38 results about "Voltage collapse" patented technology

The invention discloses a control method for improving the utilization rate of renewable energy sources in real time, particularly relates to the technical field of voltage collapse protection of a direct-current power distribution network, and is used for solving the problems of voltage collapse spreading and renewable energy source utilization rate reduction caused by photovoltaic sudden drop. The method comprises the following steps: monitoring photovoltaic output, bus voltage and load current in real time; predicting a voltage collapse spreading path; identifying an active migration source according to the time sequence difference between the voltage drop and the load current abrupt change; calculating a current increment upper limit of the active migration source cluster; generating a cross-region compensation instruction based on the current increment and the energy storage adjustable power; issuing a compensation instruction to the energy storage unit and synchronously locking the current regulation authority of the active migration source; through dynamic coupling of collapse path prediction and migration source identification, cooperative control of cross-regional power reverse compensation and local load behavior freezing is realized, voltage collapse chain propagation is blocked, and the photovoltaic local consumption rate is improved.

The invention relates to the technical field of power distribution network reactive compensation, and discloses a power distribution network reactive compensation control method. The reactive compensation control method for the power distribution network comprises the following steps: information sampling; sampling and analyzing; analyzing temperature rise; performing operation analysis; monitoring power loss; the method ensures that a large power plant can provide enough active hot standby for a load center, meets the requirement of reactive voltage support, enables sufficient reactive standby capacity to be formed at each load node and hub node during the operation of a power system, avoids the malignant event of voltage collapse caused by the lack of reactive power of the system, and improves the reliability of the system. The method can guarantee safe and stable operation of a power grid, can timely quit capacitor operation after equipment operation encounters a power-off condition, can ensure data integrity in a certain time interval, can effectively avoid adverse effects on equipment under the power-off condition, and can adjust a sampling interval in real time during actual operation of a power distribution network system. And the accuracy of information sampling analysis is ensured.

The invention relates to a vehicle output voltage adjusting method and device, a storage medium, a product and a vehicle. The method comprises the steps that under the condition that a vehicle transmits electric energy to a power grid, an alternating current voltage value currently output by an OBC is adjusted according to reactive power currently output by the OBC and a current bus alternating current voltage value of the power grid, so that the bus alternating current voltage value of the power grid is within a preset range. Under the V2G scene, the alternating current voltage value output by the vehicle can be controlled by controlling the reactive power output by the OBC, so that the stability of the bus alternating current voltage value of the power grid is improved, the voltage safety of the power grid is ensured, and the risk of voltage collapse of the power system is reduced.

The invention discloses a static var generator control method and a static var generator control system, which can quickly respond to the change of the voltage of a power grid, maintain the system voltage in a set range by dynamically adjusting the output of reactive power, are particularly important for long-distance power transmission lines and heavy-load areas, and can quickly provide or absorb the reactive power when the system is subjected to large disturbance. Voltage collapse is prevented, and stable operation of the system is ensured.

The present invention discloses a static VAR generator control method and system, which can quickly respond to changes in grid voltage and maintain the system voltage within a set range by dynamically adjusting reactive power output. This is especially important for long-distance transmission lines and heavily loaded areas. When the system is subject to large disturbances, reactive power can be quickly provided or absorbed to prevent voltage collapse and ensure stable operation of the system.

The invention relates to the technical field of new energy grid-connected system stability analysis, in particular to an SVC new energy short-circuit ratio margin assessment method, system equipment and a medium, and aims to accurately correct a real-time voltage support strength assessment model of a new energy access point by dynamically integrating SVC reactive compensation capacity into a short-circuit ratio calculation process. The defect of system strength misjudgment caused by neglecting reactive compensation in a traditional method is overcome; analyzing a static voltage stability limit based on the maximum transmission power of the new energy, and accurately defining a critical short-circuit ratio as an instability boundary threshold value; a margin index is calculated through a difference value between a short-circuit ratio and a critical short-circuit ratio, the safety redundancy of the system is directly quantified, and a single-station independent access and multi-station strong coupling scene is compatible with the positive and negative characteristics of a unified margin criterion, so that the prevention and control capability on the voltage collapse risk of a high-proportion new energy power grid is remarkably improved; and a grounding stability decision basis is provided for new energy station planning and site selection, SVC reactive compensation configuration and power grid operation scheduling.

