JP6099415B2 - Distributed power system - Google Patents

Description

  The present invention provides an AC power source connected to a power system, an auxiliary power supply device having a power storage unit connected to a first connection location of the AC line, and a power generation unit having a power generation unit connected to a second connection location of the AC line. An apparatus and a power consuming device connected to the AC line at a second connection location, and the first connection location and the second connection location are downstream from the connection location of the power system to the AC line. The present invention relates to a distributed power supply system provided in the arrangement order.

  The distributed power supply system described in Patent Document 1 includes an auxiliary power supply device (storage battery 14), a power generation device (fuel cell power generation unit 9), and a power consumption device (load 3) connected to an AC line. The auxiliary power supply device, the power generation device, and the power consumption device are provided in the arrangement order from the power system (commercial power supply source 5) toward the downstream side. In addition, in Patent Document 1, the power supplied from the power generation device to the AC line is smaller than the power consumption of the power consumption device with reference to the detection result of the power detection unit (sensor 33) in the AC line. In addition, it is described that the operation is stopped when it is detected that a state in which power flows from the power generation device to the upstream power system is generated.

  Here, the detection result of the power detection unit indicates that the power flowing from the upstream side (the power system side) is zero or the sign is positive with respect to the second connection location to which the power generator is connected. If so, it can be said that there is no reverse power flow in which the power supplied from the power generator to the AC line flows to the upstream power system side. The power detection unit used for adjusting the generated power of the power generation device is based on the current value and voltage value of the power on the AC line upstream of the location where the power generation device is connected (that is, on the power system side). A device that detects the value can be used. A current transformer used for detecting a current value is known as one of the devices constituting such a power detection unit.

JP 2011-188607 A

  An abnormality such as disconnection may occur in the current transformer. And when a disconnection arises in a current transformer, an electric power generation control part recognizes the electric power which goes to a 2nd connection location from the 1st connection location side as zero. That is, the power generation control unit recognizes that the power consumption of the power consuming device and the generated power of the power generation unit are balanced, and that no reverse power flow to the power system has occurred. As a result, the power generation control unit controls the power generation unit so as to maintain the current generated power.

  However, even if the power consumption of the power consuming device is reduced when the power generation control unit performs such misrecognition, the power generation control unit sets the power going from the first connection point side to the second connection point to zero. The recognition continues, and the misrecognition that the power consumption of the power consuming device and the power generated by the power generation unit are balanced is continued. That is, the power generation control unit maintains the generated power of the power generation unit at the current value even though the power consumption of the power consuming device has decreased. As a result, surplus power that has not been consumed by the power consuming device out of the power generated by the power generating device is directed to the AC line upstream of the second connection location. When the surplus power that has not been consumed by such a power consuming device goes to the AC line upstream of the second connection location, for example, in the situation where power supply from the power system to the AC line is not performed, the auxiliary power supply When the device and the power generation device continue to operate, the surplus power described above flows into the auxiliary power supply device. As a result, for example, the internal voltage of the power conversion circuit unit of the auxiliary power supply device rises, causing a problem that the power conversion circuit unit fails in the worst case.

  In order to avoid a problem that may occur due to the disconnection of the current transformer provided in the power generation apparatus as described above, it is possible to verify whether or not the current transformer is disconnected. For example, while the power generator is generating power, whether or not the current transformer correctly detects the fluctuation by intentionally increasing / decreasing the load power for the power generation unit to change the power at the detection part of the current transformer. There is a method to check whether or not. Specifically, the electric power at the detection part of the current transformer can be changed by consuming the electric power generated by the electric power generation unit with an electric heater provided inside the electric power generation device. However, this method is not preferable because the power generated by the power generation unit is unnecessarily consumed.

  Thus, conventionally, an effective solution to the problem that a failure of the power conversion circuit unit of the auxiliary power supply device can be caused by the failure of the power generation device of the distributed power supply system, particularly, the failure of the power detection unit of the power generation device. No plan has been proposed.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a distributed power supply system that can detect an abnormality early and cope with it.

