JP3969734B1 - Capacitor power supply life estimation evaluation system - Google Patents

Abstract

An object of the present invention is to estimate a life from a temperature rise of a capacitor power supply used in response to a load request so that a capacity evaluation of the capacitor power supply can be easily performed.
A least reference temperature T _r, the temperature deterioration coefficient of the capacitor corresponding to T _r alpha _Tr or degradation time t _Trr, the deterioration degree D _r, the deterioration degree D given at _r temperature difference T _int, the predetermined Data for life estimation consisting of the multiplication factor λ of deterioration time at each temperature corresponding to the temperature difference, and data on the operating temperature T _x of the capacitor power supply,
t _Txr = λ ^{(Tr−Tx) / Tint} × t _Trr , α _Tx = D _r / √t _Txr , t _Tx = (D _s / α _Tx ) ^2, deterioration coefficient α _{Tx at} the use temperature T _x , deterioration degree D The estimated life t _Tx up to _s is obtained.
[Selection] Figure 1

Description

  The present invention relates to a life estimation and evaluation system for a capacitor power supply that evaluates and determines the life according to the operating temperature of a capacitor power supply designed according to a load pattern.

  Electronic circuits have become more complex with higher frequency and higher speed digitalization of information communication equipment, making it difficult to predict the electrical characteristics of electronic circuits at the stage of circuit diagram creation. For this reason, the circuit is designed and prototyped, and the electrical characteristics are measured. Based on the result, trial and error of redesigning the prototype is often repeated.

  In addition, circuit simulators have been used, but circuits that use capacitors in particular have been difficult to predict and have become an obstacle to increasing the efficiency of electronic circuit design. Therefore, for such a capacitor-using circuit, an equivalent circuit model of the capacitor is formed by each step of inputting frequency characteristics, forming an equivalent circuit model, synthesizing its evaluation function, and determining a circuit constant that minimizes the evaluation function. A method of deriving has been proposed (see, for example, Patent Document 1).

For power storage devices such as primary batteries, secondary batteries, and capacitors, measure the voltage characteristics while charging / discharging, and measure the characteristic impedance spectrum for the specified frequency range, and numerically specify the specific factors of the nonlinear equivalent circuit model. Has been proposed (see, for example, Patent Document 2).
JP 2002-259482 A Japanese Patent No. 3190313

  Capacitor power supply devices that are configured by connecting a plurality of capacitors in series and parallel are spreading and expanding in various applications such as industrial equipment and power storage, as power storage density and performance are improved and a mass supply environment is improved. However, the voltage of the secondary battery, which is a typical power storage device so far, does not fluctuate very much due to charge / discharge, whereas the voltage of the capacitor fluctuates greatly depending on the charge / discharge. It is difficult to know how many capacitors are required to secure Therefore, there is a problem that the design is difficult. In addition, capacitors have higher output density than secondary batteries and are expected to be applied to applications that charge and discharge large amounts of power in a short time. There was also a problem of not knowing otherwise.

The conventional method for deriving the equivalent circuit model of the capacitor and the conventional method for quantifying the specific factors of the nonlinear equivalent circuit model use complex and complicated circuit models, and support the design of the capacitor power supply device. It is not suitable for. That is, in the former method, the impedance (Z) for each sample frequency is input, and any one of the RC circuit, the RL circuit, and the RCL circuit is formed as an equivalent circuit model, and the impedance (Z _M ) represented by the equivalent circuit model is formed. Defining and combining the evaluation function (Q) and minimizing to determine a circuit vector (P), and the latter method includes two or more of a non-linear resistor, a non-linear capacitor, and a non-linear coil. A nonlinear transmission line model composed of a circuit element and a voltage regulator, or a model of a finite number of trapezoidal nonlinear two-terminal battery circuits facing the transmission line is used.

  However, in designing the capacitor power supply, it is necessary to examine and evaluate whether the storage capacity is sufficient for the power demand of the load, whether it can be used within the allowable range, and how long it can be considered as the lifetime However, it is difficult to use the conventional method for the examination and evaluation. As for the design of the capacitor power supply, as the power is supplied to the load and discharged, and with charging with regenerative power from the load, how the voltage fluctuates and the remaining charge level is However, it is necessary to evaluate and evaluate the extent to which the temperature rise will occur, the end voltage, the remaining power storage capacity, and the temperature rise. In addition, since the lifetime of the capacitor becomes shorter as the use temperature becomes higher (the temperature rise is larger), it is necessary to perform evaluation from that aspect as well. Thus, when designing an efficient capacitor power source that does not waste according to a load requirement (load condition), it is required to perform a study specific to the capacitor power source.

  For example, in a machine tool on a production line such as a press machine or an NC machine, a machining operation of a predetermined process is repeatedly executed. When the main power supply and capacitor power supply are used together to supply power to the motor load that drives these machines, and peak cut power is supplied from the capacitor power supply, the temperature rise is generally large even if the storage capacity is sufficient. In some cases, there is a lot of waste by designing a large capacity so that there is no such thing.

