307 results about "Limiting current" patented technology

The invention discloses a thermoelectric refrigerating unit self-adaptive temperature control system and method based on transient supercooling. In the system, a temperature detection unit is used for acquiring cold end temperature information of a thermoelectric refrigerating unit; the thermal load monitoring unit is used for monitoring thermal load information of the thermoelectric refrigerating unit; the PID controller is used for controlling the cold end temperature of the thermoelectric refrigerating unit at the target temperature as an optimization target, and regulating and outputting a first current by utilizing the cold end temperature information; the transient pulse controller regulates and controls the amplitude limiting current based on the thermal load information; the feedforward controller adjusts the advanced regulation and control current based on the thermal load information and outputs a second current; the amplitude limiting output unit is used for outputting and limiting the total current of the first current and the second current to be within an amplitude limiting current according to the amplitude limiting current generated by the transient pulse controller; the power output unit drives the thermoelectric refrigerating unit based on the current generated by the amplitude limiting output unit. The thermal load resistance of the thermoelectric refrigerating unit can be remarkably improved, and the temperature control precision and stability are improved.

The invention relates to the technical field of charging optimization, and discloses a multi-stage charging optimization method based on adaptive identification of a battery, and the method comprises the following steps: S101, in-situ detection and battery type identification; step S102, applying a current step and collecting a voltage response; s103, predicting the change of the terminal voltage along with time; step S104, determining a safe amplitude limiting current; step S105, determining a pre-deceleration factor; and step S106, judging full power, generating a quota recovery instruction, and returning to the step S104 for redistribution. Battery individual parameters are obtained through in-situ detection and micro-pulse identification, current quotas are dynamically distributed based on a constant voltage proportion, a safe target current is determined by combining voltage and power amplitude limiting, current distribution unbalance is avoided, the bus current utilization rate is maximized, voltage overshoot is inhibited by means of a first-order following strategy and a pre-deceleration factor, and the safety of a battery is improved. And stable switching is ensured by matching with constant-voltage inlet current clamping.

The invention discloses a network construction converter virtual impedance and power reference cooperative adjustment method and system, and relates to the technical field of power control, a virtual synchronous generator system introduces virtual impedance to increase equivalent output impedance of an inverter, and an internal voltage reference generated by a virtual synchronous generator algorithm of the inverter is monitored in real time; monitoring the local voltage measured by the common coupling point in real time; based on the vector difference between the internal voltage reference and the local voltage, the accurate amplitude of the virtual impedance is solved in real time by combining the maximum current limit value of the power electronic device; and determining a function relationship between an active power reference value and reactive power based on the accurate amplitude of the virtual impedance, monitoring the reactive power measured at the common coupling point in real time, and adjusting the active power reference value according to the function relationship to keep a stable balance point. And virtual impedance is dynamically calculated to accurately limit current, and active power reference is adaptively adjusted according to real-time reactive response, so that maximized power grid support and safe and stable operation of the converter are realized.

The invention provides a method for determining the dynamic response characteristic of a current-limiting resonance elimination device, and belongs to the technical field of current-limiting resonance elimination devices, and the method comprises the steps: firstly, setting an initial condition for an experimental test, and obtaining experimental data including current-limiting current, resonance elimination voltage, temperature rise and the like; and generating comprehensive current-limiting resonance elimination data by changing initial conditions for multiple times. Then, establishing a dynamic response characteristic equation set covering electrical, mechanical, thermal, magnetic and other characteristics, and fitting experimental data to obtain an analytical solution and a numerical range solution; and finally, by taking the analytical solution as a dynamic response characteristic expression and the numerical range solution as a constraint condition, establishing a dynamic response characteristic model of the current-limiting resonance elimination device for performance evaluation and optimization design. The method solves the technical problem that a dynamic response characteristic model of an existing current-limiting resonance elimination device is usually designed and evaluated by adopting a simplified model or an empirical formula, and the actual performance of the device in a complex power grid environment is difficult to reflect accurately.

