118results about How to "Small time constant" patented technology

The invention provides a modularized multi-level converter with the direct-current fault ride-through capacity, wherein modules are divided into the first module and the second module. The structure of the first module is the same as the structure of a module in a traditional modularized multi-level converter, and a few semiconductor switches, a few diodes and a few damping resistors are added to the second module on the basis of the first module. The first module and the second module both have the level superposition function, but only the second module has the direct-current fault ride-through capacity. The modularized multi-level converter with the direct-current fault ride-through capacity not only can achieve the functions of a traditional modularized multi-level converter, but also has the direct-current fault ride-through capacity. Compared with an existing modularized multi-level circuit with the direct-current fault ride-through capacity, the circuit of the modularized multi-level converter is provided with fewer devices and simple in structure. The modularized multi-level converter is applicable to modulation and control strategies of the traditional modularized multi-level converter, applicable to high-voltage high-power occasions and particularly suitable for the high-voltage direct-current power transmission field in which a modularized multi-level converter is applied and prone to direct-current faults.

The invention discloses a super capacitor device containing a millet-husk-based porous active carbon material. The millet-husk-based porous active carbon material is prepared by uniformly mixing dried millet husks and an activator, performing carbonization and activation with a microwave device in the protection of an inert gas, adding distilled water to obtained black powder for suction filtration washing till the pH value is 6.4-7, and performing drying to obtain black powder. The black powder is the prepared millet-husk-based porous active carbon material. The millet-husk-based porous active carbon material (an active substance) prepared through the microwave method is mixed with a binder according to a certain mass ratio, distilled water is added for mixing to prepare a thick liquid, and the thick liquid is repeatedly rolled to obtain a sheet electrode material. The electrode material is put on a current collector with the corresponding size, cold pressing is carried out at 1-40 Mpa for 10-200 s, and drying is performed at 120 DEG C to obtain an electrode plate of the super capacitor device. The electrode material in the electrode plate is more than 14 mg per square centimeter. An electrode plate, a membrane, and an electrode plate are assembled into a sandwich structure, then different electrolytes are dropwise added, so that the super capacitor device is assembled.

The invention discloses an electric car power-grid voltage compensation method based on a virtual synchronous generator algorithm, and the method comprises the following steps: 1), employing the virtual synchronous generator algorithm for an electric car grid-connected interface, and carrying out the droop control based on P-f and Q-V; 2), obtaining the output frequency w and phase angle theta of the grid-connected interface through simulating a mechanical equation of a synchronous generator; 3), employing a voltage and current double-closed-loop control strategy based on the dp coordinate system for an electrical equation part; 4), adding virtual impedance control at the electrical equation part, wherein the virtual impedance comprises constant virtual impedance and transient virtual resistance; obtaining virtual voltage drop, and taking a voltage instruction E obtained at step 1) as a voltage ring d-axis instruction ed, wherein eq is equal to zero; respectively calculating the differences between the ed and eq and the virtual voltage drops vvd and vvq, and obtaining a voltage ring output voltage instruction (shown in the description); 5), obtaining a dq-axis modulation signal of the grid-connected interface through the output of a current ring at step 3), and obtaining a switching control signal of a converter switching network through coordinate conversion and PWM, so as to drive a switching network.

The invention discloses an integrated piezoelectric ultrasound and electromagnetic combination drive motor, mainly comprising a torsional vibration piezoelectric chip, a longitudinal vibration piezoelectric chip, a piezoelectric drive stator, a sleeve, an electromagnetic drive stator, a multiplex rotor, a pre-tightening spring, a fastening bolt, abrasion-proof material and an output shaft. The longitudinal vibration piezoelectric chip, the torsional vibration piezoelectric chip and the piezoelectric drive stator are sequentially installed on a circular thin-wall sleeve and connected by the abrasion-proof material and the multiplex rotor which is installed on the output shaft and offers pre-tightening force to compress the abrasion-proof material as well as the piezoelectric drive stator by the fastening bolt and the pre-tightening spring. The motor, on the structural basis of the traditional brushless dc torque motor, is embedded with a longitudinal and torsional combined piezoelectric drive, integrates the advantages of two drives almost without expanding the volume, and is characterized by both the high thrust, high reliability and long service life of electromagnetic drive and the high dynamic response (millisecond level), high control precision and passive self-locking of piezoelectric ultrasound drive.

The invention relates to a driving circuit, a liquid crystal device, an electronic device and a method for driving the liquid crystal device, which can restraining the decrease of the display quality at the same time of decreasing the power consumption. A pixel electrode and a common electrode which form a pixel capacitor are arranged on one of a pair of substrates used for holding the liquid crystal device. The liquid crystal device 1is provided with a scanning line driving circuit 10, a data line driving circuit 20, a control circuit 30 and partial circuits 40. In the display area under the full screen display mode and the partial screen display mode, the data line driving circuit 20 supplies the data line X with image signals after the control circuit 30 supplies a common electrode 56 with a voltage VCOML and a voltage VCOMH. In the non-display area under the partial screen display mode, if the control circuit 30 supplies the common electrode 56 with the voltage VCOML, the partial circuits 40 supply the data line X with voltage VCOMH.

