231 results about "Virtual synchronous generator" patented technology

The invention discloses a system and a method for analyzing stability and oscillation transmission of a network-forming converter system, and belongs to the technical field of virtual synchronous generator control, and the system comprises an active power control loop which takes an active power deviation value as input, and outputs a power angle of a VSG system through an active integration part and a feedback part; the reactive power control loop takes the reactive power deviation ratio as input, and outputs the voltage amplitude of the VSG system through an active integration part and a feedback part; according to the analysis method, whether each state variable is stable or not is judged firstly, and then the intensity of oscillation transmission between the state variables is judged. According to the method, the stability of the system can be evaluated more accurately, and the accuracy of system stability analysis under dynamic disturbance is ensured; an oscillation transfer effect function is introduced, and the mutual influence between different state variables is quantitatively analyzed; and the dynamic fluctuation range of each state variable in the system can be accurately evaluated.

The invention discloses an LSTM (Long Short Term Memory)-based harmonic frequency coupling model optimization method for a network construction type converter, which considers the influence of a dead zone and establishes a converter model controlled by a virtual synchronous generator based on a harmonic state space method. In the power electronic modeling process, due to approximate simplification, switch neglecting and other nonlinear relations, the model is not accurate enough, meanwhile, in the harmonic state space model modeling process, system state variable parameters need to be considered, and the precision of the model affects harmonic transmission characteristics and coupling analysis, so that the modeling efficiency is greatly improved. Errors caused by power electronic modeling are reduced through an LSTM neural network algorithm, the harmonic amplitude estimation difference is reduced, state variable parameter values in a system model are accurately estimated, the model precision is further improved, and then the harmonic coupling condition under the dead zone influence is effectively and accurately analyzed.

A grid-connection pre-synchronization method for a virtual synchronous generator parallel system, and an electronic device. The grid-connection pre-synchronization method for the virtual synchronous generator parallel system comprises: after receiving a pre-synchronization instruction, n virtual synchronous generators start to perform grid-connection pre-synchronization, wherein the grid-connection pre-synchronization comprises frequency and phase pre-synchronization, and amplitude pre-synchronization (S110). The frequency and phase pre-synchronization comprises: calculating control amounts for the frequency and phase pre-synchronization; according to the control amounts for the frequency and phase pre-synchronization, calculating a damping power; according to a mechanical power, an electromagnetic power and the damping power, calculating an output angular frequency difference of the virtual synchronous generators; and according to the output angular frequency difference of the virtual synchronous generator sand a rated angular frequency, determining a power angle of the virtual synchronous generators.

The invention discloses an MMC intelligent setting and cooperative control method and system based on deep reinforcement learning, and relates to the technical field of power transmission system regulation and control, and the method comprises the steps: obtaining the current operation state data of a converter in a power transmission system, the current operation state data comprising a system frequency, a frequency reference value, a frequency deviation and a frequency change rate; establishing a third-order active closed-loop small signal transfer function based on an active transient feedback compensation algorithm, and decoupling a damping coefficient and a primary frequency modulation coefficient in VSG control through the third-order active closed-loop small signal transfer function; inputting the current operation state data into the trained DDPG intelligent agent for processing, and obtaining an optimization result of the virtual inertia; the optimized virtual inertia is applied to a rotational inertia control link of VSG control, and self-adaptive adjustment of the virtual inertia is carried out through the trained DDPG intelligent agent; the problem that control parameters of a traditional virtual synchronous generator VSG are fixed and are difficult to adapt to system operation state changes is solved.

The invention discloses an energy storage type SOP black-start method, system and device based on improved VSG network construction control and a medium, and relates to the field of power grid black-start, and the method comprises the steps: an energy storage type converter MMC carries out the active and reactive control based on an improved VSG network construction control strategy; a non-fault side MMC is controlled to firstly close an isolation circuit breaker and slowly charge a direct-current capacitor, and when the voltage reaches a set threshold value, a current-limiting resistor is quitted; the fault side MMC is started by the same step as the non-fault side MMC; after synchronization is completed, AC circuit breakers between the non-fault side MMC and the feeder load and between the fault side MMC and the feeder load are closed respectively; based on the collected power grid power data, MMC output parameters are adjusted to meet the power grid connection condition, the control mode is switched according to the grid connection state, and the black start process is ended. And by arranging the black start resistor for current-limiting charging and sub-module voltage balance control, the phenomena of overcurrent and voltage unbalance in the black start process are avoided.

