JP3402167B2 - Battery condition analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to an electric vehicle, a personal computer,
Batteries remaining in portable devices such as
Battery state analysis method for analyzing and detecting the state such as quantity
And its device. [0002] 2. Description of the Related Art Conventional methods for analyzing the state of a battery such as a remaining battery level.
The first is to measure the voltage and current of the battery.
And secondly, the AC
AC impedance measured in advance and determined in advance
The state of the battery is determined from the correlation between the
There is a way to specify. [0003] However, in the first method,
According to the report, although the battery state detection accuracy is good,
And the analog signal for measuring the battery current and voltage.
Signal processing circuit is required, so as a battery condition analyzer
There is a problem that it is costly to implement the device. According to the second method, the first method is used.
That is, the measurement can be performed in a shorter time than the capacity test method.
The advantage is that the amplitude and
In order to measure the phase, analog signal processing is performed as in the first method.
If a circuit is required, it is costly to implement it.
There is also the problem of being susceptible to noise.
You. [0005] Our future aims are electric vehicles and personal computers.
Batteries, such as portable devices such as mobile phones or mobile phones.
The battery condition analyzer is installed in the
Battery status in real time.
Low-cost, high-precision battery condition analysis
Is desired. In view of the above problems, the present invention provides a battery
Use digital signal processing to check the status of remaining
Battery condition analysis method that can analyze the data accurately
It is an object to provide a method and an apparatus using the method.
You. [0007] Means for Solving the Problems To solve the above problems,
Therefore, the present invention relates to a transfer function of an AC equivalent circuit of a battery.
Focus on the correlation between the change of the pole and the remaining battery level
First, the transfer function of the discrete system including the battery is estimated and calculated.
From this transfer function, the AC equivalent circuit
Poles in the transfer function of the road
Is to be detected. The estimation of the transfer function of a discrete system is
Since it can be performed by digital signal processing,
In analogy, analog signal processing becomes unnecessary. [0008] The solution taken by the invention of claim 1 is a battery.
As a battery state analysis method for analyzing the state such as the remaining amount of battery,
AC voltage applied to the battery and AC voltage applied to the battery
Of discrete system of the system including the battery from time series data of flow
Estimate the function and use the discrete transfer function
This is to analyze the state of the battery. According to the first aspect of the present invention, the battery
From the time series data of the
For estimating the transfer function of the discrete system of the system including the pond
Does not require analog signal processing and all digital signal processing
One-chip microcomputer
LSI and DSP etc. can be implemented and
Cost and noise immunity. Also,
From the transfer function of the dispersion system, for example, the transfer of the AC equivalent circuit of the battery
The transfer function of the battery's AC equivalent circuit.
Using the correlation between the poles in the number and the state of the battery,
The state of the battery can be analyzed. [0010] [0011] [0012] [0013] [0014] [0015] Further, the claims1In the invention ofAC to battery
AC signal applying means for applying a signal and the battery
Sampling of AC voltage and AC current flowing through the battery
Sampling means, and the sampling means
Time series data of AC voltage and AC current sampled by
The transfer function of the discrete system of the system including the battery from the
Transfer function calculation for estimating using 1) or (Equation 2)
Means and the discrete system of the system including the determined battery
The poles in the transfer function of the discrete system from the transfer function
And the determined poles are connected to the AC equivalent circuit of the battery.
Pole calculation means for converting to poles in the transfer function of the continuation system
The transfer function of the continuous system obtained by the pole calculation means
Analyze the state of the battery based on the poles in the numberElectric
Pond condition analyzerAndThe pole calculating means is configured to
The denominator polynomial of the transfer function of the discrete system
Resolve the complex solution of the poles in the transfer function of the discrete system
Factoring operation means for determining
Therefore, the imaginary part is truncated from the complex solution of the pole found, and the remaining
From the real part, the distance corresponding to the positive and negative electrodes of the battery
A pole operation means for specifying a pole in a transfer function of a scattered system;
Positive and negative electrodes of the battery identified by the pole calculation means
The poles in the transfer function of the discrete system corresponding to
Based on the sampling period of the sampling means.
