Intelligent control junction box for on-line transformation ratio conversion of three-phase current transformer

Abstract

The utility model provides a three-phase current transformer transformation ratio on-line conversion intelligent control junction box which comprises lead sealing screws, a transparent insulation top cover, wiring copper column fixing screws, a junction box body, voltage wiring copper columns, input end wiring copper columns, output end wiring copper columns, hexagonal supporting copper columns, common end wiring copper columns, a transformation ratio switching control system circuit board and fixing screws. A control and acquisition aviation plug terminal, a transformation ratio state indicating lamp, and a junction box bottom shell. The method has the beneficial effects that the transformation ratio of the mutual inductor is switched under the condition of uninterruptible power supply, so that the operation efficiency of a power system is greatly improved, and the inconvenience of a user is reduced; when the large transformation ratio and the small transformation ratio are switched, secondary open circuit of the mutual inductor is avoided, and electric power accidents caused by secondary open circuit of the mutual inductor are avoided; complex mechanical structures and electrical circuits are avoided, the manufacturing cost and the maintenance difficulty of equipment are reduced, and the reliability and the stability of the equipment are improved.

Description

Technical Field

[0001] The present invention relates to the electromechanical field, and particularly to an intelligent control junction box for on-line conversion of the transformation ratio of a three-phase current transformer. Background Art

[0002] In the current electric energy metering system, the commonly used current transformer design mainly focuses on a single or limited dual transformation ratio (usually a two-fold transformation ratio) configuration, which is designed for electric energy metering under rated load conditions. After such a transformer is installed, its transformation ratio is fixed and cannot be adjusted online. Since directly replacing the transformation ratio involves open-circuit operation on the secondary side, which poses a major threat to the safety of the power grid, live operation is strictly prohibited. According to national standards such as "JJG 313-2010 Current Transformers for Measurement" and "JJG 1021-2007 Power Transformers", S-class current transformers can ensure the linear stability of the error limit within the range of 20% to 120% of the rated current. Beyond this range, the error increases significantly.

[0003] In the face of application scenarios with drastic fluctuations in load such as wind power, hydropower, and seasonal loads (such as heating periods, periodic production enterprises, etc.), the load change may span several times to dozens of times, far exceeding the design range of traditional transformers, resulting in inaccurate metering due to under-load leakage or over-range metering at high loads, which not only affects the metering accuracy but also exacerbates energy waste.

[0004] To address this challenge, adding multiple metering systems can partially alleviate the problem. However, this not only increases land occupation, equipment investment, and operation and maintenance complexity, but also introduces additional failure risk points, and does not conform to the current metering technical specifications and economic benefit principles.

[0005] Although composite dual or multi-ratio current transformers have been adopted by some power management departments, their transformation ratio conversion process still requires power outage operations, involving complex re-wiring processes, which are not only inefficient but also increase the user's power outage time and economic costs, and are not conducive to the continuous and stable operation of the power system. Summary of the Invention

[0006] The present invention proposes an intelligent control junction box for on-line conversion of the transformation ratio of a three-phase current transformer, which solves the above problems in the prior art.

[0007] The technical solution of the present invention is realized as follows:

[0008] The intelligent control junction box for on-line conversion of the transformation ratio of the three-phase current transformer described in the present invention includes:

[0009] Sealing screw, transparent insulating top cover, wiring copper column fixing screw, junction box body, voltage wiring copper column, input terminal wiring copper column, output terminal wiring copper column, hexagonal support copper column, common terminal wiring copper column, turns ratio switching control system circuit board, fixing screw, control and acquisition aviation plug terminal, turns ratio status indicator light, junction box bottom shell;

[0010] The junction box body has 13 holes on each of the left and right sides. The left side is the input terminal, numbered R1 - R13, and the right side is the output terminal, numbered C1 - C13;

[0011] The voltage wiring copper column includes the first voltage wiring copper column, the second voltage wiring copper column, the third voltage wiring copper column, and the fourth voltage wiring copper column, and is set at the corresponding positions of the holes R1 - C1, R5 - C5, R9 - C9, and R13 - C13 of the junction box body;

