Arrangement structure of newly-added electrical equipment of modified phase modifier of old generator set

Abstract

According to the arrangement structure, a first main transformer is connected with a second phase modifier through a main isolated-phase enclosed bus, the input side and the output side of the second phase modifier are each provided with a current transformer, and the other end of the second phase modifier is connected with a grounding transformer; the main isolated-phase enclosed bus is also connected with a variable-frequency starting device through a machine-end high-voltage isolation switch cabinet, and the other end of the variable-frequency starting device is connected with a variable-frequency isolation transformer; the main isolated-phase enclosed bus is also connected with an excitation transformer through a branch isolated-phase enclosed bus. The input side and the output side of the excitation transformer are respectively provided with a bushing current transformer. The beneficial effects of the utility model are that the synchronous phase modifier can improve the dynamic voltage and dynamic reactive power support capability of a regional power grid, and improve the transient stability of the regional power grid. And the synchronous phase modifier can provide static reactive power support, and guarantee is provided for the scheduling flexibility of a regional power grid with a complex power grid structure, a high new energy proportion or a high feed proportion.

Description

Technical Field

[0001] The utility model relates to the electrical field, in particular to a layout structure for newly adding electrical equipment to an old generator set for modifying a phase regulator. Background Art

[0002] In recent years, Henan Province has made in-depth adjustments and continuous optimizations to its energy structure. The proportion of clean electricity from outside the region and new energy power generation within the province in the power supply has continued to increase. Accepting large-scale clean electricity from outside the region and new energy power generation within the province is an inevitable choice for optimizing Henan Province's energy structure.

[0003] In order to ensure that external electricity can be placed and new energy can be generated, thermal power units in Henan Province need to provide sufficient regulation and support capabilities. Therefore, the use and transformation of thermal power units to increase the operation of phase-shifting functions and increase the number of grid-connected "generators" can improve Henan's ability to receive external electricity and new energy generation in the area, and promote the optimization and upgrading of Henan's energy structure, ecological protection of the Yellow River Basin, and the rise of the central region. Utility Model Content

[0004] The technical problem to be solved by the utility model is: how to modify old generator sets, and therefore a new electrical equipment layout structure for modifying old generator sets is provided.

[0005] The technical solution of the utility model is specifically as follows:

[0006] A new electrical equipment arrangement structure for replacing an old generator set with a phase regulator comprises a No. 1 main transformer, the No. 1 main transformer is connected to a No. 2 phase regulator through a main phase-isolated closed busbar, current transformers are respectively arranged on the input side and the output side of the No. 2 phase regulator, and the other end of the No. 2 phase regulator is connected to a grounding transformer; and the main phase-isolated closed busbar is also connected to a frequency conversion starter through a machine-end high-voltage isolation switch cabinet, and the other end of the frequency conversion starter is connected to a frequency conversion isolation transformer;

[0007] The main isolated-phase enclosed busbar is also connected to the excitation transformer through the branch isolated-phase enclosed busbar, and bushing current transformers are respectively arranged on the input side and the output side of the excitation transformer.

[0008] The variable frequency starting device is arranged in the excitation room, and the excitation room is located below the platform of the original excitation room.

[0009] The excitation transformer is arranged in the excitation room, and the excitation transformer is arranged under the main phase-isolated closed busbar, and the main phase-isolated closed busbar and the excitation transformer are T-connected.

[0010] The main phase-isolated enclosed busbar is also connected to the #1 high-voltage plant transformer through a switching switch.

[0011] The beneficial effects of the utility model are as follows: it has the following advantages: for the thermal power units to be retired or planned to be shut down, the old units can be transformed into phase-shifting units, the main significance of which includes:

[0012] (1) After the transformation, the synchronous condenser can improve the dynamic voltage and dynamic reactive power support capabilities of the regional power grid and improve the transient stability of the regional power grid.

