325 results about "Virtual synchronization" patented technology

The invention relates to the technical field of energy storage systems, in particular to a source network load storage coordination control method for multi-configuration network type energy storage coordination operation. According to the technical scheme, the source-network-load-storage coordinated control method for multi-construction-network-type energy storage coordinated operation comprises the following steps: generating a new energy output and load change trend through a dynamic prediction model based on historical power data, real-time load requirements and meteorological information; optimization is carried out to obtain a power generation plan containing a clean energy consumption target and economical efficiency constraints; decomposing the power generation plan into a photovoltaic power adjusting instruction, an energy storage charging and discharging instruction and a load control instruction according to the power grid safety priority, wherein the emergency control instruction is executed prior to the economic dispatching instruction; and controlling parallel operation of a plurality of pieces of networking type energy storage equipment, and realizing multi-machine power distribution and circulating current suppression through a virtual synchronous control technology. And through layered optimization scheduling and multi-machine cooperative control, the new energy consumption capability is remarkably improved, and the phenomenon of abandoning light and wind is reduced.

The invention relates to an offshore energy platform coordinated scheduling method based on multi-energy complementation and hierarchical optimization, which combines multi-energy complementation characteristic modeling, multi-target opportunity constraint optimization and rolling optimization, and realizes offshore multi-energy coordinated scheduling by constructing a hierarchical decoupling optimization and control system. Based on prediction and historical data of multiple types of energy such as offshore wind power, photovoltaic energy and tidal energy, complementarity and flexibility of the energy are quantified, high-quality data support is provided for scheduling optimization, a day-ahead layered optimization model containing renewable energy priority consumption and flexible standby configuration is constructed, and a medium-and-long-term output strategy is formulated. Output of various energy sources is dynamically adjusted through a rolling optimization mechanism, and flexible response to renewable energy fluctuation is achieved. And finally, second-level frequency and voltage support is realized by using a virtual synchronous machine and droop control, and the self-adaptive capability of the system is enhanced. According to the invention, the cooperative regulation capability and operation stability of the offshore platform multi-energy system can be effectively improved, and the dependence on a traditional standby power supply is reduced.

The invention discloses a network construction type inverter for a photovoltaic energy storage system and a virtual synchronous machine control method. The network construction type inverter comprises an inverter power module and a central controller. The central controller is used for collecting power grid operation data in real time and generating a power grid impedance state vector through online impedance identification; and dynamically adjusting virtual inertia and damping parameters of the inverter power module according to the impedance state vector by using an adaptive mapping function so as to realize cooperative control and circulating current suppression between the modules. Performing stability boundary evaluation based on the adjusted parameters, then performing intelligent early warning of the photovoltaic energy storage system, and smoothly switching the operation mode of the inverter power module; according to the invention, through deep integration of a modular hardware architecture and intelligent adaptive control, the inverter has strong autonomous network construction capability, the problems of weak power grid adaptability and transient stability are effectively solved, and the dynamic response and reliability of a photovoltaic energy storage system are improved.

The invention discloses a multi-mode hybrid energy storage cooperative control method and system for a megawatt-level network-building type energy storage power station, and the method comprises the steps: S1, collecting the frequency, voltage amplitude and phase of a power grid, and the charge state and temperature of each energy storage branch, and generating real-time monitoring data; s2, determining an operation mode of the energy storage power station based on a comparison result between the frequency deviation and the voltage deviation in the real-time monitoring data and a preset threshold value; s3, based on the operation mode of the energy storage power station, performing double-layer decomposition on the power instruction through a high-pass filter and a low-pass filter to generate a super-capacitor power instruction and a lithium battery power instruction; s4, generating an internal potential amplitude and a phase angle by adopting a virtual synchronous machine algorithm; and S5, on the basis of the amplitude and the phase angle of the internal potential and the detection result of the power grid connection state, executing switching control of a network construction type control mode or a network following type control mode. The millisecond-second level multi-time scale power optimal distribution is realized; self-adaptive inertia and voltage support is carried out; and island / grid-connected seamless switching is realized.

