2341 results about "Phase-locked loop" patented technology

The invention discloses a sleep monitoring and intervention method and system based on electroencephalogram signals, and belongs to the technical field of sleep monitoring and intervention. The method comprises the steps that electroencephalogram signals are collected through a dry electrode worn on the head of a user; the signals are preprocessed; performing automatic sleep staging on the pre-processed signal based on a layered space-time joint modeling network, and outputting a waking period label, an N1 period label, an N2 period label, an N3 period label and an REM period label; whether intervention conditions are met or not is judged based on the staging labels and the real-time electroencephalogram spectrum features; and if yes, generating and applying an alternating current stimulation signal for intervention. The system comprises a wearable electroencephalogram acquisition device, a signal analysis module and an intervention module. According to the method, the deep learning model integrating front-end self-adaptive processing, the graph neural network and Transform is adopted for sleep staging, closed-loop phase synchronous stimulation driven by the digital phase-locked loop is combined on the basis, connection from sleep monitoring to closed-loop intervention is achieved, and the sleep monitoring accuracy and the intervention effect are effectively improved.

The invention relates to the technical field of high-speed digital interfaces, and discloses a JESD204B multi-device deterministic delay synchronization system and method based on dynamic clock phase compensation, and the system comprises a main node which generates and dynamically distributes clock signals, and constructs a dynamic clock tree structure; the slave equipment is used for realizing cascade error elimination through a distributed compensation mechanism; the dynamic phase compensation engine adopts a hybrid phase detection framework and is combined with a digital-to-time converter (TDC) and an analog phase-locked loop (PLL); and the environment parameter compensation module is used for collecting temperature, voltage and operation time in real time, and calculating phase compensation quantity through a formula that delta phi = alpha * (T-T0) + beta * (V-V0) + gamma * delta t. On the aspect of synchronization precision, the phase error of a single device can be smaller than or equal to + / -200ps, the strict scene requirement is effectively met, the environment adaptability is high, the defects of traditional fixed compensation can be overcome, cascade error accumulation can be efficiently restrained through distributed compensation of slave devices, and on the aspect of real-time performance, an online calibration module can conduct real-time calibration without interrupting services.

The embodiment of the invention provides a grid-connected inverter control mode switching method and device, equipment, a medium and a product, and is applied to the technical field of electrical control. The method comprises the following steps: acquiring a control mode switching signal of the grid-connected inverter, and determining a switching direction of a control mode based on the switching signal; when the switching direction indicates that the current control mode is switched from the GFL mode to the GFM mode, setting an initial value of an integrator of a power synchronization loop of the GFM mode as a phase angle value of a phase-locked loop corresponding to the GFL mode; switching the control mode from the GFL mode to the GFM mode based on a first preset path and a step-by-step switching mode; when the switching direction indicates that the current control mode is switched from the GFM mode to the GFL mode, acquiring a power steady-state output value of the GFM mode, and setting a power reference value of the GFL mode as the power steady-state output value; and switching the control mode from the GFM mode to the GFL mode based on the second preset path and the step-by-step switching mode. The technical effect of improving the control mode switching fluency is achieved.

The invention provides a real-time dynamic harmonic detection method and system for a traction power supply system, and relates to the technical field of harmonic detection, and the detection method comprises the following steps: collecting a voltage signal of the traction power supply system in real time, and dynamically tracking fundamental frequency fluctuation through a phase-locked loop technology; dynamically adjusting the data window length of FFT analysis; dynamically adjusting a frequency spectrum calculation kernel of the FFT; carrying out linear compensation on the detected harmonic phase; taking the preliminarily detected harmonic parameter as an initial value, and iteratively updating the harmonic parameter until convergence by minimizing a signal reconstruction error; dynamically adjusting a sampling interval according to the fundamental frequency fluctuation, and carrying out anti-aliasing processing by adopting a filter with a variable cut-off frequency; and constructing a matrix model containing a fundamental frequency fluctuation parameter, and calculating a real harmonic parameter through a least square method. According to the method, the detection defect of the fixed window FFT during frequency fluctuation can be systematically solved, and high-reliability real-time data support is provided for harmonic resonance suppression of the electrified railway.

