64 results about "Active power flow" patented technology

A risk scenario identification method and system for a power grid cascading failure, a device, and a medium. The method comprises: acquiring power grid historical operation data (S101); performing cascading failure simulation on the power grid historical operation data, so as to obtain an active power flow entropy (S102); visualizing the power grid historical operation data and the active power flow entropy, so as to obtain a multi-row heat map (S103); dividing the multi-row heat map into a training set and a test set (S104); training a neural network by using the training set, so as to obtain a power grid cascading failure risk scenario identification model (S105); and testing the power grid cascading failure risk scenario identification model by using the test set, so as to obtain a risk scenario identification result (S106).

The invention discloses a new energy electric power robustness control method, system and device for preventing chain overload of a power transmission section and a medium. The method comprises the following steps: obtaining the active power flow size and the operation state of each branch in the power transmission section; calculating the comprehensive sensitivity of all the controllable nodes to each branch in the power transmission section, and generating a composite priority index based on the calculated comprehensive sensitivity, the classification of the nodes and the new energy fluctuation risk; performing priority ranking on the generator nodes to generate a node sequence; in combination with a reverse equivalent pairing principle, selecting an adjustment node pair, and calculating an adjustment amount of node output by considering an adjustment amount dynamic margin constraint of new energy output uncertainty; recalculating the active power flow and the operation state of each branch in the section; and judging whether the section power flow and the margin meet a termination condition or not to realize optimal control. According to the method, the operation robustness of the new energy power system is improved, and the overload of the transmission section can be quickly and efficiently eliminated.

The invention relates to the technical field of power dispatching, in particular to an energy storage combined frequency modulation control method and system in a source-network-load-storage integrated regional power grid, and the method comprises the steps: dynamically calculating the adjustable capacity of each resource, dynamically aggregating the total adjustable capacity of the system, sensing the multi-dimensional frequency situation and calculating the adjusting power, and selecting a frequency modulation mode and generating a power distribution strategy. And generating a splitting and isolated network frequency modulation stability control strategy and performing system grid-connected resynchronous operation. The method is suitable for guiding power supply, energy storage and load all-resource collaborative frequency modulation strategy generation in a regional power grid. For consistency of frequency deviation, frequency change rate and active power flow direction, multi-dimensional frequency situation awareness is constructed, power distribution strategies in different modes are generated based on a total adjustable capacity interval of a system, and a frequency stability control and grid-connected resynchronization strategy after splitting is given when the frequency and the adjustable interval exceed limits. Accurate matching of all-resource collaborative frequency modulation and strategies in a regional power grid is realized, and the frequency modulation response speed of the system is improved.

The invention discloses a power grid switching operation anti-misoperation verification method and device based on real-time topology, and relates to the technical field of power grid anti-misoperation, and the method comprises the following steps: collecting the phasor data of target equipment and the real-time active power flow direction of a power grid, constructing a real-time directed topological graph, and extracting a to-be-reconstructed sub-graph associated with an operation instruction of the target equipment; converting the target equipment operation instruction into an impedance correction term, constructing an estimated impedance matrix based on the to-be-reconstructed sub-graph, and calculating a corresponding power flow transfer vector; performing double-layer constraint decoupling on the topological structure of the to-be-reconstructed sub-graph to generate a source flow path chain set; and generating a verification result based on the power flow transfer vector, the source flow path chain set and a preset anti-error rule. The method is used for solving the problems of electrical rehearsal real-time lagging and complex topology anti-error logic confusion in a complex power grid environment.

The invention discloses a carbon flow monitoring and accounting method based on the Internet of Things. The method specifically comprises the following steps: S1, collecting power flow information of a power system; s2, performing flow calculation on the power network to obtain an active power flow matrix F of the whole power network; s3, performing hierarchical iterative calculation on the power grid carbon flow density, and gradually obtaining carbon flow data of the whole power grid; s4, arranging the carbon flow data to obtain a carbon flow matrix C, and providing a final visual result; s5, collecting carbon emission data; s6, establishing a carbon flow neural network model; s7, training the carbon flow neural network model; and S8, checking the carbon emission of the whole system by using the carbon flow neural network model. According to the invention, an Internet of Things data acquisition technology and a data analysis visualization technology are mainly utilized, the flow path of the carbon flow in the whole power network is visually displayed for a power system manager, and low carbon and greenization of the whole system are helped to be realized.

