JP2016073036A - Power supply switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable all distribution type power sources to surely detect the presence/absence of the abnormality of a system power source without causing the complication of a system/structure in a power supply system.SOLUTION: A power supply system 10 includes: a first distribution type power source 15; a second distribution type power source 16; and a third detector 16g and a power supply switching device 20 connected to the second distribution type power source 16. The third detector 16g is disposed on a second connection wire 16c. The power supply switching device 20 configured to switch power supply from each power source 11, 15 and 16 to an external load 12 includes at least a first switch 22 disposed on a main wire 13 between a first connection point 13a and a second connection point 13b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply switching device.

  As one type of power supply system, one disclosed in Patent Document 1 is known. In the power supply system, as shown in FIG. 1 of Patent Document 1, the first to third power conversion devices 3, 5, 7 are the first power conversion device 3, the second power conversion device 5, The third power converter 7 is connected to the interconnection feed path 11 in the order. The first detector 14 is provided between the first power conversion device 3 to which the solar battery 2 is connected and the second power conversion device 5 to which the storage battery 4 is connected. Detect power. The second detector 15 is provided between the second power conversion device 5 and the third power conversion device 7 to which the fuel cell 6 is connected, and detects reverse power flow on the interconnection feed path 11. The second power conversion device 5 operates so that the reverse power flow detected by the first detector 14 becomes zero, and the third power conversion device 7 is detected by the second detector 15. It operates so that the reverse power flow becomes zero.

  Furthermore, as shown in FIG. 4 of Patent Document 1, the power supply system includes a disconnector 81 provided on the interconnecting power supply path 11 and an abnormality detection unit that detects whether there is an abnormality in the power system 8 such as a power failure. 82. When the abnormality detection unit 82 detects an abnormality in the power system 8, the abnormality detection unit 82 controls the circuit breaker 81 to shut off the power system 8, and simultaneously transmits an abnormality detection signal to the second or third power converters 5 and 7. .

JP 2013-126339 A

  The power supply system described in Patent Document 1 described above transmits a signal indicating whether there is an abnormality in the power system 8 or communication to a plurality of distributed power sources. Each distributed power source detects the presence or absence of an abnormality in the power system 8 based on this abnormality presence / absence signal or communication, and the power supply system switches the power (power source) supplied to the external load. However, it is necessary to unify the signal delivery / communication standards for the presence / absence of an abnormality, or to introduce a system capable of delivering the signal / communication of the presence / absence of an abnormality.

  Therefore, the present invention has been made to solve the above-described problems, and in a power supply system, all distributed power supplies can reliably check whether there is an abnormality in the system power supply without complicating the system / structure. The purpose is to detect.

  In order to solve the above problems, a power supply switching device according to claim 1 is provided in a system power source, an external load electrically connected to the system power source via a main wire, and the main power source. The first power supply device includes a main switch that is opened when the power supply from the power supply is abnormal and connected when the power supply from the system power supply is normal, and a first power supply device that supplies power. From the main switch of the main wire is transmitted through the first connection wire connected at the first connection point, and the power supply from the system power supply is abnormal. A first distributed power source capable of power supply and a second power supply device for supplying power, and the power from the second power supply device is supplied at a second connection point downstream from the first connection point of the main wire. Second distributed power source that transmits power through the connected second connecting wire And a power supply system provided at least with a detector that is provided on the second connection wire and detects the presence or absence of power supply and transmits it to the second distributed power source. A power supply switching device for switching supply, wherein the power supply switching device is provided on the main electric wire between the first connection point and the second connection point, and when the power supply from the system power supply is abnormal, A first switch is provided that cuts off the one connection point and the second connection point and connects the first connection point and the second connection point when the power supply from the system power supply is normal.

  According to this, when the power supply from the system power supply is abnormal, the first connection point and the second connection point are the first switch even when the first distributed power supply performs the self-sustaining power generation. Is blocked by. Therefore, it can stop supplying electric power to the main electric wire between a 1st connection point and a 2nd connection point. As a result, the detector on the second connection wire detects whether or not power is supplied (for example, voltage), so that the second distributed power supply detects whether or not the power supply from the system power supply is abnormal. Can do. As described above, the power supply switching device reliably detects the presence or absence of an abnormality in the system power supply, without causing any complicated system / structure.

It is a schematic diagram of the power supply system in one embodiment of the present invention. It is a time chart which shows the action | operation at the time of a power failure of the electric power supply system shown in FIG. It is a time chart which shows the action | operation at the time of a power recovery of the electric power supply system shown in FIG.