Implementing asymmetric processor cores to enable higher operating frequencies in processor-based devices is disclosed herein. In some aspects, a processor-based device provides a core cluster that comprises a plurality of processor cores and a corresponding phase-locked loop (PLL). Each processor core is based on a common instruction set architecture (ISA) and is configured to operate synchronously based on a same clock signal from the PLL of the core cluster. A first subset of processor cores within the core cluster is implemented with a different physical characteristic relative to a second subset of processor cores within the core cluster, wherein the different physical characteristic enables each processor core of the first subset of processor cores to operate at a higher operating frequency than each processor core of the second subset of processor cores.

The invention discloses a high-precision electric power measurement method based on an intelligent electric meter, and relates to the technical field of electric power measurement. According to the invention, a plurality of high-precision voltage and current sensors with temperature compensation are uniformly arranged in a circuit, a low-noise front-end conditioning and multi-channel high-resolution ADC synchronous sampling technology is adopted, and a digital phase-locked loop is introduced to realize accurate correction of a sampling clock. And performing multi-stage weighted fusion, time domain instantaneous power calculation and FFT frequency domain decomposition compensation on the acquired data, and finally accurately calculating the real power in a power grid period. According to the method, measurement errors caused by temperature excursion, phase deviation and harmonic interference in the prior art are effectively solved, the measurement precision and stability of the system are remarkably improved, and the method is suitable for high-precision power monitoring in a complex power grid environment.

The invention discloses a stability analysis method for a hybrid grid-connected system of a grid-following converter, and the method comprises the steps: constructing precise impedance models of a grid-following type (GFL) converter and a grid-constructing type (GFM) converter respectively based on a phase-locked loop (PLL) mechanism and a virtual synchronous generator (VSG) control strategy, and the details are shown in an abstract figure 1; deducing the total equivalent impedance of the system at a point of common coupling (PCC) according to a circuit equivalence principle; performing stability analysis and sensitivity evaluation on different converter combination proportions, topological structures and key control parameters of the hybrid grid-connected system based on an impedance ratio criterion; and verifying the accuracy of the analysis result through frequency domain simulation. The method can be widely applied to a new energy power system, solves the problem of system stability evaluation and optimization under the high-proportion renewable energy access background, and has the characteristics of high adaptability, accurate model and comprehensive analysis.

The invention discloses a transient optimization control method based on a parallel system of a virtual synchronous machine and a grid-following converter. The method comprises the following steps: 1, constructing a topological structure of the parallel system of the virtual synchronous machine and the grid-following converter; 2, based on the topological structure, establishing a mathematical model of a parallel system, including an active loop equation and a reactive loop equation of a virtual synchronous machine and a phase-locked loop equation of a grid-following converter; 3, constructing an equivalent circuit, a network equation and a transient analysis model of the parallel system based on the mathematical model; 4, on the basis of the equivalent circuit, the network equation and the transient analysis model, determining conditions met by respective balance points of the virtual synchronous machine and the grid-following converter by using a balance point method; and 5, when the power grid has a fault, constructing a transient optimization strategy according to a condition satisfied by the balance point so as to realize transient optimization control of the parallel system. According to the method, the control modes of a virtual synchronous machine power loop and a grid-following type converter phase-locked loop can be improved, so that the transient stability of a parallel system converter is improved.

The invention relates to the technical field of prediction algorithms, and discloses a high-precision active power filtering and prediction algorithm for a three-phase ammeter, which comprises the following steps: acquiring original signals of three-phase voltage and current for baseline correction, performing time-frequency analysis on non-stationary harmonic waves and noise of the original signals, and dynamically adjusting filtering parameters; voltage and current phase alignment is carried out through FIR phase shift and zero crossing point detection, a phase-locked loop is constructed by using GRU to track the frequency of a power grid, the sampling frequency is dynamically adjusted, and frequency mutation is detected; iapFFT transformation is optimized to suppress spectrum leakage, a phase error is corrected through a deep learning network, and weak harmonic detection is enhanced by using an attention mechanism; classifying harmonic waves, and adaptively calculating total active power; dimensionality reduction is carried out on historical power and environmental parameters through an auto-encoder, and future active power is predicted; low-power-consumption hardware is adapted, and training efficiency and data security are optimized; three-phase signals are processed in parallel, and FPGA storage and FFT / FIR cores are optimized for filtering processing; and dynamically adjusting parameters of the phase-locked loop.

