Feeder automation method and computer system
By setting the delay time before the closing operation of the contact switch, the problem of the fault range being expanded due to the error closing of the contact switch is solved, and a more accurate and safe load transfer is achieved.
Patent Information
- Application Number
- CN202411892781.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-04-18
AI Technical Summary
In the prior art, the contact switch will be closed incorrectly, resulting in an expansion of the fault range.
Before the contact switch performs closing of load transfer, set the first delay time. If the loss side resumes power supply within the first delay time, the contact switch will not close; otherwise, the switch will be automatically closed after the first delay time. For the contact switch at the end of the line, keep the gate open to avoid tripping of the opposite line.
By setting the delay time, the error closing caused by transient faults is avoided, the fault range is expanded, and the accuracy and safety of load transfer are ensured.
Smart Images
Figure CN119852949A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of feeder automation, and in particular relates to a feeder automation method and a computer system. Background Art
[0002] Feeder terminals are distribution automation terminals installed at overhead line towers of 6kV and above distribution networks and have remote signaling, telemetry, remote control and feeder automation functions. With the development of distribution automation technology, the requirements for feeder terminal equipment are getting higher and higher, so that they need to have fault handling functions to enhance the distribution automation's ability to quickly and accurately locate distribution network faults.
[0003] A tie switch is a switch that establishes a connection between two or more power sources (such as transformers or distribution systems). When one of the power sources fails or loses power, the tie switch can quickly transfer the load of the failed power source to another normally working power source to ensure continuous power supply to the power system. Existing tie switch closing methods include manual and remote control. When a line fails, the tie switch closing time is not fixed. When the fault is instantaneous, the tie switch may be mistakenly closed due to uncertainty in time, resulting in an expansion of the fault range. Summary of the invention
[0004] The object of the present invention is to provide a feeder automation method and a computer system to solve the technical problem in the prior art that a tie switch may be mistakenly closed, resulting in an expansion of the fault range.
[0005] In order to solve the above technical problems, the present invention provides a technical solution of a feeder automation method: a feeder automation method, the method comprising: for a tie switch not at the end of a line, when it is detected that one side of the tie switch in the open position has pressure and the other side loses pressure and the line where the tie switch is located has no flow; if the line on the side where the tie switch loses pressure recovers power within a first delay time, the tie switch does not close; otherwise, the tie switch automatically closes after the first delay time;
[0006] For the tie switch at the end of the line, when it is detected that one side of the tie switch in the open position has pressure and the other side loses pressure and there is no flow in the line where the tie switch is located, the tie switch remains in the open state;
[0007] The first delay time is greater than the longest fault isolation time of the line.
[0008] The beneficial effect of the above technical scheme is that the technical scheme of a feeder automation method of the present invention belongs to an improved invention. When the line is operating normally, the contact switch generally has pressure on both sides. When a fault occurs, there is pressure on one side of the contact switch and the other side loses pressure due to the fault. At this time, the power supply of the non-fault section downstream of the fault point can be restored by closing the contact switch. Before the contact switch is closed for load transfer, the present invention sets a first delay time. Within the first delay time, if the power supply on the pressure-losing side is restored, the contact switch will not be closed to avoid transient faults; after the first delay time, if the power supply has not been restored, it means that it is not a transient fault, and the contact switch is closed to transfer the load. The first delay time needs to be greater than the longest fault isolation time to prevent the power supply from being transferred without isolation, causing the power outage to expand. If the line is a terminal fault, the contact switch has an instantaneous pressure locking function to maintain the open state to avoid causing the opposite line to trip. The present invention solves the technical problem that the contact switch in the prior art may be mistakenly closed, resulting in an expansion of the fault range.
[0009] Furthermore, the method also includes a manual opening and locking automatic closing logic: if the FTU is opened by a handle, a remote control or a switch body operation, the automatic closing is locked.
[0010] Furthermore, the method also includes a reset logic for the locked automatic closing: after the locked automatic closing, if the FTU closes the switch by means of a handle, a remote control or a switch body operation, the locked automatic closing flag is cleared.
