JP2011119046A - Fuel cell generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell generator capable of preventing deterioration and life shortening of a fuel cell by preventing temporary disorder in a raw material system, an air system, and an electrical system of the fuel cell even when an inverter is stopped upon receipt of abnormality of a power system. <P>SOLUTION: When a first abnormality determining condition that a voltage value of the power system 101 detected by a voltage sensor 111 exceeds a first allowable range Vref 1 for a predetermined time t1 is satisfied, a first abnormality determining means 112 determines abnormality to open a relay 110. When a second abnormality determining condition that the voltage value of the power system 101 detected by the voltage sensor 111 exceeds a second allowable range Vref 2 narrower than the first allowable range Vref 1 for the predetermined time t1 is satisfied, a second abnormality determining means 113 determines the abnormality to decrease and stop an output power of the inverter 108 by a control means 109 and to adjust the power consumption of a heater 106 so as to reduce a fluctuation of the output power of the fuel cell 104. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell power generator that supplies AC power to an electric power system and an AC load in linkage with the electric power system.

  Conventionally, this type of fuel cell power generator has been disclosed in, for example, the configuration shown in FIG. 5 (see, for example, Patent Document 1).

  Hereinafter, the fuel cell power generation device disclosed in Patent Document 1 will be described.

  FIG. 5 is a block diagram of a conventional fuel cell power generator.

  As shown in FIG. 5, the fuel cell power generator includes a fuel cell 1, a first DC / DC converter 2, a second DC / DC converter 3, an inverter 4, an AC load 5, a reverse power flow monitoring sensor 6, a power control unit 7, a direct current. It is comprised with the load 8, and is connected with the electric power grid | system 10 through the connection part 9. FIG.

  Here, the fuel cell 1 generates electricity by causing an electrochemical reaction between oxygen and hydrogen. The first DC / DC converter 2 receives the output voltage of the fuel cell 1, converts the input voltage to a DC voltage (for example, DC 25 V) having a different voltage value, and outputs the DC voltage. The second DC / DC converter 3 receives the output voltage of the fuel cell 1, converts the input voltage into a DC voltage (for example, DC 140 V) having a different voltage value, and outputs the DC voltage.

  The inverter 4 receives the output voltage of the second DC / DC converter 3, converts the input voltage into an AC voltage (for example, AC 100V), and outputs the AC voltage. The AC load 5 drives the AC voltage supplied from the inverter 4 as a power supply voltage. The reverse flow monitoring sensor 6 monitors (detects) whether the current of the inverter 4 does not flow to the power system 10 side, that is, whether reverse current is flowing.

  The power control unit 7 refers to the information on the reverse flow from the reverse flow monitoring sensor 6 and the system stop signal from the interconnection unit 9 to determine the output power of the fuel cell 1, the first DC / DC converter 2, and the inverter 4. Control. The DC load 8 is a load driven by a DC voltage supplied from the first DC / DC converter 2, for example, a heater made of a resistor.

  The conventional fuel cell power generator configured as described above stops the output of the inverter 4 when the stop of the power system 1 occurs due to a lightning strike or the like and the stop signal of the power system 10 is received from the interconnection unit 9. . At the same time, surplus power generated by the fuel cell 1 is consumed by the DC load 8 by increasing the output of the first DC / DC converter 2. At this time, the output power of the first DC / DC converter 2 is increased by soft start.

JP 2006-67757 A

  However, in the above conventional configuration, when an abnormality occurs in the power system 10, the inverter 4 is stopped and then the output power of the first DC / DC converter 2 is increased. appear. At that time, a temporary disturbance occurs in the raw material system, the air system, and the electric system, and there is a problem that the fuel cell 1 is stressed, the fuel cell 1 is deteriorated, and the life of the fuel cell 1 is shortened.

  The present invention solves the above-described conventional problems, and prevents the fuel cell material system, air system, and electrical system from being temporarily disturbed even when the inverter is stopped due to an abnormality in the power system. It is an object of the present invention to provide a fuel cell power generator that can prevent deterioration of the battery and shortening of its life.

