155results about How to "Guaranteed inhibitory effect" patented technology

The invention discloses a non-isolation type three-phase three-level V2G charge-discharge topological structure. The non-isolation type three-phase three-level V2G charge-discharge topological structure comprises a main circuit module and a control circuit module, wherein the main circuit module comprises three parts in cascading manner, including a DC / DC part, an H bridge balance circuit and a DC / AC part; a vehicle-mounted power battery is connected to a direct current positive bus and a direct current negative bus through a bidirectional half-bridge converter; the H bridge balance circuit and two voltage-division capacitors C1 and C2 are arranged between the direct current positive bus and the direct current negative bus, and the direct current positive bus and the direct current negative bus are connected with the output end of the bidirectional half-bridge converter in parallel; the direct current buses are connected with a diode clamping type three-level PWM converter; a three-phase alternating current power supply live wire is connected to connecting places of upper and lower bridge arms of each phase of the bridge arms through a three-phase LC filter; the direct current buses are positioned in the H bridge balance circuit; according to the H bridge balance circuit, an IGBT switch tube Tb1 is in anti-parallel connection with a rapid recovery diode, or the switch tube Tb1 with an in-vivo parasitic diode is connected with a one-way conducive free-wheeling diode Db1 in series to form one side bridge arm, and a balance inductor Lb1 is connected in the middle thereof; the other end of the balance inductor is connected to a direct current side middle point; the bridge arms on the two sides are connected with a shared negative electrode and a shared positive electrode; and namely, the upper ends of the bridge arms are both connected to the direct current positive bus while the lower ends of the bridge arms are both connected to the direct current negative bus.

The invention discloses a hydraulic pipeline fluid pulse active inhibition method based on a bilateral overflow principle. The method utilizes a piezoelectric ceramic direct drive type four-way slide valve as an executive component of fluid pulse active control, A and B ports of the slide valve are connected to same side branch of a hydraulic pipeline, and P and T ports of the slide valve are connected with an oil box; and a sine control signal drives the slide valve to finish a periodic motion process, the A and B ports realize twice overflowing through the P and T ports, namely bilateral overflowing, and the generated overflowing flow can completely counteract source pulse flow, thereby realizing the active inhibition of hydraulic pipeline fluid pulse. The active inhibition method provided by the invention has the advantages that (1) the motion frequency of the slide valve is one half of the flow pulse frequency of a hydraulic system to be eliminated; and (2) maximal overflowing flow can achieve the flow of the slide valve when a piezoelectric ceramics actuator is in maximum elongation quantity. The invention provides the fluid pulse active inhibition method for the hydraulic system which has the advantages of high speed, high pressure and high power density, and the fluid pulse active inhibition method is further easily practical.

The invention discloses an implementation method of automatic resonance type electric power filtering and continuous reactive power compensation. When a resistant of an automatic resonance type electric power filtering and continuous reactive power compensation mixing system is designed, a medium voltage side winding equivalent impedance of a rectification transformer is equal to or approximately equal to 0, meanwhile the equivalent impedance under h harmonic frequency is equal to or approximately equal to 0 under the control of a multiple target mixture controller. By using the method, the restriction to an electric power filtering function by system impedance is eliminated, the influence caused by frequency fluctuations at an electric network side and a nonlinear load side to the electric power filtering performance can be avoided, and the high-efficiency operation of a power supply system is realized.

The invention provides a mechanical arm impedance control method. A position-based impedance control method and a force-based impedance control method are fused; a joint position controller is arranged in the mechanical arm; the control architecture of an admittance controller combined with the inverse kinematics of the mechanical arm in the position-based impedance control method is replaced by the control architecture of a virtual impedance controller combined with a forward dynamics solver, an impedance controller in the force-based impedance control system is replaced by a control loop, sothat a reference impedance force Fimp obtained by a pose error of a Cartesian space through a reference impedance model is converged to an actually measured external force Fs, and then an FFC is output through a closed-loop force controller. According to the method, the control precision and the stability during interaction with the hard environment are ensured simultaneously in mechanical arm impedance control, and a new method is provided for motion control of the industrial mechanical arm.

