JP2021164310A - Power supply system - Google Patents

Abstract

To provide a power supply system capable of arbitrarily performing switching between supply to an AC system side and supply to a DC system side without considerably altering an existing power generation system.SOLUTION: A power supply system 100 comprises: a DC power supply device 10 (e.g., a photovoltaic power generation module) for supplying DC current with predetermined voltage in a managed area; a connection box 11 for synthesizing output from the DC power supply device 10; and a system interconnection inverter 22 that converts current output from the connection box 11 and supplies AC current. Between the connection box 11 and the system interconnection inverter 22 is provided a switcher 50 that performs switching between AC current supply system and DC current supply system on the basis of a switching signal from a management device 80.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply system.

For existing photovoltaic power generation facilities in a certain area, the 10-year power sale period specified in the FIT (Fixed Price Purchase System for Renewable Energy) contract will end in sequence. It was desired to operate the photovoltaic power generation equipment after the end of the power sale period.

Against the backdrop of soaring fossil fuel prices, consideration for the environment, and prevention of global warming, plug-in hybrid electric vehicles and pure electric vehicles equipped with large-capacity storage batteries are attracting attention, and their markets are expanding rapidly. This trend is expected to accelerate further.

JP-A-2015-61439

In the quick charging facility for electric vehicles shown in Patent Document 1, the DC power generated by the solar power generation module is converted into a predetermined DC voltage via the DC / DC converter power circuit for the power generation device and supplied to the DC bus. However, there is no direct description about selling power to the AC system.

The photovoltaic power generation equipment under the FIT contract is generally supplied to the AC system for sale. Therefore, for example, when the generated power of photovoltaic power generation is consumed in-house, the inventors arbitrarily supply the AC system side and the DC system side without major modification of the existing power generation system. Faced with the challenge of being difficult to switch to.

On the other hand, in order to make effective use of existing photovoltaic power generation facilities, it has been desired to switch to power supply for self-consumption in the region.

The present invention has been made to solve the above-mentioned problems, and the supply to the AC system side and the supply to the DC system side can be arbitrarily switched without major modification of the existing power generation system. The purpose is to provide a power supply system.

In order to achieve the above object, the power supply system of the present invention combines an output from a DC power supply with a DC power supply (for example, a solar power generation module) that supplies a DC current of a predetermined voltage in a controlled area. It is a power supply system equipped with a junction box to be connected and a grid interconnection inverter that converts the current output from the junction box and supplies an AC current. It is characterized by providing a switching unit for switching between an AC current supply system and a DC current supply system based on a switching signal. Other aspects of the present invention will be described in embodiments described below.

According to the present invention, the supply to the AC system side and the supply to the DC system side can be arbitrarily switched without major modification of the existing power generation system.

It is a figure which shows the structure of the electric power supply system of the management area which concerns on 1st Embodiment. It is a figure which shows the structure of the electric power supply system of the management area which concerns on 2nd Embodiment. It is a figure which shows an example of the system switching method of the power supply system which concerns on 2nd Embodiment. It is a figure which shows the structure of the electric power supply system of the management area which concerns on 3rd Embodiment. It is a figure which shows the structure of the type T1 of the existing photovoltaic power generation system. It is a figure which shows the structure of the type T2 of the existing photovoltaic power generation system. It is a figure which shows the detail of the DC line of the power supply system which concerns on embodiment. It is a figure which shows the structure of the charge mode of the electric moving body which concerns on embodiment. It is a figure which shows the structure of the traveling mode of the electric moving body which concerns on embodiment.

First, a configuration example of an existing photovoltaic power generation system will be described with reference to FIGS. 5 and 6.
FIG. 5 is a diagram showing a configuration of type T1 of an existing photovoltaic power generation system. FIG. 6 is a diagram showing a configuration of type T2 of an existing photovoltaic power generation system.

The type T1 shown in FIG. 5 is a type connected to a high voltage system. The DC power supply device 10 (for example, a photovoltaic power generation module) is connected to the power conditioner 20 via a junction box 11 that synthesizes outputs from the DC power supply device 10. The power conditioner 20 is connected to a high-voltage AC commercial system 1 (for example, a 6600V system) via a commercial step-up transformer 30. The power conditioner 20 includes a DC / DC converter 21 for boosting and a grid interconnection inverter 22. The type of voltage is based on Article 2 of the Electrical Equipment Technical Standards.