[0012] The input terminal wiring copper column includes the first input terminal wiring copper column, the second input terminal wiring copper column, the third input terminal wiring copper column, the fourth input terminal wiring copper column, the fifth input terminal wiring copper column, and the sixth input terminal wiring copper column, and is set at the corresponding positions of the holes R2, R3, R6, R7, R10, and R11 of the junction box body;

[0013] The output terminal wiring copper column includes the first output terminal wiring copper column, the second output terminal wiring copper column, the third output terminal wiring copper column, the fourth output terminal wiring copper column, the fifth output terminal wiring copper column, and the sixth output terminal wiring copper column, and is set at the corresponding positions of the holes C2, C3, C6, C7, C10, and C11 of the junction box body;

[0014] The common terminal wiring copper column includes the first common terminal wiring copper column, the second common terminal wiring copper column, and the third common terminal wiring copper column, and is set at the corresponding positions of the holes R4 - C4, R8 - C8, and R12 - C12 of the junction box body;

[0015] The input terminal wiring copper column and the output terminal wiring copper column are drilled and tapped at their middle positions;

[0016] The hexagonal support copper column is tapped at its top, and includes the first hexagonal support copper column, the second hexagonal support copper column, the third hexagonal support copper column, the fourth hexagonal support copper column, the fifth hexagonal support copper column, the sixth hexagonal support copper column, the seventh hexagonal support copper column, the eighth hexagonal support copper column, and the ninth hexagonal support copper column;

[0017] Among them, the first hexagonal support copper column is fixedly connected to the first input terminal connection copper column, the second hexagonal support copper column is fixedly connected to the second input terminal connection copper column, the third hexagonal support copper column is fixedly connected to the third input terminal connection copper column, the fourth hexagonal support copper column is fixedly connected to the fourth input terminal connection copper column, the fifth hexagonal support copper column is fixedly connected to the fifth input terminal connection copper column, and the sixth hexagonal support copper column is fixedly connected to the sixth input terminal connection copper column; the seventh hexagonal support copper column is fixedly connected to the second output terminal connection copper column; the eighth hexagonal support copper column is fixedly connected to the fourth output terminal connection copper column, and the ninth hexagonal support copper column is fixedly connected to the sixth output terminal connection copper column;

[0018] The bottom of the hexagonal support copper column is drilled and tapped for connecting the fixing screw;

[0019] For the circuit board of the turns ratio switching control system, drill holes at the corresponding positions of the hexagonal support copper columns; the fixing screws pass through these drilled holes and are fixed in the drilled holes at the bottom of the hexagonal support copper columns, so that the circuit board of the turns ratio switching control system can be fixed;

[0020] In addition to playing a role in fixing and supporting, the hexagonal support copper column also undertakes the role of connecting wires, enabling the input terminal connection copper column and the output terminal connection copper column to be electrically connected to the circuit board of the turns ratio switching control system;

[0021] Drilled holes and tapped threads are provided on the input terminal connection copper column and the output terminal connection copper column. The connection copper column fixing screws pass through the main body of the junction box and are mechanically fixed to the drilled holes and tapped threads provided on the input terminal connection copper column and the output terminal connection copper column;

[0022] A transparent insulating top cover is provided on the main body of the junction box. The lead seal screw passes through the transparent insulating top cover and the main body of the junction box in sequence and is fixed on the bottom shell of the junction box;

[0023] 6 magnetic latching relays and their adapted control circuits are provided on the circuit board of the turns ratio switching control system. The 6 magnetic latching relays include the first magnetic latching relay, the second magnetic latching relay, the third magnetic latching relay, the fourth magnetic latching relay, the fifth magnetic latching relay and the sixth magnetic latching relay;

[0024] The input end of the first magnetic latching relay is electrically connected to the first input terminal connection copper column through the first hexagonal support copper column;

[0025] The input end of the second magnetic latching relay is electrically connected to the second input terminal connection copper column through the second hexagonal support copper column;

[0026] The input end of the third magnetic latching relay is electrically connected to the third input terminal connection copper column through the third hexagonal support copper column;

[0027] The input end of the fourth magnetic latching relay is electrically connected to the fourth input terminal connection copper column through the fourth hexagonal support copper column;

[0028] The input end of the fifth magnetic latching relay is electrically connected to the fifth input terminal wiring copper post through a fifth hexagonal support copper post;

