865 results about "Reference current" patented technology

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.

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 an on-line monitoring and compensating method and system for the thickness of an electroplated layer of an automobile part based on current self-adaptive adjustment, and relates to the technical field of automation and intelligent control. Correcting the original thickness data according to the deviation degree between the current temperature and the real-time PH value and the preset reference data to obtain the real coating thickness of each subarea under the reference condition, judging that the real coating thickness reaches the standard according to the preset trigger compensation condition, if the real coating thickness reaches the standard, continuously monitoring on line, and if the real coating thickness does not reach the standard, determining the current increment of each subarea. According to the method, the current increment is compensated according to the influence of the PH value deviation, the reference current is adjusted, the final adjustment current is output, and the plating thickness of each subarea is dynamically compensated, so that the multi-dimensional process variable can be sensed, and the plating thickness of each subarea can be dynamically compensated by dynamically adjusting the current and compensating the thickness deviation caused by parameter fluctuation. And finally, the whole-course accurate control of the coating thickness of the automobile part is realized.

The invention relates to the field of three-level inverters, and particularly discloses a model-free strong-robustness predictive control method and system for a three-level SNPC inverter, and the method comprises the steps: carrying out the real-time sampling and coordinate transformation of the inverter, and obtaining the current and voltage components under a two-phase static coordinate system; establishing a hyper-local model, enabling the system parameter deviation and the external disturbance to be uniformly equivalent to lumped disturbance, and designing a full-order sliding-mode observer for real-time estimation; calculating a reference voltage vector based on the disturbance estimation value and the extrapolated reference current; and an optimal double-vector combination is selected through space vector optimization, action time is solved, redundant small vectors are selected according to midpoint voltage deviation, and PWM driving signals are generated. According to the method, excellent current tracking performance and low harmonic distortion can still be kept under the conditions of parameter mismatch and working condition change, meanwhile, neutral-point potential balance on the direct-current side is achieved, and the method has the advantages of being small in calculation amount, high in robustness, easy to achieve in engineering and the like.

The invention belongs to the technical field of grid-connected inverter harmonic analysis, and particularly discloses a grid-connected inverter harmonic closed-loop transmission analysis method and system considering broadband coupling. The method comprises the following steps: respectively establishing a harmonic component transfer function of each module; based on the harmonic component transfer function of the sampling module, calculating to obtain harmonic active power and harmonic reactive power input to the power outer loop control module; based on a harmonic component transfer function of the power outer loop control module, calculating to obtain a harmonic current component in a reference current signal output by a power outer loop; based on a harmonic component transfer function of a current inner loop control module, obtaining a three-phase modulation voltage harmonic component and an inverter port voltage harmonic component through coordinate inverse transformation; on the basis of the inverter port voltage harmonic component, a main circuit harmonic transfer equation is combined, and a grid-connected point harmonic current component is obtained through calculation; the method overcomes the defects that a traditional analysis method cannot consider the control of a whole loop by a closed loop, and the broadband coupling is insufficiently considered.

The invention relates to a ripple suppression PI loop control method, a storage medium and a device, and the method comprises the steps: extracting a frequency doubling component in an inversion power flow based on the filtering and Park transformation of a secondary second-order generalized integrator, determining the reverse compensation amount at each moment based on the frequency doubling component and a battery connected with a DC circuit, and carrying out the control of the ripple suppression PI loop. And finally, based on the sum of the reverse compensation amount at each moment and an original reference current value output by a voltage outer ring on each bridge arm of the DC circuit, determining a current reference instantaneous value after reverse compensation of a current inner ring input to each bridge arm at each moment. According to the method, a pure frequency doubling component with very high dynamic performance and related to ripple information is obtained, then according to the extracted frequency doubling component and battery parameters, the reverse compensation amount used for suppressing ripple in loop control is obtained, and then the reverse compensation amount is accumulated to a voltage outer loop, so that the ripple information is suppressed. Therefore, ripple suppression with good dynamic performance and good suppression effect in loop control is realized.

