JP2008104334A - Fuel cell type distributed power generating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell type distributed power generating apparatus that can significantly shorten trial operation time for confirming the operation of a grid-connected protective device before starting power generation and grid-connected operation after its installation at actual use location. <P>SOLUTION: A fuel cell type distributed power generating apparatus includes a DC power generating apparatus 10 provided with a fuel cell 12 that outputs DC power, a DC-to-AC conversion apparatus 21 for converting DC power that is output from the DC power generating apparatus 10 to AC power in a way allowing grid connection with a commercial AC power supply 30, a grid-connected protective device 22 for protecting the commercial AC power supply 30 from abnormal operation of the DC-to-AC conversion apparatus 21, and a control device 23 for controlling the operation of the DC-to-AC conversion apparatus 21 in cooperation with the grid-connected protective device 22, which are integrated and accommodated in a common housing 4. The apparatus is configured to allow a second DC power that is output from a second power supply 50 separate from the DC power generating apparatus 10 to be input to the DC-to-AC conversion apparatus 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell type distributed power generator that can be grid-connected to a commercial AC power source, and more particularly to shortening the time of an operation confirmation test of a grid interconnection protection device.

In recent years, the development of distributed energy systems aimed at reducing CO ₂ emissions and saving energy has been actively developed and put into practical use. It is thought that the use of power generation equipment will progress rapidly in the future. In particular, cogeneration systems capable of co-generation with heat and power are attracting attention for their high overall energy efficiency because they can effectively use not only electric power but also thermal energy generated during power generation. By the way, the distributed power generator does not cover all the power demand in the power consumption area by itself, but is connected to the system power supply such as commercial AC power supplied by the power company to A usage pattern (grid-linked usage pattern) as a grid-connected power generation apparatus that is replenished from a power source is mainly used for residential use (home use) and the like.

  Many fuel cell type distributed generators that can be connected to a commercial AC power source are disclosed in, for example, Patent Document 1 below. FIG. 5 is a block diagram schematically showing an internal schematic configuration of a general fuel cell type distributed generator 60. As shown in FIG. 5, the distributed generator 60 includes a reformer 11 that generates a fuel gas FG such as hydrogen from a primary raw material SG such as city gas (natural gas) mainly composed of methane, and a reformer. DC power generator 10 including a fuel cell 12 that generates DC power by an electrochemical reaction between the fuel gas FG generated by the device 11 and oxygen, and DC power output from the DC power generator 10 as commercial AC power 30, an orthogonal transformation device 21 that converts AC power into a grid connection, and an abnormality in grid connection between the orthogonal transformation device 21 and the commercial AC power source 30 (overvoltage or undervoltage occurrence, frequency increase or decrease, single operation, Grid connection protection to prevent the deterioration of the electrical quality of distribution lines at locations where distributed generators are used, the adverse effects on electrical products, and the loss of personal safety due to the occurrence of reverse power flow function The system interconnection protection device 22 for execution, the control device 23 that controls the operation of the orthogonal transformation device 21 in cooperation with the system interconnection protection device 22, and supplies power to the system interconnection protection device 22 and the control device 23. A power adjustment device 20 including a direct current auxiliary power supply 24 is housed in a common housing 4 and integrated as a fuel cell power generation unit. In addition, in FIG. 5, traps, such as a heat exchanger which collect | recovers exhaust heat from the reformer 11 grade | etc., And a pump of various uses, an air blower, are not shown in figure. Also, an exhaust heat recovery heat storage unit that stores the exhaust heat recovered through the heat exchanger in the form of hot water and supplies it to a predetermined heat load is provided separately from the distributed power generator 60 shown in FIG. And used in combination with the distributed generator 60.

  By the way, in order to install the distributed power generation apparatus 60 so as to be grid-connected to the commercial AC power supply 30, it is necessary to perform a grid interconnection application procedure with an electric power company that manages the commercial AC power supply 30. Furthermore, it is necessary to check the operation of the grid connection protection device 22 before starting the power generation and grid connection operation of the distributed generator 60 during the trial operation after installation.

  As a fuel cell type distributed power generation device (cogeneration system), a system using a polymer solid electrolyte fuel cell (PEFC) or an oxide solid oxide fuel cell (SOFC) as a fuel cell 12 has been developed. Although it is partially put into practical use, it takes a long time of about 1 to 2 hours to rise from the cold state to the start of power generation. This is because, for example, the catalyst temperature of the reformer 11 is 200 ° C. to 800 ° C. in the DC power generator 10, and the fuel cell 12 is also 70 ° C. to 90 ° C. for PEFC and 600 ° C. to 1000 ° C. for SOFC. This is due to the fact that it takes a long time from the start of the operation until the temperature rises to reach a stable operation.

