10results about How to "Suppress inrush current" patented technology

This utility model discloses a data processing board for trackside equipment, belonging to the technical field of subway trackside equipment. It includes a data processing module, a soft-start output module, a power-down voltage monitoring module, an RTC real-time clock module with a first energy storage capacitor, a power supply module with a second energy storage capacitor, and a data interface module. The data processing module is electrically connected to the other modules. The power supply module provides the operating voltage to the board, and its second energy storage capacitor temporarily supplies power to the data processing module during brief external power outages to record the voltage status data at the moment of power failure. The first energy storage capacitor of the RTC real-time clock module maintains clock operation for a preset duration after power failure. This utility model solves the problems of easy data loss and clock failure during power failures in traditional boards. It features high structural integration, stable operation, and accurate recording of power-down fault conditions, meeting the data continuity requirements of subway trackside equipment.

The application relates to the technical field of pre-charging circuits, and discloses a pre-charging circuit and a charging method, wherein the pre-charging circuit comprises a switching unit, a constant-current generating unit and a comparison control unit; the switching unit comprises an input end, an output end and a control end; the constant-current generating unit is connected in parallel with the input end and the output end, and generates a pre-charging current which is constant in size and is input to the output end when the input end and the output end are disconnected; the comparison control unit generates a control signal which is input to the control end based on the voltage difference between the input end and the output end; when in use, when initially powered on, the application provides the output end of the switching unit with a constant pre-charging current through the constant-current generating unit, guarantees that the current is constant and does not attenuate during the pre-charging process, can shorten the pre-charging time and inhibit the impact current in the initial power-on period, and protects the switching unit and the battery pack; and by adjusting the size of the pre-charging current output by the constant-current generating unit, the bus capacitor with different capacitances and the battery with different voltage grades can be adapted, and the generality is high.

This invention primarily relates to the field of inrush current suppression technology. To suppress circuit damage caused by instantaneous inrush current during AC power outage recovery due to the capacitor voltage being significantly lower than the peak supply voltage, this invention provides a circuit and method for suppressing instantaneous power outage current inrushes. The core improvement is that a thermistor limits the inrush current during load startup, and after startup, the relay bypasses the thermistor to achieve low-loss operation. When the load is not running, the control chip comprehensively judges based on the amplitude and rate of change of the bus DC voltage: when the bus voltage is detected to be below a first threshold and the rate of decrease is too fast, it is determined to be an instantaneous power outage state, and the relay is actively disconnected and the thermistor is reconnected in series, thereby suppressing the inrush current that may be generated during voltage recovery; after the bus voltage stabilizes and rises back to a higher second threshold, the relay is controlled to smoothly engage, restoring the low-loss power supply mode.

This invention discloses a transfer apparatus and an image forming apparatus. The transfer apparatus includes: a transfer member that is energized by a power supply to form a transfer electric field for transferring a developer image onto a recording medium; a transfer roller having a recess that accommodates a holding member, wherein at a transfer position, a transfer electric field is formed between the transfer roller and the transfer member, wherein the holding member holds the end portion of the recording medium; a short-circuit circuit that short-circuits the voltage applied to the transfer member with respect to a reference potential point; and a stop mechanism that activates the short-circuit circuit when the recess enters the transfer position as the transfer roller rotates, and deactivates the short-circuit circuit when the recess leaves the transfer position as the transfer roller rotates.

The present invention relates to a DC dual power supply starting and switching current limiting circuit. Two DC power supplies are connected to a starting / switching current limiting unit through their respective contactors. The starting / switching unit is composed of an IGBT Q1 and a peak voltage absorption circuit. The absorption circuit absorbs the voltage spike generated by the parasitic inductance on the DC power transmission line to protect the IGBT Q1 from overvoltage damage. The present invention can suppress the impact current during the switching process of the two DC power supplies, while taking into account the working conditions when the inverter power supply is started, suppressing the starting impact current, and eliminating the need for an additional soft start circuit. The present invention has a simple control strategy, can realize the closing and disconnection of the contactor without current, is reliable in operation, and has good application prospects.

