JP2012013472A - Method for estimating deterioration in power storage means, power source device, and railway vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately grasp replacement time of power storage means by accurately and simply estimating degrading of resistance in the power storage means and to achieve stable operation without imposing an overload to the power storage means.SOLUTION: In a railway vehicle which travels according to a predetermined operation method, a current value, a surface temperature, a voltage, and an environment temperature in the power storage means while travelling on a railroad are recorded. A difference ΔV between the maximum voltage and the minimum voltage is compared with an initial value ΔVini for calculating deterioration in comparison with a threshold value ΔVth, the deterioration is reflected to vehicle control and a degree of deterioration and a checkup notice are displayed in a control platform.

Description

  The present invention relates to a method for controlling power storage means capable of charging and discharging, such as lithium secondary batteries, nickel metal hydride batteries, lead batteries, and electric double layer capacitors, and in particular, the power storage means is used as part or all of drive power. The present invention relates to a railway vehicle control method.

  In recent years, there has also been a trend toward energy saving in the railway field, taking into account environmental problems. Power storage means that uses a secondary battery in a vehicle, stores regenerative current during braking, and uses all or part of driving power during powering Onboard vehicles are being developed. As power storage means for driving electric vehicles, hybrid vehicles, and trains equipped with power storage means, secondary batteries such as nickel metal hydride batteries and lithium secondary batteries, and high output batteries such as capacitors are mounted. In particular, nickel-metal hydride batteries and lithium secondary batteries have a higher energy density than lead batteries, and are therefore used as a general power storage system in a multi-series / multi-parallel configuration.

  Here, the definition of the power storage means in the present invention will be described. In a power storage device that can be repeatedly charged and discharged, a minimum power storage element composed of a pair of positive and negative electrodes is a single cell. A unit in which a plurality of unit cells are connected in series to form an assembled battery, or a configuration in which a plurality of these units are connected, and in appearance, in a single block shape or a shape accommodated in a housing, a set of positive terminal and negative electrode A module having a current input / output path at a terminal is defined as a storage battery in a narrow sense.

  When the secondary battery is repeatedly charged and discharged, the state of charge (SOC) or the state of health (SOH) changes, and when the secondary battery deteriorates, the charge / discharge capacity decreases. Increases battery internal resistance. Therefore, the output of the system gradually decreases with deterioration. Further, it is well known that deterioration due to self-discharge proceeds during storage, and there is a voltage drop.

  On the other hand, the power storage means used for railway vehicles is large and requires a large capacity, and the cost of the power storage means is high in the entire system, and control that takes advantage of the performance of the power storage means is necessary. It is desirable that the period is long.

  Therefore, since the input / output of the power storage means changes according to deterioration, it is necessary to appropriately detect the deterioration state and perform various controls.

  In order to detect the deterioration state of the storage battery, there is a method based on internal resistance measurement as described in Patent Document 1 in a hybrid vehicle. A method is shown in which the current and voltage at the time when the SOC of the storage means is estimated to be substantially the same are measured, and the internal resistance is detected based on the measured values of the voltage and current at the time of discharging and charging. Yes.

JP 2000-21455 A

  In the method represented by Patent Document 1, the internal resistance is detected and calculated while the vehicle is running.

  The hybrid vehicle frequently accelerates and decelerates, and the charge / discharge current of the power storage means is frequently switched between charge and discharge per unit time as shown in FIG. In Patent Document 1, a plurality of currents corresponding to voltages at the time of discharging and charging are collected using the characteristics, and the internal resistance is calculated from the slope of the voltage-current straight line.

  On the other hand, in a railway vehicle, EV, etc., a larger current is required, and a current pattern as illustrated in FIG. 3 is required for the power storage means, and there is little switching per unit time of input or output. For this, the duration of discharging or charging becomes longer. For this reason, it is difficult to obtain the same amount of data as that of a hybrid vehicle in a method that collects a large amount of both discharge and charge data per unit time during driving and calculates the degree of deterioration. There is a problem that it is difficult to accurately obtain the degree of deterioration (SOH). Similarly, in the method of integrating the charge amount and the discharge amount up to approximately the same SOC of the power storage means, a current change that can calculate the resistance value does not always occur at the time of substantially the same integrated capacity. In addition, in the method of obtaining SOH from the integrated value of charging power, etc., the current measurement error affects the integrated value, so the current measuring means must be highly accurate. There was a problem that was difficult. Furthermore, as seen particularly in lithium batteries, there is a phenomenon in which the resistance value temporarily rises when large current charging / discharging continues. Since the resistance rises temporarily, the period from the end of the previous run to the start is long, and if the resistance value decreases while the system is stopped, SOC calculation using the resistance value during the previous run, allowable input / output current, There is a problem that the error becomes large with respect to power. For this reason, it is difficult to easily obtain an index for replacing the storage means at an appropriate time.

