A self-closing circuit

Abstract

The present invention relates to the field of power circuit design, and discloses a standby automatic throw circuit, including three circuits, namely, an I-II standby throw circuit, an I-III standby throw circuit, and a II-III standby throw circuit. The I-II standby throw circuit, the I-III standby throw circuit, and the II-III standby throw circuit are all provided with an incoming line contactor 1XC, an incoming line contactor 2XC, a segment contactor 3XC, an incoming line intermediate relay 1ZJ, an incoming line intermediate relay 2ZJ, a segment intermediate relay 3ZJ, and a conversion switch KK. Each component is nested and used respectively through different contacts, so that the three standby throw circuits are respectively used to control the open and closed positions of the incoming line one, the incoming line two, and the contactor load contacts of the segment. Compared with the prior art, the present invention improves the design of the standby automatic throw circuit of the low-voltage system, eliminates the hidden dangers of reliable power supply, and improves the reliability and safety of power supply of the low-voltage system.

Description

Technical Field

[0001] The invention relates to the technical field of power circuits, and in particular to a standby automatic switching circuit. Background Art

[0002] At present, in order to improve the reliability of low-voltage circuit power supply in the power system, it is generally achieved through the switching of standby automatic switching devices or standby automatic switching circuits. However, the switching method is generally simple and can only achieve mutual switching of two incoming lines. For a fault on a section of bus and its equipment in the low-voltage system, it often causes power failure of both power supplies at the same time, and it is impossible to automatically switch to segmented power supply. There are certain hidden dangers for the safe and reliable operation of the low-voltage system. Therefore, it is necessary to further improve the standby automatic switching device or standby automatic switching circuit to eliminate this hidden danger. Summary of the invention

[0003] Purpose of the invention: In view of the problems existing in the prior art, the present invention provides a backup automatic switching circuit, which is realized by the mutual nesting and related actions of components in three circuits. When two power supplies fail at the same time, it can automatically switch to segmented supply, and the circuit is safe and reliable.

[0004] Technical solution: The present invention provides a standby automatic switching circuit, including three standby switching circuits, namely, I-II standby switching circuit, I-III standby switching circuit and II-III standby switching circuit; the I-II standby switching circuit, I-III standby switching circuit and II-III standby switching circuit are respectively used to control the open and closed positions of the incoming line one, the incoming line two and the load contacts of the segmented contactor.

[0005] Furthermore, the I-II backup circuit, the I-III backup circuit and the II-III backup circuit are all provided with an incoming line contactor 1XC, an incoming line contactor 2XC, a segment contactor 3XC, an incoming line intermediate relay 1ZJ, an incoming line intermediate relay 2ZJ, a segment intermediate relay 3ZJ and a conversion switch KK;

[0006] The incoming line contactor 1XC is provided with an incoming line contactor 1XC coil (10), an incoming line contactor 1XC normally open auxiliary contact 1 (11), an incoming line contactor 1XC normally open auxiliary contact 2 (13), an incoming line contactor 1XC normally closed auxiliary contact 1 (12), an incoming line contactor 1XC normally closed auxiliary contact 2 (14), and an incoming line contactor 1XC normally closed auxiliary contact 3 (15);

[0007] The second incoming line contactor 2XC is provided with a second incoming line contactor 2XC coil (20), a first normally open auxiliary contact of the second incoming line contactor 2XC (21), a second normally open auxiliary contact of the second incoming line contactor 2XC (23), a first normally closed auxiliary contact of the second incoming line contactor 2XC (22), a second normally closed auxiliary contact of the second incoming line contactor 2XC (24), and a third normally closed auxiliary contact of the second incoming line contactor 2XC (25);

[0008] The segment contactor 3XC is provided with a segment contactor 3XC coil (30), a segment contactor 3XC normally open auxiliary contact 1 (31), a segment contactor 3XC normally open auxiliary contact 2 (33), a segment contactor 3XC normally closed auxiliary contact 1 (32), a segment contactor 3XC normally closed auxiliary contact 2 (34), and a segment contactor 3XC normally closed auxiliary contact 3 (35);

[0009] The conversion switch KK includes 7 pairs of normally open contacts, namely normally open contact 1, normally open contact 2 to normally open contact 7, each pair of normally open contacts has two terminal connections, wherein two pairs of normally open contacts are respectively used to connect to the I-II standby circuit, the I-III standby circuit and the II-III standby circuit, and one pair of normally open contacts has no connection;

[0010] The incoming line intermediate relay 1ZJ is provided with an incoming line intermediate relay 1ZJ coil (16), an incoming line intermediate relay 1ZJ normally open contact (17), an incoming line intermediate relay 1ZJ normally closed contact 1 (18), and an incoming line intermediate relay 1ZJ normally closed contact 2 (19);

[0011] The second incoming line intermediate relay 2ZJ is provided with a second incoming line intermediate relay 2ZJ coil (26), a second incoming line intermediate relay 2ZJ normally open contact (27), a second incoming line intermediate relay 2ZJ normally closed contact 1 (28), and a second incoming line intermediate relay 2ZJ normally closed contact 2 (29);

[0012] The segmented intermediate relay 3ZJ is provided with a segmented intermediate relay 3ZJ coil (36), a segmented intermediate relay 3ZJ normally open contact (37), a segmented intermediate relay 3ZJ normally closed contact 1 (38), and a segmented intermediate relay 3ZJ normally closed contact 2 (39).

[0013] Furthermore, the conversion switch KK is provided with four gears, namely, first gear, second gear, third gear, and neutral gear; when switched to first gear, the normally open contact one (i.e., terminals ① and ②) and the normally open contact two (i.e., terminals ③ and ④) of the conversion switch KK in the I-II standby circuit are respectively closed; when switched to second gear, the normally open contact three (i.e., terminals ⑤ and ⑥) and the normally open contact four (i.e., terminals ⑦ and ⑧) of the conversion switch KK in the I-III standby circuit are respectively closed; when switched to third gear, the normally open contact five (i.e., terminals ⑨ and ⑩) and the normally open contact six (i.e., terminals ⑪ and ⑫) of the conversion switch KK in the II-III standby circuit are respectively closed; when switched to neutral gear, the normally open contact seven (i.e., terminals ⑬ and ⑭) of the conversion switch KK is not connected and the normally open contact is closed.

[0014] Furthermore, the I-II backup circuits are respectively connected in parallel with four branches:

[0015] The first branch: the first emergency stop button 1TA of the incoming line, the first start button 1QA of the incoming line, the second normally closed auxiliary contact 2 (24) of the second contactor 2XC of the incoming line, and the coil (10) of the first contactor 1XC of the incoming line are connected in series; the first start button 1QA of the incoming line is also connected in parallel with the first normally open auxiliary contact 1 (11) of the first contactor 1XC of the incoming line, the first normally open contact 1 (i.e., terminals ① and ②) of the conversion switch KK and the first normally closed contact 1 (28) of the second intermediate relay 2ZJ of the incoming line are connected in parallel, and the second normally open contact 2 (i.e., terminals ③ and ④) of the conversion switch KK and the first normally closed contact 1 (38) of the segmentation intermediate relay 3ZJ are connected in parallel; the second normally closed auxiliary contact 2 (24) of the second contactor 2XC of the incoming line is connected in parallel with the second normally closed auxiliary contact 2 (34) of the segmentation contactor 3XC;

[0016] The second branch: connected in series with the normally open contact (17) of the incoming line intermediate relay 1ZJ and the incoming line closing position lamp 1HD;

[0017] The third branch: connected in series with a normally closed auxiliary contact (12) of an incoming line contactor 1XC and an incoming line position lamp 1LD;

[0018] The fourth branch: the normally open auxiliary contact 2 (13) of the incoming line contactor 1XC and the coil (16) of the incoming line intermediate relay 1ZJ are connected in series.

