JP7729565B2 - Suppression circuit system for magnetizing inrush current and plant having the system - Google Patents

Description

The present invention relates to a magnetizing inrush current suppression circuit system having a circuit breaker and a suppression resistor connected to an electric path between a power grid and a transformer , and to a plant having the system .

Conventionally, when a transformer is connected to a power system, a magnetizing inrush current several tens of times the rated current of the transformer flows, and then the current reaches a steady state. To address this problem, a gas circuit breaker equipped with a magnetizing inrush current suppression device has been known (see Patent Document 1).
This gas circuit breaker with an excitation inrush current suppression device comprises a first gas circuit breaker consisting of a grounded tank filled with insulating gas, fixed and movable contacts arranged within the tank, and bushings attached to the tank and connected to the fixed and movable contacts, respectively, and a second gas circuit breaker consisting of a grounded tank filled with insulating gas, fixed and movable contacts arranged within the tank, and bushings attached to the tank and connected to either the fixed or movable contacts via an inrush current limiting resistor, and power is supplied to a transformer via a parallel circuit of the first and second gas circuit breakers.

Japanese Patent Application Laid-Open No. 2002-075145

However, as stated in paragraph 0010 of Patent Document 1, the gas circuit breaker with magnetizing inrush current suppression device is based on the premise of utilizing an existing circuit breaker for a three-phase circuit, and is primarily intended for single-phase transformers. Therefore, when using it for a three-phase transformer, it is necessary to install a separate circuit breaker, making it difficult to accommodate changes in the number of transformer phases, and posing problems such as increased workload due to the installation of a separate circuit breaker and additional costs for the installation.

In view of these points, the present invention aims to provide a magnetizing inrush current suppression circuit system and plant that can achieve "reduction in installation burden and cost" regardless of the number of phases of the transformer by connecting a system-side circuit breaker and a transformer-side circuit breaker in series in the electrical circuit between the system and the transformer, and connecting a suppression resistor in parallel with the transformer-side circuit breaker .

The suppression circuit system 1 according to the present invention is a suppression circuit system having a circuit breaker 2 and a suppression resistor 3 connected to an electric path between a system K and a transformer H, the circuit breaker 2 including a system-side circuit breaker 2a and a transformer-side circuit breaker 2b, the system-side circuit breaker 2a and the transformer-side circuit breaker 2b being connected in series in the electric path between the system K and the transformer H, and the suppression resistor 3 being connected in series in the electric path between the system-side circuit breaker 2a and the transformer-side circuit breaker 2b and the electric path between the transformer-side circuit breaker 2b and the transformer H. The first feature is that the system-side circuit breaker 2a and the transformer-side circuit breaker 2b are connected in parallel with each other over the entire circuit breaker ...

A second feature of the suppression circuit system 1 according to the present invention is that, in addition to the first feature, the predetermined time is not less than 0.01 seconds and not more than 10.00 seconds .

The plant P of the present invention has the above-mentioned suppression circuit system 1, a transformer H, and a panel case B, and is a plant that performs either power reception and distribution, power distribution only, or power reception only, and the system suppression circuit system 1 also has a control device 10 that outputs an on signal to turn on each of the system side circuit breaker 2a and the transformer side circuit breaker 2b, and a shut-off signal to shut them off, and a first feature of the plant P is that the control device 10 also outputs a shut-off signal to shut off the system side circuit breaker 2a if the transformer side circuit breaker 2b has not been closed even after the predetermined time has elapsed since the system side circuit breaker 2a was turned on .

Due to these features, by connecting the system side circuit breaker 2a and the transformer side circuit breaker 2b included in the circuit breaker 2 in series and connecting the suppression resistor 3 in parallel with the transformer side circuit breaker 2b, unlike Patent Document 1, it is not assumed that an existing circuit breaker for a three-phase circuit will be reused, and it is compatible with transformers H of any number of phases (three-phase, single-phase, etc.), so there is no need to install another circuit breaker, etc., and therefore there is no increase in the burden of installing another circuit breaker, and no extra costs such as installation fees are incurred ("reduced installation burden and cost").
The suppression circuit system 1 can also be said to be a "magnetizing inrush current suppression circuit system."