  Also, when comparing using a reference resistance, when using a resistance value calculated from a specific condition, for example, when the current changes greatly in several tens of ms in the measurement control cycle, the initial value in several tens of ms is used. The rate of increase in resistance deterioration is calculated from the relationship between resistance and temperature in the estimated SOC as the resistance standard of the power storage means. However, the actual charging / discharging of the railway vehicle often lasts for several tens of seconds, and the resistance value increases with time. . Therefore, when deterioration is predicted based on a resistance value of several tens of ms or a resistance value of several seconds, the rate of increase in resistance calculated from the limit predicted resistance value from the upper and lower operating voltage limits, and at the time of charging and discharging for several tens of seconds The rate of increase in resistance calculated from the limit resistance of the system did not match, and the problem was that the period during which the rated operation on the system could be estimated was longer than actual. For this reason, it has been found that the rated operation on the system is impaired before the life determination, and that a problem such as a reduction in fuel consumption can occur in a hybrid vehicle.

  The present invention has been developed for the purpose of solving at least one of the conventional problems, and measures the deterioration of the power storage means by a simple method.

  The present invention measures the voltage of the power storage means, records the measured voltage measurement value, calculates the voltage fluctuation width from the recorded voltage measurement value, and calculates the calculated voltage fluctuation width in advance as the initial voltage. The deterioration state of the power storage means is estimated by comparing with the fluctuation range.

  According to the present invention, it is possible to measure the deterioration of the power storage means by a simpler method.

It is an operation | movement flow schematic diagram of this invention. It is the figure which showed the example of the storage battery current of a hybrid vehicle. It is the figure which showed the example of storage battery currents, such as a railroad and EV. It is a structural example of the electrical storage system to which this invention is applied. It is a structural example of the electrical storage system to which this invention is applied. It is the figure which showed the operation | movement flow which is embodiment in this invention. It is a schematic diagram of the measurement data processing from the electrical storage means which is an embodiment of the present invention. It is the figure which showed the voltage operation | movement of an electrical storage means. It is the figure which showed the characteristic of the electrical storage means. It is the figure which showed the characteristic of the electrical storage means. It is a structural example of the electrical storage system which is embodiment of this invention. It is an example of the display apparatus of the electrical storage system which is embodiment of this invention. It is the figure which showed the operation | movement flow which is embodiment in this invention.

  In the embodiment of the present invention, in a railway vehicle that frequently performs a predetermined operation periodically, measurement of the current flowing through the power storage means, the voltage of the power storage means, the temperature of the power storage means, and the environmental temperature obtained during traveling is performed. From the data, the maximum value Vmax and the minimum value Vmin of the storage means voltage during operation on the same travel route are recorded, and deterioration is determined using the difference ΔV as an index.

  Further, a means for determining deterioration of the power storage means by comparing ΔVini at the initial stage of travel on a fixed route with ΔV at the time of travel, and displaying and visually checking the replacement index on the cab is mounted.

  Here, the voltage measuring means is an essential component in the present invention. The means for measuring the current, the power storage means temperature, and the environmental temperature is a configuration necessary for improving the accuracy of deterioration determination. Since the deterioration calculation result differs depending on the current at the time of measuring the voltage, the power storage means temperature, and the environmental temperature, these parameters are stored in association with the voltage measurement value. For example, as shown in FIG. 9, the internal resistance value of the power storage means varies greatly depending on the temperature of the power storage means. Therefore, for example, a voltage value measured when the temperature of the power storage means is 25 degrees or higher is preferably used for the deterioration estimation.

  The railway vehicle according to the embodiment of the present invention is an information control system for power storage means including at least one power storage means and a control circuit, and is configured to charge and discharge at least one power storage means 20 shown in FIG. A means 60; a voltage measuring means 30 for detecting the voltage of the power storage means 20; a current detecting means 40 for measuring the current value of each power storage means provided with a Hall CT or a shunt resistance type current sensor; A data recording unit 10 that records the detected voltage and the current value of the current detecting unit 40, and a calculation part (not shown) that calculates the resistance value of the power storage unit from the voltage information recorded in the data recording unit 10. And having a deterioration determination program, the operation command is output from the control command generation means 70 during operation of the railway vehicle, and the load current is applied by the charge / discharge means 60.