[0011] Further, the method also includes reverse blocking automatic closing logic and / or reverse blocking automatic closing reset logic;
[0012] The reverse blocking automatic closing logic is: when the switch is in the open state, there is no pressure on both sides of the switch and there is no current in the line where the switch is located, if the duration of the incoming call on either side of the switch is less than the set time and greater than or equal to the residual pressure pulse time setting value, the reverse blocking will automatically close;
[0013] The reverse lockout automatic closing reset logic is: after reverse lockout, if the switch is in the closed state or there is current in the line where the switch is located, the reverse lockout flag is cleared.
[0014] Further, the method also includes a forward blocking automatic closing reset logic and / or a forward blocking automatic closing logic;
[0015] The forward locking automatic closing reset logic is as follows: after forward locking, when the switch is in the open position, if a reverse call occurs and lasts for the second delay time, the switch is reversely closed and the forward locking flag is cleared; after forward locking, when the switch is in the closed position, if there is flow in the line where the switch is located or there is pressure on at least one side, the forward locking flag is cleared after a delay of the third delay time.
[0016] The forward locking automatic closing logic: after the switch is closed, if any one of conditions 1 and 2 is met within the fault-free confirmation time, the switch will trip and forward lock and automatically close; condition 1 is that both sides of the switch lose pressure and there is no current in the line where the switch is located; condition 2 is that a single-phase grounding fault is detected.
[0017] Furthermore, the method also includes a power-delayed automatic closing logic: for a sectionalizing switch, when the switch is in the open position, there is pressure on one side of the switch and no pressure on the other side, there is no current in the line where the switch is located, and there is no blocking closing signal, scheme 1 or scheme 2 is executed;
[0018] The scheme 1 is: after the FTU at the head end of the line trips due to a single-phase grounding fault, when power is received, the FTU at the head end of the line closes after the grounding fault reclosing time has elapsed;
[0019] The scheme 2 is: if the FTU has a phase-to-phase short-circuit fault memory or a single-phase grounding fault memory, then when the voltage is restored on the non-voltage side, the FTU will close after the fourth delay time; if the FTU does not have a phase-to-phase short-circuit fault memory and a single-phase grounding fault memory, then when the voltage is restored on the non-voltage side, the FTU will close after the fifth delay time.
[0020] Furthermore, the method also includes a single-phase grounding fault processing logic: after the single-phase grounding fault tripping function of the head-end FTU is put into use, when a single-phase grounding fault occurs during normal operation of the line, the head-end FTU performs a single-phase grounding fault judgment based on the characteristic direction of the single-phase grounding fault. If it is judged that a grounding fault has occurred in this line, the head-end FTU trips after the grounding fault tripping time.
[0021] Furthermore, the method also includes a logic of automatic tripping due to loss of pressure on both sides: if there is no pressure on both sides of the switch and there is no current in the line where the switch is located, the switch is tripped after a sixth delay time.
[0022] Furthermore, the method also includes a double-side pressure-locked automatic closing logic: if the switch is in an open state, there is pressure on both sides of the switch and there is no current in the line where the switch is located, the switch is locked and automatically closed.
