JP2006032128A - Failure diagnosis control device for fuel cell system - Google Patents

Abstract

A fault diagnosis in a DC / AC converter is performed before power generation by a fuel cell by converting AC power from a commercial power source into DC power, inputting the DC power into DC / AC converter, and outputting AC. A failure diagnosis control device for a fuel cell system is provided.
A fuel cell, a DC / AC converter connected to a commercial power source, converting DC power from the fuel cell into AC power, and supplying AC power to a household load 13 together with the commercial power source, and from startup Operation control means 15 for controlling a series of operations until power generation and AC / DC conversion means 14 for generating DC power from a commercial power source are provided. The operation control means 15 is operated by AC / DC conversion means 14 before power generation by the fuel cell 11. By converting the obtained direct current power into alternating current power by the direct current alternating current conversion means 12 and performing fault diagnosis in the direct current alternating current conversion means 12, economical and safe power generation control can be performed.
[Selection] Figure 1

Description

  The present invention relates to a failure diagnosis control device for a fuel cell system that generates power using a fuel cell.

  As a conventional failure diagnosis control device for a fuel cell system, there has been a fuel cell system for diagnosing failure of an on-off valve provided in a fuel gas supply pipe that communicates a fuel gas supply source and a fuel cell main body. (For example, refer to Patent Document 1). FIG. 7 shows a conventional failure diagnosis control apparatus for a fuel cell system described in Patent Document 1. In FIG.

In FIG. 7, a first on-off valve 2 and a second on-off valve 3 are provided in a fuel gas supply pipe 4 between the fuel gas supply source 1 and the fuel cell main body 6, and the pressure of the fuel gas is detected between the on-off valves. A gas sensor 5 is provided. At the time of start-up, when the first and second on-off valves 2 and 3 are closed by the control of the control unit 7, the gas sensor 5 performs failure diagnosis of the first on-off valve, and then opens the first on-off valve. After the valve is closed, the valve is closed and the gas sensor 5 diagnoses the failure of the second on-off valve.
JP 09-022711 A

  However, the conventional configuration has a problem that it is a failure diagnosis of a part between the fuel gas supply source and the fuel cell main body, and is not a failure diagnosis at a later stage than the fuel cell.

  An object of the present invention is to solve the above-described conventional problems, and to perform a failure diagnosis of a stage subsequent to the fuel cell, that is, a DC / AC converter, and to perform a failure diagnosis before power generation by the fuel cell.

  In order to solve the above-mentioned conventional problems, the failure diagnosis control apparatus for a fuel cell system according to the present invention performs failure diagnosis in a DC / AC conversion means by generating a DC current from a commercial power source by the AC / DC conversion means. .

  According to this configuration, before power generation by the fuel cell, it is possible to perform a failure diagnosis in the DC / AC conversion means subsequent to the fuel cell.

  According to the failure diagnosis control device of the fuel cell system of the present invention, it is possible to perform the failure diagnosis in the DC / AC conversion means subsequent to the fuel cell before the power generation by the fuel cell.

  A first invention is a fuel cell, connected to a commercial power source, converts DC power from the fuel cell into AC power, and supplies AC power to the household load along with the commercial power source; Operation control means for controlling a series of operations up to and an AC / DC conversion means for generating DC power from a commercial power source. The operation control means uses the DC power obtained by the AC / DC conversion means before power generation by the fuel cell. By converting to AC power by the DC / AC conversion means, by diagnosing a failure of the DC / AC conversion means, the power conversion unit of the internal circuit of the DC / AC conversion means can be used immediately after startup without waiting for power generation by the fuel cell. It is possible to diagnose a failure of a main circuit and a control circuit that is a driver unit or sensor unit. If a failure occurs, an abnormality can be detected without continuing the startup, and the startup energy up to power generation can be detected. It is not necessary to waste ghee.