[0019] Furthermore, the I-III backup circuits are respectively connected in parallel with four branches:

[0020] The first branch: the second incoming line emergency stop button 2TA, the second incoming line start button 2QA, the second incoming line contactor 1XC normally closed auxiliary contact 2 (14), and the second incoming line contactor 2XC coil (20) are connected in series; the second incoming line start button 2QA is connected in parallel with the first incoming line contactor 2XC normally open auxiliary contact 1 (21), the third incoming line contactor KK normally open contact (i.e., terminals ⑤, ⑥) and the first incoming line intermediate relay 1ZJ normally closed contact 1 (18) are connected in parallel, and the fourth incoming line contactor KK normally open contact (i.e., terminals ⑦, ⑧) and the second segment intermediate relay 3ZJ normally closed contact 2 (39) are connected in parallel; the second incoming line contactor 1XC normally closed auxiliary contact 2 (14) is connected in parallel with the third segment contactor 3XC normally closed auxiliary contact 3 (35).

[0021] The second branch: connected in series with the normally open contact (27) of the second incoming line intermediate relay 2ZJ and the second incoming line closing position lamp 2HD;

[0022] The third branch: connected in series with the normally closed auxiliary contact 1 (22) of the incoming line second contactor 2XC and the incoming line second position lamp 2LD;

[0023] The fourth branch: the normally open auxiliary contact 2 (23) of the second incoming contactor 2XC and the coil (26) of the second incoming intermediate relay 2ZJ are connected in series.

[0024] Furthermore, the II-III backup circuits are respectively connected in parallel with four branches:

[0025] The first branch: the segment emergency stop button 3TA, the segment start button 3QA, the normally closed auxiliary contact 3 (25) of the incoming line contactor 2XC, and the segment contactor 3XC coil (30) are connected in series; the segment start button 3QA is connected in parallel with the normally open auxiliary contact 1 (31) of the segment contactor 3XC, the series circuit of the normally open contact 5 (i.e., terminals ⑨, ⑩) of the conversion switch KK and the normally closed contact 2 (29) of the incoming line intermediate relay 2ZJ is connected in parallel, and the series circuit of the normally open contact 6 (i.e., terminals ⑪, ⑫) of the conversion switch KK and the normally closed contact 2 (19) of the incoming line intermediate relay 1ZJ is connected in parallel; the normally closed auxiliary contact 3 (25) of the incoming line contactor 2XC is connected in parallel with the normally closed auxiliary contact 3 (15) of the incoming line contactor 1XC;

[0026] The second branch: connected in series with the normally open contact (37) of the segment intermediate relay 3ZJ and the segment closing position lamp 3HD;

[0027] The third branch: connected in series with the normally closed auxiliary contact 1 (32) of the segment contactor 3XC and the segment position lamp 3LD;

[0028] The fourth branch: the normally open auxiliary contact 2 (33) of the segment contactor 3XC and the coil (36) of the segment intermediate relay 3ZJ are connected in series.

[0029] Furthermore, the line-in-line backup method of the I-II backup circuit is:

[0030] The load contact of the incoming line 1 contactor is in the open position, the load contact of the incoming line 2 contactor is in the closed position, and the load contact of the section contactor is in the closed position;

[0031] 1) Incoming line 2 fails, and incoming line 1 is put into standby mode: the normally closed auxiliary contact 2 (24) of incoming line 2 contactor 2XC and the normally closed contact 1 (28) of incoming line 2 intermediate relay 2ZJ are closed, and the normally open contact 1 (i.e. terminals ① and ②) of transfer switch KK is closed; the normally open auxiliary contact 1 (11) of incoming line 1 contactor 1XC is closed, the normally closed auxiliary contact 1 (12) of incoming line 1 contactor 1XC is opened, the normally open auxiliary contact 2 (13) of incoming line 1 contactor 1XC is closed, and the normally open contact (17) of incoming line 1 intermediate relay 1ZJ is closed;

[0032] 2) Sectional fault, standby incoming line 1: the normally closed auxiliary contact 2 (34) of the section contactor 3XC and the normally closed contact 1 (38) of the section intermediate relay 3ZJ are closed, the normally open contact 2 (i.e. terminals ③ and ④) of the transfer switch KK are closed, the normally open auxiliary contact 1 (11) of the incoming line contactor 1XC is closed, the normally closed auxiliary contact 1 (12) of the incoming line contactor 1XC is opened, the normally open auxiliary contact 2 (13) of the incoming line contactor 1XC is closed, and the normally open contact (17) of the incoming line intermediate relay 1ZJ is closed.

[0033] Furthermore, the second backup method of the incoming line of the I-III backup circuit is:

[0034] The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the open position, and the load contact of the section contactor is in the closed position;

[0035] 1) Incoming line 1 fails, and incoming line 2 is put into standby mode: the normally closed auxiliary contact 2 (14) of incoming line 1 contactor 1XC and the normally closed contact 1 (18) of incoming line 1 intermediate relay 1ZJ are closed; the normally open contact 3 (i.e. terminals ⑤ and ⑥) of the transfer switch KK are closed; the normally open auxiliary contact 1 (21) of incoming line 2 contactor 2XC is closed, the normally closed auxiliary contact 1 (22) of incoming line 2 contactor 2XC is opened, the normally open auxiliary contact 2 (23) of incoming line 2 contactor 2XC and the normally open contact (27) of incoming line 2 intermediate relay 2ZJ are closed;

[0036] 2) Sectional fault, standby incoming line 2: the normally closed auxiliary contact 3 (35) of the section contactor 3XC and the normally closed contact 2 (39) of the section intermediate relay 3ZJ are closed; the normally open contact 4 (i.e. terminals ⑦ and ⑧) of the transfer switch KK is closed; the normally open auxiliary contact 1 (21) of the incoming line 2 contactor 2XC is closed, the normally closed auxiliary contact 1 (22) of the incoming line 2 contactor 2XC is opened, the normally open auxiliary contact 2 (23) of the incoming line 2 contactor 2XC and the normally open contact (27) of the incoming line 2 intermediate relay 2ZJ are closed.

[0037] Furthermore, the segmented backup method of the II-III backup circuit is:

[0038] The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the closed position, and the load contact of the segment contactor is in the open position;

[0039] 1) Incoming line 1 fault, standby section: Incoming line 1 contactor 1XC normally closed auxiliary contact 3 (15), incoming line 1 intermediate relay 1ZJ normally closed contact 2 (19) closed; transfer switch KK normally open contact 6 (i.e. terminals ⑪, ⑫) closed; section contactor 3XC normally open auxiliary contact 1 (31) closed, section contactor 3XC normally closed auxiliary contact 1 (32) opened, section contactor 3XC normally open auxiliary contact 2 (33) and section intermediate relay 3ZJ normally open contact (37) closed;

[0040] 2) Incoming line 2 fails, standby section is switched on: the normally closed auxiliary contact 3 (25) of incoming line 2 contactor 2XC and the normally closed contact 2 (29) of incoming line 2 intermediate relay 2ZJ are closed; the normally open contact 5 (i.e. terminals ⑨ and ⑩) of transfer switch KK is closed; the normally open auxiliary contact 1 (31) of section contactor 3XC is closed, the normally closed auxiliary contact 1 (32) of section contactor 3XC is opened, the normally open auxiliary contact 2 (33) of section contactor 3XC and the normally open contact (37) of section intermediate relay 3ZJ are closed.

