21 results about "Grid synchronization" patented technology

The invention belongs to the technical field of power grids, and particularly relates to a hydrogen fuel cell grid-connected inverter fault test and ride-through method. Comprising the following steps: S1, simulating three-phase symmetrical voltage drop, inter-phase voltage drop and single-phase voltage drop of a power grid through a low-voltage fault generation device; s2, collecting the voltage of a power grid through a high-precision voltage sensor, and when the voltage of the power grid drops, judging whether the system needs to carry out low-voltage ride through at the moment according to a distributed energy low-voltage ride through curve; and S3, when the system needs to carry out low-voltage ride-through, a dual-second-order generalized integrator pre-filtering phase-locked loop (DSOGI-PLL) is combined with grid-connected point voltage full-feedback compensation, negative-sequence components generated by symmetric and asymmetric drop of the power grid voltage are eliminated, and current impact suppression and negative-sequence current elimination are realized. The problem of power grid synchronization under the condition of power grid voltage drop is finally solved.

The application provides an improved power backup control method and system based on frequency power angle feedback, and relates to the technical field of power electronic generation and conversion. The method comprises the following steps: a front stage controls the output power of a photovoltaic system through a power control loop; a rear stage controls the grid synchronization, DC side voltage and output power of a converter through a synchronization loop, a direct voltage loop and a voltage and current inner loop respectively; the improved control adjusts the reference power of the rear stage synchronization loop by feeding back the difference between the output frequency of the synchronization loop and the rated frequency of the power grid to the input of the synchronization loop; the output power of the photovoltaic system is adjusted by feeding back the difference between the output frequency of the synchronization loop and the rated frequency of the power grid to the front stage; the output power of the photovoltaic system during a fault is adjusted by feeding back the power angle to the front stage during the fault, and the output power of the converter is adjusted by feeding back the power angle to the input of the rear stage synchronization loop. The application can improve the transient stability of the system, reduce the damage risk of the converter and improve the service life of the system.

The present application relates to the technical field of energy storage, and particularly relates to an energy storage black start system and a control method thereof, the system comprising a physical layer, a coordination control layer and a network communication layer; the physical layer comprises at least one black start power module, at least one load control module and at least one grid synchronization module, the coordination control layer comprises a centralized system management unit and a local autonomous controller, and the network communication layer is a star-shaped heterogeneous redundant network based on a time-sensitive network, and is used for realizing data interaction between the coordination control layer and the physical layer. The present application avoids the whole black start failure caused by single point failure and the start interruption caused by the mismatch between the preset plan and the actual situation, improves the success rate of black start, guarantees continuous high-quality power supply to sensitive loads, enhances the robustness under incomplete or delayed communication, ensures the completion of cross-layer instruction transmission and state synchronization within milliseconds, and prolongs the service life of equipment.

The invention relates to a VSG stability evaluation and grading current limiting method based on fault power angle characteristics. The method comprises the following steps: carrying out transient stability quantitative evaluation on current amplitude limiting control and transient virtual impedance based on an equal area criterion, and generating optimization design suggestions of the current amplitude limiting controller and the transient virtual impedance; generating a power grid fault judgment logic containing a buffer area as an intermediate state based on the optimization design suggestion; respectively generating power outer ring overcurrent limiting strategies under the condition of power overload and the condition of fault ride-through; internal current limiting strategies including transient virtual impedance current limiting control and apparent current amplitude limiting control are generated respectively; and designing and generating a current-limiting state machine based on a power grid fault judgment logic, a power outer ring overcurrent limiting strategy and an internal current-limiting strategy to realize graded current limiting. According to the invention, dynamic switching of the current limiting state is realized through the adaptive power reference and impedance adjustment mechanism, and the fault current is effectively suppressed without affecting the synchronization capability of the power grid.