  The present invention solves the above-described problem, and makes it possible to estimate the life from the temperature rise of a capacitor power supply used in response to a load request and to easily evaluate the capacity of the capacitor power supply.

Therefore, the present invention is a capacitor power supply life estimation evaluation system that estimates and evaluates the life according to the operating temperature of the capacitor power supply designed according to the load pattern,
Temperature T _r, the deterioration degree D of the temperature T _r as the deterioration time period required to degrade to a predetermined degree of deterioration and the deterioration degree percentage capacitance of the capacitor is deteriorated with respect to the initial value at least based _r degradation time t _Trr required to degrade until the deterioration degree D _r, the reference temperature difference T _int, the deteriorated to the deterioration degree D _r at temperature T _a with the reference temperature difference T _int respect to the temperature T _r and lifetime estimation data holding means for holding the magnification λ as data for predicting the lifetime for the degradation time t _Trr degradation time t _Tar required for,
Temperature data holding means for holding data on the operating temperature T _x of the capacitor power supply;
Based on the temperature T _r , deterioration degree D _r , deterioration time t _Trr , reference temperature difference T _int , and magnification λ of the life estimation data , the deterioration coefficient α _Tx at the use temperature T _x is
t _Txr = λ ^{(Tr-Tx) / Tint} × t _Trr
α _Tx = D _r / √t _Txr
A deterioration coefficient calculation means obtained by :
Based on the deterioration coefficient α _Tx obtained by the deterioration coefficient calculating means , the time t _Tx required for the capacitance of the capacitor to deteriorate from the initial value to the deterioration degree D _{s that} is the estimated life,
t _Tx = (D _s / α _Tx ) ²
It is characterized by comprising life estimation calculating means for obtaining the estimated life L _Tx = t _Tx by

Further, the deterioration at each of two different temperatures T _r and T _a , with the rate of deterioration of the capacitance of the capacitor with respect to the initial value as the deterioration level, and the time required for deterioration to the predetermined deterioration level as the deterioration time. Temperature degradation degree measurement data holding means for holding the measurement data of the degradation times t _Trr and t _Ta required for degradation to the degrees D _r and D _Ta and the degradation degrees D _r and D _Ta ,
The deterioration degree D _r, based on the D _Ta and the degradation time t _Ta, the degradation time t _Tar required for degraded to the deterioration degree D _r at the temperature T _a,
α _Ta = D _Ta / √t _Ta
t _Tar = (D _r / α _Ta ) ²
The determined, the magnification λ and the temperature difference T _int degradation time,
λ = t _Tar / t _Trr
T _int = T _r −T _a
Parameter generation processing means obtained by
Temperature data holding means for holding data on the operating temperature T _x of the capacitor power supply;
Based on the temperature T _r , the degradation degree D _r , the degradation time t _Trr , the magnification λ, and the temperature difference T _int , the degradation coefficient α _Tx at the use temperature T _x is calculated as _follows :
t _Txr = λ ^{(Tr-Tx) / Tint} × t _Trr
α _Tx = D _r / √t _Txr
A deterioration coefficient calculation means obtained by :
Based on the deterioration coefficient α _Tx obtained by the deterioration coefficient calculating means , the time t _Tx required for the capacitance of the capacitor to deteriorate from the initial value to the deterioration degree D _{s that} is the estimated lifetime is expressed as follows:
t _Tx = (D _s / α _Tx ) ²
And a life estimation calculating means for estimating the life L _Tx = t _Tx .

The temperature _Tr is 70 ° C., and the temperature data holding means includes:
Holds load pattern data with power pattern information required in time series and design data including capacitor power supply rating specifications,
Based on the capacitor voltage, capacitance, internal resistance and time series load pattern of data read from the storage means according to the time series, the current of the capacitor power supply is obtained,
The output voltage and charge / discharge amount of the capacitor power supply are obtained based on the capacitor voltage, the internal resistance and the current according to the time series, and the storage capacity of the capacitor power supply after the charge / discharge is obtained. By repeating the process of updating the capacitor voltage based on the capacity, the charge / discharge characteristics including fluctuations of the capacitor voltage and the storage capacity due to the charge / discharge of the capacitor power supply corresponding to the load pattern are simulated,
Characterized by holding the total power loss due to the internal resistance based on the internal resistance and the current as a data service temperature T _x calculated temperature rise of the capacitor power supply.