The invention discloses a network construction converter virtual impedance and power reference cooperative adjustment method and system, and relates to the technical field of power control, a virtual synchronous generator system introduces virtual impedance to increase equivalent output impedance of an inverter, and an internal voltage reference generated by a virtual synchronous generator algorithm of the inverter is monitored in real time; monitoring the local voltage measured by the common coupling point in real time; based on the vector difference between the internal voltage reference and the local voltage, the accurate amplitude of the virtual impedance is solved in real time by combining the maximum current limit value of the power electronic device; and determining a function relationship between an active power reference value and reactive power based on the accurate amplitude of the virtual impedance, monitoring the reactive power measured at the common coupling point in real time, and adjusting the active power reference value according to the function relationship to keep a stable balance point. And virtual impedance is dynamically calculated to accurately limit current, and active power reference is adaptively adjusted according to real-time reactive response, so that maximized power grid support and safe and stable operation of the converter are realized.

The invention discloses a network construction type virtual synchronous generator control method and device, a controller and a storage medium, and the method comprises the steps: determining an active power small signal increment according to an active power feedback value and an active power reference value, and obtaining an active power small signal correction according to a power angle small signal, and then the angular frequency compensation amount is determined according to the power small signal correction amount and the active power small signal increment, and the angular frequency compensation amount is used for compensating the angular frequency variable amount, which is equivalent to increasing the damping torque opposite to the oscillation trend, quickly consuming the oscillation energy and quickly returning the system to a steady state. The problem of underdamping of the virtual synchronous generator is solved, the probability of frequency oscillation when the inverter executes active adjustment is reduced, and the stability of a power grid is improved. Besides, transient vector feed-forward compensation is added in voltage loop control, so that the transient stability of network construction voltage and the response speed of the system are improved, and the problem that the response speed of the system is reduced due to damping increase is solved.

The invention discloses a multi-loop anti-interference ride-through control system and method for a high-voltage three-level inverter, and is suitable for a three-phase T-type three-level grid-connected inverter. The system comprises a direct current side power supply circuit, an inversion main circuit, a filtering grid-connected circuit, a signal sampling and conditioning circuit, a multi-loop cooperative controller and a PWM driving and protecting circuit. According to the control method, a robust synchronous reference is provided through an outer ring virtual synchronous generator strategy; a middle ring adopts a virtual impedance model containing a high-frequency compensation item to selectively suppress switching noise; the inner ring adopts a quasi-proportional resonance controller to realize fundamental current zero-static-error tracking; the modulation layer dynamically optimizes a discontinuous pulse width modulation strategy based on a real-time EMI index; and the rings are switched to a low-voltage ride-through mode in cooperation when a fault occurs. On the premise of not increasing hardware, the anti-interference capability, the current quality and the ride-through stability of the inverter under the working conditions of strong electromagnetic interference and power grid drop are effectively improved.

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 network construction type converter control method suitable for multiple power grid intensities, and belongs to the field of new energy grid-connected stability. The method comprises the steps that the actual output power of an inverter is calculated according to inverter side capacitor voltage and grid-connected current; the actual output power of the inverter and the power reference value control an output internal potential amplitude reference value and an internal potential phase angle through the virtual synchronous generator; subtracting the voltage drop of the grid-connected current on the virtual impedance from the internal potential amplitude reference value to obtain a virtual internal potential; inputting the virtual internal potential as a reference voltage into a voltage and current double-loop controller, inputting a grid-connected current into a proportional differential controller, subtracting the output of the proportional differential controller from the output of the voltage and current double-loop controller, inputting an obtained result into an inverter through an SPWM modulator, and controlling the inverter; the invention also provides a control system of the network-forming converter. Grid-connected current proportional differential feedback is introduced, the inner loop control bandwidth is kept constant in the dynamic change process of the power grid strength, and power-voltage loop harmful coupling is eliminated.