Furthermore, the order of closing the system-side circuit breaker 2a and the transformer-side circuit breaker 2b may be such that the system-side circuit breaker 2a is closed first and the transformer-side circuit breaker 2b is closed second.
Here, after the suppression circuit system 1 is installed, the circuit breaker 2 is only opened and closed once or several times over a long period of time (several years to several decades, etc.). Therefore, even if an attempt is made to close each circuit breaker 2a, 2b, if the transformer side circuit breaker 2b cannot be opened for some reason (such as a malfunction), a large current from system K will flow through the suppression resistor 3, causing the suppression resistor 3 to generate excessive heat, which could result in melting or catching fire.
Therefore, if the transformer side circuit breaker 2b is not closed even after a predetermined time has elapsed since the system side circuit breaker 2a was closed, the system side circuit breaker 2a can be shut off to stop the large current from the system K from flowing to the suppression resistor 3 before the suppression resistor 3 generates excessive heat and melts or catches fire, thereby achieving "improved safety."

According to the suppression circuit system and plant of the present invention, by connecting the system-side circuit breaker and the transformer-side circuit breaker in series in the electrical circuit between the system and the transformer, and connecting the suppression resistor in parallel with the transformer-side circuit breaker, it is possible to achieve "reduction in installation burden and cost," etc.

1 is a circuit diagram showing an outline of a suppression circuit system according to the present invention; FIG. 1 is a circuit diagram illustrating an example of an outline of a suppression circuit system, in which there is one transformer and one panel housing in one plant. 1 is a circuit diagram illustrating an example of an outline of a suppression circuit system, in which a single plant has a plurality of transformers and panel housings.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<Overall Configuration of Suppression Circuit System 1>
As shown in Figures 1 to 3, the suppression circuit system 1 of the present invention is a system connected to an electric circuit between a system K and a transformer H (hereinafter also referred to as the "system-transformer electric circuit 4"), and includes a circuit breaker 2 described later and a suppression resistor 3 described later.
The suppression circuit system 1 may include a control device 10, which will be described later.
In addition, the suppression circuit system 1 can be said to have at least a part of the system-to-transformer electrical circuit 4 (such as the circuit breaker-to-circuit 4b and the circuit breaker-to-transformer electrical circuit 4c described later).The suppression circuit system 1 may be provided inside a specified panel housing B described later.
The closing (energizing) of the circuit breaker 2 in the suppression circuit system 1 will be described later.

Here, the current, breaking current, voltage, power, and capacity in the present invention may be values within a rated range, in which case they can be referred to as rated current, rated breaking current, rated voltage, rated power, and rated capacity.
These rated currents, etc. can be said to be limit values of power, etc. guaranteed by the manufacturer to ensure safe use of electrical appliances, and further, ratings can be said to be usage limits or conditions that guarantee safe and proper operation of equipment and devices.
Furthermore, when the current in the present invention is AC, the current value (current value), the interrupting current value (interrupting current value), the voltage value (voltage value), the power value (power value), and the capacity value (capacity value) may be effective values.

<Circuit Breaker 2>
As shown in Figures 1 to 3, the circuit breaker 2 is connected to the electric circuit (system-transformer electric circuit 4) between the system K and the transformer H, and is a device that can interrupt the system-transformer electric circuit 4, and includes a system-side circuit breaker 2a and a transformer-side circuit breaker 2b, which will be described later.
The circuit breaker 2 may include one or more other circuit breakers (such as the sub-circuit B9 in Figure 3) in addition to the system-side circuit breaker 2a and the transformer-side circuit breaker 2b in the system-transformer electrical circuit 4, but the circuit breakers 2 in one suppression circuit system 1 may consist only of the system-side circuit breaker 2a and the transformer-side circuit breaker 2b.
The specific configuration of these circuit breakers 2 is not particularly limited, but may be, for example, a vacuum circuit breaker (VCB), an air circuit breaker (ACB), a molded case circuit breaker (MCCB), or an earth leakage circuit breaker (ELCB).

