Method for optimizing reclosing time of outgoing circuit breaker of transformer substation and related equipment

Abstract

The embodiment of the invention discloses a reclosing time optimization method for an outgoing circuit breaker of a transformer substation and related equipment, when the reclosing time of the outgoing circuit breaker is set, the low voltage ride through time is fully considered, and the reclosing operation is ensured to be performed after the low voltage ride through of a distributed power supply is completed; by presetting the time limit Z, the sectional circuit breaker can be ensured not to act too early under the conditions that a superior bus or line breaks down and a superior power supply spare power automatic switching device acts, so that mistaken opening is avoided, and meanwhile, the sectional circuit breaker is ensured to be subjected to voltage-loss opening before the current-level line is overlapped. Therefore, the reclosing time of the outgoing circuit breaker is set by combining the low-voltage ride-through time and the preset Z time limit, so that the protection constant value matching relationship among the section circuit breaker, the outgoing circuit breaker and the inverter of the distributed power supply is optimized, and the distributed power supply can be reliably cut off when the power system fails. And the problem of misoperation of the section circuit breaker is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method for optimizing the reclosing time of a transformer substation outgoing line circuit breaker and related equipment. Background Art

[0002] In the context of new power systems, the large-scale integration of distributed generation (DGs) has altered the power flow distribution and protection logic of traditional distribution networks, impacting the operation of sectionalizer circuit breakers. On the one hand, the DGs' continuous power supply capability can slow the decay of the voltage at the fault point, affecting the accuracy of the sectionalizer circuit breaker's tripping action. On the other hand, the reverse voltage provided by the DGs can interfere with the sectionalizer circuit breaker's voltage loss detection function, preventing it from properly tripping during a fault. Summary of the Invention

[0003] In view of this, the present invention provides a method for obtaining frequency-variable inductance parameters of a transformer and related equipment.

[0004] The specific technical solution of the first embodiment of the present invention is: a method for optimizing the reclosing time of a substation outgoing line circuit breaker, applied to a power system, wherein the power system includes a substation, an outgoing line circuit breaker, multiple segmented circuit breakers, a branch circuit breaker, a connecting circuit breaker, an inverter and a distributed power supply, wherein the output end of the substation is connected to the outgoing line circuit breaker, and multiple segmented circuit breakers connected in sequence are arranged between the outgoing line circuit breaker and the connecting circuit breaker, and one end of the branch circuit breaker is used to be connected to the output end of a first target segmented circuit breaker, and the first target segmented circuit breaker is the first target segmented circuit breaker after the fault line. A first segmented circuit breaker, the other end of the branch circuit breaker is connected to one end of the inverter, the other end of the inverter is connected to the distributed power source, a processor is set in the substation, and the processor is used to set the reclosing time of the outgoing circuit breaker. The method includes: obtaining the low voltage ride-through time of the inverter, and obtaining the preset Z time limit of the second target segmented circuit breaker; the second target segmented circuit breaker is any one of the multiple segmented circuit breakers; and setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit.

[0005] Preferably, setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit includes: setting the reclosing time according to the sum of the low voltage ride-through time and the preset Z time limit.

[0006] Preferably, setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit includes: setting a reserved time margin; setting the sum of the low voltage ride-through time, the preset Z time limit and the reserved time margin as the reclosing time.

[0007] Preferably, when the preset Z time limits of the multiple segmented circuit breakers are different, the largest preset Z time limit is selected as the target Z time limit; then the sum of the low voltage ride-through time, the preset Z time limit and the reserved time margin is set as the reclosing time, including: setting the sum of the low voltage ride-through time, the target Z time limit and the reserved time margin as the reclosing time.

[0008] Preferably, the low voltage ride-through time is less than the preset Z time limit.

[0009] Preferably, the power system also includes a grid-connected boundary automatic switch, one end of the grid-connected boundary automatic switch is connected to the branch circuit breaker, and the other end of the grid-connected boundary automatic switch is connected to the inverter. The method also includes: obtaining the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch; then setting the reclosing time of the outgoing circuit breaker according to the low-voltage ride-through time and the preset Z time limit, including: setting the reclosing time of the outgoing circuit breaker according to the low-voltage ride-through time, the preset Z time limit and the low-frequency and low-voltage protection action time.

