77 results about "Crowbar" patented technology

The invention provides a dual-mode parallel competition-dominated self-synchronizing voltage source type photovoltaic power generation unit, and the power generation unit comprises a photovoltaic array which is composed of photovoltaic modules and is used for converting illumination into electric energy; the direct current / alternating current converter consists of a power electronic converter and is used for converting the direct current generated by the front-end photovoltaic array into alternating current; the self-synchronizing voltage source generation control module is composed of a dual-mode parallel competitive dominant control module, a modulation voltage control module and a synchronous phase angle control module and is used for autonomously establishing voltage, autonomously synchronizing a power grid and supporting transient frequency and voltage of the power grid; and according to DC bus voltage fluctuation characteristics and power flow characteristics, through state maintenance and competitive leading of two voltage source control modes, self-synchronizing voltage source characteristics of the photovoltaic power generation unit under multiple operation conditions such as illumination abrupt change and power grid faults are maintained, and DC bus voltage stabilization without a DC crowbar is realized. The invention is applicable to string type and centralized photovoltaic, including control, equipment and systems.

A cell (12) for a voltage source converter, comprising: a first cell connection terminal (CCI); a second cell connection terminal (CC2); a first series connection of two switches (T1, T2), a midpoint of the first series connection of the two switches forming the first cell connection terminal (CCI); an energy storage branch (ESB) comprising a capacitor (C C ); and a crowbar branch connected in parallel with the energy storage branch (ESB), the crowbar branch comprising a first switching element (SCB1) adapted to be activated to short-circuit the capacitor (Cc) of the energy storage branch (ESB) based on detection of a short circuit fault, and a resistive element (R D ) connected in series with the first switching element and arranged to improve damping in the crowbar branch.

The present application relates to the field of power system automation, and discloses a double-fed fan Crowbar circuit action identification method based on a difference hash algorithm, which filters out low-voltage ride-through test results of three-phase symmetrical and asymmetrical faults by reading double-fed fan hardware-in-the-loop simulation or on-site fault ride-through test results; respectively outputs the reactive power and reactive current of the test results as pictures, fits the reactive power and reactive current of the double-fed fan Crowbar circuit that does not act, and outputs as pictures; reduces the picture size, converts the pictures into grayscale pictures, obtains the fingerprints of the pictures by using the difference hash algorithm, calculates the Hamming distance of the reactive power and reactive current, and thus judges whether the double-fed fan Crowbar circuit acts; the method can identify whether the Crowbar circuit acts during low-voltage ride-through from the double-fed fan fault ride-through test results, and the result is not affected by the capacity of the double-fed fan, the low-voltage ride-through depth, the active power output of the fan and the like, and has the advantage of high accuracy.

Some embodiments include a nanosecond pulse generator circuit. In some embodiments, the nanosecond pulse generator circuit may include: a high-voltage power supply; a nanosecond pulse generator electrically coupled to the high-voltage power supply and switching a voltage from the high-voltage power supply at a high frequency; a transformer having a primary side and a secondary side, the nanosecond pulse generator electrically coupled to the primary side of the transformer; and an energy recovery circuit electrically coupled to the secondary side of the transformer. In some embodiments, the energy recovery circuit includes: an inductor electrically coupled to the high-voltage power supply; a crowbar diode arranged in parallel with the secondary side of the transformer; and a second diode disposed in series with the inductor and arranged to conduct current from a load to the high-voltage power supply.

The invention discloses an on-tower maintenance method for a lubricating oil pipe of a generator of a semi-direct-drive wind generating set, which comprises the following steps of: S1.1, disconnecting the threaded connection between an original connector of the lubricating oil pipe and a bearing seat; s1.2, the bearing unit is taken down, and an original connector is taken out; s1.3, a crowbar is used for adjusting the deformed, dislocated or disengaged lubricating oil pipe, so that the lubricating oil pipe is reset and fixed again; s1.4, an original oil inlet hole of the generator shell is tapped through through a screw tap, and a threaded hole is machined; s1.5, a first connector is screwed into the generator shell from the gearbox side, one end of the first connector is screwed into the threaded hole and abuts against a lubricating oil way of the bearing seat, and the other end of the first connector is connected with a 90-degree connector of a lubricating oil pipe; and S1.6, the bearing unit is reset, the bearing seat and the generator shell are connected through a connecting bolt, and maintenance of the lubricating oil pipe is completed. According to the invention, on-tower maintenance or replacement of the internal invisible lubricating oil pipe can be completed, the generator is prevented from getting off the frame, and the maintenance cost is reduced.

