JP5166072B2 - Power generation system - Google Patents

Description

  The present invention relates to a power generation system, and more particularly to a power generation system in a home cogeneration system.

  In recent years, household cogeneration systems using gas as fuel have become widespread. This type of cogeneration system includes a power generation unit A and a hot water storage unit B as main parts, as shown in FIG. The power generation unit A includes a gas engine a, a power generation device b driven by the gas engine a, an inverter c that converts DC power generated by the power generation device b into AC power, and exhaust heat of the gas engine a. And a heater e that recovers surplus power from the power generation unit A, and the AC power generated by the inverter c is used as household power. It is output. On the other hand, the hot water storage unit B is a unit for using hot water generated from the heat medium heated by the power generation unit A or hot water heated by the auxiliary heat source unit f for hot water supply or heating, and the auxiliary heat source unit f And a heat exchanger g that generates hot water from the heat medium heated by the power generation unit A and a hot water storage tank h that stores hot water generated by the heat exchanger g and the like. Since these detailed operations are well known, description thereof will be omitted.

FIG.5 (b) is explanatory drawing which shows schematic structure of the power supply system in such a conventional cogeneration system. As shown in the figure, the conventional cogeneration system converts the power supplied from the system (commercial power source m) into DC power at the power source j through the distribution board i with a breaker, and the control board of the hot water storage unit B k is supplied to the control board l of the power generation unit A through the distribution board i.
JP 2006-274850 A

  However, in such a conventional system, when the power transmission from the system is stopped, the power supply to the control boards k and l of the power generation unit A and the hot water storage unit B is stopped. There was a problem.

  Therefore, the applicant provides a power failure detection means on the downstream side of the distribution board, and also provides a power storage unit for storing power for starting the power generation device. When the power failure detection means detects a power failure, Has led to devising a power generation system that activates the power generator and performs self-sustaining power generation.

  However, it has been found that the use of such a configuration has the following problems. In other words, the configuration in which the power failure detection means is arranged on the downstream side of the distribution board is unnecessary because, for example, even when the breaker is cut off due to the absence of a user or a leakage, self-sustained power generation is determined as a power failure. There was also a problem that power generation operation was performed.

  The present invention has been made in view of such problems, and the purpose of the present invention is to generate power that is capable of self-sustained power generation during a power outage and that does not perform self-powered power generation during a power outage other than the stoppage of power transmission from the system. To provide a system.

To achieve the above object, a power generation system according to the present invention includes power generation means, grid connection switching means provided upstream of a distribution board with a breaker, and power for starting the power generation means in the event of a power failure. A power generation system comprising a storage means for storage and a control means, comprising a power failure detection means upstream of the grid connection switching means, wherein the control means detects a power failure by the power failure detection means. , to the system interconnection switch means disconnection state, then a control arrangement for starting a self power generation by activating the power means using power stored in said storage means Rutotomoni, the power failure detecting means When the power failure detection means detects a voltage and / or current within a predetermined period when the self-sustained power generation is started along with the power failure detection by the system, it is a short circuit failure of the grid connection switching means. Constant to is characterized in that a control arrangement for terminating the independence generation.
As a preferred embodiment of the present invention, the distribution board includes a main breaker and a branch wiring breaker, and one of the branch wiring breakers is connected to a start control unit that performs start control of the power generation means. In addition, a second power failure detection means is provided between the branch wiring breaker and the activation control unit .

  That is, in the power generation system of the present invention, a power failure detection means is newly provided on the further upstream side of the grid connection switching means provided on the upstream side of the distribution board with breaker. That is, the power failure detection means is provided at a position where the presence or absence of power transmission from the system can be directly confirmed. When a power failure is detected by the power failure detection means, the control means disconnects the grid connection switching means. The power generation system is electrically disconnected from the grid. Thereafter, the power generation means is activated using the electric power stored in the power storage means to start independent power generation.

