14 results about "Current constant" patented technology

This disclosure relates to a charging method, apparatus, electronic device, and medium. The charging method includes: determining a target charging current for the battery; when the target charging current is greater than or equal to a first target current, simultaneously charging the battery using a first charging circuit and a second charging circuit; when the target charging current and the total output current are not the same, adjusting the first output current of the first charging circuit while keeping the second output current of the second charging circuit constant, wherein the total output current is the sum of the first and second output currents. By adjusting the total output current in a manner that adjusts the first output current while keeping the second output current constant, the adjustment of the first output current can prevent an imbalance in the electrical parameters of the second charging circuit from triggering charging protection, thereby improving the reliability of battery charging.

The application discloses a battery test system and a test method, wherein the system comprises an alternating-current constant-current excitation source, a master control unit and a plurality of independently arranged acquisition board cards; the alternating-current constant-current excitation source is connected to the first and last ends of a measured loop formed by a plurality of measured battery cells connected in series, is used for applying the same alternating-current constant-current excitation signal to all the measured battery cells, and simultaneously outputs a synchronous reference signal consistent with the alternating-current constant-current excitation signal to the plurality of independently arranged acquisition board cards; each acquisition board card is connected to only the sensing end of the corresponding measured battery cell, processes the sensing signal between the two ends of the corresponding measured battery cell, so as to obtain measurement data; and each acquisition board card reports the measurement data to the master control unit through a CANFD bus, and the master control unit collects and uploads the measurement data to an upper computer. The application realizes parallel and synchronous alternating-current internal resistance and direct-current open-circuit voltage test of a plurality of single battery cells in a series battery cell group, and improves the consistency and test efficiency of battery test.

The application discloses a current fixed value setting method and device and electronic equipment. The method comprises the following steps: determining a set of operation scenarios of a power distribution network, and determining a set of system gears of a flexible interconnected device in the power distribution network; determining the fault current amplitude of a directional overcurrent protection device in the power distribution network under different fault categories according to the set of operation scenarios and the set of system gears; determining the fault current boundary of the directional overcurrent protection device under different fault categories according to the fault current amplitude; and determining the current fixed value corresponding to the directional overcurrent protection device according to the fault current boundary and a preset safety factor. The application solves the technical problem of low reliability of current fixed value setting due to the fact that the directional overcurrent protection setting method in the related art usually determines the fault current boundary based on a single working condition or an experience margin, and does not consider the operation uncertainty of the power distribution network and the flexible interconnected regulation capacity.

The present application relates to the technical field of electric machines, and relates to an online efficiency optimization method for a permanent magnet synchronous motor. For each preset fixed control period of a motor controller of a target vehicle, a motor battery state parameter in the fixed control period is acquired. The motor battery state parameter is preprocessed. The preprocessed motor battery state parameter is input into an input layer of a current prediction model, and then sequentially passes through a first hidden layer, a second hidden layer and an output layer to obtain a predicted current instruction. According to the predicted current instruction and a preset current constant, current values of d-axis and q-axis are determined, so as to control the motor controller according to the current values of d-axis and q-axis. Through the trained current prediction model, the best current distribution instruction can be quickly given under any combination of speed, torque, battery state and temperature, and the motor efficiency is significantly improved.

This invention provides a method for suppressing noise introduction in a current mirror circuit, comprising: sampling the gate voltage of the voltage-to-current conversion module in the current mirror on a first capacitor between the gate and the power supply to avoid introducing noise from the reference current source and the current-to-voltage conversion module; when external noise affects the output current of the current mirror, compensating for the charge of the parasitic capacitance between the gate and ground to suppress voltage changes in the first capacitor between the gate and the power supply, thereby reducing the impact of noise on the output current. This invention allows the gate-source voltage of the current source to remain constant when the power supply voltage or the voltage to ground changes, thus keeping the current source current constant. In other words, this auxiliary structure can greatly enhance the current source's immunity to power supply or ground interference and significantly reduce power supply noise and ground noise.

The application discloses a kind of inverter opening current fluctuation suppression method in double-sided LCC inductive power transmission system, belong to wireless power transmission technical field.To solve the problem that the inverter opening current fluctuation leads to large reactive power loss or large switching loss of system, the method of the present application comprises: solving implicit function equation with opening current as variable, realizing accurate prediction of opening current;Analysis of the influence of primary side capacitor and secondary side capacitor parameter deviation on opening current fluctuation characteristics;Using the characteristics that the influence of primary side capacitor and secondary side capacitor parameter deviation on opening current fluctuation trend is opposite, adopt double-capacitor collaborative deviation strategy, to keep opening current constant and meet the condition of inverter zero voltage switching as the goal, determine the deviation degree of primary side capacitor and secondary side capacitor.The inverter opening current is basically kept constant and meets the condition of inverter zero voltage switching in the whole load range by the double-capacitor collaborative deviation strategy, thereby reducing the reactive power loss and switching loss of the system, and optimizing the overall efficiency of the system.

This invention discloses a disaster early warning method for transmission lines based on capacitor leakage current characteristics. The method constructs a multi-dimensional insulation characteristic model based on the fundamental formula for leakage current, establishing a functional relationship between the leakage current constant and temperature / pressure, and between the correction value and surface contamination. By synchronously collecting capacitor voltage, leakage current, and environmental micro-meteorological data in real time, an iterative algorithm decouples the actual value and the value from the total leakage current. Logical discrimination is then performed based on the rate of change and vector direction of these two values: when the value increases sharply with high temperature and undergoes abrupt changes due to smoke and dust adhesion, it is determined to be a wildfire; when the value is stable but increases with the cumulative increase in particulate matter concentration, it is determined to be a sandstorm or heavy pollution. This invention inverts macroscopic disasters through microscopic changes in electrical physical quantities, effectively eliminating interference from normal environmental temperature rises, and achieving millisecond-level perception and accurate graded early warning of external disasters affecting transmission lines.