[0041] Furthermore, when the normally open contact seven (i.e., terminals ⑬, ⑭) of the conversion switch KK is closed, the I-II backup circuit, the I-III backup circuit, and the II-III backup circuit are not connected for use. Beneficial Effects

[0042] 1. The standby automatic switching circuit designed by the present invention is realized by mutual nesting of components in three circuits and associated actions. A conversion switch KK is provided with four gears. On the one hand, it can be switched to the corresponding gear according to different operation wiring modes of the low-voltage system to automatically realize the corresponding three standby switching modes of incoming line one, incoming line two, and segmented. On the other hand, it can be switched to the neutral gear to realize the non-automatic mode to meet the requirements of various operation modes.

[0043] 2. The backup automatic switching circuit designed in the present invention can automatically switch to segmented power supply when two power supplies fail at the same time. Its operation is more reliable, the circuit is simple and easy to understand, and it is convenient for actual wiring and operation on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is the I-II automatic control circuit diagram;

[0045] Figure 2 Prepare automatic control circuit diagram for I-III;

[0046] Figure 3 It is the II-III automatic control circuit diagram;

[0047] Figure 4 Schematic diagram of wiring for automatic switching;

[0048] Figure 5 This is the contact and gear position diagram of the transfer switch KK.

[0049] Among them: 10-incoming line contactor 1XC coil, 11-incoming line contactor 1XC normally open auxiliary contact 1, 12-incoming line contactor 1XC normally closed auxiliary contact 1, 13-incoming line contactor 1XC normally open auxiliary contact 2, 14-incoming line contactor 1XC normally closed auxiliary contact 2, 15-incoming line contactor 1XC normally closed auxiliary contact 3, 16-incoming line intermediate relay 1ZJ coil, 17-incoming line Intermediate relay 1ZJ normally open contact, 18-incoming line 1 intermediate relay 1ZJ normally closed contact 1, 19-incoming line 1 intermediate relay 1ZJ normally closed contact 2, 20-incoming line 2 contactor 2XC coil, 21-incoming line 2 contactor 2XC normally open auxiliary contact 1, 22-incoming line 2 contactor 2XC normally closed auxiliary contact 1, 23-incoming line 2 contactor 2XC normally open auxiliary contact 2, 24-incoming line 2 contactor 2XC normally closed Auxiliary contact 2, 25-Incoming line 2 contactor 2XC normally closed auxiliary contact 3, 26-Incoming line 2 intermediate relay 2ZJ coil, 27-Incoming line 2 intermediate relay 2ZJ normally open contact, 28-Incoming line 2 intermediate relay 2ZJ normally closed contact 1, 29-Incoming line 2 intermediate relay 2ZJ normally closed contact 2, 30-Segment contactor 3XC coil, 31-Segment contactor 3XC normally open auxiliary contact 1, 32-Segment contactor 3XC normally closed auxiliary contact 1, 33-Segment contactor 3XC normally open auxiliary contact 2, 34-Segment contactor 3XC normally closed auxiliary contact 2, 35-Segment contactor 3XC normally closed auxiliary contact 3, 36-Segment intermediate relay 3ZJ coil, 37-Segment intermediate relay 3ZJ normally open contact, 38-Segment intermediate relay 3ZJ normally closed contact 1, 39-Segment intermediate relay 3ZJ normally closed contact 2. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0051] See attached Figure 1 To Attachment Figure 5The present invention discloses a standby automatic switching circuit, including three standby switching circuits, namely, an I-II standby switching circuit, an I-III standby switching circuit and a II-III standby switching circuit; the I-II standby switching circuit, the I-III standby switching circuit and the II-III standby switching circuit are respectively used to control the open and closed positions of the load contacts of the incoming line 1, the incoming line 2 and the segmented contactors.

[0052] The I-II backup circuit, I-III backup circuit and II-III backup circuit are equipped with incoming line contactor 1XC, incoming line contactor 2XC, segment contactor 3XC, incoming line intermediate relay 1ZJ, incoming line intermediate relay 2ZJ, segment intermediate relay 3ZJ and transfer switch KK. These components are nested and used as follows:

[0053] The incoming line contactor 1XC is provided with an incoming line contactor 1XC coil 10, an incoming line contactor 1XC normally open auxiliary contact 1 11, an incoming line contactor 1XC normally open auxiliary contact 2 13, an incoming line contactor 1XC normally closed auxiliary contact 1 12, an incoming line contactor 1XC normally closed auxiliary contact 2 14, and an incoming line contactor 1XC normally closed auxiliary contact 3 15.

[0054] The second incoming line contactor 2XC is provided with a second incoming line contactor 2XC coil 20, a normally open auxiliary contact 1 21 of the second incoming line contactor 2XC, a normally open auxiliary contact 2 23 of the second incoming line contactor 2XC, a normally closed auxiliary contact 1 22 of the second incoming line contactor 2XC, a normally closed auxiliary contact 2 24 of the second incoming line contactor 2XC, and a normally closed auxiliary contact 3 25 of the second incoming line contactor 2XC.

[0055] The segment contactor 3XC is provided with a segment contactor 3XC coil 30, a segment contactor 3XC normally open auxiliary contact 1 31, a segment contactor 3XC normally open auxiliary contact 2 33, a segment contactor 3XC normally closed auxiliary contact 1 32, a segment contactor 3XC normally closed auxiliary contact 2 34, and a segment contactor 3XC normally closed auxiliary contact 3 35.

[0056] The transfer switch KK includes 7 pairs of normally open contacts, namely normally open contact 1, normally open contact 2 to normally open contact 7. Figure 1 To Attachment Figure 3, Normally open contact 1, Normally open contact 2 to Normally open contact 7 each include a pair of terminals, the terminals are represented by ① to ⑭, where ① and ② are a pair, ③ and ④ are a pair, and so on. There are two pairs of normally open contacts respectively used to connect to the I-II standby circuit, I-III standby circuit and II-III standby circuit, and one pair of normally open contacts is not connected. ① and ②, ③ and ④ are used to connect to the I-II standby circuit, and so on, ⑬ and ⑭ are not connected. The transfer switch KK has four gears, namely, first gear, second gear, third gear and neutral gear; when switched to first gear, the normally open contact one (i.e., terminals ① and ②) and the normally open contact two (i.e., terminals ③ and ④) of the transfer switch KK in the I-II standby circuit are closed respectively; when switched to second gear, the normally open contact three (i.e., terminals ⑤ and ⑥) and the normally open contact four (i.e., terminals ⑦ and ⑧) of the transfer switch KK in the I-III standby circuit are closed respectively; when switched to third gear, the normally open contact five (i.e., terminals ⑨ and ⑩) and the normally open contact six (i.e., terminals ⑪ and ⑫) of the transfer switch KK in the II-III standby circuit are closed respectively; when switched to neutral gear, the normally open contact seven (i.e., terminals ⑬ and ⑭) of the transfer switch KK is not connected and the contact is closed.

[0057] The incoming line intermediate relay 1ZJ is provided with an incoming line intermediate relay 1ZJ coil 16, an incoming line intermediate relay 1ZJ normally open contact 17, an incoming line intermediate relay 1ZJ normally closed contact one 18, and an incoming line intermediate relay 1ZJ normally closed contact two 19.

[0058] The second incoming line intermediate relay 2ZJ is provided with a second incoming line intermediate relay 2ZJ coil 26, a second incoming line intermediate relay 2ZJ normally open contact 27, a second incoming line intermediate relay 2ZJ normally closed contact 1 28, and a second incoming line intermediate relay 2ZJ normally closed contact 29.

