JP2002271997A - Dispersed power supplying network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent bad influence on a commercial AC power system, and to simplify the structure. SOLUTION: A system protector 12 is connected to the commercial AC power system 11, and the AC side of a power inverter 13 for performing DC to AC power conversion and the AC side of a power inverter for performing AC to DC power conversion are connected to the system protector 12. At least one DC distribution line 15 is connected to the DC side of a parallel-connected circuit composed of the power inverter 13 and the power inverter 14 connected in parallel, and a plurality of dispersed power devices 16 and a plurality of loads 17 are connected to the distribution line(s) 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed power supply network connected to a commercial AC power system via a system protection device.

[0002]

2. Description of the Related Art At present, a commercial AC power system is linked with a distributed power supply having a DC power generator such as a solar cell or a fuel cell to achieve effective use of energy (such as cogeneration and use of natural energy). Actively performed, in which case the distributed power supply is installed in the demand area, so that long-distance power transmission is unnecessary. The study results of such a distributed power supply network are summarized in, for example, "Commentary: Guideline for Power System Technical Requirements '98 (edited by the Agency for Natural Resources and Energy)", and the DC power generator is connected to the AC system via the DC / AC power converter. It is described as being connected.

FIG. 12 is a diagram showing a conventional distributed power supply network. As shown in the figure, a plurality of AC distribution lines 3 are connected to a commercial AC power system 1 via a system protection device 2,
A DC power generator 4 is connected to the AC distribution line 3 via a load 6 and a DC / AC power converter (DC / AC inverter) 5.

[0004]

In this distributed power supply network, since the DC power generator 4 cannot be directly connected to the AC power distribution line 3, the DC power generator 4 is connected via the DC / AC power converter 5 to the AC power distribution line 3. However, since it is necessary to provide the DC / AC power conversion device 5 corresponding to each DC power generation device 4, the configuration becomes complicated, and when a large number of DC power generation devices 4 are provided, Since the DC / AC power converter 5 needs to be provided, the installation cost is high. When the DC / AC power converter 5 is connected to the AC distribution line 3, the phase of the AC output of the DC / AC power converter 5 and the phase of the AC distribution line 3 are matched to prevent inrush current. Also, the magnitude of the AC output needs to be uniform. If the output voltage of the DC power generator 4 is too low,
When the magnitude of the AC output is not satisfied, a DC / DC power converter that boosts DC in the DC power generator 4 may be required. For example, the “Explanation: Power System Technical Requirements Guideline '98” described above includes, as an example, the case where there is a reverse power flow in a DC / AC power converter, that is, the power going from the premises of the installer of the private power generation facility to the AC power system side. In order to prevent a voltage rise, it states that the power factor at the power receiving point is 85% or more in principle, and that the power factor does not reach when viewed from the AC power system. As described above, in order to connect the DC power generator 4 to the distributed power supply network having the conventional AC power supply lines 3, it is necessary to provide strict restrictions so as not to adversely affect the conventional users of the commercial AC power system 1. is there. Therefore, when the DC power generator 4 is connected to the AC power supply line 3, the DC power generator 4,
Since the DC / AC power converter 5 needs to be configured in consideration of the power factor, phase, and the like, the configurations of the DC power generator 4 and the DC / AC power converter 5 are complicated, and the installation cost is high. . In addition, since the long-distance AC distribution line 3 is routed, an electromagnetic wave is generated from the AC distribution line 3, and there is a possibility that a disturbance AC voltage or a harmonic that is an integral multiple of the power supply frequency is generated due to the influence.

[0005] As described above, the system in which the output power of the DC power generator 4 is converted by the DC / AC power converter 5 and connected to the AC distribution line 3 is used when most of the power supply is performed by AC. Is valid. However, when looking around us, AC power is really only required for washing machines using refrigerators, refrigerators, air conditioners, ventilation fans, etc., and many electronic devices convert AC to DC and use it. ing. Nevertheless, when the distribution line network is constituted by an AC system, it is necessary to cooperate with the individual DC power generators 4 so as not to adversely affect the commercial AC power system 1, A large number of protection devices are required, and a technique for reducing electromagnetic waves generated from the AC distribution line 3 is required.
Performs reverse power flow, it is necessary to install a reverse power flow device for each DC / AC power conversion device 5 installed for each DC power generation device 4, which complicates the configuration.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a distributed power supply network which does not adversely affect a commercial AC power system and has a simple configuration.

