15 results about "Island state" patented technology

The invention discloses a multi-island detection method and system based on multi-frequency-point characteristic frequency band impedance increment. The method comprises the following steps: step 1, dividing frequency bands; step 2, carrying out passive island detection; when any one detection value is greater than the corresponding fluctuation early warning threshold but less than or equal to the corresponding fluctuation warning threshold, requesting to execute the step 3; step 3, triggering active island detection of a short time scale; the method comprises the following steps: injecting a broadband signal containing three different frequency point disturbance signals into a power distribution network, calculating difference values between power distribution network system impedance measurement values and corresponding historical values under the three different frequency point disturbance signals, and when the three difference values are all greater than a corresponding first island early warning threshold value and at least one difference value is smaller than a corresponding first island alarm threshold value, sending a warning signal to the power distribution network; if yes, requesting to execute step 4; 4, triggering long-time-scale active island detection; when the average values of the N system impedance difference values in the three frequency bands are all larger than a corresponding second alarm threshold value and the variable coefficients are all smaller than a variable coefficient threshold value, the island state is judged; and a detection blind area is eliminated.

The invention provides an island locking control method and control system for a power transmission system, and the method comprises the steps: obtaining an island signal according to the operation state of a converter station connected with an AC power grid in an island state under the condition of receiving the island signal; determining a priority locking pole and a rear locking pole in the double poles of the converter station connected with the alternating current power grid in the island state; and controlling the locking moment of the rear locking pole not to be earlier than the locking moment of the priority locking pole. According to the scheme, the alternating current overvoltage level after island locking in the ultra-high voltage direct current transmission system can be greatly reduced, the direct current maximum transmission power limit value is improved, and the availability rate of the direct current system is improved.

The invention provides an island division and load recovery method, device and equipment for a power distribution network. The method comprises the following steps: acquiring real-time state data of the power distribution network; preprocessing the real-time state data to obtain target state data; inputting the target state data into an island division model for processing to obtain an island division result; the island division model is obtained by training historical fault processing data; according to the island division result, utilizing a load recovery model to recover loads in sequence; the load recovery model comprises an evaluation network layer and a target network layer, the evaluation network layer outputs an action decision according to the island state data, the target network layer outputs action value evaluation according to the island state data, and the weight of the evaluation network layer is adjusted according to the action value evaluation. According to the invention, the efficiency and stability of power distribution network island division and load recovery can be improved.

The invention relates to an island separation control method and device, equipment and a medium. The method comprises the steps of obtaining operation data corresponding to a preset load node of a to-be-separated island in a power distribution network; according to the operation data, determining whether the to-be-separated island has an instability risk; setting a control mode of a current converter connected between the to-be-separated island and a main power grid as a constant-voltage and constant-frequency control mode under the condition that the to-be-separated island has an instability risk; in the constant-voltage and constant-frequency control mode, the separation time is determined according to the exchange power data of the interconnection line; wherein the interconnection line is a connection line between the to-be-separated island and the main power grid; and controlling the to-be-separated island to be separated from the main power grid at the separation time. According to the invention, stable switching of the to-be-separated island from the grid-connected state to the island state can be realized.

The invention provides an intelligent anti-islanding method based on transient characteristics, and the method comprises the steps: recognizing a link reconfiguration state of a core switch when an instantaneous power failure occurs, obtaining a link reconfiguration timestamp, calculating the time sequence correlation between reconfiguration and power failure in combination with an instantaneous power failure occurrence moment, and obtaining the triggering characteristics of link reconfiguration; performing mode matching according to the abnormal transient feature vector and a load adjustment model established based on historical operation data statistical analysis to obtain a matching degree index, and performing clustering analysis on the matching degree index to obtain an island state classification result; and carrying out weighted fusion on the classification result of the island state to obtain a final judgment result, and carrying out dynamic correction on the power supply frequency offset according to the final judgment result to obtain a corrected frequency stable signal.