This invention discloses a grid-connected / off-grid control method and system for low-voltage power supply, applied in the field of power grid-connected / off-grid technology. The method includes: transforming and decomposing acquired main power source data and backup power source data to obtain a frequency deviation value; determining a frequency synchronization accuracy value based on the frequency deviation value; extracting the rotational speed sampling value from the backup power source data and the grid synchronization rotational speed value from the main power source data, and determining a slip ratio based on the rotational speed sampling value and the grid synchronization rotational speed value; inputting the frequency synchronization accuracy value and the slip ratio into a constructed grid-connected / off-grid control model to obtain a real-time phase compensation angle; sequentially performing phase lead compensation processing and torque conversion processing on the real-time phase compensation angle to obtain an electromagnetic torque correction amount; and obtaining a grid-connected / off-grid control strategy for low-voltage power supply based on the electromagnetic torque correction amount. The method provided by this invention can achieve stable grid-connected / off-grid control.

The present application relates to the technical field of digital twinning, in particular to a photovoltaic inverter state simulation method based on digital twinning, which comprises the following steps: establishing a digital twinning architecture of a physical entity, and obtaining internal operation state and grid-connected point electrical characteristic data; establishing a phase-locked loop simulation unit, calculating closed-loop parameters and their time variation rate to generate grid synchronization simulation state sequence; establishing a state characteristic evolution unit to fuse time sequence characteristics, extract transient deviation, and construct health factor sequence; inputting a pre-trained time sequence deep learning network to calculate degradation probability distribution, and outputting residual life simulation prediction trajectory through self-recurrence algorithm iteration. The present application deeply couples and correlates the soft control stress of virtual space and the hard physical operation waveform of entity, overcomes the defect of multi-dimensional data isolation, and provides a probabilistic state deduction mechanism for inverter life evolution under complex transient operating conditions.

This invention provides a grid synchronization frequency-locked loop based on a dual generalized integrator filter (GIMF), belonging to the technical field of grid voltage and frequency signal detection and extraction. Addressing the shortcomings of conventional frequency-locked loops' poor frequency-locking performance under non-ideal grid conditions, this invention proposes a grid synchronization frequency-locked loop based on a dual GIMF. To enhance the frequency-locked loop's anti-disturbance performance, this invention designs a generalized integrator filter capable of filtering out the fundamental negative-sequence component of the grid, and thereby constructs and designs a frequency-locked loop based on the dual GIMF with DC offset cancellation function. Two frequency-locked loops based on the dual GIMF are connected in parallel to form a parallel dual GIMF frequency-locked loop. This designed frequency-locked loop is then incorporated into a three-phase grid-connected phase-locked loop (PLL), achieving the goal of accurately acquiring the grid voltage frequency and phase under non-ideal grid conditions. This invention is mainly used in grid-connected synchronization processes under non-ideal grid conditions.

The present application belongs to the field of large high-voltage transformer bushing voltage monitoring, and particularly relates to a novel electromagnetic bushing voltage divider, which comprises sequentially connected voltage input unit, step-down transformer T1, amplitude and phase modulation unit, double-winding output isolation transformer T2 and voltage output unit; the secondary coil of the step-down transformer T1, the output end of the amplitude and phase modulation unit and the output end of the voltage output unit are respectively connected with different terminals on terminal block P1. The present application is installed at the voltage tap part of the bushing, and through the adjustment of the switch state of the bushing voltage divider adjustment switch group, the secondary output voltage of the voltage divider is linearly proportional to the primary voltage borne by the bushing, the voltage division precision of 1 ‰ can be realized, the phase precision can be within 0.05° deviation, and further, the signal can be provided for grid synchronization, and the primary voltage can be monitored.

The application provides a grid synchronization control method, device, equipment and medium of a photovoltaic inverter, comprising: collecting three-phase voltage signals at a grid point of common connection in real time, and preprocessing the three-phase voltage signals to obtain q-axis voltage residuals; serializing sampling the q-axis voltage residuals to construct a short-time phase deviation time sequence; inputting the short-time phase deviation time sequence into a pre-trained recurrent neural network model to obtain a predicted phase angle increment; based on the predicted phase angle increment, combining a photovoltaic grid-connected working condition, and calculating a synchronization phase angle; and based on the synchronization phase angle, controlling the grid synchronization phase of the photovoltaic inverter. The phase deviation is predicted through the recurrent neural network, the phase error problem caused by the lag of the traditional PI control is overcome, and the accuracy and stability of the grid synchronization of the photovoltaic inverter are effectively improved.

