798results about How to "Improve frequency stability" patented technology

Inductive power transfer across an extended gap (100) from a primary conductor (119) is provided by means of a resonant intermediate loop comprised of capacitor (118) with inductor (117) carrying a larger resonating current, that can in turn generate an inductive field to be collected by a pickup coil (120). This process and device find application in an electroluminescent advertising panel.

The invention relates to a liquid crystal composition with a stable threshold voltage and an application thereof. The liquid crystal composition comprises the following components: (1) 5%-40% of a compounds shown in a general formula I; (2) 10%-40% of a compound shown in a general formula II; compounds with a dioxyheterocycle structure are taken as polar ingredients of the liquid crystal composition to overcome the defect that the photoelectric characteristic of the liquid crystal composition changes with frequency; the polar ingredients composed of compound type I having a difluoromethoxyl structure and the compound type II having a 3,4,5-trifluoro-benzene structure are used together for regulating the voltage temperature stability of the liquid crystal composition, so that the voltage characteristic of the liquid crystal composition does not change with the temperatures, and therefore the display effect of the liquid crystal composition is improved.

An improved low-cost super-regenerative receiver includes sampling phase-locked loop. Phase sampling is controlled by the quench signal (264). In the preferred embodiment, logic state HIGH to logic state LOW transition of the quench signal (264) defines the timing for the event of sampling. While the quench signal (264) is in logic state HIGH, a quenched oscillator is being turned ON and the oscillation amplitude builds-up until a steady-state level is reached. When the oscillator is turned OFF, effective quality factor of an electronically tunable resonator (206) is reduced, by increasing losses in the circuit, thus to ensure aperiodic (non-oscillatory) decay. The resonator's charge—an energy stored on internal reactive components of the resonator (206), which existed at the instant of turning the oscillations OFF, is transferred during precisely defined period of time to the charge holding capacitor (404) of a charge transfer circuit (216). Charge is stored on the charge holding capacitor (404), which is also part of a loop filter, until the described here charge transfer cycle is repeated again. A frequency control signal (268) at the output of the loop filter sets the frequency of the oscillation for the duration of the succeeding oscillator ON time.

An atomic oscillator includes an atomic cell in which alkali metal atoms are encapsulated, a light source section configured to receive the supply of a bias and emit light including a resonance light pair for causing the alkali metal atoms to resonate, a temperature adjusting element configured to adjust the temperature of the light source section, a bias detecting section configured to detect information concerning the bias, and a light-source-temperature control section configured to control the temperature adjusting element using the information detected by the bias detecting section.

The invention relates to a coating method for iron-based magnetically soft alloy powder and a preparation method of soft magnet composite material. The coating method for iron-based magnetically soft alloy powder comprises the following steps: carrying out accelerated oxidation on iron-based magnetic metal powder at high temperature, forming an oxide layer on the surface of the powder and then carrying out acid pickling, thus obtaining powder with surface coated with SiO2, Al2O3 and Cr2O3 oxides. The preparation method of the soft magnet composite material comprises the following steps: adding coupling agent, silicon resin and lubricating agent to the coated powder, carrying out pressing forming, and then carrying out annealing heat treatment, thus obtaining the soft magnet composite material. According to the invention, the advantage that an oxide produced in reaction of elements including Si, Al and Cr contained in the iron-based magnetically soft alloy powder with oxygen is high in electrical resistivity, small in thermal expansion coefficient and steady in chemical performance and can resist high temperature is fully utilized; the adopted coating technology is to produce a coating layer in situ on the surface of the alloy magnetic powder, and is simple in process, easy to operate and low in cost; the metal soft magnet composite material prepared by adopting the method disclosed by the invention has good magnetic property and frequency stability.

The invention provides a variable speed wind turbine generator frequency control method based on dynamic standby power. The method comprises the following steps that I, a frequency modulation operation strategy of a variable speed wind turbine generator is determined according to operation conditions of the variable speed wind turbine generator; II, whether the variable speed wind turbine generator participates in system frequency modulation or not is judged; III, whether the rotating speed of the wind turbine generator is out of limit or not is judged; IV, an active frequency control module is activated, and an active power set value of the wind turbine generator is modified; V, control over the system frequency is achieved. The variable speed wind turbine generator frequency control method based on dynamic standby power can achieve frequency modulation capability of the wind turbine generator in a full wind speed region, when participating in the system frequency modulation to provide active support, the wind turbine generator is not affected by the operation conditions, and therefore electric system frequency stability is improved.