The application relates to a kind of distributed power island detection method, system, terminal and medium, comprising the following steps: discrete sampling distributed power grid-connected power generation system voltage signal at the public coupling point in non-island and island state;The voltage signal of the public coupling point collected is decomposed by multilayer wavelet packet transform;Island detection characteristic quantity extraction is carried out to the multilayer signal decomposed by wavelet packet transform;A neural network training model is constructed, the extracted island detection characteristic quantity is used as the input signal of the neural network training model, island detection is carried out, and a detection result is obtained;The island detection algorithm of the wavelet decomposition reconstruction method used in the application and the LSTM neural network combination is superior to the traditional intelligent detection algorithm.

The present invention relates to the field of offshore island group design and discloses a method for offshore island group morphology design based on optimization of anti-scouring and silting resilience, comprising the following steps: measuring state data of the sea area where the target offshore island group is located, and constructing a mathematical model of sea area hydrodynamics and sediment transport based on the measured results. The island state and island group construction plan of the target offshore island group are determined using the mathematical model of sea area hydrodynamics and sediment transport, and finally, the anti-scouring resilience of the target offshore island group is optimized. The present invention can achieve the purpose of optimizing the anti-scouring and silting resilience of offshore island groups by in-depth research on the interaction mechanism between ocean dynamic processes and island group morphology, combined with advanced numerical simulation and experimental verification techniques.

The invention discloses an energy storage system island detection method and device and a medium, and relates to the technical field of data processing. Comprising the following steps: extracting local key features of frequency domain features of a target energy storage system and a time sequence change rule of time domain features and dynamic features of the target energy storage system based on a hybrid model constructed by a convolutional neural network and a long-short term memory network; the local key features and the time sequence change rule are fused based on a full connection layer, a fused high-dimensional feature vector is obtained, and the high-dimensional feature vector is used for reflecting the operation state of the target energy storage system; the high-dimensional feature vectors are analyzed based on a classification model, a classification result of whether the operation state is an island state is obtained, and the hybrid model and the classification model are obtained through training based on a dynamic weight distribution mechanism. The island state under the condition that the matching degree of the load and the output power of the energy storage system is relatively high can be effectively identified through the hybrid model and the classification model trained by using the dynamic weight distribution mechanism, so that the accuracy of island detection is improved.

The invention discloses an active island detection method, system and device for an energy storage converter, and aims to solve the problems that in an existing active island detection method, theoretical and actual circuit characteristics are inconsistent, an analytical solution can not be obtained possibly, and rapidity is poor. According to the method, RL resistive and inductive loads with the same connection relation are determined to be adopted according to the load connection condition of an actual site; calculating a per unit value of a frequency offset based on the quality factor of the RL resistance-inductance load and a set phase offset function; wherein the set phase offset function is a high-order polynomial based on the quality factor and the per unit value of the frequency offset; injecting a phase offset disturbance quantity, and detecting a frequency offset corresponding to the energy storage converter; and when the frequency offset is determined to be greater than or equal to the per-unit value of the frequency offset, judging that the energy storage converter is in an island state. In this way, the number of control parameters needing to be adjusted in the calculation process is reduced, debugging is easier, and meanwhile it is guaranteed that solutions exist under the condition of any load and parameter combination.

The invention provides an energy storage system control method and device, computer equipment and a readable storage medium, and belongs to the technical field of energy storage systems. The method comprises the following steps: acquiring voltage information and frequency information of a common coupling point of an energy storage system in real time; according to the voltage information and the frequency information, whether the energy storage system is in an island state currently is determined in real time; if not, determining the voltage drop information of the common coupling point of the energy storage system according to the voltage information; according to the voltage drop information and the frequency information of the common coupling point of the energy storage system, a preset rated voltage, a preset rated frequency, a preset voltage range, a preset frequency error threshold value and a preset time threshold value, the operation state of the energy storage system is determined in real time; and determining to-be-executed operation according to the running state of the energy storage system. The method can achieve the effects of improving the judgment accuracy of low voltage ride through and island protection, achieving the coexistence of low voltage ride through and island detection, and improving the safety and stability of an energy storage system.