  In the embodiment of the present invention, as shown in FIG. 1, when the system starts, the initial voltage Vini, current I, temperature Tc of the storage means, and environmental temperature Ta are measured and recorded (S1). Even after the start (S5), the voltage V, current I, and temperatures Tc and Ta are recorded (S6), and data is accumulated until the end of travel (S7). Thereafter, the maximum voltage Vmax during charging and the minimum voltage Vmin during discharging are extracted. Here, the extraction of the maximum voltage Vmax and the minimum voltage Vmin is performed after traveling in which the discharging operation and the charging operation are performed at least once each. For example, the extraction may be performed once a day. The maximum voltage Vmax and the minimum voltage Vmin are extracted from the voltage V when the current I and the temperature Tc, Ta recorded in association with the voltage V are within a predetermined range. As described above, by extracting the maximum voltage Vmax and the minimum voltage Vmin by excluding the voltage V when the current I and the temperatures Tc and Ta deviate from the predetermined ranges, it is possible to suppress the error in the deterioration estimation.

  The difference between the maximum voltage Vmax at the time of charging and the minimum voltage Vmin at the time of discharging is determined as ΔV (S8). ΔVini obtained in the initial stage is set as ΔVini, and ΔV and ΔVini are compared to calculate the deterioration degree SOH of the power storage means (S10). Here, the calculation of ΔVini is also performed after the power storage means has performed the discharging operation and the charging operation at least once each.

  The SOH is compared with the threshold value and ΔVth (S12). If it is larger than the threshold value, the replacement warning is displayed (S13). If it is smaller than the threshold value, the history is recorded (S14) and the process is terminated.

  Thus, the problem of the present invention is solved by determining the deterioration of the power storage means, determining the normality / abnormality, and displaying the replacement time.

Here, the voltage fluctuation range ΔV will be described with reference to FIG. The voltage waveform of the power storage means during running decreases during discharging and increases during charging. At this time, as shown in FIG. 8, the storage means voltage waveform during the progress of deterioration is as shown in (B) with respect to the initial storage means voltage waveform (A) of the storage means system. Initially, the maximum charging voltage V _max0 and the minimum discharging voltage V _min0 are set, and the voltage fluctuation range is ΔVini = (V _max0 −V _min0 ). When the deterioration proceeds, the maximum voltage Vmax and the minimum voltage become Vmin, and ΔV = (Vmax−Vmin). Here, V _clim is the maximum operating voltage during the charging operation, V _dlim is the minimum operating voltage during the discharging operation, and _ΔVth is a threshold of the voltage fluctuation range.

  The data recording unit 10 includes at least one of a RAM that performs primary recording, a ROM (Read Only Memory) that records operation data, and a rewritable large-capacity recording medium.

  In order to reduce current errors caused by travel time, increase / decrease in the number of passengers, differences in driving conditions due to weather, etc., multiple current and voltage data of power storage means when traveling on routes before passengers are present on the same route And an average power storage means current pattern I (t) is obtained for the route. Since the obtained current pattern I (t) and the route travel pattern are considered to travel substantially the same, the current I (t) ′ during travel is the current pattern I (t) obtained in the initial range within a certain range. Will not deviate within.

  Therefore, the current patterns can be regarded as the same, and the deterioration of the power storage means can be relatively evaluated.

  Further, the maximum current value in charge / discharge allowed in the power storage means is determined in advance for both the charge side Icmax and the discharge side Idmax. Therefore, it is possible to calculate the threshold ΔVth of the voltage fluctuation range based on the open circuit voltage at the limit obtained from the relationship between the maximum current and the SOC of the power storage means during operation.

When the temperature of the power storage means is room temperature or higher, the DC resistance R is constant regardless of the current if the theory of Patent Document 1 is used in the range up to the maximum current and the SOC fluctuation is within 1%. However, when the SOC variation is greatly accompanied, the tendency that the resistance value including polarization becomes large becomes remarkable. However, since the information is included in the voltage fluctuation, it is important to monitor the voltage fluctuation. The maximum voltage Vmax and the minimum voltage Vmin at the time of operation are respectively expressed by equations (1) and (2). Here, i ₁ (R) and i ₂ (R) indicate voltage polarization widths reflecting the entire resistance value including polarization at the time of the charging current i ₁ and the discharging current i ₂ .