The invention discloses a method for manufacturing high magnetic induction grain-oriented silicon steel through a short-process medium and thin slab. The method comprises hot metal pretreatment, smelting, LF furnace external refining, medium and thin slab continuous casting and rolling, normalizing acid pickling, cold rolling, decarburizing annealing and MgO coating, high-temperature annealing, hot stretching leveling and insulation layer coating and rewinding packaging. The steel comprises the following components according to the weight percent ratio: 0.01 to 0.1 of C, 2.5 to 3.5 of Si, 0.05 to 0.20 of Mn, 0.005 to 0.02 of P, 0.005 to 0.03 of S, 0.005 to 0.02 of Als, 0.006 to 0.10 of N, the balanced of Fe and inevitable impurities. The process overall finished product yield after hot rolling is improved by more than 5 percent, magnetic induction B8 is improved to be more than 1.88T, and the iron loss P1.7 is reduced to below 1.20W / kg.

The invention discloses a method for planting corn and cover crops, belongs to the field of crop planting, and particularly relates to a cultivating method of inter-annual crop rotation of corn and the cover crops. The technical problems of reduction of soil quality and non-point source pollution caused by large-scale use of chemical fertilizers, pesticides and herbicides in the corn planting process are solved. The cultivating method comprises the steps of 1, soil preparation in spring, 2, ridging and basal dressing, 3, sowing of corn, 4, sowing of the cover crops on ridges, 5, planting of the cover crops in furrows, 6, harvest of corn, 7, crushing of residual bodies of the cover crops and plowing in the spring of a next year, 8, ridging in the next year, and 9, field management in a second year. The cover crops such as gramineae are planted in the furrows, so that the field space is fully used, and the growth of weeds is avoided. The cover crops such as gramineae are planted in the furrows the biological yield is high, the absorption and utilization capacity for N in deeper layers of soil are good, and the protection effect for water resources and ecological environment is good.

The invention discloses an oligonucleotide molecule used for inhibiting expression of mRNA of a target gene and a composition set thereof, and provides siRNA which is composed a positive-sense strand which is composed of 19-27 nucleotides and a negative-sense strand being reverse-complementary with the positive-sense strand. In the positive-sense strand, both 5-9 continuous nucleotides from a 5'-terminal and 5-9 continuous nucleotides from a 3'-terminal are 2'-ribose modified nucleotides. The siRNA molecular mixture can influence expression of target genes in at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% and 90% cells, and is at least 45%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% and 95% in inhibition ratio.

The invention discloses a flexible satellite active vibration suppression method based on component force synthesis and fixed time convergence. The flexible satellite active vibration suppression method comprises the following steps of step 1, establishing a flexible satellite attitude dynamics model with two pairs of large solar panels, and simultaneously establishing a dynamic model of a piezoelectric intelligent material actuator; step 2, designing a fixed time convergence sliding mold controller; step 3, designing a disturbance observer for ensuring a double-layer self-adaptive law with fixed time convergence characteristics; and step 4, outputting a dynamic model of the piezoelectric intelligent material actuator, implementing processing by adopting a continuous component force synthesis control idea, generating a new control torque command to be applied to a flexible accessory to counteract the influence of elastic vibration, and ensuring the attitude stability of a satellite body. The flexible satellite active vibration suppression method has the advantages of high attitude control precision and strong robustness. Meanwhile, a continuous component force synthesis method is introduced into a closed-loop control process through a piezoelectric sheet attached to the flexible accessory, vibration is inhibited, and the system interference is reduced.

The invention discloses a compensation method for magnetic resonance gradient eddy current, the method is as follows: a plurality of reverse overswing modules with independent adjustable time parameter and range parameter are formed on the common gradient waveform generator; and a switching switch is added in each gradient channel for switching the each gradient channel at the main coil mode, shielding coil mode and common mode; then, adjusting the parameter for each gradient channel under the main coil mode and the shielding coil mode; finally, recovering all gradient channels to the common mode, adopting the algorithm optimization for optimizing pre-emphasis parameter and reverse overswing parameter; the method can improve the inhibitory effect of short time component of eddy current field while combining the pre-emphasis technology and self-shielding technology and keep the inhibitory effect of long time component of eddy current field.