  In the second aspect of the invention, in particular, the operation control means of the first aspect of the invention outputs the direct current power equivalent to the voltage / current characteristics of the fuel cell by the alternating current direct current conversion means, so that the actual fuel before the power generation by the fuel cell Since the voltage / current characteristics from the battery are simulated over the entire area, the operation check of the DC / AC conversion means can be performed over the entire area of the power generation output instead of the one-point output, enabling more accurate diagnosis It becomes.

  In the third invention, particularly, the operation control means of the first invention outputs the DC power outside the upper and lower limits of the voltage / current characteristics of the fuel cell by the AC / DC conversion means, and confirms the presence or absence of abnormality detection. Thus, even before the power generation by the fuel cell, it is possible to actually reproduce the power generation failure state such as a power supply decrease or a voltage increase in the fuel cell and to confirm in advance whether or not an abnormality is detected by the abnormality detection circuit.

  According to a fourth aspect of the invention, in particular, the operation control means of the first aspect of the invention converts DC power obtained by the AC / DC conversion means into AC power by the DC / AC conversion means before power generation by the fuel cell, and DC / AC conversion means. By checking whether there is an abnormality at the output end of the battery, it is possible to check in advance the output current abnormality or the line overvoltage abnormality due to the AC power output at the output end of the DC / AC converter even before power generation by the fuel cell. If an abnormality is confirmed at the output end, the operation is stopped without continuing the activation, and the activation energy until power generation is not wasted.

  The fifth aspect of the invention further includes a commercial power supply abnormality generating means in addition to the failure diagnosis control device for the fuel cell system of the first aspect of the invention, and the operation control means is obtained by the AC / DC conversion means before power generation by the fuel cell. DC power is converted into AC power by the DC / AC conversion means, and by checking whether the abnormal state generated by the commercial power supply abnormality generating means can be detected by the AC / DC conversion means connected to the commercial power supply, Even before power generation by the fuel cell, the abnormality detection circuit can check whether abnormalities in the commercial power source, that is, abnormalities such as overvoltage, undervoltage, frequency increase, frequency decrease, and power failure can be detected. Thus, the startup energy until power generation is not wasted.

  According to a sixth aspect of the invention, in particular, the operation control means of the first aspect of the invention converts the DC power obtained by the AC / DC conversion means into AC power by the DC / AC conversion means before the power generation by the fuel cell. By confirming whether there is an abnormality in the signal line or communication line between and before the power generation by the fuel cell, it is possible to confirm in advance an abnormality in the contact signal to the DC / AC conversion means and the communication line Therefore, when it is abnormal, it is stopped and the starting energy until power generation is not wasted.

  According to a seventh aspect of the invention, in particular, the operation control means of the first aspect of the invention converts the DC power obtained by the AC / DC conversion means to AC power by the DC / AC conversion means before the power generation by the fuel cell. By generating an abnormal condition in the signal line or communication line between the two and confirming whether the abnormality can be detected, contact signals to the DC / AC conversion means and abnormalities in the communication line, even before power generation by the fuel cell, Whether or not the abnormality can be detected by the abnormality detection circuit can be confirmed. If the abnormality cannot be detected, the abnormality is stopped, and the startup energy until power generation is not wasted.

  In addition to the failure diagnosis control device for the fuel cell system according to any one of the first to seventh inventions, the eighth invention is provided with a notification means, and the operation control means is detected before power generation by the fuel cell. By notifying the abnormal state with the abnormality notifying means, it becomes possible to notify various abnormalities in advance even immediately after the start-up before the power generation by the fuel cell, and it is possible to promptly notify the user of the abnormal contents. .

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a failure diagnosis control apparatus for a fuel cell system according to Embodiment 1 of the present invention.

  In FIG. 1, power generation is performed in a fuel cell 11 using a fuel containing a hydrocarbon such as methane such as city gas as a raw material. The DC / AC conversion means 12 is connected to a commercial power source, converts DC power from the fuel cell 11 into AC power, and supplies AC power to the household load 13 together with the commercial power source. The AC / DC converter 14 is also connected to a commercial power source, converts AC power from the commercial power source into DC power, and supplies the DC power to the DC / AC converter 12. The operation control means 15 controls a series of operations from starting of the fuel cell to power generation.

