A power distribution network line adaptive bypass protection method

Abstract

The application discloses a power distribution network line adaptive bypass protection method, in the current power distribution network system configured with bus fault fast removal protection, fully utilizing the existing resources, through adaptive tracking of the running state of the line interval in the bus protection area of the power distribution network and the interval bypass protection enable state change, according to the preset switching logic, adaptive switching of the line interval protection and interval bypass protection analog quantity, switching quantity, adaptive switching of the line interval protection and bypass protection optical longitudinal channel loop and bypass protection jump and close loop, realizing adaptive replacement and adaptive recovery of the bilateral and unilateral electrical quantity protection function of one or more line intervals in the bus protection area of the power distribution network, solving the problems existing in the redundant replacement or bypass replacement in the current power distribution network system, further improving the power supply reliability of the power distribution system, and having necessity, urgency and feasibility.

Description

Technical Field

[0001] This invention relates to an adaptive bypass protection method for distribution network lines, belonging to the field of power system automation technology. Background Technology

[0002] As a bridge connecting power users and the transmission system, the distribution network is an indispensable and vital public infrastructure for social development and the national economy, and is the ultimate embodiment of the reliability and quality of power supply. With continuous technological advancements and the rapid progress of smart distribution network construction, the distribution network has made significant progress in areas such as precise fault location for low-current grounding, rapid busbar fault isolation, effective protection against arcing faults, and full sharing of protection data, effectively realizing automatic fault location, isolation, and power restoration.

[0003] However, current distribution networks lack sufficient redundancy or bypass alternatives for protection devices during maintenance, faults, or abnormal situations. In distribution network substation relay protection systems, protection devices are configured individually by bay and circuit breaker. In the event of a bay protection device malfunction, abnormality, or maintenance, redundancy or load transfer is typically achieved through substation protection, temporary backup protection, self-healing systems, or switching operations.

[0004] Using station-level protection devices, temporary backup protection, self-healing systems, or switching operations to achieve redundant protection has the following disadvantages: Station-level protection is inconvenient to configure and maintain, has poor scalability, and is prone to malfunctions affecting a wide range of systems. Furthermore, due to resource limitations, it is only applicable to optical cable sampling and tripping methods, which has limitations. Temporary backup protection adds extra equipment or systems, requiring resetting, configuration, and debugging, making the process complex. It is also only applicable to a single bay, resulting in poor economic efficiency. Self-healing systems or switching operations mainly achieve rapid and accurate fault location, isolation, and power restoration in the distribution network. While they can be equipped with comprehensive protection functions, their protection functions are affected by the active and passive operating modes of the main and secondary trunk networks, and cannot be adjusted in real time according to the maintenance or fault conditions of each bay.

[0005] Therefore, how to solve the shortcomings of redundancy replacement or bypass replacement in the current power distribution network system is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] Objective: To overcome the shortcomings of existing technologies, this invention provides an adaptive bypass protection method for distribution network lines. This method efficiently reuses existing resources, deeply integrates channel bypass and trip / close switching circuits, and adaptively tracks the operating status of line bays and bay bypass protection enable status changes within the distribution network bus protection area through software. This enables redundancy and adaptive substitution of electrical quantity protection functions on both sides and one side of the distribution network line bays, thereby improving the reliability and economy of power supply in the distribution network.

[0007] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] An adaptive bypass protection method for distribution network lines includes the following steps:

[0009] Step 1: Bypass protection is set up according to the line bay. In response to the change of the soft pressure plate of the distribution network bay bypass protection, the information of the line bay that needs to be bypassed is obtained. The analog quantity and switch quantity of the corresponding bay bypass protection are adaptively obtained, and the operation status of the corresponding distribution network line bay protection and the adaptive bypass protection enable status are determined.

[0010] Step 2: When it is determined that the line bay protection is in a fault, abnormal or maintenance state and the bay bypass protection is enabled, the analog and digital quantity acquisition circuits of the line bay protection are automatically switched to the bypass protection through preset switching logic. The longitudinal differential protection channel and trip / close circuit of the line bay are automatically switched to the bypass optical longitudinal channel switching circuit and the bypass trip / close switching circuit. The bay bypass protection completes the single-sided and double-sided electrical quantity protection logic of the line bay, realizing the adaptive replacement of the bypass protection.

