49results about How to "Guaranteed frequency stability" patented technology

The invention discloses a control method for an electric automobile participating in grid frequency modulation based on V2G technology. A charge / discharge circuit is a two-stage converter circuit, which comprises a PWM rectification circuit and a matched LC filter and a Buck-Boost conversion circuit, wherein the two circuits are connected through a DC bus capacitor; the PWM rectification circuit rectifies a network voltage into a 700V DC voltage, AC-side harmonic waves are filtered through the LC filter, and the PWM rectification circuit is connected with a power grid through a network-side inductor; and the Buck-Boost conversion circuit converts the 700V DC voltage into a 60V DC voltage, and is connected with an electric automobile directly. The method adopts an AC / DC control module and a DC / DC control module, and meanwhile, enables a frequency modulation control module to be embedded into the DC / DC control module; and charge and discharge power reference values of a power battery are given through the frequency modulation control module, and a current transformer makes a response to realize primary and secondary frequency modulation of the power grid.

The invention discloses a reconfigurable single-band-pass microwave photon filtering system and method and belongs to the technical field of microwave photons. A device comprises a laser, an optical divider, an electro-optic phase modulator, an optical isolator, a first polarization controller, a high-nonlinearity medium, a pumping microwave source, an electro-optic intensity modulator, an optical amplifier, a second polarization controller, an optical circulator and a photoelectric detector. According to the microwave photon filtering system, single-band-pass photon filtering is conducted by utilizing a stimulated brillouin scattering effect in the high-nonlinearity medium, and a function of filtering reconfiguration is achieved by controlling the frequency spectrum of pumping microwave. The system and method solves the problem that the existing periodical microwave photon filtering system is limited in filtering range and the filtering waveform is not easy to reconfigure, and has the advantages of being high in stability and convenient to operate.

The invention discloses a buck converter with the connection time being controlled, and relates to electronic circuit technologies. Through a digital-to-analog converter, a reference voltage is generated, a voltage signal of a sampled inductive current is superposed to obtain a ramp signal VRAMP, after the ramp signal VRAMP is compared with an output voltage VC of a transconductance amplifier, start-up or switch-off of an upper-lower power tube is controlled through a D flip flop, when the ramp signal VRAMP is lowered to a valley current which is determined by the voltage VC of the transconductance amplifier, a first comparator Icomp outputs a logic level signal and makes an upper power tube MT be connected through the D flip flop and a lower power tube MB be switched off, thus the inductive current is increased, and the output voltage is raised, wherein the connection time of the upper power tube MT is jointly determined by a timing capacitor CTH and an output voltage signal VC of the transconductance amplifier GM. According to the buck converter with the connection time being controlled, the buck converter has smaller transient response overshoot impulse and higher transient response speed, and is particularly applicable to application occasions like an FPGA and a CPU which have high transient requirements on a power source.

The invention discloses a coherent light detection system and method for optical fiber delay line phase control. The output end of an optical fiber laser device is connected with the input end of an optical fiber branching unit. A first output end of the optical fiber branching unit is connected with an input end of a modulator. The other input end of the modulator is connected with an external RF signal generator. The output end of the modulator is connected with an input end of an optical fiber combiner. A second output end of the optical fiber branching unit is connected with the other input end of the optical fiber combiner. An optical fiber delay line is connected in series between the output end of the modulator and an input end of the optical fiber combiner, or the optical fiber delay line is connected in series between the second output end of the optical fiber branching unit and the other input end of the optical fiber combiner. The output end of the optical fiber combiner is connected with the input end of a photoelectric detector. According to the coherent light detection system and method for optical fiber delay line phase control, phase control can be achieved through the optical fiber delay line, and phase difference between reference light and a signal light branch is compensated, so that receiving sensitivity, the signal to noise ratio and system output stability are improved.

