Arc suppression device compatible with arc suppression coil operation and phase judgment mistake proofing method

Abstract

The invention provides an arc suppression device compatible with arc suppression coil operation and a phase judgment mistake proofing method, and relates to the technical field of power supply equipment. The device comprises a grounding transformer I, an arc suppression coil, a variable impedance module and a fault grounding phase selection module, a front circuit breaker I is connected in series between the grounding transformer I and a three-phase line of the bus, a neutral point of the grounding transformer I is connected with one end of an arc suppression coil, the other end of the arc suppression coil is connected with one end of a variable impedance module, and an output end of the variable impedance module is grounded; the variable impedance module comprises a plurality of current-limiting impedance sub-modules which are connected in parallel; each current-limiting impedance sub-module comprises a current-limiting impedance and an impedance access switch which are connected in series; and the fault grounding phase selection module is used for identifying a fault phase which generates a single-phase grounding fault when the grounding fault occurs. According to the arc suppression coil, the damping effect is introduced through the variable impedance module, the resonance capacity is consumed, and the voltage rise of the neutral point is inhibited, so that the resonance phenomenon possibly generated by the arc suppression coil is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply equipment, and more specifically, to an arc extinguishing device compatible with the operation of an arc suppression coil and a phase discrimination and error prevention method. Background Art

[0002] Currently, during the occurrence of a grounding fault in a distribution network, through the introduction of intelligent processing, the faulty phase of a single-phase grounding fault is identified and processed, so as to reduce the fault handling time and increase the accuracy of fault handling.

[0003] In the related art, there is a disclosed patent with publication number CN201430438Y and invention name "An Arc Extinguishing Device", which includes an arc suppression coil device, a faulty phase grounding device, and a controller; the arc suppression coil device includes an arc suppression coil, a current transformer, and a voltage transformer. One end of the current transformer is connected to a grounding transformer for leading out the neutral point of the power grid, the other end of the current transformer is connected to one end of the arc suppression coil, the other end of the arc suppression coil is grounded, and the current transformer is connected to the grounding transformer; the controller is respectively connected to the current transformer and the voltage transformer, and is used to collect the current signal and voltage signal measured by the current transformer and the voltage transformer, and control the arc suppression coil and / or the faulty phase grounding device to extinguish the arc according to the current signal, voltage signal, and the ground voltage of each phase line in the power grid.

[0004] Regarding the above technical solution, there are still the following deficiencies: during the occurrence of a single-phase grounding fault, when the capacitive current to the ground is close to the inductive current of the arc suppression coil, the arc suppression coil may generate a resonance phenomenon, resulting in the risk of overvoltage in the arc suppression coil. Summary of the Invention

[0005] In order to reduce the possible resonance phenomenon of the arc suppression coil, the present application provides an arc extinguishing device compatible with the operation of the arc suppression coil and a phase discrimination and error prevention method.

[0006] In a first aspect, the present application provides an arc extinguishing device compatible with the operation of an arc suppression coil, adopting the following technical solution: An arc extinguishing device compatible with the operation of an arc suppression coil, the device includes a first grounding transformer, an arc suppression coil, a variable impedance module, and a faulty grounding phase selection module; A first pre-breaker is connected in series between the first grounding transformer and the three-phase lines of the bus, the neutral point of the first grounding transformer is connected to one end of the arc suppression coil, the other end of the arc suppression coil is connected to one end of the variable impedance module, and the output end of the variable impedance module is grounded; The variable impedance module includes a plurality of current-limiting impedance sub-modules connected in parallel, each current-limiting impedance sub-module includes a current-limiting impedance and an impedance access switch, and the current-limiting impedance and the current-limiting access switch are connected in series; The fault grounding phase selection module is used to identify the fault phase that generates a single-phase grounding fault during a grounding fault.

[0007] In a second aspect, the application also provides a phase discrimination and error prevention method for an arc suppression device compatible with the operation of an arc suppression coil, adopting the following technical solution: A phase discrimination and error prevention method for an arc suppression device compatible with the operation of an arc suppression coil, where phase current transformers are assembled on the three-phase lines of the busbar, and the method includes: If short-circuit fault information is received from the feeder side of the power distribution system, control the first pre-positioned circuit breaker to close; Loop and execute the following steps until all phase switches are added with a screened flag or the arc suppression switch closes: Generate fault phase identification information based on the phase current values fed back by multiple said phase current transformers obtained in real time; Control the corresponding phase switch in the arc suppression phase breaker to close according to the fault phase identification information, and add a screened flag to the phase switch in the currently closed state; Receive the phase selection current feedback information fed back by the first current transformer, and generate phase selection judgment information carrying a correct identification label or an incorrect identification flag according to the phase selection feedback information; If the phase selection judgment information carries a correct identification flag, control the arc suppression switch to close; If the phase selection judgment information carries an incorrect identification flag, trip the phase switch in the currently closed state.

