72results about How to "Small voltage change" patented technology

A method for controlling dynamic response of switch power is based on a closed-loop control system including a sampling module, a dynamic control module, an error calculating module, a PID module, a mode control module and a PWM module, wherein the sampling module samples output voltage Vo, and the dynamic control module compares the Vo with set Vo max, Vo min and V ref. Whether a dynamic mode is employed is determined. When the output voltage Vo changes greatly under the dynamic mode, the voltage Vo is rapidly restored to a stable voltage by inputting large power or small power, and the load is detected by voltage change gradient to determine the working state and reduce voltage resonance. The dynamic response effect is improved.

A resistive random access memory device, a method for manufacturing the resistive random access memory device, and a method for operating the resistive random access memory device are disclosed. The resistive random access memory device includes a resistive switching memory element including two electrodes and a layer of variable-resistance material between the two electrodes, wherein the layer of variable-resistance material exhibits bipolar resistive switching behavior; and a Schottky diode including a metal layer and a p-doped semiconductor layer which contact each other, wherein the metal layer of the Schottky diode is coupled to one of the two electrodes of the resistive switching memory element. The present disclosure provides the resistive random access memory device operating in bipolar resistive switching scheme.

The invention relates to a liquid crystal display device and a driving method thereof. The liquid crystal display device comprises a time sequence control circuit, a scanning driving circuit, a data driving circuit and a liquid crystal display panel, and the liquid crystal display panel comprises multiple pixels. The time sequence control circuit comprises a data analysis module, wherein the data analysis module is used for receiving and analyzing every frame of image data; in n lines of the pixels which are displayed continuously in one frame of the image data, when m lines of pixels which are displayed continuously display a black picture (n>=4, n>m>=2), the data analysis module outputs a first polarity inversion control signal to the data driving circuit, the data driving circuit is used for processing a data signal according to the first polarity inversion control signal so as to generate a plurality of gray scale voltages and the gray scale voltages are provided to the liquid crystal display panel; and when the plurality of pixels of the liquid crystal display panel display the frame of image, in the m lines of the pixels, which are displayed continuously and display the black picture, the polarities of all the pixels positioned in the same line are the same.

The invention discloses a phase-locked loop resistant to a single particle transient state. The phase-locked loop comprises a phase frequency detector, a charge pump, a filter, a voltage-controlled oscillator and a frequency divider. A single particle suppression circuit is arranged between the charge pump and the filter and comprises a charge discharge branch, decay resistor, and a charge compensation branch. One end of the damping resistor is connected with an output end of the charge pump, and the other end of the damping resistor is connected with an input end of the voltage-controlled oscillator. When voltage of the output end of the charge pump is reduced and charging is needed, the filter charges the output end of the charge pump through the single particle suppression circuit. When the voltage of the output end of the charge pump rises and discharging is needed, the output end of the charge pump charges the filter through the single particle suppression circuit. Due to the fact that the single particle suppression circuit is arranged between the charge pump and the filter of the phase-locked loop, when receiving single particle bombardment, the output end of the charge pump discharges or be charged so as to reduce voltage disturbance caused on the input end of the voltage-controlled oscillator.

The invention discloses an inverting control system and method based on grid drop testing in a photovoltaic power generation system. The method comprises the steps that a photovoltaic array converts solar energy into electric energy, a DC-DC converter carries out MPPT of the photovoltaic power generation system, and an inverter inverts direct current into high-quality alternating current to be sent to a grid; whether the grid drops or not is detected, and if the grid does not drop, an MPPT controller in a pre-controller works, and more energy is obtained from the photovoltaic array; if the grid drops, the MPPT controller in the pre-controller stops working, a first PI controller works, voltage of direct current bus keeps stable in the low-voltage ride through process, a grid-connected current feed unit provides reactive current, and the grid-connected current amplitude is kept constant. The inverting control system and method based on grid drop testing in the photovoltaic power generation system can reduce severe sudden changes of the voltage of the direct current bus in the low-voltage ride through process and prevent the grid-connected current from exceeding a flow value.

The invention relates to a no-load closing inrush current and overvoltage suppression unit of an ultrahigh-voltage transformer and belongs to the technical field of power electronics. The unit is applicable to no-load closing inrush current and overvoltage suppression for the ultrahigh-voltage transformer; inrush current and overvoltage generated in switching the transformer are decreased; meanwhile, less arc light occurs between contacts of a breaker; the service life of the transformer is prolonged; especially under the condition that ultrahigh-voltage grids both domestic and abroad fail to allow switching of the transformers, the importance of the unit upon operational safety and stability of the grids is more highlighted.

The invention provides an off-grid and grid-connected smooth switching method of a virtual synchronous generator. The smooth switching method is characterized by comprising grid-connected/off-grid and off-grid/grid-connected smooth switching. As for off-grid/grid-connected switching, the switching strategy is added in the off-grid and grid-connected switching process without modifying the control strategy of the virtual synchronous generator, and the reference voltage of the virtual synchronous generator is changed into the command reference voltage from the grid voltage and the correction angular velocity of pre-synchronous control is enabled to be zero directly so as to realize grid-connected/off-grid smooth switching. Popularization of the virtual synchronous generator technology is further facilitated in the field of new energy power generation, and friendly accessing of distributed energy resources can be realized so as to enhance the stability of the electric power system. Besides, application of the control strategy and the theoretical analysis method related to the conventional synchronous generator to VSG is facilitated so as to play an important role in the active power distribution network and the microgrid in the future.