The circuit breaker 2 may be closed by an electric spring operation, or may be closed by a signal from the control device 10 described later, or may be closed remotely via a communication device such as the Internet or a telephone line, or may be closed manually on-site via the control device 10 (or directly), or may output a signal (answerback signal) indicating that the circuit breaker has been closed to the control device 10, etc. Furthermore, the circuit breaker 2 may be equipped with contacts for minute currents, etc.
In the following description, the system-side circuit breaker 2a and the transformer-side circuit breaker 2b are mainly vacuum circuit breakers.

The rated current of these circuit breakers 2 is not particularly limited, but may be, for example, 400 A, 600 A, or 630 A, or 1 A or more and 5000 A or less, preferably 10 A or more and 3000 A or less, and more preferably 100 A or more and 2000 A or less.
The rated interrupting current of these circuit breakers 2 is not particularly limited, but may be, for example, 8.0 kA or 12.5 kA, or 0.1 kA or more and 1000.0 kA or less, preferably 0.5 kA or more and 500.0 kA or less, and more preferably 1.0 kA or more and 100.0 kA or less, and the current that actually flows as the magnetizing inrush current may also be 18 A, for example.
The rated voltage of these circuit breakers 2 is not particularly limited, but may be, for example, 7.2 kV or 3.6 kV, or 0.1 kV to 500.0 kV, preferably 0.5 kV to 100.0 kV, and more preferably 1.0 kV to 50.0 kV.

<System-side circuit breaker 2a, transformer-side circuit breaker 2b, etc.>
As shown in Figures 1 to 3, the system-side circuit breaker 2a is the circuit breaker closer to the system K among the circuit breakers 2 described above, and the transformer-side circuit breaker 2b is the circuit breaker closer to the transformer H among the circuit breakers 2 described above.
In more detail, the system-side circuit breaker 2a may be a circuit breaker connected at least closer to the system K than the transformer-side circuit breaker 2b in the electric circuit between the system K and the transformer H (system-transformer electric circuit 4), and may be a circuit breaker connected closest to the system K. On the other hand, the transformer-side circuit breaker 2b may be a circuit breaker connected at least closer to the transformer H than the system-side circuit breaker 2a in the system-transformer electric circuit 4, and may be a circuit breaker connected closest to the transformer H.
The system-side circuit breaker 2a and the transformer-side circuit breaker 2b are connected in series in the system-transformer electrical circuit 4, and the transformer-side circuit breaker 2b is connected in parallel with the suppression resistor 3 (described later).

As described above, if the circuit breaker 2 includes another circuit breaker in addition to the system-side circuit breaker 2a and the transformer-side circuit breaker 2b, this other circuit breaker may also be connected in series with the system-side circuit breaker 2a and the transformer-side circuit breaker 2b in the system-transformer electric circuit 4.
In this case, the location where the other circuit breaker is connected is not particularly limited, and may be, for example, the electrical circuit between the system K and the system-side circuit breaker 2a (hereinafter also referred to as the "system-to-circuit breaker electrical circuit 4a"), the electrical circuit between the system-side circuit breaker 2a and the transformer-side circuit breaker 2b (hereinafter also referred to as the "inter-circuit breaker electrical circuit 4b"), or the electrical circuit between the transformer-side circuit breaker 2b and the transformer H (hereinafter also referred to as the "circuit breaker-to-transformer electrical circuit 4c"). In particular, the inter-circuit breaker electrical circuit 4b may not be connected to other devices such as another circuit breaker, and may only have a branch point (inter-circuit breaker branch point) 5b to the suppression resistor 3 described later.
In the following description, it is assumed that the circuit breakers 2 in one suppression circuit system 1 mainly consist of only the system-side circuit breaker 2a and the transformer-side circuit breaker 2b.

