JP2007024796A - Hydrogen detection element control device and hydrogen detection element control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen detection element control device and a hydrogen detection element control method for determining abnormality of the hydrogen detection element inexpensively by a simple method. <P>SOLUTION: The hydrogen detection element control device is equipped with: a hydrogen concentration calculation circuit 14 acquiring the first detection element of the hydrogen detection element 12, and calculating the hydrogen concentration by the first detection element; an element information calculation circuit 16 acquiring the second detection element which is different from the first detection element of the hydrogen detection element, and calculating element information (for example, an impedance) for determining an abnormality of the hydrogen detection element by the second detection element; and a control circuit 10 determining whether the hydrogen detection element is abnormal or not from the element information. The hydrogen detection element control method is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrogen detection element control apparatus and a hydrogen detection element control method, and more particularly to a hydrogen detection element control apparatus and a hydrogen detection element control method for determining an abnormality of a hydrogen detection element.

  In recent years, a fuel cell vehicle using a fuel cell, a household cogeneration system, and the like have attracted attention from the viewpoint of environmental consideration. Since the fuel cells used for these use a large amount of hydrogen, it is important to detect and warn of hydrogen leakage at an early stage. In order to detect hydrogen leakage, a hydrogen detection element is used. However, if the hydrogen detection element is deteriorated or broken, hydrogen leakage cannot be detected, which is very dangerous. Therefore, it is required to detect an abnormality such as deterioration or destruction of the hydrogen detection element.

Patent Document 1 discloses a control method for determining an abnormality of a hydrogen detection element by comparing a detection value from a hydrogen detection element with a determination threshold set in accordance with the operating state of a fuel cell. Patent Document 2 discloses a control method for determining an abnormality of a hydrogen detection element by providing a plurality of hydrogen detection elements and comparing their output values.
JP 2004-222999 A JP 2004-251862 A

  In the control method disclosed in Patent Document 1, it is necessary to set a determination threshold value for determining an abnormality of the hydrogen detection element from the operating state of the fuel cell. It is complicated. Furthermore, it cannot be used for different fuel cells. Further, the control method disclosed in Patent Document 2 requires a plurality of hydrogen detection elements. A noble metal such as platinum is used as a catalyst for the hydrogen detection element, which is expensive.

  In view of the above problems, an object of the present invention is to provide a hydrogen detection element control device and a hydrogen detection element control method for determining an abnormality of a hydrogen detection element at a low cost by a simple method.

  The present invention relates to a hydrogen concentration calculating means for acquiring a first detection element of a hydrogen detection element and calculating a hydrogen concentration by the first detection element, and a first detection element different from the first detection element of the hydrogen detection element. Element information calculation means for obtaining element information for obtaining an abnormality of the hydrogen detection element from the second detection element, and whether the hydrogen detection element is abnormal by the element information. An abnormality determination means for determining, a hydrogen detection element control device. According to the present invention, element information for determining an abnormality of the hydrogen detection element is calculated using a second detection element different from the first detection element for detecting the hydrogen concentration. Thereby, the abnormality of the hydrogen detection element can be determined almost without being influenced by the calculated hydrogen concentration. Therefore, it is not necessary to consider complicated elements. Further, a plurality of expensive hydrogen sensing elements are not required. Therefore, it is possible to provide a hydrogen detection element control device that determines an abnormality of a hydrogen detection element at a low cost by a simple method.

  According to the present invention, the second detection element of the element information calculation unit is acquired in a time independent manner from the acquisition of the first detection element of the hydrogen concentration calculation unit. It can be a control device. According to the present invention, the second sensing element can be made more independent of the first sensing element. Thereby, the abnormality of the hydrogen detection element can be determined almost without being influenced by the calculated hydrogen concentration.

  The present invention can be a hydrogen detection element control device characterized in that the abnormality determination means determines an abnormality of the hydrogen detection element by using an element temperature of the hydrogen detection element and the element information. According to the present invention, it is possible to more accurately determine abnormality of the hydrogen detection element.

  The present invention comprises a temperature calculation means for acquiring a temperature detection element from a temperature detection element that detects the temperature of the same medium as the hydrogen detection element, and calculating the element temperature from the temperature detection element. It can be set as a detection element control apparatus. According to the present invention, the element temperature can be calculated more accurately, and thereby the abnormality of the hydrogen detection element can be determined more accurately.

  The present invention can be a hydrogen detection element control device that calculates the element temperature from the temperature detection element, the hydrogen detection element acquired in advance, and a temperature correlation curve of the temperature detection element. According to the present invention, a more accurate element temperature can be calculated. Therefore, the abnormality of the hydrogen detection element can be determined more accurately.

