2223 results about "Reference current" patented technology

A battery management system, a battery pack, an electric vehicle and a battery charging time prediction method are provided. The battery management system includes a memory for storing a plurality of reference charging maps, a sensing unit for detecting voltage, current, and temperature of a battery, and a control unit for determining an estimated SOC value of the battery. Each reference charging map includes first to Mth reference current values and first to Mth reference power curves associated with first to Mth SOC sections. The control unit obtains a mth reference power curve and a mth reference current value associated with a mth SOC section to which the estimated SOC value belongs, from the reference charging map associated with the temperature section to which the temperature detection value of the battery belongs. The control unit determines the time required for the SOC of the battery to reach an end point of the mth SOC section, according to the result of comparing a maximum output power of a charger and the mth reference power curve, based on the difference between the end point of the mth SOC section and the estimated SOC value, and at least one of the mth reference current value, the maximum output power and the mth reference power curve.

The invention discloses a network-following flexible switching prediction control method and system for a grid-connected converter, and the method comprises the steps: calculating a short-circuit ratio according to obtained power grid impedance data, and if the short-circuit ratio is smaller than a switching threshold value, indicating that the power grid strength is reduced, and otherwise, indicating that the power grid strength is not reduced. At the moment, a prediction control reference current in the switching process is calculated through an adaptive switching function in a first switching function form and a current reference value in a grid following mode and a grid construction mode, and the grid-connected converter is switched from the grid following mode to the grid construction mode; and otherwise, indicating that the power grid intensity is increased, calculating a prediction control reference current in a switching process through an adaptive switching function in a second switching function form and a current reference value in a grid following mode and a grid construction mode, and switching the grid-connected converter from the grid construction mode to the grid following mode. Therefore, according to the adaptive switching function-based network-following flexible switching prediction control method, rapid and flexible switching of the grid-connected converter module is ensured, and the stability and the grid-connected output efficiency of the converter in the new energy grid-connected power generation system can be effectively improved.

The invention discloses a low-output-ripple automatic-current-sharing interleaving buck converter and a control method thereof.The converter comprises a main power circuit and an auxiliary compensation circuit, and the main power circuit adopts two interleaving main branches to achieve voltage conversion and energy transmission; automatic current sharing of the circuit is realized through the integrated network switch module and PWM signal control; the auxiliary compensation circuit adopts a current mirror image compensation principle, and adjusts the magnitude of the compensation current by comparing the difference between the output current of the main power circuit and the reference current, so as to effectively suppress the output current ripple; the control method comprises the steps of output voltage monitoring, PI adjustment, duty ratio modulation and a complementary control mechanism, current ripple phase offset is ensured, and the system stability and efficiency are improved. Compared with the prior art, the method has the advantages that the complexity of a control system is reduced, the working efficiency is improved, the current ripples are effectively eliminated, and the method has relatively high practical value and popularization prospect.

The invention provides an intelligent electronic switch, a current detection device, a chip, a chip product and an automobile. The intelligent electronic switch comprises a sampling end, a power switch and a control circuit. The control circuit can collect output current of the power switch and obtain first sampling current, when the first sampling current is smaller than or equal to reference current, the control circuit outputs a first indication signal to the microcontroller and outputs the first sampling current through the sampling end, and when the first sampling current is larger than the reference current, the control circuit outputs a second indication signal to the microcontroller. A second indication signal is output to the microcontroller and a second sampling current is output through the sampling end, the second indication signal is different from the first indication signal, and the second sampling current is smaller than the first sampling current and is related to the first sampling current; in this way, the microcontroller can determine the output current of the power switch according to the obtained indication signal and the collected signal, and the problem that the detection result of the microcontroller is possibly inaccurate is solved.

