JP2013090560A - Dc power feeding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power feeding system capable of reducing a loss at the conversion from AC by feeding power by DC directly to electric appliances and information communication devices most of whose models operate by a DC power thus to save power and save resources due to elimination of the need for an AC adapter, of effectively using power generated by natural energy by means of a small solar battery or the like that was conventionally difficult to be utilized in a DC power feeding system, and of functioning as an emergency power supply at an interruption of power supply.SOLUTION: A DC power feeding system comprising a DC input, an AC input, an accumulator battery, a charge and discharge control device, a power feeding control device, and an automobile power supply input-output is constructed. A DC power is transmitted by indoor wiring and supplied to respective electric appliances via DC plug sockets. A natural energy power by a solar battery and the like is connected to the DC input, a commercial power supply is connected to the AC input, and the DC input is utilized preferentially. At an interruption of power supply, power is obtained and supplied from the accumulator battery in the system and an automobile power supply connectable to the system.

Description

    The present invention relates to a system in which a DC power supply line is wired indoors, DC power is supplied, and power is supplied to a plurality of electrical devices such as home appliances and information communication devices from a DC outlet.

    Currently, although most information communication equipment and home appliances operate with direct current power, the power being supplied is alternating current, so AC adapters and AC / DC converters are used for each equipment. . If power is supplied with direct current instead of alternating current, individual adapters and converters become unnecessary, saving resources, and general AC adapters are not highly efficient, so efficiency can be improved by performing direct current conversion with a high-efficiency converter. And power saving.

    In addition, natural energy power generation such as solar cells and fuel cells, which are becoming popular in recent years, are DC power. However, in the case of small output, there is no place to receive power and the generated power is not used effectively. If you try to convert AC with an inverter, it will be converted twice with the DC conversion on the electrical product side, resulting in a large loss. However, if you can supply power with DC, this loss will not occur. A system for converting and supplying power has been filed.

JP 2008-42998 A JP 2008-43000 A JP 2010-288387 A

    However, what is shown in the patent literature describes the use of DC power converted from AC commercial power. Even if connected as it is, it does not work. Although DC power supply has many advantages, AC power supply has been used in the past, and equipment and power supply system technology for realizing efficient DC power supply even when these DC power supplies are connected to each other are insufficient. Yes.

    The present invention solves this conventional deficiency, can be installed indoors, realizes power saving, resource saving, convenience of use, utilization of low output natural energy power that was difficult with AC power feeding, power failure The purpose is to provide a direct current power supply system that realizes emergency power supply and coordination with automobile power supply.

    In order to achieve the above object, the present invention supplies DC power by a combination of DC input, AC input, DC input control device, AC / DC converter, power supply control device, DC power supply line, and DC outlet. A storage battery and charge / discharge control device are provided for the stable use of natural energy power with output fluctuations for power storage and response to power outages, and as required, input / output interfaces with automobile power supply, voltage conversion cables, cigars Equipped with lighter plug conversion cable and DC table tap.

    A direct current input control device is provided for direct current inputs mainly for renewable energy power generation, and maximum power point tracking control (MPPT) is provided for solar cells that require an optimum operating point to obtain the maximum output. For power sources with large voltage fluctuations such as wind power generation, a DC / DC converter is provided to stabilize the voltage. In addition, AC input received from a commercial power source is converted to DC by a highly efficient AC / DC converter.

    A direct current input from a solar cell or the like is taken out as an optimum operating point power by a direct current input control device, is subjected to current and voltage control by a charge / discharge control device, and is charged to a storage battery. When the battery is fully charged or when there is a margin in input power, the input power is supplied from the DC output to the load.

    The function of the power supply control device is to measure the output voltage, current, or both of the DC power supply system that fluctuates depending on the load, so that the necessary power amount for the shortage of DC input or battery discharge power can be obtained. It is efficiently obtained by feeding back to the pulse width control circuit of the AC / DC converter.

    By using priority distribution control that preferentially uses DC input as described above and compensates for the shortage of output power with DC power converted from AC, when connecting natural energy power such as solar cells to DC input, Using a storage battery as a regulating pond, natural energy power is consumed without waste.