  The abnormality determination means determines the abnormality of the hydrogen detection element based on the element temperature of the hydrogen detection element and the element information using a correlation between the element temperature and element information acquired in advance. It can be. According to the present invention, it is possible to easily determine abnormality of the hydrogen detection element.

  In the present invention, when the abnormality determination unit uses a correlation between the element temperature and the element information acquired in advance, and element information corresponding to the element temperature calculated by the temperature calculation unit is used as reference element information, the reference element When the range of a certain ratio of information is exceeded, the hydrogen detection element control device can be characterized in that the hydrogen detection element is determined to be abnormal. According to the present invention, the upper and lower limits of the normality determination range can be easily determined. Therefore, the abnormality of the hydrogen detection element can be determined more easily.

  The present invention can provide a hydrogen detection element control device that corresponds to the hydrogen concentration calculated by the hydrogen concentration calculation means, corrects the element temperature of the hydrogen detection element, and calculates the element temperature. . According to the present invention, a more accurate element temperature can be calculated. Therefore, the abnormality of the hydrogen detection element can be determined more accurately.

  According to the present invention, the abnormality determination unit corrects the element information using element information distribution information of a plurality of hydrogen detection elements acquired in advance, and determines that the hydrogen detection element is abnormal. It can be set as an element control apparatus. According to the present invention, it is possible to reduce the probability of determining normality as abnormal due to variations in the elements of the hydrogen detection elements. Therefore, the abnormality of the hydrogen detection element can be determined more accurately.

  The present invention includes a storage unit that stores the element information, and the abnormality determination unit determines an abnormality of the hydrogen detection element by using past element information and current element information stored in the storage unit. It can be set as the hydrogen detection element control apparatus characterized by doing. According to the present invention, it is possible to more accurately determine abnormality of the hydrogen detection element.

  In the present invention, the abnormality determination means calculates an average value of the previous element information and the current element information immediately before being stored in the storage means, and uses the average value to determine an abnormality of the hydrogen detection element. It can be set as the hydrogen detection element control apparatus characterized by determining. According to the present invention, it is possible to more accurately determine abnormality of the hydrogen detection element.

  According to the present invention, the abnormality determination unit calculates a difference between the previous element information stored in the storage unit and the current element information, and determines the abnormality of the hydrogen detection element using the difference. It can be set as the hydrogen detection element control apparatus characterized by these. According to the present invention, it is possible to more accurately determine abnormality of the hydrogen detection element.

  The present invention can be a hydrogen detection element control device characterized by using the element information to determine whether the hydrogen detection element is short or open. Moreover, this invention can be set as the hydrogen detection element control apparatus characterized by calculating the acquisition space | interval of a said 2nd detection element using the said element information.

  The present invention can be a hydrogen detection element control device, wherein the element information is an impedance of the hydrogen detection element. According to the present invention, when the first detection element is set to the voltage value of the hydrogen detection element by performing abnormality determination using the impedance of the hydrogen detection element, a voltage is applied to the hydrogen detection element as the second detection element. Current value. The abnormality of the hydrogen detection element can be determined almost without being influenced by the calculated hydrogen concentration.

  The present invention obtains a first sensing element of a hydrogen sensing element, calculates a hydrogen concentration by the first sensing element, and a second sensing different from the first sensing element of the hydrogen sensing element. An element information calculating step for obtaining element information and calculating element information for determining an abnormality of the hydrogen detection element from the second detection element; and an abnormality for determining whether the hydrogen detection element is abnormal based on the element information And a determination step. A method for controlling the hydrogen detection element. According to the present invention, element information for determining an abnormality of the hydrogen detection element is calculated using a second detection element different from the first detection element for detecting the hydrogen concentration. Thereby, the abnormality of the hydrogen detection element can be determined almost without being influenced by the calculated hydrogen concentration. Therefore, it is not necessary to consider complicated elements. Further, a plurality of expensive hydrogen sensing elements are not required. Therefore, it is possible to provide a method for controlling the hydrogen detection element that determines the abnormality of the hydrogen detection element at a low cost by a simple method.

  According to the present invention, acquisition of the second detection element from the hydrogen detection element in the element information calculation step is independent of acquisition of the first detection element from the hydrogen detection element in the hydrogen concentration calculation step in terms of time. It can be set as the control method of the hydrogen detection element characterized by being performed. According to the present invention, the second sensing element can be made more independent of the first sensing element. Thereby, the abnormality of the hydrogen detection element can be determined almost without being influenced by the calculated hydrogen concentration.

  The present invention may be a method for controlling a hydrogen detection element, wherein the abnormality determination step determines an abnormality of the hydrogen detection element using an element temperature of the hydrogen detection element and the element information. According to the present invention, it is possible to more accurately determine abnormality of the hydrogen detection element.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the hydrogen detection element control apparatus and the control method of a hydrogen detection element which determine the abnormality of a hydrogen detection element by a simple method cheaply.