The invention discloses a lithium nickel cobalt manganate / lithium nickel cobalt aluminate battery and a functional diaphragm for the lithium nickel cobalt manganite / lithium nickel cobalt aluminate battery as well as a production technology of the diaphragm and belongs to the technical field of battery diaphragms. The lithium nickel cobalt manganite / lithium nickel cobalt aluminate battery disclosedby the invention comprises a porous diaphragm base material and a functional coating layer which coats the surface of the base material; coating of the functional coating layer comprises a filling agent, an adhesive, a thickening agent, a dispersant and a stabilizer, wherein the stabilizer is selected from one or more of a combination of triethylenetetramine hexaacetic acid, diethylenetriamine pentaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetracetic acid, N,N-bi(2-hydroxyphenyl)ethylenediamine-N,N-diethylamine hydrochloride and dihydroxyethylglycine. By adopting the technical scheme provided by the invention, the shuttling of nickel, cobalt, manganese and aluminum metal elements can be effectively inhibited, so that the circulating performance of lithium nickel cobalt manganiteand lithium nickel cobalt aluminate ternary batteries is improved.

The invention relates to a magnetic suspension spiral twisted tape which comprises a spiral twisted tape and an axial locating device, wherein, the axial locating device is composed of a support frame and a magnet locating device; the magnet locating device is composed of a central conical magnet and an external conical sleeve magnet; the support frame is fixedly arranged on the liquid-inlet end of a heat-transfer tube; the external conical sleeve magnet is fixed with the support frame; the polarity of the central conical magnet is the same as that of the external conical sleeve magnet; one end of the spiral twisted tape is equipped with a pivot, and the pivot passes through the support frame and the external conical sleeve magnet; and the central conical magnet is fixed on the pivot. The magnetic suspension spiral twisted tape has the advantages that by adopting a magnetic suspension locating mode, the problem of severe wear caused by great contact force at a locating position of a liquid inlet is solved, and the service life of an axial locating element of the spiral twisted tape is prolonged; by utilizing a reinforced framework axis core, the strength of the spiral twisted tape can be enhanced; by means of a guide structure, the scraping action of the spiral twisted tape on a tube wall is reduced; and by means of a flow guide structure, fluid flow is further disturbed, the radial flow intensity and turbulent flow intensity of fluid are enhanced, and convective heat transfer is strengthened.

The invention discloses a compact full-balance type broadband filtering power divider which is of a central symmetry structure. Two cascaded three-wire coupling microstrip lines of which the two endsare loaded with chip capacitors and the wavelength is one eighth of that of the chip capacitors and a three-wire coupling microstrip line of which the wavelength is one fourth of that of the chip capacitors are arranged on a top metal layer. A central connection point is arranged between the middle microstrip line and the outer microstrip line of the quarter-wavelength three-wire coupling microstrip lines. Two grooves are formed in the metal ground, two metal patches and an isolation resistor connected with the two metal patches are arranged in the grooves respectively, and the four metal patches are connected with the outer microstrip lines of the two three-wire coupling microstrip lines with the one-eighth wavelength in a one-to-one correspondence mode through plated-through holes respectively. By cascading two three-wire coupling microstrip lines with one eighth wavelength and one three-wire coupling microstrip line with one quarter wavelength and combining the plurality of chip loading capacitors and resistors, the full-balanced broadband filtering power divider with the characteristics of small size, wide frequency band and low loss is obtained.