The utility model discloses an electrode boiler heating system relates to electrode boiler technical field, including crowbar piece one, the one side of crowbar piece one is provided with crowbar piece two and crowbar piece three, and crowbar piece two sets up on the upside of crowbar piece three, and the electrode type hot water boiler is contained in crowbar piece one, and the high pressure equipment is installed in crowbar piece two, and the low pressure equipment is contained in crowbar piece three. Through above-mentioned technical scheme, the electrode type hot water boiler is no longer the heating furnace of separate but a heating system, and the different crowding of setting can make the different equipment install in the different position and be convenient for management, and the electrode heating furnace main part is high -tension wire, and the high -voltage electric equipment is placed in the same place and will be more safe.

The invention relates to the technical field of power system modeling and simulation, in particular to an intelligent equivalent modeling method for a wind power plant, electronic equipment and a storage medium, and the method comprises the steps: obtaining the dynamic response data of a plurality of doubly-fed fans in the wind power plant in a typical fault scene of a power grid; performing first-layer grouping on the doubly-fed fans according to whether a crowbar circuit is put into the doubly-fed fans or not; respectively extracting low-voltage ride-through fault response characteristics of the first type of input units and the second type of non-input units to serve as second-layer grouping indexes; obtaining an initial mass center of an MI-GSA-K-means algorithm by using a gravitational search algorithm; iteratively calculating DBI indexes corresponding to different clustering numbers, and selecting the clustering number corresponding to the minimum value of the DBI indexes as the optimal clustering number; and aggregating the grouped doubly-fed fans in the same group into an equivalent unit, and determining a wind power plant dynamic equivalent model based on LVRT-GSA dual-stage clustering. According to the method, the consistency of the equivalent model and the system fault process is improved, and the model precision can be effectively improved.

The utility model relates to the field of electronic circuits, and discloses a protection device and a converter, and the device comprises a controller, and a crowbar loop and a discharge resistor loop which are respectively connected with the controller. The crowbar loop is arranged between two direct-current buses on the direct-current side of equipment to be protected and is connected with the first output end of the controller; the discharge resistor loop comprises a fling-cut switch and a discharge resistor, and the fling-cut switch and the discharge resistor are connected in series and then are arranged between two direct current buses on the direct current side of the to-be-protected equipment; when the crowbar loop breaks down and the to-be-protected device breaks down and shuts down, the switching switch is switched on, and the discharge resistor is switched into the two direct-current buses for discharging. The problem that a protection circuit of an existing device is low in discharging efficiency is solved.

The utility model discloses a wrench, include: the body, the one end of body is provided with the spigot, the other end of body is equipped with a link loop, this wrench will the link loop of wrench, the outer facade of filter core is covered, then the body is adjusted to the appropriate position, and the crowbar is worn into the spigot, through the crowbar, can complete the filter core replacement action, and the operation is simple and effective, can simply and effectively solve the problem mentioned in filter core background technology.

The utility model provides an electricity larceny prevention integrated electric energy meter housing, comprising an electric energy meter housing, a shielding cover plate rotatably connected on the side wall of the front surface of the electric energy meter housing, and an anti-prying structure arranged on the shielding cover plate. A locking rod is limited through a clamping limiting block, the locking rod limits an inserting block, the shielding cover plate is prevented from being opened, the shielding cover plate can be well fixed, a closed enclosure is formed by the shielding cover plate and the electric energy meter shell, and the electric energy meter is well protected inside; in addition, when the anti-prying block is subjected to the force of the crowbar, the anti-prying block retracts into the first sliding groove, so that the crowbar has no place to apply the force, force application is not easy when the crowbar pries, the shielding cover plate cannot be pried open, and the possibility of electricity stealing is avoided.

Provided is an auxiliary tool for dismounting a generator bar. At present, the stator bar of a large-scale generator set is mostly disassembled by finding a supporting point on site, prizing the upper end and the lower end of the bar by using a crowbar, and pulling out the bar. By adopting the mode, a proper crowbar supporting point is not easy to find, and other normal winding bars and stator iron cores are easy to damage in the crowbar using process. The ladder comprises two groups of supporting seats, the lower parts of the two groups of supporting seats are connected through a connecting rod, the upper parts of the two groups of supporting seats are connected through a ladder assembly, and a chain block is hung on the ladder assembly; the supporting base comprises two base plates, two supporting legs are welded to each base plate, and the tops of the two supporting legs are fixed to a connecting plate. The dismounting tool is used for dismounting the generator winding bar.