The invention discloses a six-winding high-voltage variable-frequency speed regulation control method and system, and belongs to the technical field of high-voltage variable-frequency speed regulation, and the method comprises the steps: building an electric-thermal-magnetic coupled six-dimensional nonlinear system model through collecting the structural parameters, thermosensitive data and an initial state of a motor; establishing a frequency domain regulation and control matrix among the six windings in combination with the operation condition and the load type; predicting a future disturbance power trend by using a weighted short-time Fourier analysis method, dynamically correcting the reference current of each winding, and generating six groups of PWM control signals; when the performance of the winding is degraded, fault-tolerant topology reconstruction and driving task redistribution are executed; periodically reconstructing a control matrix through a thermoelectric feedback mechanism, and executing parameter adaptive optimization according to a current balance coefficient and hot redundancy distribution; according to the method, high-precision current coordination control, frequency domain energy decoupling and winding thermal load balancing can be realized, and the speed regulation response speed, the stability and the fault-tolerant capability of the system are remarkably improved.

The invention relates to a detection method and system for an electromagnet assembly for rail transit and a terminal, and relates to the technical field of electromagnets, and the detection method comprises the steps that an electromagnet image is selected from image detection information according to preset electromagnet characteristics; determining an electromagnet model according to the electromagnet image; determining a reference current value according to the electromagnet model; determining a reference magnetic force value according to the electromagnet model; determining a detected magnetic force value according to the detected magnetic force value; if the detected current value is not consistent with the reference current value, a preset clamping device is controlled to move the electromagnet to the abnormal area; if the reference magnetic force value is consistent with the detection magnetic force value, obtaining a detection current value of the electromagnet assembly; and if the detected current value is not consistent with the reference current value, a preset clamping device is controlled to move the electromagnet to the abnormal area. According to the electromagnet assembly, the detection efficiency of the electromagnet assembly is improved, and the manual intervention effect is reduced.

The invention provides a piezoelectric self-feedback excitation type miniature electric field sensor, an electric field detection method and a sensor, and is applied to the technical field of electric field sensors. The piezoelectric self-feedback excitation type miniature electric field sensor comprises a substrate used for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutual shielding electric field sensing structure and an elastic beam; the piezoelectric driving structure is used for enabling the piezoelectric driving structure to deform under the condition that driving voltage is applied to the piezoelectric driving structure so as to enable the elastic beam to generate vibration; the mutual shielding electric field induction structure is used for responding to the vibration of the elastic beam, and the mutual shielding electric field induction structure outputs an induction current signal in a differential form so as to suppress common-mode noise and detect the amplitude intensity of a to-be-detected electric field; and the vibration pickup reference structure is used for responding to the vibration of the elastic beam and outputting a reference current signal so as to adjust the magnitude of the driving voltage and enable the output sensitivity of the piezoelectric self-feedback excitation type miniature electric field sensor to be a preset value.

Provided in the present application are a band-gap reference current source, a low dropout regulator and a power manager, which are applied to the technical field of power chips. The band-gap reference current source uses dual band-gap references to form a band-gap reference loop, and uses an operational amplifier clamping unit to implement clamping adjustment, so as to generate a reference current that is in direct proportion to the temperature, which is conducive to using the reference current to perform linear voltage stabilization subsequently, such that the regulator has a relatively high loading capacity, a very low quiescent current and a relatively high power noise suppression ratio, thereby improving the overall efficiency of a voltage-stabilizing circuit, and also greatly reducing the layout area.

The invention discloses an impedance characteristic remodeling method, device and equipment and a medium, and is applied to the field of wind turbine generators. Wherein the corresponding rotor reference current is determined according to the electromagnetic reactive power, the active power and the corresponding power reference value; correcting the rotor current according to the rotor reference current by adopting a virtual admittance control mode, and generating a corresponding rotor voltage given value; sequentially performing differentiation, filtering and signal extraction processing on the rotor reference current and the rotor current to obtain an impedance remodeling signal; and correcting the rotor voltage given value based on the impedance remodeling signal so as to enable the corrected rotor voltage given value to serve as the control voltage of a rotor side converter in the medium-voltage doubly-fed wind turbine generator after impedance characteristic remodeling. The virtual admittance control mode and the impedance remolding signal mode are adopted to suppress the negative resistance effect of the rotor side converter in the medium-voltage doubly-fed wind turbine generator under voltage disturbance, and therefore the damping effect on external excitation in the sub-super-synchronous frequency band and the high frequency band is higher.

