WO2020078057A1

WO2020078057A1 - Online correction device and method for power cable cross connection

Info

Publication number: WO2020078057A1
Application number: PCT/CN2019/096565
Authority: WO
Inventors: 何邦乐; 李海; 范世峰; 王媚; 杨月仲; 陈佳; 叶志豪; 韩琴琴; 邹翔宇; 许印白; 陶冶林
Original assignee: 国网上海市电力公司
Priority date: 2018-10-17
Filing date: 2019-07-18
Publication date: 2020-04-23
Also published as: CN109412146B; CN109412146A

Abstract

Disclosed are an online correction device and method for power cable cross connection. Said device is connected to a cross-connection box, said device comprises an inner core connection mechanism, an outer core connection mechanism, an inner core series resistor, an outer core series resistor, a phase sequence switching mechanism, a grounding switching mechanism, an operation control mechanism and a grounding electrode; the inner core connection mechanism is configured to connect an inner core electrode of the cross-connection box; the outer core connection mechanism is configured to connect an outer core electrode of the cross-connection box; the inner core connection mechanism is respectively connected, inside the device, to the inner core series resistor and the grounding switching mechanism, the outer core connection mechanism is respectively connected to the outer core series resistor and the grounding switching mechanism, and the operation control mechanism is respectively connected to and controls the phase sequence switching mechanism and the grounding switching mechanism.

Description

Device and method for online correction of power cable cross interconnection

This application requires the priority of the Chinese patent application filed on October 17, 2018 with the Chinese Patent Office and the application number 201811209176.2. The entire contents of this application are incorporated by reference in this application.

Technical field

The present application relates to the field of power cable cross interconnection boxes, for example, to an online power cable cross interconnection correction device and method.

Background technique

As shown in Figure 1, power cables, especially cross-linked polyethylene (XLPE) cables, are provided with two cross-connect boxes in each three-section power cable line, and different phase sequences are realized through the built-in transposition row. The cross-interconnection between cable sheaths, correct and proper cross-interconnection transposition connection, can effectively suppress the influence of the sheath induced current and induced voltage, such as heating, insulation breakdown, etc. As shown in Figure 2, due to engineering quality and other reasons, the cross-connection of the power cable sheath will sometimes occur transposition connection errors, mainly including the wrong connection of the coaxial cable of the grounding line and the phase sequence connection of the transposition row. The vector sum of the induced electromotive force of the cable sheath is too large, thus forming a large sheath current, causing heat loss and insulation degradation failure. There are other faults that occur during operation, such as theft of transposition rows, etc., which will also have a certain impact on the cable system.

At present, for the treatment method of power cable cross interconnection fault faults, a more conservative approach is to stop the power supply of the cable line and modify the transposition row, which has a greater impact on power users, especially cables with higher voltage levels The line is more obvious; you can also disassemble the transposition bar for a short time when the safety protection measures are reliable during the wave valley period, so that the node goes out of suspension. At this time, the power consumption is small, and the induced voltage and current are also Smaller, usually will not cause obvious injury to the operator and cable system, unless emergency, it is generally not recommended to do so. It can be seen that the difficulty of online correction of power cable cross-interconnection faults is that the power supply current of the cable line is large, which makes the induced voltage and induced current of the sheath larger. When removing and installing the transposition row, a large arc and excessive The surge voltage has great harm to the operator and the cable system itself.

Summary of the invention

The present application overcomes the above-mentioned shortcomings of the related art, and provides a power cable cross-connect online correction device and method.

This application can be achieved through the following technical solutions:

A power cable cross-interconnection online correction device. The device is connected to a cross-interconnection box. The device includes an inner core connection mechanism, an outer core connection mechanism, an inner core series resistance, an outer core series resistance, a phase sequence switching mechanism, and a grounding switch Mechanism, operation control mechanism and ground electrode;

The inner core connection mechanism is set to connect the inner core electrode of the cross interconnection box; the outer core connection mechanism is set to connect the outer core electrode of the cross interconnection box; the phase sequence switching mechanism is set to switch the positive phase sequence, Three phase sequence states: reverse phase sequence and short-circuit grounding; the inner core connection mechanism connects the inner core series resistance and the ground switching mechanism inside the device, and the outer core connection mechanism connects the outer core series resistance and ground respectively In the switching mechanism, the operation control mechanism is respectively connected to and controls the phase sequence switching mechanism and the ground switching mechanism, and the phase sequence switching mechanism and the ground switching mechanism are respectively connected to the ground potential through the ground electrode.

In an embodiment, the inner core connection mechanism includes an A-phase clamp, a B-phase clamp, a C-phase clamp, an inner core connecting a three-phase cable and a three-phase terminal block;

One end of the A-phase clamp, B-phase clamp, and C-phase clamp are respectively connected to the inner core electrode of the cross-connect box, and the other end are respectively connected to the three live ends of the inner core to connect the three-phase cable; the inner core is connected to the three-phase cable The inner core series resistance and the grounding switching mechanism are respectively connected through the three-phase terminal block.

