2847 results about "Phase-locked loop" patented technology

Disclosed in the present invention are a grid-connect control method and apparatus for a grid-connect inverter. The method comprises: on the basis of a control structure of a grid-connect inverter in a dp domain, passing a deviation signal of a power outer loop through power outer loop controllers, so as to generate reference values of a current inner loop, and comparing the reference values of the current inner loop with an actual output current, so as to obtain error signals, wherein the control structure comprises a PQ power control outer loop and a current control inner loop, and the actual output current is obtained by means of performing phase tracking, on the basis of a synchronous reference frame phase-locked loop, on the voltage of a point of common coupling; and adjusting the error signals by means of a current inner loop controller, so as to generate modulation signals, performing pulse width modulation (PWM) on the modulation signals, so as to generate an on-off signal of an inverter bridge power semiconductor device, and controlling the state of connection and disconnection between the grid-connect inverter and a power grid on the basis of the on-off signal. In the present embodiment, the connection and disconnection between a grid-connect inverter and a power grid are controlled, so as to improve the stability of the grid-connect inverter in weak power grids.

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 waveform synchronization method and device, and the method comprises the steps: firstly generating a dot frequency signal which has the same frequency with a low-frequency reference clock and is synchronous with the low-frequency reference clock after a system is started, feeding back the dot frequency signal in the form of a clock after passing through a signal link, carrying out the digital phase discrimination with the low-speed reference clock, and adjusting the delay of the signal link. And the feedback clock and the reference clock are aligned in phase, so that the certainty of signal link delay is realized. By adopting the thought similar to a phase-locked loop, the problems of uncertain time delay and non-synchronization between channels between the DAC and the FPGA interface can be solved under the condition that an ADC is not used for collecting a feedback waveform and carrying out complex correction calculation, the hardware complexity and cost of the system are remarkably reduced, and the digital phase discrimination speed and the calibration speed are high. In addition, the precision of delay calibration mainly depends on the establishment and retention time of the D trigger, and very high precision can be achieved. The invention also discloses synchronous waveform generation equipment.

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 method for realizing data acquisition clock synchronization through Beidou time service and an FPGA phase-locked loop, and the method comprises the steps: obtaining a short message service signal of a Beidou satellite navigation system, and carrying out the analysis to obtain time service information; controlling a digital phase-locked loop to calibrate a local clock signal according to the time service information; monitoring the deviation between the time service information and the local clock signal, and adjusting the frequency and phase of the local clock signal through feedback control of the digital phase-locked loop; monitoring a clock synchronization state, setting a clock deviation threshold value, judging the synchronization state of the time service information and the local clock signal, if the deviation exceeds a threshold value range, triggering an alarm signal, and taking a recovery measure according to an abnormity type and duration time; a hardware timestamp function is integrated, clock synchronization with other acquisition nodes is carried out through a precise time protocol, and the acquisition time of seismic data is recorded.

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 discloses a wide-speed-domain position-sensorless control method for a permanent magnet synchronous motor, and the method comprises the steps: building an extended state observer of the permanent magnet synchronous motor, and obtaining the counter electromotive force of the motor through the extended state observer; a self-adaptive vector filter is adopted to filter out higher harmonics in the back electromotive force obtained by the extended state observer, estimated back electromotive force is obtained, the obtained estimated back electromotive force serves as input, position information contained in the estimated back electromotive force is demodulated through a phase-locked loop position observer, and the rotating speed and the position angle of the motor are obtained; and controlling the permanent magnet synchronous motor according to the obtained rotating speed and position angle. The position observer is used for extracting position information from the rotor back electromotive force, a mechanical position sensor is omitted, the system structure is simplified, cost is reduced, the self-adaptive vector filter is used for filtering harmonic waves for estimating the back electromotive force, and estimation errors of the rotating speed and the position angle of the motor are reduced. And the high efficiency and the stability of position-sensorless control of the motor in a wide speed range are 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 an impedance measurement method and system. The method comprises the following steps: acquiring grid-connected point voltage, measurement frequency, disturbance amplitude and nth inverter grid-connected current of the multi-inverter grid-connected system; inputting the grid-connected point voltage into an improved phase-locked loop in a fundamental wave and disturbance control unit to generate a power grid frequency and a power grid phase; inputting the power grid phase and the nth inverter grid-connected current into the current control loop to generate a fundamental current control instruction; inputting the measurement frequency, the disturbance amplitude and the power grid frequency into the disturbance control ring to generate a disturbance instruction; inputting the disturbance instruction and the fundamental current control instruction into the modulation ring, generating a control driving signal according to a modulation strategy of an inverter, and controlling each inverter switch; and obtaining the controlled grid-connected point voltage through an impedance calculation unit, and generating the impedance of the inverter to be tested and the impedance of the power grid. By adopting the method, disturbance can be injected efficiently at low cost so as to measure impedance.

The invention relates to the technical field of intelligent power grids, in particular to a grid-connected control method for an improved RBF (Radial Basis Function) network construction type converter with active support capability. The method comprises the following steps: firstly, taking a group of initial values in a VSG system virtual inertia and equivalent damping coefficient parameter value range; determining an initial angular frequency according to the initial value and a swing equation; a VSG secondary control system is improved, an improved phase self-tracking pre-synchronization method without a phase-locked loop is added, a voltage deviation signal is responded, a frequency phase is compensated, and the rotational inertia and the damping coefficient of the system are adjusted in real time to respond to the change of the system state. According to the neural network, the virtual inertia, the damping coefficient and the angular velocity compensation amount are adaptively adjusted, and whether parameters accord with criteria is compared, so that the input parameters are corrected, the influence of disturbance on the system frequency and the output active power is reduced, the dynamic response process of the system is improved, and the stability of the system is improved. And system output power distribution errors and overshoot caused by a rotor motion equation are reduced.