The temperature data holding means holds load pattern data having power pattern information required in time series and design data including rated specifications of the capacitor power supply, and stores data read from the storage means according to the time series. Obtaining the current of the capacitor power source based on the capacitor voltage, capacitance, internal resistance and time-series load pattern, and according to the time series, the output voltage of the capacitor power source based on the capacitor voltage, internal resistance and the current, and The capacitor power supply corresponding to the load pattern is obtained by repeating the process of obtaining the charge / discharge amount, obtaining the storage capacity of the capacitor power supply after the charge / discharge, and updating the capacitor voltage based on the storage capacity and the electrostatic capacity. Of charge / discharge characteristics including fluctuation of capacitor voltage and storage capacity due to charge / discharge of battery Was carried out, when the power loss due to the internal resistance based on the internal resistance and the current in accordance with sequence seek the temperature of the capacitor power supply of the time stored as data for use temperature T _x, deterioration coefficient calculating means, wherein An average value of each temperature is obtained, and a deterioration coefficient at that temperature or an average deterioration coefficient based on the deterioration coefficient at each temperature is obtained as the deterioration coefficient α _Tx .

  ADVANTAGE OF THE INVENTION According to this invention, the estimated value of the lifetime corresponding to the temperature rise corresponding to a load pattern can be shown with respect to the capacitor power supply from which a lifetime changes a lot with use temperature. Therefore, the design data of the capacitor power supply can be reviewed and redesigned easily based on the life estimation. According to the present invention, charge / discharge simulation data, a temperature rise value, and a life estimation value can be output according to load data, capacitor data, and condition settings, so whether or not the combination of each load and capacitor power supply is suitable. Evaluation and determination can be performed, and it is possible to obtain an optimum capacitor power supply design and solution by repeatedly updating load data, capacitor data, and condition settings as variables.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a diagram for explaining an embodiment of a capacitor power supply life estimation system according to the present invention, FIG. 2 is a diagram for explaining the outline of a capacitor power supply and a load circuit, and FIG. 3 is for explaining the relationship between temperature and life. FIG. 4 and FIG. 4 are diagrams showing a configuration example of capacitor design data and load data. In FIG. 1, 1 is temperature degradation degree measurement data, 2 is a temperature degradation coefficient calculation unit, 3 is a parameter generation processing unit, 4 is a life estimation parameter, 5 is capacitor design data, 6 is load data, and 7 is charge / discharge. A simulation unit, 8 is a temperature rise calculation processing unit, 9 is a life estimation evaluation processing unit, 11 is a capacitor power supply, 12 is a charge / discharge control circuit, 13 is a motor drive circuit, and 14 is a motor.

  In the capacitor power supply life estimation evaluation system according to the present invention, as shown in FIG. 1, data such as capacitor use temperature, time, and deterioration degree are stored and held in life estimation measurement data 1, and a temperature-specific deterioration coefficient calculation unit 2 is provided. The parameter generation processing unit 3 generates a parameter necessary for lifetime estimation by storing the data in the lifetime estimation parameter 4 to obtain and evaluate the lifetime of the capacitor power source. Prepare the necessary data. When capacitor design data 5 relating to the rated specifications of the capacitor power supply and load data 6 such as time-series operation patterns and load patterns are given as design data, the charge / discharge simulation unit 7 performs time-series charge / discharge simulation based on these design data. The charging / discharging current of the power source is obtained, the voltage (capacitor voltage and terminal voltage) is subsequently obtained, the charging / discharging simulation is performed, the rising temperature is obtained by the capacitor temperature rise calculation processing unit 8, and the life estimation evaluation processing unit 9 Estimate the life of the power supply.

  As shown in FIG. 2, for example, the capacitor power supply and the load circuit to be supported by the design are transferred from the capacitor power supply 11 to the motor drive circuit 13 and the motor 14 having a predetermined load pattern through a charge / discharge control circuit 12 including a current pump and a voltage conversion circuit. This is a schematic configuration composed of a motor load circuit that supplies power. The capacitor power supply design support system is based on data related to the capacitor power supply 11 and its load circuit (charge / discharge control circuit 12, motor drive circuit 13, motor 14), for example. The capacitor power supply 11 can determine the end voltage, the storage capacity, the temperature rise, and the series-parallel number of capacitors that will be the estimated lifetime within an allowable range.

In FIG. 2, assuming that the data regarding the capacitor power supply 11 is, for example, the bank voltage (capacitor voltage, original voltage) v _Bi , capacitance C _B , internal resistance r _B , and storage amount w _Bi at t _i. In order to supply the necessary power w _li (negative in the case of regenerative power), charge / discharge control must be performed so that a predetermined current i _i corresponding to the output voltage v _ti flows. At this time, the power loss generated in the capacitor power supply is obtained as (i _i ² × r _B ) from the internal resistance r _B and the current i _i, and the bank voltage v _Bi of the capacitor power supply is set to the internal resistance r _B. obtained by adding the voltage drop caused by current i _i flows to the output voltage _{v ti (v ti + i i} × r B), the storage amount w _Bi of a capacitor power ^{_{supply, C B × v Bi 2/}} 2, the charge and discharge amount Δw _ci is obtained as (w _Bi-1 −w _Bi ), respectively. Further, the heat generation amount and the heat radiation amount are obtained based on a function corresponding to the power loss, and charge / discharge simulation data is obtained as the value of each time t _i . Storage capacity W _Bmax of the capacitor power becomes ^{_{(C B × v Bf 2/}} 2) when the charged bank until the full charge voltage v _Bf.