[0059] The segmented intermediate relay 3ZJ is provided with a segmented intermediate relay 3ZJ coil 36, a segmented intermediate relay 3ZJ normally open contact 37, a segmented intermediate relay 3ZJ normally closed contact 1 38, and a segmented intermediate relay 3ZJ normally closed contact 2 39.

[0060] The I-II backup circuits are connected in parallel with four branches, see the attached Figure 1 :

[0061] The first branch: the emergency stop button 1TA of the incoming line, the start button 1QA of the incoming line, the normally closed auxiliary contact 24 of the contactor 2XC of the incoming line, and the coil 10 of the contactor 1XC of the incoming line are connected in series; the start button 1QA of the incoming line is also connected in parallel with the normally open auxiliary contact 11 of the contactor 1XC of the incoming line, the series circuit of the normally open contact 1 of the conversion switch KK (i.e. terminals ① and ②) and the normally closed contact 28 of the intermediate relay 2ZJ of the incoming line, and the series circuit of the normally open contact 2 of the conversion switch KK (i.e. terminals ③ and ④) and the normally closed contact 38 of the segmented intermediate relay 3ZJ are connected in parallel; the normally closed auxiliary contact 24 of the contactor 2XC of the incoming line is connected in parallel with the normally closed auxiliary contact 2 34 of the segmented contactor 3XC.

[0062] The second branch: There are an incoming line intermediate relay 1ZJ normally open contact 17 and an incoming line closing position lamp 1HD in series.

[0063] The third branch: There are a line-in contactor 1XC, a normally closed auxiliary contact 12, and a line-in position lamp 1LD in series.

[0064] The fourth branch: the normally open auxiliary contact 2 13 of the incoming line contactor 1XC and the coil 16 of the incoming line intermediate relay 1ZJ are connected in series.

[0065] The I-III standby circuits are connected in parallel with four branches:

[0066] The first branch: the emergency stop button 2TA of incoming line 2, the start button 2QA of incoming line 2, the normally closed auxiliary contact 2 14 of the contactor 1XC of incoming line 1, and the coil 20 of the contactor 2XC of incoming line 2 are connected in series; the start button 2QA of incoming line 2 is connected in parallel with the normally open auxiliary contact 1 21 of the contactor 2XC of incoming line 2, and in parallel with the series circuit of the normally open contact 3 of the conversion switch KK (i.e. terminals ⑤, ⑥) and the normally closed contact 1 18 of the intermediate relay 1ZJ of incoming line 1, and in parallel with the series circuit of the normally open contact 4 of the conversion switch KK (i.e. terminals ⑦, ⑧) and the normally closed contact 2 39 of the segment intermediate relay 3ZJ; the normally closed auxiliary contact 2 14 of the contactor 1XC of incoming line 1 is connected in parallel with the normally closed auxiliary contact 3 35 of the segment contactor 3XC.

[0067] The second branch: There are two incoming intermediate relays 2ZJ, normally open contact 27, and two incoming position lamps 2HD in series.

[0068] The third branch: There are two normally closed auxiliary contacts 22 of the incoming line contactor 2XC and two position lights 2LD in series.

[0069] The fourth branch: the normally open auxiliary contact 23 of the second incoming line contactor 2XC and the coil 26 of the second incoming line intermediate relay 2ZJ are connected in series.

[0070] The II-III standby circuit has four branches in parallel:

[0071] The first branch: the segmented emergency stop button 3TA, the segmented start button 3QA, the normally closed auxiliary contact three 25 of the incoming line contactor 2XC, and the segmented contactor 3XC coil 30 are connected in series; the segmented start button 3QA is connected in parallel with the normally open auxiliary contact one 31 of the segmented contactor 3XC, and in parallel with the series circuit of the normally open contact five of the conversion switch KK (i.e. terminals ⑨, ⑩) and the normally closed contact two 29 of the incoming line two intermediate relay 2ZJ, and in parallel with the series circuit of the normally open contact six of the conversion switch KK (i.e. terminals ⑪, ⑫) and the normally closed contact two 19 of the incoming line one intermediate relay 1ZJ; the normally closed auxiliary contact three 25 of the incoming line two contactor 2XC is connected in parallel with the normally closed auxiliary contact three 15 of the incoming line one contactor 1XC.

[0072] The second branch: the normally open contact 37 of the segmented intermediate relay 3ZJ and the segmented closing position lamp 3HD are connected in series.

[0073] The third branch: the normally closed auxiliary contact 32 of the segment contactor 3XC and the segment position lamp 3LD are connected in series.

[0074] The fourth branch: the normally open auxiliary contact 2 33 of the segment contactor 3XC and the coil 36 of the segment intermediate relay 3ZJ are connected in series.

[0075] The following is an explanation of the start-up and emergency stop process of the above three circuits:

[0076] 1. Start and emergency stop process after the line is connected. Figure 1 As shown, the state before the start of the incoming line one circuit is that the incoming line one emergency stop button 1TA in the first branch is closed, the incoming line one start button 1QA is disconnected, the incoming line two contactor 2XC normally closed auxiliary contact 24 is closed, the segment contactor 3XC normally closed auxiliary contact 234 is closed, the incoming line one contactor 1XC coil 10 is not energized, the incoming line one contactor 1XC normally open auxiliary contact 11 is disconnected, the transfer switch KK is in the neutral state, and the transfer switch KK normally open contact 1 (i.e. terminals ①, ②) are disconnected from the normally open contact 2 (i.e. terminals ③, ④), the normally open contact 17 of the incoming line intermediate relay 1ZJ in the second branch is disconnected, and the incoming line closing position lamp 1HD is off, the normally closed auxiliary contact 12 of the incoming line contactor 1XC in the third branch is closed, and the green light of the incoming line opening position lamp 1LD is on, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC in the fourth branch is disconnected, and the coil 16 of the incoming line intermediate relay 1ZJ shall not be energized.

[0077] When the I-II standby circuit of the incoming line is started, the incoming line start button 1QA is closed, so that the coil 10 of the incoming line contactor 1XC is energized, and the normally open auxiliary contact 11 of the incoming line contactor 1XC is closed, realizing the circuit self-holding. Figure 4 The incoming line contactor 1XC load contact is closed; at the same time Figure 1The normally closed auxiliary contact 12 of the incoming line contactor 1XC is disconnected, the green light of the incoming line position lamp 1LD goes out, and at the same time, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is closed, the coil 16 of the incoming line intermediate relay 1ZJ is energized, the normally open contact 17 of the incoming line intermediate relay 1ZJ is closed, and the red light of the incoming line closing lamp 1HD is on.

[0078] When the I-II standby circuit of the emergency stop incoming line 1 is switched on, the emergency stop button 1TA of the incoming line 1 is disconnected, causing the coil 10 of the incoming line 1 contactor 1XC to lose power. Figure 4 The incoming line contactor 1XC load contact is disconnected; at the same time Figure 1 The normally closed auxiliary contact 12 of the incoming line contactor 1XC is closed, the green light of the incoming line position lamp 1LD is on, and at the same time, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is disconnected, the coil 16 of the incoming line intermediate relay 1ZJ loses power, the normally open contact 17 of the incoming line intermediate relay 1ZJ is disconnected, and the red light of the incoming line closing position lamp 1HD is off.

[0079] 2. Incoming line 2 start and emergency stop process, such as Figure 2 As shown, the start and emergency stop process of the same incoming line.

[0080] 3. Segmented start and emergency stop process, such as Figure 3 As shown, the start and emergency stop process of the same incoming line.

