22 results about "Virtual synchrony" patented technology

The invention discloses a method for improving stability of a network-forming converter by considering voltage and phase transients, which solves the problem of over-current control blind areas existing at the initial stage of a fault and at the moment of clearing in a traditional single current limiting method and overcomes the defect that the stability is sharply deteriorated when a traditional strategy is used for coping with a composite fault. The method comprises the following steps: S1, obtaining a virtual synchronous machine swing equation under a synchronous rotating coordinate system and an equivalent circuit model under the action of a circular current limiter; and S2, obtaining a nonlinear relation between the output power and the power angle of the converter, and analyzing a transient stability domain of the converter during a fault period. And S3, obtaining a mixed current limiting strategy, deducing an equivalent circuit model corresponding to the strategy, and further obtaining an output power expression corresponding to the strategy. And S4, obtaining a power damping term acting on an active power control loop, further obtaining a synchronization stability improvement strategy, and deducing a closed-loop model describing the system at the moment.

The invention relates to the technical field of data processing, in particular to a multi-view image acquisition fault automatic identification method for rail transit maintenance, which comprises the following steps: acquiring data and processing the data to generate fusion data; processing the fused data to generate a virtual synchronization frame sequence; inputting the aligned multi-view image sequence into a meta-learning feature extraction network coupled with physical prior for feature fusion and time sequence modeling to generate fault feature representation; constructing a digital twin model to generate a fault simulation sequence with labels, and outputting a fault mode recognition result through dynamic time warping comparison; an evidence theory is adopted to fuse a fault identification result, a similarity score and sensor time sequence data to calculate a reliability interval, and image acquisition parameters are dynamically adjusted through reinforcement learning according to the reliability interval to complete system self-optimization. According to the method, the technical problem that time synchronization errors of multi-view image acquisition cause feature time sequence confusion in a deep learning model is solved, and the false alarm rate of fault dynamic identification is reduced.

The invention discloses a low-voltage transformer area electric energy meter time synchronization method and system based on swarm intelligence, and relates to the technical field of intelligent power grid and power distribution automation. The method comprises the steps that a transformer area acquisition terminal issues reference time, and each electric energy meter collects neighborhood information through neighbor electric energy meter bidirectional message exchange; jointly estimating the clock skew and the drift rate by adopting a consistency algorithm; introducing a time-varying weight calculated according to SNR, a message success rate and historical stability to suppress the influence of an inferior link and an abnormal node; the virtual synchronization time is output through software compensation on the service side; and adjusting the synchronization period interval and the convergence step length in a linkage manner according to a double-threshold self-adaptive rule. According to the scheme, deviation and drift rate rapid convergence and stable noise suppression are realized in a time-varying and easy packet loss environment, communication energy consumption is reduced, time jump caused by hardware callback is avoided, and the method has the advantages of high precision, strong robustness and large-scale deployment.

The invention provides a self-synchronization control method, system and equipment for an isolated network dominated by a network construction type power supply, and a medium. Comprising the following steps: calculating an altitude correction factor based on a site altitude and an air density so as to correct a judgment threshold and frequency and voltage reference tolerances; judging an isolated network state based on the frequency deviation, the voltage deviation and the communication link quality; in an isolated network, calculating an output angular frequency and an equivalent potential amplitude with a droop characteristic based on a virtual synchronous machine algorithm, and taking the output angular frequency and the equivalent potential amplitude as control references of a network construction power supply; in a weak communication environment, consistency control is carried out on multiple power supply phase angles, and virtual impedance is introduced to suppress parallel circulating current; dynamically adjusting the virtual inertia and damping according to the local frequency difference and the change rate thereof, and continuously tightening the allowable deviation according to the link health degree until the communication is recovered; and after the communication is recovered, evaluating and completing grid connection. According to the method, the safety margin is guaranteed through high-altitude pre-correction, the dynamic characteristics are adaptively adjusted and improved, and parameter self-correction is realized through online identification-evaluation-limited updating.