  Hereinafter, an embodiment of a power supply system and a power supply switching device according to the present invention will be described based on a schematic diagram of a power supply system shown in FIG. The power supply system 10 includes a system power supply 11, an external load 12, a main electric wire 13, a main switch 14, a first distributed power supply 15, and a second distributed power supply 16.

  The system power supply 11 is electrically connected to the external load 12 via the main wire 13 and supplies power (AC power) to the external load 12. The external load 12 is a power load arranged separately from the distributed power sources such as the first distributed power source 15 and the second distributed power source 16, such as a television set installed in the home. It is a household appliance.

  The main switch 14 is provided on the main electric wire 13 and is opened when the power supply from the system power supply 11 is abnormal (open state), and when the power supply from the system power supply 11 is normal (system power supply 11 is Connected (if normal) (connected state). The main switch 14 is disposed on the main wire 13 on the upstream side (system power supply 11 side) of the main switch 14 and detects the state (for example, voltage value) of power supplied from the system power supply 11. Based on the detection result of the sensor 14a, it may be configured to be connected / released alone (without receiving a control command from the first distributed power supply 15).

  The first distributed power supply 15 and the second distributed power supply 16 are connected in parallel to the main electric wire 13. The first distributed power supply 15 is connected to the upstream side (system power supply 11 side) from the second distributed power supply 16. Although the power supply system 10 of this embodiment is configured to include two distributed power sources, the power supply system 10 may be configured to include three or more distributed power sources. In addition, the power supply system 10 is preferably configured to include a plurality of distributed power sources in which reverse power is prohibited. A distributed power source in which reverse tide is prohibited is a power generation device that uses fossil fuel, for example, a power supply device 15a having a fuel cell power generation device, a gas engine power generation device, a gas turbine power generation device, or the like. is there. A distributed power source in which reverse tide is not prohibited is a distributed power source that uses renewable energy (for example, sunlight, hydraulic power, wind power, etc.) that is energy generated from a phenomenon that occurs repeatedly in the natural environment.

  The first distributed power supply 15 includes a first power supply device 15a, a first power conversion device 15b, a first connecting wire 15c, a first disconnector 15d, a first control device 15e, and a first detector 15f. ing.

  The first power supply device 15a is a device (power supply device) that generates and supplies power (DC power or AC power). Examples of the power supply device include a storage battery, a solar power generation device, a fuel cell power generation device, a gas engine type power generation device, and a gas turbine type power generation device. The first power supply device 15a may be a solar power generation device or a storage battery, or may be a set of both.

  The first power conversion device 15 b is a device that converts the power supplied from the first power supply device 15 a and outputs the converted power to the main wire 13. DC power or AC power from the first power supply device 15 a is converted into AC power synchronized with the main electric wire 13.

  One end of the first connection wire 15 c is connected to the first power converter 15 b, and the other end of the first connection wire 15 c is connected to the first connection point 13 a of the main wire 13. The first connection point 13 a of the main electric wire 13 is provided in a downstream portion of the main electric wire 13 from the main switch 14. The first disconnector 15d is provided on the first connecting wire 15c. The first disconnector 15d is brought into a closed state by a closing instruction from the first control device 15e (linked state), and is brought into an opened state by a opening instruction from the first control device 15e (disconnected state).

  The first control device 15e controls the first power supply device 15a, the first power conversion device 15b, and the first disconnector 15d in an integrated manner. The first detector 15f detects the presence / absence of power supply from the system power supply 11 (power supply state), and transmits the detection result to the first control device 15e. The first detector 15 f performs power flow monitoring (reverse power flow prevention) to the system power supply 11, that is, power input / output to the system power supply 11 and power amount detection.

  The first distributed power supply 15 can perform self-sustaining power generation when the power supply from the system power supply 11 is abnormal. When the power supply from the system power supply 11 is abnormal (for example, a power failure), the first distributed power supply 15 generates power (self-sustained power generation) for the first power supply device 15a that the first distributed power supply 15 has for the first connection. It is supplied to the main electric wire 13 through the electric wire 15c. That is, the self-sustaining power generation is that only the power source (the first distributed power source 15) generates power and supplies power in a state where there is no power supply from the system power source 11. During the self-sustained power generation, the first disconnector 15d is in a closed state. It is assumed that the first disconnector 15d is opened within a predetermined time T1 after the occurrence of a power failure. If there is no predetermined time T1, that is, the first disconnector 15d may be opened almost simultaneously with the occurrence of a power failure.

  The second distributed power supply 16 includes a second power supply device 16a, a second power conversion device 16b, a second connecting wire 16c, a second disconnector 16d, a second control device 16e, a second detector 16f, and a second Three detectors 16g are provided.