The invention provides a high-precision current limiting circuit of an LDO (Low Dropout Regulator) with an NMOS (N-channel Metal Oxide Semiconductor) tube as a power tube, which is applied to the technical field of current limiting circuits and comprises a voltage loop and a current loop, and the voltage loop is used for monitoring and stabilizing the output voltage VOUT of a power tube NM1; and the current loop is used for acquiring a sampling current according to the load current of the power tube NM1, comparing the sampling current with a reference current IREF, and when the sampling current is higher than the reference current IREF, driving and controlling the output voltage VOUT of the power tube NM1 to be reduced so as to limit the load current of the power tube NM1 to continue to rise. When the LDO works normally, the output voltage VOUT of the power tube NM1 is stabilized through the voltage loop, and when the load current is too high, the output voltage VOUT of the power tube NM1 is driven and controlled to be reduced through the current loop, so that the load current of the power tube NM1 is prevented from continuing to rise, and the stability and the safety of the LDO are improved.

The embodiment of the utility model provides a resistor calibration circuit, a resistor calibration device and an electronic device. The resistor calibration circuit comprises a current source module used for outputting a reference current; the standard resistor module is connected with the current source module to receive the reference current and generate a reference voltage; in the working process of the resistor calibration circuit, a resistor to be calibrated is connected with the current source module to receive the reference current and generate a voltage to be measured, and the analog-to-digital converter is connected with the standard resistor module to perform analog-to-digital conversion on the voltage to be measured based on the reference voltage. According to the resistance calibration circuit, the analog-to-digital converter in the module to be measured is multiplexed for resistance calibration, an additional high-precision measurement calibration system is not needed, and the resistance can be calibrated only by providing the current source module and the standard resistance module, so that the resistance calibration cost is reduced.

The invention discloses a hybrid effective flux linkage observer and a permanent magnet synchronous motor control method, device and system. The method comprises the following steps: carrying out Clarke conversion on an obtained three-phase current of the permanent magnet synchronous motor to obtain a current in a static coordinate system, and carrying out park conversion based on rotor position information to obtain a current in a synchronous rotating coordinate system; the effective flux linkage of the permanent magnet synchronous motor is obtained through the hybrid effective flux linkage observer; on the basis of the obtained effective flux linkage of the permanent magnet synchronous motor, dead-zone compensation voltage is obtained through self-adaptive gain dead-zone compensation calculation based on back electromotive force reconstruction, and the rotating speed and the rotor position of the permanent magnet synchronous motor are obtained through phase-locked loop calculation; according to the rotating speed and the rotor position of the permanent magnet synchronous motor, the current under the synchronous rotating coordinate system, the dead zone compensation voltage and the obtained reference rotating speed and reference current, the reference voltage of the motor at the k moment is obtained through a rotating speed loop and a current loop and used for achieving low-speed position-sensorless control over the permanent magnet synchronous motor.

A power vector analyzer to analyze power from a device under test (DUT) includes one or more channels to measure a reference voltage signal from a power line connected to the DUT, one or more channels to measure a reference current signal from the power line, a user interface comprising a display and one or more controls, and a quadrature synchronous detector (QSD) for each phase of apparent power being measured, the QSD configured to use a reference voltage signal from the one or more channels and a reference current signal from the one or more channels to determine the apparent power for each phase of power being measured by the DUT and display the apparent power for each phase on the display.

The invention discloses an active damping control system for improving the output impedance of a current source type inverter, which comprises a current loop control loop, an active damping branch and an improved phase-locked loop, and is characterized in that the difference value of reference current and feedback network access current passes through a current controller to form the current loop control loop; the voltage of the grid-side inductor is fed back to the output of the current loop through the virtual resistor link to form a damping branch, and the voltage of the common coupling point enters the traditional phase-locked loop link through the low-pass filter and forms an improved phase-locked loop through phase compensation. The optimal feedback coefficient of the damping branch is designed according to the optimal damping ratio, the low-pass filter parameters are designed according to the phase at the maximum resonant frequency, the reasonable proportional gain link is designed according to the improvement of the output impedance amplitude, the resonance of the current source type inverter can be effectively inhibited, the output impedance of the inverter is increased, and the output impedance of the inverter is improved. And the quality of the network access current of the current source type inverter and the stability margin of the current source type inverter in a weak power grid are improved, and the stability of the system is improved.