The invention provides a reactive power control method and system for a new energy station after a direct current blocking fault. The reactive power control method comprises the steps of obtaining reactive power output data of the new energy station after the direct current blocking fault; obtaining a reactive power reference value of the new energy station by using a pre-constructed reactive power control model according to the reactive power output data; performing reactive power control on the new energy station according to the reactive power reference value; wherein the reactive power control model is constructed by taking maximization of reactive power reserve of the new energy station as a target and taking a transient voltage fluctuation degree constraint, a transient off-network risk degree constraint and an adjustable reactive power output limit constraint as constraint conditions; according to the method, the reactive power backup of the new energy station is maximized, and the constraint conditions are combined, so that the reactive power support capability of the new energy station after the direct-current locking fault can be fully excavated, dynamic reactive power support resources with considerable capacity are formed, the voltage collapse phenomenon caused by overlarge voltage fluctuation can be prevented, and the voltage stability is improved.

The invention discloses an electromechanical transient simulation method and system for the voltage stability of a power system, and the method comprises the steps: obtaining data after the system is disturbed, and obtaining a time constant when a load is disturbed to recover to a steady state, and a proportion coefficient related to a static active load and a reactive load through a parameter identification algorithm; listing a conventional ZIP static load model, constructing a dynamic ZIP load model by adopting a proportional integral differential link and an amplitude limiting link, and reflecting an input-output relationship between active and reactive loads and equivalent impedance; determining a system balance point according to a steady-state power flow calculation result, performing linearization processing on all dynamic equations of the whole network at the balance point to obtain a state space model, calculating a state matrix eigenvalue, and judging a voltage stability condition of a bus where a load is located according to a sign of a real part of a related eigenvalue; and performing dynamic time domain simulation on the adjusted system, applying N-1 or N-2 type line faults to the whole network, and simulating a possible voltage collapse scene of the system. And a theoretical support is provided for providing countermeasures after voltage instability.

The invention discloses an energy distributed control method and system applied to a micro-grid system, and relates to the technical field of distributed energy control, and the method comprises the following steps: collecting a voltage phase angle sequence at a key node of a micro-grid, constructing a phase angle extrusion dynamic fingerprint band based on the voltage phase angle sequence, and forming a time distribution rule of phase angle extrusion; and calculating an extrusion strength index according to the phase angle extrusion dynamic fingerprint band, mapping the extrusion strength index into a dynamic margin parameter of the reactive power compensation device, and limiting a reverse absorption trigger threshold according to the dynamic margin parameter. According to the method, distributed reactive power regulation and control are realized through phase angle extrusion dynamic characteristics, so that the micro-grid has adaptive stability under a multi-source fluctuation condition. The reactive power compensation device performs smooth output according to extrusion characteristics, eliminates reverse absorption and keeps voltage stable; the energy storage device implements self-adaptive derating by relying on a bus voltage dynamic support curve, coordinates active and reactive output, prevents voltage collapse, and improves the overall operation safety and continuity of the system.

An example is a method. A pseudo array supply voltage (VDDAI) of a bitcell power tracking column for a memory array is determined by a write assist circuit coupled to the memory array. An actual VDDAI provided to a bitcell in the memory array during a write operation, based on the pseudo VDDAI of the bitcell power tracking column, is tracked by the write assist circuit. A collapse level of the actual VDDAI to the bitcell is controlled during the write operation, based on the tracking.

The present invention discloses a method and system for simulating the electromechanical transient state of power system voltage stability. The method obtains data after the system is disturbed and uses a parameter identification algorithm to obtain the time constant for the load to recover to a steady state, as well as the proportional coefficients related to the static active load and reactive load. A conventional ZIP static load model is listed, and a dynamic ZIP load model is constructed using a proportional-integral-differential (PID) and a limiting step to reflect the input-output relationship between active and reactive loads and equivalent impedances. The system equilibrium point is determined based on the results of steady-state power flow calculations, and all dynamic equations of the entire network are linearized at the equilibrium point to obtain a state-space model. The eigenvalues ​​of the state matrix are calculated, and the voltage stability of the busbar where the load is located is determined based on the positive and negative signs of the real parts of the relevant eigenvalues. A dynamic time-domain simulation is performed on the adjusted system, and an N-1 or N-2 line fault is imposed on the entire network to simulate the voltage collapse scenario that may occur in the system. This provides theoretical support for proposing countermeasures after voltage instability.

