An electrical five-protection locking circuit

Abstract

The present invention provides an electrical five-protection locking circuit, including a grounding knife locking circuit, a first isolating switch locking circuit on the bus side, a second isolating switch locking circuit, a third isolating switch locking circuit on the line side, and a temporary grounding knife locking circuit; in the first isolating switch locking circuit and the second isolating switch locking circuit, the first isolating switch split contact is connected to a common node through a temporary grounding knife locking circuit, and the second isolating switch split contact is connected to a common node through a temporary grounding knife locking circuit. The common node is the node where the first isolating switch split contact and the second isolating switch split contact are connected to the same place. When the temporary grounding knife is grounded, since the temporary grounding knife locking circuit is connected or disconnected according to the bus voltage, it can adaptively solve the technical problem of casualties and equipment damage caused by mistakenly closing the isolating switch of another energized bus when debugging the isolating switch of the current bus due to the lack of effective locking of the temporary ground wire.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment maintenance, and in particular to an electrical five-protection locking circuit. Background Art

[0002] The safety of power grids has put forward the requirements of "five protections" for electrical equipment, which clearly stipulates that electrical equipment with voltage levels of 110kV and above should give priority to the design principle of electrical anti-error interlocking. Therefore, setting electrical interlocks on the secondary circuit has become an effective and feasible means to prevent accidents such as human error. The switching operation should be carried out strictly in accordance with the prescribed power-off sequence, and it is strictly forbidden to close the knife switch with the ground wire.

[0003] like Figure 1 As shown, a certain line interval bus side is equipped with disconnectors 1G and 2G, wherein one end of the 1G disconnector is connected to the first bus section 1M, and the other end is connected to the 2G disconnector and then connected to the circuit breaker DL, one end of the 2G disconnector is connected to the second bus section 2M, and the other end is connected to the 1G disconnector; the 2G disconnector is connected to the 02G earthing knife and is an integrated structure, and at the same time, there is a mechanical interlocking relationship between the 2G disconnector and the 02G earthing knife, that is, when the 2G disconnector is in the closed position, the 02G earthing knife mechanical interlocking circuit control cannot be closed, on the other hand, when the 02G earthing knife is in the closed position, the 2G disconnector mechanical interlocking circuit control cannot be closed.

[0004] when Figure 1 When the 2G isolating switch on the bus side needs maintenance, first disconnect the bus interval, that is, disconnect the bus circuit breaker ML, disconnect its 1G isolating switch and 2G isolating switch, then cut off the power to the second section bus 2M, and take the maintenance interval out of operation, that is, disconnect the circuit breaker DL, put the 1G isolating switch, 2G isolating switch, and 4G isolating switch in the disconnected position, then close the 02G grounding knife and the grounding knife IIGD1 on the second section bus 2M, and ground both sides of the maintenance isolating switch 2G to ensure the safety of maintenance personnel.

[0005] when Figure 1 When the 1G isolating switch on the bus side needs maintenance, first disconnect the bus interval, that is, disconnect the bus circuit breaker ML, disconnect its 1G isolating switch and 2G isolating switch, then cut off the power to the first section bus 1M, and take the maintenance interval out of operation, that is, disconnect the circuit breaker DL, put the 1G isolating switch, 2G isolating switch, and 4G isolating switch in the disconnected position, then close the 02G grounding knife and the grounding knife IGD1 on the first section bus 1M, and ground both sides of the maintenance isolating switch 1G to ensure the safety of the maintenance personnel.

[0006] However, since the 1G and 2G disconnectors need to be checked for their closed and open states during maintenance and debugging, the 02G grounding knife needs to be separated when the switch needs to be closed. At this time, the grounding point between the 1G and 2G disconnectors will be lost, and personnel safety cannot be protected. Therefore, a temporary grounding wire needs to be added. Figure 2 L02G inside, L02G represents the temporary grounding knife, that is, at this time L02G temporary grounding knife should be closed (in the closed position).