The temperature deterioration degree measurement data 1 is a data storage unit such as a memory that stores measurement data of the deterioration degree D _Ta (%) at _a time t _{Ta at a} certain temperature _Ta . Capacitance C is proportional to the square root of time as shown in FIG. 3 (a), using as an index how much the capacitance C has deteriorated over time from the initial 100% due to use. Is known. Moreover, the degree of deterioration greatly varies depending on the temperature T _a , T _r (> T _a ), and the time required for the deterioration of the same degree of deterioration becomes longer as the temperature decreases in proportion to the temperature difference. I know that. The deterioration coefficient calculation unit 2 for each temperature obtains the deterioration coefficient α _Ta based on the time t _Ta and the deterioration degree D _Ta of the temperature deterioration degree measurement data 1, where the deterioration degree D _Ta of the capacitor is calculated at the time t _Ta . Since it proceeds in proportion to the square root, the degradation coefficient α _Ta is
[Equation 1]
α _Ta = D _Ta / √t _Ta
Is required. This is the coefficient that takes time t _Ta to the deterioration of the deterioration degree D _Ta at a temperature T _a.

Parameter generation unit 3 is configured to generate a parameter for determining the deterioration coefficient alpha _Tx at the temperature T _a and T degradation coefficient at _r alpha _Ta, any temperature from alpha _Tr T _x. Now, setting the deterioration degree D _r to a fixed value, each of the temperature T _a, T _r the deterioration degree D _r time t _Tar required for degradation of the, t _Trr each degradation factor alpha _Ta, from alpha _Tr [ Number 2]
t _Tar = (D _r / α _Ta ) ²
t _Trr = (D _r / α _Tr ) ²
Next, the time required for the same degree of deterioration of degradation is proportional to the temperature difference, the time t _Txr required for degradation of the deterioration degree D _r are
[Equation 3]
t _Txr = λ ^{(Tr-Tx) / Tint} × t _Trr
Where λ = t _Tar / t _Trr : Deterioration time magnification
T _int = T _r −T _a : temperature difference. As a result, the degradation coefficient α _{Tx at the} temperature T _x is
[Equation 4]
α _Tx = D _r / √t _Txr
It can ask for.

Therefore, obtaining the parameter generating unit 3, the temperature T _a and T each degradation coefficient in _r alpha _Ta, t _Trr when setting the deterioration degree D _r to a fixed value from the alpha _Tr, lambda, the T _int as a parameter. On the other hand, the life estimation parameter 4 is obtained by the parameter generation processing unit 3 as shown in FIG. 3B as a parameter that can estimate and evaluate the life by _{obtaining the} deterioration coefficient α _Tx at an arbitrary temperature T _x . Further, it is a data storage unit such as a memory that stores and holds data in which T _r and D _r are added to at least t _Trr , λ, and T _int . With these parameters for the lifetime estimate, for example, the time capacitance required for 20% degradation as life L _20, or the time required for 50% degradation as life L _50, D ₂₀ each degree of deterioration Assuming = 20 and D ₅₀ = 50, the calculation of [Equation 2] results in L ₂₀ = 1600 hours and L ₅₀ = 10000 hours when the deterioration coefficient α _Ti = 0.500.

The capacitor design data 5 includes, for example, the module voltage v _M , the cell series number N _S , the module capacitance C _M , the module internal resistance r _M , the allowable temperature T _ref , the module series number N _{MS shown in FIG} . Number N _MP , bank voltage v _B (voltage at full charge v _Bf ), bank capacitance C _B , bank internal resistance r _B , number of modules N _M , heat generation / heat dissipation coefficient, temperature rise function, heat tolerance A data storage unit such as a memory that stores and holds so-called capacitor power supply design data including the rated specifications. The module is a basic structural unit of a capacitor power source in which a predetermined number of cells are connected in series, and the bank is a capacitor power source configured by connecting a plurality of modules in series and further connecting them in parallel.

For example, 25 2.5 (V) cells are connected in series to form a module having a module voltage v _M of 50 (V). Assuming that this module is the basic structural unit, when the load use (start) voltage v _L is 650 (V), a bank having a parallel number of 1 is selected and set as 13 modules connected in series. . In other words, the module series number N _MS 13, fully charged when the bank voltage (v _Bf) is by the bank configuration of 650 (V), the bank capacitance C _B C _M / 13, the bank internal resistance r _B Is obtained by 13 × r _M. When the parallel number N _MP is reduced from 1 to 2, the new bank capacitance C _B is doubled, the bank internal resistance r _B is halved, and the number of modules N _M is doubled. As described above, the rated specification value related to the bank first determines the bank voltage and other values.