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

  FIG. 1 is a block diagram of the hydrogen detection element control device 46 according to the first embodiment. A hydrogen concentration calculation circuit 14 (hydrogen concentration calculation means) is connected to the hydrogen detection element 12. Further, an impedance detection application power source 18 is connected via a resistor 20. An impedance calculation circuit 16 (element information calculation circuit) is connected to the resistor 20. A temperature calculation circuit 24 (temperature calculation means) is connected to the temperature detection element 22. The control circuit 10 (abnormality determination means) is connected to the hydrogen concentration calculation circuit 14, the impedance calculation circuit 16, the impedance detection power supply 18, and the temperature calculation circuit 24. A storage device 26 is further connected to the control circuit 10.

  In the hydrogen detection element 12, a part of the resistor is covered with a catalyst such as platinum. As the hydrogen concentration increases, hydrogen and the catalyst react and the temperature of the catalyst rises. Thereby, an electromotive force is generated in the resistor. The catalyst temperature depends on the hydrogen concentration, and the electromotive force depends on the catalyst temperature. Therefore, the hydrogen concentration can be calculated by acquiring the generated electromotive force as a voltage value. In addition, the value of the current flowing by applying a voltage across the hydrogen sensing element 12 becomes a value almost independent of the electromotive force by applying a voltage sufficiently larger than the potential difference generated by the electromotive force.

  FIG. 2 is a diagram illustrating an example when the hydrogen detection element control device 46 according to the first embodiment is mounted on a fuel cell vehicle. A hydrogen detection element 30 and a temperature detection element 40 are provided in the interior 38 of the fuel cell vehicle, a hydrogen detection element 32 and a temperature detection element 42 are provided under the vehicle body, and a hydrogen detection element 34 and a temperature detection element 44 are provided in the storage portion 36 of the fuel cell and hydrogen storage device. The hydrogen detecting elements 30, 32, and 34 and the temperature detecting elements 40, 42, and 44 are connected to the hydrogen detecting element control device 46 according to the first embodiment. Further, a warning device 48 is connected to the hydrogen detection element control device 46.

  Next, the operation of the hydrogen detection element control device 46 according to the first embodiment will be described with reference to FIG. FIG. 3 is a flowchart of the control circuit 10 (abnormality determination means). First, in step S10, N corresponding to the interval for acquiring the impedance is set. In step S12, a counter for the hydrogen concentration acquisition count I is set to zero. In step S <b> 14, the hydrogen concentration calculation circuit 14 (hydrogen concentration calculation means) is caused to acquire a voltage value (first detection element) corresponding to the hydrogen concentration from the hydrogen detection element 12. In step S16, the hydrogen concentration calculation circuit 14 is caused to calculate the hydrogen concentration using the acquired voltage value. In step S18, the hydrogen concentration acquisition count I is counted. In step S20, it is determined whether the hydrogen concentration acquisition count I has reached the set count N. If the acquisition count I has not reached the set count N, the process returns to step S14.

  When the acquisition count I reaches the set count N in step S18, steps S22 to S32 are performed to determine whether the hydrogen detection element 12 is abnormal. First, in step S <b> 22, the impedance detection power supply 18 is caused to apply a voltage to the hydrogen detection element 12 and the resistor 20. In step S24, the impedance calculation circuit 16 (element information calculation means) is caused to acquire the current flowing through the resistor 20, that is, the current value (second detection element) flowing through the hydrogen detection element 12 from the hydrogen detection element 12. The value of the current flowing through the hydrogen detection element 12 can be obtained by detecting the potential difference between both ends of the resistor 20.

  In step S26, the impedance calculation circuit 16 (element information calculation means) calculates the impedance (element information) of the hydrogen detection element 12 using the voltage value applied by the impedance detection power source 18 and the current value flowing through the hydrogen detection element 12. Let In step S28, the temperature calculation circuit 24 (temperature calculation means) is caused to acquire a voltage value (temperature detection element) from the temperature detection element 22. In step S <b> 30, the temperature calculation circuit 24 calculates the element temperature from the voltage value acquired from the temperature detection element 22. In step S32, the control circuit 10 (abnormality determination means) determines whether the element detection element 12 is abnormal using the impedance (element information) calculated by the impedance calculation circuit 16 and the element temperature calculated by the temperature calculation circuit 26. . If it is determined that the element detection element 12 is normal, the process returns to step S12. If it is determined that the element detection element 12 is abnormal, the process proceeds to step S34, where information is provided to a warning device such as a buzzer or a warning light (for example, the warning device 48 in FIG. 2) to give a warning.