The invention discloses a negative voltage clamping circuit and method. The negative voltage clamping circuit comprises a current mirroring module which is used for providing a reference current Iref and generating a corresponding reference current according to a preset current proportion mirroring; the voltage detection module is connected with the current mirror module and the negative voltage input end of the chip and is used for detecting the voltage VS of the negative voltage input end; and the clamping control module is connected with the current mirroring module and the voltage detection module, and the clamping control module is configured to be switched on when the voltage VS of the negative voltage input end exceeds a preset clamping threshold value and clamp the voltage VS of the negative voltage input end within a preset range. According to the negative voltage clamping circuit, the change of the negative voltage input end can be monitored in real time, it is ensured that the clamping control module responds rapidly when the voltage exceeds a threshold value, the negative voltage is limited within a safe range, circuit damage or performance reduction caused by too low voltage is avoided, and therefore the stability and reliability of a chip are improved.

The invention discloses a control method and device for a quasi-Z-source network inverter circuit, an inverter and a medium. The control method comprises the following steps: firstly, acquiring a direct-current chain voltage of a quasi-Z-source network, an instantaneous output power of an IPM module and an input voltage of an alternating-current power supply access module; determining an initial reference current according to the instantaneous output power and the input voltage; then, according to the direct-current chain voltage and a preset voltage threshold value, current correction is determined; then, sampling the input voltage to obtain voltage phase information, and correcting the initial reference current according to the voltage phase information and the current correction amount to obtain target reference current; according to the embodiment of the invention, a target reference current is generated, a PWM modulation signal is generated according to the target reference current, and an IPM module is driven according to the PWM modulation signal, so that the inductive current of a first inductor reaches the target reference current, and therefore, the power factor of the Z-source network inverter circuit can be effectively improved under the condition that an alternating current power supply is used as input.

The invention provides a virtual inertia adaptive control method, device and system, and relates to the technical field of inverter system control. The method comprises the following steps: calculating a reference current value according to a power reference value and an actual output voltage; calculating a current deviation value according to the reference current value and the actual output current value; outputting the current deviation value to an adaptive resonance controller to obtain a compensation control voltage signal; inputting the compensation control signal to an AHO virtual oscillator to obtain a reference value of the output voltage of the inverter; and controlling the output of the three-phase inverter circuit according to the reference value of the inverter output voltage. Wherein the adaptive resonance controller carries out adaptive control through the proportional parameter and the proportional resonance inertial parameter. The virtual inertia output can be dynamically adjusted according to the real-time requirement of the system, the overshoot phenomenon caused by power oscillation is effectively suppressed while the frequency stability is met, and the capacity of the system for resisting sudden load change and frequency disturbance is enhanced.

A seamless switching method and device for network-oriented MMC-HVDC converter station construction and network following control, relates to the field of power system control technology, without changing the inner loop current control, by constructing a unified outer loop reference current and initializing the setting of phase angle and voltage amplitude, the continuity of output voltage power angle and amplitude in the control mode switching process is ensured. The technology can quickly respond to changes in grid conditions, avoiding system disturbance and instability caused by mode switching. Simulation results show that this technology effectively reduces the impact of control switching on the system, significantly improves the stability and reliability of the system, and is suitable for flexible HVDC transmission systems under various grid conditions, especially in weak grid access and frequency support scenarios.

A battery management system includes a sensing unit to generate a sensing signal indicating a battery voltage and a battery current of a battery, a memory unit to store a charge map recording a correlation between first to nth reference state of charge (SOC) ranges, first to nth reference currents and first to nth reference voltages for multi-stage constant-current charging, and a control unit to change to constant voltage charging using a kth reference voltage corresponding to a kth reference SOC range in response to the battery voltage having reached the kth reference voltage during constant current charging using a kth reference current corresponding to the kth reference SOC range to which an SOC of the battery belongs. The control unit updates the kth reference current of the charge map based on a time-series of the battery current in a charging period of the constant voltage charging.

