JP2013214475A - Fuel cell system impedance calculation method and fuel cell vehicle incorporating impedance arithmetic unit to execute fuel cell system impedance calculation method - Google Patents

Abstract

An impedance calculation method for realizing proper state grasp of an electrolyte membrane or the like of a fuel cell is provided.
An impedance calculation means for calculating an impedance based on a current input from a current signal line connected to a fuel cell and a voltage input from a voltage signal line, a current delay check unit for checking a current delay, A voltage delay confirmation unit for confirming a voltage delay, and in a trial measurement, the current delay confirmed by the current delay confirmation unit is larger than the voltage delay confirmed by the voltage delay confirmation unit in the trial measurement. In the voltage signal line, a delay correction element having the same magnitude as the difference between the current delay and the voltage delay is added, and when the voltage delay is larger than the current delay, the current signal A delay correction element having the same magnitude as the difference between the voltage delay and the current delay is added to the line. Computing the impedance of the fuel cell.
[Selection] Figure 1

Description

  The present invention relates to an impedance measurement calibration method, in particular, a fuel cell system impedance calculation method, and a fuel cell vehicle including an impedance calculator for executing the impedance calculation method.

In recent years, fuel cell electric vehicles (FCEVs) have attracted attention for environmental measures and for reducing fossil fuel consumption.
In a fuel cell electric vehicle (hereinafter referred to as “vehicle” or “fuel cell vehicle”), the impedance characteristic of the fuel cell to be mounted is an important factor in the running characteristics of the vehicle, and needs to be grasped sequentially.
Conventionally, an FRA (Frequency Response Analyzer) method is known as a method for measuring the impedance of a fuel cell, in which measurement is performed by adding a sine wave of a predetermined frequency and measurement is repeated while changing the frequency (Patent Document 1).
As an impedance measurement other than the FRA method, there is a method of using an FFT (Fast Fourier Transform) method after inputting a pseudo white signal or an M-sequence signal.

In any of the above measurements, in the impedance measurement for grasping the power generation environment and operating conditions of the fuel cell, when trying to estimate the electrolyte membrane resistance (also simply referred to as “membrane resistance”) of the fuel cell with high accuracy, etc. It is necessary to ensure measurement accuracy in the high frequency range.
However, in the measurement, if the measurement delay and dead time of the current and voltage used for impedance calculation are different, the calculation accuracy in the high frequency region such as membrane resistance is extremely lowered. If the voltage delay is greater than the current delay, the membrane resistance is calculated to be higher than the actual delay. Conversely, if the current delay is greater than the voltage delay, the membrane resistance is calculated to be lower than the actual delay. Such a difference in current voltage delay occurs, for example, when a converter having a different time response is connected to each line.
In order to avoid these differences in current / voltage delay, conventionally, an impedance measurement line is connected to the current / voltage terminal as close as possible to the fuel cell at the shortest distance, resulting in a difference in delay and dead time in the current / voltage measurement system. The equipment was designed with careful consideration so that there was no measurement.

JP 2005-285614 A

However, since the FRA method found in Patent Document 1 is a method of measuring by inputting a sine wave having a constant frequency, only the impedance at that frequency point can be measured. In order to acquire impedance characteristics of a wide range of frequencies, it is necessary to sequentially input sine waves of different frequencies, which requires a lot of measurement time. In addition, special signal generation hardware and software are required. Furthermore, there is a problem that these special input signals need to be superimposed and applied to a normal load control signal. In addition, there is a problem that the characteristics of a fuel cell mounted on an actual vehicle cannot be measured in real time.
Also, even when measuring using the FFT method, an impedance measurement line is directly connected to the current voltage terminal as close as possible to the fuel cell, with the shortest distance, resulting in delays and differences in dead time in the current and voltage measurement systems. In the method of designing and measuring the device with great care so that there is no need, it takes time and cost to provide a special measurement line for impedance measurement. Further, labor and cost for aligning the delay levels of the elements provided in the current / voltage line are required. In addition, there is a problem that high-precision impedance cannot be calculated from data measured from a current-voltage terminal at an arbitrary position.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an impedance calculation method that realizes an appropriate state grasp of an electrolyte membrane of a fuel cell.

In order to achieve the above object, each invention is configured as follows.
That is, the fuel cell system impedance calculation method according to the first aspect of the present invention includes a current input from a current signal line having a current measurement terminal connected to the fuel cell, and a voltage signal having a voltage measurement terminal connected to the fuel cell. Impedance calculation means for calculating impedance based on the voltage input from the line, current delay check section for checking current delay based on calculation by the impedance calculation means, and voltage delay based on calculation by the impedance calculation means A voltage delay confirmation unit for confirming, in an impedance computing unit comprising a test, in a trial measurement, when the current delay confirmed by the current delay confirmation unit is greater than the voltage delay confirmed by the voltage delay confirmation unit The voltage signal line has the same magnitude as the difference between the current delay and the voltage delay. When a delay correction element is added and the voltage delay confirmed by the voltage delay confirmation unit is larger than the current delay confirmed by the current delay confirmation unit in the measurement as a trial, the current signal line is A delay correction element having the same magnitude as the difference between the voltage delay and the current delay is added, and then the impedance of the fuel cell is calculated by the impedance calculation means.

  According to a second aspect of the present invention, there is provided a method for calculating an impedance of a fuel cell system, wherein a current input from a current signal line having a current measurement terminal connected to a fuel cell having a known membrane resistance value is connected to the fuel cell. In the impedance calculator that calculates the impedance based on the voltage input from the voltage signal line having the voltage measurement terminal, in the measurement as a trial, when the measured membrane resistance value is larger than the known membrane resistance value In addition, a delay correction element is added to the voltage signal line so that the measured membrane resistance value and the membrane resistance value calculated from the impedance value are substantially the same, and in the measurement as a trial, the measured membrane resistance value is When the membrane resistance value is smaller than the known membrane resistance value, the membrane resistance value calculated from the measured membrane resistance value and the impedance value is applied to the current signal line. Substantially the same as made the delay correction element added followed by the impedance computing unit, characterized by calculating an impedance of the fuel cell.

  According to a third aspect of the present invention, there is provided a method for calculating an impedance of a fuel cell system comprising: a current input from a current signal line having a current measurement terminal connected to the fuel cell; and a voltage signal having a voltage measurement terminal connected to the fuel cell. In an impedance calculator that calculates an impedance based on a voltage input from a line, in the trial measurement, the current measurement terminal connected to the fuel cell and the voltage measurement terminal are once removed, and then the fuel cell A calibration element having a known calibration element resistance value is connected to the output terminal portion, the impedance is calculated by the impedance calculator, and the resistance value of the calibration element measured in the trial is the known calibration element. When the resistance value is larger than the resistance value of the calibration element measured in the trial and the voltage signal line, Add a delay correction element so that the known calibration element resistance value is substantially the same, and when the resistance value of the calibration element measured in the trial is smaller than the known calibration element resistance value, A delay correction element is added to the voltage signal line so that the resistance value of the calibration element measured in the trial and the known calibration element resistance value are substantially the same, and then the connected calibration element is After removing, the current measurement terminal and the voltage measurement terminal are connected to the fuel cell, and the impedance is calculated.

