2206 results about "Ripple" patented technology

The invention relates to a power supply switching control optimization method and system, and the method comprises the steps: constructing a multi-dimensional data fusion monitoring system, integrating a real-time voltage ripple coefficient detection module of a main power supply, a load transient response analysis module and an environment temperature and humidity sensor array, and generating a dynamic health degree index; the method comprises the following steps: establishing a fault prediction model based on transfer learning, pre-training through multi-scene failure data in a historical database, receiving a health degree index in real time, outputting a reliability attenuation curve, and activating a dual verification mechanism when the slope of the attenuation curve exceeds a preset threshold; extracting characteristic energy distribution of a frequency band of 0.1-10 kHz; executing a transient load impact test, and measuring dynamic response parameters of voltage recovery time and overshoot amplitude; and generating a switching confidence score based on cross processing of the dual verification result and the attenuation curve, and triggering a hierarchical switching instruction. The accuracy of the switching time of the main power supply and the standby power supply can be improved.

The invention relates to the technical field of battery management systems, in particular to a distributed battery state estimation and compensation method based on voltage and current sampling, which comprises the following steps: constructing an original characteristic matrix by synchronously acquiring voltage and current waveforms and extracting ripple characteristics and slope abrupt change points, and generating a characteristic tensor with environment correction through a coupling compensator; then constructing a state parameter space based on adaptive particle injection and an electrochemical-thermodynamic coupling model; adopting a multi-source data fusion engine to realize distributed collaborative estimation of a health state index and a charge state confidence interval, and completing SOC, SOH and temperature trend prediction and residual compensation correction through a multi-state dynamic prediction model; and based on the prediction result and the uncertainty boundary, constructing an energy compensation optimization model, and searching a Pareto optimal compensation strategy. The method can be widely applied to intelligent management and control in the fields of battery energy storage systems and electric power equipment.

The invention relates to the technical field of power electronics, in particular to a voltage ripple suppression and compensation method for a multi-output AC-DC switching power supply, and the method comprises the steps: obtaining the real-time voltage ripple signal of each AC-DC output channel and the working parameters of the switching power supply, and the working parameters comprise the switching frequency, the duty ratio, the inductance and capacitance parameters and the load current; inputting the real-time voltage ripple signal and the working parameters of the switching power supply into a preset coupling interference model, and generating ripple coupling characteristics between AC-DC output channels; determining a ripple suppression compensation coefficient through the ripple coupling characteristics; and based on the ripple suppression compensation coefficient and a preset PWM control signal, adjusting the output voltage of the switching power supply to suppress the ripple, thereby breaking through the limitation of a traditional method on independent processing of a single channel, and fundamentally solving the problem of a ripple suppression blind area caused by cross interference between channels.

The invention relates to the technical field of power supply detection, and discloses a fire-fighting equipment power supply detection method and system.The detection method comprises the following steps that voltage fluctuation, current phase and ripple coefficients are collected through a multi-channel sensor group, a feature sequence is generated through sliding window noise reduction, the Euclidean distance is calculated through Z-score standardization, and a calibration instruction is generated when a threshold value is exceeded; kalman filtering adjusts frequency output detection parameters, fast Fourier transform is executed to extract harmonic amplitude to generate a suppression vector, and a least square reconstruction model outputs a state identifier; according to the method, voltage, current and ripples are collected through multiple channels, anti-interference performance and data integrity are enhanced through sliding window noise reduction, a threshold value is adjusted through Z-score and Euclidean distance self-matching, sampling frequency and detection parameters are optimized through Kalman filtering, harmonic characteristics are extracted through FFT, and the state is evaluated through a least square reconstruction model. And a multi-dimensional classification system is constructed by fusing the distortion rate and the phase deviation, so that the detection precision, the sensitivity and the response real-time performance are improved.

The invention relates to the technical field of circuit control, in particular to a control method and system of a bidirectional charging and discharging circuit. The method comprises the following steps: collecting current monitoring data and voltage monitoring data of a bidirectional charging and discharging circuit in real time; performing arc characteristic analysis on the current monitoring data and the voltage monitoring data to obtain arc characteristic data; analyzing a high-frequency harmonic component and a current ripple fluctuation amplitude of the bidirectional charging and discharging circuit based on the arc characteristic data; performing direct-current arc detection on the bidirectional charging and discharging circuit according to the high-frequency harmonic component and the current ripple fluctuation amplitude to generate a direct-current arc fault judgment result; and calculating the instantaneous current change rate of the current monitoring data, and carrying out short-circuit detection on the bidirectional charging and discharging circuit through the instantaneous current change rate. By monitoring current and voltage data in real time, arc and short circuit characteristics are accurately analyzed, relay control is optimized, an accurate control instruction is generated, and the safety and reliability of the two-way charging and discharging circuit are improved.