This invention provides an integrated device and method for concrete 3D printing based on mesh-based synchronous reinforcement, relating to the field of concrete 3D printing equipment. It addresses the problems of low integration, discontinuous mechanical properties, and low automation levels caused by the separation of reinforcement and printing processes in existing concrete 3D printing. The device includes a concrete conveying and printing module and a mesh-based synchronous reinforcement module. The concrete conveying and printing module includes a material cylinder, a material transfer channel, and a diversion nozzle. The mesh-based synchronous reinforcement module is connected to the diversion nozzle. The diversion nozzle contains a mesh channel and symmetrical diversion channels. After being diverted, the concrete wraps around the flexible steel mesh conveyed by the mesh channel at the confluence printing port, achieving synchronous printing and reinforcement. The method achieves intra-layer and inter-layer mechanical continuity by controlling the cross-layer protrusion of the steel mesh to form overlaps. This invention achieves integrated automation of printing and reinforcement, improves the overall mechanical properties of concrete components, reduces post-processing, and adapts to complex bending printing paths.

The invention relates to the technical field of port intellectualization, and discloses a port energy storage system multi-time scale capacity configuration method, which comprises the following steps: in an offline stage, according to an innovative hybrid electro-magnetic arrival calculation (HEAC) theory, constructing a security certificate library containing HEAC fragments; in the online stage, early features of synchronous measurement data of a grid-connected point are matched with a security certificate library in real time, and a time type energy floor curve for real-time control is generated; and finally, applying a demand integral obstacle guarantee (DICB) control law to provide deterministic safety guarantee for the super capacitor, meanwhile, applying an energy-deadline feasibility release (EDE) criterion to carry out energy routing of risk perception on the lithium battery, cooperatively regulating and controlling an energy storage unit according to an energy floor curve, and finally determining an operation period control scheduling table and a capacity configuration result list. Therefore, safe, economical and refined configuration and scheduling of the port energy storage system under multiple time scales are realized.

1. Name of the product in this design: Music playback recording component for a graphical user interface for recording music playback behavior in electronic devices. 2. Purpose of this design: An electronic device. 3. The key design features of this product are: the parts in the graphical user interface, and the parts not marked with dotted lines are the parts for which protection is required. 4. The picture or photo that best illustrates the key design points: Design 1 front view. 5. Design 1 is designated as the basic design. 6. Purpose of the graphical user interface: The overall appearance design of the interface is used to display the device homepage, the component for recording music playback behavior in the application, the component's functions and interactions, etc.; the partial appearance design of the interface is used to display the component for recording music playback behavior in the application, the component's functions and interactions, etc. 7. Human-computer interaction method of graphical user interface: In the main view of Design 1, the grid in the widget synchronously displays the daily music listening behavior records in the application. When a music playback record is detected on the same day, the corresponding grid will change accordingly. Users can also click the play control to play music. Design 2 uses the same human-computer interaction method as Design 1, and there is currently no record of listening to music. Design 3 uses the same human-computer interaction method as Design 1. When the listening behavior grid records an achievement, a preset grid image style (such as a heart shape) is displayed. In the main view of Design 4, the grid within the widget synchronously displays the daily music listening behavior records and music listening statistics for the application. When a music playback record is detected for the day, the corresponding grid will change accordingly, and users can also click the play control to play music. Design 5 uses the same human-computer interaction method as Design 4, and there is currently no record of listening to music. Design 6 uses the same human-computer interaction method as Design 4.