The pole in the transfer function of the continuous system of the AC equivalent circuit of the battery
And a pole conversion operation means for conversion. [0017] DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic principle of the present invention will be described.
Will be described. (1) Definition of battery transfer function When measuring the AC impedance of a battery,
Batteries with a small AC signal with an amplitude of about 10 mV or less
When the interface between the electrode and the electrolyte is polarized,
The resulting AC signal does not disturb
Can be considered as Battery alternating current when a small AC signal is applied
The value circuit is as shown in FIG. Contact between electrode and electrolyte
Impedance is created between the electrode interface and the electrolyte interface.
Electric double layer capacity and Faraday impedance
Can be represented by a parallel connection with Where the electrode
Assuming that the charge transfer process is rate-determining,
-Impedance is equal to the polarization resistance (charge transfer resistance) of the electrode.
Expressed in series with the capacitance component of the electrode. Figure 1
31p and 31n are the polarization resistance of the positive electrode and the negative electrode,
Is the electric double layer capacity at the positive electrode, and 32n is the
Electric double layer capacity, 33p, 33n are capacity of positive electrode and negative electrode
The component, 34, is the resistance of the electrolyte and is the impedance of the positive electrode.
Is a fara consisting of a polarization resistance 31p and a capacitance component 33p.
Parallel connection between the data impedance and the electric double layer capacitance 32p
The impedance of the negative electrode is polarized
Faraday in consisting of resistance 31n and capacitance component 33n
The parallel connection of the impedance and the electric double layer capacitor 32n
Is represented. Here, the resistance value of the polarization resistor 31p is Rp,
Assuming that the resistance value of the polarization resistor 31n is Rn, [0021] (Equation 1) ## EQU2 ## In equations (1) and (2),
R is the Boltzmann constant, T is the absolute temperature, and n is the power of the electrode reaction.
Load number, F is Faraday constant, iop is positive electrode exchange current, i
on indicates the exchange current of the negative electrode. In FIG. 1, Cdp is
The capacitance value of the electric double layer capacitance 32p at the positive electrode, Cdn is negative
The capacitance value of the electric double layer capacitor 32n at the pole, Rel is the electrolytic value
The resistance value of the liquid resistance 34. The frequency of the AC signal is relatively high, and
The amount components 33p and 33n give the impedance of the battery.
If the effect can be neglected, the AC equivalent circuit of the battery
2 and the capacitance components 33p and 33n are deleted as shown in FIG.
Can be considered. A time-invariant linear system for batteries during AC polarization
Is assumed, the battery transfer in the AC equivalent circuit shown in FIG.
The transfer function HB (s) is [0025] (Equation 2) ## EQU1 ## Also, the AC impedance of the battery
The impedance of the impedance element used for measurement is H
If I (s), the battery and the impedance element
The total transfer function G (s) of the system is defined as follows: [0027] (Equation 3) Here, vB is the value at the time of measuring the AC impedance.
Is the voltage applied to the battery at, iB is the AC impedance
This is the current flowing through the battery when measuring the capacitance. All communication
The order of the pole of the number G (s) depends on the impedance of the impedance element.
The order of the poles in the dance HI (s) and the battery transfer function HB
It is the sum with the order of the pole in (s). FIG. 3 shows a battery transfer function as shown in equation (3).
Complex impedance plot of battery with HB (s)
It is. As shown in FIG. 3, the complex impedance of the battery
With the increase of the angular frequency ω of the AC signal,
After a circular locus and a semicircular locus by the positive electrode, when ω = ∞
The resistance value Rel of the electrolyte resistance 34 is obtained. The first pole s1 and the
The angular frequencies at the two poles s2 are ω1 and ω2, respectively.
