1152 results about "High-voltage direct current" patented technology

The present invention relates to the technical field of circuit control, and relates to a direct-current high-voltage generator regulation and control method and system based on intelligent feedback. A fuzzy control logic operation is performed on an output current flux value and an input voltage fluctuation factor of a load experimental object, so as to obtain the disturbance amplitude of a voltage fluctuation state for a current flux change trend; if a step-up transformer can execute a PID control technology by adjusting a transformation ratio, PID real-time adjustment parameters are calculated, and a crossover mutation operation of individuals is performed on the basis of a fitness function, so as to generate a first boost regulation and control scheme; and if the step-up transformer cannot execute the PID control technology by adjusting the transformation ratio, a calibrated state feedback controller is constructed on the basis of a state variable of the current step-up transformer and an adjustment signal output amplitude, so as to generate a second boost regulation and control scheme. The present invention achieves intelligent feedback regulation and control by independently analyzing components of direct-current high-voltage generators, improving the stability and accuracy of outputting high-voltage direct current.

The invention discloses a server power supply system and a server, relates to the field of server power supply, and is used for solving the problem of high energy loss in a traditional alternating current power supply architecture. The power conversion module converts the power supply into high-voltage direct current with the voltage not lower than the preset voltage, the high-voltage direct current is transmitted to the power distribution board of the server through the bus copper bar, and the bus copper bar serves as a transmission medium of the high-voltage direct current and has low resistance and high current-carrying capacity. Extra loss caused by electromagnetic induction and a capacitance effect in alternating current transmission is avoided; high-voltage direct current is directly input to the power distribution board, so that multiple times of conversion in an intermediate link are avoided, and energy loss in the conversion process is reduced; and the power distribution board directly converts the high-voltage direct current into the voltage required by the load, so that the loss of multi-stage conversion in the traditional architecture is reduced. According to the invention, the power transmission efficiency is improved, the energy loss is reduced, and the requirement of a modern high-computing-power and high-energy-consumption server for efficient power supply is met.

The invention relates to the technical field of new energy power transmission, and discloses a long-period power grid wind-solar-thermal storage operation scheduling optimization method, which comprises the following steps: S1, constructing a new energy base system model, and calculating an output curve; s2, constructing an extra-high voltage direct current channel power delivery model; s3, solving the extra-high-voltage direct-current channel power delivery model by using CPLEX to obtain a direct-current channel delivery power optimization curve taking maximization of a new energy consumption rate considering the proportion of wind power and photovoltaic power at a delivery end as a target; s4, constructing a receiving end power grid system model; and the optimal matched power supply scale taking the minimum power abandoning rate of the new energy at the receiving end as a target function is obtained by the CPLEX. The method has the advantages that the direct-following-source-moving sending-out mode aims at meeting the external sending power requirement of a matched new energy base, the planning cost is effectively reduced, and the direct-current sending-out power and wind-light-storage power generation are coordinated and consistent.

The invention relates to a PFC-PWM (Pulse Width Modulation) dual-mode control method for a high-voltage direct-current power supply with a wide output voltage range. The output current of the high-voltage direct-current power supply is detected in real time, the critical threshold value of the load impedance is mapped into the hysteresis interval of the output current, the theoretical boundary of mode switching is obtained, and the control mode is dynamically adjusted. In order to further guarantee smooth switching of the two control modes, hysteresis control logic is designed, and undisturbed smooth switching of the PFM mode and the PWM mode is achieved. Based on an energy equivalence principle and a frequency consistency constraint of a critical load SWL working point, a current threshold criterion and a parameter pre-synchronization strategy are constructed, seamless connection of a mode switching process in a frequency domain and an energy domain is ensured, a transient oscillation risk is remarkably reduced, and a guarantee is provided for continuous and stable output of a full-range load working condition.