[0007]

According to the present invention, there is provided a distributed power supply network interconnected with a commercial AC power system via a system protection device. And the AC side of a bidirectional inversion power device that performs AC / DC power conversion, a DC distribution line is connected to the DC side of the bidirectional inversion power device, and a plurality of distributed power supply devices are connected to the DC distribution line. A conversion control device is provided for connecting a plurality of loads and controlling the bidirectional reverse conversion power device.

Here, as the bidirectional reverse conversion power device,
A parallel connection circuit in which a reverse conversion power device for performing DC / AC power conversion and a reverse conversion power device for performing AC / DC power conversion are connected in parallel; a DC / AC power conversion function;
An inverse conversion power device having a DC power conversion function or the like can be used.

In this case, a surplus underpower detection device for detecting surplus underpower obtained by subtracting the power consumption of the load from the power generated by the distributed power supply device, that is, surplus underpower indicating whether the power on the DC distribution line side is surplus or insufficient. Provided, the conversion control device is provided with an arithmetic device for calculating the integrated surplus insufficient power obtained by integrating the surplus insufficient power detected by the surplus insufficient power detection device, the conversion control device according to the accumulated surplus insufficient power An operation signal transmitting device for transmitting the operation signal to the bidirectional inverse conversion power device may be provided.

[0010] In this case, the arithmetic unit calculates the total value of the surplus power, that is, the total surplus power from each surplus insufficiency power, and controls the output power of each of the distributed power supply devices based on the total surplus power. May be provided in the conversion control device.

Also, as the above-mentioned distributed power supply device, a series circuit of a DC power generation device and a DC / DC power conversion device, an energy storage device in which a charge / discharge control device and a power storage device are connected in series, and a DC power generation device are connected in parallel. Any of the circuits in which the DC / DC power converter is connected to the circuit described above may be used.

The load includes a circuit for supplying AC to an AC load through a DC / AC power converter,
A circuit for supplying DC to a DC load via a DC power converter, a DC / AC power converter and a DC / DC power converter are connected in parallel on the DC distribution line side, and the DC / AC power converter is Any circuit may be used for supplying AC to an AC load via the DC load and supplying DC to the DC load via the DC / DC power converter.

In these cases, a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel to the output side of a DC power generator is used as the distributed power supply device. A supplementary power detection device for detecting supplementary power supplemented from the power system to the DC distribution line is provided, the conversion control device determines whether the supplementary power has exceeded a predetermined value, and the supplementary power has a predetermined value. A judging device for outputting a start signal to the charge / discharge control device when judging that it has exceeded may be provided.

Also, a capacitor for preventing oscillation may be connected to the DC distribution line in parallel with the load.

[0015]

FIG. 1 is a diagram showing a distributed power supply network according to the present invention. As shown in the figure, a system protection device 12 is connected to a commercial AC power system 11, and the AC side and AC / DC power conversion of a first reverse conversion power device 13 that performs DC / AC power conversion are connected to the system protection device 12. The AC side of the second reverse conversion power device 14 is connected, the reverse conversion power device 13 and the reverse conversion power device 14 are connected in parallel (reverse parallel), and the reverse conversion power device 13 and the reverse conversion power device 14 are connected. Constitute a parallel connection circuit (anti-parallel device). That is, the AC side of a parallel connection circuit composed of the reverse conversion power device 13 and the reverse conversion power device 14 is connected in series to the system protection device 12. In addition, a DC distribution line network composed of one or more DC distribution lines 15 is connected to the DC side of a parallel connection circuit in which the inverse conversion power devices 13 and 14 are connected in parallel.
5, a plurality of distributed power supplies 16 having a DC power generator and a plurality of loads 17 are connected, the distributed power supply 16 and the load 17 are connected in parallel, and a pair of distributed power supplies 16 and It is installed in houses, schools and offices. The DC distribution line 15, the distributed power supply 16, and the load 17 constitute a DC distribution line system. In addition, the reverse conversion power device 13 and the reverse conversion power device 14
A conversion control device (common control unit) 18 for controlling the power supply is provided, and the distributed power supply device 16 and the conversion control device 18 are connected by a signal transmission means such as an electric cable, an optical cable, or a wireless device capable of transmitting signals in two directions. I have. The distributed power supply device 16 has a storage device that always stores state information such as an identification number, an optimum output power, an operation / stop state, an output voltage, an output power, and a temperature. The conversion control device uses the state information as a state notification signal. 18 is provided. Further, the conversion control device 18 has a storage device (database) that scans each distributed power supply device 16 at regular time intervals and stores a status notification signal transmitted from each distributed power supply device 16. It has a power integrating device for integrating output power.