[0081] The following is an explanation of the self-transfer process of the above three circuits:

[0082] like Figure 1 , 2 As shown in Figures 3 and 4, the I-II standby circuit diagram is connected to terminals ①, ②, ③ and ④ of the normally open contacts of the transfer switch KK; the I-III standby circuit diagram is connected to terminals ⑤, ⑥, ⑦ and ⑧ of the normally open contacts of the transfer switch KK; the II-III standby circuit diagram is connected to terminals ⑨, ⑩, ⑪ and ⑫ of the normally open contacts of the transfer switch KK.

[0083] like Figure 5 As shown, when the transfer switch KK is switched to the first gear, its terminals ① and ②, ③ and ④ are connected respectively, which is the incoming line one standby mode; when it is switched to the second gear, its terminals ⑤ and ⑥, ⑦ and ⑧ are connected respectively, which is the incoming line two standby mode; when it is switched to the third gear, its terminals ⑨ and ⑩, ⑪ and ⑫ are connected respectively, which is the segmented standby mode; when it is switched to the neutral gear, its terminals ⑬ and ⑭ are connected, which is the non-automatic mode (manual); the following introduces the action process of each standby automatic mode for the four gears of the transfer switch KK.

[0084] The method of line-in-line backup of I-II backup circuit is:

[0085] The load contact of the incoming line 1 contactor is open, the load contact of the incoming line 2 contactor is closed, and the load contact of the section contactor is closed. At this time, the transfer switch KK is switched to the first gear. There are two situations for the incoming line 1 standby.

[0086] 1) Incoming line 2 fails, standby incoming line 1 is used:

[0087] like Figure 2 As shown, the status is Figure 2 In the first branch, the emergency stop button 2TA of the second incoming line is closed, the start button 2QA of the second incoming line is disconnected, the normally open auxiliary contact 1 21 of the second incoming line contactor 2XC is closed, the normally closed auxiliary contact 2 14 of the first incoming line contactor 1XC is closed, the normally closed auxiliary contact 3 35 of the section contactor 3XC is disconnected, the coil 20 of the second incoming line contactor 2XC is energized, the normally open contacts ⑤ and ⑥, ⑦ and ⑧ of the conversion switch KK (switched to the first gear) are disconnected, the normally closed auxiliary contact 1 22 of the second incoming line contactor 2XC in the third branch is disconnected, and the green light of the second incoming line position lamp 2LD is off, the normally open auxiliary contact 2 23 of the second incoming line contactor 2XC in the fourth branch is closed, and the coil 26 of the second incoming line intermediate relay 2ZJ is energized, the normally open contact 27 of the second incoming line intermediate relay 2ZJ in the second branch is closed, and the red light of the second incoming line closing position lamp 2HD is on.

[0088] When a fault occurs in the incoming line 2, Figure 2 The coil 20 of the second contactor 2XC in the middle line loses power. Figure 4 The load contact of the second incoming contactor 2XC is disconnected; Figure 2 The normally closed auxiliary contact 1 22 of the second contactor 2XC of the middle incoming line is closed, and the green light of the second position lamp 2LD of the incoming line is on. At the same time, the normally open auxiliary contact 2 23 of the second contactor 2XC of the incoming line is disconnected, the coil 26 of the second intermediate relay 2ZJ of the incoming line loses power, the normally open contact 27 of the second intermediate relay 2ZJ of the incoming line is disconnected, and the red light of the second closing position lamp 2HD of the incoming line is off. At the same time, Figure 1 The normally closed auxiliary contact 24 of the incoming line contactor 2XC and the normally closed contact 28 of the incoming line intermediate relay 2ZJ are closed, and the normally open contact 1 (terminals ①, ②) of the conversion switch KK is closed (first gear), so that the coil 10 of the incoming line contactor 1XC is energized, and the normally open auxiliary contact 11 of the incoming line contactor 1XC is closed, realizing the circuit self-holding. Figure 4 The load contact of the incoming line contactor 1XC is closed, realizing the automatic input of the incoming line. Figure 1 The normally closed auxiliary contact 12 of the incoming line contactor 1XC is disconnected, the green light of the incoming line position lamp 1LD goes out, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is closed, the coil 16 of the incoming line intermediate relay 1ZJ is energized, the normally open contact 17 of the incoming line intermediate relay 1ZJ is closed, and the red light of the incoming line closing position lamp 1HD is on.

[0089] 2) Sectional fault, standby input line 1:

[0090] like Figure 3 As shown, the status is Figure 3 In the first branch, the section emergency stop button 3TA is closed, the section start button 3QA is disconnected, the section contactor 3XC normally open auxiliary contact 1 31 is closed, the incoming line contactor 1XC normally closed auxiliary contact 3 15 is closed, the incoming line contactor 2XC normally closed auxiliary contact 3 25 is disconnected, the section contactor 3XC coil 30 is energized, the transfer switch KK (switch to the first gear) contacts ⑨ and ⑩, ⑪ and ⑫ are disconnected, the section contactor 3XC normally closed auxiliary contact 1 32 in the third branch is disconnected, and the section position light 3LD turns green, the section contactor 3XC normally open auxiliary contact 2 33 in the fourth branch is closed, and the section intermediate relay 3ZJ coil 36 is energized, the section intermediate relay 3ZJ normally open contact 37 in the second branch is closed, and the section closing position light 3HD turns red.

[0091] When a segment fails, Figure 3 The middle section contactor 3XC coil 30 loses power. Figure 4 The load contact of the segment contactor 3XC is disconnected; Figure 3 The normally closed auxiliary contact 1 32 of the middle section contactor 3XC is closed, the section position indicator 3LD is green, and at the same time, the normally open auxiliary contact 2 33 of the section contactor 3XC is disconnected, the coil 36 of the section intermediate relay 3ZJ loses power, the normally open contact 37 of the section intermediate relay 3ZJ is disconnected, and the red section position indicator 3HD is off. Figure 1 The normally closed auxiliary contact 2 34 of the middle section contactor 3XC and the normally closed contact 1 38 of the section intermediate relay 3ZJ are closed, and the normally open contact 2 (terminals ③ and ④) of the transfer switch KK is closed, so that the coil 10 of the incoming line contactor 1XC is energized, and the normally open auxiliary contact 11 of the incoming line contactor 1XC is closed, realizing the self-holding of the circuit. Figure 4 The load contact of the incoming line contactor 1XC is closed, realizing the automatic input of the incoming line. Figure 1 The normally closed auxiliary contact 12 of the incoming line contactor 1XC is disconnected, the green light of the incoming line position lamp 1LD goes out, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is closed, the coil 16 of the incoming line intermediate relay 1ZJ is energized, the normally open contact 17 of the incoming line intermediate relay 1ZJ is closed, and the red light of the incoming line closing position lamp 1HD is on.

[0092] The second backup method of the incoming line of the I-III backup circuit is:

[0093] The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the open position, and the load contact of the segment contactor is in the closed position; at this time, the transfer switch KK is switched to the second gear. There are two situations for the incoming line 2 standby.

[0094] 1) Incoming line 1 fails, and incoming line 2 is put into standby mode:

[0095] like Figure 1 As shown, the status is Figure 1 In the first branch, the emergency stop button 1TA of the incoming line is closed, the start button 1QA of the incoming line is disconnected, the normally open auxiliary contact 11 of the incoming line contactor 1XC is closed, the normally closed auxiliary contact 24 of the incoming line contactor 2XC is closed, the normally closed auxiliary contact 234 of the section contactor 3XC is disconnected, the coil 10 of the incoming line contactor 1XC is energized, and the contacts ① and ②, ③ and ④ of the transfer switch KK (switched to the second gear) are disconnected. In the third branch, the normally closed auxiliary contact 12 of the incoming line contactor 1XC is disconnected, and the green light of the incoming line position lamp 1LD is off. In the fourth branch, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is closed, and the coil 16 of the incoming line intermediate relay 1ZJ is energized. In the second branch, the normally open contact 17 of the incoming line intermediate relay 1ZJ is closed, and the red light of the incoming line closing position lamp 1HD is on.