  In order to solve the above-described conventional problems, a fuel cell power generation device according to the present invention is a fuel cell power generation device that supplies AC power to a load in linkage with an electric power system. A fuel cell to be generated, an inverter that converts DC power generated by the fuel cell into AC power, an opening / closing means that is connected to and disconnected from the power system by turning on and off, and output power of the fuel cell An internal load for consumption, a control means for controlling the output power of the inverter and the power consumption of the internal load, and a first that determines an abnormality when a characteristic value of the power system satisfies a first abnormality determination condition. An abnormality determining means; and a second abnormality determining means for determining an abnormality when a characteristic value of the power system satisfies a second abnormality determination condition, and the opening / closing means when the first abnormality determining means determines an abnormality. But When the second abnormality determination means determines that the abnormality is present, the control means reduces the output power of the inverter and stops the power consumption, and the power consumption of the internal load is reduced so that the fluctuation of the output power of the fuel cell is reduced. To make adjustments.

  As a result, even if the inverter is stopped due to an abnormality in the power system, it prevents temporary disturbance of the fuel cell material system, air system, and electrical system, and prevents deterioration of the fuel cell and shortening of the service life. Can do.

  The fuel cell power generation device of the present invention prevents a temporary disturbance of the raw material system, air system, and electric system of the fuel cell even when the inverter is stopped due to an abnormality in the power system, deterioration of the fuel cell, and The shortening of the life can be prevented.

1 is a block diagram of a fuel cell power generator according to Embodiment 1 of the present invention. Timing chart showing operation of fuel cell power generator in same embodiment Timing chart showing the operation of the fuel cell power generator in Embodiment 2 of the present invention Timing chart showing the operation of the fuel cell power generator in Embodiment 3 of the present invention Block diagram of conventional fuel cell power generator

  According to a first aspect of the present invention, there is provided a fuel cell power generation apparatus that supplies AC power to a load in linkage with an electric power system, a fuel cell that generates direct-current power by reacting a fuel and an oxidant, and a direct current generated by the fuel cell. An inverter that converts electric power into AC power; an opening / closing means that is connected to and disconnected from the power system by turning on and off; an internal load that consumes output power of the fuel cell; and output power of the inverter And a control means for controlling the power consumption of the internal load, a first abnormality determination means for determining an abnormality when the characteristic value of the power system satisfies a first abnormality determination condition, and a characteristic value of the power system Second abnormality determining means for determining an abnormality when two abnormality determination conditions are satisfied. When the first abnormality determining means determines that there is an abnormality, the opening / closing means is opened, and the second abnormality determining means is abnormal. Judging Said control means in which performs adjustment of the fuel cell output power power consumption change the internal load so that small with stops decreasing the output power of the inverter.

  With this configuration, when the characteristic value of the power system satisfies the first abnormality determination condition, the first abnormality determination means determines that the abnormality is abnormal, the opening / closing means is opened, and the characteristic value of the power system is When the second abnormality determination condition is satisfied, the second abnormality determination means determines that the abnormality is present, and the control means decreases the output power of the inverter to stop it, and the fluctuation in the output power of the fuel cell is reduced. Since the internal load power consumption is adjusted, even if the inverter is stopped due to an abnormality in the power system, the fuel cell's raw material system, air system, and electrical system are prevented from being temporarily disturbed, and the fuel cell is deteriorated. , And shortening of life can be prevented.

  In the second invention, in particular, in the first invention, the control means makes the speed at which the output power of the inverter is reduced and the speed at which the power consumption of the internal load is increased substantially the same. As a result, the output destination of the fuel cell can be switched without changing the output, so that temporary disturbance of the fuel cell material system, air system, and electrical system can be prevented, and deterioration of the fuel cell and shortening of the life can be prevented. be able to.

  In the third invention, in particular, in the first or second invention, the first abnormality determination condition is that the characteristic value of the power system continuously exceeds the first allowable range for the first predetermined time, The second abnormality determination condition is that the characteristic value of the power system continuously exceeds the second allowable range for the second predetermined time. As a result, when the characteristic value of the power system changes transiently due to the balance between the power supplied by the power system and the fuel cell power generator and the power demanded by the AC load, the first abnormality determining means, and the second An erroneous determination by the abnormality determining means can be prevented, and the reliability of the apparatus can be improved.

  In the fourth invention, in particular, in the third invention, the second allowable range is narrower than the first allowable range. As a result, the second abnormality determination means can determine the abnormality prior to the first abnormality determination means, and the fuel cell varies the output power before there is no output destination via the inverter due to the opening of the opening / closing means. Since the output destination can be switched without any temporary disturbance of the fuel cell material system, air system, and electrical system, it is possible to prevent deterioration of the fuel cell and shortening of its life.

