CN215646187U

CN215646187U - Security power supply system of large thermal power generating unit

Info

Publication number: CN215646187U
Application number: CN202122295655.4U
Authority: CN
Inventors: 王团结; 何信林; 孟颖琪; 杨胜林; 李毅; 张少鹏; 李春丽; 杜宇; 史振利; 方子朝
Original assignee: Xian Thermal Power Research Institute Co Ltd
Current assignee: Xian Thermal Power Research Institute Co Ltd
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2022-01-25
Anticipated expiration: 2031-09-18

Abstract

The utility model discloses a security power supply system of a large thermal power generating unit, which comprises a station transformer, a station bus A section working incoming line switch, a station bus A section, a station bus B section working incoming line switch, a station bus B section, a startup transformer, a station bus A section standby incoming line switch, a station bus B section standby incoming line switch, a security working transformer A, a security power supply working PC I section and a security working transformer B, the system comprises a security power supply working PC II section, a security power supply MCC I section, a security power supply MCC II section, a security section first working power supply switch, a security section bus, a security section second working power supply switch, a security section bus, a high-voltage diesel generator, a diesel generator security transformer, a security section standby power supply switch, a standby automatic switching device and a diesel generator control and grid connection module.

Description

Security power supply system of large thermal power generating unit

Technical Field

The utility model belongs to the technical field of power generation side station service systems, and relates to a security power supply system of a large thermal power generating unit.

Background

Along with the increase of the unit capacity, the capacity of the accident security diesel generator set is increased. The emergency safety power supply is used as a guarantee power supply for guaranteeing that the unit can be safely shut down in an accident, and ensures that a power plant

The equipment safety and the system safety of the main machine and the auxiliary machine play very important roles. GB50660-2011 design Specification of large and medium thermal power plants stipulates in a mandatory article form that 200MW and above units are provided with an alternating current security power supply, and the diesel generating set which is started quickly is determined to be adopted by the alternating current security power supply. Except that a standby power supply of a nuclear power unit and a black start diesel generator set of a part of gas turbines adopt a high-voltage diesel generator set, a common diesel generator set takes a low-voltage diesel generator set as an alternating-current accident security power supply.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provides a security power supply system of a large thermal power generating unit, which can greatly improve the reliability of the security power supply system of the thermal power generating unit.

In order to achieve the above purpose, the security power supply system of the large thermal power generating unit comprises a station transformer, a station bus A section working incoming line switch, a station bus A section, a station bus B section working incoming line switch, a station bus B section, a startup transformer, a station bus A section standby incoming line switch, a station bus B section standby incoming line switch, a security work transformer A, a security power work PC I section, a security work transformer B, a security power work PC II section, a security power MCC I section, a security power MCC II section, a security section first working power supply switch, a security section bus, a security section second working power supply switch, a security section bus, a high-voltage diesel generator, a diesel generator security transformer, a security section standby power supply switch, a standby automatic switching device and a diesel generator control and grid-connected module;

the low-voltage side of the service transformer is connected with the service bus A section through a service bus A section working incoming switch, and the low-voltage side of the service transformer is connected with the service bus B section through a service bus B section working incoming switch;

the low-voltage side of the starting-up transformer is connected with the section A of the service bus through the section A of the service bus standby incoming switch, and the low-voltage side of the starting-up transformer is connected with the section B of the service bus through the section B of the service bus standby incoming switch;

the section A of the factory bus is connected with the high-voltage side of the security work transformer A, the low-voltage side of the security work transformer A is connected with the section I of the security power supply work PC, the section B of the factory bus is connected with the high-voltage side of the security work transformer B, and the low-voltage side of the security work transformer B is connected with the section II of the security power supply work PC;

the working PC I section of the security power supply is connected with the MCC I section of the security power supply, and the working PC II section of the security power supply is connected with the MCC II section of the security power supply;

the section MCC I of the security power supply is connected with a security section bus through a security section first working power supply switch, and the section MCC II of the security power supply is connected with the security section bus through a security section second working power supply switch;

the high-voltage diesel generator is connected with a safety section bus through a safety transformer of the diesel generator and a safety section standby power switch;

the first working power switch of the security section, the second working power switch of the security section and the standby power switch of the security section are connected with the spare power automatic switching device, and the spare power automatic switching device is connected with the diesel generator control and grid-connected module;

the working incoming line switch of the section A of the factory bus is connected with the switch auxiliary contact of the standby incoming line switch of the section A of the factory bus in series to form a first series node, the working incoming line switch of the section B of the factory bus is connected with the switch auxiliary contact of the standby incoming line switch of the section B of the factory bus in series to form a second series node, and the first series node and the second series node are connected with the diesel generator control and grid-connected module in series.