  The second power supply device 16a is a device (power supply device) that generates and supplies power (DC power or AC power). The second power supply device 16a is a power generation device that uses fossil fuel, for example, a gas engine power generation device. The second power conversion device 16 b is a device that converts the power supplied from the second power supply device 16 a and outputs the converted power to the main electric wire 13. DC power or AC power from the second power supply device 16 b is converted to AC power synchronized with the main electric wire 13.

  One end of the second connection wire 16c is connected to the second power converter 16b, and the other end side of the second connection wire 16c is connected to the second connection point 13b of the main wire 13. The second connection point 13 b of the main electric wire 13 is provided at a downstream site from the first connection point 13 a of the main electric wire 13. The second disconnector 16d is provided on the second connecting wire 16c. The second disconnector 16d is brought into a closed state by a closing instruction from the second control device 16e (linked state), and is brought into an open state by a opening instruction from the second control device 16e (disconnected state).

  The second control device 16e controls the second power supply device 16a, the second power conversion device 16b, and the second disconnector 16d in an integrated manner. The second detector 16f detects the presence or absence of power supply from the system power supply 11 (power supply state), and transmits the detection result to the second control device 16e. The second detector 16f performs power flow monitoring (reverse power flow prevention) to the system power supply 11, that is, power input / output to the system power supply 11 and power amount detection.

  The third detector 16g is provided on the second connecting wire 16c. The third detector 16g detects the presence / absence of power supply from the system power supply 11 (power supply state), and transmits the detection result to the second control device 16e. The third detector 16g is preferably a voltmeter, and may be an ammeter or a wattmeter. Note that the third detector 16g may be disposed at a place other than the second connection wire 16c. For example, the main electric wire 13 between the first switch 22 and the third switch 24 may be provided.

  The power supply system 10 further includes a power supply switching device 20 that switches power supply from the power supplies 11, 15, and 16 to the external load 12. The power supply switching device 20 includes a casing 21, a first switch 22, a second switch 23, a third switch 24, a connection portion 25, and a casing inner wire 26.

  The casing 21 is formed in a box shape, for example. The casing 21 accommodates at least one of the first switch 22, the second switch 23, and the third switch 24 therein. A connecting portion 25 is provided on the casing 21. The connection part 25 includes a first connection terminal 25a, a second connection terminal 25b, a third connection terminal 25c, a fourth connection terminal 25d, a fifth connection terminal 25e, and a sixth connection terminal 25f.

The first connection terminal 25a is connected to the portion of the main electric wire 13 on the system power supply 11 side.
The second connection terminal 25b is connected to a portion of the main wire 13 on the external load 12 side.
The third connection terminal 25c is connected to the other end of the second connection wire 16c.
The other end of the signal input wire 17 is connected to the fourth connection terminal 25d. One end of the signal input wire 17 is connected to a portion upstream of the main switch 14 of the main wire 13 (fourth connection point 13d). The signal input wire 17 is a wire for directing the power supplied from the system power supply 11 to the first switch 22, the second switch 23, and the third switch 24 and inputting them as an input signal (for example, control input current). It is.

  The fifth connection terminal 25e is connected to a portion of the first distributed power supply 15 side of the self-generated power supply electric wire 18. The sixth connection terminal 25f is connected to a portion on the external load 12 side of the electric power supply wire 18 for independent power generation. One end of the self-generated power supply electric wire 18 is connected to the first connection point 13 a of the main electric wire 13. The other end of the self-generated power supply electric wire 18 is connected to the third connection point 13 c of the main electric wire 13. The self-generated power supply wire 18 is a wire for supplying the external load 12 with the self-generated power from the first distributed power supply 15.

  Thus, the connection part 25 is electrically connected to each electric wire 13, 16c, 17, and 18. It is preferable that the connecting portion 25 has a structure (for example, a connector structure) that can be attached to and detached from the electric wires 13, 16c, 17, and 18.

  The first connection terminal 25a and the second connection terminal 25b are connected by a main wire 26a in the casing. The main electric wire 26 a in the casing constitutes a part of the main electric wire 13 in the power supply switching device 20. The second connection point 13b described above is provided in the main electric wire 26a in the casing. The second detector 16f described above is provided on the main cable 26a in the casing. The second detector 16f may be provided on the main electric wire 13 outside the power supply switching device 20 and upstream of the power supply switching device 20.

  The second connection point 13b and the third connection terminal 25c are connected by a second connection electric wire 26b in the casing. The in-casing second connection electric wire 26 b constitutes a part of the second connection electric wire 16 c in the power supply switching device 20.

  The fourth connection terminal 25d and the input signal terminal of the first switch 22 are connected by an in-casing signal input wire 26c. The connection point 26c1 of the in-casing signal input wire 26c and the input signal terminal of the second switch 23 are connected by the in-casing signal input wire 26d. The connection point 26c1 of the in-casing signal input wire 26c and the input signal terminal of the third switch 24 are connected by the in-casing signal input wire 26e.