[0007] However, the temporary grounding switch is not connected to the on-site electrical five-protection locking circuit (such as Figure 3 shown), in Figure 3 In the 1G control circuit, when the line-side disconnector 2G needs to be repaired and debugged, the 02G grounding knife is separated (in the open position). Since the DL contact, 02G contact, 04G1 contact, and 2G contact are all in the open position, the 1G control circuit can be unlocked and used. Misoperation may cause the 1G disconnector to close. Since the busbar 1M is energized, there are serious safety issues when the staff debugs the disconnector 2G at this time. It is often necessary to unlock the knife switch to debug it. The knife switch locking circuit cannot meet the needs of adaptive maintenance and is only suitable for traditional switching operations.

[0008] Therefore, due to the lack of effective locking of the temporary ground wire, casualties and equipment damage caused by mistakenly closing the disconnector of another energized bus when debugging the disconnector of the current bus has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0009] The embodiment of the present invention provides an electrical five-protection locking circuit, which is used to solve the technical problem that due to the lack of effective locking of the temporary ground wire, the disconnector of another energized bus is mistakenly closed when debugging the disconnector of the current bus, resulting in casualties and equipment damage. The locking circuit can also meet the needs of adaptive maintenance without any unlocking key.

[0010] In view of this, the present invention provides an electrical five-protection locking circuit, including a grounding knife locking circuit, a first isolating switch locking circuit on the bus side, a second isolating switch locking circuit, a third isolating switch locking circuit on the line side and a temporary grounding knife locking circuit;

[0011] In the first isolating switch locking circuit and the second isolating switch locking circuit, the first isolating switch position contact is connected to the common node through the temporary grounding knife locking circuit, and the second isolating switch position contact is connected to the common node through the temporary grounding knife locking circuit;

[0012] Wherein, the common node is a node where the first isolating switch branch contact and the second isolating switch branch contact are connected to the same place;

[0013] When the temporary grounding knife is grounded, the temporary grounding knife locking circuit is connected or disconnected according to the bus voltage.

[0014] Preferably, the temporary grounding switch locking circuit between the second isolating switch split contact and the common node comprises: a temporary grounding switch first closing contact and a first voltage contact;

[0015] The common node, the first closed contact of the temporary grounding switch, the first voltage contact and the second disconnector open contact are connected in sequence;

[0016] The first closed contact of the temporary grounding switch is connected or disconnected according to the grounding state of the temporary grounding switch, and the first voltage contact is connected or disconnected according to the voltage of the first busbar corresponding to the first isolating switch.

[0017] Preferably, the temporary grounding switch locking circuit between the first isolating switch split contact and the common node comprises: a temporary grounding switch first closed contact and a first voltage contact;

[0018] The common node, the second closed contact of the temporary grounding switch, the second voltage contact and the first open contact of the isolating switch are connected in sequence;

[0019] The second closed contact of the temporary grounding switch is connected or disconnected according to the grounding state of the temporary grounding switch, and the second voltage contact is connected or disconnected according to the voltage of the second busbar corresponding to the second isolating switch.

[0020] Preferably, the temporary grounding switch locking circuit between the second isolating switch branch contact and the common node further comprises: a temporary grounding switch first branch contact;

[0021] The branch formed by the first closed-position contact of the temporary grounding knife and the first voltage contact is connected in parallel with the first open-position contact of the temporary grounding knife.

[0022] Preferably, the temporary grounding switch locking circuit between the first isolating switch branch contact and the common node further comprises: a temporary grounding switch second branch contact;

[0023] The branch formed by the second closed-position contact of the temporary grounding knife and the second voltage contact is connected in parallel with the second open-position contact of the temporary grounding knife.

[0024] Preferably, each contact in the electrical five-protection locking circuit is derived from a relay contact.

[0025] Preferably, the first voltage contact and the second voltage contact are both from three-phase no-voltage relay contacts.

