277 results about "Differential protection" patented technology

The invention provides a method for suppressing internal misfire caused by turn-to-turn short circuit of a dry-type air-core reactor, and belongs to the technical field of dry-type air-core reactors. A turn-to-turn short circuit fault detection device combining differential protection and infrared thermal image detection is established to form a three-dimensional turn-to-turn short circuit feature vector, a four-dimensional internal misfire minimum ignition vector is obtained, and a fire development prediction model is established based on an Arrhenius equation. A double-layer game model for minimizing the upper-layer fire loss and minimizing the lower-layer fire extinguishing cost is constructed to optimize five-dimensional suppression vector parameters, and coordinated actions of suppression equipment such as power-off protection, forced ventilation, temperature suppression and inert gas release are controlled in real time through a suppression vector parameter adjustment function. The technical problem of fire suppression measure starting lag or excessive response caused by difficulty in accurately predicting the opportunity and degree of development of the turn-to-turn short circuit fault of the dry-type air-core reactor into the internal fire disaster is solved.

The invention relates to a differential protection closed-loop simulation method based on a high-performance full-electromagnetic transient simulation platform. The method comprises the steps of model construction, data interaction, closed-loop simulation and performance evaluation. According to the method, modeling is carried out based on a Cloud PSS platform, and full electromagnetic transient elements of a primary model and a secondary model can be considered. Under the background that differential protection of a novel power system and a new-generation ship power supply system faces an adaptability problem, the method can comprehensively and efficiently establish a differential protection closed-loop simulation model, and detailed description of differential protection action performance is achieved; according to the scheme, the influence of primary model modeling granularity on differential protection is fully considered, and accurate description and evaluation of the differential protection adaptability problem under the background of a novel power system and a novel ship power supply system can be realized.

The invention discloses an improved flexible direct current fault control method for improving current differential protection adaptability, and belongs to the technical field of power system relay protection and new energy power generation system grid-connected control. The method comprises the following steps: detecting a voltage drop abrupt change signal and a negative sequence voltage signal of a flexible DC output end, and starting a control strategy when the signals are satisfied; detecting a terminal voltage signal and active power of a new energy sending-out terminal, and calculating a new energy side current phase angle and a power angle; calculating a flexible DC side current phase angle control value and a negative sequence dq axis current reference value based on the parameters; and controlling the flexible DC side to output a negative-sequence current corresponding to the negative-sequence dq-axis current reference value, so as to actively adjust the current phase of the flexible DC side, reduce the phase angle difference between the fault current of the flexible DC side and the fault current of the new energy side, and discriminate the internal and external faults of the region through traditional current differential protection. According to the invention, the degree of freedom is controlled and the current phase is adjusted by using the flexible direct-current side negative-sequence current to reduce the phase angle difference of the two sides, so that the problem that the current differential protection adaptability in the double-end weak feedback system is reduced is solved, additional hardware is not needed, and the power grid safety and the new energy stable grid connection are ensured.

The invention discloses a protection control method for a differential mechanism of a pure electric vehicle, which relates to the technical field of electric vehicle driving, and comprises the following steps: acquiring wheel speed signals of wheels on two sides of a vehicle driving shaft, and calculating the rotating speed difference of the wheels on two sides; according to the rotating speed difference, a protection torque upper limit value and a protection torque lower limit value under the current rotating speed are determined through a preset rotating speed and protection torque threshold value mapping table; judging whether the motor request torque exceeds the upper limit value or the lower limit value of the protection torque; if the time exceeds the preset activation delay time, activating the differential protection function; and in the state that the differential protection function is activated, the actual output torque is controlled to be between the protection torque upper limit value and the protection torque lower limit value. Abnormal abrasion or impact damage of internal elements of the differential mechanism caused by excessive slip of a single-side wheel can be effectively avoided, so that the service life of the differential mechanism is greatly prolonged, the maintenance cost is reduced, and intense driving control and power requirements are met.

The invention discloses a distributed bus protection device for a hydropower station and a bus differential protection method, the distributed bus protection device comprises a host, the host is in communication connection with a plurality of sub-machines, and the host and the sub-machines are in single-channel or dual-channel optical fiber connection; the bus is provided with a plurality of branches, and the sub-machines are connected with the branches; wherein the branch circuit is provided with a plurality of circuit breakers used for controlling the on-off of the branch circuit, the branch circuit is also provided with a current transformer used for carrying out current sampling on the branch circuit, and the circuit breakers and the current transformer are connected with the sub-machine. The distributed topology design of cooperation of the host and the plurality of sub-machines can be adapted to various different bus systems, and a dual-channel optical fiber redundancy communication mechanism is matched to effectively overcome the fatal defect of protection failure of the whole station caused by a single-point fault of a centralized device. And when the host single board fails, the sub-machines can still realize cross-interval collaborative tripping through the preset local / opposite side identification codes.

