41results about How to "Achieve pressure equalization" patented technology

The invention discloses a voltage-equalizing and power-equalizing control method for a three-phase multi-module cascade solid-state transformer. A three-phase SST system power main circuit part applied in the method comprises an input stage, an intermediate stage and an output stage, wherein a control policy based on three-phase d-q-0 vector control is adopted in the input stage, a common duty ratio control policy is adopted in modules in the same phase so as to achieve the unit power factor of an input end of an electric network; a control policy based on voltage feedforward and voltage feedback is introduced for each module in the intermediate stage, the voltage feedforward is used as a reference of the voltage feedback, and an error between the voltage feedforward and the voltage feedback is used as a reference of an inner current loop of each module after being output by a voltage PI adjuster. The two control policies of the front stage and the intermediate stage interact so as to achieve the functions of voltage and power equalization of each SST module, electrical network side unit power factor, high electrical network current sine degree, low switching tube voltage stress and the like.

The invention discloses a lightning-protection method and a voltage-sharing lightning-protection device for a transmission line composite insulator, the device comprises: a first subpart of the voltage-sharing lightning-protection device is installed at one side of the composite insulator, wherein the first subpart comprises a first electrode with a protruding end, and the first subpart has the voltage-sharing capacity; while a second subpart of the voltage-sharing lightning-protection device is installed at the other side of the composite insulator, wherein the second subpart comprises a second electrode with a spherical end, and the second subpart has the voltage-sharing capacity; wherein, the first electrode and the second electrode construct a parallel connection gap. The method and the device of the invention realize dual functions of voltage sharing and lightning-protection for the composite insulator, prevent the metal at the end of the composite insulator from being burned by electric arc and effectively prevent the composite material from burning and damaging.

The invention discloses an IGBT (insulated gate bipolar transistor) series connection voltage balancing control method and belongs to the technical field of power electronic conversion. The method includes: utilizing an active clamping circuit equipped for each IGBT to extract working voltage spike signals of each IGBT; combining with a comparison circuit to acquire voltage spike actual lasting time value; utilizing time information acquired by detection, combining with an adjusting scheme designed in an optimized manner according to actual series connection working characteristics of each IGBT to adjust driving signal edge of each IGBT, and realizing voltage balancing of the IGBTs after adjusting for several times. The voltage balancing control method is suitable for part of mesohigh-power IGBTs, and the adjusting mode is designed according to actual working characteristics of the IGBTs, so that the method is simple and easy to realize, and quickness of series connection voltage balancing of the IGBTs can be improved while high stability is guaranteed.

The invention discloses a DC bus capacitor voltage equalizing device. A DC bus capacitor comprises N capacitor bodies which are connected in series, wherein N is an integer larger than 1. The voltage equalizing device comprises N LLC resonant converters and a Buck circuit, wherein the N capacitor bodies which are connected in series are correspondingly connected with the N LLC resonant converters in a one-to-one mode, the output ends of the N LLC resonant converters are connected in parallel, and the N LLC resonant converters work at respective series resonance points; the Buck circuit is connected with the output ends of the N LLC resonant converters, and the Buck circuit is used for conducting closed-loop regulation on the N LLC resonant converters to output stable DC voltage. The voltage equalizing device can equalize voltage of the DC bus capacitor and is low in energy loss.

The invention relates to pressure control equipment for a fuel cell, and belongs to the field of associated equipment of a fuel cell, in particular to auxiliary pressure balance equipment for a fuel cell used in the field of new energy automobiles. The pressure control equipment comprises a tubular shell, wherein a first isolation part and a second isolation part are arranged in the shell; the inside of the shell is partitioned into a fuel gas cavity, an air cavity and a pressure-regulating cavity; the fuel gas cavity and the pressure-regulating cavity are sealed and isolated through the movable first isolation part; the air cavity and the pressure-regulating cavity are sealed and isolated through the movable second isolation part; the fuel gas cavity is used for communicating with a fuel gas source; the air cavity is used for communicating with an air source; the pressure-regulating cavity is used for communicating with an inflating and deflating device. In the structure, the pressure difference between the fuel gas cavity and the air cavity can be balanced in real time through the principle that the first isolation part and the second isolation part can move under the pressure difference; moreover, the air pressures in the fuel gas cavity and the air cavity can be regulated to a required air pressure range in real time through the pressure-regulating cavity; the pressure-regulating cavity is connected to the two sides of the fuel cell, so that pressure keeping and pressure balancing in the fuel cell are realized.