[0010] Preferably, setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time, the preset Z time limit and the low frequency and low voltage protection action time includes: setting a reserved time margin; selecting the maximum value between the low voltage ride-through time and the low frequency and low voltage protection action time as the target time value; and setting the sum of the target time value, the preset Z time limit and the reserved time margin as the reclosing time.

[0011] The specific technical solution of the second embodiment of the present invention is: a reclosing time optimization system for a substation outgoing circuit breaker, the system comprising: a time acquisition module and a reclosing time setting module; the time acquisition module is used to obtain the low voltage ride-through time of the inverter, and obtain the preset Z time limit of the second target segmented circuit breaker; the second target segmented circuit breaker is any one of the multiple segmented circuit breakers; the reclosing time setting module is used to set the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit.

[0012] The specific technical solution of the third embodiment of the present invention is: a reclosing time optimization device for a substation outgoing circuit breaker, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method described in any one of the first embodiments of the present application.

[0013] The specific technical solution of the fourth embodiment of the present invention is: a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the method described in any one of the first embodiments of the present application.

[0014] The implementation of the present invention will have the following beneficial effects:

[0015] The present invention obtains the low voltage ride-through time of the inverter and the preset Z time limit of the section circuit breaker; and sets the reclosing time of the outgoing line circuit breaker according to the low voltage ride-through time and the preset Z time limit.

[0016] When setting the reclosing time of the outgoing circuit breaker, the present invention fully considers the low voltage ride-through time, ensuring that the reclosing operation is performed after the distributed power supply completes the low voltage ride-through; by presetting the Z time limit, it can be ensured that the segmented circuit breaker will not operate prematurely in the event of a fault in the upper busbar or line and the upper power supply backup automatic re-start operation, thereby avoiding false tripping, and at the same time ensuring that the segmented circuit breaker has lost pressure and tripped before the current line recloses. Therefore, by combining the low voltage ride-through time and the preset Z time limit to set the reclosing time of the outgoing circuit breaker, the protection setting coordination relationship between the segmented circuit breaker, the outgoing circuit breaker, and the inverter of the distributed power supply is optimized, ensuring that the distributed power supply can be reliably cut off in the event of a power system fault, and effectively solving the problem of false tripping of the segmented circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A flowchart of the steps of a method for optimizing the reclosing time of a substation outgoing circuit breaker;

[0019] Figure 2 This is a schematic diagram of the power system when no distributed power source is connected;

[0020] Figure 3 This is the logic diagram of voltage loss tripping;

[0021] Figure 4 This is a schematic diagram of the first embodiment of the power system when connected to distributed power sources;

[0022] Figure 5 This is a schematic diagram of a second embodiment of a power system when a distributed power source is connected;

[0023] Figure 6Schematic diagram of the power system when connected to distributed power generation and grid-connected boundary automatic switch;

[0024] Figure 7 This is a schematic diagram of the structure of the reclosing time optimization system for the outgoing circuit breaker of the substation;

[0025] Figure 8 A diagram of the internal structure of a computer device;

[0026] Among them, 201 is a time acquisition module; 202 is a reclosing time setting module. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] The terms "first," "second," and the like in the specification, claims, and drawings of this application are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or modules is not limited to the listed steps or modules but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to the process, method, product, or apparatus.

[0029] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] See also Figure 1, is a flowchart of the steps of a method for optimizing the reclosing time of a substation outgoing line circuit breaker in the first embodiment of the present application, which is applied to a power system, wherein the power system includes a substation, an outgoing line circuit breaker, multiple segmented circuit breakers, a branch circuit breaker, a connecting circuit breaker, an inverter and a distributed power source, the output end of the substation is connected to the outgoing line circuit breaker, and multiple segmented circuit breakers connected in sequence are arranged between the outgoing line circuit breaker and the connecting circuit breaker, one end of the branch circuit breaker is used to be connected to the output end of a first target segmented circuit breaker, and the first target segmented circuit breaker is the first segmented circuit breaker after the fault line, the other end of the branch circuit breaker is connected to one end of the inverter, and the other end of the inverter is connected to the distributed power source, a processor is provided in the substation, and the processor is used to set the reclosing time of the outgoing line circuit breaker to effectively solve the problem of malfunction of the segmented circuit breaker, and the method includes:

[0031] Step 101: Obtain the low voltage ride-through time of the inverter and the preset Z time limit of the second target segment circuit breaker; the second target segment circuit breaker is any segment circuit breaker among the multiple segment circuit breakers;

[0032] Step 102: Set the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit.