The invention provides a distributed photovoltaic voltage out-of-limit treatment method for active and reactive power proportion optimization. The method comprises the following steps: when detecting that the voltage of a grid-connected point is out of limit, giving up a working mode of maximum power tracking when the voltage is out of limit, and executing the following steps: calculating reactive and active power proportionality coefficients which should be injected into the grid-connected point by a photovoltaic power generation system after the voltage of the grid-connected point is out of limit; the reactive power and active power proportionality coefficient enables the active power injected into the power distribution network bus by the photovoltaic power generation system to be maximum under the condition that the grid-connected point voltage is not out of limit; calculating an active power instruction and a reactive power instruction by using reactive and active power proportionality coefficients; based on the active power instruction and the reactive power instruction, obtaining a current reference value on a dq axis in a dq coordinate system subjected to constant-amplitude coordinate transformation; and adjusting the active power and reactive power of the photovoltaic injection grid-connected point based on the current reference value on the dq coordinate axis so as to adjust the voltage of the grid-connected point. Under the condition that the voltage of the grid-connected point does not exceed the limit, the active power flowing to the grid-connected point can be ensured to be maximum.

The present invention belongs to the technical field of power electronic converters and discloses a medium-voltage distribution network flexible interconnection switch topology and control method. The medium-voltage distribution network flexible interconnection switch topology provided by the present invention includes three connected reactors L1, three connected reactors L3, two chain-type STATCOMs, two three-phase isolation transformers, two three-phase LC filters, two three-phase inverter circuits, and a DC port. Back-to-back three-phase converters are introduced at the ends of the chain-type STATCOMs of two feeders. Through the back-to-back three-phase converters, active power flow mutualization between the two medium-voltage chain-type STATCOMs, that is, between two different feeders, can be achieved. The present invention can achieve DC capacitor voltage balancing of the chain-type STATCOM submodules of the two feeders. Compared with the BTB-VSC commonly used in existing medium-voltage distribution network flexible interconnection demonstration projects, this solution has lower cost, simpler topology, easier control, and does not need to consider the active and reactive power decoupling issues between interconnected feeders, making it easy to promote and apply on a large scale.

The invention discloses a large-scale distributed photovoltaic power generation scene simplified clustering method and device suitable for annual mode calculation of a power system. The method and device are suitable for annual mode calculation of the power system. The method comprises the steps of establishing a sensitivity model between photovoltaic output and line active power flow change, quantifying influence degrees of different photovoltaic scenes on power transmission line power flow, and constructing a disturbance quantity characteristic matrix of a distributed photovoltaic output scene on the power transmission line active power flow; and clustering the large-scale distributed photovoltaic output scenes by taking the disturbance quantity feature vectors as samples. According to the method, typical photovoltaic output scenes with representativeness are constructed, so that the number of redundant scenes is reduced, and typical output characteristics which have the greatest influence on safe operation of the system are reserved, and therefore, the simulation efficiency and the result reliability are improved; depth coupling of photovoltaic scene clustering and power system physical characteristics is realized, and more accurate data support is provided for system power flow analysis, load transfer research, scheduling decision and the like.

The embodiment of the invention discloses a power grid optimal power flow calculation method based on a convex relaxation technology and related equipment, first active power flow, first reactive power flow, second active power flow and second reactive power flow can simulate operation of alternating current and direct current power grids including high-voltage direct current power transmission, and through the convex relaxation technology, the optimal power flow of the power grid can be calculated. And a non-convex optimization problem in the power flow is converted into a convex optimization problem which is easy to solve, so that the accuracy and the calculation efficiency of the optimal power flow are ensured by calculating the optimal power flow by using the branch power flow model optimized by the convex relaxation technology, and the analysis requirement of an alternating current and direct current hybrid power grid is met.

The invention discloses an energy storage converter damping enhancement control method based on feedforward control. The method comprises the following steps: establishing an active power flow model of an energy storage converter system; adding an additional degree of freedom to the model to generate an improved active power flow model; ignoring a voltage loop and a current loop, and simplifying the improved active power flow model to obtain a small signal model; designing a feedforward controller Gc (s); and substituting the Gc (s) into the small signal model to obtain a damping-enhanced active power flow model of the energy storage converter. According to the method, a feed-forward path is introduced to improve the damping level, and by applying the method, power oscillation can be effectively attenuated under the condition that original inertial response is not affected; the damping effect and the power dynamic state can be flexibly adjusted to any specific level; and under the condition that system parameters are available, automatic setting and real-time self-adaption of the feedforward controller are realized. Meanwhile, under the condition that the power grid frequency suddenly changes, the rapid change of the active power generated by the original inertia response is beneficial to maintaining the stability of the power grid frequency.