The invention provides a simulation configuration method for constant-value parameters of frequency control devices in weak interconnection power grids. According to the characteristics that the frequency changes quickly and the amplitude is large after an isolated grid runs due to a reason that the weak interconnection power grids are serially faulted, acting characteristics of frequency control devices such as a primary frequency modulation control device of a steam turbine generator set, a primary frequency modulation control device of a water turbine generator set, a steam turbine overspeed protection control device, a high-frequency generator tripping safety automatic device, a low-frequency load shedding safety automatic device and a low-voltage load shedding safety automatic device are comprehensively considered from two aspects, i.e. isolated grid frequency decrease and increase. A scientific and reasonable simulation configuration method for the constant-value parameters of the frequency control devices in the weak interconnection power grids is made and has the advantages of high applicability, comprehensive considered factors, reasonable scheme and the like.

The present invention discloses a cavity resonator which has temperature stable compensating function. The resonator comprises a cavity, a resonance rod and a tuning screw bolt. The cavity is provided with a tuning screw bolt supporting structure and a resonance rod supporting structure. The resonance rod is fixed in the resonance rod supporting structure. The tuning screw blot is fixed in the tuning screw blot supporting structure. The tuning screw bolt supporting structure or resonance rod supporting structure is a boss structure. The axial variation of the outward extension of the boss structure in the invention fundamentally compensates the gross mount of the axial variation of the inward extension of the tuning screw bolt and the resonator thereby that the equivalent physical length of the resonance rod is sustained to be relative constant and the stability of the frequency is guaranteed.

The invention discloses a dual-frequency-laser-based photoproduction tunable microwave source and a frequency stabilization control method for the same. A resonant cavity system of the photoproduction tunable microwave source comprises a semiconductor light amplifier chip, a collimating lens, a controlled half wave plate, a polarized beam splitter prism, a tunable filter and a reflector, which are sequentially arranged, wherein the reflector is formed by combining a tunable signal light vp reflection cavity mirror surface and a fixed frequency laser signal vs reflection cavity mirror surface into an L shape; the tunable signal light vp reflection cavity mirror surface and the fixed frequency laser signal vs reflection cavity mirror surface form resonant cavities with the output end face of the semiconductor light amplifier chip through corresponding beam split optical paths of the polarized beam splitter prism respectively; and a laser phase adjustment element capable of changing the optical cavity length of the resonant cavity formed by the tunable signal light vp reflection cavity mirror surface and the semiconductor light amplifier chip is arranged in the vp direction of the tunable signal light. By the microwave source and the method, a tunable microwave signal can be generated, and is large in tunable bandwidth and stable.

The invention provides a light-source management method supporting a WDM grid frequency standard of a coherent light network. The method includes: an optical-frequency-comb generator generates an optical frequency comb with distance precision; the optical frequency comb generator sends the optical frequency comb to each optical network node or after the optical frequency comb passes through a demultiplexer, each demultiplexed spectrum line which undergoes demultiplexing is sent to a corresponding network node; each network node extracts a corresponding single spectral line from the optical frequency comb or obtains directly a single spectral line which passes the demultiplexer; and a single spectral line of the optical frequency comb is used as a light carrier for local sending, local oscillating light used for receiving or injection light used for a local laser device. The optical frequency comb is highly stable in frequency output, precise in frequency interval and free from frequency deviation. The optical-frequency comb is sent to each optical node and can be used as light carrier, local oscillating light or light sent out by a main laser device for light injection and locking so that frequency and phase locking of semiconductor laser devices at the optical network nodes is realized.

The invention relates to a low-frequency low-voltage combined load shedding method. Mainly by using frequency and voltage response information measured on a load bus, on the basis of considering the load characteristic and the frequency-voltage interactive influence, a load shedding amount of low-frequency load shedding and a load shedding amount of low-voltage load shedding are respectively calculated, the bigger one thereof is used as an actual load shedding amount, and system frequency and load voltage are restored to rated values as soon as possible after disturbance by gradually shedding the load. The low-frequency low-voltage combined load shedding method can provide a guarantee for frequency stability and voltage stability of a power system under serious disturbance.

