A local feeder automatic fault handling method and device

Abstract

The present invention discloses a local feeder automation fault handling method and device, which uses a circuit breaker for multiple section switches and tie switches. The method is as follows: when a power supply line fault occurs, the outgoing line switch is protected and tripped after a set delay, while the section switch does not trip; after a set reclosing delay, the outgoing line switch recloses; if the fault is a permanent fault, the section switch is closed and power is received, and the section switch on the power supply side of the fault point performs a closed position power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power to the upstream non-fault section; the section switch on the load side of the fault point performs a short-time power detection tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section; the tie switch performs an automatic power transfer function to complete the fault handling. The present invention can achieve rapid isolation of the fault section and restoration of power supply to the non-fault section, reducing the scope of power outages and the number of switch operations.

Description

Technical Field

[0001] The present invention relates to the technical field of feeder automation of power distribution systems, and in particular to a local feeder automation fault handling method and device. Background Art

[0002] Distribution networks, spanning urban and rural areas and directly serving electricity users, are a critical component in ensuring safe and reliable power supply. Due to their complex wiring structure, operating modes, and diverse operational scenarios, distribution networks are prone to various types of faults. Quickly, accurately, and reliably handling distribution network faults is crucial for improving power supply reliability and ensuring reliable and continuous power supply to users.

[0003] At present, the main methods for handling distribution network faults include relay protection and feeder automation. Generally, after a distribution network fault occurs, the line switch protection will first trip to eliminate the fault, and then use feeder automation to further isolate the faulty section and restore power to the non-faulty sections, thereby minimizing the scope of the power outage. According to different implementation methods, feeder automation can be divided into two categories: centralized and local. Centralized feeder automation is that after a line fault occurs, the distribution automation master station collects fault information from the line section switches, centrally analyzes the faulty section, and remotely isolates the switch action. This mode relies on reliable communication and master station functions; local feeder automation automatically isolates the fault through the line switch reclosing coordination, and does not rely on the master station's analysis. It mainly includes voltage-time type, voltage-current-time type, adaptive comprehensive type and other types of local feeder automation methods.

[0004] However, since centralized feeder automation relies on reliable communication and master station analysis and judgment functions, there is a risk of failure in severe weather, unstable communication signals, and other conditions; local feeder automation does not rely on communication, and fault handling can be achieved through automatic coordination between switches. Local feeders are mainly implemented by multiple reclosing coordination of switches. When a fault occurs, the outgoing line switch of the substation will first trip for protection, and the switches on the line will automatically trip using the "voltage loss trip" logic. After the outgoing line switch is reclosed, the line switch will close step by step after a delay. After closing to the fault section, the substation will trip again to isolate the fault section. However, in this method, after the outgoing line switch trips, the section switch will lose voltage and divide the voltage without selectivity, and then reclose step by step. There are problems such as long power outage time and a large number of switch operations, and the coordination strategy of multiple switches is complex. Summary of the Invention

[0005] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides an on-site feeder automation fault handling method and device. The line section switch uses a power distribution primary and secondary integrated circuit breaker and adopts the logic of "no tripping when voltage is lost, and delayed tripping when power is supplied". For instantaneous faults, the line outlet switch can be reclosed once to restore power to the entire line, greatly reducing the power outage time. For permanent faults, when the outlet switch is reclosed, the section switch on the power supply side of the fault point detects the fault and delays the protection tripping, and the section switch on the load side of the fault point trips according to the short power supply time, completing the fault isolation. Through the above method, the outlet switch only needs to be reclosed once, the outlet switch and the section switch have fewer operations, the power outage time is short, and the fault section can be quickly isolated and the power supply to the non-fault section can be restored, reducing the power outage range and the number of switch operations caused by the fault, thereby improving the power supply reliability for users.

[0006] In a first aspect, the present invention provides a method and apparatus for handling local feeder automation faults.

[0007] A local feeder automation fault handling method, wherein two distribution lines are interconnected, and an outgoing line switch close to the distribution line, multiple section switches, and a connecting switch are sequentially arranged on the connecting channel of each distribution line. The multiple section switches and the connecting switch use a distribution primary and secondary fusion circuit breaker;

[0008] Among them, the outgoing line switch is equipped with protection delay and single reclosing function, multiple section switches are equipped with closing position power detection fault delay opening and forward locking, short-time power detection time opening and reverse locking function, and the connecting switch is equipped with automatic power transfer function;

[0009] The method comprises:

[0010] When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose.

[0011] If the fault is a permanent fault, the sectionalizer will be closed and the power will be received. The sectionalizer on the power supply side of the fault point will execute the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the sectionalizer on the load side of the fault point will execute the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section; the connecting switch will execute the automatic transfer function to complete the fault handling.