[0008] In a third aspect, the application also provides a phase discrimination and error prevention system for an arc suppression device compatible with the operation of an arc suppression coil, adopting the following technical solution: A phase discrimination and error prevention system for an arc suppression device compatible with the operation of an arc suppression coil, the system includes: An information receiving module, if short-circuit fault information is received from the feeder side of the power distribution system, control the first pre-positioned circuit breaker to close; Loop and execute the following steps until all phase switches are added with a screened flag or the arc suppression switch closes: A fault identification and partitioning module, used to generate fault phase identification information based on the phase current values fed back by multiple said phase current transformers obtained in real time; An identification adding module, used to control the corresponding phase switch in the arc suppression phase breaker to close according to the fault phase identification information, and add a screened flag to the phase switch in the currently closed state; An information receiving module, receive the phase selection current feedback information fed back by the first current transformer, and generate phase selection judgment information carrying a correct identification label or an incorrect identification flag according to the phase selection feedback information; The fault identification and classification module controls the closing of the arc suppression switch if the phase selection judgment information carries a correct identification flag. The fault identification and classification module trips the phase-separated switch that is currently in the closed state if the phase selection judgment information carries an incorrect identification flag.

[0009] In summary, the present application includes at least one of the following beneficial technical effects: When a single-phase ground fault occurs on the feeder side of the distribution system, the front-end circuit breaker is quickly controlled to close, and the arc suppression coil compensates the capacitive current of the system to ground, suppressing the arc grounding overvoltage and slowing down the rising speed of the recovery voltage of the faulty phase. At this time, the variable impedance module introduces a damping effect to consume the resonance ability and suppress the rise of the neutral point voltage, thereby reducing the possible resonance phenomenon generated by the arc suppression coil. At the same time, the series-connected variable impedance module injects an additional resistive current component, with a 90° phase difference from the inductive compensation current, significantly increasing the zero-sequence current of the faulty line and improving the detection sensitivity of the line selection device. During the process of the arc suppression coil providing inductive compensation current when connected to the fault circuit, a large amount of heat is generated due to its own impedance. At the same time, after the arc suppression coil is put into use for a long time, its internal resistance increases, which may increase the possibility of damage to the arc suppression coil due to serious self-heating. In the present application, by generating the estimated compensation current threshold and the estimated risk state probability, the heating risk of the arc suppression coil is estimated, thereby reducing the probability of damage to the arc suppression coil due to heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0011] Figure 1 It is a circuit schematic diagram of an arc suppression device compatible with the operation of an arc suppression coil provided by an embodiment of the present application.

[0012] Figure 2 It is a flowchart of a method for judging phase and preventing errors of an arc suppression device compatible with the operation of an arc suppression coil provided by an embodiment of the present application.

[0013] Figure 3 It is a supplementary flowchart of a method for judging phase and preventing errors of an arc suppression device compatible with the operation of an arc suppression coil provided by an embodiment of the present application.

[0014] Figure 4 It is a flowchart of a method for estimating the heating risk of an arc suppression coil provided by an embodiment of the present application.

[0015] Figure 5 It is a schematic flow chart for generating a compensation current threshold provided by an embodiment of the present application.

[0016] Explanation of reference numerals: 1. Variable impedance module; 2. Fault grounding phase selection module; 3. Fault grounding line selection module. Detailed implementation manners

[0017] To make the objectives, technical solutions and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail Figures 1-5 in conjunction with the accompanying drawings.

[0018] The present application provides an arc suppression device compatible with the operation of an arc suppression coil. As Figure 1 shown, the device includes a pre - circuit breaker I, a grounding transformer I, an arc suppression coil, a variable impedance module 1, a fault grounding phase selection module 2, and a fault grounding line selection module 3.

[0019] The three - phase input terminals of the pre - circuit breaker I are correspondingly connected to the three - phase lines of the bus, the three - phase output terminals of the pre - circuit breaker I are correspondingly connected to the three - phase input terminals of the grounding transformer I, the neutral point of the grounding transformer I is connected to one end of the arc suppression coil, the other end of the arc suppression coil is connected to one end of the variable impedance module, and the output terminal of the variable impedance module is grounded.

[0020] When a single - phase grounding fault occurs on the feeder side of the distribution system, quickly control the pre - circuit breaker I to close. The arc suppression coil compensates the capacitive current of the system to the ground, suppresses the arc - grounding over - voltage, and slows down the rising speed of the recovery voltage of the faulty phase. At this time, the variable impedance module 1 introduces a damping effect, consumes the resonance ability, and suppresses the rise of the neutral - point voltage, so as to reduce the possible resonance phenomenon generated by the arc suppression coil. At the same time, the series - connected variable impedance module 1 injects an additional resistive current component, which has a 90° phase difference with the inductive compensation current, making the zero - sequence current of the faulty line increase significantly and improving the detection sensitivity of the line selection device.

[0021] The line connecting the arc suppression coil and the variable impedance module 1 is also equipped with a current transformer II, which is used to monitor the compensation current of the arc suppression coil.