The invention relates to a device for dynamically adjusting the crystal oscillator stability of a WiMAX base station and a realization method thereof. The device includes a frequency counter, a phase detector, a crystal oscillator, a digital-to-analog converter and a GPS receiver. It uses the 1pps signal output by the GPS receiver to calibrate the stability of the crystal oscillator output signal frequency, which can quickly adjust the error accuracy of the crystal oscillator to within 0.5Hz, and finally stabilize the error accuracy of the crystal oscillator within 0.01Hz. The feature of this method is to pre-calculate the adjustment coefficient between the phase detector and the crystal oscillator. During dynamic calibration, the error value of the crystal oscillator can be directly calculated only by calculating the error value of the phase detector. Using the adjustment coefficient to adjust the crystal oscillator error is a novel method in the field of crystal oscillator adjustment. This method has a fast calibration speed and a simple algorithm. It can quickly adjust the oscillation frequency of an ordinary crystal oscillator to high accuracy, and has long-term stability and short-term stability. all good.

The embodiment of the invention provides a hybrid direct current station control coordination control method and device and a power transmission system, and relates to the technical field of alternate current and direct current power transmission system transient stability control. The method, the device and the power transmission system solve the problems that the frequency stabilizing effect of each receiving end can not be ensured and the reasonable power modulation rate can not be allocated according to the actual situation of each receiving end in the prior art when a direct current power transmission system adopting a frequency control method is used for frequency stabilization. The method includes the steps that the difference of a preset frequency of a conventional direct current sending end and the current frequency of the conventional direct current sending end is obtained; according to the difference, the power modulation rate is generated, filtering is conducted on the power modulation rate to obtain a first modulation rate of a first flexible direct current receiving end, and a second modulation rate of a second flexible direct current receiving end is generated through the subtraction; according to the first modulation rate, the active power of the first flexible direct current receiving end is corrected, and according to the second modulation rate, the active power of the second flexible direct current receiving end is corrected. The method, the device and the power transmission system are used for hybrid direct current station control coordination control.

Provided is a Ku wave band adaptive anti-interference frequency-dependent radar, comprising an antenna, a receiving portion and an emission portion. The receiving portion comprises a circulator, a first filter, an amplitude limiter, a low noise amplifier and a mixer which are successively in connection; the frequency of signals is converted into intermediate frequency through the receiving portion; the mixer comprises a second filter, a low noise amplifier, a voltage-controlled attenuation device, an amplifier and a third amplifier which are successively in connection; intermediate frequency filtering is amplified, controllable attenuation is amplified, and filtering is outputted. The emission portion comprises a mixer, a fourth filter and a power amplifier which are successively in connection.

The invention discloses a self-adaptive emergency load shedding method based on voltage drop amplitudes. The self-adaptive emergency load shedding method based on the voltage drop amplitudes comprises the steps that the voltage drop amplitudes of all load nodes of a whole grid are calculated; all the load nodes are ranked according to the voltage drop amplitudes; all the ranked load nodes are cut off in sequence according to the voltage drop amplitudes in a descending order, and load shedding is completed when the total amount of the shed load is equal to the active power loss of the whole grid. According to the self-adaptive emergency load shedding method based on the voltage drop amplitudes, the transient voltage response of a power system is fully considered. Compared with an existing load shedding method, a weak bus in the power grid can be effectively and rapidly selected for load shedding, the number of positions where load shedding is conducted can be adjusted according to the actual condition of the power grid and the active power loss caused when a failure occurs, the spatial and temporal distribution characteristic, existing when serious disturbance happening to the system, of the voltage of all the load nodes is fully considered, the state of the system is effectively controlled, the phenomenon of voltage collapse is avoided, and the stability of the frequency of the power system and the stability of the voltage of the power system are guaranteed.

A method for self-adaptively and emergently shedding induction motor loads based on slip responses comprises the following steps of (1) calculating voltage-slip response factors of all load nodes, (2) ranking all the load nodes according to the voltage-slip response factors, (3) selecting load shedding sites, (4) calculating the proportion of the voltage-slip response factors of all the load shedding sites in the total sum of the factors of all the load shedding sites, (5) calculating the loading shedding amounts of all the load shedding sites, and (6) checking whether the loading shedding amounts of all the loading shedding sites exceed the original total load amounts of all nodes or not. According to the method for self-adaptively and emergently shedding the induction motor loads based on the slip responses, the frequency stability and the voltage stability of a power system under serious failure disturbance can be guaranteed.