[0033] For a detailed diagram of the power system without access to distributed power sources, please refer to Figure 2 The outgoing circuit breaker is used for protection. For example, the overcurrent range for Section I is 900A / 0.2s, the overcurrent range for Section III is 600A / 0.6s, and the primary reclosing time is 1s. FB1, FB2, and FB3 are sectionalizing circuit breakers, operating with voltage-time logic. FB1 is the first voltage-time circuit breaker on the main line. The outgoing substation circuit breaker is activated with a primary reclosing function. To facilitate secondary reclosing to restore the non-faulty section and meet relay protection setting regulations, the X time limit must be greater than the circuit breaker's energy storage time plus the reclosing charge time. For example, the first sectionalizing circuit breaker (FB1) has an X time of 35s, a Y time of 3s, and a Z time of 0.6s. For non-first sectionalizing circuit breakers, the X time is 5s, a Y time of 3s, and a Z time of 0.6s. LS is a tie circuit breaker and does not activate protection.

[0034] When a permanent fault occurs between the FB1 and FB2 circuit breakers, the CB protection of the outgoing line circuit breaker in the station trips. The FB1, FB2, and FB3 circuit breakers open due to voltage loss after a Z time limit of 0.6S. After the CB reclosing time of the outgoing line circuit breaker in the station is 1S, they are successfully reclosed. The FB1 circuit breaker is energized and closed after a X time limit of 35S. Closing at the fault point causes the CB protection of the outgoing line circuit breaker in the station to trip. The FB1 circuit breaker closes the fault within a Y time limit of 3S, so the FB1 circuit breaker Y is closed. The FB2 circuit breaker is locked (positive blocking and closing on the power supply side), and the FB2 circuit breaker is within the X time limit of 5 seconds. Therefore, the FB2 circuit breaker is locked (negative blocking and closing on the power supply side). The FB1 and FB2 circuit breakers isolate the faulty section. The FB3 circuit breaker loses power and opens. The station outgoing line breaker CB successfully recloses after the reclosing time of 1 second, restoring power to the section from the station outgoing line breaker CB to the FB1 circuit breaker. Closing the tie circuit breaker LS restores power to the section from the FB2 circuit breaker to the FB3 circuit breaker. The distribution automation switch operates correctly, accurately isolating the faulty section.

[0035] like Figure 3 As shown, the voltage on the power supply side and the voltage on the load side use "AND" logic in the undervoltage trip function. This means that undervoltage is determined only when both the power supply side and the load side are voltage-free. When the local feeder automation input is set to "1," the circuit breaker is under voltage on both sides and there is no current in the three phases. There is no short-term undervoltage lockout and trip condition. After the Z time limit, the distribution automation switch under voltage on both sides trips.

[0036] like Figure 4 As shown in the figure, the distributed power source 1 is connected to the rear section of branch line A, and the distributed power source 2 is connected to the rear section of branch line B. The protection settings of the outgoing line circuit breaker CB, the section circuit breakers FB1, FB2, FB3, the tie circuit breaker LS, and the branch circuit breaker ZB1 are the same as those of the Figure 3 Maintain consistency. Due to the integration of distributed power sources, a grid-connected automatic boundary switch, ZB2, was added before distributed power sources 1 and 2, respectively, but no protection was activated. The low voltage ride-through time of the distributed power source inverter is 2 seconds.