This invention discloses a method and system for low-voltage busbar protection in distribution networks based on directional blocking. The method includes: S1. Real-time acquisition of current signals on the busbar and each branch circuit; S2. Calculation of current surges on the branch circuits, and determination of whether the current signal is abnormal based on the magnitude of the current surges; S3. When the current signal is determined to be in an abnormal state, the fault direction of the current is determined based on a current direction function; S4. The fault location is determined based on the fault direction of the current, and blocking logic is constructed based on the fault location. Determining the fault direction of the current based on a separate current direction function effectively overcomes the problem of overcurrent protection being prone to false tripping or failure to trip due to distributed power source access, and solves the problem of protection failure when the busbar voltage collapses. The method also has high speed of operation, meeting the rapid isolation requirements of active distribution networks to prevent cascading disconnection.

This invention discloses a method, device, and medium for coordinated control of DC power supply, load, and energy storage in a data center, belonging to the field of DC power supply control technology. The method includes: extracting the state of charge (SOC) value at the moment of an event, the time integral of the absolute value of charging and discharging power within a preset time period before the event, and the time constant for the discharge power to rise from its initial value to its peak value after the event, establishing a three-dimensional mapping relationship; constructing an instantaneous response capability evaluation function for the energy storage system based on the three-dimensional mapping relationship, and predicting the time constant; substituting the predicted time constant, the equivalent capacitance of the bus, and the preset maximum load step amplitude into the voltage dynamic response equation to obtain a predicted voltage drop depth; when the predicted voltage drop depth exceeds the voltage collapse threshold, calculating a dynamic adjustment margin value, and invoking distributed power sources and load regulation to move the SOC value to a safe region. This invention achieves dynamic quantitative evaluation of the instantaneous response capability of the energy storage system, reducing the risk of bus voltage collapse.

The present invention discloses a control method for improving the utilization rate of renewable energy in real time, specifically relating to the technical field of voltage collapse protection in DC distribution networks, and is used to solve the problems of voltage collapse propagation and reduced utilization rate of renewable energy caused by photovoltaic sudden drops; the method is achieved by the following steps: real-time monitoring of photovoltaic output, bus voltage and load current; prediction of voltage collapse propagation path; identification of active migration sources based on the timing difference between voltage drop and load current mutation; calculation of the current increment upper limit of the active migration source cluster; generation of cross-regional compensation instructions based on current increment and energy storage adjustable power; issuance of compensation instructions to energy storage units and synchronous locking of current regulation authority of active migration sources; dynamic coupling of collapse path prediction and migration source identification to achieve coordinated control of cross-regional power reverse compensation and local load behavior freezing, thereby blocking the chain propagation of voltage collapse and improving the on-site photovoltaic absorption rate.

The application relates to the technical field of voltage management, in particular to a power distribution network voltage management device, which comprises a data acquisition module, a data calculation module, an abnormality judgment module and a negative feedback module. The application significantly improves the voltage stability and power supply reliability of the power distribution network by monitoring and analyzing the key parameters of the power system in real time. The automatic abnormality judgment and load adjustment mechanism of the device not only reduces human intervention and operation errors, but also effectively prevents the risk of voltage collapse and power supply interruption by quickly responding to voltage deviation and stability problems. In addition, the closed-loop control strategy enables the system to dynamically adjust the load change rate threshold according to real-time feedback, enhancing the adaptive ability of the system and ensuring the stability of the voltage under various loads and operating conditions. In the long term, this intelligent voltage management helps to reduce power loss and prolong the service life of power equipment.