  According to a fourth aspect of the present invention, there is provided an impedance calculation method for a fuel cell system comprising: a current input from a current signal line having a current measurement terminal connected to the fuel cell; and a voltage signal having a voltage measurement terminal connected to the fuel cell. Based on the calculation by the impedance calculation means for calculating the impedance based on the voltage inputted from the line, the delay detection signal applying means for applying the delay detection signal to the current signal line and the voltage signal line, and the calculation by the impedance calculation means. In an impedance calculator comprising: a current delay confirmation unit that confirms a current delay; and a voltage delay confirmation unit that confirms a voltage delay based on a calculation by the impedance calculation unit. Disconnect the current signal line and the voltage signal line, and then The detection signal applying means is connected to the current signal line and the voltage signal line to calculate the impedance, and the current delay confirmed by the current delay confirmation unit is larger than the voltage delay confirmed by the voltage delay confirmation unit. If larger, a delay correction element having the same magnitude as the difference between the current delay and the voltage delay is added to the voltage signal line, and the voltage delay confirmed by the voltage delay confirmation unit is the current delay confirmation unit. If the current delay is greater than the current delay confirmed in step 1, a delay correction element having the same magnitude as the difference between the voltage delay and the current delay is added to the current signal line, and then the delay detection signal applying means Is disconnected from the current signal line and the voltage signal line, and then the fuel cell is reconnected to the current signal line and the voltage signal line. By Nsu calculating means, and calculates the impedance of the fuel cell.

  Other means will be described in the embodiment for carrying out the invention.

  ADVANTAGE OF THE INVENTION According to this invention, the impedance calculation method which implement | achieves proper state grasps, such as an electrolyte membrane of a fuel cell, can be provided.

It is a figure which shows an example of the impedance calculation method of 1st Embodiment of the impedance calculation method of the fuel cell type | system | group which concerns on this invention, (a) is a fuel with the current delay 1, 2 and the voltage delay 1, 2 as it is. (B) is a diagram for calculating the impedance by measuring the current and voltage of the battery, and (b) inserting a delay correction element on the voltage side for the larger current delay in the comparison between the current delays 1 and 2 and the voltage delays 1 and 2. (C) is a diagram for calculating the impedance by inserting a delay correction element on the current side for the large voltage delay in the comparison between the current delays 1 and 2 and the voltage delays 1 and 2. It is. It is a flowchart which shows an example of the procedure which determines whether the delay correction element in 1st Embodiment of the impedance calculation method of the fuel cell system which concerns on this invention is added. It is an example of a Cole-Cole plot showing a change in characteristics due to a difference in delay difference between an observation current and an observation voltage used for impedance calculation. (A) shows a true characteristic and a characteristic when the current delay is larger than the voltage delay. In comparison, (b) shows a comparison between the true characteristic and the characteristic when the voltage delay is larger than the current delay. It is a flowchart which shows an example of the procedure which determines whether the delay correction element in 2nd Embodiment of the impedance calculation method of the fuel cell system which concerns on this invention is added. It is a figure which shows an example of the impedance calculation method of 3rd Embodiment of the impedance calculation method of the fuel cell type | system | group which concerns on this invention, (a) is a state with the current delay 1, 2 and the voltage delay 1, 2 as it is, FIG. 5B is a diagram for calculating the impedance by measuring the current and voltage of the battery, and FIG. 5B is a diagram for calculating the impedance using a calibration element whose impedance is known in advance and adding a delay correction element to the voltage system. (C) is a figure which calculates an impedance using the element for calibration whose impedance is known beforehand, and adds a delay amendment element to a current system. It is a flowchart which shows an example of the procedure which determines how a delay correction element is added using the element for a calibration in 3rd Embodiment of the impedance calculation method of the fuel cell system which concerns on this invention. It is a figure which shows an example of the impedance calculation method of 4th Embodiment of the impedance calculation method of the fuel cell type | system | group which concerns on this invention, (a) is a state with the current delay 1, 2 and the voltage delay 1, 2 as it is, FIG. 5B is a diagram for calculating the impedance by measuring the current and voltage of the battery 101, FIG. 5B is a diagram for measuring the impedance by removing the fuel cell and applying a calibration signal from the terminal position, and FIG. ) Is a diagram for measuring the impedance of the fuel cell 101 by adding a delay correction element 424 to the voltage system based on the measurement in FIG. It is a flowchart which shows an example of the procedure which determines how a delay correction element is added using the signal for a calibration in 4th Embodiment of the impedance calculation method of the fuel cell type | system | group which concerns on this invention. It is a figure which shows an example of the effect when a delay arises with respect to an impedance true value, and an example of the additional effect of a delay correction element, (a) is a true characteristic and a characteristic when a current delay is larger than a voltage delay (B) shows a comparison between a true characteristic and a characteristic when a voltage delay is larger than a current delay, and (c) shows a characteristic when a delay correction element is added. It is a figure which shows an example of the schematic structure which uses the motor and fuel cell as a drive source in a fuel cell vehicle. FIG. 10 is a diagram illustrating an example of a schematic configuration of a fuel cell vehicle according to a fifth embodiment of the fuel cell system impedance calculation method according to the present invention, in which the second embodiment is applied to a fuel cell of the fuel cell vehicle.

  Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)
A first embodiment of an impedance calculation method for a fuel cell system according to the present invention will be described with reference to FIGS.
FIG. 1 is a diagram illustrating an example of an impedance calculation method according to the first embodiment. FIG. 1A illustrates a fuel cell (FC) 101 with current delays 1 and 2 and voltage delays 1 and 2 as they are. FIG. 7 is a diagram in which current and voltage are measured and input to an impedance calculator (impedance calculation means) 105 for calculation, and FIG. (C) is a diagram in which a delay correction element 124 is inserted on the voltage side to eliminate the delay between the current and voltage, and then the current and voltage are measured and input to the impedance calculator 105 for calculation. In the comparison between the current delays 1 and 2 and the voltage delays 1 and 2, the amount of the large voltage delay is inserted on the current side to eliminate the delay between the current and voltage by inserting the delay correction element 114, and then the current and voltage are measured. Impedance calculator 105 Input to a diagram of computing. Here, in any of (a), (b), and (c), an impedance measurement signal is transmitted from an impedance measurement signal generator (not shown) and input to the fuel cell (FC) 101.

<First embodiment, part 1>
In FIG. 1A, the current and voltage of the fuel cell (FC) 101 are measured via the current measurement terminal 112 and the voltage measurement terminal 122, respectively, and then input to the impedance calculator 105, respectively. Impedance is measured (calculated).
However, the current path has a current delay 1 (111) and a current delay 2 (113), and the voltage path has a voltage delay 1 (121) and a voltage delay 2 (123).
At this time, the total of current delay (current delay 1 + current delay 2) and the total of voltage delay (voltage delay 1 + voltage delay 2) are not necessarily equal. Therefore, the impedance based on the current and voltage input in the impedance calculator 105 is used. An error occurs in the calculation of.

