96results about How to "Good pressure equalization effect" patented technology

The invention provides a voltage balancing circuit used for a series super capacitors bank, and the voltage balancing circuit consists of a control logic device and an electrolytic capacitor. The control logic includes a divider circuit, a pulse generating circuit and a switch array. The voltage balancing circuit is connected with a super capacitor to be balanced. When the voltage difference of two adjacent supper capacitors exceeds the set range, the voltage balancing circuit transfers the electric charge from a high-voltage supper capacitor to a low-voltage supper capacitor, until the voltage difference of the high-voltage supper capacitor to the low-voltage supper capacitor enters into the set range. At that moment, the voltage balancing circuit stops working under the control of an internal empowering circuit and enters into a standby mode, and reduces the energy dissipation. The voltage balancing circuit has simple structure and low cost, can be installed easily, can effectively solve the problem that the voltage of a plurality of series super capacitors is not even.

The invention relates to a pressure-sore-preventing cushion capable of automatically regulating the pressure. The pressure-sore-preventing cushion comprises an airbag array composed of a plurality of airbags, a plurality of air channels, a base, a plurality of air guide pipes and an automatic pressure adjusting device, wherein the airbag array is divided into four airbag regions; all the airbags in each airbag region are communicated with one another; the airbags of any two adjacent airbag regions are not communicated; the plurality of air channels are located below the airbag array; each air channel is connected with at least one of the airbag regions and is communicated with the airbag region; the airbag array composed of the plurality of airbags and the plurality of air channels are arranged on the base; the plurality of air guide pipes are arranged in the base; one end of each air guide pipe is communicated with the corresponding air channel and the other end of each air guide pipe extends out of the cushion and is provided with a connector; each air guide pipe is provided with a respective valve; fluid of the automatic pressure adjusting device is communicated with all connectors of the plurality of air channels and is electrically connected with each valve on each air guide pipe so that the pressure adjusting device can inflate or deflate each air guide pipe.

In control circuit of half bridge convertor, after bias voltage at middle point of capacitance is leaded in circuit of bias voltage at middle point of capacitance composed of proportional integral controller, current generated is fed forward to current comparator. With being leaded in voltage comparator, the reference voltage and feedback voltage are connected to voltage regulator to generate given current, and then connected to the current comparator. The current feedback signal, current feedforward and given signals through the current comparator are connected to hysteresis comparator (or carrier comparator). The hysteresis comparator through the drive circuit controls the main circuit of convertor. The said bias voltage feedforward control and inductive current in half bridge convertor create part of DC component, which balances amperesecond value so as to remove DC bias in voltage at middle point of capacitance.

The invention discloses a three-phase symmetric topology for self-balance of capacitor voltage of an MMC (Modular Multilevel Converter) module. A half-bridge type MMC topology comprises inner-phase module capacitor self-circuits and inter-phase subsidiary loops. An inter-phase self-voltage-sharing circuit consists of 6(N-1) clamping diodes; and in switching of modules, unbalanced voltage of capacitors of the modules automatically flows from an i module to an (i-1) module, wherein the value of i is 2-(N-1). Each of the inter-phase subsidiary loops consists of six subsidiary capacitors, six subsidiary IGBTs (Insulated Gate Bipolar Translator) and nine subsidiary diodes, and a first module of a per-phase upper bridge arm and a last module of a per-phase lower bridge arm form two triangles by the inter-phase subsidiary loops, thereby realizing free flow of inter-phase energy. According to the topology disclosed by the invention, the self-balance of the inner-phase and inter-phase energy is realized; all the modules adopt identical sub-modules, thereby keeping consistency of the modules; and the inter-phase subsidiary loops at the two ends form the triangles, thereby keeping the symmetry of the three-phase topology.