In an embodiment, the phase A clamp includes an insulated handle, a lower jaw, a double interlocking nut, an upper jaw, a limit bolt, a fastening bolt, an upper protruding surface, and a lower protruding surface;

The insulated handle is fixed on the lower jaw for the operator to hold the clamp; the limit bolt penetrates the upper jaw and rotates into the lower jaw; the double interlocking lock nut is composed of two nuts The interlocking structure is fixed on the limit bolt and placed between the lower jaw and the upper jaw. The double interlock lock nut is driven by the limit bolt to rotate synchronously; the fastening bolt runs through the upper The jaw is rotatably inserted into the lower jaw. The upper protruding surface is provided on the upper jaw. The lower protruding surface is provided on the lower jaw and opposite to the upper protruding surface.

In an embodiment, the A-phase clamp, the B-phase clamp and the C-phase clamp have the same structure; the inner core connection mechanism and the outer core connection mechanism have the same structure;

In an embodiment, the inner core series resistance and the outer core series resistance are both three-phase resistive loads.

In an embodiment, the phase sequence switching mechanism includes a phase sequence switching first core three-phase cable, a phase sequence switching second core three-phase cable, a positive phase switch, a reverse phase switch, and a phase sequence switching A grounding switch, phase sequence switching second grounding switch, positive phase sequence wiring, reverse phase sequence wiring, first short circuit ground wiring and second short circuit ground wiring;

The phase sequence switching first inner core three-phase cable is sequentially connected to the phase sequence switching second core three phase cable through the positive phase switch and the positive phase sequence wiring; the phase sequence switching first inner core three phase cable is sequentially passed The reverse phase switch and the reverse phase sequence wiring are connected to the phase sequence switching second core three-phase cable; the phase sequence switching first core three phase cable is connected to the first short-circuit grounding wiring through the phase sequence switching first ground switch The phase sequence switching second core three-phase cable is connected to the second short-circuit grounding wiring through the phase sequence switching second ground switch.

In an embodiment, the positive phase switch, the reverse phase switch, the phase-sequence switching first ground switch and the phase-sequence switching second ground switch are all three-pole contactors with a power-off delay relay.

In one embodiment, the model of the three-pole contactor with a power-off delay relay is LC1D65 with a LADR0, and the delay time of the power-off delay relay is set to 0.5 seconds.

In an embodiment, the positive phase sequence wiring includes a positive phase sequence A1 incoming line, a positive phase sequence B1 incoming line, a positive phase sequence C1 incoming line, a positive phase sequence A2 outgoing line, a positive phase sequence B2 outgoing line, and a positive phase sequence C2 Outgoing line, the positive phase sequence A1 incoming line is connected to the positive phase sequence B2 outgoing line, the positive phase sequence B1 incoming line is connected to the positive phase sequence C2 outgoing line, and the positive phase sequence C1 incoming line is connected to the positive phase sequence A2 outgoing line;

The reverse sequence connection includes reverse sequence A1 incoming line, reverse sequence B1 incoming line, reverse sequence C1 incoming line, reverse sequence A2 outgoing line, reverse sequence B2 outgoing line and reverse sequence C2 outgoing line, the The inversion sequence A1 incoming line is connected to the inversion sequence B2 outgoing line, the inversion sequence B1 incoming line is connected to the inversion sequence C2 outgoing line, and the inversion sequence C1 incoming line is connected to the inversion sequence A2 outgoing line;

The first short-circuit ground connection includes a first ground A1 line, a first ground B1 line and a first ground C1 line all connected to the ground, and the second short-circuit ground line includes a second ground connected to the ground A1 incoming line, second grounding B1 incoming line and second grounding C1 incoming line.

In an embodiment, the ground switching mechanism includes a ground switching first core three-phase cable, a ground switching second core three-phase cable, a ground switching first ground switch, and a ground switching second ground switch; The ground-switching first inner core three-phase cable is grounded through the ground switching first ground switch; the ground-switching second inner core three-phase cable is grounded through the ground switching second ground switch.

In an embodiment, the first ground switch and the second ground switch are three-pole contactors, and the model of the contactor is LC1D205.

In an embodiment, the operation control mechanism includes a positive power supply, a negative power supply, a connection control, a multi-select control, and a ground control;

The positive connection of the power supply is connected to the on control, and the on control outputs the on signal; the on signal is connected to the multiple choice one control, and the multiple choice one control outputs three signals, which are positive phase signals, respectively 1. A protective ground signal and an inverted signal; the protective ground signal is connected to the ground control, the on signal is connected to the ground control, and the ground control outputs a direct ground signal; the negative power supply provides the negative power supply for circuit operation The positive phase signal controls the normal phase switch, the reverse phase signal controls the reverse phase switch, and the protective ground signal simultaneously controls the phase sequence switching first ground switch and the phase sequence switching second ground switch The direct ground signal simultaneously controls the first ground switch and the second ground switch.

In one embodiment, the connection control includes a connection switch, a connection control relay, a connection control relay normally open contact a and a connection control relay normally open contact b; the power supply positive connection is connected One end of the switch is connected to the positive pole of the control relay, the negative pole of the control relay is connected to the negative pole of the power supply; the positive pole of the power supply is connected to one end of the normally open contact a of the control relay, and the other end is connected to the The positive pole of the control relay; the positive pole of the power supply is connected to one end of the normally open contact b of the control relay, and the other end outputs a turn-on signal.