In this distributed power supply network, for example, when a specific distributed power supply 16 is checked or when a specific distributed power supply 16 is stopped, such as when a specific distributed power supply 16 fails, The decentralized power supply device 16 to be stopped transmits its identification number and output power to the
Notify 8. In this case, since it is necessary to operate a specific distributed power supply 16 within the optimum output power of each distributed power supply 16, the conversion control device 18 stops the distributed power supply 1
The output power information of each of the distributed power supply devices 16 other than 6 is collected and integrated, and the conversion control device 18 is stopped.
, And operates the reverse conversion power device 14 to replenish power from the commercial AC power system 11 to the DC distribution line system. When the stopped distributed power supply 16 recovers, the conversion control device 18 returns to the inverse conversion power supply 1.
Then, an operation stop signal is sent to 4 to stop replenishing power from the commercial AC power system 11 to the DC distribution system. Also,
The conversion control device 18 controls the reverse conversion power device 13 and the reverse conversion power device 14 and operates in a state where there is a reverse power flow. Therefore, the reverse conversion power device 13 synchronizes with the commercial AC power system 11 side as before, adjusts the phase difference between the AC power system 11 side and the filter before passing through the filter, and adjusts the magnitude and the flowing direction of the AC power. I do. Further, the safety of the commercial AC power system 11 can be ensured by the system protection device 12. Also, the distributed power supply devices 16 connected to the DC distribution line 15 exchange power via the DC distribution line network and operate autonomously so as not to purchase power from the commercial AC power system 11 as much as possible. .

In such a distributed power supply network, since the distributed power supply device 16 is connected to the DC power distribution line 15 without adversely affecting the commercial AC power system, the DC / DC power supply Since there is no need to provide an AC power converter, the configuration is simplified, and even when a large number of distributed power supplies 16 are provided, there is no need to provide a large number of DC / AC power converters. Become cheap. Further, since the distributed power supply 16 is connected to the DC power supply line 15, there is no need to configure the distributed power supply 16 in consideration of the power factor and the phase, so that the configuration of the distributed power supply 16 is simplified. In addition, a long-distance DC feed line 1
Even if the wire 5 is routed, no electromagnetic wave is generated from the DC power supply line 15, so that the electromagnetic wave does not generate a disturbing AC voltage or a harmonic that is an integral multiple of the power supply frequency.

FIG. 2 is a diagram showing another distributed power supply network according to the present invention. As shown in FIG.
And a pair of distributed power supply devices 16 and a load 17, a surplus underpower detection device 21 is connected, and the surplus underpower detection device 2
1 detects surplus insufficient power obtained by subtracting the power consumption of the load 17 from the power generated by the distributed power supply device 16. Further, the conversion control device 18 is provided with an arithmetic device 22 and an operation signal sending device 23, and the arithmetic device 22 calculates an integrated surplus underpower obtained by integrating the surplus underpower detected by each surplus underpower detection device 21, and performs an operation. The signal transmission device 23 transmits an operation signal corresponding to the accumulated surplus deficient power to the inverse conversion power devices 13 and 14. That is, the arithmetic unit 22 determines whether there is excess or insufficient power in the DC distribution network,
When the arithmetic unit 22 determines that there is excess power in the DC distribution network, the operation signal transmission device 23 operates the inverse conversion power device 13 to transmit power from the DC distribution network to the commercial AC power system 11. However, when the arithmetic device 22 determines that the power is insufficient in the DC distribution network, the operation signal transmission device 23 operates the inverse conversion power device 14 to switch from the commercial AC power system 11 to the DC distribution system. Replenish power. Note that the output of the surplus insufficient power detection device 21 does not need to be analog, but can be converted into digital data and transmitted, and the arithmetic device 22 can also perform digital arithmetic processing.