The invention discloses a neutral point static clamping voltage-sharing circuit for a three-level inverter. The neutral point static clamping voltage-sharing circuit comprises a stack structure of four transistors, wherein a node A is at the joint of the first transistor and the second transistor; a node C is at the joint of the second transistor and the third transistor and serves as a voltage output end; a node B is at the joint of the third transistor and the fourth transistor; direct-current voltage DC+ and direct-current voltage DC- are connected at two ends of the stack structure of fourtransistors respectively; a series capacitor C1 and a series capacitor C2 in parallel to the stack structure of four transistors are connected between the direct-current voltage DC+ and the direct-current voltage DC-; and a parallel circuit is connected between the node A and the node B. The voltage uniformity of the insulated gate bipolar transistors can be guaranteed at static state, overvoltage breakdown damage is prevented, the circuit is simple, reliable, stable in operation and small in occupied space, any type and specification of the insulated gate bipolar transistor of any type and specification can be protected by adjusting the resistance value of a resistor R, and the circuit has great application prospects.

The invention discloses a production method of a low-temperature plasticized fiber composite material and a product thereof, and the method comprises the following steps: step 1, adding a polycaprolactone raw material into a drying box, drying the raw material at 30-50 DEG C, and putting a fiber raw material into the drying box, and drying the fiber raw material at 110-130 DEG C; step 2, adding 0.03-0.04% of a cross-linking sensitizer into the dried polycaprolactone raw material, and stirring the raw material in a high-speed stirrer to obtain a polycaprolactone mixture; step 3, mixing the polycaprolactone mixture and the dried fiber raw materials according to a mass ratio of 1:0.4-1:1.2, carrying out high-temperature fusion, and cooling the mixture to obtain a composition sheet; step 4, carrying out radiation crosslinking treatment on the composition sheet to crystallize the polycaprolactone polymer, so as to obtain the low-temperature plasticized fiber composite material with high hardness at normal temperature. The material can be used for manufacturing insoles of high-heeled shoes.

The invention relates to the technical field of power electronic conversion, in particular to a switch power source of an output ripple suppression circuit topological structure. The switch power source comprises a power circuit and an output circuit connected to an output end of the power circuit. The switch power source is characterized by further comprising a filter, a first control loop and asecond control loop, the filter is connected between the power circuit and the output circuit, and an input end of the first control loop is connected with the output circuit while an output end is connected with the filter; the first control loop is used for acquiring voltage of the output circuit, comparing with a set value and taking an obtained error value as a reference to control a stable value of the filter; the second control loop is used for acquiring voltage at two ends of the filter to take as a reference, comparing with a set value and controlling output voltage of the power circuit. By adding of a filter circuit to output of the switch power source and current sharing of the filter circuit, output voltage stable control and ripple suppression are realized through two-stage control loops.

The invention discloses an automatic stress gradient loading device. The device comprises a rigid frame, wherein four rigid loading side plates are arranged in the rigid frame, a square loading cavityis defined by the four rigid loading side plates, the rigid frame is further provided with end covers for sealing two ends of the square loading cavity, a force transmission assembly is mounted in the loading cavity in a matched mode, a cylindrical sample loading cavity is formed in the middle of the force transmission assembly, the force transmission assembly comprises an elastic cylindrical sleeve, an elastic circular truncated cone arranged outside the elastic cylindrical sleeve in a sleeving mode and a square elastic body arranged outside the elastic circular truncated cone in a sleevingmode, and the force transmission assembly further comprises a loading system arranged in the rigid frame and used for applying the force to the four rigid loading side plates. The device has the characteristics of simple structure, convenience in operation and capability of realizing gradient loading of the axial stress of the sample.

