2516 results about "Current limiting" patented technology

The invention discloses a fault ride-through hierarchical control method for a network-constructed converter, and the method comprises the steps: introducing a virtual resistor formed by fault current negative feedback into the voltage and current inner loop control of the network-constructed converter based on VSG control through a current inner loop dynamic amplitude limiting control layer after the converter enters a fault ride-through state, the size of the virtual resistor is adjusted in real time along with the amplitude of the fault current so as to carry out dynamic current limiting control on the virtual resistor; and the power outer loop dynamic compensation control layer dynamically adjusts an active power instruction value and a reactive power instruction value of the network construction type converter based on VSG control during the fault ride-through period according to the voltage drop degree of the power grid after the converter enters the fault ride-through state. And respectively performing active-frequency control and reactive-voltage control based on the active power instruction value and the reactive power instruction value. In addition, the method also comprises a state coupling and parameter self-adaption module. According to the method, the GFM converter can have better dynamic performance in the fault recovery stage.

The invention provides a fault ride-through control method and system for a network-forming converter, and relates to the technical field of power electronics. The fault ride-through control method of the network construction type converter comprises the following steps: determining a real-time virtual impedance value corresponding to a control loop based on a virtual admittance control module; in response to the fact that the real-time virtual impedance value is larger than or equal to the reference virtual impedance value of the control loop, transient current output by the network-building type converter is adjusted based on first-stage current limiting, and steady-state current output by the network-building type converter is adjusted based on second-stage current limiting; calculating an active power proportionality coefficient based on the real-time parameter and the reference parameter; calculating a target active power reference value according to the active power proportionality coefficient and the reference active power reference value; and executing power control based on the target active power reference value, and adjusting the output voltage of the network-forming converter. According to the method, when the power grid breaks down, the grid-forming type converter can have the functions of current limiting and transient synchronization stability improving at the same time.

The invention provides a fusing processing method and device, electronic equipment and a storage medium, and relates to the technical field of computers. The method comprises the steps of performing current limiting on a system request based on a filter to obtain a target request; determining whether to trigger the fusing condition of the target service based on the real-time operation data of the target service corresponding to the target request and the fusing judgment rule; in response to the fact that the target service is the first service and a fusing condition of the first service is triggered, performing fusing operation on the first service; the first service is used for message transmission; in response to the fact that the target service is the second service and a fusing condition of the second service is triggered, performing degradation operation on the second service; the second service is used for data caching, and the type of the degradation operation is determined based on the dependency of the target request on the second service. According to the invention, intelligent degradation fusing processing can be realized, so that system overload and single-point fault diffusion can be effectively prevented.

A low voltage ride through control method for a grid-forming inverter based on dynamic internal potential adjustment comprises the following steps: detecting a voltage per unit value of a grid-connected point in real time, and comparing the voltage per unit value with a threshold value to judge a voltage drop event and trigger low voltage ride through control; dynamically calculating active and reactive power reference values through a reactive compensation equation and an active current limiting equation according to the voltage amplitude and the power reference value before falling during the ride-through period; inputting the active reference value into a virtual rotor motion equation to generate a reference phase, and outputting a phase reference signal in combination with a dual-mode phase compensation controller; superposing the reactive reference value with the reference voltage through a reactive voltage regulating ring to generate a voltage amplitude reference signal; synthesizing an internal potential according to the phase and the amplitude reference signal, and obtaining an inductive current reference value through virtual impedance control and current amplitude limiting; and finally, a driving signal is generated through the current inner loop controller and the modulation module. According to the invention, overcurrent can be effectively inhibited, rapid reactive power support is provided, and synchronous stability and smooth transition in a fault period and a recovery process are ensured.