A method for operating a multi-stage bridge power converter in an electrical power system includes connecting multiple phases of the power converter to a common terminal on the DC side of the power converter to effectively make the multiple phases equal at a common potential. The method may further include fault monitoring of multiple devices of the power converter via a controller. Upon detecting a fault in one or more of the multiple devices, the method includes activating one or more protective devices of the power converter via the controller to prevent further faults in the remaining devices by diverting energy from the remaining devices.

To provide a nanosecond pulser circuit and a method for creating high voltage pulses, performing efficient energy recovery in a nanosecond pulser circuit that achieves fast rise times and / or fast fall times for high voltage pulses.SOLUTION: A nanosecond pulser circuit 100 includes: a high voltage power supply; a nanosecond pulser 105 that is electrically coupled with the high voltage power supply and that switches voltage from the high voltage power supply at high frequencies; a transformer T1 that has a primary side and a secondary side, the nanosecond pulser being electrically coupled with the primary side of the transformer; and an energy recovery circuit 110 that is electrically coupled with the secondary side of the transformer. In some embodiments, the energy recovery circuit includes: an inductor 115 that is electrically coupled with the nanosecond pulser; a crowbar diode 130 that is arranged in parallel with the secondary side of the transformer; and a second diode 120 that is arranged in series with the inductor and that is arranged to conduct current from a load to the nanosecond pulser.SELECTED DRAWING: Figure 1

The application discloses a kind of based on fan crowbar and the failure crossing method of HVDC system energy consumption device, in view of the higher cost of existing HVDC system energy consumption device design scheme, and only rely on fan crowbar circuit cannot guarantee offshore wind power-HVDC system reliable failure crossing problem, research the cooperative control strategy of HVDC system and wind turbine converter, utilize wind turbine unit's own crowbar circuit and the energy consumption device of HVDC system is completed together failure crossing operation, under the condition of guaranteeing system reliable failure crossing, reduce the capacity of HVDC system energy consumption device, effectively reduce engineering construction cost.

Submodule (10) for a converter system (100) comprising a first connecting terminal (11), a second connecting terminal (12), a switching circuit (20) with a first power semiconductor switch (21) and a second power semiconductor switch (22), which are connected in series and can be turned on and off. The first connecting terminal (11) is connected to the node between the first power semiconductor switch (21) and the second power semiconductor switch (22). The submodule (10) further comprises an energy storage circuit (30) connected in parallel with the switching circuit (20): The energy storage circuit (30) comprises a first capacitor (31) with a first capacitance (311), a split inductor (32), which is connected in series with the first capacitor (31) and adapted for limiting current amplitudes and a second capacitor (41) with a second capacitance (411) acting as part of a commutating system (40), wherein the second capacitor (41) is arranged in parallel to the switching circuit (20) and in parallel to the first capacitor (31) and the split inductor (32). The submodule (10) further comprising a first crowbar (50), which is connected in parallel with the first capacitor (31) and which is adapted to dissipate energy from the first capacitor (31), comprising a first bypass thyristor (51).

Crowbar circuit (1) for use in a voltage converter, comprising: - a triggering device (P1) designed to trigger or cause a short circuit across input terminals (E1, E2) depending on a control voltage; - a comparator (IC1) which is designed to control the triggering device (P1) to trigger the short circuit depending on a comparator voltage at a comparator input of the comparator (IC1) and depending on a predetermined reference voltage threshold value, - a Zener diode (NZ1) with a predetermined breakdown voltage in series with a fifth resistor (R5) connected between one of the input terminals and the comparator input, so that when the breakdown voltage is exceeded by the applied input voltage, the reference voltage threshold is exceeded or undershot by the comparator voltage and the short circuit is thereby triggered or caused; - a series circuit of a seventh resistor (R7), an eighth resistor (R8), the fifth resistor (R5) and a sixth resistor (R6), wherein a load current at an output of the crowbar circuit (1) flows through the seventh and the sixth resistor (R7, R6) and the comparator input is electrically connected to a node between the fifth and eighth resistors (R5, R8) and the series circuit is connected between the input terminals, so that when a predetermined threshold current is exceeded, the reference voltage threshold is exceeded or undershot by the comparator voltage and the short circuit is thereby triggered.