  According to a fifth aspect of the invention, in particular, in the third or fourth aspect of the invention, the second predetermined time is shorter than the first predetermined time. As a result, the second abnormality determination means can determine the abnormality prior to the first abnormality determination means, and the fuel cell varies the output power before there is no output destination via the inverter due to the opening of the opening / closing means. Since the output destination can be switched without any temporary disturbance of the fuel cell material system, air system, and electrical system, it is possible to prevent deterioration of the fuel cell and shortening of its life.

  In a sixth aspect of the invention, in particular, in any one of the third to fifth aspects of the invention, at least a second permissible range of the first permissible range and the second permissible range, a first predetermined time, and a second Among the predetermined times, there is provided setting means capable of setting at least a second predetermined time. Thereby, the determination sensitivity of the second abnormality determination means can be adjusted in accordance with the state of the power system in which the fuel cell power generation apparatus is installed, and the reliability of the apparatus can be improved.

  In the seventh aspect of the invention, in particular, in any one of the first to sixth aspects of the invention, the characteristic value of the power system includes the frequency of the power system, the frequency variation rate, the voltage, the harmonic component, and the magnitude of the voltage phase jump. At least one of the above. Thereby, when an abnormality occurs in the power system due to lightning or the like, the abnormality of the power system can be determined.

  In the eighth invention, in particular, in any one of the first to seventh inventions, the second abnormality determination condition is determined when the second abnormality determination means determines that the second abnormality determination condition is satisfied. Is displayed on the display means, notified by the notification means, or stored in the operation history storage means. Thereby, it can be surely and easily notified to the user or the maintenance man that there is an abnormality in the power system.

  In a ninth invention, in particular, in any one of the first to eighth inventions, a predetermined time has elapsed since the control means determined that the second abnormality determination means satisfied the second abnormality determination condition. Even if the first abnormality determination means does not determine that the first abnormality determination condition is satisfied, the power consumption of the internal load is reduced so that the output of the inverter is restarted and the fluctuation in the output power of the fuel cell is reduced. Make adjustments. As a result, the output destination of the fuel cell can be switched without changing the output, so that temporary disturbance of the fuel cell material system, air system, and electrical system can be prevented, and deterioration of the fuel cell and shortening of the life can be prevented. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
Hereinafter, the fuel cell power generation apparatus according to Embodiment 1 of the present invention will be described in detail with reference to FIGS. 1 and 2.

  FIG. 1 is a block diagram showing a fuel cell power generator according to Embodiment 1 of the present invention. FIG. 2 is a timing chart showing the operation of the fuel cell power generator of the present embodiment.

  In FIG. 1, in addition to the fuel cell power generation apparatus 102, a power system 101 and an AC load 103 are shown together. Here, the electric power system 101 is a single-phase three-wire AC power source including a U phase, an O phase, and a W phase. The AC load 103 is a device that consumes AC power supplied from the power system 101 or the fuel cell power generator 102.

  As shown in FIG. 1, the fuel cell power generation apparatus 102 of the present embodiment includes a fuel cell 104, a first DC / DC converter 105, a heater 106 as an internal load, a second DC / DC converter 107, Inverter 108, control means 109, relay 110 as opening / closing means, voltage sensor 111 as voltage detection means, first abnormality determination means 112, second abnormality determination means 113, and switch as setting means 114 and an LED 115 as a notification means. In this embodiment, the internal load is the heater 106, the opening / closing means is the relay 110, the voltage detecting means is the voltage sensor 111, the setting means is the switch 114, and the notification means is the LED 115, but other means having the same function are used. May be used instead.

  Here, the fuel cell 104 generates direct-current power by generating water by chemically reacting oxygen and hydrogen. The first DC / DC converter 105 has a configuration including an insulating transformer, and boosts the DC voltage generated by the fuel cell 104. The heater 106 is driven by a DC voltage generated by the first DC / DC converter 105. The second DC / DC converter 107 has a configuration including an insulating transformer, and boosts the DC voltage generated by the fuel cell 104 to a DC voltage different from that of the first DC / DC converter 105.

  The inverter 108 converts the direct current output from the second DC / DC converter 107 into an alternating current that can be consumed by the alternating current load 103. The control means 109 controls the power consumption of the heater 106 via the first DC / DC converter 105 and also controls the output power of the second DC / DC converter 107 and the inverter 108. The relay 110 is connected to and disconnected from the power system 101 by turning on and off. The voltage sensor 111 detects the voltage at the connection point between the power system 101 and the fuel cell device 102.