  In Example 1, the current value (second detection element) when a voltage is applied to the hydrogen detection element 12 is the voltage value (first detection value) due to the electromotive force caused by the temperature increase of the catalyst of the hydrogen detection element 12. Unlike (element), it is an almost independent detection element. In this way, element information for determining an abnormality of the hydrogen detection element 12 is calculated using a second detection element that is substantially independent of the first detection element for detecting the hydrogen concentration. Thereby, abnormality of the hydrogen detection element 12 can be determined almost without being influenced by the calculated hydrogen concentration. Thereby, unlike the prior art disclosed in Patent Document 1, there is no need to consider complicated elements. Further, unlike the prior art disclosed in Patent Document 2, a plurality of expensive hydrogen detection elements are not required. Therefore, it is possible to determine abnormality of the hydrogen detection element at a low cost by a simple method.

  The first detection element may be an output from the hydrogen detection element 12 that can calculate the hydrogen concentration. For example, it may be an electrical output of the hydrogen detection element 12 and may be a current value flowing through a resistor, an output voltage value of a bridge circuit, or the like. The second detection element may be different from the first detection element. However, it is preferable that a voltage different from that for detecting the hydrogen concentration is applied to the hydrogen detection element 12. This is because the abnormality of the hydrogen detection element 12 can be determined without being more influenced by the hydrogen concentration calculated from the first detection element. For example, it may be used for calculating the impedance such as the voltage value at both ends of the resistor 20.

  When the first detection element is set to the voltage value of the hydrogen detection element 12 by performing abnormality determination using the impedance of the hydrogen detection element 12 as element information, a voltage is applied to the hydrogen detection element 12 as the second detection element. The current value can be obtained. Thereby, the abnormality of the hydrogen detection element 12 can be determined without being more influenced by the calculated hydrogen concentration.

  Even if the element information is not an impedance, it is sufficient if an abnormality of the hydrogen detection element 12 can be determined. However, it is preferably calculated from the second detection element obtained by applying a different voltage to the hydrogen detection element 12 when detecting the hydrogen concentration. The second sensing element can be more independent of the first sensing element. Therefore, the abnormality of the hydrogen detection element 12 can be determined without being more influenced by the hydrogen concentration calculated from the first detection element. For example, the current value itself of the second sensing element may be used, or the voltage value at both ends of the resistor 20 may be used.

  The acquisition (step S24) of the current value (second detection element) of the hydrogen detection element 12 of the impedance calculation circuit 16 (element information calculation means) is performed by the hydrogen detection element of the hydrogen concentration calculation circuit 14 (hydrogen concentration calculation means). Acquisition of 12 voltage values (first detection elements) (step S14) is performed independently in time. As described above, by acquiring the first detection element and the second detection element independently in time, the second detection element can be made more independent from the first detection element. .

  In the first embodiment, the abnormality determination of the hydrogen detection element 12 is performed every time the hydrogen concentration is detected N times. Since the impedance measurement causes a current to flow, the temperature of the hydrogen sensing element 12 may increase or deteriorate. Therefore, it is preferable that the abnormality determination frequency of the hydrogen detection element 12 is low. On the other hand, from the viewpoint of determining abnormality, it is preferable that the frequency of abnormality determination is high. The frequency of abnormality determination is determined in consideration of these. Moreover, abnormality determination is performed for every fixed time. Alternatively, it can be performed before and after a predetermined operation (for example, before and after the start of the fuel cell vehicle).

  The control circuit 10 can consider the change in impedance due to the element temperature by determining the abnormality of the hydrogen detection element 12 by using the element temperature and the impedance of the hydrogen detection element 12, and more accurately the hydrogen detection element 12. Abnormality can be determined.

  Further, the hydrogen detection element control device 46 according to the first embodiment acquires, for example, a voltage value (temperature detection element) from the temperature detection element 22 that detects the temperature of the same medium as the hydrogen detection element 12 in order to acquire the element temperature. And a temperature calculation circuit 24 for calculating the element temperature.

  For example, in the fuel cell vehicle shown in FIG. 2, the temperature detection element 40 is provided in the same room 38 as the hydrogen detection element 30. Similarly, the temperature detection element 42 is provided under the same vehicle body as the hydrogen detection element 32, and the temperature detection element 44 is provided in the same fuel cell and hydrogen storage device storage as the hydrogen detection element 34. Thus, the temperature detection element 22 is provided in the same medium as the hydrogen detection element 12. The same medium is a medium having an environmental temperature that is substantially the same as the environmental temperature of the hydrogen sensing element 12.

  By calculating the element temperature from such a voltage value (temperature detection element) of the temperature detection element 22, it is possible to calculate the element temperature more accurately, and thereby to determine the abnormality of the hydrogen detection element 12 more accurately. it can.