The invention discloses a micro-nano scale platinum resistor temperature sensor capable of fast measuring the temperature. The micro-nano scale platinum resistor comprises a power source, an accurate resistor and a temperature sensing part. The temperature sensing part is fixed to a fixing part, the fixing part is a substrate slice with a middle hole, and the temperature sensing part comprises a plurality of temperature sensing platinum thin-film resistor blocks which are bent and connected through connecting pieces, the connecting pieces are partly fixed to the edge of the middle hole of the substrate slice, and the platinum thin-film resistor blocks and the connecting pieces are connected in series to form a ring shape to be hung into the middle hole. The head and the tail of the ring-shaped temperature sensing part form a circuit with the power source and the accurate resistor through a wire. According to the micro-nano scale platinum resistor temperature sensor, the fluid temperature can be measured rapidly along with the changes of the temperature of a platinum resistor in the temperature sensing part in the circuit.

An absolute radiometer for solar irradiance calibration and a radiometer internal thermal structure are disclosed and relate to the field of remote sensor on-orbit optical radiation measurement. The absolute radiometer for solar irradiance calibration and the radiometer internal thermal structure can help solve a problem that while a conventional thermal structure applied to the absolute radiometer is a normal cone cavity structure having a cylinder side face, contact between an absorption cavity and a thermopile can meet precision requirement for the absolute radiometer due to limitation of processing technologies. The absolute radiometer comprises the radiometer internal thermal structure; the radiometer internal thermal structure comprises a pressing sheet, a polyimide gasket, the thermopile, a heat sink ant the absorption cavity; the absorption cavity adopts the normal cone cavity structure having a hat brim, an inner wall is coated with a mirror surface reflecting layer, and the absorption cavity has a 30 degree central angle. An upper top face of the thermopile is connected with the hat brim of the absorption cavity, a lower bottom face is connected with the heat sink, and thermoelectric effects are used for collecting temperature difference between the heat sink and the absorption cavity. Connection parts of all assemblies are connected with each other via epoxy resin glue, a time constant of an optical radiation measurement experiment for the absolute radiometer is markedly reduced, and utilizability of solar irradiance on-orbit measurement data can be improved.

The invention relates to a voltage buffer applied to a high-speed analogue-to-digital converter, and belongs to the field of mixed signal integrated circuit designing. The voltage buffer comprises three P-channel metal oxide semiconductor (PMOS) transistor and three N-channel metal oxide semiconductor (NMOS) transistors. Connection relationships among the MOS transistors are that: the drain and gate of a first NMOS transistor are connected together and connected to the gate of the second PMOS transistor and the drain of the first PMOS transistor; a positive reference input voltage is connected to the gate of the first PMOS transistor after passing through a bonding wire; the source of the first PMOS transistor and the drain of the second PMOS transistor are connected together; the sources of the second and third PMOS transistors are connected together and finally connected to an external power potential after passing through the bonding wire; the drain and gate of the third PMOS transistor are connected together and connected to the gate of the third NMOS transistor and the drain of the second NMOS transistor; a negative reference input voltage is connected to the gate of the second NMOS transistor after passing through the bonding wire; the source of the second NMOS transistor and the drain of the third NMOS transistor are connected together; and the sources of the first and third NMOS transistors are connected together and finally connected to an external ground potential after passing through the bonding wire. The voltage buffer has the characteristics of higher charging speed and reference voltage capable of reaching rated accuracy faster.

A switching power supply unit is provided which provides improved response for frequency switching with a smooth rise in voltage. The switching power supply unit includes: a rectifier circuit for rectifying an alternating current from an AC power source into a direct current; a switching circuit for switching the current rectified by this rectifier circuit using a switching device; a pulse oscillator circuit for outputting a switching signal to the switching device; and a transformer circuit for stepping a voltage up or down depending on the current switched by this switching circuit. A frequency switching unit is also used to detect a pulse output from the switching circuit. Based on the state of this pulse output, the frequency switching unit changes a resistance using resistors, thereby switching the frequency of the switching signal in the pulse oscillator circuit.

The invention provides a method for preparing a metal micro-nano array electrode by using a ZnO crystal as a template. The method employs a ZnO crystal array as the template and comprises the steps of submerging the template by photoresist, dissolving ZnO away after the photoresist is stabilized, and electrodepositing the metal crystal in holes formed by dissolving ZnO away. The obtained metal crystal has ZnO morphology, being in hexagonal prism shapes.