In an embodiment, the grounding control includes an off switch, a grounding control first relay, a grounding control first relay normally closed contact a, a grounding switch, a grounding control second relay, a grounding control second relay normally open contact Point a and ground control the second relay normally open contact b; the above-mentioned turn-on signal controls the first relay normally closed contact a through grounding to connect to one end of the ground control second relay normally open contact a and the other end to ground control The positive pole of the second relay, the negative pole of the ground control second relay is connected to the negative pole of the power supply; the protective ground signal is connected to the ground through a ground switch to control the positive pole of the second relay; the protective ground signal is connected to the ground through an off switch The positive pole of the first relay is controlled, and the negative pole of the ground control first relay is connected to the negative pole of the power supply; the protective ground signal controls the normally open contact b of the second relay to output a direct ground signal through the ground.

A method for using the power cable cross-connect online correction device includes:

Disconnect the power supply of the power cable cross interconnection correction device, and the interior is in a floating state;

The power cable cross interconnection correction device is connected to the three inner core electrodes and the three outer core electrodes of the cross interconnection box through two sets of three-phase cables, so that the power cable cross interconnection correction device and the original cross interconnection box form a parallel access structure;

The power cable cross-interconnection correction device is powered on, and the internal default is in the state of series resistance grounding. Due to the current limiting effect of the series resistance, the arc at the time of connection is limited;

The power cable cross-interconnection correction device is switched to the direct grounding state, so that the inner and outer cores of the three-phase sheathed coaxial cable are grounded;

Under the direct grounding state, disassemble the transposition row of the original cross-connect box to make it in a floating state;

Whether the fault type is clarified. If the fault type is clarified, install the transposition bar (95) of the original cross-connect box (9) in the correct phase sequence. Due to the equipotentiality and no arc generated during the installation process, remove the power cable under the equipotential The process of cross interconnection correction device and its connecting cable is completed; if the type of fault is not clear, switch back to the series resistance grounding state;

In the state of series resistance, switch to positive phase sequence and negative phase sequence respectively, observe and record the voltage and current conditions, judge and switch to the correct cross interconnection phase sequence.

Compared with related technologies, this application has the following advantages:

1. Achieve online correction of the wrong connection of the coaxial cable of the cross-connect box;

2. For the structure of the cross-connected box, it is directly connected to the inner core fixture and the outer core fixture without damaging the original structure;

3. Provide universal fixtures, suitable for inner and outer core electrodes of different sizes;

4. The operation is simple, and the operation error correction function is set, which is not easy to damage the equipment or damage the personnel;

5. The series current-limiting resistor is provided as a buffer during switching, which effectively reduces the current when switching the phase sequence and suppresses the generation of arcs;

6. Provide a direct grounding state to ensure the safety of the operator and effectively suppress the generation of arcs;

7. A special circuit is designed to ensure that it can be directly grounded only in the state of series current-limiting resistance, which realizes the soft switching operation of the ground switching, and avoids the violent electrical parameters when the positive phase sequence or the reverse phase sequence is directly grounded. Variety;

8. A special circuit is designed to ensure that the direct grounding operation can be disconnected only when the current limiting resistance is connected in series, avoiding the direct grounding to positive phase sequence or reverse phase sequence is a drastic change in electrical parameters;

9. It provides the switching between positive phase sequence and reverse phase sequence, which can temporarily replace the function of the cross-connect box, and can be used for other grounding system performance research and other experimental research;

10. Adopt the power-off delay relay to assist, so that the phase sequence switching process is always in a non-suspended state, further suppressing the generation of contact arcs;

11. After switching to the correct phase sequence, install the transposition row under the condition of equipotentiality, no arc occurs;

12. It is easy to integrate and is conducive to product promotion.

Brief description of the drawings

Figure 1 shows the normal cross-connect structure;

Figure 2 is the structure after the grounding coaxial cable is misconnected;

3 is a block diagram of the composition of the power cable cross-interconnection correction device of the present application;

4 is a block diagram of the composition of the core connection mechanism of this application;

FIG. 5 is a structural diagram of a fixture of the present application;

6 is a block diagram of the composition of the phase sequence switching mechanism of the present application;

7 is a schematic diagram of the positive phase sequence wiring of this application;

FIG. 8 is a schematic diagram of the reverse sequence wiring of this application;

9 is a schematic diagram of the short-circuit ground connection of this application;

10 is a block diagram of the composition of the grounding switching mechanism of this application;

11 is a block diagram and connection diagram of the operation control mechanism of the present application.