The section A of the station bus is connected with the high-voltage side of the security work transformer A through a security power work PC I section incoming line switch 9.

The section B of the station bus is connected with the high-voltage side of the security work transformer B through a security power work PC II section incoming line switch.

The working PC I section of the security power supply is connected with the MCC I section of the security power supply through the MCC I section incoming line switch of the security power supply.

The security power supply working PC II section is connected with the security power supply MCC II section through the security power supply MCC II section incoming line switch.

The high-voltage diesel generator is connected with the safety section bus through the diesel generator outlet circuit breaker, the diesel generator safety transformer and the safety section standby power switch.

When the automatic bus transfer device works, a bus voltage loss signal is sent to the diesel generator control and grid connection module by the automatic bus transfer device.

The utility model has the following beneficial effects:

when the security power supply system of the large-scale thermal power generating unit is operated specifically, the high-voltage diesel generator can be started quickly when power loss occurs in service, the parallel operation requirement is met, and meanwhile, the reliability of the security power supply system of the thermal power generating unit is greatly improved by utilizing the advantages of large capacity and stable loading capacity of the high-voltage diesel generator.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Wherein, 1 is a service transformer, 2 is a standby transformer, 3 is a service bus A section working incoming switch, 4 is a service bus B section working incoming switch, 5 is a service bus A section standby incoming switch, 6 is a service bus B section standby incoming switch, 7 is a service bus A section, 8 is a service bus B section, 9 is a security power supply working PC I section incoming switch, 10 is a security power supply working PC II section incoming switch, 11 is a security working change A, 12 is a security working change B, 13 is a security power supply working PC I section, 14 is a security power supply working PC II section, 15 is a security power supply MCC I section incoming switch, 16 is a security power supply MCC II section incoming switch, 17 is a security power supply MCC I section, 18 is a security power supply II section, 19 is a security section first working power switch, 20 is a security section second working power switch, 21 is a security section standby power switch, a protection section first working switch, a protection section second switch, 22 is a safety section bus, 23 is a diesel generator safety transformer, 24 is a diesel generator outlet breaker, 25 is a high-voltage diesel generator, 26 is a backup automatic switching device, and 27 is a diesel generator control and grid-connected module.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the utility model. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1, the emergency power supply system of the large-scale thermal power generating unit of the present invention includes a service transformer 1, a startup transformer 2, a service bus a-section working incoming line switch 3, a service bus B-section working incoming line switch 4, a service bus a-section standby incoming line switch 5, a service bus B-section standby incoming line switch 6, a service bus a-section 7, a service bus B-section 8, a security power working PC I-section incoming line switch 9, a security power working PC II-section incoming line switch 10, a security working transformer a11, a security working transformer B12, a security power working PC I-section 13, a security power working PC II-section 14, a security power MCC I-section incoming line switch 15, a security power MCC II-section incoming line switch 16, a security power MCC I-section 17, a security power MCC II-section 18, a security section first working power switch 19, a security section second working power switch 20, a security section standby power switch 21, a security section standby power switch 16, a security power switch 17, a security switch 18, a security switch, The system comprises a safety section bus 22, a diesel generator safety transformer 23, a diesel generator outlet circuit breaker 24, a high-voltage diesel generator 25, a backup automatic switching device 26 and a diesel generator control and grid connection module 27;

the low-voltage side of the station transformer 1 is connected with a station bus A section 7 through a station bus A section working incoming line switch 3, and the low-voltage side of the station transformer 1 is connected with a station bus B section 8 through a station bus B section working incoming line switch 4;

