Shutdown standby power supply connecting structure of multi-shaft gas-steam combined cycle unit

Abstract

The utility model discloses a shutdown standby power supply connection structure of a multi-shaft gas-steam combined cycle unit. The shutdown standby power supply connection structure comprises a generator set, a booster station, a shutdown standby transformer, a high-voltage station transformer and a station medium-voltage bus, the generator set comprises a set of gas turbine generator set and at least one set of steam turbine generator set; the gas turbine generator set comprises a gas turbine main transformer and a gas turbine generator, and the steam turbine generator set comprises a steam turbine main transformer and a steam turbine generator; the gas turbine generator is connected into the booster station through a gas turbine main transformer, and the steam turbine generator is connected into the booster station through a steam turbine main transformer. The gas turbine main transformer is connected to the plant medium-voltage bus through the high-voltage plant transformer, and the at least one set of turbine generator set shutdown standby transformer is connected to the plant medium-voltage bus. According to the utility model, the voltage class of the shutdown standby transformer is reduced, the cost is reduced, the switching failure risk caused by the switching phase angle difference problem of the factory medium-voltage power supply is avoided, and the power supply reliability is improved.

Description

Technical Field

[0001] This utility model relates to the field of power supply connection technology for power plants, and in particular to a backup power supply connection structure for a multi-shaft gas-steam combined cycle unit during shutdown. Background Technology

[0002] Gas-steam combined cycle (GSBC) is an advanced power generation technology that is gaining increasing attention and development in the power industry due to its advantages such as high efficiency and low consumption, fast start-up, flexible regulation, high availability, low investment, short construction period, and low environmental pollution.

[0003] For multi-shaft gas-steam combined cycle generator sets, it is necessary to provide shutdown power and backup power for both the gas turbine and steam turbine units. The existing conventional solution is to draw emergency shutdown / backup power from the plant's booster station, and accordingly install high-voltage emergency shutdown / backup transformers to provide shutdown power and backup power for the gas turbine and steam turbine units. However, the cost of the high-voltage distribution equipment bays at the booster station and the high-voltage emergency shutdown / backup transformers is relatively high. Furthermore, because the shutdown / backup transformers and the high-voltage plant transformers have different wiring groups, there is a phase angle difference between the working power supply and backup power supply of the plant's medium-voltage busbar, which poses a risk of power switching failure. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a backup power supply connection structure for a multi-shaft gas-steam combined cycle unit during shutdown. The specific technical solution is as follows:

[0005] This includes generator sets, substations, standby transformers, high-voltage plant transformers, and medium-voltage busbars for plant use;

[0006] The generator set includes at least one gas turbine generator set and at least one steam turbine generator set;

[0007] The gas turbine generator set includes a gas turbine main transformer and a gas turbine generator; the steam turbine generator set includes a steam turbine main transformer and a steam turbine generator.

[0008] The gas turbine generator is connected to the booster station via a gas turbine main transformer, and the steam turbine generator is connected to the booster station via a steam turbine main transformer;

[0009] The gas turbine main transformer is connected to the plant medium-voltage busbar via the high-voltage plant service transformer.

[0010] Furthermore, both the steam turbine generator set and the gas turbine generator set are equipped with one set, and the main transformer of the steam turbine is connected to the plant service medium-voltage busbar through the standby transformer.

[0011] Furthermore, both the steam turbine generator set and the gas turbine generator set are provided in two sets, with the main transformer of one set connected to the plant service medium-voltage busbar through the standby transformer.

[0012] Furthermore, a turbine generator circuit breaker is connected between the main turbine transformer and the turbine generator;

[0013] A gas turbine generator circuit breaker is connected between the gas turbine main transformer and the gas turbine generator.

[0014] Furthermore, when both the steam turbine generator set and the gas turbine generator set are provided in two sets, in only one set of the steam turbine generator set connected to the plant service medium-voltage busbar, a steam turbine generator circuit breaker is connected between the main steam turbine transformer and the steam turbine generator.

[0015] Furthermore, the plant service medium-voltage busbar is connected to the low-voltage end of the gas turbine main transformer and the steam turbine main transformer respectively through the high-voltage plant service transformer and the shutdown standby transformer.

[0016] Furthermore, the standby transformer for shutdown has the same wiring group as the high-voltage plant service transformer.

[0017] Furthermore, the standby transformer for shutdown has the same voltage level as the steam turbine generator.

[0018] The beneficial effects of this utility model are as follows:

[0019] This invention connects the standby transformer for shutdown to the plant's medium-voltage busbar on the low-voltage side of the main transformer of the turbine, enabling emergency shutdown / standby power to be drawn from the low-voltage side of the main transformer of the turbine. Compared with the existing connection structure, this saves one high-voltage distribution device bay, reduces the voltage level of the standby transformer for shutdown, and makes the voltage level of the standby transformer for shutdown the same as that of the turbine generator, thus reducing costs.