The fifth connection terminal 25e and the sixth connection terminal 25f are connected by an in-casing self-generated power supply electric wire 26f. The in-casing self-generated power supply wire 26 f constitutes a part of the self-generated power supply wire 18 in the power supply switching device 20.
As described above, the in-casing electric wire 26 includes the electric wires 26a to 26f.

  The first switch 22 is provided on the main electric wire 13 between the first connection point 13a and the second connection point 13b. The first switch 22 cuts off (opens) the first connection point 13a and the second connection point 13b when the system power supply 11 is out of power (the power supply from the system power supply 11 is abnormal), When the system power supply 11 is normal (when the power supply from the system power supply 11 is normal), the first connection point 13a and the second connection point 13b are connected.

  The first switch 22 is preferably composed of, for example, an AC relay that receives AC power and operates to open and close. The first switch 22 is connected to the main wire 13 (fourth connection point 13 d) between the main switch 14 and the system power supply 11 via the signal input wire 17 and inputs the voltage of the system power supply 11. The first switch 22 is switched to the connected state when the input voltage of the system power supply 11 is equal to or higher than the switching voltage value, and is switched to the open state when the input voltage of the system power supply 11 is less than the switching voltage value. It is done.

  Examples of the relay include an electromagnetic relay (electromagnetic relay) and a semiconductor relay (solid state relay). An electromagnetic relay is a relay that opens and closes by physically moving a contact point by means of an electromagnet (which allows a control input current to flow through a winding). The semiconductor relay is a relay that turns on and off a large output voltage with a small input power by using a semiconductor element such as a thyristor or a photocoupler.

  The first switch 22 and the third switch 24 are electromagnetic relays (a contact type, NO type) in which a contact opens when no current flows through the electromagnet and closes when a current flows through the electromagnet. The second switch 23 is an electromagnetic relay (b contact type, NC type) that opens when the current flows through the electromagnet and closes when no current flows through the electromagnet.

  The second switch 23 has a first connection point 13 a and a self-generated power supply wire 18 that connects a portion of the main wire 13 (third connection point 13 c) between the second connection point 13 b and the external load 12. Is provided. The second switch 23 connects the first connection point 13a and the third connection point 13c when the system power supply 11 is out of power (when the power supply from the system power supply 11 is abnormal). Is normal (when the power supply from the system power supply 11 is normal), the first connection point 13a and the third connection point 13c are opened.

  Similarly to the first switch 22, the second switch 23 is preferably constituted by, for example, an AC relay that receives an AC power and performs a switching operation. The second switch 23 is connected to the main wire 13 (fourth connection point 13 d) between the main switch 14 and the system power supply 11 via the signal input wire 17 and inputs the voltage of the system power supply 11. The second switch 23 is switched to the open state when the input voltage of the system power supply 11 is equal to or higher than the switching voltage value, and is switched to the connected state when the voltage of the input system power supply 11 is less than the switching voltage value. It is done.

  The third switch 24 is provided on the main electric wire 13 between the second connection point 13b and the external load 12 (third connection point 13c). The third switch 24 shuts off the second connection point 13b and the external load 12 (third connection point 13c) when the system power supply 11 is out of power (when the power supply from the system power supply 11 is abnormal). When the system power supply 11 is normal (when the power supply from the system power supply 11 is normal), the second connection point 13b and the external load 12 (third connection point 13c) are connected.

  As with the first switch 22, the third switch 24 is preferably composed of, for example, an AC relay that inputs and outputs AC power. The third switch 24 is connected to the main wire 13 (fourth connection point 13 d) between the main switch 14 and the system power supply 11 via the signal input wire 17 and inputs the voltage of the system power supply 11. The third switch 24 is switched to the connected state when the input voltage of the system power supply 11 is equal to or higher than the switching voltage value, and is switched to the open state when the input voltage of the system power supply 11 is less than the switching voltage value. .

  Next, the operation of the power supply system 10 configured as described above will be described with reference to FIG. First, a case where the system power supply 11 is normal will be described. When the system power supply 11 is normal, the main switch 14 is connected, the first disconnector 15d of the first distributed power supply 15 is also connected, and the second disconnector of the second distributed power supply 16 is connected. 16d is also connected.

  Since the first disconnector 15d of the first distributed power supply 15 is in the connected state, the first distributed power supply 15 is linked to the system power supply 11, and the power supply to the external load 12 is the first distributed power supply. 15 and the system power supply 11 can be supplied (connected power supply). Since the second decoupler 16d of the second distributed power supply 16 is in a connected state, the second distributed power supply 16 is connected to the system power supply 11, and the power supply to the external load 12 is the second distributed power supply. 16 and the system power supply 11 can be supplied (connected power supply).

