9results about How to "Small phase difference" patented technology

The invention relates to the field of intelligent control, and provides a power factor adaptive control method for a charging system, and the method employs a signal processing and analysis algorithm based on deep learning to carry out the wavelet analysis and time-frequency feature extraction of an input current signal and an input voltage signal. Therefore, the duty ratio of the PFC driving signal is automatically obtained according to the global interactive aggregation representation characteristic between the input current signal and the input voltage signal. Therefore, the dynamic information of the power grid and the load can be more accurately captured so as to quickly respond to the voltage fluctuation and load change of the power grid and reduce the phase difference between the input current and the input voltage, thereby reducing the unstable risk of the charging system caused by the drop of the power factor, and further maintaining the stability of the power grid. Therefore, the automation degree of power factor control is improved.

The invention discloses a multichannel optical transmission device based on periodic optical filters. The multichannel optical transmission device comprises a multichannel light source, a phase modulator array, a multi-wavelength light beam combiner, a light beam splitter, a first periodic optical filter, a second periodic optical filter and a balanced photoelectric detector. Multi-channel radio frequency signals are modulated to optical signals with different frequencies through the phase modulator array, bias point closed-loop control is not needed, the modulated optical signals are transmitted through the same optical fiber, the number of transmission optical fibers can be reduced, phase differences and intermodulation in the transmission process of the multi-channel radio frequency signals can be reduced, and the transmission efficiency of the multi-channel radio frequency signals can be improved. An upper sideband and a lower sideband of a radio-over-fiber signal are respectively filtered out through the periodic band-pass filter, demodulation of a phase modulation signal is realized through an upper sideband signal and a lower sideband signal through the balance detector, optical transmission common-mode noise and even-order harmonics are reduced, the optical transmission signal-to-noise ratio and the harmonic suppression ratio can be improved, the integration level is high, use is flexible, and the application range is wide.

The present invention discloses a mask machine for producing earless hanging rope masks and a method for using the same. The material rack is an inverted T-shaped frame structure arranged vertically and horizontally, and a workbench is provided in the middle thereof; four face cloth unwinding assemblies are respectively provided on the left and right sides directly above the workbench, and a first adjustable tension feeding rack is respectively provided on one side of the face cloth unwinding assembly, and the fabric is fed through the first adjustable tension feeding rack and assembled on the second adjustable tension feeding rack; a left cover body welding assembly, a right cover body welding assembly and an edge sealing welding assembly are provided in a T-shape directly above the workbench, and a mask cutting and forming assembly is provided on one side of the edge sealing welding assembly, and a conveyor belt is provided on one side of the mask cutting and forming assembly; after two groups of four layers of fabric are welded respectively, the edge sealing welding assembly is used for edge sealing and welding, and then the mask cutting and forming assembly is used for cutting and forming, and the fabric is conveyed by the conveyor belt. The overall structure of the present invention adopts a T-shaped structural design and a U-shaped transmission design, so that the traction force is symmetrical and it is not easy to form a phase difference.

Examples relate to thin films, transparent laminates, applications as cover films, and multilayer electronic devices incorporating the thin film, which possess excellent optical properties such as refractive index, haze, and yellowness, as well as excellent mechanical properties. The thin film includes an elastic layer with a refractive index of 1.48 to 1.58 and a low-temperature damage index (the difference between tensile modulus and tensile strength at a specific temperature), wherein the low-temperature damage index of the elastic layer at -40°C is below 1300 MPa.

The invention discloses a control device for reducing a THD value of a PFC circuit and a control method thereof, and relates to the technical field of PFC circuits. The control device comprises a microcontroller unit and a PI controller provided with a current loop and a voltage loop. The microcontroller unit inputs voltage change parameters to the voltage loop of the PI controller based on obtained external load information and current input voltage, and obtains a power factor value higher than a preset PFC threshold value. Obtaining an output voltage of the voltage loop, and calculating a voltage difference value between the output voltage and a preset reference voltage; calculating an input voltage effective value of the voltage loop, and obtaining a reference current value of the current loop; the input current is compared with a reference current value of a current loop, the duty ratio of a synchronous PWM signal of a PI controller is calculated and determined based on a current loop of the PFC circuit, and the microcontroller unit performs optimization control on the PFC circuit based on the duty ratio of the synchronous PWM signal; the PFC circuit has the effect of further reducing the THD value of the PFC circuit.

The invention provides a dynamic voltage control method and system for an energy storage converter, and relates to the technical field of data processing, and the method comprises the steps: carrying out the mathematical modeling of a circuit of the energy storage converter, and building the representation of a voltage in a two-phase rotating coordinate system; according to the expression of the voltage in the two-phase rotating coordinate system, a voltage signal output by the energy storage converter is filtered through a filter, and a filtered voltage signal is obtained; and modulating the filtered voltage signal, and generating a modulation waveform by calculating and distributing the duty ratio of each phase switch so as to control the output voltage of the energy storage converter. Through mathematical modeling, filtering processing, modulation control and an optimization algorithm for simulating the bacterial foraging process, accurate and real-time control of the output voltage is realized, and the response speed and the stability of the system are improved.

This invention relates to a method for manufacturing an optical film, an optical film, a polarizer, and a liquid crystal display device. The objective is to provide a method for manufacturing a wide-width optical film with low retardation values ​​in both the in-plane and thickness directions, and to suppress display unevenness caused by environmental variations in the display device, using a plant-derived resin. The method for manufacturing the optical film of this invention is characterized by comprising: a step of forming a strip film from a cellulose ester resin containing a total acetyl substitution degree of 2.30 to 2.60 and a sugar ester having a furanose or pyranose structure; and a step of stretching said strip film, wherein the retardation value R... o The range is 0–10 nm, R t The process of stretching the long strip film, with a wavelength of -10 to 10 nm, includes the following steps: a first step to obtain a first stretched film; and a second step to further stretch the first stretched film to obtain a second stretched film, wherein the stretching temperature of the second step is in the range of 190 to 220°C.

This application discloses a phase synchronization method for an energy storage inverter based on half-angle characteristics, comprising: acquiring the input voltage signal from the power grid; locking the phase angle of the input voltage signal using a rotating coordinate method; obtaining the sine and cosine values ​​of the rotation angle of the input voltage signal based on the phase angle of the input voltage signal; converting the sine and cosine values ​​of the input and output voltage signals into half-angle forms according to the half-angle characteristic formula; converting the half-angle forms into the sine and cosine values ​​of the phase angle difference between the input and output voltage signals according to the two-angle sum formula; and using PI control to adjust the phase of the output voltage signal by using the sine value of the phase angle difference as an input quantity. This application achieves phase synchronization of the inverter with the power grid before grid connection, reduces the phase difference between the inverter synchronization signal and the power grid signal, reduces the current generated by the voltage difference during grid connection, and improves the stability of the inverter.