JP2017220999A - Power supply system system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system system that implements reduction in installation area and reduction in the number of models.SOLUTION: A power supply system system comprises: a transformer 1 for stepping down high voltage to low voltage, the transformer being connected to a high-voltage metal-enclosed switchgear; and a plurality of control centers 3 for receiving power having low voltage to supply low-voltage power to a plurality of loads, the control centers being connected to the low-voltage side of the transformer 1. The plurality of control centers 3 are connected in parallel on the low-voltage side of the transformer 1. The total value of current capacity of control center main buses 9 arranged inside the plurality of control centers 3 is set so as to be larger than that of current capacity of a transformer main bus 6 connected to the low-voltage side of the transformer 1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to the configuration of a power supply system in a portion of an alternating current power supply system that steps down from a high voltage to a low voltage and supplies power to a load.

  A power plant such as nuclear power or thermal power is composed of electrical equipment for sending generated power to the power transmission system, and on-site auxiliary power supply equipment for on-site auxiliary power and control. In-house auxiliary equipment power supply equipment consists of a high-voltage switchgear that supplies power to a load such as a large-capacity motor, and a power center and control center that supplies power from the high-voltage switchgear to a load such as a medium / small-capacity motor Etc. In these power supply facilities, as a typical bus voltage, high-voltage switchgear supplies high-voltage power obtained by stepping down the generator voltage using an in-house transformer, and power center and control center supplies low-voltage power obtained by stepping down the voltage using a transformer. (For example, refer to Patent Document 1).

If the structure shown in the said patent document 1 is shown with a schematic single line figure, it will become a structure like FIG. FIG. 7 shows a configuration downstream of the high-pressure switchgear. High voltage power from the high voltage switch gear is received by the transformer 21, and the low voltage power that has been stepped down is sent to the power center 22. The power center 22 includes a power center load 23 that is directly connected to the power center 22 and a plurality of low-voltage loads 25 that are connected via a control center 24.
When a load is connected to the lower side in a device other than the transformer 21, in order to protect the load from an accident current, generally, the power center 22 has an air circuit breaker, and the control center 24 includes Is equipped with a circuit breaker.

The air circuit breaker installed in the power center serves to cut off the accident current at the time of the accident and turn on / off the power supply of the load during normal operation.
On the other hand, for the control center, the accident current at the time of the accident is interrupted by the circuit breaker for wiring, but the load power supply during normal operation is turned on and off by a load switch provided separately. .
The reason why the power center is required is that the air circuit breaker is superior in rated short-time current as compared with the circuit breaker for wiring, and only the air circuit breaker may be applicable. In particular, facilities such as nuclear power plants that require extremely high reliability have been required to have a power center.
In general, vacuum circuit breakers and air circuit breakers installed in high-voltage switchgears and power centers can be used for normal load on / off because they have a long service life. Since the circuit breaker used for wiring has a short switching life and is not suitable for turning on and off a normal load, a load switch is provided at the control center.

  As for the current supplied to the equipment on the low voltage side, the voltage applied to the high voltage metal closed switchgear is stepped down by the transformer, so a large current is generated in the power center. It is necessary to select the main circuit bus. Since the current received at the power center is shunted to the load and the control center of the power center, the main circuit bus of the control center generally has a smaller current capacity than the power center, and the outer shape is compact accordingly. It has become.

JP 2001-231159 A (paragraph [0003] etc.)

In the case of a facility such as a nuclear power plant that requires particularly high reliability in a conventional power system, as shown in FIG. 7, a high-voltage metal closed switch is used as a power system configuration from high voltage to low voltage. A gear (not shown), a transformer, a power center, and a control center were required. Therefore, in this case, it is naturally necessary to secure an installation space corresponding to that.
In addition, in nuclear power plants and the like, there is a very high demand for seismic performance compared to general industrial use, and in addition to measures such as strengthening the frame that constitutes the casing with individual models, In order to ensure the seismic performance of each model, extensive testing and analysis are required, resulting in increased costs.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power supply system that aims to reduce the installation area and the number of models to be applied by reviewing the configuration including the transformer. And

  A power supply system according to the present invention includes a transformer connected to a high voltage metal closed type switchgear to step down a high voltage to a low voltage, and a low voltage power connected to a low voltage side of the transformer to receive a low voltage power to a plurality of loads. And a plurality of control centers connected in parallel to the low voltage side of the transformer, and the total value of the current capacity of the control center main buses arranged inside the plurality of control centers is It is set larger than the current capacity of the transformer main bus connected to the low voltage side of the transformer.

  According to the power supply system of the present invention, a transformer and a plurality of control centers are provided, and the plurality of control centers are connected in parallel to the low voltage side of the transformer and are arranged inside the plurality of control centers. The total value of the current capacity of the main bus is set to be larger than the current capacity of the transformer main bus connected to the low voltage side of the transformer. Without passing through, the power can be received directly from the transformer to the control center, the system configuration is simplified, and a power supply system with a reduced installation area can be obtained.