[0012] A further technical solution is that the function of delaying tripping and positive locking when power is detected in the closing position includes: after the sectionalizing switch is closed and the power is cut off, if power is detected in the fault handling time window and the fault still exists, the sectionalizing switch will be opened and positively locked after the set delay time to complete the front end isolation of the fault section;

[0013] The short-time call detection time tripping and reverse blocking function includes: after the sectionalizer is closed and the power is cut off, if a short-time call is detected within the fault processing time window and the call time meets the preset time parameters, the circuit breaker will automatically trip and reverse block to complete the rear-end isolation of the fault section;

[0014] The automatic power transfer function includes: when a fault occurs in the line on one side of the connecting switch, the connecting switch loses pressure on one side, and a short-term call is detected within the fault handling time window and the call time meets the fault characteristics of the non-adjacent section, the power transfer delay timer is started, and when the timer ends, the circuit breaker is automatically closed and power is transferred to the non-fault section. Otherwise, the automatic power transfer is locked.

[0015] A further technical solution is that the method comprises:

[0016] When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose.

[0017] If the fault in question is a permanent fault, then:

[0018] If the outgoing line switch is closed and then protected by opening again, the line connected to the outgoing line switch is considered to be a fault section. When the sectionalizer is closed and power is received, the sectionalizer on the load side of the fault point will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically open and reverse lock, otherwise it will not operate; after the pressure on one side of the connecting switch is lost, it will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power;

[0019] If the outgoing line switch does not open after closing, it is considered that the line connected to the outgoing line switch is a non-fault section. At this time, the fault still exists and the sectionalizer is closed for power supply. When the sectionalizer on the power supply side of the fault point detects a fault, the protection delays opening and forward locking, otherwise it will not operate. The sectionalizer on the load side of the fault point detects short-term power supply and makes a judgment. If the configuration conditions are met, it will open and reverse lock, otherwise it will not operate. After the pressure on one side of the connecting switch is lost, the short-term power supply time is detected and judged. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power.

[0020] A further technical solution is that the method comprises:

[0021] When a fault occurs in the power supply line, the outgoing line switch will be protected and opened after the set delay, and the section switches will not be opened; after the set reclosing delay, the outgoing line switch will reclose; if the fault is a transient fault, the fault will disappear when the protection delay closes, and the line will resume normal operation.

[0022] A further technical solution is that the protection delay function includes overcurrent protection delay, transient principle grounding protection delay, zero-sequence overcurrent protection delay, and the outgoing line switch is configured with a variety of protection delay delay times; the overcurrent protection delay includes overcurrent I stage delay, overcurrent II stage delay and overcurrent III stage delay.

[0023] A further technical solution is that the outgoing line switch is configured with accelerated protection after closing, including zero-sequence voltage acceleration; the outgoing line switch is configured to detect pressure and reclose once, and the reclosing delay is 2s.

[0024] A further technical solution is that the delay time of the overcurrent I delay is 0s, the delay time of the overcurrent II delay is 0.4s, the delay time of the overcurrent III delay is 0.6s, the delay time of the transient principle grounding protection delay is 10s, and the delay time of the zero-sequence overcurrent protection delay is 0.5s.

[0025] A further technical solution is to open the circuit breaker and lock it in the forward direction after a set delay time. The delay time set for the first section switch is 0.3s, and the delay time set for the second section switch is 0.2s.

[0026] A further technical solution is to detect a short incoming call and the incoming call time meets the preset time parameter, the preset time parameter set by the first segment switch is less than 0.12s or greater than 0.4s, and the preset time parameter set by the second segment switch is 0.3s~0.4s.

[0027] According to a further technical solution, the fault handling time window of the section switch is 5s.

[0028] A further technical solution is to configure the section switch to delay closing on one side when it is not locked, with a delay time of 3s.

[0029] A further technical solution is that when the interconnecting switch loses pressure on one side and detects a short-term power supply within 5 seconds, the power transfer delay timer is started; when the power transfer timer reaches 10 seconds, the interconnecting switch starts automatic power transfer to the non-fault section;

[0030] If the contact switch detects a short-term power supply and the short-term power supply duration is between 0.2s and 0.3s, it will be locked and automatically transferred to the power supply.

[0031] A further technical solution is that when the distribution line is short and the distance between the first section switch and the outgoing line switch is close, the delay time of the overcurrent I section delay of the outgoing line switch is configured to be 0.1s, the delay time of the overcurrent I section delay of the first section switch is configured to be 0s, and the set preset time parameter satisfied by the first section switch for detecting short-time incoming calls is configured to be less than 0.2s or greater than 0.4s, and the set preset time parameter satisfied by the second section switch for detecting short-time incoming calls is configured to be less than 0.1s or 0.3s~0.4s.

[0032] In a second aspect, the present invention provides an on-site feeder automation fault handling device.