[0022] The variable impedance module 1 includes a plurality of current - limiting impedance sub - modules connected in parallel. Each current - limiting impedance sub - module includes a current - limiting impedance and an impedance access switch, and the current - limiting impedance is connected in series with the current - limiting access switch. By real - time monitoring of the neutral - point voltage and the fault current, the resistance value is dynamically adjusted. For example, when there is a resonant over - voltage, the total resistance of the variable impedance module 1 is reduced, and when selecting the faulty line, the total resistance of the variable impedance module 1 is briefly increased to highlight the fault characteristics.

[0023] The fault grounding phase selection module 2 is used to identify the fault phase that generates a single-phase grounding fault during a grounding fault. The fault grounding phase selection module 2 includes a prebreaker II, an arc suppression phase breaker, a current limiting resistor, and an arc suppression switch. At the same time, in order to facilitate the preliminary phase selection for grounding faults, phase current transformers are installed on the three-phase lines of the busbar.

[0024] The three-phase input terminals of the prebreaker II are connected to the three-phase lines of the busbar in one-to-one correspondence. The arc suppression phase breaker includes three phase switches corresponding to the three-phase lines of the busbar. The input terminals of multiple phase switches in the arc suppression phase breaker are connected to the three-phase output terminals of the prebreaker II. One end of the current limiting resistor is connected to the output terminals of multiple phase switches at the same time, and the other end of the current limiting resistor is grounded. The arc suppression switch is connected in parallel with the current limiting resistor. A current transformer I is installed on the common grounding line of the current limiting resistor and the arc suppression switch.

[0025] The fault grounding line selection module 3 includes a three-phase contactor and a grounding transformer II with impedance. The three-phase input terminals of the three-phase contactor are respectively connected to the three-phase output terminals of the prebreaker II, the output terminal of the three-phase contactor is connected to the three-phase input terminals of the grounding transformer II, and the neutral point of the grounding transformer II is grounded; a current transformer III is installed on the grounding line of the grounding transformer II.

[0026] After detecting a short-circuit fault current on the distribution system feeder, control the prebreaker I and the prebreaker II to close, and further perform fault phase selection and fault line selection through the fault grounding phase selection module 2 and the fault grounding line selection module 3.

[0027] Specifically, the arc suppression device is also equipped with a main controller, which receives the current information fed back by the current transformer I, the current transformer II, the current transformer III, and multiple phase current transformers. And the main controller is used to control the opening and closing of the arc suppression phase breaker, the prebreaker I, the prebreaker II, the arc suppression switch, and the impedance access switch.

[0028] During the process of the main controller performing fault phase selection, the fault phase selection sub-module first closes one of the phase switches in the arc suppression phase breaker, and then monitors the current flowing through the current limiting resistor and the relevant vector relationship through the current transformer I, so as to facilitate the judgment of whether the phase selection is accurate.

[0029] If the fault phase selection is correct, close the arc suppression switch to make the fault phase grounded metallically. If the phase selection is incorrect, open the already closed phase switch and select another phase switch to complete the re-phase selection operation.

[0030] The embodiment of the present application also provides a phase discrimination and error prevention method for an arc suppression device compatible with the operation of an arc suppression coil. The method can be applied to a phase discrimination and error prevention system for an arc suppression device compatible with the operation of an arc suppression coil. The phase discrimination and error prevention system for an arc suppression device compatible with the operation of an arc suppression coil can be composed of a main controller, a first current transformer, a second current transformer, a third current transformer, and multiple phase current transformers. The execution subject of this method can be the main controller in the phase discrimination and error prevention system for an arc suppression device compatible with the operation of an arc suppression coil.

[0031] Next, in combination with specific implementation manners, Figure 2 the following processing flow will be described in detail, and the content can be as follows: Step S101, if the short-circuit fault information fed back from the feeder side of the power distribution system is received, then control the first preposition breaker to close.

[0032] In implementation, when the main controller receives the short-circuit fault information fed back from the feeder side of the power distribution system, the main controller controls the first preposition breaker and the second preposition breaker to close, so that the arc suppression coil, the fault grounding phase selection module 2, and the fault grounding line selection module 3 work.

[0033] Loop and execute the following steps until all phase switches are added with a screened identifier or the arc suppression switch closes: Step S102, generate fault phase identification information according to the phase current values fed back by multiple phase current transformers obtained in real time.

[0034] In implementation, after the main controller receives the short-circuit fault information, it loops and processes the following steps until all phase switches are added with a screened identifier or the arc suppression switch closes, and then jumps out of the loop after processing all steps in this loop.

[0035] Specifically, the main controller obtains the phase current values fed back by multiple phase current transformers in real time. Then the main controller compares the multiple phase current values obtained in real time with the fault current threshold. If the phase current value of a certain phase is greater than the fault current threshold, it identifies that phase as the fault phase in fault operation, and marks the three-phase lines of the current bus as the fault operation state, so as to facilitate generating the fault phase identification information carrying the fault phase calibration.