The invention relates to the technical field of energy storage cooperative control, and discloses an improved energy storage converter grid following control algorithm, which comprises the following steps of: 1, extracting positive sequence and negative sequence components of three-phase voltage of a power grid through a double-sequence decoupling phase-locked loop, and acquiring a positive sequence axis component signal by adopting forward rotation coordinate transformation; and 2, when frequency locking is carried out based on the positive sequence axis component signal, extracting a voltage amplitude corresponding to the positive sequence axis component signal, and inputting the voltage amplitude to a feed-forward passivation module. An active power regulation technical scheme based on a frequency deviation threshold value is adopted, the technical effect of simulating the primary frequency modulation characteristic of a network-forming converter is achieved by detecting the power grid frequency deviation in real time and generating an active power compensation signal, and the defect that traditional network-following control lacks frequency active supporting capacity is overcome. And the converter can spontaneously increase the active power to stabilize the power grid frequency when the power grid frequency drops.

The invention relates to the technical field of power systems, in particular to a UPQC harmonic compensation method and system based on repetitive control, and the method comprises the steps: obtaining a load current signal and a voltage signal of a power distribution network, and extracting a harmonic instruction current based on the load current signal; and inputting the harmonic instruction current into a feed-forward channel constructed based on an adaptive filter, and generating a feed-forward control quantity. The phase and frequency of the voltage signal of the power distribution network are tracked in real time through a digital phase-locked loop, the fundamental frequency of the power grid is accurately solved, and the power distribution network can be accurately controlled. The internal model period and the phase lead compensation amount of the frequency adaptive repetitive controller are dynamically calculated, and the internal model structure of the repetitive controller is always matched with the current power grid frequency by updating the two core parameters in real time, so that the compensation precision decline caused by frequency deviation is avoided; and high-precision suppression of the periodic harmonic waves can be realized in a normal fluctuation range of the fundamental wave frequency of the power grid.

The invention provides a broadband tunable low-phase-noise photo-generated microwave signal source and device, and relates to the technical field of photo-generated microwaves. According to the invention, a low-frequency optical pulse and a high-frequency microwave signal are respectively input into the electro-optical sampling phase-locked loop; and the electro-optical sampling phase-locked loop determines the synchronization error of the optical pulse and the microwave signal based on the phase difference between the optical pulse center point and the microwave signal zero crossing point. And taking the synchronization error as a feedback signal, and continuously adjusting the frequency and the phase of the microwave signal by the voltage-controlled oscillation module until the frequency and the phase are synchronized with the Nth harmonic of the optical pulse. By setting different initial frequencies of the voltage-controlled oscillation module, microwave signals with different integral multiple optical pulse frequencies can be obtained, and broadband tuning of photo-generated microwave signals is realized. Furthermore, the repetition frequency of the frequency comb is locked through beat frequency of two beams of reference laser and two adjacent comb teeth, the stability of the reference laser is transmitted to the optical pulse, and the stability of the reference laser is further transmitted to the microwave signal through synchronization of the optical pulse and the microwave signal, so that the phase noise of the photo-generated microwave signal source is reduced.

The invention provides a grid-connected and off-grid seamless switching method and system for a network-constructed energy storage micro-grid, belongs to the technical field of grid-connected and off-grid switching, and realizes rapidity and stability of micro-grid mode switching through multi-stage cooperative control. The method comprises the following steps: a power grid state real-time monitoring stage: acquiring power grid short-circuit capacity, impedance angle, voltage amplitude, frequency and phase parameters through impedance spectrum analysis and phase-locked loop cooperative detection; a pre-synchronization-hybrid control-dynamic damping three-stage switching stage; a steady state maintaining stage: maintaining a system damping ratio gt through a multi-target cooperative controller; and in the whole switching process, the bus voltage fluctuation is less than or equal to 2%, and the frequency deviation is less than or equal to 0.1 Hz. According to the method, MPC pre-synchronization, hybrid control of dynamic weight, virtual impedance adaptive compensation and multi-target collaborative optimization are controlled through model prediction, so that the problems are solved, seamless switching is realized, and the quality of electric energy is improved.