[0033] An on-site feeder automatic fault handling device, wherein two distribution lines are interconnected, and an outgoing line switch close to the distribution line, multiple section switches and a connecting switch are sequentially arranged on the connecting channel of each distribution line. The multiple section switches and the connecting switch use a distribution primary and secondary fusion circuit breaker;

[0034] Among them, the outgoing line switch is equipped with protection delay and single reclosing function, multiple section switches are equipped with closing position power detection fault delay opening and forward locking, short-time power detection time opening and reverse locking function, and the connecting switch is equipped with automatic power transfer function;

[0035] The device includes an outgoing line switch action module, a section switch action module and a tie switch action module; wherein,

[0036] The outgoing line switch action module is used to protect the outgoing line switch from opening after a set delay when a power supply line fault occurs, while the section switch does not open; the outgoing line switch recloses after a set reclosing delay;

[0037] The section switch action module is used for, when the fault is a permanent fault, closing the section switch and receiving power, and the section switch on the power supply side of the fault point performs the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the section switch on the load side of the fault point performs the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section;

[0038] The interconnection switch action module is used to enable the interconnection switch to perform the automatic power transfer function and complete fault processing.

[0039] In a third aspect, the present invention further provides an electronic device comprising a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the steps of the method described in the first aspect are completed.

[0040] In a fourth aspect, the present invention further provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, complete the steps of the method described in the first aspect.

[0041] One or more of the above technical solutions have the following beneficial effects:

[0042] 1. The present invention provides an on-site feeder automation fault handling method and device. The line section switch uses a power distribution primary and secondary integrated circuit breaker and adopts the logic of "no opening when voltage is lost, and delayed opening when power is detected". For instantaneous faults, the line outlet switch can be reclosed once to restore power to the entire line, greatly reducing the power outage time. For permanent faults, when the outlet switch is reclosed, the section switch on the power supply side of the fault point detects the fault and delays the protection to open, and the section switch on the load side of the fault point opens according to the short power incoming time, completing the fault isolation. Through this method, the outlet switch only needs to be reclosed once, the outlet switch and the section switch have fewer operations, the power outage time is short, and the fault section can be quickly isolated and the power supply to the non-fault section can be restored, reducing the power outage range and the number of switch operations caused by the fault, and improving the power supply reliability for users.

[0043] 2. This invention can automatically handle 10kV line faults on-site, without requiring the line switch to communicate with the master station. A single reclosing of the outgoing line switch is all that is needed to locate and isolate the faulty section and quickly restore power to the non-faulty section. Compared to existing on-site feeder automation modes, such as voltage-time, voltage-current, and adaptive integrated, this method can restore normal operation by simply reclosing the outgoing line switch in the event of a transient fault, eliminating the need for sectionalizing switches to operate, significantly reducing outage duration. For permanent faults, the outgoing line switch only needs to be reclosed once, reducing the number of reclosings of the substation's outgoing line switch, minimizing the impact of the fault, and reducing the number of sectionalizing switch operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0045] Figure 1 This is a flow chart of the local feeder automation fault handling method according to an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the operation logic of the closed position power fault detection delay opening and forward locking function in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the operation logic of the short-time incoming call detection and reverse blocking function in an embodiment of the present invention;

[0048] Figure 4 This is a schematic diagram of the operation logic of the self-power supply function in an embodiment of the present invention;

[0049] Figure 5 A circuit topology diagram used in an embodiment of the present invention;

[0050] Figure 6 Schematic diagram of the K1 section fault handling process in an embodiment of the present invention;

[0051] Figure 7 Schematic diagram of the K2 section fault handling process in an embodiment of the present invention;

[0052] Figure 8 Schematic diagram of the K3 section fault handling process in an embodiment of the present invention;

[0053] Figure 9 Schematic diagram of the K1 section fault handling process when the I section protection is overridden in an embodiment of the present invention;

[0054] Figure 10 Schematic diagram of the K2 section fault handling process when the I section protection is overridden in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] It should be noted that the following detailed descriptions are exemplary only and are intended to describe specific embodiments and provide further explanation of the present invention, and are not intended to limit the exemplary embodiments according to the present invention. Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0056] Example 1

[0057] This embodiment provides an on-site feeder automation fault handling method, in which two distribution lines are interconnected, and an outgoing line switch close to the distribution line, multiple section switches and a connecting switch are sequentially arranged on the connecting channel of each distribution line, and multiple section switches and connecting switches use a distribution primary and secondary integrated circuit breaker; wherein, the outgoing line switch is configured with a protection delay and a primary reclosing function, and multiple section switches are configured with a closing position incoming power fault detection delay tripping and forward locking, and a short-time incoming power detection time tripping and reverse locking function, and the connecting switch is configured with an automatic power transfer function.

[0058] Furthermore, the above-mentioned function of delaying the tripping and positive locking when the power is detected in the closing position includes: after the sectionalizing switch is closed and the power is cut off, if the power is detected in the fault processing time window and the fault still exists, the sectionalizing switch will be opened and positively locked after the set delay time to complete the isolation of the front end of the fault section and provide a short-term power time judgment criterion for the rear end sectionalizing switch of the fault. The action logic is as follows: Figure 2 shown.