The load data 6 is, for example, a memory that stores and holds load pattern data having the use voltage v _L shown in FIG. 4B and the power (required power) w _li required for the capacitor power supply in time series t _i. This is a data recording unit. It may be a load capacity w _li per unit time Δt, or may be a function of a load capacity that changes with time. For example, in a certain motor selection software, a torque is calculated from an input operation pattern, and a load pattern (= rotation speed × torque) is obtained by multiplying the rotation speed torque of the operation pattern. Furthermore, when there is a main power supply and the capacitor power supply is used as a peak cut auxiliary power supply, by inputting the supply power condition for this load pattern, the load pattern exceeds the power supply from the main power supply. Electric power supplied with a peak cut from the capacitor power supply is required. This peak cut power is necessary load data in this embodiment.

First, the charge / discharge simulation unit 7 obtains a current i _i to be charged / discharged from the capacitor power supply 11 in accordance with the required power based on the capacitor design data 5 and the load data 6. Used as data. The capacitor current i _i corresponding to the required power w _li (= v _ti × i _i ) at each time t _i of the load data is
[Equation 5]
i _i = {v _Bi ± √ (v _Bi ² −4 × r _B × w _li )} / (2 × r _B )
Here, i _i × v _Bi = w _li + i _i ² × r _B = Δw _ci
Is required. Further, charge and discharge simulation unit 7, the current i _i and the bank voltage based on the data of the capacitor power supply 11 obtained (capacitor voltage, source voltage), the capacitor allylidene, at t _i in which the time update seek terminal voltage The terminal (output) voltage v _ti of the power supply 11 is
[Equation 6]
v _ti = v _Bi −i _i × r _B
The bank voltage v _{Bi + 1} of the capacitor power supply 11 after the discharge by the current i _i (at t _{i + 1} ) is
[Equation 7]
v _{Bi + 1} = √ (v _Bi ² −2 × i _i × v _Bi / C _B )
_{Here, C B × v Bi + 1} 2/2 = (C B × v Bi 2/2) - (i i × v Bi)
w _{Bi + 1} = w _Bi −Δw _ci
Is required. Then, using the bank voltage v _{Bi + 1} updated by the [Equation 7], the capacitor current i _{i + 1} the next in time subsequent t _{i + 1} commensurate with the required power w _{li + 1} of the load data in the same manner From [Equation 5], the output voltage v _{ti + 1} is obtained by [ _Equation 6], and the arithmetic processing is repeatedly executed in the same manner.

The temperature rise calculation processing unit 8 obtains the temperature of the capacitor power source by calculating the power loss i _i ² × r _B at the internal resistance r _B , the heat generation / heat dissipation coefficient, and the temperature increase function. For example, the temperature rise value is obtained as a function of power loss, and the total power loss Σi _i ² r _B × K + T ₀ is obtained. If the ratio of the temperature rise value to the allowable temperature is obtained, it can be used as a margin rate. Here, K is 1 to 3, and T ₀ is 1 to 5, which are obtained as experimental values. The value of the temperature rise may be obtained by calculating the total power loss Σi _i ² × r _B which is an integrated value and the temperature rise coefficient (value obtained as an experimental value, for example, 1 to 3). It may be converted into heat and determined using the specific heat of the module.

As a result of the above charge / discharge simulation and temperature rise calculation processing, for example, capacitor voltage (bank voltage) v _Bi , current i _i , charge / discharge amount Δw _ci , power loss i _i ² × r _B , heat generation / heat dissipation amount Q _ti , Charge / discharge simulation data such as the output voltage v _ti excluding the voltage drop due to the internal resistance r _B and the total power loss Σi _i ² × r _B (= ∫i ² × r _B di) are obtained.

The life estimation evaluation processing unit 9 includes the temperature rise value T _x calculated by the temperature rise calculation processing unit 8 and the data t _Trr , λ, T _int , T _r , D _r stored in the life estimation parameter 4. Based on the above, the deterioration coefficient α _Tx is obtained using [Equation 3] and [Equation 4], and the time L _s = (D _s required for deterioration of a predetermined deterioration degree D _{s as} the estimated life using the deterioration coefficient α _Tx. / Α _Tx ) ² is used as the estimated life value, and the estimated life is output.

  FIG. 5 is a diagram for explaining an example of calculation processing for life estimation parameters, FIG. 6 is a diagram for explaining an example of life estimation processing based on time-series temperature data, and FIG. 7 is a degradation coefficient and degradation degree obtained from temperature data. It is a figure explaining the example of the data of estimated lifetime.

In the arithmetic processing for obtaining the parameter for life estimated based on the temperature deterioration degree measurement data, for example, first, as shown in FIG. 5, by selecting the temperature, for example T _a (step S11), and the operating time t _Ta at the selected temperature The measurement data of the deterioration degree D _Ta is acquired (step S12), and the deterioration coefficient α _Ta is obtained from the use time t _Ta and the deterioration degree D _Ta (step S13). It is determined whether there is other measurement data (step S14), and if there is, the process returns to step S12 and the same process is repeated to obtain the average deterioration coefficient (step S15). Further, it is determined whether or not there is data at other temperatures (step S16), and if there is, the process returns to step S11 and the same processing is repeated, and then the life estimation is performed based on the measurement data at two temperatures and the average deterioration coefficient. Parameters (t _Trr , λ, T _int , T _r , D _r ) are generated (step S17). There may be at least one measurement data at each temperature. In that case, steps S14 and S15 are omitted.