This utility model belongs to the field of wind power generation technology, specifically a multi-stage collaborative suppression device for high voltage ride-through (HVRT) transient overvoltage in direct-drive permanent magnet wind turbines. It includes a three-stage hardware topology in series: a first-stage crowbar circuit comprising an anti-parallel thyristor module connected in series with a current-limiting inductor, and paralleled between the positive and negative terminals of the DC bus; a second-stage energy-dissipating branch comprising IGBT switching devices driving a chromium-aluminum alloy resistor array mounted on an air-cooled heat dissipation substrate; a third-stage unloading circuit comprising a mechanical contactor controlling a water-cooled resistor box, with a built-in copper water channel within the resistor box, the resistor plates inside the resistor box being tightly fitted to the copper water channel, and heat dissipation through an external circulating water cooling system; and an FPGA controller that compares the DC bus voltage with the third-stage threshold in real time, generates a trigger signal, and adjusts the duty cycle of the second-stage PWM. This device solves the problem of DC bus overvoltage caused by grid faults.

The application discloses a self-recoverable three-terminal protector, which comprises a substrate, a first electrode, a second electrode, a third electrode, a first electric heating part, a second electric heating part, a turnover plate and a crossbar are arranged on the substrate; the turnover plate is in an overall arc structure, comprising an arch part and a supporting leg located at both ends of the arch part; the crossbar comprises a supporting point and a supporting arm located at both ends of the supporting point, a connecting contact for electric connection is arranged on each of the two supporting arms, the turnover plate comprises an active layer facing away from the crossbar and a passive layer facing the crossbar, and the turnover plate has a first state of arching towards the crossbar and a second state of arching away from the crossbar; the turnover plate further comprises a shunt layer between the active layer and the passive layer, and the conductivity of the shunt layer is much greater than that of the active layer and the passive layer. The three-terminal protector can be repeatedly used through the turnover movement of the turnover plate based on temperature; in addition, the response speed of the three-terminal protector is effectively improved through the high-conductivity shunt layer arranged in the middle of the turnover plate.

The invention discloses an offshore wind power flexible direct current power transmission cooperative fault ride-through strategy parameter design method, and aims to solve the problem that an existing fault ride-through method based on a fan crowbar and a flexible direct current system energy consumption device lacks a key parameter design basis. The voltage reference value design method is given according to the maximum active power of the sending-end MMC converter, the equivalent capacitance parameters of the collected submarine cables and the sending-end alternating-current voltage reduction target in the fault ride-through process, the system fault ride-through performance can be optimized under the condition that safe and reliable operation of the system is guaranteed, the capacity of an energy consumption device of the flexible direct current system is reduced, and the fault ride-through efficiency of the system is improved. And the engineering construction cost is effectively reduced.

1. Name of the design product: Multifunctional caliper wrench crowbar. 2. Use of the design product: For multifunctional wrenches. 3. Design key points of the design product: Lies in the shape. 4. Picture or photo that best shows the design key points: Front view.

1. The name of the design product: crowbar. 2. The use of the design product: for crowbar. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: perspective view. 5. The design points have been embodied in other views, omitting the right view.

This invention presents a crowbar reversal strategy based on rotor fault current and grid voltage. This method is an improved crowbar protection strategy, adding a series protection resistor between the original crowbar circuit and the rotor-side converter. It employs a fast switching criterion based on grid connection point voltage vector drop detection, which can simultaneously limit the current surge flowing through the RSC and the rotor windings. For different fault clearing times, a crowbar reversal strategy based on rotor fault current and grid voltage is designed, which can reduce the crowbar activation time to a certain extent, thereby reducing the absorbed reactive power, and also offers greater flexibility.

The invention discloses a variable-speed hydroelectric generating set low-voltage ride-through segmented control method, system, equipment and medium, and belongs to the technical field of new energy power generation grid connection, and the method comprises the steps: according to the detected voltage of a grid connection point, taking whether the output active power of a grid-side converter during low-voltage ride-through is kept unchanged and whether a crowbar circuit is put into a segment basis; dividing a fault voltage interval into three sections; determining a reactive current proportionality coefficient calculation expression of each voltage interval according to a low-voltage ride-through requirement, a working condition of a hydroelectric generating set before a fault and a current limiting value constraint condition of a converter; and determining a grid-side converter, unloading circuit and crowbar cooperative control method according to each voltage interval. According to the method, the supporting force of the variable-speed hydroelectric generating set on the power grid voltage when the fault is shallow can be increased, meanwhile, the output active power is considered to the maximum extent, the crowbar is put into a reasonable voltage interval, and stable operation of the power grid is guaranteed.

The invention discloses a method and system for adjusting a node impedance matrix of a high-proportion wind power system containing a current limiter, and the method comprises the steps: calculating equivalent impedance before and after a fault of a doubly-fed fan, and further modifying an expansion node impedance matrix of a system containing a generator; modifying a system node impedance matrix after the current limiter is input; and calculating the short-circuit current of each node of the system according to the modified system node impedance matrix. In the working process, impedance deviation caused by the fact that a crowbar resistor is started when the doubly-fed fan breaks down seriously is considered, and the impedance of the current limiter is equivalent to a parallel impedance branch, so that the calculation process of a system node impedance matrix is simplified; the calculation efficiency of the short-circuit current of the large-scale wind power plant is improved, and the precision is ensured to be within an acceptable range.