[0020] 2. Based on the connection structure of this utility model, the connection groups of the standby transformer and the high-voltage plant service transformer are consistent. There is no phase angle difference when switching between the working power supply and the standby power supply of the plant service medium-voltage bus, which eliminates the risk of switching failure and improves the reliability of power supply.

[0021] 3. Based on the connection structure of this utility model, it is only necessary to connect the shutdown / standby power supply from the low-voltage side of one of the turbine main transformers to meet the standby power supply requirements of the entire power plant, which can be applied to the current needs of multi-unit combined cycle power plants. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the lead-in structure of Embodiment 1 of this utility model.

[0023] Figure 2 This is a schematic diagram of the lead-in structure of Embodiment 2 of this utility model.

[0024] Explanation of reference numerals in the attached diagram: 1-Step-up substation, 2-Steam turbine generator set, 201-Steam turbine main transformer, 202-Steam turbine generator circuit breaker, 203-Steam turbine generator, 3-Gas turbine generator set, 301-Gas turbine main transformer, 302-Gas turbine generator circuit breaker, 303-Gas turbine generator, 4-Standby transformer for shutdown, 5-High voltage plant service transformer, 6-Medium voltage busbar for plant service. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. The components of the embodiments of the present utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0026] In the description of the embodiments of this utility model, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly used when the utility model product is in use. These are only for the convenience of describing the utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, the terms "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Example 1

[0029] Embodiment 1 of this utility model discloses a shutdown backup power supply connection structure for a multi-shaft gas-steam combined cycle unit, such as... Figure 1 As shown, it includes a generator set, a step-up substation 1, a standby transformer 4, a high-voltage plant transformer 5, and a medium-voltage plant busbar 6.

[0030] The step-up substation 1 is the step-up substation 1 within the power plant, and the outgoing lines of the step-up substation 1 are connected to the external power grid.

[0031] The generator set includes at least one gas turbine generator set 3 and at least one steam turbine generator set 2;

[0032] The gas turbine generator set 3 includes a gas turbine main transformer 301 and a gas turbine generator 303, and the steam turbine generator set 2 includes a steam turbine main transformer 201 and a steam turbine generator 203.

[0033] Specifically, the gas turbine generator set 3 is a gas turbine generator set, the gas turbine generator 303 is a gas turbine generator, and the gas turbine main transformer 301 is the main transformer corresponding to the gas turbine generator;

[0034] The steam turbine generator set 2 is a steam turbine generator set, the steam turbine generator 203 is a steam turbine generator, and the steam turbine main transformer 201 is the main transformer corresponding to the steam turbine generator.

[0035] The gas turbine generator 303 is connected to the booster station 1 via the gas turbine main transformer 301, and the steam turbine generator 203 is connected to the booster station 1 via the steam turbine main transformer 201;

[0036] In this embodiment, the gas turbine generator set 3 is provided with one set, and the gas turbine main transformer 301 is connected to the plant service medium voltage bus 6 through the high voltage plant service transformer 5. The high voltage plant service transformer 5 is used to reduce the voltage of the gas turbine generator 303 to the voltage level of the plant service medium voltage bus 6.

[0037] In a preferred embodiment, the steam turbine generator set 2 is provided with one set, and the main steam turbine transformer 201 is connected to the plant service medium-voltage busbar 6 through the shutdown standby transformer 4.

[0038] In a preferred embodiment, a turbine generator circuit breaker 202 is connected between the turbine main transformer 201 and the turbine generator 203;

[0039] A gas turbine generator circuit breaker 302 is connected between the gas turbine main transformer 301 and the gas turbine generator 303.

[0040] In a preferred embodiment, the plant service medium-voltage busbar 6 is connected to the low-voltage terminals of the gas turbine main transformer 301 and the steam turbine main transformer 201 through the high-voltage plant service transformer 5 and the shutdown standby transformer 4, respectively.

[0041] In a preferred embodiment, the standby transformer 4 and the high-voltage plant service transformer 5 have the same wiring group;

[0042] Specifically, the wiring group is DYn11.

[0043] In a preferred embodiment, the standby transformer 4 has the same voltage level as the steam turbine generator 203.

[0044] Example 2

[0045] Embodiment 2 of this utility model discloses a shutdown backup power supply connection structure for a multi-shaft gas-steam combined cycle unit, such as... Figure 2 As shown, it includes a generator set, a step-up substation 1, a standby transformer 4, a high-voltage plant transformer 5, and a medium-voltage plant busbar 6.

[0046] The step-up substation 1 is the step-up substation 1 within the power plant, and the outgoing lines of the step-up substation 1 are connected to the external power grid.

[0047] The generator set includes at least one gas turbine generator set 3 and at least one steam turbine generator set 2;

[0048] The gas turbine generator set 3 includes a gas turbine main transformer 301 and a gas turbine generator 303, and the steam turbine generator set 2 includes a steam turbine main transformer 201 and a steam turbine generator 203.