The invention discloses a harmonic suppression method and system under a high background harmonic condition, and the method comprises the steps: carrying out the wavelet transformation of an input power grid voltage signal, and extracting the amplitude information of each harmonic in real time; dynamically determining a target harmonic set which needs to be suppressed at present through a preset threshold judgment mechanism according to the extracted amplitude information of each harmonic; for each harmonic in the target harmonic set, synchronously executing harmonic suppression and phase compensation operation; sending the signal subjected to harmonic suppression and phase compensation into a phase-locked loop to obtain a power grid synchronous phase; the system provided by the invention comprises an extraction module, a determination module, a compensation module and a suppression module, and provides a highly purified input signal for the phase-locked loop, so that the phase-locked loop can still maintain rapid and overshoot-free high-precision phase locking under serious harmonic pollution; and the operation stability and the electric energy quality of the grid-connected inverter in a complex power grid environment are remarkably improved.

The application discloses a grid-connected inverter stability analysis method and device, the method comprises the following steps: according to the circuit structure of the grid-connected inverter system in the dq domain, a small signal model of the grid-connected inverter system is established in the controller dq coordinate system; the latch voltage of the control loop of the grid-connected inverter system in the controller dq coordinate system is calculated; according to the conversion relationship between the latch voltage of the phase-locked loop control loop, the controller dq coordinate system and the grid dq coordinate system, the grid synchronization small signal model of the grid-connected inverter system in the control dq coordinate system is obtained; according to the grid synchronization small signal model, the loop gain is calculated and the synchronization stability of the grid-connected inverter system is obtained. By adopting the application, the stability margin of the system can be identified through the constructed single-input single-output grid synchronization small signal model, and the stability of the grid-connected inverter can be improved.

The invention discloses a common-bus photovoltaic energy storage AC micro-grid simulation model construction method, and the method comprises the steps: constructing a micro-grid system architecture through cooperation of four core modules, and defining a simulation target; according to the micro-grid system architecture, performing digital modeling on each functional module of the micro-grid, and constructing a simulation model; setting an initial parameter of the simulation model and a simulation scene for multi-experiment comparison; the simulation model is optimized according to the multi-experiment contrast result, the step S300 is repeated for the optimized simulation model, and a final micro-grid simulation model with qualified accuracy is obtained. And realizing accurate grid-connected synchronization through a PLL phase-locked loop according to the micro-grid simulation model. The model solves the problems of photovoltaic output fluctuation, bus voltage instability, inverter harmonic pollution and the like, is high in simulation precision and fast in dynamic response, can accurately simulate system operation characteristics under complex working conditions, provides reliable support for engineering design, parameter optimization and stability verification of a common-bus photovoltaic energy storage micro-grid, and has a wide application prospect. The method is suitable for distributed photovoltaic power stations and other scenes.

The application discloses a novel power distribution network optimization coordination control method and device based on full-cycle grid-connection pre-synchronization under feeder fault, a medium and a product, relates to the field of power distribution network coordination control, and the method comprises the following steps: monitoring the working state of each AC feeder in real time, and determining the operation state of the power distribution network system according to the working state; in the autonomous operation state, when the fault of the AC feeder corresponding to the AC port of any voltage source converter is cleared and the grid-connection signal is received, the grid-connection pre-synchronization starting instruction is sent to the AC ports of all voltage source converters at the same time; based on the grid-connection pre-synchronization starting instruction, each voltage source converter executes the multi-port full-cycle grid-connection pre-synchronization control strategy, the voltage source converter receiving the grid-connection signal executes the grid-connection operation, and the voltage source converter not receiving the grid-connection signal keeps the off-grid operation state. The application can realize the smooth transition of the island to the network without disturbance after the feeder fault is cleared.

The invention discloses a multipath power supply switching and synchronous control system suitable for an optical storage micro-grid, and the system comprises an acquisition module which is used for obtaining the electrical parameter information of each power supply end, and the electrical parameter information at least comprises the amplitude, phase, power direction and harmonic content of voltage and current, and is transmitted to a central processing unit; the synchronous clock is used for providing a time synchronization signal so as to support power supply time sequence and fault analysis; the central processing unit is used for receiving the electrical parameter information and the micro-grid operation mode signal, dynamically selecting a control strategy according to the micro-grid operation mode, and generating a circuit breaker opening and closing control instruction; and the synchronous closing measurement and control device is used for collecting voltage analog quantity and executing microgrid synchronous judgment switching grid connection. The central processing unit receives signals for comprehensive analysis and judgment, switching judgment and synchronous grid-connected control are carried out on the mains supply, the diesel generator and the micro-grid, and it is ensured that switching power supply of multiple power sources including the micro-grid is accurate and reliable.