When, ω1 = −1 / Rn Cdn [rad / s] (5) ω2 = -1 / Rp Cdp [rad / s] (6) Given by (2) Calculation of transfer function estimation We assume that the battery is a time-invariant linear system
Then, the total transfer function G (s) represented by the equation (4) is
Given as a general transfer function in a discrete system of the form
You. [0031] (Equation 4) Based on the input / output signal of the battery, the equation (7)
By determining the number, the transfer function G (z, θ) is estimated.
Set. Generally, system propagation is based on input / output data.
The method of estimating the arrival function is called system identification. FIG.
FIG. 4 is a diagram illustrating a model used for stem identification, and is a diagram illustrating transmission of noise.
The function Hn (z, θ) is Hn (z, θ) = 1 / A (z) (8) , This model is autoregressive with external inputs (A
RX) model. As shown in FIG.
(T) is the first order of the input signal u (t) and the noise signal e (t)
Given the combination, the output response is   A (z) y (t) = B (z) u (t) + e (t) (9) Becomes The coefficient parameter of the transfer function G (z, θ) to be estimated
Meter θ, regression vector φ by input / output data series
(T) [0034] (Equation 5) Then, equation (9) becomes: y (t) = φT θ + e (t) (12) And the matrix operation of Expression (12) is performed by, for example, the RLS sequential method.
, The coefficient parameter θ (t) becomes [0036] (Equation 6) Is given by This coefficient parameter θ
(T) converges after a predetermined number of repeated calculations. Note that the initial value of the operation is generally θ (0) = 0, P (0) = αId (14) But, for example, Rp = 0.001 to 10 [Ω] Rn = 0.001 to 10 [Ω] Cdp = 10-6 to 10-2 [F] Cdn = 10 @ -6 to 10 @ -2 [F] (15) Using the initial value in the range of
Can be reduced. (3) Calculation of discrete poles Explain the case of matching the number of poles in the discrete and continuous systems
I do. (3-1) When the impedance element is a pure resistance
If When the impedance element is a pure resistor, the total transfer shown in equation (4)
Since the order of the poles in the arrival function G (s) is second-order,
The pole in the discrete transfer function G (z, θ) shown in (7)
The system identification is performed on the assumption that the order of Sand
Equation (7) is [0041] (Equation 7) Is as follows. Here, in equation (16), each parameter
Assuming that the meter θ converges, the equation (16)
The poles in the discrete transfer function G (z, θ) are [0043] (Equation 8) Given by the solution of the quadratic equation of z as shown in
It is. Here, the coefficient of equation (17) is [0045] (Equation 9) In other words, two poles are obtained by the solution formula.
You. [0047] (Equation 10) This solution is generally given by the following complex solution
Can be [0049] z1 = σ1 + jβ1 z2 = σ2 + jβ2 (20) Further, the total transfer function G (s) of the continuous system originally desired is
Since the two poles are on the real axis on the s-plane,
In the transfer function G (z, θ) of the system, the two poles are in the z plane.
From the basis that the imaginary component of equation (20) is on the real axis of
Truncated, z1 = σ1 z2 = σ2 (21) Is the pole of the battery transfer function G (z, θ) in the discrete system.
You. [0050] | Z2 | <| z1 | (22)
Compare the absolute value with z2, and when the expression (22) is true,
The pole z1 is a pole corresponding to the negative electrode of the battery, and the pole z2 is a positive electrode of the battery.
And when equation (22) is false, the pole z1 is
The pole corresponding to the positive pole of the battery, pole z2, corresponds to the negative pole of the battery.
Pole. (3-2) The impedance element has a pure capacity
If included When the impedance element includes a pure capacitance,
The order of the poles in the total transfer function G (s) becomes the third order
Therefore, the discrete transfer function G (z, θ) shown in equation (7)
The system identification is performed on the assumption that the order of the poles to be obtained is also the third order.