The operation of the power supply switching device 20 when the system power supply 11 is normal will be described. Since the system power supply 11 is normal, the first switch 22 and the third switch 24 are in a connected state. Specifically, since the voltage supplied from the system power supply 11 is equal to or higher than the switching voltage value and the current flows, the contacts of the first switch 22 and the third switch 24 that are a contact type are closed, and the first The switch 22 and the third switch 24 are in a connected state.
Since the system power supply 11 is normal, the second switch 23 is open. In detail, since the voltage supplied from the system power supply 11 is equal to or higher than the switching voltage value and the current flows, the contact of the second switch 23 of the b contact type is opened, and the second switch 23 is in the open state. It is.

  Next, a case where the system power supply 11 is interrupted will be described with reference to FIG. Since the system power supply 11 is abnormal, the main switch 14 is opened. In this case, the first disconnector 15d of the first distributed power supply 15 is also opened.

  Simultaneously with the occurrence of a power failure, the first disconnector 15d is opened. Since the first disconnector 15d of the first distributed power supply 15 is in an open state, the first distributed power supply 15 is disconnected from the system power supply 11. The first disconnector 15d is connected when a predetermined time T1 (for example, 0.5 seconds) has elapsed since the occurrence of a power failure. That is, the first connection point 13 a is disconnected from the system power supply 11, but is connected to the first distributed power supply 15. At the same time, the first distributed power source 15 starts self-sustaining power generation (self-sustaining power supply). As a result, the power supply format for the external load 12 is changed from the interconnected power supply to the independent power supply. That is, the power for the external load 12 is not the power from the system power supply 11 but the power from the first distributed power supply 15.

The operation of the power supply switching device 20 when a power failure occurs (and during a power failure) will be described. When a power failure occurs, since the voltage of the system power supply 11 input to the first switch 22 is less than the switching voltage value, the first switch 22 is switched to the open state. Specifically, since no current flows through the input signal terminal of the first switch 22, the contact of the first switch 22 of the a contact type is opened, and the first switch 22 is opened.
Similarly to the first switch 22, the third switch 24 is also opened when a power failure occurs.

  On the other hand, in the second switch 23, when a power failure occurs, the voltage of the system power supply 11 input to the second switch 23 is less than the switching voltage value, so the second switch 23 is switched to the connected state. Specifically, since no current flows through the input signal terminal of the second switch 23, the contact of the second switch 23 of the b contact type is closed, and the second switch 23 is connected.

  When the first switch 22 is in the open state and the second switch 23 is in the connected state, the first connection point 13a and the third connection point 13c (and thus the external load 12) are not the main wire 13 but the self-generated power. It is connected via a supply wire 18. The first distributed power supply 15 is connected to the external load 12 via a self-generated power supply electric wire 18. The electric power from the first distributed power supply 15 is supplied to the external load 12 via the first connection point 13a, the self-generated power supply wire 18 and the third connection point 13c.

  Further, the power from the first distributed power supply 15 is not supplied to the third detector 16g (or the second detector 16f) via the first connection point 13a and the main electric wire 13. Therefore, the second distributed power supply 16 can detect by itself that power is not supplied to the main electric wire 13 and by extension, an abnormality (power failure) of the system power supply 11. As a result, the second distributed power supply 16 opens the second disconnector 16d in response to an opening instruction from the second controller 16e, and disconnects the second distributed power supply 16 from the system power supply 11 (disconnected state). ). At this time, the second distributed power supply 16 may stop power generation by the second power supply device 16a.

  Furthermore, if the 3rd switch 24 will be in an open state, the 2nd connection point 13b and the 3rd connection point 13c will be interrupted | blocked. Therefore, it is possible to prevent the power (self-sustained power) supplied from the first distributed power supply 15 via the self-generated power supply wire 18 from flowing back to the second distributed power supply 16. Since the third detector 16g is disposed on the second connecting wire 16c, the third detector 16g can be prevented from detecting the self-sustained power, and as a result, power can be restored after a power failure based on the detection result. It is possible to prevent an erroneous determination that there is.

  As described above, the power supply switching device 20 directly inputs the power state of the system power supply 11 and switches the opening / closing of the switches 22 to 24 according to the power state. As a result, the internal path Shuts down and switches connection. The second distributed power supply 16 is connected to the main electric wire 13 in parallel to the first distributed power supply 15 using the power supply switching device 20. In this way, in the power supply system 10 in which a plurality of various distributed power sources 15 and 16 are connected in parallel, each distributed power source 15 and 16 independently detects (detects) a power failure (abnormality of the system power supply 11). can do. Therefore, the power supply system 10 can perform appropriate control corresponding to a power failure of the system power supply 11 (for example, control in accordance with the interconnection rules).