[0029] The input end of the sixth magnetic latching relay is electrically connected to the sixth input terminal wiring copper post through a sixth hexagonal support copper post;

[0030] The output ends of the first magnetic latching relay and the second magnetic latching relay are electrically connected to the second output terminal wiring copper post through a seventh hexagonal support copper post;

[0031] The output ends of the third magnetic latching relay and the fourth magnetic latching relay are electrically connected to the fourth output terminal wiring copper post through an eighth hexagonal support copper post;

[0032] The output ends of the fifth magnetic latching relay and the sixth magnetic latching relay are electrically connected to the sixth output terminal wiring copper post through a ninth hexagonal support copper post;

[0033] The power supply part of the tap-changing control system circuit board is electrically connected to the voltage wiring copper post through a wire;

[0034] Preferably, the control circuit on the tap-changing control system circuit board adopts a single-chip microcomputer system, and a control program adapted to tap-changing is stored in the single-chip microcomputer chip;

[0035] Preferably, the control and acquisition aviation plug terminals are arranged on both sides of the bottom shell of the junction box, and the control and acquisition aviation plug terminals are electrically connected to the tap-changing control system circuit board;

[0036] Preferably, the tap-changing status indicator light is arranged on one side of the bottom shell of the junction box and is electrically connected to the tap-changing control system circuit board.

[0037] The beneficial effects of the present invention are as follows: realizing the switching of the transformer ratio under the condition of continuous power supply, greatly improving the operation efficiency of the power system and reducing the inconvenience of users; while switching between large and small ratios, ensuring that the secondary of the transformer is not open-circuited, avoiding power accidents caused by the open-circuit of the secondary of the transformer; avoiding complex mechanical structures and electrical circuits, reducing the manufacturing cost and maintenance difficulty of the equipment, and improving the reliability and stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a schematic structural principle diagram of an embodiment of the present invention;

[0040] Figure 2 Schematic diagram of the structural distribution of the voltage connection copper post, input terminal connection copper post, output terminal connection copper post, and common terminal connection copper post in an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of the structural distribution of the hexagonal support copper post in an embodiment of the present invention;

[0042] Figure 4 Schematic diagram of the structure of the turns ratio switching control system circuit board in an embodiment of the present invention;

[0043] Figure 5 Schematic diagram of the electrical working principle in an embodiment of the present invention.

[0044] In the figure:

[0045] 1. Sealing screw; 2. Transparent insulating top cover; 3. Connection copper post fixing screw; 4. Junction box body; 5. Voltage connection copper post; 6. Input terminal connection copper post; 7. Output terminal connection copper post; 8. Common terminal connection copper post; 9. Hexagonal support copper post; 10. Turns ratio switching control system circuit board; 11. Fixing screw; 12. Control and acquisition aviation plug terminal; 13. Turns ratio status indicator light; 14. Junction box bottom shell; 15. Compound ratio current transformer; 16. Metering electric meter; 51. First voltage connection copper post; 55. Second voltage connection copper post; 59. Third voltage connection copper post; 513. Fourth voltage connection copper post; 62. First input terminal connection copper post; 63. Second input terminal connection copper post; 66. Third input terminal connection copper post; 67. Fourth input terminal connection copper post; 610. Fifth input terminal connection copper post; 611. Sixth input terminal connection copper post; 72. First output terminal connection copper post; 73. Second output terminal connection copper post; 76. Third output terminal connection copper post; 77. Fourth output terminal connection copper post; 710. Fifth output terminal connection copper post; 711. Sixth output terminal connection copper post; 84. First common terminal connection copper post; 88. Second common terminal connection copper post; 812. Third common terminal connection copper post; 91. First hexagonal support copper post; 92. Second hexagonal support copper post; 93. Third hexagonal support copper post; 94. Fourth hexagonal support copper post; 95. Fifth hexagonal support copper post; 96. Sixth hexagonal support copper post; 97. Seventh hexagonal support copper post; 98. Eighth hexagonal support copper post; 99. Ninth hexagonal support copper post; 101. First magnetic latching relay; 102. Second magnetic latching relay; 103. Third magnetic latching relay; 104. Fourth magnetic latching relay; 105. Fifth magnetic latching relay; 106. Sixth magnetic latching relay 106; S1. Common terminal; S2. Small turns ratio terminal; S3. Large turns ratio terminal. Detailed implementation manners