  Therefore, it takes a long time for the DC power generation apparatus 10 to operate stably even during the trial operation of the fuel cell type distributed power generation apparatus, and the person in charge of the trial operation needs to wait for that time, which is a cause of the cost increase due to personnel costs. It has become.

  In Patent Document 2 below, as a test operation method for a fuel cell type distributed power generation device, in order to prevent damage to the fuel cell main body in the adjustment work of the fuel cell power generation equipment excluding the fuel cell main body, A method of using a simulated fuel cell has been proposed so that the adjustment work of the fuel cell power generation facility can be completed before the fuel cell main body is incorporated. However, the simulated fuel cell is intended to prevent damage to the fuel cell body that should be built in, and its operation simulates the fuel cell body. Therefore, the effect of shortening the time required for the test run cannot be expected.

JP 2006-84040 A JP-A-5-129030

  The present invention has been made in view of the above problems, and its purpose is to confirm the operation of the grid interconnection protection device before starting power generation and grid interconnection operation after installation in an actual use place. The object of the present invention is to provide a fuel cell type distributed power generation apparatus and a test operation method thereof that can greatly shorten the test operation time.

  In order to achieve the above object, a fuel cell type distributed generator according to the present invention includes a DC generator including a fuel cell that outputs DC power, and a DC power output from the DC generator as a commercial AC power source. In cooperation with the grid connection protection device, the grid connection protection device for protecting the commercial AC power supply from the abnormal operation of the orthogonal conversion device, and the grid connection protection device A controller for controlling the operation of the orthogonal transform device is integrated and accommodated in a common housing, and the second direct current power output from a second direct current power source different from the direct current generator is used as the orthogonal transform device. It is the first feature that it is configured to be able to input to.

  Furthermore, in addition to the first feature described above, the fuel cell type distributed generator according to the present invention further includes an input terminal for receiving the second DC power from outside. It is characterized by.

  Furthermore, in addition to the first feature, the fuel cell type distributed generator according to the present invention has a third feature that the second DC power supply is housed in the casing.

  Further, in the fuel cell type distributed power generator according to the present invention, in addition to the third feature described above, the second DC power source converts the AC power supplied from the commercial AC power source into DC power. A storage battery for storing the DC power converted with the circuit, and during the time required for the test operation for confirming the operation of the grid interconnection protection device, the orthogonal transformation device, the grid interconnection protection device, and the control A fourth feature is to have a sufficient storage capacity for supplying power to the apparatus.

  According to the fuel cell type distributed generator of any one of the first to fourth features, the second DC power output from the second DC power source different from the DC generator can be input to the orthogonal transformation device. Since it is configured, the second DC power output from the second DC power source is started instead of starting the DC power generator during the test operation for confirming the operation of the grid interconnection protection device. Can be input to the orthogonal transformation device, and the operation check of the grid connection protection device can be started immediately after the start of the second DC power supply, and the time required for the operation check of the grid connection protection device can be shortened. Become.

  In particular, according to the fuel cell type distributed power generation device of the second feature, a change in which an input terminal for receiving the second DC power from the outside is simply provided on the casing is changed to an existing fuel cell type distributed power generation. The time required for confirming the operation of the grid interconnection protection device can be shortened only by applying to the device.

  In particular, according to the fuel cell type distributed generator of the third feature, it is not necessary to separately prepare the second DC power source during the test operation, and the second DC power source is not limited to the test operation after the installation but also during the test operation during the maintenance inspection. A DC power supply can be used. Furthermore, the second DC power supply can be used in order to cope with load fluctuations accompanying the occurrence of a power failure of the commercial AC power supply during the grid connection operation.

  Furthermore, according to the fuel cell type distributed power generation device of the fourth feature, during the time required for the test operation for confirming the operation of the grid connection protection device, the orthogonal transformation device and the grid connection protection device are stored. Therefore, the operation check of the grid interconnection protection device can be performed reliably.

  Further, the fuel cell type distributed power generator according to the present invention can be connected to a DC power generator having a fuel cell that outputs DC power, and the DC power output from the DC power generator can be connected to a commercial AC power source. Of the orthogonal transform device in cooperation with the grid connection protection device for protecting the commercial AC power supply from the abnormal operation of the orthogonal transform device, the grid connection protection device, and the grid connection protection device. A control device for controlling the operation is integrated and accommodated in a common casing, and the direct current power generation device generates fuel supplied from the predetermined primary raw material to the fuel cell from the reformer. A fifth feature is that an external fuel injection port is provided for branching from a fuel supply passage for supplying the fuel to the fuel cell and supplying the fuel to the fuel cell from the outside.