1 is a schematic single line diagram of a power supply system according to Embodiment 1 of the present invention. 1 is a schematic plan view of a power supply system according to Embodiment 1 of the present invention. FIG. 3 is a front view of FIG. 2. It is an internal side view of the transformer accommodating part of FIG. FIG. 3 is an internal plan view of a bus bar conversion unit in FIG. 2. It is an internal side view of the bus-line conversion part of FIG. It is a general | schematic single-line figure of the conventional power supply system.

Embodiment 1 FIG.
Hereinafter, a power supply system according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic single line diagram of a power supply system according to the first embodiment. FIG. 2 is a schematic plan view of the power supply system according to Embodiment 1, and FIG. 3 is a front view of FIG. 4 is an internal side view of the transformer housing part 5 in FIG. 2, FIG. 5 is an internal plan view of the bus bar converting part 2 in FIG. 2, and FIG. 6 is an internal side view of the bus bar converting part 2 in FIG. It is.

The power supply system shown in the first embodiment is intended for a portion that supplies power to a load by stepping down from a high voltage to a low voltage. For example, a high voltage metal closed switchgear is applied with a high voltage of 6.6 kV from an AC power supply system. The electric power received by (not shown) is input to the transformer 1. FIG. 1 shows the part after the transformer 1.
As shown in FIG. 1, the transformer 1 steps down a high voltage of 6.6 kV, for example, to a low voltage of 440 V. On the secondary side of the transformer 1, a plurality of control centers 3 are connected in parallel via the busbar conversion unit 2 without using the power center 22 as described in the background art section. For example, a load 4 such as a motor is connected to each control center 3.

FIG. 2 is a plan view schematically showing the actual arrangement of the equipment constituting the control center 3 from the transformer 1 of FIG. The lower side of FIG. 2 will be described as the front side. FIG. 3 is a front view of FIG. 2 viewed from the front side. The entire arrangement configuration will be described with reference to FIGS.
The transformer 1 is housed in the transformer housing 5 together with the transformer main bus 6. The transformer accommodating part 5 has a door in the front, and the transformer 1 is accommodated in the inside from the front side.
The bus bar conversion unit 2 is configured by housing a branch bus 8 inside a housing 7. As shown in FIG. 2, the housing 7 is arranged symmetrically on the left and right side surfaces as viewed from the front of the transformer housing 5. A plurality of control centers 3 are arranged on the opposite side of the housing 7 from the transformer housing 5.

The plurality of control centers 3 are further divided into a plurality of groups. In FIG. 2, the control center groups 3a, 3b, 3c, 3d and 4 groups are shown.
A control center group 3a and a control center group 3b are arranged at two positions on the front side and the rear side of the housing 7 of the left busbar conversion unit 2 so as to extend outward in the left-right direction. Similarly, a control center group 3c and a control center group 3d are arranged at two locations on the front side and the rear side of the housing 7 of the right busbar conversion unit 2.

The secondary side (low voltage side) of the transformer 1 is connected to the transformer main bus 6 extending in the left-right direction above the transformer 1.
In the bus converter 2, the current of the transformer main bus 6 is branched by the branch bus 8, distributed to the front and rear control center groups 3 a, 3 b, 3 c, 3 d and connected to the respective control center main bus 9. .
As described above, the power system of the first embodiment has a configuration in which the control center 3 that is a low-pressure feeder panel is arranged on four sides on both sides with the transformer housing part 5 as the center and the busbar conversion part 2. Has characteristics.

However, depending on the facility scale, the bus bar conversion unit 2 and the control center 3 connected thereto may be arranged only on one side of the transformer housing unit 5.
Moreover, although the figure shows an example in which three control centers 3 are connected to one group, this number also varies depending on the equipment scale.

Next, each part will be described in more detail.
FIG. 4 is an internal side view of the transformer housing 5. On the primary side, a high voltage cable 11 is connected to the high voltage power receiving terminal 10 from the outside. Although the illustration of the secondary side is omitted, the three-phase transformer main bus 6 is arranged so that the terminal is drawn upward and extends in the left-right direction when viewed from the front side above the transformer 1. It is connected to the.
A control line accommodating chamber 5a is provided in the upper part on the front side inside the transformer accommodating portion 5, and a control line (not shown) is accommodated therein. In addition, a ground bus 12a is disposed at the lower part on the back side, and this ground bus 12a is combined with a ground bus 12b accommodated in a bus converter 2 described later.

  5 and 6 are diagrams showing details of the bus bar conversion unit 2. Of these, FIG. 6 is an internal side view, and FIG. 5 is an internal plan view taken along line V-V in FIG. The bus bar conversion units 2 arranged on the left and right sides of the transformer housing unit 5 are basically the same except that the interiors are arranged symmetrically, and will be described with the bus bar conversion unit 2 arranged on the left side when viewed from the front side. .