The invention belongs to the technical field of inertia evaluation, and discloses a direct current delivery system minimum inertia demand evaluation method considering multi-frequency modulation resource support characteristic difference, and the method comprises the steps: firstly analyzing the frequency response characteristics of each frequency modulation resource in a direct current delivery system in a typical control mode; a system frequency response model considering wind power, photovoltaic and extra-high voltage direct current frequency response characteristic differences is established, and an influence mechanism of different frequency modulation resources on system frequency characteristics is disclosed. Secondly, constructing a system equivalent inertia calculation model considering a wind power and photovoltaic inertia support effect, and providing a minimum inertia demand evaluation method based on an initial frequency change rate as a constraint; and then, considering the influence of a direct current frequency limit controller on the maximum frequency deviation, designing a direct current delivery system minimum inertia evaluation scheme considering the frequency dynamic safety constraint so as to support efficient, stable and continuous delivery of new energy power generation.

The invention relates to the technical field of photovoltaic grid connection, and particularly provides an active support control method and an active support control device for transient voltage of a transmitting end power grid of an LCC-HVDC (line commutated converter high voltage direct current power transmission) system, and the active support control method and the active support control device for the transient voltage of the transmitting end power grid of the LCC-HVDC system. Comprising the following steps: correcting an output voltage phase of a synchronization link in a virtual synchronous generator control strategy based on active power and frequency output by a network construction type photovoltaic converter, and correcting an output voltage amplitude of a voltage amplitude link in the virtual synchronous generator control strategy based on a measured value of a sending end power grid voltage; and using the virtual synchronous generator control strategy to control the network construction type photovoltaic current converter in the LCC-HVDC system containing the network construction type photovoltaic current converter. According to the technical scheme provided by the invention, the stability of photovoltaic access to the weak power grid can be improved, and the reactive power output by the converter can be automatically adjusted after the transient voltage of the sending-end power grid occurs due to the commutation failure of the LCC-HVDC system, so that the transient voltage is effectively supported, and the phenomenon of reverse adjustment of the reactive power is prevented.

The invention discloses a direct-current corona discharge mode recognition method and system based on YOLOv8 and a CNN model, and relates to the technical field of power equipment monitoring. The invention aims to solve the technical problem that the corona discharge phenomenon of high-voltage direct-current electrical equipment is difficult to monitor in real time and accurately classify. According to the scheme, the method comprises the following steps: firstly, shooting a corona discharge visible light image by using a digital single lens reflex camera, and carrying out manual labeling and data enhancement processing; then detecting and positioning a corona discharge source by using a YOLOv8 model; inputting the positioned corona discharge area image into a deep convolutional neural network (CNN) for classification of discharge modes; finally, the output results of the CNN models are fused through integrated learning, and the classification accuracy is improved. According to the method, real-time monitoring and accurate classification of the corona discharge phenomenon of the high-voltage direct-current electrical equipment can be realized, a powerful guarantee is provided for safe operation of power equipment, the operation and maintenance efficiency is remarkably improved, and the equipment fault risk caused by corona discharge is reduced.

The invention belongs to the field of data processing, and particularly relates to a high-voltage direct-current electric field intensity measuring method and a related device. In the device, an optical fiber direct-current electric field sensor at least comprises a signal processing unit, an optical fiber voltage sensing head, a fixed electrode and a rotating electrode. The method comprises the following steps: deploying a measuring device in a space to be measured; the rotating electrode is controlled to rotate at a constant speed, so that the center distance between the fixed electrode and the rotating electrode is periodically changed along with the rotating track; collecting an alternating current signal voltage generated by an alternating potential difference between the fixed electrode and the rotating electrode in a constant-speed rotating process through an optical fiber voltage sensing head; and performing numerical processing on the alternating current signal voltage through a signal processing unit to obtain a measured value of the high-voltage direct current electric field intensity, and optimizing the measured value in combination with a physical compensation model and a data driving compensation model. The method can realize the measurement of the high-voltage direct-current space electric field intensity, improve the measurement accuracy and expand the measurement range.

The invention relates to a controllable turn-off converter valve for a high voltage direct current (HVDC) system, each converter valve arm comprises a valve arm voltage-sharing device and a plurality of cascaded controllable turn-off converter modules, and each controllable turn-off converter module comprises an assembly voltage-sharing device and a plurality of cascaded controllable turn-off converter assemblies. Each controllable turn-off current conversion assembly is configured to comprise at least one voltage-sharing circuit and at least one controllable switching device, and two ends of each controllable switching device are provided with one voltage-sharing circuit in parallel. Therefore, the controllable turn-off converter valve can realize voltage sharing at each level, the requirement of the controllable turn-off converter valve on the consistency of controllable switching devices is reduced, a large number of controllable switching devices can be connected in series in the same converter valve arm, and reliable conversion of extra-high voltage direct current transmission at the voltage level of + / -800 kilovolts and above is realized. The problem of commutation failure of the extra-high-voltage direct-current type converter valve is solved, and safe and stable operation of a power system is ensured.