  The temperature detection element may be an output of the temperature detection element 22 as long as the temperature can be calculated. For example, it may be a current value or digital data other than the voltage value.

  In the fuel cell vehicle shown in FIG. 2, the temperature detection element 40 in the room 38 can also be used as a temperature detection element for monitoring the temperature in the room. Further, the temperature detection element 42 under the vehicle body can also be used as a temperature detection element for monitoring the outdoor temperature. Further, the temperature detection element 44 of the storage unit 36 of the fuel cell and hydrogen storage device can also be used as a temperature detection element that monitors the temperature of the storage unit 36. Thereby, the number of the temperature detection elements to install can be reduced.

  Next, a method in which the control circuit 10 determines whether the hydrogen detection element 12 is abnormal based on the impedance and the element temperature of the hydrogen detection element 12 will be described. FIG. 4 is a diagram for explaining the method. The horizontal axis indicates the element temperature of the hydrogen detection element 12, and the vertical axis indicates the impedance of the hydrogen detection element 12. The solid line in FIG. 4 is a correlation curve between the element temperature and the impedance of the hydrogen detection element 12 acquired in advance. This correlation curve is stored in the storage device 26 in advance, and is read when the abnormality determination of the hydrogen detection element 12 is performed.

  When the element temperature calculated by the temperature calculation circuit 24 is, for example, T0, the reference impedance Z0 (reference element information) is calculated from this correlation curve. Based on the reference impedance Z0, the upper limit ZU and the lower limit ZL of the normal determination region are calculated. The curve of the criterion of FIG. 4 corresponds to ZU and ZL at each element temperature. When the impedance Z calculated by the impedance calculation circuit 16 is larger than ZU or smaller than ZL (abnormality determination range), the hydrogen detection element 12 is determined to be abnormal. When Z is between ZU and ZL (normal determination range), it is determined as normal.

  As described above, the abnormality of the hydrogen detection element 12 is easily determined by determining the abnormality of the hydrogen detection element 12 based on the element temperature T0 and the impedance Z of the hydrogen detection element 12 using the correlation curve between the element temperature and the impedance acquired in advance. Can be determined.

  Further, a range of a certain ratio of the reference impedance Z0 can be set as the upper limit ZU and the lower limit ZL of the normal determination range. In the first embodiment, ZU is 1.5 times Z0 and ZL is 0.8 times Z0. As described above, when the impedance corresponding to the element temperature T0 calculated by the temperature calculation circuit 24 is defined as the reference impedance Z0 using the correlation between the element temperature and the element information acquired in advance, the range of a certain ratio of the reference impedance Z0 is exceeded. The hydrogen detection element 12 can be determined to be abnormal. Thereby, the upper and lower limits ZU and ZL of the normal determination range can be easily determined. Therefore, the abnormality of the hydrogen detection element 12 can be determined more easily.

  If the normality determination range is widened, the probability of determining an abnormality even if the hydrogen detection element 12 is normal decreases, but the probability of determining an abnormality as normal increases. On the other hand, if the normality determination range is narrowed, the probability of determining that the hydrogen detection element 12 is normal even if it is abnormal decreases, but the probability of determining that it is abnormal even if normal is increased. The upper and lower limits ZU and ZL of the normal determination range are determined in consideration of these.

  Further, the correlation curve between the impedance of the hydrogen detection element 12 and the element temperature varies from element to element. Therefore, it is possible to determine the upper and lower limits ZU and ZL of the normal determination range by using impedance distribution information (distribution information). FIG. 5 is a diagram for explaining a method of performing an abnormality determination of the hydrogen detection element 12 using impedance distribution information. The horizontal axis indicates the element temperature of the hydrogen detection element 12, and the vertical axis indicates the impedance of the hydrogen detection element 12. The solid line in FIG. 5 is the same correlation curve between the element temperature and impedance of the hydrogen sensing element 12 acquired in advance as in FIG.

  A range of a certain ratio of the reference impedance Z0, which is a determination criterion in FIG. 4, is assumed to be Zmax and Zmin. The constant ratio curve shown in FIG. 5 corresponds to Zmax and Zmin at each element temperature. Further, the correction amount based on the distribution information is added to Zmax to obtain the upper limit ZU of the normal determination range. Further, the correction amount based on the distribution information is reduced to Zmin to obtain a lower limit ZL. The determination criteria shown in FIG. 5 correspond to ZU and ZL of each element temperature. When the impedance Z calculated by the impedance calculation circuit 16 is greater than ZL or less than ZL (abnormality determination range), the hydrogen detection element 12 is determined to be abnormal. When Z is between ZU and ZL (normal determination range), it is determined as normal.