The invention provides a multi-dimensional electrical equipment insulation analysis and evaluation method, and relates to the technical field of electrical equipment insulation online detection and intelligent diagnosis. According to the method, an electrically isolated direct current detection channel is constructed in a neutral point small resistance grounding system, controllable direct current detection signals are injected, micro direct current leakage response signals are collected, and after zero drift correction, temperature compensation and power frequency ripple suppression are carried out, layered attribution is carried out in combination with primary system topology and an equipment ledger, and a multi-dimensional response matrix is formed. According to the method, environment and working condition normalization is realized through factor rejection and robust pull-back, a mechanism model containing leakage channel equivalent parameters and path constraints is established, multi-working-condition data is fused to calculate equivalent insulation parameters and credibility indication quantity, and a multi-dimensional insulation representation vector is generated. And performing time sequence analysis on the representation vector, extracting degradation and abrupt change characteristics, outputting a health index and a risk level, and realizing quantitative evaluation and intelligent early warning of the insulation state.

The invention provides a self-adaptive constraint model active mismatch prediction control method based on voltage and current ripple resistance of a power converter in a hybrid energy storage system, and the method comprises the steps: building an island DC micro-grid system model, collecting the voltage and current information of a system, and designing a model prediction control frame of a power loop and a cost function of the model prediction control frame; designing a model predictive control framework of the current loop and a cost function of the model predictive control framework; designing an active model mismatch mechanism to enhance the response capability to dynamic change; determining an optimization problem with a normal value, and designing an adaptive constraint optimization algorithm to dynamically adjust constraint parameters and optimize control performance; and designing a steady-state and dynamic-mode trigger for adapting to the running state of the system. According to the invention, the trajectory tracking precision of the system under dynamic and steady-state working conditions can be significantly improved, current ripples caused by control delay can be effectively eliminated, damage to electrical equipment due to overlarge ripples can be avoided, and the service life of the equipment can be prolonged.

The invention belongs to the technical field of power supply management, and particularly relates to a high-precision DCDC power supply voltage stabilization calibration system and method, which comprises a DCDC power conversion module, a traditional feedback control module, a high-frequency ripple sampling and digitization module, a dynamic load prediction module, a feedforward compensation generation module and a calibration management module, through high-frequency ripple sampling and digital output of ripple signals, real-time spectrum analysis is carried out to predict load transient changes, prospective compensation signals are generated, and traditional feedback control is combined to finely adjust PWM signals of the DCDC module. According to the scheme, feedback lag is overcome, transient overshoot / undershoot of voltage is remarkably restrained, the dynamic voltage stabilization error is controlled within + / -0.3%, and high-precision voltage stabilization under both static and dynamic working conditions is achieved.

The invention discloses a method for realizing dynamic regulation and control of battery charging of a battery swap station control system, particularly relates to the field of battery charging control of a battery swap station, and aims to solve the problems of impedance mismatch and non-uniform current of a charging module by analyzing a ripple current waveform of the charging module and extracting impedance phase characteristics to generate a dynamic impedance difference matrix. On the basis of the matrix, calculating generalized entropy of impedance mismatch and topology reconstruction dynamic gain, optimizing charging module connection, dynamically establishing a parallel charging module group, and balancing current and relieving current unevenness through an anti-phase compensation signal; pWM waveform phase offset adjustment is utilized to realize staggered distribution of switching actions, and the ripple influence is reduced; the virtual charging unit is combined with bus voltage volatility analysis to deduce a charging power demand in real time and optimize power distribution; in addition, based on a three-dimensional temperature field model and a topology secondary reconstruction mechanism, local overheating is quickly responded, the adaptability, reliability and operation efficiency of the charging process are improved, and the service life of equipment is prolonged.