[0037] After the distributed generation (DG) is connected to the main line, consider a permanent fault between the FB1 and FB2 circuit breakers. The DG inverter's low voltage ride-through time is 2 seconds, the station's outgoing circuit breaker (CB) reclosing time is 1 second, and the Z time limit for the sectionalizers FB1, FB2, and FB3 is only 0.6 seconds. When a permanent fault occurs on the line, after the station's outgoing circuit breaker (CB) trips, the DG inverter's low voltage ride-through time (2 seconds) exceeds the Z time limit (0.6 seconds) for the sectionalizers FB1, FB2, and FB3. The DG continues to supply power to the line. However, the DG's support may prevent the voltages on the sectionalizers FB1, FB2, and FB3 from falling below the residual voltage detection value (Un) of 30% due to the DG's support. This fails to meet the voltage loss condition on both the source and load sides. Consequently, the sectionalizers FB1, FB2, and FB3 fail to trip within the specified time limit (0.6 seconds). The station's outgoing line circuit breaker (CB) then reached its 1s reclosing time, triggering the reclosing action. However, the section breakers FB1, FB2, and FB3 remained closed, causing the outgoing line breaker to directly close to the fault, tripping again and failing to reclose. The fault occurred within the FB1 and FB2 sections. However, the integration of the distributed generation prevented the voltage-time switch from tripping due to voltage loss. Consequently, the FB1 and FB2 breakers did not receive forward and reverse blocking telesignals, resulting in a voltage loss across the entire line. Consequently, the faulty section could not be accurately located and isolated, expanding the outage's scope and increasing the number of households affected, impacting the reliability of the distribution network.

[0038] like Figure 5 As shown, the distributed power grid access point is not equipped with a grid-connected boundary automatic switch, and the reclosing time of the outgoing line circuit breaker in the station is adjusted so that the reclosing time of the outgoing line circuit breaker in the station is adjusted according to the Z time limit of the section circuit breaker and the low voltage ride-through time of the distributed power inverter.

[0039] When setting the reclosing time of the outgoing circuit breaker, the method in this embodiment fully considers the low voltage ride-through time, ensuring that the reclosing operation is performed after the distributed power source completes the low voltage ride-through. By presetting the Z time limit, it can be ensured that the segmented circuit breaker will not operate prematurely in the event of a fault in the upper busbar or line and the upper power source backup automatic re-start operation, thereby avoiding false tripping. At the same time, it is ensured that the segmented circuit breaker has lost pressure and tripped before the current line recloses. Therefore, by combining the low voltage ride-through time and the preset Z time limit to set the reclosing time of the outgoing circuit breaker, the protection setting coordination relationship between the segmented circuit breaker, the outgoing circuit breaker, and the inverter of the distributed power source is optimized, ensuring that the distributed power source can be reliably disconnected in the event of a power system fault, effectively solving the problem of false tripping of the segmented circuit breaker.

[0040] In a specific embodiment, setting the reclosing time of the outgoing circuit breaker based on the low voltage ride-through time and the preset Z time limit includes setting the reclosing time as the sum of the low voltage ride-through time and the preset Z time limit. Specifically, when the low voltage ride-through time is 2 seconds and the Z time limit of the section circuit breaker is 0.6 seconds, the reclosing time is 2 seconds + 0.6 seconds = 2.6 seconds, and may be greater than 2.6 seconds.

[0041] In a specific embodiment, setting the reclosing time of the outgoing circuit breaker based on the low voltage ride-through time and the preset Z time limit includes: setting a reserved time margin; and setting the reclosing time as the sum of the low voltage ride-through time, the preset Z time limit, and the reserved time margin. Specifically, when the low voltage ride-through time is 2 seconds and the Z time limit of the section circuit breaker is 0.6 seconds, the station reclosing time is greater than 2 seconds + 0.6 seconds = 2.6 seconds. Therefore, the reclosing time of the outgoing circuit breaker within the station is 3 seconds.

[0042] In a specific embodiment, when the preset Z time limits of the multiple segmented circuit breakers are different, the largest preset Z time limit is selected as the target Z time limit; then the sum of the low voltage ride-through time, the preset Z time limit and the reserved time margin is set as the reclosing time, including: setting the sum of the low voltage ride-through time, the target Z time limit and the reserved time margin as the reclosing time.

[0043] Specifically, if the low voltage ride-through time is 2s, the Z time limit of the section circuit breaker FB1 is 0.6s, the Z time limit of the section circuit breaker FB2 is 0.7s, and the Z time limit of the section circuit breaker FB3 is 0.8s, then the reclosing time in the station is greater than 2S+0.8S=2.8S.