The invention provides a method and system for controlling a three-phase four-wire inverter. The method comprises the steps of 1, acquiring all on-off states of a three-phase four-wire inverter to be predicted, and building a variable relation model of the three-phase four-wire inverter at a load disturbance state; 2, acquiring a voltage change pattern of a DC-side capacitor of the three-phase four-wire inverter, and acquiring predicted values of inductor current and capacitor voltage of an output side of the three-phase four-wire inverter in the next sampling period; and 3, selecting an on-off state, which enables a cost function result value to be the minimum, from all of the on-off states in each sampling period of the three-phase four-wire inverter to act as the on-off state of the three-phase four-wire inverter in the next sampling period. According to the invention, the distortion in voltage of an output filtering capacitor under load disturbance can be effectively suppressed, the inverter is enabled to output sinusoidal asymmetric three-phase voltage, and the voltage-sharing effect at the DC side is good; and meanwhile, the DC side can be enabled to acquire a good voltage-sharing effect under the condition that capacitance values of the capacitor are inconsistent.

The invention discloses a line-shaped series-connection small-gap dual-fracture vacuum arc-extinguishing chamber which can effectively reduce cost and promote the voltage withstanding level, and is provided with an insulated shell. An insulated support is located on the inner side in the insulated shell in the vertical direction, a transverse separating sheet is arranged on the middle portion on the inner side of the insulated support, fixed contacts protruding upward are symmetrically arranged on the upper and lower faces of the transverse separating sheet, and a shielding case is further connected on the inner side of the insulated support. An upper guide sleeve and an upper electric conductive rod arranged in the upper guide sleeve are arranged on the upper portion of the insulated shell, an upper moving contact is arranged at the lower end of the upper electric conductive rod, and is located above the fixed contacts. A lower guide sleeve and a lower electric conductive rod arranged in the lower guide sleeve are arranged on the lower portion of the insulated shell, and a lower moving contact is arranged at the upper end of the lower moving electric conductive rod and is located below the fixed contacts.

The invention discloses a novel safe grounding method of a transmission line tower. The method includes that a linoleum insulating layer is laid on the upper layer, and a three-dimensional ring-shaped grounding body is laid on the lower layer, so that hazard caused by step voltage and touch voltage of the transmission line tower is reduced. The three-dimensional ring-shaped grounding body comprises an upper layer cylindrical grounding body (4), a middle layer vertical connection body (5), a bottom circular ring (6) and a peripheral welding level radiation pole (7) with a circular ring structure. According to the method, dispersion resistance is effectively reduced, a GPF-94 resistance reducing agent is filled to the inside of the ring shape to improve soil parameters, reduce ground resistance and enlarge an effective cross section of the grounding body, and a good voltage balancing function is achieved. By means of the level radiation pole, current dispersing is greatly performed. The linoleum insulating layer is laid at a position of a peripheral ground voltage balancing body, which is 0.8m above the ground surface, so that permissible value of the step voltage is increased, and value of current which flows through a human body is decreased. The grounding method for decreasing step voltage of the transmission line tower has the advantages of being good in current dispersing and voltage balancing effects of the bottom layer, wide in application range, convenient to construct, corrosion resistant, safe and reliable.

The invention provides an automatic control pressure-equalizing fire preventing and extinguishing system in a large area. Master control equipment is used for transmitting signals of air pressures at two ends of an air leakage channel in a pressure-equalizing area and a signal of pressure difference of two sides of an air window to an upper industrial control computer and transmitting a command for adjusting the current frequency and a command for adjusting the air window according to a control command for pressure-equalizing adjustment transmitted by the upper industrial control computer; the upper industrial control computer is used for determining whether to transmit a control command for pressure-equalizing adjustment to the master control equipment or not according to the signals of the air pressures at the two ends of the air leakage channel and the signal of the pressure difference of the two sides of the air window; a first frequency converter is used for adjusting the rotating speed of a fan and the outlet air pressure according to the command for adjusting the current frequency; a second frequency converter is used for controlling a stepper motor to regulate the opening area of the air window according to the command for adjusting the air window. According to the automatic control pressure-equalizing fire preventing and extinguishing system provided by the invention, the revolution number of the fan and the air passing port area of the air window can be automatically controlled and adjusted, so that the pressure-equalizing area is always kept in a pressure balancing state, and the problem that the pressure-equalizing area is not equalized in pressure due to poorer precision and timelinesses is solved.