1 is the inner core connection mechanism, 2 is the outer core connection mechanism, 3 is the inner core serial resistance, 4 is the outer core serial resistance, 5 is the phase sequence switching mechanism, 6 is the grounding switching mechanism, 7 is the operation control mechanism, 8 is a ground electrode, 9 is a cross-connect box, 91 is an inner core electrode, 92 is an outer core electrode, 101 is a phase A clamp, 102 is a phase B clamp, 103 is a phase C clamp, and 104 is an inner core connected to a three-phase cable. 105 is a three-phase terminal block, 1011 is an insulated handle, 1012 is a lower jaw, 1013 is a double interlocking nut, 1014 is an upper jaw, 1015 is a limit bolt, 1016 is a fastening bolt, and 1017 is an upper protruding surface. 1018 is the lower protruding surface, 501 is the phase sequence switching first core three-phase cable, 502 is the phase sequence switching second core three-phase cable, 503 is the positive phase switch, 504 is the reverse phase switch, and 505 is the phase sequence Switching the first ground switch, 506 is the phase sequence switching second ground switch, 507 is the positive phase sequence wiring, 508 is the reverse phase sequence wiring, 509 is the first short-circuit ground connection, 510 is the second short-circuit ground connection, 507A1 is Positive phase sequence A1 incoming line, 507B1 is positive phase sequence B1 incoming line, 507C1 is positive phase sequence C1 incoming line, 507A2 is positive phase sequence A2 outgoing line, 507 B2 is the positive phase sequence B2 outlet, 507C2 is the positive phase sequence C2 outlet, 508A1 is the reverse phase sequence A1 inlet, 508B1 is the reverse phase sequence B1 inlet, 508C1 is the reverse phase sequence C1 inlet, 508A2 is the reverse phase sequence A2 outlet , 508B2 is the out-of-phase sequence B2 outlet, 508C2 is the out-of-phase sequence C2 outlet, 509A1 is the first ground A1 inlet, 509B1 is the first ground B1 inlet, 509C1 is the first ground C1 inlet, 510A1 is the second ground A1 Incoming line, 510B1 is the second grounding B1 incoming line, 510C1 is the second grounding C1 incoming line, 601 is the ground switching first core three-phase cable, 602 is the ground switching second core three-phase cable, and 603 is the ground switching A grounding switch, 604 is the grounding switching second grounding switch, 701 is the power supply positive pole, 702 is the power supply negative pole, 703 is the on control, 704 is the multiple choice control, 705 is the ground control, 7033 is the on signal, 7041 It is a positive phase signal, 7042 is a protective ground signal, 7043 is a reverse phase signal, 7055 is a direct ground signal, 7031 is an on switch, 7032 is an on control relay, and 7032-1 is an on control relay normally open contact a, 7032-2 is the normally open contact b of the control relay, 7051 is the off switch, and 7052 is the ground control One relay, 7052-1 is the grounding control first relay normally closed contact a, 7053 is the grounding switch, 7054 is grounding control second relay, 7054-1 is the grounding control second relay normally open contact a, and 7054-2 is The grounding control second relay normally open contact b.

detailed description

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in this application, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

As shown in FIG. 3, a power cable cross-interconnection online correction device includes an inner core connection mechanism 1, an outer core connection mechanism 2, an inner core serial resistance 3, an outer core serial resistance 4, and a phase sequence switching mechanism 5 、 Ground switching mechanism 6, operation control mechanism 7 and ground electrode 8; the inner core connection mechanism 1 is set to connect the inner core electrode 91 of the cross interconnection box 9; the outer core connection mechanism 2 is set to connect the cross interconnection box The outer core electrode 92 of 9; the phase sequence switching mechanism 5 is set to switch three phase sequence states of positive phase sequence, reverse phase sequence and short circuit grounding; the inner core connection mechanism 1 is respectively connected to the inner core string inside the device Connect the resistance 3 and the grounding switching mechanism 6, the outer core connecting mechanism 2 connects the outer core serial resistance 4 and the grounding switching mechanism 6, the operation control mechanism 7 connects and controls the phase sequence switching mechanism 5 and the grounding switching respectively The mechanism 6, the phase sequence switching mechanism 5 and the ground switching mechanism 6 are connected to the ground potential through the ground electrode 8 respectively.

As shown in FIG. 4, the inner core connecting mechanism 1 includes an A-phase clamp 101, a B-phase clamp 102, a C-phase clamp 103, an inner core connecting a three-phase cable 104 and a three-phase terminal block 105, and the A-phase clamp 101. One end of the B-phase jig 102 and the C-phase jig 103 are connected to the inner core electrode 91 of the cross interconnection box 9, and the other end are respectively connected to the three live ends of the inner core connected to the three-phase cable 104; the inner core is connected to the three-phase cable 104 The three-phase terminal block 105 is respectively connected to the inner core serial resistance 3 and the ground switching mechanism 6.

As shown in FIG. 5, the A-phase clamp 101 includes an insulating handle 1011, a lower jaw 1012, a double interlocking nut 1013, an upper jaw 1014, a limit bolt 1015, a fastening bolt 1016, an upper protruding surface 1017 and The lower protruding surface 1018, the insulated handle 1011 is fixed on the lower jaw 1012 for the operator to hold the clamp; the limit bolt 1015 penetrates the upper jaw 1014, and is rotatably inserted into the lower jaw 1012; the double The interlocking nut 1013 is an interlocking structure composed of two nuts, fixed on the limit bolt 1015, and placed between the lower jaw 1012 and the upper jaw 1014. The double interlocking nut 1013 The synchronous rotation is driven by the limit bolt 1015; the fastening bolt 1016 passes through the upper jaw 1014 and is inserted into the lower jaw 1012 rotatably.

Turn the limit bolt 1015 to drive the double interlocking nut 1013, which provides the supporting force F1 to the upper jaw 1014; turn the tightening bolt 1016 to provide a pressing force F2 to the upper jaw 1014; the upper protruding surface 1017 and the lower The protruding surface 1018 clamps the target together.

During the entire operation process, the grip is held with an insulated handle 1011, and a wrench with an insulated handle is used to turn the bolt, which realizes electrical isolation during the operation process and protects the safety of the operator.

