JP2006267066A - Diagnostic device for cogeneration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diagnostic device for a cogeneration system capable of confirming a connection condition between a current detector and a system control means, without operating an electric power generator. <P>SOLUTION: A connection setting condition between the first current detecting means 2a and the second current detecting means 2b, and the system control means 10 is maintained in the condition as it is, when a detection current of a U-phase line input part of the system control means 10 is fluctuated synchronized with voltage fluctuation of a U-phase line 3a, and when a detection current of a V-phase line input part of the system control means 10 is fluctuated synchronizing with voltage fluctuation of a V-phase line 3b, in the condition where an operation of the power generator 6 is stopped, and the connection setting condition between the first current detecting means 2a and the second current detecting means 2b, and the system control means 10 is set in a reverse condition, when the detection current of the V-phase line input part of the system control means 10 is fluctuated synchronized with the voltage fluctuation of the U-phase line 3a, and when the detection current of the U-phase line input part of the system control means 10 is fluctuated synchronizing with the voltage fluctuation of the V-phase line 3b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power generation device for cogeneration, a grid interconnection inverter for linking power from the power generation device to a commercial distribution line from a commercial power supply via the grid interconnection distribution line, The current detector that detects the current flowing through the distribution line, and the current detected by the current detector is sent from the generator to the commercial distribution line via the grid connection inverter and the distribution line. System control means for controlling the power to be supplied, the commercial distribution line has a single-phase three-wire circuit configuration, the current detector is composed of a first current detection means and a second current detection means, The present invention relates to a diagnostic apparatus for a cogeneration system in which first current detection means is disposed on a U-phase line of a distribution line, and second current detection means is disposed on a V-phase line of a commercial distribution line.

In a cogeneration system provided with a power generation device for cogeneration such as a gas engine power generation device and a fuel cell power generation device capable of generating both electricity and heat, the generated power is distributed to the grid interconnection line and the grid connection. The generated heat is supplied to the commercial distribution line through the system inverter, and the generated heat is collected in a hot water tank or the like and stored. The generated power is supplied to and consumed by the power load device in the cogeneration system, and the amount of heat stored in the hot water storage tank is consumed by a hot water heater such as a water heater or a floor heater when necessary. The
When no reverse power flow from such a cogeneration system to a commercial distribution line is allowed, all generated power must be consumed in the cogeneration system. For this reason, there is a cogeneration system provided with a reverse power flow prevention device for the purpose of eliminating the surplus power of the difference between the generated power and the power consumption of the power load device so that no reverse power flow occurs (for example, Patent Literature 1).

  Further, in order to operate the reverse power flow prevention device, it is necessary to accurately detect whether or not a reverse power flow from the cogeneration system to the commercial distribution line has occurred. Therefore, the commercial distribution line connected to the grid interconnection inverter is provided with a current detector and is supplied with power from the commercial distribution line, or the surplus power is generated to generate commercial power from the grid interconnection inverter. It detects whether a reverse power flow is occurring on the distribution line side.

  However, the detection result of the current detector must be accurate, and the detection result must be accurately transmitted to the system control means for controlling the operation of the reverse power flow prevention device. Therefore, the current detector accurately connects the polarity (plus and minus) to the commercial distribution line, and the detection signal from the current detector disposed on the U-phase line of the commercial distribution line is the system control means. The detection signal from the current detector disposed on the U-phase side of the system and the V-phase line must be input to the V-phase side input of the system control means. In view of such a problem, it has been desired to realize a diagnostic apparatus that can easily diagnose whether a detection signal from a current detector disposed on a commercial distribution line is correctly input to the system control means. Therefore, while the power generator is in operation, the output power from the grid interconnection inverter to the commercial distribution line is intentionally varied, and the current detector is commercialized based on the detection result of the current detector. There is a diagnostic device that diagnoses the connection state to the distribution line and the connection state between the current detector and the system control means (see, for example, Patent Document 2).

JP 2000-320401 A JP 2002-286785 A

  As described above, in the diagnostic device described in Patent Document 2, the grid interconnection inverter is controlled in a state where the power generation device is operated, and the output power from the grid interconnection inverter to the commercial distribution line is intentionally A method of changing is used. However, this method cannot be used in a situation where, after installing the power generation device, permission for grid-connected operation to a commercial distribution line has not yet been granted. Accordingly, there is a need for a diagnostic device that can diagnose the connection state between the current detector and the system control means in a state where the operation of the power generation device is stopped.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a diagnostic device for a cogeneration system capable of confirming a connection state between a current detector and system control means without operating a power generation device. There is in point to do.

In order to achieve the above object, a first characteristic configuration of a cogeneration system diagnostic apparatus according to the present invention is a power generation apparatus for cogeneration, and the power from the power generation apparatus is commercially used via a grid interconnection. A grid interconnection inverter for linking to a commercial distribution line from a power source, a current detector for detecting a current flowing through the commercial distribution line, and the power generation device using a detection current of the current detector System control means for controlling the power supplied to the commercial distribution line via the grid connection inverter and the grid connection distribution line,
The commercial distribution line has a single-phase three-wire circuit configuration, the current detector includes first current detection means and second current detection means, and the first current is connected to the U-phase line of the commercial distribution line. A diagnostic device for a cogeneration system in which detection means is provided and the second current detection means is provided on a V-phase line of the commercial distribution line,
A freezing prevention heater capable of consuming power supplied from the commercial distribution line or generated power of the power generation device, and adjusting the power consumption of the freezing prevention heater to adjust the water temperature in the water circulation system in the cogeneration system Alternatively, anti-freezing means for heating the water circulation system is provided when the outside air temperature is equal to or lower than the set anti-freezing temperature,
In the state where the operation of the power generation device is stopped, the system control means,
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change. The connection setting of the 1 current detection means and the second current detection means and the system control means is set and maintained in that state;
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, and the When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change. It is configured to execute connection state diagnosis control for setting the connection setting of the first current detection means and the second current detection means and the system control means in reverse.
When the system control means executes the connection state diagnosis control, the power supplied from the commercial distribution line by changing the power consumption of the anti-freezing heater electrically connected to the commercial distribution line It is in the point comprised so that it may be fluctuated.