[0011] Step 3: When maintenance or troubleshooting is completed and the line bay protection is operating normally, the bay bypass protection automatically switches the line bay analog and digital quantity acquisition circuits, longitudinal differential protection channel circuits, and trip and close circuits according to the preset switching logic, and exits the bay bypass protection replacement, so as to realize the bay protection adaptive recovery and re-evaluation.

[0012] As a preferred embodiment, step 1 includes:

[0013] Step 1.1: Obtain the bypass protection soft pressure plate S of the distribution network line bay k. k State, when S k Upon activation, the bypass protection identifies the line bay k information and automatically obtains the analog and switching quantities corresponding to the bus protection bay to replace the analog voltage of the bypass protection in line bay k. Analog current and the i-th input switch quantity DI ki Output switch quantity DO ki .

[0014] Step 1.2: Obtain the position DI of the m-th circuit breaker in line bay k. km Obtain the nth switching quantity DI of the same dual-path protection of line interval k. kn and the j-th switching quantity DI kj Real-time tracking of the operating status of line bay protection.

[0015] Step 1.3: Integrated line bay k bypass protection soft pressure plate Sk On / off status, line bay k bypass protection analog quantity and and digital input / output (DI) ki With DO ki The status of the data acquisition and the operating status of the line interval are used to determine the enable status of the adaptive bypass protection.

[0016] The judgment conditions are as follows:

[0017] (1)S k Investment.

[0018] (2) Analog quantity and and digital input / output (DI) ki With DO ki The data acquisition circuit is functioning normally.

[0019] (3) Line bay circuit breaker position DI km Combination position.

[0020] When the above three conditions are met, the adaptive bypass protection of line bay k is enabled, enters hot standby, and triggers the enable switch DO. kena .

[0021] If any condition is not met, the adaptive bypass protection of line bay k is disabled, the adaptive bypass protection is blocked, and DO... kena Set to false.

[0022] As a preferred embodiment, step 2 includes:

[0023] Step 2.1: Any group of DI kn =true and DI kj =true and simultaneously satisfy the condition for a duration of t1s, the switching logic is initiated, and step 2.2 is executed; if the duration from the start of the switching logic to its completion exceeds t2s, a switching exception is reported, the switching logic is exited, and the adaptive bypass protection of the line interval k is disabled. true represents an input quantity of 1.

[0024] Step 2.2: Automatically switch the analog quantity and switch quantity acquisition circuit of the bypass protection in line bay k. After successful switching, the analog quantity of the bypass protection will be used for data acquisition. and digital input / output (DI) ki DO ki The replacement line bay protection implements distance protection, zero-sequence overcurrent protection, overvoltage directional overcurrent protection and reclosing functions, and executes step 2.3; if the switching fails, it reports an abnormality in the switching analog quantity and switch quantity acquisition circuit, exits the switching logic, and sets the line bay k adaptive bypass protection to disabled.

[0025] Step 2.3: Utilize the enable switch quantity DO kenaThe reactivation relay triggers the optical bypass device in the bypass optical longitudinal channel switching circuit, automatically switching the longitudinal differential protection channel circuit. After successful switching, the bypass protection analog signal... and digital input / output (DI) ki DO ki Analog quantity of protection device on the opposite side of the line bay and switch quantity DI′ ki DO′ ki The longitudinal differential protection channel forms a longitudinal current differential protection, which replaces the line bay protection to realize longitudinal differential protection. Step 2.4 is executed. If the switching fails, an abnormality is reported in the longitudinal current differential protection channel, the longitudinal current differential protection function is blocked, the switching logic is exited, and the adaptive bypass protection of line bay k is disabled.

[0026] Step 2.4: Utilize the enable switch quantity DO kena The re-operation relay automatically switches the trip and close circuits. If the switch is successful, the bypass protection trip and close circuit replaces the line bay protection trip and close circuit, drives the trip and close mechanism to work, and executes step 2.5. If the switch fails, an abnormality in the trip and close circuit switching is reported, the switching logic is exited, and the adaptive bypass protection of line bay k is disabled.

[0027] Step 2.5: Switching complete. The bay bypass protection replaces the line bay protection and automatically sends protection information.

[0028] As a preferred option, in step 2.1, t1 = 0.03s; the value of t2 ranges from 10s to 3600s.

[0029] As a preferred option, in step 2.3, during the switching of the longitudinal differential protection channel circuit, the longitudinal current differential protection function of the corresponding line bay is locked; after the switching is successful and the data on both sides are synchronized, the longitudinal current differential protection function is opened.