The invention provides a power distribution network load flow calculation method, a power distribution network load flow calculation device and a power distribution network load flow calculation system. The method comprises the following steps: establishing a power distribution network load flow equation; under the condition that any node in the power distribution network is disconnected, a first equation is established according to the voltage phase angle, the reactance and the initial power flow quantity of each target branch, and the target branch is an affected branch after the node is disconnected; determining the ratio of the load flow increment of the target branch to the initial load flow quantity of the node as a distribution factor; establishing a second equation according to a vector formed by the distribution factors and an active power flow vector of an affected branch when the power distribution network is in a steady state; carrying out calculation by combining the power distribution network power flow equation, the first equation and the second equation to obtain a power flow increment of the influenced branch; and adjusting the power distribution of the affected power equipment in the power distribution network according to the power flow increment of the affected branch. According to the method, the problem that affected power equipment cannot be adjusted in time due to low load flow calculation efficiency in the prior art is solved.

It is proposed a method for actively controlling an output voltage of a first energy storage system connected in parallel to a second energy storage system for controlling reactive or active power flow from or into any one of the energy storage systems; the method comprises the following steps: providing (S1) at least one reactive or active power flow demand value of at least one phase load and / or phase network; providing (S2) an output voltage measurement and a current measurement of the second energy storage system; calculating (S3) a reactive or active power flow demand current value for the second energy storage system on the basis of the at least one reactive or active power flow demand value and the output voltage measurement value; calculating (S4) a control output voltage value of the first energy storage system based on the reactive or active power flow demand current value and the current measurement value of the second energy storage system; modulating (S5) the control output voltage value into at least one control signal; and controlling (S6) an output voltage of the first energy storage system based on the at least one control signal.

Provided is a power conversion device disposed at an end of a high-voltage DC power transmission system connected to a renewable energy power source, the power conversion device making it possible to configure a multi-pole high-voltage DC power transmission system by connecting a plurality of power conversion devices in parallel to the same renewable energy power source. The power conversion device includes a power converter and a control device. The power converter converts AC power supplied by the renewable energy power source to DC power and outputs the converted DC power to a DC power transmission line. The control device controls the AC voltage outputted by the power converter to the renewable-energy-power-source side. The control device has a voltage control unit and a current control unit. The voltage control unit generates a voltage command value for controlling the amplitude and the phase of the AC voltage on the basis of at least the power value of active power flowing in from the renewable energy power source. The current control unit corrects the voltage command value via current feedback for reducing at least a DC current component of a lateral-flow current flowing between the current control unit and the power converter of another pole on the renewable-energy-power-source side.

The invention provides a three-level converter midpoint voltage control and leakage current suppression method based on SVPWM (Space Vector Pulse Width Modulation), which comprises the following steps of: firstly, defining a basic output voltage vector of a three-level converter, and dividing a space voltage vector diagram sector; thirdly, combining the small vectors and the small vectors as well as the small vectors and the medium vectors, ensuring that the sum of midpoint currents generated by the combined vectors is zero, and forming a first constraint condition; taking a zero vector and a large vector as fixed output, introducing a combined vector, and ensuring that the action time of the introduced front and rear axle arm states is unchanged to obtain a second constraint condition; and establishing a third constraint condition according to the small vector, the neutral-point voltage unbalance degree and the active power flow direction. Unbinding and optimizing a three-phase bridge arm switch state so as to suppress leakage current; and in combination with the constraint condition and the optimization sequence, solving the vector action time, and generating a driving signal. According to the method, the neutral-point voltage can be accurately controlled, the leakage current can be effectively suppressed, the switching frequency is reduced, smooth switching is realized, and the operation performance of the converter is improved.

The invention provides a carbon footprint tracking method and system based on electric vehicle path planning, and belongs to the technical field of path planning and carbon footprint tracking, and the method comprises the steps: obtaining the road network planning reference data of a target region, and inputting the data into a preset road network planning model, so as to enable the road network planning model to generate a corresponding road network planning result; according to the road network planning result and the real-time operation data of the power system of the target area, performing power flow planning on the power system through a preset power flow planning model, and determining the active power flow distribution of the power system and the actual active power of each generator; and according to the carbon emission intensity of each generator, the actual active power of each generator and the active power flow distribution of the power system, calculating the node carbon potential of each power grid node. The problem that in the prior art, carbon emission accounting is disjointed with the dynamic behavior of an electric vehicle user can be solved.