The invention belongs to the technical field of optical storage combined power generation system virtual inertia compensation, and relates to a virtual inertia compensation method for an optical storage combined power generation system based on active support control. The method comprises: modeling a photovoltaic power generation system, analyzing the virtual inertia of the optical storage combined power generation system, and including inertia analysis of a photovoltaic-energy storage system. The active support control strategy based on the standard three-order model of the synchronous machine is adopted for the photovoltaic power generation unit, the port characteristics of the synchronous generator are better simulated, necessary inertia and damping are provided for the system, the voltage stability support capacity and the frequency stability support capacity of the system after photovoltaic grid connection are improved, and the robustness of the system is effectively improved. According to the invention, the low-frequency oscillation suppression capability of the photovoltaic-energy storage combined system can be enhanced, the system stability is improved, and the new energy photovoltaic absorption capability of the power grid is further promoted.

The invention relates to a device and a method for continuously measuring the arrival time of a photon sequence. The device comprises a single photon detector, a preamplifier, a constant ratio discriminator, an atomic clock, a counter, a time-to-digital converter, a controller, a memory unit and a computer, wherein the output end of the constant ratio discriminator is connected with the controller; a square-wave pulse output by the atomic clock is used as a counting object of the counter and is transmitted into the time-to-digital converter; the rising edge of the square-wave pulse is used as a start signal of the time-to-digital converter, and the rising edge of a digital pulse signal is used as a stop signal of the time-to-digital converter; and the control end of the controller is respectively connected with the counter, a digit converter and the memory unit and used for controlling the synchronous storage of rough measuring time and fine measuring time into the memory unit. The invention solves the technical problems of continuous measurement incapability, narrow measurement range and limited application range of a traditional photon sequence arrival time measuring device, and the device has a wide measurement range and high accuracy in measuring the photon arrival time.

The invention discloses a method for compensating wind power plant virtual inertia by utilizing energy accumulation device; the method utilizing an energy accumulation device of about 5% of the rated installed capacity of the wind power plant is able to make the wind power plant generate a virtual inertia effect which is almost equal to a synchronous generator of the same capacity. The method generates active commands need to be output by the energy accumulation device by measuring the frequency bias and the frequency change rate at the outlet generatrix of the wind power plant, and processing the frequency bias and the frequency change rate with fuzzy logic. The energy accumulation device outputs power for compensating the virtual inertia of the wind power plant based on the commands. The method for compensating wind power plant virtual inertia by utilizing energy accumulation device effectively evaluates the capacity requirement of the energy accumulation device, and can be used for guide the energy accumulation configuration of the wind power plant; moreover, the structure of the controller thereof is simple, reliable and easy to be implemented, thus providing a foundation for developing a 'friendly' wind power plant, being beneficial to absorbing the large-scale wind power by the power grid, and increasing the safe and stable running level of wind power integration power system.

The invention relates to an automatic low-frequency low-voltage load-reduction centralized optimization control system for power systems in the technical field of industrial control. The control system comprises a data acquisition module, an off-line computation module and an on-line control module, wherein the data acquisition module acquires EMS data through a data server, and acquires the operation information of a system through data acquisition devices arranged on a PMU, a UFLS device and an important element, as well as the operation condition of every element; the off-line computation module computes voltage stability boundary of nodes, as well as load frequency response functions; and the on-line control module computes load shedding amount, determines the order of UFLS movements, transmits control instructions to the UFLS device, and determines a next control instruction according to the information fed back by the UFLS. The control system is based on the parameters of the real-time changes of the power systems, and determines the movement order and load shedding amount of the UFLS device of a whole network, thereby speeding up the frequency recovery of the systems and improving the operation stability of the systems.

The invention relates to a cavity type film bulk acoustic resonator, comprising a substrate, an isolation layer, a support layer, a bottom electrode layer, a piezoelectric layer and a top electrode layer that are sequentially arranged from bottom to top, wherein the middle part of the upper surface of the isolation layer is recessed downwards to form a groove, the groove is sealed by the support layer and the substrate to form a sealed cavity, the height of the lower surface of the sealed cavity is less than the height of the upper surface of the substrate, the lower surface of the sealed cavity is a flat surface, and the material of the support layer is SiC. And meanwhile, the invention also discloses a preparation method of the acoustic resonator. According to the cavity type film bulk acoustic resonator and the preparation method thereof disclosed by the invention, the structure of the device is stabilized by the SiC support layer, and the power capacity can be improved; the heat can be effectively dissipated, the thermal steady-state temperature of the device can be reduced, and good thermal stability can be achieved; and according to the method, amorphous silicon layers are removed by using an acetone solution lift-off process, a CMP process can be simplified, the grinding time can be reduced, the grinding uniformity can be improved, and the frequency stability and the rate of finished products of the device can be improved.

