66results about How to "Good current limiting effect" patented technology

Disclosed a short-circuit accidence amperite relates to the accidence amperite of power transmission and distribution network. The invention is characterized in that: it serially connects a current limited resistance an a parallel connection circuit with solid switch on the current limited inductance (common inductance or superconducting inductance) of present bridge short-circuit accidence amperite, and parallel connects a diode (reverse parallel connection) and a afterflow circuit serially connected to the resistance with the current limited inductance, to form said short-circuit accidence amperite. The added afterflow circuit can reduce the A. C. power loss and the back-pressure of current limited inductance. And it utilizes the hysteresis comparison control strategy to realize the switch of current limited resistance. In addition, the provided two connection in series-parallel structure of switch tubes and limited current resistance can meet the demand of high voltage of power network. The invention can limit the peak and the steady-state value of accident current. And said amperite has higher current limited ability, lower effect on the circuit, while it can improve the power quality of power network, and the stability, the safety and the reliability of high voltage or super-high transmission power network.

The invention discloses a contact system of a low-voltage switch device, such as, a circuit breaker, the contact system utilizes the principle of combining the electromagnetic repulsive force and the gas pressure, a structure with a moving contact and a static contact which can simultaneously swing and be repulsed and an automatic magnetic blow-out system, thus being able to accelerate the breaking speed between the moving contact and the static contact, widen the repulsion distance between the moving contact and the static contact, accelerate the arc extinguishment and further enhance the performance indicators for rapid flow limit and arc extinguishment. The contact system of the invention has compact structure, small volume and low production cost.

The invention discloses a combined current-limiting direct-current circuit breaker for a direct-current power grid. The combined current-limiting direct-current circuit breaker comprises a current-carrying transfer branch and a current-limiting blocking branch; the current-carrying transfer branch is formed by connecting an ultra-fast mechanical switch and a load converter switch in series, one end of the current-carrying transfer branch is connected with a direct-current bus of a direct-current power grid, and the other end of the current-carrying transfer branch is connected to the direct-current power transmission line of the direct-current power grid in series; the current-limiting blocking branch comprises a current-limiting branch, a main circuit breaker branch and an energy absorption branch, one end of the main circuit breaker branch and one end of the energy absorption branch are connected in series with one end of the current-limiting branch after the main circuit breaker branch and the energy absorption branch are connected in parallel, and the other end of the current-limiting branch is connected to a potential point A1; and the other end of the main circuit breaker branch and the other end of the energy absorption branch are connected with a potential point A2 after the main circuit breaker branch and the energy absorption branch are connected in parallel. According to the invention, an expensive cutoff assembly can be separated from the circuit breaker for sharing, and the investment cost and the occupied area can be effectively reduced. A thyristor in the current-limiting blocking branch can share voltage to ground, and a charging resistor and a current-limiting inductor can effectively reduce the acceleration of a fault current and reduce the breaking current of the circuit breaker.

The invention supplies a DC superconduction fault current limiter, whose structure is: two superconduction coupling coil w1 and w2, has the same inductance wrapped on ring shaped core and one superconduction coil w1 is current limiting inductor whose two ends are connected to load loop, and another superconduction coil w2 as bias winding is connected to DC power source E2 and resistor R2 in series, w1 and w2 cooled by cooling device current limiting effect. The invention has advantages is: notable current limiting effect and low loss; short response time and high reliability, when the system operates normally, superconduction coil has very small stored energy and won't create overvoltage after accident protection; detecting, triggering and current limiting are integrated without need of adding control circuit, simple structure and small volume. The invention can satisfy DC fault protective device of individual system such as ship, plane, oil platform, mobile communication station and electric automobile.