    When the DC input is a solar battery, it is a common usage to charge the storage battery during the daytime when the generated power is generated, and to discharge and consume it at night. In addition, when a plurality of storage batteries are provided and charged sequentially, power can be charged more efficiently. By using a storage battery, it is possible to supply power even during a power failure. If an electric double layer capacitor is provided as an auxiliary to the storage battery, the supply is more reliable.

    The function of DC power supply system is further enhanced by providing input / output for connection with the car power supply. In the event of a power failure, the car battery can serve as a backup for the DC power storage system battery, and in the event of an emergency, power generation by the car alternator can also be used. In addition, when there is a surplus in natural energy power, power can be stored in the car battery.

    As another advantage when connecting to an automobile power source, when the automobile battery rises, it can be charged by transmitting power from the DC power supply system side.

    Since there is a risk of failure if the DC power supply system and the vehicle power supply are always connected, it is safe to install a transmitter / receiver in the DC power supply system and the vehicle so that the circuit starts connection upon receiving a signal from the DC power supply system. .

    When the DC power supply output voltage is set to DC12V, most of the information communication equipment can be used, it is the same as the car power supply voltage, it can be easily connected to the car power supply, and the car supplies can be used in the house. is there.

    In addition to the above 12V, it is also possible to supply 5V in addition to 12V from a DC outlet by using two sets of DC feed lines and an AC / DC converter with multiple voltage output types, for example, 12V and 5V. is there.

    If a signal line is provided in addition to the DC power supply line and a signal terminal is provided in the DC connector, it is possible to equip a mechanism for performing mutual communication between the load device and the power supply system using a serial signal or the like. As a result, detailed system operation such as forecasting demand and supplying power becomes possible.

    The DC output is connected to a DC power supply line, a DC outlet is provided where necessary, and a DC connector is connected to a DC plug for an electrical outlet. The DC connector for power supply must be different from the existing AC outlet in order to prevent errors. The DC outlet may be provided alone or may be incorporated into an AC outlet box. When incorporated in an AC outlet box, the outlet box does not need to be provided separately from the existing AC power supply, and construction and handling are facilitated.

    If the LED indicator is incorporated in the connector itself or installed in the vicinity of the DC connector, it is easy to find the position in the event of a power failure.

    In order to supply electric products that operate at a voltage other than the set DC output voltage, it is convenient to use a voltage conversion cable incorporating a DC / DC converter.

    The use of the DC power supply system of the present invention eliminates the need for individual AC adapters and converters, saves resources, and improves the safety because the area around the outlet and the floor surface are clean. In addition, it is generally more energy efficient to use a batch of high-efficiency AC / DC converters than to perform direct current conversion with individual AC adapters or converters. Furthermore, in order to use power from solar cells and storage batteries in conventional AC power supply, the voltage is increased to 100V AC by an inverter, and on the electrical product side, it is converted to step-down DC by an AC adapter or converter and used in equipment. There were many losses. As an example, if the conversion efficiency of the inverter and the converter is 80%, the direct-current input is directly used for direct-current power supply, which results in a power saving of 36%. Traditionally, small-output natural energy generated power cannot be linked to the grid and has been used only in houses, etc., but if it is connected to a DC power supply system, the power can be effectively consumed, and the grid is burdened. A smooth transition to the use of renewable energy without the need to pay is possible.

    Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. In addition, this form is a thing when all of Claim 1 to 12 are satisfy | filled, In implementation, the form remove | eliminated unnecessary element according to use conditions may be sufficient.

    As shown in FIG. 1, the control device of the DC power supply system of the present invention is housed in a DC power supply control panel, and a DC input 1, an AC input 2, and an automobile power input / output 3 are provided there. A plurality of inputs 1 and 3 may be provided.

    In the DC input 1 in FIG. 1, a natural energy generated power such as a solar cell 4 is mainly input. A DC input control device 5 is provided in this input system having a large voltage and current fluctuation. As shown in FIG. 2, the DC input control device 5 has a maximum power point tracking control (MPPT) for solar cells and an input load current squared for wind power generation according to the characteristics of the connected power source. A constant voltage DC / DC converter that changes sharply as described above is provided, and control is performed so that the maximum generated power can be obtained.