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] As shown in the figure, the intelligent control junction box for on-line conversion of the transformation ratio of the three-phase current transformer according to the present invention includes: a lead seal screw 1, a transparent insulating top cover 2, a wiring copper column fixing screw 3, a junction box body 4, a voltage wiring copper column 5, an input terminal wiring copper column 6, an output terminal wiring copper column 7, a common terminal wiring copper column 8, a hexagonal support copper column 9, a transformation ratio switching control system circuit board 10, a fixing screw 11, a control and acquisition aviation plug terminal 12, a transformation ratio status indicator light 13, and a junction box bottom shell 14.

[0048] The junction box body 4 has 13 openings on each of the left and right sides. The left side is the input terminal, numbered R1 to R13, and the right side is the output terminal, numbered C1 to C13;

[0049] There are 4 voltage wiring copper columns 5, including a first voltage wiring copper column 51, a second voltage wiring copper column 55, a third voltage wiring copper column 59, and a fourth voltage wiring copper column 513, which are arranged at the corresponding positions of the openings R1-C1, R5-C5, R9-C9, and R13-C13 of the junction box body 4;

[0050] There are 6 input terminal wiring copper columns 6, including a first input terminal wiring copper column 62, a second input terminal wiring copper column 63, a third input terminal wiring copper column 66, a fourth input terminal wiring copper column 67, a fifth input terminal wiring copper column 610, and a sixth input terminal wiring copper column 611, which are arranged at the corresponding positions of the openings R2, R3, R6, R7, R10, and R11 of the junction box body 4;

[0051] There are 6 output terminal wiring copper columns 7, including a first output terminal wiring copper column 72, a second output terminal wiring copper column 73, a third output terminal wiring copper column 76, a fourth output terminal wiring copper column 77, a fifth output terminal wiring copper column 710, and a sixth output terminal wiring copper column 711, which are arranged at the corresponding positions of the openings C2, C3, C6, C7, C10, and C11 of the junction box body 4;

[0052] There are 3 common terminal wiring copper columns 8, including a first common terminal wiring copper column 84, a second common terminal wiring copper column 88, and a third common terminal wiring copper column 812, which are arranged at the corresponding positions of the openings R4-C4, R8-C8, and R12-C12 of the junction box body 4;

[0053] The input terminal wiring copper column 6 and the output terminal wiring copper column 7 are drilled and tapped at their middle positions;

[0054] There are nine hexagonal support copper columns 9, and their tops are tapped. They include the first hexagonal support copper column 91, the second hexagonal support copper column 92, the third hexagonal support copper column 93, the fourth hexagonal support copper column 94, the fifth hexagonal support copper column 95, the sixth hexagonal support copper column 96, the seventh hexagonal support copper column 97, the eighth hexagonal support copper column 98, and the ninth hexagonal support copper column 99;

[0055] Among them, the first hexagonal support copper column 91 is fixedly connected to the first input terminal wiring copper column 62, the second hexagonal support copper column 92 is fixedly connected to the second input terminal wiring copper column 63, the third hexagonal support copper column 93 is fixedly connected to the third input terminal wiring copper column 66, the fourth hexagonal support copper column 94 is fixedly connected to the fourth input terminal wiring copper column 67, the fifth hexagonal support copper column 95 is fixedly connected to the fifth input terminal wiring copper column 610, and the sixth hexagonal support copper column 96 is fixedly connected to the sixth input terminal wiring copper column 611; the seventh hexagonal support copper column 97 is fixedly connected to the second output terminal wiring copper column 73; the eighth hexagonal support copper column 98 is fixedly connected to the fourth output terminal wiring copper column 77, and the ninth hexagonal support copper column 99 is fixedly connected to the sixth output terminal wiring copper column 711;

[0056] The bottom of the hexagonal support copper column 9 is drilled and tapped for connecting the fixing screw 11;

[0057] For the ratio change switching control system circuit board 10, drill holes at its corresponding positions to the hexagonal support copper column 9; the fixing screw 11 passes through this drill hole and is fixed in the bottom drill hole of the hexagonal support copper column 9, so that the ratio change switching control system circuit board 10 can be fixed;