[0026] Preferably, the three-phase no-voltage relay detects the voltages of A630, B630, C630 and N600 on the busbars.

[0027] Preferably, when the voltages among A630, B630, C630 and N600 are all less than the adjustable low voltage setting 1, the three-phase no-voltage relay detects that the bus is no-voltage.

[0028] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0029] The present invention provides an electrical five-protection locking circuit, including a grounding knife locking circuit, a first isolating switch locking circuit on the bus side, a second isolating switch locking circuit, a third isolating switch locking circuit on the line side, and a temporary grounding knife locking circuit; in the first isolating switch locking circuit and the second isolating switch locking circuit, the first isolating switch split contact is connected to a common node through a temporary grounding knife locking circuit, and the second isolating switch split contact is connected to a common node through a temporary grounding knife locking circuit. The common node is the node where the first isolating switch split contact and the second isolating switch split contact are connected to the same place. When the temporary grounding knife is grounded, since the temporary grounding knife locking circuit is connected or disconnected according to the bus voltage, it can solve the technical problem of casualties and equipment damage caused by mistakenly closing the isolating switch of another energized bus when debugging the isolating switch of the current bus due to the lack of effective locking of the temporary ground wire, and can meet the needs of the locking circuit for adaptive maintenance and hanging of the temporary ground wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 This is the actual main wiring diagram on site;

[0032] Figure 2 This is the actual main wiring diagram after the temporary grounding wire is connected on site;

[0033] Figure 3 It is a structural diagram of an existing electrical five-protection locking circuit;

[0034] Figure 4 A schematic diagram of the structure of an embodiment of an electrical five-protection locking circuit provided by an embodiment of the present invention;

[0035] Figure 5It is a structural schematic diagram of a temporary grounding switch locking circuit between the second disconnector split contact and the common node;

[0036] Figure 6 It is a structural schematic diagram of a temporary grounding switch locking circuit between the first disconnector split contact and the common node;

[0037] Figure 7 Schematic diagram of the structure of the first voltage contact. DETAILED DESCRIPTION

[0038] The embodiment of the present invention provides an electrical five-protection locking circuit, which is used to solve the technical problem of casualties and equipment damage caused by mistakenly closing the disconnector of another energized bus when debugging the disconnector of the current bus due to the lack of effective locking of the temporary ground wire. The original practice of relying on unlocking for debugging is abandoned, and the locking circuit is adaptive.

[0039] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] See also Figure 4 An embodiment of an electrical five-protection locking circuit provided by the present invention includes: a temporary grounding knife locking circuit b, a temporary grounding knife locking circuit c, a grounding knife locking circuit, a first isolating switch locking circuit on the bus side, a second isolating switch locking circuit and a third isolating switch locking circuit on the line side.

[0041] It should be noted that Figure 4 Each contact point and Figure 2Each isolating switch and grounding knife in the embodiment of the present invention corresponds to each other. The first isolating switch locking circuit in the embodiment of the present invention includes: DL split contact, 02G split contact, 04G1 split contact, temporary grounding knife locking circuit b, 2G split contact, 2G closing contact and 1G control circuit. The second isolating switch locking circuit includes: DL split contact, 02G split contact, 04G1 split contact, temporary grounding knife locking circuit c, 1G split contact, 1G closing contact and 2G control circuit. The third isolating switch locking circuit includes: DL split contact, 02G split contact, 04G1 split contact, 04G2 split contact and 4G control circuit. There are three grounding switch locking circuits: (1) the circuit consisting of DL split contact, 1G split contact, 2G split contact, 4G split contact and 02G control circuit; (2) the circuit consisting of DL split contact, 1G split contact, 2G split contact, 4G split contact and 04G1 control circuit; (3) the circuit consisting of DK7 closing contact, YJS split contact, 4G split contact and 04G2 control circuit.