  As described above, in the power generation system of the present invention, when a power failure is detected, the power generation means is activated using the power of the power storage means, so that independent power generation can be started even without external power supply. Moreover, it is detected by the power failure detection means newly provided upstream of the grid connection switching means whether the external power supply stoppage is due to the stoppage of power transmission from the system or due to the power interruption at the distribution board breaker. Therefore, since the self-sustaining power generation is not started by the power interruption on the distribution board side, unnecessary power generation can be suppressed.

In the present invention, when self-sustained power generation is started, the control means uses the newly provided power failure detection means for a predetermined period (for example, a period of about 0.3 to 0.5 seconds) from the start of self-sustained power generation. Monitor the current. In other words, if the grid connection switching means has a short circuit failure, the power failure detection means will detect the voltage / current due to the independent power generation as the independent power generation starts. The means determines that there is a short circuit failure in the grid connection switching means and stops the independent power generation.

Thus, according to the present invention , when self-sustaining power generation is started by stopping power transmission from the grid, it is possible to prevent the power generated due to a short-circuit fault of the grid interconnection switching means from flowing to the grid side, which is an excellent security measure. In addition, it is possible to provide a power generation system that does not place an excessive burden on the power generation means.
In this case, the control means is provided with a control configuration in which a predetermined warning notification is performed by the notification means when it is determined that the short-circuit fault of the grid connection switching means. Can be informed promptly.

  As another preferred embodiment of the present invention, the control means stops the independent power generation when the power failure detection means detects the cancellation of the power failure during the independent power generation, and then stops the grid connection. A control configuration is provided in which the system switching means is connected.

  That is, according to this embodiment, when power transmission from the system is resumed during the independent power generation, the power failure detection means detects the power transmission restart (elimination of power failure), stops the self-sustained power generation, and switches to the grid connection Since the control for bringing the means into the interconnected state is performed, it is possible to automatically recover from the self-sustained power generation when the power failure is resolved, and it is possible to provide a convenient power generation system.

  In the power generation system according to the present invention, the power failure detection means is constituted by an AC input type relay, and the contact signal is inputted to the control means. A power generation system can be provided.

  According to the power generation unit of the present invention, since the power generation means is activated using the power of the power storage means at the time of a power failure, independent power generation can be performed even without external power supply. In addition, since the self-sustaining power generation is started only when the power outage is due to the suspension of power transmission from the system, the self-sustaining power generation is not performed in the case where the power supply on the distribution board side is cut off, and unnecessary power generation is suppressed. can do.

  In addition, when the grid connection switching means has a short circuit failure, the self-sustained power generation is automatically stopped, so that it is possible to provide a power generation system that is excellent in safety measures and has a low burden on the power generation means. Further, by providing the notification means, it is possible to promptly notify the user of a short circuit failure of the grid connection switching means.

  Furthermore, when power transmission from the system is resumed during the self-sustaining power generation, the self-sustained power generation is automatically stopped and restored to the normal state, so that a convenient power generation system can be provided.

Embodiment 1
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of a power generation system of the present invention, and FIG. 2 is a power source of a home cogeneration system (a cogeneration system including a power generation unit and a hot water storage unit not shown) to which the power generation system is applied. It is explanatory drawing which shows schematic structure of a system.

  In FIG. 1, reference numeral 1 denotes a commercial power source (system), 2 denotes a distribution board, and 3 denotes an activation control unit that performs activation control of a power generator (power generation means) (not shown). As shown in FIG. 1, the power generation system of the present invention includes a system interconnection switching unit (system interconnection switching unit) 4 and a voltage detection unit (power failure detection unit) 5 on the upstream side (system side) of the distribution board 2. And a power failure detection unit (second power failure detection means) 6 on the downstream side of the distribution board 2. Here, the power failure detection unit 6 provided on the downstream side of the distribution board 2 is a power failure detection means already provided in the power generation system previously proposed by the applicant. In addition, the voltage detector 5 is newly provided as a power failure detection means.

  Specifically, the distribution board 2 is a distribution board having a known structure provided to branch the wiring from the main line of the commercial power supply 1 into the home. In the figure, reference numeral 21 denotes a main breaker (main wiring). Circuit breaker), 22 is a power distribution circuit, and 23 is a branch wiring breaker (power generation device side circuit breaker) for the power generation system. In FIG. 1, illustrations of branch wirings and earth leakage breakers other than those for the power generation system are omitted.

