7results about How to "Smooth and precise control" patented technology

The invention discloses a grid-connected control method, a grid-connected control system and grid-connected control equipment for a four-quadrant frequency converter, and particularly relates to the technical field of grid-connected control, and the technical key points are as follows: determining a grid voltage phase sequence and a phase reference angle of a grid voltage signal by using a three-phase phase-locked loop under a DQ coordinate system; determining a voltage input signal and an initialization angle of an SOGI phase-locked loop according to the power grid voltage phase sequence and the phase reference angle, performing phase locking on the power grid voltage of which the total harmonic distortion rate exceeds a preset distortion threshold by using the SOGI phase-locked loop, and outputting a grid-connected feedforward signal when the power grid voltage and the power grid voltage phase sequence meet a grid-connected condition; according to a preset grading rule, each power unit in the four-quadrant frequency converter is divided into different grid-connected grades, and based on a grid-connected feedforward signal, the phase-locked four-quadrant frequency converter controls a switching device to realize grading grid-connected control on the power units of different grid-connected grades according to a preset grid-connected mode.

The utility model discloses a naphthalene water reducer neutralization reaction device capable of automatically adding alkali, and belongs to the technical field of water reducer production equipment. The naphthalene water reducer neutralization reaction device with the automatic alkali adding function comprises a reaction tank, a tank cover is installed at the top end of the reaction tank, four supporting columns are installed on the outer side of the bottom end of the reaction tank, a cooling mechanism is installed on the outer side of the reaction tank, an alkali liquor tank is arranged on one side of the reaction tank, a ring pipe is installed on the inner side of the reaction tank, and a plurality of alkali liquor spray heads are installed at the bottom end of the ring pipe. The top end of the alkali liquor tank is provided with a liquor feeding mechanism for supplying liquor to the annular pipe, the top end of the annular pipe is provided with a cleaning mechanism for cleaning the alkali liquor spray head, the reaction tank is internally provided with a mixing mechanism, the bottom end of the reaction tank is provided with a liquor outlet pipe, and one end of the liquor outlet pipe is provided with a valve. The neutralization reaction efficiency is improved, and the practical value is relatively high.

The invention discloses a gas-liquid erosion experimental device for a U-shaped pipeline. The gas-liquid erosion experimental device comprises a gas phase injection system, a liquid phase injection system and an erosion device which are connected with the pipeline, the gas phase injection system is used for injecting gas into the pipeline; the liquid phase injection system is used for injecting an ammonium chloride solution into the pipeline, and an atomizing nozzle is assembled at the tail end of the liquid phase injection system; a U-shaped sample tube for carrying out an erosion experiment is assembled in the erosion device; a data collecting and processing system is assembled on the erosion device; the detection precision is high, and the injection conditions of a gas phase and a liquid phase can be accurately controlled through the gas phase injection system and the liquid phase injection system; the applicability is wide, and the influence on pipeline erosion under different ammonium chloride solution concentrations and air flows can be tested; operation steps are simple, phenomena are obvious, direct observation is facilitated, and experiment efficiency is improved.

A driving device includes a corrector, an actuator, and a position sensor. The actuator includes a nut connected to a movable part, a ball screw shaft onto which the nut is screwed, and a pulse motor that drives to rotate the ball screw shaft. The corrector includes a correction amount map in which a position correction amount for calibrating a predictable error is mapped for each position of the movable part. The corrector estimates an ideal movement position to which the movable part moves based on a command signal and refers to the correction amount map to calculate the position correction amount corresponding to a present position detected by the position sensor. The corrector generates a correction signal by correcting the command signal so as to reduce the difference between a corrected present position obtained by correcting the present position by the position correction amount and the ideal movement position.

This invention relates to the field of crusher technology, specifically to a metal scrap anti-jamming crusher, comprising two crushing rollers. Each crushing roller is equipped with: crushing rings, multiple of which are evenly arranged along the axis of the crushing roller, with crushing gaps between adjacent crushing rings; the crushing rings on adjacent crushing rollers are staggered and interlocked into the crushing gaps on the other crushing roller to form intersecting areas; first crushing teeth, evenly distributed around the periphery of the crushing rings along their axis; a telescopic groove, which sequentially penetrates the crushing roller and the crushing rings along the radial direction of the crushing roller; second crushing teeth, movable within the telescopic groove along its extension direction; and a second driving device, disposed within the crushing roller and used to drive the movement of the second crushing teeth. This invention avoids material jamming or metal scrap getting stuck during the crushing process.

The invention discloses an electrochemical polishing method for a metal workpiece, electronic equipment and a storage medium. The method comprises the steps that the pressure value of a polishing wheel on the metal workpiece and the rotating speed of a motor or the rotating speed of the polishing wheel are obtained; according to the pressure value and the rotating speed, a reference current value is obtained through calculation based on a calculation model; and controlling a power supply to output the reference current value as a polishing current. The polishing current value is adjusted in real time through the pressure value and the rotating speed, so that the pressure value and the rotating speed do not need to be fixed, and the situation that the polishing effect is affected by fluctuation of power supply equipment in the polishing process is avoided.

This utility model belongs to the technical field of expansion joint construction equipment, specifically relating to an expansion joint construction device, including a base, a movable component disposed on the surface of the base, and a cleaning component. The surface of the base has a notch for placing the cleaning component. The cleaning component includes a cleaning disc vertically placed in the notch, a bracket for driving the vertical movement of the cleaning disc, and a driving component fixed on the surface of the bracket for driving the rotation of the cleaning disc. The outer surface of the cleaning disc is smooth, and the outer surface of the cleaning disc has multiple placement grooves circumferentially spaced around its axis. Each placement groove has a movable block, and one side surface of the movable block is covered with bristles. The outer surface of each movable block away from the axis of the cleaning disc is arc-shaped, and the end of each movable block near the axis of the cleaning disc is elastically hinged to the surface of the cleaning disc. By adopting the technical solution of this utility model, the problem of the cleaning disc not being well protected during the current expansion joint cleaning can be effectively solved.