JP2013146121A - Power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system capable of stopping an output of power from a power supply such as a solar cell panel at the time of occurrence of a large-scale disaster.SOLUTION: A power supply system includes: a first power output line 5 and a second power output line 6 for outputting power from a DC power supply 2; a disconnection detection line 7 for detecting the disconnection of the first power output line 5; a disconnection detection circuit 8 for detecting the disconnection of the first power output line 5; a cut-off circuit 9 maintaining the conduction between the DC power supply 2 and the second power output line 6 when the disconnection detection circuit 8 does not detect the disconnection of the first power output line 5, and cutting off the conduction between the DC power supply 2 and the second power output line 6 when the disconnection detection circuit 8 detects the disconnection of the first power output line 5; and a first connector 10 provided on the first power output line 5. The first connector 10 is composed of a plug and a socket, and is configured so that the plug and the socket are disconnected when tensile force is applied to the first power output line 5.

Description

  The present invention relates to a power supply system such as a solar power generation system and a storage battery power supply system, and more particularly to a power supply system including a protection circuit that stops power output in the event of a disaster.

  In recent years, buildings equipped with a power supply system such as a solar power generation system and a storage battery power supply system are increasing. On the other hand, every year, there are cases where houses are destroyed or swept away by natural disasters such as river floods and debris flows caused by heavy rain. In addition, it is a new memory that many buildings were destroyed and submerged by the 2011 off the Pacific coast of Tohoku Earthquake and the accompanying tsunami (Great East Japan Earthquake).

  In a power supply system such as a solar power generation system or a storage battery power supply system, for example, a solar circuit panel or a storage battery is provided with a circuit breaker. It is configured not to output power to the na. Generally, this circuit breaker is operated by an operator at the time of work, and is not designed to operate automatically when a disaster occurs. Moreover, the wiring which connects a solar cell panel, a storage battery, a power conditioner, and a power conditioner, a switchboard, etc. is comprised so that it may not remove easily according to an earthquake. Therefore, even in a large-scale disaster that destroys buildings, these wirings will not be cut, and power will continue to be output from the power supply system as long as the solar panel generates electricity. . In the Hyogoken-Nanbu Earthquake that occurred on January 17, 1995 (the Hanshin-Awaji Great Earthquake), a fire occurred from a collapsed house with the resumption of commercial power transmission, so power continues to be output from the power supply system. In the state, a fire in a collapsed house is expected. In addition, if seawater or the like flows in a state where power is continuously output from the power supply system, a person in the vicinity may receive an electric shock.

  Patent Document 1 discloses a device that operates a relay to cut an output voltage when a voltage detection line for monitoring a state of an output voltage is disconnected in a DC stabilized power supply. However, the detection line is not easily disconnected, and this device is a safety measure for accidents that rarely occur in practice. For this reason, even if the apparatus of Patent Document 1 is simply incorporated in the power supply system, it is not possible to prevent the occurrence of fire and electric shock as described above unless the voltage detection wiring is cut off.

JP-A-5-64350

  The present invention has been made to solve the above-described problems of the conventional example, and an object thereof is to provide a power supply system that stops power output when a large-scale disaster occurs while having a relatively simple structure. And

  To achieve the above object, a power supply system according to the present invention detects a first power output line and a second power output line for outputting power from a DC power source, and disconnection of the first power output line. A disconnection detection line, a disconnection detection circuit connected between the first power output line and the disconnection detection line for detecting disconnection of the first power output line, the DC power source, and the disconnection When the disconnection detection circuit is connected to a detection line and the second power output line and the disconnection detection circuit does not detect the disconnection of the first power output line, the DC power supply and the second power output line are secured. A disconnection circuit that interrupts conduction between the DC power supply and the second power output line when the disconnection detection circuit detects a disconnection of the first power output line; and between the DC power supply and the disconnection detection circuit. The first connector provided on the first power output line Wherein the first connector is composed of a plug and socket, when pulling force to said first power output line is applied, wherein the plug and the socket is configured to disengage.