The invention provides a double-bus differential protection processing method, device and equipment. The method comprises the following steps: acquiring state information of a bus coupler switch and polarity requirement information of a bus coupler current transformer; according to the polarity requirement information, input information in a functional soft pressing plate of the protection device is obtained; obtaining a bus coupler current coefficient of each bus according to the state information and the input information; according to the bus coupler current coefficient of each bus, obtaining a small-difference action current of each bus; and performing control protection processing on each bus according to the small difference action current of each bus and a preset setting value. According to the scheme, polarity self-adaption of the protection device can be realized, the calculation accuracy of small-difference action current of each bus is ensured, the protection device is prevented from generating abnormal differential current to give an alarm or even malfunction, a secondary wiring mode of the current transformer does not need to be changed, and the reliability is high. The workload of technical improvement work of the transformer substation is reduced; and the working safety and the working efficiency are improved.

The embodiment of the invention provides a differential relay protection device, equipment, system and method and a storage medium, the differential relay protection device comprises a clock module, the clock module is configured to create a first clock for the differential relay protection device, the first clock is configured in a precision time protocol domain, and the clock module is configured to create a second clock for the differential relay protection device, the second clock is configured in a precision time protocol domain; the second clock and the first clock operate independently; a power data obtaining module configured to obtain power data collected based on a second clock; and a processing module configured to perform a differential relay protection function through the first clock. According to the differential relay protection device disclosed by the invention, an independent precise time protocol domain can be configured for a differential relay protection function, so that power data synchronization is realized in a mode of low hardware cost, low system framework complexity, high flexibility and high operation stability, and the differential relay protection function is realized.

The invention discloses a differential protection function test method and system based on remote data synchronization, and relates to the technical field of power system relay protection tests.The method comprises the steps that host and slave test devices are deployed remotely, and communication is established through standby optical fibers; the host test device responds to the configuration parameters to generate two-dimensional test data, synchronizes the two-dimensional test data to the slave test device and calculates channel delay; based on the FPGA logic architecture and channel delay, the two test devices synchronously output test data to the differential protection device; the system comprises a remote testing device, a differential protection device and a standby optical fiber link, the testing device is integrated with a plurality of functional units such as an FPGA, the method supports fault-tolerant recovery, multi-scene expansion and result analysis, the remote synchronous testing problem is solved, the testing accuracy and comprehensiveness are improved, and the testing efficiency is improved. The method is suitable for substation differential protection function verification.

The invention relates to the technical field of fire sensing, and discloses an electrical fire state sensing system and method for a low-voltage distribution line, and the method comprises the steps: setting a first monitoring point at a wire inlet end of a distribution loop, setting a second monitoring point at a load access end, setting a differential protection region, and calculating a first on-resistance; performing moving average processing on the first on-resistance to obtain a second on-resistance, calculating a first reference on-resistance according to the second on-resistance, and performing temperature correction on the first reference on-resistance to obtain a second reference on-resistance; according to the method, the on-resistance deviation rate, the on-resistance growth rate and the on-resistance fluctuation coefficient are calculated, whether the on-resistance is in an early warning state, an alarm state or a dangerous state is judged, the on-resistance of the section is calculated in real time according to the ratio of the differential voltage drop to the current, and the technical problem that a fault section cannot be accurately positioned through traditional whole-line monitoring is solved.

The application relates to an adaptive current differential protection method based on a communication noise fault-tolerant mechanism. Real-time current information transmitted via a non-ideal communication channel at both ends of a protected line is acquired; the amplitude ratio and phase angle difference of a current operating point on a rho plane are calculated; absolute braking zone boundary conditions and absolute action zone boundary conditions are set according to the signal-to-noise ratio of a current communication channel; the adaptive amplitude boundary and adaptive phase boundary of a noise adaptive zone are calculated in the form of a sine function according to the phase angle difference of the current operating point; the current operating point is compared with each boundary condition to determine the region to which the current operating point belongs, wherein the action condition of the noise adaptive zone is that the amplitude is less than an adaptive threshold or the phase absolute value is less than the adaptive threshold; and corresponding protection actions are performed according to the determination result. By introducing the noise adaptive zone with the dynamically sine-adjusted boundary of the phase angle difference between the traditional action zone and the braking zone, the noise resistance of the differential protection under the non-ideal communication condition is significantly improved.