  The first abnormality determination unit 112 determines that an abnormality has occurred when the voltage value detected by the voltage sensor 111 satisfies the first abnormality determination condition. The second abnormality determination unit 113 determines that an abnormality has occurred when the voltage value detected by the voltage sensor 111 satisfies the second abnormality determination condition. The switch 114 sets the second abnormality determination condition of the second abnormality determination unit 113. The LED 115 is turned on when the second abnormality determination unit 113 determines that there is an abnormality.

  Note that the first abnormality determination condition of the first abnormality determination unit 112 is that the voltage value detected by the voltage sensor 111 is a first allowable range (in this embodiment, 100 ± 10 V). The second abnormality determination condition of the second abnormality determination means 113 is that the voltage value detected by the voltage sensor 111 is the first value. The allowable range of 2 (100 ± 8 V in this embodiment) is continuously exceeded for a second predetermined time (1.0 s in this embodiment).

  2, in the fuel cell power generator of the present embodiment, the AC voltage when the power system 101 is stopped due to lightning or the like (indicated by an effective value in the present embodiment), output power of each unit, power consumption, and Indicates a change in state.

  Here, (A) is a voltage at the interconnection point, that is, a voltage value detected by the voltage sensor 111. (B) is the output power of the fuel cell 104. (C) is the output power of the inverter 108. (D) is the power consumption of the heater 106. (E) is the state of the relay 110. In (A), Vref1 is a first allowable range, Vref2 is a second allowable range, and t1 is a first predetermined time and a second predetermined time.

  The operation and action of the fuel cell power generator of the present embodiment configured as described above will be described with reference to FIGS.

  When the fuel cell 104 starts power generation, the fuel cell power generation device 102 is connected to the power system 101 by turning on the relay 110 and supplies power to the AC load 103.

  In the flow of power supply from the fuel cell 104 to the AC load 103, first, the DC power generated by the fuel cell 104 is boosted by the second DC / DC converter 107 to a voltage that the inverter 108 can output. In the present embodiment, the voltage is boosted to, for example, DC 400V. Then, the voltage boosted by the inverter 108 is converted from direct current to alternating current (in this embodiment, for example, AC 200 V) and supplied to the alternating current load 103.

  In a state where the power system 101 is connected to the AC load 103 and the power generation apparatus such as a fuel cell is connected to the power system 101, the power system 101 is stopped when the power system 101 is stopped for the maintenance and safety of the power system 101. It is obliged to detect the stop of the system 101, stop the output of the inverter 108, and disconnect the power system 101 by opening the relay 110.

  At this time, since it is difficult to rapidly reduce the output power of the fuel cell 104, when the output of the inverter 108 is stopped, surplus power is generated inside the fuel cell power generation device 102, and the fuel cell raw material system, air Systems and electrical systems are temporarily disturbed. Therefore, it is necessary to consume surplus power. Hereinafter, the operation of the fuel cell power generation apparatus 102 for preventing surplus power from being generated when the power system 101 is stopped will be described with reference to FIG.

  When the power system 101 stops (timing T1 in FIG. 2), an islanding phenomenon occurs between the fuel cell power generation apparatus 102 and the AC load 103, and the power supplied by the fuel cell power generation apparatus 102 and the AC load 103 are in demand. The voltage rises slowly due to the balance of power.

  In such a state, the second abnormality determination unit 113 determines that an abnormality occurs when the voltage value detected by the voltage sensor 111 exceeds the second allowable range Vref2 for a predetermined time t1 (timing T2 to T4 in FIG. 2).

  When the second abnormality determination unit 113 determines that the abnormality is present, the control unit 109 gradually reduces and stops the output power Pac of the inverter 108 in order to prevent stress on the wiring and to suppress noise emission. The power consumption P1 of the heater 106 is increased at the same speed as the decrease speed of the output power Pac of the inverter 108, and finally the output power Pdc of the fuel cell 104 is completely consumed by the heater 106 (timing T4 to T5 in FIG. 2). ).

  Further, when the second abnormality determining means 113 determines that the second abnormality determining means 113 is abnormal, the LED 115 is lit to notify that the second abnormality determining condition is satisfied, and notify the user, maintenance man, etc. that abnormality has occurred (see FIG. 2 timing T4).