  The disconnection detection line between at least the disconnection detection circuit and the disconnection circuit further includes a second connector provided separately from the first connector, and the first connector and the second connector have a predetermined distance. Preferably, the predetermined distance is set so as to generate a predetermined electric resistance when the first connector and the second connector are in seawater.

  Moreover, it is preferable that the plug of the first connector is configured such that when the plug and the socket are detached, a conductor portion thereof is covered with an insulating gel-like resin.

  The cutoff circuit includes a semiconductor switch element connected between the DC power supply and the second power output line, and the disconnection detection circuit is configured to input a predetermined gate voltage to the gate electrode of the semiconductor switch element. It is preferable that the voltage generation circuit is.

  According to the present invention, when a large-scale disaster in which a tensile force is applied to the first power output line occurs, the plug and socket of the first connector are disconnected, and the first power output line is disconnected relatively easily. To do. When the first power output line is disconnected, the interruption circuit cuts off the continuity between the DC power source and the second power output line. Therefore, the plug between the first connector and the socket, or between the plug of the first connector and the second power output line. Even if the conductor portion is conducted by seawater, wood, etc., in most cases, power is not output from the DC power source. As a result, electric shock and fire can be prevented.

The block diagram which shows the 1st structural example of the electric power supply system which concerns on one Embodiment of this invention. The figure which shows the specific circuit structure of the 1st structural example of the said electric power supply system. It is a figure which shows the structural example of the 1st connector in the 1st structural example of the said electric power supply system, (a) shows the state which isolate | separated the plug and the socket, (b) shows the state which couple | bonded the plug and the socket. The block diagram which shows the 2nd structural example of the electric power supply system which concerns on one Embodiment of this invention. The figure which shows the specific circuit structure of the 3rd structural example of the electric power supply system which concerns on one Embodiment of this invention. (A) is a figure which shows the relationship between the voltage applied to the gate of the semiconductor switch element in the interruption | blocking circuit 9 shown in FIG. 2, and the voltage output from the terminal of DC power supply, (b) is the interruption | blocking circuit shown in FIG. The figure which shows the relationship between the voltage applied to the gate of the semiconductor switch element in, and the voltage output from the terminal of DC power supply.

  A power supply system according to an embodiment of the present invention will be described. FIG. 1 shows a first configuration example of a power supply system according to the present embodiment. The power supply system 1 includes a DC power source 2 such as a solar battery panel or a storage battery, and a power conditioner 4 including an inverter circuit 12. The inverter circuit 12 converts the DC power output from the DC power source 2 into AC power and outputs the AC power. The DC power supply 2 and the power conditioner 4 are used to detect the disconnection of the first power output line 5 and the first power output line 5 and the second power output line 6 for outputting power from the DC power supply 2. Connected by a disconnection detection line 7. The power conditioner 4 includes a disconnection detection circuit 8 that is connected between the first power output line 5 and the disconnection detection line 7 and detects the disconnection of the first power output line 5. The DC power supply 2 is connected to the disconnection detection line 7 and the second power output line 6, and is a cutoff circuit that controls conduction and cutoff between the DC power supply 2 and the second power output line 6 according to the detection result of the disconnection detection circuit 8. 9 is provided. The first power output line 5 is connected to the high voltage side output terminal of the DC power source 2 and the high voltage side input terminal of the power conditioner 4, and a first connector 10 composed of a plug and a socket is provided in the middle part thereof. Is provided. One end of the disconnection detection circuit 8 is connected to the high voltage side input terminal of the power conditioner 4, that is, the first power output line 5. Further, the other end of the disconnection detection circuit 8 is connected to the power conditioner 4 side terminal of the disconnection detection line 7. The second power output line 6 is connected to the cutoff circuit 9 of the DC power source 2 and the low voltage side input terminal of the power conditioner 4. In the first configuration example, a connector is not provided at an intermediate portion between the second power output line 6 and the disconnection detection line 7. Further, when the DC power source 2 is a solar cell panel and a plurality of the solar cell panels are provided, the plurality of solar cell panels are connected to the power conditioner via a connection box (not shown).