The invention relates to an extra-high-voltage direct-current line pin repairing tool. The extra-high-voltage direct-current line pin repairing tool comprises an insulating rod, a driving mechanism, a pin positioning mechanism, a screw positioning mechanism, a camera shooting mechanism, a manipulator and a displayer. Wherein the driving mechanism is arranged at the far end of the insulating rod. And the pin positioning mechanism is arranged on the driving mechanism and is used for fixedly holding a pin. And the screw positioning mechanism is connected with the pin positioning mechanism and is used for fixedly holding the screw. The camera shooting mechanism is arranged on the driving mechanism and used for obtaining an image of the screw fixedly held on the screw positioning mechanism. And the manipulator is arranged at the near end of the insulating rod and is used for controlling the driving mechanism to drive the pin to be separated from the pin positioning mechanism and inserted into the pin hole of the screw rod. The displayer is arranged at the near end of the insulating rod and used for displaying images obtained by the camera shooting mechanism. The extra-high voltage direct current line pin repairing tool can improve the safety of pin repairing operation.

The invention discloses a high-voltage direct-current cable state online monitoring method and system based on MMC low-frequency injection. The method comprises the steps that an MMC controller injects a low-frequency three-phase alternating-current signal into a direct-current cable based on an MMC low-frequency injection control strategy; the MMC low-frequency injection control strategy comprises the steps that an MMC controller adopts a double-closed-loop control mode composed of an outer voltage loop and an inner current loop; a voltage error is calculated through an outer voltage loop, and a differential-mode voltage Udiffdq * and a common-mode voltage Ucomdq * are calculated through an inner current loop, so that the MMC outputs a target voltage Ugoal signal to a direct-current cable; according to the method, active injection of the low-frequency alternating-current signal with the specific frequency and amplitude is achieved by setting the specific MMC control strategy, a hardware structure of a main loop of an MMC system does not need to be modified, and implementation is safe, easy, convenient and flexible; and meanwhile, online quantitative evaluation of the insulation state of the direct-current cable is realized, and the monitoring process is high in precision, simple, convenient and efficient.

A monitoring circuit for a high-voltage DC charging apparatus provides for the monitoring circuit to have a first high-voltage busbar and a second high-voltage busbar as well as a reference potential. This is electrically insulated from the high-voltage busbars. The monitoring circuit has a current sensor apparatus which is configured to capture a common-mode current flowing through the high-voltage busbars. The monitoring circuit also has a control device. The current sensor apparatus has a signal-transmitting connection to the control device, and the control device is configured to emit a fault signal if the magnitude of the common-mode current exceeds a limit. Furthermore, a DC voltage charging station, a DC voltage charging cable, a vehicle charging circuit and a method for detecting a fault in a high-voltage DC charging process are described.

The invention discloses a polypropylene insulation high-voltage direct-current cable and a production method thereof, and relates to the technical field of cables, the polypropylene insulation high-voltage direct-current cable comprises an insulation layer, the insulation layer comprises an insulation part arranged between a conductor shielding layer and an insulation shielding layer, the insulation part is provided with a plurality of limiting holes communicated with the insulation shielding layer, the limiting holes are filled with phase change parts, and the phase change parts can transmit heat on the inner side of the insulation layer to the outer side of the insulation layer; and the cable can be converted between solid and liquid along with the temperature of the cable so as to fill an air gap between the insulating layer and the insulating shielding layer. The plurality of limiting holes are formed in the insulating part, the limiting holes are filled with the phase change parts capable of generating phase change at low temperature, and the temperature difference between the two sides of the insulating part is reduced through the heat conduction capability of the phase change parts, so that the problem of charge accumulation caused by the overlarge temperature difference between the two sides of the insulating part is avoided; and meanwhile, separation or air gaps between the insulating part and the insulating shielding layer are filled through phase change of the phase change part.