The impedance calculator 105 includes an impedance calculation function (impedance calculation means), a current delay check unit (not shown) for checking the current delay based on the calculation by the impedance calculation means, and a voltage delay check for checking the voltage delay. Part (not shown).
The current and voltage are converted into time constants of the first-order lag transfer function by the current delay confirmation unit and the voltage delay confirmation unit, respectively, and the magnitude of the time constant and the corresponding delay are confirmed. The impedance calculator 105 can determine which of the current delay and the voltage delay is delayed based on the magnitude of the first-order delay time constant.

<Relationship between observed current and observed voltage delay difference used for impedance calculation>
First, referring to FIG. 3, in the impedance measurement of the electrolyte membrane of the fuel cell 101, if the measurement delay and the dead time of the current and voltage are different from each other, how the impedance calculation (calculation) is affected. explain.
1 (b) and 1 (c) will be described later.
FIG. 3 is a Cole-Cole plot (figure) showing an example of the relationship between the observed current and the observed voltage lag difference used for impedance calculation. (A) shows the true characteristic (C01) and the current lag is greater than the voltage lag. The characteristic (C02) in the case of being large is compared and shown, and (b) shows the characteristic (C01) in the true case and the characteristic (C03) in the case where the voltage delay is larger than the current delay.
3A and 3B, the horizontal axis is the resistance value, the vertical axis is the reactance value, and is a Cole-Cole plot (figure) when the measurement frequency is changed from a low frequency to a high frequency.

In FIG. 3A, a characteristic line C01 is a characteristic when there is no delay difference between the observation current and the observation voltage, which is a true value characteristic.
A characteristic line C02 is a characteristic when the current delay is larger than the voltage delay.
There is not much difference between the characteristic line C01 and the characteristic line C02 in the low frequency range (right side of the horizontal axis), but the difference between the characteristic line C01 and the characteristic line C02 is large in the high frequency range (left side of the horizontal axis). ing.
The resistance value (horizontal axis) at each intersection of the real axis having the reactance value (vertical axis) of 0, the characteristic line C01, and the characteristic line C02 corresponds to the resistance value (membrane resistance value) of the electrolyte membrane of the fuel cell 101. However, the resistance value indicated by the characteristic line C02 is larger than the resistance value, which is the true value indicated by the characteristic line C01, and is greatly different, resulting in a measurement error.

In FIG. 3B, a characteristic line C01 is a characteristic when there is no delay difference between the observed current and the observed voltage, which is a true value characteristic, and the characteristic line C03 has a voltage delay greater than the current delay. This is a characteristic when the value is also large.
There is not much difference between the characteristic line C01 and the characteristic line C03 in the low frequency range (right side of the horizontal axis), but the difference between the characteristic line C01 and the characteristic line C03 is large in the high frequency range (left side of the horizontal axis). ing.
The resistance value indicated by the characteristic line C03 is smaller than the resistance value that is the true value indicated by the characteristic line C01 at each intersection of the real axis having the reactance value (vertical axis) of 0, the characteristic line C01, and the characteristic line C02. This is a measurement error.

<First embodiment, part 2>
As described above, since there is a measurement error if there is a delay difference between the observation current and the observation voltage, it is necessary to take measures to eliminate this delay difference. Returning to FIG. 1 again, FIGS. 1B and 1C will be described.

In FIG. 1B, the total delay of the voltage-side voltage delay 1 (121) and the voltage delay 2 (123) is greater than the total delay of the current-side current delay 1 (111) and the current delay 2 (113). And the delay difference between the current and the voltage is grasped by the measurement in FIG. 1A, and the delay correction element 124 corresponding to this delay difference is set to the voltage-side voltage delay 2 (123) and the impedance. It is added between the calculator 105.
That is, (the delay of current delay 1 + the delay of current delay 2 = the delay of voltage delay 1 + the delay of voltage delay 1 + the delay of delay correction element 124) is established.
By adjusting the delay difference by the delay correction element 124, the voltage and current input to the impedance calculator 105 are in an original relationship in the fuel cell 101, so that accurate impedance measurement of the fuel cell 101 is performed.

In FIG. 1C, the total delay of the current-side current delay 1 (111) and the current delay 2 (113) is greater than the total delay of the voltage-side voltage delay 1 (121) and the voltage delay 2 (123). And the delay difference between the current and the voltage is grasped by the measurement of FIG. 1A, and the delay correction element 114 corresponding to the delay difference is determined as the current-side current delay 2 (113) and the impedance. It is added between the calculator 105.
That is, (the delay of voltage delay 1 + the delay of voltage delay 2 = the delay of current delay 1 + the delay of current delay 2 + the delay of the delay correction element 124) is established.
By adjusting the delay difference by the delay correction element 114, the voltage and current input to the impedance calculator 105 have the original relationship in the fuel cell 101, so that the impedance of the fuel cell 101 is accurately measured.

  Note that the delay correction elements 124 and 114 in FIGS. 1B and 1C may be configured by electronic components (electronic elements) or software. Further, when configured by software, the impedance calculator 105 may be provided.

<Flowchart for determining whether to add a delay correction element>
Next, a procedure for determining whether or not to add a delay correction element in the impedance measurement of the fuel cell 101 will be described.
FIG. 2 is an example of a flowchart for determining whether or not to add a delay correction element in the first embodiment. This will be described below based on the flowchart.

<< Step S11 >>
First, in the impedance measurement of the fuel cell 101, a determination is made as to whether or not to add a delay correction element.
In step S11, it is compared whether or not the current system delay is equal to the voltage system delay.
Here, the current system delay corresponds to the delay of current delay 1 (111) + current delay 2 (113) in FIG. 1, and the voltage system delay is voltage delay 1 (121) + voltage delay 2 in FIG. This corresponds to (123).
In this comparison, when the current system delay is equal to the voltage system delay (Y: S11), this flow ends. That is, impedance measurement is performed without adding a delay correction element.
As shown in FIG. 1A, this corresponds to impedance measurement (calculation) by the impedance calculator 105 in a state where there is no delay correction element.
In this comparison, when the current system delay and the voltage system delay are not equal (N: S11), the process proceeds to step S12.

<< Step S12 >>
In step S12, it is compared whether or not the current system delay is larger than the voltage system delay.
In this comparison, when the current system delay is larger than the voltage system delay (Y: S12), the process proceeds to step S13.
In this comparison, when the current system delay is not larger than the voltage system delay (N: S12), the process proceeds to step S14.

<< Step S13 >>
In step S13, a delay correction element, which is a delay element corresponding to a part in which the current system delay is larger than the voltage system delay, is added to the voltage system.
This corresponds to adding the delay correction element 124 of FIG. 1B to the voltage system.
Then, this flow ends. That is, the delay correction element 124 is added to the voltage system, the current system delay is made equal to the voltage system delay, and impedance measurement is performed.

<< Step S14 >>
In step S14, a delay correction element, which is a delay element corresponding to a part in which the voltage system delay is larger than the current system delay, is added to the current system.
This is equivalent to adding the delay correction element 114 of FIG. 1C to the current system.
Then, this flow ends. That is, the delay correction element 114 is added to the current system, the current system delay is made equal to the voltage system delay, and impedance measurement is performed.

