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792 results about "Pulse width modulated" patented technology

Pulse Width Modulation (PWM) is a fancy term for describing a type of digital signal. Pulse width modulation is used in a variety of applications including sophisticated control circuitry. A common way we use them here at SparkFun is to control dimming of RGB LEDs or to control the direction of a servo motor.

Single battery equalization management method of lithium battery BMS (Battery Management System) protection board

The invention belongs to the field of electrical variable measurement, and particularly relates to a single battery equalization management method for a lithium battery BMS (Battery Management System) protection board, which comprises the following steps of: acquiring voltage, temperature, total current and cycle index of each single battery in real time; based on a second-order equivalent circuit model and an extended Kalman filtering algorithm, multi-source information is fused, and the health state and the charge state are estimated with high precision; constructing a dynamic equilibrium trigger threshold fusing the charge state standard deviation, the range and the health state attenuation factor; a bidirectional flyback or multi-winding transformer active equalization strategy is selected according to the inconsistent distribution characteristics and the temperature field, and equalization current is accurately controlled through pulse width modulation; and continuously monitoring the efficiency, the temperature rise rate and the convergence in the equalization process, and dynamically optimizing the equalization parameters by using the fuzzy logic controller until the inconsistency reaches the standard. According to the technical scheme, accurate, self-adaptive, high-efficiency and safe single battery equalization management can be realized, the service life of the battery pack is effectively prolonged, and the operation reliability of the system is improved.
Owner:SHENZHEN KESHENG POWER TECHNOLOGY CO LTD

Display device

The invention relates to a display device. The display device comprises a light-emitting device and a pixel circuit. The pixel circuit comprises an amplitude modulation module, a pulse width modulation module and a switch module. A first capacitor in the pulse width modulation module is used for storing a first electric charge quantity corresponding to a pulse width data signal received by the pulse width modulation module. And a second capacitor in the amplitude modulation module is used for storing a second electric charge quantity corresponding to the amplitude data signal received by the driving unit. A connection node of the first capacitor and the driving unit is a first node, a connection node of the second capacitor and the pulse width control unit is a second node, and the switch module is connected between the first node and the second node and used for conducting the first node and the second node before a reset stage so as to neutralize charges stored in the first capacitor and the second capacitor. Therefore, the voltage of the first node is reduced, the influence on the reset signal is reduced, the problem that the light-emitting device emits light abnormally in the reset stage is solved, and the display effect of the display device is improved.
Owner:HISENSE VISUAL TECH CO LTD

Direct current brushless motor control method and system based on current prediction

The invention relates to the technical field of motor control, discloses a direct current brushless motor control method and system based on current prediction, and aims to solve the problems of large torque ripple, low efficiency and poor stability caused by current loop lag in the prior art. The method comprises the following steps: acquiring a motor operation state signal in real time; determining a sector and an electrical angular velocity based on the rotor position and the rotational speed; inputting related parameters into the mixed current prediction model to obtain a three-phase current prediction value of the next period; a prediction error is calculated in combination with a current instruction, and an optimal voltage vector enabling a cost function to be minimum is solved through a model prediction control algorithm; and finally, a space vector pulse width modulation signal is generated to drive an inverter. According to the method, advanced control is realized by fusing a physical model and a data-driven prediction mechanism, the torque ripple is remarkably reduced, and the energy efficiency and robustness are improved.
Owner:LOUDI CHUANGWEIDA ELECTRICAL APPLIANCE CO LTD

Methods and apparatus for charging with direct current and alternating current

Systems, apparatus, articles of manufacture, and methods are disclosed to charge an energy storage device on a vehicle. The system includes instructions to detect direct current or alternating current on or at an input terminal of a vehicle electrical system, the input terminal to receive electrical energy to charge the energy storage device on the vehicle; based on detection of direct current, generate a first pilot signal that includes a first pulse width modulated signal associated with a first mode including a first duty cycle range; based on detection of alternating current, generate a second pilot signal that includes a second pulse width modulated signal associated with a second mode including a second duty cycle range, wherein the first duty cycle range is lower than the second duty cycle range; and charge the energy storage device based on detection of the first pilot signal or the second pilot signal.
Owner:DEERE & CO

Scan driving method for rendering high-contrast image and cholesteric liquid-crystal display device using the same