The invention relates to the technical field of new energy power system control, and relates to a power decoupling method for cooperative control of voltage feed-forward compensation and adaptive virtual impedance. The method comprises the following steps: acquiring a power grid current and a power grid voltage, and calculating a reactive power measured value and an active power measured value of a power grid; virtual synchronous machine control is carried out, and a voltage feed-forward pre-compensation item is introduced into a reactive power control loop; calculating a reactive power control loop after VSG compensation, and obtaining VSG output side voltage and instantaneous angular frequency; self-adaptive virtual impedance control is adopted, a self-adaptive virtual impedance reference value is calculated, line impedance is dynamically adjusted, and a voltage loop input instruction voltage is calculated according to the line impedance; and adjusting the output performance of the inverter according to the instruction voltage. According to the invention, the problem of power fluctuation caused by VSG output voltage amplitude variation is effectively solved, and the dynamic influence of a power coupling item is weakened.

The invention discloses a virtual synchronous direct drive fan subsynchronous oscillation suppression method based on two-stage lagging link phase compensation control. The method comprises the steps that 1, a phase compensation control module formed by connecting two stages of lagging links in series is constructed; 2, performing parameter setting on the phase compensation control module of the two-stage lagging link by using a momentum gradient descent optimization algorithm and a Newton-Rafson iteration method to obtain a set optimized phase compensation control module; and 3, analyzing damping characteristics of the system, and further selecting a proper compensation point to configure an optimized phase compensation control module for suppressing subsynchronous oscillation control of the virtual synchronous direct-drive fan grid-connected system. Through the design and reasonable configuration of the damping compensation module, the damping characteristic correction of the system can be realized, so that the subsynchronous oscillation of the grid construction type direct-driven fan grid-connected system is effectively inhibited, and the system stability is improved.

The invention discloses a cooperative autonomous synchronous networking method for a multi-networking type energy storage converter without communication interconnection. The method comprises the following steps: S1, state perception and estimation based on local measurement: acquiring local electrical parameters in real time by using a sensor, and performing state estimation through an improved Kalman filtering algorithm and a local dynamic model; s2, a cooperation mechanism of the virtual synchronous machine and droop control: combining the virtual synchronous machine with the droop control mechanism, and realizing automatic power adjustment and cooperation work by setting a virtual inertia, a damping coefficient and a droop coefficient; s3, self-adaptive synchronization algorithm: based on the local state estimation and the output of the virtual synchronous machine, adjusting the phase and frequency of the output voltage, and dynamically adjusting synchronization parameters according to the state of the power grid; and S4, detecting a fault by monitoring local electrical parameters and a self state in real time, and automatically adjusting a control strategy and realizing system fault tolerance when the fault occurs.

The invention discloses a grid-connected inverter control method, system and device and a medium. The method comprises the steps of obtaining a power grid operation parameter, a system power instruction and a direct current bus voltage provided by a photovoltaic side hybrid energy storage system; a virtual inertia parameter is dynamically adjusted through an active-frequency control loop of the virtual synchronous machine in combination with an adaptive inertia algorithm, and a virtual rotor angular speed and an active power reference value are obtained through calculation according to a second-order motion equation of the synchronous generator; in combination with a reactive power instruction, a virtual internal potential amplitude is calculated according to a reactive-voltage droop relation through a reactive-voltage control loop of the virtual synchronous machine; and generating a three-phase voltage reference signal of the grid-connected inverter through synchronous rotation coordinate transformation. According to the invention, the dynamic performance, the operation efficiency and the grid-connected stability of the system under complex working conditions are obviously improved.

The invention discloses a voltage source type energy storage small signal stability analysis method based on a virtual synchronous machine. A small signal state space model including active control, reactive control, double closed-loop control and a lithium battery energy storage module is established, a characteristic value analysis method is used for solving a state matrix characteristic root, system stability is evaluated, and an oscillation mode is identified. By drawing characteristic root trajectories of key parameters such as virtual rotational inertia, virtual damping coefficients and double-closed-loop PI parameters, an influence rule of the parameters on system stability is analyzed. According to the method, the dynamic response characteristics of the system can be accurately quantified, theoretical support is provided for control strategy optimization and parameter design of the voltage source type energy storage system, and the stability and reliability of a power grid in a renewable energy source grid-connected scene are effectively improved.