The characteristic configuration of the distributed power supply system according to the present invention for achieving the above object includes an AC line connected to a power system, an auxiliary power supply device connected to the AC line at a first connection location, A power generator connected to the AC line at a second connection location; and a power consuming device connected to the AC line at the second connection location; from a connection location of the power system to the AC line A distributed power supply system in which the first connection portion and the second connection portion are provided in the arrangement order toward the downstream side as viewed,
In the case where the power going from the power system side to the power consuming device is positive power,
The power generation device includes a power generation unit, a power detection unit that detects power traveling from the first connection location side to the second connection location, and a detection result of the power detection unit, and the first connection location side A power generation control unit that controls the power supplied from the power generation unit to the AC line so that the power going from the power source to the second connection point does not become negative power,
The auxiliary power supply is configured to output from the power storage unit to the AC line so that the voltage of the AC line is within a reference voltage range when the power supply unit and the power supply from the power system to the AC line are independent. A power conversion circuit unit for adjusting power, and a power supply control unit for controlling the operation of the power conversion circuit unit,
When the power supply from the power system to the AC line is not performed independently, an internal voltage detection unit that detects a voltage at a predetermined portion inside the power conversion circuit unit sets the voltage inside the power conversion circuit unit. An output power detection unit for detecting a high voltage state higher than an upper limit voltage or detecting power output from the power conversion circuit unit to the AC line is provided from the AC line to the power conversion circuit unit. An abnormality determination device that determines that an abnormal state is detected when a reverse flow state in which power flows is detected;
When the abnormality determining device determines that the abnormal state is present, the abnormality determining device includes a notification device that notifies the abnormal state.

According to the above characteristic configuration, the internal voltage detection for detecting a voltage at a predetermined portion inside the power conversion circuit unit of the auxiliary power supply device when the abnormality determination device is in a self-supporting state where power supply from the power system to the AC line is not performed. Output power detection for detecting a high voltage state in which the internal voltage of the power conversion circuit unit is higher than the set upper limit voltage, or detecting power output from the power conversion circuit unit to the AC line When the unit detects a backflow state in which power flows from the AC line toward the power conversion circuit unit, it is determined that the state is abnormal. And it can alert | report to the user of a distributed type power supply system, etc. from an alerting device that the abnormal state (high voltage state or backflow state) occurred. As a result, the user or the like of the distributed power supply system that has received the notification can then start to cope with the abnormal state before the power conversion circuit unit of the auxiliary power supply device fails.
Therefore, it is possible to provide a distributed power supply system that can detect an abnormality early and cope with it.

  Another characteristic configuration of the distributed power supply system according to the present invention is that the notification device causes an abnormality in the power detection unit that detects power in which the abnormal state is directed from the first connection location side to the second connection location. It is in the point that it is considered that there is a cause and that is notified.

When an abnormality occurs in the power detection unit that detects the power from the first connection location to the second connection location of the power generation device, the power generation control unit of the power generation device uses the power consumption of the power consumption device and the generated power of the power generation unit. There is a possibility of misrecognizing that is balanced. Then, of the generated power of the power generation device, surplus power that has not been consumed by the power consumption device goes to the AC line upstream of the second connection location and flows into the auxiliary power supply device. . As a result, for example, the internal voltage of the power conversion circuit unit of the auxiliary power supply device rises, causing a problem that the power conversion circuit unit fails in the worst case.
However, according to this characteristic configuration, a user or the like of the distributed power supply system has found that an abnormality has occurred in the power detection unit of the power generation device that detects the power whose abnormal state is directed from the first connection location side to the second connection location. You can receive notification that there is a cause. As a result, the user or the like of the distributed power supply system that has received the notification can deal with the abnormality in the power detection unit at an early stage without taking time to diagnose the failure location and the cause of the failure.

  Still another characteristic configuration of the distributed power supply system according to the present invention is provided with a circuit breaker in the AC line between the auxiliary power supply device and the power generation device, and the circuit breaker is configured so that the abnormality determination device is in the abnormal state. Is determined to be open, and the auxiliary power supply device and the power generation device are electrically disconnected.

  According to the above characteristic configuration, the circuit breaker is opened to electrically disconnect the auxiliary power supply device and the power generation device, so that power is not supplied to the auxiliary power supply device from the power generation device. That is, even if an abnormality occurs in the power detection unit of the power generation device, the power supplied from the power generation device to the AC line does not flow into the auxiliary power supply device. As a result, it is possible to avoid the occurrence of a high voltage state in which the internal voltage of the power conversion circuit unit is higher than the set upper limit voltage and the occurrence of a reverse flow state in which power flows from the AC line toward the power conversion circuit unit. .

  Still another characteristic configuration of the distributed power supply system according to the present invention is that the power supply control unit of the auxiliary power supply device is configured such that the power supply control unit of the auxiliary power supply device is independent of power supply from the power system to the AC line. When the abnormality determination device determines that the abnormality state is in the abnormal state while controlling the operation of the power conversion circuit unit to output power from the power storage unit to the AC line, the AC line to the power storage unit It is in the point which controls operation | movement of the said power converter circuit part so that the electric power of this may be charged.