That is, equation (7) is [0052] [Equation 11] Is as follows. Transfer function G shown in equation (23)
The pole of (z, θ) is [0054] (Equation 12) Given by the solution of the cubic equation of z as shown in
It is. And the three poles z1, z2, z3 are [0056] (Equation 13)This solution is generally given by the following complex solution.
available. [0058] z0 = σ0 + jβ0 z1 = σ1 + jβ1 z2 = σ2 + jβ2 (26) Further, 3 of the total transfer function G (s) of the continuous system originally desired
Since the two poles lie on the real axis on the s-plane,
In the transfer function G (z, θ), the poles are on the real axis of the z-plane.
Therefore, the imaginary component of Expression (26) is discarded.
Z0, z1 and z2 are in the order of their absolute values, z0 = σ0 z1 = σ1 z2 = σ2 (27) Is obtained as The pole z0 having the largest absolute value is z
= 1 except for the pole of the impedance element that should be
Poles z1 and z2, | Z2 | <| z1 | (28) The absolute values are compared in magnitude according to Equation (28)
When true, the pole z1 is the pole corresponding to the negative electrode of the battery, and the pole z2 is
When the electrode corresponds to the positive electrode of the battery and the equation (28) is false
Is the pole corresponding to the positive electrode of the battery, and z2 is the negative pole of the battery.
It will be the pole corresponding to the pole. (4) Conversion of pole from discrete system to continuous system FIG. 5 is a diagram illustrating a mapping from the z plane to the s plane. Figure
By the mapping as shown in FIG.
From z2, in a continuous system as shown in equations (5) and (6)
The poles s1 and s2 are determined. Sampling in discrete systems
Assuming that the logging time is T [s], the pole from the z plane to the s plane is
The mapping is [0060] [Equation 14] The operation is performed according to the following. (5) Correlation between battery state and pole transition Battery status can be assessed, for example, by battery level
You. Remaining is the remaining amount of electricity charged in the battery.
U. The transition of the pole in the battery transfer function and the remaining battery power
There is a correlation between them. FIG. 6 shows the complex impedance of a lithium ion battery.
FIG. 6 is a diagram showing a dance plot, which is associated with a change in the remaining battery level.
FIG. 9 is a diagram illustrating a change in a complex impedance plot.
In the figure, (a), (b), (c), and (d) are respectively
When the remaining amount is 100%, 50%, 10% and 0%
You. The resistance of each of the polarization resistors 31p and 31n shown in FIG.
The values Rp and Rn are the values of the positive and negative electrodes associated with the charging and discharging of the battery.
The change of the exchange current density iop and ion caused by the chemical reaction
Change. For this reason, the polarization
The resistance values Rp and Rn of the resistors 31p and 31n change.
Then, as shown in FIG.
Also, it changes according to the change in the remaining amount of the battery. Therefore,
The angular frequency of the pole also changes with changes in the battery level. FIG. 7 shows the relationship between the remaining battery charge and the battery transfer function.
It is a graph showing the correlation with the pole angular frequency ω, in the figure,
(A) and (b) are for the first pole and the second pole, respectively.
is there. As shown in FIG. 7, the higher the angular frequency ω of the pole is,
The remaining capacity of the pond is large, and the lower the angular frequency ω of the pole, the lower the remaining battery capacity
Is less. (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
explain. FIG. 8 shows the state of the battery according to the embodiment of the present invention.
It is a figure which shows the structure of an analyzer, (a) is a battery in the figure.
FIG. 1B is a diagram showing a system for applying an AC signal to a battery, and FIG.
FIG. 3 is a block diagram illustrating a configuration of a part that performs analysis. In FIG.
The battery state analyzer according to the present embodiment shown
For estimating and evaluating the state of the battery 11, for example, the degree of remaining charge
It is. In FIG. 8, 11 is a battery to be analyzed, and 12 is a battery to be analyzed.
Pseudo-random noise that outputs an AC signal applied to the battery 11
The sound generating means 13 is a battery 11 and a pseudo random noise generating means.
