Multistage loop connection power supply system

Abstract

The utility model relates to the technical field of data power supply, discloses a multi-stage loop-linked power supply system, and aims to solve the problem of poor power supply reliability of an existing station service power system, and the scheme mainly comprises a main power supply and distribution center and a far-end area power distribution center, the main power supply and distribution center comprises a first section of medium-voltage bus, a second section of medium-voltage bus, a third section of medium-voltage bus, a fourth section of medium-voltage bus, a first main power supply, a second main power supply, a third main power supply, a fourth main power supply and a first external power supply; the far-end area distribution center comprises a fifth section of medium-voltage bus, a sixth section of medium-voltage bus and a VII section of medium-voltage bus; each section of medium-voltage working bus of the main power supply and distribution center forms a ring connection wiring structure, and the main power supply and distribution center provides two main power supplies for the far-end area distribution center to form a large ring connection wiring structure with the medium-voltage bus of the far-end area distribution center. The system improves the reliability and continuity of power supply and the flexibility of operation, and is especially suitable for an auxiliary power system of a large-scale power plant.

Description

Technical Field

[0001] The present application relates to the technical field of power supply, and in particular to a multi-level ring-connected power supply system. Background Art

[0002] The power supply system of a large power plant has the characteristics of large power supply load, wide power supply range, dispersed load points, and large capacity of a single motor. The power supply of the power supply system usually includes the main power supply, external backup power supply and emergency security power supply. Among them, the main power supply is connected from the generator outlet, the external backup power supply is connected from the nearby regional power grid or the external construction power supply is changed to the backup power supply. The emergency security power supply mostly uses diesel generator sets. Sometimes the power plant also reverses power from the power system as the power supply of the power plant. The power supply distance of a large power plant usually exceeds the power supply radius of the 0.4kV primary voltage, and two-level voltage levels are mostly used for power supply (for example, 10kV power supply voltage and 0.4kV power supply voltage), which is connected from the generator outlet to the high-voltage main distribution center, and then stepped down to the nearby low-voltage distribution center. In the power supply area far away from the main distribution center, a remote regional distribution center is set up. The remote regional distribution center also uses two-level voltage power supply. The main power supply is connected from the main distribution center and stepped down to the low-voltage distribution center near the area.

[0003] The medium-voltage power supply system wiring of the main power supply and distribution center and the remote regional power distribution center of a large power plant usually adopts a single busbar segmented wiring method. Each main power supply is connected to a section of the single busbar segment. The external backup power supply is selected to connect to a certain section of the busbar. The emergency security power supply can be connected to the main power supply and distribution center or the remote regional power distribution center as needed. Both can be used as the emergency security power supply for the whole plant. Its voltage level can be selected according to the scale of the power plant, and it is connected to the medium-voltage power supply system busbar or to the key load section busbar of the low-voltage power distribution center of the power plant. The low-voltage power supply system wiring of the power plant adopts single busbar or single busbar segmented wiring as needed.

[0004] The current wiring method of the power supply system of large power plants is that when the main power supply of a section of bus is lost, the adjacent bus needs to be used as the main power supply to supply power to this section of bus. When the adjacent bus is under maintenance or fails, and this section of bus is not connected to an external backup power supply, this section of bus will lose power. Similarly, for the bus connected to an external backup power supply, when the main power supply of this section of bus is lost, the adjacent bus is under maintenance or fails, which may block the external backup power supply to other normal bus sections. Similar situations will occur when the emergency security power supply is put into use. Such a power supply system has low power supply reliability, continuity and operational flexibility, which will increase the probability of accidents in serious cases. Utility Model Content

[0005] The present application aims to solve the problem of poor reliability of power supply in existing factory power systems and proposes a multi-level ring-connected power supply system.