  According to the fuel cell type distributed power generator of the fifth feature, the external fuel injection port for supplying the fuel to the fuel cell from the outside is provided, so that the test operation for confirming the operation of the grid interconnection protection device is performed. Sometimes, instead of starting the reformer, the fuel cell is started by supplying the ready-made fuel from the external fuel inlet to the fuel cell, and a stable output can be obtained from the fuel cell in a short time. As a result, the DC power output from the fuel cell can be input to the orthogonal transformation device, and the operation check of the grid connection protection device can be started in a short time from the start of the fuel cell. It is possible to shorten the time required for the operation check.

  Furthermore, a test operation method for a fuel cell type distributed power generation device according to the present invention for achieving the above object is a test operation method for a fuel cell type distributed power generation device according to the second aspect, wherein During a test operation for confirming the operation of the system protection device, the output of the second DC power source is connected to the input terminal without starting the fuel cell of the DC power generation device, and the second DC power is supplied to the input terminal. The first feature is that the signal is supplied to the orthogonal transformation device.

  Furthermore, a test operation method for a fuel cell type distributed generator according to the present invention is a test operation method for a fuel cell type distributed generator according to the third or fourth feature, wherein During the test run for operation confirmation, the second DC power source is started without starting the fuel cell of the DC power generator, and the second DC power output from the second DC power source is the orthogonality. The second feature is to supply the converter.

  According to the test operation method of the fuel cell type distributed generator of the first or second feature, instead of starting the fuel cell of the DC generator during the test operation for confirming the operation of the grid interconnection protection device, Since the second DC power source is activated and the second DC power output from the second DC power source is input to the orthogonal transformation device, the operation check of the grid connection protection device is started immediately after the second DC power source is activated. Therefore, it is possible to reduce the time required for checking the operation of the grid connection protection device.

  Furthermore, a test operation method of a fuel cell type distributed power generation device according to the present invention is a test operation method of the fuel cell type distributed power generation device of the fifth feature, wherein the operation check of the grid interconnection protection device is performed. DC power output from the fuel cell by supplying external fuel to the fuel cell from the external fuel inlet and operating the fuel cell without starting the reformer Is supplied to the orthogonal transformation device as a third feature.

  According to the trial operation method of the fuel cell type distributed generator of the third feature, the external fuel is externally supplied without starting the reformer during the trial operation for confirming the operation of the grid interconnection protection device. Since the fuel cell is operated by supplying the fuel cell from the fuel inlet, the operation check of the grid connection protection device can be started in a short time from the start of the fuel cell, which is necessary for the operation check of the grid connection protection device. Time can be shortened.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a fuel cell type distributed power generation apparatus and its test operation method (hereinafter simply referred to as “the present invention apparatus” and “the present invention method” as appropriate) according to the present invention will be described below with reference to the drawings. In the drawings for explaining the device of the present invention, the same parts as those of the conventional fuel cell type distributed power generation device shown in FIG.

<First Embodiment>
FIG. 1 is a block diagram showing a schematic configuration of the device 1 of the present invention. As shown in FIG. 1, the device 1 of the present invention includes a reformer 11 that generates a fuel gas FG such as hydrogen from a primary raw material SG such as city gas (natural gas) mainly composed of methane, and a reformer. 11, a DC power generator 10 including a fuel cell 12 that generates DC power by an electrochemical reaction between the fuel gas FG generated in 11 and oxygen, and a DC power output from the DC power generator 10 as a commercial AC power supply 30. And an orthogonal transformation device 21 that converts the AC power into a grid interconnection, and an abnormality in the grid interconnection between the orthogonal transformation device 21 and the commercial AC power supply 30 (overvoltage or undervoltage occurrence, frequency increase or decrease, single operation, reverse Grid connection protection function to prevent the deterioration of the electrical quality of the distribution lines at the place where the distributed generator is used from the generation of tidal power, etc., the adverse effects on electrical products, and the loss of personal safety Run For supplying power to the grid connection protection device 22, the control device 23 for controlling the operation of the orthogonal transformation device 21 in cooperation with the grid connection protection device 22, and the grid connection protection device 22 and the control device 23. A power adjustment device 20 including a DC auxiliary power supply 24 is housed in a common housing 4 and integrated as a fuel cell power generation unit. In FIG. 1, a heat exchanger that recovers exhaust heat from the reformer 11 and the like, and traps such as pumps and blowers for various uses are not shown. In addition, an exhaust heat recovery heat storage unit that stores the exhaust heat recovered through the heat exchanger in the form of hot water and supplies it to a predetermined heat load is provided separately from the distributed power generator 1 shown in FIG. The cogeneration system is configured by being used together with the distributed power generator 1. However, the device 1 of the present invention may be used as a distributed power generator that can be connected to the grid independently without being used together with the exhaust heat recovery heat storage unit.