[0036] Step S103, control the corresponding phase switch in the arc suppression phase breaker to close according to the fault phase identification information, and add a screened identifier to the phase switch in the current closed state.

[0037] In implementation, the main controller controls the corresponding phase switch in the arc suppression phase breaker to close with the fault phase identification information, and then adds a screened identifier to the phase switch in the current closed state.

[0038] Step S104: Receive the phase selection current feedback information fed back by Current Transformer 1, and generate phase selection judgment information carrying a correct identification label or an incorrect identification label based on the phase selection feedback information.

[0039] In implementation, after the main controller closes the corresponding split-phase switch, the main controller receives the phase selection current feedback information fed back by Current Transformer 1, and generates phase selection judgment information carrying a correct identification label or an incorrect identification label through the current value and relevant vector relationship in the phase selection current feedback information.

[0040] Step S105: If the phase selection judgment information carries a correct identification label, control the arc suppression switch to close.

[0041] In implementation, when the main controller recognizes that there is a correct identification label in the current phase selection judgment information, it controls the arc suppression switch to close, making the fault phase grounded metallically. The current of the fault phase flows to the ground through the arc suppression switch, so that the current flowing through the fault phase at the feeder end is smaller, reducing the impact caused by the single-phase short-circuit fault.

[0042] Step S106: If the phase selection judgment information carries an incorrect identification label, open the split-phase switch that is currently in the closed state.

[0043] In implementation, when the main controller recognizes that there is an incorrect identification label in the current phase selection judgment information, it opens the split-phase switch that is currently in the closed state.

[0044] At this time, if there are still split-phase switches without the screened label added, repeat the above steps S102 to S104 until there is a correct label in the phase selection judgment information, and then execute step S105.

[0045] If all three split-phase switches are added with the screened label, end the loop.

[0046] Optionally, in this application, after there is a correct identification label in the phase selection judgment information, there is also a processing as Figure 3 shown below. The specific operation process is as follows: Step S107: After waiting for a preset instantaneous delay judgment duration, control the split-phase switch that is currently in the closed state to open, and identify the operating state of the three-phase line of the bus with the currently obtained multiple phase current values.

[0047] In implementation, after the main controller screens out the fault phase, it waits for a preset instantaneous delay judgment duration. The preset instantaneous delay judgment duration here can be 50ms, 80ms, 2s, etc.

[0048] After waiting for the instantaneous delay judgment duration, the main controller then controls the arc suppression switch and the split-phase switch that is in the closed state to open in sequence.

[0049] Then, the main controller compares the currently obtained multiple phase current value information with the fault current threshold again to determine whether the single-phase grounding short-circuit fault has disappeared after experiencing the instantaneous delay judgment duration. If the single-phase grounding short-circuit fault has disappeared, the current single-phase grounding short-circuit fault is recorded as an instantaneous fault, and at this time, the three-phase bus line is in normal operation; if the single-phase grounding short-circuit fault has not disappeared, the current single-phase grounding short-circuit fault is recorded as a permanent fault, and at this time, the three-phase bus line is in fault operation.

[0050] Step S108, if normal operation is identified in the operating state of the three-phase bus line, control the first pre-positioned circuit breaker to trip.

[0051] In implementation, if the main controller identifies that the operating state of the three-phase bus line is normal operation, that is, the current single-phase short-circuit fault is an instantaneous fault, it controls the first pre-positioned circuit breaker and the second pre-positioned circuit breaker to trip.

[0052] Step S109, if fault operation is identified in the operating state of the three-phase bus line, periodically obtain the operating state of the three-phase bus line with a preset residence duration until the operating state of the three-phase bus line is normal operation, control the first pre-positioned circuit breaker to trip, or the fault operation duration of the three-phase bus line is greater than the preset arc suppression coil operating duration, and control the first pre-positioned circuit breaker to trip.

[0053] In implementation, if the main controller identifies that the operating state of the three-phase bus line is fault operation, that is, the current single-phase short-circuit fault is a permanent fault, at this time, the main controller controls the corresponding disconnector switch and arc suppression switch of the fault phase to close.

[0054] Furthermore, the main controller performs periodic cyclic detection and evaluation processing on the operating state of the three-phase bus line with a preset residence duration, and the residence duration can be 10 minutes. Specifically: After every 10 minutes, the main controller trips the corresponding disconnector switch and arc suppression switch of the fault phase again, and then obtains the operating state of the three-phase bus line to determine whether the fault has been eliminated.

[0055] If the fault is eliminated, control the first pre-positioned circuit breaker and the second pre-positioned circuit breaker to trip, and the cycle stops.

[0056] If the fault has not been eliminated, control the arc suppression switch and the target disconnector switch to close, and then perform the next 10-minute cycle.

[0057] Here, when the operating duration of the fault is greater than the preset arc suppression coil operating duration, the cycle also stops, and the main controller controls the first pre-positioned circuit breaker to trip. Here, the arc suppression coil operating duration is generally between 1 and 2 hours, and the specific time here can be set according to different devices.