The present invention discloses a charging and discharging control method and system for an electric vehicle based on virtual synchronization, and relates to the technical field of virtual synchronization. The method includes: establishing connection between a power grid and the electric vehicle, and acquiring a charging and discharging operation demand; acquiring, according to the charging and discharging operation demand, a corresponding control instruction and constraint condition, and executing a charging and discharging operation; and providing a human-computer interaction interface for measuring and settling charging and discharging energy, along with authentication. The present invention achieves efficient and coordinated charging and discharging control, precise measurement and convenient authentication, and improves availability and reliability of the system.

The invention discloses a wind and light energy storage power generation distribution control method and system. The method comprises the following steps: acquiring related parameters of a wind and light energy storage system; a multi-target control function is constructed based on a multi-target Harris eagle optimization algorithm, and system constraint conditions are combined in the directions of wind and light output fluctuation suppression, energy storage charge and discharge loss reduction and power grid supply and demand matching degree improvement; monitoring and adjusting the state of charge of the multi-mode hybrid energy storage unit through a wind storage combined wide-area SOC virtual synchronous control strategy, establishing association mapping and determining an initial threshold value; preliminarily distributing a power difference value between wind and light output and a power grid load by using the platform; iteratively optimizing the preliminary distribution power and then outputting target power; and sending a control instruction to realize real-time distribution. The number of the system is six, and all the units work cooperatively. According to the invention, the energy storage resource utilization efficiency and the system operation stability are improved, and the dynamic adaptation capability of the wind-solar energy storage system to the power grid load is enhanced.

The invention relates to an alternating-current trunk line or an alternating-current power distribution network, in particular to a method for improving the stability of a wind power system through combined control of network construction type energy storage and a nine-switch UPQC. The method comprises the following steps: firstly, proposing an active regulation and inertial support control method based on a virtual synchronous machine mechanism for network construction type energy storage; and secondly, by constructing a coordination control framework, dynamic response complementation of the energy storage system and the UPQC under disturbance is realized, so that the overall frequency stability and voltage supporting capability of the system are improved. And finally, building a system model in Matlab / Simulink, setting three typical working conditions of wind power fluctuation, frequency disturbance and serious voltage drop, and carrying out scheme validity verification. Simulation results show that the method can effectively stabilize the wind power output fluctuation, enhance the frequency and voltage support capability, and significantly improve the stability of a wind power system.

The invention relates to a new energy scene collaborative energy compensation system based on multi-energy complementation and a control method. The system comprises a power supply input and conversion module, an energy storage system, a power distribution and energy distribution module, a charging and battery replacement facility and a control system. The power input and conversion module is connected to an alternating current bus through a box-type substation, a photovoltaic panel and a photovoltaic inverter; the energy storage system is connected with an AC-DC bus through a power conversion system and a DC conversion module by utilizing an energy storage battery pack and a mobile power transmission vehicle; the power distribution and energy distribution module transmits electric energy through an AC-DC bus. The charging and battery replacing facility takes power from the AC / DC bus; the control system collects data and dispatches energy through a communication protocol, and cooperates with the power electronic transformer and the virtual synchronous machine control module to realize power grid frequency compensation and voltage stability control. According to the invention, by integrating photovoltaic, energy storage and charging facilities and power grid interaction capability, an intelligent scheduling mechanism is constructed, and multi-energy cooperative control and intelligent scheduling are realized.