In this distributed power supply network, when there is excess power in the DC distribution network,
When power is transmitted from the DC distribution network to the commercial AC power system 11 and power is insufficient in the DC distribution network, power is replenished from the commercial AC power system 11 to the DC distribution system. Can be accurately controlled. Further, since the surplus power and the shortage power of the DC distribution line network are detected based on the detection value of the surplus shortage power detection device 21, each distributed power supply device 1
Even if the capacity of the load 6 or the load 17 is not accurately grasped, the power flow can be controlled. Further, since the surplus insufficient power detection device 21 can obtain the surplus insufficient power from the voltage of the DC distributed power supply device 16 and the current flowing through the surplus insufficient power detection device 21, the surplus insufficient power can be accurately measured. Further, when each distributed power supply device 16 is regarded as a separate customer installed in a home or a building, there is a case where how to distribute the power rate purchased from the commercial AC power system 11 becomes a problem. However, the conversion control device 18 is provided with a storage device (database) for storing the surplus power shortage (power consumption) corresponding to each distributed power supply device 16, and the power rate is set according to the surplus power shortage corresponding to each distributed power supply device 16. If it is distributed, fairly fair collection will be possible.

FIG. 3 is a diagram showing another distributed power supply network according to the present invention. As shown in FIG.
8 is provided with a power generation control device (power generation control unit) 31. The power generation control device 31 is connected to the arithmetic device 22 and each distributed power supply device 16. The output power of the device 16 is controlled. That is, the arithmetic unit 22 calculates the total value of the surplus power, that is, the total surplus power from the surplus insufficient power detected by each surplus insufficient power detection device 21, and the arithmetic unit 22 determines that the total surplus power is equal to or less than the first specific value. When the power generation control device 31 determines that the total surplus power is equal to or greater than the second specific value, the power generation control device 31 increases the output power of the distributed power supply device 16. 16 output power is reduced. As a method of increasing or decreasing the output power of each distributed power supply device 16, for example, when the distributed power supply device 16 is a polymer electrolyte fuel cell, a device that increases or decreases the amount of inflow gas is used as the distributed power supply device 16. A method of providing is conceivable. In the case of a polymer electrolyte fuel cell, the operating temperature is as low as about 80 ° C., so that the output power can respond to the increase or decrease of the fuel at a considerably high speed.

Next, the operation in the distributed power supply network shown in FIG. 3 will be described with reference to FIG. First, the surplus insufficient power detection device 21 detects the surplus insufficient power,
Calculates the total surplus power, and when the arithmetic device 22 determines that the total surplus power is equal to or less than the first specific value, the power generation control device 31 increases the output power of the distributed power supply device 16 and the arithmetic device 22 When it is determined that the surplus power is equal to or greater than the second specific value, the power generation control device 31
6, the output power is reduced. It is appropriate that the calculation of the total surplus power of the arithmetic unit 22 is performed at intervals of time, and when the output power of the distributed power supply 16 is increased to the maximum, the total power consumption of the DC distribution system is not sufficient. , The reverse conversion power device 14 is operated to request assistance from the commercial AC power system 11.

In this distributed power supply network, a storage device for storing the identification number of each distributed power supply device 16 and the price per unit output of the DC power generator, that is, the unit price of power generation, is provided in the arithmetic device 22. The distributed power supply device 16 having the cheap DC power generation device notifies the power generation control device 31 so as to increase the output power, and the arithmetic device 22 outputs the output power from the distributed power supply device 16 having the DC power generation device having a high power generation unit. If the power generation control device 31 is configured to be notified so as to reduce the power consumption, the power usage fee in the DC distribution line network can be reduced.

FIG. 5 is a diagram showing a configuration example of a distributed power supply device of a distributed power supply network according to the present invention. As shown in the drawing, a DC / DC power converter 42 is connected in series to a DC power generator 41, and the DC power generator 41 and the DC / DC power converter 42 constitute a distributed power supply 16a. That is, the distributed power supply 16a is configured by a series circuit of the DC power generator 41 and the DC / DC power converter 42.

In this distributed power supply, even if the output voltage of the DC power generator 41 fluctuates due to the output current,
The voltage of the DC distribution line 15 can be stabilized by the DC / DC power converter 42. The DC power generator 41
Currently, fuel cells and solar cells are the main products, and devices with a wide selection range of several hundred W to over 100 kW can be used.