The invention discloses a method for the compressed air energy storage system responding to the frequency modulation of the electric network. The method comprises the following steps: the compressor of the compressed air energy storage system is a direct current motor, which is controlled by a direct current frequency conversion device; the direct current frequency conversion device comprises a frequency modulation function module and a frequency conversion function module; the frequency modulation function module comprises a frequency difference unit, a dead zone unit and a difference adjustment unit; The frequency conversion function module comprises a correction unit and a limiting unit. A frequency signal f of a power network is converted into a frequency difference Deltaf by a frequency difference unit, The frequency difference is compared by the dead-zone unit, the frequency difference is greater than the dead-zone delta delta, and then the frequency difference is outputted, thepower adjustment amount Delta P of the compressor is calculated by the difference adjustment unit, the corrected power value P1 is obtained by the correction unit, and the control power P is finally outputted by the amplitude limiting unit, and the compressor is driven by the DC frequency conversion motor. The invention can utilize the bi-directional characteristic of compressed air energy storageto realize the response regulation of the load side to the frequency of the electric network, ensure the frequency stability of the electric network operation and improve the frequency qualificationrate.

The present invention discloses a multi-type power supply joint operation system assembly ratio calculation method which comprises the steps of (A) measuring wind speed data and solar data of a whole year, (B) designing an assembly ratio scheme and establishing a force output value change simulation curve, (C) verifying the stability of the assembly ratio scheme, continuing verification if a total force output value can be stable, recording a threshold-crossing time if the total force output value decreases, and abandoning wind amount or light amount if the total force output value increases, (D) counting the threshold-crossing time, the wind abandoned amount or light abandoned amount in the whole year, and (E) verifying other schemes to select a best scheme. According to the method, the assembly ratio of maximum wind power generation and photovoltaic power generation on the basis of ensuring system frequency stability can be calculated.

The invention discloses an automatic power generation control method. The automatic power generation control method comprises that: each power grid area j determines a current load variation quantity, a frequency deviation value of a power grid area i and a frequency deviation value of a power grid area k in each preset control cycle in the area, wherein the power grid area i is each area of the power grid area j that power flows to, and the power grid area k is each power grid area that the power of the power grid area j flows to; the power grid area j determines a power output control order and a control evaluation parameter of the local area in a current control cycle according to the load variation quantity and the frequency deviation value and according to a principle that a sum of system regulation expenditure and frequency deviation punishment is minimum; power generation control in a local area is performed according to the power output control order and frequency stability is obtained according to a control evaluation parameter. The automatic power generation control method can effectively realize stable frequency and low cost in the electric power system.

The invention relates to a device for dynamically adjusting crystal oscillation stability of a WiMAX base station and an implementation method thereof. The device consists of a frequency counter, a phase detector, a crystal oscillator, a digital-analog converter and a GPS receiver. The device calibrates the stability of crystal oscillation output signal frequency by applying 1pps signal output bythe GPS receiver, rapidly adjusts error precision of the crystal oscillation within 0.5Hz, and finally keeps the error precision of the crystal oscillation steady within 0.01Hz. The method is characterized in that an adjustment coefficient between the phase detector and the crystal oscillation is calculated in advance and at the time of dynamic calibration, an error figure of the crystal oscillation is calculated out directly after the calculation of the error figure of the phase detector. Adjusting the crystal oscillation error by applying the adjustment coefficient is a new method in the field of crystal oscillation adjustment. The method has the advantages of a fast calibration speed and a simple algorithm, thus adjusting shock frequency of ordinary crystal oscillation to quite high accuracy rapidly with good stability for long-term and short-term.

A 32k crystal oscillator based on high signal-to-noise ratio pulse injection adopts a T / 4 clock delay shaping circuit with high phase noise performance, high frequency precision and ultra-low power consumption and a pulse generation circuit to realize a crystal oscillator with a pulse injection structure with a high signal-to-noise ratio. A T / 4 clock delay shaping circuit designed on the basis ofa delay circuit structure is used for accurately positioning wave crests and wave troughs; a pulse generation circuit designed based on the structure of a frequency divider and a bootstrap circuit isused for generating pulses, voltage superposition is carried out on the basis of power supply voltage by utilizing the principle of the bootstrap circuit, so that pulse signals are amplified, high-energy signals are generated, and on the premise that the frequency precision and stability are guaranteed, the contradictory relationship between the power consumption and stability of the crystal oscillator and the phase noise performance is solved.