[0042] In the first isolating switch locking circuit and the second isolating switch locking circuit, the first isolating switch position contact (i.e., 1G position contact) is connected to the common node a through the temporary grounding knife locking circuit c, and the second isolating switch position contact (i.e., 2G position contact) is connected to the common node a through the temporary grounding knife locking circuit b.

[0043] The common node a is a node where the first isolating switch branch contact and the second isolating switch branch contact are connected to the same location.

[0044] When the temporary grounding knife is grounded, the temporary grounding knife locking circuit b or c is connected or disconnected according to the bus voltage, which can solve the technical problem of casualties and equipment damage caused by mistakenly closing the disconnector of another energized bus when debugging the disconnector of the current bus due to the lack of effective locking of the temporary grounding wire.

[0045] Furthermore, if Figure 5 As shown, the temporary grounding switch locking circuit b between the second isolating switch split contact and the common node a includes: a temporary grounding switch first closing contact k1, a first voltage contact k2 and a temporary grounding switch first split contact k3.

[0046] The common node a, the first closed contact k1 of the temporary grounding switch, the first voltage contact k2 and the open contact of the second isolating switch are connected in sequence.

[0047] The first closing contact k1 of the temporary grounding knife and the first voltage contact constitute a branch k2 which is connected in parallel with the first opening contact k3 of the temporary grounding knife.

[0048] The first closing contact k1 of the temporary grounding knife is connected or disconnected according to the grounding state of the temporary grounding knife. Figure 2 When the temporary grounding switch L02G is grounded, the first closed position contact k1 of the temporary grounding switch is connected, and disconnected if it is not grounded. The first voltage contact k2 is connected or disconnected according to the voltage of the first busbar corresponding to the first isolating switch, that is, Figure 2 When the busbar 1M voltage is lower than the set low voltage setting value 1, the first voltage contact k2 is connected, and when it is higher than the voltage setting value 2, it is disconnected. It should be noted that the judgment condition for the connection or disconnection of the first open position contact k3 of the temporary grounding knife is opposite to that of the first closed position contact k1 of the temporary grounding knife.

[0049] Furthermore, if Figure 6 As shown, the temporary grounding switch locking circuit c between the first isolating switch branch contact and the common node a includes: a temporary grounding switch second closing contact k4, a first voltage contact k5 and a second temporary grounding switch branch contact k6.

[0050] The common node a, the second closed contact k4 of the temporary grounding switch, the second voltage contact k5 and the open contact k6 of the first isolating switch are connected in sequence.

[0051] The branch formed by the second closing contact k4 of the temporary grounding knife and the second voltage contact k5 is connected in parallel with the second opening contact k6 of the temporary grounding knife.

[0052] Among them, the second closing contact k4 of the temporary grounding knife is connected or disconnected according to the grounding state of the temporary grounding knife, that is, Figure 2 When the temporary grounding switch L02G is grounded, the second closed position contact k4 of the temporary grounding switch is connected, and disconnected if not grounded. The second voltage contact k5 is connected or disconnected according to the voltage of the second busbar corresponding to the second isolating switch, that is, Figure 2 When the busbar 2M voltage is lower than the set low voltage setting value 1, the second voltage contact k5 is connected, and when it is higher than the voltage setting value 2, it is disconnected. It should be noted that the judgment condition for the connection or disconnection of the second open position contact k6 of the temporary grounding knife is opposite to that of the second closed position contact k4 of the temporary grounding knife.

[0053] Furthermore, each contact in the electrical five-protection locking circuit provided by the embodiment of the present invention is from an auxiliary contact or a relay contact. And the first voltage contact k2 and the second voltage contact k5 are both from three-phase voltage-free relay contacts. Figure 7 As shown (taking the first voltage contact k2 as an example), the three-phase no-voltage relay detects the voltage between A630, B630, C630 and N600 on the bus. When the voltage between A630, B630, C630 and N600 is less than the adjustable low voltage setting 1, the three-phase no-voltage relay detects that the bus is no voltage.