The invention relates to the technical field of converter control, in particular to a novel four-level efficient grid-connected system and a control method, and the method comprises the steps: determining the target output power, the target input power, the actual output power and the actual input power of a converter based on a 4L-HCC converter; determining a phase angle and an output voltage amplitude based on a preset virtual synchronous machine control strategy, and converting to obtain a corresponding three-phase reference voltage; performing HCC internal capacitor voltage control on the converter, establishing a corresponding loss function, and determining a reference wave change range corresponding to each switching device on the converter based on actual setting; the corresponding reference wave signal with the minimum loss function derivative is calculated; and carrying out phase shift pulse width modulation on the converter, taking high-frequency triangular waves with different phases as carriers, comparing the calculated reference wave signals with the carriers, calculating the duty ratio of each switching device of the converter and a switch driving signal, and driving each switching device of the converter.

The invention discloses a village island micro-grid virtual synchronous machine parameter optimization and cooperative control method oriented to frequency support, and relates to the technical field of electrical automation, and the method comprises the steps: obtaining village power distribution network parameters and load side parameters, and basic technical parameters of each virtual synchronous machine unit; constructing a standard dynamic model of the virtual synchronous machine based on the obtained parameters; introducing uncertainty integrated design on the basis of the standard dynamic model of the virtual synchronous machine, and performing equivalent aggregation on all the virtual synchronous machines to obtain a virtual synchronous machine uncertainty model; based on the uncertainty model of the virtual synchronous machine, establishing a cooperative control model by taking system frequency fluctuation minimization as a target; and solving the cooperative control model by using a commercial solver, and solving the power of each device. According to the invention, by constructing an optimization and cooperative control mechanism oriented to frequency support, the problem of over-limit of frequency deviation and frequency change rate is effectively suppressed, and the dynamic response capability of the island micro-grid under the condition of sudden load change is improved.

The invention relates to a terminal voltage flexible regulation and control method, and the method comprises the following steps: presetting target voltage parameters which comprise an amplitude value, a frequency and an initial phase angle; calculating a three-phase sinusoidal voltage reference signal based on a virtual synchronous machine algorithm according to the target voltage parameter; according to the three-phase sinusoidal voltage reference signal, generating a driving signal by using pulse width modulation, and controlling the on and off of an IGBT power switch device to generate a three-phase sinusoidal compensation voltage; injecting the three-phase sine compensation voltage into the tail end of a power grid; monitoring the voltage state of the power grid in real time, and calculating the deviation between the actual voltage of the tail end of the power grid and the target voltage parameter; and according to the deviation, adjusting a control parameter in the virtual synchronous machine algorithm, and updating the three-phase sine compensation voltage to compensate the voltage deviation at the tail end of the power distribution network. Voltage deviation can be compensated in time, and the problem of voltage change caused by large fluctuation of electrical load can be effectively solved.

The invention provides a network construction type bidirectional low-harmonic energy storage converter based on virtual synchronous control and an intelligent load identification method thereof, and belongs to the field of power electronics. The converter comprises a power module and a control module, wherein the power module is used for bidirectional conversion and output of electric energy; the control module comprises a virtual synchronous control module and a harmonic suppression control module, and the virtual synchronous control module adopts a virtual synchronous generator technology to realize active / reactive power bidirectional adjustment during electric energy bidirectional conversion of the power module and network construction level voltage and frequency support during electric energy output; and the harmonic suppression module is provided with a parallel QPR controller group (comprising a first QPR controller, a second QPR controller and a third QPR controller) which are used for processing third-time, fifth-time and seventh-time characteristic harmonics respectively and suppressing the characteristic harmonics of the electric energy output side of the power module. According to the invention, the dual modules are arranged in the control module, so that the cooperation of a network construction function and low harmonic output is realized, and the electric energy quality and the system operation stability are effectively improved.