[0030] As a preferred option, in step 2.4, during the switching of the trip and close circuits, the adaptive bypass protection function of the corresponding line bay is blocked.

[0031] As a preferred embodiment, step 3 includes:

[0032] Step 3.1: Track the change in the enabling status of the adaptive bypass protection during the operation of the alternative line bay protection. When the enabling status of the adaptive bypass protection does not change, the adaptive bypass protection continues to operate and steps 3.2 are executed. When the enabling status changes to the de-enabling status, the adaptive bypass protection is exited and reassessed.

[0033] Step 3.2: Track the operating status of the line bay protection, all groups of DI kn =true and DI kj=true if none of them are met, and the duration is t3s, and the maintenance or fault is confirmed to be completed on-site according to the operating procedures, and the line bay protection is operating normally, then the switching logic is started and step 3.3 is executed; otherwise, step 3.1 is executed. If the switching logic is started and the duration from the start of the switching logic to its completion exceeds t4s, a switching abnormality is reported, the switching logic is exited, and the adaptive bypass protection of line bay k is set to disabled.

[0034] Step 3.3: Automatically switch the analog and digital quantity acquisition circuits for the bypass protection of line bay k, stop acquiring the analog and digital quantities of the bypass protection, and after successful switching, the analog and digital quantity acquisition circuits for the line bay protection will operate normally, realizing the functions of distance protection, zero-sequence overcurrent protection, overcurrent protection in the overvoltage direction, and reclosing, and then execute step 3.4; if the switching fails, report an abnormality in the switching analog and digital quantity acquisition circuits, exit the switching logic, and set the adaptive bypass protection of line bay k to be disabled and the line bay protection to be blocked.

[0035] Step 3.4: The line bay protection uses its own tripping and closing circuit to drive the tripping and closing mechanism. When the circuit is normal, the line bay k adaptive bypass protection is set to the disabled state, and the switching quantity DO is... kena When the reactivation relay resets, it automatically disconnects the bypass protection tripping and closing circuit of line bay k and the longitudinal differential protection channel circuit of the bypass protection. The longitudinal differential protection is realized on both the local and opposite sides of the line bay, and step 3.5 is executed. If the tripping and closing circuit of the line bay protection itself is abnormal or the longitudinal current differential protection channel is abnormal, the switching logic is exited, the adaptive bypass protection of line bay k is disabled, and the line bay protection is blocked.

[0036] Step 3.5: Switching complete, line bay protection resumes normal operation and automatically sends protection information.

[0037] As a preferred option, in step 3.1, t3 = 0.03s; the value of t4 ranges from 10s to 3600s.

[0038] As a preferred option, the adaptive bypass protection independently sets and adjusts protection settings, control words, protection events, and alarm information according to line bay k, and maintains consistency with the line protection for bay k; the soft pressure plate S for line bay k bypass protection... k When exiting, the corresponding interval bypass protection settings and control words are automatically hidden, and protection events and alarm information are automatically masked to avoid accidental or incorrect modification of settings and control words and the transmission of invalid events or alarm messages.

[0039] As a preferred solution, the adaptive bypass protection is equipped with a CT polarity identification method word to ensure that the CT polarity of the bypass protection and the line bay protection is consistent, providing directional reference for distance protection, overcurrent protection in the overvoltage direction, and zero-sequence overcurrent protection, and adapting to the situation where the reference polarity of the bypass protection is inconsistent with the reference polarity of the line bay protection.

[0040] Beneficial effects: The adaptive bypass protection method for distribution network lines provided by this invention is mainly applied to medium and high voltage distribution network lines. It simplifies the complexity and risk of redundant configuration of distribution line protection, improves the feasibility and operational efficiency of uninterrupted maintenance of distribution line intervals, and ensures the reliability of power supply in the distribution system.

[0041] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0042] 1. Low investment cost and high reliability: It efficiently reuses the existing bus protection hardware and software architecture and resources, and integrates channel bypass and trip / close switching circuits as needed, resulting in low investment cost and outstanding economic efficiency; based on comprehensive judgment of actual operating conditions, the risk of errors and misoperations caused by human factors is small, and the reliability is high.

[0043] 2. Uninterrupted maintenance and highly targeted: It can adaptively replace any line bay protection device within the bus protection range according to actual needs, so as to achieve uninterrupted maintenance of line bay protection devices with faults or abnormalities.