The invention provides a high-voltage direct-current bus direct-hanging energy storage power grid strength support type device, which is connected with a high-voltage alternating-current bus and comprises a plurality of cascaded direct-current sub-modules, a high-voltage direct-current bus and a converter valve, each direct current sub-module comprises an energy storage unit cluster; outgoing lines at two ends of the plurality of cascaded DC sub-modules are connected with a high-voltage DC bus, and the other side of the high-voltage DC bus is connected with a converter valve; the direct current sub-modules convert initial low-voltage direct current output by the energy storage unit cluster into low-voltage direct current needed by power grid strength support, the multiple cascaded direct current sub-modules convert the low-voltage direct current into high-voltage direct current and output the high-voltage direct current to the high-voltage direct current bus, and the high-voltage direct current output by the high-voltage direct current bus is inverted through the converter valve. Stable voltage support is provided for the high-voltage alternating-current bus; isolation of the energy storage unit cluster and the high-voltage alternating-current bus is achieved through the high-voltage direct-current bus, and the influence of reactive power fluctuation of a power grid on energy storage elements is reduced.

The invention discloses an isolation activation circuit. The circuit comprises a voltage division isolation module which is used for dividing a power supply voltage into a first voltage and a second voltage and isolating the power supply voltage from the first voltage; the pulse activation module is used for generating a first pulse signal according to the first voltage and the second voltage; the first power supply conversion module is used for converting a power supply voltage into a first power-on voltage according to the first pulse signal or the second pulse signal; the second power supply conversion module is used for converting the first power-on voltage into a second power-on voltage according to the first control signal, or terminating the conversion of the first power-on voltage into the second power-on voltage according to the second control signal; the power-on self-holding module is used for generating a second pulse signal according to the second power-on voltage and the second voltage; and the detection module is used for enabling the battery management system to output a second control signal. The isolation activation circuit provided by the invention directly takes electricity from the power supply module, and realizes the isolation driving of a low-voltage battery management system by using high-voltage direct current.

The invention relates to an electric engine, a power device and an aircraft, and belongs to the technical field of aircraft power equipment.The electric engine comprises a power motor and a liquid cooling flow path arranged in the power motor and comprises a stator support; the heat dissipation system comprises a fan, a radiator and a heat dissipation motor, an outlet of the radiator is connected with an inlet of the liquid cooling flow path, an inlet of the radiator is communicated with an outlet of the liquid cooling flow path, and the fan is used for cooling the radiator and / or the power motor; the motor rear cover is fixedly connected with the stator bracket; and the two direct-current converters are both mounted on the motor rear cover and are both electrically connected with the heat dissipation motor. The two direct-current converters convert high-voltage direct current accessed by the electric engine into low-voltage direct current capable of being used by the heat dissipation motor, and the electricity utilization requirement of the heat dissipation motor is met. Due to the redundancy design of the two direct-current converters, when one path of low-voltage power supply breaks down, the other path of low-voltage power supply can still supply power to the heat dissipation motor in a low-voltage mode, and enough fault handling time can be provided for the whole power supply system.

The invention discloses a machine learning-based ultra-high-voltage direct-current transmission locking fault diagnosis method and system, and the method comprises the steps: obtaining various electrical quantity change data of each network node before and after a fault, screening out feature electrical quantities and feature nodes from the electrical quantity change data, and forming fault feature data; extracting a fault occurrence time point and a frequency component from the fault feature data through wavelet transform, constructing a fault signal model, and judging a fault position by adopting an extreme point detection method; constructing an input sequence according to the extracted fault occurrence time point and frequency component, and constructing a convolutional neural network model; expanding the input sequence into a time feature matrix, redistributing the weight of each feature in the time feature matrix by adopting a channel attention mechanism, and performing weighted average on the input time sequence of each time step length in the time feature matrix by adopting a time attention mechanism to obtain an improved convolutional neural network model; and training the improved convolutional neural network model, and extracting fault features of extra-high voltage direct current locking to complete fault diagnosis.