FIG. 6 is a diagram showing a configuration example of another distributed power supply device of the distributed power supply network according to the present invention. As shown in the figure, the DC / DC power converter 4
2 are connected in series, and an energy storage device including a charge / discharge control device 43 and a power storage device 44 connected in series with the DC power generation device 41 is connected in parallel.
The DC / DC power conversion device 42, the charge / discharge control device 43, and the power storage device 44 constitute a distributed power supply device 16b. That is, the charge / discharge control device 43 and the power storage device 44
Energy storage device and DC power generator 4 connected in series
1 and a DC / DC power converter 4 in a circuit connected in parallel.
2 form a distributed power supply device 16b. The power storage device 44 is a lead storage battery, Ni-MH
Cells utilizing chemical reactions such as batteries and lithium batteries,
Alternatively, it is configured using an electric component such as an electric double layer capacitor. The charge / discharge control device 43 of the energy storage device charges the power storage device 44 and discharges the power storage device 44 as necessary.

In this distributed power supply device, since the energy storage device stores part of the output power of the DC power generation device 41 and releases it in an emergency, the distributed power supply device 16b having the power storage device 44 is an uninterruptible power supply. The distributed power supply device 16b has high reliability because the power storage device 44 can perform power leveling and can cope with a sudden load change.

In particular, when the power storage device 44 is a cell utilizing a chemical reaction, it is difficult to detect the full charge and the maximum discharge amount, and the manufacturer has much know-how (for example, the full charge is determined by the peak value of the battery voltage). And a method of detecting the maximum discharge amount with a gas gauge, and correcting this value with the self-discharge amount, temperature and aging).

FIG. 7 is a diagram showing a configuration example of a load of the distributed power supply network according to the present invention. As shown in the figure, a DC / AC power converter (inverter) 51 for converting DC to AC is connected to the DC distribution line 15, an AC load 52 is connected to the DC / AC power converter 51 in series, and The load 17a is constituted by the AC power converter 51 and the AC load 52. That is, the DC / AC power converter 5
The load 17a is configured by a circuit that supplies AC to the AC load 52 via the power supply 1.

In the distributed power supply network having such a load 17a, the DC / AC power converter 51 does not need to be connected to the commercial AC power system 11, so that the configuration is very simple.

FIG. 8 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention. As shown in the figure,
A DC / DC power converter (converter) 53 for converting DC to DC is connected to the DC distribution line 15, a DC load 54 is connected to the DC / DC power converter 53 in series, and the DC / DC power converter 53 is connected to the DC / DC power converter 53. Load 17 by DC load 54
b. That is, the load 17b is configured by a circuit that supplies DC to the DC load 54 via the DC / DC power converter 53.

In the distributed power supply network having such a load 17b, the DC load 54 can be operated even when the required voltage of the DC load 54 is different from the voltage of the DC distribution line 15.

If the required voltage of the DC load 54 is the same as the voltage of the DC distribution line 15, the DC / DC power converter 53 can be omitted.

FIG. 9 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention. As shown in the figure,
A DC / AC power converter 51 and a DC / DC power converter 53 are connected to the DC distribution line 15, and the DC / AC power converter 51 and the DC / DC power converter 53 are connected in parallel to each other. An AC load 52 is connected to the converter 51.
Are connected in series, a DC load 54 is connected to the DC / DC power converter 53 in series, and the DC / AC power converter 5
1, a load 17c is constituted by an AC load 52, a DC / DC power converter 53, and a DC load 54. That is, the DC / AC power converter 51 and the DC / DC power converter 53 are connected in parallel on the DC distribution line 15 side,
The load 17c is configured by a circuit that supplies AC to the AC load 52 via the AC power converter 51 and supplies DC to the DC load 54 via the DC / DC power converter 53.

In the distributed power supply network having such a load 17c, the AC load 52 and the DC load 5
4 can supply power to both the current and the DC load 54 at the same time.

FIG. 10 is a diagram showing another distributed power supply network according to the present invention. As shown in the figure, the reverse conversion power device 14 is provided with a supplementary power detection device 61 for detecting the passing power of the reverse conversion power device 14, that is, the supplementary power supplied from the commercial AC power system 11 to the DC distribution line 15. The controller 18 determines whether or not the supplementary power detected by the supplementary power detection device 61 has exceeded a predetermined value, and outputs a start signal to the charge / discharge control device 43 when it determines that the supplementary power has exceeded the predetermined value. A device 62 is provided.