[0054] In this embodiment, it should be noted that the closed position contact means that the switch or grounding knife corresponding to the contact is in Figure 2If it is in the closed state, Figure 4 The closed contact in the open position is connected, and the open contact means that the switch or grounding knife corresponding to the contact is Figure 2 If it is in disconnected state, Figure 4 The closed contact in the circuit is connected.

[0055] The working process of an electrical five-protection locking circuit provided by the present invention is introduced below:

[0056] exist Figure 2 When the isolating switch 2G needs to be repaired and a temporary ground wire L02G needs to be installed, in order to operate the isolating switch 1G, due to the existence of the temporary grounding knife locking circuit b of the electrical five-protection locking circuit provided by the present invention, it is necessary to satisfy that both the "L02G closed position" and "bus 1M no voltage" contacts (i.e., the first closed position contact k1 of the temporary grounding knife and the first voltage contact k2) are connected, that is, when the temporary grounding knife L02G is grounded, it is necessary to satisfy that "the three phases of the first section bus 1M voltage transformer are all without electricity" to allow the operation of the 1G isolating switch. When the temporary grounding knife L02G is not grounded, the split contact of the temporary grounding knife L02G (the first split contact k3 of the temporary grounding knife) is connected to short-circuit the above-mentioned locking circuit to restore the state as shown in the figure. Figure 3 Normal locking wiring in. When the disconnector 2G needs to be repaired and a temporary ground wire L02G needs to be installed, in order to operate the disconnector 2G, the two contacts of "L02G closed" and "2M no voltage" (that is, the second closed contact k4 and the second voltage contact k5 of the temporary grounding knife) must be connected. That is, when the temporary grounding knife L02G is grounded, the "second busbar 2M voltage mutual inductance three-phase no electricity" must be met to allow the disconnector 2G to be operated. When the "temporary grounding knife L02G is not grounded", the split contact of the temporary grounding knife L02G (the second split contact k6 of the temporary grounding knife) is connected, short-circuiting the above-mentioned locking circuit to restore the state as shown in the figure. Figure 3 Normal latching wiring in.

[0057] Similarly, when the isolating switch 1G needs to be repaired and a temporary ground wire L02G needs to be installed, in order to operate the isolating switch 2G, due to the existence of the temporary grounding knife locking circuit c of the electrical five-protection locking circuit provided by the present invention, it is necessary to satisfy that both the "L02G closed position" and "2M no voltage" contacts (i.e., the second closed position contact k4 of the temporary grounding knife and the second voltage contact k5) are connected, that is, when the temporary grounding knife L02G is grounded, it is necessary to satisfy that "the three phases of the second busbar 2M voltage mutual inductance are all without electricity" to allow the isolating switch 2G to be operated. When the "temporary grounding knife L02G is not grounded", the temporary grounding knife L02G's split contact (the temporary grounding knife's second split contact k6) is connected to short-circuit the above-mentioned locking circuit to restore the state as shown in the figure. Figure 3Normal locking wiring in. When the disconnector 1G needs to be repaired and a temporary ground wire L02G needs to be installed, in order to operate the disconnector 1G, the two contacts of "L02G closed" and "bus 1M no voltage" (that is, the first closed contact k1 and the first voltage contact k2 of the temporary grounding knife) must be connected. That is, when the temporary grounding knife L02G is grounded, the "three phases of the first bus 1M voltage transformer are all without electricity" must be met to allow the operation of the 1G disconnector. When the temporary grounding knife L02G is not grounded, the split contact of the temporary grounding knife L02G (the first split contact k3 of the temporary grounding knife) is connected to short-circuit the above-mentioned locking circuit and restore the state as follows. Figure 3 Normal latching wiring in.