The invention discloses a pre-synchronization method, a pre-synchronization device and a medium, relates to the technical field of grid-connected converter control, and provides the pre-synchronization method for solving the problems of relatively high threshold and insufficient efficiency of parameter pre-synchronization through a phase-locked loop method at present. Synchronization of amplitude, frequency and phase can be completed only by processing alternating current bus voltage and inverter output voltage through a simple mathematical method. Parameter difference before grid connection of a grid-forming system can be eliminated without depending on a phase-locked loop or a control link needing parameter setting, and the purposes of suppressing grid-connected impact current, avoiding current distortion and harmonic problems and ensuring smooth transition of grid-connected and off-grid mode switching are achieved. Therefore, compared with a common pre-synchronization scheme based on a phase-locked loop, the method occupies less computing resources, has a lower threshold and is easy to realize in an engineering manner. And moreover, the synchronization efficiency is higher, and the switching efficiency of the grid-connected and off-grid modes of the network construction type system is improved.

The application discloses a metro pulse passenger flow-oriented escalator control method, equipment and medium, the method comprises the following steps: according to metro train operation data, construct the pulse passenger flow trigger sequence based on discrete events, calculate the continuous passenger flow injection curve arriving at the entrance of the escalator;The future dynamic load torque of the escalator is predicted by using PINN network;In combination with the predicted dynamic load torque, the minimum system operation energy consumption, mechanical wear and queuing congestion penalty are taken as the comprehensive target, the multi-objective nonlinear model predictive control optimization problem is constructed and solved, the optimal speed control instruction is generated and issued to the escalator frequency converter for execution.The application can accurately reconstruct the real-time quality distribution on the escalator, and calculate the future dynamic load torque accordingly, and the controller adjusts the motor operation accordingly, so that it always works at the optimal slip frequency point, reduces the energy consumption of the escalator, reduces the wear of parts, prolongs the service life.

The invention relates to the technical field of medical equipment control, in particular to a power supply circuit of a cold-state light source and electronic equipment. The input end of an output management module is connected with a power supply module, and the output end of the output management module is connected with an output interface for accessing an external load; the input end of the voltage reference module is connected with the power supply module. The first output end of the voltage reference module is connected with the reference input end of the current-limiting protection module. The sampling input end of the current-limiting protection module is connected with the output end of the output management module, and the output end of the current-limiting protection module is connected with the feedback end of the output management module; the second output end of the voltage reference module is connected with the reference input end of the boost control module; the sampling input end of the boost control module is connected with the output end of the output management module, and the output end of the boost control module is connected with the feedback end of the output management module. Intelligent management of the cold-state light source is realized, and the starting success rate, the operation stability and the safety of the light source system of the medical equipment are improved.

The invention relates to the technical field of energy storage converters, and provides a transient performance improvement control method and system for a network construction type energy storage converter, and the method comprises the steps: employing an active reference adjustment coefficient to adjust an active power reference value for active power, calculating the deviation between the active power and the active power reference value, and obtaining a phase angle through an active ring; for reactive power, the deviation between the reactive power and a reactive power reference value is calculated, and internal potential is obtained through a reactive ring; by controlling the on-off of the first switch, the internal potential is used as the input of the impact current suppression ring during normal operation, and the voltage regulation parameter is used as the input of the impact current suppression ring when a power grid has a fault; and the impulse current suppression ring obtains the output of the impulse current ring by controlling the on-off of the second switch and controlling the input or exit of the impulse current suppression impedance, obtains a modulation signal through the voltage ring and the current ring, and generates a driving pulse of each power switch device. And the transient performance, the robustness and the engineering applicability are obviously improved.

The present invention discloses a power supply circuit for suppressing instantaneous inrush current at startup, comprising an input protection module, a rectifier filter module, a startup module and an output module; the input protection module is respectively connected to the rectifier filter module and the startup module, and the output module is respectively connected to the rectifier filter module and the startup module; the rectifier filter module is connected in series with a first thermistor, a self-locking circuit is connected in parallel at both ends of the first thermistor, and the self-locking circuit is connected to the startup module, and when the output module outputs normally, the startup module controls the self-locking circuit to be turned on, thereby short-circuiting the first thermistor. The setting of the first thermistor can suppress instantaneous inrush current at startup; after the first thermistor is short-circuited by the setting of the self-locking circuit, the loss caused by the existence of the first thermistor can be avoided, thereby improving the power supply efficiency; at the same time, the problem of high inrush current at startup caused by the small resistance value of the first thermistor is avoided, thereby preventing product damage.