[0006] The technical solution adopted by this application to solve the above technical problems is:

[0007] A multi-stage ring-linked power supply system, the system includes a main power supply and distribution center and a remote area power distribution center, the main power supply and distribution center includes a section I medium-voltage bus, a section II medium-voltage bus, a section III medium-voltage bus, a section IV medium-voltage bus, a first main power supply, a second main power supply, a third main power supply, a fourth main power supply and a first external power supply, the remote area power distribution center includes a section V medium-voltage bus, a section VI medium-voltage bus and a section VII medium-voltage bus; the first main power supply is connected to the section I medium-voltage bus through a first circuit breaker, the second main power supply is connected to the section II medium-voltage bus through a second circuit breaker, the third main power supply is connected to the section III medium-voltage bus through a third circuit breaker, the fourth main power supply is connected to the section IV medium-voltage bus through a fourth circuit breaker, the section I medium-voltage The busbar is connected to the medium-voltage busbar of section V through the fifth circuit breaker, the medium-voltage busbar of section IV is connected to the medium-voltage busbar of section VI through the sixth circuit breaker, the medium-voltage busbar of section I is connected to the medium-voltage busbar of section II through the seventh circuit breaker, the medium-voltage busbar of section II is connected to the medium-voltage busbar of section III through the eighth circuit breaker and the ninth circuit breaker in sequence, the medium-voltage busbar of section III is connected to the medium-voltage busbar of section IV through the tenth circuit breaker, the medium-voltage busbar of section I is also connected to the medium-voltage busbar of section IV through the eleventh circuit breaker and the twelfth circuit breaker in sequence, the first external power supply is connected to the medium-voltage busbar of section I through the thirteenth circuit breaker, the medium-voltage busbar of section V is connected to the medium-voltage busbar of section VII through the fourteenth circuit breaker, and the medium-voltage busbar of section VII is connected to the medium-voltage busbar of section VI through the fifteenth circuit breaker.

[0008] Furthermore, the remote area power distribution center also includes a second external power supply, and the second external power supply is connected to the medium voltage busbar of section VII through the sixteenth circuit breaker.

[0009] Furthermore, the remote area power distribution center also includes an emergency power supply, which is connected to the medium voltage busbar section VII through the seventeenth circuit breaker.

[0010] The beneficial effects of the present application are as follows: the multi-level ring-connected power supply system provided by the present application, by planning the power supply area, setting up the main power supply and distribution center and the remote regional power distribution center, enables the power supply to be operated relatively independently, realize the power supply nearby, and facilitate on-site maintenance and management, and can also be operated jointly to ensure continuous power supply. The medium-voltage working busbars of each section of the main power supply and distribution center form a ring connection wiring structure. The main power supply and distribution center provides two main power supplies to the remote regional power distribution center, and constructs a large ring connection wiring structure with the medium-voltage busbars of the remote regional power distribution center, thereby ensuring that when any section of the medium-voltage working busbar is maintained or fails, the other sections of the medium-voltage working busbars can operate normally, thereby improving the reliability, continuity and flexibility of power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram of the structure of a multi-level ring-connected power supply system provided in an embodiment of the present application;

[0012] Figure 2 A schematic diagram of the structure of another multi-level ring-connected power supply system provided in an embodiment of the present application;

[0013] Description of reference numerals:

[0014] 1-main power distribution center; 2-remote regional power distribution center; 3-section I medium voltage bus; 4-section II medium voltage bus; 5-section III medium voltage bus; 6-section IV medium voltage bus; 7-section V medium voltage bus; 8-section VI medium voltage bus; 9-section VII medium voltage bus; 10-local low voltage bus at various locations in the main power distribution center; 11-first circuit breaker; 11'-first main power supply; 12--second circuit breaker; 12'-second main power supply; 13-third circuit breaker; 13'-third main power supply; 14-fourth circuit breaker; 14'-fourth main power supply; 15 -fifth circuit breaker; 16-sixth circuit breaker; 17-seventh circuit breaker; 18-eighth circuit breaker; 19-ninth circuit breaker; 20-tenth circuit breaker; 21-eleventh circuit breaker; 22-twelfth circuit breaker; 23-thirteenth circuit breaker; 23'-first external power supply; 24-fourteenth circuit breaker; 25-fifteenth circuit breaker; 26-sixteenth circuit breaker; 26'-second external power supply; 27-seventeenth circuit breaker; 27'-emergency power supply; 28-local low-voltage busbars in various locations in the remote area distribution center; 29-local low-voltage busbars for key loads in the remote area distribution center. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0016] See also Figure 1The multi-stage ring-connected power supply system provided in the embodiment of the present application includes a main power distribution center 1 and a remote regional power distribution center 2, wherein the main power distribution center 1 includes a section I medium-voltage bus 3, a section II medium-voltage bus 4, a section III medium-voltage bus 5, a section IV medium-voltage bus 6, a first main power supply 11', a second main power supply 12', a third main power supply 13', a fourth main power supply 14' and a first external power supply 23', and the remote regional power distribution center 2 includes a section V medium-voltage bus 3, a section II medium-voltage bus 4, a section III medium-voltage bus 5, a section IV medium-voltage bus 6, a first main power supply 11', a second main power supply 12', a third main power supply 13', a fourth main power supply 14' and a first external power supply 23'. The first main power supply 11' is connected to the medium voltage bus 3 of section I through the first circuit breaker 11, the second main power supply 12' is connected to the medium voltage bus 4 of section II through the second circuit breaker 12, the third main power supply 13' is connected to the medium voltage bus 5 of section III through the third circuit breaker 13, the fourth main power supply 14' is connected to the medium voltage bus 6 of section IV through the fourth circuit breaker 14, and the The first section medium voltage bus 3 is connected to the fifth section medium voltage bus 7 through the fifth circuit breaker 15, the fourth section medium voltage bus 6 is connected to the sixth section medium voltage bus 8 through the sixth circuit breaker 16, the first section medium voltage bus 3 is connected to the second section medium voltage bus 4 through the seventh circuit breaker 17, the second section medium voltage bus 4 is connected to the third section medium voltage bus 5 through the eighth circuit breaker 18 and the ninth circuit breaker 19 in turn, the third section medium voltage bus 5 is connected to the fifth section medium voltage bus 5 through the tenth circuit breaker 20 is connected to the IV section medium voltage bus 6, the I section medium voltage bus 3 is also connected to the IV section medium voltage bus 6 through the eleventh circuit breaker 21 and the twelfth circuit breaker 22 in sequence, the first external power supply 23' is connected to the I section medium voltage bus 3 through the thirteenth circuit breaker 23, the V section medium voltage bus 7 is connected to the VII section medium voltage bus 9 through the fourteenth circuit breaker 24, and the VII section medium voltage bus 9 is connected to the VI section medium voltage bus 8 through the fifteenth circuit breaker 25.

[0017] In the embodiment of the present application, the remote area power distribution center 2 further includes a second external power source 26 ′, and the second external power source 26 ′ is connected to the section VII medium voltage bus 9 through the sixteenth circuit breaker 26 .

[0018] In the embodiment of the present application, the remote area power distribution center 2 further includes an emergency power supply 27 ′, and the emergency power supply 27 ′ is connected to the section VII medium voltage bus 9 via the seventeenth circuit breaker 27 .

[0019] In the embodiment of the present application, the medium-voltage busbar 3 of the first section of the main power distribution center 1 is connected to the medium-voltage busbar 4 of the second section, the medium-voltage busbar 5 of the third section, and the medium-voltage busbar 6 of the fourth section in a ring connection through the seventh circuit breaker 17 to the twelfth circuit breaker 22. The medium-voltage busbar 3 of the first section of the main power distribution center 1 leads out a power supply, which is connected to the medium-voltage busbar 7 of the fifth section of the remote regional power distribution center 2 through the fifth circuit breaker 15; the medium-voltage busbar 6 of the fourth section of the main power distribution center 1 leads out a power supply, which is connected to the medium-voltage busbar 8 of the sixth section of the remote regional power distribution center 2 through the sixth circuit breaker 16; the medium-voltage busbar 7 of the fifth section of the remote regional power distribution center 2 is connected to the medium-voltage busbar 9 of the seventh section and the medium-voltage busbar 8 of the sixth section in a ring connection through the fourteenth circuit breaker and the fifteenth circuit breaker, so that the medium-voltage busbars of the main power distribution center 1 and the remote regional power distribution center 2 form a large ring connection line structure.

[0020] See also Figure 2 In the embodiment of the present application, in the main power supply and distribution center 1, the power supply of the local low-voltage busbars 10 at various locations in the main power supply and distribution center is respectively drawn from two adjacent sections of medium-voltage busbars, and is connected to the corresponding low-voltage busbar sections through transformer step-down. In the remote regional power distribution center 2, the power supply of the local non-critical load low-voltage busbars 28 at various locations in the remote regional power supply and distribution center is respectively drawn from the Vth section medium-voltage busbar 7 and the VIth section medium-voltage busbar 8, and is connected to the corresponding low-voltage busbar sections through transformer step-down, or is directly supplied; the power supply of the local critical load low-voltage busbars 29 at various locations in the remote regional power supply and distribution center is drawn from the VIIth section medium-voltage busbar 9, and is connected to the corresponding low-voltage busbar sections through transformer step-down, or is directly supplied.