  FIG. 2 shows a specific circuit configuration example of the disconnection detection circuit 8 and the cutoff circuit 9. The disconnection detection circuit 8 is configured by a resistor R2 having one end connected to the high voltage side input terminal of the power conditioner 4, that is, the first power output line 5, and generates a predetermined voltage. The cutoff circuit 9 is configured by a semiconductor switch element Q1, such as an FET, a Zener diode ZD1, a resistor R1, and the like, which are connected between the low voltage side of the DC power supply 2 and the second power output line 6. The gate electrode of the semiconductor switch element Q1 is connected to the other end of the resistor R2 of the disconnection detection circuit 8 via the disconnection detection line 7, and a predetermined voltage generated by the resistor R2 is used as a gate drive signal of the semiconductor switch element Q1. Input to the gate electrode. When the first power output line 5 is not disconnected, the gate drive signal is input to the gate electrode of the semiconductor switch element Q1 of the cutoff circuit 9, and the semiconductor switch element Q1 is conductive. That is, when the disconnection detection circuit 8 does not detect disconnection of the first power output line, DC power is input from the DC power supply 2 to the inverter circuit 12 via the first power output line 5 and the second power output line 6. AC power is output from the inverter circuit 12. On the other hand, when the first power output line 5 is disconnected, the gate drive signal is not input to the gate electrode of the semiconductor switch element Q1 of the cutoff circuit 9, and the semiconductor switch element Q1 becomes non-conductive. That is, when the disconnection detection circuit 8 detects the disconnection of the first power output line, the DC power supply 2 and the second power output line 6 become non-conductive, DC power is not input to the inverter circuit 12, and AC power is supplied from the inverter circuit 12. Will not be output.

  As shown in FIG. 3, the first connector 10 includes a plug 21 and a socket 22. The plug 21 and the socket 22 are only inserted and coupled to each other, and do not have a screwing structure for making it difficult to come off or a structure for engaging the claw and the recess. Further, for example, the surface of the male terminal 23 of the plug 21 is coated with a gel-like insulating resin 24, or the recess 21b of the housing 21a of the plug 21 is filled with the gel-like insulating resin 24. . In the state where the plug 21 and the socket 22 are coupled, the tip of the housing 22a of the socket 22 pushes the insulating resin 24 into the back of the recess 21b of the housing 21a of the plug 21, and the male terminal 23 of the plug 21 and the female of the socket 22 are inserted. The terminal 25 contacts and is electrically connected. Here, when a tensile force acts on the first power output line 5, the plug 21 and the socket 22 constituting the first connector 10 are detached, and the first power output line 5 is disconnected. When the plug 21 and the socket 22 are detached, that is, when the male terminal 23 of the plug 21 and the female terminal 25 of the socket 22 are separated from each other, the gel-like insulating resin 24 tries to restore its original shape by its elastic force. The surface of the male terminal 23 is covered with a gel-like insulating resin 24. Therefore, even if the house collapses due to a large-scale disaster and the first power output line 5 is disconnected, the surface of the male terminal 23 of the plug 21 is covered with the gel-like insulating resin 24. Even if the DC power supply 2 continues to output power and both the plug 21 and the socket 22 are submerged in seawater, no current flows from the plug 21 to the socket 22, and the disconnection detection circuit 8 has the first function. The disconnection of the power output line can be detected. As a result, the interruption circuit 9 interrupts conduction between the DC power supply 2 and the second power output line. Further, no current flows between the male terminal 23 of the plug 21 and other conductor portions, for example, the terminals of the disconnection detection line 7 and the second power output line 6.