According to the first characteristic configuration, the system control unit varies the power supplied from the U-phase line and the V-phase line of the commercial distribution line in a state where the operation of the power generation device is stopped, The connection state between the first current detecting means and the second current detecting means and the system control means can be diagnosed by the tuning relationship of the detected currents of the first current detecting means and the second current detecting means.
That is, when the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and the commercial When the power supplied from the V-phase line of the distribution line is changed, and the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, the first current detecting means In addition, it can be diagnosed that the connection state between the second current detection means and the system control means is correct. The system control means maintains this connection state setting.
On the other hand, when the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input part of the system control means changes in synchronization with the change, and When the power supplied from the V-phase line of the distribution line is changed, when the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, the first current detecting means It can be diagnosed that the detection signal is input to the V-phase line side input unit of the system control unit and the detection signal of the second current detection unit is input to the U-phase line input unit of the system control unit. Therefore, the system control means can correctly set the connection state between the first current detection means and the second current detection means and the system control means by reversing the connection settings. Even if this occurs, the system control means automatically responds and there is no need to reconnect the first current detection means, the second current detection means, and the system control means.

Further, the system control means varies the power supplied from the commercial distribution line by varying the power consumption of the anti-freezing heater connected to the commercial distribution line even if the power generator is stopped. be able to. And the connection state of a current detector and a system control means can be diagnosed as mentioned above by fluctuating the electric power supplied from a commercial distribution line.
Furthermore, since the electric power supplied from the commercial distribution line is changed using the anti-freezing heater, a dedicated power consumption means is not provided only for changing the electric power supplied from the commercial distribution line. Also gets better. In addition, when the heater for freezing prevention is energized, relatively large and stable power consumption can be generated. Therefore, the electric power supplied from the commercial distribution line also fluctuates clearly with a relatively large and stable power amount. It will be. As a result, it is possible to satisfactorily diagnose the connection state between the current detector and the system control means.

In order to achieve the above object, the second characteristic configuration of the cogeneration system diagnostic device according to the present invention is a power generation device for cogeneration, and commercial power is supplied from the power generation device via a power distribution line. A grid interconnection inverter for linking to a commercial distribution line from a power source, a current detector for detecting a current flowing through the commercial distribution line, and the power generation device using a detection current of the current detector System control means for controlling the power supplied to the commercial distribution line via the grid connection inverter and the grid connection distribution line,
The commercial distribution line has a single-phase three-wire circuit configuration, the current detector includes first current detection means and second current detection means, and the first current is connected to the U-phase line of the commercial distribution line. A diagnostic device for a cogeneration system in which detection means is provided and the second current detection means is provided on a V-phase line of the commercial distribution line,
The commercial distribution line is electrically connected to the electric auxiliary machine of the cogeneration system,
In the state where the operation of the power generation device is stopped, the system control means,
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change. The connection setting of the 1 current detection means and the second current detection means and the system control means is set and maintained in that state;
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, and the When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change. It is configured to execute connection state diagnosis control for setting the connection setting of the first current detection means and the second current detection means and the system control means in reverse.
The system control means is configured to change the power supplied from the commercial distribution line by changing the power consumption of the electric auxiliary machine when executing the connection state diagnosis control. is there.

According to the second characteristic configuration, the system control unit varies the power supplied from the U-phase line and the V-phase line of the commercial distribution line in a state where the operation of the power generation device is stopped, The connection state between the first current detecting means and the second current detecting means and the system control means can be diagnosed by the tuning relationship of the detected currents of the first current detecting means and the second current detecting means.
That is, when the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and the commercial When the power supplied from the V-phase line of the distribution line is changed, and the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, the first current detecting means In addition, it can be diagnosed that the connection state between the second current detection means and the system control means is correct. The system control means maintains this connection state setting.
On the other hand, when the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input part of the system control means changes in synchronization with the change, and When the power supplied from the V-phase line of the distribution line is changed, when the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, the first current detecting means It can be diagnosed that the detection signal is input to the V-phase line side input unit of the system control unit and the detection signal of the second current detection unit is input to the U-phase line input unit of the system control unit. Therefore, the system control means can correctly set the connection state between the first current detection means and the second current detection means and the system control means by reversing the connection settings. Even if this occurs, the system control means automatically responds and there is no need to reconnect the first current detection means, the second current detection means, and the system control means.

In addition, the system control means fluctuates the power supplied from the commercial distribution line by varying the power consumption of the electric auxiliary equipment connected to the commercial distribution line, even if the power generator is stopped. Can be made. And the connection state of a current detector and a system control means can be diagnosed as mentioned above by fluctuating the electric power supplied from a commercial distribution line.
Furthermore, since the electric power supplied from the commercial distribution line is changed using the electric auxiliary machine, a dedicated power consumption means is not provided only for changing the electric power supplied from the commercial distribution line. It will be better. In addition, when the electric auxiliary machine is energized, relatively large and stable power consumption can be generated, so that the power supplied from the commercial distribution line also fluctuates clearly with a relatively large and stable amount of power. Will do. As a result, it is possible to satisfactorily diagnose the connection state between the current detector and the system control means.