  Further, a case where the system power supply 11 is restored will be described with reference to FIG. Since the system power supply 11 returns to normal from the abnormality, the main switch 14 is connected. In this case, the first disconnector 15d of the first distributed power supply 15 is also opened.

  Simultaneously with power recovery, the first disconnector 15d is opened. Since the first disconnector 15 d of the first distributed power supply 15 is in an open state, the first distributed power supply 15 is disconnected from the system power supply 11. Thereafter, the first disconnector 15d is connected when a predetermined time T2 (for example, 300 seconds) has elapsed since the power was restored. That is, the first connection point 13 a is connected to the system power supply 11 and is connected to the first distributed power supply 15. As a result, the power supply format for the external load 12 is changed to the interconnected power supply. During the predetermined time T2, the interconnection connection is prohibited and the power supply is stopped.

The operation of the power supply switching device 20 at the time of power recovery (and after power recovery) will be described. When power is restored, since the voltage of the system power supply 11 input to the first switch 22 is equal to or higher than the switching voltage value, the first switch 22 is switched to the connected state. Specifically, since a current flows through the input signal terminal of the first switch 22, the contact of the first switch 22 of the a contact type is closed, and the first switch 22 is in a connected state.
Similarly to the first switch 22, the third switch 24 is connected when the power is restored.

  On the other hand, in the second switch 23, when the power is restored, the voltage of the system power supply 11 input to the second switch 23 is equal to or higher than the switching voltage value, so the second switch 23 is switched to the open state. More specifically, since a current flows through the input signal terminal of the second switch 23, the contact of the second switch 23 of the b contact type is opened, and the second switch 23 is opened.

  When the first switch 22 is in the connected state and the second switch 23 is in the open state, the first connection point 13a and the third connection point 13c (and thus the external load 12) are not Without being connected via the main electric wire 13. The system power supply 11 is connected to the external load 12 via the main electric wire 13. The first distributed power source 15 is connected to the external load 12 via the main electric wire 13. Each power from the system power supply 11 and the first distributed power supply 15 is supplied to the external load 12 via the first connection point 13a, the main electric wire 13 and the third connection point 13c.

  Moreover, the electric power from the system power supply 11 is supplied to the second detector 16f and the third detector 16g via the first connection point 13a and the main electric wire 13. Therefore, the second distributed power supply 16 can detect by itself that power is supplied to the main electric wire 13 and that the system power supply 11 is normal (recovery). As a result, the second distributed power supply 16 closes the second disconnector 16d in response to a closing instruction from the second control device 16e when a predetermined time T2 has elapsed from the time when the power is restored. The power supply 16 is connected to the system power supply 11 (connected state). That is, the second connection point 13b is connected to the system power supply 11 and also to the second distributed power supply 16. At the same time, the second distributed power source 16 starts power generation by the second power supply device 16a. As a result, the power supply format for the external load 12 is changed to the interconnected power supply.

  Further, when the third switch 24 is connected, the second connection point 13b and the third connection point 13c are connected. Therefore, the system power supply 11, the first distributed power supply 15, and the second distributed power supply 16 are connected to the external load 12 via the main electric wire 13. That is, the power supply form of the first distributed power supply 15 and the second distributed power supply 16 is a grid power supply.

  As described above, in the power supply system 10 in which a plurality of various distributed power sources 15 and 16 are connected in parallel, each of the distributed power sources 15 and 16 independently detects (detects) power recovery of the system power supply 11. Can do. Therefore, the power supply system 10 can perform appropriate control corresponding to power recovery of the system power supply 11 (for example, control in accordance with the interconnection rules).

  As is clear from the above description, the power supply switching device 20 according to the present embodiment includes the system power supply 11, the external load 12 electrically connected to the system power supply 11 via the main wire 13, and the main wire. 13 is opened when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is out of power), and when the power supply from the system power supply 11 is normal (the system power supply 11 is normal). A main switch 14 connected to the main switch 14 and a first power supply device 15a for supplying power, and the power from the first power supply device 15a is supplied to the main switch 13 downstream of the main switch 14 Power is transmitted through the first connection wire 15c connected at one connection point 13a, and independent power generation is possible when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is out of power). A first distributed power source 5 and a second power supply device 16a for supplying power, and the power from the second power supply device 16a is connected at a second connection point 13b downstream of the first connection point 13a of the main wire 13. A second distributed power source 16 that transmits power via the second connecting wire 16c, and a third detection that is provided on the second connecting wire 16c and detects the presence or absence of power supply and transmits it to the second distributed power source 16 A power supply switching device 20 that switches power supply from each of the power supplies 11, 15, 16 to the external load 12, which is applied to a power supply system 10 including at least a detector 16 g (detector). The apparatus 20 is provided in the main electric wire 13 between the first connection point 13a and the second connection point 13b, and when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is a power failure), The first connection point 13a and the first The first opening / closing that connects the first connection point 13a and the second connection point 13b when the connection point 13b is disconnected and the power supply from the system power supply 11 is normal (when the system power supply 11 is normal). A container 22 is provided.

