48results about How to "Not to be broken down" patented technology

The invention discloses an MMC power module adopting double-bypass switches and an overvoltage three-bypass method. The MMC power module adopting the double-bypass switch comprises a first bypass switch and a second bypass switch, wherein the first bypass switch is connected with two ends of the MMC power module in parallel, when a capacitor voltage of the MMC power module exceeds a set safety value, the first bypass switch is closed, so the MMC power module is bypassed, when the MMC power module fails and refuses to operate, the second bypass switch receives a closing instruction, the secondbypass switch is closed, so the MMC power module is bypassed. The MMC power module is advantaged in that by arranging the two bypass switches, reliability of bypass of the power module is improved, and shutdown of a flexible direct current system caused by unreliable bypass of the power module is avoided.

The invention discloses a manufacturing method for a groove type MOSFET. The manufacturing method is characterized by comprising the steps that 1), a groove is etched, and side walls of the groove of a grid channel incline; 2), grid-oxide grows, and polycrystalline silicon is deposited and etched back; 3), injecting and annealing are carried out on a body region and a source region; 4), a dielectric medium between layers is deposited, and a contact hole is etched, injected and annealed; 5), a barrier layer of the contact hole is deposited, tungsten is deposited and etched back, top layer metal is deposited and etched to form a grid electrode and a source electrode, and back metal is deposited to form a drain electrode. The invention further discloses a structure of the MOSFET manufactured through the method. By optimizing the etching parameters of the groove, the vertical shape of the groove of the grid channel is adjusted to the inclining shape, the polycrystalline silicon filling the groove does not generate gaps after being etched back, the situation that CT etching is carried out downwards along the gaps in the polycrystalline silicon is avoided, and it is ensured that the edge of a device is not broken down.

The invention discloses a multi-level boosted circuit, and a device and a system thereof. TVS tubes are arranged between an output node and a first capacitor as well as between the output node and a second diode, and other auxiliary devices are matched, so that the problem that a lower arm switching tube is easy to break down during power-on can be solved, the breakdown problem of the second diodeunder the condition of low input voltage can also be solved, the model selection of related devices is easier, and the cost is lower; moreover, after corresponding devices are added to the circuit, the normal boosting process is not affected, the voltage at the output end is easy to control, Meanwhile, the probability of electric shock accidents when the input end is operated is also reduced.

The invention discloses a semiconductor voltage-stabilizing and rectifying integrated device. In the invention, a cathode of the core of a voltage-stabilizing diode and an anode of the core of a rectifying diode are tightly jointed together; aluminum sheet layers are adhered to the anode end of the core of the voltage-stabilizing diode and the cathode end of the core of the rectifying diode; a molybdenum electrode is adhered to the other end of each of aluminum sheet layers; the two molybdenum electrodes are connected with leads respectively; and the core of the voltage-stabilizing diode, thecore of the rectifying diode, the aluminum sheet layers and the molybdenum electrodes are packaged in the same shell. The integrated device of the invention has the combined functions of voltage-stabilizing tube and a rectifying tube, has the obviously advantages of small size, light weight and low manufacturing cost, has the advantage of use in circuits which are susceptible to generating surge voltage and surge current. The integrated circuit is particularly suitable to be used in highly integrated, small-sized and micro-sized electronic equipment and apparatus with a relay and a contactor.

The invention discloses a metal nanowire detector and method for measuring vacuum ultraviolet intensity. By means of the metal nanowire detector and method for measuring the vacuum ultraviolet intensity, a vacuum ultraviolet spectral signal is absolutely measured. The detector is composed of a multihole anodised alumina template with nanometer holes, and single substance metal on which single substance metal nanowires can grow is deposited inside the nanometer holes of the multihole anodised alumina template. The detector is used for measuring the 30-250eV ultraviolet signal intensity under the vacuum environment. The measuring method comprises the steps that a copper ring sheet serves as a positive electrode, the metal nanowire detector serves as a negative electrode, an insulating washer is inserted between the copper ring sheet and the metal nanowire detector, the negative electrode is connected with a current meter in series, and a DC stabilized power supply which can provide positive voltage or back bias voltage for the positive electrode and the negative electrode is additionally arranged in a measuring loop; the metal nanowire detector is demarcated through a transmission standard detector; the demarcated detector is placed at a corresponding position in the light intensity signal measuring light path layout; a light path system is started to provide the positive voltage or the back bias voltage for the positive electrode and the negative electrode; the light intensity signal is measured based on the full electron yield method, measuring is efficient, and the signal is stable.