The application relates to the technical field of differential protection, in particular to a power distribution network distributed differential protection method and system suitable for a 1.4GIGS communication network, which comprises the following steps: based on the current and voltage parameters of each node of the power distribution network, real-time data is extracted and analyzed, the difference between the nodes is calculated, the nodes meeting the conditions are screened out by analyzing the difference values, signal receiving monitoring is carried out, and a list of key monitoring nodes is generated. In the application, the node signal transmission path is optimized through a power distribution algorithm, the time-frequency resource distribution of the signal is dynamically adjusted, the efficiency and stability of signal transmission are realized, the bit error rate in the signal transmission process is effectively reduced, the response speed and accuracy of the power distribution network differential protection system are improved, the interference information in the signal is processed through a particle swarm optimization algorithm, the frequency spectrum structure of the signal is optimized by rearranging and rotating the interference signal, the transmission parameters of the signal are adjusted, and the stability and anti-interference ability of signal receiving are greatly improved.

The invention discloses a current differential protection adaptability analysis method for an alternating current line of a new energy network flexible direct output system, and belongs to the technical field of power system relay protection. Establishing a system fault equivalent model based on a low-voltage ride-through control strategy of power electronic equipment at two sides of the outgoing line; according to different asymmetric fault types and a fault point boundary condition equation, deriving mathematical models of positive-sequence, negative-sequence and zero-sequence currents on the two sides of a fault phase line; calculating a differential current and a braking current, and establishing a function relationship between the differential current and the braking current and the VSG internal potential reference value, the transition resistance and the current sequence component ratio; and the action sensitivity of protection under different working conditions is judged by comparing the current differential protection ratio braking coefficient setting value with the current differential protection ratio braking coefficient setting value. The association rule of the current differential protection refusal risk and the low-pass control parameters under the high transition resistance fault is disclosed, a basis is provided for protection setting and control strategy optimization of a network construction flexible direct output system, and the problems that a protection adaptability analysis method is weak and the influence rule of the control parameters is not clear yet are solved.

The utility model discloses a differential protection device for a power distribution network, and relates to the technical field of power grid facilities, in particular to the differential protection device for the power distribution network, which comprises a device body, an adjusting bin is arranged on the back of the device body, a connecting shaft rod is arranged in the adjusting bin, and a transmission gear is arranged on the outer surface of the connecting shaft rod. A connecting rack is arranged on the outer surface of the transmission gear, a connecting plate is arranged at one end of the connecting rack, a connecting sliding rod is slidably connected into the connecting plate, one end of the connecting sliding rod is arranged on the inner wall of the adjusting bin, a limiting piece is arranged at one end of the connecting sliding rod, and an adjusting sliding groove is formed in the back of the device body. According to the differential protection device for the power distribution network, the transmission gear, the connecting rack, the connecting plate, the limiting clamping block, the positioning plate, the control ring, the limiting plate, the first spring, the limiting hole and the limiting column are arranged in a matched mode, so that the differential protection device for the power distribution network has the effect that the protection device can be conveniently and rapidly mounted and dismounted.

The invention discloses a line current differential protection false information detection method based on a delay observer, and is applied to the technical field of line current differential protection. Comprising the following steps: establishing a distribution parameter model of the power transmission line, and discretizing the distribution parameter model to obtain a discrete model of the power transmission line; constructing a delay observer based on the discrete model of the power transmission line, solving a parameter matrix of the delay observer, and estimating a negative sequence voltage predicted value at the current moment; reading a negative sequence voltage measured value at the current moment, and calculating an error between the negative sequence voltage predicted value and the negative sequence voltage measured value; and if the error is greater than a preset error threshold value, judging that the line current differential protection system is attacked by false information injection. According to the method, false information injection can be effectively identified by monitoring the negative sequence voltage prediction error, and the reliability of current differential protection and the safe operation level of a power grid are improved.