The application relates to a power grid safety and stability operation mode pre-control method and device; the method comprises the following steps: establishing a plurality of sets of operation mode simulation models according to preset operation data; determining all risks under each set of operation mode simulation models; simulating the development of power grid safety and stability operation mode pre-control for all scanned risks to obtain simulation pre-control results meeting stability criteria; and determining corresponding pre-control parameters according to the simulation pre-control results of each set of operation mode. The scheme of the application formulates a safety and stability operation mode pre-control method, effectively improves the safety and stability of regional power grid operation, reduces the influence of faults on the interconnection of AC and DC receiving ends in heavy load areas, guarantees the safety and stability of the power grid, and avoids the situation that DC blocking, AC system voltage collapse and other large influences are caused by faults.

The invention provides a micro-grid on-grid and off-grid all-condition simulation circuit, which comprises a data processing unit, a power grid architecture model, an energy storage unit model, a load unit model and a power supply unit model, and is characterized in that the power grid architecture model comprises a section I bus, a section II bus and a power transmission line; the energy storage unit model, the load unit model and the power supply unit model are configured in the range of the I-section bus and the II-section bus in a high-voltage direct hanging mode, and loads in the range of the I-section bus and the II-section bus are unequal. According to the invention, the source, the network, the load and the operation mode of the micro-grid are used as a whole for systematic testing for the first time, and the limitation of traditional single fault simulation is avoided. Potential risks such as grid-connected and off-grid switching failure and voltage collapse can be exposed in advance, and passive-to-active conversion is realized. A simulation result is directly used for guiding energy storage capacity configuration, protection constant value setting, control strategy optimization and equipment type selection, and the success rate and reliability of actual engineering are remarkably improved.

The invention provides a power grid voltage stability margin optimization control method, and belongs to the field of power grid voltage optimization control. The method comprises the following steps: acquiring multi-source data influencing the voltage stability margin of a power grid based on a deployed data acquisition sensor; preprocessing the multi-source data by using various systematic processing methods to generate a standardized data set; constructing, training and optimizing a mixed deep learning model, and generating a voltage stability margin early warning level and a corresponding energy storage cooperative regulation and control demand; building a block chain alliance chain architecture, and designing a smart contract and data chaining rule; executing distributed energy storage collaborative optimization regulation and control, and maintaining the voltage stability margin of the power grid in a preset range; and monitoring the operation state and execution data of the power grid after collaborative optimization regulation and control, and verifying the voltage stability margin improvement effect. According to the invention, the dynamic adaptation of the operation state change of the power grid is realized, the dispatching instruction issuing and execution response time is shortened, the safety space of the voltage stability margin is expanded, and the voltage collapse risk of the power grid is reduced.

This invention belongs to the field of communication equipment security protection technology, and discloses a method for characterizing the static safety margin of power systems based on the truncated polynomial approximation method. This method first maps the load growth factor to complex-domain embedded variables, establishing a fully embedded power flow model; then, it expands the system state variables into high-order truncated polynomials, transforming nonlinear terms into linear convolutions between coefficients through Cauchy products, and solving for the polynomial coefficients using linear recursion; subsequently, it constructs Padé approximation rational functions to achieve analytical extension, directly calculating the high-load operating condition solution exceeding the original series convergence radius; finally, through a multi-stage continuity tracking strategy, it adaptively approximates the voltage collapse critical point, synthesizing the system's static safety margin. This invention abandons the reliance of traditional iterative algorithms on Jacobian matrix inversion and initial value guessing, fundamentally avoiding numerical ill-conditioned problems near the critical point, and achieving rapid characterization of static safety margins with large step size, high precision, and global robustness.

The invention discloses a power distribution network low-voltage bus protection method and system based on directional locking. The method comprises the steps that S1, current signals on a bus and all branch circuits are collected in real time; s2, calculating a current break variable on the branch circuit, and judging whether the current signal is abnormal or not based on the size of the current break variable; s3, when it is judged that the current signal is in the abnormal state, the fault direction of the current is judged based on a current direction function; and S4, judging a fault position based on the fault direction of the current, and constructing locking logic according to the fault position. The fault direction of the current is judged based on an independent current direction function, so that the problem that over-current protection is easy to operate by mistake or reject to operate due to access of the distributed power supply is effectively solved, and the problem of protection failure when the bus voltage collapses is solved; the method also has high speed, and meets the quick isolation requirement of the active power distribution network for preventing chain off-network.

