JP2024069959A - Transformer replacement method - Google Patents

Abstract

[Problem] To provide a transformer replacement method that can replace a transformer installed in the premises of a substation or the like in a short period of time. [Solution] A transformer replacement method for replacing a transformer installed in the premises adjacent to a transformer retention steel structure includes the steps of: installing a new second transformer in an empty space in the vicinity of a first transformer to be replaced in the premises and in the vicinity of the transformer retention steel structure, where foundation work has been performed; performing a predetermined modification work on the transformer retention steel structure to install the second transformer, forming a shape for installing lead wires from a main circuit that is arranged in the transformer retention steel structure; connecting the lead wires to the second transformer according to the formed lead wires; and disconnecting the first transformer from the main circuit and removing the first transformer. [Selected Figure] Figure 3

Description

The present invention relates to a transformer replacement method for replacing a transformer installed within the premises of a substation or the like.

Transformers installed in primary substations and other facilities are devices that transform AC power. Such transformers are several meters to several tens of meters in size, and are usually installed on foundations that have been laid within the premises of the substation or other facility.

When a transformer needs to be replaced due to breakdowns or aging, a period of time must be secured for the work to replace the transformer and the transformer must be shut down for that period. However, when it is difficult to secure such a shutdown period, the usual procedure is to carry out foundation work in a new space within the premises, install a new transformer, and then carry out work to remove the old transformer.

As a technique for replacing equipment in such facilities, a construction method that enables equipment (switchgear) replacement without laying a new foundation is known (see, for example, Patent Document 1). The switchgear replacement method described in Patent Document 1 involves installing a secondary distribution box and in-house GPT of a new switchgear in the surplus space of the foundation, connecting it to a transformer in parallel with the existing switchgear, removing the distribution line box of the existing switchgear from the foundation, installing the distribution line box of the new switchgear on the foundation and connecting it to the transformer, and removing the secondary distribution box and in-house GPT box of the existing switchgear from the foundation.

JP 2021-097482 A

However, when replacing the transformer itself, the switchgear replacement method described in Patent Document 1 cannot be applied, and a method that allows the transformer to be replaced in a short period of time is required.

The present invention aims to provide a transformer replacement method that allows for the replacement of transformers in a short period of time.

In order to solve the above problem, the invention of claim 1 is a transformer replacement method in which a transformer retention steel structure is installed and a transformer installed within the premises adjacent to the transformer retention steel structure is replaced, the transformer replacement method comprising the steps of: installing a new second transformer in an empty space in the premises adjacent to the first transformer to be replaced and adjacent to the transformer retention steel structure, where foundation work has been done; carrying out predetermined modification work for installing the second transformer on the transformer retention steel structure, making a mold for installing lead wires from the main circuit arranged on the transformer retention steel structure; connecting the lead wires to the second transformer according to the mold for the lead wires; and disconnecting the first transformer from the main circuit and removing the first transformer.

The invention of claim 2 is characterized in that in the step of installing the second transformer in the transformer replacement method described in claim 1, the second transformer is installed in a position adjacent to the transformer retaining steel structure so as to face the first transformer adjacent to the transformer retaining steel structure.

The invention of claim 3 is characterized in that in the step of carrying out specified modification work on the transformer retaining steel structure in the transformer replacement method described in claim 1, the insulators installed on the transformer retaining steel structure are changed to correspond to the second transformer.

The invention of claim 4 is characterized in that, in the transformer replacement method described in any one of claims 1 to 3, in a process prior to the step of installing the second transformer, a step is carried out in which a device that has been installed on the secondary side of the first transformer and whose foundation has been laid is relocated to secure the free space.

The invention of claim 5 is characterized in that in the transformer replacement method described in claim 4, in the step of relocating the device, the device includes either or both of a shunt reactor and a neutral reactor installed within the premises.

According to the invention described in claim 1, a new second transformer is installed in an empty space near the first transformer to be replaced and near the transformer retaining steel structure, where foundation work has been done, the specified modification work is carried out on the transformer retaining steel structure, a mold is made for installing lead wires from the main circuit, the lead wires are connected to the second transformer, and the first transformer is removed. This makes it possible to reuse the circuit breakers, disconnecting switches, busbar steel structure, etc. already installed on the premises. This makes it possible to replace the transformer in a short period of time.