  Here, the operation control means 15 converts AC power from a commercial power source into DC power by the AC / DC conversion means 14 at the time of startup before power generation by the fuel cell 11. The converted direct current power is input to the direct current alternating current conversion means 12, converted into alternating current power and output. In this series of controls, failure diagnosis of the internal circuit of the DC / AC conversion means 12 is performed.

  As shown in the block diagram of FIG. 2, the internal circuit of the DC / AC conversion means 12 is roughly classified into a main circuit 12a of the power conversion circuit section and a control circuit 12b such as a driver circuit and a sensor circuit section. The main circuit 12a is mainly composed of a DC-DC converter bridge circuit 12a-1 composed of switching elements such as IGBTs, a rectifier circuit 12a-2 composed of diodes, and switching elements such as IGBTs in order from the input side. The inverter bridge circuit 12a-3 and the output current control circuit 12a-4 are included. The control circuit 12b is mainly composed of sensors and driver circuits in the main circuit 12a, and in order from the input side, an input voltage sensor circuit 12b-1, a converter driver circuit 12b-2, a converter output voltage sensor circuit 12b-3, and an inverter. It comprises a driver circuit 12b-4, an output current sensor circuit 12b-5 composed of a current transformer and the like, and a system voltage sensor circuit 12b-6.

  The circuit operations in the main circuit 12a and the control circuit 12b described above are performed here in a simulated manner and in a short time based on the DC power obtained from the AC power of the commercial power supply before the power generation by the fuel cell 11. It is done within 1 second.

  This will be described with reference to the flowchart of FIG.

  In step 1, the operation control means 15 starts the fuel cell system. If it is determined in step 2 that power generation by the fuel cell 11 is not yet performed, direct current power is generated from alternating current power in the commercial power source by the alternating current direct current conversion means 14 in step 3. Next, in step 4, the DC power is input to the DC / AC converter 12, and in step 5, the operation of the internal circuit of the DC / AC converter 12 is checked based on the DC power. In step 6, when it is determined that the internal circuit is abnormal, the operation control means 15 stops the fuel cell system in step 7 and displays an abnormality in step 8.

  According to such a configuration, without waiting for the power generation by the fuel cell, failure diagnosis of the main circuit as the power conversion unit and the control circuit as the driver unit and the sensor unit of the internal circuit of the DC-AC conversion means can be performed even immediately after startup. If a failure occurs, an abnormality can be detected without continuing the activation, and the activation energy until power generation is not wasted.

  In addition, the operation control means 15 outputs DC power equivalent to the voltage / current characteristics of the fuel cell 11 by the AC / DC conversion means 14.

  In the voltage / current characteristic diagram of the fuel cell 11 in FIG. 4, the horizontal axis indicates the DC current I, and the vertical axis indicates the DC voltage V. Point A indicates the open voltage (Voc) when no load is connected. Here, 60Vdc. Point B indicates the current (Isc) when the load is short-circuited. Here, 40 Adc. Point C indicates the voltage and current when the fuel cell system is rated output. Here, the voltage value is 40 Vdc and the current value is 30 Adc. In other words, since the output region during normal power generation in the fuel cell 11 is an operation region between the point A and the point C, the AC / DC conversion means 14 generates equivalent voltage / current characteristics. In the DC / AC conversion means 12, the circuit operation check is performed over the entire area.

  According to such a configuration, voltage / current characteristics from an actual fuel cell are simulated over the entire region even before power generation by the fuel cell. Since an operation check can be performed, more accurate diagnosis is possible.

  Further, the operation control means 15 outputs DC power outside the upper and lower limits of the voltage / current characteristics of the fuel cell 11 by the AC / DC conversion means 14 to confirm the presence or absence of abnormality detection.