[0059] In this embodiment, the protection detects faults including short circuits and ground faults. Short circuits are detected using overcurrent protection, ground faults in low-current grounding systems are detected using transient directional protection, and ground faults in low-resistance grounding systems are detected using zero-sequence overcurrent protection. Furthermore, the incoming power threshold is set to 20% of the rated voltage; any phase or line voltage greater than the threshold is considered incoming power; and the no-voltage threshold is set to 15% of the rated voltage; all voltages less than the threshold are considered no-voltage.

[0060] The above-mentioned short-time call detection time tripping and reverse blocking function includes: after the sectionalizing switch is closed and the power is cut off, if a short-time call is detected within the fault processing time window and the call time meets the preset time parameters, the circuit breaker will automatically trip and reverse block to complete the back-end isolation of the fault section. The action logic is as follows: Figure 3 shown.

[0061] The above-mentioned automatic power transfer function includes: under normal operation, the interconnecting switch is in the open position and there is voltage on both sides. When a fault occurs in the line on one side of the interconnecting switch, the interconnecting switch loses voltage on one side, and a short-term power supply is detected within the fault handling time window and the power supply time meets the fault characteristics of the non-adjacent section, the power transfer delay timer is started, and the circuit breaker is automatically closed after the timer ends, and the power is transferred to the non-fault section. On the contrary, if the short-term power supply time meets the fault characteristics of the adjacent section of the interconnecting switch, the automatic power transfer will not be started, that is, the automatic power transfer is locked. The action logic is as follows: Figure 4 shown.

[0062] The local feeder automation fault handling method proposed in this embodiment includes:

[0063] When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose.

[0064] If the fault is a permanent fault, the sectionalizer will be closed and the power will be received. The sectionalizer on the power supply side of the fault point will execute the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the sectionalizer on the load side of the fault point will execute the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section; the connecting switch will execute the automatic transfer function to complete the fault handling.

[0065] The following content introduces the local feeder automation fault handling method proposed in this embodiment in more detail.

[0066] In this embodiment, the Figure 5The line topology shown in the figure describes the local feeder automation fault handling method proposed in this embodiment. In it, CB1 and CB2 are the outgoing line switches of two interconnected lines, FB1 and FB2 are the section switches of 10kV line 1, FB3 is the branch switch, FS is the user boundary switch, LS1 is the tie switch, black indicates the switch is closed, white indicates the switch is open, K1 to K3 indicate the line section, red lines indicate the line is energized, black lines indicate the line is de-energized, and dotted lines indicate omitted line sections.

[0067] First, configure the line switch parameters as shown in Table 1 below.

[0068] Table 1 Line switch parameter configuration table

[0069]

[0070] That is, configure the protection delay function of the outgoing switch, which includes overcurrent protection delay, transient principle grounding protection delay, and zero-sequence overcurrent protection delay, and configure the outgoing switch to configure the delay time of multiple protection delays; wherein, the overcurrent protection delay includes overcurrent I stage delay, overcurrent II stage delay, and overcurrent III stage delay. Further, configure the outgoing switch to detect voltage and reclose once, and the reclosing delay is 2s. Further, configure the outgoing switch to accelerate protection after closing, including zero-sequence voltage acceleration, and the acceleration time is 0.5s. The delay time of the above-mentioned overcurrent I stage delay is 0s, the delay time of overcurrent II stage delay is 0.4s, the delay time of overcurrent III stage delay is 0.6s, the delay time of transient principle grounding protection delay is 10s, and the delay time of zero-sequence overcurrent protection delay is 0.5s.

[0071] Furthermore, the delay time set for the first section switch FB1 to close and detect faults when power is received and the delay time for opening and forward locking is 0.3s, and the delay time set for the second section switch FB2 is 0.2s; the preset time parameter set for the first section switch FB1 to open and reverse lock when detecting short-time power is less than 0.12s or greater than 0.4s, and the preset time parameter set for the second section switch FB2 is 0.3s~0.4s; the fault handling time window of the two section switches is 5s; the section switch is configured to delay closing on one side when there is pressure in the unlocked state, and the delay time is 3s.

[0072] Furthermore, when the interconnecting switch loses pressure on one side and detects a short-term power supply within 5 seconds, the transfer delay timer is started; when the transfer timing is 10 seconds, the interconnecting switch starts automatic transfer to the non-fault section; when the interconnecting switch detects a short-term power supply and the short-term power supply duration is between 0.2s and 0.3s, the automatic transfer is locked.

[0073] The local feeder automation fault handling method proposed in this embodiment is as follows:

[0074] When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose.

