Powerline fault traveling wave head precision positioning method based on S-transform

The invention relates to an S-transform based transmission fault traveling wave heat positioning method and belongs to the technical field of relay protection of a power system. The method comprises the following steps: carrying out data window truncation of a fault traveling wave signal and S-transform of a small quantity of key data, with amplitude-time-frequency information of the traveling wave signal expressed by an S-transform modular matrix; basically filtering influence of noise and initially determining the position of a head of the traveling wave according the different performance of the head of the traveling wave and the noise in different frequency range; intensively inspecting an amplitude-time graph at a point of the highest frequency in which a point of maximum amplitude represents a point of the most intensive vibration of the head of the traveling wave, namely a point of the arrival time of the head of the traveling wave; and marking polarity information of the head of ...

Bus sharing method and device for distributed multi-master CPUs

The invention provides bus sharing method and device for distributed multi-master CPUs. The communication among the CPUs in multi-task multi-CPU distributed processing is improved into a multi-mastermode from a traditional master and slave mode, any a processor suspended on a bus can obtain the control right of a data bus by bus arbitration so as to carry out data communication with other processors or external equipment, and the utilization ratio of the bus can be greatly improved.

Belt-turning mechanism

The invention relates to a belt-turning mechanism for a sewing machine. The mechanism comprises a folding drum gradually furling from the back end to the front end; one side of the folding drum sinks inwards; a first channel convenient for an outer wrapping strip to bend to pass is formed between the inner edge of the one side and the other side of the folding drum, while a second channel for pulling back a turning belt is formed by the outer edge of the folding drum; the front end of the second channel is connected with a hollow liner tube communicated with the second channel; the front opening of the liner tube is formed into an inlet for stretching into and pulling back the front end of the turning belt; a gap for the outer wrapping strip to pass is reserved between the outer edge of the liner tube and the front outlet of the first channel; the upper end of the folding drum is connected with a first snakelike frame used to guide a liner elastic belt, while the back end is connected with ...

LIQUID INSECTICIDAL MIXTURE

The present invention refers to liq. insecticide mixture, which is made by combining effective components, e. g. trifluoro-cypermethrin, methyl-parathion, and/or salithion, with proper amount of synergist, aid, and solvent, for synergistic prevention and control of agricultural pests, esp. bollworm, with high toxicity for killing both insects and their ovum. The said product can delay drug resistance of bollworm and is current one of the most effective insecticides for bollworm control.

Efficient suspension of chloro-cyanide pyrethrin insecticide

This efficient insecticide suspension contains such components (Wt.%) as cis-and trans-alpha chloro-cyanide pyrethrin (0.5-20), thickening agent (0.5-2), anti-freezing agent (1-5), anticorrosive agent (0.2-1.0), surfactant (1-5) and water (rest) and features high effect and low cost.

Efficient suspension of chloro-cyanide pyrethrin insecticide

Edge covering mechanism of sewing machine

The invention discloses an edge covering mechanism of a sewing machine, comprising a snake-shaped frame and a flat tube connected to the front end of the snake-shaped frame to limit the location. The front end of the flat tube is connected with an edge covering tube which is gradually closed up; the edge covering tube is formed by surrounding an upper guide plate and a lower guide plate; the lower guide plate is arched at the middle part and has concave arc sections at two sides; the joints at two sides of the upper guide plate and the lower guide plate are provided with ribs, which combine with the arc sections to form curling passages; the front end of the edge covering tube is provided with a U-shaped tube for folding and gathering a cloth strap; the edge covering tube comprises a primary edge covering tube and a secondary edge covering tube; the primary edge covering tube corresponds to the first rib, the first arc section and the first curling passage; the secondary edge covering tube ...

Rat eradication agent

The invention relates to development and application of anticoagulative compound synergistic rodenticide. The rodenticide mainly comprises bromadiolone and sodium dichlorophenolate, and is added with metronidazole, ethanol, glycerin and the like. The rodenticide can be prepared into liquid and powder. Bioassay shows that the rodenticide has good toxic effect for albino rats, mice, sewer rats, cricetulus tritons, microtus brandtis and apodemus agrariuses; the death ratio basically reaches 100 percent; and a large-are field test proves that prevention ratio for the sewer rats reaches more than 96 percent. When the bromadiolone content in the rodenticide is 0.002 percent, the control effect is better than or equal to the control effect of 0.005 percent of bromadiolone, so that cost is lowered greatly, environmental pollution is reduced, human and animal safety is ensured, and the national policy of energy saving and discharge reduction is firmly implemented. The rodenticide has the advantages ...

Alternating-current powerline thunderbolt shielding failure and counterattack recognition method

The invention relates to a method for recognizing lighting shielding failure and counterattack of an AC transmission line. The different theories generated by the electromagnetic transient component of the lighting shielding failure and the counterattack of the high-voltage DC transmission line and different paths of transmission of the thunderbolt electromagnetic transient component on the circuit cause that the energy distribution of different frequency bands of the generated current transient state signals are different greatly. Therefore, in a travelling wave analysis and high-speed acquisition system at the protective installation position, the small wave analysis is adopted to extract the energy of the zero modulus current in different frequency bands. The shielding failure and the counterattack are differentiated according to the property of the energy distribution. A large amount of emulations show that the method is reliable and effective and can recognize accurately the shielding ...