The initial voltage fluctuation ΔV0 and the voltage fluctuation width ΔV during traveling are expressed by equations (3) and (4), respectively. Here, assuming that the initial resistance R ₁ and the running resistance R ₂ are the voltage polarization in this state, the voltage difference can be a constant a when the upper limit SOC and the lower limit SOC during operation are the same. Formula (5). A difference obtained by subtracting the constant a from the fluctuation range ΔV is a voltage fluctuation equation (6) including deterioration information.

  Therefore, the voltage fluctuation width ΔV directly includes deterioration information and is easy to confirm. As the value of the voltage fluctuation width ΔV increases, the deterioration progresses. For example, by comparing the absolute value of the voltage fluctuation range ΔV with a table value obtained by grading deterioration, it is possible to determine whether the replacement or abnormality has occurred.

  In addition, from the detected temperature information of the temperature detection unit (not shown) that measures the temperature of the power storage means, the temperature of the resistance value held as internal information in advance is converted and compared with the reference value, The above-described problem is solved by detecting the deterioration state from the running data.

  Alternatively, by comparing the obtained value of the voltage fluctuation width ΔV with the voltage fluctuation width ΔVth assumed at the time of system life, the deterioration degree of the power storage means is determined, replaced, and an abnormality warning is displayed on the cab. By allowing the driver to visually recognize this method, it is urged to replace the power storage unit appropriately. Furthermore, the determined degree of deterioration is reflected in the input / output control of the power storage means, and when the deterioration progresses, the absolute value of the current is reduced, thereby reducing the burden on the power storage means and contributing to extending the life of the power storage means. Is.

  By calculating the degree of deterioration using the voltage fluctuation range ΔV calculated from the average value of two or more measured data of daily driving data during actual driving, the calculation variation in the degree of deterioration of the power storage means is suppressed and the accuracy is high. The degree of deterioration can be estimated, and temporary resistance changes can be separated from deterioration.

  Alternatively, by combining the resistance value of the power storage means calculated by the resistance measurement method when the vehicle is stopped, the deterioration data calculated by another algorithm, and the above-described deterioration estimation method, the voltage of the power storage means can be changed by another algorithm while traveling. The problem of the present invention can also be solved by further comparing with the calculated deterioration data, changing the control parameter of the power storage means according to the detected resistance value, and determining the deterioration and abnormality.

  In the embodiment of the present invention, the deterioration state of the power storage means is also used in the usage of the power storage means in which the number of times of switching to charging or discharging per unit time as shown in FIG. 3 is small and the current change is not steep. Can be estimated easily, and the inspection and replacement time can be appropriately managed. Since the charging / discharging time is long and the processing is performed statistically, the deterioration state of the entire operation of the macro power storage means can be confirmed. Therefore, the deterioration can be determined without being affected by the accuracy of the SOC estimation calculation. It becomes possible. Further, the state of the power storage means can be determined by comparison with SOH calculated by another algorithm, and charge / discharge control in accordance with the deterioration of the power storage means becomes possible.

  Capturing the degradation of the power storage means in a macro improves the accuracy of the SOC calculation using the resistance of the power storage means, so that an input / output command exceeding the allowable input / output of the power storage means does not occur and the power storage means becomes overloaded. Can be prevented. An error that causes the system to stop due to overload is eliminated, the system becomes more stable, and the performance of the power storage means can be sufficiently extracted, and the optimum use according to the state at that time becomes possible.

  In addition, by having the deterioration checking operation unit, the operator can easily check the deterioration of the power storage means, and it is possible to replace the battery having a severe deterioration of the power storage means before the start of traveling. Furthermore, since the read value can be compared with the current deterioration state and the state of the power storage means can be confirmed, the charge / discharge amount of the power storage means can be controlled in accordance with the deterioration state of the power storage means. Therefore, more stable control is possible, leading to stable running, and in the case of a hybrid system, fuel efficiency is also improved.

  When the present invention is applied to a railway vehicle or the like, it is possible to calculate a voltage fluctuation range at the start of business before business, and by incorporating it into a series of inspections before traveling, the accuracy of the power storage means can be obtained without special maintenance. Good degradation estimation is possible. And it becomes possible to maintain more stable operation.