[0075] If the fault in question is a permanent fault, then:

[0076] If the outgoing line switch is closed and then protected by opening again, the line connected to the outgoing line switch is considered to be a fault section. When the sectionalizer is closed and power is received, the sectionalizer on the load side of the fault point will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically open and reverse lock, otherwise it will not operate; after the pressure on one side of the connecting switch is lost, it will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power;

[0077] If the outgoing line switch does not open after closing, it is considered that the line connected to the outgoing line switch is a non-fault section. At this time, the fault still exists and the sectionalizer is closed for power supply. When the sectionalizer on the power supply side of the fault point detects a fault, the protection delays opening and forward locking, otherwise it will not operate. The sectionalizer on the load side of the fault point detects short-term power supply and makes a judgment. If the configuration conditions are met, it will open and reverse lock, otherwise it will not operate. After the pressure on one side of the connecting switch is lost, the short-term power supply time is detected and judged. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power.

[0078] Furthermore, when a fault occurs in the power supply line, the outgoing line switch will be protected and opened after a set delay, and the section switches will not be opened; after a set reclosing delay, the outgoing line switch will be reclosed; if the fault is a transient fault, the fault will disappear when the protection delay is closed, and the line will resume normal operation.

[0079] The specific troubleshooting process is as follows:

[0080] 1.1.1 K1 section fault

[0081] K1 section fault Figure 6 As shown in Figure (a). When a fault occurs, the outgoing line switch CB1 protection action delays opening, the line loses pressure, and the section switches FB1 and FB2 lose pressure but do not open, and remain in the closed state. Figure 6 As shown in Figure (b), CB1 recloses after a delay of 2s. If it is a transient fault, the fault has disappeared when the circuit breaker is closed, and the line resumes normal operation. Figure 6As shown in Figure (c); if it is a permanent fault, CB1 will open again for protection and will not reclose. FB1 will detect a short-term power supply, and the duration is less than 0.12s (CB1 overcurrent stage I action, delay 0s, the switch opening time will not be greater than 0.12s) or greater than 0.4s (CB1 overcurrent stage II, stage III or grounding protection action, the minimum delay is 0.4s), and will automatically open and reverse lock. FB2 will not operate if it detects that the short-term power supply duration is not between 0.3s and 0.4s. Figure 6 As shown in Figure (d), after the voltage on one side of the contact switch LS1 is lost, a short-term power supply is detected and the duration is not within 0.2s to 0.3s. The circuit breaker automatically closes after a delay of 10s to restore the power supply to the faulty rear end. At the same time, FB1 is in the reverse blocking state and will not close after reverse power is received. The fault is handled. Figure 6 As shown in Figure (e).

[0082] 1.1.2 K2 section fault

[0083] K2 section fault Figure 7 As shown in Figure (a). When a fault occurs, the outgoing line switch CB1 protection action delays opening, the line loses pressure, FB1 and FB2 lose pressure but do not open, and remain in the closed state. Figure 7 As shown in Figure (b), CB1 recloses after a delay of 2s. If it is a transient fault, the fault has disappeared when the circuit breaker is closed, and the line resumes normal operation. Figure 7 As shown in Figure (c), if it is a permanent fault, the fault still exists when CB1 is closed. When FB1 is closed, the fault is detected and the protection delay is 0.3s to open the circuit breaker and lock it in the forward direction. CB1 will not operate again before the protection delay is reached. FB2 detects a short-term power supply with a duration of 0.3s to 0.4s and automatically opens the circuit breaker and locks it in the reverse direction. Figure 7 As shown in Figure (d), after the voltage on one side of the contact switch LS1 is lost, a short-term power supply is detected and the duration is not within 0.2s to 0.3s. The circuit breaker automatically closes after a delay of 10s to restore the power supply to the fault rear end. FB2 is in the reverse blocking state and will not close after reverse power is received. The fault is handled. Figure 7 As shown in Figure (e).

[0084] 1.1.2 K3 section fault

[0085] K3 section fault Figure 8 As shown in Figure (a). When a fault occurs, the outgoing line switch CB1 protection action delays opening, the line loses pressure, FB1 and FB2 lose pressure but do not open, and remain in the closed state. Figure 8 As shown in Figure (b), CB1 recloses after a delay of 2s. If it is a transient fault, the fault has disappeared when the circuit breaker is closed, and the line resumes normal operation. Figure 8As shown in Figure (c), if it is a permanent fault, the fault still exists when CB1 is closed. When FB2 is closed, the fault is detected and the protection delay is 0.2s to open and positive lock. CB1 and FB1 will not operate before the protection delay. After the voltage on one side of the tie switch LS1 is lost, a short-term power supply is detected, but the duration is between 0.2s and 0.3s. The lock delays closing to prevent the fault from being transferred to the opposite line. Figure 8 As shown in Figure (d).

[0086] Furthermore, this embodiment also considers fault handling in special circumstances. Specifically, when the distribution line is short and the distance between the sectionalizer FB1 and the outgoing sectionalizer CB1 is close, the protection range of Section I of CB1 may exceed that of FB1. Therefore, in this case, the switches are configured as shown in Table 2 below to achieve local automatic fault handling.