The invention relates to a Ka frequency range miniaturization broadband multimode auto-tracking feed source network. Two polarization degenerate modes of TE21 mode transmitted by center circular waveguide are coupled to four rectangular waveguide by adopting a four-arm circular polarization TE21 coupler. Two four-way polarization degenerate modes of the TE21 mode is combined into two two-way polarization degenerate modes of the TE21 mode by two broadband magic Ts. A left-handed or right-handed circular polarization difference mode is output by a broadband 90-degree electrical bridge. The TE21 coupler center circular waveguide is capable of simultaneously transmitting a TE11 mode. Due to the fact that the TE21 coupler is connected with a broadband circular polarization machine, and two polarization modes of a signal are respectively output from two ports of the broadband circular polarization machine, the Ka frequency range miniaturization broadband multimode auto-tracking feed source network is capable of simultaneously receiving a signal of double-circular polarization and a difference signal, and thereby the auto-tracking function is realized. The Ka frequency range miniaturization broadband multimode auto-tracking feed source network has the advantages of not only simplifying composition of the feed source network, reducing the volume and the weight of the whole device, but also reducing network construction, saving feed source cost and broadening working band of the feed source network.

The invention discloses a double-codebook multi-user multiple-input multiple-output (MU-MIMO) precoding method based on Schmidt orthonormalization, and belongs to the communication field. The precoding method includes the following steps: (1) constructing a codebook I according to the Grossmann space packing principle, then constructing a codebook II according to the Schmidt orthonormalization principle and considering the chordal distance between vectors, and storing the two codebooks together in a base station end and a mobile station, (2) carrying out channel estimation according to pilot signals sent by a base station, then going through precoding vectors in the codebook I, selecting out best matching code words, and sending indexes and corresponding signal interference plus noise ratio (SINR) values of the code words to the base station as feedback, (3) the base station ensuring a present precoding matrix in the codebook II according to the collected feedback information, and carrying out user scheduling on the basis. Through adoption of the method, an expanded space of the codebooks are enabled to be larger, moreover orthogonal property of the precoding matrix is guaranteed, and restraining capacity to color contribution index (CCI) is ensured. Meanwhile, the user scheduling scheme of the base station end enables the failure phenomenon of user matching not to exist.

The invention discloses a method for cultivating crayfish in a rice field and solves the problems that crayfish is easily attacked by diseases and is long in growth cycle and low in yield in the priorart. The method includes: selecting a field; preparing the field; planting seedlings; adding young crayfish into the field; performing feeding management; catching the crayfish. By the method which is scientific and simple to operate, the cultivated crayfish cannot be easily attacked by diseases and is short in growth cycle and high in yield.

The invention discloses a method and device for setting the critical gain of a power system stabilizer. The method comprises steps of constructing an electromechanical transient model for the single-machine infinite system of a generator to be tested; performing simulation by using electromechanical transient model according to a preset gain step from the preset initial gain of the power system stabilizer of the generator to be tested, so as to obtain the root trajectory of an excitation oscillation mode; according to a preset critical damping ratio threshold, processing the root trajectory ofthe excitation oscillation mode so as to obtain the critical gain of the power system stabilizer; inputting the critical gain of the power system stabilizer to the electromechanical transient model,performing time-domain simulation verification of a terminal voltage step so as to set the critical gain of the power system stabilizer of the generator to be tested. The method can reduce the actually measured error of the critical gain, set the gain value of the power system stabilizer, and further ensures the safe and stable operation of the power system.

The invention relates to a horizontal type fixed-weight compression bagging machine. The horizontal type fixed-weight compression bagging machine comprises a rack, a weighing mechanism, a material feeding compression mechanism and a material pushing and discharging mechanism, wherein the weighing mechanism, the material feeding compression mechanism and the material pushing and discharging mechanism are sequentially arranged on the rack; the material feeding compression mechanism is vertical to the material pushing and discharging mechanism; the material feeding compression mechanism comprises a main cylinder, a pushing plate, a material feeding door and a material feeding cabin; a piston rod of the main cylinder is connected with a pressing plate and push the pressing plate to press materials in the material feeding cabin; the upper end of the material feeding cabin is hinged to the material feeding door; a hollow cavity which enables the pressing plate to move is formed in the material feeding cabin; the material pushing and discharging mechanism comprises a pushing cylinder, a pushing plate and a material outlet; a piston rod of the pushing cylinder is connected with the pushing plate and can be used for pushing the materials out of the material outlet. The horizontal type fixed-weight compression bagging machine disclosed by the invention has the advantages that the materials can be weighed through the weighing mechanism, the materials can be directly fed into the material feeding cabin for being machined after needed weight is achieved, and the use is very convenient.