In this distributed power supply network, when the supplementary power detected by the supplementary power detection device 61 exceeds a predetermined value, the judging device 62 outputs an activation signal to the charge / discharge control device 43 connected to the power storage device 44. Then, the power storage device 44 immediately transmits DC power to the DC distribution line 15 in cooperation with the DC power generation device 41 of the distributed power supply device 16b by the start signal. For this reason, even when the DC power consumption of the DC distribution line network temporarily increases, the supplementary power can be prevented from exceeding a predetermined value. It is possible to prevent the contracted amount of electric power from being exceeded, and
Can be prevented from exceeding the rated output of the power converter, and the reverse conversion power device 14 can be protected.

FIG. 11 is a diagram showing another distributed power supply network according to the present invention. As shown in FIG.
5, a plurality of capacitors 71 are connected in parallel with the load 17.

In this distributed power supply network, since the power supply system of the DC distribution line system constitutes an LRC circuit, oscillation may occur depending on conditions. However, since the capacitor 71 is connected to the DC distribution line 15, Oscillation of the power supply system of the DC distribution line system can be prevented.

In the above embodiment, the parallel connection circuit in which the inverse conversion power device 13 and the inverse conversion power device 14 are connected in parallel is used as the bidirectional inverse conversion power device. A reverse conversion power device having a DC / AC power conversion function and an AC / DC power conversion function may be used as the device. In this case, the bidirectional reverse conversion power device can be made compact.

[0040]

In the distributed power supply network according to the present invention, since the distributed power supply is connected to the DC distribution line without adversely affecting the commercial AC power system, the DC / DC power supply corresponding to each distributed power supply is provided. There is no need to provide an AC power conversion device, and it is not necessary to configure the distributed power supply device in consideration of the power factor and phase, so that the configuration is simplified.

Further, a surplus underpower detection device for detecting a surplus underpower obtained by subtracting the power consumption of the load from the power generated by the distributed power supply device is provided, and the conversion control device detects the surplus underpower detected by the surplus underpower detection device. When an operation device for calculating integrated accumulated surplus power is provided, and when the conversion control device is provided with an operation signal transmitting device for transmitting an operation signal corresponding to the accumulated surplus power to the bidirectional inverse conversion power device, control of power flow is performed. Can be performed accurately.

Further, the conversion controller calculates the total value of the surplus power, that is, the total surplus power, from each surplus deficient power and controls the output power of each distributed power supply device based on the total surplus power to the conversion control device. When provided, the power usage fee in the DC distribution line network can be reduced.

Further, when a series circuit of a DC power generator and a DC / DC power converter is used as the distributed power supply, the voltage of the DC distribution line is reduced even if the output voltage of the DC power generator fluctuates due to the output current. Can be stabilized.

Further, a circuit in which a DC / DC power converter is connected to a circuit in which an energy storage device in which a charge / discharge control device and a power storage device are connected in series and a DC generator is connected in parallel is used as the distributed power supply device. In some cases, power leveling can be performed by the power storage device, and rapid load fluctuation can be dealt with, so that the reliability of the distributed power supply device can be increased.

When a circuit for supplying AC to the AC load via the DC / AC power converter is used as the load, the DC / AC power converter does not need to be connected to the commercial AC power system. The configuration is very simple.

When a circuit for supplying DC to a DC load via a DC / DC power converter is used as a load, the DC load can be changed even if the required voltage of the DC load is different from the voltage of the DC distribution line. Can be activated.

As a load, a DC / AC power converter and a DC / DC power converter are connected in parallel on the DC distribution line side, and AC is supplied to an AC load via the DC / AC power converter. In addition, when a circuit that supplies DC to a DC load via a DC / DC power converter is used, power can be supplied to both the AC load and the DC load. In addition, power can be supplied to the DC load at the same time.

Also, a circuit in which a charge / discharge control device and a power storage device connected in series are connected in parallel to the output side of a DC power generation device as a distributed power supply device is used. A replenishment power detection device for detecting replenishment power supplied to the electric wire is provided, and a conversion control device determines whether or not the replenishment power exceeds a predetermined value and a charge / discharge control device when it determines that the replenishment power exceeds a predetermined value. When a determination device that outputs a start signal is provided, the supplementary power can be prevented from exceeding a predetermined value even when the DC power consumption of the DC distribution line network temporarily increases, and the reverse conversion can be performed. Exceeding the rated output of the power device can be prevented.