An impedance element 14 provided between the stage 12 and
The AC voltage vB applied to the battery 11 and the
Sampling current iB to convert analog value to digital
Analog / digital as sampling means to convert to value
Tal converter. Reference numeral 15 denotes an analog / digital converter 1
Battery 11 and impedance based on the output data of
Estimate the transfer function of a discrete system representing the characteristics of the system composed of the elements 13.
Transfer function calculating means for performing a constant calculation;
15 from the transfer function of the discrete system estimated and calculated by
A pole calculator for calculating poles in a transfer function of 11 continuous systems
Steps 17 are based on the poles calculated by the pole calculation means 16.
State determination means for determining the state of the battery by
1 is the temperature to be measured and output to the pole calculation means 16
It is a temperature sensor as measuring means. Transfer function calculation means
15, pole calculation means 16 and state determination means 17
In the state, it is realized by the microcomputer 20.
You. FIG. 9 shows the structure of the battery according to this embodiment shown in FIG.
It is a flowchart which shows operation | movement of a state analysis apparatus. Less than
Below, referring to FIG. 9, the battery according to the present embodiment shown in FIG.
The operation of the state analysis device will be described. First, in step S1, an analysis target
AC signal is applied to the battery 11. At this time, the frequency is
Of the battery 11 by using a strange pseudo-random noise generating means.
Sweep the frequency to include the pole frequency in the transfer function
Although it is good,
In the embodiment, the pseudo random noise generating means 12 is a battery 11
Frequency band that sufficiently covers the pole frequency in the transfer function of
It outputs the AC signal of the area. FIG. 10 shows the pseudo random noise generating means 12.
It is a graph which shows an example of a frequency characteristic, a horizontal axis is a frequency.
[Hz], and the vertical axis represents amplitude [dB]. As shown in FIG.
As shown in FIG.
The frequency band of the flow signal is the first pole S of the transfer function of the battery 11.
1 and the angular frequency at the second pole S2
It is necessary to include the component of the number ω2. Such a pseudo
By using the random noise generating means 12, the frequency
No sweep is required. Also, a pseudo random noise generating means 12
Of the AC signal output from the sensor is affected by the disturbance at the electrode interface
Is about negligible, and about 10 mV or less.
You. The pseudo random noise generating means 12 is, for example, white
Configuration using a noise source that generates a noise signal such as color noise
do it. Further, an M-sequence code as shown in FIG.
Pseudo-random codes such as noise sources
Sound signal generating means may be used. In FIG. 11, 41
Is a flip as a delay operator with a given delay time
The flop 42 is an exclusive OR operation unit. FIG. 1
In 1, the pseudo noise signal generating means is excluded from the flip-flop.
Implemented by hardware using other OR
But the pseudo-random memory in the microprocessor
Software for storing and outputting code patterns
There is also a method of realizing it. The impedance element 13 is connected to the battery 11
Battery 11 and pseudo-random noise when applying an AC signal to
It is also possible to prevent a DC path from being formed with the generating means 12.
The state analysis of the battery according to the present embodiment shown in FIG.
In the device, the capacity is large enough and the capacity value is known
Using a capacitor as the impedance element 13
You. Next, in step S2, the battery 11
The AC voltage vB and the AC current iB flowing through the battery 11 are
Sampled and used for estimation of discrete transfer function
Time-series input / output data. Step S2 is analog
This is performed by the analog / digital converter 14. Battery 11
And the AC current i flowing through the battery 11
B are the input signals in the ARX model shown in FIG.
Signal u (t) and the output signal y (t), thus
For a predetermined time by the analog / digital converter 14
From the digital values sampled at intervals,
Regression vector φ by input / output data series as shown in
(T) is required. In other words, the battery 11
The AC voltage vB and the AC current iB flowing through the battery 11 are
Analog / digital converter 1 as sampling means
4 for use in estimating the transfer function of the discrete system
It becomes time-series input / output data. Next, in step S3, step S2
Transfer function of discrete system using time series input / output data obtained in
Is estimated. Step S3 is a transfer function calculating means 15
Thus, according to the basic principle of the present invention, (2) battery transmission
Performed according to the procedure described in the section
It is. That is, the transfer function calculating means 15 outputs the analog /
AC sampled by digital converter 14
The voltage vB and the AC current iB are converted into time-series input / output data u.