The invention discloses a converter collaborative current limiting method based on adaptive virtual impedance and a power loop, and the method comprises the steps: firstly building an equivalent impedance model of a converter and a power grid, analyzing the steady-state and transient characteristics of fault current, and extracting key parameters for current limiting design; when it is detected that the voltage drop of the grid-connected point exceeds a threshold value, a self-adaptive virtual impedance link is automatically put into use, and virtual resistance and reactance values are dynamically calculated according to the variation amplitude of voltage or current, so that the virtual resistance and reactance values are proportionally adjusted along with the fault degree; and when the system voltage returns to normal, the virtual impedance automatically quits, and the control continuity is ensured. Then, the active and reactive power reference values are dynamically corrected according to the voltage drop depth, a power reference signal matched with the voltage amplitude is generated, it is guaranteed that power output does not exceed the limit, and the voltage supporting capacity is improved. Finally, real-time current-limiting control of the converter and stable operation of the system are realized on the premise of not switching the control mode through the synergistic effect of the virtual impedance ring and the power ring. The method has the advantages of being high in response speed, excellent in current limiting effect, good in control continuity and the like, and is suitable for fault current limiting and voltage support control of the grid-forming converter.

The invention discloses a battery pack short circuit early warning and protection method based on multi-sensor fusion, and the method comprises the steps: S1, collecting the multi-dimensional sensor data, including temperature distribution data, voltage fluctuation data, gas component data, deformation data and current ripple data, of a battery pack in real time; s2, performing space-time alignment and feature extraction on the multi-source sensor data, and constructing a fusion feature vector; s3, based on the fusion feature vector, performing short circuit type identification and risk level evaluation through a two-stage short circuit risk judgment model; and S4, triggering a grading response mechanism according to the risk grade, wherein the grading response mechanism comprises an early warning signal, current limiting, fuse action or battery cluster isolation. By fusing five-dimensional data of temperature, voltage, gas, deformation and current, a two-stage short circuit risk judgment model is constructed, and accurate classification and risk grading evaluation of short circuit types are realized. A four-level response mechanism is triggered based on an evaluation result, and protection is strengthened step by step from early warning to physical isolation.

The invention provides an electronic temperature protection control method for a direct current brushless motor, and relates to the technical field of motor control, and the method comprises the steps: temperature sampling: employing a controller or a motor internal sensor and a winding resistor to estimate and collect a temperature signal in real time; temperature filtering: eliminating noise interference by adopting mean value or Kalman filtering; temperature comparison: comparing the filtered temperature value with a preset multi-level threshold value (from one level to three levels); and protection control is carried out, and measures such as power reduction, current limiting or driving signal closing are taken according to the threshold exceeding degree. Through multi-point sampling, heat conduction installation, dynamic filtering parameter adaptation and threshold setting based on the insulation grade, the temperature monitoring precision and response speed are improved, the problems of response lag and cost of traditional hardware protection are avoided, dynamic and precise temperature protection of the motor is achieved in combination with a thermal response time constant and temperature change rate pre-judgment mechanism, and the reliability of the motor is improved. The service life of equipment is effectively prolonged.

The invention relates to the technical field of intelligent power distribution and electrical equipment state monitoring, in particular to an intelligent power distribution cabinet data acquisition control system and method, and the method comprises the steps: presetting a temperature sensor and a Hall sensor at the lap joint of a circuit breaker contact and a copper bar of an intelligent power distribution cabinet; calibrating inherent parameters of the system; in response to starting operation of the intelligent power distribution cabinet, the following steps are triggered: obtaining real-time load current, real-time environment temperature and actual temperature through filtering processing; generating a theoretical healthy temperature through a thermoelectric coupling evolution equation; calculating aging resistance increment through dynamic impedance differential evolution processing; generating an aging resistance estimated value through contact state multi-dimensional evaluation; generating a dynamic current limit value through an intelligent current limiting control model; outputting a control signal to adjust the operation state of the intelligent power distribution cabinet; according to the invention, the problem that a traditional single threshold scheme cannot accurately identify a real health state is solved, and the sensitivity and accuracy of contact aging detection are remarkably improved.

The invention provides a general electromechanical transient modeling method and system for a network-building converter, and relates to the technical field of electromechanical transient modeling, and the method comprises the steps: simplifying the electromagnetic transient models of network-building converters of different topologies into a grid-connected equivalent circuit of an electromechanical transient time scale; uniformly representing by using an internal potential series reactance model controlled by a power outer ring so as to establish an electromechanical transient general grid-connected interface model of the grid-forming converter; combining mathematical transformation of active power control with a reactive power control mode to form a general power outer loop control model of the network construction type converter; through a method based on internal potential reconstruction, reconstructing a new internal potential satisfying a current limiting constraint, and establishing a general current limiting model suitable for a network construction type electromechanical transient model; according to the method, various topological structures, various power outer loop control and various current limiting strategies can be simulated, flexible use of models in large-scale power system simulation is facilitated, and the complexity of model development and maintenance is reduced.