  On the other hand, the first abnormality determining means 112 determines that an abnormality occurs when the voltage value detected by the voltage sensor 111 exceeds the first allowable range Vref1 for a predetermined time t1 (timing T3 to T6 in FIG. 2).

  Then, when the first abnormality determination unit 112 determines that the relay 110 is abnormal, the relay 110 disconnects the fuel cell power generator 102 from the power system 101 by opening the contact (timing T6 in FIG. 2). At this time, since all the output power Pdc of the fuel cell 104 is already consumed by the heater 106, no power that is not consumed inside the fuel cell power generation apparatus 102 is generated, and it is necessary to reduce the output power Pdc of the fuel cell 104. The operation can be continued stably.

  Here, by allowing the switch 114 to switch between the second allowable range and the second predetermined time in advance, for example, the voltage value detected by the voltage sensor 111 depending on the state of the power system 101 is frequently changed to the second allowable range. If it exceeds the range, the determination sensitivity of the second abnormality determination unit 113 is lowered by widening the second allowable range or extending the second predetermined time. Conversely, if the control means 109 determines that the first abnormality determination means 112 is abnormal during power adjustment, the second allowable range is narrowed or the second predetermined time is shortened. Thus, the determination sensitivity of the second abnormality determination unit 114 is made sensitive.

  In this embodiment, the abnormality of the power system 101 is determined based on the magnitude of the voltage of the power system 101 at the interconnection point. However, the frequency, the fluctuation rate of the frequency, the harmonic component, and the jump of the voltage phase are determined. An abnormality may be determined based on any one or more of the sizes.

  Further, in the present embodiment, when the second abnormality determination unit 113 determines that the second abnormality determination condition is satisfied, the abnormality is notified by turning on the LED 115, but notification by a buzzer or the like, LCD, etc. It is also possible to notify the user, maintainer, or the like that the second abnormality determination condition has been satisfied by performing display on the display means and storage in the operation history storage means using a memory or the like.

  In the present embodiment, the second abnormality determination unit 113 determines that the second predetermined time is shorter than the first predetermined time, so that the second abnormality determination unit 113 determines that there is an abnormality before the first abnormality determination unit 112. By making the first abnormality determination condition and the second abnormality determination condition the same, the first abnormality determination means 113 and the second abnormality determination means 114 simultaneously determine that there is an abnormality, or the second allowable range is It may be determined that the second abnormality determination means 113 is abnormal after the first abnormality determination means 112 by setting the second predetermined time longer than the first predetermined time or larger than the allowable range of 1. . However, in that case, when an AC load is provided between the inverter 108 and the relay 110 and the first abnormality determination unit 112 determines that the abnormality is detected and the relay 110 is opened, the fuel cell 104 is temporarily connected via the inverter 108. The output is consumed by an AC load, and the output destination is switched without changing the output power of the fuel cell 104 by switching the output destination when the second abnormality determination means determines that the abnormality has occurred.

  As described above, in the present embodiment, when the first abnormality determination condition that the voltage value of the power system 101 detected by the voltage sensor 111 exceeds the first allowable range Vref1 for the predetermined time t1 is satisfied, The abnormality determination unit 112 determines that an abnormality has occurred, the relay 110 is opened, and the first abnormality determination condition that the voltage value of the power system 101 detected by the voltage sensor 111 exceeds the second allowable range Vref2 for a predetermined time t1. Then, the second abnormality determination means 113 determines that there is an abnormality, and the control means 109 reduces the output power of the inverter 108 to stop it, and the power consumption of the heater 106 so that the fluctuation of the output power of the fuel cell 104 becomes small. Therefore, even if the inverter 108 is stopped due to an abnormality in the power system 101, the fuel cell 104 raw material system, air system, electrical system Preventing temporary disturbances, it is possible to prevent deterioration of the fuel cell 104, and a shortening of life.

  Further, in the present embodiment, the control means 109 makes the speed at which the output power of the inverter 108 decreases and the speed at which the power consumption of the heater 106 increase substantially the same, so that the fuel cell 104 does not fluctuate the output. Since the output destination can be switched, temporary disturbance of the raw material system, air system, and electrical system of the fuel cell 104 can be prevented, and deterioration of the fuel cell 104 and shortening of the life can be prevented.