The invention discloses a short trouble current limiter which is composed of a rectifier bridge, a first protective resistor (Rv), a high-temperature superconducting coil (SL), a switching tube (K), a direct current reactor (Lb), a second protective resistor (Ra) and a protected diode (Da), wherein the rectifier bridge is composed of a first diode (D1), a second diode (D2), a third diode (D3) and a fourth diode (D4); a protective resistor (Rs), the switching tube (K) and the high-temperature superconducting coil (SL) are connected in parallel, and the parallel branch is connected between the first direct current end M and the third direct current end P of the rectifier bridge; the second protective resistor (Ra) and the serial branch of the protected diode (Da) are connected with the direct current reactor (Lb) in parallel, and the parallel branch is connected between the second direct current end N and the third direct current end P of the rectifier bridge. The current limiter is connected with the direct current reactor and the high-temperature superconducting coil on the direct current end of the diode rectifier bridge to realize mutual current limiting.

The invention discloses a throttling component used for a once-through steam generator. The whole throttling component is composed of two parts. The first part is a fixed damping type throttling component which is used for preventing the occurrence of steam-liquid unstable flowing of flowing media inside a heat exchange tube, and a single-stage or multi-stage throttling orifice is arranged according to the relation between the inner diameter of the heat exchange tube and the whole throttling pressure drop. The second part is an extra throttling piece which is mainly used for flow adjusting when the heat exchange tube is blocked, and the extra throttling piece can be removed or the throttling damping is adjustable. The throttling component used for the once-through steam generator is simple in structure and can be installed at the tube end of the heat exchange tube of the steam generator conveniently. When the heat exchange tube breaks, the throttling component can throttle well to prevent the accident from expanding. When the heat exchange tube is blocked, the flow adjustment of the media in the heat exchange tube can be realized conveniently, the installation and test of the throttling component of the steam generator can be greatly simplified, and safety guarantee can be provided for the accident that the heat exchange tube breaks.

The invention discloses an impedance composite superconducting fault current limiter based on a novel superconducting material. The superconducting fault current limiter comprises a square iron core (18), wherein an MgB2 superconducting winding (11) is arranged on the upper side of the iron core (18) and connected with a reactor (10) in parallel; a high temperature superconducting winding (17) isarranged on the lower side of the iron core (18) and connected with a direct current voltage source (13) in series; and a magnetic switch (16) and a value adjustable first resister (12) are connectedin series between the high temperature superconducting winding (17) and the direct current voltage source (13) to form a first circuit. Under the condition of satisfying the line current-carrying capacity, the superconducting fault current limiter uses the fewest superconductors, can improve the inductive impedance level in case of fault, and also can reduce voltage loss in normal operation and ensure the reliability of operation.

The invention relates to the technical field of flexible DC networks, in particular to a collaborative optimization configuration method for current limiting reactors and fault current limiters in a flexible DC network. A multi-objective optimization configuration mathematical model is established by comprehensively considering the performance of a system and the cost of current limiting equipmentand taking the current limiting effect, the total inductance value of the current limiting reactors and the quantity of the fault current limiters as objective functions and breaking current of DC circuit breakers, overcurrent protection of converter valves and the current limiting reactors as constraint conditions; the multi-objective optimization configuration mathematical model is solved by adopting a multi-objective shuffled frog-leaping algorithm to obtain an optimal solution set; and a proper configuration scheme is selected from the optimal solution set by combining the actual situation. According to the method, optimization configuration is carried out on the current limiting reactors and the fault current limiters in the flexible DC network, so that the global optimization objectives of the best current limiting effect, the minimum total inductance value of the current limiting reactors and the minimum installation number of the fault current limiters are achieved and continuous and stable operation of a health part of the flexible DC network in a fault can be ensured.

The invention provides a resistance-inductance hybrid fault current limiter and a control method thereof. The hybrid current limiter comprises an on-state low loss branch, a current transfer branch and a current limiting branch, adopts semi-controlled devices and is simple in logic, economic and reliable. According to the current limiter, a current limiting reactor and a current limiting resistorare inputted by utilizing the coordination of thyristors and a commutation capacitor, the steady-state loss is low, a bidirectional current limiting ability is possessed, and short-circuit current ofa DC power grid can be effective suppressed; meanwhile, the locking time of sub-module IGBTs is greatly delayed, and enough time is obtained for the operation of the remaining protective devices; andthe dissipated energy of a lightning arrester can be reduced, so that the hybrid current limiter has the advantages of economy and reliability. The control method provided by the invention of the resistance-inductance hybrid fault current limiter provided realizes control for the resistance-inductance hybrid fault current limiter when a DC line where the current limiter is located operates normally or before a fault of the DC line where the current limiter is located is detected and after the fault of the DC line where the resistance-inductance hybrid fault current limiter is located is detected.