The invention relates to the technical field of network construction type converter control, in particular to a network construction type converter fault ride-through method and system based on dynamic virtual resistance control, and the method comprises the steps: adding a control link based on virtual impedance in a network construction type converter control system; detecting the actual value of the power grid voltage, and judging whether the power grid voltage drops or not; detecting the current amplitude output by the grid-forming converter in real time, and judging whether the current amplitude exceeds a set value or not; if one of the two conditions is met, a virtual impedance control link is started: stage-type current limiting control is performed on the virtual resistor, and the size of the virtual resistor provided by the network-forming converter to the power system is adjusted in real time along with the amplitude of the fault current; and when the power grid voltage recovers and the current amplitude is smaller than the set value, the virtual resistor staged current-limiting control exits. According to the invention, the amplitude limiting of the fault current in the fault ride-through of the network-constructed converter can be realized, so that the fault ride-through capability and transient stability of the network-constructed converter are improved.

The invention provides a fault ride-through control method for a network construction type converter, and belongs to the technical field of energy storage converters and the like. The method comprises the following steps: firstly, measuring PCC voltage and power grid side current, calculating amplitudes of the PCC voltage and the power grid side current, and then judging whether the PCC voltage drops below a set threshold value or not; if not, keeping the active power reference and the voltage amplitude reference unchanged; and if so, performing active power reference modification: judging whether a current limiting strategy is triggered, if not, locking the PCC voltage reference as a measured value, and if so, gradually decreasing the PCC voltage reference by an increment value based on the measured value. According to the invention, accurate evaluation of the existence of the stable equilibrium point is realized; meanwhile, an improved fault ride-through control method is provided, active power reference and voltage amplitude reference are dynamically modified, so that the grid-forming converter is transited to a new stable balance point during a fault period, and current limiting, transient synchronization stability improvement, PCC voltage source characteristic maintenance and maximum fault current output can be taken into account.

The invention relates to the technical field of wireless communication networks, and provides a low-channel electroencephalogram amplification circuit and brain-computer interface equipment oriented to an after-ear electroencephalogram signal, and the low-channel electroencephalogram amplification circuit comprises a dry electrode sensing module which is used for collecting an electroencephalogram signal; the front active amplification module comprises an operational amplifier circuit with high input impedance; the anti-aliasing filtering module is formed by cascading a multi-order passive filtering network and an active filtering circuit, is connected with the output end of the front active amplification module and is used for filtering high-frequency interference signals; the right leg driving feedback module comprises a programmable impedance adjusting circuit and a current limiting protection circuit, the right leg driving feedback module and the front active amplification module form a closed-loop feedback loop, and the output end of the right leg driving feedback module and the human body form a current loop through a protection resistor; the analog-to-digital conversion module adopts an integrated low-power-consumption analog front-end chip; a wireless transmission module; and the power supply management module provides independent power supply for the analog front-end chip, the operational amplifier circuit and the wireless transmission module.

The invention relates to the technical field of motor current limiting, and discloses a cooling fan motor starting current limiting method, device and equipment, and the method comprises the steps: carrying out the starting power calculation of a radiator, and obtaining a drive power prediction value; rotor angle position detection and blade aerodynamic resistance calculation are carried out, and aerodynamic load distribution parameters of all phase change points are obtained; performing starting current limitation to obtain a current limitation control instruction; performing motor commutation time sequence control to obtain a basic commutation control signal, and meanwhile, monitoring a starting torque abnormal increment to obtain a reverse airflow recognition result; according to the method, the current limit value is increased in the emergency mode to accelerate the starting response, the current limit is reduced in the energy-saving mode to reduce the energy consumption, and the starting current phase difference compensation is carried out to obtain a reverse airflow compensation control parameter and fuse the reverse airflow compensation control parameter with the basic phase-change control signal to obtain a target phase-change control signal. And the intelligent balance between the starting performance and the energy efficiency is realized.