(T), y (t), the regression vector of equation (11)
(T) is obtained, and the first value given by equation (14) or (15) is obtained.
Transfer function estimation calculation as shown in equation (13) using the period value
To obtain the coefficient parameter θ (t) of the equation (10).
Thus, a transfer function of a discrete system as shown in Expression (7) is obtained. Next, in step S4, step S3
From the transfer function of the discrete system obtained in
Calculate the pole. Step S4 is performed by the pole calculation unit 16.
Therefore, (3) discrete poles in the basic principle of the present invention
And (4) terms of pole conversion from discrete to continuous
This is performed according to the procedure described in. FIG. 12 is a block diagram showing the construction of the pole calculating means 16.
FIG. First, the factorization computing means 16a
In step S3, the distance estimated by the transfer function
Factor a rational polynomial that is the denominator of the transfer function of a scattered system
You. In this embodiment, pure impedance is used as the impedance element 13.
Given the quantity, the basic principles of the present invention
As described in (3-2), the estimated equation (7)
A polynomial A (z) which is a denominator of the transfer function as shown in FIG.
After cutting off higher-order terms than the following,
Factor according to 5). The pole operation means 16b is expressed by the following equation (27).
As described above, the imaginary part is cut from the complex solution obtained from equation (25).
Discarded to make only the real part, and according to equation (28)
To determine the electrodes corresponding to the positive and negative electrodes of battery 11
I do. The pole conversion calculating means 16d complies with the equation (29).
From the z region to the s region using the sampling period T
Perform pole conversion. Factoring operation means 16a, pole operation means
16b and the polar conversion operation means 16c,
Battery transfer function of the continuous system given by equation (3) from the transfer function
The pole at HB (s) is determined. In the present embodiment, the pole calculating means 16 calculates the extreme temperature.
And a factor correction means 16d.
Stage 16a, pole calculation means 16b, and pole conversion calculation means 16c
Battery transfer function HB (s) of the continuous system obtained by
Is the battery measured by the temperature sensor 18.
Is corrected by the ambient temperature. The temperature correction of the pole is performed as follows. Temperature
The sensor 18 measures the surface temperature or the ambient temperature of the battery 11.
You. As shown in the equations (1) and (2), the polarization resistance of the positive electrode 3
The resistance value Rp of 1p and the resistance value R of the polarization resistance 31n of the negative electrode
Since n is proportional to the absolute temperature T, equations (5) and (6)
The angular frequency of the pole, indicated by, is inversely proportional to absolute temperature
You. Here, the temperature inside the battery 11 is measured by the temperature sensor 18.
Is assumed to be equal to the measured temperature. Reference temperature (with pole
The experimental temperature at which the correlation with the state of the battery was obtained was defined as Ta [K],
The temperature measured by the temperature sensor 18 is Td [K].
And the resistance values Rp and Rn of the polarization resistance at the reference temperature Ta.
And the resistance values Rp 'and Rn' of the polarization resistance at the temperature Td.
From the equations (1) and (2), [0081] (Equation 15) Is as follows. Equations (30) and (31)
Therefore, the pole angular frequencies ω1 and ω2 at the reference temperature Ta are
The angular frequencies ω1 ′ and ω2 ′ of the poles at the temperature Td are given by
It is obtained by correcting as follows. [0083] (Equation 16)Is obtained. The pole temperature correction means 16d performs pole conversion.
The continuous battery transmission function determined by the calculating means 16c
Equation (32), (3)
The temperature is corrected according to 3) and output. Finally, in step S5, step S
Based on the angular frequency of the pole determined in step 4,
judge. Step S5 is performed by the state determination means 17
(5) The state of the battery and the pole
Follow the procedure described in the section on correlations with transitions.