A scan driving method for rendering a high-contrast image, for use in a cholesteric liquid-crystal display device, is provided. The cholesteric liquid-crystal display device includes a display panel and a driving circuit section. The method includes: utilizing the driving circuit section to sequentially activate each scanning electrode using a modified pulse-width modulation (PWM) scanning procedure including a first stage, a second stage, and a third stage in sequence; and utilizing the driving circuit section to apply one or more alternating-current (AC) voltage pulses to pixel circuits on a first scanning electrode during the first stage to manipulate grayscale values of the pixel circuits thereon to be written in the second stage. During the first stage of the first scanning electrode, the pixel circuits on the remaining scanning electrodes within the third stage sense a zero voltage during a high-voltage period within the first stage of the first scanning electrode.
Owner:IRIS OPTRONICS INC

Conversion control circuit for controlling a stackable multi-phase power converter

A conversion control circuit for controlling a stackable multi-phase power converter, the conversion control circuit including: a master transfer terminal, wherein a master transfer trigger signal is coupled to plural master transfer terminals of plural parallel-connected conversion control circuits; and a master transfer circuit configured to generate or receive the master transfer trigger signal through the master transfer terminal, wherein the master transfer trigger signal is generated according to an output voltage or an output current of the output power, or a pulse-width modulation related signal; when the master transfer trigger signal switches to an enabled state, the conversion control circuits perform a phase sequence swapping procedure, which includes: the master transfer circuit triggering a transfer of a master role from the stackable sub-converter originally acting as the master circuit to another stackable sub-converter of the stackable sub-converters.
Owner:RICHTEK TECH

Gallium nitride totem-pole circuit and control evaluation system of gallium nitride totem-pole circuit

The embodiment of the invention provides a gallium nitride totem-pole circuit and a control evaluation system of the gallium nitride totem-pole circuit, and the circuit comprises a gallium nitride power device which comprises an integrated semiconductor tube and an integrated drive circuit; the isolation chip is connected between the control module and an integrated driving circuit of the gallium nitride power device and is used for sending the pulse width modulation signal sent by the control module to the integrated driving circuit, and the isolation chip can ensure the electrical safety of weak current and strong current; the gallium nitride power device is used for controlling the on-off state of the integrated semiconductor tube through the integrated driving circuit according to the pulse width modulation signal sent by the isolation chip; under the condition that the integrated semiconductor tube is conducted, the voltage is output to the control module based on the bus voltage through the integrated semiconductor tube, and the driving circuit is integrated on the gallium nitride power device, so that the circuit design can be simplified, overcurrent protection and undervoltage protection are simultaneously carried out, and the safety of the gallium nitride totem pole circuit is improved.
Owner:EDGELESS SEMICON CO LTD OF ZHUHAI +1

Polar field magnet coil power supply system and power supply method

The invention relates to the technical field of electronic circuits, in particular to a polar field magnet coil power supply system and a power supply method. The polar field magnet coil power supply system comprises a super capacitor, a control module and a driving module. The control module is coupled with the driving module and the polar field magnet coil, and the control module is configured to obtain feedback current of the polar field magnet coil, generate a first pulse width modulation signal group and generate a second pulse width modulation signal group. And the driving module is configured to respond to the first pulse width modulation signal group and generate the second pulse width modulation signal group, transmit energy stored by the super capacitor to the polar field magnet coil in the current rising sub-stage and the current maintaining sub-stage, and feed back the energy of the polar field magnet coil to the super capacitor in the current feedback sub-stage. According to the polar field magnet coil power supply system, the energy utilization rate can be greatly improved, the problem that energy cannot be recycled in the prior art is solved, and the problem that the failure rate is high is solved.
Owner:ENN SCI & TECH DEV

Multi-loop anti-interference ride-through control system and method for high-voltage three-level inverter

The invention discloses a multi-loop anti-interference ride-through control system and method for a high-voltage three-level inverter, and is suitable for a three-phase T-type three-level grid-connected inverter. The system comprises a direct current side power supply circuit, an inversion main circuit, a filtering grid-connected circuit, a signal sampling and conditioning circuit, a multi-loop cooperative controller and a PWM driving and protecting circuit. According to the control method, a robust synchronous reference is provided through an outer ring virtual synchronous generator strategy; a middle ring adopts a virtual impedance model containing a high-frequency compensation item to selectively suppress switching noise; the inner ring adopts a quasi-proportional resonance controller to realize fundamental current zero-static-error tracking; the modulation layer dynamically optimizes a discontinuous pulse width modulation strategy based on a real-time EMI index; and the rings are switched to a low-voltage ride-through mode in cooperation when a fault occurs. On the premise of not increasing hardware, the anti-interference capability, the current quality and the ride-through stability of the inverter under the working conditions of strong electromagnetic interference and power grid drop are effectively improved.
Owner:HANGZHOU DIANZI UNIV +1