Circuits and methods that limit current through power FETs of power converter to reduce damaging current in-rush events, independent of switching frequency, device mismatches, and PVT variations. Embodiments utilize a closed-loop feedback circuit and / or a calibrated compensation circuit to regulate, substantially independent of frequency, the control voltage VGATE applied to a power FET gate. In a reduced gate-drive mode, connecting a feedback or compensation circuit to the gate of an LDO source-follower FET allows the gate voltage to be regulated to control the LDO output voltage to a final inverter coupled to the gate of a power FET so that VGATE is adjusted to provide a reduced gate-drive to the power FET; connecting to the output of the LDO allows the LDO output voltage to the final inverter to be directly regulated to adjust VGATE; connecting to the gate of the power FET allows VGATE to be directly set.

The invention discloses a high-efficiency current amplification circuit based on H-bridge structural design, the current amplification circuit comprises a power supply module, two control modules, an H-bridge amplification module, a logic control module, a protection module and a load module, the power supply module is used for providing a direct current input voltage, each control module comprises a half-bridge controller, two resistors and two capacitors, and the logic control module is connected with the H-bridge amplification module. Pins of each half-bridge controller are set to be a VCC end, an IN end, an SD end, a COM end, a VB end, an HO end, a VS end and an LO end, and the two resistors are used for limiting current and adjusting voltage. The H-bridge structure is cooperated with the IRF540N MOS tube, high voltage, large current output, multiple protection and redundancy design are realized, long-term stable operation in an industrial environment is ensured, general elements and a modular architecture are adopted, the purchase and maintenance cost is reduced, and by adjusting the capacitance value of a capacitor, the resistance value of a resistor or the model of the MOS tube, the device can be expanded to scenes with higher power or different voltages.

The invention discloses a quick charging safety control method for a mobile power supply, and particularly relates to the technical field of charging control of an electrochemical energy storage device. The method is started when a charging adapter is connected after the mobile power supply completes high-power discharging, and an ion relaxation index is obtained through open circuit detection; entering rhythm cycle control of charging-charging stopping-measuring, and limiting current according to risk levels; the charging current and the charging stopping duration are adjusted in a self-adaptive mode according to the ion relaxation index and the terminal voltage change rate in the circulation, finally, when the index is stabilized within the safety range, the constant-current and constant-voltage charging stage is smoothly switched, and safety control over rapid charging is achieved; according to the method, the distribution state of the battery cell ions is accurately detected before charging, current is limited in a graded mode according to risk grades in rhythm slow start, dynamic optimization of the charging current and the charging stopping duration is achieved in combination with self-adaptive adjustment, a constant current stage and a constant voltage stage are smoothly switched to when the state is stable, and safety and efficiency are both considered in the whole process.

The invention relates to the technical field of lead frame coarsening, in particular to a nickel coarsening process of a lead frame. A nickel coarsening process of a lead frame comprises the following procedures of oil removal, acid pickling, nickel electroplating coarsening and acid pickling, the nickel electroplating coarsening refers to that an electroplating coarse nickel layer is obtained in an electroplating bath loaded with nickel electroplating coarsening liquid in an electroplating mode, and the nickel electroplating coarsening liquid comprises 90-130 g / L of nickel aminosulfonate, 40-50 g / L of boric acid and 0.1-0.3 g / L of an additive. According to the nickel roughening process of the lead frame, the rough nickel layer can be directly obtained, and the copper substrate does not need to be treated, namely additional electroplating pretreatment is not needed. According to the nickel coarsening process, crystallization of nickel ions on the surface of the lead frame is remarkably affected in the nickel electroplating deposition process through the additive in the nickel electroplating coarsening liquid, the limiting current density of the nickel electroplating coarsening liquid is reduced, deposition of a high-current-density area is restrained, nearly-spherical round grains are formed, and the nickel electroplating quality is improved. Meanwhile, the process of electron deposition of nickel ions is accelerated, cathodic polarization is reduced, growth of nickel crystal nucleuses is promoted instead of nucleation, large-size particles are formed, the surface roughness is improved, an electroplating coarse nickel layer with certain roughness is finally formed, the content of nickel metal in an electroplating nickel coarsening solution cannot be continuously increased, wastewater discharge is reduced, and the production cost is reduced. The environment is protected.