[0058] The hexagonal support copper column 9, in addition to playing a role in fixing and supporting, also undertakes the role of connecting wires, enabling the input terminal wiring copper column 6 and the output terminal wiring copper column 7 to be electrically connected to the ratio change switching control system circuit board 10;

[0059] The control circuit on the ratio change switching control system circuit board 10 adopts a single-chip microcomputer system, and the control program for adapting ratio change switching is stored in the single-chip microcomputer chip;

[0060] Drill holes and tap on the input terminal wiring copper column 6 and the output terminal wiring copper column 7. The wiring copper column fixing screw 3 passes through the wiring box main body 4 and is mechanically fixed to the drill holes and taps set on the input terminal wiring copper column 6 and the output terminal wiring copper column 7;

[0061] A transparent insulating top cover 2 is provided on the wiring box main body 4. The lead sealing screw 1 passes through the transparent insulating top cover 2 and the wiring box main body 4 in sequence and is fixed on the wiring box bottom shell 14.

[0062] As shown in the figure, in a three-phase four-wire system circuit, for the voltage wiring copper column 5, the input end of its first voltage wiring copper column 51 is electrically connected to the A phase of the line to be measured;

[0063] The input end of the second voltage connection copper post 55 is electrically connected to the B phase of the line to be measured;

[0064] The input end of the third voltage connection copper post 59 is electrically connected to the C phase of the line to be measured;

[0065] The input end of the fourth voltage connection copper post 513 is electrically connected to the N phase of the line to be measured;

[0066] The output end of the first voltage connection copper post 51 is electrically connected to the A-phase voltage terminal of the metering electric meter 16;

[0067] The output end of the second voltage connection copper post 55 is electrically connected to the B-phase voltage terminal of the metering electric meter 16;

[0068] The output end of the third voltage connection copper post 59 is electrically connected to the C-phase voltage terminal of the metering electric meter 16;

[0069] The output end of the fourth voltage connection copper post 513 is electrically connected to the N-phase voltage terminal of the metering electric meter 16.

[0070] The compound ratio current transformer 15 is provided with a small transformation ratio current winding and a large transformation ratio current winding, and includes a common terminal S1, a small transformation ratio terminal S2 and a large transformation ratio terminal S3;

[0071] The common terminal connection copper post 8, the input end of its first common terminal connection copper post 84 is electrically connected to the common terminal S1 of the compound ratio current transformer 15 of the A phase of the line to be measured;

[0072] The input end of the second common terminal connection copper post 88 is electrically connected to the common terminal S1 of the compound ratio current transformer 15 of the B phase of the line to be measured;

[0073] The input end of the third common terminal connection copper post 812 is electrically connected to the common terminal S1 of the compound ratio current transformer 15 of the C phase of the line to be measured;

[0074] The output end of the first common terminal connection copper post 84 is electrically connected to the current input terminal of the A phase of the metering electric meter 16;

[0075] The output end of the second common terminal connection copper post 88 is electrically connected to the current input terminal of the B phase of the metering electric meter 16;

[0076] The output end of the third common terminal connection copper post 812 is electrically connected to the current input terminal of the C phase of the metering electric meter 16.

[0077] The input end connection copper post 6, its first input end connection copper post 62 is electrically connected to the large transformation ratio terminal S3 of the compound ratio current transformer 15 of the A phase of the line to be measured;

[0078] The wiring copper post 66 of the third input terminal is electrically connected to the large transformation ratio terminal S3 of the complex ratio current transformer 15 of the B phase of the line to be measured;

[0079] The wiring copper post 610 of the fifth input terminal is electrically connected to the large transformation ratio terminal S3 of the complex ratio current transformer 15 of the C phase of the line to be measured;

[0080] The wiring copper post 63 of the second input terminal is electrically connected to the small transformation ratio terminal S2 of the complex ratio current transformer 15 of the A phase of the line to be measured;

[0081] The wiring copper post 67 of the fourth input terminal is electrically connected to the small transformation ratio terminal S2 of the complex ratio current transformer 15 of the B phase of the line to be measured;

[0082] The wiring copper post 611 of the sixth input terminal is electrically connected to the small transformation ratio terminal S2 of the complex ratio current transformer 15 of the C phase of the line to be measured.