[0096] When a fault occurs in the incoming line, Figure 1 The coil 10 of the contactor 1XC in the middle incoming line loses power. Figure 4 The incoming line contactor 1XC load contact is disconnected; at the same time Figure 1 The normally closed auxiliary contact 12 of the incoming line contactor 1XC is closed, and the green light of the incoming line position lamp 1LD is on. At the same time, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is disconnected, the coil 16 of the incoming line intermediate relay 1ZJ loses power, the normally open contact 17 of the incoming line intermediate relay 1ZJ is disconnected, and the red light of the incoming line position lamp 1HD is off. Figure 2 The normally closed auxiliary contact 214 of the incoming line contactor 1XC and the normally closed contact 18 of the incoming line intermediate relay 1ZJ are closed; the normally open contact 3 (terminals ⑤, ⑥) of the conversion switch KK is closed, so that the coil 20 of the incoming line contactor 2XC is energized, and the normally open auxiliary contact 21 of the incoming line contactor 2XC is closed, realizing the self-holding of the circuit. Figure 4 The load contact of the incoming line contactor 2XC in the middle is closed, and the incoming line 2 is automatically put into operation. The normally closed auxiliary contact 1 22 of the incoming line contactor 2XC is disconnected, the green light of the incoming line 2 open position 2LD is off, the normally open auxiliary contact 2 23 of the incoming line contactor 2XC is closed, the coil 26 of the incoming line 2 intermediate relay 2ZJ is energized, the normally open contact 27 of the incoming line 2 intermediate relay 2ZJ is closed, and the red light of the incoming line 2 closed position lamp 2HD is on.

[0097] 2) Sectional fault, standby input line 2:

[0098] like Figure 3 As shown, the status is Figure 3In the first branch, the section emergency stop button 3TA is closed, the section start button 3QA is disconnected, the section contactor 3XC normally open auxiliary contact 1 31 is closed, the incoming line contactor 1XC normally closed auxiliary contact 3 15 is closed, the incoming line contactor 2XC normally closed auxiliary contact 3 25 is disconnected, the section contactor 3XC coil 30 is energized, the KK (shift to second gear) contacts ⑨ and ⑩, ⑪ and ⑫ are disconnected, the section contactor 3XC normally closed auxiliary contact 1 32 in the third branch is disconnected, the section position light 3LD green light goes out, the section contactor 3XC normally open auxiliary contact 2 33 in the fourth branch is closed, the section intermediate relay 3ZJ coil 36 is energized, the section intermediate relay 3ZJ normally open contact 37 in the second branch is closed, and the section closing position light 3HD red light is on.

[0099] When a segment fails, Figure 3 The middle section contactor 3XC coil 30 loses power. Figure 4 The load contact of the segment contactor 3XC is disconnected; Figure 3 The normally closed auxiliary contact 1 32 of the middle section contactor 3XC is closed, the section position indicator 3LD is green, and at the same time, the normally open auxiliary contact 2 33 of the section contactor 3XC is disconnected, the coil 36 of the section intermediate relay 3ZJ loses power, the normally open contact 37 of the section intermediate relay 3ZJ is disconnected, and the red section position indicator 3HD is off. Figure 2 The normally closed auxiliary contact 35 of the middle section contactor 3XC and the normally closed contact 2 39 of the section intermediate relay 3ZJ are closed; the normally open contact 4 (terminals ⑦, ⑧) of the transfer switch KK is closed, so that the coil 20 of the second incoming contactor 2XC is energized, and the normally open auxiliary contact 1 21 of the second incoming contactor 2XC is closed, realizing the self-holding of the circuit. Figure 4 The load contact of the incoming line two contactor 2XC is closed, and the incoming line two is automatically put into operation; the normally closed auxiliary contact 22 of the incoming line two contactor 2XC is disconnected, the green light of the incoming line two position lamp 2LD goes out, the normally open auxiliary contact 23 of the incoming line two contactor 2XC is closed, the coil 26 of the incoming line two intermediate relay 2ZJ is energized, the normally open contact 27 of the incoming line two intermediate relay 2ZJ is closed, and the red light of the incoming line two closing position lamp 2HD is on.

[0100] The segmented backup method of the II-III backup circuit is:

[0101] The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the closed position, and the load contact of the segment contactor is in the open position; at this time, the transfer switch KK is switched to the third gear. There are two situations for segment standby.

[0102] 1) Incoming line failure, standby switching on sections:

[0103] like Figure 1 As shown, the status is Figure 1In the first branch, the emergency stop button 1TA of the incoming line is closed, the start button 1QA of the incoming line is disconnected, the normally open auxiliary contact 11 of the incoming line contactor 1XC is closed, the normally closed auxiliary contact 24 of the incoming line contactor 2XC is closed, the normally closed auxiliary contact 234 of the section contactor 3XC is disconnected, the coil 10 of the incoming line contactor 1XC is energized, and the contacts ① and ②, ③ and ④ of the transfer switch KK (switched to the third gear) are disconnected. In the third branch, the normally closed auxiliary contact 12 of the incoming line contactor 1XC is disconnected, and the green light of the incoming line position lamp 1LD is off. In the fourth branch, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is closed, and the coil 16 of the incoming line intermediate relay 1ZJ is energized. In the second branch, the normally open contact 17 of the incoming line intermediate relay 1ZJ is closed, and the red light of the incoming line closing position lamp 1HD is on.

[0104] When a fault occurs in the incoming line, Figure 1 The coil 10 of the contactor 1XC in the middle incoming line loses power. Figure 4 The incoming line contactor 1XC load contact is disconnected; at the same time Figure 1 The normally closed auxiliary contact 12 of the incoming line contactor 1XC is closed, and the green light of the incoming line position lamp 1LD is on. At the same time, the normally open auxiliary contact 2 13 of the incoming line contactor 1XC is disconnected, the coil 16 of the incoming line intermediate relay 1ZJ loses power, the normally open contact 17 of the incoming line intermediate relay 1ZJ is disconnected, and the red light of the incoming line position lamp 1HD is off. Figure 3 The normally closed auxiliary contact 3 15 of the incoming line contactor 1XC and the normally closed contact 2 19 of the incoming line intermediate relay 1ZJ are closed; the normally open contact 6 (terminals ⑪, ⑫) of the conversion switch KK is closed, so that the coil 30 of the segment contactor 3XC is energized, and the normally open auxiliary contact 1 31 of the segment contactor 3XC is closed, realizing the self-holding of the circuit. Figure 4 The load contact of the segment contactor 3XC in the circuit is closed, realizing automatic segmentation; the normally closed auxiliary contact 1 32 of the segment contactor 3XC is disconnected, the green light of the segment position lamp 3LD goes out, the normally open auxiliary contact 2 33 of the segment contactor 3XC is closed, the coil 36 of the segment intermediate relay 3ZJ is energized, the normally open contact 37 of the segment intermediate relay 3ZJ is closed, and the red light of the segment closing position lamp 3HD is on.