The invention discloses an overcurrent protection control circuit of a low-dropout linear regulator and the low-dropout linear regulator, and relates to the field of voltage regulators. A first sampling module is connected with a drain electrode, a grid electrode and a source electrode of a power control tube in the low-dropout linear regulator and a first current comparator; the first current comparator is further connected with the grid electrode of the first protection switch and the input voltage end of the low dropout linear regulator, the source electrode of the first protection switch is connected with the grid electrode of the power control tube, the drain electrode of the first protection switch is grounded, and the source electrode of the power control tube is connected with the voltage output end of the low dropout linear regulator; the second sampling module is respectively connected with the drain electrode of the power control tube, the grid electrode of the power control tube and the clamping module, the clamping module is connected with the grid electrode of the second protection switch through the second current comparator and is also connected with the source electrode of the power control tube, the drain electrode of the second protection switch is grounded, and the source electrode of the second protection switch is connected with the grid electrode of the power control tube. The reliability of current limiting can be improved.

An example cooling system includes a power source, a first pump cassette configured to circulate fluid through the cooling system, and a second pump cassette configured to circulate fluid through the cooling system. The first pump cassette is connected to the power source and includes a first inrush current limiter circuit and a first pump controller. The second pump cassette is also connected to the power source and includes a second inrush current limiter circuit and a second pump controller. The first inrush current limiter circuit is connected in series between the power source and the first pump controller, and the second inrush current limiter circuit is connected in series between the power source and the second pump controller.

The present disclosure provides a multi-stage charge pump, a current limiting circuit, a driver circuit, a charge pump, a chip, and an electronic device. A control circuit controls a first charge pump circuit to boost an input voltage of a multi-stage charge pump, and controls, based on a second-phase clock signal, a second charge pump circuit to be charged using an output voltage of the first charge pump circuit, such that the second charge pump circuit boosts an output voltage of the first charge pump circuit, and hence a high-side switch driver circuit satisfies a drive requirement of a high-side switch. This ensures normal operation of the charge pump is ensured while reducing the cost and circuit area. In this way, the reliability and safety of the charge pump are improved.

The invention discloses a short-circuit current limiting and short-circuit recovery transient voltage control device and method for an aviation three-stage power generation system, and the device comprises a three-stage power generator, a power generator controller, a current sensor, a voltage and current collection module, and an asymmetric half-bridge excitation control circuit. Collecting the output current iL and voltage UL of the generator through a digital processor of the generator controller; when short circuit occurs, the given voltage USet of the voltage regulating loop is linearly reduced in a piecewise mode according to the relation between the iL and a preset threshold value, so that the generator works in a constant power interval; and when the short circuit is recovered, closing the upper / lower power tubes of the asymmetric half-bridge excitation control circuit according to the relationship between UL and a preset threshold value in a grading manner, and triggering a negative-pressure follow-current mode of a main excitation winding of the generator controller to quickly extinguish the field. The method can adapt to different generators without adjusting hardware circuit parameters, has no motor ablation risk during short circuit, has transient voltage less than 350V after short circuit recovery, has no power supply interruption in the whole process, has response delay less than 1ms, and greatly improves the safety and robustness of an aviation power supply and distribution system.

The invention discloses a multi-dimensional layered current limiting method based on spatio-temporal feature fusion. The method comprises the following steps: acquiring a hardware limit speed, and generating a global quota based on a reinforcement learning model; calculating a variable coefficient, and if the variable coefficient exceeds a preset critical value, introducing a conservative coefficient and generating a weight factor through nonlinear function mapping to suppress the micro network jitter; constructing a priority factor matrix based on the service priority and the service type, and obtaining a service priority factor; correcting the average bandwidth of the node by integrating the multi-dimensional dynamic weight factor and the service priority factor to obtain a suggested speed, inputting a historical performance index into the LSTM model to predict the load of the next period, and if the historical performance index exceeds a critical value, triggering connection migration before executing current limiting to realize active avoidance; otherwise, comparing and selecting the minimum value of the global quota, the suggested speed and the hardware limit speed as the final current-limiting speed. The problems of current limiting strategy lag and wide oscillation can be solved, and the bandwidth utilization rate and the system stability are improved.