The invention discloses a depth control method for an energy storage power station participating in primary frequency modulation of a power grid, which is characterized in that a grid-connected inverter of the energy storage power station is equivalent to a synchronous voltage source with excitation control and speed regulation control, the energy storage power station adopts a control strategy ofa synchronous machine third-order model, and the frequency modulation depth of the battery energy storage power station participating in the primary frequency modulation of the power grid by settinga difference adjustment coefficient sigma<battery>% of the energy storage power station according to a flexibility index and a static frequency characteristic of the battery energy storage power station. The invention further discloses a contribution calculation method for the energy storage power station participating in primary frequency modulation of the power grid. The frequency modulation depth of the energy storage power station participating in system primary frequency modulation is controlled, so that the rated power, the rated capacity and the climbing rate of the energy storage powerstation are reasonably configured to stabilize the steady-state frequency of the system after primary frequency modulation in a reasonable range, the frequency stability and the voltage stability ofthe energy storage power station for supporting grid connection of the new energy system are improved, a contribution factor lambda is defined, and the importance of the energy storage power station in the power grid system to frequency modulation is analyzed.

The invention discloses a GNSS (Global Navigation Satellite System) multi-mode multiplexer module. The GNSS multi-mode multiplexer module comprises an antenna multiplexer and a channel multiplexer, wherein the antenna multiplexer is used for receiving a downlink channel satellite signal and transmitting the downlink channel satellite signal into a four-in-one low-noise filtering combination amplifier for combination; the combined signal further comprises a Beidou first-generation uplink channel signal transmitted through a Beidou first-generation power amplifier; the combined downlink channel signal and an uplink channel transmitted signal are subjected to bidirectional equivalent shunting through a signal transmitting and receiving hybrid circuit I; and the channel multiplexer is used for performing bidirectional equivalent combination on the downlink channel signal and the uplink channel signal through the a signal transmitting and receiving hybrid circuit II, and shunting a four-path downlink channel satellite signal in a four-in-one signal power divider. A plurality of signals are shunted through a multi-mode power divider; the isolation degree between a transmitted signal and a received signal is increased through adoption of a transmitting and receiving hybrid filtering circuit pair; interference among signals is eliminated; and low-power-consumption running of a whole system is ensured through adoption of a controllable power amplifier.

The invention discloses a device for achieving a minitype CPT atomic clock physical system. The device comprises a Bias-Tee, a VCSEL, a first quarter wave plate, an atomic gas chamber, a second quarter wave plate, a polarization beam splitter, a first photoelectric detector and a second photoelectric detector. The invention further discloses a method for achieving the minitype CPT atomic clock physical system. Elliptically-polarized light is adopted for resonance with atom CPT, and difference detection is conducted on the optical rotation effect generated by the resonance. According to the device and method for achieving the minitype CPT atomic clock physical system, background noise generated by optical frequency components which do not interact with atoms in multi-color light output by the VCSEL and conversion noise generated by light interacting with the atoms due to light frequency jitter which is converted into signal amplitude jitter through action with the atoms are eliminated, and the signal to noise ratio of CPT resonance signals is greatly increased; in addition, the device and the method further have the advantages that the influence on the obtained CPT resonance signals by environment magnetic field intensity fluctuation is small, and laser frequency stabilization can be easily achieved through an achieved atomic clock.

The invention provides a laser frequency stabilization realization method. The laser frequency stabilization realization method comprises steps that: step 1, a single-block dual-wavelength laser device is utilized to output 532nm laser; step 2, an iodine saturation absorption frequency stabilization device is utilized to carry out determination processing on the 532nm laser, if a frequency of the 532nm laser deviates from a reference frequency of the iodine saturation absorption frequency stabilization device, a feedback signal is generated by the iodine saturation absorption frequency stabilization device and is sent to a servo control device, and a step 3 is carried out; if the frequency of the 532nm laser is in the reference frequency of the iodine saturation absorption frequency stabilization device, laser frequency stabilization is realized, and no processing is needed; and step 3, chamber length of the single-block dual-wavelength laser device is adjusted by utilizing the servo control device according to the feedback signal, and the frequency of the 532nm laser is made to be in the reference frequency. The laser frequency stabilization realization method greatly improves stability and reproducibility of the frequency of the laser device.