  In addition, in the case of the lithium storage means, the resistance value changes according to the SOC. However, according to this method, the deterioration measurement can be performed at the same SOC value and compared with the previous value. Therefore, it is possible to estimate and reflect deterioration without having a complicated algorithm.

  Further, since temporary resistance increase due to continuation of a large current is also included in the voltage information, the power management means can be implemented regardless of the length of time that the current is continuously flowed by performing the voltage management of the present invention. It becomes possible to detect the deterioration of. Further, compared to the SOC obtained by the SOC estimation calculation and the deterioration calculation method using the estimated OCV, in the present invention, the fluctuation range ΔV is substantially constant even if the operating SOC is not completely the same. Therefore, there is an advantage that the estimation error when the deterioration progresses can be reduced.

  In addition, in the method in which the calculation using the estimated SOC value and the estimated OCV is performed and the deterioration state of the power storage means immediately after the end of travel obtained by the real-time SOH calculation is reflected in the next travel, the system starts after the end of the previous travel. If the resistance value temporarily increased during the system stoppage is long and the previous value is reflected, there is a problem that errors in SOC calculation, allowable input / output current, and power increase. In response to the problem, by applying the present invention, an input / output command that more reflects the actual resistance of the power storage means becomes possible, and in the case of an arithmetic method using a reference resistance value for SOC estimation, the estimation accuracy is improved. Further, by combining with control parameter correction by learning, the battery state detection accuracy is improved.

  By improving the control accuracy of the power storage means, it is possible to avoid overloading the power storage means, and more stable travel can be realized.

  There is an advantage that deterioration of the power storage means can be easily discriminated when the vehicle is stopped and maintenance is easy. Deterioration can be determined quantitatively from the relationship between upper and lower limit voltage and time, especially in the case of a running pattern with a constant current.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  A case where the present invention is applied to a hybrid system configured as shown in FIG. 5 and driven by the engine 201 and the power storage means 206 will be described. A configuration example of the vehicle system is shown below. The engine 201 and the generator 202 directly connected to the engine 201 via a shaft generate three-phase AC power of U, V, and W, and the converter device 203 converts this AC power into DC power and outputs it. The inverter device 204 converts the DC power output from the converter device 203 into three-phase AC power of variable voltage and variable frequency, and supplies it to the induction motor 205. Power storage device 206 is connected in parallel to the output side (DC side) of converter device 203 and replenishes power when the vehicle is started. The smoothing capacitor 207 is connected in parallel to the input side (DC side) of the inverter device 204, and suppresses fluctuations in the inverter input voltage.

  On the other hand, the control unit 210 executes converter control calculation based on the converter output current Is detected by the current detector 209a, the smoothing capacitor voltage detected by the voltage detector 208, and the generator rotation frequency, and A PWM control signal is output. Further, the control unit 210 executes inverter control calculation based on the motor currents Iu, Iv, Iw detected by the current detectors 209b, 209c, and 209d, the smoothing capacitor voltage detected by the voltage detector 208, and the motor rotation frequency, and the inverter An inverter PWM control signal is output to the device 204. The battery state calculation unit of the power storage means calculates the operating state of the power storage device 206 from the input / output current and voltage of the power storage device 206, the temperature of the power storage device, and the environmental temperature. Further, the control unit 210 is configured to determine the operating state of the power storage device 206 from the information of the power storage device 206 output from the battery state calculation unit of the power storage means, and to output a charge / discharge control signal for the power storage device.

  A procedure for estimating the deterioration of the power storage device executed by the battery state calculation unit will be described with reference to FIG. First, after the power storage system is activated, the initial voltage Vini, the current I, the temperature Tc of the power storage means, and the environmental temperature Ta are measured (S1), and the start charge state SOCini is calculated (S2). The start voltage Vini and the SOCini are recorded (S3). When the start voltage is not reached, the start voltage is adjusted by charging (S4), and the vehicle starts running (S5). During traveling, the measured values of voltage V, current I, temperature Tc, Ta are recorded in association with each other (S6), and after traveling is completed (S7), the maximum voltage Vmax and minimum voltage Vmin during traveling are represented by the current value I and Extracted together with the temperatures Tc and Ta to obtain ΔV (S8). The obtained ΔV is compared with a predetermined initial value ΔVini (S9). The threshold value ΔVth of ΔV is also compared, and after the deterioration degree SOH is calculated (S10), it is displayed on the operator confirmation screen (S11). Further, SOH is compared with a threshold value (S12), a case where the SOH is larger than the threshold value is regarded as deterioration, a replacement inspection warning is displayed (S13), and a history is recorded (S14). When the degree of deterioration SOH is smaller than the threshold value, the history is recorded as it is without displaying the replacement inspection warning (S14).