When a capacitor is connected to the DC distribution line in parallel with the load, oscillation of the power supply system of the DC distribution line system can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a distributed power supply network according to the present invention.

FIG. 2 is a diagram showing another distributed power supply network according to the present invention.

FIG. 3 is a diagram showing another distributed power supply network according to the present invention.

4 is an explanatory diagram of an operation in the distributed power supply network shown in FIG.

FIG. 5 is a diagram illustrating a configuration example of a distributed power supply device of a distributed power supply network according to the present invention.

FIG. 6 is a diagram showing a configuration example of another distributed power supply device of the distributed power supply network according to the present invention.

FIG. 7 is a diagram illustrating a configuration example of a load of the distributed power supply network according to the present invention.

FIG. 8 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention.

FIG. 9 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention.

FIG. 10 is a diagram showing another distributed power supply network according to the present invention.

FIG. 11 is a diagram showing another distributed power supply network according to the present invention.

FIG. 12 is a diagram showing a conventional distributed power supply network.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Commercial AC power system 12 ... System protection device 13 ... 1st reverse conversion power device 14 ... 2nd reverse conversion power device 15 ... DC distribution line 16 ... Distributed power supply 17 ... Load 18 ... Conversion control device 21 ... Surplus Insufficient power detection device 22 ... Operation device 23 ... Operation signal transmission device 31 ... Power generation control device 41 ... DC power generation device 42 ... DC / DC power conversion device 43 ... Charge / discharge control device 44 ... Power storage device 51 ... DC / AC power conversion device 52: AC load 53: DC / DC power conversion device 54: DC load 61: supplementary power detection device 62: judgment device 71: capacitor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuhiko Yamashita 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 5G066 HA15 HB09 JA07 JB03

Claims (7)

[Claims] In a distributed power supply network interconnected with a commercial AC power system via a system protection device, an AC of a bidirectional reverse conversion power device for performing DC / AC power conversion and AC / DC power conversion is applied to the system protection device. Side, connect a DC distribution line to the DC side of the bidirectional reverse conversion power device, connect a plurality of distributed power supplies and a plurality of loads to the DC distribution line, A distributed power supply network comprising a conversion control device for controlling. 2. A surplus underpower detection device for detecting surplus underpower obtained by subtracting the power consumption of the load from the power generated by the distributed power supply device, wherein the surplus underpower detection device detects the surplus underpower in the conversion control device. An operation device for calculating the accumulated surplus insufficient power obtained by integrating the surplus insufficient power is provided, and the conversion control device is provided with an operation signal transmitting device for transmitting an operation signal corresponding to the accumulated surplus insufficient power to the bidirectional inverse conversion power device. The distributed power supply network according to claim 1, wherein: 3. A power generation control device that calculates a total value of surplus power, that is, a total surplus power, from each surplus insufficiency power and controls an output power of each of the distributed power supply devices based on the total surplus power. The distributed power supply network according to claim 2, wherein the distributed power supply network is provided in the conversion control device. 4. A DC power generator is connected in parallel with an energy storage device in which a series circuit of a DC power generator and a DC / DC power converter, a charge / discharge controller and a power storage device are connected in series. The distributed power supply network according to claim 1, wherein any one of a circuit in which a DC / DC power converter is connected to the circuit is used. 5. A circuit for supplying AC to an AC load via a DC / AC power converter, a circuit for supplying DC to a DC load via a DC / DC power converter, and a DC / AC power converter. A device and a DC / DC power converter are connected in parallel on the DC distribution line side, AC is supplied to an AC load via the DC / AC power converter, and the DC / DC power converter is connected via the DC / DC power converter. The distributed power supply network according to claim 1, wherein any one of circuits for supplying DC power to the DC load is used. 6. A circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel to the output side of a DC power generator as the distributed power supply device, and the commercial AC power system is connected to the bidirectional reverse conversion power device. A supplementary power detection device for detecting supplementary power to be supplemented to the DC distribution line is provided, and it is determined whether or not the supplementary power has exceeded a predetermined value in the conversion control device, and that the supplementary power has exceeded a predetermined value. The distributed power supply network according to any one of claims 1 to 3, further comprising a determination device that outputs a start signal to the charge / discharge control device when the determination is made. 7. The distributed power supply network according to claim 1, wherein a capacitor is connected to the DC distribution line in parallel with the load.