The invention provides a stability analysis method and system for a tracking and networking inverter hybrid system and a medium, and the method comprises the steps: selecting the active power of a tracking inverter and the reactive power of a networking inverter as core variables through working condition variable dimensionality reduction; determining a working condition range in combination with capacity constraint, performing discretization processing, and calculating dq components of voltage and current of an inverter port based on a discrete working condition; discrete impedance models of the two types of inverters are respectively constructed; the influence of a phase-locked loop controller, a current loop controller and a power loop controller is considered in a following network type, and the effect of a virtual synchronous controller, a current loop controller and a voltage loop controller is included in a construction network type; and calculating a closed-loop transfer admittance matrix of the power grid through the discretized impedance of the inverter to realize stability analysis of the hybrid system. According to the method, the modeling complexity is effectively reduced, the stable working areas of the system under different working conditions can be quantified, and an accurate reference basis is provided for stable operation of the hybrid inverter system.

The invention provides a fault voltage support capability quantification and improvement method for a network-constructed converter, and the method comprises the steps: controlling a network-constructed inverter converter through a virtual synchronous machine, and limiting a fault current through employing an annular current limiting strategy under a fault condition; determining the active-power angle and reactive-power angle relation of the constructed network type converter under annular current limiting during the fault period; analyzing fault scenes in which the network-forming converter adopts an annular current limiting strategy under different voltage drop scenes, and quantifying the fault voltage support capability of the network-forming converter; calculating the partial derivative of the reactive power with respect to the power angle, solving an extreme value corresponding to a pole set of the reactive power-power angle equation, and determining a pole corresponding to the maximum extreme value and a corresponding power angle; and on the basis of the poles and the corresponding power angles, power angle amplitude limiting control is applied in a network construction synchronous control link. According to the method, the fault voltage supporting capability of the network-building type converter under different voltage sags can be accurately quantified, and the reactive power output of the network-building type converter during the fault period is remarkably improved through power angle amplitude limiting.

The invention provides a method and a system for suppressing low-frequency oscillation of a network-forming converter under a weak power grid, and the method comprises the steps: obtaining a power grid short-circuit ratio through employing a preset dual-mode identification strategy, adaptively adjusting the control parameters of the network-forming converter through a preset parameter mapping relation, carrying out the stability sufficiency verification of the adjusted control parameters, and obtaining the low-frequency oscillation of the network-forming converter under the weak power grid. After verification is passed, the adjusted control parameters are applied to a virtual synchronous machine control algorithm to execute grid-connected control, low-frequency oscillation characteristics are extracted from monitored grid-connected point frequency signals, and an enhanced suppression mechanism is triggered after the low-frequency oscillation characteristics exceed a threshold value; real-time sensing of power grid intensity, multi-parameter collaborative adaptive adjustment, active monitoring and rapid suppression of low-frequency oscillation and continuous self-learning optimization are realized, stability adequacy check is realized, and the problem of low-frequency oscillation of a grid-forming converter under a weak power grid is effectively solved.

The invention discloses a virtual synchronous machine key parameter optimization method giving consideration to transient power angle stability and short-circuit current suppression. The method comprises the following steps: establishing a VSG dynamic model; analyzing and calculating VSG short-circuit current and transient power angle stability respectively; analyzing key parameters influencing VSG short-circuit current and transient power angle stability by using small signal modeling to obtain a key parameter configuration range; according to the key parameter configuration range and the requirements for short-circuit current suppression and transient power angle stability, a VSG parameter optimization model is designed, and an improved genetic algorithm IGA is used for solving. And it is ensured that short-circuit current is suppressed during the optimized VSG fault period, and the transient power angle is kept stable. The invention aims to realize the effects of transient stability improvement and short-circuit current suppression only by optimizing parameters without adding extra strategies.

The invention relates to the technical field of distributed energy grid-connected control, in particular to an intelligent monitoring ball enhanced distributed power supply coordination pre-synchronization control method and system, and the method comprises the steps: deploying a master intelligent monitoring ball at a grid-connected point, deploying slave intelligent monitoring balls at the output ends of all distributed power supplies, and forming a star-shaped sensing network; based on a multi-objective optimization algorithm, calculating a pre-synchronization target parameter and an adjustment weight of each distributed power supply, and generating a coordination control instruction; the virtual synchronous motor module receives the coordination control instruction, dynamically adjusts a virtual inertia and a damping coefficient, and adjusts output voltage, frequency and phase through a pre-synchronization execution unit; and after the synchronization reaches the standard, sequentially closing the grid-connected switches according to a preset power supply response priority sequence to complete the grid-connected action. According to the invention, a technical architecture of global monitoring-coordinated decision-precise execution-closed loop optimization is constructed, so that the stability and precise control problem during high-permeability distributed energy grid connection is solved.