[0044] 3. Highly adaptable and easy to operate: Based on multi-source information integrated decision-making, it can adaptively replace and withdraw; it can adapt to dual-sided and single-sided electrical quantity protection functions; it can adapt to protection devices with different sampling and tripping methods; it has comprehensive functions, simple structure, and convenient protection enabling / disabling and configuration settings.

[0045] 4. High scalability and simple maintenance: When the substation is renovated or expanded, the number of line bays within the bus protection range may increase or decrease. This can be achieved by adjusting the protection configuration information of the newly added or reduced line bays and adjusting the bypass and trip / close switching circuits. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the implementation method of adaptive bypass protection for distribution network lines according to the present invention.

[0047] Figure 2 This is a schematic diagram of the bypass protection channel bypass switching method of the present invention.

[0048] Figure 3 This is a schematic diagram of the adaptive bypass protection tripping and closing switching method of the present invention. Detailed Implementation

[0049] The present invention will be further described below with reference to specific embodiments.

[0050] like Figure 1As shown, the first embodiment of the present invention provides an adaptive bypass protection method for distribution network lines. In the current distribution network system configured with bus fault rapid clearing protection, it makes full use of existing resources. By adaptively tracking the operating status of line bays and the enable status changes of bay bypass protection within the distribution network bus protection area, and according to preset switching logic, it adaptively switches the analog and digital quantities of line bay protection and bay bypass protection, and adaptively switches the optical longitudinal channel circuit and bypass protection trip and close circuit of line bay protection and bypass protection. This achieves adaptive substitution and adaptive recovery of the double-sided and single-sided electrical quantity protection functions of one or more line bays within the distribution network bus protection area, solves the shortcomings of redundancy substitution or bypass substitution in the current distribution network system, and further improves the power supply reliability of the distribution system. This method is necessary, urgent, and feasible.

[0051] The analog and digital quantities of the adaptive switching bay bypass protection adopt the analog and digital quantities of the corresponding bay of the bus protection at the same voltage level within the station.

[0052] like Figure 2 As shown, the adaptive switching optical longitudinal channel loop for line bay protection and bypass protection includes multiple sets of optical bypassers. Each set of optical bypassers is connected to one line bay and the corresponding bay bypass protection, realizing the switching between one set of optical longitudinal channel for line bay protection and optical longitudinal channel for bay bypass protection. Each set of optical bypassers includes two input ports and two output ports. The bay bypass protection and the line bay protection local channel are connected through ports a (Txa, Rxa) and c (Txc, Rxc), respectively, and output through ports b (Rxb, Txb) and d (Rxd, Txd). Each set of optical bypassers has two working states: when the bay bypass protection is active, the optical bypasser switches to bypass mode, with port a as input and port d as output; when the line bay protection is operating normally, the optical bypasser operates in normal communication mode, with port c as input and port d as output for the line bay protection, and port a as input and port b as output for the bay bypass protection.

[0053] like Figure 3 As shown, the adaptive switching bypass protection trip and close circuit includes multiple sets of switching input, output circuits and operating circuits. Each set of switching input, output circuits and operating circuits realizes the trip and close output of one bay bypass protection.

[0054] Each group of switching input circuits in the bypass trip-close switching circuit is connected to the interval bypass protection trip, permanent trip, manual trip, and close signals, as well as the positive terminal of the control power supply, and is enabled by the switch quantity DO. kena The re-operating relay is connected to the input terminal of the operating circuit, and the output circuit is switched via the enable switch DO. kena The re-operation relay is connected to the output terminal of the operating circuit, and the closing coil, tripping coil, negative terminal of TWJ, negative terminal of HWJ and negative terminal of control power supply are connected out.

[0055] Step 1: Bypass protection is set up according to the line bay. In response to the change of the soft pressure plate of the distribution network bay bypass protection, the information of the line bay that needs to be bypassed is obtained. The analog quantity and switch quantity of the corresponding bay bypass protection are adaptively obtained, and the operation status of the corresponding distribution network line bay protection and the adaptive bypass protection enable status are determined.