The application belongs to the technical field of power electronics and power grid synchronization, and discloses a frequency adaptive sliding mode observer phase-locked loop for power grid synchronization, which comprises a quadrature signal generator based on a sliding mode observer, a phase detector, a loop filter, a voltage-controlled oscillator and a frequency feedforward branch, and the loop filter is a PI controller; the proportional coefficient of the PI controller is Kp; the integral coefficient of the PI controller is Ki; and the frequency estimation value of the phase-locked loop is ω0; the frequency feedforward branch is used for returning the frequency reference of the quadrature signal generator to the quadrature signal generator; and the phase-locked loop can adapt to frequency changes and ensure high-precision power grid synchronization technology, so as to meet the strict demand of MEA power grid on real-time state estimation.

The invention belongs to the technical field of electronic power equipment control, and particularly relates to a power grid synchronization system and method based on an improved SOGI and a self-adaptive phase-locked loop, and the system comprises a signal collection module, an improved SOGI module, a positive and negative sequence separation module, a self-adaptive phase-locked loop module and a synchronous output module. A high-precision orthogonal fundamental wave signal is generated through an improved SOGI structure, rapid separation of positive and negative sequences is achieved in combination with complex power conversion, the frequency is dynamically adjusted through a self-adaptive phase-locked loop based on a positive sequence component, and finally an accurate synchronous phase angle is output through integral operation. According to the method, the problems of insufficient synchronization precision, slow dynamic response and poor anti-interference capability of the traditional phase locking technology under the conditions of power grid frequency fluctuation, voltage imbalance and phase sequence disturbance are effectively solved, and the synchronization stability and reliability in a complex power grid environment are remarkably improved.

The invention discloses a control method and device of energy storage equipment, the energy storage equipment and a storage medium, and the method comprises the steps: responding to a power-on instruction, and determining a current operation mode according to a power grid state; when the battery state is a normal state, controlling the battery converter to start the direct current bus according to the target stable voltage corresponding to the mode; when the real-time voltage of the direct-current bus reaches the voltage stability condition and the current operation mode is a grid-connected operation mode, starting an inverter and executing power grid synchronization; and after the power grid synchronization is completed, the relay is closed, and the inverter is controlled to carry out bus voltage stabilization through the grid-connected current. Through the above mode, the automatic matching of the power grid state response and the operation mode is realized through the staged system state switching logic and the battery priority bus voltage stabilization strategy, the stability and reliability of the starting and operation of the energy storage system and the adaptability of the energy storage system to the power grid are effectively improved, and the reliability of the energy storage system is improved. And optimal control and efficient energy conversion of the multi-port hybrid inverter of the energy storage system are ensured.

The invention provides a control method for synchronous grid connection of a thermal energy storage system and a power grid, belongs to the technical field of thermal energy storage systems, and realizes rapid synchronous tracking by constructing a self-adaptive phase-locked loop controller adopting a fuzzy control algorithm and combining with a feed-forward compensation mechanism. A heat storage power prediction model based on a heat transfer differential equation is established to provide a prospective control basis, a sliding mode variable structure power controller is designed, power fluctuation is eliminated by adopting a reaching law method, and a neural network control model based on progressive network growth and element gradient optimization is constructed to realize intelligent multi-target coordination optimization. Meanwhile, power factor compensation control and an electric energy quality comprehensive treatment strategy are established to guarantee grid-connected electric energy quality, and finally safe and reliable operation of the system is ensured through a system operation state evaluation mechanism and a standby control strategy, so that the technical problems of response lag and insufficient control precision during synchronous grid connection of the thermal energy storage system and the power grid are solved.