[0083] The output terminal wiring copper post 7, and its second output terminal wiring copper post 73 is electrically connected to the current output terminal of the A phase of the metering electric meter 16;

[0084] The fourth output terminal wiring copper post 77 is electrically connected to the current output terminal of the B phase of the metering electric meter 16;

[0085] The sixth output terminal wiring copper post 711 is electrically connected to the current output terminal of the C phase of the metering electric meter 16.

[0086] Six magnetic latching relays and their adapted control circuits are arranged on the transformation ratio switching control system circuit board 10. The six magnetic latching relays include a first magnetic latching relay 101, a second magnetic latching relay 102, a third magnetic latching relay 103, a fourth magnetic latching relay 104, a fifth magnetic latching relay 105 and a sixth magnetic latching relay 106;

[0087] The input end of the first magnetic latching relay 101 is electrically connected to the first input terminal wiring copper post 62 through the first hexagonal support copper post 91;

[0088] The input end of the second magnetic latching relay 102 is electrically connected to the second input terminal wiring copper post 63 through the second hexagonal support copper post 92;

[0089] The input end of the third magnetic latching relay 103 is electrically connected to the third input terminal wiring copper post 66 through the third hexagonal support copper post 93;

[0090] The input end of the fourth magnetic latching relay 104 is electrically connected to the fourth input terminal wiring copper post 67 through the fourth hexagonal support copper post 94;

[0091] The input end of the fifth magnetic latching relay 105 is electrically connected to the fifth input terminal wiring copper post 610 through the fifth hexagonal support copper post 95;

[0092] The input terminal of the sixth magnetic latching relay 106 is electrically connected to the sixth input terminal wiring copper post 611 through the sixth hexagonal support copper post 96;

[0093] The output terminals of the first magnetic latching relay 101 and the second magnetic latching relay 102 are electrically connected to the second output terminal wiring copper post 73 through the seventh hexagonal support copper post 97;

[0094] The output terminals of the third magnetic latching relay 103 and the fourth magnetic latching relay 104 are electrically connected to the fourth output terminal wiring copper post 77 through the eighth hexagonal support copper post 98;

[0095] The output terminals of the fifth magnetic latching relay 105 and the sixth magnetic latching relay 106 are electrically connected to the sixth output terminal wiring copper post 711 through the ninth hexagonal support copper post 99;

[0096] Preferably, for the large current loop S1 - S3 of the complex ratio current transformer 15, its transformation ratio is 20 times that of the small current loop S1 - S2;

[0097] The power supply part of the transformation ratio switching control system circuit board 10 is electrically connected to the voltage wiring copper post 5 through a wire.

[0098] The control and acquisition aviation plug terminals 12 are arranged on both sides of the bottom shell 14 of the junction box;

[0099] The control and acquisition aviation plug terminals 12 are electrically connected to the transformation ratio switching control system circuit board 10.

[0100] For the three - phase current transformer ratio on - line conversion intelligent control junction box of the present invention, its working principle is as follows:

[0101] In the normal metering working state, under the control of the transformation ratio switching control system circuit board 10, only one path of its current loop is conducted with the complex ratio current transformer 15, that is, S1 - S2, or S1 - S3; the switching of the current loop of each phase circuit in the three - phase circuit is realized by controlling the actions of two magnetic latching relays by the transformation ratio switching control system circuit board 10, that is: when the transformation ratio of the current transformer is switched, first conduct the originally disconnected path, at this time both S1 and S2, S3 are in the conducting state; after the switching time set by the internal program of the transformation ratio switching control system circuit board 10 (the set switching time is ≤ 5 seconds), the initially conducted path of current is disconnected, and thus the transformation ratio switching of the current transformer is completed. In this way, the switching of the transformation ratio of the current transformer can be satisfied, and at the same time, the secondary - side current loop of the complex ratio current transformer 15 is not open - circuited during the switching process, and the entire switching process does not require power - off.