The invention relates to a high-end PMOS power tube driving circuit, and the circuit comprises a high-end linear voltage stabilization module, a bias voltage generation module, a high-voltage level shift module and an output buffer module, wherein the high-end linear voltage stabilization module is used for generating a control level according to an input reference voltage signal VREF; the bias voltage generation module is used for generating a bias level and providing a bias voltage for the high-end linear voltage stabilization module and the high-voltage level shift module; and the high-voltage level shifting module is used for performing level shifting on the input first square wave control signal Pctrl and converting the input first square wave control signal Pctrl into a second square wave control signal Pctrl-hs to be output. And the output buffer module is used for charging or discharging the grid electrode of the high-end PMOS power tube according to the second square wave control signal P_ctrl-hs so as to control the high-end PMOS power tube to be turned on or turned off. According to the drive circuit, the gate-source voltage of the high-end PMOS power tube can be effectively controlled within the safety voltage, the high-end PMOS power tube is conducted to the maximum extent, and the conduction loss is reduced.

The invention relates to a quick opening and closing method of a high-speed electromagnetic switch valve. For solving the problem that the closing time of an existing high-speed electromagnetic switch valve is unsatisfied, a follow current branch circuit resistor Rx is replaced by a resistor of a switch array, a follow current branch circuit resistor value is dynamically adjusted by detecting voltage UD at two ends of a coil during the opening and closing process of the high-speed electromagnetic switch valve, so that on the one hand, the voltage at two ends of the coil is ensured to be stabilized and lower than safe backward voltage, a previous-stage switch is ensured not to be broken down during the opening and closing process of the high-speed electromagnetic switch valve; and on the other hand, when the voltage at two ends of the coil is lower than safe voltage UA for a certain value (named as adjusting voltage UT in the method), the coil discharging speed is improved by increasing the follow current branch circuit resistor value, and accordingly the effects of ensuring safety of the previous-stage switch and shortening the closing time of a valve core of the high-speed electromagnetic switch valve.

The invention provides a method and a system for detecting a ground fault of a converter valve arm, wherein the method comprises the steps as follows: collecting a three-phase valve arm current and adirect current of a converter valve; calculating a zero-sequence current of the valve arm according to the three-phase valve arm current; calculating a differential current according to the zero-sequence current and the direct current of the valve arm; monitoring an amplitude value of the differential current, determining the theoretical occurrence of an intra-valve ground fault when monitoring that the amplitude value of the differential current is greater than a first predetermined threshold value, and disconnecting an AC (alternating current) circuit breaker connected with the converter valve. According to the invention, whether the ground fault occurs inside the converter valve can be accurately determined through the differential current calculated according to the zero-sequence current and the direct current of the valve arm; and through the disconnection of the AC circuit breaker connected with the converter valve, a valve arm sub-module can be protected from being broken down,and the stability and the reliability of the system operation can be improved.

The invention discloses a system capable of performing electric leakage protection for a cable. The system comprises a cable body arranged underground. The outer side of the cable body is provided with a protective layer; a gap is formed between the cable body and the protective layer; the protective layer is protected and separated every 1km through a separator plate; one end of the separator plate is connected with the inner wall of the protective layer, and the other end of the separator plate is connected with the outer wall of the cable body; different alarm modules and detection modulesare arranged in the protective layers of the partitions, and a control center receives signals sent by the alarm modules, monitors the operation condition of the cable in real time and disconnects power transmission of the cable body after receiving the alarm signals of the alarm modules. And various detection modules and alarm modules are arranged in the gap between the cable body and the protective layer, so that the condition of the cable can be detected in time, the detected data can be sent to the control center in real time, and a worker of the control center can know the working condition of each section of the cable.

The invention relates to a vertical charge transfer type photon demodulator and a working method thereof. The upper surface of a semiconductor is provided with a modulation-demodulation part, and the lower surface of the semiconductor extends to the bottom of a substrate to form a photosensitive part; the photosensitive part converts photons into photon-generated carriers, photo-generated electron-hole pairs are separated by using a vertical electric field, and electrons or holes are vertically transported to the surface of a semiconductor for optical signal demodulation. The two charge collection regions are 1.8 V, the modulation switch I is connected with 1.2 V, the modulation switch II is connected with 0V, the substrate electrode is grounded, a transverse electric field is generated at the upper part of the semiconductor substrate, and a vertical electric field is generated in other regions; photons are absorbed by the semiconductor and excite an electron-hole pair, the electron-hole pair is separated under the action of an electric field, and electrons move upwards to the surface of the semiconductor; and under the action of a transverse electric field, the electrons further move to the vicinity of a charge collection region and enters a depletion region generated by the electrons through diffusion to form a light current signal. The photon demodulator is small in size and high in sensitivity and quantum efficiency.

The invention relates to an air-switch working-state displaying device. The air-switch working-state displaying device comprises an air switch and three groups of displaying circuits with identical circuit structures; and in order to make up and overcome the defect of no working-state display existing in the traditional air switch, the working state of the air switch can be rapidly judged by additionally installing multiple simple electronic displaying circuits to provide favorable references for electricity users to clear faults and prevented from enlarging the range of the faults or generating electric-shock accidents due to the blind operation of the electricity users. The displaying circuits not only can be used as an upgrading device for the ordinary air switch, but also can be used for researching and developing new-style air switches by using the technical scheme of the displaying circuits.