[0058] Optionally, in this application, after the pre - circuit breaker one and the pre - circuit breaker two are closed, there is also a process as follows: Figure 4 as shown, and the specific operation process is as follows: Step S201: Real - time obtain the working temperature value of the arc suppression coil and the current compensation value feedback by the current transformer two.

[0059] In implementation, the main controller real - time obtains the working temperature value of the arc suppression coil feedback by the temperature sensor, and at the same time, the main controller also obtains the current compensation value feedback by the current transformer two.

[0060] Step S202: According to the current compensation value, match the corresponding target theoretical working temperature value in the preset theoretical temperature rise data of the arc suppression coil. The theoretical temperature rise data of the arc suppression coil is used to reflect the corresponding relationship between the theoretical compensation value and the theoretical working temperature value.

[0061] In implementation, the main controller presets the theoretical temperature rise data of the arc suppression coil, and the theoretical temperature rise data of the arc suppression coil is used to reflect the corresponding relationship between the theoretical compensation value and the theoretical working temperature value. Here, the theoretical temperature rise data of the arc suppression coil can be obtained from a constant - temperature environment in the laboratory.

[0062] The main controller uses the current compensation value to match the corresponding theoretical working temperature value in the theoretical temperature rise data of the arc suppression coil, and the theoretical working temperature value matched here is called the target historical working temperature value.

[0063] Step S203: Calculate and generate the current estimated temperature difference according to the current actual working temperature value and the target theoretical working temperature value.

[0064] In implementation, the main controller subtracts the actual working temperature value feedback by the temperature sensor from the target theoretical working temperature value to calculate and generate the current estimated temperature difference.

[0065] Step S204: Obtain the historical compensation current data and historical working temperature data of the current arc suppression coil.

[0066] In implementation, the main controller obtains the historical compensation current data and historical working temperature data of the current arc suppression coil from the storage database or the specified network address. The historical compensation current data includes multiple historical compensation current values, and the historical working temperature data includes multiple historical working temperature values.

[0067] Step S205: Generate historical estimated temperature difference information according to the historical compensation current data, historical working temperature data, and the theoretical temperature rise data of the arc suppression coil.

[0068] In implementation, the master controller matches multiple theoretical compensation current values from the theoretical temperature rise data of the arc suppression coil using the historical compensation current data. Then, the master controller subtracts the corresponding theoretical compensation current value from the historical working temperature value to calculate and generate the historical estimated temperature difference. Subsequently, the historical estimated temperature difference information is generated by aggregating multiple historical estimated temperature differences.

[0069] Step S206: Generate a compensation current threshold based on the historical estimated temperature difference information, the current estimated temperature difference, and a preset temperature upper limit threshold.

[0070] In implementation, the master controller calculates and generates an average estimated temperature difference using multiple historical estimated temperature differences and the current estimated temperature difference.

[0071] Then, the temperature upper limit threshold is subtracted from the average estimated temperature difference to generate a target temperature value. Subsequently, the corresponding compensation current threshold is matched in the theoretical temperature rise data of the arc suppression coil using the target temperature value.

[0072] Step S207: Obtain the same - type compensation current data in the distribution network at the same distribution voltage level as the current arc suppression device.

[0073] In implementation, the master controller obtains the historical compensation power data in the distribution network at the same distribution voltage level as the current arc suppression device from a specified network address. Here, the compensation current data is referred to as the same - type compensation current data.

[0074] Step S208: Generate predicted risk status information based on the same - type compensation current data and the compensation current threshold.

[0075] In implementation, the master controller pre - divides multiple current division gradients. Then, based on the distribution of the same - type compensation current in each current division gradient, the distribution probability within each current division gradient is generated. Subsequently, the distribution probability corresponding to the current division gradient where the compensation current threshold is located is used as the risk probability to generate the predicted risk status information carrying the risk probability.

[0076] During the process of the arc suppression coil providing inductive compensation current when connected to a fault circuit, a large amount of heat is generated due to its own impedance. At the same time, after the arc suppression coil is put into use for a long time, its internal resistance increases, which may increase the possibility of damage to the arc suppression coil due to severe self - heating. In this application, the predicted compensation current threshold and the predicted risk status probability are generated through the above - mentioned calculation method to estimate the heating risk of the arc suppression coil, thereby reducing the probability of damage to the arc suppression coil caused by heating.

[0077] Optionally, in step S206, there is also a process as Figure 5 shown, and the specific operation process is as follows: Step S301: Calculate and generate a plurality of temperature difference gradient change amounts based on historical estimated temperature difference information and current estimated temperature difference.

[0078] In implementation, the main controller subtracts two adjacent historical estimated temperature differences in the timeline from the plurality of historical estimated temperature differences and the current estimated temperature difference in the historical estimated temperature difference information, and at the same time subtracts the nearest historical estimated temperature difference in the timeline from the current estimated temperature difference to generate a plurality of temperature difference gradient change amounts.