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 relates to the technical field of capacitor manufacturing and state monitoring, in particular to a capacitor aging curve optimization method based on deep learning, which comprises the following steps: step 1, multi-modal data acquisition and standardization processing; 2, modeling and training a physical constraint neural network; 3, executing a dynamic control and maintenance strategy: dynamically adjusting the switching frequency of the inverter based on a comparison result of the residual life prediction value output in the step 2 and a preset threshold value, and enabling the ripple frequency to deviate from a capacitor impedance sensitive frequency band; and according to the aging mode classification result output in the step 2, triggering a corresponding temperature sampling frequency adjustment or bus voltage reduction operation. Through fusion of multi-modal data, a physically constrained neural network model and a dynamic control strategy based on a prediction result, the aging process of the capacitor is successfully optimized, the use efficiency of the capacitor is improved, and the life cycle of the capacitor is effectively prolonged.

The invention discloses a high-precision power supply output correction method based on a digital pre-distortion technology, and relates to the technical field of power electronics, and the method comprises the steps: integrating an electricity-heat-magnetism real-time combined observer, and inputting parameters including a power supply output voltage, a current, a power device junction temperature, a magnetic element surface temperature, an environment temperature, and an input voltage ripple; using a hierarchical memory depth pre-distortion compensator to generate an anti-phase pre-distortion signal containing long time domain thermal constant compensation and short time domain capacitance energy storage compensation based on modeling engine output; based on a double-ring adaptive updating module, an inner ring updates electrical parameters, including on resistance and dead time, by taking a switching period as a reference, and an outer ring updates thermomagnetic parameters, including thermal resistance and a magnetic core saturation point, in a minute-level period; and the DAC is connected in series with a pre-distortion signal output end through an anti-interference execution channel, and comprises a noise shaping DAC and a driving stage for delay matching. According to the invention, through an electric-thermal-magnetic three-field combined observation architecture, the limitation of traditional single physical field monitoring is broken through.

The invention relates to the technical field of servo control, in particular to a high-precision current closed-loop control system and method for a servo driver, and the method comprises the steps: collecting three-phase current, rotor position, winding temperature and bus voltage, and constructing a state data set; constructing a parameter identification model fusing physical prior and an attention mechanism, deducing inductance and flux linkage parameters influenced by temperature, saturation and cross coupling, and correcting a motor model in real time; the correction parameters are injected into an FOC decoupling and feedforward link, and a self-adaptive PI regulator is linked to set the gain of a current loop on line; calculating a d-q axis voltage command according to the update model to respectively control excitation and torque components; an extended state observer is introduced to estimate load abrupt change and parameter disturbance, feed-forward compensation is carried out, and three-phase PWM is generated through anti-Parker and SVPWM; and an inverter nonlinear compensation model of a dead zone and switch delay is constructed, PWM is pre-distorted and output to a power device, and robust and low-ripple current closed-loop control of the servo motor is realized.

The embodiment of the invention discloses a voltage conversion circuit and a switching power supply. A control module magnetizes or demagnetizes an inductor by controlling alternate conduction of a main switching tube and a follow current switching tube in a voltage conversion module, and charges and discharges a first capacitor. A virtual inductive current ripple signal is constructed through a virtual ripple generation module, and the virtual inductive current ripple signal replaces ESR information on a first capacitor to be superposed on a feedback voltage, so that after the feedback voltage is superposed with the virtual inductive current ripple signal, the phase difference between the feedback voltage and an inductive current is reduced, and the feedback voltage is reduced. The control module outputs a first control signal according to a virtual inductive current ripple signal and a feedback voltage to control the conduction time of the main switching tube and the follow current switching tube, so that the problem of harmonic oscillation caused by a time-lag effect between an inductive current and the output voltage on the first capacitor is solved, and the generation of harmonic waves is suppressed; the stability of the output voltage of the voltage conversion circuit is improved.

The invention discloses an output voltage detection method and system based on an aviation power supply, and relates to the technical field of aviation power supply voltage detection. A differential voltage sensor is connected to the output end of an aviation power supply, a high-frequency suppression capacitor is connected in parallel, the sampling rate of 20-50 times of the working frequency is set according to the type of the power supply, and the signals are collected and converted into analog voltage signals; the analog signal is subjected to two-stage filtering, is amplified to 0-5V through an instrument amplifier, and is converted into a digital voltage sequence through a 16-bit ADC (Analog to Digital Converter); calculating AC power supply effective value, peak value and other parameters, DC power supply average value, ripple coefficient and other parameters; comparing the characteristic parameters with a preset threshold value, determining that the characteristic parameters exceed the threshold value and recording related information; and a detection result is transmitted to a monitoring terminal through an RS485, data is locally stored, and a switching value is output to an alarm device when the data is abnormal. The method adapts to aviation power supply load fluctuation and environment temperature change, detection precision is high, data transmission and storage are safe, abnormity is accurately identified and early warning is carried out in advance, and aviation power supply operation and maintenance reliability and efficiency are improved.