The invention discloses a direct current SSPC current limiting control system and a control method thereof, and relates to the field of power electronics and electricians. The RC network generates a control voltage according to the switch control signal; the driving power amplification circuit carries out power amplification processing on the control voltage; the main power circuit conducts or cuts off the branch power distribution channel according to the processed voltage so as to provide a current path; the current-limiting state judgment circuit judges whether to enter or exit a current-limiting state according to information data fed back by the feedback circuit, and outputs a signal to the current closed-loop current-limiting control circuit; and the current closed-loop current-limiting control circuit receives the signal output by the current-limiting state judgment circuit and adjusts a control voltage corresponding to a main branch power tube in the RC network according to the SSPC channel current so as to realize constant-current control of the power distribution channel. The invention aims to improve the stability and thermal reliability of direct current SSPC current-limiting control.

The utility model relates to the field of resonance eliminators, and discloses a protection element and a current limiting type resonance eliminator, the protection element comprises at least two groups of protection units, the two adjacent groups of protection units are connected in series, and each protection unit comprises a protection module; the current-limiting resonance eliminator based on the current-sensitive resistor made of the current-sensitive material is connected in series between the PT neutral point and the ground. Under the normal operation condition, the current-limiting resonance eliminator is in a low-resistance state, and system parameters and PT performance are not affected; when excitation energy is generated due to a system fault, the current-limiting resonance eliminator suddenly changes into a high resistance state, quickly absorbs resonance energy, destroys resonance parameters, suppresses PT excitation current below 200mA, and ensures that a voltage transformer is unsaturated and a PT fuse is not fused; and a built-in current sensor is connected, so that the running state of the current-limiting resonance eliminator can be monitored in real time.

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 discloses a full-range drop-out fuse which comprises a base, the upper end and the lower end of the base are fixedly connected with an upper contact seat and a lower contact seat respectively, and a fuse carrier is installed between the upper contact seat and the lower contact seat. The fuse carrier is of a split type and comprises a current limiting part and a spraying part which are connected with each other in a detachable mode, and a first fuse wire in the current limiting part and a second fuse wire in the spraying part are connected between the upper contact seat and the lower contact seat in series. The fuse carrier comprises a current limiting part and an injection part which are connected in series, and has the advantages that a current limiting type fuse limits peak current under large fault current and does not inject combustible materials, and an injection type fuse is reliably switched on and off under the condition of small fault current, so that full-range fault current protection is realized; and meanwhile, the system has the advantages of good compatibility, low improvement cost and the like.

The invention provides a turn-back overcurrent protection circuit and a linear voltage regulator, and the turn-back overcurrent protection circuit comprises a turn-back switch module which compares an output voltage with a preset voltage, and outputs a turn-back current when the output voltage is smaller than or equal to the preset voltage; and the overcurrent protection module is connected with the turn-back switch module, performs overcurrent protection on the linear voltage regulator based on the first current limiting point when the turn-back switch module does not output the turn-back current, and reduces the current limiting point from the first current limiting point to a second current limiting point based on the turn-back current when the turn-back switch module outputs the turn-back current, and over-current protection is carried out on the linear voltage regulator based on the second current limiting point. According to the invention, the problem of circuit damage caused by overlarge output current due to short circuit or overload in the prior art is solved.

The invention relates to the technical field of electrochemical energy storage, in particular to a balance control method for an electrochemical energy storage management system, which comprises the following steps of: connecting batteries in parallel to form battery modules, connecting the battery modules in series to form a battery cluster, performing heat dissipation treatment on the battery cluster for storing electric energy, and performing current limitation on the stored electric energy to stably output. Periodically detecting each battery module to obtain the residual capacity of each battery module in a single period, judging whether the balance management of the energy storage system meets the standard or not based on the variation of the residual capacity, determining a reason when the balance management does not meet the standard, generating a corresponding processing mode based on the determined reason, and sending the corresponding processing mode to the battery module. And generating a corresponding instruction based on the determined processing mode, and transmitting the instruction to the corresponding component to enable the component to adjust the operation parameter to a corresponding value. According to the invention, real-time monitoring and accurate adjustment for balance management of the energy storage system are realized, and the operation efficiency of the energy storage system is effectively improved.