(Second Embodiment)
Next, a second embodiment of the impedance calculation method for a fuel cell system according to the present invention will be described with reference to FIG. 4 and FIG.
In the first embodiment, the difference in delay between current and voltage can be grasped. However, in the second embodiment, the current and voltage delays are unknown. However, a method for calculating the delay correction element using the known case where the membrane resistance value of the fuel cell 101 (the resistance value of the electrolyte membrane) is known will be described.
Since the addition of the delay correction elements (124, 114) is the same as that in FIG. 1, FIG. 1 is also used.
In FIG. 4, the procedure of the method for calculating the delay correction element of the second embodiment will be described.
FIG. 4 is a flowchart illustrating an example of a procedure for determining whether or not to add a delay correction element in the second embodiment. This will be described below based on the flowchart.

<Flowchart for determining how to add a delay correction element using a known membrane resistance>
<< Step S21 >>
First, in the impedance measurement of the fuel cell 101, a determination is made as to whether or not to add a delay correction element using a known membrane resistance.
In step S21, first, the membrane resistance value of the fuel cell 101 is measured in a state where there is no delay correction element as shown in FIG.
And the known value (known membrane resistance, known membrane resistance value) of the membrane resistance value of the fuel cell 101 that has been grasped in advance, and the resistance value measured without a delay correction element as shown in FIG. (Measurement membrane resistance, measurement membrane resistance value).

In addition, although the impedance measurement of the fuel cell 101 is performed by the impedance calculator 105 in FIG. 1, it is measured in a wide range of frequencies as shown in FIG. Both the known membrane resistance and the measured membrane resistance mean the resistance value at the intersection of the impedance characteristic line in FIG. 3 and the reactance 0, that is, the real axis.
If the measured membrane resistance (measured membrane resistance value) and the known membrane resistance (known membrane resistance value) are equal (approximately within 5% of the error) (Y: S21), whether or not to add a delay correction element The determination is finished.
That is, it is assumed that there is no delay difference that causes a problem between the current system delay and the voltage system delay, and impedance measurement is performed without adding a delay correction element. As shown in FIG. 1A, this corresponds to impedance measurement (calculation) by the impedance calculator 105 in a state where there is no delay correction element.

  If the measured membrane resistance and the known membrane resistance are not equal (generally the error exceeds 5%) (N: S21), the process proceeds to step S22.

<< Step S22 >>
In step S22, it is determined whether the measured membrane resistance is greater than the known membrane resistance.
If the measured membrane resistance is greater than the known membrane resistance (Y: S22), the process proceeds to step S23.
If the measured membrane resistance is not greater than the known membrane resistance (N: S22), the process proceeds to step S24.
When the current system is delayed compared to the voltage system, the measured membrane resistance tends to be calculated higher.

<< Step S23 >>
In step S23, a predetermined delay element is added to the voltage system (voltage signal) as a delay correction element 124 (FIG. 1B).
And it returns to step S21 and re-measures.

<< Step S24 >>
In step S24, a predetermined delay element is added to the current system (current signal) as a delay correction element 114 (FIG. 1C).
And it returns to step S21 and re-measures.

  Thus, a predetermined delay element is added in step S23 or step S24. However, by adding this delay element, the measured membrane resistance (measured membrane resistance value) becomes close to the known membrane resistance (known membrane resistance value), but there is no guarantee that they match. Therefore, the procedure (flow) shown in FIG. 4 is repeated until they substantially match.

In the above flowchart, the delay correction elements 114 and 124 are added as a delay model by software.
When adding a first-order lag model as an example of the lag model, the membrane resistance (measured membrane resistance value) determined from the impedance calculated by increasing or decreasing the delay time constant is the known membrane resistance (known membrane resistance value). The time constant of the delay correction element (software) is repeatedly increased or decreased so that it is within about 5% of.

(Third embodiment)
Next, a third embodiment of the fuel cell system impedance calculation method according to the present invention will be described with reference to FIGS.
In the third embodiment, a case will be described in which the delay between current and voltage is unknown, but a calibration element can be installed at the fuel cell output terminal.

  FIG. 5 is a diagram showing an impedance calculation method according to the third embodiment. FIG. 5A shows the impedance and impedance of the fuel cell 101 by measuring the current and voltage of the fuel cell 101 and leaving the current delays 1 and 2 and the voltage delays 1 and 2 as they are. (B) shows that the measurement line is once disconnected from the output terminal of the fuel cell (FC101), and the calibration element 301 whose impedance is known in advance is connected to the end of the measurement line. It is a diagram in which a delay model (delay correction element 324) is added to the voltage system so that an error from a known impedance is reduced by installing it at the battery output terminal, and (c) Similarly, the measurement line is once disconnected from the output terminal portion of the fuel cell (FC101), and a calibration element 301 whose impedance is known in advance is connected to the end of the measurement line. Placed in, and calculates the impedance, which is a diagram obtained by adding the model delayed by software (delay correction element 314) to the current system so that the error is reduced with the known impedance. Here, in any of (a), (b), and (c), an impedance measurement signal is transmitted from an impedance measurement signal generator (not shown) and input to the fuel cell (FC) 101 or the calibration element 301. .

  Since FIG. 5A is substantially the same as FIG.

FIG. 5B is obtained by adding a calibration element 301 and a delay correction element 324 to the configuration of FIG.
In FIG. 5B, the calibration element 301 includes a resistor and a capacitor. Furthermore, a coil may be provided as necessary. The impedance of the calibration element 301 is known. That is, the resistance value of the pure resistance component of the calibration element 301 is known.
The calibration element 301 is installed at the end of the measurement line from which the fuel cell (FC101) is removed, and a delay correction element 324 is added between the voltage delay 2 (123) and the impedance calculator 105.
With the configuration of FIG. 5B, the impedance of the calibration element 301 is measured. Then, the delay correction element 324 is adjusted so that the intersection of the calculated impedance with the real axis, that is, the resistance value of the pure resistance component is equal to the resistance value of the pure resistance component of the known calibration element 301.

The delay correction element 324 is configured by software, and in the case of the first-order delay model, the delay time constant is adjusted by increasing / decreasing, and the measured resistance value of the pure resistance component is the resistance of the pure resistance component of the calibration element 301. Adjust it repeatedly so that it is within 5% of the value. The convergence algorithm may be a general one.
In the configuration of FIG. 5 using the delay correction element 324 when this error is approximately within 5%, if the calibration element 301 is removed from the fuel cell output terminal portion and measured, the film is the impedance of the fuel cell 101 Resistance can be measured accurately.
In the measurement of the delay difference between the current and the voltage, it is assumed that the time constants of the first-order delays of the current and the voltage are compared, and the delay difference between the current and the voltage disappears when the time constants are aligned.

FIG. 5C shows a configuration in which a delay correction element 314 is added to the current system instead of the delay correction element 324 with respect to the configuration of FIG.
When the voltage system is faster in the relationship between the delay difference between the current and the voltage, the delay correction element 314 is added to the current system as shown in FIG. Except for this difference, the description is generally the same as the description of FIG.