The invention discloses a grounding method of reducing local impact grounding resistance of a power plant and a substation, which comprises an inner-layer annular horizontal grounding body, an outer-layer annular horizontal grounding body, a horizontal connection body and a vertical grounding body. According to the grounding method of reducing local impact grounding resistance of a power plant and a substation, local impact grounding resistance of a power plant and a substation can be reduced, diffusion of local impact grounding current is enhanced, a grounding grid local electric potential can be prevented from rising, and safety of primary and secondary devices such as a transformer can be protected; electric potential and electric field distribution around a grounding electrode can be improved, the step voltage, device contact voltage values and the like can be reduced; and the grounding method of reducing local impact grounding resistance of a power plant and a substation has the advantages of wide application range, convenient construction, corrosion resistance, safety and reliability, and long service life.

The invention relates to a mixed voltage-sharing control method of cascaded STATCOM (static synchronous compensator) submodules. When in voltage-sharing control, a PWM pulse signal of each submodule is finally generated by adopting average direct-current voltage closed-loop control, positive-negative sequence separation current closed-loop decoupling control, submodule direct-current voltage closed-loop feedback control and carrier phase-shifting high-frequency alternating control, the voltage imbalance caused by the loss difference of various submodules can be eliminated by virtue of the submodule direct-current voltage closed-loop feedback control, and the effective balanced control of the voltage of the cascaded STATCOM submodules is realized; moreover, the carrier is alternated by adopting a high-frequency alternating period, so that the alternating period is short, the control speed is high, and the voltage-sharing effect is very remarkable; and moreover, the pulse difference caused by the carrier phase shifting among various submodules can be effectively eliminated, and the voltage-sharing effect of the submodules in a chain is improved.

The invention relates to a pressure sore prevention seat cushion. The pressure sore prevention seat cushion comprises an airbag layer, an airway layer, a base layer and a plurality of air conduits; the airbag layer is provided with a plurality of airbags; the airbag layer is divided into at least four airbag regions; all the airbags in each airbag region are communicated mutually, however, the airbags in any two adjacent airbag regions are not communicated; the airway layer is positioned below the airbag layer, and a plurality of airways are formed in the airway layer, wherein each airway is connected and communicated with at least one airbag region; the airway layer and the airbag layer are arranged on the base layer; one end of each air conduit is communicated with the corresponding airway and the other end of the air conduit extends out of the seat cushion and is provided with a joint; each air conduit is provided with a respective valve. The pressure sore prevention seat cushion disclosed by the invention can enable the hip of a human body to be intermittently pressed so as to effectively prevent pressure sores.

The invention provides a mixed double sub-module MMC voltage balancing control method and device. For any bridge arm, comprehensive voltage indexes of each sub-module are ranked according to the current direction of the bridge arm, plus or minus of the sum of voltage differences in modules of the whole bridge arm and plus or minus of the number of input sub-modules, and the output states corresponding to the sub-modules are determined; the comprehensive voltage indexes are relevant to the plus or minus of capacitor voltage sum in the modules and the capacitor voltage difference in the modules. Based on voltage balancing control of inter-module ranking of the comprehensive voltage indexes, the effects of capacitor voltage balance in the modules and capacitor voltage balance between the modules are achieved, and a good voltage balancing effect can be achieved under multiple working conditions of start, normal operation, fault ride-through and the like of a mixed double sub-module MMC system.

The invention provides a distributed sub module control method. The method comprises steps that sub modules of each bridge arm are grouped, each group corresponds to one valve control device, weight of each group is calculated by an upper level control device according to a bridge arm current, the average voltage of each set of normal sub modules and the quantity, the quantity of involved sub modules of each group is calculated through combination with the quantity of involved sub module of the corresponding bridge arm and is issued to the valve control device, and the valve control device realizes operation according to the voltage sharing strategy and the gating method provided in the prior art.