  According to the above characteristic configuration, even if the power supplied from the power generation device to the AC line flows into the auxiliary power supply device, the power is charged in the power storage unit. As a result, it is possible to avoid that the voltage inside the power conversion circuit unit becomes higher than the set upper limit voltage, and it is also possible to avoid the problem that the power conversion circuit unit breaks down with such a voltage increase.

  Still another characteristic configuration of the distributed power supply system according to the present invention is that the auxiliary power supply device includes power consuming means capable of acquiring and consuming electric power from the AC line, and the power supply control unit of the auxiliary power supply device. Is configured to control the operation of the power conversion circuit unit so that power is output from the power storage unit of the auxiliary power supply device to the AC line when power is not supplied from the power system to the AC line. If the abnormality determination device determines that the abnormality is in the abnormal state, the operation of the power consumption means is controlled so as to consume the power acquired from the AC line.

  According to the above characteristic configuration, even if the power supplied from the power generation device to the AC line flows into the auxiliary power supply device, the power is consumed by the power consuming means. As a result, it is possible to avoid that the voltage inside the power conversion circuit unit becomes higher than the set upper limit voltage, and it is also possible to avoid the problem that the power conversion circuit unit breaks down with such a voltage increase.

It is a figure explaining the structure of the distributed power supply system of 1st Embodiment. It is a figure explaining the structure of the distributed power supply system of 2nd Embodiment. It is a figure explaining the structure of the distributed power supply system of 3rd Embodiment.

<First Embodiment>
The distributed power supply system according to the first embodiment will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the configuration of the distributed power supply system according to the first embodiment. As shown in FIG. 1, the distributed power supply system includes an AC power line 2 connected to the power system 1, an auxiliary power supply device 10 having a power storage unit 11 connected to the first connection point P <b> 1 of the AC power line 2, and an AC power supply. The electric power generating apparatus 20 which has the electric power generation part 21 connected to the 2nd connection location P2 of the line 2 and the electric power consumption apparatus 30 connected with respect to the alternating current line 2 by the 3rd connection location P3 are provided. A first connection point P1, a second connection point P2, and a third connection point P3 are provided in the arrangement order toward the downstream side when viewed from the connection point of the power system 1 to the AC line 2. In FIG. 1, since the power consuming device 30 is connected to the second connecting location P2 through the third connecting location P3, the power consuming device 30 can be regarded as being connected to the second connecting location P2. it can. That is, it can be considered that both the power generation device 20 and the power consumption device 30 are connected to the AC line 2 at the second connection point P2. In the following description, power directed from the power system 1 side to the power consuming device 30 is assumed to be positive power.

[Power generation device 20]
The power generation device 20 refers to the power generation unit 21, the power detection unit 23 that detects power from the first connection point P1 side to the second connection point P2, and the detection result of the power detection unit 23. The power generation control unit 22 controls the power supplied from the power generation unit 21 to the AC line 2 so that the power from the P1 side toward the second connection point P2 does not become negative power. The power generation unit 21 can be configured using a device capable of controlling its own generated power, such as a fuel cell or a generator that operates by the driving force of the engine. The power generation device 20 may also include a power conversion circuit unit for converting the power generated by the power generation unit 21 into a desired voltage, frequency, phase, and the like and supplying the converted power to the AC line 2. The power detection unit 23 is configured using a current transformer used to detect the current value of power in the AC line 2, a potential transformer used to detect the voltage value of power in the AC line 2, and the like.

  The power generation control unit 22 refers to the detection result of the power detection unit 23, from the power generation unit 21 to the AC line 2 so that the power from the first connection point P1 side to the second connection point P2 does not become negative power. To control the power supply. That is, the power generation device 20 generates power so that the power traveling from the first connection location P1 side to the second connection location P2 is not negative power means that the generated power of the power generation device 20 is on the power system 1 side. Means not supplied, i.e. no reverse flow.

[Auxiliary power supply 10]
The auxiliary power supply device 10 is connected to the AC power line 11 from the power storage unit 11 and the AC line 2 so that the voltage of the AC line 2 falls within the reference voltage range when the power supply from the power system 1 to the AC line 2 is not performed independently. The power conversion circuit unit 13 that adjusts the output power and the power supply control unit 12 that controls the operation of the power conversion circuit unit 13 are provided. The electrical storage part 11 can be comprised with various apparatuses which have an electrical storage function, such as a storage battery (chemical battery) and an electrical double layer capacitor.