The invention relates to a vehicle control method and a vehicle, and belongs to the technical field of vehicle control, and the method comprises the steps: obtaining an environment temperature, and determining the total peak current, corresponding to the environment temperature, of all loads to be started in a load characteristic database; estimating and determining the internal resistance value of the corresponding storage battery by using the storage battery internal resistance model; combining the total peak current, the internal resistance value and the open-circuit voltage of the storage battery, calculating a minimum voltage point when the to-be-started load is started at the same time, comparing the minimum voltage point with a preset safe voltage threshold value to obtain a comparison result, and determining that the starting strategy of the to-be-started load is peak shifting starting or parallel starting based on the comparison result; the starting time of the to-be-started loads is determined based on the starting strategy, the to-be-started loads are controlled to be started based on the starting time, the voltage collapse risk caused by simultaneous starting of multiple loads can be effectively avoided, and the starting reliability and stability of the vehicle electronic system in the low-temperature scene are improved.

The invention provides a transient voltage stability evaluation method and system. The method comprises the following steps: establishing a transient voltage stability time domain simulation model meeting the voltage support capability of a power transmission and distribution network connection point; the time domain simulation model comprises a synchronous generator model, a dynamic load model, a network topology structure model and a fault model; solving the time domain simulation model to obtain voltage support capability data of the power transmission and distribution network connection point; the historical power system data and the voltage supporting capability data form training data; training the convolutional neural network by using the training data; inputting the active power, the reactive load, the active load and the key voltage area node voltage of the synchronous generator into the trained network input layer; and outputting a transient voltage collapse index and a voltage deviation severity index at an output layer to realize transient voltage stability evaluation. Based on the method, the invention further provides a transient voltage stability evaluation system. According to the invention, efficient and accurate quantification of the transient stability index can be realized.

A transient voltage stability evaluation method based on a probabilistic neural network comprises the following steps: step 1, analyzing characteristics after wind power grid connection based on historical operation data of a power system to obtain system operation data samples, and classifying the samples according to critical fault clearing time margin values to form a corresponding initial sample set; 2, for the initial sample set, using a fusion feature t distribution-based random neighbor embedding algorithm to carry out dimension reduction processing on the feature quantity; 3, optimizing parameters of the probabilistic neural network by adopting a genetic ant colony hybrid algorithm; and 4, performing model training by using the training set as the input characteristic quantity of the optimized PNN to obtain an evaluation model, and finally performing transient voltage stability evaluation. According to the method, for security risk situation cognition, prospective early warning and formulation of prevention and emergency control measures, voltage instability and voltage collapse caused by the fact that large-scale new energy is merged into the power grid can be prevented.

The invention discloses a power grid power flow convergence adjustment method based on PPO-HELM. The method comprises the following steps: firstly, introducing a voltage stability judgment index and a voltage collapse point index by using a power flow calculation method of HELM; secondly, after a power flow non-convergence state is generated by adjusting the power grid load level, voltage collapse point index values in the state are calculated through HELM and ranked from large to small, and first m corresponding load nodes are selected to participate in power flow adjustment according to the ranking result; and then according to the voltage stability judgment index, the voltage collapse point index and the selected load node, establishing a PPO algorithm environment based on HELM. And finally, constructing an objective function, building a PPO algorithm model, outputting a power flow convergence adjustment action, and carrying out training and testing. The number of load nodes needing capacitor switching operation is reduced, the active power and reactive power adjusting time is shortened, and the adjusting efficiency is improved.

The invention provides a power grid power flow convergence adjustment method based on SAC-HELM, and the method comprises the following steps: 1, building a power grid model through a power flow calculation method based on a full-pure function embedding power flow calculation method, and introducing a voltage stability judgment index and a voltage collapse point index; and step 2, adding an index for judging power flow convergence, and screening out generators and loads participating in power flow adjustment. Step 3, establishing an SAC model based on HELM, wherein the reward of the SAC is set by combining a voltage stability judgment index and a voltage collapse point index; and step 4, training and testing the model to obtain a load flow convergence adjustment result. According to the method, the power grid can quickly find a convergence solution, and the workload is greatly reduced.