The invention provides a high-precision electric energy metering and fault diagnosis method adaptive to multiple working conditions, and the method comprises the following steps: carrying out the multi-rate synchronous sampling of an electric parameter through a double-AD parallel sampling architecture, collecting a fundamental wave voltage / current signal through a low-speed AD module at a sampling rate of 4kHz, capturing a high-frequency harmonic wave and a transient signal through a high-speed AD module at a sampling rate of 256kHz, and carrying out the fault diagnosis of the high-frequency harmonic wave and the transient signal; a sampling mode is dynamically switched according to the load harmonic content; a sliding window mechanism is adopted to carry out multiple times of repeated detection on the same electric parameter, five times of independent measurement are completed in a 200ms time window, an outlier is eliminated based on a Pauta criterion, then a weighted mean value of a signal-to-noise ratio is calculated, AD reference voltage is calibrated in real time through a PT100 temperature sensor, and the accuracy of the AD reference voltage is improved. Carrying out nonlinear dynamic compensation by combining a cubic spline interpolation method of a pre-stored load characteristic curve; and constructing a composite electric energy calculation model, summing the fundamental wave electric energy and the harmonic electric energy weighted according to the standard to generate a total electric energy value, and comparing a metering result with a theoretical value in real time by using a digital phase-locked loop.

The invention relates to the technical field of mining permanent magnet synchronous motor sensorless control, and particularly discloses a composite sliding mode control and adaptive phase-locked loop collaborative optimization method. Aiming at the technical bottlenecks of a traditional control strategy in the aspects of rotating speed fluctuation suppression, load disturbance compensation and rotor position observation precision, a collaborative architecture of a time-varying integral terminal sliding mode control module, a sliding mode disturbance observation module and a self-adaptive phase-locked loop module is constructed, so that the dynamic performance optimization of the system is realized. According to the method, through the dynamic coupling design of the time-varying gain nonlinear reaching law and the fast integral terminal sliding mode surface, the convergence speed and the buffeting suppression requirement are balanced while the disturbance dynamic influence is eliminated; multi-dimensional decoupling observation of external load disturbance is realized based on a hierarchical disturbance observer architecture, and a disturbance real-time suppression path is established in combination with a feed-forward compensation strategy; and constructing an error self-adaptive correction mechanism of rotor position observation by dynamically adjusting a phase-locked loop proportionality coefficient and a phase compensation parameter. The limitation of parameter solidification and observation coupling in traditional control is broken through, the rotating speed tracking stability, the position observation precision and the anti-interference capability under complex working conditions are remarkably improved, and an innovative solution is provided for a high-precision servo driving system.

The invention discloses a permanent magnet synchronous motor current dynamic coupling correction method, which comprises the following steps of collecting motor three-phase stator current, performing Clark transformation to obtain a current value under an alpha-beta static coordinate system, and meanwhile, collecting through a position sensor to obtain an electrical angle true value; performing low-pass filtering calculation on the current value under the alpha-beta static coordinate system to obtain a filtering current value, and performing operation through a sliding-mode observer and a PLL phase-locked loop to obtain an electrical angle observation value; calculating to obtain a compensation adjustment coefficient according to the true value and the observed value of the electrical angle, and further calculating to obtain a current value after phase offset compensation; and performing complementary filtering calculation on the filtering current value and the current value after phase offset compensation to obtain a coupling correction current value for current loop calculation, inputting the coupling correction current value into a motor control current loop PID algorithm, and generating a PWM driving signal to drive a motor in combination with vector control. According to the method, the problems of high-frequency interference and phase deviation of current sampling can be solved, so that the motor control efficiency and the dynamic performance are improved.

The invention relates to the technical field of inverter control, and discloses a VSG-based inverter phase-locked loop-free pre-synchronization method, system and device and a medium, and the method comprises the steps: eliminating the voltage deviation between the VSG inverter voltage of a virtual synchronous generator and the output voltage of a micro-grid through a deviation integral feedback method; a general signal delay superposition operator is adopted to filter the power grid voltage so as to construct virtual power, then the virtual power is introduced into an active-frequency loop of the virtual synchronous generator as a feedback signal, and a power angle feedback control model is formed so as to adjust the VSG inverter voltage; and detecting the voltage deviation between the power grid voltage and the adjusted VSG inverter voltage in real time, and when it is judged that the voltage deviation is smaller than a deviation threshold value, generating a grid-connected connection point switching-on instruction and controlling a switch of a grid-connected connection point to be switched on, so that phase-locked loop-free pre-synchronization of the distributed power supply inverter is realized, the grid-connected stability of the distributed power supply inverter is enhanced, and the grid-connected stability of the distributed power supply inverter is improved. And the current and voltage impact of the grid-connected instant system is reduced.