The invention provides a method for preparing a nitrogen, phosphorus and sulfur tri-doped hollow carbon nanocage material derived from a covalent triazine polymer. The method comprises the following steps: by taking zinc nitrate hexahydrate and 2-methylimidazole as reactants and methanol as a solvent, stirring at room temperature to synthesize ZIF-8; the preparation method comprises the following steps: by taking phosphonitrilic chloride trimer and bisphenol S as monomers and ZIF-8 as a template agent, carrying out polymerization under the induction of an N, N-diisopropylethylamine initiator so as to generate ZIF-8 (at) PZS; and performing high-temperature pyrolysis to synthesize the nitrogen, phosphorus and sulfur triple-doped hollow carbon nanocage material. The invention also discusses the application of the nitrogen, phosphorus and sulfur tri-doped hollow carbon nanocage material in an air electrode material of a zinc-air battery. Meanwhile, the conductivity and the oxygen reduction reaction electro-catalytic performance of the obtained carbon material are remarkably improved through the nitrogen, phosphorus and sulfur doped synergistic effect, the half-wave potential of the carbon material reaches up to 0.85 V vs. RHE, and the limiting current density can reach 5.19 mA cm. A zinc-air battery assembled by using the material as an air electrode shows high peak power density of 194 mW cm.

A system for partially pre-charging an electrical power system having a high voltage power source, a DC link device with a DC Link capacitor, a low voltage power source and a DC / DC converter. In one embodiment a partial pre-charge of the DC Link capacitor can be achieved in three ways: first, through a DC / DC converter boosting from the low voltage power source, second, through a first circuit provided to charge the DC link capacitor to a partial pre-charge state using the voltage directly from the low voltage power source, and third, through a second circuit provided to limit current flowing to the DC link capacitor from the high voltage power source to charge the DC Link capacitor only to a partial pre-charge level. A controller selectively operates the first circuit, the second circuit, or the DC / DC converter for charging the DC link capacitor to the partial pre-charge state

A bridgeless power factor correction (PFC) circuit for reducing electromagnetic interference (EMI) is disclosed herein. A current source is placed in parallel with a switch of a low frequency leg. The current source may be turned on during zero crossings of the AC input voltage to limit current and reduce the rate of change in voltage. In turn, EMI may be advantageously reduced without the need for large passive filters or complicated circuitry.

The invention relates to the technical field of hot water supply equipment, and discloses a control method and device of a gas water heater, the water heater and a storage medium The water inlet temperature, the water outlet temperature and the water flow of the gas water heater are obtained, and the current actual load corresponding to a proportional valve is determined based on the water inlet temperature, the water outlet temperature and the water flow; the current current of the proportional valve is obtained, and the current theoretical load corresponding to the proportional valve is determined based on the current current; based on the proportion of the difference value between the current theoretical load and the current actual load relative to the current theoretical load, the current load deviation rate of the gas water heater is determined; and adjusting the limiting current of the proportional valve based on the size relation of the current load deviation ratio relative to the preset deviation ratio. According to the method, the current working state of the gas water heater is determined based on the current load deviation rate, and the limiting current of the proportional valve is adjusted based on the current working state, so that the flame leaving phenomenon or flameout of the gas water heater is prevented, and the gas water heater can work stably.

The invention discloses a method for activating a proton exchange membrane fuel cell. The specific process is as follows: S1) preparing a small molecular organic acid solution with a certain concentration; s2) introducing the solution prepared in the step S1 into a fuel cell according to a certain flow rate, and activating for a certain time; s3) after activation of the small molecular organic acid is completed, flushing the fuel cell with deionized water for 2-3 times; s4) connecting the fuel cell to a fuel cell test system, purging the fuel cell with N2, and setting the temperatures of the humidifier, the gas path pipeline and the cell at the same time; s5) after reaching the specified temperature, replacing the reaction gas air and H2, testing an I-V curve, and determining the maximum current; s6) activating for a certain time under the maximum current density; s7) after activation is completed, an I-V curve is obtained through testing, and the limiting current density and the peak power density can be obtained.According to the method, the proton exchange membrane fuel cell is subjected to small-molecule organic acid activation through the efficient method, and compared with a traditional activation method, the limiting current density and the peak power density of fuel cell operation are obviously improved.