The order (closing sequence) of closing the system-side circuit breaker 2a and the transformer-side circuit breaker 2b described above may be such that the system-side circuit breaker 2a is closed first and the transformer-side circuit breaker 2b is closed later.
In this case, the time difference between the closing of the system-side circuit breaker 2a and the closing of the transformer-side circuit breaker 2b is not particularly limited, but may be, for example, 0.02 seconds, or 0.001 seconds or more and 5.000 seconds or less, preferably 0.005 seconds or more and 1.000 seconds or less, and more preferably 0.010 seconds or more and 0.500 seconds or less.
The order in which the system-side circuit breaker 2a and the transformer-side circuit breaker 2b are turned on may be controlled by a control device 10, which will be described later.

Furthermore, when the system side circuit breaker 2a and the transformer side circuit breaker 2b are turned on, if a predetermined time has elapsed since the system side circuit breaker 2a was turned on but the transformer side circuit breaker 2b has not been turned on, the system side circuit breaker 2a may be shut off.
In this case, the above-mentioned predetermined time is not particularly limited, but may be, for example, 2 seconds, or 0.01 seconds or more and 10.00 seconds or less, preferably 0.05 seconds or more and 8.00 seconds or less, and more preferably 0.10 seconds or more and 5.00 seconds or less.
In addition, if the transformer side circuit breaker 2b is not closed even after a predetermined time has elapsed since the system side circuit breaker 2a was closed, the control device 10 described later may also control the closing of the system side circuit breaker 2a.

<Suppression resistance 3>
As shown in Figures 1 to 3, the suppression resistor 3 is a resistor connected to the electrical path between the system K and the transformer H (system-transformer electrical path 4), and may be an overcurrent limiting resistor or the like.
The suppression resistor 3 is connected in parallel with the transformer side circuit breaker 2b across the electrical path between the system side circuit breaker 2a and the transformer side circuit breaker 2b (inter-circuit circuit 4b) and the electrical path between the transformer side circuit breaker 2b and the transformer H (inter-circuit circuit 4c).
To explain in detail the parallel connection with this transformer-side circuit breaker 2b, the suppression resistor 3 is connected to an electric circuit extending from the inter-circuit breaker branch point 5b of the inter-circuit breaker circuit 4b to the inter-circuit breaker-transformer branch point 5c of the inter-circuit breaker-transformer electric circuit 4c (this can also be said to be the electric circuit between the inter-circuit breaker branch point 5b and the inter-circuit breaker-transformer branch point 5c, hereinafter also referred to as the "resistance electric circuit 4d").

The resistance value of the suppression resistor 3 is not particularly limited, but may be, for example, 300Ω or 500Ω, or 10Ω to 5000Ω, preferably 50Ω to 3000Ω, and more preferably 100Ω to 1000Ω.
The rated current of the suppression resistor 3 is not particularly limited, but may be, for example, 20 A, or 0.1 A to 100.0 A, preferably 1.0 A to 70.0 A, and more preferably 5.0 A to 40.0 A.
The rated power of the suppression resistor 3 is not particularly limited, but may be, for example, 120 kW, or 1 kW to 5000 kW, preferably 10 kW to 1000 kW, and more preferably 50 kW to 500 kW.

<System-transformer circuit 4, etc.>
As shown in FIGS. 1 to 3, the system-transformer electric circuit 4 is an electric circuit between the system K and the transformer H, as described above, and can also be said to be a main electric circuit.
As described above, the system-to-circuit breaker electric circuit 4a is an electric circuit between the system K and the system-side circuit breaker 2a, the circuit breaker-to-circuit breaker electric circuit 4b is an electric circuit between the system-side circuit breaker 2a and the transformer-side circuit breaker 2b, the circuit breaker-to-transformer electric circuit 4c is an electric circuit between the transformer-side circuit breaker 2b and the transformer H, and the resistance electric circuit 4d is an electric circuit between the circuit breaker branch point 5b and the circuit breaker-to-transformer branch point 5c, and it can be said that these electric circuits 4a to 4d are part of the system-to-transformer electric circuit 4 (included in the system-to-transformer electric circuit 4).
Here, the term "electrical circuit" in the present invention refers to a circuit that allows electricity to flow, and includes conductors such as copper, aluminum, silver, gold, and nichrome, cables in which such conductors are covered with an insulator, and general electric wires.
The current flowing through the system-transformer electric circuit 4 described above may be three-phase three-wire (3φ3W) AC of 60 Hz or 50 Hz, or alternatively, single-phase three-wire (1φ3W) or single-phase two-wire (1φ2W) AC.