As shown in FIGS. 5 and 6, the three-phase transformer main bus 6 extends from the transformer housing 5 to the inside of the housing 7 of the bus converter 2 through the side wall. Further, a three-phase control center main bus 9 extends through the side wall from each of the front control center group 3a and the rear control center group 3b. Actually, it is configured to be separable at the through wall portion from the viewpoint of transportation and assembly. That is, the vicinity of the penetrating wall is a coupling point.
Inside the housing 7, the transformer main bus 6 and the front control center main bus 9 are connected by a branch bus 8a, and the transformer main bus 6 and the rear control center main bus 9 are connected by a branch bus 8b. It is connected. The branch buses 8a and 8b are portions corresponding to the branch bus 8 in FIG.

An instrument transformer 13 is provided through the three-phase branch buses 8 a and 8 b branched from the transformer main bus 6. Further, a control line path 7 a is secured in front of the inside of the housing 7, and a control line housing portion 7 b is secured in the upper part.
The control line from the transformer accommodating part 5 is taken into the control line path 7a and the control line accommodating part 7b, and is delivered to each of the control center groups 3a and 3b via the control line coupling port 7c.
In addition, the ground bus 12a of the transformer housing 5 is connected to the ground bus 12b at the joint and distributed within the housing 7, and is connected to the control center 3 at the control center group 3a, 3b side. Connected to each ground bus 12c.

Although the detailed illustration of the control center 3 is omitted, a plurality of control units are arranged in multiple stages in a metal casing, and each control unit has a circuit breaker or a load switch, and controls them. Control equipment to be housed is housed. A three-phase control center main bus 9 is arranged in the horizontal direction in the uppermost stage, and the control units are connected in parallel by branch conductors branched from the main bus. A load 4 (see FIG. 1) such as a motor is connected to the lower side of each control unit. When a plurality of control centers 3 are arranged in a row, the control center main bus 9 is common to the row.
Here, the total current capacity of the control center main bus 9 is set to be larger than the current capacity of the transformer main bus 6.

Next, the effect of the power supply system of Embodiment 1 is demonstrated.
Since the transformer 1 receives the high voltage power from the high voltage metal closed switchgear and steps down, a large current flows on the secondary side of the transformer 1, that is, the low voltage side. Therefore, a bus converter 2 that distributes the current on the low voltage side of the transformer 1 is provided, and control center groups 3a, 3b, 3c, and 3d in which a plurality of control centers 3 are arranged are connected to a plurality of distribution destinations. In addition, since the low-voltage side current is divided into the control center main bus 9 substantially evenly, the amount of current that can be supplied to each control center 3 is limited, but a plurality of control center groups 3a, 3b, 3c, 3d are provided. The current flowing from the transformer 1 can be directly received by the control center 3 by matching the current capacity flowing in the main bus of the current line and the current capacity on the secondary side of the transformer 1.
From such a viewpoint, it is desirable to arrange the plurality of control center groups 3a, 3b, 3c, 3d as evenly as possible.

In addition, the entire arrangement configuration is controlled so that the transformer housing part 5 is at the center and the bus bar conversion part 2 is arranged on both sides thereof, and the bus bar conversion part 2 is extended to the left and right from a total of four places. Center groups 3a, 3b, 3c, and 3d are arranged, so that the rigidity of the entire structure is increased, and it is possible to handle equipment that requires high reliability and earthquake resistance, such as nuclear power plant equipment. It becomes.
Therefore, the power center described in the background art section can be eliminated by applying to a nuclear power plant.

In the case of using a power center as in the prior art, the power center is arranged near the transformer, and the power center and the control center are connected by a power cable. On the other hand, in the configuration of the first embodiment, since the control center 3 is directly connected to the transformer housing 5 via the busbar conversion unit 2, the installation area of the entire system can be reduced.
In addition, the ease of maintenance improves the maintainability.

The load power supply during normal operation is turned on and off by a load switch mounted on the control center 3. When an accident occurs on the load side after the transformer 1, the accident current at the time of the accident is interrupted by the circuit breaker of the control center 3. This is because the load switch is not suitable for interrupting a large current, but has a long life of switching, and the circuit breaker for wiring can interrupt an accident current but has a short life of switching. If the load on / off frequency is not high, the load switch mounted in the control center 3 can be omitted and replaced with a circuit breaker.
Moreover, even the load directly connected to the power center described in the background section can be handled by the control of the present embodiment.

In the above description, the control center 3 is connected to the low voltage side of the transformer 1. If the individual loads to be connected are relatively large, it is possible to adopt a configuration using a low-pressure metal closed switch gear instead of the control center 3. An air circuit breaker is mounted on the opening / closing part of the low-pressure metal closed switchgear.
In this case as well, the current capacity of the main bus of the low voltage metal closed switchgear is set in consideration of the current capacity on the low voltage side of the transformer 1.