This invention relates to the field of power supply circuit technology, and specifically discloses an adaptive constant current control method and system for DC-DC converter power supplies. This invention acquires the output voltage in real time and compares it with multiple preset voltage thresholds to identify the range in which the output voltage is located. Within the voltage limiting region, in response to an increase in output voltage, the input current constant current setpoint is reduced by a first step value. Within the current sharing region, in response to an increase in output voltage, the input current constant current setpoint is reduced by a second step value, where the first step value is greater than the second step value. This achieves rapid suppression of voltage overshoot caused by load shedding, resulting in stable output voltage control, improved dynamic response capability of the system, and reduced risk of power device damage due to overvoltage.

This application discloses a 3.3V powered RS485 interface circuit, relating to the field of RS485 bus interface circuit driving, including: a high-level short-circuit protection unit for outputting a constant limiting current when short-circuited to ground; and a low-level short-circuit protection unit for outputting a constant limiting current when short-circuited to the power supply. The output port of the output stage unit is connected to the RS485 differential bus pin, and can withstand high or negative bus voltage while switching the output signal by turning it on and off according to the drive signal. A dynamic bias voltage node is formed inside the output stage unit, so that the substrate of the first PMOS transistor is always connected to a higher potential, avoiding the body diode from conducting. This application adopts a high-voltage PMOS single transistor and a high-voltage NMOS series diode structure, which simultaneously meets the bus voltage withstand of -7V to +12V and the RS485 protocol requirements at 3.3V; and can keep the short-circuit current constant at the threshold level when short-circuited to ground and short-circuited to the power supply, achieving constant current protection.

The application provides a formation and capacity grading method and application of a lithium iron phosphate battery, and relates to the technical field of secondary batteries. The formation and capacity grading method optimizes the standing condition after liquid injection, adopts a small-current aging, and adopts a high-voltage charging mechanism in the constant-current constant-voltage charging phase of capacity grading, so that the formation and capacity grading process is collectively optimized, the direct-current impedance of the lithium iron phosphate battery is effectively reduced, the cell polarization is reduced, the cell performance is effectively improved, the cell temperature rise is reduced, and the safety performance of the battery is improved. The application also provides the application of the formation and capacity grading method of the lithium iron phosphate battery. In view of the advantages of the formation and capacity grading method, the application has a good application prospect in the fields of lithium ion battery preparation and performance testing.

The application relates to the technical field of wireless power transmission, and discloses a constant-current constant-voltage charging regulation method and system based on wireless power transmission, which comprises the following steps: acquiring an electrical parameter signal, determining a change trend estimation value of a coupling coefficient in combination with a support vector machine, weighting and processing measurement residuals through a Kalman gain matrix, and determining a load real-time adjustment value; when a preset impedance threshold is exceeded, judging a charging stage through fuzzy logic reasoning; collecting transmission efficiency correlation indexes, determining an accurate coupling coefficient and a load joint value through a support vector machine regression model; deducing and correcting a prior state estimation value, and generating a transmission power parameter; evaluating a final power regulation instruction through a charging stability model; refining a transmission state in combination with a distance position offset, and outputting a stable charging result. Through multi-algorithm cooperation and multi-dimensional parameter optimization, the application realizes accurate switching and whole-process stable regulation and control in the constant-current constant-voltage stage, and improves the efficiency, stability and safety of wireless power transmission.

The application discloses a constant-current constant-voltage output self-switching wireless power transmission system based on voltage doubling rectification. The system comprises a clamping rectifier bridge, a half-bridge inverter, a voltage doubling rectification circuit, a transmitting coil, a clamping coil, a receiving coil, a primary series compensation capacitor, a secondary parallel compensation capacitor, a secondary series compensation inductor and a clamping circuit compensation capacitor. When the system starts to work, the primary coil current increases with the increase of the load, the clamping coil induced voltage amplitude gradually increases until E / 2, the clamping rectifier bridge starts to be incompletely conducted, and the system behaves as a constant-current output before this time; when the induced voltage amplitude reaches 2 E / π / 2, the clamping rectifier bridge is fully conducted, at this time, the primary coil current is clamped to a constant value, the system input changes from a constant-voltage source to a constant-current source, and the system realizes constant-voltage output. The application can realize constant-current constant-voltage output self-switching without any control, has an open-circuit self-protection function, and has the advantages of few compensation elements and switching devices, high design freedom and the like. In addition, the design also has the effect of improving the system efficiency.

The utility model relates to lithium cell technical field, concretely is a kind of constant-current constant-voltage heating pad control circuit based on PWM. Including asynchronous buck circuit, gate drive circuit, voltage control drive circuit, PWM control circuit, MCU chip, the LCSG_DriveA0 port of asynchronous buck circuit, LCSG_DriveB0 port are sequentially connected the LCSG_DriveA0 port of gate drive circuit, LCSG_DriveB0 port, the VSamp port of asynchronous buck circuit is connected the VSamp port of PWM control circuit, the CON_PWM port of gate drive circuit is connected the CON_PWM port of PWM control circuit, the REF_PWM port of voltage control drive circuit is connected the VRef port of PWM control circuit, the one PE pin of MCU chip is connected the HEAT_OFF port of gate drive circuit, another PE pin of MCU chip is connected the CL_PWM port of voltage control drive circuit. Compared with prior art, realize the dynamic regulation of heating pad current, ensure that constant-current constant-voltage output is to heating pad both ends, improve energy conversion efficiency.