[0105] 2) Incoming line 2 fault, standby switching section:

[0106] like Figure 2 As shown, the status is Figure 2In the first branch, the emergency stop button 2TA of the second incoming line is closed, the start button 2QA of the second incoming line is disconnected, the normally open auxiliary contact 1 21 of the second incoming line contactor 2XC is closed, the normally closed auxiliary contact 2 14 of the first incoming line contactor 1XC is closed, the normally closed auxiliary contact 3 35 of the section contactor 3XC is disconnected, the coil 20 of the second incoming line contactor 2XC is energized, the normally open contacts ⑤ and ⑥, ⑦ and ⑧ of the conversion switch KK (switched to the third gear) are disconnected, the normally closed auxiliary contact 1 22 of the second incoming line contactor 2XC in the third branch is disconnected, and the green light of the second incoming line position lamp 2LD is off, the normally open auxiliary contact 2 23 of the second incoming line contactor 2XC in the fourth branch is closed, and the coil 26 of the second incoming line intermediate relay 2ZJ is energized, the normally open contact 27 of the second incoming line intermediate relay 2ZJ in the second branch is closed, and the red light of the second incoming line closing position lamp 2HD is on.

[0107] When a fault occurs in the incoming line 2, Figure 2 The coil 20 of the second contactor 2XC in the middle line loses power. Figure 4 The load contact of the second incoming contactor 2XC is disconnected; Figure 2 The normally closed auxiliary contact 22 of the second contactor 2XC in the middle incoming line is closed, and the green light of the second position lamp 2LD in the incoming line is on. At the same time, the normally open auxiliary contact 23 of the second contactor 2XC in the incoming line is disconnected, the coil 26 of the second intermediate relay 2ZJ in the incoming line loses power, the normally open contact 27 of the second intermediate relay 2ZJ in the incoming line is disconnected, and the red light of the second closing position lamp 2HD in the incoming line is off. Figure 3 The normally closed auxiliary contact 3 25 of the second contactor 2XC in the middle incoming line and the normally closed contact 2 29 of the second intermediate relay 2ZJ in the incoming line are closed; the normally open contact 5 (terminals ⑨, ⑩) of the conversion switch KK is closed, so that the coil 30 of the segment contactor 3XC is energized, and the normally open auxiliary contact 1 31 of the segment contactor 3XC is closed, realizing the self-holding of the circuit, Figure 4 The load contact of the segment contactor 3XC in the circuit is closed, realizing automatic segmentation; the normally closed auxiliary contact 1 32 of the segment contactor 3XC is disconnected, the green light of the segment position lamp 3LD goes out, the normally open auxiliary contact 2 33 of the segment contactor 3XC is closed, the coil 36 of the segment intermediate relay 3ZJ is energized, the normally open contact 37 of the segment intermediate relay 3ZJ is closed, and the red light of the segment closing position lamp 3HD is on.

[0108] The non-automatic (manual) method is:

[0109] When the normally open contact seven (terminals ⑬, ⑭) of the transfer switch KK is closed, the I-II backup circuit, the I-III backup circuit, and the II-III backup circuit are not connected. At this time, the transfer switch KK is switched to neutral. Figure 1 , 2 , 3, there is no KK normally open contact closed, so if Figure 4 As shown, in any operating mode, if there is a power failure, the backup automatic transfer circuit will not be started, that is, it will not be automatically transferred. This method can be applied to operations during power outages and maintenance.

[0110] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-closing circuit, characterized in that: It includes three backup circuits, namely, I-II backup circuit, I-III backup circuit and II-III backup circuit; the I-II backup circuit, I-III backup circuit and II-III backup circuit are used to control the open and closed positions of the load contacts of the incoming line 1, the incoming line 2 and the segmented contactor respectively; The I-II standby circuit, the I-III standby circuit and the II-III standby circuit are all provided with an incoming line contactor 1XC, an incoming line contactor 2XC, a segment contactor 3XC, an incoming line intermediate relay 1ZJ, an incoming line intermediate relay 2ZJ, a segment intermediate relay 3ZJ and a conversion switch KK; The incoming line contactor 1XC is provided with an incoming line contactor 1XC coil (10), an incoming line contactor 1XC normally open auxiliary contact 1 (11), an incoming line contactor 1XC normally open auxiliary contact 2 (13), an incoming line contactor 1XC normally closed auxiliary contact 1 (12), an incoming line contactor 1XC normally closed auxiliary contact 2 (14), and an incoming line contactor 1XC normally closed auxiliary contact 3 (15); The second incoming line contactor 2XC is provided with a second incoming line contactor 2XC coil (20), a first normally open auxiliary contact of the second incoming line contactor 2XC (21), a second normally open auxiliary contact of the second incoming line contactor 2XC (23), a first normally closed auxiliary contact of the second incoming line contactor 2XC (22), a second normally closed auxiliary contact of the second incoming line contactor 2XC (24), and a third normally closed auxiliary contact of the second incoming line contactor 2XC (25); The segment contactor 3XC is provided with a segment contactor 3XC coil (30), a segment contactor normally open auxiliary contact 1 (31), a segment contactor normally open auxiliary contact 2 (33), a segment contactor 3XC normally closed auxiliary contact 1 (32), a segment contactor 3XC normally closed auxiliary contact 2 (34), and a segment contactor 3XC normally closed auxiliary contact 3 (35); The conversion switch KK includes 7 pairs of normally open contacts, namely normally open contact 1, normally open contact 2 to normally open contact 7, each pair of normally open contacts has two terminal connections, wherein two pairs of normally open contacts are respectively used to connect to the I-II standby circuit, the I-III standby circuit and the II-III standby circuit, and one pair of normally open contacts has no connection; The incoming line intermediate relay 1ZJ is provided with an incoming line intermediate relay 1ZJ coil (16), an incoming line intermediate relay 1ZJ normally open contact (17), an incoming line intermediate relay 1ZJ normally closed contact 1 (18), and an incoming line intermediate relay 1ZJ normally closed contact 2 (19); The second incoming line intermediate relay 2ZJ is provided with a second incoming line intermediate relay 2ZJ coil (26), a second incoming line intermediate relay 2ZJ normally open contact (27), a second incoming line intermediate relay 2ZJ normally closed contact 1 (28), and a second incoming line intermediate relay 2ZJ normally closed contact 2 (29); The segmented intermediate relay 3ZJ is provided with a segmented intermediate relay 3ZJ coil (36), a segmented intermediate relay 3ZJ normally open contact (37), a segmented intermediate relay 3ZJ normally closed contact 1 (38), and a segmented intermediate relay 3ZJ normally closed contact 2 (39); The transfer switch KK is provided with four gears, namely, the first gear, the second gear, the third gear, and the neutral gear; when switched to the first gear, the normally open contact 1 and the normally open contact 2 of the transfer switch KK in the I-II standby circuit are closed respectively; when switched to the second gear, the normally open contact 3 and the normally open contact 4 of the transfer switch KK in the I-III standby circuit are closed respectively; when switched to the third gear, the normally open contact 5 and the normally open contact 6 of the transfer switch KK in the II-III standby circuit are closed respectively; when switched to the neutral gear, the normally open contact 7 of the transfer switch KK is not connected and the normally open contact is closed; The I-II backup circuits are respectively connected in parallel with four branches: The first branch: the first emergency stop button 1TA of the incoming line, the first start button 1QA of the incoming line, the second normally closed auxiliary contact (24) of the second contactor 2XC of the incoming line, and the coil (10) of the first contactor 1XC of the incoming line are connected in series; the first start button 1QA of the incoming line is also connected in parallel with the first normally open auxiliary contact (11) of the first contactor 1XC of the incoming line, the first normally open contact of the conversion switch KK and the first normally closed contact (28) of the second intermediate relay 2ZJ of the incoming line are connected in parallel, and the second normally open contact of the conversion switch KK and the first normally closed contact (38) of the segmentation intermediate relay 3ZJ are connected in parallel with the second normally closed auxiliary contact (24) of the second contactor 2XC of the incoming line are connected in parallel with the second normally closed auxiliary contact (34) of the segmentation contactor 3XC; The second branch: connected in series with the normally open contact (17) of the incoming line intermediate relay 1ZJ and the incoming line closing position lamp 1HD; The third branch: connected in series with a normally closed auxiliary contact (12) of an incoming line contactor 1XC and an incoming line position lamp 1LD; The fourth branch: the normally open auxiliary contact 2 (13) of the incoming line contactor 1XC and the coil (16) of the incoming line intermediate relay 1ZJ are connected in series; The I-III backup circuits are respectively connected in parallel with four branches: The first branch: the second incoming line emergency stop button 2TA, the second incoming line start button 2QA, the second incoming line contactor 1XC normally closed auxiliary contact (14), and the second incoming line contactor 2XC coil (20) are connected in series; the second incoming line start button 2QA is connected in parallel with the first incoming line contactor 2XC normally open auxiliary contact (21), the third in series circuit of the transfer switch KK normally open contact and the first incoming line intermediate relay 1ZJ normally closed contact (18), and the fourth in series circuit of the transfer switch KK normally open contact and the second in series circuit of the segmentation intermediate relay 3ZJ normally closed contact (39); the second in series circuit of the first incoming line contactor 1XC normally closed auxiliary contact (14) is connected in parallel with the third in series circuit of the segmentation contactor 3XC normally closed auxiliary contact (35); The second branch: connected in series with the normally open contact (27) of the second incoming line intermediate relay 2ZJ and the second incoming line closing position lamp 2HD; The third branch: connected in series with the normally closed auxiliary contact 1 (22) of the incoming line second contactor 2XC and the incoming line second position lamp 2LD; The fourth branch: the second normally open auxiliary contact 2 (23) of the second incoming contactor 2XC and the coil (26) of the second incoming intermediate relay 2ZJ are connected in series; The II-III standby circuit has four branches connected in parallel: The first branch: the segment emergency stop button 3TA, the segment start button 3QA, the normally closed auxiliary contact 3 (25) of the incoming line contactor 2XC, and the segment contactor 3XC coil (30) are connected in series; the segment start button 3QA is connected in parallel with the normally open auxiliary contact 1 (31) of the segment contactor 3XC, the series circuit of the normally open contact 5 of the conversion switch KK and the normally closed contact 2 (29) of the incoming line intermediate relay 2ZJ is connected in parallel, and the series circuit of the normally open contact 6 of the conversion switch KK and the normally closed contact 2 (19) of the incoming line intermediate relay 1ZJ is connected in parallel; the normally closed auxiliary contact 3 (25) of the incoming line contactor 2XC is connected in parallel with the normally closed auxiliary contact 3 (15) of the incoming line contactor 1XC; The second branch: connected in series with the normally open contact (37) of the segment intermediate relay 3ZJ and the segment closing position lamp 3HD; The third branch: connected in series with the normally closed auxiliary contact 1 (32) of the segment contactor 3XC and the segment position lamp 3LD; The fourth branch: the normally open auxiliary contact 2 (33) of the segment contactor 3XC and the coil (36) of the segment intermediate relay 3ZJ are connected in series.