  The correction amount based on the distribution information is acquired as follows, for example, and stored in the storage device 26 in advance. In advance, a correlation curve between the impedance and the element temperature is obtained for the plurality of hydrogen detection elements 12. Then, the standard deviation σ is calculated, and 3σ of each element temperature is set as a correction amount based on the distribution information. In addition to this, the correction amount based on the distribution information can be a maximum value, a minimum value, or an arbitrary multiple of the standard deviation.

  As described above, the control circuit 10 corrects the impedance using the distribution information of the impedance (element information) of the plurality of hydrogen detection elements acquired in advance and determines whether the hydrogen detection element 12 is abnormal. The probability of determining normality as abnormal can be reduced due to the variation of each element.

  In step S32, the content of the abnormality of the hydrogen detection element 12 can also be determined. For example, it is possible to determine whether the hydrogen detection element 12 is short-circuited or opened by using impedance. When the impedance is very small, it can be determined that the short circuit between the terminals of the hydrogen detection element 12 or the short circuit between the hydrogen detection element 12 and the ground. When the impedance is very high, it can be determined that the hydrogen detection element 12 is open.

  Furthermore, the impedance calculated by the impedance calculation circuit 16 can be used for other purposes.

  For example, it is possible to calculate the abnormality determination interval of the hydrogen detection element 12 using impedance. As described above, if the frequency of abnormality determination is high, the temperature of the hydrogen detection element 12 increases. Therefore, when the temperature of the hydrogen detection element 12 is high due to impedance, the frequency of abnormality determination can be reduced.

  In step S32 in FIG. 3, when the impedance is in the normal determination range but lower than the predetermined value, the setting of N is increased and the process returns to step S12. Thereby, it can prevent that the temperature of the hydrogen detection element 12 becomes high resulting from frequent abnormality determination. At this time, it is preferable not to exceed a certain value so that the value of N does not become too large. This is because when N increases, the frequency of abnormality determination decreases.

  The second embodiment is an example of a control device in which a function for correcting the temperature detected by the temperature detection element 22 is added to the hydrogen detection element control device 46 according to the first embodiment. Other configurations are the same as those of the first embodiment. As correction of the element temperature, correction of the temperature difference between the temperature detection element 22 and the hydrogen detection element 12 and correction of the temperature rise of the hydrogen detection element 12 due to the hydrogen concentration are performed.

  First, correction of the temperature difference between the temperature detection element 22 and the hydrogen detection element 12 will be described. Although the temperature detection element 22 and the hydrogen detection element 12 are provided on the same medium, depending on the installation location of the temperature detection element 22, their temperatures may be different. FIG. 6 is a diagram for explaining the function of correcting the element temperature, in which the horizontal axis indicates the temperature of the temperature detection element 22 and the vertical axis indicates the temperature of the water element detection element 12. When these temperatures match, it becomes a broken line in the figure.

  The solid line in FIG. 6 is a correlation curve between the temperatures of the hydrogen detection element 12 and the temperature detection element 22 acquired in advance. This temperature correlation curve is stored in the storage device 26 in advance. In step S30 of the first embodiment, when the element temperature of the hydrogen detection element 12 is calculated, the element temperature calculated from the voltage value acquired from the temperature detection element 22 is T0. At this time, the element temperature T01 of the hydrogen detection element 12 is calculated from the temperature correlation curve and set as the element temperature used for abnormality determination.

  Thus, by calculating the element temperature used for the abnormality determination from the voltage value (temperature detection element) of the temperature detection element 22 and the temperature correlation curve of the hydrogen detection element 12 and the temperature detection element 22 acquired in advance, a more accurate value can be obtained. The element temperature can be calculated. Therefore, the abnormality of the hydrogen detection element 12 can be determined more accurately.

  The storage medium 26 may store an element temperature correction amount ΔT1 = T1−T0 and a temperature element temperature curve. Further, the temperature correction may be performed by the temperature calculation circuit 24 or the control circuit 10.

  Next, correction of the element temperature rise of the hydrogen detection element 12 due to the hydrogen concentration will be described. The hydrogen detection element 12 is an element that detects a temperature increased by a reaction between hydrogen and a catalyst. Therefore, when the hydrogen concentration is increased, the element temperature of the hydrogen detection element 12 is increased. FIG. 7 is a diagram for explaining correction of the element temperature rise of the hydrogen detection element 12 caused by the hydrogen concentration. The curve in FIG. 7 shows a correlation curve between the temperature rise of the hydrogen detection element 12 and the concentration hydrogen acquired in advance. As the correlation curve, the temperature rises ΔT1, ΔT2, and ΔT3 of the hydrogen detection element 22 are obtained for each element temperature before the main correction, for example, T1, T2, and T3. This correlation curve is stored in the storage device 26.