The invention discloses a series-parallel hybrid five-port energy router capable of realizing transformer area interconnection and a control method of the series-parallel hybrid five-port energy router. The five-port energy router comprises four low-voltage alternating current ports AC1, AC2, AC3 and AC4, a direct current port DC, two parallel converters PCM1 and PCM3, and two series converters SCM2 and SCM4. AC ports of the PCM1 and the PM3 are respectively connected with the AC1 and the AC3, and AC ports of the SCM2 and the SCM4 are respectively connected with the AC2 and the AC4 through series transformers; dC ports of the PCM1, the SCM2, the PCM3 and the SCM4 are connected together to form a common DC bus; dC is led out from the common DC bus. The five-port energy router supports parallel connection-series connection and parallel connection-parallel connection power flow mutual aid modes, DC bus voltage is stabilized through the PCM, reactive power and active power are controlled through the PCM, voltage amplitude and phase control active power flow are adjusted through the SCM, and the required configuration capacity is small. According to the invention, the flexible interconnection of the low-voltage transformer area can be realized, the dynamic capacity increase of the transformer area and the fault rapid transfer are realized, and the power supply reliability and the distributed power supply acceptance capability are improved.

The invention discloses an electric power system effective reserve capacity analysis method and system, a medium and a terminal, and the method comprises the steps: carrying out the anticipated fault analysis of an electric power system based on an anticipated fault set of the electric power system, and constructing a channel power flow safety constraint based on a power flow transfer relation generated through analysis; analyzing the maximum possible value and the minimum possible value of each constraint function on the basis of describing the channel active power flow as a linear function of source load injection power and direct current receiving power, and filtering out the constraint functions of which the maximum possible values and the minimum possible values are located in corresponding allowable ranges in the channel power flow security constraints so as to obtain network security constraints; a model for solving the effective reserve capacity of a power system is established by taking maximization of the active output variation of a conventional unit of each node in an extremely severe state as an optimization target and combining with network security constraints. By adopting the method, the number of free variables can be reduced, unnecessary constraints can be filtered out, and the analysis efficiency of the effective reserve capacity is improved.

The invention discloses a carbon reduction strategy optimization method, system and device and a storage medium, and the method comprises the steps: obtaining active power flow data and the carbon emission intensity of a power supply point, and calculating an electric carbon factor of each load enterprise node according to the active power flow data and the carbon emission intensity of the power supply point; identifying the carbon emission characteristics of each load enterprise node according to the electrical carbon factors, and generating an enterprise portrait corresponding to the carbon emission characteristics; and based on the enterprise portrait and the production process and energy consumption elasticity of each load enterprise, generating a differentiated carbon reduction strategy, realizing optimization of the carbon reduction strategy, and providing the differentiated carbon reduction strategy for power consumption subjects with different positions and different characteristics in the park.

The invention relates to an anticipated fault scanning method and device applied to a power system element, computer equipment, a storage medium and a computer program product, and relates to the technical field of power grid safety monitoring. The method can shorten the time of detailed load flow calculation and improve the efficiency of anticipated fault scanning. The method comprises the steps of obtaining a node susceptance matrix and an active power flow total increment of a to-be-detected element under an expected fault condition, and obtaining a voltage phase angle increment corresponding to each bus in the to-be-detected element according to the node susceptance matrix and the active power flow total increment; for each branch in the to-be-detected element, obtaining the active power flow increment of the current branch according to the first voltage phase angle increment, the second voltage phase angle increment and the reactance value of the current branch; and determining a weight coefficient and a power flow limit value of the current branch, and inputting the active power flow, the weight coefficient and the power flow limit value into a preset severity index operation model to obtain an anticipated fault severity index when the current branch is disconnected.

The present application discloses a carbon emission assessment method, device, storage medium and product, and relates to the field of carbon emission technology. The present application is based on node power parameters, node heat parameters, heating carbon emission intensity of various sources in the park, and power supply carbon emission intensity of various sources in the park. For any node, the heat loss of the branches between each node, the heat transfer amount of the branches between nodes, the actual heat consumption corresponding to the node, and the heating carbon emission intensity of various sources in the park are calculated; based on the power load of each node, the active power flow between each node, and the power supply carbon emission intensity of various sources in the park, the power consumption carbon emission intensity of the node is calculated, thereby effectively transmitting the carbon emission responsibility of electricity and thermal resources to specific nodes, helping users corresponding to the nodes understand the cleanliness of energy use, and providing basic signals for users' low-carbon response.