The invention provides a noise suppression method and device, a medium and electronic equipment. The method comprises the following steps: acquiring a low-frequency spectrum feature and a high-frequency spectrum feature of an original voice signal, and performing feature combination processing on the low-frequency spectrum feature and the high-frequency spectrum feature to obtain a frequency band energy feature; determining a current frame of voice signal and a previous frame of voice signal in the original voice signals, and performing linear domain transformation processing on the current frame of voice signal and the previous frame of voice signal to obtain spectrum characteristic parameters; performing correlation calculation on the frequency spectrum characteristic parameters and the frequency band energy characteristics to obtain cepstrum characteristics, and dimension reduction mapping processing is carried out on the cepstrum characteristics to obtain dimension reduction characteristics; and performing feature fusion processing on the dimension reduction feature and the cepstrum feature to obtain gain information, and performing noise suppression processing on the gain information to obtain a noise reduction voice signal of the original voice signal. According to the method, the noise suppression effect and efficiency of the key noise type are ensured, and the complexity of noise suppression is greatly reduced.

This disclosure provides a slot array antenna, which includes an emission waveguide having a conductor surface where emission slot rows are formed and for guiding electromagnetic waves to be emitted from the emission slot rows, each of the emission slot rows having a plurality of emission slots are arrayed in line, and a lattice. The lattice includes a plurality of conductor walls formed in a planer shape so as to extend in a direction intersecting with the conductor surface and repeatedly arranged corresponding to the plurality of emission slots, and a base plate coupling and fixing the plurality of conductor walls thereto, the base plate being fastened to the conductor surface of the emission waveguide.

The invention discloses an LLCL filter with an LRC (Longitudinal Redundancy Check) parallel passive damping circuit. A parallel damping circuit (7) is in tandem connection between a connection joint (3) of a bridge arm inductance (L1) and a grid-side inductance (L2) and a parallel resonance branch circuit; the parallel damping circuit (7) is formed by a damping resistor (Rd), a damped inductance (Ld) and a damping capacitor (Cd) which are in parallel connection; the LC resonance frequency of the parallel damping circuit is identical to that of the LLCL filter; two ends of the LLCL filter are provided with an inverter (1) bridge arm lateral output terminal (2) and a grid (3) terminal (4) after the bridge arm inductance (L1) and the grid-side inductance (L2) are in tandem connection; a series resonance branch circuit which is formed by an additional inductance (Lf) and a filter capacitor (Cf) is in bridge joint between the connection joint (3) and a common terminal (6) of the inverter (1) and the power grid (5). The LLCL filter with the LRC parallel passive damping circuit in a large-power grid-connected inverter can meanwhile satisfy the high-frequency filter effect, the damping loss and the system stability.

The invention provides a loudspeaker unit. The loudspeaker unit comprises a basin frame with an accommodating space, a magnetic circuit system and a vibration system that are accommodated in the basinframe; the magnetic circuit system comprises a lower clamping plate and a magnet part attached to the lower clamping plate. The vibrating system comprises an upper vibrating diaphragm fixed on the basin frame; a voice coil which is fixed on one side, facing the magnetic circuit system, of the upper vibrating diaphragm; and a lower vibrating diaphragm which is connected with the voice coil and isfixed on the basin frame; wherein the lower clamping plate comprises a first side edge arranged oppositely and a second side edge connected with the first side edge and arranged oppositely, the lowerclamping plate comprises a notch part formed by recessing towards the middle area along the first side edge, the lower clamping plate comprises a first side wall which is bent and extends towards thelower vibrating diaphragm from the edge of the notch part, and the lower vibrating diaphragm is provided with a through hole for avoiding the first side wall. According to the loudspeaker unit, the lower clamping plate subjected to special-shaped processing is matched with the lower vibrating diaphragm structure provided with the opening, so that the inhibition effect of the lower vibrating diaphragm on swinging can be ensured, and meanwhile, the magnetic field intensity of the short axis of the loudspeaker unit can be improved.