The invention provides a non-erosive flow-limiting valve used for sealing surface of a glue gun. The non-erosive flow-limiting valve comprises a valve seat and a valve element arranged in the valve seat and capable of moving back and force along the axis direction of the valve seat. The outer diameter of the valve element is smaller than the inner diameter of the valve seat and matches with the inner side wall on the inner portion of the valve seat to form a flow limiting tunnel to buffer the glue liquid. The non-erosive flow-limiting valve used for sealing surface of glue gun can limit and buffer high pressure glue liquid on the middle portion of the inner side via the flow limiting tunnel, can effectively prevent high pressure glue liquid from eroding the sealing surface of the valve directly during dispensing process, has good flow limiting function, can effectively prolong service life of the valve, and is simple in structure and convenient to process.

The invention relates to a contact mechanism for a double-breakpoint circuit breaker. The contact mechanism comprises a revolution shaft, a movable contact which can be arranged in the revolution shaft in a rotatable way, two baffle rods, two compression bar pieces, and at least two springs, wherein the movable contact comprises two end arms which are rotational symmetric with each other; the two baffle rods are fixedly arranged on the two end arms of the movable contact respectively; the two compression bar pieces are arranged on the two end arms respectively and two ends of each compression bar piece extend to upper and lower sides of each end arm; a first end of each compression bar piece is provided with a shaft, two ends of each shaft are connected to the revolution shaft and the whole compression bar piece can rotate around the shaft, and the middle part of each compression bar piece is pressed against each baffle rod; and one end of each spring is hooked at the first end of one compression bar piece, and the other end of each spring is hooked at a second end of the other compression bar piece. The contact mechanism for the double-breakpoint circuit breaker can improve the positioning stability of the movable contact, has obvious separating and clamping effects and can guarantee a good current limit effect.

The invention discloses a zero-loss deep current-limiting protection device based on first-wave breaking technology, which includes a protection device body and high-speed switches distributed inside the protection device body; device, display and control, indicator light, button, analog plate, observation window and nameplate, and the inner side of the protection device body is provided with a through-bus bar, a supporting insulator, a quick switch, a first current transformer, a second current transformer and two contact boxes , wherein the through busbar is connected to one of the contact boxes through the supporting insulator, the other contact box is connected to the second current transformer through the first current transformer, and the two contact boxes are connected through a fast switch. The invention has fast action speed, strong breaking capacity, good current limiting effect of the current-limiting reactor, no energy loss, no voltage drop, and no leakage magnetic field, long service life, reliable performance, small action dispersion, and no switching on. rebound.

The invention discloses a saturated bridge type short circuit fault current limiter, which comprises a saturated reactor and a rectifier bridge. The connecting point of a first diode (D1) and a second diode (D2) of the rectifier bridge (Br) is a first alternating current end (A); the connecting point of a third diode (D3) and a fourth diode (D4) of the rectifier bridge (Br) is a second alternating current end (B); the connecting point of the first diode (D1) and the third diode (D3) of the rectifier bridge (Br) is a first direct current end (M); the connecting point of the second diode (D2) and the fourth diode (D4) of the rectifier bridge (Br) is a second direct current end (N); the saturated reactor (L) is connected between the first direct current end (M) and the second direct current end (N); one end of an alternating current power supply (Uac) is connected to the first alternating current end (A); the other end of the alternating current power supply (Uac) is grounded; one end of a circuit breaker (SW) is connected to the second alternating current end (B); the other end of the circuit breaker (SW) is connected with a load (RL) in series and is then grounded. The saturated reactor is realized by a permanent magnet and a direct current coil.