The A-phase clamp 101, the B-phase clamp 102 and the C-phase clamp 103 have the same structure; the inner core connection mechanism 1 and the outer core connection mechanism 2 have the same structure;

The inner core series resistance 3 and the outer core series resistance 4 are both three-phase resistance loads.

As shown in FIG. 6, the phase sequence switching mechanism 5 includes a phase sequence switching first inner core three-phase cable 501, a phase sequence switching second inner core three-phase cable 502, a positive phase switch 503, and a reverse phase switch 504 , Phase sequence switching first grounding switch 505, phase sequence switching second grounding switch 506, positive phase sequence wiring 507, reverse phase sequence wiring 508, first short circuit ground wiring 509 and second short circuit ground wiring 510; Phase sequence switching of the first inner core three-phase cable 501 is connected to the phase sequence switching second inner core three-phase cable 502 through the positive phase switch 503 and the positive phase sequence wiring 507 in sequence; the phase sequence switching first inner core three-phase cable 501 Connect the phase-sequence switching second core three-phase cable 502 through the phase-sequence switch 504 and the phase-sequence wiring 508 in sequence; the phase sequence switching first core three-phase cable 501 switches the first grounding switch through the phase sequence 505 is connected to the first short-circuit ground connection 509; the phase sequence switching second core three-phase cable 502 is connected to the second short circuit ground connection 510 through the phase sequence switching second ground switch 506.

The normal-phase switch 503, the reverse-phase switch 504, the phase-sequence switching first ground switch 505 and the phase-sequence switching second ground switch 506 are all three-pole contactors with a power-off delay relay.

The model of the three-pole contactor with power-off delay relay is LC1D65 with LADR0, and the delay time of the power-off delay relay is set to 0.5 seconds.

As shown in FIG. 7, the positive phase sequence wiring 507 includes a positive phase sequence A1 incoming line 507A1, a positive phase sequence B1 incoming line 507B1, a positive phase sequence C1 incoming line 507C1, a positive phase sequence A2 outgoing line 507A2, a positive phase sequence B2 Outgoing line 507B2 and positive phase sequence C2 outgoing line 507C2, the positive phase sequence A1 incoming line 507A1 is connected to the positive phase sequence B2 outgoing line 507B2, the positive phase sequence B1 incoming line 507B1 is connected to the positive phase sequence C2 outgoing line 507C2, the normal phase Sequence C1 incoming line 507C1 is connected to normal phase sequence A2 outgoing line 507A2.

As shown in FIG. 8, the reverse sequence wiring 508 includes reverse sequence A1 input line 508A1, reverse sequence B1 input line 508B1, reverse sequence C1 input line 508C1, reverse sequence A2 output line 508A2, reverse sequence B2 Outgoing line 508B2 and inversion sequence C2 outgoing line 508C2, the inversion sequence A1 incoming line 508A1 is connected to the inversion sequence C2 outgoing line 508C2, the inverting sequence B1 incoming line 508B1 is connected to the inversion sequence A2 outgoing line 508A2, the inverse The phase sequence C1 incoming line 508C1 is connected to the reverse phase sequence B2 outgoing line 508B2.

As shown in FIG. 9, the first short-circuit ground connection 509 includes a first ground A1 incoming line 509A1, a first ground B1 incoming line 509B1 and a first ground C1 incoming line 509C1, all of which are connected to ground. The ground wire 510 includes a second ground A1 incoming line 510A1, a second ground B1 incoming line 510B1, and a second ground C1 incoming line 510C1 all connected to ground.

As shown in FIG. 10, the ground switching mechanism 6 includes a ground switching first core three-phase cable 601, a ground switching second core three-phase cable 602, a ground switching first ground switch 603, and a ground switching second ground Switch 604; the first three-phase cable 601 of the grounding switch is grounded by the first grounding switch 603; the second three-phase cable 602 of the grounding switch is the second grounding switch 604 by the grounding Ground.

The first grounding switch 603 and the second grounding switch 604 are three-pole contactors, and the model of the contactor is LC1D205.

As shown in FIG. 11, the operation control mechanism 7 includes a power supply positive electrode 701, a power supply negative electrode 702, a connection control 703, a multiple selection control 704, and a ground control 705; the power supply positive electrode 701 is connected to the connection control 703, so The turn-on control 703 outputs a turn-on signal 7033; the turn-on signal 7033 is connected to a multiple-select one control 704, and the multiple-select one control 704 outputs three signals, which are a normal-phase signal 7041 and a protective ground signal 7042, respectively. And the inverted signal 7043; the protective ground signal 7042 is connected to the ground control 705, the turn-on signal 7033 is connected to the ground control 705, and the ground control 705 outputs a direct ground signal 7055; the negative power supply 702 provides a circuit Working power supply negative pole; the normal phase signal 7041 controls the normal phase switch 503, the reverse phase signal 7043 controls the reverse phase switch 504, and the protective ground signal 7042 simultaneously controls the phase sequence switching of the first ground switch 505 and the phase sequence switching second ground switch 506; the direct ground signal 7055 controls the ground switching first ground switch 603 and the ground switching second ground switch 604 at the same time.

Only when the protective ground signal 7042 is valid, the ground control 705 will act; the effectiveness of the direct ground signal 7055 is not affected by the failure of the protective ground signal 7042.