The invention relates to a gel product instant-dissolving novel dosage, and in particular relates to a gel product instant-dissolving block and a preparation method of the gel product instant-dissolving block. The preparation method comprises the following steps: adding water into a raw material so that the raw material is dissolved, and carrying out concentrating to obtain a gel solution; carrying out drying treatment on the gel solution, thus obtaining an irregular cellular gel body; grinding the gel body, and carrying out screening to obtain gel powder with the partical size not being smaller than 80 meshes; and wetting the gel powder by adopting 85-95 % alcohol, and carrying out compressing according to the compression ratio of 30%-60% for obtaining a block, wherein the obtained pressed block is the gel product instant-dissolving block. The gel product instant-dissolving block provided by the invention has the loose pore structure inside, has high superficial area / volume ratio, hasthe product density being 0.4-0.8 g / cm<3>, and can rapidly dissolve within 2min in hot water, in addition, the gel product instant-dissolving block is crisp in mouthfeel and can be directly orally administrated, and thus the convenient taking demand of consumers under different conditions can be satisfied.

The invention discloses a preparation method of a shale inhibitor with a filtrate reduction property. The method comprises the following steps: (1) adding an inorganic base to an n-amine solution, and uniformly mixing and stirring the inorganic base and the n-amine solution, wherein n is an integer larger than 1, the dosage of the inorganic base is 0.05-3% of the mass of the n-amine, preferably 0.5-1%; (2) adding an etherifying agent to the mixed fluid of the step (1), carrying out a reaction under 60-100 DEG C for 6-10 hours, preferably under 80-100 DEG C for 8-10 hours, the molar ratio of the etherifying agent to the n-amine is larger than 1.0, preferably 2.0-4.0; (3) reducing the temperature to indoor temperature after the reaction in the step (2) is over, and regulating the pH value of the solution to the neutral value so as to obtain the shale inhibitor with the filtrate reduction property. The preparation method is simple in preparation process and low in cost, the prepared shale inhibitor has good performance of shale inhibition and good filtrate reduction property at the same time, requirements for the performances of the shale inhibitor and a filtrate reducer which are used for a drilling fluid can be satisfied at the same time, one agent integrates multiple functions, and therefore, the actual problems of hydration, dispersion and swelling of clay shales, the collapse of a borehole wall, and the like can be solved.

The invention relates to a use of supersonic wave in sewage treatment biological denitrification. A short-distance nitration process is stimulated by supersonic wave so that sewage is subjected to high efficiency denitrification. The short-distance nitration comprises that in a microbe nitration reaction, ammonia nitrogen is oxidized into nitrite and nitrate is not produced A supersonic generator probe is arranged in an aeration tank of an activated sludge process-based sewage treatment system or is connected in a sludge return pipe in series so that the short-distance nitration is stably realized by a bioreactor. The microbe screening characteristics of supersonic wave realizes stimulation of activity of nitrite bacteria and inhibits activity of nitrite bacteria. Supersonic wave is convenient for operation, has stable effects and has a wide application prospect in a sewage treatment biological denitrification technology.

The invention discloses a dynamic calibration device and method for a wavelength scanning working curve of a tunable laser. The dynamic calibration device comprises a laser driving circuit, an opticalpulse modulator, an optical amplifier, an optical circulator, an optical fiber, a spectrum detection unit, a computer and the tunable laser; a working curve of the laser is calibrated under the parameters of wavelength range, wavelength point number, retention time of each wavelength point, wavelength scanning period and the like of actual scanning work; output light of the laser is modulated into the light pulse, and the Rayleigh scattering light of the light pulse transmitted in the optical fiber is measured, so that the laser wavelength and the side mode rejection ratio under different control signals are obtained, and the consistency of the scanning work and the calibration state of the laser is ensured.

