19 results about "Power-system protection" patented technology

The invention provides a cable fault arc temperature distribution calculation method based on multi-physics field coupling, and the method comprises the steps: building a cable fault arc simulation model; setting boundary conditions of multi-physics field coupling of an electric field equation, a magnetic field equation, a fluid heat transfer equation and a laminar flow equation for the cable fault arc simulation model; the arc temperature distribution is obtained by controlling the voltage and current parameters of the arc simulation loop, the distance between the copper core conductor and the grounding electrode and the air velocity. A cable fault arc simulation model is built, high risks of electric shock and explosion in laboratory tests are avoided, the loss cost of laboratory test equipment is reduced, the defect that only the peripheral temperature of the arc can be measured in the laboratory tests is overcome through a multi-physics field coupling equation, and global continuous arc temperature data are obtained. And a theoretical basis is provided for power system protection design, cable laying optimization, fire-fighting strategy formulation and cable fire risk assessment.

This invention belongs to the field of power electronics and DC power system protection technology, specifically relating to a boost converter topology and control method. The structure includes: a power supply and a boost inductor L. boost Main switch tube Q 1. Converter circuit breaker Q conv capacitor circuit breaker Q cap The components include a first resistor R1, a second resistor R2, a load resistor R3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first diode Dsnub1, a second diode Dsnub2, a varistor MOV, and a line inductor Lline. This invention can replace traditional DC circuit breakers, improving system operating efficiency and protection performance. It can interrupt the discharge current of the DC bus capacitor in microseconds and safely release the inductor's stored energy in milliseconds, avoiding voltage overshoot in semiconductor devices and effectively improving the safety and reliability of the DC power grid.

The invention relates to the technical field of power system protection and control, in particular to a temperature rise monitoring method and device for a converter of a high-inertia energy storage type synchronous phase modifier, and aims at the converter of the high-inertia energy storage type synchronous phase modifier adopting an integrated gate commutated thyristor. The method comprises the following steps: establishing a converter thermal network model by considering the mutual influence of motor electrical quantity, converter loss, thermal impedance and device junction temperature, calculating the device junction temperature of the converter in real time according to the terminal voltage and the rotating speed of the high-inertia energy storage type synchronous phase modifier, and monitoring the temperature rise of the converter by monitoring the highest junction temperature of the device in real time; according to the method, the junction temperature change of the converter device of the high-inertia energy storage type synchronous phase modifier under different working conditions can be monitored in real time, the mutual influence of the electric quantity of the motor, the thermal network parameters of the converter and the junction temperature is considered, and the junction temperature calculation precision of the converter device is improved.

The invention relates to the field of power system protection and control, in particular to a full-time-domain short-circuit current direct analysis method and device for network construction type power electronic conversion equipment, and the method comprises the steps: calculating a virtual short-circuit fault parameter of a grid-connected point of the network construction type power electronic conversion equipment, and building a fault power grid dimension reduction equivalent model; calculating port voltage amplitudes and power angles of the network construction type power electronic conversion equipment in a subtransient stage, a transient stage and a steady-state stage under a power grid fault; establishing external characteristic equivalent models of a subtransient stage, a transient stage and a steady-state stage of the network construction type power electronic conversion equipment under a power grid fault; and calculating the short-circuit current in the sub-transient stage, the transient stage and the steady-state stage of the network construction type power electronic conversion equipment. The method does not depend on actual fault parameters, and online calculation of subtransient, transient and steady-state short-circuit currents of the network construction type power electronic conversion equipment at any fault position and fault transition resistance is achieved.

The invention discloses a cooperative override trip prevention decision-making system for a power supply network, and relates to the technical field of power system protection and control, and the system comprises a data collection module which is connected with a multi-level protection device, a monitoring terminal and an environment sensor in the power supply network, and is used for obtaining electrical quantity data, non-electrical quantity data and environment parameters in real time. According to the cooperative override trip prevention decision-making system for the power supply network, cross-protocol analysis and space-time fusion of multi-source heterogeneous data are realized through a multi-dimensional space-time alignment engine, a dynamic semantic gateway and a wavelet packet decomposition technology are combined, a power frequency quantity, a transient quantity and an environmental parameter are uniformly mapped to a fault characteristic spectrum, and the fault characteristic spectrum is analyzed and analyzed. The problem of incomplete fault feature extraction caused by data islands in the prior art is solved, key fault features can be accurately screened, the Pareto optimal action sequence can be generated, the misjudgment rate of override trip is reduced, meanwhile, the unnecessary power failure duration is shortened, and the fault isolation accuracy and the power supply reliability are improved.