In the life estimation process based on the time-series temperature data, for example, as shown in FIG. 6, after reading the life estimation parameters (step S21), the temperature _Ti is read according to the time series t _i (step S22). A degradation coefficient α _Ti is obtained from the degradation time t _Tir up to the degradation level D _r (step S23). When the processing of steps S22 and S23 is repeated for all time series temperature data and the processing of all the data is completed (step S24), an average deterioration coefficient is obtained (step S25), and the life estimation value L _{s is} calculated based on the deterioration coefficient. Is obtained (step S26). Further, instead of such process, merely an average value of each temperature time series, may be calculated lifetime estimate at that temperature, determine the deterioration degree D _i at the respective temperatures in chronological A final life estimation value may be obtained based on the integrated value of the deterioration degree. FIG. 7 shows an example of the generated data, and α _i and L _i are values corresponding to ΣD _i , respectively.

FIG. 8 is a diagram illustrating an example of charge / discharge simulation processing, and FIG. 9 is a diagram illustrating a configuration example of charge / discharge simulation data. It is assumed that capacitor data of a module, which is one basic structural unit of the capacitor power supply, is already stored in the data file. 8 First, by inputting a load data (step S31), obtains the desired voltage (v _L, v _B) module series number N _MS capable of obtaining (step S32). Next, by inputting the parallel number N _MP (step S33), each rated value (bank voltage v _B , bank capacitance C _B , bank internal resistance r _B , module number N _M ) of the capacitor power supply is obtained ( Step S34).

The capacitor current i _i corresponding to the required power w _li at each time t _i of the load data is obtained (step S35), and further the bank voltage v _Bi , the output voltage v _ti , the charge / discharge amount Δw _ci , and the power loss i _i ² × r. _B , heat generation / heat radiation amount _Qti, etc. are obtained and capacitor data is stored (step S36). Then, the time is updated (t _i ← t _{i + 1} ) (step S37), it is determined whether or not the process has been completed for all times (step S38), and step S35 is performed until the process is completed for all times. Return to the above and repeat the same process. FIG. 9 shows a configuration example of charge / discharge simulation data obtained by such processing.

When the process for all the time, extracts the minimum value v _Bmin bank voltage (step S39), the maximum value W _max of required power amount ^{_{(= C B × v Bf 2}} /2-C B × v Bmin 2/2 ) Is obtained (step S40). Further, the maximum value is extracted from the rising temperature at each time obtained based on the heat generation and the heat radiation, or the temperature rising value is obtained from the power loss (step S41), and each processing including the utilization factor η and the margin rate γ of the capacitor power source is performed. Data is output (step S42). Further, it is determined whether or not there is a condition change such as an increase in the capacity of the capacitor power supply (step S43). If the condition is changed, the process returns to step S33 and a new parallel number is input and the same processing is repeated thereafter. To do. In the condition change, as shown in FIG. 8B, load data, module data, or the like may be newly input and set again (steps S31 → S32 ′).

  In the capacitor power supply, when the number of modules in series is increased, the use starting voltage increases and current loss can be reduced. Further, when the number of parallel is increased, the storage capacity is increased and the internal resistance can be reduced. That is, the number of series can be increased within a range where the withstand voltage of the motor or the power converter on the output side is allowed, and the number of series-parallel can be increased within a range where the volume, weight, and cost are allowed. According to the above processing, it is possible to find an optimum capacitor power supply within an allowable range by repeating while increasing / decreasing the number of modules in series and the number of parallel to predetermined load data. Further, if the initial value is set to 1 and the analysis is performed by the above process, the place within the allowable range can be set as the optimum design value.

  Next, the deterioration characteristics of the capacitor and its temperature dependence will be described based on the measured data. FIG. 10 is a diagram showing an example of measured data of the capacitor power supply at a temperature of 70 ° C., FIG. 11 is a diagram showing deterioration characteristics obtained based on the measured data, and FIG.

In FIG. 10, a, i, c, and d are separate capacitors, and the use time t (hr) of 50, 100, 300, 500, and 1000 hours at 70 ° C. with the initial capacitance C being 100%. The data which measured how much the electrostatic capacitance C deteriorated in the stage which passed, and those average values are shown. For example, at 100 hours, the capacitance C deteriorates to an average of 94.9%, and the degree of deterioration becomes 5.1%. Therefore, the degradation coefficient α becomes 0.51, and at 1000 hours, the capacitance C Deteriorates to an average of 84.39% and the degree of deterioration becomes 15.61%, so the deterioration coefficient α becomes 0.493. For this average value data, the vertical axis represents the capacitance (%) and the horizontal axis represents the square root of time (√t). FIG. 11 shows that the horizontal axis extends to √t = 100. The electrostatic capacity (%) of the battery deteriorates to 50%, that is, D ′ = 50, so that the deterioration degree D ₇₀ = 50. Therefore, the degradation coefficient α ₇₀ is 0.500 according to [Equation 1], and the life estimation value L ₅₀ with the degradation degree D _s = 50% is 10,000 hours.