The invention relates to a liquid-gas mixer and a gas-liquid recovery device by employing the liquid-gas mixer, the mixer is composed of a power drive chamber and a jet mixing chamber which are mutually connected, several jet pipes are arranged on a separator plate in the power drive chamber, the inlet end of the jet pipe is positioned on in the power drive chamber, the outlet end is positioned in the jet mixing chamber, the jet mixing chamber is composed of a suction chamber, a reducing pipe, a trunnion and a increasing pipe which are connected in order from up to down or from left to right, a pressure liquid inlet is arranged on the power drive chamber, an inlet of gas to be treated is arranged in the jet mixing chamber, the gas-liquid recovery device comprises the liquid-gas mixer and a pressurization circulating system, and a liquid discharge pipe is connected to a liquid return pipe of the pressurization circulating system. The liquid-gas mixer and the gas-liquid recovery device have the advantages of good liquid-gas mixing effect, low energy consumption, large processing amount and low operation cost, and are especially adapted to liquid substance recovery in a certain gaseous substance, such as recovery of waste vapour in flue gas.

The invention provides an optimized merging and sorting based modular multilevel converter capacitor voltage equalizing method, which is characterized in that a merging and sorting algorithm is optimized through analyzing a capacitor voltage law of nearest level modulation in an ideal condition by using a modular multilevel converter modulation technology, the time complexity of optimized merging and sorting is further reduced, the execution time of actual sorting is reduced to the minimum, the sorting efficiency is very high, and sorting is not restricted by the number of sub-modules. In addition, a non-ideal condition correction optimized merging and sorting algorithm is provided by combining a direct insertion sorting method, the sorting accuracy can be ensured by correcting the optimized algorithm, the voltage equalizing effect is good, and the extra time overhead is small.

The invention provides a doubly-fed frequency converter and a modulation method thereof, the doubly-fed frequency converter comprises a three-phase bridge arm and a control unit, and each phase bridgearm comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module and a sixth switch module. The control unit controls the on and off of the first switch module, the second switch module, the third switch module, the fourth switch module, the fifth switch module and the sixth switch module, thereby enabling each phase of bridge arm to enter a positive half-wave period state, a positive dead zone state, a positive zero state, an all-zero state, a negative zero state, a negative dead zone state and a negative half-wave period state.

The invention relates to a dynamic voltage-sharing simulation test method for a multi-break high-voltage direct-current fast mechanical switch. The dynamic voltage-sharing simulation test method is used for solving the problem of multi-break series-connection dynamic voltage sharing of the direct-current fast mechanical switch. The dynamic voltage-sharing simulation test method comprises the following steps that (1) the maximum stroke difference of moving contact actions of all breaks is determined; (2) a switch equivalent resistance-capacitance network is established; (3) voltage-sharing resistance-capacitance parameters of all the breaks are calculated; (4) a voltage-sharing test is conducted; (5) a voltage division ratio test is conducted; and (6) the optimum voltage-sharing resistance-capacitance parameter is determined. The dynamic voltage-sharing simulation test method for the multi-break high-voltage direct-current fast mechanical switch can equivalently solve the problem that it is difficult to adjust different periods by adopting a quick operating mechanism during an actual real-type test, the testing cost is lowered, and the testing efficiency is improved.

The invention discloses a capacitor voltage balance control method for a cascaded H-bridge rectifier. A DC side capacitor voltage balance control strategy based on PI control is researched on the basis of establishing a mathematical model of the CHBR, a carrier phase-shifting modulation strategy is adopted, a relation between a modulation ratio and an active power is derived theoretically, and a voltage-sharing range of the capacitor voltage balance control is obtained, so that the voltage-sharing capacity is good.