High voltage direct current transmission line thunderbolt shielding failure and counterattack recognition method

The invention relates to a method for recognizing the shielding failure and the counterattack of a high-voltage DC transmission line. The shielding failure of the line means that the thunderbolt directly strikes on the transmission line by steering clear of a ground wire; the counterattack means that the thunderbolt directly strikes on the ground wire or a pole tower, the electric potential on thetop of the tower increases instantaneously, which causes the insulation flashover due to the existence of a pole tower earth resistor. The different theories generated by the electromagnetic transient component of the shielding failure and the counterattack of the high-voltage DC transmission line and different paths of transmission of the thunderbolt electromagnetic transient component on the circuit cause that the energy distribution of different frequency bands of the generated voltage transient state signals are different greatly. In a travelling wave analysis and high-speed acquisition system ...

High voltage direct current transmission line thunderbolt shielding failure and counterattack recognition method

The invention relates to a method for recognizing the shielding failure and the counterattack of a high-voltage DC transmission line. The shielding failure of the line means that the thunderbolt directly strikes on the transmission line by steering clear of a ground wire; the counterattack means that the thunderbolt directly strikes on the ground wire or a pole tower, the electric potential on the top of the tower increases instantaneously, which causes the insulation flashover due to the existence of a pole tower earth resistor. The different theories generated by the electromagnetic transient component of the shielding failure and the counterattack of the high-voltage DC transmission line and different paths of transmission of the thunderbolt electromagnetic transient component on the circuit cause that the energy distribution of different frequency bands of the generated voltage transient state signals are different greatly. In a travelling wave analysis and high-speed acquisition system ...

Rodenticide

The invention relates to development and application of anticoagulative compound synergistic rodenticide. The rodenticide mainly comprises bromadiolone and sodium dichlorophenolate, and is added with metronidazole, ethanol, glycerin and the like. The rodenticide can be prepared into liquid and powder. Bioassay shows that the rodenticide has good toxic effect for albino rats, mice, sewer rats, cricetulus tritons, microtus brandtis and apodemus agrariuses; the death ratio basically reaches 100 percent; and a large-are field test proves that prevention ratio for the sewer rats reaches more than 96 percent. When the bromadiolone content in the rodenticide is 0.002 percent, the control effect is better than or equal to the control effect of 0.005 percent of bromadiolone, so that cost is lowered greatly, environmental pollution is reduced, human and animal safety is ensured, and the national policy of energy saving and discharge reduction is firmly implemented. The rodenticide has the advantages ...

Thunder failure recognition method for row wave protection of DC power transmission line

The invention relates to a lightning striking fault identifying method of a direct current power transmitting line traveling wave protection. According to the characteristic difference of voltage traveling wave shape between the formed faults and unformed faults, two-pole voltage traveling wave weight and origin direct current weight are used to identify changing trend of the wave shape; ratio of a initial traveling wave mode maximum value and the second mode maximum value is used for representing saltation that the wave shape is cut; combining the two characteristics to achieve the identification of the voltage traveling wave while not causing the faults by lightning pole tower, lightning striking lightning line, lightning striking line shift central distance and the voltage traveling wave of non-lightning short circuit fault by the lightning pole tower, lightning striking line shift central distance. The interference and identification of the two lightning weaves are combined to improve ...

Powerline fault traveling wave head precision positioning method based on S-transform

The invention relates to an S-transform based transmission fault traveling wave heat positioning method and belongs to the technical field of relay protection of a power system. The method comprises the following steps: carrying out data window truncation of a fault traveling wave signal and S-transform of a small quantity of key data, with amplitude-time-frequency information of the traveling wave signal expressed by an S-transform modular matrix; basically filtering influence of noise and initially determining the position of a head of the traveling wave according the different performance of the head of the traveling wave and the noise in different frequency range; intensively inspecting an amplitude-time graph at a point of the highest frequency in which a point of maximum amplitude represents a point of the most intensive vibration of the head of the traveling wave, namely a point of the arrival time of the head of the traveling wave; and marking polarity information of the head of ...

Method for precisely marking arriving time of initial wave of fault generated traveling waves for electricity transmission line

The invention relates to a method for precisely calibrating the arrival moment of initial wave head of traveling wave in transmission line faults by utilizing Hilbert-Huang transformation (HHT). The method comprises the following steps that: HHT transformation is carried out to faulty traveling wave data; EMD decomposition is carried out first, and IMF1 component intensively embodies the high frequency information of raw data and completely self-adapts to the time scale of the raw data; the IMF1 component is taken as an investigation object; an order difference curve of the IMF1 component is evaluated, and Hilbert transformation is carried out to the order difference curve so as to obtain an instantaneous frequency curve of the IMF1 component; the advantages of two curves are combined to seek an extreme point, and the extreme point is compared with the raw data to obtain the precise calibration for the arrival moment of the head of a traveling wave, and error is controlled to be less than ...