[0021] Based on the above-mentioned multi-level ring-connected power supply system, the embodiment of the present application includes power supply control of the main power distribution center 1 and power supply control of the remote area power distribution center 2.

[0022] Among them, the power supply control of the main power distribution center 1 mainly includes the following aspects:

[0023] 1. When the first main power supply 11', the second main power supply 12', the third main power supply 13' and the fourth main power supply 14' of the main power supply and distribution center 1 are required to supply power to the section I medium voltage bus 3, the section II medium voltage bus 4, the section III medium voltage bus 5 and the section IV medium voltage bus 6 respectively, the first circuit breaker 11 to the sixth circuit breaker 16 are controlled to be closed, and the seventh circuit breaker 17 to the thirteenth circuit breaker 23 are controlled to be opened.

[0024] When the circuit breakers 11 to 16 are all closed and the circuit breakers 17 to 23 are all opened, the medium-voltage busbar 3 of section I is powered by the first main power supply 11' via the first circuit breaker 11, the medium-voltage busbar 4 of section II is powered by the second main power supply 12' via the second circuit breaker 12, the medium-voltage busbar 5 of section III is powered by the third main power supply 13' via the third circuit breaker 13, the medium-voltage busbar 6 of section IV is powered by the fourth main power supply 14' via the fourth circuit breaker 14, and each section of the busbar is powered independently.

[0025] 2. When the main power distribution center 1 needs to be powered by only one main power source, the first circuit breaker 11 and the fifth circuit breakers 15 to the tenth circuit breakers 20 are controlled to be closed, and the second circuit breakers 12 to the fourth circuit breakers 14 and the eleventh circuit breakers 21 to the thirteenth circuit breakers 23 are controlled to be opened.

[0026] When the circuit breakers 11, 15-20 are all closed and the circuit breakers 12-14, 21-23 are all opened, the section I medium-voltage bus 3 is powered by the first main power supply 11' via the first circuit breaker 11, the section II medium-voltage bus 4 is powered by the section I medium-voltage bus 3 via the seventh circuit breaker 17, the section III medium-voltage bus 5 is powered by the section II medium-voltage bus 4 via the eighth circuit breaker 18 and the ninth circuit breaker 19, and the section IV medium-voltage bus 6 is powered by the section III medium-voltage bus 5 via the tenth circuit breaker 20, that is, all the medium-voltage busbars of the main power distribution center 1 are powered by the first main power supply 11'.

[0027] 3. When the first main power supply 11' of the main power supply and distribution center 1 supplies power to the first section medium voltage bus 3, the second main power supply 12' supplies power to the first section medium voltage bus 4, and the third main power supply 13' and the fourth main power supply 14' need to be repaired or fail, the first circuit breaker 11, the second circuit breaker 12, and the fifth circuit breakers 15 to the tenth circuit breakers 20 are controlled to be closed, and the third circuit breaker 13, the fourth circuit breaker 14, and the eleventh circuit breakers 21 to the thirteenth circuit breakers 23 are controlled to be opened; or the first circuit breaker 11, the second circuit breaker 12, the fifth circuit breaker 15 to the seventh circuit breaker 17, and the tenth circuit breaker 20 to the twelfth circuit breaker 22 are controlled to be closed, and the third circuit breaker 13, the fourth circuit breaker 14, the eighth circuit breaker 18, the ninth circuit breaker 19, and the thirteenth circuit breaker 23 are controlled to be opened.

[0028] When the circuit breakers 11, 12, 15-20 are all closed, and the circuit breakers 13, 14, 21-23 are all open, the first section medium voltage bus 3 is powered by the first main power supply 11' through the first circuit breaker 11, the second section medium voltage bus 4 is powered by the second main power supply 12' through the second circuit breaker 12, the third section medium voltage bus 5 is powered by the second section medium voltage bus 4 through the eighth circuit breaker 18 and the ninth circuit breaker 19, and the fourth section medium voltage bus 6 is powered by the third section medium voltage bus 5 through the tenth circuit breaker 20. At this time, the third main power supply 13' and the fourth main power supply 14' can be overhauled without affecting the normal power supply of the third section medium voltage bus 5 and the fourth section medium voltage bus 6.