[0056] Taking the distribution network busbar connected to N line bays as an example, the adaptive bypass protection implementation method for the k-th line bay is as follows:

[0057] Step 1.1: Obtain the bypass protection soft pressure plate S of the distribution network line bay k. k State, S k The bypass protection identifies the line bay k information and automatically obtains the corresponding analog quantity to replace the bus protection bay. and digital input / output (DI) ki DO ki N, k, and i are natural numbers; These are the bus voltage, line extraction voltage, zero-sequence voltage, phase current, and zero-sequence current required to achieve the bypass protection function of bay k; DI ki To achieve the bypass protection function of bay k, the required functional hard-press board, other protection inputs, low air pressure (spring not stored energy) closing weight, and reclosing lockout inputs are needed; DO ki It provides protection trip, permanent trip, manual trip, closing and protection action signals for the K-interval bypass protection.

[0058] Step 1.2: Obtain the circuit breaker position DI of line bay k. km To obtain the maintenance status, device alarms, DC power failure and other switch quantities (DI) of the line bay protection. kn Real-time tracking of the operating status of line bay protection, and the use of DI kn With DI kj The same source dual-channel switch input is used to ensure the reliability of the switch input and prevent related switch inputs from being mistakenly opened due to interference, which would lead to incorrect identification of the line interval protection operation status. m, n, and j are natural numbers.

[0059] Step 1.3: Integrated bypass protection soft pressure plate S k Engagement / Departure Status, Bypass Alternate Analog Quantities and and digital input / output (DI) ki With DO ki The adaptive bypass protection enable status is determined by collecting multi-source information such as the status of the data acquisition and the operating status of the line bay: S k Input, bypass replacement analog quantity and and digital input / output (DI) ki With DO kiThe acquisition circuit is normal, and the position of the line interval circuit breaker is DI. km When the switch is closed, the adaptive bypass protection of this line interval is enabled, entering hot standby mode, and triggering the enable switch DO. kean If any condition is not met, the adaptive bypass protection of the line bay is disabled, the adaptive bypass protection is blocked, and DO... kean Set to false.

[0060] Step 2: When it is determined that the line bay protection is in a fault, abnormal or maintenance state and the bay bypass protection is enabled, the analog and digital quantity acquisition circuits of the line bay protection are automatically switched to the bypass protection through preset switching logic. The longitudinal differential protection channel and trip / close circuit of the line bay are automatically switched to the bypass optical longitudinal channel switching circuit and the bypass trip / close switching circuit. The bay bypass protection completes the single-sided and double-sided electrical quantity protection logic of the line bay, realizing the adaptive replacement of the bypass protection.

[0061] The preset adaptive replacement switching logic includes the following steps:

[0062] Step 2.1: Any group of DI kn With DI kj Simultaneously, if the input quantity is 1 and the duration is t1s, the switching logic is started and step 2.2 is executed; if the duration from the start of the switching logic to completion exceeds t2s, a switching exception is reported, the switching logic is exited, and the line interval adaptive bypass protection is disabled.

[0063] Step 2.2: Automatically switch the analog quantity and switch quantity acquisition circuit of the bypass protection in line bay k. After successful switching, the analog quantity of the bypass protection will be used for data acquisition. and digital input / output (DI) ki DO ki The replacement line bay protection implements distance protection, zero-sequence overcurrent protection, overvoltage directional overcurrent protection and reclosing functions, and executes step 2.3; if the switching fails, it reports an abnormality in the switching analog quantity and switch quantity acquisition circuit, exits the switching logic, and disables the line bay adaptive bypass protection.

[0064] Step 2.3: Utilize the enable switch quantity DO kena The reactivation relay triggers the optical bypass device in the bypass optical longitudinal channel switching circuit, automatically switching the longitudinal differential protection channel circuit. After successful switching, the bypass protection analog signal... and digital input / output (DI) ki DO ki Analog quantity of protection device on the opposite side of the line bay and switch quantity DI′ ki DO′ kiThe longitudinal differential protection channel forms a longitudinal current differential protection, which replaces the line bay protection to realize longitudinal differential protection. Step 2.4 is executed. If the switching fails, an abnormality is reported in the longitudinal current differential protection channel, the longitudinal current differential protection function is blocked, the switching logic is exited, and the line bay adaptive bypass protection is disabled.

[0065] Step 2.4: Utilize the enable switch quantity DO kean The re-operation relay automatically switches the trip and close circuits. If the switch is successful, the bypass protection trip and close circuit replaces the line bay protection trip and close circuit, drives the trip and close mechanism to work, and executes step 2.5. If the switch fails, an abnormality in the trip and close circuit switching is reported, the switching logic is exited, and the line bay adaptive bypass protection is disabled.