The invention provides a micro-grid system source detection method, system and device, and relates to the technical field of power grids, and the method comprises the steps: responding to a line state collection instruction through a plurality of substations, respectively collecting the electrical quantity of a preset key line, the position of a split-phase switch and a protection tripping signal, judging the line switching and tripping states, and obtaining a detection result; the state information is sent to a master control station, so that the master control station performs processing based on the state information in combination with electrical quantities, switch positions and protection tripping signals, collected by the station, of the high-voltage side and the medium-voltage side of a main transformer and a tie line, and a processing result is obtained; the load control station receives the processing result and acquires the electrical quantity and switch position information of the tie line, the high and low voltage side of the main transformer and the energy storage line to obtain the small island state; and the master control station generates a result containing the states of the large island, the medium island and the total island based on the state of the small island. According to the scheme, the self-healing capability and the operation stability of the micro-grid in an off-grid scene can be improved.

The invention discloses a method and system for detecting and terminating a remote control Trojan horse in an island state based on an ETW event, and relates to the field of network and information security. In order to solve the defect that high-precision and low-overhead detection and timely termination cannot be carried out on the remote control Trojan horse in an island state in the prior art, the technical scheme provided by the invention comprises the following steps of: capturing an ETW event in real time, constructing an event sequence according to a process identifier, and extracting characteristics such as reconnection frequency, receiving and transmitting event quantity, receiving and transmitting proportion and memory use; quickly screening out high-confidence Trojan horses through a threshold model; and constructing an event Markov matrix for other sequences, and inputting the event Markov matrix into a depth detection model to carry out further discrimination, thereby identifying the remote control Trojan horse in the island state. If the Trojan horse is judged to be the remote control Trojan horse at any stage, the corresponding process is immediately terminated according to the process identifier, and alarm information is sent. The method is used for real-time detection and automatic processing of the remote control Trojan horse in the island state by the terminal host, and the system safety is improved.

The invention relates to the technical field of isolated island operation of a power distribution network, and discloses an isolated island operation method, system and equipment of a power distribution network containing a network construction type distributed power supply, and a medium, and the method comprises the steps: configuring a decision and executing a switch in the power distribution network, achieving the precise control, and laying a foundation for the isolated island operation. The switches are reasonably configured to ensure rapid isolation of a problem area during a fault and guarantee power supply. The first judgment logic based on the switch is established, the island range is automatically determined, and the fault processing efficiency and accuracy are improved. The island range is obtained according to logic, execution operation is generated, power supply is recovered quickly, power failure influence is reduced, and reliability is improved. Island operation is performed stably, power supply and demand balance is ensured, and voltage and frequency problems are avoided. The second judgment logic is used for monitoring the island state, processing problems in time and guaranteeing operation stability and safety. Island range is automatically identified, electric energy quality is monitored, fault power failure time is reduced, and power supply reliability and clean energy utilization efficiency are improved.

The present invention discloses a hybrid island detection method based on Lissajous curve and impedance identification, which belongs to the technical field of grid-type energy storage converter on-grid switching. The present invention first constructs a model in which a grid-type energy storage and an RLC load are connected in parallel to a common coupling point PCC, collects the voltage and current at the PCC point and calculates the area and short axis of the Lissajous figure, and then compares the island detection index with the preset threshold. When it is less than the threshold, active detection is triggered, and an 8-fold frequency disturbance is injected into the line. The line impedance is then calculated by fast Fourier decomposition and the mean of ten samples is compared and judged. When the load power and the grid-type energy storage have zero mismatch and the quality factor is 2.5, the present invention can accurately identify the island within 200ms, the detection blind area is extremely small, the anti-interference ability is strong in the non-island state, the detection index threshold is flexibly set, and it has significant universality, which has strongly promoted the development of island detection technology.

A method and system for island detection based on the collaborative identification of harmonic dynamic characteristics and reactive slip, relating to the field of new energy island detection. To address the shortcomings of existing island detection, such as low feature extraction accuracy, rigid thresholds, and insufficient response speed, the method collects a microgrid system's operating data set based on its topological structure; implements dynamic feature data fusion processing to calculate harmonic voltages; uses harmonic voltage mutations as the initiation criterion for island detection; sequentially determines whether the harmonic voltage mutation, fundamental voltage amplitude, and each harmonic voltage offset exceed limits, thereby determining whether the microgrid is in an island state; constructs a virtual orthogonal signal to calculate the three-phase reactive slip rate, and determines whether the three-phase reactive slip rate exceeds limits. If not, the microgrid is in a non-island state; if so, the microgrid is in an island state. The present invention is primarily used to determine whether a microgrid is in an island state.