the low-voltage side of the starting-up transformer 2 is connected with a station bus A section 7 through a station bus A section standby incoming line switch 5, and the low-voltage side of the starting-up transformer 2 is connected with a station bus B section 8 through a station bus B section standby incoming line switch 6;

the station bus A section 7 is connected with the high-voltage side of the security work transformer A11 through a security power work PC I section incoming line switch 9, the low-voltage side of the security work transformer A11 is connected with the security power work PC I section 13, the station bus B section 8 is connected with the high-voltage side of the security work transformer B12 through a security power work PC II section incoming line switch 10, and the low-voltage side of the security work transformer B12 is connected with the security power work PC II section 14;

the Personal Computer (PC) I section 13 of the security power supply is connected with the MCC I section 17 of the security power supply through a security power supply MCC I section incoming line switch 15, and the Personal Computer (PC) II section 14 of the security power supply is connected with the MCC II section 18 of the security power supply through a security power supply MCC II section incoming line switch 16;

the security power MCC I section 17 is connected with a security section bus 22 through a security section first working power switch 19, and the security power MCC II section 18 is connected with the security section bus 22 through a security section second working power switch 20;

the high-voltage diesel generator 25 is connected with the security section bus 22 through a diesel generator outlet circuit breaker 24, a diesel generator security transformer 23 and a security section standby power switch 21;

the first working power switch 19 of the security segment, the second working power switch 20 of the security segment and the standby power switch 21 of the security segment are connected with a backup automatic switching device 26, the backup automatic switching device 26 is connected with a diesel generator control and grid-connected module 27, and when the backup automatic switching device 26 works, a bus voltage loss signal is sent to the diesel generator control and grid-connected module 27;

the working incoming line switch 3 of the section A of the service bus is connected in series with the switch auxiliary contact of the standby incoming line switch 5 of the section A of the service bus to form a first series node, the working incoming line switch 4 of the section B of the service bus is connected in series with the switch auxiliary contact of the standby incoming line switch 6 of the section B of the service bus to form a second series node, and the first series node and the second series node are connected in series with the diesel generator control and grid connection module 27.

The start and grid-tie operation of the high voltage diesel generator 25 is controlled by a diesel generator control and grid-tie module 27.

It should be noted that, in the conventional security power supply system, the spare automatic switching device 26 starts the diesel engine after receiving a voltage loss signal, and since the service transformer 1 performs a protection action or the switch trips secretly and the service transformer spare incoming line switch cannot be switched on, the service bus voltage loss is caused, so that the security section bus 22 voltage loss has a long time delay, and in addition, when the diesel generator is switched on after voltage is built, the bus voltage is often reduced by a large range, the instantaneous current impact of the diesel generator set is large, and the security power supply system cannot recover power supply due to load failure caused by the low-voltage action of the diesel generator.

The switch auxiliary contacts of the working incoming line switch 3 of the section A of the service bus and the standby incoming line switch 5 of the section A of the service bus are connected in series, the switch auxiliary contacts of the working incoming line switch 4 of the section B of the service bus and the standby incoming line switch 6 of the section B of the service bus are connected in series, and the two series-connected contacts are connected with the diesel generator control and grid-connected module 27 after being connected in series.

When a series connection contact action instruction is received, the diesel generator control and grid connection module 27 starts the high-voltage diesel generator 25 to simultaneously lock the synchronous function, the high-voltage diesel generator 25 starts voltage build-up, and after the voltage build-up succeeds, the diesel generator control and grid connection module 27 controls the diesel generator outlet circuit breaker 24 to be directly switched on.