The invention belongs to the field of preparation of insulating materials, and particularly relates to a peroxide crosslinked polyethylene insulating material for a 500kV ultrahigh-voltage direct-current cable and a preparation method of the peroxide crosslinked polyethylene insulating material. The preparation method of the peroxide cross-linked polyethylene insulation material comprises the following preparation steps: adding a low-density polyethylene base material into a reciprocating mixer for preliminary melting, adding hindered phenol antioxidant modified silicon dioxide for uniform mixing, finally adding dicumyl peroxide, and carrying out heat preservation and absorption at 70-110 DEG C for 10-12 hours, so as to obtain the peroxide cross-linked polyethylene insulation material. The peroxide crosslinked polyethylene insulation material is obtained. The hindered phenol antioxidant modified silicon dioxide improves the direct current breakdown strength of the polyethylene insulating material, so that the peroxide crosslinked polyethylene insulating material has excellent performance.

A multiphase inverter for an electric drive system comprises a multitude of H-type multilevel power converters arranged between a high-voltage direct current (HVDC) supply and an electric machine. Each of the multitude of H-type multilevel power converters is an integrated solid-state circuit (IC) comprising a positive DC power bus, a negative DC power bus, a neutral bus, and a multitude of semiconductor switches arranged in a stacked configuration. The multitude of semiconductor switches are interconnected via the positive DC power bus, the negative DC power bus, and the neutral bus.

The invention discloses a high-voltage direct-current cable electromagnetic transient frequency domain modeling and time domain solving method, system, medium and equipment, and the method comprises the steps: obtaining an initialization parameter of a high-voltage direct-current cable, calculating an internal impedance matrix [Zi] of a multi-layer cross-section cable body during frequency calculation, and calculating an admittance coefficient matrix of the multi-layer cross-section cable body during frequency calculation; calculating ground loop impedance [] and potential coefficient [] of the air laying cable or the direct burial laying cable, and obtaining a total impedance matrix [] and a total admittance matrix [] of the cable at the time of frequency: importing obtained multi-frequency [] and [] calculation results into a PSCAD TLine module, and realizing time domain solution of frequency domain calculation by using a vector fitting model.

The invention discloses an antioxidant grafted modified high-voltage direct-current cable polyethylene material and a preparation method thereof, and belongs to the technical field of modification of high-voltage direct-current cable insulating materials. The material is prepared from the following raw materials: polyethylene, an antioxidant GS and an initiator DCP. The preparation method comprises the following steps: firstly, mixing the polyethylene, the antioxidant GS and the initiator DCP to obtain an antioxidant GS / initiator DCP / polyethylene material blend; and then carrying out grafting and cross-linking treatment on the blend to obtain the cross-linked polyethylene insulating material grafted and modified by the antioxidant. The antioxidant grafted polyethylene material prepared by the invention has excellent oxidation resistance, electrical properties and good color, and is beneficial to prolonging the service life of a high-voltage direct-current cable. The antioxidant is grafted to a polyethylene molecular chain, so that the emigration of the antioxidant can be reduced, the compatibility of the antioxidant and a polyethylene matrix is improved, the oxidation resistance of polyethylene is improved, and the accumulation of space charges of a polyethylene insulating material can be inhibited.

The invention discloses an ion pump power supply circuit. The circuit comprises a voltage regulation output module, a control module and a current-voltage conversion module, the input end of the voltage regulation output module receives low-voltage direct-current input voltage; the high-voltage output end of the voltage regulation output module is connected with the anode of the ion pump; the ion pump shell is electrically connected with the input end of the current and voltage conversion module through the electron gun shell; the output end of the current-voltage conversion module is electrically connected with the control module; the grounding end of the current-voltage conversion module is connected with the signal ground; the voltage regulation output module converts the low-voltage direct-current input voltage and outputs high-voltage direct-current voltage to the anode of the ion pump, so that working current is generated in the cavity of the ion pump and returns to the current-voltage conversion module through the shell of the ion pump and the shell of the electron gun; the current and voltage conversion module detects working current in the ion pump cavity and converts the working current into a voltage signal; and the control module determines the vacuum degree in the ion pump cavity according to the voltage signal.