  As described above, according to the power supply system of the first embodiment, the transformer connected to the high voltage metal closed switchgear to step down the high voltage to the low voltage, and the low voltage power connected to the low voltage side of the transformer. A plurality of control centers that receive power and supply low-voltage power to a plurality of loads, the plurality of control centers being connected in parallel to the low-voltage side of the transformer and arranged inside the plurality of control centers The total current capacity is set to be larger than the current capacity of the transformer main bus connected to the low voltage side of the transformer. For example, even when applied to facilities such as a nuclear power plant, it passes through the power center. Power supply system can be directly received from the transformer to the control center, the system configuration is simplified, the installation area is reduced, and the model is reduced. Door can be.

  In addition, it has a bus converter having a branch bus for distributing the current of the transformer main bus, and since the transformer main bus and the control center main bus are connected via the branch bus of the bus converter, the transformer It is easy to distribute current from the main bus to the control center main bus and change the bus position between the transformer main bus and the control center main bus, and easily supply power to multiple control centers via the bus converter. It becomes possible to distribute.

  The transformer is housed in the transformer housing together with the transformer main bus, the bus converter is configured by housing the branch bus in the housing, and the control center is divided into a plurality of control center groups. Since the housing of the bus bar conversion unit is arranged adjacent to the side surface of the transformer housing unit, and a plurality of control center groups are connected to the side surface of the housing of the bus bar converting unit, the transformer housing unit and the bus bar converting unit By combining the housing and the control center group, a power system excellent in earthquake resistance can be obtained.

  Also, the bus bar conversion unit is composed of two bus bar conversion units, arranged adjacent to the left and right side surfaces of the transformer storage unit, and the control center group is composed of four groups. Since two groups are connected to the opposite side to the part side, it is possible to provide a compact power system that is excellent in earthquake resistance and can handle a large number of control center loads.

  The housing of the bus bar conversion unit further contains a ground bus and a control line connected from the transformer housing to the control center group, and the ground bus and the control line are distributed to the control center group inside the housing. Therefore, using the bus converter, in addition to the main circuit bus, the position of the ground bus and the control line can be easily changed and distributed, so the ground wire and the control power supply wire to drop the ground bus to ground. In addition, the number of controls and the like for reporting alarms etc. to the host system can be reduced, and the cost can be reduced by saving labor of the installation work.

  In the present invention, each embodiment can be appropriately changed or omitted within the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Transformer, 2 Bus conversion part, 3 Control center, 3a, 3b, 3c, 3d Control center group, 4 Load, 5 Transformer storage part, 5a Control line accommodation room, 6 Transformer main bus line, 7 Case, 7a Control line route, 7b Control line accommodating part, 7c Control line joint, 8, 8a, 8b Branch bus, 9 Control center main bus, 10 High voltage power receiving terminal, 11 High voltage cable, 12a, 12b, 12c Ground bus, 13 For instrument Transformer, 21 Transformer, 22
Power center, 23 Power center load, 24 Control center, 25 Low pressure load

Claims (5)

A transformer connected to a high voltage metal closed type switchgear for stepping down the high voltage to a low voltage; and a plurality of control centers connected to the low voltage side of the transformer for receiving the low voltage power and supplying the low voltage power to a plurality of loads And
The plurality of control centers are connected in parallel to the low voltage side of the transformer,
The total value of the current capacities of the control center main buses arranged inside the plurality of control centers is set larger than the current capacities of the transformer main buses connected to the low voltage side of the transformer, Power system to be used. In the power supply system according to claim 1,
A bus converter having a branch bus for distributing the current of the transformer main bus,
The transformer main bus and the control center main bus are connected to each other via the branch bus of the bus converter. In the power supply system according to claim 1 or 2,
The transformer is housed in a transformer housing portion together with the transformer main bus, the bus converter is configured by housing the branch bus in a housing, and the control center is divided into a plurality of control center groups. The housing of the bus bar conversion unit is disposed adjacent to the side surface of the transformer housing unit, and a plurality of the control center groups are connected to the side surface of the housing of the bus bar conversion unit. Power system system characterized by In the power supply system according to claim 3,
The bus bar conversion unit is composed of two bus bar conversion units, arranged adjacent to the left and right side surfaces of the transformer housing unit, the control center group is composed of four groups, and the housing of the two bus bar conversion units is Two groups of power supply systems are connected to the opposite side to the transformer housing side. In the power supply system according to claim 3 or 4,
The housing of the bus bar conversion unit further contains a ground bus and a control line connected from the transformer housing unit to the control center group, and the ground bus and the control line are inside the housing. A power supply system distributed to control centers.

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