<Control device 10>
As shown in FIGS. 1 to 3, the control device 10 is a device that controls the closing and opening of the system-side circuit breaker 2a and the transformer-side circuit breaker 2b.
The control device 10 may output a signal (on signal) to turn on the system side circuit breaker 2a and a signal (off signal) to turn off the transformer side circuit breaker 2b, respectively, or may input an answerback signal from each of the system side circuit breaker 2a and the transformer side circuit breaker 2b.
The specific configuration of the control device 10 is not particularly limited, but may be, for example, a digital multimeter (e.g., one having the functions of an overcurrent relay (OCR) or an undervoltage relay (UVR)) B7, or the control device 10 may include, in addition to the digital multimeter B7, a power fuse B1 connected between the digital multimeter B7 and the system-to-circuit-breaker electric circuit 4a or the circuit-to-circuit-breaker electric circuit 4b, an instrument voltage transformer B2, a circuit protector B3, a voltmeter B4, a voltmeter changeover switch B5, an instrument current transformer B6, etc. (see FIG. 2). Alternatively, the control device 10 may be a smart logger, a sequencer or computer that executes a predetermined program, etc.
In one suppression circuit system 1, the number of control devices 10 may be one or more.
The control device 10 may also be installed inside the same specified panel housing B in which the suppression circuit system 1 is installed, or it may also be installed inside another box outside the specified panel housing B.
The power supply for the control device 10 may be input from a predetermined uninterruptible power supply provided inside the same predetermined panel housing B in which the control device 10 is provided.
The monitoring, setting changes, operation, etc. of the control device 10 may be performed manually by a user on-site by directly touching it, or may be performed remotely via a communication device such as the Internet or a telephone line.

The control device 10 may control the closing of the system side circuit breaker 2a and the transformer side circuit breaker 2b so that the system side circuit breaker 2a is closed first and the transformer side circuit breaker 2b is closed later. In more detail, the control device 10 may output a closing signal to the system side circuit breaker 2a and then output a closing signal to the transformer side circuit breaker 2b.
In this case, the time difference between the closing of the system side circuit breaker 2a and the closing of the transformer side circuit breaker 2b may be the value or range as described above, but this closing time difference may also be set by the control device 10 to a value or range as described above.
Furthermore, when closing the system-side circuit breaker 2a and the transformer-side circuit breaker 2b, if a predetermined time has elapsed since the system-side circuit breaker 2a was closed but the transformer-side circuit breaker 2b has not been closed, the control device 10 may control the system-side circuit breaker 2a to be shut off. In more detail, if a predetermined time has elapsed since the control device 10 output a closing signal to the system-side circuit breaker 2a but an answerback signal (a signal indicating that the circuit has been closed) has not been input from the transformer-side circuit breaker 2b, the control device 10 may output a shut-off signal to the system-side circuit breaker 2a.
In this case, the predetermined time after the system side circuit breaker 2a is turned on may be the value or range described above, or this predetermined time may be set by the control device 10 to a value or range described above.