[0079] Step S301: Calculate and generate a predicted gradient change amount based on the plurality of temperature difference gradient change amounts.

[0080] In implementation, the main controller calculates and generates a predicted gradient change amount with the average value of the temperature difference gradient change amounts.

[0081] Step S302: Calculate and generate a predicted temperature difference based on the predicted gradient change amount and the current estimated temperature difference.

[0082] In implementation, the main controller superimposes the predicted gradient change amount and the current estimated temperature difference to calculate and generate a predicted temperature difference.

[0083] Step S303: Calculate and generate a compensation current threshold based on the predicted temperature difference and the temperature upper limit threshold.

[0084] Specifically, the processing flow of step S301 is as follows: Calculate and generate a target temperature threshold corresponding to the temperature upper limit threshold based on the temperature upper limit threshold and the predicted temperature difference; Match the corresponding compensation current threshold in the arc suppression coil theoretical temperature rise data according to the target temperature threshold.

[0085] In implementation, the main controller subtracts the predicted temperature difference from the temperature upper limit threshold to calculate and generate a target temperature threshold corresponding to the temperature upper limit threshold.

[0086] Then, the main controller matches the corresponding compensation current value in the arc suppression coil theoretical temperature rise data with the target temperature threshold, and calls the matched compensation current value the compensation current threshold.

[0087] Optionally, in step S208, there is also the following processing, and the specific operation flow is as follows: Calculate and generate the compensation current distribution rate of the same-type compensation current values within each current division gradient based on the plurality of same-type compensation current values in the same-type compensation current data and the pre-divided current division gradient; Match the corresponding target current division gradient according to the compensation current threshold; Divide the compensation current distribution rate corresponding to the gradient according to the target current to generate the estimated risk status information.

[0088] In implementation, multiple current division gradients are pre-divided in the main controller. When the main controller obtains the same type of compensation current data, it calculates the probability of the distribution of the same type of compensation current values within each current division gradient, which is called the compensation current distribution rate here.

[0089] Then the main controller matches the current division gradient where the compensation current threshold is located, and calls the matched current division gradient the target current division gradient.

[0090] Then the main controller uses the compensation current distribution rate corresponding to the target current division gradient as the risk status probability, and generates the estimated risk status information carrying the risk status probability.

[0091] The embodiment of the present application also discloses a phase discrimination and anti-error system for an arc suppression device compatible with the operation of an arc suppression coil, characterized in that the system includes: An information receiving module, if receiving the short-circuit fault information fed back from the feeder side of the power distribution system, controls the closing of the first preposed circuit breaker; Circularly execute the following steps until all the phase-separated switches are added with the screened flag or the arc suppression switch is closed: A fault identification and division module, used to generate fault phase identification information according to the phase current values fed back by multiple phase current transformers obtained in real time; An identification adding module, used to control the closing of the corresponding phase-separated switch in the arc suppression phase-separated circuit breaker according to the fault phase identification information, and add the screened flag to the phase-separated switch in the current closed state; The information receiving module receives the phase selection current feedback information fed back by the first current transformer, and generates the phase selection judgment information carrying the correct identification number or the incorrect identification flag according to the phase selection feedback information; The fault identification and division module, if the phase selection judgment information carries the correct identification flag, controls the closing of the arc suppression switch; The fault identification and division module, if the phase selection judgment information carries the incorrect identification flag, opens the phase-separated switch in the current closed state.

[0092] Optionally, the system can also be used for: The fault identification and division module controls the opening of the phase-separated switch in the current closed state after waiting for the preset instantaneous delay judgment duration, and identifies the operating state of the three-phase bus line with the multiple phase current values obtained currently; The fault identification and division module, if it identifies normal operation in the operating state of the three-phase bus line, controls the opening of the first preposed circuit breaker; The fault identification and division module, if a fault operation is identified in the operating state of the three-phase bus line, periodically obtains the operating state of the three-phase bus line with a preset residence duration until the operating state of the three-phase bus line is normal operation, controls the front breaker to trip, or if the fault operation duration of the three-phase bus line is greater than the preset arc suppression coil operating duration, controls the front breaker to trip.

[0093] Optionally, the system can also be used for: The information receiving module is used to obtain the working temperature value of the arc suppression coil and the current compensation current value fed back by the current transformer in real time; The data matching module is used to match the corresponding target theoretical working temperature value in the preset theoretical temperature rise data of the arc suppression coil according to the current compensation current value. The theoretical temperature rise data of the arc suppression coil is used to reflect the corresponding relationship between the theoretical compensation current value and the theoretical working temperature value; The data calculation module is used to calculate and generate the current estimated temperature difference according to the current actual working temperature value and the target theoretical working temperature value; The information receiving module is used to obtain the historical compensation current data and historical working temperature data of the current arc suppression coil; The data calculation module is used to generate historical estimated temperature difference information according to the historical compensation current data, historical working temperature data and the theoretical temperature rise data of the arc suppression coil; The data calculation module is used to generate a compensation current threshold according to the historical estimated temperature difference information, the current estimated temperature difference and the preset temperature upper limit threshold; The information receiving module is used to obtain the same type of compensation current data in the distribution network at the same distribution voltage level as the current arc suppression device; The data matching module is used to generate estimated risk status information according to the same type of compensation current data and the compensation current threshold.