  FIG. 4 shows a second configuration example of the power supply system according to the present embodiment. In the second configuration example, a second connector 11 similar to the first connector 10 is also provided in an intermediate portion between the second power output line 6 and the disconnection detection line 7. Further, even when the first power output line 5, the second power output line 6, and the disconnection detection line 7 are wired in parallel, the first connector 10 and the second connector 11 may be provided in different places. preferable. Even if a house collapses due to a large-scale disaster, the plug 21 and the socket 22 of the first connector 10 do not always come off successfully. If the 1st connector 10 and the 2nd connector 11 are provided in another place, possibility that either one of the 1st connector 10 and the 2nd connector 11 will come out becomes high. If the plug and socket of the second connector 11 are disconnected, the disconnection detection line 7 is disconnected, the gate drive signal is not input to the gate electrode of the semiconductor switch element Q1 of the cutoff circuit 9, and the semiconductor switch element Q1 becomes non-conductive. In FIG. 4, the second power output line 6 and the disconnection detection line 7 are connected by one second connector 11, but may be connected by individual second connectors 11. Further, the second connector 11 may have a configuration in which a plug and a socket are inserted and coupled to each other, similarly to the first connector shown in FIG. Further, a gel-like insulating resin may be provided on the plug side.

  Further, when the first connector 10 and the second connector 11 are provided at different locations, even if both the first connector 10 and the second connector 11 are submerged in seawater, a predetermined distance is generated so as to generate a predetermined electric resistance. It is preferable that they are provided apart from each other. As is well known, fresh water (in the sense of distinguishing it from seawater) has a relatively high electrical resistance, and even if the first connector 10 and the second connector 11 are submerged, they do not immediately short-circuit. Therefore, even when a current flows through fresh water, the voltage applied to the gate electrode of the semiconductor switch element Q1 of the cutoff circuit 9 is low and becomes less than the gate-drain voltage threshold, and the semiconductor switch element Q1 is non-conductive. Is likely to be. On the other hand, when the electrolyte is dissolved in a large amount like seawater, the electric resistance is smaller than that of fresh water. Therefore, if the first connector 10 and the second connector 11 are provided at a close distance, current flows through seawater, and a voltage equal to or higher than the gate-drain voltage threshold is applied to the gate electrode of the semiconductor switch element Q1 of the cutoff circuit 9. When applied, the semiconductor switch element Q1 may remain conductive. Accordingly, if the first connector 10 and the second connector 11 are provided at a predetermined distance so as to generate a predetermined electric resistance even if they are submerged in seawater, the gate of the semiconductor switch element Q1 of the breaking circuit 9 is provided. A voltage higher than the gate-drain voltage threshold is not applied to the electrode, and the semiconductor switch element Q1 can be made non-conductive. Such an arrangement is effective when the gel-like insulating resin 24 of the plug 21 of the first connector 10 is not originally provided or when the gel-like insulating resin 24 is deteriorated due to aging. It is.

  FIG. 5 shows a third configuration example of the power supply system according to the present embodiment. In the third configuration example, the specific configuration of the cutoff circuit 9 is different from that of the first configuration example shown in FIG. FIG. 6A shows the relationship between the voltage applied to the gate of the semiconductor switch element Q1 and the voltage output from the terminal of the DC power supply 2 in the cutoff circuit 9 shown in FIG. On the other hand, FIG. 6B shows the relationship between the voltage applied to the gate of the semiconductor switch element Q1 and the voltage output from the terminal of the DC power supply 2 in the cutoff circuit 9 shown in FIG. In the figure, Vth represents the gate-drain voltage threshold of the semiconductor switch element Q1, and VZD1 represents the Zener voltage of the Zener diode ZD1. Vs indicates a voltage output from the terminal of the DC power supply 2. In the following description, a voltage applied to the gate electrode of the semiconductor switch element Q1 is a gate voltage.