The invention provides a multi-section transmission power optimization method and device, equipment and a storage medium, and relates to the technical field of electrical engineering, and the method comprises the steps: generating a sample data set according to power grid parameters; evaluating the power limit of each power transmission section in the sample data set by using an integrated learning model; for any power transmission section, the optimization process is executed and comprises the following steps: S1, calculating the sensitivity of the power transmission power of the section when the power is injected into the generator so as to determine a target generator; s2, calculating an average value of a node voltage stable state and a maximum value of a voltage collapse critical point; s3, calculating the difference between the actual power and the target power of the section; and S4, taking the power limit as a constraint, and selecting at least one item from the voltage index and the difference value according to the difference value to construct a reward function. And S5, adjusting the output of the target generator through a reward function to converge the actual power of the section to the target power. According to the application, the output of the generator is dynamically adjusted by fusing the ensemble learning evaluation and the multi-index reward mechanism, and accurate optimization of the transmission power is realized.

The embodiment of the specification provides a data screening and sorting method and device of a power system, wherein the data screening and sorting method of the power system comprises the following steps: determining an initial power system, determining an observation bus based on the initial power system; wherein the initial power system comprises at least two buses; determining an initial power parameter based on the observation bus, determining a target power system based on the initial power parameter; simulating the target power system based on the reactive power parameter, determining a power simulation result; sorting and screening data of the at least two buses based on the power simulation result, and determining a sorting result and a screening result. By determining how close the load at the nodes of the buses is to the limit of the system that can be powered before voltage collapse occurs, the fault screening problem is solved, and the sorting accuracy is improved.

The application discloses a power grid power flow convergence adjustment method based on PPO-HELM, which firstly introduces voltage stability judgment indexes and voltage collapse point indexes by using a power flow calculation method of HELM.Secondly, after generating a power flow non-convergence state by adjusting a power grid load level, the voltage collapse point index values in the state are calculated by using HELM, and are sorted from large to small, and according to the sorting result, the first m corresponding load nodes are selected to participate in power flow adjustment.Then, according to the voltage stability judgment indexes, the voltage collapse point indexes and the selected load nodes, a PPO algorithm environment based on HELM is established.Finally, a target function is constructed, a PPO algorithm model is built, power flow convergence adjustment actions are output, and training and testing are performed.The application reduces the number of load nodes needing capacitor switching operation, shortens the active power and reactive power regulation time, and improves the adjustment efficiency.

The invention provides a rapid frequency support controller of a droop control type network construction converter, which comprises a differential link, a stability controller and a network construction converter system, and is characterized in that the network construction converter system comprises a network construction converter and a power-voltage formula; in the differential link, the differential component of the voltage deviation is obtained by making a difference between the reference direct-current voltage and the actual output direct-current voltage, the stability controller receives the differential component of the voltage deviation and regulates and controls the differential component in a stability domain, a control signal is output through the stability controller, and the control signal is imported into the grid-forming converter system to control the grid-forming converter system. Combining the active power output of the source side and the demand of the load side to quantify the output of the network construction converter, and iteratively outputting voltage by means of a power-voltage relation formula; according to the method, the nonlinearity of the internal state variable of the network construction converter and the deviation of the frequency deviation value are corrected, and the droop control type network construction converter is allowed to keep the maximum support for the system frequency under the condition of avoiding the direct current link voltage collapse.

The invention relates to the technical field of electronics and electrical, in particular to a USB charging line automatic power-off method and system based on short circuit detection, and the method comprises the steps: confirming a charging detection environment based on a USB charging detection instruction, and carrying out the current and voltage analysis of a current sampling unit and an MOS power-off unit through a microcontroller in a circuit control board, obtaining a current transformation time sequence, a current abrupt change rate, a voltage transformation time sequence and a voltage collapse rate, calculating a circuit anomaly index according to the current abrupt change rate, the voltage collapse rate and the transient response duration, and performing short-circuit evaluation on the basic parameter set based on a pre-constructed circuit analysis model to obtain a short-circuit danger probability. And calculating a short-circuit state score according to the circuit abnormity index, the short-circuit risk probability and the short-circuit risk coefficient, determining a charging termination device based on the short-circuit state score and the operation charging device, and completing automatic power-off of the USB charging line. According to the invention, the short circuit risk of the USB charging line can be identified in advance, and the accuracy and timeliness of automatic power-off are improved.