The connection control 703 includes a connection switch 7031, a connection control relay 7032, a connection control relay normally open contact a7032-1 and a connection control relay normally open contact b7032-2; the power supply positive pole 701 is connected Connect one end of the switch 7031, the other end is connected to the positive pole of the control relay 7032, the negative pole of the connection control relay 7032 is connected to the negative power supply 702; the positive power supply 701 is connected to the normally open contact a7032- of the control relay At one end of 1, the other end is connected to the positive pole of the control relay 7032; the positive pole 701 of the power supply is connected to one end of the normally open contact b7032-2 of the control relay, and the other end outputs the on signal 7033.

The connection control 703 realizes that after the device is powered on, when no operator closes the connection switch 7031, the connection signal 7033 cannot be generated, so that the device is always in a suspended state, and the device is electrically isolated from the original cross-connect system. The safety of personnel.

The ground control 705 includes an off switch 7051, a ground control first relay 7052, a ground control first relay normally closed contact a7052-1, a ground switch 7053, a ground control second relay 7054, and a ground control second relay normally open The contact a7054-1 and the ground control second relay normally open contact b7054-2; the above-mentioned turn-on signal 7033 connects the ground control first relay normally closed contact a7052-1 to the ground control second relay normally open contact a7054 -1, the other end is connected to the positive pole of the ground control second relay 7054, and the negative pole of the ground control second relay 7054 is connected to the negative power supply 702; the protective ground signal 7042 is connected to the ground control second relay through a ground switch 7053 The positive pole of 7054; the protective ground signal 7042 is connected to the positive pole of the first relay 7052 through the grounding switch 7051, and the negative pole of the ground control first relay 7052 is connected to the negative pole of the power supply 702; the protective ground signal 7042 is passed The ground control second relay normally open contact b7054-2 outputs a direct ground signal 7055.

When the multi-select control 704 selects the output protection ground signal 7042 to be effective, the self-locking function formed by the wiring of the second relay normally open contact a7054-1 of the ground control, and the ground control of the second relay normally open contact a7054-1 The signal comes from the ground control first relay normally closed contact a7052-1 and the turn-on signal 7033, so that after closing the ground switch 7053, the ground control second relay 7054 always maintains the action mode, at this time no matter which one of the multiple control 704 selects any output The signal, the direct ground signal 7055 is always kept in an effective state, which avoids the occurrence of misoperation, thereby protecting the safety of the operator, especially when disassembling the transposition row, it must be ensured that it is always grounded.

Similarly, in the operation of disconnecting the direct grounding state, only when the closing switch 7051 is closed, and the multi-select control 704 selects to output the protective ground signal 7042, can the grounding control the first relay normally closed contact a7052-1, Furthermore, the self-locking function of the normally open contact a7054-1 of the second relay for ground control is cut off, and the direct ground signal 7055 is invalidated. The error correction function of the misoperation in the directly grounded state is realized, and the drastic change of the electrical parameters from the directly grounded state to the positive phase sequence or the reverse phase sequence is avoided, thereby ensuring the reliability of the device.

The principle of the application method of the correction device in this application: a cross-connection system using a power cable cross-interconnection correction device and the original cross-interconnection box 9 connected in parallel to the power cable, and the induced voltage of the transposition box of the interconnection box is greatly reduced by switching to the direct ground state The operator, at the same time, the induced current is mainly passed through the temporarily connected power cable cross-interconnection correction device, forming a short-circuit effect on the transposition row, effectively reducing the arc when the transposition row is disassembled, after replacing the original cross interconnection box 9 Switching the positive phase sequence and the reverse phase sequence to restore the correct cross-interconnection state of the interconnection system, so that the installation of the transposition row is in an equipotential state and thus eliminates the arc.

The power cable cross interconnection correction device is connected to the three inner core electrodes 91 and the three outer core electrodes 92 of the cross interconnection box 9 through two sets of three-phase cables, so that the power cable cross interconnection correction device and the original cross interconnection box 9 are composed Parallel access structure;

The power cable cross-interconnection correction device is switched to the direct grounding state, so that the inner and

outer cores

93 and 94 of the three-phase sheathed grounding coaxial cable are in the grounding state;

Under the direct grounding state, remove the transposition row 95 of the original cross interconnection box 9 to make it in a floating state; whether the fault type is clear, if the fault type is clear, install the replacement of the original cross interconnection box (9) in the correct phase sequence Position (95), due to the equipotentiality and no arcing during the installation process, in the equipotential state, remove the power cable cross interconnection correction device and its connecting cable, the process ends; if the type of failure is not clear, switch back to serial connection Resistance grounding state;

Claims

A power cable cross-interconnection online correction device, which is connected to a cross-interconnection box (9), and includes an inner core connection mechanism (1), an outer core connection mechanism (2), an inner core serial resistance (3), and an outer core string Connect resistance (4), phase sequence switching mechanism (5), ground switching mechanism (6), operation control mechanism (7) and ground electrode (8);