<First Embodiment>
Hereinafter, a diagnostic apparatus for a cogeneration system according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a diagnostic device for a cogeneration system, and FIG. 2 is a block circuit diagram schematically showing the circuit configuration of the cogeneration system system of FIG. The cogeneration system shown in FIG. 1 includes a power generation device 6 including a generator 7 driven by an engine 8 and a hot water storage device 42 that stores heat discharged from the cooling water of the engine 8 in the form of hot water. The device 42 includes a hot water storage tank 41 for storing hot water. The engine 8 is a gas engine, a diesel engine, or the like. A fuel cell or the like can be used instead of the power generation device 6. A grid interconnection inverter 5 is provided on the output side of the power generator 6. The grid interconnection inverter 5 sets the generated power of the power generator 6 to the same voltage and the same frequency as the commercial power supplied from the commercial power source 1. The commercial power source 1 is, for example, a single-phase three-wire system 100V, and is electrically connected to the power load 33, that is, various electric devices such as a television, a refrigerator, and a washing machine through the commercial distribution line 3. The grid interconnection inverter 5 is electrically connected to the commercial distribution line 3 via the grid connection distribution line 4 including the cogeneration switch 34 (switches 34a and 34b), and the switch 34 is in a closed state. Occasionally, the generated power generated by the power generator 6 is supplied to the commercial distribution line 3 via the grid connection inverter 5, the grid connection distribution line 4, and the cogeneration switch 34.

  The hot water storage device 42 includes a hot water circulation channel 39 for circulating hot water. One end of the hot water circulation channel 39 is connected to the bottom of the hot water storage tank 41, and the other end of the hot water circulation channel 39 is the hot water storage tank 41. The hot water in the hot water storage tank 41 is circulated through this hot water circulation passage 39. The hot water circulation channel 39 is provided with a circulation pump 40 for circulating hot water. Furthermore, an electric heater means 23 is provided in the hot water storage tank 41, and the electric heater means 23 is electrically connected to the output side of the grid interconnection inverter 5 via the electric heater switch means 20. The electric heater means 23 heats the hot water in the hot water storage tank 41.

In addition, a freezing prevention heater 28 capable of consuming power supplied from the commercial distribution line 3 or generated power of the power generation device 6 is provided, and the power consumption of the freezing prevention heater 28 is adjusted to adjust the water circulation system in the cogeneration system. An anti-freezing means 26 is provided for heating the water circulation system when the water temperature or the outside air temperature at the temperature becomes equal to or lower than a set anti-freezing temperature (eg, 0 ° C.).
As shown in FIG. 1, for example, in the freeze prevention means 26, the energization control unit 29 is provided in the hot water supply line 19 when the detection result of the hot water supply temperature sensor 32 provided in the hot water supply line 19 becomes equal to or lower than the set freezing prevention temperature. The hot water supply line 19 is heated by adjusting the power consumption of the anti-freezing heater 28. As a result, the hot water flowing through the hot water supply line 19 does not freeze. The control of the freeze prevention heater 28 and the freeze prevention heater switch means 27 provided in the freeze prevention means 26 will be described in detail later.

  Furthermore, as shown in FIG. 1, the cogeneration system includes a load unit such as a pump, a fan motor, or a solenoid valve that can consume power supplied from the commercial distribution line 3 or power generated by the power generation device 6. An electric auxiliary machine 30 is also provided. These electric auxiliary machines preferably have relatively low power consumption and are stable. Then, the system control means 10 turns on and off energization to the load portion of each auxiliary machine 30 when necessary when operating the cogeneration system. Regarding the control of the U-phase load section 30a and the V-phase load section 30b and the auxiliary switch means 31 (the U-phase auxiliary switch 31a and the V-phase auxiliary switch 31b) provided in the electric auxiliary machine 30. This will be described in detail later.

  A heat exchanger 38 is disposed in association with the hot water circulation passage 39. The heat exchanger 38 performs heat exchange between the cooling water flowing through the cooling water circulation passage 35 for circulating the cooling water from the radiator 37 of the engine 8 and the hot water flowing through the hot water circulation passage 39. The hot water flowing through the hot water circulation passage 39 is heated by the cooling water from 8. In the cooling water circulation passage 35, a circulation pump 36 for circulating the cooling water is disposed. In this embodiment, the electric heater means 23 is disposed in the hot water storage tank 41. However, instead of such a configuration, the electric heater means 23 is disposed in the cooling water circulation channel 35, and this cooling water circulation flow is provided. The cooling water flowing through the passage 35 may be heated.

  The hot water storage tank 41 is connected to a water supply line 17 that constitutes a water supply channel for supplying water. One end side of the water supply line 17 is connected to the bottom of the hot water storage tank 41, and the other end side is connected to a water supply source (not shown) such as a water pipe. The water supply line 17 is provided with a pressure reducing check valve 18 to prevent warm water from flowing back from the hot water storage tank 41 to the water supply line 17 side.