  In the voltage / current characteristic diagram of the fuel cell 11 in FIG. 4, the point E indicates the upper limit value (Vhigh) of the voltage. Here, 80 Vdc. The point F indicates the lower limit value (Vlow) of the voltage. Here, it is 30 Vdc. The operation control unit 15 generates a voltage larger than the upper limit value of the voltage at the point E in the AC / DC conversion unit 14. The point F generates a voltage smaller than the lower limit value of the voltage.

  A voltage larger than the upper limit value of the voltage at point E means an overvoltage in each cell of the fuel cell 11, and switching of an IGBT or the like in the DC-DC converter bridge circuit 12a-1 in FIG. The breakdown voltage is higher than the breakdown voltage of the element, causing a failure such as element breakdown. A voltage smaller than the lower limit value of the voltage at the point F means a low voltage in each cell of the fuel cell 11, that is, a deterioration of the cell. In the DC-DC converter bridge circuit 12a-1 in FIG. A DC voltage (350V in this case) cannot be generated, and as a result, a predetermined AC voltage cannot be output.

  A voltage outside this upper limit / lower limit value is input to the DC / AC conversion means 12 to check whether an abnormality is detected in the input voltage sensor circuit 12b-1 in the internal circuit of FIG.

  According to such a configuration, even before power generation by the fuel cell, it is possible to actually reproduce a power generation failure state such as a power supply decrease or a voltage increase in the fuel cell and to confirm in advance whether or not an abnormality is detected in the abnormality detection circuit. It becomes like this.

  Further, the operation control means 15 converts the DC power obtained by the AC / DC conversion means 14 into AC power by the DC / AC conversion means 12 before power generation by the fuel cell 11, and at the output end of the DC / AC conversion means 12. This is to check whether or not an abnormality has occurred.

  The operation control means 15 converts the AC power from the commercial power source into DC power by the AC / DC conversion means 14 at the start before the power generation by the fuel cell 11 and inputs the converted DC power to the DC / AC conversion means 12. , Converted to AC power. During this series of controls, it is checked whether there is an abnormality at the output terminal of the output current control circuit 12a-4 of the internal circuit of the DC / AC conversion means 12 in FIG. That is, in the output current sensor circuit 12b-5, an output current abnormality, here, a current of 9 Arms or more or 13 Apeek or more is detected in 0.5 seconds or less. Moreover, in the system voltage sensor circuit 12b-6, an overvoltage abnormality between lines, here, 120Vrms or more is detected in 0.5 seconds or less. Alternatively, 250 Vpeak or more is detected in 50 milliseconds or less.

  As described above, whether or not an abnormality has occurred at the AC output end of the DC / AC converting means 12 is simulated in a short time based on the DC power obtained from the AC power before the power generation by the fuel cell 11. Is to be done.

  According to such a configuration, even before power generation by the fuel cell, it is possible to confirm in advance output current abnormality or line overvoltage abnormality due to AC power output at the output terminal of the DC / AC converter, and confirm abnormality at the output terminal. If it is done, it stops without continuing the activation, and the activation energy until power generation is not wasted.

(Embodiment 2)
FIG. 5 is a block diagram of a failure diagnosis control apparatus for a fuel cell system according to Embodiment 2 of the present invention. In FIG. 5, the same components as those in FIG.
In FIG. 5, the commercial power supply abnormality generating means 16 is in an abnormal state in the commercial power supply, for example, the U-phase and the W-phase which are the two phases of the U-phase, O-phase and W-phase which are single-phase three wires of the system voltage Overvoltage, undervoltage, frequency increase, frequency decrease, and abnormal conditions such as power failure are generated in a pseudo manner.

  The operation control means 15 converts the DC power obtained by the AC / DC conversion means 14 into AC power by the DC / AC conversion means 12 before the power generation by the fuel cell 11, and an abnormal state generated by the commercial power supply abnormality generating means 16. Can be detected by the DC / AC conversion means 12 connected to the commercial power source.

  That is, the operation control means 15 indicates the above-described abnormal state of the commercial power source at the system voltage sensor circuit 12b-6 in the control circuit b of the internal circuit of the DC / AC conversion means 12 in FIG. Whether or not it can be detected is simulated in a short period of time based on the DC power obtained from the AC power.