According to this, even when the first distributed power supply 15 performs self-sustaining power generation when the system power supply 11 is out of power (the power supply from the system power supply 11 is abnormal), the first connection The point 13a and the second connection point 13b are blocked by the first switch 22. Therefore, it can stop supplying electric power to the main electric wire 13 between the 1st connection point 13a and the 2nd connection point 13b. As a result, when the third detector 16g (detector) on the second connection wire detects the presence or absence (for example, voltage) of power supply, the second distributed power supply 16 has an abnormal power supply from the system power supply 11. (Whether or not the system power supply 11 is a power failure) can be detected. As described above, the power supply system 10 reliably detects whether or not the distributed power source 15 or 16 has an abnormality in the system power source 11 without complicating the system / structure.
Furthermore, the power supply system 10 reliably detects whether the distributed power sources 15 and 16 are abnormal in the system power source 11 even when power is restored.
Furthermore, the power supply switching device 20 can switch the power (power source) supplied to the external load 12 with a simple configuration.

Further, the power supply switching device 20 is a self-generated power supply wire that connects the first connection point 13 a and the third connection point that is a part of the main wire 13 between the second connection point 13 b and the external load 12. When the power supply from the system power supply 11 is abnormal (when the system power supply 11 is out of power), the first connection point 13a and the third connection point are connected to supply power from the system power supply 11. Is provided with a second switch for cutting off the first connection point 13a and the third connection point when the power supply is normal (when the system power supply 11 is normal).
According to this, when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is in a power failure) and the first distributed power supply 15 performs self-sustaining power generation, the second switch Connects the first connection point 13a and the third connection point, and the self-generated power supply electric wire is in communication. As a result, the power (self-sustained power) from the first distributed power supply 15 is reliably supplied to the external load 12.

The power supply switching device 20 is provided in the main electric wire 13 between the second connection point 13b and the external load 12, and when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is a power failure) ), The second connection point 13b and the external load 12 are cut off, and when the power supply from the system power supply 11 is normal (when the system power supply 11 is normal), the second connection point 13b and the external load 12 And a third switch for connecting the.
According to this, when the power supply from the system power supply 11 is abnormal (when the system power supply 11 is in a power failure) and the first distributed power supply 15 performs self-sustaining power generation, the third switch Shuts off the second connection point 13b and the external load 12. As a result, it is possible to suppress the self-generated power supplied to the external load 12 from the first distributed power supply 15 to the external load 12 from flowing back to the second connection point 13b and thus the second distributed power supply 16. Further, it is possible to suppress erroneous determination that the power flowing back to the second distributed power supply 16 is the power recovery of the system power supply 11.

The first switch 22 is connected to the main wire 13 between the main switch 14 and the system power supply 11 via a signal input wire, and inputs the voltage of the system power supply 11, and the input voltage is the switching voltage. The AC relay is switched to a connected state when the value is equal to or greater than the value, and is switched to an open state when the input voltage is less than the switching voltage value.
According to this, since the first switch 22 is constituted by an AC relay, the first switch 22 is reliably operated with a simple configuration.

The second switch is connected to the main wire 13 between the main switch 14 and the system power supply 11 via a signal input wire, and the voltage of the system power supply 11 is input. The input voltage is a switching voltage value. In this case, the AC relay is switched to an open state and switched to a connected state when the input voltage is less than the switching voltage value.
According to this, since the second switch is configured with an AC relay, the second switch is reliably operated with a simple configuration.

The third switch is connected to the main wire 13 between the main switch 14 and the system power supply 11 via a signal input wire, and the voltage of the system power supply 11 is input. The input voltage is the switching voltage value. In this case, the AC relay is switched to the connected state and switched to the open state when the input voltage is less than the switching voltage value.
According to this, since the third switch is configured by an AC relay, the third switch is reliably operated with a simple configuration.

The power supply switching device 20 further includes a casing that houses at least one of the switches, and a connection portion that is provided in the casing and is electrically connected to the electric wires.
According to this, the power supply switching device 20 can be installed in the already installed power supply system 10 by simple construction.