The type T2 shown in FIG. 6 is a type connected to a low voltage system. The DC power supply device 10 is connected to the power conditioner 20 via the junction box 11. The power conditioner 20 has a grid interconnection inverter 22 and a commercial isolation transformer 23, and is interconnected to a low-voltage AC commercial grid 1A (for example, a 200V grid).

That is, the type T1 is a type having a built-in DC / DC converter 21 for boosting, and the type T2 is a type having no DC / DC converter 21.

Maximum power point tracking (MPPT) is implemented in photovoltaic power generation systems. The MPPT is a control device that can automatically obtain the product of the optimum current x voltage (maximum power point or optimum operating point) that can maximize the output when the solar cell generates electricity. The optimum operating point of a solar cell varies depending on the installation location and the weather, but MPPT makes it possible to automatically obtain the maximum output.

The maximum power point tracking control is carried out by the DC / DC converter 21 in the type T1 and the grid interconnection inverter 22 in the type T2. Further, even in the type T1, there is a case where MPPT control is performed by the grid interconnection inverter 22 at the time of low voltage.

Hereinafter, a power supply system capable of arbitrarily switching between supply to the AC system side and supply to the DC system side without major modification of the existing power generation system described above will be described.
Embodiments for carrying out the present invention will be described in detail with reference to the drawings as appropriate.

<< First Embodiment >>
FIG. 1 is a diagram showing a configuration of a power supply system 100 in a management area according to the first embodiment. In FIG. 1, as compared with FIG. 5, a switch 50 (switching unit) is provided between the junction box 11 and the power conditioner 20. In this embodiment, the DC power supply device 10 corresponds to a photovoltaic power generation module. A junction box 11 of a photovoltaic power generation module is connected to one of the switch 50s, and a power conditioner 20 and a DC line 2 are switchably connected to the other.

Since the switch 50 is provided between the junction box 11 and the power conditioner 20, when the DC line 2 is additionally installed, it can be easily constructed by dropping the breaker of the junction box 11. Is.

Then, the DC line 2 has a DC / DC converter 53 (MPPT control is performed), a storage battery 62 via a bidirectional DC / DC converter 61, and a quick charger 63 (charging equipment for an electric mobile body) in order from the switch 50 side. ) Is connected. In the present embodiment, the storage battery 62 and the quick charger 63 (charging equipment for an electric mobile body) correspond to a DC load. When the electric power generated by the solar power generation module is supplied to the DC line 2, after the electric power is converted by the DC / DC converter 53, the electric power storage device 4 of the electric mobile body V (electric mobile body V1) from the quick charger 63 (FIG. 8) is supplied. Further, the electric moving body (electric moving body V2) can be charged from the DC line 2 without going through the quick charger 63. Details will be described later with reference to FIGS. 7 to 9.

The switch 50 can receive an external signal 51s (command) from the management device 80 via the input unit 51 and automatically switch the connection destination (power conditioner 20 and DC line 2). For example, when the selling price of renewable energy is low, the switch 50 is switched to the DC line 2 side, and the power generated by the photovoltaic power generation module is used for the storage battery 62 / electric mobile body V. When the selling price of the electric power is high, the switch 50 can be switched to the power conditioner 20 side, and the electric power can be supplied to the commercial system to sell the electric power.

As another switching method, the switch 50 is normally switched to the power conditioner 20 to sell power. When the electric moving body V is physically connected to the DC line 2 via the quick charger 63 (charging equipment for the electric moving body), the management device 80 acquires the identification information given in advance to the electric moving body V. .. When this identification information is determined to be registration information that can be electrically connected to the DC line 2, the management device 80 sets the non-traveling mode in the electric moving body V and transmits a command to switch to the DC line 2 to the switch 50. .. Upon receiving the command, the switch 50 supplies a current to the DC line 2 by switching the circuit to the DC line 2 side. Further, the electric mobile body V can be charged by transmitting a command from the management device 80 to allow the electric connection to the charging equipment for the electric mobile body. Further, when a direct current of a predetermined voltage cannot be obtained from the direct current power supply device 10, it is possible to supply the direct current from the storage battery 62 to the charging equipment for the electric mobile body.