  The hot water storage tank 41 is further connected to a hot water supply line 19 that constitutes a hot water supply passage for supplying hot water. One end of the hot water supply line 19 is connected to the upper part of the hot water storage tank 41, and one or a plurality of curans (not shown) are connected to the other end of the hot water supply line 19. Is discharged through the hot water supply line 19.

  As shown in FIG. 2, the commercial distribution line 3 from the commercial power source 1 has a single-phase, three-wire circuit configuration, and includes a U-phase line 3a, a V-phase line 3b, and a neutral line 3c (O-phase line). There is a potential difference of, for example, 100V between the U-phase line 3a and the neutral line 3c, and there is a potential difference of, for example, 100V between the V-phase line 3b and the neutral line 3c. There is a potential difference of, for example, 200 V between the phase wire 3b. In the circuit configuration of such a single-phase three-wire commercial distribution line 3, the power load 33 has a configuration in which a portion 33a is connected between the U-phase wire 3a and the neutral wire 3c, and The remaining portion 33b is connected between the V-phase wire 3b and the neutral wire 3c.

  In this embodiment, the grid connection distribution line 4 from the power generation device 6 of the cogeneration system is a single-phase two-wire type, and the U-phase line 4a of the grid connection distribution line 4 is a commercial distribution line. 3 U-phase line 3 a, and V-phase line 4 b of grid connection distribution line 4 is connected to V-phase line 3 b of commercial distribution line 3.

  The electric heater means 23 is connected to the U-phase wire 4a of the grid interconnection 4 in connection with the fact that the grid interconnection 4 is a single-phase two-wire system. And the V-phase heater means 25 connected to the V-phase line 4b of the grid interconnection 4 and each of the U-phase heater means 24 and the V-phase heater means 25 includes three heaters, that is, a first heater. 24a, 25a, second heaters 24b, 25b and third heaters 24c, 25c. The first heaters 24a and 25a, the second heaters 24b and 25b, and the third heaters 24c and 25c have different power consumption. The first heaters 24a and 25a are, for example, 100 W, and the second heaters 24b and 25b are, for example, The 200 W heater and the third heaters 24c and 25c are, for example, 300 W heaters.

  In relation to the above-described configuration of the electric heater means 23, the electric heater switch means 20 operates the U-phase heater switch 21 for turning on / off the operation of the U-phase heater means 24 and the V-phase heater means 25. It comprises a V-phase heater switch 22 for turning on / off. The U-phase heater switch 21 includes a first switch 21a, a second switch 21b, and a third switch for turning on / off the first heater 24a, the second heater 24b, and the third heater 24c of the U-phase heater means 24. 21c. The V-phase heater switch 22 includes a first switch 22a, a second switch 22b, and a third switch 22c for turning on and off the first heater 25a, the second heater 25b, and the third heater 25c of the V-phase heater means 25. Have. Accordingly, when the first switch 21a (or the second switch 21b, the third switch 22c) of the U-phase heater switch 21 is closed, the first heater 24a (or the second heater 24b, third) of the U-phase heater means 24 is operated. The heater 24c) is energized to heat the hot water in the hot water storage tank 41. When the first switch 22a (or the second switch 22b, the third switch 22c) of the V-phase heater switch 22 is closed, the first heater 25a (or the second heater 25b, third) of the V-phase heater means 25 is operated. The heater 25c) is energized to heat the hot water in the hot water storage tank 41.

  The anti-freezing heater 28 of the anti-freezing means 26 includes the U-phase anti-freezing heater means 28a connected to the U-phase wire 4a of the grid interconnection 4 and the V-phase of the grid interconnection 4. The anti-freeze heater means 28b for V-phase connected to the line 4b. In connection with the above-described configuration of the anti-freezing heater 28, the anti-freezing heater switch means 27 includes a U-phase anti-freezing heater switch 27a for turning on / off the operation of the U-phase anti-freezing heater means 28a. And a V-phase antifreeze heater switch 27b for turning on / off the operation of the V-phase antifreeze heater means 28b. Therefore, when the U-phase antifreeze heater switch 27a is closed, the U-phase antifreeze heater means 28a is energized to heat the hot water in the hot water supply line 19. When the V-phase freeze prevention heater switch 27b is closed, the V-phase freeze prevention heater means 28b is energized and the hot water in the hot water supply line 19 is heated.

  Further, the electric auxiliary machine 30 is connected to the U-phase load section 30 a connected to the U-phase line 4 a of the grid connection distribution line 4 and the V-phase line 4 b of the grid connection distribution line 4. It is comprised from the load part 30b for V phases. In connection with the above-described configuration of the auxiliary machine 30, the auxiliary machine switch means 31 includes a U-phase auxiliary machine switch 31a for turning on / off the operation of the U-phase load section 30a, and a V-phase load. It comprises a V-phase auxiliary machine switch 31b for turning on / off the operation of the section 30b. Therefore, when the U-phase auxiliary machine switch 31a is closed, the U-phase load section 30a is energized and the corresponding auxiliary machine 30 is operated. Further, when the V-phase auxiliary machine switch 31b is closed, the V-phase load section 30b is energized and the corresponding auxiliary machine 30 is operated.

  The cogeneration system further includes system control means 10 for controlling the operation of the entire system. As shown in FIG. 3, the system control means 10 is composed of, for example, a microprocessor. In this embodiment, the system interconnection inverter 5, the cogeneration switch 34, the electric heater switch means 20, and the freeze prevention heater switch means. 27, an operation control means 11 for controlling the operation of the auxiliary switch means 31 and the like, a diagnosis control means 12 for performing a diagnostic operation of the cogeneration system as will be described later, and determining whether there is an erroneous connection in the diagnostic operation described later An abnormality determination means 13, an abnormality signal generation means 14 for generating an abnormality signal in an abnormal state, a current inversion means 15 for inverting a current signal, and a connection state of a current detector 2 described later are set. Connection setting means 16.