The invention belongs to the technical field related to operation control of a power system, and provides a transient instability judgment method and system of a network-building type converter in order to solve the problem that an existing transient instability judgment method of the network-building type converter is prone to causing maloperation or missed judgment of a control strategy, and a nonlinear equivalent circuit model of the network-building type converter is established. Calculating transient total energy and critical instability energy of the system in real time, and adaptively switching a control mode according to the magnitude relationship of the transient total energy and the critical instability energy; during normal operation, an original control strategy of the virtual synchronous machine is maintained, and oscillation is suppressed by using the damping characteristic of the virtual synchronous machine, so that the voltage and frequency supporting capacity of a power grid is maximized; and when an instability risk is detected, entering a fault ride-through mode to realize rapid and accurate identification and control of the instability risk.

The invention provides a virtual synchronous machine grid-connected control method and device and a readable storage medium, and relates to the technical field of electric power. The method comprises the following steps: calculating grid-connected active power and actual reactive power according to inverter parameters and power grid parameters of previous grid-connected control; determining the output voltage of the inverter according to the actual reactive power and the reference reactive power; inputting the grid-connected active power, the reference active power and the rated angular frequency into a first-order low-pass filtering module to obtain a frequency deviation and a frequency change rate, and adaptively adjusting the virtual inertia according to the power difference and the frequency deviation; updating the output angular frequency of the inverter according to the sum of the frequency deviation and the rated angular frequency; and performing voltage and current double-closed-loop control on the output voltage and the output angular frequency to obtain a modulated wave signal, and performing sine pulse width modulation based on the modulated wave signal to obtain a switching control signal of the inverter. Therefore, the active power oscillation is eliminated, the active steady-state deviation is reduced, and the frequency deviation and the frequency change rate are effectively inhibited.

The invention provides an active support control method for a single-phase cascaded optical storage grid-connected system, aiming at challenges caused by fluctuation, intermittency and reverse peak regulation of photovoltaic resources in a photovoltaic energy consumption process and the problem of insufficient active support capability of a micro-grid for a large power grid under the access of high power electronic equipment. The low-voltage photovoltaic units are boosted by inverter cascading, and each photovoltaic unit is equipped with stored energy to stabilize photovoltaic fluctuation. A grid-side current source inverter is controlled by a virtual synchronous generator (VSG), so that the active support of the inverter on a large power grid frequency is ensured; other voltage source inverters adopt power factor angle droop control, and an active power compensation item is introduced, so that self-synchronization between the inverters and accurate power equalization between energy storage units are ensured. Compared with a traditional control method, the method can control active power and reactive power at the same time, has frequency supporting capacity, is low in communication cost, and provides a new solution thought for the problem of large-scale photovoltaic grid connection.

The invention discloses a voltage-sharing control method for a cascaded H-bridge direct-hanging energy storage converter, and the method comprises the following steps: collecting the SOC (state of charge) value of a battery of each sub-module, and carrying out the in-phase equalization calculation to obtain an in-phase equalization correction voltage; carrying out inter-phase equalization calculation based on the SOC error, and obtaining a zero-sequence voltage needing to be injected; according to the active power and the reactive power of the system, a virtual synchronous machine is adopted to control and generate a current reference value, a modulation voltage is generated based on the current reference value, and the in-phase equalization correction voltage and the zero sequence voltage are superposed to the modulation voltage; and carrying out carrier phase-shifting modulation on the superposed modulation voltage to generate an H-bridge sub-module switching signal. According to the method, in-phase and inter-phase SOC balance and power control are realized through hierarchical control, and the balance efficiency and the system reliability are improved.