The invention discloses an adaptive current decoupling control method for a sliding mode of a permanent magnet synchronous motor, and the method comprises the steps: designing an extended state observer to observe a d-q axis current and a voltage disturbance term, carrying out the difference between a current observation value and a reference current, and inputting the difference into a non-singular integral terminal sliding mode controller, thereby obtaining a d-q axis voltage; and then the observed d-q axis voltage disturbance term is superposed to form a total d-q axis voltage. And then identifying the d-q axis inductance and permanent magnet flux linkage of the permanent magnet synchronous motor by using a recursive least square method with dynamic forgetting and adaptive regularization factors, and sending the d-q axis inductance into the extended state observer to realize a closed-loop adaptive extended state observer. And after coordinate transformation and space vector pulse width modulation are carried out on the d-q axis total voltage, the d-q axis total voltage is used for driving an inverter to control the permanent magnet synchronous motor. The method improves the current decoupling effect and anti-disturbance capability of the permanent magnet synchronous motor, adaptively adjusts the parameters of the controller according to the change of working conditions, and improves the robustness of the system.

The invention relates to a multi-frequency bioelectrical impedance-based body fat accurate measurement method and system. The method comprises the following steps: receiving a mode selection instruction sent by a user to determine a current working mode; if the mode is a rapid measurement mode, applying single reference frequency and reference current intensity excitation, obtaining a single group of bioelectrical impedance data, and calculating a rapid body fat rate result; if the measurement mode is an accurate measurement mode, acquiring bioelectrical impedance data under a plurality of preset frequencies and a plurality of preset current intensities through a complete electrode system, performing signal processing on the data, extracting impedance amplitude and phase information, constructing an impedance characteristic curve, extracting characteristic parameters related to the body fat rate from the impedance characteristic curve, and calculating the body fat rate based on the characteristic parameters. And obtaining a final body fat rate result of the accurate measurement mode. According to the method, the body fat rate can be accurately measured, and the accuracy and reliability of a measurement result are improved.

According to an embodiment, a method includes adjusting a reference generator into a first configuration based on a temporary trim value resulting, in a first reference voltage and a first reference current being generated for a first memory. The method further includes performing an integrity check on an initial set of data downloaded from the first memory based on the first reference voltage and the first reference current. The initial set of data includes a first trim value. The method further includes downloading contents from the first memory into a second memory in response to a successful integrity check after adjusting the reference generator into a second configuration. In the second configuration, the reference generator generates a second reference voltage and a second reference current for the first memory. The reference generator is adjusted by the first trim value in response to a successful integrity check.

The invention relates to a lightning arrester leakage ammeter self-calibration method and system, and the method comprises the following steps: disconnecting a main leakage ammeter from an external main measurement loop, and closing a calibration loop of a redundancy calibration sensor and a reference current source after a preset time is delayed; controlling a reference current source to output standard signals with different current magnitudes, collecting the standard signals by using a redundancy calibration sensor, extracting effective signal components, and performing environment compensation; iteratively calculating a relative error between the effective signal component and the standard signal, if the relative error is less than or equal to a second threshold value, updating a calibration coefficient according to a ratio of the standard signal to the effective signal component, and correcting a measurement result of the main leakage ammeter based on the calibration coefficient; if the relative error is greater than a third threshold value, locking output and uploading fault information; otherwise, recording as one exception, and carrying out maintenance early warning according to the number of exceptions. Compared with the prior art, the self-checking and real-time calibration of the leakage ammeter of the lightning arrester can be completed on the premise of not influencing the operation of power equipment.

A DC-DC converter includes: a master converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current, and a slave converter configured to operate to generate the panel power voltage with the master converter based on the input voltage when the panel current is greater than a reference current. The master converter and the slave converter are connected to a first inductor.