[0023] The present invention also provides a technical solution of a computer system: a computer system, comprising a processor, wherein the processor is used to execute a computer program to implement the steps of the feeder automation method as described above. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a general process framework diagram of feeder terminal fault protection handling in the feeder automation method embodiment of the present invention;
[0025] Figure 2 It is a common processing logic flow chart in the feeder automation method embodiment of the present invention;
[0026] Figure 3 It is a logic flow chart of automatic closing with delayed incoming call in the embodiment of the feeder automation method of the present invention;
[0027] Figure 4 It is a logic flow chart of automatic closing with delay during voltage loss in the embodiment of the feeder automation method of the present invention;
[0028] Figure 5 It is a logic flow chart of automatic tripping due to pressure loss on both sides in the feeder automation method embodiment of the present invention;
[0029] Figure 6 A logic flow chart of single-phase ground fault processing in an embodiment of a feeder automation method of the present invention;
[0030] Figure 7 It is a logic flow chart of positive locking automatic closing in the embodiment of the feeder automation method of the present invention;
[0031] Figure 8 It is a reverse blocking automatic closing logic flow chart in the feeder automation method embodiment of the present invention;
[0032] Fig. 9 It is a logic flow chart of double-side pressure-locked automatic closing in the feeder automation method embodiment of the present invention;
[0033] Fig.10 It is a logic flow chart of forward locking automatic closing reset in the feeder automation method embodiment of the present invention;
[0034] Fig.11 It is a logic flow chart of reverse blocking automatic closing and resetting in the embodiment of the feeder automation method of the present invention;
[0035] Fig.12 It is a logic flow chart of manual opening, locking and automatic closing in the feeder automation method embodiment of the present invention;
[0036] Fig.13 The figure is a logic flow chart of the reset of the locked automatic closing in the feeder automation method embodiment of the present invention. DETAILED DESCRIPTION
[0037] In the prior art, when the line is operating normally, the interconnecting switch generally has pressure on both sides. When a fault occurs, there is pressure on one side of the interconnecting switch and the other side loses pressure due to the fault. At this time, the power supply to the non-fault section downstream of the fault point can be restored by closing the interconnecting switch. However, before the interconnecting switch is closed for load transfer, the present invention sets a first delay time. If the power supply is restored on the pressure-losing side within the first delay time, the interconnecting switch will not be closed to avoid transient faults. After the first delay time, if the power supply has not been restored, it means that it is not a transient fault, and the interconnecting switch is closed to transfer the load. The first delay time must be greater than the longest fault isolation time to prevent the power supply from being transferred without isolating the fault, causing the power outage to expand. If the line is an end fault, the interconnecting switch has an instantaneous pressure locking function to maintain the open state to avoid causing the opposite line to trip. The present invention solves the technical problem that the interconnecting switch in the prior art may be mistakenly closed, resulting in an expansion of the fault range.
[0038] Feeder automation method embodiment:
[0039] A feeder automation method, in this embodiment, divides the feeder terminal fault protection handling process into two parts, namely: common processing logic (mainly alarm) and feeder automation (mainly internal logic action).
[0040] The common processing logic includes: short circuit fault alarm, zero current ground fault alarm, low current ground fault alarm, shielding current blocking logic, disconnection alarm, synchronization detection, continuous opening blocking and automatic closing, etc.
[0041] Feeder automation includes: delayed automatic closing due to incoming power, delayed automatic closing due to loss of voltage, automatic opening due to loss of voltage on both sides, single-phase grounding fault handling, forward interlock automatic closing, reverse interlock automatic closing, double-side pressure interlock automatic closing, forward interlock automatic closing reset, reverse interlock automatic closing reset, manual opening interlock automatic closing, interlock automatic closing reset, etc.
[0042] The overall process framework of the feeder terminal fault protection handling in this embodiment is as follows: Figure 1 As shown in the figure, the precondition of the feeder terminal fault processing function is that the panel "fault processing" lever is turned on, and the public processing logic function is valid at this time. Then, according to the setting of the fixed value, it is determined whether the FA mode is "centralized FA / conventional protection" or "local FA". Then it enters the respective protection mode to work. It is worth mentioning that the public processing logic and centralized FA (Feeder Automation) described here generally only issue alarm information.
[0043] The common processing logic flow of this embodiment is as follows: Figure 2As shown in the figure, the common processing logic functions include short circuit fault alarm, zero current ground fault alarm, small current ground fault alarm, shielding current (large current) blocking logic, disconnection alarm, synchronous detection, continuous opening and closing (automatic) functions. According to the collected voltage, current and other data, compared with the threshold value set by the fixed value, after a delay time (settable), the alarm information is issued. Among them, the fault detection in the small current ground fault alarm and disconnection alarm is relatively important and difficult.