The invention discloses an active support control method and device for a grid-connected system containing a virtual synchronous machine. The method comprises the following steps: acquiring a grid-connected point voltage amplitude of each virtual synchronous generator in a grid-connected system and reactive power injected into the grid-connected system based on a wide-area measurement system; performing preliminary support control on the grid-connected system according to the grid-connected point voltage amplitude and reactive power of each virtual synchronous generator and a preset stability criterion set; determining a key branch of the grid-connected system after the grid-connected system is subjected to preliminary support control; and judging whether the branch parameters of the key branch meet a preset key branch criterion or not, if so, proving that the grid-connected system is recovered to be stable, otherwise, searching a minimum cut set range containing the key branch, and taking an active splitting measure on the branch in the minimum cut set range.

The invention discloses an additional stabilizer design-based weak power grid operation stability enhancement method for a network construction type converter, and belongs to the technical field of stability analysis and control of a new energy power system. The method comprises the following steps: constructing a network construction type converter overall control structure of a network construction type converter grid-connected system by adopting a virtual synchronous control method, and constructing an optimization strategy of an additional stabilizer of the network construction type converter overall control structure, and the stability control voltage output of the power system is completed through the overall control structure of the network-forming converter added with the optimization strategy. According to the method provided by the invention, the problem of low-frequency oscillation under a weak power grid condition can be effectively suppressed on the premise of not changing a main body control framework of the network construction type converter. The design method not only improves the overall stability and dynamic performance of the grid-connected system of the network-forming converter, but also can provide theoretical basis and engineering reference for control parameter optimization and system stability design under the weak network condition.

The invention discloses an offshore wind power flexible direct output control method based on transmitting end V / F network construction and a receiving end virtual synchronous machine. A transmitting end converter adopts dynamic V / F network construction control to generate a network construction angle, and electromagnetic wave propagation time delay and wave impedance are calculated based on distribution parameter characteristics of a long-distance direct current transmission line; phase compensation is performed on the network construction angle, and voltage compensation is performed on the output reference voltage, so that phase deviation and voltage attenuation caused by long-distance transmission can be offset; the receiving-end converter is controlled by a variable-parameter virtual synchronous machine, the inertia coefficient of the receiving-end converter is adjusted in real time according to double feedback of the amplitude and the change rate of the frequency deviation of an alternating-current power grid connected with the receiving-end converter, and the damping coefficient is dynamically corrected through a proportional-integral-differential feedback mechanism; the transmitting-end converter dynamically adjusts the network construction frequency through frequency-DC voltage coordination control, and the fan of the offshore wind power plant adjusts the active power output according to the DC voltage change rate, thereby achieving the cooperative operation of the system.

The invention discloses a multi-target collaborative asymmetric fault ride-through method based on network construction type control, and is applied to the technical field of new energy power generation and grid connection. According to the method, on the basis of a virtual synchronous machine VSG control architecture, a current instruction calculation module is introduced, a positive sequence component of power grid voltage is extracted through a positive and negative sequence separation algorithm, and an instruction for suppressing negative sequence current is generated; the rotational inertia and the damping coefficient of the VSG are dynamically adjusted, and parameter abrupt change is eliminated by a smoothing filter so as to improve the stability of the system frequency; a current inner loop control and amplitude limiting mechanism based on feed-forward decoupling effectively suppresses transient current impact and guarantees equipment safety. Therefore, based on the measures, the transient system safety and stability of the new energy power generation grid connection in the asymmetric fault period are realized, and the voltage source network construction characteristic of the converter is reserved.

The invention provides a new energy transient overvoltage control method, device and equipment and a storage medium, the method is applied to a controller of a power supply system, a networking SVG connected with the controller in the power supply system is connected with a new energy power supply system through a passive filter, and the method comprises the following steps: determining a virtual synchronization phase angle according to a power synchronization loop of the networking SVG; establishing a dq rotating coordinate system based on the virtual synchronous phase angle; if it is determined that the new energy power supply system enters a transient overvoltage state according to the collected three-phase voltage, the dq rotating coordinate system and a preset voltage threshold value, a d-axis reference current and a q-axis reference current are determined according to the three-phase voltage and a dq-axis cross control strategy; and performing space vector pulse width modulation based on the d-axis reference current and the q-axis reference current, and determining a control signal for controlling the network-forming SVG. According to the invention, the new energy power supply system can be timely determined to enter the transient overvoltage state and controlled, and the safety is improved.

