JP5461445B2 - Power usage system - Google Patents

Description

  The present invention relates to a power use system that uses power generated by power generation in a house.

  As natural energy, for example, the installation of a solar panel that generates electricity by using sunlight has spread to ordinary houses. Solar power generation using solar panels is mainly daytime power generation. In households that consume less electricity during the daytime, the amount of power generated by solar power generation is greater than the power used at home, and surplus power is generated. Electricity sales that power companies purchase such surplus power are common in solar power generation at home.

  On the other hand, there is a power generation system using a fuel cell that stores surplus power generated in the fuel cell and energizes a heater of a water heater (see, for example, Patent Document 1). According to this system, surplus power is used in addition to power sales.

JP 2009-266476 A

By the way, when selling surplus power, the sale of power may be suppressed depending on the form of interconnection with another solar power generation device. The following cases can be considered when the suppression of power sales occurs.
(A1) The commercial-side voltage is higher than the voltage generated by photovoltaic power generation (a2) A plurality of photovoltaic power generation devices are connected to one transformer on the pillar (a3) General to transformer on the pillar When there is no load and there is only a load of solar power generation, the suppression of power sales occurs, and when the customer requests a cancellation of the suppression, the power company measures the voltage on the commercial side. As a result of the measurement, if the commercial voltage is equal to or lower than the predetermined voltage, the electric power company takes no particular measures. If the commercial voltage is not appropriate, the power company will take measures such as adjusting the output voltage of the transformer. Even if the commercial voltage is appropriate, in the cases (a2) and (a3), the power company and the customer consider measures such as installing a dedicated transformer at home. In this case, the subject that the burden of the customer who owns a solar power generation device becomes large generate | occur | produces.

  An object of the present invention is to solve the above-described problems and to provide a power utilization system that makes it possible to effectively use generated power even when power sales are suppressed.

In order to solve the above-mentioned problem, the invention of claim 1 includes a power generator that generates DC power,
A power storage device that stores DC power, a conversion device that converts and outputs the applied DC power to commercial power, a switching device that switches the DC power from the power generation device to the power storage device or the conversion device and outputs the power, It has a monitoring means for detecting a power flow from the commercial power supply side to the indoor side, and normally the DC power from the power generator is added to the converter , and the direction of the monitoring means changes from the commercial power supply side to the indoor side . When a tidal current is detected, DC power from the power generation device is added to the power storage device, and when the monitoring unit detects a tidal current whose direction has changed from the indoor side to the commercial power source side, the DC power from the power generation device is converted into the conversion power. A power usage system comprising: a watt-hour meter that performs control applied to the device to the switching device.

In the invention of claim 1, for example, in a house, a power generation device that generates DC power, a power storage device that stores DC power, a conversion device that converts the applied DC power into commercial power, and outputs, A switching device that switches and outputs DC power to a power storage device or a conversion device and a watt hour meter are provided. The watt hour meter has monitoring means for detecting a power flow from the commercial power source side to the indoor side, and normally adds DC power from the power generator to the converter. When the watt-hour meter detects a tidal current whose direction has changed from the commercial power supply side to the indoor side, the watt-hour meter performs control on the switching device to add DC power from the power generation device to the power storage device.

  According to a second aspect of the present invention, there is provided the power usage system according to the first aspect, further comprising charging means for charging the electric vehicle based on the DC power of the power storage device.

According to a third aspect of the present invention, in the power usage system according to the first or second aspect, the monitoring unit detects a power failure of the commercial power source, and when the monitoring unit detects a power failure, the DC power of the power storage device is reduced. Switching means for enabling output to the conversion device.

According to the first aspect of the present invention, the direct current power output from the power generator is stored even when a tidal current whose direction is changed from the commercial power supply side to the indoor side is generated and the power sale is suppressed. Can be used effectively.

  According to the invention of claim 2, the electric vehicle can be charged based on the DC power charged when the power sale is suppressed.