The inner core connection mechanism (1) is configured to connect the inner core electrode (91) of the cross interconnection box (9); the outer core connection mechanism (2) is configured to connect the outer core electrode of the cross interconnection box (9) (92); the phase sequence switching mechanism (5) is set to switch three phase sequences of positive phase sequence, reverse phase sequence and short circuit to ground; the inner core connection mechanism (1) is connected to the inner core in the device respectively Series resistance (3) and ground switching mechanism (6), the outer core connection mechanism (2) connects the outer core serial resistance (4) and ground switching mechanism (6), the operation control mechanism (7) ) Connect and control the phase sequence switching mechanism (5) and the ground switching mechanism (6) respectively. The phase sequence switching mechanism (5) and the ground switching mechanism (6) are respectively connected to the ground potential through the ground electrode (8).
The device according to claim 1, wherein the inner core connecting mechanism (1) includes an A-phase clamp (101), a B-phase clamp (102), a C-phase clamp (103), and an inner core connecting a three-phase cable ( 104) and three-phase terminal block (105);

One end of the A-phase jig (101), B-phase jig (102), and C-phase jig (103) are respectively connected to the inner core electrode (91) of the cross-connect box (9), and the A-phase jig (101) , The other ends of the B-phase clamp (102) and the C-phase clamp (103) are respectively connected to the three live ends of the inner core connection three-phase cable (104); the inner core connection three-phase cable (104) passes through the three-phase terminal block (105) Connect the inner core serial resistance (3) and the ground switching mechanism (6) respectively.
The device according to claim 2, wherein the phase A clamp (101) includes an insulated handle (1011), a lower jaw (1012), a double interlocking nut (1013), and an upper jaw (1014) , Limit bolt (1015), fastening bolt (1016), upper protruding surface (1017) and lower protruding surface (1018);

The insulated handle (1011) is fixed on the lower jaw (1012) for the operator to hold the clamp; the limit bolt (1015) penetrates the upper jaw (1014) and is rotatably inserted into the lower jaw (1012) ; The double interlocking nut (1013) is an interlocking structure composed of two nuts, fixed on the limit bolt (1015), and placed in the lower jaw (1012) and the upper jaw (1014) Between, the double interlocking lock nut (1013) is driven by a limit bolt (1015) to rotate synchronously; the tightening bolt (1016) penetrates the upper jaw (1014) and rotates to insert into the lower jaw ( 1012), the upper protruding surface (1017) is provided on the upper jaw (1014), and the lower protruding surface (1018) is provided on the lower jaw (1012) and opposite to the upper protruding surface (1017).
The device according to claim 3, wherein the A-phase clamp (101), the B-phase clamp (102) and the C-phase clamp (103) have the same structure; the inner core connecting mechanism (1) and the outer The core connection mechanism (2) has the same structure.
The device according to claim 1, wherein the inner core series resistance (3) and the outer core series resistance (4) are both three-phase resistive loads.
A power cable cross-connect online correction device according to claim 1, wherein the phase sequence switching mechanism (5) includes a phase sequence switching first inner core three-phase cable (501), a phase sequence switching second inner Core three-phase cable (502), normal phase switch (503), reverse phase switch (504), phase sequence switch first ground switch (505), phase sequence switch second ground switch (506), normal phase Sequence wiring (507), reverse sequence wiring (508), first short-circuit ground connection (509) and second short-circuit ground connection (510);

The phase-sequence switching first inner core three-phase cable (501) is connected to the phase-sequence switching second core three-phase cable (502) in sequence through a positive phase switch (503) and a positive phase sequence wiring (507); Phase sequence switching of the first inner core three-phase cable (501) in turn through an inverting switch (504) and inverting sequence wiring (508) to connect the phase sequence switching of the second inner core three-phase cable (502); Phase-switching first inner core three-phase cable (501) is connected to the first short-circuit grounding wiring (509) through the phase-sequence switching first ground switch (505); the phase sequence switching second inner-core three-phase cable (502) The second short-circuit ground connection (510) is connected through the phase sequence switching second ground switch (506).
The device according to claim 6, wherein said normal phase switch (503), reverse phase switch (504), phase sequence switching first ground switch (505) and phase sequence switching second ground switch (506) All three-pole contactors are equipped with a power-off delay relay.
The device according to claim 7, wherein the model of the three-pole contactor with a power-off delay relay is LC1D65 with a LADR0, and the delay time of the power-off delay relay is set to 0.5 seconds.
The device according to claim 6, wherein the positive phase sequence wiring (507) includes a positive phase sequence A1 incoming line (507A1), a positive phase sequence B1 incoming line (507B1), a positive phase sequence C1 incoming line (507C1 ), The positive phase sequence A2 outlet (507A2), the positive phase sequence B2 outlet (507B2) and the positive phase sequence C2 outlet (507C2), the positive phase sequence A1 inlet (507A1) is connected to the positive phase sequence B2 outlet (507B2), The positive phase sequence B1 incoming line (507B1) is connected to the positive phase sequence C2 outgoing line (507C2), and the positive phase sequence C1 incoming line (507C1) is connected to the positive phase sequence A2 outgoing line (507A2);

The reverse-phase sequence wiring (508) includes reverse-phase sequence A1 incoming line (508A1), reverse-phase sequence B1 incoming line (508B1), reverse-phase sequence C1 incoming line (508C1), reverse phase sequence A2 outgoing line (508A2), The reverse sequence B2 outlet (508B2) and the reverse sequence C2 outlet (508C2), the reverse sequence A1 incoming line (508A1) is connected to the reverse sequence B2 outgoing line (508B2), and the reverse sequence B1 incoming line (508B2) 508B1) connected to the outgoing line of the reverse phase sequence C2 (508C2), and the incoming line of the reversed phase sequence C1 (508C1) is connected to the outgoing line of the reverse phase sequence A2 (508A2);