<Flowchart for determining how to add a delay correction element using a calibration element>
FIG. 6 is a flowchart illustrating an example of a procedure for determining how to add a delay correction element using the calibration element 301 (FIG. 5) according to the third embodiment. This will be described below based on the flowchart.

<< Step S31 >>
First, in the impedance measurement of the fuel cell 101 (FIG. 5), the determination of how to add the delay correction elements 314 and 324 (FIG. 5) using the calibration element 301 is started.
In step S31, impedance measurement is performed using the calibration element 301, and the resistance value (measurement resistance value) measured by the calibration element 301 is compared with a known resistance value (calibration element resistance value).
If the measured resistance value is equal to the calibration element resistance value (Y: S31), the process ends. That is, in the delay correction elements 314 and 324 that have no delay correction element or have been added at the time of measurement, the adjustment of the delay correction element is finished, and the impedance measurement of the fuel cell 101 is performed.
If the measured resistance value is not equal to the calibration element resistance value (N: S31), the process proceeds to step S32.

<< Step S32 >>
In step S32, it is determined whether or not the measured resistance value is larger than the calibration element resistance value.
If the measured resistance value is larger than the calibration element resistance value (Y: S32), the process proceeds to step S33.
If the measured resistance value is not greater than the calibration element resistance value (N: S32), the process proceeds to step S34.

<< Step S33 >>
In step S33, a predetermined delay element is added to the voltage system (voltage signal) as a delay correction element 324 (FIG. 5B).
And it returns to step S31 and re-measures.

<< Step S34 >>
In step S34, a predetermined delay element is added to the current system (current signal) as a delay correction element 314 (FIG. 5C).
And it returns to step S31 and re-measures.

The above is repeated, and an appropriate adjustment amount of the delay correction element and an addition side are determined.
In the above flowchart, the delay correction elements 324 and 314 are added as a delay model by software.
When a first-order lag model is added as an example of the lag model, the measured membrane resistance value determined from the impedance calculated by increasing or decreasing the lag time constant is approximately within 5% of the known calibration element resistance value. In this way, the time constant of the delay correction element (software) is repeatedly increased or decreased.
When an appropriate delay correction element is determined and the flow of FIG. 6 is completed, the calibration element 301 is removed. However, an appropriate delay correction element (324 or 314) is provided as it is.

(Fourth embodiment)
Next, a fourth embodiment of the fuel cell system impedance calculation method according to the present invention will be described with reference to FIGS.
In the fourth embodiment, a case will be described in which the delay between current and voltage is unknown and there is no calibration element, but a calibration signal can be applied to the fuel cell output terminal.

  FIG. 7 is a diagram showing an example of the impedance calculation method of the fourth embodiment. FIG. 7A shows the current and voltage of the fuel cell 101 measured with the current delays 1 and 2 and the voltage delays 1 and 2 as they are. The impedance is input to the impedance calculator and the impedance is measured. (B) is a diagram for measuring the impedance by applying a calibration signal to the fuel cell output terminal, and (c) is the measurement in (b). It is a figure which adds the delay correction element 424 to a voltage system based on the basis, and measures the impedance of the fuel cell 101. FIG. Here, in (a) and (c), an impedance measurement signal is transmitted from an impedance measurement signal generator (not shown) and input to the fuel cell (FC) 101.

  Since FIG. 7 (a) is substantially the same as FIG. 1 (a), redundant description is omitted.

FIG. 7B shows a case where a measurement line (current signal line, voltage signal line) is temporarily disconnected from the fuel cell output terminal portion of the fuel cell 101 and a delay detection signal is applied to the end of the measurement line.
In FIG. 7B, the delay detection signal applied as the calibration signal 401 is preferably an M-sequence signal, a step signal, or a sine wave. Observe the delay detection signal from the impedance measurement terminal and identify the signal delay and dead time level.
In this case, the difference between the current and voltage delay is actually compared with the time constant of the first-order lag transfer function.
The time constant of the first-order lag transfer function is estimated in both current and voltage from the gain and phase in the Bode diagram, and the difference between both time constants is defined as the lag difference.
When applying an M-sequence signal (maximum length sequence signal, power spectrum is almost constant in a wide frequency range), the time constant of the first-order lag is estimated after Fourier-transforming each time-series data of current and voltage. (System identification) is performed.

In FIG. 7C, a delay correction element 424, which is a delay element (software or actual electronic circuit), is added to a line having a smaller time constant as a result of the identification shown in FIG. to correct.
Then, the calibration signal 401 is removed, and the fuel cell output terminal portion of the fuel cell 101 and the measurement line including the current measurement terminal 112 and the voltage measurement terminal 122 are connected again.
In addition, FIG.7 (c)
(Delay of current delay 1 + Delay of current delay 2)> (Delay of voltage delay 1 + Delay of voltage delay 2)
Was corrected, and a delay correction element 424 was added to the voltage system after calibration.
(Delay of current delay 1 + Delay of current delay 2) = (Delay of voltage delay 1 + Delay of voltage delay 2 + Delay of delay correction element 424)
It is what.

If (current delay 1 delay + current delay 2 delay) <(voltage delay 1 delay + voltage delay 2 delay), a delay correction element is added to the current system after calibration.
Note that the illustration at this time is omitted.

<Flowchart for determining how to add a delay correction element using a calibration signal>
FIG. 8 is a flowchart illustrating an example of a procedure for determining how to add a delay correction element using a calibration signal according to the fourth embodiment. This will be described below based on the flowchart.

<< Step S41 >>
First, in the impedance measurement of the fuel cell 101 (FIG. 7), a determination is made as to how to add a delay correction element using a calibration signal.
In step S41, the measurement line is temporarily disconnected from the fuel cell output terminal of the fuel cell 101, and a calibration signal is applied to the end of the measurement line and transmitted.

<< Step S42 >>
In step S42, the current of the calibration signal via the current delay 1 (111), current measurement terminal 112, and current delay 2 (113) in FIG. 7B, the voltage delay 1 (121), the voltage measurement terminal 122, The impedance calculator 105 measures each delay of the voltage of the calibration signal via the voltage delay 2 (123).
As described above, the current and voltage delays are converted to the time constant of the first-order delay transfer function.

<< Step S43 >>
In step S43, it is determined whether the current system delay and the voltage system delay of the calibration signal are equal. Note that the current system delay and the voltage system delay are compared with the time constants of the respective first-order lag transfer functions as described above.
If the current system delay is equal to the voltage system delay (Y: S43), the process ends.
That is, the process is terminated without adding a delay correction element, and the impedance of the fuel cell 101 is measured.
If the current system delay and the voltage system delay are not equal (N: S43), the process proceeds to step S44.
The current system delay and the voltage system delay are measured by the current delay confirmation unit and the voltage delay confirmation unit provided in the impedance calculator 105, respectively.

<< Step S44 >>
In step S44, it is determined whether or not the current system delay of the calibration signal is greater than the voltage system delay.
When the current system delay is larger than the voltage system delay (Y: S44), the process proceeds to step S45.
If the current system delay is not greater than the voltage system delay (N: S44), the process proceeds to step S46.