The invention relates to a solar photovoltaic power generation control method and system, and the method comprises the steps: adjusting a power reference value of a virtual synchronous generator based on the predicted photovoltaic power change trend information of a micro-grid after a mode switching request is detected, and controlling the output power of the micro-grid to approach a steady-state power value under a target grid-connected working condition; in different operation modes, the virtual inertia of the virtual synchronous generator is configured to be an adaptive set value, and the virtual damping coefficient is adjusted; calculating a comprehensive switching preparation index based on the photovoltaic power prediction error, the convergence characteristic of the actual power deviation and the bus voltage and frequency fluctuation amplitude; and when the comprehensive switching preparation degree index meets a preset condition, generating a synchronous starting instruction, and entering an off-grid to grid-connected switching stage. Therefore, the stability and the reliability of mode switching can be remarkably improved, transient impact is effectively inhibited, and the power supply continuity and the power quality are guaranteed.

The invention discloses a VSG deadbeat prediction control method based on impedance identification adaptive compensation, and the method comprises the following steps: collecting the grid-connected point voltage and current of a three-phase grid-connected converter, and converting the voltage and current into corresponding components in a rotating coordinate system; and identifying a power grid impedance parameter based on the component, calculating a system short-circuit ratio, comparing the system short-circuit ratio with a preset threshold value, and selecting a standard predictive control or impedance adaptive compensation mode. In a standard mode, a virtual synchronous generator discretization mathematical model considering system delay is constructed, and first control voltage is generated through dead-beat predictive current control; and in the compensation mode, self-adaptive compensation of a power grid impedance parameter is introduced on the basis of the first control voltage, a final control voltage is obtained, a PWM driving signal is generated according to the final control voltage, and grid-connected operation of the converter is controlled. According to the method, dead-beat predictive current control and a virtual synchronous generator technology are combined, a power grid impedance identification and self-adaptive compensation mechanism is added, and self-adaptive high-performance control of the converter under strong and weak power grid conditions is realized.

The invention relates to an asymmetric fault ride-through cooperative control method and system for a virtual synchronous generator, and belongs to the technical field of power electronics and new energy power generation. Aiming at the problems of three-phase current asymmetry, overcurrent, transient instability and the like faced by a virtual synchronous generator when a power grid has an asymmetric fault, the method comprises the following steps: firstly, setting a negative sequence current reference to be zero through positive and negative sequence separation control so as to keep output current symmetry, and freezing a reactive power ring; secondly, comprehensively considering current amplitude limiting, voltage supporting capacity and system capacity, and dynamically calculating optimal solutions of positive sequence excitation reference amplitudes under different fault depths; finally, positive and negative sequence power components and excitation dynamic changes are considered, an active reference instruction real-time dynamic adjustment method is provided, and a power angle is controlled to be stabilized at a target value by adjusting a power reference value in real time. The method can effectively improve the transient stability during the fault ride-through period, maximally supports the power grid voltage while ensuring that the current is not out of limit, and improves the system capacity utilization rate.

The embodiment of the invention provides a direct-current bus power control method and device, equipment and a storage medium, and the method comprises the steps: collecting the direct-current bus voltage and direct-current bus current of a virtual synchronous generator under the operation condition of the virtual synchronous generator; determining a direct current bus voltage differential value according to the direct current bus voltage and a preset sampling frequency; determining the direct current side capacitance power according to the direct current bus voltage, the direct current bus voltage differential value and the preset direct current side capacitance; determining direct current side transmission power according to the direct current bus voltage and the direct current bus current; converting the direct-current side capacitance power and the direct-current side transmission power into direct-current side power observation values; performing frequency separation on the DC side power observation value, and determining secondary ripple power; determining an active power instruction according to the secondary ripple power; and the output power of the grid-side converter of the virtual synchronous generator is adjusted based on the active power instruction, so that the grid-side converter actively generates compensation power, the pulsating power is offset in real time, and the service life is prolonged.

The invention discloses a pre-synchronization control method for a network-building converter based on a virtual synchronous generator, and the method comprises the steps: collecting the three-phase voltage of the output end of the virtual synchronous generator VSG and the three-phase voltage of a power grid side, converting the three-phase voltage into a voltage component in a two-phase static coordinate system through Clark conversion, and extracting a positive-sequence component; calculating a phase difference compensation coefficient based on the positive sequence component; based on the phase difference compensation coefficient, adaptively setting a PI parameter; and calculating and adjusting the amplitude of the internal potential to finish pre-synchronization. In the working process, through self-adaptive PI parameter setting and amplitude accurate judgment, the pre-synchronization time is shortened, the grid-connected impact current is reduced, and the grid-connected success rate of the micro-grid in a weak grid scene is improved.