A fluid feeding pump which varies a volume of a pump chamber and thus feeds a fluid out of the pump chamber, includes: a piezoelectric element which accumulates electric charges inside when a voltage is applied, and which deforms according to an amount of accumulated electric charges and thus increases or decreases the volume of the pump chamber; a drive unit which applies a drive signal with a waveform increasing to a predetermined maximum voltage and then decreasing, and thus drives the piezoelectric element; and an air bubble determining unit which detects a current flowing through the piezoelectric element within a predetermined period after the drive signal is applied to the piezoelectric element, and thus determines whether there are air bubbles in the pump chamber or not.

The invention discloses a two-stage type AC-DC converter and a control method thereof and belongs to the power electronic converter technical field. The two-stage AC-DC converter is composed of a double-output PFC converter and two DCX circuits; the dual-output PFC converter provides voltage-constant high-voltage direct current output and voltage-variable low-voltage direct current output; the high-voltage direct current output and the low-voltage direct current output are respectively adopted as the inputs of the two DCX circuits; and the outputs of the two DCX circuits are connected in series and are connected with a load. According to the two-stage type AC-DC converter and the control method thereof of the invention, the voltage-variable low-voltage direct current output of the double-output PFC converter is utilized to directly realize wide-range regulation of the voltage of the load side, and therefore, the power loss of the PFC converter can be decreased, and the high-efficiency DCX circuits can be adopted at the later stage, and overall efficiency can be improved significantly. The two-stage type AC-DC converter and the control method thereof are especially suitable for AC-DC conversion conditions where load voltage varies substantially and have a high application value and a bright application prospect in fields such as the electric vehicle charging and energy storage field.

The invention discloses a distributed voltage source converter cooperative control method and an AC-DC hybrid microgrid. The distributed voltage source converter cooperative control method comprises the following steps of: adjusting a power flow between an AC sub-grid and a DC sub-grid through a bidirectional interconnection converter; when the load of the AC sub-grid suddenly changes, calculating the total optimal power input of the AC sub-grid, and judging whether the DER total power in the current AC sub-grid reaches the total optimal power input of the AC sub-grid or not; if so, calculating the input power contribution of each DER in the AC sub-grid through using a virtual inertia algorithm; and if not, indicating that the DER in the DC sub-grid has redundant power, the DC sub-grid participates in cooperative control. According to the distributed voltage source converter cooperative control method, the inertia of the micro-grid is remarkably improved, the communication bandwidth is reduced, the service life of storage equipment is prolonged, and the method has the characteristic of quick and stable control.

An electronic device comprising at least a first part of a housing and a second part of a housing joined together with a fixing element and configured to be movable with respect to each other, wherein the first part of a housing comprises a first battery configured to provide power to functional elements comprised by the first part of a housing, and the second part of a housing comprises at least a second battery configured to provide power to functional elements comprised by the second part of a housing, and a method for managing power distribution in the electronic device.

The invention provides a liquid crystal display device, which comprises a liquid crystal panel and a data driver, wherein the data driver drives the liquid crystal panel to perform display. The liquidcrystal display device further comprises plug-in gray data generating circuit which outputs a plug-in gray data voltage to a data driving circuit. Each frame of the liquid crystal display device comprises a first subframe and a second subframe. The data driving circuit outputs an image data voltage at the first subframe, outputs the plug-in gray data voltage at the second subframe and drives theliquid crystal panel, and the plug-in gray data voltage of the current frame has the same polarity as that of the image data voltage of the next frame. The liquid crystal display device can eliminatethe phenomenon of blurred images during reverse driving. The invention simultaneously provides a driving method of the liquid crystal display device.

A transparent electrode includes a conductive layer and an intermediate layer disposed adjacent to the conductive layer. The transparent electrode has a light transmittance of 50% or more at a wavelength of 550 nm and a sheet resistance of 20Ω/□ or less. The intermediate layer contains an organic compound containing a sulfur atom having an unshared electron pair. The conductive layer is composed of silver as a main component.

The invention provides an operation vehicle and an electricity leakage detecting method thereof employing a simple circuit for judging electricity leakage with high precision. The operation vehicle is provided with a leakage detecting part (5) used for leakage detection of the electric capacitor; a circuit transferring switch cutting the capacitor (2) from a load circuit (1) and connecting the leakage detecting part (5) to the capacitor and besides cutting the leakage detecting part (5) from the capacitor and connecting the capacitor (2) to the load circuit (1); and a microcontroller making the circuit transferring switch (SW) to work, cutting the capacitor (2) off from the load circuit (1) and connecting the leakage detecting part (5) to the capacitor (2) when that the capacitor (2) is fully charged and current of the load circuit (1) is zero are detected, making the circuit transferring switch work, cutting the leakage detecting part (5) off from the capacitor (2) and connecting the capacitor (2) to the load circuit (1) after leakage detection of the capacitor is done by the leakage detecting part (5).