The invention discloses a PMSLM adaptive optimization harmonic current suppression method based on a multi-rotating coordinate system. According to the method, high-precision extraction of target harmonic waves is realized through a multi-rotating reference coordinate system and a complex coefficient filter; an adaptive moment estimation algorithm (AdamW) with weight attenuation is used to quickly solve an optimal harmonic reference current; and harmonic compensation voltage is output by combining the zero static error characteristic of the proportional resonance PR controller, so that the harmonic current is effectively suppressed. The harmonic current of the permanent magnet synchronous linear motor is quickly and effectively suppressed through a harmonic injection method adopting a multi-rotation reference coordinate system, a complex coefficient filter and an AdamW optimization algorithm. The inherent defects of large phase lag and slow dynamic response when a low-pass filter is used in a traditional harmonic current injection method can be effectively overcome by adopting a complex coefficient filter for current extraction; and an AdamW optimization algorithm is adopted to suppress overfitting through a weight attenuation strategy, and an optimal solution is efficiently and stably obtained.

The application discloses a multi-phase motor communication-free redundancy control system and a control method, which comprises a rotating speed controller, a reference current selection module, a plurality of inner loop current controllers and a plurality of modulation and driving modules. The rotating speed controller receives a given reference rotating speed of a motor and an actual rotating speed of each set of windings, and outputs a q-axis reference current in a dq rotating coordinate system. The reference current selection module receives the q-axis reference current, specifies a master winding and a slave winding in the plurality of windings, and outputs a d-axis and q-axis reference current of each redundancy. The inner loop current controller is connected with the reference current selection module, receives the d-axis and q-axis reference current of the corresponding winding and a feedback current thereof, and outputs corresponding d-axis and q-axis reference voltage. The plurality of modulation and driving modules drive and control each winding. The application realizes communication-free control through master-slave following of the windings, can avoid the problem of collaborative failure caused by communication failure, and thus improves the steady-state performance of the motor.

The invention discloses a mode-hopping-free scanning control method for a narrow-linewidth laser, and belongs to the technical field of laser control. The method comprises the following steps: generating a reference current scanning signal and a reference voltage scanning signal; generating a high-frequency jitter signal, and superposing the high-frequency jitter signal with the reference current scanning signal to generate a total injection current for driving the narrow linewidth laser; acquiring a real-time optical power feedback signal of the narrow linewidth laser; according to the optical power feedback signal and the high-frequency jitter signal, a mode margin error signal is generated through demodulation, and the mode margin error signal is used for representing the mode stability of the current working state of the narrow linewidth laser; and generating a dynamic correction voltage according to the mode margin error signal, and superposing the dynamic correction voltage and the reference voltage scanning signal to generate a total driving voltage for driving piezoelectric ceramics of the narrow linewidth laser. Through predictive feed-forward correction, mismatch is compensated and controlled in real time, and the mode hopping phenomenon is effectively inhibited.

The invention discloses a programmable low-temperature-drift under-voltage locking circuit, and the circuit comprises a reference current generation module which is used for outputting an initial reference current, and the input end of the reference current generation module is connected with a first reference voltage; the zero-temperature-drift current source array is used for generating reference current according to the initial reference current and the second reference voltage and mirroring the reference current to a plurality of parallel branches; the trimming module is used for adjusting the total current of the parallel branches by using a programmable resistor and a capacitor; the sampling module is used for sampling the total current and the power supply voltage of the parallel branches output by the trimming module; and the comparison output module is used for comparing the power supply voltage with a sampling voltage generated according to the programmable resistor and the total current of the parallel branches, and outputting a pair of differential signals. Through the reference current generation module, the zero-temperature-drift current source array, the trimming module, the sampling network and the voltage comparator, the problems that in an existing resistance voltage division type undervoltage locking scheme, a threshold value is fixed and cannot be adjusted, and the scheme is sensitive to temperature changes are solved.

According to the light-load current limiting circuit of the switching circuit provided by the embodiment of the invention, the voltage and current conversion module generates the initial error current and the pulse frequency modulation current according to the fixed voltage when the clamping module locks the error voltage to the fixed voltage; the clamping module is used for locking the error voltage received by the voltage-current conversion module to a fixed voltage when the error current is smaller than the first reference current; the trigger signal generation module is used for generating a first trigger signal at a first preset moment and generating a second trigger signal at a second preset moment when the clamping module locks the error voltage received by the voltage and current conversion module to a pulse signal period corresponding to the fixed voltage; and the switch module is connected in a first mode when receiving the first trigger signal and determines a target voltage input to the pulse width modulation module, and the switch module is connected in a second mode when receiving the second trigger signal and the second resistor is connected to an output load of the switch circuit through the switch module.

