14 results about "Zero crossing" patented technology

The application discloses a zero point dynamic learning method and device, computer equipment and a storage medium. The method belongs to the technical field of zero current detection and comprises the following steps: determining the number of pulse width modulation periods for zero point dynamic learning; generating a trigger signal in a power tube off window period in each pulse width modulation period; acquiring first voltage data collected on a sampling resistor in the power tube off window period in response to the trigger signal; calculating a zero voltage estimation value based on the first voltage data of multiple pulse width modulation periods; and calculating a dynamic zero reference value based on the zero voltage estimation value and a current zero reference value. The embodiment of the application adopts an online sampling strategy of a power tube synchronous off window. In a current zero crossing window period of each PWM period, the voltage of the sampling resistor is continuously collected by an ADC, and the zero reference of current detection is dynamically updated after sliding average processing, so that the detection accuracy and consistency are guaranteed under all working conditions.

This invention provides a crystal oscillator and a method for suppressing phase noise of the same. The crystal oscillator may include a crystal oscillator core circuit, a bias circuit coupled to the output of the crystal oscillator core circuit, a pulse wave buffer coupled to the output of the crystal oscillator core circuit, and a phase noise suppression circuit coupled to the output of the crystal oscillator core circuit. The crystal oscillator core circuit can generate a sine wave. The bias circuit can provide a bias voltage for the sine wave. The pulse wave buffer can generate a pulse wave according to the sine wave. The phase noise suppression circuit can generate a reset signal containing at least one reset pulse for resetting the bias voltage. Furthermore, a reset signal is generated without calibrating at least one reset pulse to the zero-crossing point of the sine wave.

This invention belongs to the field of wind turbine gearbox fault diagnosis technology. Addressing the problems of existing assessment methods that rely solely on amplitude statistical characteristics, are susceptible to noise interference, and depend on complex model training, this invention proposes a method and system for assessing the degradation degree of wind turbine gearboxes. It performs structured analysis of vibration signals through zero-crossing interval division, extracting interval extrema as impact intensity features; constructs amplitude reference thresholds using healthy state samples, and enhances the characterization of abnormal impacts through multi-level amplitude coding; furthermore, it identifies periodic impact structures in the vibration signals through autocorrelation analysis and calculates the periodic intensity of intervals; and introduces periodic weights on the traditional Gini index to construct a periodically perceived weighted Gini index, achieving a quantitative assessment of the degradation degree of wind turbine gearboxes, which is beneficial for condition monitoring and life prediction.

The application discloses a kind of multi-scene equipment communication methods and electric energy meter based on intelligent internet of things electric energy meter, it is related to electric energy meter communication technical field, comprising: obtaining voltage sampling sequence and current sampling sequence, according to signal zero crossing and disturbance event starting point determine phase anchor point, and combine event register and measurement state to determine scene number;With phase anchor point as center, extract integer fundamental period window, calculate voltage total harmonic distortion, current total harmonic distortion, harmonic amplitude and equivalent impedance amplitude, generate measurement fingerprint, and combine table in counter derived time slot seed;According to scene number configuration time slot length and maximum waiting time delay, based on measurement fingerprint and time slot seed, determine sending time slot and sending time, and after combining bearing state table selects main communication bearing and standby communication bearing, send message, and based on receipt check switch retransmission, to improve time slot determination accuracy, sending real-time and communication stability.

This invention discloses a method, device, and medium for precision testing of linear guideways, relating to the field of guideway precision testing technology. The method includes: constructing a separable multi-condition detection input; acquiring five-component observation errors along the travel path under each condition; defining different travel positions of the linear guideway; constructing an event type library, including zero-crossing events and straightness extreme value events; defining corresponding event functions and event conditions for each event; and performing deduplication processing on selected event state sequences. The method of this invention maps the raw output of multi-channel sensors to straightness and attitude error expressions with clear engineering semantics based on a unified measurement model, enabling comparability and composability of observations with different dimensions and installation positions within the same error space.

A power modulation method (20) for the supply of an electrical load (30) connected by means of a switch (SSR) to a network (5) with alternating-current supply voltage (10), in which to said network (5) there are also connected other loads such as lighting sources (40), in which said method comprises the step of feeding (16) said load (30) over time alternately with a first percentage power value (V1) and a second percentage power value (V2), i.e., with two percentage power values (V1, V2) defined with respect to the total alternating-current supply voltage (10) considered, obtaining a resultant average power (VM) intermediate between the two selected percentage power values (V1, V2), in which said method comprises the step of using the two different percentage power values (V1, V2) for time periods of different length, in which said method comprises the step of defining at least one of the two percentage power values (V1, V2) by means of a fixed on / off repetition scheme (22) of said switch (SSR) which, when switched off, prevents the passage of the half-15waves of the alternating-current supply voltage (10) to the load (30), wherein the fixed repetition scheme (22) defines, within a time period, how many and which half-waves are switched on and how many and which are switched off, in which said method comprises the step of selecting said fixed repetition scheme (22) so as to keep balanced the number of positive half-waves and negative half-waves, so as not to unbalance the network (5), and in which said repetition scheme (22) works with complete half-waves, and in particular using an on / off command of said switch(SSR) in zero crossing mode, in which said method comprises the step of selecting said two percentage power values (V1, V2) and said repetition scheme (22) so as to generate a signal of resultant power (16) modulated in power to feed the load (30), in which said signal of resultant power (16) generates periodic disturbances on the network (5), caused by the fixed repetition scheme (22) and by the transition between the two percentage power values (V1, V2), at a frequency equal to or greater than 25Hz, preferably equal to or greater than 33 Hz, thereby obtaining a continuous adjustment of the power that minimizes the undesired flickering phenomenon on the other loads such as lighting sources (40).