The invention provides a resistance sensing type capacitor commutation hybrid current limiter and a control method thereof. The hybrid current limiter includes an on-state low-loss branch, a current-transfer branch and a current-limiting branch. The hybrid current limiter adopts a half-controlled device, is simple in logic, and is economical and reliable. The current limiter has low steady-state loss and has bidirectional current limiting capability, which can effectively suppress the short-circuit current of a DC grid and reduce the dissipated energy of a lighting arrester. The current limiter greatly delays the blocking time of a sub-module IGBT, and obtains sufficient time for the remaining protection devices. The use of half-controlled power electronic device can save the parallel number of power electronic devices and save costs, and ensure that a current limiting resistor and corresponding heat sinks are fully utilized to improve the current limiting effect. The control method ofthe resistance sensing type capacitor commutation hybrid current limiter provided by the invention realizes the control of the resistance sensing type capacitor commutation hybrid current limiter ina condition when a DC line where the current limiter is located operates normally or in a condition before or after the DC line where the resistance sensing type capacitor commutation hybrid current limiter is located is disconnected.

The invention relates to a hybrid short-circuit fault current limiter and a current limiting method. The hybrid short-circuit fault current limiter comprises a current transfer branch and a fault current limiting branch, wherein the current transfer branch comprises a rapid mechanical switch and a power electronic switch in series. In a steady state, a current passes through the current transfer branch, and the loss during normal running is reduced; when a fault occurs, a switch on the transfer branch acts, and the current is transferred to the fault current limiting branch; the fault currentlimiting branch comprises a dual-split reactor and a switch, and a first winding of the dual-split reactor is connected in series with the switch and is connected in parallel with a second winding; the switch is switched on in the steady state, and the fault current limiting branch shows low impedance; and the switch is switched off when the fault occurs, and the fault current limiting branch shows high impedance. By matching of the current transfer branch and the fault current limiting branch, the loss of the current limiter during normal running is reduced, meanwhile, fault current limitingis achieved by the dual-split reactor, and running economy and reliability of the current limiter are improved.

The invention discloses an energy quick transfer-based hybrid direct current super-conductive current limiter, and belongs to the technical field of electrical engineering. The energy quick transfer-based hybrid direct current super-conductive current limiter comprises two inductive coils, a direct current quick switch, a bypass resistor, a fixed value resistor, and metal oxide lightning arresters, wherein the two inductive coils are connected in parallel; the two inductive coils are wound by super-conductive wires with the same number of turns and consistent structures, and the magnetic fluxes of the coils are coupled forwardly; the direct current quick switch is connected with the super-conductive inductive coils in series as a whole to form a series branch; the bypass resistor is connected with the two ends of the series branch in parallel; the fixed value resistor is connected with the two ends of the quick switch in parallel; and the two metal oxide lightning arresters are connected at the two ends of the two inductive coils in parallel respectively. The current limiter disclosed by the invention can provide a super-conductive-state and resistance-loss-free smoothening electric reactance for a power transmission line at a normal state of a direct current system, can rapidly and effectively suppress peak of a short circuit current when the direct current system suffers from a monopole grounding fault or a two-stage short-circuit fault, and also can protect safe and stable operation of the super-conductive inductive coils.

The invention provides a fast and reliable current limiting device for faults of a traction power supply system. The device is composed of a main switch and a standby switch, and includes a main control unit, an electromagnetic ultra-high speed switch, current limiting reactors, an insulation cabinet, a current transformer, a switch control unit, a lightning protection unit, an inlet and outlet wire terminal, a standby solid-state switch and the like, wherein the main control unit controls the operation of an anti-parallel thyristor of the electromagnetic ultra-high speed mechanical switch andthe standby switch; when the circuit is normal in operation, both the electromagnetic ultra-high speed mechanical switch and the solid-state switch are in an off state, a current limiting inductor and a capacitor constitute series resonance, and the current limiting device shows zero impedance to the outside; and when the circuit has an overcurrent or short circuit fault, the switch control unitautomatically detects that the current flowing through the circuit exceeds the set threshold, the electromagnetic ultra-high speed mechanical switch is quickly closed when the short-circuit current passes the zero point at the first big half wave, the inductor and the capacitor constitute parallel resonance at the main switch, and the current limiting device shows high impedance so as to suppressthe short-circuit current.