Voltage output method and system based on high-voltage power supply widening controller

The invention relates to a voltage output method and system based on a high-voltage power supply widening controller, and belongs to the technical field of high-voltage power supplies. The method comprises the following steps: acquiring a wide-range voltage parameter, and dividing a frequency control region and a pulse width modulation control region of a high-voltage power supply through an arbitration control algorithm to obtain switching judgment information of a power supply working region; constructing a working area switching logic according to the resistance-capacitance network, executing the working area switching logic through a frequency pulse correlation algorithm, coordinating the pulse width and the working frequency, and generating a double-modulation execution signal; a closed-loop negative feedback mechanism is established, and a wide-range overvoltage-free voltage regulation and control instruction is obtained by combining a proportional-integral compensation circuit with a resistance measurement full-right control working frequency and a pulse width; and broadening the output voltage range and inhibiting the overshoot voltage through power supply power driving, coordinating the working frequency and the pulse width in combination with the wide-range overvoltage-free voltage regulation and control instruction, and outputting the wide-range voltage of the high-voltage power supply.
Owner:SHANGHAI FENGJING ENVIRONMENTAL PROTECTION EQUIP CO LTD

Voice instruction recognition and cleaning control method for sweeping robot

The invention relates to the technical field of voice recognition, and discloses a voice instruction recognition and cleaning control method for a sweeping robot, which comprises the following steps: synchronously reading a dust collection motor driving pulse width modulation value and a rolling brush motor load current value of the sweeping robot while acquiring an audio signal acquired by a microphone; retrieving and interpolating in a preset working condition noise spectrum mapping table according to the non-acoustic operation state data, determining a predicted mechanical noise power spectrum at the current moment, taking the predicted mechanical noise power spectrum as a priori reference, calculating an instantaneous signal-to-noise ratio of the predicted mechanical noise power spectrum and the frequency domain feature sequence, and constructing a frequency domain confidence mask; according to the method, a feedforward prediction mechanism is constructed by introducing non-acoustic prior information, and response lag of traditional acoustic posteriori estimation during sudden change of working conditions is avoided.
Owner:ZHUHAI KAIHAO ELECTRONICS CO LTD

Flexible regulation and control method and system for terminal voltage

The invention relates to a terminal voltage flexible regulation and control method, and the method comprises the following steps: presetting target voltage parameters which comprise an amplitude value, a frequency and an initial phase angle; calculating a three-phase sinusoidal voltage reference signal based on a virtual synchronous machine algorithm according to the target voltage parameter; according to the three-phase sinusoidal voltage reference signal, generating a driving signal by using pulse width modulation, and controlling the on and off of an IGBT power switch device to generate a three-phase sinusoidal compensation voltage; injecting the three-phase sine compensation voltage into the tail end of a power grid; monitoring the voltage state of the power grid in real time, and calculating the deviation between the actual voltage of the tail end of the power grid and the target voltage parameter; and according to the deviation, adjusting a control parameter in the virtual synchronous machine algorithm, and updating the three-phase sine compensation voltage to compensate the voltage deviation at the tail end of the power distribution network. Voltage deviation can be compensated in time, and the problem of voltage change caused by large fluctuation of electrical load can be effectively solved.
Owner:KUNSHAN TYSEN KLD PHOTOELECTRIC TECH

Control system for frequency conversion and speed regulation of refrigerator compressor

The invention provides a control system for frequency conversion and speed regulation of a refrigerator compressor, and belongs to the technical field of refrigerator compressors. Stator resistance parameters are identified on line through an extended Kalman filter, and an extended state observer is established to estimate the total disturbance quantity of a direct axis and a quadrature axis; calculating a flux-weakening direct-axis current instruction value in a flux-weakening operation region according to the rotating speed and the direct-current bus voltage, and inputting the current instruction value, the actual current value and the rotor rotating speed into a current loop parameter adaptive optimization model to obtain a proportional integral gain and a feedforward decoupling coefficient; calculating a proportional-integral control voltage and a feedforward decoupling voltage, superposing the proportional-integral control voltage and the feedforward decoupling voltage with total disturbance quantity compensation to obtain an output voltage, and generating a driving signal through space vector pulse width modulation to control an inverter; the technical problem that a refrigerator compressor permanent magnet synchronous motor is low in parameter setting efficiency of a current controller in a weak magnetic operation area and is difficult to adapt to full-speed-domain dynamic working condition changes is solved.
Owner:NINGBO JUHU INTELLIGENT TECHNOLOGY CO LTD