The invention discloses a rechargeable battery management system based on negative side current limiting, and the system comprises a power circuit which comprises a positive bus, a negative bus, and a battery interface and an equipment interface which are disposed at the two ends of the positive bus and the negative bus; the charging switch and the discharging switch are connected to the negative bus in series; the detection circuit is used for detecting state parameters of the battery and / or the power supply loop; one end of the current limiting circuit is electrically connected with a node between the charging switch and the discharging switch, and the other end of the current limiting circuit is electrically connected with the negative electrode end of the equipment interface; and the controller is electrically connected with the charging switch, the discharging switch, the current limiting module and the detection circuit, and is used for controlling the current limiting module to access or exit from the power supply loop according to the state parameters detected by the detection circuit. According to the battery management system, the current limiting circuit is arranged on the cathode bus side, and the cooperative work of the detection circuit and the controller is combined, so that the accurate dynamic control of the current of a power supply loop is realized, and the limitation of a traditional hardware current limiting scheme is overcome.

The invention discloses an incremental double-variable fuzzy control method for a DC / DC converter of an electric vehicle, and relates to the technical field of electric vehicles, and the method comprises the steps: obtaining an actual output voltage Vreal and an actual output current Ireal of the DC / DC converter; based on the actual output voltage Vreal and the target output voltage Vref, a voltage error is calculated; calculating a current error Ierror based on the actual output current Ireal and a target limiting current Iref; and on the basis of the voltage error Veror and the current error Ierror, an incremental fuzzy control strategy is adopted, and a PWM duty ratio adjustment amount delta D is calculated so as to adjust the output voltage and the output current of the DC / DC converter. The voltage and current overshoot and oscillation phenomena existing in a traditional mode can be effectively restrained, the control precision and the anti-interference performance are high, the response speed is high, and implementation is easy.

Provided is a power supply control device provided in a switching power supply apparatus that converts an input voltage into an output voltage through switching of an output transistor, including a switching control circuit that stabilizes the output voltage by switching control of the output transistor, based on a feedback voltage corresponding to the output voltage, a signal output terminal, and a signal output circuit that is capable of outputting a signal corresponding to whether the output voltage is normal from the signal output terminal, based on the feedback voltage, the switching control circuit being capable of performing an overcurrent protecting operation that limits a current flowing through the output transistor to a limit current or less, and the signal output circuit outputting a specific signal indicating execution of the overcurrent protecting operation from the signal output terminal when the current flowing through the output transistor reaches the limit current.

Portable power supply with a maximum charge rate feature. The portable power supply includes a power source; a power input unit configured to receive power from an external source; a core charger coupled to the power source and the power input unit; and an electronic processor coupled to the core charger. The electronic processor is configured to receive a power limit value and determine a supportable charge current of the internal power source. The core charger is configured to determine a power-limited current based on the power limit value and an output voltage of the core charger, determine a target output current by comparing the power-limited current and the supportable charge current, and charge the power source with the received power at the target output current.

Provided are a control method for an energy storage system and the energy storage system. The energy storage system includes N energy storage sub-modules, where N is a positive integer greater than 1. The control method for the energy storage system includes: acquiring an SOC and a charge-discharge limiting current of each of the N energy storage sub-modules; and controlling working states of the N energy storage sub-modules according to the SOC and the charge-discharge limiting current of each of the energy storage sub-modules, where the working states include a switched-on state and a switched-off state. According to the technical solution provided by embodiments of this application, the problem of SOC imbalance among the energy storage sub-modules can be solved, so that the utilization rate of the energy storage system is improved.

The invention discloses an integrated circuit magnetic field auxiliary electroplating system which comprises electroplating equipment provided with a cathode assembly and an anode assembly which are opposite to each other; the magnetic field generator comprises a magnet N pole and a magnet S pole, the magnet N pole is arranged on one side of an anode assembly of the electroplating equipment, the magnet S pole is arranged on one side of a cathode assembly of the electroplating equipment, and the magnetic field generator generates a transverse magnetic field between the cathode assembly and the anode assembly. The invention belongs to the field of micro rapid prototyping processing, and particularly relates to a magnetic field auxiliary electroplating system for an integrated circuit. The transverse magnetic field is applied to adjust the electric field through the magnetic force, and according to the electromagnetic induction principle and the Larentz force law, liquid phase mass transfer is accelerated, the deposition speed and the limiting current density are improved, the time of reaction bubbles staying on the deposition surface is shortened, grains are refined, and the deposition quality is improved.