The invention discloses a renewable energy converter-oriented distributed control method and system. The method comprises the following steps of S1, establishing an alternating current micro-grid system comprising a plurality of renewable energy converters, a sparse communication network and a multi-agent system; s2, calculating to obtain frequency and active power; s3, constructing a distributed event triggering secondary control strategy; s4, modulating the voltage and the frequency into a three-phase PWM switch control signal, and applying the three-phase PWM switch control signal to the renewable energy converter; according to the renewable energy converter distributed control method disclosed by the invention, the frequency deviation caused by virtual synchronous machine control is eliminated, so that the active power distribution achieves an expected effect; according to the disclosed event triggering secondary control method, calculation and communication burdens are effectively reduced, and stable operation of the system in a load fluctuation scene is guaranteed.

The invention relates to the technical field of signal monitoring, in particular to a multi-mode sensing forest fire danger monitoring method, system, equipment and medium, and the monitoring method comprises the steps: firstly building a fire danger flow field monitoring model through meteorological time sequence data, calculating a fire scene displacement vector, and carrying out the space coordinate transformation of remote sensing data; generating a virtual synchronous satellite feature map aligned with the current moment; secondly, a confidence coefficient weight matrix is generated based on an information entropy graph of the inspection image, adaptive feature fusion and residual error correction are carried out in combination with a physically guided gating fusion neural network, and an accurate fire danger state is obtained; and finally, the flow field model is reused to deduce a spreading boundary, and a rescue target is positioned through heterogeneous transfer learning to plan a path. According to the invention, the space-time deviation of multi-source data is effectively eliminated, and the robustness of fire danger monitoring and the accuracy of rescue decision in a complex environment are remarkably improved.

The invention discloses a rail transit multi-station collaborative energy storage virtual inertia response method and system, which are applied to energy storage stations dispersedly deployed along a rail transit line. The method comprises the following steps: generating local active, reactive and harmonic compensation instructions at each station through an integrated virtual synchronous machine control model based on a locally monitored energy storage state and grid-connected point electrical quantity information; collecting local state information of each station through an inter-station communication network, and calculating global frequency, voltage deviation and harmonic current amplitude by using a weighted average consistency algorithm; and according to the local capability weight of each station, power requirements determined based on the global parameters are shared, a final instruction of each station is generated, and the energy storage converter is controlled to output compensation current. According to the invention, cooperative control of virtual inertia support of multi-station energy storage aggregation and voltage and harmonic suppression is realized, and the problems of equipment redundancy and poor collaboration in a traditional scheme are solved.

The invention relates to a subsynchronous oscillation suppression and parameter optimization method and system based on network construction type energy storage, and the method comprises the steps: carrying out the analysis of a system oscillation mode through building a small-signal state space model of an optical storage grid-connected system comprising a network-following type photovoltaic inverter and a network construction type energy storage converter, and recognizing a subsynchronous oscillation mode; on the basis, a damping path reconstruction method is introduced, and separation and quantitative characterization are carried out on interaction damping between the grid-forming type energy storage converter and the grid-following type photovoltaic inverter. And further, equivalent positive damping provided by the interaction damping in a subsynchronous frequency range is taken as a parameter optimization target, and optimal configuration is carried out on virtual synchronous machine control parameters of the network-forming type energy storage converter on the premise of meeting a system stability constraint condition. The system is used for realizing the method, and the optimized control parameters are applied to the network-forming type energy storage converter control system so as to suppress the subsynchronous oscillation of the optical storage grid-connected system.