  The start control unit 3 is configured by a circuit including a power storage unit that stores power for starting the power generation device in the event of a power failure and a control unit of the present system. Specifically, as shown in FIG. 2, the activation control unit 3 includes a power supply unit 31, a hot water storage unit control board 32, a power generation unit control board 33, a power storage unit (power storage unit) 34, a charge switching circuit 35, The storage capacity detection circuit 36 and the power cut-off relay 37 are configured as main parts.

  More specifically, the power supply unit 31 includes an AC / DC converter that converts AC power (AC 100 V) supplied from the distribution board 2 via the power transmission line 30 into DC power of a predetermined voltage (DC 12 to 15 V). The DC power generated by the power supply unit 31 is used as drive power for the control board 32 of the hot water storage unit and charging power for the power storage unit 34.

  The control board 32 of the hot water storage unit is an electrical board provided with a microcomputer 32a that constitutes the control center of the hot water storage unit. The microcomputer 32a is a remote control (not shown) of the control board 33 of the power generation unit and the cogeneration system. And a control function to be described later as control means of the power generation system. The control board 32 is configured to receive power supply from the power supply unit 31 via a DC power supply line 38.

  On the other hand, the control board 33 of the power generation unit is an electrical board provided with a microcomputer 33a that constitutes the control center of the power generation unit. The control board 33 is divided into a power distribution line 30 via the power transmission line 30 in addition to the microcomputer 33a. An AC / DC converter 33b for converting AC power supplied from the panel 2 into DC power and an inverter 33c are provided. The DC power generated by the AC / DC converter 33b is supplied to each part of the power generation unit including the microcomputer 33a. The inverter 33c is connected to the power transmission line 30 so that the generated AC power can be supplied to the power supply unit 31 and the like. The microcomputer 33a mounted on the control board 33 stops the power generator (specifically, a drive source such as a gas engine that drives the generator) for safety when the power supply to the microcomputer 33a is stopped. It is configured to perform processing.

  The power storage unit 34 constitutes a power storage unit that stores the DC power output from the power source unit 31, and is connected to the DC power line 38 through the charge switching circuit 35. And as this electrical storage part 34, the storage battery which can store the electrical storage capacity required at least to perform the independent power generation control mentioned later is used. In the present embodiment, a lead storage battery is employed as the power storage unit 34. On the other hand, the charge switching circuit 35 is a circuit for switching permission / stop of charging to the power storage unit 34, and includes a switch circuit that is controlled to be opened and closed by the microcomputer 32a of the hot water storage unit. That is, when charging is permitted, the switch circuit is closed so that a current flows from the DC power supply line 38 to the power storage unit 34, and when charging is stopped, the switch circuit is opened, and a second electric circuit 41 to be described later is connected from the power storage unit 34. In this way, a current flows through the DC power supply line 38.

  And in this electrical storage part 34, when there is no power supply from the distribution board 2 at the time of a power failure, etc., the 1st electric circuit 40 for supplying DC power to the control board 33 of a power generation unit, and control of the said hot water storage unit A second electric circuit 41 for supplying DC power to the substrate 32 is connected. Incidentally, 42, 43 and 44 shown in the figure are all diodes for preventing backflow. The power storage unit 34 is provided with a power storage capacity detection circuit 36 for detecting the power storage capacity, and the power storage capacity of the power storage unit 34 can be monitored by the control board 32 (microcomputer 32a) of the hot water storage unit.

  The grid connection switching unit 4 includes a circuit for electrically connecting or disconnecting (disconnecting) the commercial power source (system) 1 and the power generation system (distribution panel 2). Specifically, it is connected to the control board 32 (microcomputer 32a) of the hot water storage unit via a signal line 45, and from the grid to the distribution board 2 according to a grid connection switching signal given from the microcomputer 32a via this signal line 45. A circuit (for example, a DC input type relay that opens and closes the contact with a signal from the microcomputer 32a) is used. The relay is configured to close the contact and connect the system and the distribution board 2 when the microcomputer 32a stops. That is, even if the user performs an operation to turn off the branch wiring breaker 23 for the power generation system, the operation does not affect other branch wirings other than the power generation system.