  Furthermore, in the first embodiment, the inventive device 1 is configured so that the second DC power output from the external second DC power source 50 can be input to the orthogonal transform device 21 separately from the DC power generator 10. A pair of input terminals 5 for receiving DC power from the outside is provided on the housing 4. In FIG. 1, a state where the second DC power supply 50 is connected to the input terminal 5 is illustrated.

  In the present embodiment, it is assumed that the fuel cell 12 includes PEFC or SOFC cells connected in series in multiple stages (generally referred to as a cell stack) and is configured to be able to output direct current of 30 V to 100 V. is doing. The reformer 11 uses a known configuration for generating hydrogen, which is a fuel gas of the fuel cell 12, from city gas (natural gas) mainly composed of methane, and includes a desulfurizer, a steam reformer, a CO 2 A (carbon monoxide) transformer, a CO remover, and the like are provided in the processing order.

  The orthogonal transform device 21 includes a DC / DC converter 25 that boosts the DC voltage output from the fuel cell 12 to 350 V, an inverter circuit 26, and an interconnection relay 27. The inverter circuit 26 is a smoothing capacitor that smoothes the DC voltage output from the DC / DC converter 25, and a bridge circuit that converts the DC power output from the DC / DC converter 25 into a pulse output that is pulse-width-modulated. , And a low-pass filter circuit that converts the pulse output into a sinusoidal AC output, and the DC power (350 V) output from the DC / DC converter 25 is converted into a single-phase AC power with an effective voltage of 200 V. The signal is converted and output from a pair of output terminals OUT1 and OUT2 connected to the output side of the interconnection relay 27.

  The grid interconnection protection device 22 receives an instantaneous value (analog value) from an AC ammeter 28 provided on the input side of the interconnection relay 27 and an AC voltmeter 29 provided on the input side of the interconnection relay 27. Accepting, system voltage monitoring (AC overvoltage detection, AC undervoltage detection) on the commercial AC power supply 30 side, system frequency monitoring (AC frequency rise detection, AC frequency reduction detection), and power failure monitoring (single operation of the power adjustment device 20) Detection (active method, passive method)), power monitoring device 20 side output monitoring (AC overcurrent detection, AC voltage rise detection), etc., and synchronization control with commercial AC power supply 30, system It is a device that exhibits system interconnection protection functions such as protection coordination and prevention of isolated operation during a system power failure in cooperation with the control device 23 and the interconnection relay 27. When the device 1 of the present invention is used in a grid-connected usage pattern that does not allow a reverse power flow to the commercial AC power supply 30 side, any one of the following three methods is currently provided according to the power grid interconnection technical requirement guidelines. Depending on the situation, it is necessary to secure the function to prevent isolated operation. That is, 1) a reverse power relay (RPR) and an underpower relay (UPR) are provided, or 2) a reverse power relay (RPR) and an isolated operation prevention function (one or more of each of an active method and a passive method). Or 3) It is necessary to provide an isolated operation prevention function (one or more of the active method and the passive method). In the passive type single operation determination, the voltage of the commercial AC power supply 30 is monitored and a change appearing during the single operation of the device 1 of the present invention due to a system power failure is detected. Voltage phase jump detection type, third harmonic distortion There are methods such as a rapid increase detection method and a frequency change rate detection method. In addition, the active system isolated operation determination is to detect a change appearing during the isolated operation by giving a specific change to the output from the device 1 side of the present invention. There are methods. Therefore, the grid interconnection protection device 22 according to the present embodiment employs a known or novel circuit configuration that guarantees any one of the above isolated operation prevention functions. A detailed description of each circuit configuration is omitted because it is not the gist of the present invention.