The invention discloses a residual current reclosing control method, device and system, a medium and a program product, and relates to the technical field of power system protection, and the method comprises the following steps: if a residual current action circuit breaker set for a to-be-detected line is detected to be opened, or the residual current in the to-be-detected line is detected to meet a preset opening condition; if the preset switching-off condition is the same as the switching-off condition of the residual current operated circuit breaker set for the to-be-detected circuit, the connection between a release set for the to-be-detected circuit and the electric operation accessory is disconnected, the release is a release with a time-delay detection voltage switching-on function, and the preset switching-off condition is the same as the switching-off condition of the residual current operated circuit breaker set for the to-be-detected circuit; and if the residual current in the to-be-detected line is detected to meet the closing condition, connecting the release and the electric operation accessory. According to the invention, the conflict between the residual current protection function of the residual current operated circuit breaker and the voltage detection closing function of the release is avoided.

This application provides a grounding protection system, method, electronic equipment, and storage medium for a new energy power plant, relating to the field of new energy power system protection technology. The system comprises a grounding protection device, as well as a grounding transformer neutral point equipment, a first current transformer, and a voltage transformer. The voltage transformer is used to detect the voltage of the busbar, and the first current transformer is used to detect the current of the transmission line. The neutral point of the grounding transformer is sequentially grounded via an isolation switch, a circuit breaker, and a resistor. The grounding protection device collects the voltage of the busbar and the current of the transmission line, performs amplitude-phase comparison, collects the closed / open state of the circuit breaker, determines whether a grounding fault has occurred on the transmission network side to which the transmission line is connected, generates a corresponding open / close command, and controls the circuit breaker to perform the corresponding open / close operation according to the open / close command. By adopting the above method, there is no need to install additional equipment such as isolation transformers and secondary control panels, saving human and equipment resources.

The embodiment of the invention discloses a power distribution network single-phase earth fault sensing method based on a resonance gain effect, relates to the technical field of power system protection and control, and aims to solve the problem of low detection sensitivity caused by the fact that fault features are covered by a strong capacitive background in an existing signal injection method. The method comprises the following steps: under a preset working condition that a zero-sequence loop resonant frequency point of a power distribution network is located near a system power frequency point, injecting a current signal with a preset frequency near the resonant frequency point into a zero-sequence loop; measuring a zero-sequence voltage steady-state signal generated by excitation of the current signal; on the basis of the injection current and the measurement voltage, determining characteristic parameters representing resistive component changes in the zero-sequence loop; and judging whether a single-phase earth fault occurs or not according to the variation of the characteristic parameters before and after the fault. Resonance characteristics near a power frequency under a specific working condition are utilized, resonance which is considered to be harmful traditionally is converted into a favorable factor, amplification recognition of fault characteristics is achieved, and detection sensitivity is improved.

The invention discloses an intelligent circuit breaker cooperative control method based on artificial intelligence and a graph network, and relates to the technical field of power system protection and control, and the method comprises the following steps: extracting topological transition segments based on a line switching event in a dynamic operation environment of an intelligent circuit breaker, recording the starting and ending moments of each transition segment, generating a topological transition index list; according to the topological transition index list, time mapping is carried out on the historical connection relation between the circuit breakers, the connection detected to be invalid is calibrated as an attenuation priority area, and a continuous attenuation sequence is formed according to the time sequence. According to the method, the topology transition index list and the continuous attenuation sequence are constructed, so that time synchronization of topology and actual electrical connection is realized, and backflow and weight accumulation deviation of failure connection are avoided. Dynamic closed-loop regulation and control are carried out by using the purification topology, the edge weight is tightened in the uplink stage, and the edge weight is relaxed in the downlink stage, so that the circuit breaker group has the self-adaptive cooperative capability, and the accuracy and the operation stability of power grid protection are improved.