[0013] (2) After the transformation, the synchronous condenser can provide static reactive power support, ensuring the dispatching flexibility of regional power grids with complex grid structures, high proportion of renewable energy, or high feed-in ratio. At the same time, it can make positive contributions to the rotational inertia and short-circuit power of the regional power grid system.

[0014] (3) After the transformation, the synchronous condenser fully exerted its overload excitation capability and, under some extreme operating modes, weakened the minimum startup mode constraint of the regional power grid to a certain extent.

[0015] (4) After the transformation, only the main electrical equipment and related control systems are retained in the original thermal power unit, and the boiler, steam turbine and related auxiliary systems are basically dismantled or shut down. From the perspective of environmental protection and economy, it is equivalent to shutting down the original thermal power unit, which greatly improves environmental protection, energy consumption and other indicators and has good social value.

[0016] (5) On the one hand, the reuse and reconstruction of thermal power units basically meets the relevant requirements of the power grid system for the main performance parameters of phase-shifting units. On the other hand, the reuse and reconstruction has a very high cost-effectiveness, with an investment cost of about 30% of the construction cost of a new unit, saving investment and having good economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the main electrical wiring diagram of the utility model;

[0018] Figure 2 This is the equipment layout diagram of the excitation room before the transformation;

[0019] Figure 3 This is the equipment layout diagram of the excitation room after the transformation;

[0020] Figure 4 This is the layout diagram of the closed busbar after transformation;

[0021] Figure 5 for Figure 4 Middle AA view;

[0022] Figure 6 for Figure 4 Middle BB view. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0025] This utility model patent is based on the Nanyang Yahekou Unit 2 reuse and reconstruction project, and proposes a new electrical layout structure in combination with the actual situation on site.

[0026] The No. 2 generator unit of Yahekou Power Plant was renovated to add phase-shifting function, and the original main plant equipment layout and unit grid connection plan were maintained unchanged. The phase-shifting transformer unit outgoing line was used to step up the voltage and connect to the power distribution device in the plant. No new system outgoing lines were added in this period.

[0027] like Figure 1 As shown, an arrangement structure of newly added electrical equipment for the old generator set to be replaced with a phase regulator includes a No. 1 main transformer 1, which is connected to a No. 2 phase regulator 4 through a main phase-isolated closed bus 2, and current transformers 5 are respectively provided on the input side and output side of the No. 2 phase regulator 4, and the other end of the No. 2 phase regulator 4 is connected to a grounding transformer 6; and the main phase-isolated closed bus 2 is also connected to a variable frequency starting device 8 through a machine-end high-voltage isolation switch cabinet 7. In the Nanyang Yahekou Unit 2 reconstruction project, the other end of the variable frequency starting device 8 is connected to a 6KV desulfurization 2-stage 20BBK10 standby cabinet through a variable frequency isolation transformer 9.

[0028] Furthermore, the main isolated-phase enclosed busbar 2 is also connected to an excitation transformer 11 through a branch isolated-phase enclosed busbar 10 , and bushing current transformers 12 are respectively provided on the input side and the output side of the excitation transformer 11 .

[0029] Furthermore, the main phase-closed busbar 2 can also be connected to the #1 high-voltage plant transformer 3 through a switching switch, and the switching switch is used to control whether the #1 high-voltage plant transformer 3 is put into operation. In the Nanyang Yahekou Unit 2 reconstruction project, the #1 high-voltage plant transformer 3 stopped operating.

[0030] like Figure 2As shown in the figure, it is the equipment layout of the excitation room before the transformation, which is equipped with a PT cabinet, an excitation transformer cabinet and an excitation cabinet, which contain primary components such as the excitation system rectifier bridge, demagnetization switch, demagnetization resistor, and RC absorption module. However, the existing devices do not meet the phase-shifting phase operation requirements, and the entire system needs to be updated.