The invention discloses a dual-frequency positive-sequence impedance modeling method for a network-building type energy storage converter considering frequency coupling. The method comprises the following steps: 1, injecting a dual-frequency positive-sequence disturbance voltage signal at a grid-connected point of the network-building type energy storage converter based on a virtual synchronous machine; 2, establishing a linearized small signal model for each control link of an active-frequency loop, a reactive-voltage loop, a virtual impedance-containing voltage and current double closed loop and the like to form a multi-frequency signal model; and 3, according to the multi-frequency coupling relationship between the current and the voltage, constructing a frequency coupling impedance matrix, and reducing a coupling term into output impedance to obtain the positive sequence output impedance and the negative sequence output impedance of the converter considering the frequency coupling, thereby simplifying the model stability analysis. According to the method, dual-frequency positive sequence disturbance is introduced, the coupling effect between different frequency components is effectively described, the defect that a traditional single-frequency modeling method cannot reflect the multi-frequency interaction characteristic is overcome, and the accuracy and applicability of the impedance model of the network construction type energy storage converter under the multi-frequency disturbance scene are remarkably improved.

The invention provides a virtual synchronization mechanism network type control method, system and device based on flux linkage synchronization control and a medium, and the method comprises the steps: obtaining a three-phase AC voltage reference value based on the grid-connected point output data of a network type inverter through employing a virtual synchronization machine control strategy; based on the three-phase alternating current flux linkage measurement value, synchronous feedback correction is carried out on the three-phase alternating current voltage reference value, a PWM modulation input signal is obtained, and a trigger pulse is generated to carry out synchronous control on the network-forming inverter; according to the method, a virtual synchronous machine control strategy is combined with flux linkage synchronous control, and a three-phase alternating-current voltage reference value is subjected to synchronous feedback correction by utilizing a three-phase alternating-current flux linkage measurement value before PWM (Pulse-Width Modulation) modulation, so that synchronous control is performed on the grid-forming type inverter, the deceleration area of a transient power angle curve of the grid-forming type inverter can be increased, and the stability of the grid-forming type inverter is improved. Therefore, the limit clearing time of the grid-forming inverter is prolonged, and the transient stability and the large disturbance fault resistance of the grid-type inverter of the virtual synchronization mechanism are improved.

The invention relates to a unified distributed dynamic optimization control method and device for a micro-grid in an autonomous station area, and the method comprises the steps: embedding a frequency regulator at a virtual synchronous converter, estimating the average frequency of the autonomous micro-grid through the frequency regulator, comparing the average frequency with a rated frequency to generate an error term, and calculating the optimal value of the error term; inputting the error term into an integrator to obtain a first power correction term; embedding a benefit optimizer at the virtual synchronous converter, generating a neighborhood error through the benefit optimizer, and inputting the neighborhood error into an integrator to obtain a second power correction term; and adding the first power correction item and the second power correction item with a reference power item to obtain a power setting item, and taking the power setting item as the input of the virtual synchronous converter. According to the invention, stable voltage and frequency support can be provided, and global optimal control is realized.

The invention discloses a method for analyzing transient stability of a hybrid synchronous control grid-forming inverter considering damping influence, and belongs to the field of DC / AC converters, the method comprises the following steps: dividing a power angle interval to be analyzed into a plurality of sub-intervals, constructing an explicit damping-power angle function in each sub-interval, further quantifying the damping influence, and calculating the transient stability of the hybrid synchronous control grid-forming inverter. And depicting a transient stability boundary of the network-constructing inverter system. According to the method, the damping influence is quantified, the defect that a traditional equal-area method is too conservative is overcome, meanwhile, compared with a traditional transient stability analysis method needing iteration, the method does not need to solve a nonlinear differential equation through complex numerical iteration, an explicit transient stability boundary can be obtained, and the method is suitable for being used for transient stability analysis. And the method is also used for the grid-forming inverter with droop control and virtual synchronous machine control of a linear damping item, and an effective method with high analyzability and low complexity is provided for transient stability analysis of the grid-forming inverter. And the method has good practical application value.