1240 results about "Pulse width modulated" patented technology

The invention relates to the technical field of vibration and noise control, discloses a new energy automobile motor high-frequency vibration and noise active suppression system and method, and aims to solve the problems of poor high-frequency vibration and noise suppression effect, real-time performance, adaptive capacity and system cost complexity of an existing new energy automobile motor. The method comprises the following steps: acquiring and preprocessing motor operation state data, extracting high-frequency harmonic characteristics, and generating predicted harmonic characteristics in combination with working condition prediction; and superposing the self-adaptive compensation quantity to a motor voltage instruction, and driving an inverter through pulse width modulation to realize active suppression of high-frequency vibration and noise. The system comprises a data acquisition preprocessing module, a harmonic feature extraction module, a working condition sensing prediction module, a self-adaptive compensation quantity generation module and a pulse width modulation correction module. By the adoption of the technical scheme, efficient, real-time and self-adaptive suppression of high-frequency vibration and noise of the motor can be achieved, the level of the high-frequency vibration and noise is remarkably reduced, the driving comfort is improved, and the complexity and cost of the system are optimized.

The invention provides a power distribution network single-high-frequency resonance rapid tracking and adaptive suppression method, a multi-mode dynamic cooperative adaptive suppression system is established based on a PCCVF adaptive method, and the damping characteristics of a power distribution network are remodeled by injecting compensation current into a power distribution network system so as to realize broadband resonance suppression of the power distribution network. The compensation current injection method comprises the following steps: step 1, detecting resonant frequency deviation of a power distribution network through real-time FFT (Fast Fourier Transform); 2, performing dynamic phase angle correction based on a phase prediction residual error of real-time frequency deviation; step 3, constructing a layered impedance remodeling module, and ensuring stable power transmission; 4, establishing a frequency-variable impedance model of the power distribution network based on resonance energy spectral density analysis, dynamically optimizing parameters through fuzzy logic of a bell-shaped membership function, and feeding harmonic compensation current into the power distribution network by using a space vector pulse width modulation technology; according to the invention, single high-frequency resonance can be effectively suppressed, the response and tracking performance of the system is improved, and the spectrum analysis efficiency and bandwidth occupation are optimized.

The embodiment of the invention provides an excitation signal generation method and system and a digital eddy current sensor, and the method comprises the steps: outputting a square wave signal through a pulse width modulation assembly of a microcontroller unit, and enabling the frequency and resolution of the square wave signal to be adaptive to eddy current probes with different inductance values; inputting the square wave signal into a low-pass filter for filtering, and setting the cut-off frequency of the low-pass filter, the suppression times of higher harmonics and the attenuation slope so as to output a sine wave signal with a target total harmonic distortion range; the amplitude of the sine wave signal is collected in real time, and the pulse width modulation duty ratio and the passband gain of a low-pass filter are dynamically adjusted in combination with a digital control algorithm, so that the sine wave signal is subjected to self-adaptive adjustment and correction and is output; and taking the sine wave signal as an excitation source of an eddy current probe, and driving the eddy current probe to carry out nondestructive testing. According to the invention, the excitation signal which gives consideration to high-frequency signal generation, deep harmonic suppression and digital adaptive adjustment can be generated.

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.

The invention relates to an FOC control method based on an automobile air conditioner module motor without a Hall sensor, and belongs to the technical field of automobile electronics. The method comprises the following steps: injecting double-frequency voltage pulses into a stator in stages to position a rotor; collecting current through a sampling resistor and filtering to construct a rotor flux linkage distribution model, and presetting rectangular axis current in combination with noise reduction of a miniature acoustic sensor and air speed gear of an air conditioner; an extended Kalman filter observer is adopted to reversely deduce the load torque, and the torque change rate is monitored to trigger instantaneous load impact protection; the voltage space vector amplitude is corrected through voltage feed-forward compensation, a resistor-capacitor series filter circuit is additionally arranged, and phase dislocation pulse width modulation is adopted for resisting interference; and establishing a motor efficiency-rotating speed-load three-dimensional optimization method, starting dynamic flux-weakening control, and estimating the winding temperature through the stator resistance to adjust the flux-weakening depth. Accurate starting and dynamic load adaptation of the Hall-sensor-free motor are achieved, starting out-of-step and noise exceeding are avoided, and stable air volume of an automobile air conditioner and long-term reliable operation of the motor are guaranteed.

The invention relates to the technical field of power conversion, in particular to a collaborative optimization control method, system and equipment of a multi-mode power conversion device and a storage medium. The method comprises the following steps: constructing a double-layer collaborative architecture by collecting multi-source heterogeneous operation parameters, obtaining a device operation state, power grid dynamic characteristics and environment change information, establishing a cross-level communication protocol to realize data synchronization, and outputting a real-time working condition feature vector; deploying a dynamic mode switching engine based on a real-time working condition feature vector, triggering multi-mode operation strategy reconstruction through a state transition probability model, constructing a self-adaptive switching mechanism comprising a parallel power supply mode, an island operation mode and a hybrid modulation mode, and establishing a composite fault response system to realize pre-diagnosis and grading disposal of an abnormal state; millisecond-level real-time control is implemented in the edge control layer to generate a pulse width modulation driving signal, multi-target global optimization is implemented in the cloud optimization layer to dynamically adjust an operation parameter combination, and closed-loop control is formed through bidirectional data interaction and strategy feedback.

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.

The invention provides an energy-saving method for an LED display screen. The energy-saving method comprises the following steps: acquiring ambient brightness and original image data; generating a brightness control parameter through a preset model according to the ambient brightness; dividing a feature pixel set and a non-feature pixel set based on the image feature recognition model, and executing differential brightness adjustment to generate an optimized image; monitoring power consumption data in real time, triggering a dynamic energy-saving mode when a threshold value is exceeded, and reducing the overall brightness by adopting a pulse width modulation signal grading adjustment strategy; and dynamically switching a standard mode, an extreme energy-saving mode or a highlight display mode according to the ambient brightness change rate and the viewing distance. The power consumption of the LED display screen can be reduced, and the energy utilization efficiency is improved.