  The control device 23 includes a gate drive circuit that drives each gate of a power switching element such as a power MOSFET or IGBT (insulated gate bipolar transistor) that forms a bridge circuit of the inverter circuit 26, an AC ammeter 28, and an AC voltage. The gate control circuit is configured to control the gate drive circuit based on the total 29 output signals and the control signal from the grid connection protection device 22. The gate control circuit controls the on / off operation of the switching element of the bridge circuit by pulse width modulation (PWM) method so that the output voltage and output current waveform after passing through the low-pass filter circuit become a sine wave, and the system is normal In some cases, phase synchronization control is performed so that the frequency and phase of the sine wave output coincide with the frequency and phase of the single-phase three-wire AC power 200 V / 100 V supplied from the commercial AC power supply 30. Further, the gate control circuit, for example, when the grid connection protection device 22 detects an overvoltage state, suppresses the overvoltage state, that is, the output voltage (in the overvoltage state) of the output terminals OUT1 and OUT2 ( The on / off operation of each switching element is controlled so as to reduce the absolute value of the instantaneous value, and the switching element is finally turned off while the output voltage in an overvoltage state is suppressed to a predetermined reference voltage or less. When the grid connection protection device 22 detects the single operation state, the gate control circuit turns off each switching element and stops the output of the inverter circuit 26.

  The DC auxiliary power supply 24 converts the DC power output from the DC power generator 10 or the AC power supplied from the AC power output from the inverter circuit 26 into DC power of a predetermined voltage, and the grid interconnection protection device 22. And a power supply circuit for supplying power to the control device 23.

  In the first embodiment, the pair of input terminals 5 for second DC power input provided in the housing 4 includes a pair of output terminals of the fuel cell 12 and a pair of input terminals of the DC / DC converter 25. Each wiring is connected directly to each wiring.

  The second DC power supply 50 used by connecting to the input terminal 5 includes, for example, an AC / DC conversion circuit 51 that converts AC power supplied from a commercial AC power source into DC power, and a storage battery 52 that stores the converted DC power. Can be used. The output voltage of the second DC power supply 50 is the same as the output voltage of the fuel cell 12 (DC 30V to 100V). Note that the storage battery 52 built in the second DC power supply 50 is connected to the orthogonal transformation device 21 and the grid connection protection device of the device 1 of the present invention during the time required for a test run for confirming the operation of the grid connection protection device 22 described later. 22 and the controller 23 having a sufficient storage capacity to supply power. For example, when the rated output of the device 1 of the present invention is 1 kW and it takes 15 minutes to check the operation of the grid connection protection device 22, the storage capacity may be a maximum of 250 Wh, which is practically 20%. A storage capacity of about ˜50% is considered sufficient.

  In the usage mode of the present embodiment in which the device 1 of the present invention is used in a grid connection with a commercial AC power supply 30 that supplies single-phase three-wire AC power 200V / 100V, as shown in FIG. Between the commercial AC power supply 30 and the mains breaker 41, a distribution board 44 having a main breaker 41, a branch breaker 42, and an interconnection breaker 43 is interposed. 41 and the interconnection breaker 43, and between the interconnection breaker 43 and the device 1 of the present invention are connected by a single-phase three-wire power line (two voltage lines U and V and one neutral line N). Yes. The output terminals OUT1 and OUT2 of the orthogonal transform device 21 are connected to voltage lines U and V of a single-phase three-wire power line. A power load 40 (electric equipment) that receives power supply from the apparatus 1 of the present invention and the commercial AC power supply 30 is connected to each power line of the single-phase two-wire 100V extending from the branch breaker 32. Each power line of the single-phase two-wire 100V is connected to the first voltage line U and the neutral line N or the second voltage line V and the neutral line via the branch breaker 42 between the main breaker 41 and the interconnection breaker 43. Connected to N. In addition, the connection between this invention apparatus 1 and the commercial alternating current power supply 30 is not limited to the form shown in FIG.

  The configuration of the device 1 of the present invention shown in FIG. 1 is the same as that of a general fuel cell type distributed power generator capable of grid connection, except that the housing 4 has an input terminal 5. is there. Therefore, a detailed description of the portions overlapping with a general fuel cell type distributed generator capable of grid connection is omitted.

  Next, the method of the present invention for confirming the operation of the grid interconnection protection device 22 after the device of the present invention 1 is installed at the actual use place will be described.

  First, the charged second DC power supply 50 is prepared before starting a test operation for confirming the operation of the grid connection protection device 22. By connecting the second DC power supply 50 to the input terminal 5 without starting the DC power generation apparatus 10, instead of supplying DC power from the DC power generation apparatus 10, the second DC power supply 50 supplies the second DC power. Is supplied to the power adjustment device 20. As a result, since the power adjustment device 20 is activated, a test for confirming the operation of the grid connection protection device 22 can be performed. When the operation check test corresponding to the grid interconnection protection function of the grid interconnection protection device 22 is completed, the output of the second DC power supply 50 is turned off and the operation of the power adjustment device 20 is stopped. The second DC power supply 50 is removed from the input terminal 5 and the operation check of the grid connection protection device 22 is finished. In the first embodiment, since the DC power generation device 10 is not activated, the time required for the DC power generation device 10 to operate stably is shortened, and the operation confirmation of the grid connection protection device 22 can be terminated early.