[0044] Specifically, the common processing logic may refer to the prior art, and will not be described in detail in this embodiment.
[0045] Figure 3 to Figure 9 They are respectively the feeder automation action logic flow charts of this embodiment.
[0046] in, Figure 3 This is a logic flow chart of delayed automatic closing for incoming power, which is applicable to sectionalized switches. When the switch is in the open position, there is pressure on one side of the switch and no pressure on the other side, there is no current in the line where the switch is located, and there is no locking closing signal, then (1) after the FTU at the head end of the line trips due to a single-phase grounding fault, it closes after [grounding fault reclosing time]; (2) if the non-head end FTU has a phase-to-phase short circuit fault memory under the zero current alarm of the common processing logic or a single-phase grounding fault memory under the short circuit alarm of the common processing logic, when the pressure is restored on one side, it closes after [X time] (i.e., the fourth delay time); (3) if the non-head end FTU does not have a line fault memory (i.e., phase-to-phase short circuit fault memory and single-phase grounding fault memory), when the pressure is restored on one side, it closes after [S time] (i.e., the fifth delay time).
[0047] Among them, [X time] and [S time] are obtained by the State Grid Electric Power Research Institute after collecting data from power supply companies in various power grids and provinces. Generally speaking, [X time] is set to 7s and [S time] is set to 57s. It can also be set independently according to the actual project.
[0048] Figure 4 This is a logic flow chart of automatic closing after voltage loss delay, which is applicable to tie switches. When the line is operating normally, the tie switch generally has voltage on both sides; when a fault occurs, one side has voltage and the other side (after voltage loss) has no voltage. For lines with the ability to transfer power through ties, the power supply to the non-fault section downstream of the fault point can be restored by closing the tie switch.
[0049] The logic of automatic delayed closing is: when a short circuit occurs in the line, the contact switch will detect a loss of pressure on one side. If the loss of pressure time is longer than the confirmation time (XL) before the contact switch closes (i.e. the first delay time), the contact switch will automatically close, transfer the load, and restore power supply to the non-fault area; if the power supply is restored to the line on the pressure-losing side within the XL time, the contact switch will not close to avoid instantaneous faults; if the line is a terminal fault, the contact switch has an instantaneous pressure lock function to maintain the open state to avoid tripping the opposite line. When setting the XL time, it should be greater than the longest fault isolation time to prevent the power supply from being transferred without fault isolation, causing the power outage to expand.
[0050] Figure 5 This is the logic flow chart of automatic opening when voltage is lost on both sides. When voltage is lost on both sides of the switch and no current flows, the switch will automatically open after [Z time] (i.e. the sixth delay time).
[0051] Figure 6 This is a single-phase ground fault processing logic flow chart, which is applicable to the head-end FTU (Feeder Terminal Unit). After the single-phase ground fault tripping function of the head-end FTU is put into use, when a single-phase ground fault occurs during normal operation of the line, the head-end FTU will make a ground fault judgment based on the characteristic direction of the small current single-phase ground fault or the zero-current ground fault alarm. After judging that it is a ground fault on this line, it will trip after [ground fault tripping time].
[0052] Figure 7 This is the logic flow chart of forward blocking automatic closing. After the switch is closed, if the switch loses voltage and current within [Y time], or a single-phase grounding fault is detected within [Y time], the switch will automatically open and block the forward closing immediately, so that the switch will not be closed when forward power is supplied. Y time is the fault-free confirmation time after the switch is closed.
[0053] Combination Figure 6 , Figure 3 , Figure 7 From the perspective of single-phase ground fault, it can be summarized as follows: after the first-end FTU line selection trips, it closes after [ground fault reclosing time] ( Figure 3 ), if a single-phase ground fault is detected within [Y time] after closing, it will immediately trip and positively lock after a short delay (0s) ( Figure 7 ); if no single-phase ground fault is detected after [Y time] after closing, the circuit breaker will not trip ( Figure 7 ).