[0029] When the circuit breakers 11, 12, 15-17, 20-22 are all closed, and the circuit breakers 13, 14, 18, 19, 23 are all open, the first section medium voltage bus 3 is powered by the first main power supply 11' through the first circuit breaker 11, the second section medium voltage bus 4 is powered by the second main power supply 12' through the second circuit breaker 12, the IV section medium voltage bus 6 is powered by the I section medium voltage bus 3 through the eleventh circuit breaker 21 and the twelfth circuit breaker 22, and the III section medium voltage bus 5 is powered by the IV section medium voltage bus 6 through the tenth circuit breaker 20. At this time, the third main power supply 13' and the fourth main power supply 14' can also be repaired, and the normal power supply of the III section medium voltage bus 5 and the IV section medium voltage bus 6 will not be affected.

[0030] 4. When the first main power supply 11' of the main power supply and distribution center 1 supplies power to the section I medium-voltage bus 3, the third main power supply 13' supplies power to the section III medium-voltage bus 5, and the second main power supply 12' and the fourth main power supply 14' need to be repaired or fail, the first circuit breaker 11, the third circuit breaker 13, and the fifth circuit breakers 15 to the tenth circuit breakers 20 are controlled to be closed, and the second circuit breaker 12, the fourth circuit breaker 14, and the eleventh circuit breakers 21 to the thirteenth circuit breakers 23 are controlled to be opened; or the first circuit breaker 11, the third circuit breaker 13, the fifth circuit breaker 15, the sixth circuit breaker 16, the eighth circuit breaker 18, the ninth circuit breaker 19, the eleventh circuit breaker 21 and the twelfth circuit breaker 22 are controlled to be closed, and the second circuit breaker 12, the fourth circuit breaker 14, the seventh circuit breaker 17, the tenth circuit breaker 20 and the thirteenth circuit breaker 23 are controlled to be opened.

[0031] When the circuit breakers 11, 13, 15-20 are all closed, and the circuit breakers 12, 14, 21-23 are all open, the first section medium voltage bus 3 is powered by the first main power supply 11' through the first circuit breaker 11, the third section medium voltage bus 5 is powered by the third main power supply 13' through the third circuit breaker 13, the second section medium voltage bus 4 is powered by the first section medium voltage bus 3 through the seventh circuit breaker 17, and is also powered by the third section medium voltage bus 5 through the ninth circuit breaker 19 and the eighth circuit breaker 18, and the fourth section medium voltage bus 6 is powered by the third section medium voltage bus 5 through the tenth circuit breaker 20. At this time, the second main power supply 12' and the fourth main power supply 14' can be overhauled without affecting the normal power supply of the second section medium voltage bus 4 and the fourth section medium voltage bus 6.

[0032] When the circuit breakers 11, 13, 15, 16, 18, 19, 21, and 22 are all closed and the circuit breakers 12, 14, 17, 20, and 23 are all opened, the section I medium voltage bus 3 is powered by the first main power supply 11' via the first circuit breaker 11, the section III medium voltage bus 5 is powered by the third main power supply 13' via the third circuit breaker 13, the section II medium voltage bus 4 is powered by the section III medium voltage bus 5 via the ninth circuit breaker 19 and the eighth circuit breaker 18, and the section IV medium voltage bus 6 is powered by the section I medium voltage bus 3 via the eleventh circuit breaker 21 and the twelfth circuit breaker 22. At this time, the second main power supply 12' and the fourth main power supply 14' can be overhauled without affecting the normal power supply of the section II medium voltage bus 4 and the section IV medium voltage bus 6.

[0033] 5. When the first main power supply 11', the second main power supply 12', the third main power supply 13' and the fourth main power supply 14' of the main power supply and distribution center 1 all need maintenance or fail and are powered by the first external power supply 23', the seventh circuit breaker 17 to the tenth circuit breaker 20 and the thirteenth circuit breaker 23 are controlled to be closed, and the first circuit breaker 11 to the sixth circuit breaker 16, the eleventh circuit breaker 21 and the twelfth circuit breaker 22 are controlled to be opened; or the eighth circuit breaker 18 to the thirteenth circuit breaker 23 are controlled to be closed, and the first circuit breaker 11 to the fifth circuit breaker 15 to the seventh circuit breaker 17 are controlled to be opened.