FIG. 1 shows a case where the switch 50 is arranged in the type T1 of FIG. 5, but the switch 50 may be arranged in the type T2 of FIG.

As described above, when the type T1 and the type T2 are put together, the junction box 11 to which the DC power supply device 10 is connected and the grid interconnection inverter 22 that converts the power generated by the DC power supply device 10 are switched. A device 50 is provided, and a junction box 11 of a DC power supply device 10 (solar power generation module) is connected to one of the switch 50s, and a grid interconnection inverter 22 and a DC line 2 are switchably connected to the other. ing. As described above, the junction box 11 is a device that synthesizes the output from the DC power supply device 10, and the grid interconnection inverter 22 is a device that converts the power generated by the DC power supply device 10 into alternating current.

Then, the DC current generated by the DC power supply device 10 is supplied to the in-vehicle rechargeable battery of the electric mobile body V without passing through the DC / DC converter 21 on the commercial system side. Therefore, when the photovoltaic power generation is consumed in-house, the supply to the AC system side and the supply to the DC system side can be arbitrarily switched without major modification of the existing power generation system.

<< Second Embodiment >>
FIG. 2 is a diagram showing a configuration of a power supply system 100A in a management area according to a second embodiment. In the power supply system 100A shown in FIG. 2, the junction box 11 is changed to the junction box 11A with a switching function including the switch 50, as compared with FIG.

The switching unit in this embodiment corresponds to a junction box provided with a switching function. A DC power supply device 10 (solar power generation module) is connected to one of the junction boxes 11A with a switching function, and the power conditioner 20 and the DC line 2 are switchably connected to the other. The control circuit 52 of the junction box 11A with a switching function can switch the wiring for each string of the photovoltaic power generation module based on the external signal 51s received by the input unit 51, and the output of the photovoltaic power generation module is DC with the power conditioner 20 side. It can be distributed to the line 2 side. That is, a part of the output of the photovoltaic power generation module can be supplied to the power conditioner 20 side, and the rest can be supplied to the DC line 2 side.

Further, the junction box 11A with a switching function can automatically switch the connection destination (power conditioner 20 and DC line 2) by receiving a command from the management device 80, as in the first embodiment. In the first embodiment, the power generated by the photovoltaic power generation module is supplied to only one of the power conditioner 20 side and the DC line 2 side, but in the second embodiment, the connection destination can be switched for each string of the photovoltaic power generation module. .. An example of a system switching method utilizing this feature will be described with reference to FIG.

FIG. 3 is a diagram showing an example of a system switching method of the power supply system 100A according to the second embodiment. When the power company 90 receives a command to suppress the output of photovoltaic power generation from the resource aggregator 91, the resource aggregator 91 requests the area manager 92 that owns the photovoltaic power generation to suppress the output. Upon receiving the command signal from the resource aggregator 91 to reduce the output of the photovoltaic power generation module, the area manager 92 distributes most of the output of the photovoltaic power generation module to the DC line 2 side and consumes most of the photovoltaic power generation power in-house. The management device 80 can issue a command to the junction box 11A with a switching function so as to turn the power to.

<< Third Embodiment >>
FIG. 4 is a diagram showing a configuration of a power supply system 100B in a management area according to a third embodiment. A DC / DC converter 21 and a grid interconnection inverter 22 are provided inside the power conditioner 20.

Therefore, the power supply system 100B shown in FIG. 4 is connected between the DC / DC converter 21 inside the power conditioner 20 and the grid interconnection inverter 22 and has a branch switch 54 to the DC line 2 and has a DC / DC /. It is connected to the DC line 2 via the DC converter 55. In this case, the DC / DC converter 55 provided on the DC line 2 does not require MPPT control.

According to the third embodiment, the branch switch 54 is turned on based on the turn-on signal of the management device 80, and a direct current can be supplied to the direct current line 2. The branch switch 54 may be inside or outside the housing of the power conditioner 20.