  According to such a configuration, even before power generation by the fuel cell, it is possible to confirm whether the abnormality detection circuit can detect abnormality in the commercial power source, that is, abnormality such as overvoltage, undervoltage, frequency increase, frequency decrease, power failure, etc. If it cannot be detected, the system is stopped and the startup energy until power generation is not wasted.

  Further, the operation control means 15 converts the DC power obtained by the AC / DC conversion means 14 into AC power by the DC / AC conversion means 12 before the power generation by the fuel cell 11, and a signal to / from the DC / AC conversion means 12. This is to check whether there is an abnormality in the line or communication line.

  The operation control means 15 exchanges various data with the DC / AC conversion means 12. For example, a contact ON / OFF signal for turning on / off the input of DC power from the fuel cell 11, a power generation state signal at the DC / AC conversion means 12, an output power command signal, a DC current limiter signal, an output power value, and an input voltage value , And data such as input current values are exchanged via signal lines or communication lines.

  In other words, the operation control means 15 generates power in a simulated manner and in a short time based on the DC power obtained from the AC power at the time of startup before the power generation by the fuel cell 11, and the DC / AC conversion means 12 during power generation. It is possible to confirm in advance whether or not an abnormality has occurred in the exchange of various data with the.

  According to such a configuration, even before power generation by the fuel cell, it becomes possible to confirm in advance an abnormality in the contact signal to the DC-AC conversion means and the communication line, and if it is abnormal, it stops and generates power. The starting energy up to is not wasted.

  Further, the operation control means 15 converts the DC power obtained by the AC / DC conversion means 14 into AC power by the DC / AC conversion means 12 before the power generation by the fuel cell 11, and a signal to / from the DC / AC conversion means 12. An abnormal state is generated in the communication line or the communication line, and it is confirmed whether the abnormality can be detected.

  Here, if the operation control means 15 sends a signal to the DC / AC conversion means 12 and does not receive a signal from the DC / AC conversion means 12 within a certain time, a communication abnormality is assumed. Also, after transmitting a contact ON / OFF signal for turning on / off the DC power input from the fuel cell 11 to the DC / AC conversion means 12, the received signal from the DC / AC conversion means 12 is reflected in the ON / OFF state of the contact. If not, it is abnormal.

  As described above, the operation control means 15 generates power in a simulated manner and in a short time based on the DC power obtained from the AC power by the AC / DC conversion means 14 at the time of startup before the power generation by the fuel cell 11. An abnormal state is generated in the exchange of signals with the DC / AC converter 12 during power generation, and it is confirmed whether or not the abnormality can be detected.

  According to such a configuration, even before power generation by the fuel cell, it is possible to check whether the abnormality in the contact signal or the communication line to the DC / AC conversion means can be detected in the abnormality detection circuit, and stop if the abnormality cannot be detected, The starting energy until power generation is not wasted.

(Embodiment 3)
FIG. 6 is a configuration diagram of a failure diagnosis control apparatus for a fuel cell system according to Embodiment 3 of the present invention. In FIG. 6, the same components as those in FIG. 1 or FIG.

  In FIG. 6, the abnormality notification means 17 notifies the detected abnormal state, and is notified by letters, numbers, pictographs, symbol diagrams, voice, communication means, and the like. As the display element, a liquid crystal display of an operation remote controller, an LED display, a fluorescent display tube, or the like may be used.

  The operation control means 15 is for notifying the detected abnormal state by the abnormality notification means 17 before power generation by the fuel cell 11.

  The operation control unit 15 displays the above-described input / output of the DC / AC conversion unit 12 and the abnormality in the internal circuit in the abnormality notification unit 17.

  Here, DC input voltage drop, DC input voltage rise, output current abnormality, line overvoltage abnormality, U-phase and W-phase overvoltage, undervoltage, frequency rise, frequency drop, power failure detection, signal line or communication line abnormality, And an abnormality in the internal circuit of the DC / AC converting means 12.