When power is supplied from the power system 1 to the AC line 2 (hereinafter sometimes referred to as “interconnection”), the voltage of the AC line 2 matches the voltage of the power system 1. That is, the electric power system 1 functions as a voltage source that operates so as to maintain the voltage of the AC line 2 within the reference voltage range. The power generation device 20 and the auxiliary power supply device 10 connected to the AC line 2 function as a current source that supplies current to the AC line 2. At the time of interconnection, the circuit breaker 3 and the circuit breaker 4 are closed to electrically connect the power system 1 and the AC line 2, and the power supplied from the power system 1 to the AC line 2 is supplied to the power consuming device 30. Can also be supplied.
On the other hand, when the power supply from the power system 1 to the AC line 2 is not performed (hereinafter sometimes referred to as “self-sustained”), the auxiliary power supply device 10 uses the voltage of the AC line 2 as a reference voltage. The output power from the power storage unit 11 to the AC line 2 is adjusted so as to function as a voltage source that operates so as to be maintained within the range. At the time of independence, the circuit breaker 3 is opened due to a power failure of the power system 1 or other reasons, the power system 1 and the AC line 2 are electrically disconnected, and the power supply from the power system 1 to the AC line 2 is performed. It is gone. That is, the self-sustained time corresponds to, for example, when the power system 1 is interrupted or when the AC line 2 is disconnected from the power system 1 by the circuit breaker 3.

  The power conversion circuit unit 13 can convert the electric power of the power storage unit 11 into a desired voltage, frequency, phase, and the like and supply it to the AC line 2. For example, as illustrated in FIG. 1, the power conversion circuit unit 13 may include an inverter circuit 13a and a DC / DC converter circuit 13b. The inverter circuit 13a, the DC / DC converter circuit 13b, and the like can be realized using semiconductor switching elements. And the power supply control part 12 can make the power conversion circuit part 13 perform desired power conversion operation | movement by switching ON / OFF of these semiconductor switching elements. Further, the inverter circuit 13a and the DC / DC converter circuit 13b are configured to be either bidirectional or unidirectional. For example, in this embodiment, the power conversion circuit unit 13 is configured by combining a bidirectional inverter circuit 13a and a unidirectional (output direction to the AC line 2) DC / DC converter circuit 13b. The reason why such a configuration is adopted is that the main purpose is to output power in one direction from the power storage unit 11 to the AC line 2. That is, since the DC / DC converter circuit 13b does not need to have bidirectionality, the cost required for manufacturing the circuit can be reduced.

  The auxiliary power supply device 10 includes an output power detection unit 14 for detecting power output from the power conversion circuit unit 13 to the AC line 2 between the power conversion circuit unit 13 and the AC line 2. . The output power detection unit 14 is a current transformer used to detect the current value of power, a potential transformer used to detect the voltage value of power, and the like, similar to the power detection unit 23 of the power generation device 20 described above. It is configured using. When the AC line 2 is a single-phase three-wire AC line 2 composed of two voltage lines and one neutral line, the power conversion circuit unit 13 includes two voltage lines Each is connected to one neutral wire. And the output electric power detection part 14 detects the electric power output to the alternating current line 2 by detecting the voltage value and electric current value of electric power in each of two voltage lines. By transmitting the detection result of the output power detection unit 14 to the power supply control unit 12, the power supply control unit 12 can know the power actually output from the power conversion circuit unit 13 to the AC line 2.

In the present embodiment, the AC line 2 on the upstream side (the power system 1 side) of the first connection point P1 to which the auxiliary power supply device 10 is connected is provided with the circuit breaker 3, and downstream of the first connection point P1. The AC line 2 on the side is provided with a circuit breaker 4. In addition, the auxiliary power supply device 10 includes a voltage detection unit 15 that detects the voltage of power on the AC line 2. The voltage detection unit 15 is provided on the upstream side (the power system 1 side) of the circuit breaker 3. For example, the power supply control unit 12 refers to the detection result of the voltage detection unit 15 and from the power system 1 to the AC line 2 if the power voltage on the AC line 2 upstream of the circuit breaker 3 is less than a predetermined voltage. If the voltage detected by the voltage detector 15 is not less than a predetermined voltage, it is determined that the power supply from the power system 1 to the AC line 2 is normally performed. To do.
The circuit breaker 4 is normally closed, and the auxiliary power supply device 10, the power generation device 20, and the power consumption device 30 are electrically connected to each other.