<< Step S45 >>
In step S45, a delay correction element corresponding to the current system delay larger than the voltage system delay is added to the voltage system. And it ends. That is, with the addition of this delay correction element, the process is completed and the impedance measurement of the fuel cell 101 is performed.
Note that this case corresponds to the addition of the delay correction element 424 in FIG.
The delay correction element is software of a first-order delay transfer function.

<< Step S46 >>
In step S46, a delay correction element corresponding to the voltage system delay larger than the current system delay is added to the current system. And it ends. That is, with the addition of this delay correction element, the process is completed and the impedance measurement of the fuel cell 101 is performed.
In this case, it is not shown in FIG.

<Measurement Example of Fourth Embodiment>
Next, a measurement example showing the effect of the delay correction element of the above-described embodiment will be shown.
FIG. 9 is a diagram illustrating an example of an effect when a delay occurs with respect to the true impedance value (a state in which there is no delay difference between current and voltage, true characteristics) and an additional effect of a delay correction element. ) Shows a comparison between the true characteristics and the characteristics when the current delay is larger than the voltage delay, and (b) compares the true characteristics with the characteristics when the voltage delay is larger than the current delay. (C) shows the characteristics when a delay correction element is added.
9A, 9B, and 9C, the horizontal axis is the resistance value, the vertical axis is the reactance value, and is a Cole-Cole plot when the measurement frequency is changed from a low frequency to a high frequency. .

In FIG. 9A, a characteristic line C01 is a characteristic when there is no delay difference between the observation current and the observation voltage, which is a true value characteristic.
In the characteristic line C02, the current system has a primary delay with a time constant of 20 ms, and the voltage system has a primary delay with a time constant of 5 ms. Therefore, this is a characteristic when the current delay is larger than the voltage delay.
At this time, in the comparison of the resistance value (horizontal axis) at each intersection of the real axis having the reactance value (vertical axis) of 0, the characteristic line C01, and the characteristic line C02, the characteristic line has a larger current delay than the voltage delay. The resistance value of C02 is measured to be larger than the resistance value of the true characteristic line C01, and a difference corresponding to the reference numeral M12 in FIG.

In FIG. 9B, the characteristic line C01 is a characteristic when there is no delay difference between the observation current and the observation voltage, as in the characteristic line C01 shown in FIG.
In the characteristic line C03, the current system has a primary delay with a time constant of 5 ms, and the voltage system has a primary delay with a time constant of 20 ms. Therefore, this is a characteristic when the voltage delay is larger than the current delay.
At this time, the resistance value of the characteristic line C03 in which the voltage delay is larger than the current delay is the true value in the comparison between the real axis having the reactance value of 0 and the resistance value at each intersection of the characteristic line C01 and the characteristic line C03. Is measured to be smaller than the resistance value of the characteristic line C01, and there is a difference corresponding to the reference numeral M13 in FIG. 9B.

In FIG. 9C, the characteristic line C01 is a characteristic when there is no delay difference between the observation current and the observation voltage, as in the characteristic line C01 shown in FIGS. is there.
A characteristic line C04 indicates characteristics when a delay correction element having a first-order delay with a time constant of 15 ms is added to the voltage system shown in FIG.
At this time, the characteristic line C02 in (a) is improved to the characteristic line C04 in (c), and becomes quite close to the true characteristic line C01.
The characteristic line C04 is also a characteristic when a delay correction element of a first-order delay with a time constant of 15 ms is added to the current system shown in (b).
At this time, the characteristic line C03 in (b) is improved to the characteristic line C04 in (c), and becomes quite close to the true characteristic line C01.

  By appropriately adding a delay correction element of the first-order lag time constant to the above current system or voltage system, not only a pure resistance component (resistance value at the intersection of the real axis of the Cole-Cole plot and the characteristic line), The characteristics from the low frequency range to the high frequency range can be considerably corrected.

(Fifth embodiment)
Next, in a fuel cell vehicle equipped with a fuel cell as a driving source, when measuring the impedance of the fuel cell, the fifth embodiment of the second embodiment of the fuel cell system impedance calculation method of the present invention is applied. Will be described.

<Schematic configuration using a motor and a fuel cell as a drive source in a fuel cell vehicle>
First, a schematic configuration using a motor and a fuel cell as a drive source in a fuel cell vehicle will be described first. After this description, the fifth embodiment will be described.
FIG. 10 is a diagram showing an example of a schematic configuration using a motor and a fuel cell as drive sources in a fuel cell vehicle.
In FIG. 10, a fuel cell vehicle (not shown) includes a fuel cell (FC) 1001, which is an energy source for driving the vehicle, a storage battery 1002 serving as a complement to the fuel cell 1001, a motor 1003 for driving the vehicle, Control operation unit 1004 for instructing electric power output from battery 1001 and storage battery 1002, deviation signal unit 1005 for comparing motor output instruction value and motor output information signal of motor 1003, and controlling fuel cell 1001 and storage battery 1002 A control arithmetic unit 1004.

The motor output instruction value G1000 and the motor output value (motor output) G1003 reflecting the drive output of the motor 1003 are respectively input to the deviation signal unit 1005, and the deviation is output from the deviation signal unit 1005 as the deviation signal G1005. Input to the control calculation unit 1004.
The control calculation unit 1004 refers to the deviation signal G1005 and sends a power command value G1004 to the fuel cell 1001 and the storage battery 1002.
Further, the fuel cell 1001 outputs the fuel cell output power P1001 to the drive power summation unit 1006.
In addition, the storage battery 1002 outputs the storage battery output power P1002 to the drive power summation unit 1006.

In the drive power summation unit 1006, the fuel cell output power P1001 and the storage battery output power P1002 are summed and output to the motor 1003 as the motor drive power P1006, and the motor 1003 is driven by the power.
The motor 1003 is driven to become a power source of the vehicle, and sends the motor output value G1003 of the signal reflecting the drive output to the deviation signal unit 1005 as described above.
Note that a chopper and an inverter (not shown) are provided between the fuel cell 1001, the storage battery 1002, the driving power summing unit 1006, and the motor 1003. The output of the fuel cell 1001 is consumed not only by the motor but also by an auxiliary device (device) (not shown).

The above configuration is a schematic configuration of the fuel cell vehicle including the motor 1003 using the fuel cell 1001 as a drive source.
The characteristics of the fuel cell 1001 vary depending on the environment and usage conditions. In particular, it is important to understand the impedance characteristics of the fuel cell, particularly the resistance value of the electrolyte membrane, which greatly affect the characteristics of the fuel cell 1001.
For the measurement of the impedance characteristics of the fuel cell, it is effective to use the fuel cell system impedance calculation method according to the first to fourth embodiments of the present invention.