You. It should be noted that the pseudo random noise generating means 12
If the DC offset voltage is equal to that of the
It is possible to omit the impedance element 13. Figure
13 is an AC signal to the battery 11 without passing through an impedance element.
FIG. 2 is a diagram showing a configuration of a battery state analysis device for applying a signal;
Only the system for applying an AC signal to the battery 11 is shown.
You. In FIG. 13, reference numeral 12A denotes a DC
Voltage offset pseudo-random noise generation with offset voltage
It is a raw means. Voltage offset pseudo random noise generator
The stage 12A includes the pseudo random noise generating means 12 shown in FIG.
In the same way as for
Therefore, you may comprise. FIG. 8 also shows the battery state analyzer of FIG.
As with the battery state analyzer, the AC power
The voltage vB and the AC current iB flowing through the battery 11 are
To calculate the transfer function of the discrete system
Eleven states can be determined. However, the power of FIG.
In the case of a pond condition analyzer, the basic principle of the present invention is used.
(3-1) Applicable when the impedance element is a pure resistance
Factor calculation means constituting the pole calculation means 16
16a is the distance estimated by the transfer function calculating means 15.
The rational polynomial A (z), which is the denominator of the transfer function of the scattered system, is expressed as 2
After cutting off higher-order terms than the following,
Factorize according to 9). Note that the transfer function calculating means 15
Based on the polarization resistance and capacitance component of the electrode of the battery 11 to be analyzed.
Alternatively, a configuration may be employed in which an initial value calculated in advance is provided. this
Improves the convergence of the estimation of the transfer function of the discrete system
be able to. It should be noted that in the pole calculating means 16, the extreme temperature compensation
The corrector 16d is not an indispensable component and may be omitted.
No. In this case, the temperature sensor 18 becomes unnecessary. The transfer function calculating means 15 determines
From the discrete transfer function obtained,
A battery state analysis device for determining is also conceivable. For example, discrete
Judgment of battery safety and deterioration from battery transfer function
Can be considered. As another method different from the present embodiment, the estimation
The order of the poles of the transfer function of the discrete system is
Considering how to directly correlate the change with the remaining battery level
available. For example, the pole of the transfer function of the discrete
Of the AC equivalent circuit predetermined for the battery 11
Higher order than the order of the poles in the transfer function of a continuous system
Assume that Here, the order of the poles of the transfer function is assumed to be 30 order.
Assuming that the transfer function G (z, θ) is expressed by the following equation:
Is done. [0092] [Equation 17] After the convergence of the coefficient parameter θ, the discharge method
Transfer function G obtained by calculation using algorithm
Find 30 poles of (z, θ). Figure 14 shows the 30th order pole
6 is a graph showing an example of a position on the z plane of FIG. FIG.
As shown in the figure, the battery 11 and the impedance element 12
Extract all relevant poles and analyze the transition of specific poles in them
By doing so, the state of the battery 11 is analyzed. Remaining amount
Is determined that there is a correlation with the remaining amount in advance through experiments, etc.
This can be done by observing the poles made. [0094] As described above, according to the present invention, first, the battery
The transfer function of the discrete system of the system including
From the transfer function of this discrete system, the continuous system of the AC equivalent circuit of the battery
The poles in the transfer function of
Between the poles in the transfer function of the road and the state of the battery, etc.
Since the state of the battery is analyzed using the correlation,
The state can be reliably and quantitatively performed. Also, the transfer function of the discrete system is estimated and calculated.
Analog signal processing is not required
One-chip my
LSIs can be implemented using a computer or DSP, resulting in low cost
And a highly accurate battery condition analyzer can be realized.