<Others>
The present invention is not limited to the above-described embodiment. The individual components or the overall structure, shape, dimensions, etc. of the suppression circuit system 1 and the plant P can be appropriately modified in accordance with the spirit of the present invention.
The suppression circuit system 1 may not include the control device 10 .
The suppression circuit system 1 may be retrofitted to a predetermined plant such as an existing power receiving and distribution plant, or may be used in place of a high-voltage AC load break switch when a predetermined plant is newly installed.
The suppression circuit system 1 does not have any particular restrictions on the order in which the system side circuit breaker 2a and the transformer side circuit breaker 2b are turned on, and it is not necessary to turn off the system side circuit breaker 2a depending on the situation in which the transformer side circuit breaker 2b is turned on after the system side circuit breaker 2a is turned on.
Furthermore, as a method of using the suppression circuit system 1, the order in which the system-side circuit breaker 2a and the transformer-side circuit breaker 2b are turned on may be such that the system-side circuit breaker 2a is turned on first and the transformer-side circuit breaker 2b is turned on later, and when turning on the system-side circuit breaker 2a and the transformer-side circuit breaker 2b, if the transformer-side circuit breaker 2b has not been turned on even after a predetermined time has elapsed since the system-side circuit breaker 2a was turned on, the system-side circuit breaker 2a may be shut off.
The system K and transformer H related to the suppression circuit system 1 described above, as well as the load F, the storage device T, the power generation device S, the specified panel housing B, and the specified plant P will be explained in detail below.

<Series K>
1 to 3, the system K transmits (receives) power to the suppression circuit system 1 and the transformer H, and refers to the entire system through which electric power companies and the like supply electricity to consumers, and can also be called the power system K. Specifically, the system K includes facilities such as substations, transmission lines, and distribution lines, and may also include a power plant. The system K may also include a utility transformer, a power purchase watt-hour meter, a power sale watt-hour meter, a pole-mounted air switch, a protective relay device, and the like, which are located outside the predetermined panel housing B in which the suppression circuit system 1 is installed.
The power handled by such system K may be either AC or DC, but the following description will be given assuming that it is AC.
In System K, most of the transmitted electricity is AC, so it is transmitted using a three-phase, three-wire (3φ3W) transmission line. In order to reduce transmission losses during this transmission, the main long-distance transmission sections transmit electricity at as high a voltage as possible (for example, 6600V or 22000V).
The electricity transmitted by system K is transformed (stepped down) in several stages at locations close to the point of consumption, and after the pole-mounted transformer, the electricity is distributed via single-phase two-wire (1φ2W) or the like.
System K may be a system (commercial power system) of an electric power company or the like, or a system independently owned by an organization such as a company or local government, or a system within a plant (independent power system).

<Transformer H>
1 to 3, the transformer H is a so-called transformer that transforms AC current from the system K into AC current with a voltage suitable for the above-mentioned load F. Note that "transformer" is an abbreviation for "transformer."
The specific configuration of the transformer H is not particularly limited, but may be, for example, a two-winding transformer (see Figures 1 and 3), a three-winding transformer (see Figure 2), or a transformer with four or more windings.
The transformer H is not particularly limited in terms of the connection method of each winding thereof, but may be, for example, a star connection (Y connection) or a delta connection (Δ connection).
Furthermore, the transformer H may be provided with a grounding terminal or a contact prevention plate, and may be an oil-immersed transformer (self-cooled, air-cooled, water-cooled, etc.) or a dry-type transformer (self-cooled, air-cooled, water-cooled, etc.).

<Load F>
As shown in FIGS. 2 and 3 , the load F is a load (load equipment) that consumes power received from a grid K via a transformer H, and consumes stored power from a power storage device T (described later) and power generated by a power generation device S.
The load F may be, for example, an automobile dealership or a gas station, a rental car store (rental car shop), a charger Fa (described below) in a factory or workshop, or may include electrical equipment and facilities that use power such as electric and electronic devices (general lighting loads Fb such as incandescent lamps, fluorescent lamps, and mercury lamps (lighting fixtures), and general power loads Fc such as air conditioners, motors, and pumps), or may even include the factory or workshop itself.
Furthermore, the load F may include electrical equipment that uses electricity, such as electrical and electronic devices in corporations, organizations, individuals, government offices, unions, and other such offices, homes, stores, warehouses, garages, parking lots, bicycle parking lots, school buildings, auditoriums, gymnasiums, research facilities, hospitals, clinics, inns, hotels, theaters, movie theaters, stadiums, baseball stadiums, etc., as well as the offices of companies, etc. themselves, or may include a combination of these.
In the following, the charger Fa will be particularly described in detail.
The charger Fa may be configured as a rapid charger, a normal charger, an ultra-rapid charger, or the like. Here, the "charger Fa" in this invention refers to a stationary charging device or charging facility used to charge vehicles equipped with a battery (storage battery), such as electric vehicles (EVs), plug-in hybrid vehicles, and electric motorcycles, and is also referred to as a charging stand, charging station, charging spot, or the like. Note that the charger Fa may also be a charging device or charging facility used to charge communication devices equipped with a battery (storage battery), such as smartphones and mobile phones, portable PCs (personal computers), electrical appliances, and the like, in addition to vehicles.