[0044] In a specific embodiment, the low voltage ride-through time is less than the preset Z time limit. Specifically, optimizing the Z time limit of the segmented circuit breaker so that it is greater than the low voltage ride-through time of the distributed power inverter can provide a more stable operating environment for the distributed power supply during the grid fault and recovery phase. Specifically, when the grid voltage drops sharply, the inverter of the distributed power supply needs to have low voltage ride-through capability, that is, it does not go off-grid during the voltage drop, and continues to provide reactive support to the grid to help the grid voltage recover. If the Z time limit of the segmented circuit breaker is less than the low voltage ride-through time of the inverter, the circuit breaker may have attempted to reclose before the inverter has completed the low voltage ride-through process, causing the inverter to go off-grid due to unstable voltage recovery. Extending the Z time limit can ensure that the inverter has enough time to complete the low voltage ride-through and avoid accidental disconnection from the grid.

[0045] After the main line of the line is connected to the distributed power supply, after the fixed value is changed, take the permanent fault of the FB1 circuit breaker and the FB2 circuit breaker section as an example. When a permanent fault occurs on the line, the protection of the outgoing line circuit breaker CB in the station trips, the voltage provided by the bus power disappears, and the distributed power supply still provides voltage within the inverter low voltage ride-through cut-off time. After the inverter low voltage ride-through cut-off time of 2S, the distributed power supply is cut off, and the voltage provided by the distributed power supply disappears. The Z time limit starts timing, so the section circuit breakers FB1, FB2, and FB3 lose pressure and trip within 2.6S. The outgoing line circuit breaker CB in the station is successfully reclosed after 3S. The FB1 circuit breaker is energized and closed after the X time limit of 35S, closing at the fault point, causing the outgoing line circuit breaker CB in the station to be protected. The circuit breaker tripped. FB1 closed to the fault within the Y time limit of 3 seconds, so FB1 circuit breaker Y was locked (forward locking and closing on the power supply side). FB2 closed within the X time limit of 5 seconds, so FB2 circuit breaker X was locked (reverse locking and closing on the power supply side). FB1 and FB2 circuit breakers isolated the faulty section. FB3 circuit breaker lost power and tripped. The station outgoing line breaker CB successfully reclosed after the reclosing time of 1 second, restoring power to the section from the station outgoing line breaker CB to the FB1 circuit breaker. Closing the tie breaker LS restored power to the section from the FB2 circuit breaker to the FB3 circuit breaker. The distribution automation switches operated correctly, accurately isolating the faulty section.

[0046] In a specific embodiment, the power system also includes a grid-connected boundary automatic switch, one end of the grid-connected boundary automatic switch is connected to the branch circuit breaker, and the other end of the grid-connected boundary automatic switch is connected to the inverter. The method also includes: obtaining the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch; then setting the reclosing time of the outgoing circuit breaker according to the low-voltage ride-through time and the preset Z time limit, including: setting the reclosing time of the outgoing circuit breaker according to the low-voltage ride-through time, the preset Z time limit and the low-frequency and low-voltage protection action time.

[0047] Specifically, such as Figure 6 As shown, a grid-connected boundary automatic switch is installed at the distributed power access point. Further considering the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch, the reclosing time of the station-outgoing line circuit breaker is adjusted to make the reclosing time of the station-outgoing line circuit breaker greater than the maximum sum of the Z time limit of the section circuit breaker, the low-voltage ride-through time of the distributed power inverter, and the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch. Since the low-voltage ride-through time of the distributed power inverter 2S is greater than the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch 0.4S, the maximum value is still the low-voltage ride-through time of the distributed power inverter 2S, that is, the station-inside reclosing time is set to 2S+0.6S=2.6S, or greater than 2.6s.

[0048] In a specific embodiment, setting the reclosing time of the outgoing circuit breaker based on the low voltage ride-through time, the preset Z time limit, and the low frequency and low voltage protection operation time includes: setting a reserved time margin; selecting the maximum value between the low voltage ride-through time and the low frequency and low voltage protection operation time as the target time value; and setting the sum of the target time value, the preset Z time limit, and the reserved time margin as the reclosing time. Specifically, if the reclosing time within the station is greater than 2S + 0.6S = 2.6S, a margin is retained, so the reclosing time of the outgoing circuit breaker within the station is 3S.