  According to the invention of claim 3, in the event of a power failure, the switching means can output the DC power of the power storage device to the conversion device, thereby responding to the power failure based on the DC power charged when power sale is suppressed. Make it possible to do.

1 is a configuration diagram illustrating a power usage system according to Embodiment 1. FIG. It is a block diagram which shows an example of a distribution board. It is a block diagram which shows an example of a switching device and an electrical storage apparatus. It is a block diagram which shows an example of a converter. It is a block diagram which shows an example of a smart meter. It is a flowchart which shows an example of a switching process. It is a block diagram which shows an example of the switching apparatus and power storage device by Embodiment 2. FIG. 10 is an explanatory diagram for explaining the flow of electricity according to the second embodiment.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
A power utilization system according to this embodiment is shown in FIG. The power usage system of FIG. 1 includes a smart meter 10, a distribution board 20, a solar power generation device 30, a switching device 40, a power storage device 50, and a conversion device 60. Each equipment of smart meter 10-conversion device 60 is installed in residence A of a customer who is a consumer of electricity. In FIG. 1 and the subsequent drawings, for simplification of the drawing, the configuration for selling power is omitted, but the watt-hour meter for selling power is connected in series to the smart meter 10. . Further, in this embodiment, the signal wiring system is indicated by a thin line in the figure, and the power wiring system in the house A is indicated by a thick line to distinguish the two. Furthermore, the house A shows a representative example among many.

In the house A, electricity from the distribution line 101 is branched by the distribution board 20 through the smart meter 10. The distribution line 101 supplies commercial power to the house A. Note that the commercial power source is electric power sent from an electric power company to a general household. As shown in FIG. 2, the distribution board 20 includes a main breaker 21, a power generation side breaker 22, and branch breakers 23 ₁ to 23 _n .

  A current flows through the main breaker 21 installed in the house A by the AC power supplied from the smart meter 10, and the main breaker 21 detects and shuts off the overcurrent. Similarly, a current flows through the power generation side breaker 22 by AC power based on the solar power generation device 30, and the power generation side breaker 22 detects and shuts off the overcurrent. The current breakage by the main breaker 21 and the power generation side breaker 22 can be manually operated.

The branch breakers 23 ₁ to 23 _n of the distribution board 20 detect and block the leakage of the distribution lines of each circuit when the branched current flows through the circuit in each room of the house A. Each room circuit has an electrical outlet. The current flowing through the circuit in each room is due to the power supplied from the distribution line 101 and the solar power generation device 30 and is supplied to the television 101 and the air conditioner 102 in the house A, for example. That is, AC power from the commercial power supply side or the solar power generation side is supplied to the television 101, the air conditioner 102, and the like.

  The solar power generation device 30 installed in the house A includes a solar panel 31. The solar panel 31 is installed on the roof by a support tool or the like. And the solar panel 31 raise | generates electricity with the irradiated sunlight, and performs solar power generation. The DC power from the solar panel 31 is output to the switching device 40 through a distribution line that runs from the roof of the house A to the indoors.

  The switching device 40 switches the DC power from the solar panel 31 to either the power storage device 50 or the conversion device 60 and outputs it. For this purpose, the switching device 40 includes a magnet switch (electromagnetic switch) 41 as shown in FIG. That is, in this embodiment, the switching device 40 is the magnet switch 41. The magnet switch 41 performs a switching operation under the control of the smart meter 10. The magnet switch 41 normally outputs DC power from the solar power generation device 30 to the conversion device 60. In this state, when receiving a switching signal from the smart meter 10, the magnet switch 41 switches the connection and outputs the DC power from the solar power generation device 30 to the power storage device 50.