The invention relates to a photovoltaic storage grid-connected control method and device for smoothing photovoltaic power fluctuation. The method comprises the following steps: 1) collecting grid-connected voltage of an optical storage hybrid microgrid system; 2) when that grid-connected voltage is great than or equal to the first set value and less than or equal to the second set value, judging that it is in a normal grid-connected mode, performing a certain voltage control on DC/AC, performing MPPT control on photovoltaic DC/DC, performing a first filter leveling control on battery DC/DC, and performing hot standby control on super capacitor DC/DC; 3) when that grid-connected voltage is low than the first set value, it is judging that it is in the low-voltage grid-connected mode, whereinthe DC/AC is subjected to reactive power setting control and current limiting control, the photovoltaic DC/DC is subjected to power limiting control, the battery DC/DC is subjected to hot standby control, and the super capacitor DC/DC is subjected to a second constant voltage control. The fine control of DC/AC, photovoltaic DC/DC, battery DC/DC and super capacitor DC/DC in normal grid-connected mode and low voltage grid-connected mode of the invention effectively suppresses power fluctuation in grid-connected mode of an optical storage hybrid micro-grid system.

The invention belongs to the technical field of aero-engine air inlet dynamic temperature distortion testing, and particularly relates to an air-breathing type pluggable thermocouple probe for the engine air inlet total temperature dynamic distortion test. The air-breathing pluggable thermocouple probe comprises a thermocouple support 1, a micro thermocouple 2, a galvanic couple socket, a galvaniccouple contact pin, an air collecting head 3, a probe outer shell 4, a locking nut 11, a positioning ring 12, a probe tail shell 13, a galvanic couple extension line 14 and an air entraining pipe 15.

A bipolar electrostatic chuck which has excellent dielectric breakdown strength and provides excellent attracting performance. The bipolar electrostatic chuck eliminates difficulty in peeling off a sample from a sample attracting plane as much as possible after application of a voltage to electrodes is finished. The bipolar electrostatic chuck is provided with a first electrode and a second electrode in an insulator and permits a surface of the insulator to be the sample attracting plane. The insulator has the first electrode, an interelectrode insulating layer and the second electrode in this order from the sample attracting plane in the depth direction. The second electrode has a region not overlapping with the first electrode in a normal line direction of the sample attracting plane.

The invention discloses a generator-rotor inter-turn short circuit diagnosis device based on excitation step method. The device comprises a direct current constant voltage source and data acquisition analyzers. The direct current constant voltage source is connected to an excitation winding through a first program control switch. A sampling resistor is connected in series to the excitation winding. The data acquisition analyzers are connected in parallel to two ends of the sampling resistor. The data acquisition analyzers determine whether a motor rotor winding generates an inter-turn short circuit through collecting an excitation current of the rotor winding. Two ends of the excitation winding are connected in parallel to a de-excitation resistor through a second program control switch. By using the device and the method of the invention, disadvantages in the prior art can be overcome, and an off-line diagnosis level of a turbonator rotor winding inter-turn short circuit fault is improved.

The present invention relates to a high stability thermistor capable of being used in fast temperature measurement of deep sea up to 3000 m. The thermistor prepared by using the oxides of Co, Mn and Ni and through compounding, grinding, dropping to form bead, sintering, painting and baking glass glaze, welding, soldering glass rod and aging. Test shows it has time constant of 20-50 ms in sea water, deep sea pressure resistance over 30 MPa and stability up to 0.001 deg.c per month.

The invention discloses a chip applicable to electrochemical real-time PCR and a preparation method of the chip. The preparation method comprises the following steps: growing an insulating layer on a substrate, and then preparing three electrodes including a working electrode, an auxiliary electrode and a reference electrode; then growing an insulating film on the surface of the working electrode, and transferring a mask pattern from a microarray electrode to the insulating film by virtue of a photoetching process and an etching process; and etching a region of the insulating film on the working electrode, so as to generate the microarray electrodes. Each microarray electrode is an independent reaction unit and is applied to electrochemical real-time PCR. The chips can be combined in series or in parallel for use and can be used for simultaneously carrying out multiple PCRs, so that the detection throughput is greatly increased; the chip has the advantages of being high in precision and throughput and capable of realizing low-concentration quantitative detection.

The present invention relates to a radiation detector basing on the flat-plate substrate; the detector comprises a substrate, a radiation-absorbing material, a thermistor and a heating wire; the substrate adopts the material which has the advantages of high heat conductivity, high insulating property and low heat capacity; the heating wire and theremistor respectively contact and are fixed on the surface of the substrate, the radiation-absorbing material is arranged at the upper side of the heating wire, and an insulating layer is used for insulating between the heating wire and the radiation-absorbing material. The invention has the advantages of small volume, small heat capacity; the electric impedance of the heating wire is large and the effect of electric impedance of the wire lead can be ignored; the sensitivity of the thermistor is high and the dynamic area can be detected is large, the radiation detector can be taken as the novel embedded scaling reference source on the spacecraft and can also be applied to other thermal radiation detecting field.