The invention discloses a high-performance lithium-sulfur battery diaphragm and a preparation method and application thereof, and belongs to the technical field of battery diaphragms. The high-performance lithium-sulfur battery diaphragm comprises a porous diaphragm matrix, and the porous diaphragm matrix is prepared from the following raw materials in percentage by mass: 20-40% of polyethylene, 0.5-10% of carbon nanotubes and 0.5-10% of conductive carbon black and / or graphene. The preparation process of the diaphragm comprises the following steps: blending and modifying polyethylene, carbon nanotubes and conductive carbon black and / or graphene through an extruder, and carrying out two-way stretching and extraction to prepare a honeycomb-shaped porous diaphragm matrix; and coating or compounding the surface of the porous diaphragm matrix with an inorganic nano ceramic layer to obtain the high-performance lithium-sulfur battery diaphragm. By adopting the technical scheme provided by theinvention, the shuttle effect of lithium polysulfide of the lithium-sulfur battery can be inhibited, and the use performance of the lithium-sulfur battery can be improved.

The invention discloses a multichannel low noise amplifier. The multichannel low noise amplifier comprises an LNA body, a second-level amplifier, a first duplexer, a low-frequency-band filter, a high-frequency-band filter, a second duplexer and a third-level amplifier, wherein the LNA body, the second-level amplifier and the first duplexer are connected in sequence, the output end of the first duplexer is divided into two branches, one branch is connected with the low-frequency-band filter, the other branch is connected with the high-frequency-band filter, the output end of the low-frequency-band and the output end of the high-frequency-band filter are combined to be connected to the second duplexer, and the output end of the second duplexer is connected with the third-level amplifier. According to the multichannel low noise amplifier, three-level amplification is achieved so that the gain of a signal can be high enough, the signal is divided into branches to be processed, multiple channels are achieved, out-of-band rejection of each branch of signal is guaranteed through a corresponding filter, the structure is simple, and performance is stable.

The invention relates to a universal conducted interference filter for multi-port equalizing multilevel filtering. The universal conducted interference filter comprises a casing, at least one common mode choke, at least one differential mode capacitor plate, and at least one common mode capacitor plate. The universal conducted interference filter is characterized in that the common mode choke is an integral structure formed by respectively winding two magnetic rings on a copper bar for one circle, and the integral structure is connected with the pedestal of the casing; the differential mode capacitor plate is placed on a side surface of the common mode choke; the common mode capacitor plate is arranged below the common mode choke; and the differential mode capacitor plate and the common mode capacitor plate are connected with the front, intermediate and rear ends of the copper bar penetrating the two magnetic rings through cables to form a multi-port equalizing multilevel filtering structure. The universal conducted interference filter has simple structure and is convenient to install by designing the common mode choke into the integral structure. The number of magnetic rings in the common mode choke is 1 / 4 that of the conventional choke with the same inductance by winding the two magnetic rings on the copper bar for one circle, so that the common mode choke has the advantages of small size and light weight.

The invention discloses an optimal delay compensation method for active damping of an LCL-type converter. The method includes determining the delay time of a system to acquire an active damping control model; simplifying the active damping control model, and calculating the virtual impedance generated by an inner loop delay to acquire a resonance peak and the reason why the resonance frequency isaffected by the delay; from the perspective of resonance inhibition, determining the optimal compensation method: feedback coefficients plus lead phase compensation; designing a lead compensation device, determining the feedback coefficients, comparing the ideal and the corrected amplitude-frequency response figures, and verifying the optimality to acquire the optimal amplitude-frequency responsefigures. The optimal delay compensation method has the advantages that resonance frequency shifting and resonance peak amplification both caused by the delay during the active damping control can be suppressed, the stability margin of the system is improved, and the attenuation ability of the LCL to high-frequency harmonic waves and the high anti-interference ability to the grid-side impedance fluctuations are guaranteed.