The invention relates to the technical field of permanent magnet synchronous motor control, in particular to a diagnosis-free adaptive fault-tolerant control method and system for a six-phase permanent magnet synchronous motor under an open-circuit fault, and discloses the following steps: S1, converting the voltage and current of the six-phase permanent magnet synchronous motor from a three-phase static coordinate system to a two-phase static coordinate system through Clark conversion, voltage and current in the two-phase static coordinate system are converted into a two-phase synchronous rotating coordinate system through Park conversion; s2, acquiring a current relation between q-axis current of the six-phase permanent magnet synchronous motor and the two-phase static coordinate system according to the two-phase synchronous rotating coordinate system, and further acquiring two-phase static coordinate system reference current for realizing fault tolerance under an open-circuit fault; and S3, optimizing the control signal of the reference current through a phase-locked loop of a second-order generalized integrator. According to the method, diagnosis-free adaptive fault-tolerant control under the open-circuit fault of the six-phase permanent magnet synchronous motor can be realized, and the problems of misdiagnosis and time delay are reduced.

Techniques for controlling a low-dropout (LDO) voltage regulator. In an example, an LDO voltage regulator circuit includes an amplifier having an output coupled to a transistor. First and second inputs of the amplifier are coupled to a power supply node via first and second resistors, respectively. The transistor gate is coupled to the amplifier output, the transistor source is coupled to the second input of the amplifier, and the transistor drain is coupled to a reference voltage node. The second resistor is variable based on the amplifier output and a reference voltage from the reference voltage node. In an example, the reference voltage node is connectable to ground via a reference resistor connected in parallel with a noise-filtering capacitor, which causes a reference current to flow through the transistor. The reference current is adjusted based on the drain-to-source voltage of the transistor.

The invention relates to the technical field of fuel cell testing, in particular to a fuel cell performance degradation analysis method based on big data and polarization curve fitting. The performance attenuation amplitude and attenuation rate of the fuel cell stack under different reference currents and different total accumulative operation time can be calculated, so that the performance change condition of the fuel cell stack under the actual road working condition can be accurately reflected; based on the data uploaded by the fuel cell vehicle in the big data platform and the polarization curve fitting method, the performance degradation condition of the fuel cell stack can be obtained, a durability bench test does not need to be carried out, the test period is greatly shortened, and the labor cost is greatly reduced. The attenuation analysis of the output voltage and the output power of the fuel cell stack under any running current within the rated power range can be realized, and the method is wide in applicability, simple and convenient to operate and high in flexibility.

Systems and methods are provided for generating a stable reference current that has low sensitivity to operating temperature and supply voltage variations and is stable across process corners. In an example implementation, an improved reference current generator circuit is provided that includes a first circuit generating a first current that is proportional to absolute temperature and a second circuit generating a second current that is complementary to absolute temperature based on first transistors operating in respective triode regions. The second current compensates for process, voltage, and temperature variations in the first current at a node. According to some examples, the second current is also generated based on second transistors operating in respective saturation regions. The first current may be generated using a forward biased PN junction diode.

The invention relates to the technical field of electromagnetic compatibility testing, and provides a current-based magnetic field radiation emission limit value cutting method and device and electronic equipment. Comprising the steps of obtaining working current parameters of tested equipment; determining a basic limit value of magnetic field radiation emission, obtaining a working current of the tested equipment when the magnetic field radiation is the basic limit value, and taking the working current as a reference current threshold value; when the working current parameter is greater than the reference current threshold value, calculating the clipping amount of the magnetic field radiation emission limit value based on the ratio of the working current parameter to the reference current threshold value; and cutting the basic limit value according to the cutting amount to obtain the magnetic field radiation emission limit value of the tested equipment. The limit value is compatible with the existing electromagnetic compatibility national military standard magnetic field radiation emission limit value, so that the electromagnetic compatibility test assessment of the large-current equipment can be evaluated more reasonably and accurately, and the method has high engineering application value.