The invention discloses a TCM-mode-based Si-SiC hybrid power multi-phase staggered H-bridge converter structure and a control method thereof, according to the scheme, a three-phase staggered parallel topology of a two-phase low-frequency Si-IGBT bridge arm and a one-phase high-frequency SiC-MOSFET bridge arm is adopted, and a TCM control strategy is combined, so that zero voltage switching (ZVS) of a Si device is successfully realized, the switching loss is remarkably reduced, and the switching efficiency is improved. The system efficiency is greatly improved; and meanwhile, through pilot frequency interleaving and ripple compensation technologies, total output current ripples are greatly reduced, and optimal balance between system performance and manufacturing cost is realized while the power capacity of the converter is remarkably expanded and the dynamic response speed and the output electric energy quality are improved.

The invention discloses a switch control method, a switch control circuit and electronic equipment. The switch control method comprises the following steps: acquiring an output voltage of a voltage conversion circuit; obtaining a first turn-on time by using the output voltage; generating a first control signal by using the first turn-on time; acquiring an accumulated count value from a first period termination moment corresponding to the host conversion circuit at present to a second period termination moment corresponding to the slave conversion circuit; obtaining second turn-on time by using the first turn-on time and the accumulated counting value; generating a second control signal by using the second turn-on time; and the first control signal and the second control signal are respectively sent to a host conversion circuit and a slave conversion circuit so as to respectively trigger the host conversion circuit and the slave conversion circuit to change the on-off state, thereby adjusting the output voltage. Through the above mode, the switch control method can reduce output voltage ripples, reduce the current harmonic distortion rate, and guarantee the stability, reliability and operation efficiency of power supply.

The invention discloses a high-precision charging pile direct-current electric energy metering method based on ripple compensation, and relates to the technical field of charging pile control. Dual-path signal acquisition and processing are executed to obtain a direct-current component metering result and ripple characteristic parameters; averaging the sampling points to obtain a high-frequency direct current component; subtracting the high-frequency direct-current component from the original sampling signal to obtain a pure ripple signal, performing FFT conversion and time domain analysis on the pure ripple signal, and extracting ripple characteristic parameters; according to the charging pile direct-current electric energy high-precision metering method based on ripple compensation, a main metering path and ripple analysis path dual-path architecture is adopted, the main path guarantees the direct-current component metering precision through a low-sampling-rate and high-precision ADC, the ripple path only extracts features rather than reconstructs waveforms, high hardware cost is not needed, and the charging pile direct-current electric energy metering precision is improved. Metering errors caused by ripples can be reduced to meet and be superior to national standard requirements. The transient scene is defined through the ripple mutation coefficient Ktrans and the ripple decay time tau, and the problem that the transient precision of a traditional method is out of control is solved.

The invention relates to the technical field of electric energy meters, in particular to an intelligent electric energy meter with a power saving function. A communication module; the power supply module generates power according to the temperature difference between the surface temperature of the electric energy meter chip and the air temperature in the electric energy meter so as to provide electric energy for the communication module; and the control module is used for respectively adjusting the monitoring sampling mode of the detection module from a low-frequency sampling mode to a low-frequency full-frequency composite sampling mode according to the fluctuation ratio of the electrical load, and adjusting the data transmission mode of the communication module from a periodic transmission mode to an encrypted transmission mode based on the power generation voltage ripple of the power supply module. The signal transmission frequency band of the communication module is adjusted to be a low frequency band; wherein the alternating transmission frequency of single transmission of the periodic transmission mode is determined according to the average power generation voltage of the power supply module. The working stability of the electric energy meter is improved.

An alternating current (AC) impedance spectroscopy method includes providing an AC impedance spectroscopy ripple from power electronics into an electrochemical device, and absorbing the ripple in the power electronics.