A short trouble current limiter in particular relates to transmission and distribution network failure current limiter. It features on available bridge circuit type short trouble current limiter basic, rectifying bridge arm consisting of controllable solid-state switch tube series connected with current limiting resistance shunt circuit and then series connected with diode. The present invention realizes inductor and resistor combined current limiting, not only limiting failure current peak value but also steady state value.

The invention relates to one breaker to cut fault current circuit and to one remove device of one flow limit protection, wherein, the breaker limit flow rapid remove device comprises the following parts: rotation axis fixed on conductive system unit case; one cover remove structure composed of conductive system unit case top remove part and lock part; one slide block set in the conductive system unit case slide tank for upper and down.

The invention discloses a coaxial reversing box. The coaxial reversing box comprises a box body. Rotating cavities are correspondingly formed in the front face and the left and right side walls of thebox body. A rotating shaft is rotationally connected in each rotating cavity. Lubricating devices are correspondingly arranged on the front face and the left and right side walls of the box body. According to the coaxial reversing box, when the box body is connected with a power source to drive the rotating shafts to rotate, valves are turned on to enable lubricating oil in oil tanks to flow intohoppers through oil inlet pipes, and slight vibration occurs to the box body in the rotating process of the rotating shafts, so that the lubricating oil is accelerated to soak into oil absorption sponge faster, and the lubricating oil slowly flows into pulleys along the side walls of guide rods through the oil absorption sponge; and when the rotating shafts drive the pulleys to rotate together, the surfaces of the rotating shafts are uniformly coated with the lubricating oil, so that the surfaces of the rotating shafts are wetter and smoother, the friction force between the rotating shafts and the inner walls of the rotating cavities is reduced, the rotating shafts can rotate more smoothly, and the working efficiency is improved.

The invention discloses a resistance-inductance type DC current limiting apparatus and method based on magnetic coupling enhancement characteristics. The current limiting apparatus comprises a switching device S, a resistive element, and a pair of full-coupling inductance coils L1 and L2 wound on the same iron core and having equal self-inductance. When the double-pole double-throw switch S is closed at an end b and an end d, the apparatus is in an inductance current-limiting normal operation state. When the switch S is switched to an end a and an end c, the apparatus is in an inductance current-limiting short-circuit fault state. The resistive element is arranged on an end-a inductance coil side of the switch S and is used for realizing resistance-inductance common DC current limiting. Compared with the prior art, the apparatus and the method have the characteristics of good current limiting effect, capability of simultaneously inputting inductance and resistance for current limiting,and high recovery speed after a fault.

The invention relates to a sealing decompression ring arranged in a high and low teeth labyrinth for compressor fillers, in specific to filler sealings between compression chambers and piston rods of compressor air cylinders. The invention belongs to the field of sealing technologies and mainly adopts a plurality of high teeth on the interior loop of decompression rings, so as to form a main sealing chamber between every two adjacent high teeth. Each high tooth is composed of two low teeth, and between the two low teeth, a secondary sealing chamber is formed. The invention is characterized by simple, compact and reasonable structure; because of the labyrinth sealing structure with high and low teeth on the interior loop of the decompression rings, it is possible to lower impulse pressure of the air cylinder compression chambers to filler O-rings, and meanwhile, to reduce contact area between the decompression rings and the piston rods, and to decrease friction heat; Moreover, flow restriction effects are so considerable as to lower impulse pressure by 70 percent, prolong service life of filler O-rings, and lower the cost in compressor manufacturing, utilization and maintenance.

The invention provides a flow control valve with a three-way ball. The flow control valve comprises a valve body, wherein the top of the valve body is rotationally connected with a handle through a valve rod; a valve ball is arranged in the valve body; a valve seat and a flow limiting sheet are arranged on the two sides of the valve ball respectively, and are positioned between the outer wall of the valve ball and the inner wall of a main flow channel; the valve seat is annular; the area of an annular opening is larger than the sectional area of an auxiliary flow channel; a flow limiting opening is formed in the flow limiting sheet; the area of the flow limiting opening is smaller than the sectional area of the auxiliary flow channel; the valve ball is a hollow three-way ball body; three medium through holes are formed in the valve ball; two of the three medium through holes are circular, and the other one is a flow limiting hole; and the area of the flow limiting hole is smaller than that of the circular through hole. The flow control valve is reasonable in design; when the valve is completely opened, the flow of a circulating medium is accurately controlled through the flow limiting sheet and the valve ball; and by the structure, raw materials are saved, and the combination of the flow limiting opening and the flow limiting hole with complex shapes and structures can be realized, so that a better flow limiting effect is achieved.