  As described above, the output power from the power conversion circuit unit 13 to the AC line 2 is adjusted. Depending on the power consumption of the power consuming device 30 and the generated power of the power generation device 20, the power conversion circuit unit may be connected to the AC line 2. There is also a possibility that a reverse flow state in which power flows toward 13 occurs. For example, in the power generation device 20, as the power detection unit 23 used for adjusting the generated power of the power generation device 20, the AC line 2 on the upstream side (i.e., the power system 1 side) from the location where the power generation device 20 is connected. A device (such as the above-described current transformer) for detecting electric power is used. Then, there is no problem when the power detection unit 23 can detect the power (that is, the current value and the voltage value) normally. For example, when an abnormality such as disconnection occurs in the current transformer, the power generation control unit 22 The power from the first connection point P1 side to the second connection point P2 is recognized as zero. That is, the power generation control unit 22 recognizes that the power consumption of the power consumption device 30 and the power generation unit 21 are balanced. As a result, the power generation control unit 22 controls the power generation unit 21 so as to maintain the current generated power.

However, even if the power consumption of the power consuming device 30 is reduced when the power generation control unit 22 recognizes in this way, the power generation control unit 22 is directed to the power from the first connection point P1 to the second connection point P2. Is mistakenly recognized as being zero, and the generated power of the power generation unit 21 is balanced. That is, the power generation control unit 22 maintains the generated power of the power generation unit 21 at the current value, even though the power consumption of the power consumption device 30 has decreased. As a result, the surplus power that has not been consumed by the power consuming device 30 out of the power generated by the power generating device 20 goes to the AC line 2 upstream of the second connection location P2. Then, when the power supply from the power system 1 to the AC line 2 is not performed independently, the surplus power described above flows into the auxiliary power supply 10 and the above-described backflow state occurs.
When this reverse flow state occurs, there arises a problem that, for example, a voltage at a predetermined portion inside the power conversion circuit unit 13 (for example, an intermediate portion between the inverter circuit 13a and the DC / DC converter circuit 13b) increases. . Then, the power conversion circuit unit 13 breaks down.

  Therefore, the distributed power supply system of the present embodiment includes the abnormality determination device 40 and the notification device 50, and the abnormality determination device 40 is in an independent state where power is not supplied from the power system 1 to the AC line 2. When it is determined that an abnormal state is detected in which a reverse flow state in which power flows from the power converter circuit unit 13 toward the power conversion circuit unit 13, the notification device 50 in which the determination result is transmitted from the abnormality determination device 40 notifies the abnormal state. Has been.

  The abnormality determination device 40 can know from the power supply control unit 12 that power supply from the power system 1 to the AC line 2 is not performed, and power is transmitted from the AC line 2 toward the power conversion circuit unit 13. It can be known from the output power detection unit 14 that a flowing backflow state has occurred.

  The notification device 50 can be realized by using a device (for example, a speaker or the like) that can transmit information by voice or a device that can visually transmit information by characters or light. In the present embodiment, the notification device 50 is caused by the occurrence of an abnormality in the power detection unit 23 of the power generation apparatus 20 that detects the electric power in which the abnormal state is directed from the first connection point P1 to the second connection point P2. It is assumed that the notification is made. As a result, the user or the like of the distributed power supply system that has received the notification can cope with the abnormality in the power detection unit 23 at an early stage without taking time to diagnose the failure location or the cause of the failure.

  Further, when the circuit breaker 4 provided on the AC line 2 between the auxiliary power supply device 10 and the power generation device 20 determines that the abnormality determination device 40 is in an abnormal state, the circuit breaker 4 opens and generates power. The apparatus 20 may be configured to be electrically disconnected. For example, when the abnormality determination device 40 determines that the abnormality is present, the determination result is transmitted to the power control unit 12 of the auxiliary power supply device 10. Then, the circuit breaker 4 is opened by an instruction from the power supply control unit 12 to electrically disconnect the auxiliary power supply device 10 and the power generation device 20, so that no power is supplied to the auxiliary power supply device 10 from the power generation device 20. It becomes like this. That is, even if an abnormality occurs in the power detection unit 23 of the power generation device 20, the power supplied from the power generation device 20 to the AC line 2 does not flow into the auxiliary power supply device 10. As a result, a high voltage state occurs in which the voltage inside the power conversion circuit unit 13 of the auxiliary power supply device 10 is higher than the set upper limit voltage, or a reverse flow in which power flows from the AC line 2 toward the power conversion circuit unit 13. A situation can be avoided.