Electromagnetic detection multi-level current emission system for plateau environment and control method

The invention belongs to the technical field of electromagnetic detection, and relates to an electromagnetic detection multi-level current emission system for a plateau environment and a control method. The control method comprises the steps of calculating load model impedance; analyzing an MFPWM control process, and determining an optimal control parameter by using an optimization target of transmitting spectrum intensity maximization; and MFPWM optimization control: realizing directional power distribution and independent regulation and control of each frequency component by adjusting the frequency and amplitude of each modulation signal component. A multi-level topological structure is adopted, high output voltage is achieved while switching voltage stress is reduced, and the problems that cost rises and system complexity is too high due to the fact that a traditional H-bridge inverter depends on high power supply voltage are solved; by matching with multi-frequency pulse width modulation optimization control, spectrum energy can be flexibly configured, high-frequency components of transmitted signals are enhanced, and the spectrum energy utilization rate and the signal-to-noise ratio are improved; grounding impedance changes in a high dynamic range can be accurately tracked, and the requirements of deep geological electromagnetic detection in an extreme environment are met.
Owner:JILIN UNIVERSITY

Harmonic current suppression method for six-phase motor driver based on multi-subspace control

The invention discloses a six-phase motor driver harmonic current suppression method based on multi-subspace control, and belongs to the technical field of motor control. In order to solve the problem that low-order harmonic current of a six-phase motor in a z1-z2 subspace is difficult to effectively suppress, the invention provides a scheme that a mathematical model of the six-phase permanent magnet synchronous motor is established, multi-subspace decomposition is carried out, and stator current is divided into a d-q subspace and the z1-z2 subspace; a double-closed-loop control architecture with a speed loop as an outer loop and a current loop as an inner loop is constructed, a d-q subspace adopts a PID regulator to realize fundamental current control, and z1-z2 subspaces realize suppression of fifth and seventh harmonic currents through a parallel structure of PI and a quasi-proportional resonance controller; and a PWM signal is synthesized through inverse transformation and dual three-phase space vector pulse width modulation, and an inverter is driven to realize stable output of fundamental wave energy and harmonic suppression. The method effectively reduces the harmonic distortion rate, improves the operation efficiency and stability, and is suitable for occasions of new energy vehicles, ship propulsion, rail transit and the like.
Owner:HARBIN ELECTRIC GRP ADVANCED MOTOR TECH CO LTD

Isolated gate drive circuit and driver

An isolated gate drive circuit and a driver, the isolated gate drive circuit includes signal restoration module, modulation module with first terminal and second terminal, high-pass filter module, and falling edge monitoring module; first pulse signal output from the first and second terminals are rail-to-rail differential pulse signals; When the isolated gate drive circuit restores the pulse width modulation signal, the isolated gate drive circuit monitors the first pulse signals output from the first and second terminals of the modulation module. When the pulse signal in the first pulse signal output from the first terminal or the second terminal of the modulation module is in a falling edge state, the falling edge monitoring module outputs a third pulse signal to the signal restoration module, the signal restoration module can quickly output the restored the pulse width modulation signal, improving the reliability of the isolated gate drive circuit.
Owner:TREX TECHNOLOGIES CORP

Intelligent low-voltage servo system based on three-loop control

The invention discloses an intelligent low-voltage servo system based on three-ring control, and relates to the technical field of servo control, and the system comprises a double-shaft servo driver, an azimuth servo motor, a pitching servo motor, an azimuth angle sensor and a pitching angle sensor. The double-shaft servo driver comprises a control board assembly and a driving board assembly. The control panel assembly comprises a position loop controller, a speed loop controller and a current loop controller, and a three-ring cascaded closed-loop control structure is formed based on the position loop controller, the speed loop controller and the current loop controller; and the driving board assembly comprises a power amplification circuit and is used for driving an azimuth servo motor or a pitching servo motor to operate according to the pulse width modulation signal output by the current loop controller. According to the invention, a three-loop control structure of a position loop, a speed loop and a current loop is adopted, and feedforward compensation, disturbance observation and an intelligent management strategy are integrated to improve the dynamic performance and robustness of the system.
Owner:CHENGDU XIWU SECURITY SYST ALLIANCE