The invention discloses a power distribution area energy storage-photovoltaic oscillation cooperative suppression method based on impedance remodeling, and belongs to the technical field of power system stability control. According to the method, the impedance characteristic of the system is scanned online in real time, the virtual impedance controller parameters of the photovoltaic inverter are dynamically optimized, and the impedance frequency characteristic of the zone area network is actively remodeled, so that the zone area network is always far away from a stable critical point, and oscillation is prevented from occurring from the source. When it is detected that the oscillation energy exceeds the standard, the system immediately triggers the energy storage device to be switched to a virtual synchronous generator mode, phase information of a plurality of energy storage units in a fiber channel synchronization cluster is used, anti-phase damping current opposite to the oscillation trend is injected, and the oscillation energy is rapidly consumed. The invention provides a double-layer suppression strategy based on impedance remodeling and energy storage cooperation, the cooperation of photovoltaic impedance active prevention and energy storage instantaneous suppression is realized, the problem that a traditional fixed parameter damper loses efficacy due to frequency drift is solved, and the operation stability of a high-proportion renewable energy power distribution network is improved.

The invention discloses a hydrogen production system flexibility improving method based on multi-source cooperation and self-adaptive regulation and control, and belongs to the technical field of new energy. The method is executed by taking a digital twinborn body as a global decision center, and comprises the following steps: acquiring predicted data of wind-solar power generation power, a real-time frequency deviation signal of a power grid and an operation state of each electrolytic cell in a hydrogen production system; based on the prediction data and the frequency deviation signal of the wind-solar power generation power, a global optimization scheduling instruction is generated by taking improvement of the flexibility and the economy of the system as a target; according to the global optimization scheduling instruction, cooperatively controlling dynamic reconfiguration of the electrolytic cell and applying virtual synchronous generator (VSG) control to a hydrogen production load; and actual operation data after cooperative control are collected and fed back to the equipment fatigue loss analysis model and the wind and light output prediction model for dynamic correction of fatigue damage evaluation and power prediction in the next period. According to the method, the operation cost of the system is effectively reduced, and meanwhile the flexibility of the new energy hydrogen production system is greatly improved.

The invention discloses a network construction type converter pre-synchronization control method based on Taylor compensation, and the method comprises the steps: collecting the three-phase voltage of an output end of a virtual synchronous generator (VSG) and the three-phase voltage of a power grid side, carrying out the Clark transformation, and extracting a positive sequence voltage component; on the basis of the positive sequence voltage component, calculating a phase difference sine value of the VSG output voltage and the power grid voltage; based on the phase difference sine value, compensating the phase difference sine value through Taylor expansion to obtain a compensated real-time phase difference; and fusing the compensated real-time phase difference into a VSG phase-locked loop-free pre-synchronization control strategy, and driving a PI regulator to dynamically correct the output frequency and phase of the VSG. A phase-locked loop is completely abandoned, and the frequency oscillation risk is eliminated; expanding a phase difference calculation range through third-order Taylor compensation; voltage vector analysis and a dynamic compensation function are fused, phase synchronization is achieved, and grid-connected impact current is reduced.

The invention provides a frequency modulation method and a voltage stability control method of a three-machine VSG parallel system, and relates to the technical field of virtual synchronous generators. According to the method, the mathematical model of the three-machine VSG parallel system is constructed, and the LADRC control framework is introduced into multi-machine parallel problem research, so that tedious setting of parameters such as J and D can be avoided, and the stability of the multi-machine parallel system is improved. Meanwhile, robust control over the output voltage of the system is achieved through the RISE module, the output voltage can accurately track reference input, better steady-state rapidity is achieved, the influence of strong disturbance on tracking performance is effectively reduced, and therefore the comprehensive stability and operation reliability of the three-machine VSG parallel system are improved.

The invention belongs to the technical field of VSG network construction active support, and particularly discloses a transient support power coordination control method and system for a network construction type optical storage system, and the method comprises the steps: building an equivalent mathematical model of the network construction type optical storage system, and obtaining key control parameters of a virtual synchronous generator control link of the optical storage system based on the equivalent mathematical model; constructing an internal energy flow characteristic analysis model of the network construction type optical storage system based on key control parameters of a control link of the virtual synchronous generator, and further obtaining a core defect of passive participation of energy storage in transient response; and based on the core defects, designing an energy storage driving control strategy based on VSG transient response power decomposition to control an energy storage subsystem to charge and discharge, and completing transient support power coordination control of the network construction type optical storage system. The problems that in the prior art, due to the fact that energy storage passively participates in frequency modulation, response timeliness and accuracy are insufficient, and due to the fact that VSG transient control complexity is high, large-scale engineering application adaptability is poor are solved.

