4results about How to "Guaranteed frequency stability" patented technology

The application discloses a low-noise high-precision voltage control current source for a semiconductor laser, comprising a voltage control signal generation module, a PID control module and an output current sampling and feedback module, wherein the voltage control signal generation module receives a host computer instruction and generates a voltage control signal of an output current; the PID control module receives and processes the voltage control signal generated by the voltage control signal generation module and the feedback voltage generated by the output current sampling and feedback module, generates a control voltage to control the output current of the output current sampling and feedback module; and the output current sampling and feedback module provides a stable output current for a load and provides the amplified voltage quantity of the current feedback compared with the voltage control signal to the PID control module to provide the feedback voltage for the PID control module. The application can realize accurate and stable current output, the output current is adjustable, and the application can provide stable low-noise high-precision driving current for semiconductor lasers and the like.

The application relates to the technical field of power systems, and discloses a power system source-network-load-storage collaborative intelligent planning system, which obtains the power grid load value of a target power grid at fixed time intervals; carries out discrete wavelet transform processing on the time-series power grid load value to obtain M time-scale wavelet coefficients, and constructs a corresponding fractal elastic demand kernel in combination with a preset fractal order; obtains the energy storage value of each energy storage device in the nth physical node and the phase angle of each energy storage device at fixed time intervals, and determines the inertia vector phase field of the nth physical node in combination with a preset angular frequency; constructs a synchronous offset matrix based on the inertia vector phase field of each physical node and the fractal elastic demand kernel of each time scale; and constructs a target function in combination with the synchronous offset matrix based on the energy storage unit cost and the response unit cost, so as to determine the energy storage configuration and demand response strategy of each physical node.

The application provides a communication frequency selection method and system based on multi-factor heuristic adaptive scoring, which first initializes a candidate frequency point set and related parameters, and then collects channel state parameters of each frequency point in each decision time slot. After normalization processing, the collected parameters enter the EWMA history smoothing link to obtain more stable frequency point evaluation results. According to the current communication environment, corresponding weight configuration is selected, and the comprehensive heuristic score of each selected frequency point is calculated. If the SINR of the current working frequency point is lower than the set threshold or the packet loss rate is higher than the set threshold, the fast reselection mechanism is triggered to directly select the frequency point with the better score; if the fast reselection mechanism is not triggered, the regular hysteresis judgment is entered, and only when the selected frequency point has sufficient score advantage over the current frequency point and overcomes the switching cost, the frequency switching is performed, thereby improving the stability of the communication frequency selection.

This invention belongs to the field of power electronic conversion and microgrid control technology, specifically involving a synchronous control method for grid-connected / off-grid switching of an islanded microgrid based on a virtual generator. The method includes transforming the three-phase voltage signals from the microgrid side and the grid side from a three-phase stationary coordinate system to a two-phase stationary coordinate system, obtaining orthogonal components of the microgrid voltage and grid voltage. These orthogonal components are then substituted into a calculation formula to obtain a real-time phase difference signal. This real-time phase difference signal is then fed into a regulator for proportional-integral and filtering processing to generate a phase compensation coefficient. This phase compensation coefficient is then superimposed onto the active frequency control loop of the virtual synchronous generator to correct the phase angle of the virtual synchronous generator's output voltage. This achieves the goal of maintaining the simplicity of the non-phase-locked loop structure while reducing the inrush current during grid-connected / off-grid switching.