The invention discloses a wind power converter oscillation characteristic suppression method, system and device based on broadband impedance scanning and a storage medium, and relates to the technical field of wind power grid-connected control, and the method comprises the steps: based on grid-connected steady-state small signal voltage disturbance injection, respectively extracting broadband response data of positive sequence impedance and negative sequence impedance, and constructing a machine end broadband impedance model; constructing an impedance phase and amplitude matching criterion based on the broadband impedance model in combination with the power grid side equivalent impedance, identifying risk frequency bands of subsynchronous and super-synchronous oscillation, and determining a dynamic influence interval related to the phase-locked loop bandwidth; adjusting a phase-locked loop bandwidth and a filtering parameter based on a risk frequency band and a dynamic influence interval, and executing d / q control link collaborative constraint in combination with a leakage matrix parameter; according to the method, accurate modeling of positive and negative sequence impedance of the wind power converter and bandwidth adaptive vibration suppression control are realized, and the stability and the anti-oscillation capability of the system are improved.

The invention discloses an active island detection method and system based on harmonic impedance characteristic identification, and the method comprises the steps: analyzing the harmonic impedance difference of grid-connected points in a grid-connected state and an island state, and building a state criterion based on resonant frequency deviation and impedance amplitude through the comparison of the frequency response characteristics of island impedance and grid-connected impedance; fitting the grid impedance into an RLC parallel model in a selected frequency band, and mapping the topological difference of the power grid into a parameter difference; embedding a low-voltage ride-through strategy in the control of the voltage source converter, and adjusting reactive current in a grading manner according to the voltage drop degree of a grid-connected point; fundamental waves and harmonic waves are separated through a cascade notch filter, two synchronous harmonic waves are injected into the system through constant current control, and it is ensured that injection signals of a multi-voltage source converter are in the same phase in a phase locking link; and solving an overdetermined equation set based on the double-frequency response data to identify RLC parameters, setting an island criterion, and synchronously completing island judgment in a low-voltage ride-through time window. Detection precision is improved, dynamic response is optimized, and power generation efficiency is improved.

The invention discloses a hybrid effective flux linkage observer and a permanent magnet synchronous motor control method, device and system. The method comprises the following steps: carrying out Clarke conversion on an obtained three-phase current of the permanent magnet synchronous motor to obtain a current in a static coordinate system, and carrying out park conversion based on rotor position information to obtain a current in a synchronous rotating coordinate system; the effective flux linkage of the permanent magnet synchronous motor is obtained through the hybrid effective flux linkage observer; on the basis of the obtained effective flux linkage of the permanent magnet synchronous motor, dead-zone compensation voltage is obtained through self-adaptive gain dead-zone compensation calculation based on back electromotive force reconstruction, and the rotating speed and the rotor position of the permanent magnet synchronous motor are obtained through phase-locked loop calculation; according to the rotating speed and the rotor position of the permanent magnet synchronous motor, the current under the synchronous rotating coordinate system, the dead zone compensation voltage and the obtained reference rotating speed and reference current, the reference voltage of the motor at the k moment is obtained through a rotating speed loop and a current loop and used for achieving low-speed position-sensorless control over the permanent magnet synchronous motor.

The invention relates to the technical field of material detection, in particular to a silver coating adhesive force detection method based on multi-frequency impedance imaging, which comprises the following steps: applying a dual-mode multi-frequency excitation signal to the surface of a silver coating through an attached microelectrode array, synchronously acquiring voltage-current response data, and generating a dual-mode multi-frequency impedance original data set; performing time-varying impedance phase-locked separation on the dual-mode multi-frequency impedance original data set, extracting a dynamic impedance component of a coating-matrix interface region, and reconstructing a three-dimensional sub-interface impedance distribution diagram; and outputting an adhesive force quantized value through an oscillation frequency-adhesive force conversion model according to the spatial oscillation frequency characteristics of the impedance phase in the three-dimensional sub-interface impedance distribution diagram. According to the invention, a double-phase-locked loop system is adopted to realize the time-varying component demodulation of the impedance response of the silver coating-matrix interface, the low-frequency dynamic impedance signal modulated by silver ion migration is effectively extracted, and the weak change of the interface bonding state is sensitively reflected.