[0094] Optionally, the system is specifically used for: The data calculation module is used to calculate and generate multiple temperature difference gradient change amounts according to the historical estimated temperature difference information and the current estimated temperature difference; The data calculation module is used to calculate and generate an estimated gradient change amount according to the multiple temperature difference gradient change amounts; The data calculation module is used to calculate and generate an estimated temperature difference according to the estimated gradient change amount and the current estimated temperature difference; The data calculation module is used to calculate and generate a compensation current threshold according to the estimated temperature difference and the temperature upper limit threshold.

[0095] Optionally, the system is specifically used for: A data calculation module, configured to calculate and generate a target temperature threshold corresponding to the upper temperature threshold according to the upper temperature limit threshold and the estimated temperature difference. A data matching module, configured to match a corresponding compensation current threshold in the theoretical temperature rise data of the arc suppression coil according to the target temperature threshold.

[0096] Optionally, the system is specifically configured to: A data matching module, configured to calculate and generate a compensation current distribution rate of the same-type compensation current values within each current division gradient according to multiple same-type compensation current values in the same-type compensation current data and the pre-divided current division gradients. A data matching module, configured to match a corresponding target current division gradient according to the compensation current threshold. A data matching module, configured to generate estimated risk status information according to the compensation current distribution rate corresponding to the target current division gradient.

[0097] The main controller may vary significantly due to configuration or performance differences, and may include one or more central processing units (e.g., one or more processors) and a memory, and one or more storage media for storing applications or data (e.g., one or more mass storage devices). Among them, the memory and the storage media may be transient storage or persistent storage. The programs stored in the storage media may include one or more modules (not shown in the figure), and each module may include a series of instruction operations on the main controller.

[0098] The main controller may further include one or more power supplies, one or more wired or wireless network interfaces, one or more input / output interfaces, one or more keyboards, and / or one or more operating systems.

[0099] The main controller may include a memory and one or more programs, where one or more programs are stored in the memory and are configured to be executed by one or more processors. One or more programs include the processing of the main controller in the phase discrimination and error prevention method of the arc suppression device for compatible operation of the arc suppression coil as described above.

[0100] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware or by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, etc.

[0101] Although the present invention is disclosed as above, the scope of protection of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the scope of protection of the present invention.

Claims

1. An arc extinguishing device compatible with arc extinguishing coil operation, characterized in that: The device comprises a grounding transformer, an arc suppression coil, a variable impedance module (1) and a fault grounding phase selection module (2); A pre-circuit breaker 1 is connected in series between the grounding transformer 1 and the three-phase line of the busbar, the neutral point of the grounding transformer 1 is connected to one end of the arc extinguishing coil, the other end of the arc extinguishing coil is connected to one end of the variable impedance module (1), and the output end of the variable impedance module (1) is grounded; The variable impedance module (1) comprises a plurality of current limiting impedance sub-modules connected in parallel with each other, each current limiting impedance sub-module comprises a current limiting impedance and an impedance access switch, and the current limiting impedance and the current limiting access switch are connected in series; The fault grounding phase selection module (2) is used to identify the fault phase that generates a single-phase grounding fault when a grounding fault occurs.

2. The device according to claim 1, characterized in that: The fault grounding phase selection module (2) comprises an arc-extinguishing phase-splitting circuit breaker, a current-limiting resistor and an arc-extinguishing switch; The arc-extinguishing phase-splitting circuit breaker includes three phase-splitting switches corresponding to the three-phase lines of the busbar, and the arc-extinguishing phase-splitting circuit breaker is connected to the three-phase lines of the busbar; One end of the current limiting resistor is connected to the output ends of multiple phase switches, the other end of the current limiting resistor is grounded, the arc extinguishing switch is connected in parallel to the current limiting resistor, and a current transformer is installed on the common grounding circuit of the current limiting resistor and the arc extinguishing switch.

3. A method for phase judgment and error prevention of arc extinguishing device compatible with arc extinguishing coil operation, using the arc extinguishing device described in claim 2, characterized in that: The three-phase lines of the busbar are all equipped with phase current transformers, and the method comprises: If short-circuit fault information fed back from the feeder side of the power distribution system is received, the front circuit breaker is controlled to close; The following steps are executed repeatedly until all phase switches are marked with the filtered flag or the arc extinguishing switch is closed: Generate fault phase identification information according to the phase current values ​​fed back by the phase line current transformers acquired in real time; Control the corresponding split-phase switch in the arc-extinguishing split-phase circuit breaker to close according to the fault phase identification information, and add a filtered mark to the split-phase switch currently in the closed state; Receiving the phase selection current feedback information fed back by the current transformer 1, and generating the phase selection judgment information carrying the identification correct label or the identification error label according to the phase selection feedback information; If the phase selection judgment information carries a correct identification mark, the arc extinguishing switch is controlled to close; If the phase selection judgment information carries an identification error mark, the phase switch currently in the closed state is disconnected.