The invention discloses a laser device with high stability, and belongs to the technical field of laser devices. The laser device comprises a laser tube, a piezo-electric crystal driver, a beam splitter, a photoswitch, a resonant cavity, a synchronous detection unit, a low-frequency modulator, an interferometer, a data processing unit and a temperature compensation unit, wherein the beam splitter is arranged on a laser output light path of the laser tube; the beam splitter splits a laser generated by the laser tube to obtain two light path branches; the photoswitch, the resonant cavity and the synchronous detection unit are sequentially arranged on one of the two light path branches; the interferometer is arranged on the other one of the two light path branches; the low-frequency modulator is electrically connected with the photoswitch and the synchronous detection unit simultaneously; the data processing unit is electrically connected with the interferometer; and the piezo-electric crystal driver is electrically connected with the synchronous detection unit, the data processing unit and the temperature compensation unit simultaneously.

The present invention discloses a multi-type power supply joint operation system assembly ratio calculation method which comprises the steps of (A) measuring wind speed data and solar data of a whole year, (B) designing an assembly ratio scheme and establishing a force output value change simulation curve, (C) verifying the stability of the assembly ratio scheme, continuing verification if a total force output value can be stable, recording a threshold-crossing time if the total force output value decreases, and abandoning wind amount or light amount if the total force output value increases, (D) counting the threshold-crossing time, the wind abandoned amount or light abandoned amount in the whole year, and (E) verifying other schemes to select a best scheme. According to the method, the assembly ratio of maximum wind power generation and photovoltaic power generation on the basis of ensuring system frequency stability can be calculated.

The invention relates to base station carrier wave distributors and the communication network composed of the distributors. The base station carrier wave distributors comprise local terminal equipment and remote terminal equipment, and the local terminal equipment consists of up and down intermediate frequency converters, signaling combiners and splitters, radio frequency up and down converters, radio frequency filters, automatic radio frequency gain controllers, up and down power amplifiers, pilot frequency signal generators, pilot frequency signal separation detectors, diplexers and radio frequency transmitting / receiving antennas. The remote terminal equipment is similar with the local terminal equipment, and intermediate frequency power amplifiers and intermediate frequency low noise amplifiers are increased. The radio frequency signal of the base station is frequency-converted by the local terminal equipment, and the radio frequency signal is sent to the remote terminal equipment;the radio frequency signal is then frequency-converted by the remote terminal equipment into the intermediate frequency signal and sent to the cell phone subscriber. The central base station of the communication network composed of the base station carrier wave distributors is provided with a plurality of base station carrier wave distributors, and the covered area is enlarged by tens times. The superior and inferior base station carrier wave distributors with identical carrier wave signal are in relay connection relation, to realize complicated and flexible base station signaling coverage. The networking expense is saved, and the networking speed is improved.

The invention provides a simulation configuration method for constant-value parameters of frequency control devices in weak interconnection power grids. According to the characteristics that the frequency changes quickly and the amplitude is large after an isolated grid runs due to a reason that the weak interconnection power grids are serially faulted, acting characteristics of frequency control devices such as a primary frequency modulation control device of a steam turbine generator set, a primary frequency modulation control device of a water turbine generator set, a steam turbine overspeed protection control device, a high-frequency generator tripping safety automatic device, a low-frequency load shedding safety automatic device and a low-voltage load shedding safety automatic device are comprehensively considered from two aspects, i.e. isolated grid frequency decrease and increase. A scientific and reasonable simulation configuration method for the constant-value parameters of the frequency control devices in the weak interconnection power grids is made and has the advantages of high applicability, comprehensive considered factors, reasonable scheme and the like.