[0034] When circuit breakers 17-20, 23 are all closed and circuit breakers 11-16, 21, 22 are all opened, the section I medium voltage bus 3 is powered by the first external power supply 23' via the thirteenth circuit breaker 23, the section II medium voltage bus 4 is powered by the section I medium voltage bus 3 via the seventh circuit breaker 17, the section III medium voltage bus 5 is powered by the section II medium voltage bus 4 via the eighth circuit breaker 18 and the ninth circuit breaker 19, and the section IV medium voltage bus 6 is powered by the section III medium voltage bus 5 via the tenth circuit breaker 20, that is, all medium voltage busbars of the main power distribution center 1 are powered by the first external power supply 23'. At this time, the first main power supply 11', the second main power supply 12', the third main power supply 13' and the fourth main power supply 14' can be repaired without affecting the normal power supply of the section I medium voltage bus 3, the section II medium voltage bus 4, the section III medium voltage bus 5 and the section IV medium voltage bus 6.

[0035] When the circuit breakers 18-23 are all closed and the circuit breakers 11-17 are all open, the first section medium voltage bus 3 is powered by the first external power supply 23' through the thirteenth circuit breaker 23, the IV section medium voltage bus 6 is powered by the I section medium voltage bus 3 through the eleventh circuit breaker 21 and the twelfth circuit breaker 22, the III section medium voltage bus 5 is powered by the IV section medium voltage bus 6 through the tenth circuit breaker 20, and the II section medium voltage bus 4 is powered by the III section medium voltage bus 5 through the ninth circuit breaker 19 and the eighth circuit breaker 18. At this time, the first main power supply 11', the second main power supply 12', the third main power supply 13' and the fourth main power supply 14' can be overhauled without affecting the normal power supply of the I section medium voltage bus 3, the II section medium voltage bus 4, the III section medium voltage bus 5 and the IV section medium voltage bus 6.

[0036] The power supply control of the remote regional distribution center 2 mainly includes the following aspects:

[0037] 1. When it is necessary for the section I medium-voltage bus 3 of the main power distribution center 1 to supply power to the section V medium-voltage bus 7 of the remote area power distribution center 2, and the section IV medium-voltage bus 6 to supply power to the section VI medium-voltage bus 8 of the remote area power distribution center 2, the fifth circuit breaker 15, the sixth circuit breaker 16 and the fourteenth circuit breaker 24 are all controlled to be closed, and the fifteenth circuit breakers 25 to the seventeenth circuit breakers 27 are all controlled to be opened; or the fifth circuit breaker 15, the sixth circuit breaker 16 and the fifteenth circuit breaker 25 are all controlled to be closed, and the fourteenth circuit breaker 24, the sixteenth circuit breaker 26 and the seventeenth circuit breaker 27 are controlled to be opened.

[0038] When circuit breakers 15, 16, and 24 are all closed and circuit breakers 25 to 27 are all open, the section V medium-voltage bus 7 is powered by the section I medium-voltage bus 3 via the fifth circuit breaker 15, the section VI medium-voltage bus 8 is powered by the section IV medium-voltage bus 6 via the sixth circuit breaker 16, and the section VII medium-voltage bus 9 is powered by the section V medium-voltage bus 7 via the fourteenth circuit breaker 24.

[0039] When circuit breakers 15, 16, and 25 are all closed and circuit breakers 24, 26, and 27 are all open, the section V medium-voltage bus 7 is powered by the section I medium-voltage bus 3 via the fifth circuit breaker 15, the section VI medium-voltage bus 8 is powered by the section IV medium-voltage bus 6 via the sixth circuit breaker 16, and the section VII medium-voltage bus 9 is powered by the section VI medium-voltage bus 8 via the fifteenth circuit breaker 25.