<Details of DC line 2>
FIG. 7 is a diagram showing details of the DC line 2 of the power supply system 100 according to the embodiment. FIG. 7 illustrates in detail the connecting device 70 arranged on the DC line 2 based on FIG. The same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. Further, the DC line 2 and the like are schematically shown as a single line.

A DC line 2 is arranged in the control area A1, and a plurality of connecting devices 70 are provided in the DC line 2. The connection device 70 includes an energization switch 71, an output connection unit JL (power supply spot), and a control unit 74.

The management area is an area managed by one administrator, such as within the jurisdiction of the local government or the business office of a company, and when laying the DC line 2 and registering the electric mobile body V, there is nothing from a third party. It is an area that is not restricted by.

The DC line 2 has one or more output connection portions JL (feeding spots) for supplying electric power to the electric mobile body V via the connection devices 70 and 70A. The electric mobile body V receives electric power via a cable C having connection portions JC1 and JC2 (see FIG. 8) at both ends. When the cable C to the electric moving body V is not connected, the connecting device 70 is cut off. The connecting device 70 and the connecting device 70A have different DC voltages and supply capacities to be supplied to the electric mobile body V.

The management device 80 selects a charging mode such as normal charging or high-speed charging when the electric moving body V is physically connected to the DC line 2 via the connecting devices 70 and 70A, and is previously assigned to the electric moving body V. When the electric moving body identification information is acquired and the electric moving body identification information is determined to be the registration information that can be electrically connected to the DC line 2, the charging mode is set for the electric moving body V, and the electric moving body is transmitted from the DC line 2. The charging mode is set when the required amount of DC power is supplied to V to charge the power storage device 4 (see FIG. 8) mounted on the electric mobile body V and the required amount of DC power is supplied to the electric mobile body V. It is released, and the DC line 2 and the electric moving body V are disconnected.

That is, when the electric moving body V is physically connected to the output connection portion JL, the electric moving body identification information given to the electric moving body V is acquired, and the electric moving body is based on the electric moving body identification information. It is determined whether or not V is an electric moving body to be fed, and when it is determined to be an electric moving body to be fed, the connecting device 70 electrically connects the DC line 2 and the electric moving body V, and the electric moving body V is connected. DC power is supplied from the output connecting portion JL to the electric moving body V until the storage capacity of the electric moving body V is reached or until the electric moving body V is disconnected from the output connecting portion JL.

The management device 80 is connected to an information terminal of a car navigation system or a mobile terminal having a communication function linked to the registration identification information by a communication unit which is a wireless communication facility, and is electrically connected to the registration identification information and each registration identification information. The current storage amount information indicating the current power storage amount of the power storage device arranged in the mobile body V is periodically acquired by the wireless communication equipment, updated and stored. The information terminal transmits and receives various information to and from the control device 7 (see FIG. 8) of the electric mobile body V.

FIG. 8 is a diagram showing a configuration of a charging mode of the electric mobile body V according to the present embodiment. FIG. 9 is a diagram showing a configuration of a traveling mode of the electric moving body V according to the present embodiment. See FIG. 7 as appropriate. The electric moving body V is an electric moving body that supplies electric power to rotate and drive a driving electric device 5 provided on a first driving wheel axle and a second driving wheel axle to travel.

The electric moving body V receives DC power from a DC line 2 (see FIG. 7) that supplies DC power of a predetermined voltage in a controlled area (for example, controlled area A1). Connection unit), a first power conversion device 1C that converts the DC power received from the first receiving connection unit J1 into AC power, and a first driving electric device 5a and a second drive that stores the power. The power storage device 4 that supplies the power required to drive the electric power device 5b to rotate, the second power conversion device 2C that converts the DC power of the power storage device into AC power, and the second power conversion device 2C. Is arranged at an intermediate position between the first power conversion device 1C and the second electric power conversion device 5b, and the second electric power conversion device 2C is connected to the first electric power conversion device 1C or the second electric power for driving. It is configured to include a power receiving switching device 3 for selecting and connecting any of the devices 5b. Further, the electric moving body V is arranged at an intermediate position between the first receiving connection unit J1 and the first power conversion device 1C, and the first receiving connection unit J1 or the first receiving connection unit J1 or the electric power conversion device 1C is connected to the first power conversion device 1C. The first switch 8 to select and connect any of the power storage devices 4 and the first power conversion device 1C are connected to the power receiving switching device 3 via the first driving electric device 5a or the electrical insulation device 6. A control device 7 that controls a second switch 9 connected to, a first power conversion device 1C, a second power conversion device 2C, a power reception switching device 3, a first switch 8, a second switch 9, and the like. It is configured to include and. Further, the electric mobile body V has a second receiving connection portion J2 that is directly connected to the power storage device 4.