Further, the power supply switching device 20 may be configured to be included in the second distributed power source 16.
According to this, when retrofitting the 2nd distributed power supply 16, it can construct easily.

  Further, the power supply system 10 can obtain the operation and effect of the power supply switching device 20 described above.

  In the embodiment described above, the first distributed power source 15 may be configured with a distributed power source in which reverse power is prohibited instead of being configured with a distributed power source in which reverse power is not prohibited. Good. The second distributed power source 16 may be configured by a distributed power source in which reverse power is not prohibited, instead of a distributed power source in which reverse power is prohibited.

  Further, when the power supply system 10 described above is configured by three or more distributed power sources, the first distributed power source 15 is the distributed power source arranged at the most upstream side with respect to the system power source 11. The subsequent distributed power source is the second distributed power source 16.

  DESCRIPTION OF SYMBOLS 10 ... Power supply system, 11 ... System power supply, 12 ... External load, 13 ... Main electric wire, 13a ... First connection point, 13b ... Second connection point, 13c ... Third connection point, 13d ... Fourth connection point, 14 ... Main switch, 15 ... First distributed power source, 15a ... First power supply device, 15b ... First power converter, 15c ... First connection wire, 15d ... First disconnector, 15e ... First control Device, 15f ... First detector, 16 ... Second distributed power source, 16a ... Second power supply device, 16b ... Second power converter, 16c ... Second connecting wire, 16d ... Second disconnector, 16e DESCRIPTION OF SYMBOLS ... 2nd control apparatus, 16f ... 2nd detector, 16g ... 3rd detector (detector), 17 ... Electric wire for signal input, 18 ... Electric power supply electric power supply wire, 20 ... Electric power supply switching device, 21 ... Casing 22 ... 1st switch, 23 ... 2nd switch, 24 ... 3rd switch, 2 ... connecting portion, 26 ... casing wire.

Claims (6)

System power supply,
An external load electrically connected to the system power supply via a main wire;
A main switch that is provided in the main electric wire, is opened when the power supply from the system power supply is abnormal, and is connected when the power supply from the system power supply is normal;
A first connection electric wire comprising a first electric power supply device for supplying electric power, wherein electric power from the first electric power supply device is connected at a first connection point downstream of the main switch of the main electric wire. A first distributed power source that is capable of autonomous power generation when power supply from the system power source is abnormal,
A second power supply device for supplying power, and for connecting the power from the second power supply device at a second connection point downstream of the first connection point of the main wire. A second distributed power source for transmitting power via the electric wire;
A detector provided on the second connecting wire, for detecting the presence or absence of power supply and transmitting to the second distributed power source;
A power supply switching device that is applied to a power supply system including at least a power supply that switches power supply from each power source to the external load,
The power supply switching device is provided in the main electric wire between the first connection point and the second connection point, and when the power supply from the system power supply is abnormal, the first connection point and the A power supply switching device comprising a first switch that cuts off the second connection point and connects the first connection point and the second connection point when the power supply from the system power supply is normal .   The power supply switching device is provided in a self-generated power supply electric wire that connects the first connection point and a third connection point that is a part of the main electric wire between the second connection point and the external load. When the power supply from the system power supply is abnormal, the first connection point and the third connection point are connected, and when the power supply from the system power supply is normal, the first connection The power supply switching device according to claim 1, further comprising a second switch that cuts off a point and the third connection point.   The power supply switching device is provided in the main electric wire between the second connection point and the external load, and when the power supply from the system power supply is abnormal, the second connection point and the external load And a third switch for connecting the second connection point and the external load when the power supply from the system power supply is normal. Power supply switching device.   The first switch is connected to the main wire between the main switch and the system power supply via a signal input wire, and inputs the voltage of the system power supply, and the input voltage is a switching voltage value. The power supply according to any one of claims 1 to 3, wherein the power supply is an AC relay that is switched to a connected state when it is above and is switched to an open state when the input voltage is less than the switching voltage value. Switching device.   The second switch is connected to the main wire between the main switch and the system power supply via a signal input wire, and inputs the voltage of the system power supply, and the input voltage is a switching voltage value. 4. The power supply switching device according to claim 2, wherein the power supply switching device is switched to an open state in the case of the above, and is switched to a connected state when the input voltage is less than the switching voltage value.   The third switch is connected to the main wire between the main switch and the system power supply via a signal input wire, and inputs the voltage of the system power supply, and the input voltage is a switching voltage value. 4. The power supply switching device according to claim 3, wherein the power supply switching device is switched to a connected state in the case of the above, and is switched to an open state when the input voltage is less than the switching voltage value.

Images