Line protection device with short lead protection function

Abstract

The utility model provides a line protection device with a short lead protection function, which relates to the technical field of substation operation protection and comprises a line protection device body and a short lead protection module. The short lead protection module is integrated in the line protection device body; the line protection device body comprises a line protection module, the line protection module is used for inputting a line protection function when a line runs, and the short lead protection module is used for inputting a short lead protection function when the line is not put into operation and needs to run in series; the line protection module and the short lead protection module are switched on and off through the protection function pressing plate. According to the scheme, line protection before and after the line is put into operation can be realized in a low construction cost and labor cost mode.

Description

Technical Field

[0001] The utility model relates to the technical field of substation operation protection, in particular to a line protection device with a short lead protection function. Background Art

[0002] In the application of the 3 / 2 breaker wiring form in the actual power grid construction project, the engineering design will be planned and constructed according to all complete strings in the long term. Considering economy, protection is usually not configured for the transition period. However, considering that the actual progress of the substation supporting projects will not be exactly the same during the construction process, especially the line intervals generally will not be all constructed at the initial stage. For example, a certain line will not be planned to be installed at the initial stage of construction. Therefore, in the actual construction process, it is generally carried out in phases. At the initial stage, it is designed and constructed according to an incomplete string. In the middle stage, it is expanded into a hybrid wiring of an incomplete string and a complete string. Only in the later stage is it all built into a complete string, and the line commissioning often lags behind the substation interval construction.

[0003] However, due to the situation that the line cannot be commissioned simultaneously with the local substation, during the period before the line is commissioned, the two adjacent breakers of the line interval must be closed-loop operated to maintain the string. If the short lead protection is not configured, there will be a protection dead zone between the two breakers of the line, which will lead to the inability to operate in series and affect the reliable operation of the power grid. If short lead protection equipment is configured during the transition period, not only is it necessary to invest extra in purchasing dedicated short lead protection equipment and expand the building area, but also the short lead protection equipment needs to be successively removed after each line is commissioned, which greatly increases the construction cost and labor cost. Summary of the Utility Model

[0004] In view of this, aiming at the above deficiencies, it is necessary to propose a line protection device with a short lead protection function to realize the line protection before and after the line is commissioned at a low construction cost and labor cost.

[0005] The utility model provides a line protection device with a short lead protection function, including: a line protection device body and a short lead protection module; the short lead protection module is integrated in the line protection device body; the line protection device body includes: a line protection module, which is used to input the line protection function when the line is commissioned in series, and the short lead protection module is used to input the short lead protection function when the line is not commissioned in series; both the line protection module and the short lead protection module are switched on and off through protection function pressure plates.

[0006] Preferably, the line protection device body includes: a housing, a display module and a keying module, and the display module and the keying module are arranged on the front surface of the housing in an embedded manner;

[0007] The display module is used to display the corresponding status and monitoring data;

[0008] The keying module includes an up key, a down key, a left key, a right key, an increase key, a decrease key, a confirmation key, a cancellation key, and a reset key, so that the operator can adjust and select according to needs.

[0009] Preferably, the line protection device body further includes an acquisition module and a main control module;

[0010] The acquisition module is used to acquire the CT current of each current transformer between the I terminal and the II terminal in the line, and upload the acquired current signal to the main control module;

[0011] The main control module is used to determine the operating mode of the current line according to the current signal; wherein, the operating mode includes a transmission line operating mode and a short lead operating mode.

[0012] Preferably, when the current line is in the transmission line operating mode and the short lead protection function is enabled, the main control module is further used to give an alarm prompt through the display module.

[0013] Preferably, when the current line is in the short lead operating mode and the line protection function is enabled, the main control module is further used to give an alarm prompt through the display module.

[0014] Preferably, the line protection device body further includes an alarm indication module;

[0015] The alarm indication module includes an operating indicator light, an abnormal indicator light, a maintenance indicator light, a longitudinal connection protection blocking indicator light, a charging completion indicator light, a protection trip indicator light, and a reclosing indicator light arranged on the front of the housing, so as to give alarm indications for the corresponding states.

[0016] Preferably, the line protection device body further includes an Ethernet interface arranged on the front of the housing, which is used for debugging the device.

[0017] Preferably, ear plates are further arranged on both sides of the housing, and mounting holes are provided on the ear plates for fixedly installing the device.