[0049] Specifically, the gas turbine generator set 3 is a gas turbine generator set, the gas turbine generator 303 is a gas turbine generator, and the gas turbine main transformer 301 is the main transformer corresponding to the gas turbine generator;

[0050] The steam turbine generator set 2 is a steam turbine generator set, the steam turbine generator 203 is a steam turbine generator, and the steam turbine main transformer 201 is the main transformer corresponding to the steam turbine generator.

[0051] The gas turbine generator 303 is connected to the booster station 1 via the gas turbine main transformer 301, and the steam turbine generator 203 is connected to the booster station 1 via the steam turbine main transformer 201;

[0052] In this embodiment, the gas turbine generator set 3 is provided in two sets. The gas turbine main transformer 301 is connected to the plant service medium-voltage bus 6 through the high-voltage plant service transformer 5. The high-voltage plant service transformer 5 is used to reduce the voltage of the gas turbine generator 303 to the voltage level of the plant service medium-voltage bus 6.

[0053] In a preferred embodiment, the steam turbine generator set 2 is provided in two sets, one of which has a main steam turbine transformer 201 connected to the plant service medium-voltage busbar 6 through the shutdown standby transformer 4.

[0054] In a preferred embodiment, a turbine generator circuit breaker 202 is connected between the turbine main transformer 201 and the turbine generator 203 in a turbine generator set 2 connected to the plant service medium-voltage busbar 6.

[0055] A gas turbine generator circuit breaker 302 is connected between the gas turbine main transformer 301 and the gas turbine generator 303.

[0056] In a preferred embodiment, the plant service medium-voltage busbar 6 is connected to the low-voltage ends of the gas turbine main transformer 301 and the steam turbine main transformer 201 through the high-voltage plant service transformer 5 and the shutdown standby transformer 4, respectively.

[0057] In a preferred embodiment, the standby transformer 4 and the high-voltage plant service transformer 5 have the same wiring group;

[0058] Specifically, the wiring group is DYn11.

[0059] In a preferred embodiment, the standby transformer 4 has the same voltage level as the steam turbine generator 203.

[0060] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A shutdown standby power lead structure of a multi-shaft gas-steam combined cycle unit, characterized by, The power generation unit, a booster station, a shutdown standby transformer, a high-voltage auxiliary transformer and an auxiliary medium-voltage bus; The power generation unit comprises at least one gas turbine power generation unit and at least one steam turbine power generation unit; The gas turbine power generation unit comprises a gas turbine main transformer and a gas turbine generator, and the steam turbine power generation unit comprises a steam turbine main transformer and a steam turbine generator; The gas turbine generator is connected to the booster station through the gas turbine main transformer, and the steam turbine generator is connected to the booster station through the steam turbine main transformer; The gas turbine main transformer is connected to the auxiliary medium-voltage bus through the high-voltage auxiliary transformer, and at least one steam turbine power generation unit shutdown standby transformer is connected to the auxiliary medium-voltage bus.

2. The multi-shaft gas-steam combined cycle unit shutdown standby power source lead-through structure according to claim 1, characterized in that, The steam turbine power generation unit and the gas turbine power generation unit are each provided with one set, and the steam turbine main transformer is connected to the auxiliary medium-voltage bus through the shutdown standby transformer.

3. The multi-shaft gas-steam combined cycle unit shutdown standby power source lead-through structure according to claim 1, characterized in that, The steam turbine power generation unit and the gas turbine power generation unit are each provided with two sets, and the steam turbine main transformer of one set is connected to the auxiliary medium-voltage bus through the shutdown standby transformer.

4. The multi-shaft gas-steam combined cycle unit shutdown standby power supply lead-through structure according to any one of claims 1-2, characterized in that, A steam turbine generator circuit breaker is connected between the steam turbine main transformer and the steam turbine generator. A gas turbine generator circuit breaker is connected between the gas turbine main transformer and the gas turbine generator.

5. The multi-shaft gas-steam combined cycle unit shutdown backup power supply lead-through structure according to claim 3, characterized in that, A gas turbine generator circuit breaker is connected between the gas turbine main transformer and the gas turbine generator of the two sets of gas turbine power generation units. A steam turbine generator circuit breaker is connected between the steam turbine main transformer and the steam turbine generator in one set of steam turbine power generation units connected to the auxiliary medium-voltage bus.

6. The multi-shaft gas-steam combined cycle unit shutdown standby power supply lead-through structure according to any one of claims 2-3, characterized in that, The auxiliary medium-voltage bus is connected to the low-voltage end of the gas turbine main transformer and the steam turbine main transformer through the high-voltage auxiliary transformer and the shutdown standby transformer, respectively.

7. The multi-shaft gas-steam combined cycle unit shutdown standby power supply lead-through structure according to any one of claims 2-3, characterized in that, The shutdown standby transformer and the high-voltage auxiliary transformer have the same wiring group.

8. The multi-shaft gas-steam combined cycle unit shutdown standby power supply lead-through structure according to any one of claims 2-3, characterized in that, The shutdown standby transformer and the steam turbine generator have the same voltage level.

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