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining the principle of the present invention, and is a circuit diagram showing an AC equivalent circuit of a battery. FIG. 2 is a diagram for explaining the principle of the present invention. FIG. 3 is a circuit diagram showing an AC equivalent circuit of the battery when the frequency of the AC signal is relatively high. FIG. 3 is a diagram for explaining the principle of the present invention, and is a graph showing a complex impedance plot of the battery. FIG. 5 is a diagram for explaining the principle of the present invention, and is a diagram showing an ARX (autoregression) model used for system identification. FIG. FIG. 6 is a diagram illustrating a mapping from a z plane to an s plane for converting the poles into poles in a transfer function of a continuous system. FIG. 6 is a diagram for explaining the principle of the present invention. (A) remaining showing the change of the complex impedance plot (B) A diagram showing a case where the remaining amount is 50% (c) A diagram showing a case where the remaining amount is 10% (d) A diagram showing the case where the remaining amount is 0% 7 is a diagram for explaining the principle of the present invention, showing a correlation between the remaining amount of the battery and the angular frequency of the pole in the transfer function of the battery. FIG. 7A is a diagram showing the case of the first pole. FIG. 8A is a diagram showing a configuration of a battery state analyzing apparatus according to an embodiment of the present invention, and FIG. 8B is a diagram showing a system for applying an AC signal to the battery. ) Is a block diagram showing a configuration of a part for performing a battery state analysis. FIG. 9 is a flowchart showing an operation of the battery state analyzing apparatus according to the embodiment of the present invention shown in FIG. 8; FIG. 11 is a graph showing an example of a frequency characteristic of pseudo random noise generating means used in the embodiment. FIG. 12 is a diagram showing a configuration of a noise source using an M-sequence code used as a pseudo-random noise generating unit in one embodiment. FIG. 12 shows a configuration of a pole calculating unit in a battery state analyzing apparatus according to one embodiment of the present invention. FIG. 13 is a diagram showing a configuration of a battery state analysis apparatus according to one embodiment of the present invention, which applies an AC signal to a battery without passing through an impedance element, and applies an AC signal to the battery. FIG. 14 is a diagram showing only the system. FIG. 14 is a graph showing an example of the positions of the poles on the z-plane when the order of the poles in the transfer function of the battery is 30. AC current 11 flowing Battery 12 Pseudo random noise generating means 12A Voltage offset pseudo random noise generating means 13 Impedance element 14 Analog / digital converter (sample Packaging means) 15 transfer function calculating unit 16-pole calculating means 16a factoring operation means 16b-pole calculating means 16c polar transformation calculating means 16d pole temperature correction means 17 the state determination unit 18 Temperature sensor (temperature measuring means)

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Kumamoto 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-8-96855 (JP, A) JP-A-8- 254573 (JP, A) JP-A-8-220197 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 31/36 H01M 10/42-10/48 H02J ⁷ /00- 7/12

Claims (1)

(57) [Claims] [Claim 1] AC signal application for applying an AC signal to a battery
Means, and an AC voltage applied to the battery and a current flowing to the battery.
Sampling means for sampling the alternating current
AC power sampled by the sampling means
From the time series data of voltage and AC current,
The transfer function of the discrete system is estimated using (Equation 1) or (Equation 2).
A transfer function calculating means for performing a constant calculation, and a transfer function of the discrete system of the system including the obtained battery.
Finding the poles in the transfer function of the discrete system from the numbers
Then, the obtained pole is used as a continuous system of the AC equivalent circuit of the battery.
Pole calculating means for converting to a pole in a transfer function,
In the transfer function of the continuous system obtained by the pole calculating means,
Analyzing the state of the battery based on the poles of the battery
An analysis apparatus, wherein the pole calculation means is configured to transmit the discrete system of a system including the battery.
Factor the polynomial in the denominator of the transfer function
Factoring means for finding the complex solution of poles in the arrival function
And the complex solution of the pole determined by the factorization operation means
From the remaining real part,
Poles in the discrete transfer function corresponding to the poles and the negative poles
Pole calculation means for specifying
Of the discrete system corresponding to the positive and negative electrodes of the battery
The pole in the transfer function
Based on the pulling cycle, a series of AC equivalent circuits
Pole conversion operation means for converting to a pole in a transfer function of a continuation system;
A battery state analysis device, comprising: (Equation 1) (Equation 2)