  As shown in FIG. 6A, in the case of the configuration of the cutoff circuit 9 shown in FIG. 2, for example, even when the DC power source 2 is a solar cell panel and its power generation amount is small, the gate electrode of the semiconductor switch element Q1 When a gate voltage higher than the gate-drain voltage threshold Vth is applied, the semiconductor switch element Q1 becomes conductive. The FET used as the semiconductor switch element Q1 has a smaller on-resistance as the gate voltage is higher. In other words, when the gate voltage is lower, the on-resistance is larger, the loss due to the semiconductor switch element Q1 is larger, and the semiconductor switch element Q1 generates heat. Large amount. In the third configuration example shown in FIG. 5, the control switch element Q2 is connected to the gate of the semiconductor switch element Q1, and the comparator COM1 is connected to the gate of the control switch element Q2. Therefore, the control switch element Q2 is turned on and the semiconductor switch element Q1 is not turned on until the voltage input to the comparator COM1 reaches a predetermined threshold value. Therefore, as shown in FIG. 6B, in the region where the loss of the semiconductor switch element Q1 is large, the semiconductor switch element Q1 is non-conductive (off), and loss or heat generation by the semiconductor switch element Q1 does not occur. Of course, no electric power is output from the terminals of the DC power supply 2 during this period. When the voltage input to the comparator COM1 reaches a predetermined threshold value, the control switch element Q2 becomes non-conductive (off) and the semiconductor switch element Q1 becomes conductive (on). Then, power is output from the terminal of the DC power supply 2. The voltage threshold value for conducting the semiconductor switch element Q1 can be set to an arbitrary value by appropriately selecting the resistance values of the resistors R2, R5, and R6.

  In the power supply system according to the present invention, the installation locations of the DC power supply, the first power output line, the second power output line, the disconnection detection line, the disconnection detection circuit, the disconnection circuit, and the first connector are not particularly limited. In short, when a tensile force is applied to the first power output line, the plug and socket constituting the first connector are disconnected, and the disconnection detection circuit detects that the first power output line is disconnected, and shuts off. It is only necessary that the circuit is configured to cut off the connection between the DC power supply and the second power output line. With such an extremely simple configuration, it is possible to stop the output of power from a DC power source such as a solar battery panel or a storage battery when a large-scale disaster occurs.

DESCRIPTION OF SYMBOLS 1 Power supply system 2 DC power supply 4 Power conditioner 5 1st power output line 6 2nd power output line 7 Disconnection detection line 8 Disconnection detection circuit 9 Breaking circuit 10 1st connector 11 2nd connector 12 Inverter circuit

Claims (4)

A first power output line and a second power output line for outputting power from a DC power source;
A disconnection detection line for detecting disconnection of the first power output line;
A disconnection detection circuit connected between the first power output line and the disconnection detection line for detecting disconnection of the first power output line;
The DC power source and the second power are connected to the DC power source, the disconnection detection line, and the second power output line, and the disconnection detection circuit does not detect the disconnection of the first power output line. A disconnection circuit that secures conduction of the output line, and interrupts conduction of the DC power supply and the second power output line when the disconnection detection circuit detects disconnection of the first power output line;
A first connector provided on the first power output line between the DC power source and the disconnection detection circuit;
The power supply system according to claim 1, wherein the first connector includes a plug and a socket, and the plug and the socket are disconnected when a tensile force is applied to the first power output line. The disconnection detection line between at least the disconnection detection circuit and the cutoff circuit further includes a second connector provided separately from the first connector,
The first connector and the second connector are provided at a predetermined distance, and the predetermined distance generates a predetermined electric resistance when the first connector and the second connector are in seawater. The power supply system according to claim 1, wherein the power supply system is set as follows.   The said plug of the said 1st connector is comprised so that when the said plug and the said socket will remove | deviate, the conductor part will be covered with an insulating gel-like resin. 2. The power supply system according to 2. The cutoff circuit includes a semiconductor switch element connected between the DC power supply and the second power output line, and the disconnection detection circuit is configured to input a predetermined gate voltage to the gate electrode of the semiconductor switch element. The power supply system according to claim 1, wherein the power supply system is a voltage generation circuit.

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