<Power storage device T>
As shown in FIGS. 2 and 3, the power storage device T is a device that stores power received from a power grid K via a transformer H, power generated by a power generation device S (to be described later), and the like.
The power storage device T may be, for example, a storage battery such as a lead storage battery, a lithium ion storage battery, a nickel-metal hydride storage battery, or a nickel-cadmium storage battery; it may store hydrogen generated by electrolysis of water using the power generated by the power generation device S, and extract electricity when needed using a fuel cell or the like; or it may be a device that stores electricity as kinetic energy using a flywheel or the like, stores electricity as potential energy using pumped water, or stores electricity directly as electrical energy using a capacitor or the like.

<Power generation device S>
As shown in Figures 2 and 3, the power generation device S may have any configuration as long as it generates electricity, and may be, for example, a device that generates electricity using solar power, wind power, hydroelectric power, geothermal power, solar thermal power, atmospheric heat or other heat present in nature, or biomass (organic matter derived from plants and animals that can be used as an energy source).
In addition, the power generation device S may generate power by utilizing ocean temperature differences, wave power, tidal currents (ocean currents), or tides.
The power generated by the power generation device S may be consumed by a load F, stored in a power storage device T, or sold to a power grid K via a transformer H.

<Prescribed panel case B>
As shown in FIGS. 2 and 3, a predetermined panel housing B (hereinafter also referred to as "panel housing B") is a housing that houses devices such as the suppression circuit system 1 and the control device 10 described above.
As described above, the panel housing B may be provided inside with a power fuse (PF) B1, a voltage transformer (VT) B2, a circuit protector (CP) B3, a voltmeter B4, a voltage change over switch (VS) B5, a current transformer (CT) B6, and a digital multimeter (e.g., one having the functions of an overcurrent relay (OCR) or an undervoltage relay (UVR)) B7 (see FIG. 2).
Furthermore, inside the panel housing B, circuit breakers (which can be called circuit breakers downstream of the transformer, particularly, circuit breakers for wiring or earth leakage current breakers) B8 may be provided between the transformer H and each load F (Fa, Fb, Fc), the storage device T, and the power generation device S. In more detail, a charging load circuit breaker B8Fa connected to the electrical path between the transformer H and the charger Fa and capable of interrupting the electrical path, a lighting load circuit breaker B8Fb connected to the electrical path between the transformer H and the lighting load Fb and capable of interrupting the electrical path, a power load circuit breaker B8Fc connected to the electrical path between the transformer H and the power load Fc and capable of interrupting the electrical path, a storage circuit breaker B8T connected to the electrical path between the transformer H and the storage device T and capable of interrupting the electrical path, and a power generation circuit breaker B8S connected to the electrical path between the transformer H and the power generation device S and capable of interrupting the electrical path may be provided (see Figures 2 and 3).
In addition, the inside of the panel housing B may be provided with a disconnect switch (DS), a high-voltage AC load break switch with current-limiting fuse (LBS), a zero-phase potential device (ZPD), a synchronism detector, an autotransformer, an uninterruptible power supply (UPS), a fuse (F), an ammeter, an ammeter change over switch (AS), and a wattmeter.