The electric moving body V connects the power storage device 4 and the first power conversion device 1C by the first switch 8, and the first power conversion device 1C and the first drive electric device by the second switch 9. 5a is connected, the second power conversion device 2C and the second drive electric device 5b are connected by the power reception switching device 3, and the AC power output from the first power conversion device 1C is the first. The drive electric device 5a has a traveling mode in which the AC power output from the second power conversion device 2C is supplied to the second drive electric device 5b.

Further, the electric moving body V connects the first receiving connection unit J1 and the first power conversion device 1C by the first switch 8, and receives power from the first power conversion device 1C by the second switch 9. The switching device 3 is connected, the second power conversion device 2C and the first power conversion device 1C are connected by the power receiving switching device 3, and the AC power output from the first power conversion device 1C is used as the second power conversion device 1. It has a charging mode of converting power into DC power by the power conversion device 2C of the above and supplying power to the power storage device 4.

The configuration of FIG. 8 will be further described.
When the first receiving connection unit J1 is physically connected to the DC line 2 via the connecting device 70 (first connecting device) in the charging mode, the electric moving body V obtains the electric moving body identification information. While transmitting to the management device 80, the DC line is transmitted through the first receiving connection unit J1 from the time when the electrical connection is established between the first receiving connection unit J1 and the DC line 2 until the connection is disengaged. The DC power received from 2 is converted into AC power by the first power conversion device 1C and supplied to the second power conversion device 2C, converted into DC power and supplied to the power storage device 4 for charging.

Further, the electric moving body V is an electric moving body when the second receiving connection portion J2 is physically connected to the quick charger 63 via the connecting device 70A (second connecting device) in the charging mode. While transmitting the identification information to the management device 80, the second receiving connection unit J2 is connected from the establishment of the electrical connection between the second receiving connection unit J2 and the quick charger 63 until the disconnection. The DC power received from the quick charger 63 is supplied to the power storage device 4 to charge the power storage device 4.

When the charging mode is released, the electric moving body V supplies the DC power output from the power storage device 4 to the first power conversion device 1C to convert it into AC power, and the first driving electric device. In addition to being supplied to 5a, it is supplied to the second power conversion device 2C to convert it into AC power, and is supplied to the second drive electric device 5b to shift to the traveling mode.

Further, in the electric moving body V, the first drive electric device 5a and the first power conversion device 1C are used, and the second drive electric device 5b and the second power conversion device 2C are used as regenerative braking devices. It functions, and when the output of the power storage device 4 is suppressed in the traveling mode, the power generated by the driving electric device 5 is stored via the first power conversion device 1C or the second power conversion device 2C. It is preferable to supply the device 4 to charge the power storage device 4.

According to the power supply system of the present embodiment, the supply to the AC system side and the supply to the DC system side can be arbitrarily switched without major modification of the existing power generation system. Further, according to the power demand, a part of the output of the DC power supply device 10 (solar power generation module) can be supplied to the commercial system 1 side, and the rest can be supplied to the DC line 2 side.