Disclosed is a novel supercapacitor voltage sharing circuit. The novel supercapacitor voltage sharing circuit comprises resistors, operational amplifiers, a triode and a supercapacitor single body. The negative input end of the operational amplifier I is used for inputting a single body reference voltage, a module reference voltage is input to the positive input end of the operational amplifier I through a wire and the resistor R3, one end of the resistor R4 is connected to the positive input end of the operational amplifier I, the other end of the resistor R4 is connected to the output end of the operational amplifier I, the output end of the operational amplifier I is connected to the negative input end of the operational amplifier II through the resistor R5, the positive input end of the operational amplifier II is connected to a VCC, the output end of the operational amplifier II is connected with the base of the triode through a wire and the resistor R2, and the emitter of the triode is connected back to the collector of the triode through a wire, the supercapacitor single body and the resistor R1. The novel supercapacitor voltage sharing circuit solves the problems that the difference between the supercapacitor single body and a single body can not be fed back and the voltage sharing speed is low in the prior art.

The invention discloses a solid-sealed polar pole for primary and secondary deep fusion, which comprises an insulating shell, and is characterized in that the insulating shell is internally provided with a vacuum arc-extinguishing chamber, an electricity taking device, a current detection device, a first voltage sensor, a second voltage sensor, a metal shielding net, a first conductive insert, a second conductive insert, a third conductive insert and a fourth conductive insert; the insulating shell is provided with an inlet wire electric connecting piece and an outlet wire electric connectingpiece. According to the invention, the power taking device, the current sensor and the voltage sensor can be integrated in the pole; a capacitor electricity taking function can be achieved, the current condition can be monitored in real time, the two voltage sensors poured in the pole can monitor the voltage on the two sides of the fracture of the vacuum arc-extinguishing chamber, monitored voltage and current signals can be used for estimating the equipment state and supporting feeder automation, and the purpose that primary equipment and secondary equipment are deeply fused in one step is achieved.

The invention discloses a cable insulation comprehensive diagnosis and test system, which comprises a high-voltage generating unit, a high-voltage switch, a high-voltage electric reactor, a capacitivevoltage divider, a PC control unit and a partial discharge coupling capacitor, wherein the PC control unit is connected with the high-voltage generating unit, the high-voltage switch and the partialdischarge coupling capacitor separately, an output end of the high-voltage generating unit is connected with input ends of the high-voltage switch and the high-voltage electric reactor, an output endof the high-voltage electric reactor is connected with an input end of the capacitive voltage divider and a tested cable separately, and an output end of the capacitive voltage divider is connected with an input end of the partial discharge coupling capacitor; and the upper ends of the high-voltage electric reactor and the capacitive voltage divider are each provided with a voltage equalizing mechanism. The cable insulation comprehensive diagnosis and test system has the advantages of convenient installation and capability of improving voltage equalization effect.

The invention discloses a compact integrated power supply device for an ion accelerator. The compact integrated power supply device comprises a shell body and a base, wherein the shell body is provided with a high-voltage output interface and an isolation power supply output interface, and the base is provided with a vacuum exhaust port, an oil injection port, a high-voltage input interface and anisolation power input interface; a high-voltage power supply circuit, an isolation power supply circuit, a high-voltage measuring circuit and a voltage equalizing circuit are arranged in the shell body; the high-voltage power supply circuit comprises a high-voltage step-up transformer, a high-voltage voltage-multiplying circuit and a high-voltage protection circuit; the isolation power supply circuit comprises an isolation transformer system and an isolation power supply sampling circuit; the high-voltage measuring circuit comprises a measuring resistor and a filtering capacitor; the voltageequalizing circuit comprises a voltage equalizing resistor; and input voltages of the isolation transformer system and the high-voltage step-up transformer are adjusted by setting a microprocessor. The high-voltage step-up circuit and the isolation transformer circuit share a set of voltage equalizating system, thereby ensuring that the isolation transformer and levels of the high-voltage step-upcircuit can be at the same potential, improving the voltage equalization effect, and simplifying the voltage equalizing device.