The first short-circuit grounding connection (509) includes a first grounding A1 incoming line (509A1), a first grounding B1 incoming line (509B1) and a first grounding C1 incoming line (509C1) all connected to ground. The two short-circuit ground connection (510) includes a second ground A1 incoming line (510A1), a second ground B1 incoming line (510B1) and a second ground C1 incoming line (510C1) all connected to ground.
The device according to claim 1, wherein the ground switching mechanism (6) includes a ground switching first core three-phase cable (601), a ground switching second core three-phase cable (602), a ground switching A ground switch (603) and a ground switch second ground switch (604); the ground switch first inner core three-phase cable (601) is grounded through the ground switch first ground switch (603); the The ground switching second core three-phase cable (602) is grounded through the ground switching second ground switch (604).
The device according to claim 10, wherein the ground switching first ground switch (603) and the ground switching second ground switch (604) are both three-pole contactors, and the model of the contactor is LC1D205.
The device according to claim 1, wherein the operation control mechanism (7) includes a power supply positive electrode (701), a power supply negative electrode (702), a turn-on control (703), a multiple selection control (704) and a ground control (705);

The positive power supply (701) is connected to the on-control (703), and the on-control (703) outputs an on-signal (7033); the on-signal (7033) is connected to a multi-select control (704) , The multiple selection one control (704) outputs three signals, which are a positive phase signal (7041), a protective ground signal (7042) and a reverse phase signal (7043); the protective ground signal (7042) is connected to ground Control (705), the on signal (7033) is connected to the ground control (705), the ground control (705) outputs a direct ground signal (7055); the negative power supply (702) provides power for circuit operation Negative pole; the positive phase signal (7041) controls the normal phase switch (503), the reverse phase signal (7043) controls the reverse phase switch (504), and the protective ground signal (7042) also controls the phase Sequence switching first ground switch (505) and phase sequence switching second ground switch (506); the direct ground signal (7055) simultaneously controls the ground switching first ground switch (603) and ground switching second ground Switcher (604).
The device according to claim 12, wherein the on-control (703) includes an on-switch (7031), an on-control relay (7032), an on-control relay normally open contact a (7032-1) And the normally open contact b (7032-2) of the control relay; the positive pole (701) of the power supply is connected to one end of the switch (7031), and the other end is connected to the positive pole of the control relay (7032), the Connect the negative pole of the control relay (7032) to the negative pole of the power supply (702); the positive pole (701) of the power supply is connected to one end of the normally open contact a (7032-1) of the control relay, and the other end is connected to the control relay (7032-1) The positive pole of 7032); the positive pole of the power supply (701) is connected to one end of the normally open contact b (7032-2) of the control relay, and the other end outputs a turn-on signal (7033).
The device according to claim 12, wherein the ground control (705) includes an off switch (7051), a ground control first relay (7052), a ground control first relay normally closed contact a (7052-1 ), Ground switch (7053), ground control second relay (7054), ground control second relay normally open contact a (7054-1) and ground control second relay normally open contact b (7054-2); The above-mentioned turn-on signal (7033) connects the first relay normally closed contact a (7052-1) to the ground control second relay normally open contact a (7054-1) at one end, and the other end connects to the ground control second The positive pole of the relay (7054), the negative pole of the ground control second relay (7054) is connected to the negative pole of the power supply (702); the protective ground signal (7042) is connected to the ground control second relay (7054) through a ground switch (7053) ); The protective ground signal (7042) is connected to the positive pole of the ground control first relay (7052) through the off switch (7051), and the negative pole of the ground control first relay (7052) is connected to the negative pole of the power supply (702) ); The protective ground signal (7042) controls the second relay normally open contact by grounding b (7054-2) directly to ground output signal (7055).
A method for adopting the power cable cross-connect online correction device according to any one of claims 1 to 14, comprising:

Disconnect the power supply of the power cable cross interconnection correction device, and the interior is in a floating state;

The power cable cross interconnection correction device is connected to three inner core electrodes (91) and three outer core electrodes (92) of the cross interconnection box (9) through two sets of three-phase cables, so that the power cable cross interconnection correction device and The original cross interconnection box (9) forms a parallel access structure;

The power cable cross-interconnection correction device is powered on, and the internal default is in the state of series resistance grounding. Due to the current limiting effect of the series resistance, the arc at the time of connection is limited;

The power cable cross interconnection correction device is switched to the direct grounding state, so that the inner and outer cores (93) and (94) of the three-phase sheathed grounding coaxial cable are in the grounding state;

When the power cable cross interconnection correction device is in the direct grounding state, remove the transposition row (95) of the original cross interconnection box (9) to make it in a floating state;

Whether the type of fault is clarified, in the case of clarifying the type of fault, in accordance with the correct phase sequence, install the transposition row (95) of the original cross-connect box (9), due to the equipotential and no arc generated during the installation process, under the equipotential state, Remove the power cable cross interconnection correction device and its connecting cable, and the process ends;

In the case of unclear fault type, switch back to the series resistance grounding state;

In the state of series resistance, switch to positive phase sequence and negative phase sequence respectively, observe and record the voltage and current conditions, judge and switch to the correct cross interconnection phase sequence.