[0018] Preferably, a plug-in module is arranged on the back of the housing, and the plug-in module includes: a regulated power supply, an input plug-in, a trip plug-in, a signal plug-in, an interface plug-in, a process layer interface plug-in, and an AC plug-in.

[0019] Preferably, the line protection device body is a high-voltage line protection device.

[0020] As can be seen from the above technical solutions, the line protection device with short lead protection function provided by the present utility model includes a line protection device body and a short lead protection module, and the short lead protection module can be integrated into the line protection device body; the body of the line protection device includes a line protection module that can input the protection function when the line is put into operation in series, and the short lead protection module can input the short lead protection function when the line is not put into operation in series. In this way, through this protection device, during the transition process of the line interval expanding from an incomplete string to a complete string, the short lead protection function can be input in the early stage, and the line protection function can be input after the construction of the complete string is completed, so as to realize the protection before and after the line is put into operation. Moreover, by integrating the short lead protection module into the line protection device, there is no need to invest extra in purchasing dedicated short lead protection equipment, nor to expand the building area. After the line is put into operation in series, the line protection function can be directly put into operation, and there is no need to remove the short lead protection equipment, thus greatly reducing the construction cost and labor cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of short lead protection.

[0022] Figure 2 It is a schematic diagram of line protection in Mode 1.

[0023] Figure 3 It is a schematic diagram of line protection in Mode 2.

[0024] Figure 4 It is a schematic diagram of line protection in Mode 3.

[0025] Figure 5 It is a schematic diagram of a line protection device with short lead protection function provided by the present utility model.

[0026] Figure 6 It is a schematic diagram of the plug-in of the line protection device with short lead protection function provided by the present utility model.

[0027] In the figure: housing 1, display module 2, keying module 3, alarm indication module 4, Ethernet interface 5, ear plate 6, mounting hole 7, regulated power supply 8, input plug-in 9, trip plug-in 10, signal plug-in 11, interface plug-in 12, process layer interface plug-in 13, AC plug-in 14. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0029] A short lead refers to the lead between the disconnecting switch belonging to the circuit breaker between two circuit breakers and the incoming / outgoing line disconnecting switch or the infrastructure reserved connection point in the main wiring of power plants or substations with 3 / 2 breaker wiring, bridge-type wiring, and extended unit wiring. The short lead protection is mainly used for protecting this section of the lead. For example, in the 3 / 2 breaker wiring, when the line or transformer connected between two adjacent circuit breakers in a string is out of service, to ensure the reliability of power supply, the two adjacent string switches are still required to be closed in loop to maintain the string. In this case, since the line protection has been withdrawn, a short section of the connection between the two circuit breakers becomes a dead zone for protection. Therefore, a short lead protection is set up to selectively cut off the faults between the two circuit breakers. For example, when L1 is not put into operation, its protection range is as Figure 1 shown by the dashed box. In the figure, TV1, TV2, TV3, and TV4 are all voltage transformers, CTM, CTM1, CTN1, and CTN are all current transformers, and QF1, QF2, and QF3 are all circuit breakers.

[0030] In the actual power grid construction project application of the 3 / 2 wiring form, the engineering design will plan and construct according to all complete strings in the long term. Considering economy, usually no short lead protection is configured for the transition period. However, during the construction process, considering that the actual progress of the substation supporting projects will not be exactly the same, especially the line intervals generally will not be all constructed at the initial stage. For example, Figure 1 the L1 line is not planned to be installed at the initial stage of construction. Therefore, the actual project construction generally proceeds in stages. It is designed and constructed as an incomplete string at the initial stage, expanded into a mixed wiring of incomplete strings and complete strings in the middle stage, and all completed into complete strings in the later stage.

[0031] The occurrence of the situation where the line interval cannot be put into operation simultaneously with the local substation leads to a dead zone for protection between the two circuit breakers of the line interval during this transition period before the line is put into operation, and they cannot be operated in a string, seriously affecting the reliable operation of the power grid.

[0032] In the actual project application, in order to enable the equipment to operate in a loop and form a string in the above situation and increase the reliability of the power grid, the following three methods are usually adopted to solve the problem:

[0033] Method 1: As shown in the Figure 2 schematic diagram, connect the middle circuit breaker to the bus protection to expand the bus protection range and include the short lead area in the bus protection range, thus solving the problem of short lead area protection during the transition period.