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 an optical frequency comb repetition frequency locking device and method based on automatic power control, and relates to the technical field of optical frequency combs, the device comprises an optical frequency comb optical system, an optical fiber length automatic control system and an automatic power control system, the optical frequency comb optical system is used for generating optical frequency comb repetition frequency, the optical fiber length automatic control system locks the optical frequency comb repetition frequency output by the optical frequency comb optical system, and the automatic power control system is used for adaptively adjusting the signal power in a corresponding link when the optical frequency comb optical power or the reference source power changes. The input power of the mixer local oscillator and the radio frequency port is maintained at the preset power; according to the technical scheme of the invention, the stability and accuracy of the input power of the radio frequency and local oscillation port of the mixer are improved, the suppression of noise in a link is enhanced, a phase-locked loop of an optical fiber length automatic control system can be maintained in an optimal working state for a long time, and the practicability of an optical frequency comb product is improved.

The invention relates to the technical field of organic light-emitting display data processing, in particular to a high-resolution organic display driving waveform generation method, which comprises the following steps of: dividing a pixel matrix into space blocks through distributed parameter analysis, extracting parasitic parameters in parallel by utilizing GPU (Graphics Processing Unit) nodes, and constructing a cross-block coupling model; generating a block parasitic parameter mapping table and a feature vector matrix; generating a segmented waveform parameter set containing curvature parameters based on the residual charge quantity data and dynamic gray scale segmented regulation and control; calling the brightness and voltage response data to execute nonlinear brightness correction, and generating a compensation pulse parameter in combination with a light intensity feedback loop; multi-mode driving strategies are classified and switched according to display content features, time sequence faults are eliminated through phase synchronization of a phase-locked loop, parasitic effect interference and brightness sudden change overshoot are effectively suppressed, gray scale compensation precision and refresh rate collaboration are improved, and display uniformity and dynamic picture smoothness are enhanced.

The invention relates to the technical field of permanent magnet synchronous motor control. The invention provides a permanent magnet synchronous motor adaptive high-order terminal sliding mode observer control method. The method comprises the following steps: establishing an expansion equation of a motor under an alpha-beta two-phase static coordinate system; designing a high-order terminal sliding mode surface based on the extension equation; designing a self-adaptive gain; designing a current signal control law and a back electromotive force signal control rate of the high-order terminal sliding mode surface based on the adaptive gain, the expansion equation and the high-order terminal sliding mode surface; obtaining constraint conditions of the adaptive gain and the control gain k; defining an expression of the adaptive gain; designing an adaptive high-order terminal sliding mode observer based on a current signal control law and a back electromotive force signal control rate; acquiring an electrical angular speed and a rotor electrical angle based on an orthogonal component phase-locked loop method; and controlling the operation of the motor based on field-oriented control and space vector pulse width modulation. According to the invention, the control system can maintain robustness and high-precision output at the same time under the high dynamic response requirement.

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 relates to a phase-locked loop circuit, a clock generator, a chip and electronic equipment, and the phase-locked loop circuit mainly comprises a phase frequency detector which is used for generating a phase detection output signal according to the phase of a reference clock signal and the phase of a feedback clock signal; the proportional path module is used for generating a first control current according to the phase discrimination output signal; the integral path module is used for generating a second control current according to the phase discrimination output signal; the current control oscillation module is used for generating a clock output signal according to the first control current and the second control current; and the feedback frequency divider is used for obtaining a feedback clock signal through frequency division of the clock output signal. According to the phase-locked loop, the advantages of the analog charge pump phase-locked loop and the full-digital phase-locked loop are combined, the generation of a high-performance clock which is small in area, high in bandwidth, stable in loop and low in quantization noise is facilitated, the applicability of the phase-locked loop to the high bandwidth requirement is facilitated, the quantization noise is reduced, and the performance of the phase-locked loop is improved. And unconditional stability of the phase-locked loop is realized theoretically.

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.

A method and apparatus are provided for processing a GNSS signal received at a receiver. The GNSS signal may be tracked in different ways in two or more respective operation modes. A first epoch is processed according to a first operation mode. In this mode, a carrier phase of a local carrier signal is controlled to track the carrier phase of the GNSS signal using a phase locked loop. A second epoch is processed according to a second operation mode. In this operation mode, the carrier phase is controlled based at least in part on at least one Doppler estimate. The at least one Doppler estimate depends on inertial measurements made at the receiver.

The invention provides a novel clock control method and system based on FPGA, and relates to the technical field of signal processing. The system provided by the invention comprises: a VCXO voltage-controlled crystal oscillator, a digital-to-analog converter, a PLL phase-locked loop module, a DDMTD measurement module and an adaptive clock control module. The phase-locked loop is implemented, a phase detection algorithm and a clock control algorithm are executed based on a single FPGA chip, and the hardware design complexity is low. The invention uses a digital dual-mixing time difference method (DDMTD) to measure and obtain a clock phase detection result, and cooperates with a dynamic PID clock control algorithm to quickly adjust the local clock frequency, so as to realize the fast tracking and locking of the frequency and phase between the local clock and the clock source. The dynamic PID clock control algorithm of the invention dynamically adjusts the parameter P of the PID algorithm in real time according to the state, the clock frequency deviation and the clock phase difference, so that the algorithm has the advantages of stronger locking ability, shorter convergence time and faster response.