Second Embodiment
In the distributed power supply system of the second embodiment, when the abnormality determination device 40 is self-supporting when power supply from the power system 1 to the AC line 2 is not performed, the voltage inside the power conversion circuit unit 13 is higher than the set upper limit voltage. It is different from the distributed power supply system of the first embodiment in that it is determined to be an abnormal state when a high voltage state is detected. Hereinafter, the distributed power supply system of the second embodiment will be described, but the description of the same configuration as that of the distributed power supply system of the first embodiment will be omitted.

  FIG. 2 is a diagram illustrating the configuration of the distributed power supply system according to the second embodiment. In the present embodiment, the auxiliary power supply device 10 includes an internal voltage detection unit 16 that detects a voltage at a predetermined portion inside the power conversion circuit unit 13. As described in the first embodiment, for example, when an abnormality such as disconnection occurs in the current transformer, a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13 occurs. As a result, the power conversion circuit There arises a problem that the voltage inside the portion 13 increases. For example, the voltage at the intermediate portion between the inverter circuit 13a and the DC / DC converter circuit 13b increases. Then, the power conversion circuit unit 13 (for example, the DC / DC converter circuit 13b) may be broken.

  However, in the distributed power supply system of the second embodiment, the abnormality determination device 40 refers to the detection result of the internal voltage detection unit 16 and the internal voltage of the power conversion circuit unit 13 is higher than the set upper limit voltage. When the voltage state is detected, it is determined that the state is abnormal. Then, the notification device 50 is configured to notify the abnormal state when the abnormality determination device 40 determines that the abnormal state is present. As a result, the user or the like of the distributed power supply system that has received the notification can start to cope with the abnormal state before the power conversion circuit unit 13 of the auxiliary power supply device 10 fails. As in the first embodiment, the notification device 50 is a device that can transmit information by voice (for example, a speaker), a device that can visually transmit information by characters or light, and the like.

<Third Embodiment>
The distributed power supply system according to the third embodiment is different from the above-described embodiment in that the auxiliary power supply device 10 has power consuming means that can acquire and consume power from the AC line 2. Hereinafter, the distributed power supply system according to the third embodiment will be described, but the description of the same configuration as that of the above embodiment will be omitted.

  FIG. 3 is a diagram illustrating the configuration of the distributed power supply system according to the third embodiment. The distributed power supply system of the third embodiment described with reference to FIG. 3 is shown as a modified example of the first embodiment shown in FIG. 1, but the second embodiment shown in FIG. A modification of the configuration in which the apparatus 10 includes the internal voltage detection unit 16 may be used.

  As shown in FIG. 3, the auxiliary power supply device 10 has a power consumption heater as a power consumption means that can acquire and consume power from the AC line 2. In the present embodiment, the power consuming heater 17 is electrically connected to the AC line 2 via the power conversion circuit unit 13. And the power supply control part 12 of the auxiliary | assistant power supply device 10 is made to output electric power from the electrical storage part 11 of the auxiliary | assistant power supply apparatus 10 to the alternating current line 2 at the time of the independence when the power supply from the electric power grid | system 1 to the alternating current line 2 is not performed. When it is determined that the abnormality determination device 40 is in an abnormal state while controlling the operation of the power conversion circuit unit 13, information indicating that is received from the abnormality determination device 40 and the power acquired from the AC line 2 is consumed. Thus, the operation of the power consuming means is controlled. For example, a switch (not shown) for turning on / off the energization of the power consumption heater 17 is provided, and the power consumption control unit 12 switches on / off of the switch so that the power consumption by the power consumption heater 17 is achieved. The power can be adjusted.

  Specifically, as described in the first and second embodiments, the abnormality determination device 40 is configured so that the power conversion circuit unit 13 has an internal power supply when the power supply from the power system 1 to the AC line 2 is not performed independently. When a high voltage state in which the voltage of the power is higher than the set upper limit voltage is detected, or when a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13 is detected, the abnormal state is determined. ing. For example, as described in the first embodiment, when the output power detection unit 14 detects that a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13 is generated, the abnormality determination device 40 is detected. Is determined to be in an abnormal state. Alternatively, as described in the second embodiment, when the internal voltage detection unit 16 detects a high voltage state in which the voltage inside the power conversion circuit unit 13 is higher than the set upper limit voltage, the abnormality determination device 40 is in an abnormal state. It is determined that When the power supply control unit 12 receives a determination result indicating that the abnormality is present from the abnormality determination device 40, the power supply control unit 12 energizes the heater 17 for power consumption (that is, by switching the switch to the on state). ), The electric power received from the AC line 2 by the electric power consumption heater 17 can be consumed. As a result, it is possible to suppress the occurrence of a problem that the voltage inside the power conversion circuit unit 13 increases.