  The power storage device 50 is a device that stores DC power and outputs the stored DC power to the electric vehicle 201. For this purpose, the power storage device 50 (FIG. 3) includes a storage battery 51, a switch 52, and a DC / DC converter 53. The storage battery 51 stores the DC power from the switching device 40. The DC / DC converter 53 is connected to the storage battery 51 side via a switch 52 that is manually turned on / off. The DC / DC converter 53 operates with direct current power of the storage battery 51 and converts this direct current power into direct current power having a voltage required for the electric vehicle 201. A connection portion (not shown) that can be connected to the electric vehicle 201 is attached to the output side of the DC / DC converter 53. When the electric vehicle 201 is connected to this connection portion and the switch 52 is operated, the DC / DC converter 53 outputs the converted DC power to the electric vehicle 201. Thereby, the electric vehicle 201 is charged.

  Conversion device 60 receives the DC power from power storage device 50 to perform a conversion operation, and converts this DC power into AC power. For this purpose, the conversion device 60 includes relays 61 and 63 and a DC / AC inverter 62 as shown in FIG. The DC / AC inverter 62 converts the DC power from the power storage device 50 that has passed through the switching device 40 into AC power having the same frequency and voltage as the commercial power supply. Further, when the DC / AC inverter 62 receives an open signal from the smart meter 10, the DC / AC inverter 62 stops the conversion operation.

  The relay 63 of the conversion device 60 is provided on the input side of the DC / AC inverter 62, that is, between the DC / AC inverter 62 and the switching device 40. The relay 61 is provided on the output side of the DC / AC inverter 62, that is, between the DC / AC inverter 62 and the distribution board 20. Usually, the relays 61 and 63 are in a state where the contacts are closed. That is, it is normal for the DC power from the power storage device 50 to be applied to the DC / AC inverter 62 and the AC power from the DC / AC inverter 62 to be applied to the distribution board 20. Further, when the relays 61 and 63 receive the opening signal from the smart meter 10, the relays 61 and 63 open the contacts. Thereby, the converter 60 stops the output of AC power.

  The smart meter 10 is a watt-hour meter that measures the amount of power supplied from the distribution line 101 to the house A, and is a watt-hour meter having various functions. A smart meter 10 according to this embodiment is shown in FIG. The smart meter 10 includes a detection unit 11, a measurement unit 12, and a monitoring control unit 13. The detection unit 11 includes a measurement transformer, a current transformer (not shown), and the like, and detects the voltage of the commercial power supply and the current flowing through the house A. The detection unit 11 sends detected values of voltage and current to the monitoring control unit 13.

  The measuring unit 12 of the smart meter 10 measures the amount of AC power that flows from the distribution line 101 toward the distribution board 20. The metering unit 12 sends the power consumption metering result to the monitoring control unit 13.

  The monitoring control unit 13 of the smart meter 10 functions as a watt hour meter by recording the measurement result from the measurement unit 12 and calculating the amount of power used in the house A. Further, the monitoring control unit 13 checks the presence or absence of a tidal current that flows from the converter 60 via the distribution board 20 based on the detected voltage and current values from the detecting unit 11, that is, the reverse power flow, and determines the direction of the tidal current. To detect. When the monitoring control unit 13 detects the direction of the power flow from the commercial power supply side toward the indoor distribution board 20 (hereinafter referred to as “indoor direction”), it performs a switching process. An example of this switching process is shown in FIG. When the monitoring control unit 13 starts the switching process, it outputs an open signal to the conversion device 60 (step S1). As a result, the conversion device 60 stops the conversion operation. When step S1 ends, the monitoring controller 13 outputs a switching signal to the switching device 40 (step S2). Thereby, the switching device 40 outputs the DC power from the solar power generation device 30 to the power storage device 50.

  Thereafter, the monitoring control unit 13 checks the passage of time (step S3). When the passage of time passes the predetermined time (step S4), the monitoring control unit 13 stops outputting the switching signal (step S5) and stops outputting the release signal (step S6). Thereby, the DC power from the solar power generation device 30 is output to the distribution board 20 again.