Second Embodiment
Next, a second embodiment of the device of the present invention will be described. FIG. 3 is a block diagram showing a schematic configuration of the inventive device 2 according to the second embodiment. As shown in FIG. 3, as in the first embodiment, the device 2 of the present invention includes a DC power generation device 10 including a reforming device 11 and a fuel cell 12, an orthogonal transformation device 21, a grid connection protection device 22, and the like. A power adjustment device 20 including a control device 23 and a DC auxiliary power supply 24 is housed in a common housing 4 and integrated as a fuel cell power generation unit. In addition, in FIG. 3, traps, such as a heat exchanger which collect | recovers exhaust heat from the reformer 11 grade | etc., And a pump of various uses, an air blower, are not shown in figure. In addition, an exhaust heat recovery heat storage unit that stores the exhaust heat recovered through the heat exchanger in the form of hot water and supplies it to a predetermined heat load is provided separately from the distributed power generator 2 shown in FIG. The cogeneration system is configured by being used in combination with the distributed power generator 2. However, the device 2 of the present invention may be used as a distributed power generator that can be connected to the grid independently without being used together with the exhaust heat recovery heat storage unit.

  Further, in the second embodiment, the device 2 of the present invention is configured to include the second DC power source 6 in the housing 4 instead of providing the pair of input terminals 5 in the housing 4. The second DC power supply 6 is installed so that the second DC power output from the second DC power supply 6 can be input to the orthogonal transformation device 21 in place of the DC power generation device 10 during the trial operation of the inventive device 2. Specifically, a pair of output terminals of the second DC power supply 6 select one of the DC / DC converters 25 via an input switching circuit 9 that alternatively selects two input pairs and connects them to the output pair. Connected to the pair of input terminals separately.

  The second DC power supply 6 is connected to, for example, the output terminals OUT1 and OUT2 of the orthogonal transformation device 21 in the same manner as the external second DC power supply 50 used by connecting to the pair of input terminals 5 in the first embodiment. The AC / DC conversion circuit 7 that converts AC power supplied from the commercial AC power supply 30 into DC power and the storage battery 8 that stores the converted DC power can be used. The output voltage of the second DC power source 6 is the same as the output voltage of the fuel cell 12 (DC 30V to 100V). The storage battery 8 built in the second DC power source 6 is connected to the orthogonal transformation device 21 and the grid connection protection device of the present invention device 1 during the time required for a test run for confirming the operation of the grid connection protection device 22 described later. 22 and the controller 23 having a sufficient storage capacity to supply power.

  The configuration of the device 2 of the present invention shown in FIG. 2 is different from the first embodiment in which the housing 4 is provided with the second DC power supply 6 and the housing 4 is provided with the input terminal 5. Since the configurations of the other DC power generation device 10 and the power adjustment device 20 are the same as those in the first embodiment, a duplicate description is omitted. In addition, the configuration in which the device 2 of the present invention is grid-connected via the commercial AC power supply 30 for supplying the single-phase three-wire AC power 200V / 100V and the distribution board 44 is also the same as that of the first embodiment, and therefore redundant. I will omit the explanation.

  Next, the method of the present invention for confirming the operation of the grid connection protection device 22 after the device 2 of the present invention is installed at the actual use place will be described.

  First, before starting the test operation for confirming the operation of the grid connection protection device 22, the second DC power supply 6 is charged. Instead of supplying DC power from the DC power generation device 10 by operating the input switching circuit 9 and connecting the second DC power supply 6 to the DC / DC converter 25 without starting the DC power generation device 10. The second DC power is supplied from the second DC power source 6 to the power adjustment device 20. As a result, since the power adjustment device 20 is activated, a test for confirming the operation of the grid connection protection device 22 can be performed. When the operation check test corresponding to the grid connection protection function of the grid connection protection device 22 is completed, the output of the second DC power supply 6 is turned off and the operation of the power adjustment device 20 is stopped. In the second embodiment, as in the first embodiment, since the DC power generation device 10 is not started, the time required for the DC power generation device 10 to operate stably is shortened, and the operation check of the grid connection protection device 22 is performed early. Can be terminated.