The invention discloses a global cooperative control method and system for unbalanced fault ride-through of a multi-terminal DC power grid, and the method comprises the steps: constructing a fault detection model based on the positive sequence voltage drop depth and the negative sequence voltage size of the AC side of each converter station, automatically judging an unbalanced fault, and carrying out the fault detection when the fault is detected. Calculating the maximum allowable active current based on a fault station unbalanced current control model to carry out current limiting control on the converter station; and carrying out output power adjustment on the DC voltage deviation of the non-fault station based on the non-fault station power cooperation model. Asymmetric fault ride-through is carried out by using a constrained and optimized current instruction generation algorithm, and the capacity of a converter is dynamically and accurately distributed and utilized in a limited manner, so that the voltage support capability of a fault alternating-current power grid is maximized, and globally optimized adaptive power distribution is realized; the power of the non-fault station is calculated and distributed in a centralized manner and is dynamically adjusted according to the real-time available capacity, so that the self-adaption and global optimization of the running state change of the power grid are realized, and the fault handling toughness and reliability of the power grid are improved.

The invention discloses a zone area edge security linkage method based on an electricity utilization information acquisition terminal, and relates to the technical field of power distribution terminal security, and the method comprises the steps: only reading an object, an action and a time window to generate an intention fingerprint, building an edge security access partition, and allowing a certificate and a one-time token to enter and carrying out retention audit; generating an exclusive session window, and implementing selective communication between virtual segments and a switch array, carrier communication session key rolling (secret exchange), four and eight exclusive sessions and white list current limiting; a shadow integrity label and a sequence commitment are calculated in the end, abnormity is judged in combination with physical fingerprints, grading processing is carried out according to the minimum influence range, and bypass mirror images and equivalent migration mapping are recorded; performing dual authorization and time limit and range checking on the related control, solidifying an evidence chain, and completing rotation and upgrading of a key certificate; on the premise of not changing the meter, the reading and control reliability, traceability and compliance verifiability are improved, the port layer contention is reduced, and the influence radius is reduced.

The invention discloses a high-safety anti-overload fast-charging electronic wire harness system and an electronic wire harness, and belongs to the technical field of electronic wire harness safety protection, and the system comprises a sensing module, a load prediction modeling module, an anomaly detection module, a bypass control module, a central fast-charging regulation and control module and an optimization module. A local load prediction function is constructed by collecting a current change rate and a conductor thermal response curve at the initial stage of fast charging in real time, a resistance abrupt change area is judged, and dynamic current limiting and bypass shunting are carried out; the central module can adjust charging parameters of the next cycle according to historical load characteristics, and the optimization module corrects a prediction model through multi-cycle learning to realize adaptive control; the electronic wire harness integrates a thermoelectric sensor, a resistance sampling unit and a controllable bypass path, and has quick response and local shunting functions; the overload protection capability and the operation safety of the electronic wire harness in the fast charging system can be effectively improved, and the method is suitable for high-power application scenes such as new energy automobiles and high-speed charging piles.

The invention discloses a variable virtual impedance implementation method and system for a network-building type converter. The method comprises the following steps: acquiring a ratio of a network-side voltage amplitude of the network-building type energy storage converter to a system rated voltage amplitude; when the ratio is smaller than a set threshold value, voltage drop occurs; at the moment, the active power given value is controlled to keep the power angle stable without divergence; meanwhile, a saturation characteristic function is calculated according to the drop amplitude of the grid-side voltage, and the output value of the virtual internal potential is changed based on the saturation characteristic function, so that the virtual impedance value in the control structure is changed, and the current limiting and voltage supporting requirements of the low-voltage ride-through strategy are met. The virtual impedance value can be changed according to different voltage drop degrees, and meanwhile the saturation characteristic is achieved.

The present application belongs to the grid-connected converter technical field, disclose a kind of droop control inverter current-limiting control method and system, the virtual impedance size and active reference value restriction condition when the fault current is equal to current-limiting value are accurately obtained by phasor analysis, virtual impedance-current difference proportional coefficient and active reference value-current difference proportional coefficient are designed considering the most serious situation of current-limiting, proportional increase virtual impedance and reduce active reference value with the change of adaptive current at fault, can meet the current-limiting requirement under different depth grid voltage drop.The current-limiting control method proposed in the present application is adaptive to fault current, without fault detection device, the transient stability of inverter is enhanced due to the reduction of active reference value at fault, and the fault current is indirectly limited by adjusting virtual impedance and active reference value, the voltage source characteristics of droop control inverter are retained, and the system fault ride-through capability is significantly enhanced.

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.