  When step S6 ends, the monitoring control unit 13 checks the power flow (step S7). If the tidal current is in the indoor direction (step S8), the monitoring controller 13 returns the process to step S1. On the other hand, in step S8, if the power flow is in the direction from the distribution board 20 toward the commercial power source (hereinafter referred to as “outdoor direction”), that is, if power is being sold, the monitoring control unit 13 performs the switching process. Exit.

  As described above, by the switching process, the monitoring control unit 13 supplies AC power from the commercial power supply side or the solar power generation side to each indoor circuit, or supplies DC power from the solar power generation side to the power storage device 50. The switching of whether to do is performed based on the direction of the tidal current.

  Next, the operation of the power usage system according to this embodiment will be described. Since the smart meter 10 normally stops outputting the open signal to the conversion device 60, the switching device 40 outputs the DC power from the solar power generation device 30 to the conversion device 60. Moreover, since the smart meter 10 has stopped outputting the switching signal to the switching device 40, the conversion device 60 converts the DC power from the switching device 40 to the same AC power as the commercial power supply by performing a conversion operation. Convert. Then, conversion device 60 outputs the generated AC power to distribution board 20. In this state, if the amount of power generated by the solar power generation device 30 is larger than the amount of power used by each electrical device in the house A, the tidal current is in the outdoor direction and power is sold.

  By the way, if the electric energy which the solar power generation device 30 raises becomes small compared with the electric energy used with each electric equipment of the house A, a tidal current will change to an indoor direction. That is, power sales are suppressed. When the smart meter 10 detects a tidal current whose direction has changed, it performs a switching process. Thereby, the conversion device 60 stops the conversion operation, and the switching device 40 adds the output from the solar power generation device 30 to the power storage device 50. As a result, when power sale is suppressed, the power storage device 50 stores DC power generated by solar power generation.

  In such a state, when the tidal current changes in the outdoor direction, the smart meter 10 detects this tidal current change by the switching process. As a result, the switching device 40 adds the output from the solar power generation device 30 to the conversion device 60, and the conversion device 60 converts the DC power generated by the solar power generation into the same AC power as the commercial power source. Then, conversion device 60 outputs the generated AC power to distribution board 20. As a result, power sale is performed again.

  By the way, when charging the electric vehicle 201, the customer connects the electric vehicle 201 to the connection part on the DC / DC converter 53 side and turns on the switch 52. Thereby, the DC / DC converter 53 performs a conversion operation. That is, the DC power stored in the power storage device 50 is converted into DC power having a voltage required for the electric vehicle 201 by the DC / DC converter 53 of the power storage device 50. Thereby, the electric vehicle 201 is charged with the electric power generated by the solar power generation.

  According to this embodiment, DC power generated by solar power generation can be stored in the power storage device 50 even when the power flow in the house A changes and power sales are suppressed. Furthermore, the electric vehicle 201 can be charged with the DC power stored in the power storage device 50.

(Embodiment 2)
In the first embodiment, the DC power stored in the power storage device 50 is charged in the electric vehicle 201. In this embodiment, the DC power is used as follows. In this embodiment, components that are the same as or the same as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In this embodiment, as shown in FIG. 7, the switching device 40 includes a magnet switch 41 and a changeover switch 42. The changeover switch 42 is manually switched and is provided between the magnet switch 41 and the power storage device 50. The changeover switch 42 switches whether the direct-current power of photovoltaic power generation, which is the output of the magnet switch 41, is output to the power storage device 50 or the conversion device 60. Normally, the changeover switch 42 outputs DC power from the magnet switch 41 to the power storage device 50. When the customer of the house A manually switches the changeover switch 42, the changeover switch 42 outputs the DC power from the magnet switch 41 to the switching device 40.

  Moreover, in this embodiment, the smart meter 10 detects the power failure of the distribution line 101 side, ie, a commercial power source. And the smart meter 10 will send a switching signal with respect to the magnet switch 41 of the switching apparatus 40, if a power failure is detected.