Crinkle sewing structure and crinkle self-guiding device

The invention discloses a crinkle sewing structure. A pressing sheet for compacting the cloth strips for crinkling on a feed dog is arranged in front of a frame needle, the front end of a presser foot presses shell fabric on the pressing sheet, and the rear end of the presser foot presses the shell fabric and the cloth strips for crinkling which are sewed together on the feed dog. The invention also discloses a crinkle self-guiding device, comprising the pressing sheet which is fixed on a pressing sheet shaft. The pressing sheet shaft is rotatably arranged on a support and is parallel to a sewing machine panel, and a rotating seat is fixed in the circumferential direction of the pressing sheet shaft and is connected with the support through an elastic mechanism, wherein the support can be installed on the sewing machine panel, and the elastic mechanism enables the pressing sheet which is fixed in the circumferential direction of the pressing sheet shaft like the rotating seat to have a ...

Thunder failure recognition method for row wave protection of DC power transmission line

The invention relates to a lightning striking fault identifying method of a direct current power transmitting line traveling wave protection. According to the characteristic difference of voltage traveling wave shape between the formed faults and unformed faults, two-pole voltage traveling wave weight and origin direct current weight are used to identify changing trend of the wave shape; ratio ofa initial traveling wave mode maximum value and the second mode maximum value is used for representing saltation that the wave shape is cut; combining the two characteristics to achieve the identification of the voltage traveling wave while not causing the faults by lightning pole tower, lightning striking lightning line, lightning striking line shift central distance and the voltage traveling wave of non-lightning short circuit fault by the lightning pole tower, lightning striking line shift central distance. The interference and identification of the two lightning weaves are combined to improve ...

Alternating-current powerline thunderbolt shielding failure and counterattack recognition method

The invention relates to a method for recognizing lighting shielding failure and counterattack of an AC transmission line. The different theories generated by the electromagnetic transient component of the lighting shielding failure and the counterattack of the high-voltage DC transmission line and different paths of transmission of the thunderbolt electromagnetic transient component on the circuit cause that the energy distribution of different frequency bands of the generated current transient state signals are different greatly. Therefore, in a travelling wave analysis and high-speed acquisition system at the protective installation position, the small wave analysis is adopted to extract the energy of the zero modulus current in different frequency bands. The shielding failure and the counterattack are differentiated according to the property of the energy distribution. A large amount of emulations show that the method is reliable and effective and can recognize accurately the shielding ...

Single signal wire synchronous clock transfer method

The invention provides a single signal wire synchronous clock transfer method, which is a technology for time sharing multiplex transfer of second pulse signals and time packet information on a same signal wire or an optical transmission media. The method can only use the single signal wire or an optical cable for transferring the reference time synchronous signals between equipment which need torealize the time synchronization, thereby greatly reducing the cost.

Method for precisely marking arriving time of initial wave of fault generated traveling waves for electricity transmission line

The invention relates to a method for precisely calibrating the arrival moment of initial wave head of traveling wave in transmission line faults by utilizing Hilbert-Huang transformation (HHT). The method comprises the following steps that: HHT transformation is carried out to faulty traveling wave data; EMD decomposition is carried out first, and IMF1 component intensively embodies the high frequency information of raw data and completely self-adapts to the time scale of the raw data; the IMF1 component is taken as an investigation object; an order difference curve of the IMF1 component is evaluated, and Hilbert transformation is carried out to the order difference curve so as to obtain an instantaneous frequency curve of the IMF1 component; the advantages of two curves are combined to seek an extreme point, and the extreme point is compared with the raw data to obtain the precise calibration for the arrival moment of the head of a traveling wave, and error is controlled to be less than ...

LIQUID INSECTICIDAL MIXTURE

The present invention refers to liq. insecticide mixture, which is made by combining effective components, e. g. trifluoro-cypermethrin, Meiduowei and/or methyl-parathion, with proper amount of synergist, aids, and solvent, for synergistic prevention and control of agricultural pests, esp. for drug-fast bollworm, with high toxicity for killing both insects and their ovum. The said product can delay drug resistance of bollworm and is currently the one of the most effective insecticides for bollworm control.

Belt-turning mechanism

The invention relates to a belt-turning mechanism for a sewing machine. The mechanism comprises a folding drum gradually furling from the back end to the front end; one side of the folding drum sinks inwards; a first channel convenient for an outer wrapping strip to bend to pass is formed between the inner edge of the one side and the other side of the folding drum, while a second channel for pulling back a turning belt is formed by the outer edge of the folding drum; the front end of the second channel is connected with a hollow liner tube communicated with the second channel; the front opening of the liner tube is formed into an inlet for stretching into and pulling back the front end of the turning belt; a gap for the outer wrapping strip to pass is reserved between the outer edge of the liner tube and the front outlet of the first channel; the upper end of the folding drum is connected with a first snakelike frame used to guide a liner elastic belt, while the back end is connectedwith ...