A piezoelectric resonating element includes a piezoelectric substrate that includes a rectangular vibrating section and a thick section integrally formed with the vibrating section, excitation electrodes, and lead electrodes. The thick section includes a first thick section and a second thick section of which one end is formed continuous to the first thick section. The first thick section includes a first inclined section of which the thickness changes and a first thick section main body of a quadrangle column shape, and at least one slit is provided in the first thick section.

The invention discloses a method for controlling the frequency modulation of a micro-grid battery energy storage system based on fuzzy control, and belongs to the technical field of electric power system micro-grids. On the basis of the conventional proportion integration differentiation (PID) control, fuzzy control and an implementation mode thereof are introduced into the method, and the method comprises important components such as fuzzification, fuzzy rules, fuzzy reasoning, defuzzification, PID control and the like. According to the method, the micro-grid frequency deviation and the micro-grid frequency change rate are fuzzified into input of a fuzzy controller, PID control parameters of active power output control are output according to a fuzzy control rule, and an active power output reference value Pref of the battery energy storage system is finally output to control the active power output of the micro-grid battery energy storage system. Compared with the conventional PID control, the method has very strong adaptability to the switching of micro-grid parallel network/isolated network operational modes and to the nonlinearity and the time variability of electric network operational parameters, has a good dynamic response characteristic, and effectively improves the active power control accuracy of the battery energy storage system and the frequency stability of the micro-grid.

The invention discloses a sinusoidal phase modulation type laser self-mixing interferometer and a measuring method thereof. The interferometer comprises a helium-neon laser, a variable neutral density filter, an electro-optical crystal modulator, a target to be measured, a photoelectric detector and a signal generator. The signal generator is used for generating sinusoidal signals with frequency of omega<m>, wherein one loop of signals is used for driving the electro-optical crystal modulator, one loop of signals is used as base-frequency signal output and the other loop of signals passes through a frequency doubler and a phase shifter and then outputs doubled-frequency signals with frequency of 2 omega<m>. The output of the photoelectric detector is amplified by an operational amplifier and then is respectively mixed with the base-frequency signals and the doubled-frequency signals to obtain two loops of signals. The signals are subject to low-pass filtering and then a computer unit controls an analog-to-digital conversion unit to acquire and demodulate a phase, so as to obtain and display the real-time displacement of the target to be measured. After the interferometer is calibrated, relative measurement accuracy of 10<-6>*L can be obtained, the measurement uncertainties within the measurement ranges of 100mum and 300mum are respectively 10nm and 0.15mum, and the measurable speed range is 0-60mm/s.

The invention discloses a FBAR (film bulk acoustic resonator) substrate and a preparation method thereof. The FBAR substrate is of a W/piezoelectric film/W/ DLC/air gap/Si structure. The FBAR substrate with a W/piezoelectric film/W/ DLC/air gap/Si structure has the characteristics of high frequency, high Q (quality) and good frequency stability. The FBAR substrate can be used for manufacturing filters and duplexers and the like in wireless communication systems, and also can be used for manufacturing high-performance sensors in combination with sensitive films.

The invention discloses a primary frequency modulation adjusting performance determination method of a generating set, and determination of primary frequency modulation adjusting performance is carried out on the generating set with automatic generating control. An improved additional weight integration electric quantity algorithm is provided in the invention, according to real contribution degree of primary frequency modulation to an electrical network, different weight coefficients are employed to carry out integration contribution electric quantity calculation on different frequency differences or time quanta in large and small frequency disturbances, thus primary frequency modulation motions of different generating sets can be distinguished scientifically, a correct rate and contribution electric quantity of the primary frequency modulation motion can be taken into consideration comprehensively to calculate deserved primary frequency modulation economy compensation, and through carrying out verification with real-time measurement data, the novel performance determination method is completely operable. An instance in the invention shows that the additional weight integration electric quantity algorithm has rationality compared with a common integration electric quantity algorithm.