<Schematic Configuration of Fuel Cell Vehicle to which Second Embodiment is Applied (Fifth Embodiment)>
FIG. 11 is a diagram showing an example of a schematic configuration of a fuel cell vehicle according to a fifth embodiment of the impedance calculation method for a fuel cell system according to the present invention, in which the second embodiment is applied to a fuel cell of the fuel cell vehicle. It is.
In FIG. 11, the elements newly added to apply the second embodiment from the schematic configuration of the fuel cell vehicle shown in FIG. 10 are the Imp calculator 504 with a delay correction mechanism, the signal generation logic 541 for impedance measurement. , Signal inversion unit 603 and adders 601 and 602.
The Imp calculator with a delay correction mechanism includes impedance calculation means, a current delay confirmation unit, a voltage delay confirmation unit, and a delay correction element.
The new signals are G51, G52, G53, G504, G541, G601, G602, and G603. The fuel cell 501 and the fuel cell output power P501 have different signs.

The current and voltage are measured by the current signal G51 and the voltage signal G52 included in the observation signal G53 from the fuel cell (FC) 501, and input to the imp calculator 504 with a delay correction mechanism. The Imp calculator 504 with a delay correction mechanism measures and calculates the impedance of the fuel cell 501 based on these currents and voltages, and calculates the resistance value of the electrolyte membrane of the fuel cell 501.
The calculation method and procedure at this time are as described in the second embodiment. A duplicate description is omitted.
Further, the calculation result (measurement information) of the Imp calculator 504 with a delay correction mechanism is input to the control calculation unit 1004. That is, the power calculation value G1004 reflecting the environment and usage status of the fuel cell 501 is improved so that it is output by the control calculation unit 1004.

The impedance measurement signal generation logic 541 generates a delay detection signal G541 including an M-sequence signal, and inputs the delay detection signal G541 to the adder 601. The adder 601 adds the power instruction value G1004 and the delay detection signal G541, and outputs a fuel cell control signal G601.
The fuel cell control signal G601 is input to the fuel cell 501. Then, the fuel cell output power P501 of the fuel cell 501 is controlled. However, since the fuel cell control signal G601 includes the M series signal of the delay detection signal G541 in addition to the power instruction value G1004, the current and voltage of the fuel cell 501 have a wide frequency component (power spectrum). Including and respond.
For the current and voltage of the fuel cell 501 including a wide frequency component based on this M-sequence signal, if the calculation including the Fourier transform is performed by the Imp calculator 504 with a delay correction mechanism, the impedance characteristics of the fuel cell 501 in a wide frequency band can be obtained. The resistance value of the electrolyte membrane is calculated.
If the second embodiment is applied in the process of measurement, it is possible to perform more accurate and accurate measurement that eliminates errors due to observation current, observation voltage, and delay difference.

Further, the delay detection signal G541 of the impedance measurement signal generation logic 541 is also input to the signal inversion unit 603. The delay detection signal G541 becomes an inverted signal G603 inverted by the signal inverter 603 and is input to the adder 602.
Adder 602 adds power instruction value G1004 and inverted signal G603 (including an inverted signal of the M-sequence signal) to output battery control signal G602.
The battery control signal G602 is input to the storage battery 1002. And storage battery output electric power P1002 of the storage battery 1002 is controlled.

Next, the reason why the signal inverting unit 603 is provided and the background will be described.
The fuel cell control signal G601 includes a delay detection signal G541, that is, an M-sequence signal, in addition to the power instruction value G1004. The point including this M-sequence signal is different from the basic configuration shown in FIG.
Therefore, the fuel cell output power P 501 influenced by the M-sequence signal is output from the fuel cell 501 and is input to the drive power summation unit 1006. The motor driving power P1006 of the driving power summing unit 1006 drives the motor 1003.
Therefore, if the path is left as it is, the motor drive power P1006 includes power derived from the M-sequence signal. The M series signal is effective for impedance analysis, but is unnecessary and undesirable for the motor 1003.

A path including the signal reversing unit 603 is provided to remove the influence of the M-sequence signal on the motor 1003. First, the delay detection signal G541 (including the M series signal) from the impedance measurement signal generation logic 541 is inverted by the signal inversion unit 603 to become the inverted signal G603 (including the inverted signal of the M series signal), and the adder 602 Then, a battery control signal G602 is applied to the storage battery 1002 together with the power instruction value G1004, and the storage battery output power P1002 of the storage battery 1002 is added to the drive power summation unit 1006.
Accordingly, in drive power summation unit 1006, the M-sequence signal that has passed through fuel cell 501 and the inverted signal of the M-sequence signal that has passed through storage battery 1002 are summed, so that the M-sequence signal is canceled (cancelled) in drive power summation unit 1006. ) As a result, the M-sequence signal that is not necessary for the motor 1003 and is undesirable is reduced from reaching the motor 1003.
For this reason, the signal inverting unit 603 and its path are provided.

In FIG. 11, the description overlapping with FIG. 10 is omitted.
As described above, the second embodiment is applied with the configuration of FIG.
That is, as a summary, the membrane resistance value of the electrolyte membrane of the fuel cell 501 is known (measured in advance in a predetermined environment and use state), and the known membrane resistance (known membrane resistance value) is grasped.
In the configuration of FIG. 11, the impedance (including membrane resistance) of the fuel cell 501 is measured. In the configuration of FIG. 11, the length and shape of each measurement line may actually be different, or converters having different time responses may be connected.
Therefore, the measured impedance (including membrane resistance) in this state is not guaranteed to be accurate.

Next, the measured membrane resistance (measured membrane resistance, measured membrane resistance value) at this time is compared with the known membrane resistance (known membrane resistance value). Then, the delay correction element is appropriately selected and added so that the measured film resistance value is approximately equal to the known film resistance value.
When the correction element is properly added, the impedance including the membrane resistance value of the electrolyte membrane of the fuel cell 501 is accurately measured (calculated).
The above is an outline. Details of selection and addition of the delay correction element are as described in the second embodiment.

(Other embodiments)
Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to these embodiments and modifications thereof, and there are design changes and the like without departing from the scope of the present invention. An example is given below.

<< 1st delay model >>
In the first to fourth embodiments, the method of adding the delay correction element by software has been described. However, there is a method of using a first-order delay model as software. By substituting the delay calculation by the time constant of the first-order lag of the first-order lag model, the calculation processing is reduced.

<< Fourier transform function >>
As described above, when the current delay confirmation unit or the voltage delay confirmation unit converts to the time constant of the first-order lag transfer function, or when the delay correction element uses the software of the first-order lag model, the first-order lag Estimate the time constant of the model. The input signal may be other than a sine wave. Therefore, it is desirable that the impedance calculator 105 has a Fourier transform function for Fourier transforming the response signal, and an improvement in accuracy can be expected.

《Time constant estimation processing》
In the third embodiment, the difference in delay between the current and the voltage is compared with the time constant of the first-order lag of each of the current and the voltage. In order to estimate the time constant of the first-order lag model, the M-sequence signal It was explained that the time constant of the first-order lag was estimated by applying Fourier transform to the current and voltage that responded to each other and applying Fourier transform. In addition, the accuracy is further improved by performing predetermined processing such as average zeroing processing and window function processing on the data before Fourier transform.

<< Calibration signal >>
In the fourth embodiment, the method of applying the M-sequence signal in the calibration signal has been described. However, the method is not limited to the M-sequence signal. A step response signal may be used.