Embodiments of the present disclosure provide a data alignment method, a differential protector and a differential protection system. The data alignment method comprises: at a first time node, obtaining first sampled current data from a first sampling device; at the first time node, receiving a second message from a second differential protector, the second message comprising second sampled current data and a sampling time mark thereof, first time information about a receiving time difference of the second differential protector from receiving a first message to the second time node, and second time information about a second sending processing delay of the second differential protector from the second time node to sending the second message, the second time node being a time point at which the second sampling device obtains the second sampled current data; when time synchronization is maintained, calculating and storing a time calculation deviation between a third time node and a first calculation value of the second time node; when time synchronization is lost, determining the third time node according to the stored time calculation deviation.

The present application relates to the technical field of power system relay protection, and particularly relates to a kind of offshore wind power through flexible low-frequency transmission system sending out line protection method, offshore wind farm is connected with modular multi-level matrix converter after being sent out by low-frequency through booster transformer, and is incorporated into large power grid after being frequency converted by M3C. When M3C of offshore wind farm fails, negative sequence current suppression and positive sequence current limiting strategy are adopted for fault ride-through, and relay protection devices are installed at both ends of low-frequency sending out line and communicate. The current sampling values before and after the fault on both sides of the line are reconstructed in phase space, and the difference between the permutation entropies is used to construct a protection scheme, which overcomes the problem of sensitivity reduction of traditional current differential protection for sending out line, reduces the amount of data interaction, and reduces the pressure of protection communication and the requirement of data synchronization. It is not affected by the control strategy of wind turbine and modular multi-level matrix converter at both ends of the line, fault ride-through mode, transition resistance and fault location, and has high reliability and good speed.

The application discloses a kind of dynamic response 5G communication differential protection data transmission method, so that the differential protection service based on 5G communication is widely applied in low-voltage distribution network field, promote the development of new technology of power grid relay protection, solve the protection terminal of traditional low-voltage power grid not dependent on channel cannot give consideration to speed and selectivity requirement, by using advanced 5G communication technology, with the high bandwidth of 5G communication network, low latency and high reliability wireless communication environment, realize the large-scale application of longitudinal differential protection in closed-loop operation low-voltage power grid, improve the protection level of power grid.The application applies dynamic response transmission mode in the communication process of distribution network transmission line differential protection based on 5G communication, meets the rapidity requirement of relay protection, reduces 5G communication transmission flow, saves communication resources and reduces communication cost.

This invention discloses a power line carrier-synchronized 5G differential protection synchronization method for power distribution networks, comprising: a master carrier transmitter sending synchronization signal pulses, and a carrier receiver receiving the synchronization signal pulses simultaneously; the carrier receiver counting each time it receives a synchronization signal pulse; when the count value reaches a set value, the carrier receiver sending a synchronization signal to the data acquisition module of the intelligent power distribution terminal equipment; the data acquisition module receiving the synchronization signal and entering an interrupt to directly calibrate the AD sampling pulses, thereby achieving synchronization. This invention achieves a low-cost, high-synchronization, and delay-free differential protection function through power line carrier, enabling rapid fault location and timely repair in case of faults; it has broad feasibility and ease of use.

The invention discloses a multi-terminal differential protection control method and device for automatic identification of a topological structure and a storage medium, and belongs to the technical field of electricians, the method comprises the following steps: enabling each single-terminal device in a multi-terminal differential protection device to communicate through a multi-terminal differential channel, and enabling a data frame transmitted in the communication process to be used for identifying a communication state; recording a communication state between each single-ended device and other single-ended devices through the single-ended device, and sending the communication state to the other single-ended devices; judging a topological structure of a multi-terminal differential channel according to the communication state of each single-terminal device and the received communication states of other single-terminal devices; according to the differential protection method and device, the corresponding differential logic calculation is carried out according to the topological structure judgment result, the corresponding differential protection is executed according to the calculated differential logic, and the differential protection is locked when the topological structure is invalid, so that the risk that the differential protection quits and has no protection due to the fact that the differential channel is abnormal is avoided or reduced, and the utilization rate of the differential protection is improved.

The application discloses a kind of current transformer wire breakage fault positioning processing method and system, method includes: in protection device, additional redundant current transformer;With current mutation variable, real-time calculation N line and current amplitude and N line and current mutation variable amplitude;Set criterion, judge N line and current amplitude whether greater than flow threshold value, identify whether the stable CT wire breakage occurs outside protection device;And, judge N line and current mutation variable amplitude whether greater than mutation variable threshold, identify whether the intermittent CT wire breakage occurs outside protection device;According to the discrimination condition of conventional differential protection CT wire breakage, and in combination with criterion distinguishes wire breakage position, again in combination with three-phase CT sampling balance and distinguish result, determine the phase of specific CT wire breakage and position.The application has less demand to hardware resource, can distinguish whether CT wire breakage occurs in device CT primary side or secondary side, and according to fault position, provide corresponding processing mode.Improves the reliability of differential protection.