The invention discloses a twelve-phase three-level H-bridge direct-current side cascade propulsion frequency converter which is formed by cascading the direct-current sides of two six-phase three-level H-bridge propulsion frequency converters, wherein the cascade upper-end propulsion frequency converter is provided with a non-return diode at a direct-current input positive electrode, the cascade lower end propulsion frequency converter is provided with a non-return diode at a direct current input negative electrode; the three-level H-bridge direct-current side cascade topology suitable for direct-current 10kV is developed based on a mature three-level H-bridge topology, and compared with other five-level or modular multi-level topologies, the three-level H-bridge direct-current side cascade topology does not involve an absorption loop or a complex large commutation loop, and is provided with a simple main circuit. The invention further discloses a capacitor voltage balance control method; neutral-point potential adjustment based on zero-sequence voltage injection is adopted; three-level upper and lower H bridges are adjusted through loads; and themethod is easy to implement and does not affect an original control strategy.

The invention provides a circular ring type self-pressure equalizing tension hanging plate. The hanging plate comprises a hanging plate body, a plurality of ball head hanging rings, a plurality of bowl head pressing plates and a plurality of rubber gaskets for bearing pressure and reducing vibration, wherein the hanging plate body is formed by combining two tension circular ring hanging plates ina symmetrical structure through a fastening piece; after the combination of the two tension circular ring hanging plates, the radial cross sections of the two tension circular ring hanging plates forma circular cross section for pressure-equalizing and shielding; the upper edges of the tension circular ring hanging plates are evenly distributed with a plurality of holes of which the internal diameter is larger than the bowl head diameter of the ball head hanging rings along a circumferential direction; each bowl head pressing plate is provided with a ball head hanging hole through which the bowl head of the ball head hanging ring passes to hold the bowl head hanging hole of the bowl head; each rubber gasket is provided with a bowl head hole through which the bowl head on the bowl head hanging ring passes; and the bowl heads of the bowl head hanging rings pass the holes of the tension circular ring hanging plates, the bowl head holes of the rubber gaskets and the bowl head hanging holes of the bowl head pressing plates in sequence and then are hung on the bowl head pressing plates. The hanging plate has the advantages of having good self-pressure equalizing effect, avoiding addingpressure-equalizing rings and saving cost.

The invention belongs to the technical field of molecular sieve oxygen generators, and particularly relates to an intelligent medical molecular sieve oxygen generation system. The intelligent medical molecular sieve oxygen generation system comprises an air compressor, an oxygen generator body, a paramagnetic oxygen concentration analysis instrument, a gas pressure reducing valve, a flow regulator, an oxygen generator body, an oxygen generator full-automatic controller, an oxygen output protection device, an alarm assembly, a power supply, an oxygen generation main machine control system and an uninterruptible power supply. The system is simple in structure, the air quality is further improved through multiple times of filtration, the oxygen production concentration can be displayed in real time through the oxygen generator full-automatic controller, the pressure equalizing assembly equalizes the pressure of gas in an oxygen generation molecular sieve tower, and molecular sieve damage caused by the instant gas amount when the gas pressure is large is prevented, so that the oxygen production efficiency is improved. The oxygen output end of the medical molecular sieve oxygen generation system is provided with an automatic regulation and control electromagnetic valve and the alarm assembly for monitoring and feeding back whether oxygen passes through the electromagnetic valve or not, so that the situation that oxygen does not reach the standard is avoided.

The invention discloses a double-tube flyback power supply circuit, which comprises: a flyback transformer, wherein one end of the primary side coil of the flyback transformer is connected to a firstnode, and the other end of the primary side coil of the flyback transformer is connected to a second node; a first MOS tube, wherein the source electrode of the first MOS tube is connected to the first node, and the drain electrode of the first MOS tube is connected to a first direct-current bus end; a second MOS tube, wherein the source electrode of the second MOS tube is connected to a second direct-current bus end, and the drain electrode of the second MOS tube is connected to the second node; a first diode, wherein the cathode of the first diode is connected to the first node, and the anode of the first diode is connected to a fourth node; a second diode, wherein the anode of the second diode is connected to the second node, and the cathode of the second diode is connected to a third node; an absorption capacitor, wherein one end of the absorption capacitor is connected to the third node, and the other end of the absorption capacitor is connected to the fourth node; a first auxiliary voltage-sharing circuit; and a second auxiliary voltage-sharing circuit.