[0034] However, when adopting Method 1, the L1 line interval is not put into operation in the initial stage of construction. It is necessary to use the disconnector circuit breaker QF2 as an interval of Bus I. Correspondingly, the CT of the disconnector circuit breaker QF2 needs to be introduced into the bus protection of Bus I. At the same time, the tripping circuit of the Bus I bus protection needs to introduce the operation circuit of the circuit breaker. If the L1 line interval is put into operation in the later stage, when restoring the 3 / 2 breaker connection to the normal operation mode of a complete string, on-site circuit transformation from an incomplete string to a complete string is required. At this time, the side circuit breaker QF1 needs to be used as an interval of Bus I. For a conventional substation, the corresponding circuit breaker current circuit and tripping secondary circuit need to be changed. For an intelligent substation, it involves re-changing the process layer configuration file and conducting necessary transmission tests on the corresponding changed secondary circuits or virtual terminals for verification. The above transformation work is generally carried out when the substation is already in operation. Due to the limitation that primary equipment cannot be powered off, it is usually necessary to withdraw two sets of protection devices in turn for circuit test verification for protection devices such as buses, circuit breakers, and line protection. There are quite significant risks in on-site circuit transformation work.

[0035] Method 2: As Figure 3 shown in the schematic diagram, the optical differential protection of the line protection is used as the temporary short lead protection. The optical differential protection is set to the self-loop mode, and the sum current is used as the action criterion.

[0036] However, although Method 2 can also solve the problem of the protection dead zone between the two circuit breakers when L1 is not put into operation, the prerequisite for adopting Method 2 is that the protection on the L1 side is optical differential protection. Since the current action criterion is the sum current of two adjacent circuit breakers, in the case of the self-loop mode, there is only the operating current and no restraining current for the differential protection. Therefore, the ratio restraint function cannot be realized. At the same time, in this protection mode, on the one hand, it is necessary to adjust the channel optical fiber wiring of the line optical differential protection, and on the other hand, it is also necessary to adjust the setting value of the line optical differential protection. In fact, it is difficult to set the protection action setting value under this working condition, and there are also risks such as the protection malfunction cannot be blocked when the TA is disconnected, thus affecting the reliability of this temporary short lead protection.

[0037] Method 3: As Figure 4 shown, a dedicated short lead protection device is added.

[0038] Although when adopting Method 3, the problem of the protection dead zone between the two circuit breakers when L1 is not put into operation can be solved. However, when adopting Method 3, it is necessary to invest additional funds to purchase dedicated short lead protection equipment. At the same time, it is necessary to consider adding corresponding screen positions during the design stage of the relay protection cubicle. Therefore, the building area will be expanded, resulting in a certain amount of investment waste. Moreover, these short lead protection screens need to be removed one after another after each outgoing line interval is put into operation.

[0039] Based on this, considering that the line protection of the local line interval in the 3 / 2 breaker connection mode is an essential equipment, it is considered to integrate the short lead protection function into this essential line protection. During the transition process of expanding the line interval from an incomplete string to a complete string, the short lead function can be only enabled in the early stage, and the line protection function can be enabled after the completion of the construction of the complete string. For the two function modes that can be switched, when the function mode is switched, since there is no change in the secondary circuit, a large number of high-risk modification and verification tests on site during the expansion process can be avoided, reducing the safety pressure of on-site secondary work; since it can be switched to the dedicated short lead function and cooperate with the preset short lead function setting value, the action reliability of the short lead protection can be effectively guaranteed; moreover, since the short lead protection and the line protection function are integrated together, there is no need to additionally add equipment, and there is no need to remove the equipment after the line is put into operation in series, increasing the labor cost. Specifically, as Figures 5-6 shown, the present utility model provides a line protection device with a short lead protection function, including: a line protection device body and a short lead protection module; the short lead protection module is integrated in the line protection device body; the line protection device body includes: a line protection module, which is used to enable the line protection function when the line is put into operation in series, and the short lead protection module is used to enable the short lead protection function when the line is not put into operation in series; both the line protection module and the short lead protection module are switched on and off through protection function pressure plates.

[0040] In this embodiment, the line protection device body may include a housing 1, a display module 2 and a keying module 3, and the display module 2 and the keying module 3 are arranged on the front surface of the housing 1 in an embedded manner;

[0041] The display module 2 is used to display the corresponding status and monitoring data;

[0042] The keying module 3 includes an up key, a down key, a left key, a right key, an increase key, a decrease key, an enter key, a cancel key and a reset key, so that the operator can adjust and select according to needs.