The invention discloses a flow channel structure of a redox flow battery, and particularly relates to a three-dimensional staggered snake-shaped flow channel structure and an all-vanadium redox flow battery, the flow channel structure comprises two parts, and the two parts are positioned on the two sides of an electrode in the thickness direction and are respectively processed on the side surface, close to an electrode, of a bipolar plate and the side surface, close to a diaphragm, of the electrode; an inlet of the runner structure is formed in the bipolar plate side part, and an outlet is formed in the electrode side part; the flow channel structure of each part is snake-shaped, and the flow channel structures of the two parts are distributed in a staggered manner in the plane direction of the electrode. The technical problem that the convective mass transfer effect of reactive ions in the thickness direction of the electrode is improved by changing pressure gradient distribution in the electrode is solved. Under the same electrolyte flow supply and different current densities, the flow channel structure promotes the mass transfer process of reactive ions in the electrode, the brought overpotential loss is lower than that of a traditional flow channel, and the limiting current density is higher. In a charge-discharge experiment, the flow battery disclosed by the invention is smaller in overpotential and higher in charge-discharge capacity.

The invention discloses a method for lifting a GPa-grade high-strength galvanized steel spot welding window, and belongs to the field of high-strength steel welding processes. The method comprises the following steps that firstly, high-strength galvanized steel is selected to machine a spot welding test plate, and an electrode is selected; and secondly, a two-stage spot welding process is adopted, spot welding parameters are set, and welding is conducted. According to the two-stage spot welding process, comprehensive heat input is controlled through two pulses, so that the growth speed of the nugget diameter is restrained, the limiting current when splashing occurs is improved, and the purpose of lifting a spot welding window is achieved.

The invention discloses a Ru / Ni-3DONMC catalyst as well as a preparation method and application thereof, and relates to the technical field of new energy materials and electrochemical catalysis. According to the invention, self-designed ordered SiO2 microspheres are self-assembled as a template, a nitrogen-doped carbon carrier with a three-dimensional ordered hierarchical pore structure is constructed, and a composite catalytic system with a multi-stage active center is successfully prepared by combining a bimetallic precursor adsorption impregnation and thermal reduction process. The catalyst disclosed by the invention shows excellent bifunctional catalytic performance in an alkaline medium; only 16 mV overpotential is needed in a hydrogen evolution reaction under the current density of 10 mA cm <-2 >, and the Tafel slope is as low as 40.54 mV / dec; and in a hydroxide reaction, the material has high limiting current density of 2.55 mA cm <-2 > and excellent mass activity. And it is powerfully proved that the intrinsic catalytic activity and long-term operation stability of the hydrogen-electricity reaction can be effectively improved through a monatomic-nanocluster cooperative regulation strategy.

The invention relates to a high-conductivity low-grinding gallium-based liquid metal electric contact composite material and a preparation method thereof. The electrical contact composite material according to the invention comprises an electrically conductive ceramic as a matrix material and a gallium-based liquid metal as an electrically conductive additive phase, and optionally further comprises an electrically conductive lubricating phase. According to the electric contact composite material, both high conductivity and low abrasion performance are achieved, the limit current-carrying density of the electric contact material is improved, and the electric contact composite material has important significance in improving the performance of an electric contact device.

The invention discloses a current limiting method and system for a virtual synchronous generator after a power grid fault. The method comprises the following steps: monitoring a ratio of a power grid voltage to a rated voltage; comparing the ratio with a voltage drop degree threshold value; when the ratio is smaller than a voltage drop degree threshold value, a fault current limiting strategy is started; when a current-limiting strategy stopping condition is reached, judging whether the amplitude of the power grid current is smaller than or equal to a current-limiting threshold value or not; if the amplitude of the power grid current is smaller than or equal to the current limiting threshold value, ending, otherwise, carrying out the fault current limiting strategy again; when the ratio is greater than or equal to the voltage drop degree threshold value, the fault current limiting strategy does not need to be started; wherein the fault current limiting strategy comprises an active ring adjustment strategy based on angular frequency deviation feedback and a reactive adjustment strategy based on an adaptive adjustment reactive droop coefficient. According to the invention, the response capability and the operation stability of the converter during sudden power grid disturbance can be improved.