[0066] Step 2.5: Switching complete. The bay bypass protection replaces the line bay protection and automatically sends protection information.

[0067] Furthermore, in step 2.1, t1 = 0.03s; the value of t2 ranges from 10s to 3600s.

[0068] Furthermore, in step 2.3, during the switching of the longitudinal differential protection channel circuit, the longitudinal current differential protection function of the corresponding line bay is locked; after the switching is successful and the data on both sides are synchronized, the longitudinal current differential protection function is opened.

[0069] Furthermore, in step 2.4, during the trip-close circuit switching process, the adaptive bypass protection function of the corresponding line bay is blocked.

[0070] Step 3: When maintenance or troubleshooting is completed and the line bay protection is operating normally, the bay bypass protection automatically switches the line bay analog and digital quantity acquisition circuits, longitudinal differential protection channel circuits, and trip and close circuits according to the preset switching logic, and exits the bay bypass protection replacement, so as to realize the bay protection adaptive recovery and re-evaluation.

[0071] The preset adaptive recovery handover logic includes the following steps:

[0072] Step 3.1: Track the change in the enabling status of the adaptive bypass protection during the operation of the alternative line bay protection. If there is no change in the enabling status, the adaptive bypass protection continues to operate and Step 3.2 is executed; when the enabling status changes to the de-enabling status, the adaptive bypass protection is deactivated and reassessed.

[0073] Step 3.2: Track the operating status of the line bay protection, all groups of DI kn With DI kjIf none of the input values ​​are 1 and the duration is t3s, and the line bay protection is operating normally after on-site confirmation of maintenance or fault resolution in accordance with the operating procedures, the switching logic will be initiated and step 3.3 will be executed; otherwise, step 3.1 will be executed. If the duration of the switching logic from initiation to completion exceeds t4s, a switching abnormality will be reported, the switching logic will be exited, and the line bay adaptive bypass protection will be disabled.

[0074] Step 3.3: Automatically switch the analog and digital acquisition circuits for the bypass protection of line bay k, stop acquiring the analog and digital quantities of the bypass protection, and after successful switching, the analog and digital acquisition circuits for the line bay protection will operate normally, realizing the functions of distance protection, zero-sequence overcurrent protection, overcurrent protection in the overvoltage direction and reclosing, and then execute step 3.4; if the switching fails, report an abnormality in the switching analog and digital acquisition circuits, exit the switching logic, and set the adaptive bypass protection of the line bay to be disabled and the line bay protection to be blocked.

[0075] Step 3.4: The line bay protection uses its own tripping and closing circuit to drive the tripping and closing mechanism. When the circuit is normal, the line bay k adaptive bypass protection is set to the disabled state, and the switching quantity DO is... kena When the reactivation relay resets, it automatically disconnects the trip and close circuit of the bypass protection of bay k and the longitudinal differential protection channel circuit of the bypass protection. The longitudinal differential protection is realized on the local and opposite sides of the line bay, and step 3.5 is executed. When the trip and close circuit of the line bay protection itself is abnormal or the longitudinal current differential protection channel is abnormal, the switching logic is exited, and the adaptive bypass protection of line bay k is disabled and the line bay protection is blocked.

[0076] Step 3.5: Switching complete, line bay protection resumes normal operation and automatically sends protection information.

[0077] Furthermore, in step 3.1, t3 = 0.03s; the value of t4 ranges from 10s to 3600s.

[0078] Furthermore, the adaptive bypass protection independently sets and adjusts protection settings, control words, protection events, and alarm information according to line bay k, and maintains consistency with the line protection for bay k; S k When exiting, the corresponding interval bypass protection settings and control words are automatically hidden, and protection events and alarm information are automatically masked to avoid accidental or incorrect modification of settings and control words and the transmission of invalid events or alarm messages.

[0079] Furthermore, the adaptive bypass protection is equipped with a CT polarity identification method word to ensure that the CT polarity of the bypass protection and the line bay protection is consistent, providing directional reference for distance protection, overcurrent protection in the overvoltage direction, and zero-sequence overcurrent protection, and adapting to the situation where the reference polarity of the bypass protection is inconsistent with that of the line bay protection.