The application discloses a hand-automatic high-voltage power distribution cabinet protection pressing plate, which comprises a shell, a pressing plate assembly and a driving assembly. The shell is communicated at both ends. The pressing plate assembly comprises a pressing plate located in the shell, a movable rod located on the upper part of the pressing plate and a first electrode located on the upper part of the pressing plate. A second electrode is arranged in the shell and located on both sides of the first electrode. The driving assembly is rotationally arranged with the movable rod. On the basis of the traditional pressing plate, the use of the frequency converter can realize the input and cut-out of the differential protection in the protection pressing plate through the state signal point of the frequency converter.

The invention provides a composite differential protection method, a control device, a storage medium and a system, and belongs to the technical field of power distribution networks. The method comprises the following steps: after a power distribution network starts differential protection, exchanging electrical quantities measured by protection at two sides of a protected section; predicting the electrical quantities before and after the fault of the protected section by using the exchanged electrical quantities measured by the protectors at the two sides of the protected section; predicting the voltage of a fault point based on the predicted electrical quantities before and after the fault of the protected section, and calculating the action condition of differential protection; and when the calculated action condition of the differential protection meets the requirement, sending a tripping signal to realize composite differential protection. According to the method, the current and the active power of the T-connection DPV and the load branch under the fault are estimated by using the electrical data at the two ends of the protected section, and the protection principle is ensured to accord with the KCL and the active power conservation law, so that the problem of differential protection refusal or maloperation when the T-connection DPV and the load branch exist in the protected section at the same time is solved.

The invention provides a current differential protection method and device based on a sliding time window, and relates to the technical field of power system relay protection. The method comprises the following steps: acquiring differential current of two ends of a protected line at the current moment, comparing the differential current at the current moment with differential current at the moment corresponding to the last period, and judging whether the line starts a protection device at the current moment; if the line starts the protection device at the current moment, constructing a first sliding time window by taking the current moment as a starting point, and obtaining differential current data in the first sliding time window; based on frequency band energy characteristics of the differential current data in the first sliding time window, decomposing the differential current data in the first sliding time window into different frequency bands, and determining low-frequency energy and high-frequency energy in the first sliding time window; and judging whether the protection device acts or not based on the size relationship between the ratio of the low-frequency energy to the high-frequency energy and a preset setting value. By means of the method, the action speed, sensitivity and selectivity of differential protection are improved.

The application discloses a small integrated portable relay protection test teaching device and a use method thereof. The device comprises a box body, a reset button and a reclosing mode switching handle are arranged on the front side of the box body, a rectifier bridge and a line differential protection device are arranged in the box body, the operation surface and the display surface of the line differential protection device are located on the front side of the box body, a bottom protection plate is arranged at the bottom of the box body, a plurality of universal wheels are arranged at the bottom of the bottom protection plate, a front protection plate is hingedly connected to the bottom protection plate and arranged on the front side of the box body, a rear protection plate is hingedly connected to the bottom protection plate and arranged on the rear side of the box body, a top protection plate is arranged above the box body, the front side of the top protection plate is hingedly connected to the front protection plate, and the rear side of the top protection plate is hingedly connected to the rear protection plate. A first positioning assembly is arranged between the front protection plate and the top protection plate. A second positioning assembly is arranged between the top protection plate and the rear protection plate. A connecting mechanism in a separated state is arranged between the box body and the front protection plate. The device has the advantages of being not prone to faults and convenient to use.

The invention discloses a busbar differential protection test workbench, which relates to the technical field of test devices and specifically comprises a base plate and an upper cover plate, a microcomputer protection tester is placed in the upper cover plate, and a scissor type lifting mechanism is arranged between the base plate and the upper cover plate. The base plate and the upper cover plate can be separated for expansion or close for storage under adjustment of the scissor type lifting mechanism, side baffles are arranged outside the two sides of the base plate and the two sides of the upper cover plate, and semi-open sliding grooves are formed in the side baffles. According to the multifunctional detection platform, in the using process, flexible expansion and automatic limiting can be carried out through the arranged base plate, the upper cover plate, the first supporting rod, the second supporting rod and other structures, the detection supporting requirement is met, in the transferring process, the multifunctional detection platform can carry out storage adjustment of maximum limiting, and the practicability is high. And the occupied area is reduced, and meanwhile the flexibility in the transferring process can be fully improved.