The invention relates to the technical field of fuel cell monitoring and life prediction, in particular to a fuel cell life prediction method combining mechanism and data driving, which comprises the following steps: calculating reversible potential of a fuel cell through a Nernst equation, and establishing a theoretical output voltage model by combining three voltage losses of activation, concentration difference and ohm; acquiring historical data of voltage attenuation under actual operation conditions, and determining a life end voltage threshold value; training historical data by using a time sequence algorithm, identifying an aging rule function of key parameters (ohmic impedance, hydrogen permeation current density, exchange current density and limiting current density), and evaluating parameter identification precision through RMSE; and substituting the parameter aging function into the voltage model to predict future voltage, and when a predicted value is lower than a life end threshold for the first time, calculating the remaining service life. According to the method, the electrochemical mechanism and the data driving technology are fused, and the prediction accuracy is remarkably improved.

The present application provides a control method for an energy storage system, and an energy storage system. The energy storage system comprises N energy storage submodules, N being a positive integer greater than 1. The control method for an energy storage system comprises: obtaining a battery state of charge (SOC) and charging / discharging limit current of each energy storage submodule of N energy storage submodules; and controlling the operating state of the N energy storage submodules according to the SOC and the charging / discharging limit current of each energy storage submodule, the operating state comprising an input state and a removed state. According to the technical solution provided in the embodiments of the present application, the problem of SOC imbalance among the energy storage submodules can be solved, thereby improving the utilization rate of the energy storage system.

The invention discloses a voltage source type current converter amplitude limiting current phase angle value obtaining method and a related product, relates to the technical field of voltage source type current converters, and solves the problem that a traditional direct current limiting method cannot obtain the value range and the optimal value of a current phase angle. The method is characterized by comprising the steps of obtaining relevant parameters of the converter; calculating the maximum allowable value of the output active power of the converter in the normal operation state and the amplitude limiting operation state; calculating a value range of an output current phase angle of the current converter after amplitude limiting; calculating a power angle of a stable operation point of the converter and a power angle of an unstable operation point of the converter after amplitude limiting; calculating a limit cut-off angle corresponding to an output current phase angle of the current converter after amplitude limiting; calculating the limit clearing time of the output current of the current converter after amplitude limiting; comparing the limit cut-off time corresponding to the phase angle of the output current of the current converter after amplitude limiting to obtain an optimal value of the phase angle of the output current of the current converter after amplitude limiting; through the steps, the value range of the current phase angle and the value of the optimal value after amplitude limiting of the voltage source type current converter are determined.

The application belongs to the field of fuel cells, and particularly relates to a preparation method of a single-iron atom catalyst. A solution containing component A, component B and component C is subjected to a coprecipitation reaction to obtain a precipitate; the precipitate is aged in a component D solution to obtain an aged product; and the aged product is subjected to gradient calcination to obtain the single-iron atom catalyst. The component A contains a compound of formula 1; the component B contains at least one of iron cyanide, dopamine and a salt thereof; the component C contains an iron source and a zinc source; and the component D contains a water-soluble compound having a fragment of formula 3. The application also discloses a material prepared by the method and an application of the material in ORR and fuel cells. Research shows that the material prepared by the method has excellent catalytic activity and stability in ORR, and a metal-air battery assembled by using the material can have excellent limiting current density, peak power and discharge specific capacity.

The invention discloses a charging efficiency adjusting method, a controller and an energy storage device, and the method comprises the steps: determining a charging limiting current according to a charging voltage, a charging current and a charging cut-off voltage when the energy storage device is in a charging state; and determining a charging demand current based on the charging preset current, the charging limit current and the electric quantity value, wherein the charging demand current is used for indicating the charging current output to the energy storage device by the charger. The invention aims to solve the problem of how to further shorten the charging time.

A system for partially pre-charging an electrical power system having a high voltage power source, a DC link device with a DC Link capacitor, a low voltage power source and a DC / DC converter. In one embodiment a partial pre-charge of the DC Link capacitor can be achieved in three ways: first, through a DC / DC converter boosting from the low voltage power source, second, through a first circuit provided to charge the DC link capacitor to a partial pre-charge state using the voltage directly from the low voltage power source, and third, through a second circuit provided to limit current flowing to the DC link capacitor from the high voltage power source to charge the DC Link capacitor only to a partial pre-charge level. A controller selectively operates the first circuit, the second circuit, or the DC / DC converter for charging the DC link capacitor to the partial pre-charge state.