causes the needle core to be falsely triggered; the structural design is ingenious, and the state of whether the needle core is ejected is accurately judged.

The invention discloses an inverter reactive power control method based on a virtual synchronization mechanism. At present, the inverter reactive power control method is not accurate in control. Whenthe grid voltage fluctuates slightly, the voltage cannot be controlled without any difference; when the grid voltage drops deeply, and the whole reactive power ability of the inverter cannot be played. The reactive power control method is divided into three phases: when it is monitored that the voltage of the grid-connected point is normal, a reactive power control module aims to control the output reactive power of the inverter; when the voltage drop of the grid-connected point is monitored, the reactive power control module superimposes the voltage of the grid-connected point to reduce the voltage drop; and when it is monitored that the voltage of the grid-connected point is further dropped, an LVRT control module controls the inverter to switch to a low voltage ride-through control modeto perform low voltage ride through. The invention can automatically and flexibly control the output reactive power of the inverter, improve the reactive power utilization rate of the inverter, stabilize the grid-connected point voltage, reduce the grid voltage drop degree, and does not affect the low voltage ride through capability of the inverter.

The invention discloses a method for preparing a corn-cob structure morph-genetic ceramic-based composite material, which comprises the following steps of: preparing a corn-cob structure template or a corn-cob structure / precursor composite template; raising the temperature of the corn-cob structure template or the corn-cob structure / precursor composite template to the temperature of between 500 and 2,000 DEG C at the temperature rise speed of 3 to 20 DEG C per minute in the protective atmosphere of vacuum or inert gases; maintaining the temperature for 1 to 10 hours, and cooling to obtain a morph-genetic carbon template or morph-genetic ceramic composite material; after impregnating in the precursor solution or precursor sol, raising the temperature to the temperature of between 1,300 and 2,000 DEG C at the temperature rise speed of 3 to 20 DEG C per minute in the protective atmosphere of vacuum or inert gases; maintaining the temperature for 1 to 10 hours, and performing vacuum carbothermal reduction to obtain the corn-cob structure morph-genetic ceramic-based composite material; or performing liquid-phase siliconizing or gas-phase siliconizing on the morph-genetic carbon template in the protective atmosphere of vacuum or inert gases to obtain the corn-cob structure morph-genetic ceramic-based composite material. The composite material prepared by the invention has the advantages of light weight, shock absorption, sound absorption, high temperature resistance, antioxidation, antifriction and abrasive resistance, load bearing, excellent sensing property, and wide application prospects.