[0080] A second embodiment of the present invention provides an adaptive bypass protection system for distribution network lines, characterized in that it includes a processor and a memory, wherein the processor is used to process instructions stored in the memory to implement the adaptive bypass protection method for distribution network lines.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An adaptive bypass protection method for distribution network lines, characterized in that: Includes the following steps: Step 1: Bypass protection is set up according to the line bay. In response to the change of the soft pressure plate of the distribution network bay bypass protection, the information of the line bay that needs to be bypassed is obtained. The analog and switch quantities of the corresponding bay bypass protection are adaptively obtained, and the operation status of the corresponding distribution network line bay protection and the adaptive bypass protection enable status are determined. Step 2: When it is determined that the line bay protection is in a fault, abnormal or maintenance state and the bay bypass protection is enabled, the analog and digital quantity acquisition circuits of the line bay protection are automatically switched to the bypass protection through preset switching logic. The longitudinal differential protection channel and trip / close circuit of the line bay are automatically switched to the bypass optical longitudinal channel switching circuit and the bypass trip / close switching circuit. The single-sided and double-sided electrical quantity protection logic of the line bay is completed by the bay bypass protection, realizing the adaptive replacement of the bypass protection. Step 3: When maintenance or troubleshooting is completed and the line bay protection is operating normally, the bay bypass protection automatically switches the line bay analog quantity and digital quantity acquisition circuit, longitudinal differential protection channel circuit, and trip and close circuit according to the preset switching logic, and exits the bay bypass protection replacement, so as to realize the bay protection adaptive recovery and re-evaluation. Step 1 includes: Step 1.1: Obtain the soft pressure plate for bypass protection of distribution network line bay k. State, when Upon activation, the bypass protection identifies the line bay k information and automatically obtains the analog and switching quantities corresponding to the bus protection bay to replace the analog voltage of the bypass protection in line bay k. Analog current Passing the exam Input switch quantity Output switch quantity ; Step 1.2: Obtain the first line interval k. Circuit breaker location Obtain the line interval protection of the same source dual path of the line interval k. A switch quantity and the j-th switch quantity Real-time tracking of the operating status of line bay protection; Step 1.3: Integrated line bay k bypass protection soft pressure plate On / off status, line bay k bypass protection analog quantity and and switch quantity The status of the data acquisition and the operating status of the line interval are used to determine the enable status of the adaptive bypass protection. The judgment conditions are as follows: (1) Investment; (2) Analog quantity and and switch quantity The data acquisition circuit is functioning normally. (3) Location of line bay circuit breakers Combination; When the above three conditions are met, the adaptive bypass protection of line bay k is enabled, enters hot standby, and triggers the enable switch quantity. ; If any condition is not met, the adaptive bypass protection of line bay k is disabled, and the adaptive bypass protection is blocked. Set to false; Step 2 includes: Step 2.1: Any group =true and =true simultaneously, and lasting for a duration s, switch logic start, execute step 2.2; the duration from switching logic start to completion exceeds When s, a switching error is reported, the switching logic is exited, and the adaptive bypass protection of the line interval k is disabled; true represents that the input quantity is 1. Step 2.2: Automatically switch the analog quantity and switch quantity acquisition circuit of the bypass protection in line bay k. After successful switching, the analog quantity of the bypass protection will be used for data acquisition. , and switch quantity The replacement line bay protection implements distance protection, zero-sequence overcurrent protection, overvoltage directional overcurrent protection and reclosing functions, and executes step 2.3; if the switching fails, it reports an abnormality in the switching analog quantity and switch quantity acquisition circuit, exits the switching logic, and sets the line bay k adaptive bypass protection to disabled. Step 2.3: Utilize enable switch input The reactivation relay triggers the optical bypass device in the bypass optical longitudinal channel switching circuit, automatically switching the longitudinal differential protection channel circuit. After successful switching, the bypass protection analog signal... , and switch quantity Analog quantity of protection device on the opposite side of the line bay , and switch quantity The longitudinal differential protection channel forms a longitudinal current differential protection, which replaces the line bay protection to realize longitudinal differential protection. Step 2.4 is executed. If the switching fails, an abnormality is reported in the longitudinal current differential protection channel, the longitudinal current differential protection function is locked, the switching logic is exited, and the adaptive bypass protection of line bay k is disabled. Step 2.4: Utilize enable switch signals The re-operation relay automatically switches the trip and close circuits. After a successful switch, the bypass protection trip and close circuit replaces the line bay protection trip and close circuit, drives the trip and close mechanism to work, and executes step 2.