  In the first embodiment, for example, the system control means 10 energizes the anti-freezing heater means 28 so that no reverse current flow occurs (that is, no current flows from the power generator 6 side to the commercial power supply 14 side). In order to control the switching, and in this way, a current detector 2 for detecting a reverse current flow is disposed in the commercial distribution line 3. In this embodiment, in connection with the commercial distribution line 3 having a single-phase three-wire circuit configuration, the current detector 2 includes a first current detection unit 2a and a second current detection unit 2b. The current detection means 2 a is disposed on the U-phase line 3 a of the commercial distribution line 3, and the second current detection means 2 b is disposed on the V-phase line 3 b of the commercial distribution line 3. The first current detection means 2a detects the current flowing through the U-phase line 3a, and the second current detection means 2b detects the current flowing through the V-phase line 3b, and the first current detection means 2a and the second current detection means 2b The detection signal from is sent to the system control means 10.

  The cogeneration system is provided with a flow rate adjusting valve 9 that adjusts the amount of fuel supplied to the engine 8. The power generation output of the power generation device 6 is closely related to the output of the engine 8, and the output of the engine 8 is controlled by controlling the fuel supply amount by the flow rate adjusting valve 9, thereby generating power generated by the power generation device 6. Can be controlled. Further, alarm means 44 for notifying an erroneous connection related to the current detector 2 is provided. The alarm means 44 includes, for example, an alarm lamp, an alarm buzzer, and the like.

  The system control means 10 is installed in the cogeneration system when executing connection state diagnosis control when diagnosing the connection state between the current detector 2 and the system control means 10, and supplies power from the commercial distribution line 3. The power supplied from the commercial distribution line 3 is changed by changing the power consumption of the power consumption means (in this embodiment, the anti-freezing heater 28).

This connection state diagnosis control is performed as follows, for example. The diagnostic operation in the above-described cogeneration system will be described mainly with reference to FIGS.
In the diagnosis operation by the diagnosis control means 12 of the system control means 10, the U-phase anti-freezing heater switch 27a and the V-phase anti-freezing prevention are performed in the state where the operation of the power generator 6, that is, the operation of the engine 8 is stopped (step S1). The heater switch 27b is turned on to energize the freeze prevention heater 28 (step S2a). At this time, it is not necessary to turn on both the U-phase freeze prevention heater switch 27a and the V-phase freeze prevention heater switch 27b, and only a part of them may be turned on.

  And in the energization state to this freeze prevention heater 28, the electric current of the U-phase line 3a of the commercial distribution line 3 is detected by the 1st electric current detection means 2a (step S3). And the detection signal of the 1st electric current detection means 2a is sent to the system control means 10, and the system control means 10 diagnoses the connection state of the 1st electric current detection means 2a based on this detection signal (step S4). That is, the abnormality determination unit 13 of the system control unit 10 determines whether the current value of the detection signal from the first current detection unit 2a is positive or negative, and if the current value is positive, the first current Assuming that the detection means 2a is correctly connected, the process proceeds from step S4 to step S5. When the current value is negative, the abnormality determining means 13 determines that the connection is incorrect, and the current reversing means 15 reverses the detected current value of the first current detecting means 2a, in other words, a current value that is a negative value. Is inverted to a positive value (step S6). Thereafter, the system control means 10 performs signal processing with the inverted current value. As in this embodiment, no reverse current flow occurs when the power generation device 6 is not operating, and the negative detection current value of the first current detection means 2a is opposite to the connection state. (That is, positive and negative are connected in reverse). Therefore, if the detected current value of the first current detecting means 2a is inverted by the current inverting means 15, it is not necessary to correct the connection state of the first current detecting means 2a correctly.

  When the process proceeds from step S4 to step S5, or from step S4 to step S6 to step S5, the connection state of the second current detection unit 2b is diagnosed. This diagnosis is performed in the case of the first current detection unit 2a. It is done in the same way. That is, the second current detection means 2 b detects the current of the V-phase line 3 b of the commercial distribution line 3, and this detection signal is sent to the system control means 10. And the system control means 10 diagnoses the connection state of the 2nd electric current detection means 2b based on this detection signal (step S7). The abnormality determination means 13 determines whether the current value of the detection signal from the second current detection means 2b is positive or negative. If the current value is positive, the process proceeds from step S7 to step S9a. On the other hand, when the current value is negative, the abnormality determining means 13 determines that the connection is incorrect, and the current reversing means 15 reverses the detected current value of the second current detecting means 2b, in other words, a negative value. A certain current value is inverted to a positive value (step S8). Thereafter, the system control means 10 performs signal processing with the inverted current value.

  When diagnosis of the connection state of the first current detection means 2a and the second current detection means 2b is completed as described above, power is supplied from the U-phase line 3a of the commercial distribution line 3 while the operation stop state of the power generator 6 is maintained. The power to be changed is changed (step S9a). The fluctuation of the power supplied from the commercial distribution line 3 can be performed, for example, by changing the energization state of the anti-freezing heater 28 by the system control means 10, for example, the energization amount to the anti-freezing heater 28. Increasing (or decreasing) increases the power supplied from the commercial distribution line 3 (or decreases).