[0040] 2. When it is required that only the first section medium voltage bus 3 of the main power distribution center 1 supplies power to the fifth section medium voltage bus 7, the sixth section medium voltage bus 8 and the seventh section medium voltage bus 9 of the remote area power distribution center 2, the fifth circuit breaker 15, the fourteenth circuit breaker 24 and the fifteenth circuit breaker 25 are all controlled to be closed, and the sixth circuit breaker 16, the sixteenth circuit breaker 26 and the seventeenth circuit breaker 27 are controlled to be opened.

[0041] When circuit breakers 15, 24, and 25 are all closed and circuit breakers 16, 26, and 27 are all open, the section V medium-voltage bus 7 is powered by the section I medium-voltage bus 3 via the fifth circuit breaker 15, the section VII medium-voltage bus 9 is powered by the section V medium-voltage bus 7 via the fourteenth circuit breaker 24, and the section VI medium-voltage bus 8 is powered by the section VII medium-voltage bus 9 via the fifteenth circuit breaker 25.

[0042] 3. When the second external power supply 26' is needed to supply power to the VIIth section medium voltage bus 9 of the remote regional power distribution center 2, and there is no need to supply power to the emergency load of the main power distribution center 1, the fourteenth circuit breaker 24 to the sixteenth circuit breaker 26 are controlled to be closed, and the fifth circuit breaker 15, the sixth circuit breaker 16 and the seventeenth circuit breaker 27 are controlled to be opened.

[0043] When circuit breakers 24-26 are all closed and circuit breakers 15, 16, and 27 are all opened, the section VII medium-voltage bus 9 is powered by the second external power supply 26' via the sixteenth circuit breaker 16, the section V medium-voltage bus 7 is powered by the section VII medium-voltage bus 9 via the fourteenth circuit breaker 24, and the section VI medium-voltage bus 8 is powered by the section VII medium-voltage bus 9 via the fifteenth circuit breaker 25.

[0044] 4. When the emergency power supply 27' is needed to supply power to the VII section medium voltage bus 9 of the remote regional power distribution center 2, if it is not necessary to supply power to the emergency load of the main power distribution center 1, the seventeenth circuit breaker 27 is controlled to be closed, and the fifth circuit breaker 15, the sixth circuit breaker 16 and the fourteenth circuit breakers 24 to the sixteenth circuit breakers 26 are controlled to be disconnected; if it is necessary to supply power to the emergency load of the main power distribution center 1, the fifth circuit breaker 15 to the tenth circuit breaker 20 and the fourteenth circuit breaker 24 are controlled to be closed, and the first circuit breaker 11 to the fourth circuit breaker 14, the eleventh circuit breaker 21 to the thirteenth circuit breaker 23, the fifteenth circuit breaker 25 and the sixteenth circuit breaker 26 are controlled to be disconnected, or the fifth circuit breaker 15 to the tenth circuit breaker 20 and the fifteenth circuit breaker 25 are controlled to be closed, and the first circuit breaker 11 to the fourth circuit breaker 14, the eleventh circuit breaker 21 to the fourteenth circuit breaker 24 and the sixteenth circuit breaker 26 are controlled to be disconnected.

[0045] When the circuit breaker 27 is closed and the circuit breakers 15, 16, 24-26 are all disconnected, the section VII medium voltage bus 9 is powered by the emergency power supply 27' through the seventeenth circuit breaker 27, and the section VI medium voltage bus 8 and the section VII medium voltage bus 9 are not powered. At this time, the emergency equipment powered by the section VII medium voltage bus 9 can work normally.

[0046] When the circuit breakers 15-20 and 24 are all closed and the circuit breakers 11-14, 21-23, 25 and 26 are all opened, the section VII medium-voltage bus 9 is powered by the emergency power supply 27' through the seventeenth circuit breaker 27, the section V medium-voltage bus 7 is powered by the section VII medium-voltage bus 9 through the fourteenth circuit breaker 24, the section I medium-voltage bus 3 is powered by the section V medium-voltage bus 7 through the fifth circuit breaker 15, the section II medium-voltage bus 4 is powered by the section I medium-voltage bus 3 through the seventh circuit breaker 17, the section III medium-voltage bus 5 is powered by the section II medium-voltage bus 4 through the eighth circuit breaker 18 and the ninth circuit breaker 19, and the section IV medium-voltage bus 6 is powered by the section III medium-voltage bus 5 through the tenth circuit breaker 20, that is, all the medium-voltage busbars of the main power distribution center 1 are powered by the emergency power supply 27'.