This invention relates to the field of online detection and condition monitoring technology for power system switchgear, and discloses a method for accurately measuring the opening and closing time of disconnecting switches. By synchronously collecting voltage data on both sides of the disconnecting switch to construct a voltage difference sequence, the action interval is extracted through differential and sliding window energy analysis. Within this interval, differential features are used to determine the action index and convert it into the action time. The average voltage difference before and after the action time is calculated to determine the action type. The stability of the action time is evaluated by combining a reference action time and statistical analysis of multiple measurement deviations. Simultaneously, key data from the entire process are compiled into an identifiable dataset. Through these steps, the measurement of the opening and closing behavior and action time of disconnecting switches is achieved, overcoming the problems of asynchronous single-sided sampling or mechanical triggering, poor reliability of threshold and zero-crossing detection, and difficulty in quantifying time stability, thus providing an improved means for disconnecting switch condition assessment without adding complex hardware.

A method for reducing reflected radio frequency (RF) power is described. The method includes receiving a voltage signal from an output of a match. The method further includes dividing the voltage signal into a plurality of bins and identifying a bin from the plurality of bins that includes a zero crossing. The bin is associated with a frequency of a high frequency (HF) signal. The method also includes applying a fixed multiplier to the frequency of the HF signal to generate a plurality of offsets. The method includes operating an HF RF generator according to the plurality of offsets during a time period in which the voltage signal is positive or negative.

Signal processing circuit (10) comprising a modulation unit (11) for generating a modulated signal, an amplification unit (12) for amplifying the modulated signal and thereby creating an amplified modulated signal and a demodulation unit (14) for demodulating the amplified modulated signal and thereby creating a demodulated signal. The signal processing circuit (10) further comprises a zero current detection unit (13) connected to an output of the amplification unit (12) upstream of the demodulation unit and configured to detect a zero crossing of a current based on the amplified modulated signal.

According to an embodiment, a time-of-flight sensor system includes a light emitter, a detector array, and a histogram processing circuit. The histogram processing circuit processes time-of-flight measurement data using sequential bin-by-bin histogram processing. This approach enables efficient processing with minimal memory requirements, suitable for low-power applications. The circuit applies on-the-fly operations during processing, including crosstalk removal and peak detection. A correlator circuit within the system uses multiply-accumulate (MAC) circuits to calculate ambient light contribution, perform main correlation, and compute crosstalk contribution in a bin-serial manner. Additionally, a phase / bin computation circuit applies filter coefficients to preprocessed histogram data and detects positive zero crossings to calculate the median phase.

The embodiment of the invention provides a control method of a dual-active-bridge micro inverter and related equipment, and belongs to the technical field of power electronic converter control. The method comprises the following steps: firstly, establishing a unilateral asymmetric duty ratio modulation model based on three variables of an external phase shift angle D1, an internal phase shift angle D2 and switching frequency, and deducing transmission power and soft switching constraint conditions; secondly, the switching frequency is dynamically adjusted according to the voltage phase of the power grid, and high frequency is adopted near voltage zero crossing to expand the soft switching range; thirdly, in a rated frequency interval of main power transmission, taking minimization of current stress as a target, adopting an improved self-adaptive particle swarm algorithm to carry out on-line optimization on D2 under the soft switching constraint, and calculating a corresponding D1; and finally, combining the optimized frequency with the phase shift angle feed-forward quantity and the feedback compensation quantity to generate a PWM driving signal. According to the invention, the large-range soft switching of a whole power frequency period is realized, the conduction loss is obviously reduced, and the system efficiency and reliability are improved.

This application relates to the field of test strip image processing technology, specifically a method and system for identifying dichlorvos colloidal gold tomography bands based on multi-feature fusion. The method includes: acquiring a macro image of the color development area of ​​the test strip, extracting the A channel of the Lab color space and constructing a chromaticity attenuation gradient field, and obtaining edge seed points through multi-scale Gaussian convolution and second-derivative zero-crossing detection; establishing a virtual temporal cumulative development model, simulating the spatial accumulation of color development particles with anisotropic thermal diffusion, and generating a probability connectivity graph of discontinuous segments based on the overlap of diffusion fronts; semantically completing the gaps between bands through an edge prediction model to obtain a continuous edge probability map, and generating a smooth edge map through non-maximum suppression and distance confidence attenuation compensation; extracting straight line segments using Hough transform and combining position prior to screen matching bands, and calculating the regional integral optical density to realize the restoration and identification of discontinuous bands.

A system for calibrating voltage measurements in a system for measuring electrical quantities includes a calibration device configured to determine a first reference time instant of a zero-crossing event of a voltage signal that it measures, and transmit a calibration message including the first reference time instant and a measured voltage amplitude value to at least one device for measuring electrical quantities. The at least one device for measuring electrical quantities is configured to receive the calibration message, extract the first reference time instant and the voltage amplitude, determine a second reference time instant, of zero crossing of the voltage signal measured locally, corresponding to the first reference instant, calculate a phase shift of the locally-measured voltage signal, as a function of the difference between the first and the second reference time instants and apply a phase and amplitude voltage calibration as a function of the voltage amplitude and of the phase shift.