  In step S30 of the first embodiment, when calculating the element temperature of the hydrogen detection element 12, the hydrogen concentration calculated by the hydrogen concentration calculation circuit 14 is H0, and the element temperature calculated from the voltage value acquired from the temperature detection element 22 is T1. Then, T1 + ΔT1 obtained by adding the temperature increase ΔT1 of the hydrogen detection element 12 to the element temperature T1 is calculated as the element temperature of the hydrogen detection element 12.

  In this way, by correcting the element temperature of the hydrogen detection element 12 and calculating the element temperature corresponding to the hydrogen concentration calculated by the hydrogen concentration calculation circuit 14, a more accurate element temperature can be calculated. Therefore, the abnormality of the hydrogen detection element 12 can be determined more accurately.

  The temperature correction may be performed by the temperature calculation circuit 24 or the control circuit 10.

  The third embodiment is an example of a control device that uses the past impedance and the current impedance for the hydrogen detection element control device 46 according to the first embodiment to determine an abnormality. Other configurations are the same as those of the first embodiment. In the third embodiment, the impedance calculated each time is stored in the storage device 26 (storage means). The storage device 12 is, for example, a RAM, a magnetic disk, an optical disk, or the like. In step S32 of the first embodiment, abnormality determination is performed by the following method. 8 and 9 are diagrams for explaining the method. The horizontal axis is time, the vertical axis is the impedance of the figure (a), the figure (b) is the average value of the previous two points and the current impedance, and the figure (c) is the difference between the previous one point impedance and the current impedance. is there.

  FIG. 8 is not an abnormality of the hydrogen detection element 12 as shown in FIG. 8A, and when the impedance is increased only at one point for some reason, FIG. 9 is a hydrogen detection element as shown in FIG. 9A. It is the figure which drawn typically the case where impedance became high by 12 abnormalities. When the impedance exceeds the determination criterion, the method of determining that the abnormality is abnormal is not the abnormality of the hydrogen detection element 12 as shown in FIG. May be determined.

  Therefore, as shown in FIG. 8B, several previous impedances in the past are read from the storage device 12, and an average with the current impedance is calculated. Abnormality of the hydrogen detection element 12 is determined based on this average value. As a result, the possibility of determining that there is no abnormality is reduced. As described above, even when an abnormality is determined based on the average value, as shown in FIG. 9B, an abnormality can be reliably determined as abnormal.

  Further, even if the impedance exceeds the determination criterion as shown in FIG. 8A, if the impedance difference exceeds the determination criterion as shown in FIG. Without. It can also be determined that there is an abnormality when the impedance exceeds a determination criterion several times (for example, three points) continuously. Even in such a determination, as shown in FIG. 9, it is possible to reliably determine that an abnormality has occurred in the case of an abnormality.

  As described above, the storage device 12 (storage means) that stores past impedance (element information) is provided, and the control circuit 10 determines the abnormality of the hydrogen detection element 12 using the past impedance and the current impedance. Thus, the abnormality of the hydrogen detection element 12 can be determined more accurately.

  In addition, the control circuit 10 can calculate the average value of the past impedance and the current impedance immediately before being stored in the storage device 26, and determine the abnormality of the hydrogen detection element 12 using the average value. Further, the difference between the past impedance and the current impedance can be calculated, and the abnormality can be determined using the difference. Thus, the abnormality of the hydrogen detection element 12 can be determined more accurately.

  Note that the impedance data stored in the storage device 26 may be for the period used for the determination of the abnormality, and the old impedance data is preferably deleted sequentially.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

FIG. 1 is a block diagram of the hydrogen detection element control apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example when the hydrogen detection element control device according to the first embodiment is used in a fuel cell vehicle. FIG. 3 is a flowchart illustrating a control method of the control circuit of the hydrogen detection element control apparatus according to the first embodiment. FIG. 4 is a diagram for explaining a method of determining whether the hydrogen detection element is abnormal based on the impedance of the hydrogen detection element and the element temperature, and is a diagram showing the impedance with respect to the element temperature. FIG. 5 is a diagram for explaining a method for determining abnormality of a hydrogen detection element using information on impedance distribution, and is a diagram showing impedance with respect to element temperature. FIG. 6 is a diagram for explaining the function of correcting the element temperature, and is a diagram showing the temperature of the hydrogen detection element with respect to the temperature of the temperature detection element. FIG. 7 is a diagram for explaining correction of the element temperature rise of the hydrogen detection element due to the hydrogen concentration, and is a diagram showing the temperature increase of the hydrogen detection element with respect to the hydrogen concentration. FIG. 8 is a diagram (part 1) for explaining a method of determining an abnormality using past impedance and current impedance. FIG. 8 (a) shows impedance against time, and FIG. 8 (b) shows time against time. Average value, FIG. 8C is a diagram showing a difference with respect to time. FIG. 9 is a diagram (part 2) for explaining a method of determining an abnormality using past impedance and current impedance. FIG. 9 (a) shows impedance with respect to time, and FIG. 9 (b) shows with respect to time. Average value, FIG. 9C is a diagram showing a difference with respect to time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control circuit 12 Hydrogen detection element 14 Hydrogen concentration calculation circuit 16 Impedance calculation circuit 18 Power supply for impedance detection 20 Resistance 22 Temperature detection element 26 Memory | storage device