[0087] Table 2 Line switch parameter configuration table when I section protection oversteps

[0088]

[0089] When the distribution line is short and the first sectionalizer is close to the outgoing line switch, set the outgoing line switch's overcurrent delay for stage I to 0.1s and the first sectionalizer's overcurrent delay for stage I to 0s. Also, set the first sectionalizer's short-duration incoming call detection time to less than 0.2s or greater than 0.4s, and the second sectionalizer's short-duration incoming call detection time to less than 0.1s or between 0.3s and 0.4s. Other switch configurations are the same as above.

[0090] In addition to the overcurrent stage I protection, the other protections mentioned above, such as overcurrent stage II, overcurrent stage III, transient ground fault protection, and zero-sequence overcurrent protection, have the same fault handling process after startup. The following describes the case where the overcurrent stage I protection is started by a short-circuit fault.

[0091] When the distribution line is short and the first section switch is close to the outgoing line switch, and a short circuit fault triggers the overcurrent I stage protection, the specific fault handling process is as follows:

[0092] 1.2.1 K1 section fault when I section protection oversteps

[0093] When the I section protection is overstepped, the K1 section fault is as follows Figure 9 As shown in Figure (a). When a fault occurs, the outgoing line switch CB1 is tripped (delay of stage I is 0.1s), the line loses pressure, and FB1 and FB2 remain closed. Figure 9 As shown in Figure (b), CB1 recloses after a delay of 2s. If it is a transient fault, the fault has disappeared when the circuit breaker is closed, and the line resumes normal operation. Figure 9As shown in Figure (c), if it is a permanent fault, CB1 closes until the fault occurs, and then restarts the I-stage protection. After a 0.1s delay, the circuit breaker opens and no longer recloses. FB1 detects that the short-term power supply duration is less than 0.2s, and automatically opens and reverse locks. FB2 detects that the short-term power supply duration is between 0.1s and 0.2s and does not open. Figure 9 As shown in Figure (d), after the voltage on one side of the tie switch LS1 is lost, a short-term power supply is detected and the duration is not between 0.2s and 0.3s. The breaker is closed after a delay of 10s to restore the power supply to the faulty rear end. Figure 9 As shown in Figure (e).

[0094] 1.2.2 K2 section fault when I section protection oversteps

[0095] When the I section protection is overstepped, the K2 section fault is as follows Figure 10 As shown in Figure (a). When a fault occurs, the sectionalizer FB1 opens for overcurrent protection in section I (delay 0s), CB1 will not operate until the delay of section I is reached, and FB2 remains closed. Figure 10 As shown in Figure (b), FB1 is closed after a 3s delay when there is voltage on one side. If it is a transient fault, the fault has disappeared and the line resumes normal operation. If it is a permanent fault, FB1 is closed until the fault protection opens again and is positively blocked. CB1 will not operate until the protection delay is reached. FB2 detects a short-term power supply duration of less than 0.1s and automatically opens and is negatively blocked. Figure 10 As shown in Figure (c), after the voltage on one side of the tie switch LS1 is lost, a short-term power supply is detected and the duration is not within 0.2 to 0.3 seconds, and the circuit breaker is closed with a delay to restore the power supply to the fault rear end. Figure 10 As shown in Figure (d).

[0096] This embodiment, through the above-mentioned on-site feeder automation fault handling method, can automatically handle 10kV line faults on-site, without the need for the line switch to communicate with the main station; the outgoing line switch only needs to be reclosed once to achieve the location and isolation of the fault section and rapid restoration of power to the non-fault section. Compared with existing on-site feeder automation modes, such as voltage-time type, voltage-current type, adaptive comprehensive type, etc., the outgoing line switch can be reclosed to restore normal operation in the event of an instantaneous fault, and the section switch does not need to be operated, which greatly reduces the power outage time; in the event of a permanent fault, the outgoing line switch only needs to be reclosed once, which can reduce the number of reclosing times of the substation outgoing line switch, reduce the impact of the fault, and at the same time, the number of line section switch operations is also minimized. Using this method for on-site feeder automation fault handling can effectively reduce the number of outgoing line switch and section switch operations, reduce the line power outage time and power outage range, and effectively improve the power supply reliability to users compared to existing on-site feeder automation fault handling methods.

[0097] Example 2

[0098] This embodiment provides an on-site feeder automation fault handling device. Two distribution lines are interconnected, and the communication channel of each distribution line is sequentially provided with an outgoing line switch close to the distribution line, multiple section switches, and a connecting switch. The multiple section switches and the connecting switch use a distribution primary and secondary integrated circuit breaker.

[0099] Among them, the outgoing line switch is equipped with protection delay and single reclosing function, multiple section switches are equipped with closing position power detection fault delay opening and forward locking, short-time power detection time opening and reverse locking function, and the connecting switch is equipped with automatic power transfer function;

[0100] The device includes an outgoing line switch action module, a section switch action module and a tie switch action module; wherein,

[0101] The outgoing line switch action module is used to protect the outgoing line switch from opening after a set delay when a power supply line fault occurs, while the section switch does not open; the outgoing line switch recloses after a set reclosing delay;

[0102] The section switch action module is used for, when the fault is a permanent fault, closing the section switch and receiving power, and the section switch on the power supply side of the fault point performs the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the section switch on the load side of the fault point performs the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section;

[0103] The interconnection switch action module is used to enable the interconnection switch to perform the automatic power transfer function and complete fault processing.