  Further, in the present embodiment, the first abnormality determination condition of the first abnormality determination unit 112 is that the characteristic value of the power system 101 continuously exceeds the first allowable range for the first predetermined time, The second abnormality determination condition of the second abnormality determination means 113 is that the characteristic value of the electric power system 101 continuously exceeds the second allowable range for the second predetermined time, so that the electric power system 101 and the fuel When the characteristic value of the power system 101 changes transiently due to the balance between the power supplied by the battery power generation apparatus 102 and the power demanded by the AC load 103, the first abnormality determination means 112 and the second abnormality determination means 113 Can be prevented, and the reliability of the apparatus can be improved.

  In the present embodiment, the second abnormality determination unit 113 can determine the abnormality before the first abnormality determination unit 112 by making the second allowable range narrower than the first allowable range. Since the output destination of the fuel cell 104 can be switched without changing the output power before the output destination via the inverter 108 due to the opening of the relay 110 disappears, the fuel cell 104 is temporarily connected to the raw material system, air system, and electrical system. Can be prevented, and deterioration of the fuel cell 104 and shortening of its life can be prevented.

  Further, in the present embodiment, at least the second allowable range of the first allowable range and the second allowable range, and at least the second predetermined time of the first predetermined time and the second predetermined time are set. Since the switch 114 is provided, the determination sensitivity of the second abnormality determination unit 113 can be adjusted in accordance with the state of the power system 101 in which the fuel cell power generation apparatus 102 is installed. Can be improved.

  Further, in the present embodiment, the characteristic value of the power system 101 is at least one of the frequency of the power system 101, the frequency variation rate, the voltage, the harmonic component, and the magnitude of the voltage phase jump, When an abnormality occurs in the power system 101 due to a lightning strike or the like, the abnormality of the power system 101 can be determined.

  In the present embodiment, when the second abnormality determination unit 113 determines that the second abnormality determination condition is satisfied, the display unit displays that the second abnormality determination condition is satisfied, and the LED 115 By performing either notification or storage in the operation history storage means, it is possible to reliably and easily notify the user or maintenance man that there is an abnormality in the power system 101.

(Embodiment 2)
Hereinafter, a fuel cell power generator according to Embodiment 2 of the present invention will be described with reference to FIGS. 1 and 3. FIG. 3 is a timing chart showing the operation of the fuel cell power generator according to Embodiment 2 of the present invention.

  3, as in FIG. 2, in the fuel cell power generator of the present embodiment, the AC voltage when the power system 101 is stopped due to lightning strike (indicated by the effective value in the present embodiment), the output of each part Shows power, power consumption, and state changes.

  Here, (F) is a voltage at the interconnection point, that is, a voltage value detected by the voltage sensor 111. (G) is the output power of the fuel cell 104. (H) is the output power of the inverter 108. (I) is the power consumption of the heater 106. (J) is the state of the relay 110. In (F), Vref3 is a first allowable range and a second allowable range, t2 is a first predetermined time, and t3 is a second predetermined time.

  That is, as shown in FIG. 3, in the fuel cell power generation device of the present embodiment, the first allowable range and the second allowable range are the same (in the present embodiment, the first allowable range, the second allowable range, In the present embodiment, the first predetermined time is set to 1.0 s, and the second predetermined time is set to 0. 9s), which is different from the method described in Embodiment 1 with reference to FIG.

  Here, it is assumed that the first predetermined time t2 is set longer than the time including the second predetermined time t3 and the soft stop time until the inverter 108 stops from the rated output.

  The configuration of the fuel cell power generation device of the present embodiment is the same as the configuration of the fuel cell power generation device of Embodiment 1 shown in FIG.

  Hereinafter, the operation of the fuel cell power generator according to the present embodiment will be described with reference to FIG.

  When the power system 101 is stopped (timing T7 in FIG. 3), an islanding phenomenon occurs between the fuel cell power generation device 102 and the AC load 103, and the power supplied by the fuel cell power generation device 102 and the AC load 103 are in demand. The voltage rises stepwise due to the balance of power.

  In such a state, the second abnormality determination unit 113 determines that an abnormality occurs when the voltage value detected by the voltage sensor 111 exceeds the second allowable range Vref3 for a predetermined time t2 (timing T7 to T8 in FIG. 3).