When a serial connection contact action instruction is not received, but a bus voltage loss signal of the spare automatic switching device 26 is received, the diesel generator control and grid connection module 27 starts the high-voltage diesel generator 25, the high-voltage diesel generator 25 starts voltage building, after the voltage building works, when the voltage reduction amplitude of the bus 22 of the security segment is within a grid connection pressure difference fixed value, the diesel generator control and grid connection module 27 adjusts the rotating speed of the high-voltage diesel generator 25 within a frequency difference and angle difference fixed value range so as to control the outlet circuit breaker 24 of the diesel generator to be connected to the grid; when the voltage reduction amplitude of the safety section bus 22 exceeds the grid-connected differential pressure fixed value, the diesel generator control and grid-connected module 27 locks the synchronous function and controls the diesel generator outlet circuit breaker 24 to be directly switched on.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A security power supply system of a large-scale thermal power generating unit is characterized by comprising a station transformer (1), a station bus A section working incoming line switch (3), a station bus A section (7), a station bus B section working incoming line switch (4), a station bus B section (8), a startup transformer (2), a station bus A section standby incoming line switch (5), a station bus B section standby incoming line switch (6), a security working transformer A (11), a security power working PC I section (13), a security working transformer B (12), a security power working PC II section (14), a security power MCC I section (17), a security power MCC II section (18), a security section first working power switch (19), a security section bus (22), a security section second working power switch (20), a security section bus (22), a high-voltage diesel generator (25), The system comprises a diesel generator security transformer (23), a security section standby power switch (21), a standby automatic switching device (26) and a diesel generator control and grid connection module (27);

the low-voltage side of the station transformer (1) is connected with a station bus A section (7) through a station bus A section working incoming line switch (3), and the low-voltage side of the station transformer (1) is connected with a station bus B section (8) through a station bus B section working incoming line switch (4);

the low-voltage side of the starting-up transformer (2) is connected with a section A of the service bus through a section A of the service bus standby incoming line switch (5), and the low-voltage side of the starting-up transformer (2) is connected with a section B of the service bus through a section B of the service bus standby incoming line switch (6);

the section A of the factory bus (7) is connected with the high-voltage side of the security work transformer A (11), the low-voltage side of the security work transformer A (11) is connected with the security power supply work PC I section (13), the section B of the factory bus (8) is connected with the high-voltage side of the security work transformer B (12), and the low-voltage side of the security work transformer B (12) is connected with the security power supply work PC II section (14);

the security power supply working PC I section (13) is connected with the security power supply MCC I section (17), and the security power supply working PC II section (14) is connected with the security power supply MCC II section (18);

the security power MCC I section (17) is connected with a security section bus (22) through a security section first working power switch (19), and the security power MCC II section (18) is connected with the security section bus (22) through a security section second working power switch (20);

the high-voltage diesel generator (25) is connected with a security section bus (22) through a diesel generator security transformer (23) and a security section standby power switch (21);

the first working power switch (19) of the security section, the second working power switch (20) of the security section and the standby power switch (21) of the security section are connected with a spare power automatic switching device (26), and the spare power automatic switching device (26) is connected with a diesel generator control and grid connection module (27);

the working incoming line switch (3) of the section A of the factory bus is connected with the auxiliary switch contact of the standby incoming line switch (5) of the section A of the factory bus in series to form a first series node, the working incoming line switch (4) of the section B of the factory bus is connected with the auxiliary switch contact of the standby incoming line switch (6) of the section B of the factory bus in series to form a second series node, and the first series node and the second series node are connected with the diesel generator control and grid connection module (27) in series.

2. The emergency power supply system of a large thermal power generating unit according to claim 1, wherein the station bus a section (7) is connected to the high-voltage side of the emergency operating transformer a (11) through an emergency power supply operating PC I section incoming line switch (9).

3. The emergency power supply system of a large thermal power generating unit according to claim 1, wherein the station bus B section (8) is connected to the high-voltage side of the emergency work substation B (12) through an emergency power work PC II section incoming line switch (10).

4. The emergency power supply system of a large thermal power generating unit according to claim 1, wherein the emergency power supply working PC I section (13) is connected to the emergency power supply MCC I section (17) through an emergency power supply MCC I section incoming line switch (15).

5. The emergency power supply system of a large thermal power generating unit according to claim 1, wherein the emergency power supply working PC II section (14) is connected to the emergency power supply MCC II section (18) through an emergency power supply MCC II section incoming line switch (16).

6. The security power supply system of a large thermal power generating unit according to claim 1, wherein the high voltage diesel generator (25) is connected to the security section bus (22) through a diesel generator outlet circuit breaker (24), a diesel generator security transformer (23) and a security section standby power switch (21).

7. The safety power supply system of a large thermal power generating unit according to claim 6, wherein in operation, the backup automatic switching device (26) sends a bus voltage loss signal to the diesel generator control and grid connection module (27).