2. The automatic backup circuit according to claim 1, characterized in that: The line-input-reserve method of the I-II standby circuit is: The load contact of the incoming line 1 contactor is in the open position, the load contact of the incoming line 2 contactor is in the closed position, and the load contact of the section contactor is in the closed position; 1) Incoming line 2 fails, and incoming line 1 is put into standby mode: the normally closed auxiliary contact 2 (24) of incoming line 2 contactor 2XC and the normally closed contact 1 (28) of incoming line 2 intermediate relay 2ZJ are closed, and the normally open contact 1 of transfer switch KK is closed; the normally open auxiliary contact 1 (11) of incoming line 1 contactor 1XC is closed, the normally closed auxiliary contact 1 (12) of incoming line 1 contactor 1XC is opened, the normally open auxiliary contact 2 (13) of incoming line 1 contactor 1XC is closed, and the normally open contact (17) of incoming line 1 intermediate relay 1ZJ is closed; 2) Sectional fault, standby incoming line 1: the normally closed auxiliary contact 2 (34) of the section contactor 3XC and the normally closed contact 1 (38) of the section intermediate relay 3ZJ are closed, the normally open contact 2 of the transfer switch KK is closed, the normally open auxiliary contact 1 (11) of the incoming line contactor 1XC is closed, the normally closed auxiliary contact 1 (12) of the incoming line contactor 1XC is opened, the normally open auxiliary contact 2 (13) of the incoming line contactor 1XC is closed, and the normally open contact (17) of the incoming line intermediate relay 1ZJ is closed.

3. The automatic backup circuit according to claim 1, characterized in that: The second backup method of the incoming line of the I-III backup circuit is: The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the open position, and the load contact of the section contactor is in the closed position; 1) Incoming line 1 fails, and incoming line 2 is put into standby mode: the normally closed auxiliary contact 2 (14) of incoming line 1 contactor 1XC and the normally closed contact 1 (18) of incoming line 1 intermediate relay 1ZJ are closed; the normally open contact 3 of transfer switch KK is closed; the normally open auxiliary contact 1 (21) of incoming line 2 contactor 2XC is closed, the normally closed auxiliary contact 1 (22) of incoming line 2 contactor 2XC is opened, the normally open auxiliary contact 2 (23) of incoming line 2 contactor 2XC and the normally open contact (27) of incoming line 2 intermediate relay 2ZJ are closed; 2) Segment fault, standby incoming line 2: the normally closed auxiliary contact 3 (35) of the segment contactor 3XC and the normally closed contact 2 (39) of the segment intermediate relay 3ZJ are closed; the normally open contact 4 of the transfer switch KK is closed; the normally open auxiliary contact 1 (21) of the incoming line 2 contactor 2XC is closed, the normally closed auxiliary contact 1 (22) of the incoming line 2 contactor 2XC is opened, the normally open auxiliary contact 2 (23) of the incoming line 2 contactor 2XC and the normally open contact (27) of the incoming line 2 intermediate relay 2ZJ are closed.

4. The automatic backup circuit according to claim 1, characterized in that: The segmented backup method of the II-III backup circuit is: The load contact of the incoming line 1 contactor is in the closed position, the load contact of the incoming line 2 contactor is in the closed position, and the load contact of the segment contactor is in the open position; 1) Incoming line 1 fault, standby section: Incoming line 1 contactor 1XC normally closed auxiliary contact 3 (15), incoming line 1 intermediate relay 1ZJ normally closed contact 2 (19) closed; transfer switch KK normally open contact 6 closed; section contactor 3XC normally open auxiliary contact 1 (31) closed, section contactor 3XC normally closed auxiliary contact 1 (32) opened, section contactor 3XC normally open auxiliary contact 2 (33) and section intermediate relay 3ZJ normally open contact (37) closed; 2) Incoming line 2 fails, standby section is switched on: the normally closed auxiliary contact 3 (25) of incoming line 2 contactor 2XC and the normally closed contact 2 (29) of incoming line 2 intermediate relay 2ZJ are closed; the normally open contact 5 of transfer switch KK is closed; the normally open auxiliary contact 1 (31) of section contactor 3XC is closed, the normally closed auxiliary contact 1 (32) of section contactor 3XC is opened, the normally open auxiliary contact 2 (33) of section contactor 3XC and the normally open contact (37) of section intermediate relay 3ZJ are closed.

5. The automatic backup circuit according to claim 1, characterized in that: When the normally open contact seven of the conversion switch KK is closed, the I-II standby circuit, the I-III standby circuit and the II-III standby circuit are not connected for use.

Images