The application discloses a single-core independent phase-shifting transformer and a control method thereof. The single-core independent phase-shifting transformer comprises an excitation winding, a source-side voltage regulation winding, a load-side voltage regulation winding and an on-load voltage regulation switch. The excitation winding is a primary side of the single-core independent phase-shifting transformer and is connected in a triangle mode. The source-side voltage regulation winding and the load-side voltage regulation winding are secondary sides of the single-core independent phase-shifting transformer and are directly connected in series in a circuit. The source-side voltage regulation winding and the load-side voltage regulation winding are both provided with the on-load voltage regulation switch. The source-side voltage regulation winding and the load-side voltage regulation winding are divided into several sections according to phase-shifting angles, that is, the phase-shifting angle of each section is changed by the same value, and the voltage of each section is changed by different values. The application can independently adjust the phase and effective value of the circuit voltage, independently adjust the active power flow and the reactive power flow of the circuit, and further optimizes the adjustment performance of the phase-shifting transformer.

The invention belongs to the technical field of low-frequency alternating-current power transmission, and provides an alternating-current fault ride-through control method and system of a multi-terminal low-frequency power transmission system, and the technical scheme is based on an alternating-current fault ride-through control strategy of the multi-terminal low-frequency power transmission system. The fault frequency conversion station controls and reduces the amplitude of the alternating voltage of the low-frequency side, so that other frequency conversion stations receive a fault generation signal, and then one or more power control frequency conversion stations with the power flow direction opposite to that of the fault frequency conversion station control and reduce the active power flowing into / out of the low-frequency power transmission line. Therefore, the serious overvoltage / undervoltage phenomenon in the fault frequency conversion station is avoided. And reliable fault ride-through of the multi-terminal low-frequency power transmission system is ensured.

The invention discloses a power system carbon emission flow calculation method and system, electronic equipment and a medium, and relates to the technical field of power system carbon emission flow calculation. The method comprises the following steps: calculating an extended incidence matrix according to active power transmitted by each branch, power injected to a corresponding node by an upstream node of each node and power injected to a generator set at each node; determining a unit power injection distribution matrix of the power generation side of the power system, the carbon emission intensity of each generator set and a unit injection carbon flow rate matrix according to the generator set injection power at each node; determining a system load distribution matrix according to the active power of the load at each node; and calculating the carbon emission flow of the power system according to the matrix, the active power flowing through the nodes, the carbon emission intensity and the active power flowing through each branch. According to the invention, the accuracy of the calculation result of the carbon emission flow of the power system can be improved.

The invention discloses a two-stage reactive power flow generation method considering the switching times of a reactive power compensation device. According to the method, a two-stage solving strategy is adopted to solve the reactive power flow generation problem considering the switching frequency limitation of the parallel reactive power compensation device, and in the first stage, the minimum branch active power flow deviation and the voltage square difference between the two ends of a branch serve as a target function; an optimization model containing constraints such as the switching frequency limitation of the discrete reactive power compensation device is constructed, linear processing is carried out, and rapid convergence of the alternating current power flow is achieved by adjusting the switching state of the reactive power compensation device; and in the second stage, fixing the switching state obtained in the first stage, and further adjusting the active output, the reactive output and the terminal voltage of the generator set by taking the minimization of the active adjustment amount of the generator set as a target function, so that the system meets the AC feasibility requirement. According to the method, the solving complexity of the reactive power flow generation problem can be remarkably reduced, the solving efficiency is improved, and the rapid generation and feasibility requirements of the reactive power flow of the power system are met.

The invention provides a carbon management evaluation method and system based on edge calculation. The method comprises the following steps: combining the carbon injection rate of each power distribution side edge node with the active power flow distribution of each line of the power distribution network, and generating a carbon flow vector of each line; generating a carbon emission feature vector based on the carbon flow vector, the power grid topological data and the equipment current waveform parameter of the user side edge node; generating a carbon emission characteristic divergence rate based on the phase space parameter of the power grid frequency change rate of the power distribution side edge node; when the carbon emission characteristic divergence rate exceeds a stability threshold value, generating carbon flow optimization regulation and control data based on the dynamic control signal through an edge control node; and based on the carbon flow net injection rate and the fusion state vector of each power distribution network node, positioning an abnormal user side edge node and generating an exception handling instruction, and the method can solve the problems that carbon emission accounting is distorted, low-carbon and safety cooperation is difficult to realize, and exception judgment has deviation.