  And the connection state of the 1st electric current detection means 2a and the system control means 10 can be diagnosed by changing the electric power feeding from the U-phase line 3a of the commercial distribution line 3 as mentioned above. That is, the abnormality determination unit 13 of the system control unit 10 is configured such that the current of the U-phase line input unit of the system control unit 10 fluctuates in synchronization with the fluctuation of the power supplied from the U-phase line 3a of the commercial distribution line 3. That is, when the power supplied from the U-phase line 3a of the commercial distribution line 3 becomes large (or small), the detected current value of the first current detecting means 2a decreases (or increases), thereby the system control means 10 It is determined whether or not the current value of the U-phase line input section of the current line decreases (or increases) (step S10). When the current of the U-phase line input section of the system control means 10 fluctuates synchronously, the first current detection means 2a and the system control means 10 are correctly connected, and the detection signal from the first current detection means 2a is the system. It can be diagnosed that the signal is input to the U-phase line input unit of the control means 10. As a result, the connection setting unit 16 sets the U-phase line input unit as the input unit from the first current detection unit 2a (step S11), and then proceeds to step S12a.

  On the other hand, when the electric power supplied from the U-phase line 3a of the commercial distribution line 3 is changed in step S10, if the current of the U-phase line input unit does not change synchronously, the process proceeds to step S13. And the abnormality determination means 13 determines whether the electric current of the V-phase line input part of the system control means 10 fluctuates synchronizing with the fluctuation | variation of the electric power supplied from the U-phase line 3a of the commercial distribution line 3 ( Step S13). When the current of the V-phase line input unit fluctuates synchronously, the abnormality determination unit 13 determines that the connection state between the first current detection unit 2a and the system control unit 10 is not correct, and the connection setting unit 16 Contrary to the connection setting, the V-phase line input unit is set as the input unit from the first current detection means 2a (step S14). Thereafter, the system control means 10 performs signal processing with the current value set as described above. As described above, the current of the V-phase line input portion of the system control means 10 fluctuates synchronously even though the power supplied from the commercial distribution line 3 to the U-phase line 3a varies. This means that the detection signal of the 2-current detection means 2b is input to the U-phase line input section of the system control means 10. Therefore, by setting this V-phase line input unit as the input unit of the first current detection unit 2a by the connection setting unit 16, it is not necessary to correct the connection state correctly, and the connection state can be automatically corrected to the correct connection state. it can.

  If the currents of the U-phase line input unit and the V-phase line input unit of the system control means 10 do not fluctuate synchronously even when the power supplied from the commercial distribution line 3 is varied as described above, the process proceeds to step S15. The abnormality determination unit 13 generates an abnormality signal that there is a connection abnormality such as the first current detection unit 2a and the system control unit 10 not being connected. Based on this abnormality signal, the alarm means 44 is activated (step S16) to notify that the connection state is abnormal.

  As described above, when the process proceeds to step S12a, the power supplied from the V-phase line 3b of the commercial distribution line 3 is then changed. The fluctuation of the power supply from the V-phase line 3b of the commercial distribution line 3 is performed in the same manner as described above. And the connection state of the 2nd electric current detection means 2b and the system control means 10 can be diagnosed by changing the electric power feeding from the V phase line 3b of the commercial distribution line 3 as mentioned above. That is, the abnormality determination unit 13 of the system control unit 10 determines whether or not the current of the V-phase line input unit of the system control unit 10 varies in synchronization with the variation of the power supplied from the V-phase line 3b of the commercial distribution line 3. Is determined (step S17). When the current of the V-phase line input portion of the system control means 10 fluctuates synchronously, the second current detection means 2b and the system control means 10 are correctly connected, and the detection signal from the second current detection means 2b is the system. It can be determined that the signal is input to the V-phase line input unit of the control means 10. Therefore, the connection setting unit 16 sets the V-phase line input unit as the input unit from the second current detection unit 2b (step S18).

  On the other hand, when the electric current supplied from the V-phase line 3b of the commercial distribution line 3 is changed in step S17 described above, if the current in the V-phase line input unit does not change synchronously, the process proceeds to step S19. Next, the abnormality determination unit 13 determines whether the current of the U-phase line input unit of the system control unit 10 fluctuates in synchronization with the above-described fluctuation of the feeding power from the V-phase line 3b of the commercial distribution line 3. When the current of the U-phase line input section fluctuates synchronously, the abnormality determination unit 13 determines that the connection state between the second current detection unit 2b and the system control unit 10 is not correct. Then, the connection setting unit 16 sets the U-phase line input unit opposite to the initial connection setting with the input unit from the second current detection unit 2b (step S20). Signal processing is carried out with the current value set for connection to.

  Further, when the currents of the U-phase line input unit and the V-phase line input unit of the system control means 10 do not fluctuate synchronously even if the power supplied from the commercial distribution line 3 is varied as described above, the same as described above. In step S15, the abnormality determination unit 13 generates an abnormality signal, and the alarm unit 44 is activated based on the abnormality signal (step S16). In the cogeneration system diagnostic apparatus, as described above, the connection state of the first current detection means 2a and the second current detection means 2b, and the first current detection means 2a and the second current detection means 2b and the system control. The connection status with the means 10 can be automatically diagnosed, and even if there is a misconnection, the connection status can be automatically corrected so that it can be processed as required. In this embodiment, the connection state between the first current detection unit 2a and the second current detection unit 2b and the connection state between the first current detection unit 2a and the second current detection unit 2b and the system control unit 10 are as follows. Although both are diagnosed, it is not always necessary to perform both of these diagnoses, and even if one of these diagnoses is performed, the required effect is achieved.