Thermal printing device and printing method

The invention relates to the technical field of application of thermal printing heads, in particular to a thermal printing device and a printing method for simplifying gray scale printing and achieving fine gray scale control, and the thermal printing device is provided with an external printing host and a thermal printing head. A PWM modulation unit, a clock unit CLK, a frequency divider, a latch unit LATCH, a printing gating unit STB and a plurality of control units in one-to-one correspondence with a plurality of heating points in the heating resistor are arranged in the printing logic control component, and the printing gating unit STB is used for outputting a current line printing gating control signal to the control units; the PWM modulation unit is used for carrying out pulse width modulation on a printing pulse number mi issued by an external host and outputting heating time pulse signals superposed with different duty ratio pulses to the control unit so as to meet different color development temperature requirements; compared with an existing mode that multiple times of sending of printing data are combined with STB gating, the cost requirement for printer control resources is remarkably reduced on the premise that gray level fine control is met.
Owner:SHANDONG HUALING ELECTRONICS

Servo driver based on heterogeneous computing architecture

The invention discloses a servo driver based on a heterogeneous computing architecture, and relates to the field of servo drive control, and the servo driver comprises a first processing unit which is configured to execute an upper-layer control loop and a real-time communication protocol of a servo system; the second processing unit is a heterogeneous processor integrated with a processing system and programmable logic, the processing system is used for executing system management and man-machine interaction tasks, and the programmable logic is configured to realize lower-layer current loop control, pulse width modulation signal generation and hardware acceleration calculation; and the high-speed parallel data interface is connected with the first processing unit and the second processing unit and is used for realizing bidirectional interaction of the control data and the state data. According to the scheme, through collaborative optimization of a heterogeneous computing architecture and a hardware acceleration mechanism, the comprehensive performance of the servo driver is remarkably improved.
Owner:SHANGHAI BODU TECHNOLOGY CO LTD

Unbalance compensation method and system for energy storage converter

The invention discloses an unbalance compensation method and system for an energy storage converter, and belongs to the field of power electronics and electric energy quality treatment. The system comprises a power instruction analysis module, a current reference generation module, a negative sequence current control loop module, a zero sequence control loop module, a positive sequence control loop module, a pulse width modulation module, a first conversion module and a second conversion module, the current reference generation module is respectively connected with the negative sequence current control loop module and the positive sequence control loop module; the third end and the fourth end of the negative sequence current control loop module are connected with the pulse width modulation module through the second conversion module; the third end and the fourth end of the zero sequence control loop module and the third end and the fourth end of the positive sequence control loop module are connected with the pulse width modulation module through the first conversion module. According to the method, the energy storage and compensation functions of the PCS can be seamlessly integrated under a unified control framework, so that the control system is greatly simplified, and the performance is remarkably improved.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD RESEARCH INSTITUTE +1

Temperature-based discontinuous pulse width modulation control system

An inverter controller configured to control an inverter includes a microprocessor that is configured to measure or estimate a temperature of a first phase and to measure or estimate a temperature of a second phase; determine whether the temperature of the first phase is greater than the second phase; and select a switch in the inverter to clamp based on the determination.
Owner:BORGWARNER INC

3D printer hot bed temperature closed-loop control method and system based on PID algorithm

The invention relates to the technical field of 3D printing temperature control, and particularly discloses a 3D printer hot bed temperature closed-loop control method and system based on a PID (Proportion Integration Differentiation) algorithm. The method comprises the following steps: acquiring a temperature change trend prediction parameter based on multi-point temperature data and temperature change historical data, dynamically optimizing a PID parameter reference value according to the parameter to obtain an adaptive PID parameter, and performing online adaptive adjustment on the hot bed temperature according to the adaptive PID parameter, including converting a control output value into a pulse width modulation signal to adjust the overall heating power. And dynamically allocating partition power based on the trend vector, and switching the heating mode according to the dynamic stage. On-line real-time self-adaptive optimization of PID parameters is achieved, the problems of heating overshoot and slow cooling caused by dynamic asymmetry of a hot bed can be solved, temperature field distribution uniformity is improved, and adaptability to different printing working conditions and temperature control precision are improved.
Owner:SHENZHEN JINSHI 3D SOFTWARE TECHNOLOGY CO LTD