This invention discloses a communication configuration method, device, electronic equipment, and storage medium for differential protection of distribution network ring networks, belonging to the field of power automation technology. The method includes: disconnecting all differential protection circuits within the first target differential ring where the fault differential protection device is located; disconnecting the optical fiber link between the fault protection device and other differential protection devices; after replacing the fault differential protection device with a new differential protection device, restoring the optical fiber link between the new differential protection device and other differential protection devices; controlling the static routing table corresponding to the first target differential ring to be updated, setting the differential protection activation identifier of the first target differential ring in the static routing table, and the differential protection activation identifier of each differential protection device within the first target differential ring, to the corresponding activation status identifier. Therefore, by implementing this invention, the problems of existing technologies that rely on manual on-site parameter setting, resulting in high cost and low reliability can be solved.

The utility model relates to the technical field of power system protection and measurement and control, in particular to a transformer differential protection measurement and control device. The device comprises a shell, a control module, a sampling module, a processing module, a power supply module, a heat dissipation module and an environment adaptation module. A plurality of partition plates are arranged in the shell and divide the internal space into a plurality of functional areas. The control module comprises a main control board and a plurality of control circuits, the sampling module comprises a current transformer and a voltage transformer, the processing module comprises a signal processing board and a data processing board, the power supply module comprises a power supply board and a battery, and the heat dissipation module comprises a heat dissipation fan and heat dissipation fins. The environment adaptation module comprises a temperature sensor, a humidity sensor, a heater and a condenser. According to the invention, stable operation of the device in an extreme environment condition can be ensured, the high efficiency and accuracy of signal transmission are improved, and the heat dissipation effect is improved.

The invention relates to the field of electric power business scheduling, and particularly discloses an electric power system business collaborative scheduling method based on a 5G technology, which constructs a high-low layer collaborative double-layer intelligent scheduling architecture. In a high level, situation prediction is carried out by fusing power grid operation data and historical traffic, and the macroscopic resource ratio of network slices is adjusted prospectively to cope with the sudden demand of power business, so that the problem of insufficient resources of static resource allocation in sudden scenes such as faults is solved. And at the lower layer, service semantic analysis is carried out deeply in the data packet, so that the real-time emergency level of key services such as differential protection and the like is accurately identified, and resources are further refined into a micro resource pool special for the services in combination with slice configuration issued by the higher layer, so that real-time scheduling and preemption based on semantics are realized. Through the combination of macroscopic predictive reservation and microscopic semantic scheduling, it is ensured that high-priority power services can obtain communication guarantee under any network load.

The invention provides a current differential protection method and system based on low-voltage current limiting control, and relates to the technical field of new energy relay protection. The method comprises the following steps: acquiring a voltage value of an alternating-current collection line and a phase difference value of current on two sides of the alternating-current collection line; when the voltage value is smaller than a preset voltage threshold value, a control mode of the converter station is switched to a low-voltage current-limiting control mode, and a voltage reference value of the converter station is set as an initial voltage reference value; when the phase difference value of the currents on the two sides is larger than a preset phase difference threshold value, a target voltage reference value of the converter station is determined based on the current positive sequence components on the two sides of the alternating current collection line, and the initial voltage reference value is switched into the target voltage reference value; and based on the relation between the ratio braking coefficient of the converter station under the target voltage reference value and a preset coefficient threshold value, current differential protection action or protection non-action of the converter station is determined. The problem that traditional differential protection cannot reliably act in the low-voltage current limiting period is solved.

The present invention discloses a method and system for fault reopening protection during transformer excitation inrush current lockout, wherein the method comprises: performing a first judgment based on a first round of judgment conditions after the protection judgment criterion is started; when the result of the first judgment is that the current differential protection lockout condition is satisfied, a lock current differential protection signal is issued, and the final lockout result is outputted together with the existing lockout judgment criterion and gate of the protection device; or when the result of the first judgment is that the current differential protection lockout condition is not satisfied, an open current differential protection signal is issued, and the final open result is outputted together with the existing open judgment criterion or gate of the protection device; performing a second judgment based on a second round of judgment conditions during the current differential protection lockout period; when the result of the second judgment is that the current differential protection openness condition is satisfied, the current current differential protection lockout is interrupted.