The invention relates to the technical field of cables, in particular to a polyethylene insulating material, a preparation method thereof and a high-voltage direct-current cable. The polyethylene insulation material provided by the invention is prepared from the following preparation raw materials: 70 to 100 parts of polyethylene matrix, 0.1 to 30 parts of grafting master batch, 1 to 2 parts of cross-linking agent and oxidation inhibitor, the grafting master batch is prepared from the following raw materials: polyethylene resin, a grafting monomer and an antioxidant, wherein the grafting monomer comprises one or more of compounds with a structure as shown in a formula (I). The polyethylene insulating material provided by the invention has relatively high breakdown strength and relatively low conductivity.

The invention relates to the technical field of high-voltage electric appliance detection, in particular to a device and method for detecting the vacuum degree of a vacuum arc-extinguishing chamber, and the method comprises the steps: arranging a field emission cathode on one metal end cover of the vacuum arc-extinguishing chamber; an anode is arranged on the metal shielding cover close to the field emission cathode in the vacuum arc-extinguishing chamber; the high-voltage direct-current power supply is connected to the field emission cathode and the anode and is used for applying voltage to the electrodes so as to drive the field emission cathode to emit electron beams to impact the anode; the X-ray energy spectrum detector directly faces the anode, the X-ray energy spectrum detector is used for measuring bremsstrahlung X-ray energy spectrum generated when the electron beam impacts the anode, an electron emission source is actively arranged in the arc extinguish chamber, and the distribution of the X-ray energy spectrum generated by the electron emission source is measured. And high signal-to-noise ratio, high-precision and high-sensitivity vacuum degree quantitative detection is realized by utilizing the strong correlation between the energy spectrum form and the internal gas pressure.

The utility model belongs to the technical field of new energy automobiles, and particularly discloses a new energy automobile high-pressure liquid heater which comprises a heater body, a thick film heating plate, a heat insulation plate, a cover plate and an overheating protection circuit which are sequentially installed from bottom to top. The overheating protection circuit comprises four thermistors Rt1, Rt2, Rt3 and Rt4, an N-type MOS tube, a relay KJ, a heating resistance wire Rh, a resistor R1, a resistor R2, a resistor R3, a low-voltage direct-current power supply and a high-voltage direct-current power supply. According to the thick film heating plate, the water-drop-shaped turbulent flow columns and the turbulent flow teeth are arranged, so that the heat conduction efficiency and the heat exchange efficiency of the thick film heating plate in liquid are improved, and better convective heat exchange is realized; and the overheating protection circuit is arranged, so that the reliability of the heater during over-temperature protection is improved, and the heater is not only controlled by software.

The invention provides a resistance voltage division control redundancy power supply circuit for a multi-level converter power sub-module, and relates to the technical field of power supply of the multi-level converter power sub-module. The resistor voltage division control redundancy power supply circuit comprises n voltage division resistors which are connected in series and are connected with a high-voltage direct-current capacitor in parallel; one end of the first through-current unit is connected with a connection point of the (k-1) th divider resistor and the kth divider resistor; one end of the second through-flow unit is connected with a connection point of the (j-1) th divider resistor and the jth divider resistor, and the other end of the second through-flow unit is connected with an energy storage capacitor of the bypass switch; one end of the resistance voltage division control branch is connected with one end of the first through-current unit, and the other end is connected with the negative electrode of the high-voltage direct-current capacitor; and two ends of the redundant power supply and energy taking module are respectively connected with the other end of the first through-current unit and the negative electrode of the high-voltage direct-current capacitor. In the low-voltage pre-charging stage of the multi-level converter power sub-module, starting of redundant power supply is achieved, black module faults are avoided, and the system reliability is improved.

Embodiments of the present application provide a power supply system and method of a server, an electronic device, and a storage medium. By means of cooperative work of main circuit structures such as a high-voltage battery power master control unit, battery string management and control units, and power conversion string management and control units, power information of each subsystem in the power supply system is collected and analyzed in real time, and the high-voltage battery power master control unit can also issue a corresponding control instruction to each subsystem according to the analysis result so as to realize power control of each subsystem, thereby controlling the total output power of the server. The whole main power utilization power path is simple and reliable, electric energy conversion on a high-voltage direct-current power supply at an input side is not required, the design structure between a high-voltage direct-current power supply inlet and a power utilization inlet of the server is simplified, thus the working efficiency of the power supply system can be effectively improved, and the heat loss is reduced; additionally, when a main power supply system outside the server works abnormally, the power utilization requirement of the server can be ensured, and the conversion efficiency and the working reliability of the power supply system are ensured.