The present application relates to the technical field of data processing, and more particularly to a multi-view image acquisition fault automatic identification method for rail transit maintenance, comprising collecting data and processing the data to generate fusion data; processing the fusion data to generate a virtual synchronous frame sequence; inputting the aligned multi-view image sequence to a meta-learning feature extraction network coupled with physical prior to perform feature fusion and time sequence modeling to generate fault feature representation; constructing a digital twin model to generate a labeled fault simulation sequence, comparing and outputting fault mode recognition results through dynamic time warping; using evidence theory to fuse fault recognition results, similarity scores and sensor time sequence data to calculate a confidence interval, and dynamically adjusting image acquisition parameters through reinforcement learning based on the confidence interval to complete system self-optimization. The present application solves the technical problem of feature time sequence confusion caused by time synchronization error in multi-view image acquisition in a deep learning model, and reduces the false alarm rate of fault dynamic identification.

The invention discloses a new energy cluster system-level multi-time scale comprehensive stability control method and system, and the method comprises the steps: carrying out the transient stability hybrid control of a new energy unit at a millisecond level, and carrying out the switching of a virtual synchronous machine and a current source type control mode, and carrying out the self-adaptive hybrid PD feedforward control, so as to deal with a transient fault of a power grid; the second level dynamically optimizes reactive compensation to stabilize node voltage based on real-time data of a wide-area measurement system in combination with particle swarm optimization and reactive discharge effect analysis; constructing an output prediction model at a minute level, and calculating and issuing reference active and reactive power set values of each station through an optimization function; and establishing an information interaction and instruction closed loop among the millisecond-level time scale control, the second-level time scale control and the minute-level time scale control. According to the method, a cooperative control framework is constructed, the existing independent control situation of each scale of equipment under the fault condition is changed, multi-type control resources can be effectively coordinated, and the comprehensive stability of a new energy cluster delivery system is remarkably improved.

The invention relates to the technical field of new energy power generation of power distribution systems in mountainous areas, and discloses a stability control method, system, equipment and medium for a grid-forming type brushless doubly-fed fan, and the method comprises the steps: firstly constructing a BDFIG mathematical model, deducing an active power expression under a fault condition, and determining the quantitative relation between the power grid voltage fault depth and the system stability; secondly, an LESO improvement strategy is introduced into a virtual synchronous control (VSynC) loop, power angle oscillation disturbance is observed and compensated in real time, and the transient stability of the BDFIG grid-connected system is remarkably improved.

The invention provides a small-disturbance stable virtual impedance networking control method and device, and relates to the technical field of power grid control. The method comprises the following steps: according to a pre-established small signal model of a power control ring of a virtual synchronous control grid-forming inverter and a state space model containing grid impedance, determining a critical impedance value of oscillation instability of the grid-forming inverter; obtaining a power grid impedance estimated value, and determining a power grid actual impedance value according to the power grid impedance estimated value and the virtual impedance; and comparing the actual impedance value of the power grid with the critical impedance value, updating a virtual reactance according to a first comparison result to obtain a virtual reactance update value, and outputting the virtual reactance update value to a voltage control loop. According to the method and the device provided by the embodiment of the invention, the stable operation of the grid-forming inverter under the wide-range power grid intensity change is ensured, and the problems of poor adaptability, large disturbance or high cost in the prior art are solved.

The invention discloses a method, a system, equipment and a medium for improving the dynamic frequency modulation capability of a network construction type converter based on a second-order virtual synchronization link, and belongs to the technical field of safe operation of a power system, and the method comprises the steps: collecting the output current, the terminal voltage and the active power instruction value of the converter, and carrying out the calculation to obtain the instantaneous active power of the converter; setting an attention frequency band and calculating a damping ratio, a reference frequency and a reference phase of a second-order virtual synchronization link; calculating an internal potential vector of the converter according to the reference frequency, the reference phase, the output current and the terminal voltage of the converter; performing pulse width modulation on the internal potential vector to generate a control signal acting on the converter; on the premise of keeping the virtual inertia and the damping parameter unchanged, the amplitude-frequency and phase-frequency characteristics of the virtual synchronization link are observed by adopting the Bode diagram, the frequency response characteristics of the virtual synchronization link are optimized by adjusting the damping ratio, and the phase-frequency characteristics at the concerned frequency band are increased, so that the converter has better dynamic frequency modulation capability.