Permanent magnet synchronous motor wide speed range model prediction control method and system based on mean value reduction optimization

The invention discloses a permanent magnet synchronous motor wide speed range model prediction control method and system based on a mean value reduction optimization algorithm, and belongs to the technical field of motor control. According to the method, a discrete mathematical model of the permanent magnet synchronous motor is established under a d-q rotating coordinate system, a q-axis current reference value is generated by an outer ring through a speed PI regulator, and a d-axis current reference value is calculated in combination with a maximum torque per ampere (MTPA) principle and a weak magnetic region voltage constraint; finite control set model prediction control is adopted in an inner ring, enumeration prediction is conducted on candidate voltage vectors of the three-phase voltage source type inverter, a cost function containing a d-axis current error, a q-axis current error and an electromagnetic torque error is constructed, an optimal voltage vector is selected, and a three-phase PWM signal is generated through space vector pulse width modulation to drive a motor. The system is provided with a mean value reduction optimization module, joint optimization is carried out on speed outer ring PI parameters and cost function weight coefficients in the off-line stage, the parameters are stored in a lookup table, and automatic setting of control parameters is achieved. The permanent magnet synchronous motor can improve the dynamic response performance of the rotating speed and the current in the base speed area and the weak magnetic area, reduce the total harmonic distortion of the stator current, improve the voltage utilization rate and the overall operation efficiency of the permanent magnet synchronous motor, and is suitable for occasions such as electric vehicle driving and high-performance servo systems.
Owner:CHANGCHUN UNIV OF TECH

Totem pole PFC circuit control method and device based on improved SOGI-PLL

The invention discloses a totem-pole PFC circuit control method and device based on an improved SOGI-PLL, and belongs to the technical field of totem-pole PFC circuits, and the method comprises the steps: collecting the input voltage, input current and bus voltage of a totem-pole PFC circuit; synchronous phase information of the power grid voltage is obtained through an improved second-order generalized integral phase-locked loop; generating a current amplitude reference signal, and combining the current amplitude reference signal with the synchronous phase information to synthesize a current reference signal; generating a pulse width modulation signal for controlling a high-frequency switching tube; and a switching signal of the power frequency switching tube is generated based on the synchronous phase information, and the power frequency switching tube and the high-frequency switching tube are driven in combination with the pulse width modulation signal, so that the action time sequence is synchronous with the phase of the power grid voltage, and therefore, waveform tracking of the input current is realized, and current distortion at the zero crossing point is suppressed. Precise phase synchronization is realized based on the improved SOGI-PLL, totem pole PFC zero-crossing current distortion is effectively suppressed, and the power factor and waveform quality are improved.
Owner:GREE ELECTRIC APPLIANCE INC OF ZHUHAI

Cross-coupled charge pump for driving a bootstrap switch

According to an embodiment, a bootstrap drive circuit for driving a bootstrap switch in a DC-DC converter is proposed. The bootstrap drive circuit includes a non-overlapping circuit, a first and a second capacitor, and a first and a second n-channel transistor. The non-overlapping circuit is configured to receive an input signal, the input signal being a function of a pulse width modulated (PWM) signal, wherein the input signal and the PWM signal are characterized by a first logic level, generate a first control signal from the input signal at a first output terminal of the non-overlapping circuit, the first control signal having the first logic level, and generate a second control signal from the input signal at a second output terminal of the non-overlapping circuit, the second control signal being characterized by a second logic level different from the first logic level.
Owner:STMICROELECTRONICS INT NV

Motor high-reliability commutation method based on same-frequency displacement conversion of magnetic suspension rotor

The invention relates to the field of magnetic suspension motor driving control, and discloses a high-reliability motor commutation method based on same-frequency displacement conversion of a magnetic suspension rotor, and the method comprises the following steps: collecting a multi-channel rotor displacement signal of a magnetic suspension bearing system; carrying out same-frequency positive-sequence component extraction and phase locking calculation to obtain a rotor space angle position estimation value; multiple paths of redundant rotor angular position signals are constructed, and main rotor space angular position signals are generated; executing initial alignment and error correction of a motor rotor angle, and locking an angle compensation value in a closed loop mode based on the waveform change rate of the direct current bus current at the pre-estimated commutation moment; synthesizing the motor commutation angle, and generating a pulse width modulation signal to drive the motor to operate. A magnetic suspension rotor displacement signal is processed through a second-order generalized integrator cascade instantaneous symmetric component method, so that the effect of high signal-to-noise ratio rotor position detection is realized by directly utilizing an existing magnetic bearing displacement sensor under the condition that a Hall element or a photoelectric encoder does not need to be additionally arranged.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Sine pulse width modulation circuit and switching power supply