  The voltage detection unit 5 is a circuit provided on the upstream side of the grid connection switching unit 4 for monitoring the transmission voltage from the commercial power source 1 and transmitting it to the control board 32 (microcomputer 32a) of the hot water storage unit. In the embodiment, an AC input type relay (not shown) whose contacts are opened and closed depending on the presence or absence of an AC voltage is used as the voltage detection unit 5. That is, the relay is interposed in the electric path from the commercial power source 1, and the contact signal is input to the microcomputer 32a. The reason why the AC input type relay is used as the voltage detector 5 in this way is that the voltage detector can be provided easily and inexpensively. Therefore, other circuit configurations can be adopted for the voltage detection unit 5 as long as the circuit configuration can monitor the transmission voltage from the commercial power source 1.

  The power failure detection unit 6 is a circuit that monitors the power transmission of the branch wiring for the power generation system and transmits it to the control board 32 (microcomputer 32a) of the hot water storage unit. In this embodiment, the power failure detection unit 6 is described above. Similar to the voltage detector 5, an AC input type relay (not shown) whose contacts are opened and closed depending on the presence or absence of an AC voltage is used. That is, the relay is interposed in the power transmission line 30, and the contact signal is input to the microcomputer 32a. The reason why the AC input type relay is used as the power failure detection unit 6 is the same as that of the voltage detection unit 5. Therefore, it is also possible to adopt another circuit configuration as long as the power failure detection unit 6 can monitor the power transmission of the branch wiring for the power generation system.

  The operation when the power transmission from the commercial power supply (system) 1 is stopped (power failure) in the cogeneration system configured as described above will be described with reference to FIG. FIG. 3 is a flowchart showing an example of a processing procedure at the time of a power failure in the cogeneration system. Since various operations such as power generation, hot water supply, and heating by the cogeneration system are well known, description thereof is omitted here.

  That is, the control means 32 (microcomputer 32a) of the hot water storage system monitors the contact signals from the voltage detection unit 5 and the power failure detection unit 6, and at least the voltage detection unit 5 (both detection units 5 and 6 in the present embodiment) detects the voltage. Is not detected (when both steps S1 and S2 in FIG. 3 are positive), the microcomputer 32a determines that power transmission from the commercial power source 1 is stopped (power failure) and starts self-sustained power generation by the power generation unit (step S3 in FIG. 3). reference).

  Specifically, when detecting a power failure, the microcomputer 32a first outputs a system interconnection switching signal that instructs the system interconnection switching unit 4 to disconnect from the system (see step S3 in FIG. 3). Thereby, in the grid connection switching unit 4, the relay contact is opened, and the power generation system is disconnected from the grid.

  Thereafter, the microcomputer 32a controls the charge switching circuit 35 to be in a charge stop state. Note that the processing until the charge switching circuit 35 is controlled to the charge stop state is performed for a while from when the microcomputer 32a detects a power failure until the power supply to the microcomputer 32a is stopped. Thereby, the switch circuit of the charge switching circuit 35 is opened, and DC power is supplied from the power storage unit 34 to the microcomputer 33a of the power generation unit 33 and the microcomputer 32a of the hot water storage unit via the first electric circuit 40 and the second electric circuit 41. Is done.

  When the power from the power storage unit 34 is supplied to the hot water storage unit and the power generation unit microcomputers 32a and 33a in this way, the microcomputer 32a and the microcomputer 33a can communicate with each other. A signal for instructing the microcomputer of the unit to drive the power generation device to 33a to generate power is output, and the microcomputer 33a controls the start of power generation. (See step S4 in FIG. 3).