The Arrhenius equation is often cited as the rationale for accelerated tests performed at elevated temperatures. In the field of electric field capacitors, a ratio of twice for every 10 ° C. increase over a temperature range of about 30 ° C. to 125 ° C. is widely used for industrial production. Therefore, in the above-described [Equation 3] and [Equation 4], when the reference temperature _Tr is 70 ° C., the degradation time magnification λ = 2 and the temperature difference T _int = 10. FIG. 12 shows the degradation characteristics obtained by decreasing the temperature from 70 ° C. by 10 ° C., and also at the temperature of 65 ° C.

In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, it is possible to evaluate whether or not the capacitor power supply is sufficient as the power supply capacity by obtaining the life estimation value. However, it is possible to output charge / discharge simulation data together and provide it as design support data for the capacitor power supply. You may do it. For example, use the capacitor power supply rate, the temperature rise value, the temperature rise value of the temperature rise value, the ratio of the temperature rise value to the upper limit value, the difference between the temperature rise value and the upper limit value, the ratio of the temperature rise value to the upper limit value, etc. In addition, regarding the temperature of the capacitor power supply, it may be determined whether the temperature rise value falls within the temperature rise allowable range or the upper limit value. In addition, the total power loss Σi _i ² × r _B (= ∫i ² × r _B di), the minimum value v _Bmin of the bank voltage, the maximum value W _max of the required power, the utilization factor η of the capacitor power supply, and the temperature rise value T Data including _max and margin rate γ may be edited and output as a table, list, waveform diagram, graph, or the like.

In the motor load circuit, the load pattern is input. However, not only the motor load circuit but also the operation pattern and load pattern based on the power supply history data and simulation data in the composite load power supply system are input, and the peak cut power is supplied from the capacitor power supply. You may apply to a case etc. Further, for example, an operation pattern including an acceleration area A, a constant speed area B, and a deceleration area C may be given, and the torque τ and load power P corresponding to the torque τ may be obtained according to the load characteristics. At this time, the load power P becomes negative in the deceleration region C and is used as the regenerative power for charging the capacitor power supply. The voltage drops due to discharging to supply the necessary power w _li , but the regenerative power is charged. Since the voltage increases and recovers as the amount of stored electricity increases, the voltage fluctuates up and down according to charge and discharge. When the motion pattern is given by speed, the acceleration is obtained by the rate of change (differentiation) of speed per unit time. When there are multiple different types of loads, the torque required to obtain the desired acceleration and the power required to obtain the torque differ depending on the type of load. , The type of load may be specified, and the required power may be obtained correspondingly.

The figure explaining embodiment of the lifetime estimation evaluation system of the capacitor power supply which concerns on this invention Diagram explaining the outline of capacitor power supply and load circuit Diagram explaining the relationship between temperature and life The figure which shows the structural example of capacitor design data and load data The figure explaining the example of the calculation process of the parameter for lifetime estimation The figure explaining the example of the lifetime estimation process based on time series temperature data The figure explaining the example of the data of the degradation coefficient calculated from temperature data, the degradation degree, and the estimated life The figure explaining the example of charging / discharging simulation processing Diagram showing an example of charge / discharge simulation data configuration The figure which shows the example of the measurement data of the capacitor power supply in temperature 70 degreeC The figure which shows the deterioration characteristic which is obtained based on the actual measurement data Diagram showing examples of calculation of deterioration characteristics at each temperature

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Temperature degradation degree measurement data, 2 ... Degradation coefficient calculation part classified by temperature, 3 ... Parameter generation process part, 4 ... Life estimation parameter, 5 ... Capacitor design data, 6 ... Load data, 7 ... Charge / discharge simulation part, 8 DESCRIPTION OF SYMBOLS ... Temperature rise calculation processing part, 9 ... Life estimation evaluation processing part, 11 ... Capacitor power supply, 12 ... Charge / discharge control circuit, 13 ... Motor drive circuit, 14 ... Motor

Claims (5)