<Fourth embodiment>
In the distributed power supply system of the fourth embodiment, after the abnormality determination device 40 determines that the abnormality is present, the power control unit 12 of the auxiliary power supply device 10 charges the power from the AC line 2 to the power storage unit 11. It differs from the said 1st and 2nd embodiment by the point comprised by. The distributed power supply system according to the fourth embodiment will be described below, but the description of the same configuration as that of the first and second embodiments will be omitted.

  The configuration of the distributed power supply system of the fourth embodiment is similar to the configuration of the distributed power supply system of the first embodiment shown in FIG. However, in the present embodiment, both the inverter circuit 13a and the DC / DC converter circuit 13b have a bidirectional circuit configuration. As a result, the power supply control unit 12 of the auxiliary power supply device 10 can control the operation of the inverter circuit 13a and the DC / DC converter circuit 13b to charge power from the AC line 2 to the power storage unit 11. That is, the power supply control unit 12 of the auxiliary power supply device 10 outputs power from the power storage unit 11 of the auxiliary power supply device 10 to the AC line 2 when the power supply from the power system 1 to the AC line 2 is not performed independently. When the abnormality determination device 40 determines that the power conversion circuit unit 13 is in an abnormal state while controlling the operation of the power conversion circuit unit 13, the operation of the power conversion circuit unit 13 is performed so as to charge power from the AC line 2 to the power storage unit 11. To control.

  Specifically, as described in the first and second embodiments, the abnormality determination device 40 is configured so that the power conversion circuit unit 13 has an internal power supply when the power supply from the power system 1 to the AC line 2 is not performed independently. When a high voltage state in which the voltage of the power is higher than the set upper limit voltage is detected, or when a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13 is detected, the abnormal state is determined. ing. For example, as described in the first embodiment, when the output power detection unit 14 detects that a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13 is generated, the abnormality determination device 40 is detected. Is determined to be in an abnormal state. Alternatively, as described in the second embodiment, when the internal voltage detection unit 16 detects a high voltage state in which the voltage inside the power conversion circuit unit 13 is higher than the set upper limit voltage, the abnormality determination device 40 is in an abnormal state. It is determined that Then, when the power supply control unit 12 receives the determination result that the power supply control unit 12 is in an abnormal state from the abnormality determination device 40, the inverter circuit 13 a and the DC / DC converter circuit 13 b of the power conversion circuit unit 13 charge the power storage unit 11. To make it work. That is, the power flowing from the AC line 2 toward the power conversion circuit unit 13 is charged in the power storage unit 11 via the power conversion circuit unit 13. As a result, it is possible to suppress the occurrence of a problem that the internal voltage of the power conversion circuit unit 13 increases with the occurrence of a backflow state in which power flows from the AC line 2 toward the power conversion circuit unit 13.

<Another embodiment>
<1>
The configuration of the distributed power supply system exemplified in the above embodiment can be changed as appropriate. For example, although the configuration in which the auxiliary power supply device 10 includes the circuit breakers 3 and 4 has been described, the circuit breakers 3 and 4 may be provided outside the auxiliary power supply device 10. Further, the function of the abnormality determination device 40 may be provided inside the auxiliary power supply device 10. In addition, although the circuit configuration example in which the power conversion circuit unit 13 includes the inverter circuit 13a and the DC / DC converter circuit 13b has been described, the power conversion circuit unit 13 may be realized by other circuit configurations.

<2>
In the said embodiment, the electric power generation control part 22 which the electric power generating apparatus 20 has is supply to the alternating current line 2 from the electric power generation part 21 so that the electric power which goes to the 2nd connection location P2 from the 1st connection location P1 side may not become negative electric power. Although the power control has been described, the power generation control unit 22 from the power generation unit 21 to the AC line 2 if the condition that the power from the first connection point P1 to the second connection point P2 is not negative power is satisfied. The power supplied to can be changed as appropriate.
For example, if it is desired to improve the operating rate of the power generation unit 21, the power generation control unit 22 generates power while satisfying the condition that the power from the first connection point P1 to the second connection point P2 is not negative power. It is only necessary to maximize the power supplied from the unit 21 to the AC line 2 (that is, the power generation unit 21 so that the power from the first connection point P1 side to the second connection point P2 is minimized and does not become negative power). To adjust the power supplied to the AC line 2).
In addition, the power generation control unit 22 satisfies the condition that power supplied from the power generation unit 21 to the AC line 2 is not negative power from the first connection point P1 to the second connection point P2. Instead of the maximum power allowed as described above, the power may be adjusted to a power less than the maximum power. For example, when the power generation unit 21 functions as a combined heat and power supply device, that is, a heat consuming device (not shown) collects heat discharged from a fuel cell used as the power generation unit 21 or a generator operating by the driving force of the engine. 2), the power generation output of the power generation unit 21 (that is, the power supplied from the power generation unit 21 to the AC line 2) may be adjusted according to the heat demand in the heat consuming apparatus. Explaining with specific numerical values, the power generation control unit 22 generates 700 W of power generation output in order to satisfy the condition that the power from the first connection point P1 side to the second connection point P2 is not negative power. Even if the power is allowed to 21 (that is, even if the maximum power is 700 W), for the purpose of suppressing the heat output, adjustment is performed so that the power generation unit 21 is operated with a power output of 250 W. Also good.