[0049] The distributed power supply access point is equipped with a grid-connected boundary automatic switch. Take the case of a permanent fault between the FB1 circuit breaker and the FB2 circuit breaker as an example. When a permanent fault occurs on the line, the outgoing line circuit breaker CB in the station trips, the busbar voltage disappears, the grid-connected boundary automatic switches ZB2 and ZB3 are de-energized and opened after 0.4S, the voltage provided by the distributed power supply disappears, and the section circuit breakers FB1, FB2, and FB3 lose voltage completely after 0.4S. The Z time limit starts timing, so the section circuit breakers FB1, FB2, and FB3 lose voltage and open after 1S. After the low voltage ride-through removal time of 2S, the inverter is removed. The outgoing line circuit breaker CB in the station is successfully reclosed after 3S. The FB1 circuit breaker is energized and closed after the X time limit of 35S. It is closed at the fault point, causing the station to The outgoing line circuit breaker CB tripped, and FB1 closed to the fault within the Y time limit of 3 seconds. Therefore, FB1 circuit breaker Y was locked (forward blocking and closing on the power supply side). FB2 circuit breaker X was locked (reverse blocking and closing on the power supply side) within the X time limit of 5 seconds. FB1 and FB2 circuit breakers isolated the faulty section. FB3 circuit breaker lost power and opened. The station's outgoing line circuit breaker CB successfully reclosed after the reclosing time of 1 second, restoring power to the section from CB to FB1. Closing the tie circuit breaker LS restored power to the section from FB2 to FB3. The distribution automation switches operated correctly, accurately isolating the faulty section.

[0050] Comparison of implementation effects:

[0051] 1. Overview of solution comparison

[0052]

[0053] 2. The outstanding advantages and effects of Schemes 3 and 4 compared with Scheme 2

[0054] (1) Option 3 (delayed reclosing) vs. Option 2 (distributed power supply connected to traditional configuration)

[0055]

[0056] (2) Achieved results: The traditional configuration of "full power outage" is transformed into "controllable isolation", which correctly isolates only the fault section, reduces the scope of the power outage, and has a small impact on power supply reliability. Solution 3 solves the low voltage ride-through problem by coordinating time, and the transformation cost is only the fixed value adjustment. Solution 4 solves the low voltage ride-through problem by transforming the boundary switch and coordinating time, reducing the number of households during the power outage and improving power supply reliability. Solution 3 is an economical solution for distributed power supply access, suitable for small-capacity new energy scenarios, and has low transformation costs. Solution 4 is a high-reliability solution that achieves rapid fault isolation through the boundary switch, suitable for areas with high power supply quality requirements or high-proportion new energy distribution networks. By comparison, it can be seen that Solution 3 / 4 fundamentally solves the fault isolation failure problem of Solution 2, and achieves a qualitative improvement in power supply reliability, fault handling speed, etc.

[0057] In the specific embodiment, see Figure 7 , is a structural diagram of a reclosing time optimization system for a substation outgoing circuit breaker in the second embodiment of the present application, the system comprising: a time acquisition module 201 and a reclosing time setting module 202; the time acquisition module 201 is used to obtain the low voltage ride-through time of the inverter and obtain the preset Z time limit of the second target segmented circuit breaker; the second target segmented circuit breaker is any one of the multiple segmented circuit breakers; the reclosing time setting module 202 is used to set the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit.

[0058] When setting the reclosing time of the outgoing circuit breaker, the system in this embodiment fully considers the low voltage ride-through time, ensuring that the reclosing operation is performed after the distributed power source has completed the low voltage ride-through. By presetting the Z time limit, it can be ensured that the segmented circuit breaker will not operate prematurely in the event of a fault in the upper busbar or line and the upper power source backup automatic re-start operation, thereby avoiding false tripping. At the same time, it is ensured that the segmented circuit breaker has lost pressure and tripped before the current line recloses. Therefore, by combining the low voltage ride-through time and the preset Z time limit to set the reclosing time of the outgoing circuit breaker, the protective setting coordination relationship between the segmented circuit breaker, the outgoing circuit breaker, and the inverter of the distributed power source is optimized, ensuring that the distributed power source can be reliably disconnected in the event of a power system fault, effectively solving the problem of false tripping of the segmented circuit breaker.