The utility model discloses a sine pulse width modulation circuit and a switching power supply, and the circuit comprises a sine wave generation circuit which comprises a voltage division circuit, an RC oscillation circuit, a differential comparison amplification circuit, and a gating circuit; the voltage division circuit is used for carrying out voltage division processing on power supply voltage input by the input end of the sine pulse width modulation circuit and then outputting a direct-current voltage signal; the RC oscillating circuit is used for converting the direct-current voltage signal into an alternating-current oscillating signal and outputting the alternating-current oscillating signal; the differential comparison amplification circuit is used for comparing and amplifying the AC oscillation signal and the DC voltage signal and then outputting an AC voltage signal; the gating circuit is used for gating the AC voltage signal and then outputting a sine wave signal; the negative half-cycle rectifying circuit is used for overturning and rectifying a negative half-cycle signal in the sine wave signal and then outputting the negative half-cycle signal; and the positive half-cycle rectifying circuit is used for overturning and rectifying a positive half-cycle signal in the sine wave signal and then outputting the positive half-cycle signal. According to the utility model, the cost, volume and weight of the product can be reduced.
Owner:GUANGZHOU XUZHIYUAN TECHNOLOGY CO LTD

Model prediction fault-tolerant control method and system for dual three-phase permanent magnet synchronous motor

The invention relates to a model prediction fault-tolerant control method and system for a dual three-phase permanent magnet synchronous motor, and the method comprises the steps: estimating the lumped disturbance in the operation process of the motor in real time based on an extended state observer, and carrying out the feed-forward compensation of the reference voltage of the motor according to the lumped disturbance information; and based on the compensated voltage reference value, constructing a dynamic voltage vector set and correcting an initial voltage vector set, searching an optimal voltage vector in the dynamic voltage vector set, and driving the motor through three-phase decoupling space vector pulse width modulation. According to the field loss fault-tolerant control strategy designed by the invention, phase current harmonics caused by local field loss faults of the dual three-phase permanent magnet synchronous motor can be effectively suppressed, and the steady-state precision and the dynamic response capability of the system under the local field loss faults are enhanced.
Owner:HUNAN UNIV

Methods and apparatuses for imaging under pulse-width modulated illumination

A system for reducing artifacts when imaging under pulse-width modulated illumination. A controller captures, with an image sensor, images as frames of a video of a target in an environment in which the target is illuminated by a pulse-width modulated light source. In doing so, the controller sets a first parameter for the image sensor as a function of a light pulsation period of the pulse-width modulated light source to reduce artifacts in the images associated with the pulse-width modulation of the light source. Further, the controller determines whether residual banding artifacts resulting from the pulse-width modulation of the light source are unacceptable in the images captured with the image sensor. Additionally, the controller performs, in response to a determination that residual banding artifacts are present in the images, image processing to correct the residual banding. The system outputs the resulting images with reduced artifacts for viewing by a user.
Owner:UNIFY MEDICAL INC

A portable electrochemical impedance spectroscopy online measurement system and method for lithium ion batteries

This application discloses a portable online electrochemical impedance spectroscopy measurement system and method for lithium-ion batteries, relating to the field of lithium-ion battery technology. The system includes: a power supply system for powering a power transmission system and an online measurement system, connected in parallel with a charger connected to the battery pack to achieve synchronous charging and impedance measurement; a power transmission system for converting direct current into a step function current, which is superimposed on the DC charging current and injected into the battery pack as an excitation signal; a control system for adjusting the frequency of the step function current using pulse width modulation technology; a measurement circuit module for acquiring the current and voltage signals of the battery pack; and a data analysis module for processing the time-domain signal using wavelet transform to calculate the electrochemical impedance spectrum. This application achieves low-cost, portable online measurement, enabling monitoring of the battery impedance spectrum during charging and providing support for safety early warning.
Owner:INNER MONGOLIA UNIV OF TECH