[0104] Example 3

[0105] This embodiment provides an electronic device, including a memory and a processor, and computer instructions stored in the memory and running on the processor. When the computer instructions are run by the processor, the steps in the local feeder automation fault handling method described above are completed.

[0106] Example 4

[0107] This embodiment further provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the steps in the local feeder automation fault handling method described above are completed.

[0108] The steps involved in the above embodiments 2 to 4 correspond to those in the method embodiment 1. For detailed implementation, please refer to the relevant description of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media that includes one or more instruction sets; it should also be understood to include any medium that can store, encode, or carry an instruction set for execution by a processor and cause the processor to perform any method of the present invention.

[0109] Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using a general-purpose computer device. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0110] The above description is only a preferred embodiment of the present invention. Although the specific implementation of the present invention is described in conjunction with the accompanying drawings, it does not limit the scope of protection of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A local feeder automation fault handling method, characterized in that: The two distribution lines are interconnected, and the connecting channel of each distribution line is sequentially provided with an outgoing line switch close to the distribution line, multiple section switches and a connecting switch. Multiple section switches and connecting switches use a primary and secondary integrated circuit breaker for distribution; Among them, the outgoing line switch is equipped with protection delay and single reclosing function, multiple section switches are equipped with closing position power detection fault delay opening and forward locking, short-time power detection time opening and reverse locking function, and the connecting switch is equipped with automatic power transfer function; The method comprises: When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose. If the fault is a permanent fault, the sectionalizer is closed and the power is received. The sectionalizer on the power supply side of the fault point performs the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the sectionalizer on the load side of the fault point performs the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section; the tie switch performs the automatic power transfer function to complete the fault handling; The function of delaying tripping and forward locking upon power failure detection in the closed position includes: after the sectionalizer is closed and the power is cut off, if power is detected in the fault handling time window and the fault still exists, the sectionalizer will trip and forward lock after the set delay time to complete the front end isolation of the fault section; The short-time call detection time tripping and reverse blocking function includes: after the sectionalizer is closed and the power is cut off, if a short-time call is detected within the fault processing time window and the call time meets the preset time parameters, the circuit breaker will automatically trip and reverse block to complete the rear-end isolation of the fault section; The automatic power transfer function includes: when a fault occurs in the line on one side of the connecting switch, the connecting switch loses pressure on one side, and a short-term call is detected within the fault handling time window and the call time meets the fault characteristics of the non-adjacent section, the power transfer delay timer is started, and when the timer ends, the circuit breaker is automatically closed and power is transferred to the non-fault section. Otherwise, the automatic power transfer is locked.

2. The local feeder automation fault handling method according to claim 1, characterized in that: The method comprises: When a power supply line fails, the outgoing line switch will trip after a set delay, but the section switch will not trip; after a set reclosing delay, the outgoing line switch will reclose. If the fault in question is a permanent fault, then: If the outgoing line switch is closed and then protected by opening again, the line connected to the outgoing line switch is considered to be a fault section. When the sectionalizer is closed and power is received, the sectionalizer on the load side of the fault point will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically open and reverse lock, otherwise it will not operate; after the pressure on one side of the connecting switch is lost, it will detect the short-term power time and make a judgment. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power; If the outgoing line switch does not open after closing, it is considered that the line connected to the outgoing line switch is a non-fault section. At this time, the fault still exists and the sectionalizer is closed for power supply. When the sectionalizer on the power supply side of the fault point detects a fault, the protection delays opening and forward locking, otherwise it will not operate. The sectionalizer on the load side of the fault point detects short-term power supply and makes a judgment. If the configuration conditions are met, it will open and reverse lock, otherwise it will not operate. After the pressure on one side of the connecting switch is lost, the short-term power supply time is detected and judged. If the configuration conditions are met, it will automatically close with a delay, otherwise it will lock and automatically transfer power.

3. The local feeder automation fault handling method according to claim 1, characterized in that: The method further comprises: When a fault occurs in the power supply line, the outgoing line switch will be protected and opened after the set delay, and the section switches will not be opened; after the set reclosing delay, the outgoing line switch will reclose; if the fault is a transient fault, the fault will disappear when the protection delay closes, and the line will resume normal operation.

4. The local feeder automation fault handling method according to claim 1, characterized in that: The protection delay function includes overcurrent protection delay, transient principle grounding protection delay, zero-sequence overcurrent protection delay, and the outgoing line switch is configured with a variety of protection delay delay times; the overcurrent protection delay includes overcurrent I stage delay, overcurrent II stage delay and overcurrent III stage delay.