  When the second abnormality determination unit 113 determines that the abnormality is present, the control unit 109 gradually reduces and stops the output power Pac of the inverter 108 in order to prevent stress on the wiring and to suppress noise emission. Then, the power consumption P1 of the heater 106 is increased at the same speed as the decrease speed of the output power Pac of the inverter 108, and finally the output power Pdc of the fuel cell 104 is completely consumed by the heater 106 (timing T8 to T9 in FIG. 3). ).

  On the other hand, the first abnormality determination means 112 determines that an abnormality occurs when the voltage value detected by the voltage sensor 111 exceeds the first allowable range Vref3 for a predetermined time t3 (timing T7 to T10 in FIG. 3).

  Then, when the first abnormality determination unit 112 determines that the relay 110 is abnormal, the relay 110 disconnects the fuel cell power generator 102 from the power system 101 by opening the contact (timing T10 in FIG. 3). At this time, since all the output power Pdc of the fuel cell 104 is already consumed by the heater 106, no power that is not consumed inside the fuel cell power generation apparatus 102 is generated, and it is necessary to reduce the output power Pdc of the fuel cell 104. The operation can be continued stably.

  As described above, in the present embodiment, the first abnormality determination is performed by making the second predetermined time of the second abnormality determination means 113 shorter than the first predetermined time of the first abnormality determination means 112. The second abnormality determination means 113 can determine the abnormality before the means 112, and the fuel cell 104 outputs the output destination without changing the output power before the output destination via the inverter 108 due to the opening of the relay 110 disappears. Therefore, temporary disturbance of the raw material system, air system, and electric system of the fuel cell 104 can be prevented, and deterioration of the fuel cell 104 and shortening of the life can be prevented.

(Embodiment 3)
Hereinafter, a fuel cell power generator according to Embodiment 3 of the present invention will be described with reference to FIGS. 1 and 4. FIG. 4 is a timing chart showing the operation of the fuel cell power generator according to Embodiment 3 of the present invention.

  4, as in FIG. 2, in the fuel cell power generation device of the present embodiment, the AC voltage of the power system 101 (indicated by the effective value in the present embodiment), the output power, the power consumption, and the state of each unit Shows changes.

  Here, (K) is a voltage at the interconnection point, that is, a voltage value detected by the voltage sensor 111. (L) is the output power of the fuel cell 104. (M) is the output power of the inverter 108. (N) is the power consumption of the heater 106. (O) is the state of the relay 110.

  That is, as shown in FIG. 4, the fuel cell power generation device of the present embodiment uses FIG. 2 in Embodiment 1 except that the voltage Vac does not continuously exceed the first allowable range for the first predetermined time. This is different from the method described above.

  The configuration of the fuel cell power generation device of the present embodiment is the same as the configuration of the fuel cell power generation device of Embodiment 1 shown in FIG.

  Hereinafter, the operation of the fuel cell power generator of the present embodiment will be described with reference to FIG.

  The voltage may rise due to the balance between the power supplied by the power system 101 and the fuel cell power generator 102 and the power demanded by the AC load 103 (timing T11 in FIG. 4).

  In such a state, the second abnormality determination unit 113 determines that an abnormality occurs when the voltage value detected by the voltage sensor 111 exceeds the second allowable range Vref2 for a predetermined time t1 (timing T12 to T15 in FIG. 4).

  When the second abnormality determination unit 113 determines that the abnormality is present, the control unit 109 gradually reduces and stops the output power Pac of the inverter 108 in order to prevent stress on the wiring and to suppress noise emission. The power consumption P1 of the heater 106 is increased at the same speed as the decrease speed of the output power Pac of the inverter 108, and finally the output power Pdc of the fuel cell 104 is completely consumed by the heater 106 (timing T15 to T16 in FIG. 4). ).

  On the other hand, the first abnormality determination unit 112 starts time measurement when the voltage value detected by the voltage sensor 111 is out of the first allowable range Vref1 (timing T13 in FIG. 4). However, when the voltage value detected by the voltage sensor 111 during the time measurement falls within the first allowable range, the time measurement is terminated (timing T14 in FIG. 4).

  Under such circumstances, the control means 109 starts time measurement after the second abnormality determination means 113 determines that there is an abnormality (timing T15 in FIG. 4). If the first abnormality determination unit 112 does not determine that there is an abnormality even after the predetermined time t5 has elapsed since the start of time measurement, the output power of the inverter 108 is prevented in order to prevent stress on the wiring and suppress noise emission. While increasing Pac, the power consumption P1 of the heater 106 is decreased at the same speed as the increase speed of the output power Pac of the inverter 108, and the output destination of the fuel cell 104 is switched to the inverter 108 (timing T17 to T18 in FIG. 4). Thereafter, the same operation as before the timing T11 in FIG. 4 is performed.