A sigma-delta analog-to-digital converter is provided that includes an initial continuous-time integration stage having a variable input resistor and an integration capacitor. A switched-capacitor circuit charges and discharges a replica capacitor to a reference voltage to generate a bias current. A SAR-based tuning circuit includes a variable tuning resistor that generates a tuning voltage while conducting a mirrored version of the bias current. A resistance of the variable input resistor is adjusted responsive to a tuning code from the SAR-based tuning circuit.

The invention provides a dynamic impedance matching charger based on battery aging, a method, electronic equipment and a medium. The charger comprises a master control unit, and a battery state monitoring module, an aging grade evaluation module, a dynamic charging control module, a battery cell balancing module, an optimization control module and an anti-interference module which are connected with the master control unit to cooperatively realize charging closed-loop control. The battery state monitoring module injects a preset frequency alternating current signal and outputs an impedance parameter, a charge state and a temperature parameter; the aging grade evaluation module outputs a battery aging grade in combination with a preset model; the dynamic charging control module is matched with an adaptive charging mode instruction; the battery cell balancing module calculates the battery cell impedance difference, and balancing operation is executed if the battery cell impedance difference reaches the standard; the optimization control module generates an optimized current instruction through a preset algorithm according to the related parameters, and superposes the optimized current instruction to the reference current; the anti-interference module improves the signal-to-noise ratio of collected signals to a preset standard through isolation and shielding design.

The invention discloses a network construction type and network following type control seamless switching method and device oriented to an MMC-HVDC converter station, relates to the technical field of power system control, and aims at realizing seamless switching of network construction type and network following type control by constructing unified initialization setting of outer ring reference current and phase angle and voltage amplitude on the premise of not changing inner ring current control. And the continuity of the power angle and the amplitude of the output voltage in the control mode switching process is ensured. The technology can quickly respond to changes of power grid conditions, and system disturbance and instability caused by mode switching are avoided. Simulation results show that the technology effectively reduces the impact of control switching on the system, significantly improves the stability and reliability of the system, is suitable for flexible direct current transmission systems under various power grid conditions, and especially has significant advantages in weak power grid access and frequency support scenes.

The invention discloses a current distribution regulation and control voltage balance SOC optimization method, and the method comprises the specific steps: determining the type of a balance strategy according to the SOC difference between battery modules; according to the determined equalization strategy, the total cluster current of the system is distributed to each module according to SOC, and module reference current is generated and calculated; and finally, converting the module reference current into a bus voltage reference instruction, and controlling each module to track a voltage target to realize current distribution. According to the current distribution regulation and control voltage balance SOC optimization method provided by the invention, the target current is calculated, and then the current reference is converted into the bus voltage reference, so that the dynamic response speed and stability of the DC bus voltage are improved.

The invention relates to the technical field of LED dimming, in particular to an LED bulb dimming system based on user preference, comprising a signal acquisition module used for acquiring dimming signal data of user preference, the dimming signal data comprising current, voltage, dimming type and dimming target during dimming; the signal conversion module is used for performing conversion processing on the dimming signal data and determining a data use range of the dimming signal data under a normal use condition; the range identification module is used for identifying the input condition of the dimming signal data in the data use range, acquiring a reference current and a reference voltage in the data use range, and determining a state influence coefficient and a consistency coefficient corresponding to the change condition of the reference voltage and the reference current when the data use range changes; and the dimming accuracy and efficiency are improved.

An isolated DC-DC converter is provided, including a full-bridge switching stage, a resonant network, a transformer, an output stage, an output stage, an error amplifier, a feedforward controller, a charge sensor and a switch controller. The output stage generates an output signal, wherein the output signal is an output voltage or output current. The error amplifier generates an error signal based on the output signal and a reference signal, wherein the reference signal is a reference voltage or reference current. The feedforward controller senses an input voltage of the full bridge switching stage, and generates a feedforward control signal based on the sensed signal. The charge sensor generates at least one charge sensing signal. The switch controller generates and provides switch control signals to the plurality of active switches in charge control mode based on at least the error signal, the feedforward control signal and the charge sensing signal.