    A vehicle power supply 6 is connected to the vehicle power input / output 3 of FIG. When the power supply system output voltage is 12V, a general DC 12V vehicle can be connected as it is, and in the case of a diesel vehicle 24V or a high voltage power source of an electric vehicle, a DC / DC converter is provided to meet the input voltage standard. In addition, a stable power source such as an external storage battery or a fuel cell other than an automobile can be connected in a similar manner if the input voltage standard matches. In the case of an automobile power supply, it is safe to provide an overvoltage protection circuit 7 in order to avoid the influence of a high voltage that may be generated from an alternator.

    Since the connection line with the automobile power supply usually passes outdoors, in order to avoid the risk of a ground fault and malfunction due to disconnection of the connector, the transceiver 8 is provided in both the automobile power supply 6 and the DC power supply control panel in FIG. It is safe to provide an open / close switch on the power supply side and start connection of the automobile power supply in response to a command signal from the DC power supply system side. As a signal transmission method, it is certain that the signal is transmitted in a wired manner through a signal line provided in addition to a connection line with the automobile power supply. However, a method of superimposing a signal on the connection line may be used, or radio may be used.

    An AC commercial power source is connected to the AC input 2 in FIG. The input power is converted into direct current by the AC / DC converter 9.

    The electric power input from the DC input 1, AC input 2, and vehicle power input / output 3 in FIG. 1 passes through the respective converters or control devices, and is then given control and distributed by the power supply control device 10. . In normal times, the DC input 1 is prioritized and the shortage is introduced from the AC input 2.

    One embodiment of the above priority control is shown in FIG. The power input from the DC input control device 5 to the power supply control device 10 is distributed to the charge / discharge control device 11 mainly as charging power in the distribution circuit A, and the surplus power is distributed to the DC output. The DC power converted by the AC / DC converter 9 is mainly distributed to the DC output by the distribution circuit B, and is also output to the charge / discharge control device 11 when the charging power is insufficient. The distribution circuits A and B are equipped with a backflow prevention element as necessary.

    A load is connected as shown in FIG. 3 in order to supply constant voltage power corresponding to fluctuations in power input from DC input, power input / output to / from the charge / discharge control device, and power consumed by the load. After measuring and calculating the voltage and current of the DC output in the state, the control signal is fed back to the pulse width control circuit of the AC / DC converter to control the DC conversion power amount of the AC / DC converter. This control maintains a constant DC power supply voltage and optimizes power consumption.

    The vehicle power supply 6 connected to the vehicle power supply input / output 3 in FIG. 1 is controlled by the charge / discharge control device 11 and used as a backup power supply. In the event of a power failure, if the power stored in the system storage battery becomes insufficient, power can be supplied from the car battery, and in the event of an emergency, power generation by the car alternator can also be used. Further, when the input power from the DC input 1 is excessive with respect to the load, it is possible to use an automobile power source as a storage destination.

    The charge / discharge control device 11 in FIG. 1 controls voltage and current in order to realize an optimum charge / discharge cycle for the storage battery 12. When the power of the DC input 1 is input, the power is stored in the storage battery 12, and when the charging power is insufficient, the power from the AC input 3 is also introduced. When the battery is fully charged, the output from the storage battery 12 to the load is consumed in the time zone without the DC input 1 determined by monitoring the DC input voltage to free up capacity, and then the power from the DC input 1 is introduced. However, it maintains a certain amount of power in preparation for a power outage or the like, and supplies the stored power during a power outage. The charge / discharge control device 11 also controls charge / discharge of the battery of the automobile power source connected to the automobile power input / output 3 to prevent overcharge and overdischarge.

    As shown in FIG. 1, when a plurality of storage batteries 12 are used and one battery is fully charged, when the charging destination is sequentially transferred to the next battery, the amount of available stored power can be increased. Moreover, if the electric double layer capacitor 13 is installed in parallel with the storage battery as desired, the reliability is improved. The electric double layer capacitor has a lower energy density than the secondary battery at present, but is maintenance-free and has a long life, and is effective for short-time power outages and peak leveling.