<Third Embodiment>
Next, a third embodiment of the device of the present invention will be described. FIG. 4 is a block diagram showing a schematic configuration of the inventive device 3 according to the third embodiment. As shown in FIG. 4, as in the first and second embodiments, the device 3 of the present invention includes a DC power generation device 10 including a reforming device 11 and a fuel cell 12, an orthogonal transformation device 21, and grid connection protection. The power adjustment device 20 including the device 22, the control device 23, and the DC auxiliary power supply 24 is housed in a common housing 4 and is integrated as a fuel cell power generation unit. In addition, in FIG. 4, heat exchangers which collect | recover the waste heat from the reformer 11 grade | etc., And traps, such as a pump and a fan for various uses, are not shown in figure. Further, an exhaust heat recovery heat storage unit that stores the exhaust heat recovered through the heat exchanger in the form of hot water and supplies the heat to a predetermined heat load is provided separately from the distributed power generator 2 shown in FIG. The cogeneration system is configured by being used in combination with the distributed power generator 2. However, the device 2 of the present invention may be used as a distributed power generator that can be connected to the grid independently without being used together with the exhaust heat recovery heat storage unit.

  Furthermore, in the third embodiment, the inventive device 3 branches from a fuel supply path for supplying hydrogen gas from the reforming device 11 of the DC power generation device 10 to the fuel cell 12, and hydrogen gas is supplied from the outside to the fuel cell 12. An external fuel inlet 13 for supply is provided in the housing 4. Note that whether hydrogen gas is supplied to the fuel cell 12 from the reformer 11 or the external fuel inlet 13 is selected by switching an on-off valve or a three-way valve (not shown) provided in each branch path.

  The configuration of the device 3 of the present invention shown in FIG. 3 is different from that of the first embodiment in which the housing 4 is provided with the external fuel injection port 13 in that the housing 4 is provided with the input terminal 5. The other configurations of the DC power generation device 10 and the power adjustment device 20 are the same as those in the first embodiment, and thus redundant description is omitted. In the third embodiment, the fuel cell 2 uses a solid polymer electrolyte fuel cell (PEFC) whose operating temperature is as low as 70 ° C. to 90 ° C. compared to an oxide solid oxide fuel cell (SOFC). Assumed. In addition, the configuration in which the device 3 of the present invention is connected to the system via the commercial AC power supply 30 for supplying the single-phase three-wire AC power 200V / 100V and the distribution board 44 is the same as that in the first embodiment, and therefore redundant. I will omit the explanation.

  Next, the method of the present invention for confirming the operation of the grid connection protection device 22 after the device of the present invention 3 is installed at the actual use place will be described.

  First, a hydrogen cylinder 53 filled with hydrogen is prepared and connected to the external fuel inlet 13 before starting a test operation for confirming the operation of the grid interconnection protection device 22. Hydrogen gas is supplied to the fuel cell 12 from the hydrogen cylinder 53 via the external fuel inlet 13 without starting the reformer 11 of the DC power generator 10. As a result, the fuel cell 12 is activated to start power generation. When the fuel cell 12 reaches a stable operation, the power adjustment device 20 is activated, so that a test for confirming the operation of the grid connection protection device 22 can be performed. When the operation check test corresponding to the grid interconnection protection function of the grid interconnection protection device 22 is completed, the hydrogen supply from the hydrogen cylinder 53 is stopped, the fuel cell 12 is turned off, and the operation of the power adjustment device 20 is stopped. To do. When the fuel cell 12 is a PEFC, the operation temperature is relatively low, so that the time until the DC voltage is stably output can be reduced as compared with the case where the reformer 11 is started.

  As described above, the first to third embodiments of the present invention device and the present invention method have been described in detail. It is not limited to the embodiment. For example, the output of the power adjustment device 20 is not limited to the single-phase three-wire AC power 200V / 100V. Further, the fuel cell 12 is not limited to PEFC or SOFC. Further, the configuration of the reformer 11 is not limited to the configurations of the above embodiments.

  Further, in the first embodiment, the pair of input terminals 5 are directly connected to the pair of input terminals 5 of the DC / DC converter 25. However, the same input switching circuit 9 as in the second embodiment is used. Then, the pair of input terminals 5 may be individually connected to the pair of input terminals of the DC / DC converter 25 via the input switching circuit 9.

  Further, in the second embodiment, the second DC power supply 6 is separately connected to the pair of input terminals of the DC / DC converter 25 via the input switching circuit 9. A pair of output terminals may be directly connected to a pair of input terminals of the DC / DC converter 25 without going through the input switching circuit 9.

  A fuel cell type distributed power generation device according to the present invention is a fuel cell type distributed power generation device in which a DC power generation device provided with a fuel cell and a power adjustment device are housed in a common casing and integrated as a fuel cell power generation unit. In particular, it is useful for shortening the time for the operation check test of the grid connection protection device.