The invention discloses an enhanced power decoupling control method for a virtual synchronous generator, relates to the technical field of virtual synchronous generators, and solves the problems that a systematic analysis method for a resistance-inductance line power coupling mechanism is lacked and a collaborative design framework of a dynamic power decoupling condition and a steady-state power transmission requirement cannot be established in the prior art. According to the method, firstly, a dynamic coupling coefficient is accurately quantified through small signal modeling, then a voltage amplitude compensation mechanism based on virtual impedance is established, steady-state power transmission constraints are embedded into dynamic decoupling conditions, and virtual impedance parameters have the dual functions of eliminating dynamic coupling and guaranteeing steady-state tracking. The method does not depend on ideal working condition assumption, can calculate the optimal virtual resistance and virtual reactance on line according to real-time line parameters and operation working conditions, improves the adaptability of the VSG to a weak power grid resistance-inductance line, effectively inhibits dynamic cross coupling between power, and enhances the frequency support and voltage support capability of the VSG under a complex power grid condition.

The invention belongs to the technical field of optical storage operation control, and particularly relates to an operation mode seamless switching control method of a photovoltaic-energy storage system, which comprises the following steps of: for an optical storage system comprising an energy storage system and a photovoltaic system, performing seamless switching on the operation modes of the photovoltaic-energy storage system; obtaining a direct current bus voltage, a photovoltaic output voltage and current, an energy storage battery voltage and current, an LC filter inductance current and a grid-connected point voltage and current in the current optical storage system; aiming at an energy storage system, constructing a switching mechanism based on photovoltaic voltage feedforward; aiming at a photovoltaic system, constructing a dynamic control strategy based on photovoltaic power feed-forward compensation; based on a switching mechanism and a dynamic control strategy, network construction control is carried out by combining an inverter virtual synchronous generator control technology, and stable operation of the optical storage system in strong power grid and weak power grid environments is realized. The system is suitable for an optical storage system, can cover various typical operation modes, and has high responsiveness and high stability.

The invention relates to the technical field of electric power systems, and discloses a network construction type energy storage converter control method and device and a related product. The method comprises the following steps: constructing a corresponding MPC controller based on a pre-constructed discrete state space equation of a to-be-controlled network-building type energy storage converter; the MPC controller comprises a cost function and a constraint condition; the cost function comprises a state error term; performing optimization solution on the MPC controller by adopting a preset optimization algorithm to obtain an active power reference value and a reactive power reference value when the cost function reaches the minimum; and utilizing a virtual synchronous generator module and a voltage and current double closed-loop control module to generate a pulse width modulation signal based on the active power reference value and the reactive power reference value so as to control the target network-building type energy storage converter. According to the invention, the problems of current impact, power angle instability and the like which are easy to occur in the grid-forming type energy storage converter during voltage drop can be effectively solved, and stable grid-connected operation of the grid-forming type energy storage converter under the working condition of power grid voltage drop is ensured.

The invention provides a virtual synchronous power generation mechanism network control method and device, electronic equipment and a computer readable storage medium. The method comprises the following steps: constructing a mathematical model of a virtual synchronous power generation mechanism network control system; acquiring an initial value of a control parameter of the virtual synchronous power generation mechanism network control system; performing Tent chaotic mapping on the initial value to obtain a chaotic value corresponding to each element in the matrix; an initial matrix is calculated according to the chaotic value and the upper bound and the lower bound of a preset control parameter, and each row of the initial matrix represents a second value corresponding to each category; parameter optimization is carried out on the initial matrix according to an ICOOT algorithm and a mathematical model, a target row in the initial matrix is obtained, and elements of the target row represent updated target values of the second value after parameter optimization; and controlling the virtual synchronous power generation mechanism grid control system according to the target value. The parameter design process of the virtual synchronous power generation mechanism network control system can be simplified, and the system stability is improved.