According to the invention described in claim 2, the second transformer is installed adjacent to the transformer retaining steel structure so as to face the first transformer adjacent to the transformer retaining steel structure. This allows replacement work to be carried out near the existing transformer, making it possible to replace the transformer in a short period of time.

According to the invention described in claim 3, the insulators installed on the transformer retaining steel structure are changed to accommodate the second transformer. This allows the work to be carried out in parallel with other process work, making it possible to replace the transformer in a short period of time.

According to the inventions described in claims 4 and 5, the equipment installed on the secondary side of the first transformer with foundation work done, specifically the shunt reactor or neutral point reactor, is relocated to secure free space. This makes it possible to reuse the circuit breakers, disconnectors, busbar ironwork, etc. already installed on the premises. This makes it possible to replace the transformer in a short period of time.

1 is a plan view of a premises showing an example of a premises 1 in which a transformer 10 is installed, which is the subject of a transformer replacement method according to a first embodiment of the present invention. FIG. FIG. 2 is a side view showing the premises 1 of FIG. 1. 4 is a flowchart showing a transformer replacement method according to the first embodiment of the present invention. 2 is a plan view showing a state in which a shunt reactor 40 and a neutral point reactor 50 have been moved from the state shown in FIG. 1 . 5 is a plan view showing a state in which a new transformer 60 has been installed, following the state shown in FIG. 4. FIG. FIG. 5 is a side view showing the premises 1 of FIG. 4. 6 is a plan view showing a state in which the transformer 10 has been removed from the state shown in FIG. 5. FIG. FIG. 8 is a side view showing the premises 1 of FIG. 7.

The present invention will be described below based on the illustrated embodiment.

(overview)
The transformer replacement method according to the embodiment of the present invention is a transformer replacement method for replacing a transformer installed in a primary substation, etc. This transformer replacement method is a method that makes it possible to shorten the continuous shutdown period of a transformer even in cases where it is difficult to shut down the transformer for a long period of time when replacing the transformer due to its failure or aging.

Figure 1 is a plan view of a premises 1 showing an example of a premises in which a transformer 10 is installed, in which the transformer replacement method according to the first embodiment of the present invention is carried out. Also, Figure 2 is a side view showing the premises 1 of Figure 1.

The premises 1 shown in FIG. 1 is a plan view showing an excerpt of the premises of a facility such as a primary substation. The substation, which is an example of the premises 1, is a primary substation that converts the voltage of electricity in a power system and controls the flow of power by connecting and opening and closing each power system. Such substations also reduce the voltage of electricity transmitted from power plants and transmit it to large factories, etc. Such substations are also facilities that send electricity to secondary substations, where the voltage is further reduced and transmitted to small and medium-sized factories, etc.

As shown in Figs. 1 and 2, the premises 1 includes a transformer 10, a transformer retaining steel structure 20, multiple high-voltage lines (main circuits) (high-voltage lines 31, 32, and 33 are shown in Fig. 1. Hereinafter, they may be collectively referred to as "high-voltage lines 30"), a shunt reactor 40, and a neutral point reactor 50. The transformer 10 is a facility that transforms the voltage transmitted from a power plant, which is an example of the premises 1 (e.g., from 110,000V to 66,000V). The transformer retaining steel structure 20 is a gate-shaped facility (shown as a tower in Fig. 2, but has a shape that extends in the depth direction) for supporting the high-voltage line 30, and is usually a steel structure of several tens of meters in length. The high-voltage line 30 is a power transmission line that transmits high-voltage power (e.g., 6,600V power) output from a substation. The shunt reactor (ShR) 40 is a device that is connected to the shunt of the AC circuit and compensates for the leading reactive power by supplying lagging reactive power of the high-voltage line 30. The neutral point reactor (NGL) 50 is a device that is connected to the neutral point of the power system and prevents an abnormal rise in the voltage to ground in the event of a ground fault in the power system, as well as compensating for the system's capacitance to ground.

As shown in Figures 1 and 2, the transformer 10 is installed adjacent to the transformer retaining iron structure 20, and a lead wire branching from the high-voltage line 30 is connected to it. The shunt reactor 40 and neutral point reactor 50 are installed adjacent to the transformer retaining iron structure 20, facing the transformer 10, and on the secondary side of the transformer 10. As shown in Figure 2, the high-voltage line 30 passes above the transformer 10, the shunt reactor 40, and the neutral point reactor 50, and is installed while being supported by the transformer retaining iron structure 20.