1 is a block diagram schematically showing a schematic configuration in a first embodiment of a fuel cell type distributed generator according to the present invention. The block diagram which shows typically the connection relation with the commercial alternating current power supply of the fuel cell type distributed generation device concerning the present invention. The block diagram which shows typically schematic structure in 2nd Embodiment of the fuel cell type | mold distributed generation device which concerns on this invention. The block diagram which shows typically schematic structure in 3rd Embodiment of the fuel cell type | mold distributed generation device which concerns on this invention. A block diagram schematically showing a schematic configuration of a conventional fuel cell type distributed generator

Explanation of symbols

1, 2, 3: Fuel cell type distributed power generation device according to the present invention 4: Case 5: Input terminal 6, 50: Second DC power source 7, 51: AC / DC converter circuit 8, 52: Storage battery 9: Input switching Circuit 10: DC power generation device 11: reforming device 12: fuel cell 13: external fuel injection port 20: power adjustment device 21: orthogonal transformation device 22: grid interconnection protection device 23: control device 24: DC auxiliary power supply 25: DC / DC converter 26: Inverter circuit 27: Interconnection relay 28: AC ammeter 29: AC voltmeter 30: Commercial AC power supply 40: Power load 41: Master breaker 42: Branch breaker 43: Interconnection breaker 44: Distribution board 53 : Hydrogen cylinder 60: Conventional fuel cell type distributed generator OUT1, OUT2: Output terminal of inverter circuit section FG: Fuel (hydrogen)
SG: Primary raw material (city gas)
N: Neutral line of single-phase three-wire power line U: Voltage line of single-phase three-wire power line V: Voltage line of single-phase three-wire power line

Claims (8)

A DC power generation device including a fuel cell that outputs DC power, an orthogonal transform device that converts the DC power output from the DC power generation device into AC power that can be connected to a commercial AC power source, and an abnormality in the orthogonal transform device A grid connection protection device for protecting the commercial AC power supply from operation and a control device for controlling the operation of the orthogonal transformation device in cooperation with the grid connection protection device are integrated and accommodated in a common housing. A fuel cell type distributed power generator,
2. A fuel cell type distributed power generator, wherein a second DC power output from a second DC power source different from the DC power generator can be input to the orthogonal transform device.   2. The fuel cell type distributed generator according to claim 1, wherein an input terminal for receiving the second DC power from the outside is provided in the housing.   The fuel cell type distributed generator according to claim 1, wherein the second DC power supply is housed in the casing. The second DC power source includes an AC / DC converter circuit that converts AC power supplied from the commercial AC power source into DC power, and a storage battery that stores the converted DC power,
The storage battery has a storage capacity sufficient to supply power to the orthogonal transformation device, the grid connection protection device, and the control device during a time required for a test run for confirming the operation of the grid connection protection device. The fuel cell type distributed generator according to claim 3. A direct-current power generator including a fuel cell that outputs direct-current power, an orthogonal transform device that converts the direct-current power output from the direct-current power generator into alternating-current power that can be connected to a commercial alternating-current power supply, and the orthogonal transform device A system interconnection protection device for protecting the commercial AC power supply from abnormal operation, and a control device for controlling the operation of the orthogonal transformation device in cooperation with the system interconnection protection device are integrated in a common housing. It is a fuel cell type distributed power generation device,
The DC power generation device branches from a fuel supply path for supplying the fuel to the fuel cell from a reformer that generates fuel to be supplied to the fuel cell from a predetermined primary raw material. An external fuel injection port for supplying to a battery is provided. A test operation method for a fuel cell type distributed generator according to claim 2,
During a test operation for confirming the operation of the grid interconnection protection device, the output of the second DC power source is connected to the input terminal without starting the fuel cell of the DC power generation device, A test operation method for a distributed power generator, wherein power is supplied to the orthogonal transform device. A test operation method for a fuel cell type distributed generator according to claim 3 or 4,
At the time of a test run for confirming the operation of the grid interconnection protection device, the second DC power source is started without starting the fuel cell of the DC power generation device, and is output from the second DC power source. A test operation method for a distributed generator, wherein the second DC power is supplied to the orthogonal transform device. A test operation method for a fuel cell type distributed generator according to claim 5,
During a test operation for confirming the operation of the grid interconnection protection device, the fuel cell is operated by supplying external fuel to the fuel cell from the external fuel inlet without starting the reforming device. A method for trial operation of a distributed power generator, wherein DC power output from the fuel cell is supplied to the orthogonal transform device.

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