The invention provides an open-type comprehensive current sensor data analysis method, which comprises the steps of simulating asymmetric distribution of a magnetic field according to an actual offset coordinate of a guide mass center in a clamp opening coordinate system, and generating a magnetic field compensation coefficient about a current eccentric state; compensating the real-time magnetic field intensity data according to the magnetic field compensation coefficient related to the current eccentric state, and eliminating random noise to obtain calibrated symmetrical magnetic field signal distribution; generating a reference curve of dynamic measurement current and magnetic field conversion according to the optimized conductor eccentric position state description, and determining a current measurement calibration curve; performing conversion processing on the input magnetic field signal through the current measurement calibration curve so as to correct signal distortion caused by eccentricity, and obtaining a comprehensive current reading without eccentric interference; and according to the relevance between the comprehensive current reading without eccentric interference and historical reference current data, analyzing the stability of a current measurement state, and obtaining a real-time clamp operation state feedback record.

The invention provides a light load control method, an LLC resonant converter using the same and a storage medium, the method is based on a double closed-loop control structure of a voltage outer loop and a current inner loop, different load conditions are adapted by automatically switching a PFM mode, a PWM mode and a BURST mode, and the method comprises the following steps: setting control parameters; sampling an output voltage Vout and an output current Iout of the LLC resonant circuit; inputting a voltage error obtained by comparing a preset reference voltage Vref with the output voltage Vout into a PI controller of a voltage outer loop, and calculating to obtain a reference current Iref; a current error obtained by comparing the reference current Iref output by the voltage outer loop with the output current Iout is input into a PI controller of the current inner loop; and judging the working mode of the current control period according to the duty ratio Duty of the previous control period and the frequency demand f output by the current inner loop. According to the invention, through combination of double closed-loop control and three-mode intelligent switching, comprehensive optimization of efficiency, dynamic response and output voltage quality in a full-load range is realized.

The invention relates to the technical field of control of a hybrid energy storage system of a direct-current optical storage overcharge station, and provides a double-layer fuzzy dynamic power distribution control method of a hybrid energy storage system, which comprises the following steps of: performing combined optimization by taking a direct-current bus reference current Idcref, a super capacitor state SOCsc and a storage battery state SOCbat as input; a first-layer fuzzy controller is constructed to dynamically adjust a filtering time constant T to serve as a parameter of a high-pass filter, and an initial power distribution instruction is generated; constructing a second-layer fuzzy controller to dynamically adjust the super capacitor protection state instruction Isc; and finally, based on the data obtained in the above process, adjusting the output reference current of the hybrid energy storage battery and the output reference current of the super capacitor in real time. According to the method, the charge states of the storage battery and the super capacitor are comprehensively considered at the same time to dynamically distribute the power, and the economical efficiency and the safety of operation of the hybrid energy storage system are improved.

To reduce the area requirements for sensing circuits of 3D NAND-based vector-matrix multiplication circuitry where weight values for a neural network are stored differentially as current levels on pairs of memory cells, techniques are presented for reducing the common mode current levels during sensing operations. When discharging a first capacitor through a first of a memory cell of a pair of memory cells storing a weight value by a first bit line and discharging second capacitor through a second memory cell of the pair by a second bit line, a reference current is applied to the bit lines. The product of a weight value with an input vector values is then determined by comparing the voltage levels on the two capacitors. The use of the reference current reduces the amount of voltage swing in the two capacitors, reducing the size requirements for the capacitors.

The invention discloses an electric energy meter operation state inspection and evaluation method and system, and relates to the technical field of electric power metering safety, and the method comprises the steps: collecting and preprocessing the electrical working data of an electric energy meter, obtaining the reference current and working current of the electric energy meter, extracting error features, and generating a current error signal; carrying out voiceprint collection on the electric energy meter, and capturing a voiceprint signal of the ammeter; converting the voiceprint signal into a discrete pulse sequence through a coding algorithm, and obtaining a standardized pulse sequence through dimension conversion and optimization compression; performing feature extraction on the standardized pulse sequence by applying a pulse neural network, and obtaining fault probability distribution through synaptic weight calculation and neuron state updating after obtaining pulse sequence features; the feedback control signal and the electric energy meter evaluation report are generated based on the fault probability distribution, and the problem of poor real-time performance of fault mode recognition is solved.