[0059] In a specific embodiment, the third embodiment of the present application provides a reclosing time optimization device for a substation outgoing circuit breaker, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method described in any one of the first embodiments of the present application.

[0060] In a specific embodiment, the fourth embodiment of the present application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor performs the steps of the method described in any one of the first embodiments of the present application.

[0061] Figure 8 The internal structure of a computer device in one embodiment is shown. The computer device can be a terminal or a server. Figure 8 The computer device includes a processor, a memory, etc. connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement the method of this embodiment. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement the method of this embodiment. It will be understood by those skilled in the art that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0062] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0063] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any person skilled in the art may utilize the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change, and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for optimizing the reclosing time of a substation outgoing circuit breaker, applied to a power system, characterized in that: The power system includes a substation, an outgoing line circuit breaker, multiple segmented circuit breakers, a branch circuit breaker, a tie circuit breaker, an inverter, and a distributed power source. The output end of the substation is connected to the outgoing line circuit breaker. Multiple segmented circuit breakers connected in sequence are provided between the outgoing line circuit breaker and the tie circuit breaker. One end of the branch circuit breaker is used to connect to the output end of a first target segmented circuit breaker, which is the first segmented circuit breaker after a faulty line. The other end of the branch circuit breaker is connected to one end of the inverter, and the other end of the inverter is connected to the distributed power source. A processor is provided in the substation, and the processor is used to set the reclosing time of the outgoing line circuit breaker. The method includes: Obtaining the low voltage ride-through time of the inverter and obtaining a preset Z time limit of a second target segmented circuit breaker; the second target segmented circuit breaker is any one of the multiple segmented circuit breakers; The reclosing time of the outgoing circuit breaker is set according to the low voltage ride-through time and the preset Z time limit.

2. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 1, characterized in that: The step of setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit includes setting the reclosing time according to the sum of the low voltage ride-through time and the preset Z time limit.

3. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 1, wherein: The step of setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit includes: Set the reserve time margin; The sum of the low voltage ride-through time, the preset Z time limit and the reserved time margin is set as the reclosing time.

4. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 3, characterized in that: When the preset Z time limits of the multiple section circuit breakers are different, selecting the largest preset Z time limit as the target Z time limit; Then, setting the sum of the low voltage ride-through time, the preset Z time limit and the reserved time margin as the reclosing time includes: The sum of the low voltage ride-through time, the target Z time limit and the reserved time margin is set as the reclosing time.

5. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 1, wherein: The low voltage ride-through time is less than the preset Z time limit.

6. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 1, wherein: The power system further includes a grid-connected boundary automatic switch, one end of the grid-connected boundary automatic switch is connected to the branch circuit breaker, and the other end of the grid-connected boundary automatic switch is connected to the inverter. The method further includes: Obtaining the low-frequency and low-voltage protection action time of the grid-connected boundary automatic switch; Then, setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit includes: The reclosing time of the outgoing circuit breaker is set according to the low voltage ride-through time, the preset Z time limit and the low frequency and low voltage protection action time.

7. The method for optimizing the reclosing time of a substation outgoing circuit breaker according to claim 6, characterized in that: The step of setting the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time, the preset Z time limit, and the low frequency and low voltage protection action time includes: Set the reserve time margin; Selecting the maximum value between the low voltage ride-through time and the low frequency and low voltage protection action time as the target time value; The sum of the target time value, the preset Z time limit and the reserved time margin is set as the reclosing time.

8. A reclosing time optimization system for outgoing circuit breakers of a substation, characterized in that: The system includes: a time acquisition module and a reclosing time setting module; The time acquisition module is used to obtain the low voltage ride-through time of the inverter and obtain the preset Z time limit of the second target segment circuit breaker; the second target segment circuit breaker is any segment circuit breaker among the multiple segment circuit breakers; The reclosing time setting module is used to set the reclosing time of the outgoing circuit breaker according to the low voltage ride-through time and the preset Z time limit.

9. A device for optimizing the reclosing time of a substation outgoing circuit breaker, comprising a memory and a processor, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

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