  According to such a configuration, various abnormalities can be notified in advance even immediately after startup before power generation by the fuel cell, and the contents of the abnormality can be notified to the user immediately.

  The failure diagnosis control device for a fuel cell system according to the present invention is capable of performing failure diagnosis in a DC / AC conversion means subsequent to the fuel cell before power generation by the fuel cell, and is economical using the fuel cell. Useful for safe power generation. This can also be applied to power generation systems using other batteries and power sources.

1 is a configuration diagram of a failure diagnosis control device for a fuel cell system according to Embodiment 1 of the present invention. Configuration diagram of internal circuit of DC / AC conversion means of failure diagnosis control device of the same system Flow chart of failure diagnosis control device of the same system Voltage / current characteristics diagram of the fuel cell of the fault diagnosis control device of the system Configuration diagram of a failure diagnosis control device for a fuel cell system according to Embodiment 2 of the present invention Configuration diagram of a failure diagnosis control device for a fuel cell system in Embodiment 3 of the present invention Configuration diagram of conventional fuel cell system failure diagnosis control device

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Fuel cell 12 DC / AC conversion means 13 Domestic load 14 AC / DC conversion means 15 Operation control means 16 Commercial power supply abnormality generation means 17 Abnormality notification means

Claims (8)

A series of steps from starting the fuel cell to power generation, and a DC / AC conversion means connected to the fuel cell, converting DC power from the fuel cell to AC power, and supplying AC power to the household load along with the commercial power source Operation control means for controlling the operation of the power supply, and AC / DC conversion means for generating DC power from a commercial power source, wherein the operation control means uses the DC power obtained by the AC / DC conversion means before power generation by the fuel cell. A failure diagnosis control apparatus for a fuel cell system, wherein the DC / AC conversion means performs failure diagnosis by converting the DC / AC conversion means into AC power. 2. The failure diagnosis control apparatus for a fuel cell system according to claim 1, wherein the operation control means outputs DC power equivalent to the voltage / current characteristics of the fuel cell by the AC / DC conversion means. 2. The fuel cell system according to claim 1, wherein the operation control means outputs the DC power outside the upper and lower limits of the voltage / current characteristics of the fuel cell by the AC / DC conversion means and confirms whether or not an abnormality has been detected. Fault diagnosis control device. The operation control means converts the DC power obtained by the AC / DC conversion means to AC power by the DC / AC conversion means before power generation by the fuel cell, and confirms whether or not an abnormality has occurred at the output end of the DC / AC conversion means. The failure diagnosis control device for a fuel cell system according to claim 1. A commercial power supply abnormality generating means for generating an abnormal state in the commercial power supply is provided, and the operation control means converts the DC power obtained by the AC / DC conversion means to AC power by the DC / AC conversion means before power generation by the fuel cell. 2. The failure of the fuel cell system according to claim 1, wherein it is confirmed whether or not the abnormal state generated by the commercial power supply abnormality generation means can be detected by the AC / DC conversion means connected to the commercial power supply. Diagnostic control device. The operation control means converts the direct current power obtained by the alternating current direct current conversion means into alternating current power by the direct current alternating current conversion means before power generation by the fuel cell, and a signal line or a communication line between the direct current alternating current conversion means The failure diagnosis control device for a fuel cell system according to claim 1, wherein presence or absence of abnormality is confirmed. The operation control means converts the DC power obtained by the AC / DC conversion means to AC power by the DC / AC conversion means before power generation by the fuel cell, and the signal line or communication line between the DC / AC conversion means is abnormal. 2. The failure diagnosis control device for a fuel cell system according to claim 1, wherein a state is generated to check whether or not an abnormality can be detected. The abnormality notifying means for notifying an abnormal condition is provided, and the operation control means displays the detected abnormal condition on the abnormality notifying means before power generation by the fuel cell. The failure diagnosis control device of the fuel cell system according to the item.

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