  The present invention can be used for a distributed power supply system that can detect an abnormality early and cope with it.

DESCRIPTION OF SYMBOLS 1 Power system 2 AC line 3 Circuit breaker 4 Circuit breaker 10 Auxiliary power supply device 11 Power storage unit 12 Power supply control unit 13 Power conversion circuit unit 13a Inverter circuit 13b DC / DC converter circuit 14 Output power detection unit 15 Voltage detection unit 16 Internal voltage detection Part 17 Electric power consumption heater (electric power consumption means)
20 power generation device 21 power generation unit 22 power generation control unit 23 power detection unit 30 power consumption device 40 abnormality determination device 50 notification device

Claims (5)

An AC power line connected to a power system; an auxiliary power supply device having a power storage unit connected to a first connection location of the AC line; and a power generation device having a power generation unit connected to a second connection location of the AC line; A power consuming device connected to the AC line at the second connection point, and the first connection point and the second point toward the downstream side as viewed from the connection point of the power system with respect to the AC line. A distributed power supply system in which connection locations are provided in the order of arrangement,
In the case where the power going from the power system side to the power consuming device is positive power,
The power generator includes the power generation unit, a power detection unit that detects power from the first connection point side to the second connection point, and a detection result of the power detection unit. A power generation control unit that controls the power supplied from the power generation unit to the AC line so that the power from the side toward the second connection point does not become negative power,
The auxiliary power unit is configured to connect the power storage unit to the AC line so that the voltage of the AC line is within a reference voltage range when the power storage unit and the power system are not supplied with power from the power system. A power conversion circuit unit for adjusting output power, and a power supply control unit for controlling the operation of the power conversion circuit unit,
When the power supply from the power system to the AC line is not performed independently, an internal voltage detection unit that detects a voltage at a predetermined portion inside the power conversion circuit unit sets the voltage inside the power conversion circuit unit. An output power detection unit for detecting a high voltage state higher than an upper limit voltage or detecting power output from the power conversion circuit unit to the AC line is provided from the AC line to the power conversion circuit unit. An abnormality determination device that determines that an abnormal state is detected when a reverse flow state in which power flows is detected;
A distributed power supply system comprising: a notification device that notifies the abnormal state when the abnormality determination device determines that the abnormal state is present.   The informing device regards that the abnormal state is caused by an abnormality in the power detection unit that detects electric power from the first connection location to the second connection location, and notifies the fact. Item 2. The distributed power supply system according to Item 1. A breaker is provided on the AC line between the auxiliary power supply and the power generator,
3. The distributed power supply system according to claim 1, wherein when the abnormality determination device determines that the abnormality determination device is in the abnormal state, the circuit breaker is opened to electrically disconnect the auxiliary power supply device and the power generation device. .   The power supply control unit of the auxiliary power supply device is configured to output the power from the power storage unit of the auxiliary power supply device to the AC line in a self-supporting state where power supply from the power system to the AC line is not performed. When the abnormality determination device determines that the abnormality is in the abnormal state while controlling the operation of the conversion circuit unit, the operation of the power conversion circuit unit is performed so as to charge power from the AC line to the power storage unit. The distributed power supply system according to claim 1 or 2 to be controlled. The auxiliary power supply device has power consuming means capable of acquiring and consuming power from the AC line,
The power supply control unit of the auxiliary power supply device is configured to output the power from the power storage unit of the auxiliary power supply device to the AC line in a self-supporting state where power supply from the power system to the AC line is not performed. 2. The operation of the power consuming means is controlled so that the power acquired from the AC line is consumed when the abnormality determination device determines that the abnormality is in the abnormal state while controlling the operation of the conversion circuit unit. Or the distributed power supply system of 2.

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