The invention discloses a long-time-domain predictive control and undisturbed switching method for a hybrid system networking converter, and belongs to the technical field of power system control. In order to solve the problems of poor dynamic performance and easy impact of mode switching of a grid construction / grid following converter hybrid system under new energy high-proportion grid connection, the method specifically comprises the following steps: constructing long time domain model prediction current control, replacing a traditional PI current inner loop, performing discrete modeling based on a dq coordinate system, performing double-step prediction compensation delay, and updating reference current through Lagrange extrapolation. The current tracking precision and the harmonic suppression capability are improved; designing an undisturbed switching strategy, unifying an alpha-beta coordinate system and a current control loop, locking a switching angle, synchronizing an initial value of an integrator, and dynamically adjusting reference voltage to ensure that variables are continuous; two strategies are integrated in a hybrid framework, and stable operation and smooth switching under strong / weak power grids and transition working conditions are realized. According to the invention, the total harmonic distortion rate of the grid-connected current is reduced to below 0.85%, and the method has the advantages of no voltage and current impact in switching and enhanced stability and flexibility of the power system.

The invention relates to the technical field of battery charging protection circuits, and discloses a battery charging overcurrent checking circuit which comprises a triode PNP0, a substrate of a charging power tube PM0 is electrically connected with a base electrode of a PNP type triode PNP0, an emitting electrode of the triode PNP0 is connected with charging input voltage VIN, a collector electrode of the triode PNP0 is connected with one end of a resistor R1, and the other end of the resistor R1 is grounded; the negative input end of the comparator COMP is connected to a connection node of the triode PNP0 and the resistor R1 to obtain voltage VC, the output end of the reference voltage generation module is electrically connected with the positive input end of the comparator COMP to obtain reference voltage Vref, the output end of the comparator COMP outputs an overcurrent detection signal, substrate current of the charging power tube PM0 is adopted as a detection signal source, and the voltage Vref is detected through the detection signal source. A detection circuit is built by matching a PNP type triode PNP0 and a resistor R1, and an additional reference PMOS tube and a continuously working reference current source are omitted, so that the chip layout area is saved, and miniaturization of a charging chip is facilitated.

The invention relates to a fault positioning method and system for a multi-terminal hybrid DC power transmission system, and the method comprises the steps: calibrating a fault moment, and improving a Bergeron model; intercepting a theoretical current traveling wave of a preset time window; performing waveform processing on the intercepted theoretical current traveling wave at low, medium and high frequencies by adopting a time redistribution multi-synchronous compression transformation method based on wavelet transformation, and performing waveform correction in combination with a random forest to obtain a reconstructed current traveling wave; performing weighted least square fitting on the reconstructed current traveling wave to obtain a fitted current traveling wave; constructing a waveform reference library comprising a plurality of interval reference current traveling waves according to the fitting current traveling waves; and calculating a current traveling wave at any fault position, performing similarity calculation on the current traveling wave and the reference current traveling wave of each interval in the waveform reference library based on the arrival time and the amplitude to obtain a comprehensive similarity, and positioning a fault interval according to the comprehensive similarity.

The invention discloses a five-phase permanent magnet synchronous motor current control method based on virtual impedance. Comprising the following steps: obtaining stability boundaries of virtual impedance of each axis in d1-q1 and d3-q3 synchronous rotating coordinate systems, and obtaining optimal virtual impedance of each axis through simulation; according to the optimal virtual impedance of each coordinate axis, obtaining a proportional-integral control parameter; in the operation process of the five-phase permanent magnet synchronous motor, reference currents and actual currents of all shafts in d1-q1 and d3-q3 synchronous rotating coordinate systems are obtained in real time and input into corresponding two-degree-of-freedom current controllers respectively, and control voltages of all the shafts are obtained; and generating a driving signal according to the control voltage of all coordinate axes in the d1-q1 and d3-q3 synchronous rotating coordinate systems, and controlling the five-phase permanent magnet synchronous motor. According to the method, high-performance harmonic suppression and dynamic response optimization control of the five-phase permanent magnet synchronous motor under the influence of multiple odd harmonic currents is realized.