In the premises 1, the transformer 10, the transformer retaining iron structure 20, the shunt reactor 40, and the neutral reactor 50 are installed on the ground on which foundation work has been performed. Here, foundation work refers to digging the ground to perform earthing work, installing cable pits, etc., and pouring concrete to prepare the various devices such as the transformer 10 for installation.

The transformer replacement method according to the first embodiment is a method for replacing transformer 10, but if there is no free space near transformer 10 to install a new replacement transformer, it must be installed at a location away from transformer 10. This requires the installation of new circuit breakers, disconnecting switches, busbar steel structures, etc., and foundation work if not done at the locations where these devices will be installed, so it is necessary to ensure a long construction period.

For example, when replacing a transformer at a distribution substation, it is possible to shut down the transformer to be replaced for an extended period of time by installing a temporary portable transformer. However, in the case of transformers at primary substations, the capacity is so large that installing a temporary portable transformer is not possible.

In this embodiment, the shunt reactor 40 and neutral point reactor 50 are relocated, and a new transformer is installed in the space created, making effective use of existing facilities, which makes it possible to replace the transformer in a short period of time and shorten the period of continuous shutdown of the transformer.

In this embodiment, the shunt reactor 40 and neutral point reactor 50 are shown as examples of equipment to be relocated, but the equipment is not limited to these, and other equipment that can be relocated within the premises 1 may be used.

(Embodiment 1)
<Process flow>
3 to 8 show this embodiment, and Fig. 3 is a flowchart showing the transformer replacement method according to the first embodiment of the present invention. An example of the flow of the transformer replacement method according to the first embodiment of the present invention will be described with reference to Figs. 3 to 8.

In step S101, the shunt reactor 40 and neutral point reactor 50 are relocated from their current positions facing the transformer (first transformer) 10. The shunt reactor 40 and neutral point reactor 50 may be relocated to any position that allows the respective devices to function, and it is preferable that they are not far from their current positions in terms of the wiring, etc.

Figure 4 is a plan view showing the state in which the shunt reactor 40 and neutral point reactor 50 have been relocated from the state shown in Figure 1. As shown in Figure 4, in the process of step S101, the shunt reactor 40 and neutral point reactor 50 are relocated to a position that does not face the transformer 10. This position is close to the original installation positions of the shunt reactor 40 and neutral point reactor 50, and wiring work is also easy, so it is a desirable position.

If foundation work has not been done at the new location of the shunt reactor 40 and neutral point reactor 50, foundation work is also done to relocate them to that location. However, even if foundation work has been done beforehand, improvement work is required to install the shunt reactor 40 and neutral point reactor 50. In addition, wiring work is also done in the process of step S101, but if existing circuit breakers and disconnectors can be used, they may be used.

In step S102, a new transformer (second transformer) 60 is installed in the premises 1. The transformer 60 is a replacement for the current transformer 10, and is a device that has the same functions as the transformer 10. The location where the transformer 60 is installed is, for example, the location where the shunt reactor 40 and neutral point reactor 50 were installed, and is the vacant space secured by relocating the shunt reactor 40 and neutral point reactor 50.

Figure 5 is a plan view showing the state in which a new transformer 60 has been installed, following the state shown in Figure 4. As shown in Figure 5, in the process of step S102, the transformer 60 is moved to a position opposite the transformer 10, where the shunt reactor 40 and neutral point reactor 50 were originally installed. This position is near the transformer 10 and near the transformer retaining iron structure 20, specifically, adjacent to the transformer retaining iron structure 20 and opposite the transformer 10, which is a desirable position for connecting the lead wires to the high voltage line 30.

In this embodiment, the shunt reactor 40 and neutral point reactor 50 are relocated and the transformer 60 is installed in that position, but if there is vacant space in a similar position, the transformer 60 may be installed without relocating the equipment.

The process of step S103 involves making a specified modification to the transformer retaining steel structure 20. Modification to the transformer retaining steel structure 20 specifically refers to, for example, work to change the insulators installed on the transformer retaining steel structure 20 to accommodate the transformer 60, but is not limited to such work and refers to general refurbishment work to accommodate the transformer 60.

Figure 6 is a side view showing the premises 1 of Figure 4. As shown in Figure 6, in the process of step S103, the insulators 70 installed on the transformer retaining iron structure 20 are changed to insulators for 110 kV, for example, to correspond to the transformer 60. The process of step S103 may be performed in parallel with the process of step S102.