[0102] The transformation ratio status indicator light 13 is arranged on one side of the bottom case 14 of the junction box and is electrically connected to the transformation ratio switching control system circuit board 10, and is used to display the transformation ratio switching status. When the transformation ratio status indicator light 13 shows red, it is in the large transformation ratio state, and when it shows green, it is in the small transformation ratio state.

[0103] The beneficial effects of the present invention are as follows: The transformation ratio of the mutual inductor can be switched without power interruption, which greatly improves the operation efficiency of the power system and reduces the inconvenience of users; when switching between the large and small transformation ratios, it is ensured that the secondary side of the mutual inductor is not open-circuited, avoiding power accidents caused by the open-circuit of the secondary side of the mutual inductor; complex mechanical structures and electrical circuits are avoided, reducing the manufacturing cost and maintenance difficulty of the equipment, and improving the reliability and stability of the equipment.

[0104] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Intelligent control junction box for on-line conversion of three-phase current transformer ratio, characterized in that, Including: Sealing screw (1), transparent insulating top cover (2), wiring copper post fixing screw (3), junction box body (4), voltage wiring copper post (5), input terminal wiring copper post (6), output terminal wiring copper post (7), hexagonal support copper post (9), common terminal wiring copper post (8), turns ratio switching control system circuit board (10), fixing screw (11), control and acquisition aviation plug terminals (12), turns ratio status indicator light (13) and junction box bottom shell (14); The junction box body (4) has 13 openings on each of the left and right sides. The left side is the input terminal, numbered R1 - R13, and the right side is the output terminal, numbered C1 - C13; The voltage wiring copper post (5) includes a first voltage wiring copper post (51), a second voltage wiring copper post (55), a third voltage wiring copper post (59) and a fourth voltage wiring copper post (513), and is arranged at the corresponding positions of the openings R1 - C1, R5 - C5, R9 - C9 and R13 - C13 of the junction box body (4); The input terminal wiring copper post (6) includes a first input terminal wiring copper post (62), a second input terminal wiring copper post (63), a third input terminal wiring copper post (66), a fourth input terminal wiring copper post (67), a fifth input terminal wiring copper post (610) and a sixth input terminal wiring copper post (611), and is arranged at the corresponding positions of the openings R2, R3, R6, R7, R10 and R11 of the junction box body (4); The output terminal wiring copper post (7) includes a first output terminal wiring copper post (72), a second output terminal wiring copper post (73), a third output terminal wiring copper post (76), a fourth output terminal wiring copper post (77), a fifth output terminal wiring copper post (710) and a sixth output terminal wiring copper post (711), and is arranged at the corresponding positions of the openings C2, C3, C6, C7, C10 and C11 of the junction box body (4); The common terminal wiring copper post (8) includes a first common terminal wiring copper post (84), a second common terminal wiring copper post (88) and a third common terminal wiring copper post (812), and is arranged at the corresponding positions of the openings R4 - C4, R8 - C8 and R12 - C12 of the junction box body (4); The input terminal wiring copper post (6) and the output terminal wiring copper post (7) are drilled and tapped at their middle positions; The hexagonal support copper post (9) has its top tapped, and includes a first hexagonal support copper post (91), a second hexagonal support copper post (92), a third hexagonal support copper post (93), a fourth hexagonal support copper post (94), a fifth hexagonal support copper post (95), a sixth hexagonal support copper post (96), a seventh hexagonal support copper post (97), an eighth hexagonal support copper post (98) and a ninth hexagonal support copper post (99); The first hexagonal support copper post (91) is fixedly connected to the first input terminal wiring copper post (62); The second hexagonal support copper post (92) is fixedly connected to the second input terminal wiring copper post (63); The third hexagonal support copper post (93) is fixedly connected to the third input terminal wiring copper post (66); The fourth hexagonal support copper post (94) is fixedly connected to the fourth input terminal wiring copper post (67); The fifth hexagonal support copper column (95) is fixedly connected to the fifth input terminal connection copper column (610); The sixth hexagonal support copper column (96) is fixedly connected to the sixth input terminal connection copper column (611); The seventh hexagonal support copper column (97) is fixedly connected to the second output terminal connection copper column (73); The eighth hexagonal support copper column (98) is fixedly connected to the fourth output terminal connection copper column (77); The ninth hexagonal support copper column (99) is fixedly connected to the sixth output terminal connection copper column (711); The hexagonal support copper column (9) has its bottom drilled and tapped for connecting the fixing screw (11); For the ratio conversion control system circuit board (10), holes are drilled at positions corresponding to the hexagonal support copper column (9); the fixing screw (11) passes through this hole and is fixed in the bottom hole of the hexagonal support copper column (9), so that the ratio conversion control system circuit board (10) can be fixed; The hexagonal support copper column (9), in addition to playing a role in fixing and supporting, also undertakes the role of connecting wires, electrically connecting the input terminal connection copper column (6) and the output terminal connection copper column (7) to the ratio conversion control system circuit board (10); Holes are drilled and tapped on the input terminal connection copper column (6) and the output terminal connection copper column (7). The connection copper column fixing screw (3) passes through the junction box body (4) and is mechanically fixed to the drilled and tapped holes on the input terminal connection copper column (6) and the output terminal connection copper column (7); A transparent insulating top cover (2) is provided on the junction box body (4). The lead seal screw (1) passes through the transparent insulating top cover (2) and the junction box body (4) in sequence and is fixed on the junction box bottom shell (14); Six magnetic latching relays and their adapted control circuits are provided on the ratio conversion control system circuit board (10). The six magnetic latching relays include the first magnetic latching relay (101), the second magnetic latching relay (102), the third magnetic latching relay (103), the fourth magnetic latching relay (104), the fifth magnetic latching relay (105) and the sixth magnetic latching relay (106); The input terminal of the first magnetic latching relay (101) is electrically connected to the first input terminal connection copper column (62) through the first hexagonal support copper column (91); The input terminal of the second magnetic latching relay (102) is electrically connected to the second input terminal connection copper column (63) through the second hexagonal support copper column (92); The input terminal of the third magnetic latching relay (103) is electrically connected to the third input terminal connection copper column (66) through the third hexagonal support copper column (93); The input terminal of the fourth magnetic latching relay (104) is electrically connected to the fourth input terminal connection copper column (67) through the fourth hexagonal support copper column (94); The input terminal of the fifth magnetic latching relay (105) is electrically connected to the fifth input terminal connection copper column (610) through the fifth hexagonal support copper column (95); The input terminal of the sixth magnetic latching relay (106) is electrically connected to the sixth input terminal connection copper column (611) through the sixth hexagonal support copper column (96); The output terminals of the first magnetic latching relay (101) and the second magnetic latching relay (102) are electrically connected to the second output terminal connection copper column (73) through the seventh hexagonal support copper column (97); The output terminals of the third magnetic latching relay (103) and the fourth magnetic latching relay (104) are electrically connected to the fourth output terminal wiring copper post (77) through the eighth hexagonal support copper post (98); The output terminals of the fifth magnetic latching relay (105) and the sixth magnetic latching relay (106) are electrically connected to the sixth output terminal wiring copper post (711) through the ninth hexagonal support copper post (99).