    Various power supply voltages for a DC power supply system have been proposed, but a DC 12V that can operate many electronic devices and can be integrated with an automobile power supply is essential. If the breaker 14 is provided in the DC output path, the system is protected in the event of a short circuit or overload.

    If there is a margin in the number of the DC power supply lines 16 and the number of poles of the DC connector in FIG. 1 and the AC / DC converter is a multiple voltage output type, for example, 5V or DC12V (−) other than DC12V (+) Different voltages can be supplied, and a communication line between the power feeding system and the connected device can be provided. Using this signal line, if the power supply system exchanges signals with electrical products that support communication, detailed power consumption and on-demand power supply are possible, leading to the promotion of smart grids. FIG. 4 shows an example of pin assignment of a DC connector provided with multiple voltages and communication lines.

    The DC connector 18 used in the DC power supply system of the present invention is always formed in a different shape from the existing AC outlet 19 to prevent errors. The DC connector 18 may be provided in a single DC outlet as shown in FIG. 1, or may be incorporated in the composite outlet box 20 together with the AC outlet 19 as shown in FIG. In this way, when a composite outlet is used, it is not necessary to provide a new outlet box space in the building, and construction and handling become easy. If the LED indicator 21 is incorporated in the DC connector 18 or installed in the vicinity as shown in FIG.

    A DC power supply compatible electric product that is expected to appear in the implementation of the present invention can be supplied with power simply and reliably by providing the outlet DC plug 22 at the tip of the power cable. For existing products, use the corresponding cable as shown below.

    Among the electrical products using the AC adapter, for the equipment whose power supply voltage is equal to the supply voltage of the DC power supply system of the present invention, as shown in FIG. A cable having a side DC plug 24 is used. The equipment-side DC plug is compatible with most equipment by preparing an EIAJ unified type DC plug of a corresponding voltage classification and a pin diameter 2.1 mm plug.

    For a device whose required power supply voltage is different from the supply voltage, a voltage conversion cable using a combination of the outlet DC plug 22, the small DC / DC converter 23, and the device-side DC plug 24 shown in FIG. 6B is used. It is easy to understand if the voltage is displayed on the converter.

    In order to use automobile supplies, a cable having a DC plug 22 for outlet at one end and a cigar lighter socket 25 at the other end shown in FIG. 6C is used.

    When there are many devices to be connected and the number of outlet DC connectors 18 is insufficient, the case shown in FIG. 6 (d) in which a DC plug 22 for outlets is attached to one end and a plurality of DC connectors 18 are attached to the other end. Use a direct current table tap.

    The DC power supply system of the present invention is installed and installed indoors in the form of an existing AC power supply, and is used for power supply of home appliances and information communication equipment in which DC is used inside the equipment. Power loss is minimized. In addition, by connecting a natural energy generated power such as a solar battery that is a direct current output, a loss due to the AC inverter can be eliminated and the power can be used without waste. Furthermore, it can also be used as an emergency power source in the event of a power failure by using a storage battery in the system or connecting to a car power source. When the supply voltage is set to 12V, it is possible to combine both markets, such as using automobile accessory equipment in a house or conversely using 12V-compatible home appliances in a car.

  The block diagram which shows the structure of the DC power supply system of this invention.   The block diagram which shows the structure of the direct-current input control apparatus of the direct-current power feeding system of this invention.   The block diagram which shows the structure and operation | movement of the electric power feeding control apparatus of the direct current electric power feeding system of this invention.   The figure which shows the pin assignment example of the direct-current connector of the direct-current power feeding system of this invention.   A composite outlet box provided with a DC connector and an AC power supply outlet of the DC power supply system of the present invention.   Various cables used for connecting home appliances in the DC power supply system of the present invention. (A) Connector conversion cable (b) Voltage conversion cable (c) Cigarette lighter plug conversion cable (d) DC table tap