A life estimation and evaluation system for a capacitor power supply that estimates and evaluates the life according to the operating temperature of the capacitor power supply designed according to the load pattern,
Temperature T _r, the deterioration degree D of the temperature T _r as the deterioration time period required to degrade to a predetermined degree of deterioration and the deterioration degree percentage capacitance of the capacitor is deteriorated with respect to the initial value at least based _r degradation time t _Trr required to degrade until the deterioration degree D _r, the reference temperature difference T _int, the deteriorated to the deterioration degree D _r at temperature T _a with the reference temperature difference T _int respect to the temperature T _r and lifetime estimation data holding means for holding the magnification λ as data for predicting the lifetime for the degradation time t _Trr degradation time t _Tar required for,
Temperature data holding means for holding data on the operating temperature T _x of the capacitor power supply;
Based on the temperature T _r , deterioration degree D _r , deterioration time t _Trr , reference temperature difference T _int , and magnification λ of the life estimation data , the deterioration coefficient α _Tx at the use temperature T _x is
t _Txr = λ ^{(Tr-Tx) / Tint} × t _Trr
α _Tx = D _r / √t _Txr
A deterioration coefficient calculation means obtained by :
Based on the deterioration coefficient α _Tx obtained by the deterioration coefficient calculating means , the time t _Tx required for the capacitance of the capacitor to deteriorate from the initial value to the deterioration degree D _{s that} is the estimated lifetime is expressed as follows:
t _Tx = (D _s / α _Tx ) ²
A life estimation and evaluation system for a capacitor power supply, comprising life estimation calculation means for estimating the lifetime L _Tx = t _Tx by A life estimation and evaluation system for a capacitor power supply that estimates and evaluates the life according to the operating temperature of the capacitor power supply designed according to the load pattern,
Deterioration degree D at each of two different temperatures T _r and T _a , with the rate of deterioration of the capacitance of the capacitor with respect to the initial value as the deterioration degree, and the time required for deterioration to the predetermined deterioration degree as the deterioration time temperature deterioration degree measurement data holding means for holding measurement data of deterioration times t _Trr and t _Ta required for deterioration to _r and D _Ta and their deterioration degrees D _r and D _Ta ;
The deterioration degree D _r, based on the D _Ta and the degradation time t _Ta, the degradation time t _Tar required for degraded to the deterioration degree D _r at the temperature T _a,
α _Ta = D _Ta / √t _Ta
t _Tar = (D _r / α _Ta ) ²
The determined, the magnification λ and the temperature difference T _int degradation time,
λ = t _Tar / t _Trr
T _int = T _r −T _a
Parameter generation processing means obtained by
Temperature data holding means for holding data on the operating temperature T _x of the capacitor power supply;
Based on the temperature T _r , the degradation degree D _r , the degradation time t _Trr , the magnification λ, and the temperature difference T _int , the degradation coefficient α _Tx at the use temperature T _x is calculated as _follows :
t _Txr = λ ^{(Tr-Tx) / Tint} × t _Trr
α _Tx = D _r / √t _Txr
A deterioration coefficient calculation means obtained by :
Based on the deterioration coefficient α _Tx obtained by the deterioration coefficient calculating means , the time t _Tx required for the capacitance of the capacitor to deteriorate from the initial value to the deterioration degree D _{s that} is the estimated lifetime is expressed as follows:
t _Tx = (D _s / α _Tx ) ²
A life estimation and evaluation system for a capacitor power supply, comprising life estimation calculation means for estimating the lifetime L _Tx = t _Tx by The lifetime estimation evaluation system for a capacitor power supply according to claim 1 or 2, wherein the temperature _Tr is 70 ° C. The temperature data holding means is
Holds load pattern data with power pattern information required in time series and design data including capacitor power supply rating specifications,
Based on the capacitor voltage, capacitance, internal resistance and time series load pattern of data read from the storage means according to the time series, the current of the capacitor power supply is obtained,
The output voltage and charge / discharge amount of the capacitor power supply are obtained based on the capacitor voltage, the internal resistance and the current according to the time series, and the storage capacity of the capacitor power supply after the charge / discharge is obtained. By repeating the process of updating the capacitor voltage based on the capacity, the charge / discharge characteristics including fluctuations of the capacitor voltage and the storage capacity due to the charge / discharge of the capacitor power supply corresponding to the load pattern are simulated,
Life Prediction of capacitor power supply according to claim 1 or 2, wherein the holding as data for use temperature T _x from the total power loss due to the internal resistance based on the internal resistance and the current calculated temperature rise of said capacitor power supply Evaluation system. The temperature data holding means is
Holds load pattern data with power pattern information required in time series and design data including capacitor power supply rating specifications,
Based on the capacitor voltage, capacitance, internal resistance and time series load pattern of data read from the storage means according to the time series, the current of the capacitor power supply is obtained,
The output voltage and charge / discharge amount of the capacitor power supply are obtained based on the capacitor voltage, the internal resistance and the current according to the time series, and the storage capacity of the capacitor power supply after the charge / discharge is obtained. By repeating the process of updating the capacitor voltage based on the capacity, the charge / discharge characteristics including fluctuations of the capacitor voltage and the storage capacity due to the charge / discharge of the capacitor power supply corresponding to the load pattern are simulated,
The temperature of the capacitor power source at each time is obtained from the power loss due to the internal resistance based on the current and the internal resistance according to time series, and is stored as data of the use temperature T _x .
The deterioration coefficient calculating means obtains an average value of the respective temperatures and obtains a deterioration coefficient at that temperature or an average deterioration coefficient based on the deterioration coefficient at each temperature as the deterioration coefficient α _Tx. Lifetime estimation system for capacitor power supply.

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