The invention discloses a flow limiting method based on a long connection message channel, relates to the technical field of communication, solves the technical problem of service crash caused by access of a large number of clients in a short time. The flow limiting method comprises a step of carrying out flow limiting at a server according to the current connection number and a step of carrying out flow limiting at a client according to the connection failure number. The invention further discloses a flow limiting system based on the long connection message channel. According to the scheme of combining the server and the client, it is preferentially guaranteed that the server obtains a good current limiting effect, and meanwhile the instantaneous high-concurrency scene problem caused by the client is reduced.

The invention discloses a configuration method and device of a sliding window, computer equipment and a storage medium, and relates to the technical field of safety protection, and the method comprises the steps: employing a current-limiting burr factor to quantize the probability of current-limiting burrs of the sliding window, wherein the current-limiting burr factor represents the product of the request density of the sliding window and the burr coverage degree; quantifying the influence of a memory factor on the division number of a sliding window on memory occupation, with the memory factor representing the memory occupied by a target project determined based on the division number of the sliding window; determining intersection point information of the current-limiting burr factor and the memory factor; and taking the coordinate data representing the horizontal ordinate value of the intersection point in the intersection point information as the optimal segmentation number of thesliding window. The optimal segmentation number can be obtained, so that the probability of occurrence of current-limiting burrs is effectively reduced. The occupied memory is reduced, and the optimal current-limiting effect is achieved.

The invention discloses a control valve with a flow limiting function. The control valve comprises a bottom plate. A valve seat and first supporting columns are sequentially arranged on the top of the bottom plate from left to right. A water outlet pipe and a water inlet pipe are clamped and connected to the two side faces of the valve seat correspondingly. Third supporting columns are fixedly connected to the two sides of the top of the valve seat. A sealing ring is arranged on the top of the valve seat. The tops of the third supporting columns are fixedly connected with a baffle. According to the control valve with the flow limiting function, the vertical movement of an adjusting valve is achieved through cooperative usage of connecting rods, a sliding rod, a motor, a gear and a gear rail, and therefore the flow limiting effect is achieved. The effect of connecting rod limiting is achieved through cooperative usage of a connecting plate, a limiting groove and a sliding block, and deflection cannot happen when the connecting rods drive a connecting beam to move up and down. The control valve is ideal in flow limiting effect, and the work efficiency is improved.

The invention discloses an active resistance-capacitance type direct current limiter based on double-capacitor oscillation and a control method. The active resistance-capacitance type direct current limiter comprises a through-flow branch and a resistance-capacitance branch which are connected in parallel, the through-flow branch is composed of a mechanical switch, and the resistance-capacitance branch is composed of a high-voltage arm capacitor branch, a low-voltage arm capacitor branch and a semiconductor assembly which are connected in series. The high-voltage arm capacitor branch comprisesa high-voltage capacitor, a lightning arrester and a controllable discharge branch which are connected in parallel, the low-voltage arm capacitor branch comprises a low-voltage capacitor and a controllable charging power supply which are connected in parallel, and the semiconductor assembly is formed by antiparallel connection of a thyristor and a diode. The cathode of the low-voltage capacitor is electrically connected with the high-voltage capacitor, and the anode of the low-voltage capacitor is electrically connected with the anode of the semiconductor assembly. The beneficial effects of the present invention are that the current limiter is mainly composed of the mechanical switch, the high-voltage capacitor, the low-voltage capacitor, the thyristor, the diode and other conventional power devices, so that the manufacturing cost is low; and meanwhile due to the fact that the superconducting materials or power electronic devices are not applied, the daily operation and maintenance ofthe current limiter are simpler and more convenient.