  As described above, in the cogeneration system shown in the present embodiment, when power transmission from the commercial power source 1 is stopped, power is generated using the power stored in the power storage unit 34 after disconnecting the connection with the commercial power source 1. The device is activated and self-sustaining power generation is performed. Therefore, even if the power transmission from the commercial power source 1 is stopped, the self-sustained power generation by the power generation unit is automatically started, and the power supply to the home is ensured.

  In addition, this self-sustained power generation control at the time of power failure is not only when the cogeneration system is in operation (gas engine is in operation), but also when the system is in standby mode (the gas engine is stopped and the hot water storage unit side also supplies hot water). -Even when all functions such as heating are stopped and the auxiliary heat source machine is also stopped), it is configured to be executed when power transmission from the commercial power source 1 is stopped.

  In addition, since this self-sustained power generation control is performed only when there is no voltage in both the voltage detection unit 5 and the power failure detection unit 6, for example, the branch wiring breaker 23 for the power generation system due to the absence of the user for a long period of time. When the power is cut off, only the power failure detection unit 6 has no voltage, and the voltage detection unit 5 detects the voltage, so that no self-sustained power generation is performed. That is, according to the present invention, useless power generation is prevented in such a case.

  On the other hand, this self-sustained power generation is stopped as follows. That is, when self-sustaining power generation starts, the microcomputer 32a thereafter monitors whether or not the voltage detection unit 5 has a voltage based on the contact signal from the voltage detection unit 5 (see step S5 in FIG. 3). That is, when the suspension of power transmission from the commercial power supply 1 is resolved, the voltage is detected by the voltage detection unit 5, and the microcomputer 32a monitors the presence or absence of this voltage.

  If it is determined that there is a voltage in this determination, the microcomputer 32a then gives a command to stop the power generation of the power generation device to the microcomputer 33a of the power generation unit to stop the power generation by the power generation device (see step S6 in FIG. 3). .

  Then, when the power generation by the power generation device stops, the microcomputer 32a then outputs a grid connection switching signal that instructs the grid connection switching unit 4 to restore the connection to the grid (see step S7 in FIG. 3). . Thereby, in the grid connection switching part 4, the contact of a relay is made into a short circuit state, and a power generation system and a grid | system are linked.

  Thereby, the self-sustained power generation of the power generation system is stopped, and normal control (that is, general power generation control as a cogeneration system) is performed on the power generation system.

Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart illustrating an example of a processing procedure at the time of a power failure in the cogeneration system according to the present embodiment.

  The power generation system shown in the second embodiment determines whether or not there is a short circuit failure at the contact point of the grid connection switching unit 4 when performing self-sustained power generation in the power generation system of the above-described first embodiment. In this case, control for stopping the self-sustained power generation is added, and the other points are the same as those in the first embodiment.

  That is, also in this embodiment, when the microcomputer 32a of the hot water storage unit has no voltage in both the voltage detection unit 5 and the power failure detection unit 6, the grid connection switching unit 4 disconnects the system from the grid and starts independent power generation. This is the same as in the first embodiment (see steps S1 to S4 in FIG. 4).

  And in this embodiment, when self-sustained power generation is started in this way, the microcomputer 32a of the hot water storage unit has a very short period of time (for example, a period of about 0.3 to 0.5 seconds), It is determined in the voltage detector 5 whether or not the state of no voltage continues (see step S5 in FIG. 4).

  That is, when independent power generation is started in a state where the contact of the grid connection switching unit 4 is short-circuited, the electric power generated by the power generation device wraps around the voltage detection unit 5 and appears as a voltage. Therefore, in the present embodiment, the voltage detector 5 is configured to detect the presence or absence of such sneak power.

  If the voltage is detected by the voltage detection unit 5 as a result of this determination (when the determination in step S5 in FIG. 4 is negative), the microcomputer 32a has a short circuit fault in the contact of the grid connection switching unit 4. And a command to stop the independent power generation is given to the microcomputer 33a of the power generation unit 33 to stop the independent power generation (see step S6 in FIG. 4).

  Therefore, according to the present embodiment, when independent power generation is started by stopping power transmission from the grid, if the grid interconnection switching unit 4 has a short circuit failure, the independent power generation is immediately stopped, and thus power is generated. It is possible to prevent electric power from going around to the grid side. Therefore, it is possible to provide a power generation system that is excellent in safety measures and that does not place an excessive burden on the power generation device.