The invention discloses an automatic pressing device and method. The device relates to the field of industrial control and comprises a code scanning gun, a bearing disc, a plate arranging table and apressing machine. The traditional kraft paper is replaced by the pressing pads with different sizes, and a corresponding pressing pad is selected according to a first identification code information of a to-be-processed PCB, so that the problem that laminated sundries, pits and the like are scrapped due to the fact that kraft paper easily carries the sundries to enter the inner periphery during use is avoided; and meanwhile, the heat insulation and pressure equalizing effects of the pressing pad are good, the pressing quality can be improved, automatic operation of the laminating procedure isachieved by changing the pressing process, and due to the automatic operation mode, operation posts for replacing kraft paper, arranging plates and disassembling the plates are reduced, the labor costis reduced, the pressing quality is improved, and meanwhile the working efficiency is improved.

The invention discloses an output voltage-sharing method and system for multi-path series charging piles. The method comprises the steps: respectively collecting the output voltage and output currentsignals of each path of three-phase interleaved LLC; subtracting the output current from a set current reference value, and performing PI operation; subtracting the output voltage of the two paths ofthree-phase interleaved LLC, and then performing PI operation; subtracting results of the two PI operations to serve as modulation waves of a PWM output signal, and generating the PWM output signal; and enabling a PWM to output a signal to drive a switching tube of the three-phase interleaved LLC to adjust the output voltage of the corresponding three-phase interleaved LLC so as to realize the output voltage equalization of the two paths of three-phase interleaved LLC. The invention has the beneficial effects that the output voltage of the three-phase interleaved LLC can be kept consistent ina constant-current mode, so the voltages at the two ends of a bus C1 and a bus C2 are kept balanced, and the voltage equalizing effect is good.

The invention provides a microsecond electronic switch apparatus. The microsecond electronic switch apparatus comprises two IGBTs, two diodes, five heat dissipation plates, two press-mounting plates,an absorption capacitor and a direct-current bus capacitor group, thereby finally implementing microsecond turn-off. According to the microsecond electronic switch apparatus, the microsecond protection can be implemented; moreover, a protected current grade is relatively high and can be up to a grade of a current flowing through a device in a testing process; the microsecond electronic switch apparatus can implement the effects that when the protection switch is turned off, an overvoltage is relatively low, the voltage equalization performance is good, and an output voltage and an output current can be improved to a required range; not only is the cost saved, but an inductance value of a parasitic inductor also is reduced; and the diode and the absorption capacitor are arranged, so the possibility that the device is broken through by the overvoltage is avoided, and the voltage equalization is implemented via a static partial voltage of an equalization resistor.

The invention discloses a half-V-shaped suspension string for preventing windage yaw. The half-V-shaped suspension string sequentially comprises an overhanging yoke plate, a yoke plate, a pillar insulator string and an I-type insulator, an iron tower cross arm arranged from bottom to top. The suspension yoke plate is connected with a yoke plate. The yoke plate is respectively connected with the post insulator string and the I-shaped insulator string, an acute included angle is formed between the lower end of the post insulator string and the lower end of the I-shaped insulator string, the postinsulator string and the I-shaped insulator string are both connected with an iron tower cross arm, and the I-shaped insulator string is vertically connected with the iron tower cross arm. The structure can ensure that the air gap between the wire and the iron tower does not exceed the limit under severe weather conditions such as sand storm, thereby being suitable for the side phase of the powertransmission line straight line iron tower in a gale area, preventing the overhead power transmission line from windage yaw flashover, avoiding large-area power failure accidents, and improving the power supply reliability of a power grid.