The invention provides a novel topological structure of a thyristor control type phase-shifting transformer combined with a cascaded H-bridge converter. The novel topological structure comprises a series transformer, a parallel transformer, a thyristor control circuit and a continuous regulation control circuit, the parallel transformer obtains voltage from a power grid line through the series transformer, according to a power grid line power control target, secondary side adjustable voltage is generated through the thyristor control circuit, coarse adjustment of phase-shifting voltage is achieved, the coarse adjustment is combined with output voltage of the continuous adjustment control circuit, and phase-shifting voltage with adjustable phase amplitude is generated. And the phase-shifting voltage is compensated into the power grid line through the series transformer, so that the power of the power grid line is adjusted to the target power. The method not only inherits the characteristics of quick adjustment and quick response of the traditional TCPST, but also overcomes the defect that the power of the traditional TCPST cannot be continuously adjusted, and realizes the quick and continuous adjustment of the active power flow of the line.

The invention provides a method for calculating power grid active loss caused by automatic voltage control based on sensitivity, and belongs to the technical field of power system voltage control. The method comprises the following steps: when a current automatic voltage control cycle arrives, obtaining a reactive power equipment set influencing the active power loss of the power grid and calculating the sensitivity of reactive power output of each reactive power equipment in the set to the active power flow loss of the power grid; calculating the active power flow loss of the power grid caused by the reactive power equipment in combination with the reactive power output variable quantity of the reactive power equipment in the current automatic voltage control period; and based on the power grid active power flow loss caused by the reactive equipment, performing integration by adopting a rectangular method to obtain the power grid active power loss caused by the reactive equipment. According to the method, the quantitative calculation result of the active loss of the power grid caused by automatic voltage control after the automatic voltage control system is put into closed-loop operation can be obtained online in real time, and safe and efficient operation of the power grid is facilitated.

This invention provides a method for managing voltage exceedance in distributed photovoltaic (PV) systems by optimizing the active and reactive power ratio. When the grid connection point voltage exceeds the limit, this application abandons the maximum power point tracking (MPPT) mode and performs the following steps: calculating the reactive and active power ratios that the PV system should inject into the grid connection point after the voltage exceedance, ensuring that the active power injected into the distribution network bus is maximized when the grid connection point voltage does not exceed the limit; calculating active and reactive power commands using the calculated reactive and reactive power ratios; obtaining current reference values ​​on the dq axis in a dq coordinate system with equal amplitude coordinate transformation based on the active and reactive power commands; and adjusting the active and reactive power injected into the grid connection point based on the current reference values ​​on the dq coordinate axis to regulate the grid connection point voltage. This invention ensures maximum active power flowing to the grid connection point while maintaining the grid connection point voltage within the specified limits.

The application relates to a method and device for scanning a predicted fault applied to an element of a power system, a computer device, a storage medium and a computer program product, and relates to the technical field of power grid safety monitoring. The application can shorten the time of detailed power flow calculation and improve the efficiency of the predicted fault scanning. The method comprises the following steps: obtaining a node admittance matrix and an active power flow total increment of an element to be detected under a predicted fault condition; obtaining a voltage phase angle increment corresponding to each bus in the element to be detected according to the node admittance matrix and the active power flow total increment; obtaining an active power flow increment of a current branch according to a first voltage phase angle increment, a second voltage phase angle increment and a current reactance value of the current branch for each branch in the element to be detected; determining a weight coefficient and a power flow limit value of the current branch; and inputting the active power flow, the weight coefficient and the power flow limit value into a preset severity index operation model to obtain a predicted fault severity index when the current branch is disconnected.

The application discloses a method and system for improving structural controllability of a power system, and belongs to the field of structural controllability optimization of a power system, which comprises the following steps: taking a generator, a transformer substation and a power consumption unit as a node, taking a power transmission line as an edge, the direction of the edge being consistent with the active power flow direction of the power transmission line, establishing an original network model of the power system, deleting the incoming edges of the generator nodes in the original network model to obtain a power network, solving the maximum matching of the power network, merging the edges with the same nodes in the maximum matching to obtain a matching path set and a matching circle set, marking the paths with the generator nodes as starting points in the matching path set as control paths, marking the remaining paths as uncontrollable paths, adding a directed edge between the terminal point of the control path and the starting point of the uncontrollable path, and adding a power transmission line between the nodes corresponding to the added edges. The application makes the power system structurally controllable only when the generator nodes are used as driving nodes, and effectively improves the structural controllability of the power system.