[0058] Therefore, through the electrical five-protection locking circuit provided by the present invention, when the "temporary grounding wire is in the access position", the corresponding isolating switch is allowed to be operated only when the corresponding bus three-phase voltage is not available. When the "temporary grounding wire is not in the access position", the newly added locking circuit is short-circuited to restore the original locking state without affecting other operations. An external unlocking circuit is also required. Therefore, the newly added locking circuit in this issue only works after the temporary grounding wire is put into use. It has good pertinence, can effectively prevent accidents of mistakenly closing the isolating switch with a temporary grounding wire, can also avoid mislocking, and is adaptive.

[0059] The present invention overturns the previous method of ensuring that the temporary grounding wire does not have malicious misoperation by manual management. Due to human factors, the wrong interval often occurs, and the method of malicious misoperation caused by manual unlocking will be transformed from human defense to technical defense. As long as the temporary grounding wire (that is, the temporary grounding knife in the present invention) is hung, the isolating switch on the bus side where the maintenance interval is energized, that is, the voltage relay is pressurized, will not be able to operate, and the occurrence of malicious misoperation will be eliminated, but the normal switching operation will not be affected in any way. This comprehensive anti-misoperation locking circuit using voltage and switch quantities has both adaptability and reliability.

[0060] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrical five-protection locking circuit, comprising a grounding switch locking circuit, a first isolating switch locking circuit on the bus side, a second isolating switch locking circuit and a third isolating switch locking circuit on the line side, characterized in that: Also includes: Temporary grounding knife locking circuit; In the first isolating switch locking circuit and the second isolating switch locking circuit, the first isolating switch position contact is connected to the common node through the temporary grounding knife locking circuit, and the second isolating switch position contact is connected to the common node through the temporary grounding knife locking circuit; Wherein, the common node is a node where the first isolating switch branch contact and the second isolating switch branch contact are connected to the same place; When the temporary grounding knife is grounded, the temporary grounding knife locking circuit is connected or disconnected according to the bus voltage; The temporary grounding switch locking circuit between the first isolating switch split contact and the common node comprises: a second closed contact of the temporary grounding switch, a second voltage contact and a second split contact of the temporary grounding switch; The common node, the second closed contact of the temporary grounding switch, the second voltage contact and the first open contact of the isolating switch are connected in sequence; The branch formed by the second closed contact of the temporary grounding knife and the second voltage contact is connected in parallel with the second open contact of the temporary grounding knife; The second closed-position contact of the temporary grounding knife is connected or disconnected according to the grounding state of the temporary grounding knife; The second voltage contact is connected or disconnected according to the voltage of the second busbar corresponding to the second isolating switch; The temporary grounding switch locking circuit between the second isolating switch split contact and the common node comprises: a temporary grounding switch first closing contact, a first voltage contact and a temporary grounding switch first split contact; The common node, the first closed contact of the temporary grounding switch, the first voltage contact and the second disconnector open contact are connected in sequence; The branch formed by the first closed contact of the temporary grounding knife and the first voltage contact is connected in parallel with the first open contact of the temporary grounding knife; The first closed-position contact of the temporary grounding knife is connected or disconnected according to the grounding state of the temporary grounding knife; The first voltage contact is connected or disconnected according to the voltage of the first bus corresponding to the first isolating switch.

2. The electrical five-protection locking circuit according to claim 1 is characterized in that: Each contact point in the electrical five-protection locking circuit is a contact point of a relay.

3. The electrical five-protection locking circuit according to claim 2 is characterized in that: The first voltage contact point and the second voltage contact point are both contacts of a three-phase no-voltage relay.

4. The electrical five-protection locking circuit according to claim 3 is characterized in that: The three-phase no-voltage relay detects the voltages of A630, B630, C630 and N600 on the busbars.

5. The electrical five-protection locking circuit according to claim 4 is characterized in that: When the voltages between A630, B630, C630 and N600 are all less than the adjustable low voltage setting 1, the three-phase no-voltage relay detects that the bus is no voltage.

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