[0054] Figure 8 This is the reverse blocking automatic closing logic flow chart. When the switch is in the open position and there is no pressure and no current, if residual pressure is detected on the power supply side or the load side, the residual pressure timing starts until the residual pressure disappears (that is, no pressure is detected on both the power supply side and the load side), and the residual pressure time is obtained. Figure 8 When the residual voltage time on one side of the switch reaches [X set value], that is, the residual voltage time is greater than [X set value], it means that the voltage on both sides of the switch is caused by the residual voltage in the power supply or load, not the voltage generated by power transmission after the fault is isolated. In this case, the reverse lock is closed, and the switch is not closed when the other side is powered in the reverse direction to avoid accidental closing and further faults. When the power-on time on one side of the switch reaches [X set value], that is, the residual voltage time is greater than [X set value], it means that the voltage on both sides of the switch is not caused by the residual voltage in the power supply and load, but the voltage generated by power transmission after the fault is isolated. At this time, the line has resumed normal operation.
[0055] Among them, [X setting value] and residual voltage pulse time setting value are set according to the requirements of State Grid Electric Power Research Institute. Generally speaking, [X setting value] is 7s and residual voltage pulse time setting value is 60ms. It can also be set independently according to the actual project.
[0056] Fig. 9 This is the logic flow chart of automatic closing when there is pressure on both sides of the switch. When it is detected that there is pressure on both sides of the switch and the switch is in the open position and there is no current, automatic closing is avoided to cause closed-loop operation.
[0057] Figure 10 to Figure 13 They are respectively the manual locking and reset logic flow charts of the feeder automation in this embodiment.
[0058] Fig.10 This is the logic flow chart of the automatic closing reset of the forward lockout. The forward lockout will automatically reset when any of the following conditions are met: (1) When reverse power is received, when the normal time of reverse power is greater than [X time] (i.e., the second delay time), the reverse circuit breaker will be closed and the switch will change from open to closed; (2) The line returns to normal: the switch is closed and there is flow or the switch is closed and there is pressure on at least one side.
[0059] Fig.11 This is the reverse lockout automatic closing reset logic flow chart. When any of the following conditions is met, the reverse lockout flag is cleared: (1) the switch is closed; (2) there is current in the switch.
[0060] Fig.12 This is the logic flow chart of manual opening and locking automatic closing. If the FTU handle opens, the remote control opens, or the switch body operates the opening, the lock call will automatically close the switch.
[0061] Fig.13 It is the reset logic flow chart of the locked automatic closing. If the FTU handle is closed, the remote control is closed, or the switch body is closed, the automatic closing lock is reset (including manual opening-locked automatic closing, double-side pressure-locked automatic closing, forward-locked automatic closing, reverse-locked automatic closing, continuous opening-locked automatic closing and other types of locked automatic closing).
[0062] from Figures 1 to 13It can be seen that from the perspective of software design process control, the feeder terminal can well detect the operation status of the distribution line in real time and perform corresponding protection actions based on the detection results, thereby ensuring the safety and reliability of the power consumption process.
[0063] Computer System Embodiment:
[0064] A computer system includes a processor, wherein the processor is used to execute a computer program to implement the steps of the feeder automation method described above. The specific feeder automation method has been described in sufficient detail in the feeder automation method embodiment described above, and will not be repeated here.
[0065] The present invention has the following characteristics:
[0066] Compared with the existing feeder terminal, the present invention improves the operation monitoring and fault handling level of the distribution line, reduces the frequency of distribution line misoperation and user power outage time, increases the reliability and safety of distribution line operation, and improves the practical level of distribution automation.