5. If the switch fails, an abnormality is reported in the trip and close circuit switching, the switching logic is exited, and the line bay k adaptive bypass protection is disabled. Step 2.5: Switching complete. The bay bypass protection replaces the line bay protection and automatically sends protection information.

2. The adaptive bypass protection method for distribution network lines according to claim 1, characterized in that: In step 2.1, t1 = 0.03s; t2 ranges from 10s to 3600s.

3. The adaptive bypass protection method for distribution network lines according to claim 1, characterized in that: In step 2.3, during the switching of the longitudinal differential protection channel circuit, the longitudinal current differential protection function of the corresponding line bay is locked; after the switching is successful and the data on both sides are synchronized, the longitudinal current differential protection function is opened.

4. The adaptive bypass protection method for distribution network lines according to claim 1, characterized in that: In step 2.4, during the trip-close circuit switching process, the adaptive bypass protection function of the corresponding line bay is locked.

5. The adaptive bypass protection method for distribution network lines according to claim 1, characterized in that: Step 3 includes: Step 3.1: Track the change in the enabling status of the adaptive bypass protection during the operation of the alternative line bay protection. When the enabling status of the adaptive bypass protection does not change, the adaptive bypass protection continues to operate and steps 3.2 are executed. When the enabling status changes to the de-enabling status, the adaptive bypass protection is exited and reassessed. Step 3.2: Track the operating status of line bay protection, all groups =true and =true does not satisfy any of the conditions, and the duration is... s, and in accordance with the operating procedures, after on-site confirmation that the maintenance or fault troubleshooting is completed and the line bay protection is operating normally, the switching logic is initiated, and step 3.3 is executed; otherwise, step 3.1 is executed; if the switching logic is initiated, and the duration from the initiation of the switching logic to its completion exceeds When s, a handover error is reported, the handover logic is exited, and the adaptive bypass protection of line interval k is disabled; Step 3.3: Automatically switch the analog and digital quantity acquisition circuits for the bypass protection of line bay k, stop acquiring the analog and digital quantities of the bypass protection, and after successful switching, the analog and digital quantity acquisition circuits for the line bay protection will operate normally, realizing the functions of distance protection, zero-sequence overcurrent protection, overcurrent protection in the overvoltage direction, and reclosing, and then execute step 3.4; if the switching fails, report an abnormality in the switching analog and digital quantity acquisition circuits, exit the switching logic, and set the adaptive bypass protection of line bay k to be disabled and the line bay protection to be blocked. Step 3.4: The line bay protection uses its own tripping and closing circuit to drive the tripping and closing mechanism. When the circuit is normal, the line bay k adaptive bypass protection is set to the disabled state, and the switching quantity... When the reactivation relay resets, it automatically disconnects the bypass protection tripping and closing circuit of line bay k and the longitudinal differential protection channel circuit of the bypass protection. The longitudinal differential protection is realized on both the local and opposite sides of the line bay, and step 3.5 is executed. If the tripping and closing circuit of the line bay protection itself is abnormal or the longitudinal current differential protection channel is abnormal, the switching logic is exited, and the adaptive bypass protection of line bay k is disabled and the line bay protection is blocked. Step 3.5: Switching complete, line bay protection resumes normal operation and automatically sends protection information.

6. The adaptive bypass protection method for distribution network lines according to claim 5, characterized in that: In step 3.1, =0.03s; The value range is 10s-3600s.

7. The adaptive bypass protection method for distribution network lines according to claim 5, characterized in that: The adaptive bypass protection is set and adjusted independently according to the line interval k, including protection settings, control words, protection events, and alarm information, and is consistent with the line protection at interval k. Line bay k bypass protection soft pressure plate When exiting, the corresponding interval bypass protection settings and control words are automatically hidden, and protection events and alarm information are automatically masked to avoid accidental or incorrect modification of settings and control words and the transmission of invalid events or alarm messages.

8. The adaptive bypass protection method for distribution network lines according to claim 5, characterized in that: The adaptive bypass protection is equipped with a CT polarity identification method word to ensure that the CT polarity of the bypass protection and the line bay protection is consistent, providing directional reference for distance protection, overcurrent protection in the overvoltage direction, and zero-sequence overcurrent protection, and adapting to the situation where the reference polarity of the bypass protection is inconsistent with the reference polarity of the line bay protection.

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