The invention relates to a preparation method of an epoxy and DCP bi-crosslinked EAA and LDPE cable material, and belongs to the technical field of preparation of high-voltage direct-current cable materials. The preparation method of the cable material comprises the following steps: taking an ethylene acrylic acid copolymer EAA and low-density polyethylene LDPE as matrix resin, taking a biphenyl type micromolecular epoxy compound 4, 4 '-biphenol diglycidyl ether and dicumyl peroxide DCP as double crosslinking agents, and carrying out cross-linking reaction to prepare the cable material. And heating and pressurizing in a press vulcanizer to obtain the biphenyl micromolecular epoxy and DCP bi-crosslinked EAA / LDPE high-voltage direct-current cable material. A bi-crosslinking structure formed by biphenyl type micromolecule epoxy and DCP bi-crosslinking EAA / LDPE material and an in-situ introduced voltage stabilizing segment effectively improve the direct current resistance of the cable material. The high-voltage direct-current cable material prepared by the method is simple in preparation process and low in cost, and has excellent mechanical properties and electrical properties.

The invention discloses a protective fence with a dustproof function and a using method, and relates to the technical field of protective fences. The protective fence with the dustproof function comprises a mounting base and a protective fence body, a mounting top cover is fixedly mounted at the top end of the protective fence body, and an air inlet pipe head is fixedly mounted on the front face of the mounting top cover; the operation method comprises the following steps: S1, electrifying the device; an electrostatic dust collection structure composed of the discharge electrode and the dust collection electrode is connected with high-voltage direct current, and the air exhaust flow guide fan is connected with a construction site circuit to extract flying dust generated on a construction site. In the foundation pit excavation process, air mixed with dust is rapidly sucked into an air inlet pipe head through an air suction flow guide fan and then enters an electrostatic dust removal structure, dust in the air is rapidly removed, the air is rapidly discharged in cooperation with a dust filter screen column, the dust cleaning speed in the foundation pit excavation process is increased, and the dust removal efficiency is improved. And the dust treatment effect of the whole device is ensured.

The invention provides a high-gain DC / DC converter based on a coupling inductor. The high-gain DC / DC converter can convert input low-voltage direct-current voltage into high-voltage direct-current voltage of another grade to be output. The invention discloses a high-gain DC / DC converter based on a coupling inductor. The high-gain DC / DC converter comprises a DC input power supply Vin, a switching tube S, a coupling inductor unit, a clamping capacitor C1, a first energy storage capacitor C2, a second energy storage capacitor C3, a first diode D1, a second diode D2, a third diode D3, an output diode Do and a load unit. High output voltage gain of the converter is realized through the characteristics of parallel charging and series discharging of a different-stage CLC coupling inductor voltage-multiplying unit composed of a coupling inductor unit and energy storage capacitors C2 and C3, and meanwhile, a passive clamping circuit is arranged through a clamping capacitor C1 to absorb energy released by primary side leakage inductance of a coupling inductor at the moment of switching-off of a switching tube. And the voltage stress of the switching tube is reduced. According to the scheme provided by the invention, the different-stage CLC coupling inductor voltage-multiplying unit and the passive clamping circuit clamped to the ground are combined into a whole, the freewheeling diode is additionally arranged in one branch of the different-stage CLC coupling inductor voltage-multiplying unit, the freewheeling loop is arranged for the clamping capacitor, energy released by the primary side leakage inductance of the coupling inductor is recycled, and the energy utilization rate is improved. While the voltage stress of the switching tube is relieved, the output voltage gain of the converter is further improved. The high-gain DC / DC converter based on the coupling inductor has higher output voltage gain, the output voltage can be further improved by changing the turn ratio of the coupling inductor, and the high-gain DC / DC converter based on the coupling inductor has the potential that the high-gain DC / DC converter based on the coupling inductor can meet the requirement for higher output voltage.