[0067] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A feeder automation method, characterized in that: The method comprises: for a tie switch not at the end of a line, when it is detected that one side of the tie switch in the open position has pressure and the other side loses pressure and the line where the tie switch is located has no current; if the line on the side where the tie switch loses pressure recovers power within a first delay time, the tie switch does not close; otherwise, the tie switch automatically closes after the first delay time; For the tie switch at the end of the line, when it is detected that one side of the tie switch in the open position has pressure and the other side loses pressure and there is no flow in the line where the tie switch is located, the tie switch remains in the open state; The first delay time is greater than the longest fault isolation time of the line.
2. The feeder automation method according to claim 1, characterized in that: The method also includes manual opening and locking automatic closing logic: if the FTU is opened by handle opening, remote control opening or switch body operation, the automatic closing is locked.
3. The feeder automation method according to claim 1, characterized in that: The method also includes a reset logic for the locked automatic closing: after the locked automatic closing, if the FTU closes the switch by means of a handle, a remote control or a switch body operation, the locked automatic closing flag is cleared.
4. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method further includes reverse blocking automatic closing logic and / or reverse blocking automatic closing reset logic; The reverse blocking automatic closing logic is: when the switch is in the open state, there is no pressure on both sides of the switch and there is no current in the line where the switch is located, if the duration of the incoming call on either side of the switch is less than the set time and greater than or equal to the residual pressure pulse time setting value, the reverse blocking will automatically close; The reverse lockout automatic closing reset logic is: after reverse lockout, if the switch is in the closed state or there is current in the line where the switch is located, the reverse lockout flag is cleared.
5. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method also includes forward blocking automatic closing reset logic and / or forward blocking automatic closing logic; The forward locking automatic closing reset logic is as follows: after forward locking, when the switch is in the open position, if a reverse call occurs and lasts for the second delay time, the switch is reversely closed and the forward locking flag is cleared; after forward locking, when the switch is in the closed position, if there is flow in the line where the switch is located or there is pressure on at least one side, the forward locking flag is cleared after a delay of the third delay time. The forward locking automatic closing logic: after the switch is closed, if any one of conditions 1 and 2 is met within the fault-free confirmation time, the switch trips and forward locking automatically closes; The condition 1 is that the voltage is lost on both sides of the switch and there is no current in the line where the switch is located; the condition 2 is that a single-phase grounding fault is detected.
6. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method also includes a power-delayed automatic closing logic: for a sectionalizing switch, when the switch is in the open position, there is pressure on one side of the switch and no pressure on the other side, there is no current in the line where the switch is located, and there is no blocking closing signal, scheme 1 or scheme 2 is executed; The scheme 1 is: after the FTU at the head end of the line trips due to a single-phase grounding fault, when power is received, the FTU at the head end of the line closes after the grounding fault reclosing time has elapsed; The scheme 2 is: if the non-line head-end FTU has a phase-to-phase short-circuit fault memory or a single-phase grounding fault memory, the FTU will close after the fourth delay time when the voltage is restored on the no-voltage side; if the non-line head-end FTUFTU does not have a phase-to-phase short-circuit fault memory and a single-phase grounding fault memory, the FTU will close after the fifth delay time when the voltage is restored on the no-voltage side.
7. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method also includes single-phase grounding fault processing logic: after the single-phase grounding fault tripping function of the head-end FTU is put into use, when a single-phase grounding fault occurs during normal operation of the line, the head-end FTU performs a single-phase grounding fault judgment based on the characteristic direction of the single-phase grounding fault. If it is judged that a grounding fault has occurred in this line, the head-end FTU trips after the grounding fault tripping time.
8. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method also includes a logic of automatic tripping due to loss of pressure on both sides: if there is no pressure on both sides of the switch and there is no current in the line where the switch is located, the switch will be tripped after a sixth delay time.
9. The feeder automation method according to claim 1, 2 or 3, characterized in that: The method also includes a double-side pressure-locked automatic closing logic: if the switch is in an open state, there is pressure on both sides of the switch and there is no current in the line where the switch is located, the switch is locked and automatically closed.
10. A computer system comprising a processor, characterized in that: The processor is used to execute a computer program to implement the steps of the feeder automation method according to any one of claims 1 to 9.