The invention provides a technological method for electrostatically spraying 10-5017 blue epoxy powder on copper components. The method has the advantages that the components are preheated at the temperatures ranging from 100 DEG C to 104 DEG C for 5 minutes to 10 minutes, so that the thicknesses of electrostatically sprayed coatings can be effectively increased; the component preheating temperatures and various electrostatic spraying parameters are controlled, so that the thicknesses of the coatings can range from 101 micrometers to 254 micrometers under the control after the 10-5017 epoxy powder is electrostatically sprayed on bus bars, the maximum leakage currents of the bus bars with certain voltage withstand values are not higher than 0.83mA within 30 seconds under the conditions of frequencies of 50HZ and voltages of 1250V, and accordingly requirements of designers on the electrostatically sprayed coatings, with the 10-5017 blue epoxy powder, of the bus bars can be met.

The invention provides a silicon carbide MOSFET and a preparation method thereof. The silicon carbide MOSFET comprises a silicon carbide substrate, a first conductive type lightly doped epitaxial layer, a second conductive type lightly doped epitaxial layer, a contact region, a source region, a gate groove, a lightly doped injection region, a gate oxide layer, a gate, a dielectric layer, a metal electrode and a drain. According to the silicon carbide MOSFET, the first conductive type lightly doped injection region is arranged on the inner wall of the gate groove, so that the carrier concentration of a channel surface region can be effectively increased, the channel mobility is effectively improved, and the channel resistance is reduced.

The invention discloses a high-sensitivity array type passive lightning current sensor, which comprises a U-shaped pipe. The upper end of the U-shaped pipe is detachably connected with a sealing cover, the sealing cover and the U-shaped pipe form a symmetrical annular pipe, and the annular pipe is of a fillet square structure; a plurality of abutting blocks are arranged on the side face, adjacent to the sealing cover, of the outer side wall of the U-shaped pipe. A plurality of magnetoelectric structures are uniformly distributed in the annular pipe; magnetic aggregators are arranged at the positions between the magnetoelectric structures, and the magnetic aggregators are the same in structure and symmetrical to each other; the magnetoelectric structure comprises two mutually overlapped magnetostrictive sheets, and a piezoelectric sheet is arranged between the magnetostrictive sheets. The problem that in the prior art, an outdoor lightning current measuring device is insufficient in sensitivity can be solved, and measurement can be completed without an external power source; an opening-closing type detachable structure is used for solving the problem that an existing device cannot be detached after being installed; the performance of the sensor is improved by utilizing an array structure and combining a combined magnetic aggregator; the structure is simple, reliability is high and accuracy is good.

The invention discloses an electric leakage protection system for protecting a cable. The system comprises a cable body arranged underground, and also comprises a protective layer, wherein the protective layer is disposed at an outer side of the cable body. A gap is formed between the cable body and the protective layer; the protective layer is protected and partitioned by every 1km through a partition plate; one end of the partition plate is connected with the inner wall of the protective layer, and the other end of each partition is connected with the outer wall of the cable body; differentalarm modules and detection modules are arranged in the protective layers of the partitions, and a control center receives signals sent by the alarm modules, monitors the operation condition of the cable in real time and disconnects power transmission of the cable body after receiving alarm signals of the alarm modules. Various detection modules and alarm modules are arranged in the gap between the cable body and the protective layer, so that the condition of the cable can be detected in time, the detected data can be sent to a control center in real time, and a worker of the control center can know the working condition of each section of the cable.

The present invention provides a lightning arrester grounding overvoltage protection device and a using method thereof. A push rod motor is arranged on the lower side of the lightning arrester, and when a grounding fault occurs in a system, a controller controls the contraction motion of the push rod motor, and a non-fault phase (a voltage rising phase) is connected in series with the divider resistor, so that the voltage borne by the lightning arrester is reduced to protect the lightning arrester from being broken down; in a normal state, the push rod motor is controlled to extend out to isolate the divider resistor, so that the loss of the lightning arrester in an overvoltage state is effectively avoided.

The invention provides a three-phase AC motor power saver. A three-phase power supply is connected with three groups of output circuits respectively; after being connected in series, inductances L4 and L5 are connected an inductance L1 in parallel and connected with the A phase of the three-phase power supply; after being connected in series, inductances L6 and L7 are connected with an inductance L2 in parallel and connected with the B phase of the three-phase power supply; after being connected in series, inductances L8 and L9 are connected with an inductance L3 in parallel and connected with the C phase of the three-phase power supply; the invention has the advantages that the invention can avoid the breakdown of capacitors by adopting the technical proposal, has optimum compensation effect which is higher than the compensation index of the power factor in the prior art, effectively restrains the high harmonic generated by the motor, reduces the interference to the power network, and has simple structure, reliable works and obvious power-saving effect, etc.