[0043] The display module 2 can adopt a large-screen 320*240 liquid crystal display screen, which can be designed in a menu mode using the Windows operating system. For example, the primary menu can include: information viewing, operation, report query, setting value setting, debugging menu, printing, etc. For example, the secondary menu corresponding to the primary menu information viewing can include protection status, viewing setting values, pressure plate status, version information, device settings, etc. For the tertiary menu of the secondary menu protection status, it can include analog quantity, digital quantity, GOOSE status, pilot channel information, alarm information, protection function status, etc.

[0044] As for the input module 3, it can be a 9-key keyboard, which includes an up key, a down key, a left key, a right key, an increase key, a decrease key, a confirmation key, a cancel key and a reset key, for performing corresponding input operations. For example, the increase key can be used to select a number increase, select a time synchronization mode, a soft pressure plate, the switching of control words and the selection of an outlet circuit breaker, and can be used to switch the main interface during normal operation.

[0045] Furthermore, the line protection device body also includes an alarm indication module 4;

[0046] The alarm indication module 4 includes an operation indicator light, an abnormality indicator light, a maintenance indicator light, a longitudinal protection locking indicator light, a charging completion indicator light, a protection tripping indicator light and a reclosing indicator light arranged on the front side of the housing 1, for providing alarm indications for the corresponding states.

[0047] In this embodiment, the operation indicator light is used to monitor the operation status of the protection CPU. It is always green during normal operation and goes out when the device fails. The abnormal indicator light is used to indicate that an abnormal situation has occurred in the device. It is extinguished during normal operation and lights up red when the protection is partially locked. The maintenance indicator light is used to indicate the working status of the device. It is extinguished during normal operation and lights up red when the protection is in maintenance status. The longitudinal protection lock indicator light is used to indicate the working status of the longitudinal protection. It is extinguished during normal operation and lights up red when the longitudinal protection is locked. The charging completion indicator light is used to indicate the charging status of the reclosing switch. It goes out when the reclosing switch is discharging and lights up green when the reclosing switch is fully charged. The protection tripping indicator light is used to indicate the tripping exit of the protection device. It is extinguished during normal operation and lights up red when a line fault occurs. The reclosing indicator light is used to indicate the reclosing exit of the protection device. It is extinguished during normal operation and lights up red when the reclosing switch is actuated.

[0048] In one embodiment, the line protection device body further includes an Ethernet interface 5 disposed on the front side of the housing 1 for debugging personnel to debug the device.

[0049] In order to conveniently fix and install the device at a corresponding position, ear plates 6 are further provided on both sides of the housing 1 , and mounting holes 7 are opened on the ear plates 6 for fixing and installing the device.

[0050] In addition, the line protection device provided by the present solution can adopt a plug-in structure of a rear plug-in board. For example, a plug-in module can be further provided on the back of the housing 1, and the plug-in module includes: a voltage stabilizer 8, an input plug-in 9, a trip plug-in 10, a signal plug-in 11, an interface plug-in 12, a process layer interface plug-in 13 and an AC plug-in 14. For example, Figure 6As shown, the plug-in model of the regulated power supply 8 is NDY302, the plug-in model of the process layer interface plug-in 13 is NPU303, the plug-in model of the input plug-in 9 is NKR302, the plug-in model of the trip plug-in 10 is NCK306, the plug-in model of the signal plug-in 11 is NXH304, the plug-in model of the interface plug-in 12 is NTX307, and the plug-in model of the AC plug-in 14 is NJL307.

[0051] In one embodiment, the line protection device body further includes an acquisition module and a main control module;

[0052] The acquisition module is used to acquire the CT currents of each current transformer between the I terminal and the II terminal in the line, and upload the acquired current signals to the main control module;

[0053] The main control module is used to determine the operation mode of the current line according to the current signals; wherein, the operation modes include the transmission line operation mode and the short lead operation mode.

[0054] Furthermore, the main control module is further used to give an alarm prompt through the display module 2 when the current line is in the transmission line operation mode and the short lead protection function is enabled. The main control module is also used to give an alarm prompt through the display module 2 when the current line is in the short lead operation mode and the line protection function is enabled.