1,1A Commercial system 2 DC line 1C 1st power conversion device 2C 2nd power conversion device 3 Power reception switching device 4 Power storage device 5 Drive electric device 5a 1st drive electric device 5b 2nd drive Electric device 6 Electrical insulation device 7 Control device 8 First switch 9 Second switch 10 DC power supply device 11 Junction box 11A Junction box with switching function (switcher)
20 Power conditioner 21 DC / DC converter 22 System interconnection inverter 23 Commercial isolation transformer 30 Commercial step-up transformer 50 Switch (switching unit)
51 Input section 51s External signal 52 Control circuit 53 DC / DC converter 54 Branch switch (switch)
61 Bidirectional DC / DC converter 62 Storage battery 63 Quick charger 70 Connection device 71 Power supply switch 74 Control unit 80 Management device 90 Power company 91 Resource aggregator 92 Area manager 100, 100A, 100B Power supply system A1, A2, A3 management Area C cable J1 1st receiving connection (power receiving connection)
J2 2nd receiving connection part JC1, JC2 connection part JL output connection part (power supply spot)
V, V1, V2 Electric mobile

In order to achieve the above object, the power supply system of the present invention combines the output from the DC power supply device with the DC power supply device (for example, a solar power generation module) that supplies a DC current of a predetermined voltage in a controlled area. It is a power supply system equipped with a junction box to be connected and a grid interconnection inverter that converts the current output from the junction box and supplies an AC current. It is characterized in that a switching unit for switching between an AC current supply system and a DC current supply system is provided based on a switching signal generated according to the operation of the output of the DC power supply device. Other aspects of the present invention will be described in embodiments described below.

In order to achieve the above object, the power supply system of the present invention combines the output from a DC power supply device with a DC power supply device (for example, a solar power generation module) that supplies a DC current of a predetermined voltage in a controlled area. It is a power supply system equipped with a junction box to be connected and a grid interconnection inverter that converts the current output from the junction box and supplies an AC current. , A switching unit is provided to switch between the AC current supply system and the DC current supply system based on the switching signal generated according to the operation of the output of the DC power supply device. It is connected, and the grid interconnection inverter and the DC line are switchably connected to the other side of the switching section. The DC / DC converter and the DC load are connected in order from the line switching part side, and the switching signal is sent by the management device when the electric moving body is physically connected to the DC line via the DC line connecting device. When the identification information given in advance to the electric moving body is acquired and the identification information is determined to be the registration information that can be electrically connected to the DC line, the non-traveling mode is set for the electric moving body and the command is used to switch to the DC line. characterized in that there. Other aspects of the present invention will be described in embodiments described below.

Claims (10)

In a controlled area, a DC power supply that supplies a DC current of a predetermined voltage, a junction box that synthesizes the output from the DC power supply, and a junction box that converts the current output from the junction box to supply an AC current. It is a power supply system equipped with a grid-connected inverter.
A power supply system characterized in that a switching unit for switching between an AC current supply system and a DC current supply system is provided between the junction box and the grid interconnection inverter based on a switching signal from a management device. The power supply system according to claim 1.
A power supply system characterized in that a junction box of the DC power supply device is connected to one of the switching units, and the grid interconnection inverter and a DC line are switchably connected to the other of the switching units. .. The power supply system according to claim 2.
The switching unit is a power supply system including the grid interconnection inverter and an input unit for an external signal instructing switching of the DC line. The power supply system according to claim 3.
A power supply system characterized in that a DC / DC converter and a DC load are connected in order from the switching portion side of the DC line. The power supply system according to claim 4.
With respect to the external signal, when the electric moving body is physically connected to the DC line via the DC line connecting device, the management device acquires the identification information previously given to the electric moving body, and the above-mentioned external signal is used. A power supply system characterized in that when it is determined that the identification information is registration information that can be electrically connected to the DC line, a non-traveling mode is set for the electric moving body and a command is given to switch to the DC line. The power supply system according to claim 5.
The switching unit is a power supply system characterized by being a switching device. The power supply system according to claim 5.
The power supply system is characterized in that the switching unit is the junction box provided so that wiring can be switched for each string of the DC power supply device. In a controlled area, a DC power supply that supplies a DC current of a predetermined voltage, a junction box that synthesizes the output from the DC power supply, and a system that converts the current output from the junction box and supplies AC current. A power supply system equipped with an interconnected inverter
A power supply system characterized by having a branch switch connected between the junction box and the grid interconnection inverter and supplying a direct current to a direct current line based on an input signal from a management device. The power supply system according to claim 5.
The DC power supply device is a power supply system characterized in that it is a photovoltaic power generation device. The power supply system according to claim 5.
A power supply system characterized by supplying an alternating current from the grid-connected inverter to a commercial system.

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