The invention discloses a method for the compressed air energy storage system responding to the frequency modulation of the electric network. The method comprises the following steps: the compressor of the compressed air energy storage system is a direct current motor, which is controlled by a direct current frequency conversion device; the direct current frequency conversion device comprises a frequency modulation function module and a frequency conversion function module; the frequency modulation function module comprises a frequency difference unit, a dead zone unit and a difference adjustment unit; The frequency conversion function module comprises a correction unit and a limiting unit. A frequency signal f of a power network is converted into a frequency difference Deltaf by a frequency difference unit, The frequency difference is compared by the dead-zone unit, the frequency difference is greater than the dead-zone delta delta, and then the frequency difference is outputted, thepower adjustment amount Delta P of the compressor is calculated by the difference adjustment unit, the corrected power value P1 is obtained by the correction unit, and the control power P is finally outputted by the amplitude limiting unit, and the compressor is driven by the DC frequency conversion motor. The invention can utilize the bi-directional characteristic of compressed air energy storageto realize the response regulation of the load side to the frequency of the electric network, ensure the frequency stability of the electric network operation and improve the frequency qualificationrate.

The present invention is a design method for improving the normal temperature characteristics of SMD quartz crystal resonators by using a network analyzer. The contact position parameters of the pad; 3) According to the contact position parameters, the contact design of the test slot is changed from the traditional dot shape to the strip shape, so that it is suitable for resonators of all sizes. Advantages: Applicable to resonators of all sizes, realizing high-reliability contact and high-precision testing of room temperature characteristics of quartz crystal resonators of different specifications and sizes, so that testing resonators of different specifications does not require replacement of test slots and calibration, improving testing precision and work efficiency. It has promotional value for improving the test efficiency of similar products.

The invention discloses a hydroelectric generating set guide vane dynamic segmented closing method which comprises the steps that in the set grid-connected normal operation process, servomotor adjustment under the set rated working condition guarantees calculation to obtain an inflection point, during set grid-connected operation, current set parameter values are collected in real time through a collection system, and when the set operates under certain load working conditions, a dynamic change value of an inflection point is calculated through a current unit parameter value, and the obtained dynamic inflection point is used as an optimal closing inflection point under different loads and different water heads and pressures; and the calculated dynamic inflection points comprise a power load inflection point, a water head influence inflection point, a pressure influence inflection point and a comprehensive inflection point calculated according to the power load inflection point, the water head influence inflection point and the pressure influence inflection point. According to the method, the optimal closing inflection points under different loads, different water heads and different pressures are obtained, and the optimal closing of the unit when faults such as load shedding occur is realized, so that the frequency stability of a power system is ensured by the hydroelectric generating set.

The invention discloses a dual-frequency-laser-based photoproduction tunable microwave source and a frequency stabilization control method for the same. A resonant cavity system of the photoproduction tunable microwave source comprises a semiconductor light amplifier chip, a collimating lens, a controlled half wave plate, a polarized beam splitter prism, a tunable filter and a reflector, which are sequentially arranged, wherein the reflector is formed by combining a tunable signal light vp reflection cavity mirror surface and a fixed frequency laser signal vs reflection cavity mirror surface into an L shape; the tunable signal light vp reflection cavity mirror surface and the fixed frequency laser signal vs reflection cavity mirror surface form resonant cavities with the output end face of the semiconductor light amplifier chip through corresponding beam split optical paths of the polarized beam splitter prism respectively; and a laser phase adjustment element capable of changing the optical cavity length of the resonant cavity formed by the tunable signal light vp reflection cavity mirror surface and the semiconductor light amplifier chip is arranged in the vp direction of the tunable signal light. By the microwave source and the method, a tunable microwave signal can be generated, and is large in tunable bandwidth and stable.

The invention discloses a drive circuit of a fine engraving instrument. The circuit includes an optocoupler isolated input signal circuit, 4M active crystal oscillator signal circuit, logic gate control circuit, primary signal amplifying circuit. A secondary signal amplification circuit and a terminal signal output circuit. At that output end of the optocoupler isolate input signal circuit and the4M active crystal oscillator signal circuit, The output end of the logic gate control circuit is connected with the input end of the primary signal amplification circuit, the output end of the primary signal amplification circuit is connected with the input end of the secondary signal amplification circuit. And the output end of the secondary signal amplification circuit is connected with the input end of the terminal signal output circuit. The invention ensures the isolation of the signal input terminal and the subsequent driving signal, and reduces the interference between each other. The 4M active crystal oscillator signal is used as the driving signal to drive MOS transistor, which ensures the frequency stability of the input signal source. The first-order signal amplification circuitguarantees the advantages of the second-order signal driving ability.