The invention belongs to the technical field of power system protection control and user side load management, and particularly relates to a control method and system for achieving user branch load low-frequency load shedding through cooperation of a terminal and a master station. The method comprises the steps of main station side low-frequency load shedding research and judgment and strategy control; performing real-time frequency monitoring and load shedding strategy execution on the terminal side; and load shedding strategy optimization and regulation and control effect analysis are completed at the main station side. According to the method, traditional substation low-frequency load shedding management is advanced and applied to user branch load monitoring control, low-frequency load shedding management monitoring of a third defense line of a power grid is more advanced, load shedding is more timely, management and control are more accurate, the influence of system frequency characteristic deterioration caused by large-scale new energy grid connection and terminal electrification can be effectively restrained, and the system reliability is improved. The defects of low-frequency load shedding of a traditional transformer substation are overcome, the safety lean management level of a power grid is improved, the production influence and economic loss of users are reduced to the maximum extent, and rapid development of new energy and terminal electrification application and popularization are served.

The present invention relates to the field of power system protection technology, and in particular to a multi-port DC circuit breaker topology structure, control method, and parameter determination method thereof, including a flow branch that provides a low-impedance current conduction path for the load current when the multi-port DC power grid system is operating normally, and forces the fault current to be quickly transferred from the flow branch to the disconnect branch when a fault occurs in the multi-port DC power grid system; the disconnect branch instantaneously conducts the transfer branch and receives the transferred fault current in the initial stage of a fault in the multi-port DC power grid system, automatically conducts the energy-consuming branch when the voltage difference across the energy-consuming branch reaches a preset overvoltage threshold, utilizes the energy-consuming branch to absorb the line overvoltage energy and quickly cuts off the fault current, and completes the voltage-free and arc-free disconnection by shutting off the fast mechanical switch of the flow branch, thereby completing the complete isolation of the fault current. The present invention effectively improves the DC power grid system's ability to cope with faults through the coordinated cooperation of the flow branch, the disconnect branch, and the grounding branch.

The invention relates to the technical field of power system protection, and discloses a circuit breaker protection method, device and equipment, and the method comprises the steps: collecting multi-source data; performing credibility evaluation on the acquired multi-source data based on corresponding sensing data acquired by different types of sensors to obtain sensing data credibility of corresponding physical quantities; according to the fault type, the priority of the sensors participating in protection judgment is distributed, and the protection action of the circuit breaker is executed in combination with the corresponding sensing data credibility. According to the method, the multi-source data is collected and credibility evaluation is carried out, and the sensor priority is allocated according to the fault type to execute the protection action, so that the problem of low reliability caused by dependence on a single sensor in the prior art is solved, and the accuracy and reliability of the protection function are improved; and misoperation and failure risks caused by sensor faults or data distortion are reduced.

The invention relates to the technical field of power system protection, in particular to a chemical enterprise electrical anti-interference electricity method, which comprises the following steps of: comparing adaptive characteristics of an anti-interference electricity contactor, a restart control device, a UPS (Uninterrupted Power Supply) power supply device and a special anti-interference electricity device to determine an applicable scene; comparing adaptation characteristics of frequency converter restarting, frequency converter low-voltage ride-through, UPS power supply and DC support technologies, and determining an applicable scene; determining an anti-interference electricity priority of the key equipment and a corresponding anti-interference electricity adaptation scheme according to production process characteristics and operation environment requirements; respectively executing targeted anti-interference electricity configuration on an incoming cabinet, common equipment and a frequency converter system, and optimizing a power supply scheme; risk assessment and countermeasure making are carried out by setting operation parameters and carrying out a simulation test. The anti-interference electricity requirements of different equipment of a chemical enterprise can be accurately matched, the power supply stability is improved, the shutdown risk is reduced, and continuous production is guaranteed.

The embodiment of the invention provides a maintenance method and equipment of a magnetically controlled circuit breaker and a storage medium, and belongs to the field of power system protection and control. The method comprises the steps of obtaining a target digital twinborn model of a target magnetically controlled circuit breaker, according to the method, an electrical acquisition data set, mechanical action acquisition data, a temperature acquisition data set and an action mechanism acquisition data set acquired in a current period are subjected to parameter supplementation through an electrical sub-model, an opening and closing mechanical sub-model, a heat dissipation sub-model and an action mechanism sub-model in a target digital twin model; obtaining an electrical operation and maintenance parameter set, a mechanical operation and maintenance parameter set, a temperature operation and maintenance parameter set and an action mechanism operation and maintenance parameter set of the current period; and according to the electrical operation and maintenance parameter set, the mechanical operation and maintenance parameter set, the temperature operation and maintenance parameter set and the action mechanism operation and maintenance parameter set, state management is performed on the operation state of the target magnetically controlled circuit breaker, so that accurate evaluation of the operation state of the magnetically controlled circuit breaker can be realized, and the monitoring cost is considered.

