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

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 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 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 invention discloses a method for self-adaptive emergency load shedding based on the voltage drop amplitude, which includes calculating the voltage drop amplitude of each load node in the whole network; sorting each load node according to the voltage drop amplitude; sorting the sorted load Nodes are removed in order of voltage drop amplitude from large to small, until the total load shedding is equal to the active power deficit of the whole network, then the load shedding is completed. The present invention fully considers the transient voltage response of the power system. Compared with the existing load shedding method, the present invention can more quickly and effectively select weak buses in the power grid for load shedding, and the number of selected load shedding locations can be determined according to The actual situation of the power grid and the size of the active power deficit when a fault occurs fully consider the time-space distribution characteristics of the voltage of each load node after a large disturbance in the system, effectively control the system state, avoid voltage collapse, and protect the power system. frequency stability and voltage stability.

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.