[0055] In this embodiment, the line protection input function integrated with the short lead during operation is consistent with the operation mode of the primary line, avoiding possible incorrect actions and unnecessary alarms. In the transmission line operation mode, if the short lead protection function is enabled, an alarm prompt can be given; or in the short lead operation mode, if the line protection function is enabled, an alarm prompt is given, which can timely detect and take corresponding countermeasures when incorrect actions occur, reducing the damage caused by incorrect actions.

[0056] In addition, in one embodiment, the line protection device body can be a high-voltage line protection device, which can implement the line protection function, and integrate the short lead protection function on the basis of this device. For example, the short lead protection hard pressure plate terminal is integrated in the input loop of the device.

[0057] In summary, the line protection device with the short lead protection function provided by the present utility model has at least the following beneficial effects:

[0058] (1) The line protection device with the integrated short lead protection function can well solve the short lead protection problem existing during the switching of the 3 / 2 breaker connection from an incomplete string to a complete string, and better exert the advantages of high reliability, good operation flexibility, and convenient operation and maintenance of the 3 / 2 breaker connection method.

[0059] (2) On the basis of the existing line protection device, the utility model integrates the short lead protection. Without adding additional equipment, the short lead protection function can be realized, which can reduce the overall investment of the substation, reduce the operation and maintenance risks, improve the power supply reliability, and has good economic and social benefits.

[0060] The modules or units in the device of the embodiment of the utility model can be combined, divided and deleted according to actual needs. The above-disclosed is only the preferred embodiment of the utility model, and of course, the scope of the rights of the utility model cannot be limited by this. Those of ordinary skill in the art can understand all or part of the processes of the above embodiments, and the equivalent changes made according to the claims of the utility model still fall within the scope covered by the utility model.

Claims

1. A line protection device with short lead protection function, characterized in that: include: Line protection device body and short lead protection module; The short lead protection module is integrated into the line protection device body; The line protection device body comprises: a line protection module, which is used to activate the line protection function when the line is put into operation in a string, and the short lead protection module is used to activate the short lead protection function when the line is not put into operation in a string; the line protection module and the short lead protection module are both activated and deactivated by a protection function pressure plate.

2. The line protection device with short lead protection function according to claim 1, characterized in that: The line protection device body comprises: a housing, a display module and a key-in module, wherein the display module and the key-in module are arranged on the front side of the housing; The display module is used to display the corresponding status and monitoring data; The input module includes an up key, a down key, a left key, a right key, an increase key, a decrease key, a confirmation key, a cancel key and a return key, so that the operator can adjust and select according to needs.

3. The line protection device with short lead protection function according to claim 2, characterized in that: The line protection device body also includes a collection module and a main control module; The acquisition module is used to acquire the CT current of each current transformer between the I end and the II end in the line, and upload the acquired current signal to the main control module; The main control module is used to determine the operation mode of the current line according to the current signal; wherein the operation mode includes a transmission line operation mode and a short lead operation mode.

4. The line protection device with short lead protection function according to claim 3, characterized in that: The main control module is also used to issue an alarm prompt through the display module when the current line is in the transmission line operation mode and the short lead protection function is put into use.

5. The line protection device with short lead protection function according to claim 3, characterized in that: The main control module is also used to issue an alarm prompt through the display module when the current line is in the short-lead operation mode and the line protection function is activated.

6. The line protection device with short lead protection function according to claim 2, characterized in that: The line protection device body also includes an alarm indication module; The alarm indication module includes an operation indicator light, an abnormality indicator light, a maintenance indicator light, a longitudinal protection lock indicator light, a charging completion indicator light, a protection trip indicator light and a reclosing indicator light, which are arranged on the front side of the shell, so as to provide alarm indications for each corresponding state.

7. The line protection device with short lead protection function according to claim 2, characterized in that: The line protection device body also includes an Ethernet interface arranged on the front side of the shell body for debugging the device.

8. The line protection device with short lead protection function according to claim 2, characterized in that: Ear plates are also arranged on both sides of the shell, and mounting holes are opened on the ear plates for fixing and installing the device.

9. The line protection device with short lead protection function according to claim 2, characterized in that: A plug-in module is arranged on the back of the shell, and the plug-in module includes: a voltage-stabilized power supply, an input plug-in, a trip plug-in, a signal plug-in, an interface plug-in, a process layer interface plug-in and an AC plug-in.

10. The line protection device with short lead protection function according to any one of claims 1 to 9, characterized in that: The line protection device body is a high-voltage line protection device.

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