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 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 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.

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 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 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.