Claims (18)

A hydrogen concentration calculating means for acquiring a first detection element of the hydrogen detection element and calculating a hydrogen concentration by the first detection element;
Element information calculation means for acquiring a second detection element different from the first detection element of the hydrogen detection element and calculating element information for determining abnormality of the hydrogen detection element from the second detection element When,
An abnormality determination means for determining whether the hydrogen detection element is abnormal based on the element information;
A hydrogen sensing element control device comprising: 2. The hydrogen detection according to claim 1, wherein the acquisition of the second detection element of the element information calculation unit is performed independently of the acquisition of the first detection element of the hydrogen concentration calculation unit in terms of time. Element control device. 3. The hydrogen detection element control device according to claim 1, wherein the abnormality determination unit determines an abnormality of the hydrogen detection element using an element temperature of the hydrogen detection element and the element information. The temperature detection element which acquires a temperature detection element from the temperature detection element which detects the temperature of the same medium as the said hydrogen detection element, and calculates the said element temperature from the said temperature detection element is provided, The temperature calculation means characterized by the above-mentioned. Hydrogen sensing element control device. 5. The hydrogen detection element control device according to claim 4, wherein the element temperature is calculated from the temperature detection element, a temperature correlation curve of the hydrogen detection element and the temperature detection element acquired in advance. 6. The abnormality determination unit determines an abnormality of the hydrogen detection element based on an element temperature of the hydrogen detection element and the element information using a correlation between an element temperature and element information acquired in advance. The hydrogen detection element control device according to any one of the above. The abnormality determination unit uses a correlation between the element temperature and the element information acquired in advance, and when the element information corresponding to the element temperature calculated by the temperature calculation unit is used as reference element information, a certain ratio of the reference element information The hydrogen detection element control device according to claim 6, wherein the hydrogen detection element is determined to be abnormal when exceeding the range. 8. The hydrogen detecting element control apparatus according to claim 6, wherein the element temperature is calculated by correcting an element temperature of the hydrogen detecting element corresponding to the hydrogen concentration calculated by the hydrogen concentration calculating means. The abnormality determination unit corrects the element information using element information distribution information of a plurality of hydrogen detection elements acquired in advance, and determines that the hydrogen detection element is abnormal. The hydrogen detection element control device according to any one of the preceding claims. Comprising storage means for storing the element information;
The abnormality determination unit determines an abnormality of the hydrogen detection element by using past element information stored in the storage unit and current element information. The hydrogen detection element control apparatus of description. The abnormality determination unit calculates an average value of previous element information and the current element information stored in the storage unit, and determines an abnormality of the hydrogen detection element using the average value. The hydrogen detection element control device according to claim 10. The abnormality determination means calculates a difference between the previous element information immediately before stored in the storage means and the current element information, and determines an abnormality of the hydrogen detection element using the difference. The hydrogen detection element control apparatus according to claim 10. The hydrogen detection element control device according to claim 1, wherein the element information is used to determine whether the hydrogen detection element is short-circuited or open. The hydrogen detection element control device according to any one of claims 1 to 12, wherein an acquisition interval of the second detection element is calculated using the element information. 15. The hydrogen detection element control device according to claim 1, wherein the element information is an impedance of the hydrogen detection element. Obtaining a first sensing element of a hydrogen sensing element and calculating a hydrogen concentration with the first sensing element;
An element information calculation step of acquiring a second detection element different from the first detection element of the hydrogen detection element and calculating element information for determining an abnormality of the hydrogen detection element from the second detection element. When,
An abnormality determination step for determining whether the hydrogen detection element is abnormal based on the element information. A method for controlling the hydrogen detection element. Acquisition of the second detection element from the hydrogen detection element in the element information calculation step is performed independently of the acquisition of the first detection element from the hydrogen detection element in the hydrogen concentration calculation step. The method for controlling a hydrogen sensing element according to claim 16. The method of controlling a hydrogen detection element according to claim 16 or 17, wherein the abnormality determination step determines an abnormality of the hydrogen detection element by using an element temperature of the hydrogen detection element and the element information.

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