  Next, the operation of the power usage system according to this embodiment will be described. When the commercial power supply from the distribution line 101 is normal, the operation is the same as that of the first embodiment, and thus the description of the operation in this state is omitted.

When the commercial power supply fails in the house A, the smart meter 10 detects the power failure and sends a switching signal to the magnet switch 41 of the switching device 40. Thereby, at the time of a power failure, as shown by arrow A1 of FIG. 8, the electrical storage apparatus 50 stores the direct-current power by solar power generation. In such a state, when the customer of the house A uses the power storage device 50, the customer manually opens the main breaker 21 of the distribution board 20, and cuts off between the smart meter 10 and the branch breakers 23 ₁ to 23 _n. To do. Further, when the customer manually switches the changeover switch 42 of the changeover device 40 (illustrated by a broken line of the changeover switch 42), the power storage device 50 is connected to the conversion device 60 and is stored in the power storage device 50 as indicated by an arrow A2. The direct current power is output to the converter 60. Thereby, the alternating current power based on the direct current power of the power storage device 50 is output from the conversion device 60 to the distribution board 20, and further to the circuit in each room by the branch breakers 23 ₁ to 23 _{n of the} distribution board 20. Sent.

  When the power failure is resolved, the customer of the house A switches the changeover switch 42 of the changeover device 40 and closes the main breaker 21 of the distribution board 20. Thereafter, the smart meter 10 performs a switching process, and controls the switching device 40 and the conversion device 60 in the same manner as in the first embodiment based on the direction of the power flow.

  According to this embodiment, in the event of a power failure, the DC power of power storage device 50 is converted into AC power and supplied to each room of house A, so that the DC power of power storage device 50 can be used effectively.

  In this embodiment, the DC power of the power storage device 50 is used at the time of a power failure. For example, when the amount of power used in the house A is small at night, the customer performs the above switching, You may make it sell the alternating current power based on direct current power.

(Embodiment 3)
In each of the previous embodiments, the monitoring control unit 13 of the smart meter 10 checks the presence or absence of reverse power flow based on the detected voltage and current values from the detection unit 11 and detects the direction of power flow. On the other hand, in this embodiment, the conversion device 60 has a function of detecting the direction of tidal current. The conversion device 60 sends the detection result of the tidal current direction to the smart meter 10. Then, the smart meter 10 performs a switching process based on the direction of the tidal current.

  According to this embodiment, since the conversion device 60 has a function of detecting the direction of tidal current, the processing of the smart meter 10 can be reduced.

  The present invention is not limited to solar power generation and can be used for various power generation systems that use energy such as gas and wind.

10 Smart meter (electricity meter and monitoring means)
20 Distribution board 30 Solar power generation device 40 Switching device 41 Magnet switch 42 Changeover switch (switching means)
50 Power storage device 51 Storage battery 52 Switch (charging means)
53 DC / DC converter (charging means)
60 Converter

Claims (3)

A generator that generates direct current power;
A power storage device for storing DC power;
A conversion device that converts the applied DC power into commercial power and outputs it;
A switching device that switches and outputs DC power from the power generation device to the power storage device or the conversion device;
It has a monitoring means for detecting a power flow from the commercial power supply side to the indoor side, and normally the DC power from the power generator is added to the converter , and the direction of the monitoring means changes from the commercial power supply side to the indoor side . When a tidal current is detected, DC power from the power generation device is added to the power storage device, and when the monitoring unit detects a tidal current whose direction has changed from the indoor side to the commercial power source side, the DC power from the power generation device is converted into the conversion power. A watt-hour meter for performing control applied to the device to the switching device;
A power utilization system comprising:   The power utilization system according to claim 1, further comprising charging means for charging the electric vehicle based on DC power of the power storage device. The monitoring means detects a power failure of the commercial power supply ,
When the monitoring means detects a power failure, switching means that enables output of DC power of the power storage device to the conversion device;
The power usage system according to claim 1, further comprising:

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