≪Example of application of this embodiment to a vehicle≫
Although the case where the second embodiment (the membrane resistance value is known) is applied to the fuel cell of the fuel cell vehicle has been described in the fifth embodiment, the present invention is not limited to the second embodiment.
The first embodiment (the delay difference between current and voltage is obvious), the third embodiment (calibration element), and the fourth embodiment (calibration signal) can also be applied.

≪Application example of this embodiment≫
In the fifth embodiment, the impedance measurement in a fuel cell mounted on a fuel cell vehicle (fuel cell vehicle) has been described. Is possible. Moreover, application to not only a primary battery but a secondary battery is also possible.

(Supplement of the present invention and embodiments)
Improve impedance calculation accuracy by adding a delay correction element that detects the measurement delay difference between the current line and the voltage line using various methods and corrects this delay difference in the measurement line with a small delay. I let you.
Although described as a method for calculating the impedance of a fuel cell system, various methods of the present invention are applied and applied as effective methods in various impedance measurements in which a delay element in the measurement line is a measurement problem.

101, 501, 1001 Fuel cell, FC
105 Impedance calculator 111 Current delay 1
112 Current measurement terminal 113 Current delay 2
114, 124, 314, 324, 424 Delay correction element 121 Voltage delay 1
122 Voltage measurement terminal 123 Voltage delay 2
301 Calibration Element 401 Calibration Signal 504 Imp Calculator with Delay Correction Mechanism (Impedance Calculation Means, Current Delay Confirmation Unit, Voltage Delay Confirmation Unit, Delay Correction Element), Impedance Calculator 601 and 602 Adder 603 Signal Inversion Unit 1002 Storage Battery 1003 Motor 1004 Control operation unit 1005 Deviation signal unit 1006 Drive power summation unit G51 Current signal G52 Voltage signal G53 Observation signal G541 Delay detection signal (M-sequence signal)
G601 Fuel cell control signal G602 Storage battery control signal G603 Inversion signal G1000 Motor output command value G1003 Motor output, motor output value G1004 Power command value G1005 Deviation signal P1001 Fuel cell output power P1002 Storage battery output power P1006 Motor drive power

Claims (10)

Impedance calculation means for calculating impedance based on a current input from a current signal line having a current measurement terminal connected to the fuel cell and a voltage input from a voltage signal line having a voltage measurement terminal connected to the fuel cell When,
A current delay confirmation unit for confirming a current delay based on the calculation by the impedance calculation means;
A voltage lag confirmation unit for confirming the voltage lag based on the calculation by the impedance calculation means;
In an impedance calculator comprising:
In the measurement as a trial, when the current delay confirmed by the current delay confirmation unit is larger than the voltage delay confirmed by the voltage delay confirmation unit, the current delay and the voltage delay are connected to the voltage signal line. Add a delay correction element of the same size as the difference between
Further, in the measurement as a trial, when the voltage delay confirmed by the voltage delay confirmation unit is larger than the current delay confirmed by the current delay confirmation unit, the voltage delay and the Add a delay correction factor of the same size as the difference from the current delay,
Then, the impedance calculation means calculates the impedance of the fuel cell by the impedance calculation means. Based on a current input from a current signal line having a current measurement terminal connected to a fuel cell having a known membrane resistance value and a voltage input from a voltage signal line having a voltage measurement terminal connected to the fuel cell. In an impedance calculator that calculates impedance,
In the measurement as a trial, when the measured membrane resistance value is larger than the known membrane resistance value, the measured membrane resistance value and the membrane resistance value calculated from the impedance value are approximately in the voltage signal line. Add the same delay correction factor,
Further, in the measurement as a trial, when the measured membrane resistance value is smaller than the known membrane resistance value, a membrane resistance value calculated from the measured membrane resistance value and the impedance value on the current signal line, and Add a delay compensation element that is almost the same,
Thereafter, the impedance calculator calculates the impedance of the fuel cell using the impedance calculator. An impedance calculator for calculating impedance based on a current input from a current signal line having a current measurement terminal connected to the fuel cell and a voltage input from a voltage signal line having a voltage measurement terminal connected to the fuel cell. In
In measurement as a trial, once the current measurement terminal and the voltage measurement terminal connected to the fuel cell are removed, a calibration element having a known calibration element resistance value is connected to the output terminal of the fuel cell. And calculating the impedance by the impedance calculator,
When the resistance value of the calibration element measured in the trial is larger than the known calibration element resistance value, the resistance value of the calibration element measured in the trial and the known value are connected to the voltage signal line. Add a delay correction element so that the element resistance value for calibration is almost the same,
When the resistance value of the calibration element measured in the trial is smaller than the known calibration element resistance value, the resistance value of the calibration element measured in the trial and the known value are connected to the voltage signal line. Add a delay correction element so that the calibration element resistance value is almost the same,
Thereafter, after removing the connected calibration element, the impedance is calculated by connecting the current measuring terminal and the voltage measuring terminal to the fuel cell and calculating the impedance.   The fuel cell system impedance calculation method according to claim 3, wherein the calibration element includes a resistance element and a capacitor. Impedance calculation means for calculating impedance based on a current input from a current signal line having a current measurement terminal connected to the fuel cell and a voltage input from a voltage signal line having a voltage measurement terminal connected to the fuel cell When,
A delay detection signal applying means for applying a delay detection signal to the current signal line and the voltage signal line;
A current delay confirmation unit for confirming a current delay based on the calculation by the impedance calculation means;
A voltage lag confirmation unit for confirming the voltage lag based on the calculation by the impedance calculation means;
In an impedance calculator comprising:
In the measurement as a trial,
Disconnecting the fuel cell from the current signal line and the voltage signal line;
Thereafter, the delay detection signal applying means, the current signal line and the voltage signal line are connected to calculate the impedance,
When the current delay confirmed by the current delay confirmation unit is larger than the voltage delay confirmed by the voltage delay confirmation unit, the voltage signal line has the same magnitude as the difference between the current delay and the voltage delay. Add a delay compensation factor,
When the voltage delay confirmed by the voltage delay confirmation unit is larger than the current delay confirmed by the current delay confirmation unit, the current signal line has the same magnitude as the difference between the voltage delay and the current delay. Add a delay compensation factor,
Next, the connection between the delay detection signal applying means and the current signal line and the voltage signal line is released,
Next, the fuel cell, the current signal line and the voltage signal line are connected again,
Then, the impedance calculation means calculates the impedance of the fuel cell by the impedance calculation means.   6. The fuel cell system impedance calculation method according to claim 5, wherein the delay detection signal output from the delay detection signal applying means includes an M-sequence signal.   2. The time constant of the first delay of each of the current and the voltage is used in the comparison of the magnitude relationship between the current delay in the current delay confirmation unit and the voltage delay in the voltage delay confirmation unit. Alternatively, the fuel cell system impedance calculation method according to claim 5.   The fuel cell system impedance calculation method according to any one of claims 1 to 5, wherein the impedance calculation means has a Fourier transform function.   9. The fuel cell system impedance calculation method according to claim 1, wherein the delay correction element is configured by software and is provided in the impedance calculation means.   A fuel cell vehicle comprising an impedance calculator for executing the fuel cell system impedance calculation method according to any one of claims 1 to 9.

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