The invention provides a voltage stability control method for a multi-output switching power supply, which comprises the following steps of: sampling a main output channel in real time to obtain a voltage signal; the voltage signal is processed through a wide bandwidth error amplifier, a main channel adjusting signal is generated, and the main channel adjusting signal is used for driving a main power switch device; receiving an input voltage fluctuation frequency band of an auxiliary channel, a load current transient change gradient and a frequency spectrum coupling characteristic of a main channel adjusting signal through a dynamic prediction model, and generating an auxiliary channel adjusting signal with a phase lead compensation characteristic; a cross coupling active offset mechanism is constructed, time domain-frequency domain characteristics of coupling interference are extracted through a high-precision differential detection circuit, amplitude-frequency adjustable reverse correction signals are generated in real time through an adaptive compensation algorithm and injected into control nodes of an auxiliary output channel, and dynamic decoupling and ripple suppression are carried out. According to the method, high-stability control of multi-channel voltage under all working conditions is realized, and the dynamic response speed and the anti-interference capability are improved.

The invention belongs to the technical field of power distribution, and discloses a direct current transformer soft switch and a control method.The direct current transformer soft switch comprises a medium-voltage direct current bus and low-voltage direct current buses, the medium-voltage direct current bus is electrically connected with a modular multi-level multi-port direct current converter, and the modular multi-level multi-port direct current converter is electrically connected with a plurality of low-voltage direct current converters; the plurality of low-voltage direct-current converters are electrically connected with a low-voltage direct-current bus and are used for realizing bidirectional power transmission from medium-voltage direct current to low-voltage direct current; according to the method, the medium-voltage side inductance value is reduced, the medium-voltage side current ripple is enabled to pass zero, the M3DC operates in an approximate critical conduction mode, a constant valley current control strategy is adopted, the minimum value of the medium-voltage side inductance current is controlled to be constant under different working conditions, and then zero-voltage switching-on of a switching device in a wide operation range and zero-current switching-off of an anti-parallel diode are achieved.

The invention relates to the technical field of self-synchronizing voltage source control, and discloses a balance current controlled self-synchronizing voltage source control method and system. The method comprises the following steps: acquiring and preprocessing operation data of a grid-connected inverter to obtain active / reactive components of voltage and current of a filter element; generating a three-phase terminal voltage instruction of the self-synchronizing voltage source based on the components, and determining a current instruction signal in combination with the grid-connected voltage; a three-phase modulation signal is generated through adjustment of a PIR controller and coordinate inverse transformation, then a filter inductance value is calculated according to the ripple characteristic of the modulation signal and a switching period, a filter capacitance value is determined by combining resonant frequency, and finally accurate control of the self-synchronizing voltage source is realized according to a filter parameter. By dynamically calculating the matching parameters of the filter inductance and the filter capacitance, the active regulation and control capability of the output impedance characteristic of the inverter is enhanced, and the resonance risk during the impedance change of the power grid is effectively inhibited. The technical problem that the stability is limited due to insufficient impedance regulation and control in the prior art is solved.

The invention discloses an isolation circuit, a three-phase isolation circuit, a controller, a method and a storage medium, and the isolation circuit comprises an input filter capacitor (Ci), a first inductor (Lf1), a second inductor (Lf2), an upper tube (Q1), a lower tube (Q2), a first energy transfer capacitor (C1), a second energy transfer capacitor (C2), a first transformer (T1) and a second transformer (T2). Meanwhile, a single-stage isolation topology control algorithm is simplified, the conversion efficiency is greatly improved, the requirements of higher power level design and wider output voltage range can be met, and higher input voltage working capacity can be achieved; the electromagnetic compatibility of the power supply module can be greatly improved due to the double-inductor design of input energy transfer; furthermore, an active power factor calibration function can be realized, and input and output current ripples and voltage ripples can be greatly reduced through upper and lower tube staggered phase-shifting control, so that the service life of an output capacitor is prolonged.

The utility model provides a power assembly and a converter. The power assembly comprises a machine-side power module, a network-side power module, a positive direct-current bus conducting bar, a negative direct-current bus conducting bar and a direct-current bus capacitor, the machine side power module is connected with a motor, the network side power module is connected with a power grid, and the positive direct current bus conducting bar and the negative direct current bus conducting bar are connected between the machine side power module and the network side power module. The direct current bus capacitor is arranged between the positive direct current bus conducting bar and the negative direct current bus conducting bar; the power assembly further comprises at least one magnetic ring arranged on the positive direct current bus conducting bar and / or the negative direct current bus conducting bar. According to the power assembly and the converter, through the at least one magnetic ring arranged on the positive direct current bus conducting bar and / or the negative direct current bus conducting bar, the ripple current of the bus capacitor is prevented from being too large, the loss of the bus capacitor is reduced, and the bus capacitor is prevented from being burnt.