[0047] When the circuit breakers 15-20, 25 are all closed and the circuit breakers 11-14, 21-24, 26 are all opened, the section VII medium-voltage bus 9 is powered by the emergency power supply 27' through the seventeenth circuit breaker 27, the section VI medium-voltage bus 8 is powered by the section VII medium-voltage bus 9 through the fifteenth circuit breaker 25, the section IV medium-voltage bus 6 is powered by the section VI medium-voltage bus 8 through the sixth circuit breaker 16, the section III medium-voltage bus 5 is powered by the section IV medium-voltage bus 6 through the tenth circuit breaker 20, the section II medium-voltage bus 4 is powered by the section III medium-voltage bus 5 through the ninth circuit breaker 19 and the eighth circuit breaker 18, the section I medium-voltage bus 3 is powered by the section II medium-voltage bus 4 through the seventh circuit breaker 17, and at this time all the medium-voltage busbars of the main power distribution center 1 are also powered by the emergency power supply 27'.

[0048] In summary, the multi-level ring-connected power supply system provided by the present application, by planning the power supply area, setting up the main power supply and distribution center and the remote regional power distribution center, enables the power supply to operate relatively independently to realize the power supply nearby, which is convenient for on-site maintenance and management, and can also operate jointly to ensure continuous power supply. The medium-voltage working busbars of each section of the main power supply and distribution center form a ring connection wiring structure. The main power supply and distribution center provides two main power supplies to the remote regional power distribution center, and constructs a large ring connection wiring structure with the medium-voltage busbars of the remote regional power distribution center, thereby ensuring that when any section of the medium-voltage working busbar is maintained or fails, the other sections of the medium-voltage working busbars can operate normally, thereby improving the reliability, continuity and flexibility of power supply.

Claims

1. A multi-stage ring-connected power supply system, characterized in that: The system includes a main power supply and distribution center and a remote area power distribution center, the main power supply and distribution center includes a section I medium-voltage bus, a section II medium-voltage bus, a section III medium-voltage bus, a section IV medium-voltage bus, a first main power supply, a second main power supply, a third main power supply, a fourth main power supply and a first external power supply, the remote area power distribution center includes a section V medium-voltage bus, a section VI medium-voltage bus and a section VII medium-voltage bus; the first main power supply is connected to the section I medium-voltage bus through a first circuit breaker, the second main power supply is connected to the section II medium-voltage bus through a second circuit breaker, the third main power supply is connected to the section III medium-voltage bus through a third circuit breaker, the fourth main power supply is connected to the section IV medium-voltage bus through a fourth circuit breaker, the section I medium-voltage bus is connected to the section IV medium-voltage bus through a fifth circuit breaker, and the section I medium-voltage bus is connected to the section II medium-voltage bus through a fifth circuit breaker. The circuit breaker is connected to the medium-voltage busbar of section V, the medium-voltage busbar of section IV is connected to the medium-voltage busbar of section VI through the sixth circuit breaker, the medium-voltage busbar of section I is connected to the medium-voltage busbar of section II through the seventh circuit breaker, the medium-voltage busbar of section II is connected to the medium-voltage busbar of section III through the eighth circuit breaker and the ninth circuit breaker in sequence, the medium-voltage busbar of section III is connected to the medium-voltage busbar of section IV through the tenth circuit breaker, the medium-voltage busbar of section I is also connected to the medium-voltage busbar of section IV through the eleventh circuit breaker and the twelfth circuit breaker in sequence, the first external power supply is connected to the medium-voltage busbar of section I through the thirteenth circuit breaker, the medium-voltage busbar of section V is connected to the medium-voltage busbar of section VII through the fourteenth circuit breaker, and the medium-voltage busbar of section VII is connected to the medium-voltage busbar of section VI through the fifteenth circuit breaker.

2. The multi-level ring-connected power supply system according to claim 1, characterized in that: The remote area power distribution center also includes a second external power source, which is connected to the medium-voltage busbar section VII through a sixteenth circuit breaker.

3. The multi-level ring-connected power supply system according to claim 1, characterized in that: The remote area power distribution center also includes an emergency power supply, which is connected to the medium voltage busbar section VII through the seventeenth circuit breaker.

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