Catalyst deterioration suppression device

1 . A catalyst deterioration suppression device comprising:

first means for obtaining a voltage V (= catalyst voltage V cat ) of a fuel cell as a variable to estimate a response speed (time constant τ) at which a coverage ratio of an oxide film of catalyst particles contained in a cathode of the fuel cell changes;

second means for reading out a time constant τ t corresponding to the voltage V at a current time t from a pre-made map A representing a relationship between the voltage V and the time constant τ and corresponding to the catalyst particles;

third means for generating a continuous-time type dynamic filter F(s, τ) by using the time constant τ t , converting the continuous-time type dynamic filter F(s, τ) to a discrete-time type dynamic filter F(z, τ), and mounting the discrete-time type dynamic filter on an in-vehicle controller provided in a vehicle; and

fourth means for inputting a target voltage V r to the discrete-time type dynamic filter F(z, τ) and outputting a corrected target voltage V r-fil to an actuator controller provided in the vehicle.

2 . The catalyst deterioration suppression device according to claim 1 , wherein the dynamic filter F(s, τ) is represented by the following expression (4) or (6),

F

⁡

(

s

,

τ

)

=

(

τ

·

s

+

1

)

/

(

2

⁢

τ

·

s

+

1

)

(

4

)

here, s is a Laplacian operator,

F

⁡

(

s

,

τ

)

=

G

m

(

s

)

/

G

⁡

(

s

,

τ

)

(

6

)

here, G m (s) is a transfer function of an ideal response model and G(s, τ) is a transfer function of a model.

3 . The catalyst deterioration suppression device according to claim 1 , wherein the first means further includes:

(a) means A for obtaining an interterminal voltage V cell , a current I, and a resistance value R of the fuel cell and calculating the voltage V from a relational expression V=Vcell+IR;

(b) means B for obtaining V cell , substituting V cell in a previously obtained relational expression V=f(V cell ) between V cell and the voltage V, and estimating the voltage V; or

(c) means C for installing a reference electrode at a cathode side catalyst layer in the fuel cell in advance and actually measuring the voltage V by using a potential difference between the reference electrode and a cathode side current collector.

4 . The catalyst deterioration suppression device according to claim 1 ,

wherein the first means includes means for obtaining a voltage decrement ΔV as another variable;

the second means includes means for reading out a correction gain k t corresponding to the voltage decrement ΔV at a current time t from a pre-made map B representing a relationship between the voltage decrement ΔV and a correction gain k of the time constant τ and corresponding to the catalyst particles and multiplying the time constant τ by the correction gain k t ; and

the third means includes means for generating the continuous-time type dynamic filter F(s, τ) by using the time constant τ corrected by the correction gain k t and converting the continuous-time type dynamic filter F(s, τ) to the discrete-time type dynamic filter F(z, τ).

5 . The catalyst deterioration suppression device according to claim 1 ,

wherein the first means includes means for obtaining a temperature T of the fuel cell as another variable;

the second means includes means for reading out a correction gain p t corresponding to the temperature T at a current time t from a pre-made map C representing a relationship between the temperature T and a correction gain p of the time constant τ and corresponding to the catalyst particles and multiplying the time constant τ by the correction gain p t ; and

the third means includes means for generating the continuous-time type dynamic filter F(s, τ) by using the time constant τ corrected by the correction gain p t and converting the continuous-time type dynamic filter F(s, τ) to the discrete-time type dynamic filter F(z, τ).

6 . The catalyst deterioration suppression device according to claim 1 ,

wherein the first means includes means for obtaining humidities RH of gasses supplied to the cathode and an anode of the fuel cell respectively as another variable;

the second means includes means for reading out a correction gain r t corresponding to the humidity RH at a current time t from a pre-made map D representing a relationship between the humidity RH and a correction gain r of the time constant τ and corresponding to the catalyst particles and multiplying the time constant τ by the correction gain r t ; and

the third means includes means for generating the continuous-time type dynamic filter F(s, τ) by using the time constant τ corrected by the correction gain r t and converting the continuous-time type dynamic filter F(s, τ) to the discrete-time type dynamic filter F(z, τ).

7 . The catalyst deterioration suppression device according to claim 1 , wherein

the first means includes means for obtaining a voltage decrement ΔV as another variable, the voltage decrement ΔV being a difference between an initial state voltage V 0 and a voltage V t after used for t hours (=V t -V 0 ) at a reference current I 0 ,

a correction gain value k t is read from a pre-made map B different from the pre-made map A based on the voltage decrement ΔV, and

the time constant T t read from the pre-made map A is multiplied by the correction gain value k t read from the pre-made map B to obtain corrected time constant τ.