The invention discloses a multipath signal conversion crosstalk-free optimization system and method, and relates to the technical field of data acquisition and signal processing, and the system comprises a detection module which is used for generating an initial calibration parameter based on a synchronization signal phase deviation detection result, and an adjustment module which is used for adjusting the frequency and phase of a sampling clock according to the initial calibration parameter, the calibration module is used for carrying out alignment calibration on multiple paths of data to obtain an alignment error value, and the optimization module is used for further optimizing a sampling clock based on the alignment error value to realize accurate calibration; compared with a traditional hardware phase-locked loop system, the multipath signal conversion crosstalk-free optimization system and method have higher adjustment flexibility and synchronization precision, are suitable for a high-frequency and high-precision data acquisition application environment, and improve overall sampling accuracy and data analysis reliability while maintaining system stability.

The invention belongs to the technical field of inverter control, and discloses a self-adaptive adjustment strategy for the inertia of a network-forming inverter in a large-disturbance scene of a parallel system, and the parallel system comprises the network-forming inverter and a network-following inverter, and is used for carrying out the self-adaptive adjustment of the inertia of the network-forming inverter in the large-disturbance scene. The method specifically comprises the following steps that a phase-locked loop is used for controlling the following grid type inverter, and following grid type dynamic influence factors of the following grid type inverter in a large disturbance scene are analyzed based on a following grid type inverter control block diagram; based on the following network type dynamic influence factors, constructing a following network type dynamic control equation used for describing the large disturbance process of the following network type inverter; according to the method, the inertia of the network-building type inverters is effectively adjusted in a large disturbance scene of the multi-inverter parallel system, the transient synchronization characteristic of the network-building type inverters in the multi-inverter parallel system is improved, the parallel system has more stable voltage and frequency support, and the stability of the whole system is further improved.

The invention discloses a mutual inductor digital output synchronism detection method and system, particularly relates to the field of electric power engineering detection, and is used for solving the problem of synchronism deviation concealment caused by phase-locked loop drift of digital output of an electronic mutual inductor in an intelligent substation. A uniform time frame is utilized to penetrate through the whole process, synchronization deviation is continuously mapped into a phase migration track, long-term drift and instantaneous jitter are analyzed on two scales by means of phase shift stacking quantity and pulse dispersion rate, two kinds of heterogeneous features are converted into a single drift tradeoff coefficient through Gaussian process regression, and a stability domain threshold value is dynamically revised according to the single drift tradeoff coefficient; after the threshold is triggered, the minimum adjustment amount is immediately issued to the phase-locked loop and is synchronously verified, so that the clock adjustment action and the drift monitoring are mutually nested; the protection device continuously receives the stable sampling sequence, the tripping misjudgment rate is remarkably converged, the inspection period is prolonged, and additional hardware investment is not needed.

Disclosed in the present invention is a variable coefficient equivalent SISO model based stability analysis method for a grid-connected converter system, comprising the following steps: constructing a variable coefficient equivalent SISO model; obtaining a complex space vector open-loop transfer function on the basis of the variable coefficient equivalent SISO model; and obtaining Nyquist curves under different current loop parameters or phase-locked loop parameters on the basis of the complex space vector open-loop transfer function. If the Nyquist curves surround point (-1,0), the grid-connected converter system is stable; and if the Nyquist curves do not surround point (-1,0), the grid-connected converter system is unstable. The present invention performs small disturbance modeling on the grid-connected converter system, considers the influence of mutual coupling between the phase-locked loop and the inner current loop, and derives a variable coefficient SISO open-loop transfer function capable of characterizing an MIMO system. Compared with the technical solution in the prior art that actual working conditions are not considered, the method disclosed in the present invention can more accurately analyze the system stability of the system under variable working conditions and variable parameters.