The invention relates to the technical field of chip detection, and discloses a high-reliability power supply chip circuit fault detection system, which comprises a built-in self-test architecture integrated in a low dropout regulator chip, and the built-in self-test architecture is provided with a first test mode and a second test mode which are switched based on a mode switching control circuit. The detection module is used for detecting key performance parameters of an error amplifier sub-circuit in a low dropout linear regulator chip, the detection module is used for measuring the direct current loop gain, the offset voltage, the common mode rejection ratio and the power supply ripple rejection ratio of the amplifier in the first test mode, and the detection module is used for measuring the unity gain bandwidth of the amplifier in the second test mode. According to the invention, through the design of a built-in self-test architecture and two test modes, abnormal states such as differential circuit imbalance and feedback loop fault can be identified in a bare chip stage, chips with poor performance are rejected in advance, and the LDO chip is ensured to reach a ppb-magnitude high reliability standard.

The invention relates to the technical field of variable frequency motor control, and discloses an energy consumption optimization regulation method for a variable frequency motor of a shot blasting machine, which comprises the following steps of: acquiring a real-time current signal of the motor, and converting an endogenous high-frequency ripple form into a discrete gear signal reflecting a mechanical load through a signal processing module; according to the invention, the dependence on an external load sensor is eliminated, the adjustment basis is completely established on the electromagnetic characteristics of the motor, the control precision is improved, and the control precision is improved. Not only is the failure risk caused by sensor faults avoided structurally, but also response delay of traditional feedback control is replaced by an instantaneous feedforward mode in control logic, and close following of energy consumption and load is achieved.

The invention relates to a motor bench test safety management method and device, equipment and a medium, and relates to the field of motors. The method comprises the following steps: acquiring three-phase current ripple data of an energy flow in a feedback path; performing feature analysis based on the three-phase current ripple data, and determining abnormal heat source information; calculating an impedance value and an impedance change rate of each feedback path based on the monitoring data of the feedback paths, and determining a risk path; wherein the feedback path is a path through which the energy flow flows from the motor to the power grid and / or the energy storage unit; updating a first feedback path based on the abnormal heat source information and the risk path; and performing path switching based on the first feedback path, and triggering an early warning signal. By adopting the method, the test safety can be ensured.

The invention is applied to the technical field of charging, and provides a charging method, a medium and an electronic device, and the method comprises the steps: obtaining a battery voltage of the electronic device in real time, and obtaining a target charging current based on the obtained battery voltage, the target charging current, and a first voltage between a battery and the charging device when the target charging current is used for charging the battery; and determining the output voltage of the power adapter. Then, the electronic device can send a notification of adjusting the output voltage to the target charging voltage to the power adapter, so that the power adapter can adjust the output voltage to the target charging voltage, and then the charging current of the battery is adjusted to the target charging current. Thus, in the constant current stage in the fast charging mode, constant current ripples can be reduced, then the average charging current is increased, the charging electric quantity in unit time is increased, and the charging time is saved. And moreover, the time of charging current climbing and falling can be shortened, so that the charging efficiency can also be improved.

The invention discloses a low-output-ripple ultralow-offset-voltage operational amplifier and a working method thereof. The low-output-ripple ultralow-offset-voltage operational amplifier comprises a first chopper circuit, a first-stage operational amplifier additionally provided with an offset voltage adjusting circuit, a second chopper circuit, a notch filter, a second-stage operational amplifier and a third-stage operational amplifier which are sequentially connected. The offset voltage adjusting circuit trims the input offset voltage of the first-stage operational amplifier to hundreds of microvolts and then outputs the offset voltage to the second chopper circuit; the first chopper circuit and the second chopper circuit are used for modulating the offset voltage of the first-stage operational amplifier to a chopping frequency, and then the ripple voltage at the chopping frequency is filtered by the notch filter; the first-stage operational amplifier is designed to be a high-gain amplifier so as to restrain input offset voltage errors caused by the second-stage operational amplifier and the third-stage operational amplifier. According to the invention, low output ripple voltage and ultralow input offset voltage can be realized only by using the wave trap with a small area.