  As described above, in the present embodiment, the control unit 109 determines that the first abnormality has occurred even after a predetermined time has elapsed since the second abnormality determination unit 113 determined that the second abnormality determination condition was satisfied. When the determination unit 112 does not determine that the first abnormality determination condition is satisfied, the output of the inverter 108 is restarted and the power consumption of the heater 106 is adjusted so that the fluctuation of the output power of the fuel cell 104 is reduced. Thus, since the fuel cell 104 can switch the output destination without changing the output, temporary disturbance of the raw material system, air system, and electrical system of the fuel cell 104 is prevented, and the deterioration of the fuel cell 104 and the life of the fuel cell 104 are prevented. Shortening can be prevented.

  As described above, the fuel cell power generator according to the present invention prevents temporary disturbance of the fuel cell material system, the air system, and the electrical system even when the inverter is stopped due to an abnormality in the power system. Because it can prevent deterioration of the fuel cell and shortening of its life, it can be applied to applications such as power generators connected to the power system using fuel cells installed in homes, factories, hospitals, schools, etc. Can do.

DESCRIPTION OF SYMBOLS 101 Electric power system 102 Fuel cell power generation device 104 Fuel cell 106 Heater (internal load)
108 Inverter 109 Control means 110 Relay (open / close means)
112 First abnormality determination means 113 Second abnormality determination means 114 Switch (setting means)
115 LED (notification means)

Claims (9)

In a fuel cell power generation apparatus that supplies AC power to a load in connection with a power system, a fuel cell that generates direct-current power by reacting a fuel and an oxidant, and converts the direct-current power generated by the fuel cell into AC power An inverter that connects and disconnects the power system by turning on and off, an internal load that dissipates the output power of the fuel cell, an output power of the inverter, and a consumption of the internal load Control means for controlling power; first abnormality determining means for determining an abnormality when the characteristic value of the power system satisfies a first abnormality determination condition; and a characteristic value of the power system satisfying a second abnormality determination condition. Second abnormality determining means for determining an abnormality when satisfying, the opening / closing means is opened when the first abnormality determining means determines to be abnormal, and the control means is determined when the second abnormality determining means is determined to be abnormal. Adjusting the fuel cell power plant for performing the fuel cell output power power consumption change the internal load so that small with stops decreasing the output power of the inverter. 2. The fuel cell power generator according to claim 1, wherein the control means makes the speed at which the output power of the inverter is reduced and the speed at which the power consumption of the internal load is increased substantially the same. The first abnormality determination condition is that a characteristic value of the power system continuously exceeds a first allowable range for a first predetermined time, and the second abnormality determination condition is a characteristic value of the power system. 3. The fuel cell power generator according to claim 1 or 2, wherein the second allowable range is continuously exceeded for a second predetermined time. The fuel cell power generator according to claim 3, wherein the second allowable range is narrower than the first allowable range. The fuel cell power generator according to claim 3 or 4, wherein the second predetermined time is shorter than the first predetermined time. At least the second permissible range of the first permissible range and the second permissible range and at least the second predetermined time of the first predetermined time and the second predetermined time can be set. The fuel cell power generator according to any one of claims 3 to 5, further comprising setting means. The characteristic value of the power system is at least one of a frequency of the power system, a frequency variation rate, a voltage, a harmonic component, and a magnitude of a voltage phase jump. The fuel cell power generator described in 1. When the second abnormality determination means determines that the second abnormality determination condition is satisfied, the fact that the second abnormality determination condition is satisfied is displayed on the display means, the notification means notifies, and the driving history is stored. The fuel cell power generator according to any one of claims 1 to 7, wherein one of storage is performed in the means. The control means may be configured such that the first abnormality determination means does not exceed the first abnormality determination condition even if a predetermined time has elapsed after the second abnormality determination means determines that the second abnormality determination condition is satisfied. The power consumption of the internal load is adjusted so that the output of the inverter is restarted and the fluctuation of the output power of the fuel cell is reduced when it is not determined that the condition is satisfied. Fuel cell power generator described in

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