[0031] like Figure 3 As shown, the equipment layout diagram of the excitation room after the transformation, in the utility model, the phase modulator starting system is recommended to adopt a variable frequency starting device 8, and a variable frequency starting device 8 is configured in the project. The other end of the variable frequency starting device 8 is connected to a variable frequency isolation transformer 9, wherein the variable frequency starting device 8 mainly includes an excitation regulator, an excitation output switch, an excitation isolation switch, a starting power supply cabinet, etc. The variable frequency starting device 8 is arranged in the excitation room 13, and the excitation room 13 is located below the original excitation room platform.

[0032] like Figure 4 , Figure 5 and Figure 6 As shown, the excitation transformer 11 is disposed in the excitation room 13 , and the excitation transformer 11 is arranged under the main isolated-phase closed bus 2 , so that the isolated-phase bus T is connected to the excitation transformer 11 .

[0033] For thermal power units to be retired or planned to be shut down, the transformation of old units into phase-shifting units has the following main significances:

[0034] (1) After the transformation, the synchronous condenser can improve the dynamic voltage and dynamic reactive power support capabilities of the regional power grid and improve the transient stability of the regional power grid.

[0035] (2) After the transformation, the synchronous condenser can provide static reactive power support, ensuring the dispatching flexibility of regional power grids with complex grid structures, high proportion of renewable energy, or high feed-in ratio. At the same time, it can make positive contributions to the rotational inertia and short-circuit power of the regional power grid system.

[0036] (3) After the transformation, the synchronous condenser fully exerted its overload excitation capability and, under some extreme operating modes, weakened the minimum startup mode constraint of the regional power grid to a certain extent.

[0037] (4) After the transformation, only the main electrical equipment and related control systems are retained in the original thermal power unit, and the boiler, steam turbine and related auxiliary systems are basically dismantled or shut down. From the perspective of environmental protection and economy, it is equivalent to shutting down the original thermal power unit, which greatly improves environmental protection, energy consumption and other indicators and has good social value.

[0038] (5) On the one hand, the reuse and reconstruction of thermal power units basically meets the relevant requirements of the power grid system for the main performance parameters of phase-shifting units. On the other hand, the reuse and reconstruction has a very high cost-effectiveness, with an investment cost of about 30% of the construction cost of a new unit, saving investment and having good economic value.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A layout structure for newly adding electrical equipment to an old generator set for modification of a regulated phase, characterized in that: The invention comprises a No. 1 main transformer (1), wherein the No. 1 main transformer (1) is connected to a No. 2 phase regulator (4) via a main phase-isolated closed busbar (2), current transformers (5) are respectively arranged on the input side and the output side of the No. 2 phase regulator (4), and the other end of the No. 2 phase regulator (4) is connected to a grounding transformer (6); and the main phase-isolated closed busbar (2) is also connected to a variable frequency starting device (8) via a machine-end high-voltage isolating switch cabinet (7), and the other end of the variable frequency starting device (8) is connected to a variable frequency isolation transformer (9); The main isolated-phase enclosed busbar (2) is also connected to an excitation transformer (11) via a branch isolated-phase enclosed busbar (10), and bushing current transformers (12) are respectively arranged on the input side and the output side of the excitation transformer (11).

2. The arrangement structure of newly added electrical equipment for replacing old generator sets with regulated power generators according to claim 1 is characterized by: The variable frequency starting device (8) is arranged in an excitation room (13), and the excitation room (13) is located below the platform of the original excitation room.

3. The new electrical equipment layout structure for replacing old generator sets with a regulated power generator according to claim 2 is characterized by: The excitation transformer (11) is arranged in an excitation room (13), the excitation transformer (11) is arranged under a main phase-isolated closed busbar (2), and a T-connection is formed between the main phase-isolated closed busbar (2) and the excitation transformer (11).

4. The new electrical equipment layout structure for replacing old generator sets with a regulated power generator according to claim 1 is characterized by: The main phase-isolated enclosed busbar (2) is also connected to the #1 high-voltage plant transformer (3) via a switching switch.

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