The invention discloses a sensorless motor control method based on self-adaptive NT-SMO. The method comprises the following steps: acquiring phase current and phase voltage of a motor; based on the phase current and the phase voltage, a self-adaptive NT-SMO model is adopted to determine the rotating speed of the motor and the position of a rotor; performing first coordinate transformation on the current of the motor according to the rotor position to obtain d-axis and q-axis feedback current; obtaining a q-axis reference current through a sliding mode controller based on the error between the motor rotating speed and the reference rotating speed; according to the d-axis feedback current, the q-axis feedback current and the reference current, a PI controller is adopted to determine d-axis reference voltage and q-axis reference voltage; and performing second coordinate transformation on the d-axis reference voltage and the q-axis reference voltage to obtain a control voltage, and driving an inverter to control a motor to operate by adopting an SVPWM modulation mode based on the control voltage. According to the method, the rotating speed and the position information are estimated by directly utilizing the phase current and the phase voltage of the motor in combination with the self-adaptive NT-SMO model, so that the operation of the motor is controlled, and the control precision and the stability in high-temperature, high-humidity, strong-vibration and electromagnetic interference environments are improved.

This application provides a smart electronic switch capable of providing reminders, comprising: a power switch whose gate is connected to a switch control unit; and an aging assessment control module connected to a first terminal, a second terminal, and the gate of the power switch, respectively. The smart electronic switch includes an aging assessment mode. In this mode, the aging assessment control module controls the power switch to turn on, sets the gate-source voltage of the power switch to a first preset voltage, and compensates the drain-source current of the power switch to a first reference current. The aging assessment control module obtains first parameter information characterizing the on-resistance and compares this first parameter information with reference parameter information. If the comparison result between the first parameter information and the reference parameter information meets a preset condition, the aging assessment control module issues a reminder signal. Embodiments of this application also provide a chip, an automobile, and a method.

Techniques for generating reference voltages and reference currents from a supply voltage are disclosed. A disclosed reference voltage and reference current generator circuit includes a combination of transistor (e.g., MOS) devices and interconnect resistors. The interconnect resistors have temperature coefficients that are selected to negate temperature sensitive effects in the transistor devices due to electron mobility temperature behavior in the transistor devices. The interconnect resistors may be implemented as resistor stacks that include interconnected metal layers separated by electrically insulating layers.

The invention discloses a three-level inverter open-circuit fault diagnosis method based on fault feature vector prediction, and the method comprises the steps: reconstructing a theoretical stator current through reference current based on a motor steady-state model, and introducing an amplitude per-unit algorithm to calculate a current residual error, thereby recognizing the fault, and locking a fault phase; collecting a system state at the moment of fault triggering, deducing a modulation switch sequence in a future detection period on line by using a reference voltage vector time sequence prediction model, and generating a dynamic reference value of theoretical action times of each switch state; performing real-time statistics on the actually-measured cutoff times of the fault phase in different switch states by using an edge triggering mechanism, and constructing an actually-measured feature vector; and determining a fault device by calculating the minimum distance between the actual measurement vector and each fault modal theoretical feature. The method can effectively eliminate the influence of the rotating speed and load change of the motor on the diagnosis threshold, solves the problem that the fault features of the inner tube and the clamping diode are overlapped and are difficult to distinguish, and improves the robustness and accuracy of fault diagnosis.

The application belongs to the field of range hood, and discloses a control method and device of a range hood, computer equipment and a readable storage medium. The method comprises the following steps: acquiring a first motor rotating speed of a motor under the condition that the motor operates according to a reference current; determining a first fan wheel rotating speed of a second fan wheel according to the first motor rotating speed and a transmission ratio of a transmission mechanism stored in advance; inquiring a current corresponding to the first fan wheel rotating speed as a target current in a corresponding relationship between the current required by each flue resistance interval and the oil fume suction capacity of the fan wheel rotating speed interval, and controlling the motor to operate according to the target current. The application can enhance the oil fume suction capacity of the range hood.