4. The method according to claim 3, characterized in that: After the phase selection judgment information has a correct identification mark, the method further includes: After waiting for a preset instantaneous delay time, the phase switch currently in the closed state is controlled to open, and the operating state of the bus three-phase line is identified by the currently acquired multiple phase current values; If normal operation is identified in the operating state of the busbar three-phase line, the front circuit breaker is controlled to open; If faulty operation is identified in the operating status of the bus three-phase line, the operating status of the bus three-phase line is periodically obtained with a preset dwell time until the operating status of the bus three-phase line is normal, and the front circuit breaker is controlled to open; or if the bus three-phase line has a faulty operation time that is greater than the preset arc extinguishing coil working time, the front circuit breaker is controlled to open.

5. The method according to claim 3, characterized in that: A second current transformer is installed on the line connecting the arc suppression coil to the variable impedance module (1); After the front circuit breaker is closed, the method further includes: Real-time acquisition of the operating temperature value of the arc suppression coil and the current compensation current value fed back by the second current transformer; According to the current compensation current value, a corresponding target theoretical operating temperature value is matched in the preset arc extinguishing coil theoretical temperature rise data, wherein the arc extinguishing coil theoretical temperature rise data is used to reflect the corresponding relationship between the theoretical compensation current value and the theoretical operating temperature value; Calculating and generating a current estimated temperature difference value according to the current actual operating temperature value and the target theoretical operating temperature value; Obtaining historical compensation current data and historical operating temperature data of the arc suppression coil; Generate historical estimated temperature difference information according to the historical compensation current data, the historical operating temperature data and the arc suppression coil theoretical temperature rise data; Generate a compensation current threshold value according to the historical estimated temperature difference information, the current estimated temperature difference value and a preset upper temperature limit threshold value; Obtain the same type of compensation current data in the distribution network at the same distribution voltage level as the current arc extinguishing device; Estimated risk state information is generated according to the same type of compensation current data and the compensation current threshold.

6. The method according to claim 5, characterized in that The generating of the compensation current threshold value according to the historical estimated temperature difference information, the current estimated temperature difference value and the preset upper temperature limit threshold value includes: Calculating and generating a plurality of temperature difference gradient change amounts according to the historical estimated temperature difference information and the current estimated temperature difference; Calculating and generating an estimated gradient change amount according to the plurality of temperature difference gradient change amounts; Calculating and generating an estimated temperature difference value according to the estimated gradient change amount and the current estimated temperature difference value; A compensation current threshold is calculated and generated according to the estimated temperature difference and the upper temperature limit threshold.

7. The method according to claim 6, characterized in that The step of calculating and generating a compensation current threshold value according to the estimated temperature difference and the upper temperature limit threshold value comprises: Calculate and generate a target temperature threshold corresponding to the upper temperature threshold according to the upper temperature threshold and the estimated temperature difference; According to the target temperature threshold, a corresponding compensation current threshold is matched in the arc extinguishing coil theoretical temperature rise data.

8. The method according to claim 5, characterized in that The generating estimated risk state information according to the same type of compensation current data and the compensation current threshold comprises: According to the multiple same-type compensation current values ​​in the same-type compensation current data and the pre-divided current division gradients, a compensation current distribution rate of the same-type compensation current value in each current division gradient is calculated and generated; According to the compensation current threshold matching corresponding target current division gradient; Estimated risk state information is generated according to the compensation current distribution rate corresponding to the target current division gradient.

9. An arc extinguishing device phase error detection and prevention system compatible with arc extinguishing coil operation, applied to the arc extinguishing device according to claim 2, characterized in that: The system comprises: The information receiving module controls the front circuit breaker to close if short-circuit fault information fed back from the feeder side of the power distribution system is received; The following steps are executed repeatedly until all phase switches are marked with the filtered flag or the arc extinguishing switch is closed: A fault identification and classification module, used to generate fault phase identification information according to the phase current values ​​fed back by the phase line current transformers acquired in real time; An identification adding module, used for controlling the closing of the corresponding split-phase switch in the arc-extinguishing split-phase circuit breaker according to the fault phase identification information, and adding a screened identification to the split-phase switch currently in the closed state; An information receiving module receives the phase selection current feedback information fed back by the current transformer 1, and generates phase selection judgment information carrying a correct identification mark or an error identification mark according to the phase selection feedback information; A fault identification and classification module controls the arc extinguishing switch to close if the phase selection judgment information carries a correct identification mark; The fault identification and classification module disconnects the phase switch currently in the closed state if the phase selection judgment information carries an identification error mark.

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