In step S104, a mold is made for connecting and installing the lead wire from the high-voltage line 30 to the transformer 60. As shown in FIG. 6, in step S104, a mold is made for installing the lead wire 80 that is drawn from the high-voltage line 30. Step S104 may be performed in parallel with steps S102 and S103.

In step S105, the lead wire 80 from the high-voltage line 30 is connected to the transformer 60. In step S105, the lead wire 80 drawn from the high-voltage line 30 is connected to the transformer 60 according to the mold made in step S104. Step S105 may be performed in parallel with steps S102 and S103.

In step S106, the transformer 10 to be replaced is removed. At this time, work is performed to disconnect the transformer 10 from the lead wires 80. Note that step S106 is performed simultaneously with step S105, but is separated into separate steps for the sake of explanation.

Figure 7 is a plan view showing the state after the transformer 10 has been removed from the state shown in Figure 5. Also, Figure 8 is a side view showing the premises 1 of Figure 7. As shown in Figures 7 and 8, in the process of step S106, the transformer 10 shown in Figures 5 and 6 is removed.

＜Effects＞
According to the transformer replacement method of the first embodiment, a new transformer (second transformer) 60 is installed in an empty space installed in the premises 1, near the transformer (first transformer) 10 to be replaced and near the transformer dead-end ironwork 20, where foundation work has been done (the position before the shunt reactor 40 and neutral point reactor 50 are relocated), a predetermined modification work is performed on the transformer dead-end ironwork 20, a mold is made for installing lead wires from the high-voltage line (main circuit) 30, the lead wires are connected to the transformer 60, and the transformer 10 is removed. Therefore, it is possible to reuse the circuit breakers, disconnectors, busbar ironwork, etc. already installed in the premises 1. This makes it possible to replace the transformer 10 with the transformer 60 in a short period of time.

The transformer 60 is also installed adjacent to the transformer retaining steel structure 20 so as to face the transformer 10 adjacent to the transformer retaining steel structure 20. This allows replacement work to be carried out near the existing transformer 10, making it possible to replace the transformer in a short period of time.

The insulators 70 installed on the transformer retaining steel structure 20 are also changed to accommodate the transformer 60. This allows the work to be carried out in parallel with other process steps, such as the installation process of the transformer 60, making it possible to replace the transformer in a short period of time.

Furthermore, the shunt reactor 40 and neutral point reactor 50 (either one or both may be used), which are devices installed on the secondary side of the transformer 10 after foundation work has been completed, are relocated to secure free space. This makes it possible to reuse the circuit breakers, disconnecting switches, busbar ironwork, etc. already installed on the premises 1. This makes it possible to replace the transformer in a short period of time.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and even if there are design changes within the scope of the invention that do not deviate from the gist of the invention, they are still included in the invention.

1: Premises 10: Transformer 20: Transformer dead-end iron structure 30: High-voltage line 31: High-voltage line 32: High-voltage line 33: High-voltage line 40: Shunt reactor 50: Neutral reactor 60: Transformer 70: Insulator 80: Lead wire

Claims (5)

A transformer replacement method in which a transformer retention iron structure is installed and a transformer installed in a premises adjacent to the transformer retention iron structure is replaced,
a step of installing a new second transformer in an empty space in the vicinity of the first transformer to be replaced and in the vicinity of the transformer dead-end steel structure in the premises, where foundation work has been carried out;
carrying out predetermined remodeling work for installing the second transformer on the transformer dead-end iron structure, and taking a mold for installing lead wires from a main circuit arranged on the transformer dead-end iron structure;
connecting the leads to the second transformer along the lead pattern;
disconnecting the first transformer from the main circuit and removing the first transformer;
A transformer replacement method comprising the steps of: In the step of installing the second transformer, the second transformer is installed at a position adjacent to the transformer dead-end ironwork so as to face the first transformer adjacent to the transformer dead-end ironwork.
The transformer replacement method according to claim 1 . In a step of carrying out a predetermined modification work on the transformer retention iron structure, insulators installed on the transformer retention iron structure are changed to correspond to the second transformer.
The transformer replacement method according to claim 1 . In a process prior to the step of installing the second transformer,
a step of relocating a device installed on the secondary side of the first transformer with foundation work completed, and securing the free space;
The transformer replacement method according to any one of claims 1 to 3. In the step of relocating the device, the device includes either or both of a shunt reactor and a neutral point reactor installed in the premises,
The transformer replacement method according to claim 4.