5. The local feeder automation fault handling method according to claim 4, characterized in that: The delay time of the overcurrent I delay is 0s, the delay time of the overcurrent II delay is 0.4s, the delay time of the overcurrent III delay is 0.6s, the delay time of the transient principle grounding protection delay is 10s, and the delay time of the zero-sequence overcurrent protection delay is 0.5s.

6. The local feeder automation fault handling method according to claim 1, characterized in that: The outgoing line switch is configured with accelerated protection after closing, including zero-sequence voltage acceleration; the outgoing line switch is configured to reclose once after detecting pressure, and the reclosing delay is 2s.

7. The local feeder automation fault handling method according to claim 1, characterized in that: After the set delay time, the circuit breaker opens and locks in the forward direction. The delay time set for the first section switch is 0.3s, and the delay time set for the second section switch is 0.2s.

8. The local feeder automation fault handling method according to claim 1, characterized in that: A short incoming call is detected and the incoming call time meets the preset time parameter. The preset time parameter set by the first segment switch is less than 0.12s or greater than 0.4s, and the preset time parameter set by the second segment switch is 0.3s~0.4s.

9. The local feeder automation fault handling method according to claim 1, characterized in that: The sectionalizer is configured to close with a delay of 3s when there is pressure on one side in the unlocked state; the fault handling time window of the sectionalizer is 5s.

10. The local feeder automation fault handling method according to claim 1, wherein: When the interconnecting switch loses pressure on one side and detects a short-term power supply within 5 seconds, the power transfer delay timer starts; when the power transfer timer reaches 10 seconds, the interconnecting switch starts automatic power transfer to the non-fault section; If the contact switch detects a short-term power supply and the short-term power supply duration is between 0.2s and 0.3s, it will be locked and automatically transferred to the power supply.

11. The local feeder automation fault handling method according to claim 1, wherein: When the distribution line is short and the distance between the first section switch and the outgoing line switch is close, the delay time of the overcurrent I section delay of the outgoing line switch is configured to be 0.1s, the delay time of the overcurrent I section delay of the first section switch is configured to be 0s, and the set preset time parameter for the first section switch to detect short-term incoming calls is configured to be less than 0.2s or greater than 0.4s, and the set preset time parameter for the second section switch to detect short-term incoming calls is configured to be less than 0.1s or 0.3s~0.4s.

12. A local feeder automation fault handling device, characterized in that: The two distribution lines are interconnected, and the connecting channel of each distribution line is sequentially provided with an outgoing line switch close to the distribution line, multiple section switches and a connecting switch. Multiple section switches and connecting switches use a primary and secondary integrated circuit breaker for distribution; Among them, the outgoing line switch is equipped with protection delay and single reclosing function, multiple section switches are equipped with closing position power detection fault delay opening and forward locking, short-time power detection time opening and reverse locking function, and the connecting switch is equipped with automatic power transfer function; The device includes an outgoing line switch action module, a section switch action module and a tie switch action module; wherein, The outgoing line switch action module is used to protect the outgoing line switch from opening after a set delay when a power supply line fault occurs, while the section switch does not open; the outgoing line switch recloses after a set reclosing delay; The section switch action module is used for, when the fault is a permanent fault, closing the section switch and receiving power, and the section switch on the power supply side of the fault point performs the closing power detection fault delay tripping and forward locking function to isolate the front end of the section where the fault point is located and restore power supply to the upstream non-fault section; the section switch on the load side of the fault point performs the short-time power detection time tripping and reverse locking function to isolate the back end of the section where the fault point is located and ensure power supply to the downstream non-fault section; The tie switch action module is used to make the tie switch perform the automatic power transfer function and complete fault processing; The function of delaying tripping and forward locking upon power failure detection in the closed position includes: after the sectionalizer is closed and the power is cut off, if power is detected in the fault handling time window and the fault still exists, the sectionalizer will trip and forward lock after the set delay time to complete the front end isolation of the fault section; The short-time call detection time tripping and reverse blocking function includes: after the sectionalizer is closed and the power is cut off, if a short-time call is detected within the fault processing time window and the call time meets the preset time parameters, the circuit breaker will automatically trip and reverse block to complete the rear-end isolation of the fault section; The automatic power transfer function includes: when a fault occurs in the line on one side of the connecting switch, the connecting switch loses pressure on one side, and a short-term call is detected within the fault handling time window and the call time meets the fault characteristics of the non-adjacent section, the power transfer delay timer is started, and when the timer ends, the circuit breaker is automatically closed and power is transferred to the non-fault section. Otherwise, the automatic power transfer is locked.

13. An electronic device, characterized in that: The method comprises a memory and a processor, and computer instructions stored in the memory and executed on the processor. When the computer instructions are executed by the processor, the method completes the steps of a local feeder automation fault processing method according to any one of claims 1 to 11.

14. A computer-readable storage medium, characterized in that: Used to store computer instructions, which, when executed by a processor, complete the steps of a local feeder automation fault handling method according to any one of claims 1 to 11.

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