The invention relates to the technical field of cooperative control, in particular to a storage and charging cooperative control method and system based on electric power response and distributed optimization. The method comprises the following steps: acquiring micro-grid operation data; performing flexible load slicing according to the micro-grid operation data to obtain flexible load data; heterogeneous communication time sequence evolution is carried out on the flexible load data to obtain heterogeneous communication data; performing virtual synchronous machine control according to the heterogeneous communication data to obtain synchronous compensation data; and performing collaborative optimization according to the synchronous compensation data to obtain collaborative control data. According to the method, combined modeling is performed on the flexible load response characteristics and the heterogeneous communication time sequence, and a virtual synchronous machine compensation mechanism and distributed collaborative optimization are combined, so that time sequence coordination adjustment between the energy storage system and the charging load is realized, the problems of power overcompensation and control oscillation caused by equipment response difference are effectively reduced, and the system reliability is improved. And the power regulation stability and the storage and charging cooperative control efficiency of the micro-grid in a communication environment are improved.

The invention discloses a new energy station frequency modulation and inertia response optimization method and system, and relates to the technical field of power systems and automation thereof, and the method comprises the following steps: configuring a virtual synchronous machine control strategy for each power generation assembly of a new energy station, and connecting the power generation assemblies into a cluster through a high-speed communication network, the method comprises the steps of establishing an energy sharing mechanism in a cluster, determining the energy providable capability of each power generation assembly for frequency modulation and inertia response, generating a power distribution instruction based on the energy providable capability, outputting compensation power to an energy limited assembly by using an energy sufficient assembly according to the power distribution instruction, and completing optimization of frequency modulation and inertia response. By constructing an energy sharing and cooperative compensation mechanism in the cluster, the problem of insufficient collaboration caused by independent response of each component in the prior art is effectively solved, the collaboration of technical performance and economic benefits is realized, and the economic value of operation of a new energy station is improved while the stability of a power grid is ensured.

The invention relates to a network construction energy storage type DSTATCOM active voltage support method, which comprises the steps of collecting a power grid voltage signal and a distribution network power demand signal, selecting a corresponding compensation mode according to a system compensation demand, obtaining a to-be-compensated current, selecting the corresponding compensation mode according to different scene demands, and then obtaining the to-be-compensated current. Sending the to-be-compensated current obtained in the above step into a current inner loop, obtaining a three-phase sinusoidal modulation signal through a PI controller, controlling the generation of PWM pulses, and further controlling the on-off of a DSTATCOM bridge arm switch tube to form a closed-loop control system. The virtual synchronous control technology is introduced, so that the device has adjustable inertia, the stability in a weak power grid is improved, meanwhile, an active-reactive cooperative voltage regulation strategy based on the optimal power factor angle is introduced into a power outer ring, and according to the power distribution proportion defined by the optimal power factor angle, the optimal power factor angle is adjusted according to the optimal power factor angle. More effective voltage support can be provided for the power distribution network, and meanwhile, the power burden of the energy storage type DSTATCOM is reduced.

This invention discloses a method and related device for islanded operation and seamless recovery of rural microgrids based on dynamic scene recognition and adaptive power coordination, belonging to the field of smart grid and distributed energy technology. Addressing the problems of rural power grids being prone to complete outages, communication-dependent recovery, significant impact, and lack of autonomous operation capabilities during main grid failures, this invention collects and preprocesses local electrical data to construct a net load prediction model for adaptive scheduling of energy storage under islanded conditions; designs a communication-independent main grid recovery self-sensing criterion, and dynamically matches the optimal recovery strategy using a lightweight scene classification model; and employs a virtual synchronous machine and adaptive phase compensation mechanism to achieve low-impact seamless grid connection. This invention significantly improves the power supply resilience and self-recovery capability of rural power grids in weak communication environments, and has the advantages of strong autonomy, low cost, and ease of implementation.