The embodiment of the invention discloses a delay-locked loop circuit, a clock generator, a chip and electronic equipment, and belongs to the technical field of integrated circuits. The delay-locked loop circuit includes: a digital control circuit for transmitting a first adjustment code adapted to adjust the number of delay units in a coarse adjustment phase, and determining whether to adjust the first adjustment code based on a first feedback signal; in the fine adjustment stage, a third adjustment code suitable for adjusting the delay attribute parameter of the delay unit is sent, and whether the third adjustment code is adjusted or not is determined based on the second feedback signal; in the locking phase, transmitting a second adjustment code suitable for adjusting the control voltage of the delay unit, and determining whether to adjust the second adjustment code based on the third feedback signal; and the phase detection unit is used for sending the first feedback signal, the second feedback signal and the third feedback signal to the digital control circuit. A hybrid circuit of digital design and analog design is provided, high-precision clock phase adjustment is achieved, and an output clock in a wide frequency range can also be achieved.

Disclosed in the present invention are a switching converter and a zero-crossing detection circuit thereof. The zero-crossing detection circuit comprises: a low-side transistor control circuit used for generating a low-side transistor control signal on the basis of a high-side transistor control signal; a switching node voltage detection circuit used for generating a first pulse signal having a first pulse width when a synchronous power transistor is turned off in each switching cycle, and generating a second pulse signal having a second pulse width on the basis of a comparison result between a turn-off moment of the synchronous power transistor and an inductor current zero-crossing moment; and a phase-locked loop circuit used for providing a delayed current signal to the low-side transistor control circuit on the basis of the first pulse signal and the second pulse signal, so that the low-side transistor control circuit controls an effective level time of the low-side transistor control signal in a next switching cycle on the basis of the delayed current signal. Therefore, the inductor current can fluctuate within a tiny interval near 0 A, improving the accuracy of zero-crossing detection, reducing the circuit loss of the switching converter, and improving the efficiency of the switching converter.

The invention relates to the technical field of integrated circuits, in particular to a charge pump phase-locked loop circuit, a radar and a charge pump phase-locked loop locking control method.The circuit comprises a charge pump, the charge pump comprises a first branch circuit, a second branch circuit, a third branch circuit and a fourth branch circuit, the frequency sweeping state refers to the state when the frequency of the signal output by the phase-locked loop is linearly changed; the at least one second branch is connected to the first branch under the condition that the hopping amplitude of the frequency of the signal output by the phase-locked loop is greater than or equal to a preset amplitude threshold value so as to increase the magnitude of the current output by the charge pump, and is disconnected with the first branch when the phase-locked loop enters a frequency sweeping state; the circuit can effectively shorten the locking time of the phase-locked loop when the phase-locked loop has relatively large frequency hopping, and is beneficial to improving the response speed and performance of a system.

The invention discloses an intermittently operated phase-locked loop and an implementation method thereof. The phase-locked loop can be controlled to be switched between an open loop and a closed loop. The phase-locked loop is controlled to be switched between an open loop and a closed loop by judging whether the performance of a phase-locked loop circuit meets a preset standard of a system applying the phase-locked loop or not in real time; or, the phase-locked loop circuit is controlled to be switched between the open loop and the closed loop according to a preset period according to a time period preset period required by the system for the preset standard of the phase-locked loop circuit. Therefore, the open loop or the closed loop of the phase-locked loop can be controlled according to actual needs, and the influence of the phase-locked loop on the system can be reduced while the phase-locked performance of the phase-locked loop can be completed.

The invention relates to the technical field of voltage sensitivity photovoltaic stability regulation and control of a power distribution network, in particular to a multi-parameter photovoltaic grid-connected voltage stability control method, system equipment and a medium, and aims to improve the transient modeling precision by constructing a second-order equivalent transient model of a photovoltaic system and decoupling a mapping relation between phase-locked loop parameters and equivalent inertia and damping; quantifying a transient stability boundary under voltage disturbance based on a phase-locked loop sensitive parameter, and determining a photovoltaic power angle critical safety threshold; for the whole voltage fluctuation process, dynamically and cooperatively regulating and controlling phase-locked loop parameters according to the voltage and frequency of the power grid; equivalent damping and inertia suppression oscillation are enhanced in the voltage drop period, inertia acceleration recovery is reduced while high damping is maintained in the voltage recovery period, rated parameters are reset in the steady state, the transient stability of the system for coping with voltage sag is remarkably improved, and the risk of power angle instability is avoided.