The invention relates to a high and low voltage compatible wireless power transmission system and a manufacturing method of a resonant inductor integrated transformer thereof. The system comprises a transmitting coil end and a receiving coil end, the receiving coil end further comprises a resonant inductance integrated transformer, a primary winding of the resonant inductance integrated transformer is connected with the receiving end LCC compensation network, and a secondary winding of the resonant inductance integrated transformer is connected with the receiving end rectifier bridge. The leakage inductance of the primary winding of the resonant inductance integrated transformer replaces the compensation inductance of the LCC compensation network at the receiving end to enable the receiving coil end to reach a resonant state at a rated frequency, and the transformation ratio of the primary winding and the secondary winding of the resonant inductance integrated transformer is changed to be compatible with a rechargeable battery charged at high and low voltages. The beneficial effects are that the resonant inductor integrated transformer replaces a resonant compensation inductor to realize impedance matching, and the charging requirements of different voltage levels are met.

The invention provides a high-voltage isolation transformer with a combined insulation structure and belongs to the technical field of isolation transformers. The high-voltage isolation transformer comprises a bottom plate, an insulating sleeve, a top plate and a grading ring; the insulating sleeve is coiled to form a cylinder with an internal mounting space; a transformer assembly is suitable forbeing arranged in the mounting space; and an insulating gas is suitable for being accommodated in the insulating sleeve. According to the high-voltage isolation transformer of the invention, a mode combining gas insulation and solid insulation is adopted, wherein the gas insulation is used as the main insulation for high-voltage isolation, and the gas insulation is used as auxiliary insulation for improving the surface insulation characteristic of the transformer. The high-voltage isolation transformer can be flexibly expanded to high-voltage isolation transformers with voltage classes of more than 35kV. Compared with a conventional dry-type transformer, the high-voltage isolation transformer of the invention has the advantages of higher insulating strength, low partial discharge suppression, low noise and high heat dissipation. The application of the isolation transformer under direct-current high voltages of 100KV or more can be realized; and the long-term reliable application of the isolation transformer under direct-current voltages or alternating-current voltages is realized.

The invention discloses a voltage-sharing method of an IGBT (insulated gate bipolar transistor) serial connection opening process, and belongs to the technical field of power electronics conversion. The voltage-sharing control method utilizes an opening process active clamping circuit configured to every IGBT, increases a simple isolation detecting circuit and detects voltage reduction moment of an IGBT set emitter. The FPGA is used for performing information treatment on a returning signal of the detecting circuit, extracting delay time numerical value of the opening process of every IGBT, and applying these time information to adjust the rising edge of the IGBT driving signal; after adjusting for many times, the voltage sharing of every IGBT is realized. The voltage-sharing control method proposed in the invention is applicable to a part of middle and high voltage power IGBT; the method is simple and easy to practice; besides, the method has the advantages of realizing the voltage-sharing speedability of the opening process of the IGBT serial connection while guaranteeing high stability.

The utility model provides a reactor grading ring. The reactor grading ring is provided with a separation rod, the two ends of the separation rod are respectively provided with grading rings, the lower end of the separation rod is provided with a base, a telescopic link is arranged between the base and the separation rod, the telescopic link is provided with a press tongue, the rear side of the press tongue is provided with a cavity, the cavity is internally provided with a compressed spring, and the press tongue and the compressed spring are connected to each other. The telescopic link is arranged at the lower portions of the grading rings to regulate the heights of the grading rings so as to achieve different-height grading work, connection grooves are arranged at the inner sides of thegrading rings, and pressure equalizing plates can be put in the connection grooves to achieve further pressure equalizing of the pressure equalizing plates.