1. The name of this design product: Crowbar (Mining). 2. Purpose of this design product: used to pry objects. 3. The key point of the design of this product lies in its shape. 4. The picture or photo that best illustrates the design points: Stereoscopic drawing 1.

The invention discloses a staged grouping method and system for a whole wind power plant fault process and electronic equipment, and the method comprises the steps: carrying out the grouping equivalence of a whole wind power plant group based on a slip ratio and an rsc inner ring proportionality coefficient of a rotor-side converter in an unreacted stage of a converter; when at least one fan action enters a crowbar protection Crowbar input-asynchronous machine stage, performing initial classification on a whole fan group based on whether the fan action exists, and performing grouping equivalence based on a slip ratio and an inner ring proportionality coefficient of a rotor side converter on the basis of an initial classification result; and when the Crowbar exits and all the fans return to the rsc control stage, keeping the grouping result until the fault is removed. According to the method, the wind power plant short-circuit current dynamic characteristics in the whole fault process can be accurately described, accurate calculation of the wind power plant short-circuit current is achieved, and technical support is provided for high-proportion new energy power system short-circuit calculation and wind power plant equivalent grouping.

The application discloses a kind of network type fan through diode rectification DC sending system fault ride-through method, for the power surplus problem of network type fan through diode rectification sending system under the fault of receiving end ac power grid, a kind of fault ride-through method is proposed, receiving end MMC converter and the collaborative control strategy of wind turbine generator set are used, when the fault of receiving end ac power grid occurs, surplus power of DC power transmission system is transferred to fan DC bus, and surplus power is realized by fan crowbar circuit The accommodation, without additional measures such as energy consumption device of DC power transmission system, the fault ride-through of network type fan through diode rectification DC sending system can be realized, with significant economic benefits and good application prospect.

The utility model provides a mine forcible entry device which comprises a crowbar and a baffle, the front end and the rear end of the crowbar are respectively provided with a prying head, the baffle is fixedly connected with the crowbar, and the axial direction of the crowbar is perpendicular to the surface of the baffle. By the adoption of the technical scheme, when an operator uses a crowbar to lift a heavy object in a mine, due to the fact that the crowbar is fixedly connected with the baffle, when the heavy object is lifted into the air, even if some matter components fall off, the baffle blocks the falling matter components, the situation that the falling matter components injure the body of the operator can be avoided, and the safety of the operator is guaranteed. And in addition, after one end of the crowbar is inserted into the ground, the baffle can also serve as a stable lever fulcrum, so that a heavy object is convenient to lift, and the labor intensity of an operator is reduced.

The invention provides a control and protection cooperative control method for a flexible interconnection device based on an energy storage Crowbar, and aims to improve the low voltage ride through capability of a grid-connected power generation system. The method comprises the following steps: (1) connecting a direct current bus and an energy storage device by adopting a voltage reversible chopper circuit, realizing bidirectional flow of energy through a step-down / step-up chopper circuit, and performing interlocking control on a switch tube trigger signal by utilizing a double-PI controller; (2) establishing a coupling inductance model based on the magnetic coupling coefficient, and describing a current dynamic response; (3) limiting the speed increase of the fault current by using an inductance obstruction characteristic, and analyzing the current change in combination with an RL circuit differential equation; and (4) carrying out constant current control on an inverter side converter, and maintaining the stability of the current by adjusting the output voltage. According to the invention, through stored energy management, inductive coupling modeling and fault current limitation, stable operation of the system can be maintained and reactive power support can be provided when the power grid fails.

A crowbar circuit for a voltage transformer, comprising: a triggering device for triggering a short circuit via input terminals depending on control voltage; a comparator configured to trigger the triggering device depending on a comparator voltage at a comparator input and a reference voltage threshold value, a Zener diode with a breakdown voltage in series with a fifth resistor, connected between an input terminal and the comparator input, such that when the input voltage exceeds the breakdown voltage, the comparator voltage triggers the short circuit; a series connection of a seventh resistor, an eighth resistor, the fifth resistor and a sixth resistor, wherein load current at an output flows through the seventh and sixth resistors and wherein the comparator input is connected to a node between the fifth and eighth resistors, and the series connection is connected between the input terminals, such that upon exceeding a predetermined threshold current, the comparator voltage triggers the short-circuit.