  In the above-described embodiment, when the first current detection unit 2a and the second current detection unit 2b are erroneously connected, the connection state is automatically corrected to a correct state. Instead of such a configuration, for example, the alarm unit 44 may issue an alarm of erroneous connection, and the operator may manually reconnect so that the connection state is correct. The flow of diagnosis in this case is, for example, as shown in FIG.

  In FIG. 5, in the state where the operation of the power generation device 6 is stopped (step S31), the anti-freezing heater 28 is energized with the U-phase anti-freezing heater switch 27a and the V-phase anti-freezing heater switch 27b turned on (step S32). ). In the energized state of the anti-freezing heater 28, the current of the U-phase line 3a of the commercial distribution line 3 is detected by the first current detector 2a (step S33), and the detection signal of the first current detection means 2a is detected. Based on this, the connection state of the first current detection means 2a is diagnosed (step S34). In this case, the abnormality determination unit 13 of the system control unit 10 determines whether the current value of the detection signal from the first current detection unit 2a is positive or negative, and when the current value is positive, Assuming that the current detection means 2a is correctly connected, the routine proceeds from step S34 to step S39. On the other hand, when the current value is negative, the abnormality determining unit 13 determines that the connection is incorrect, the abnormal signal generating unit 14 generates an abnormal signal (step S35), the alarm unit 44 is activated, and the first current is generated. The detection hand 2a stage is informed of an erroneous connection (step S36). When the operator corrects the connection state of the first current detection means 2a correctly, the process proceeds from step S37 to step S38, the operation of the alarm means 44 is stopped, and thus the diagnosis of the first current detection means 2a is completed. To do.

  When the process proceeds to step S39 in this manner, the connection state diagnosis of the second current detection unit 2b is performed next, and the connection state diagnosis of the second current detection unit 2b performed by steps S39 to S44 is described above. This is performed in the same manner as the diagnosis of the connection state of the first current detection means 2a performed in steps S33 to S38. Even in this way, the connection state of the first current detection means 2a and the second current detection means 2b can be diagnosed.

<Second Embodiment>
The cogeneration system diagnosis apparatus according to the second embodiment includes a freeze prevention heater 28 in that the power consumption means used when executing the connection state diagnosis control is the electric auxiliary machine 30 of the cogeneration system. Different from the first embodiment used. Although the diagnostic apparatus of the cogeneration system of 2nd Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to 1st Embodiment.

  Since the connection state diagnosis control of this embodiment is the same as the connection state diagnosis control of the first embodiment as shown in the flowchart of FIG. 6, detailed description thereof is omitted. Specifically, in the connection state diagnosis control of the first embodiment, in order to control the energization state to the freeze prevention heater means 28, the U phase freeze prevention heater switch 27a and the V phase freeze prevention heater switch 27b are turned on. In this embodiment, in order to control the energization state of the electric auxiliary machine 30, the on / off of the U-phase auxiliary machine switch 31a and the V-phase auxiliary machine switch 31b is controlled. ing.

That is, the flowchart of the connection state diagnosis control of the present embodiment shown in FIG. 6 includes steps S2a, S9a, and S12a of the first embodiment shown in FIG. This is replaced with S9b and step S12b.
Specifically, in step S <b> 2 b, the system control means 10 energizes the auxiliary machine 30 with the U-phase auxiliary machine switch 31 a and the V-phase auxiliary machine switch 31 b inserted in the operation stop state of the power generation device 6.
Further, in step S9b, the system control means 10 changes the energization state of the auxiliary machine 30 so that the power supplied from the U-phase line 3a of the commercial distribution line 3 while maintaining the operation stop state of the power generation device 6 is maintained. Is fluctuating. For example, when the energization amount to the U-phase load section 30a is increased (or decreased), the power supplied from the U-phase line 3a of the commercial distribution line 3 increases (or decreases).
Furthermore, in step S12a, the system control means 10 is fed from the V-phase line 3b of the commercial distribution line 3 while changing the energization state of the auxiliary machine 30 while maintaining the operation stop state of the power generator 6. Electric power is fluctuating. For example, when the energization amount to the V-phase load section 30b is increased (or decreased), the power supplied from the V-phase line 3b of the commercial distribution line 3 is changed.

  Further, in the flowchart shown in FIG. 6, when the first current detection means 2a and the second current detection means 2b are erroneously connected, their connection states are automatically corrected to the correct state. However, instead of such a configuration, for example, in the same manner as described with reference to FIG. 5 in the first embodiment, the alarm means 44 issues an erroneous connection alarm so that the worker is in a correct connection state. You may make it reconnect manually.

<Another embodiment>
<1>
In the above embodiment, as shown in FIG. 2, a case where 100 V AC power is supplied to each of the U-phase heater means 24 and the V-phase heater means 25 constituting the electric heater means 23 is used. Although described, the present invention is not limited to the configuration shown in FIG. For example, FIG. 7 shows a state in which the electric heater means 46 provided for surplus power consumption is provided across the U-phase line 4a and the V-phase line 4b of the distribution grid 4 for grid connection. FIG. Therefore, 200V AC power is supplied to the electric heater means 46.
Even in the cogeneration system configured as shown in FIG. 7, as shown in the first and second embodiments, the anti-freezing heater 28 of the anti-freezing means 26 and the electric auxiliary machine 30 are provided. The connection state between the current detector 2 and the system control means 10 can be diagnosed by using and varying the power supplied from the commercial distribution line 3.