The invention discloses a low-voltage distribution network protection control method, device and equipment and a medium, and relates to the technical field of power system protection and control. According to the scheme, when it is monitored that the voltage values and the current values of the distributed power supply grid-connected points and the installation positions of the line protection devices are lower than the safe operation threshold values, the fault scene of the current low-voltage power distribution network is determined according to the voltage values and the current values, and therefore the actual fault condition of the current low-voltage power distribution network is determined; then, based on the fault scene, determining a short-circuit current at the installation position of a target line protection device at the downstream / upstream of the distributed power supply grid-connected point, and dynamically reforming a protection setting value according to the short-circuit current, thereby improving the sensitivity and adaptability level of the line protection device; when the current value at the installation position of the target line protection device is larger than the protection setting value, the target line protection device is controlled to output the tripping instruction and / or the alarm signal, rapid implementation of protection action is achieved, and the reliability, the safety and the intelligent level of the low-voltage power distribution network are improved.

The invention relates to the field of offshore platform power system protection, and discloses a collaborative current-limiting offshore oil and gas field short-circuit current limiting system and method, and the system comprises a first-stage current limiting structure which comprises a rapid current limiter and a medium-voltage bus tie switch, and the rapid current limiter is connected with the medium-voltage bus tie switch in series; the rapid current limiter is connected with a controller in an offshore platform power system, and the controller detects a fault signal and controls the working state of the rapid current limiter; the second-stage current limiting structure is provided with a plurality of circuit breakers, each generator is connected with one circuit breaker in series to form a first parallel branch, a plurality of first parallel branches form a second-stage current limiting branch, and the second-stage current limiting branch is connected to a medium-voltage bus where the rapid current limiter is located in parallel; and the working state of each circuit breaker is controlled by a controller in the offshore platform power system. When a three-phase short-circuit fault occurs, the short-circuit current can be effectively limited, and reliable operation quitting of the generator is ensured.

The invention discloses a compensation method, system, equipment and medium for short-circuit capacity measurement under a three-phase imbalance condition, and belongs to the technical field of electrical variable processing, and the compensation method comprises the steps: building a short-circuit capacity measurement model under the three-phase imbalance condition based on a sequence component theory and a short-circuit calculation principle, and measuring the impedance of each sequence through an injection method; and a compensation algorithm is designed to eliminate the influence of unbalanced factors on a measurement result, and accurate measurement of the short-circuit capacity is realized. According to the invention, effective compensation of three-phase imbalance factors is realized, the accuracy and reliability of short-circuit capacity measurement are improved, and accurate technical parameters are provided for power system protection setting and equipment type selection.

The present invention relates to the field of power system protection and control, and discloses a method, device and equipment for controlling the voltage at the receiving end of a flexible direct current transmission system. The receiving-end converter station of the flexible direct current transmission system collects the AC bus voltage, active and reactive currents before and after the fault, and calculates the equivalent complex impedance and potential vector after the receiving-end power grid fault; calculates and compares the maximum AC current phase angle of the receiving-end converter station that avoids DC transient overvoltage of the flexible direct current transmission system and the AC current phase angle of the receiving-end converter station required for maximizing the voltage at the receiving-end grid connection point of the flexible direct current transmission system, and calculates the maximum feasible value of the voltage at the receiving-end grid connection point of the flexible direct current transmission system under the premise of avoiding DC transient overvoltage; calculates and adjusts the active and reactive current reference values ​​of the receiving-end converter station of the flexible direct current transmission system, and controls the voltage at the receiving-end grid connection point of the flexible direct current transmission system to the maximum feasible value under the grid fault. The present invention quantifies and realizes the maximum voltage increase at the receiving-end grid connection point under the DC voltage safety condition of the flexible direct current transmission system under the grid fault by coordinating the active and reactive currents of the receiving-end converter station of the flexible direct current transmission system.