The invention provides a control method and device for improving strong network adaptability of a network construction converter and a storage medium, and relates to the technical field of power grids. The method comprises the following steps: acquiring active power and reactive power of a grid-connected point, and inputting the active power and the reactive power into a VSG ring to obtain a virtual synchronous machine internal potential amplitude and a virtual synchronous machine internal potential phase; adaptively acquiring a reference node phase, and subtracting the reference node phase from the internal potential phase of the virtual synchronous machine to obtain a power angle; generating an active reference current and a reactive reference current based on the power angle and the potential amplitude in the virtual synchronous machine; and inputting the active reference current and the reactive reference current into a current inner ring to obtain a switching control signal of the target grid-connected converter. The power angle observer is added in the power outer loop, the current reference value is generated according to the power angle, dependence on a voltage loop is not needed, the reference node phase is obtained in a self-adaptive mode, and better stability performance is achieved under a strong power grid and a weak power grid.

The invention relates to an equivalent modeling method and device for a lithium battery energy storage power station, computer equipment, a readable storage medium and a program product, and relates to the technical field of simulation modeling. The accuracy of the equivalent model obtained through simulation can be improved. The method comprises the following steps: determining a plurality of lithium battery energy storage power stations needing equivalence in a power system, constructing single body models of lithium batteries, and carrying out equivalence modeling by adopting an arrangement mode of connecting in series and then connecting in parallel on the basis of the single body models to obtain an equivalence model of a lithium battery pack; performing parameter aggregation on the LCL filter according to the equivalent circuit diagram of the LCL filter in the lithium battery energy storage power station to obtain equivalent reactance values respectively corresponding to two inductors and one capacitor in the LCL filter; simulating a rotor motion equation of the virtual synchronous generator by adopting a VSG control strategy, and performing controller parameter aggregation based on the rotor motion equation to obtain a parameter aggregation result; and performing equivalent modeling on the plurality of lithium battery energy storage power stations based on the equivalent model, the equivalent reactance value and the parameter aggregation result.

The application provides a kind of energy storage converter control system stability analysis method, the method will model predictive control as the virtual synchronous generator control upper control system of energy storage converter, will model predictive control output value as the active power, reactive power reference value of virtual synchronous generator.This application realizes real-time correction virtual synchronous generator power, improves the stability of control system, avoids frequency oscillation.

The invention relates to a power outer loop collaborative optimization virtual synchronous generator transient stability improvement method, and belongs to the technical field of virtual synchronous generator transient stability, and the method comprises the following steps: S1, building a virtual synchronous generator small signal power angle model; s2, performing active transient compensation and capacity constraint of power angle-frequency difference cooperative state feedback; s3, voltage deviation driven adaptive reactive power coefficient and active-reactive power combined current limiting are carried out; and S4, fault current impact suppression of the current-driven virtual impedance. The method can effectively reduce peak values and oscillation time of a power angle and a frequency difference, limit a fault current not to exceed a set upper limit, consider voltage support and active support capabilities, has good stability and robustness, and is suitable for controlling the grid-connected virtual synchronous generator under different short-circuit ratios and various fault working conditions.

The invention relates to an asymmetric fault ride-through control method and system based on a three-phase four-leg virtual synchronous generator, and belongs to the technical field of power electronics and new energy power generation. The invention provides a solution for solving the problems of asymmetric output current, transient overcurrent, weakening of system supporting capability and the like under the asymmetric fault of a power grid in the prior art. The method comprises the following steps: detecting an asymmetric fault of a power grid; freezing a reactive power ring and retaining an active power ring when a fault occurs; determining a voltage drop coefficient and a phase jump angle according to the fault type; directly calculating a three-phase asymmetric excitation electromotive force reference value based on a system phasor geometrical relationship and a current amplitude limiting constraint; and giving the reference value to a voltage loop, and controlling the output of the inverter.

A device, method, and non-transitory computer readable medium for controlling a power distribution system includes an islanded microgrid and a control system. The islanded microgrid includes battery energy storage systems (BESSs) that operate as a primary energy source, and a decentralized consensus-based virtual synchronous generator (VSG). The control system simultaneously, emulates inertial response of a synchronous generator by the virtual synchronous generator during grid disruptions to regulate and stabilizes frequency of the islanded microgrid, and maintain consensus among the plurality of battery energy storage systems (BESSs).