2. The intelligent control junction box for on-line conversion of the transformation ratio of a three-phase current transformer according to claim 1, characterized in that, The control circuit on the turns ratio switching control system circuit board (10) adopts a single-chip microcomputer system, and a control program adapted to the turns ratio switching is stored in the single-chip microcomputer chip.

3. The intelligent control junction box for on-line conversion of the transformation ratio of a three-phase current transformer according to claim 1, wherein The control and acquisition aviation plug terminals (12) are arranged on both sides of the wiring box bottom shell (14); The control and acquisition aviation plug terminals (12) are electrically connected to the turns ratio switching control system circuit board (10).

4. The intelligent control junction box for on-line conversion of the transformation ratio of a three-phase current transformer according to claim 1, wherein The turns ratio status indicator light (13) is arranged on one side of the wiring box bottom shell (14), and is electrically connected to the turns ratio switching control system circuit board (10), and is used to display the turns ratio switching status. When the turns ratio status indicator light (13) shows red, it is in the large turns ratio state, and when it shows green, it is in the small turns ratio state.

5. The intelligent control junction box for on-line conversion of the ratio of a three-phase current transformer according to claim 1, wherein, The power supply part of the turns ratio switching control system circuit board (10) is electrically connected to the voltage wiring copper post (5) through a wire.

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