1. DC input2. 2. AC input Automobile power input / output4. 4. Solar cell DC input control device 6. 6. Auto power supply Overvoltage protection circuit8. 8. Transceiver AC / DC converter10. 10. Power supply control device Charge / discharge control device 12. Storage battery 13. Electric double layer capacitor 14. Breaker 15. DC output 16. DC power supply line 17. DC outlet 18. DC connector 19. AC outlet 20. Composite outlet box 21. LED indicator light 22. DC plug for outlet 23. Small DC / DC converter 24. Device side DC plug 25. Cigarette lighter socket

Claims (12)

    AC input, AC / DC converter, DC input, storage battery, charging / discharging control device, DC power supply line, DC outlet are provided, and it is possible to accept natural energy generated power such as solar cells from DC input, from AC input , AC commercial power can be received and converted into direct current by an AC / DC converter, and the direct current power can be supplied to electrical products from a DC outlet at all times. DC power supply system that can supply the power stored in the storage battery from a DC outlet when the battery is charged to the specified charge.     The DC power supply system according to claim 1, wherein a plurality of storage batteries are used, and when one storage battery is fully charged, the charging destination is sequentially switched to the next storage battery. DC power supply system that expands the capacity to respond to fluctuations in the amount of natural energy generated, load fluctuations, and power outages by switching to discharge from storage batteries and flexibly changing stored power.     3. The DC power feeding system according to claim 1, wherein an electric double layer capacitor is used instead of the storage battery or in combination with the storage battery.     4. The DC power supply system according to claim 1, wherein the AC / DC converter has a plurality of voltage outputs, and a plurality of sets of power supply lines can supply a plurality of voltages from a DC outlet.     The DC power supply system according to any one of claims 1 to 4, wherein a signal line is provided in addition to the DC power supply line, and is connected to an electrical product that supports signal transmission and reception at a DC outlet. DC power supply system that enables transmission and reception of information between them.     The DC power supply system according to any one of claims 1 to 5, wherein a DC input control device is provided by connecting to a DC input, and a maximum power point tracking control (MPPT) suitable for a solar cell as a component, and Suitable for wind power generation, equipped with a control circuit that matches the characteristics of the natural energy power to be connected, such as a DC / DC converter with an input load characteristic in which the current changes sharply with voltage change, A direct current power supply system that can efficiently use the input power of natural energy, such as wind power, that has output fluctuations.     7. The DC power supply system according to claim 1, wherein the DC power supply system has an input / output of an automobile power supply, is connected to the automobile power supply, and outputs electric power input from the automobile power supply from a DC outlet. DC power supply system that can charge the vehicle battery and, if desired, the vehicle battery when the battery goes up.     8. The DC power supply system according to claim 7, wherein a transmitter / receiver is provided in the power supply system and the vehicle, a connection command signal is sent from the DC power supply system by wire or wirelessly, and the signal is received by the vehicle-side transmitter / receiver. A DC power supply system with improved safety by starting the connection between the power supply and the DC power supply system.     The DC power supply system according to any one of claims 1 to 8, wherein a power supply control device capable of setting priority is provided, and natural energy power input from a DC input, storage power of a storage battery in the system, automobile power supply, AC power supply A DC power supply system that controls the supply power based on the commercial power supply and the usage priority assigned to each.     The means for implementing the DC power supply system according to claim 9 measures the voltage and / or current of the DC power output to the load of the DC power supply system, and uses the control signal calculated by comparison with the reference value for AC / By controlling the switching pulse width of the DC converter, the DC power supply system can stabilize the supply power from the DC output even when DC power with large fluctuations is input to the DC power supply system.     11. The DC power feeding system according to claim 1, wherein a DC outlet is a composite outlet box in which a DC connector is provided in the AC outlet box, thereby reducing installation space and convenience of construction. .     12. A DC power feeding system according to claim 1, wherein the DC power supply system includes a DC plug for outlet at one end, a DC plug for equipment on the other end, and a voltage conversion cable provided with a DC / DC converter in its path. DC power supply system that enables power supply to electrical products with a required voltage different from the voltage supplied from the DC output.

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