  In the microcomputer 32a, when the short circuit failure of the grid connection switching unit 4 is determined, the result is displayed on, for example, a display unit of a remote control (not shown) of the cogeneration system, or a predetermined value is determined by the remote control. It is possible to provide a predetermined warning notification through a notification means such as outputting an alarm sound, and by doing so, a short circuit failure of the grid connection switching unit 4 can be promptly notified to the user or the like. Can be informed.

  Further, in the present embodiment, during the determination of the short circuit failure of the grid connection switching unit 4, that is, during the predetermined period, the above-described self-sustained power generation stop control (control of steps S5 to S7 in FIG. 3) is not performed. This control is performed after the predetermined period has elapsed.

  Note that the above-described embodiments merely show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope thereof.

  For example, in the above-described embodiment, the voltage detection unit 5 and the power failure detection unit 6 that constitute the power failure detection means employ a configuration in which a power failure is detected by detecting the voltage, but it is possible to detect a power failure. For example, it is possible to perform a power failure detection using a circuit that detects both current and voltage and current.

  Moreover, although the case where the gas engine was used as the drive source of the power generation unit has been described in the above-described embodiment, the present invention is naturally applicable to a case where a power generation device having a structure other than this is provided.

It is a schematic structure figure showing an example of a power generation system concerning the present invention. It is explanatory drawing which shows schematic structure of the power supply system of the household cogeneration system to which the same electric power generation system is applied. It is a flowchart which shows an example of the process sequence at the time of the power failure in the cogeneration system. It is a flowchart which shows another example of the process sequence at the time of the power failure in the cogeneration system. FIG. 5A is an explanatory diagram showing a conventional cogeneration system, FIG. 5A is an explanatory diagram showing the operating principle of the system, and FIG. 5B is an explanatory diagram showing a schematic configuration of a power supply system.

Explanation of symbols

1 Commercial power (system)
2 Distribution board 3 Start-up control unit 4 System interconnection switching unit (system interconnection switching means)
5 Voltage detector (power failure detection means)
6 Power Failure Detection Unit 31 Power Supply Unit 32 Hot Water Storage Unit Control Board 32a Microcomputer 33 Power Generation Unit Control Board 33a Microcomputer 34 Power Storage Unit (Power Storage Unit)
35 Charge switching circuit 36 Storage capacity detection circuit

Claims (5)

A power generation system comprising: power generation means; grid connection switching means provided upstream of a distribution board with a breaker; power storage means for storing power for starting the power generation means in the event of a power failure; and control means. There,
Provided with a power failure detection means upstream of the grid connection switching means,
The control means, when detecting a power failure by the power failure detection means, causes the grid connection switching means to be disconnected, and then activates the power generation means using the power stored in the power storage means. Rutotomoni a control arrangement for starting self power generation, when to initiate the self power generation with the power failure detection by the power failure detecting means, when said power failure detecting means detects the voltage and / or current within the predetermined time period Includes a control configuration that determines that a short circuit failure has occurred in the grid connection switching means and terminates the self-sustained power generation. The distribution board includes a main breaker and a branch wiring breaker, and one of the branch wiring breakers is connected to a start control unit that performs start control of the power generation means, and the branch wiring breaker and the start control unit The power generation system according to claim 1, further comprising a second power failure detection means . 3. The power generation according to claim 1, wherein the control unit includes a control configuration in which a predetermined warning notification is performed by a notification unit when it is determined that a short circuit failure has occurred in the grid connection switching unit. system.   The control means includes a control configuration in which, when the power failure detection means detects the cancellation of the power failure during the self-sustained power generation, the self-sustained power generation is stopped, and then the grid connection switching means is brought into a connected state. The power generation system according to any one of claims 1 to 3, wherein   5. The power generation system according to claim 1, wherein the power failure detection unit is configured by an AC input type relay, and a contact signal thereof is input to the control unit. .

Images