  Further, as shown in FIGS. 8 and 9, when the electric heater means 48 provided for surplus power consumption is connected between the power generator 6 and the inverter 5, the freezing prevention means 26 is similarly applied. The connection state between the current detector 2 and the system control means 10 can be diagnosed by varying the power supplied from the commercial distribution line 3 using the freezing prevention heater 28 and the electric auxiliary machine 30. .

<2>
In the above embodiment, the U-phase heater means 24 and the V-phase heater means 25 are each composed of three heaters, but may be composed of one, two, or four or more heaters.

<3>
In the above embodiment, the freeze prevention means 26 is configured to energize the freeze prevention heater 28 when the water temperature in the water circulation system detected by the hot water supply temperature sensor 32 is equal to or lower than the set freeze prevention temperature. Whether or not the heater 28 is energized may be determined based on other determination criteria. For example, instead of the detection result of the hot water supply temperature sensor 32, a thermometer (not shown) capable of measuring the outside air temperature is provided, and when the outside air temperature detected thereby falls below the set freezing prevention temperature, the antifreezing heater 28 is provided. May be energized.

<4>
In the above-described embodiment, the example in which the auxiliary switch means 31 is controlled to be turned on and off to change the electric load of the electric auxiliary machine 30 has been described. However, when the auxiliary machine 30 is a rotator such as a fan or a pump. The power load can be varied by increasing / decreasing the rotation speed.

  The cogeneration system diagnosis device of the present invention can be used when diagnosing the connection state between the current detector and the system control means without operating the power generation device.

Schematic configuration diagram of a cogeneration system equipped with the diagnostic device of the present invention Diagram showing the circuit configuration of the cogeneration system Functional block diagram of the cogeneration system control system Flow chart of connection state diagnosis control by diagnostic device Flow chart of connection state diagnosis control by diagnostic device Flow chart of connection state diagnosis control by diagnostic device Diagram showing the circuit configuration of the cogeneration system Schematic configuration diagram of a cogeneration system equipped with the diagnostic device of the present invention Diagram showing the circuit configuration of the cogeneration system

Explanation of symbols

2a 1st current detection means 2b 2nd current detection means 3a U phase wire 3b V phase wire 10 System control means

Claims (2)

A power generation device for cogeneration, a grid interconnection inverter for linking power from the power generation device to a commercial distribution line from a commercial power supply via a grid interconnection distribution line, and the commercial distribution A current detector for detecting a current flowing through the wire, and the commercial distribution line from the power generation device using the detection current of the current detector via the grid connection inverter and the grid connection distribution line System control means for controlling the power delivered, and
The commercial distribution line has a single-phase three-wire circuit configuration, the current detector includes first current detection means and second current detection means, and the first current is connected to the U-phase line of the commercial distribution line. A diagnostic device for a cogeneration system in which detection means is provided and the second current detection means is provided on a V-phase line of the commercial distribution line,
A freezing prevention heater capable of consuming power supplied from the commercial distribution line or generated power of the power generation device, and adjusting the power consumption of the freezing prevention heater to adjust the water temperature in the water circulation system in the cogeneration system Alternatively, anti-freezing means for heating the water circulation system is provided when the outside air temperature is equal to or lower than the set anti-freezing temperature,
In the state where the operation of the power generation device is stopped, the system control means,
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change. The connection setting of the 1 current detection means and the second current detection means and the system control means is set and maintained in that state;
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, and the When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change. It is configured to execute connection state diagnosis control for setting the connection setting of the first current detection means and the second current detection means and the system control means in reverse.
When the system control means executes the connection state diagnosis control, the power supplied from the commercial distribution line by changing the power consumption of the anti-freezing heater electrically connected to the commercial distribution line A diagnostic device for a cogeneration system configured to fluctuate. A power generation device for cogeneration, a grid interconnection inverter for linking power from the power generation device to a commercial distribution line from a commercial power supply via a grid interconnection distribution line, and the commercial distribution A current detector for detecting a current flowing through the wire, and the commercial distribution line from the power generation device using the detection current of the current detector via the grid connection inverter and the grid connection distribution line System control means for controlling the power delivered, and
The commercial distribution line has a single-phase three-wire circuit configuration, the current detector includes first current detection means and second current detection means, and the first current is connected to the U-phase line of the commercial distribution line. A diagnostic device for a cogeneration system in which detection means is provided and the second current detection means is provided on a V-phase line of the commercial distribution line,
The commercial distribution line is electrically connected to the electric auxiliary machine of the cogeneration system,
In the state where the operation of the power generation device is stopped, the system control means,
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change, and When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change. The connection setting of the 1 current detection means and the second current detection means and the system control means is set and maintained in that state;
When the electric power supplied from the U-phase line of the commercial distribution line is changed, the detected current input from the V-phase line input unit of the system control means changes in synchronization with the change, and the When the electric power supplied from the V-phase line of the commercial distribution line is changed, the detected current input from the U-phase line input unit of the system control means changes in synchronization with the change. It is configured to execute connection state diagnosis control for setting the connection setting of the first current detection means and the second current detection means and the system control means in reverse.
The system control means is configured to change the power supplied from the commercial distribution line by changing the power consumption of the electric auxiliary machine when executing the connection state diagnosis control. System diagnostic device.

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