<Prescribed plant P>
As shown in Figures 1 to 3, a specified plant P (hereinafter also referred to as "plant P") according to the present invention is, for example, a plant such as a power distribution plant, and has the above-mentioned suppression circuit system 1 and a transformer H, and may also have a load F, a storage device T, a power generation device S, and a specified panel housing B.
The plant P may be a power receiving and distribution plant, a plant that only distributes power, or a plant that only receives power, and depending on its use, there are no particular restrictions on which of the load F, storage device T, power generation device S, and panel housing B the plant P has.
In one plant P, the number of transformers H and panel housings B may be one (see Figure 2) or multiple (see Figure 3), but the number of transformers H and panel housings B may be the same.
In particular, FIG. 3 shows a case where there are a plurality of transformers H and panel housings B in one plant P. In this case, the suppression circuit system 1 may be provided only in the panel housing B that is directly connected to the system K among the plurality of panel housings B. The panel housing B that is directly connected to the system K can be said to be a mother panel housing B', and the panel housings B other than this mother panel housing B' can be said to be child panel housings B". The same applies to the transformer H, and the transformer H provided in the mother panel housing B' can be said to be a mother transformer H'. That is, the transformer H provided in the slave panel housing B" can be said to be the slave transformer H", the circuit breaker-transformer electric circuit 4c provided inside the master panel housing B' can be said to be the master circuit breaker-transformer electric circuit 4c', and the electric circuit branching from this master circuit breaker-transformer electric circuit 4c' to the slave transformer H" can be said to be the slave circuit breaker-transformer electric circuit (or connecting electric circuit) 4c". Furthermore, this slave circuit breaker-transformer electric circuit 4c" can also be said to be part of the system-transformer electric circuit 4 (included in the system-transformer electric circuit 4).
A sub-circuit breaker B9 that is connected to this sub-circuit breaker-transformer electric circuit 4c'' and that can break this electric circuit may be provided inside the sub-panel housing B''.

The suppression circuit system and plant of the present invention can be used with any power contract or connection type, not only when there is a high-voltage contract (high-voltage incoming, high-voltage incoming) for power of 50 kW or more from the grid, but also when there is a low-voltage contract (low-voltage incoming, low-voltage incoming) for power of less than 50 kW, or when there is an extra-high voltage (extra-high) contract (extra-high incoming, extra-high voltage incoming) for power of 20,000 kW or more, and can be used both indoors and outdoors.

1 Suppression circuit system 2 Circuit breaker 2a System side circuit breaker 2b Transformer side circuit breaker 3 Suppression resistor K System H Transformer

Claims (3)

A suppression circuit system having a circuit breaker (2) and a suppression resistor (3) connected to an electric circuit between a system (K) and a transformer (H),
The circuit breaker (2) includes a system-side circuit breaker (2a) and a transformer-side circuit breaker (2b),
The system-side circuit breaker (2a) and the transformer-side circuit breaker (2b) are connected in series in an electric circuit between the system (K) and the transformer (H),
The suppression resistor (3) is connected in parallel with the transformer-side circuit breaker (2b) across an electric path between the system-side circuit breaker (2a) and the transformer-side circuit breaker (2b) and an electric path between the transformer-side circuit breaker (2b) and the transformer (H),
The order of closing the system-side circuit breaker (2a) and the transformer-side circuit breaker (2b) is such that the system-side circuit breaker (2a) is closed first and the transformer-side circuit breaker (2b) is closed later;
In the case where the system-side circuit breaker (2a) and the transformer-side circuit breaker (2b) are closed, if the transformer-side circuit breaker (2b) is not closed even after a predetermined time has elapsed since the system-side circuit breaker (2a) was closed, the system-side circuit breaker (2a) is shut off. 2. The suppression circuit system according to claim 1, wherein the predetermined time is between 0.01 seconds and 10.00 seconds. A plant having the suppression circuit system (1) according to claim 1 or 2, a transformer (H), and a panel housing (B), and performing any one of power reception and distribution, power distribution only, and power reception only,
The system suppression circuit system (1) also includes a control device (10) that outputs a closing signal to close the system-side circuit breaker (2 a) and the transformer-side circuit breaker (2 b) and a shut-off signal to shut them off,
The plant is characterized in that the control device (10) also outputs a shutoff signal to shut off the system-side circuit breaker (2a) when the transformer-side circuit breaker (2b) is not closed even after the predetermined time has elapsed since the system-side circuit breaker (2a) was closed.