  At this time, the degree of deterioration SOH can be calculated by comparing the absolute values of ΔV and ΔVini. Alternatively, it may be calculated by ΔV / ΔVini, or may be calculated by comparison with a value obtained by subtracting the voltage width corresponding to the SOC fluctuation from ΔV and dividing by the current value.

  Further, FIG. 7 shows data processing of deterioration calculation in the battery state calculation unit. As shown in FIG. 7, in the deterioration calculation, the input of voltage V, current I, temperature Tc, Ta from each sensor is A / D converted, correlated and recorded in the recording unit, and data is selected and extracted from the recording unit. After calculating the deterioration degree SOH, the calculation result of the deterioration degree SOH is displayed on the display unit, and the calculation result of the deterioration degree SOH is reflected on the control unit 210. The control unit 210 calculates the current resistance value of the power storage unit based on the calculation result of the deterioration degree SOH, calculates an allowable current value from the obtained resistance value, and further performs SOC calculation correction. The technique disclosed in paragraphs [0028] to [0079] of Japanese Patent No. 4157317 can be applied to the SOC calculation and allowable current calculation.

  It is preferable to perform the deterioration degree SOH calculation when traveling on a route when the vehicle weight is constant, such as when traveling from the garage to the starting station or from the terminal station to the garage. When the vehicle weight is constant, the output fluctuation is small and the current pattern is almost constant, so that a more accurate deterioration diagnosis can be performed.

  As another example, an embodiment will be described in which each of a plurality of power storage means includes voltage measurement means as shown in FIG. Parts not mentioned in the present embodiment are assumed to have the same configuration as in the first embodiment.

  A current detecting means 40 for measuring the current value of each power storage means in series with a power storage means in which a plurality of power storage means 211 and 212 shown in FIG. 11 are connected in series, and a voltage measuring means 31 for measuring the voltage of each power storage means, 32, a data recording unit 10 for recording the detection voltage of the total voltage detection unit and the current value of the current detection unit, and a calculation part for calculating the resistance value of the power storage unit from the voltage information recorded in the data recording unit 10 (FIG. In a vehicle configuration in which a command is issued from the control command generating means 70 and a load current is applied by the charging / discharging means 60 during traveling, the power storage means 211 is configured to have a deterioration determination program. The storage unit 212 monitors and records the voltage of the voltage measurement unit 31 and records the voltage of the voltage measurement unit 32, thereby calculating the voltage fluctuation width ΔV for each storage unit. The degree of deterioration of each power storage means is calculated by comparing with the initial value or the representative value ΔVini of the system, and when ΔV is equal to or greater than a threshold value, deterioration information is individually displayed for each power storage means. Thereby, the abnormality of each power storage means and the deterioration variation of the power storage means can be determined, and it is possible to easily know whether the power storage means needs to be replaced or maintained. Moreover, according to the deterioration state of each electrical storage means, charge / discharge current can be controlled and partial maintenance can be easily performed.

As another example, an embodiment related to the stable maintenance operation of the system will be described. Parts not mentioned in the present embodiment are assumed to have the same configuration as in the first embodiment. The voltage waveform of the power storage means during running decreases during discharging and increases during charging. At this time, as shown in FIG. 8, the storage means voltage waveform during the progress of deterioration is as shown in (B) with respect to the initial storage means voltage waveform (A) of the storage means system. Initially, the maximum charging voltage V _max0 and the minimum discharging voltage V _min0 are set, and the voltage fluctuation range is ΔVini = (V _max0 −V _min0 ). When the deterioration proceeds, the maximum voltage Vmax and the minimum voltage become Vmin, and ΔV = (Vmax−Vmin). Here, V _clim is the maximum operating voltage during the charging operation, and V _dlim is the minimum operating voltage during the discharging operation.

When the power storage means deteriorates, the current is generally reduced when the voltage reaches the maximum voltage V _clim or the minimum voltage V _dlim in order to protect the power storage means from being overcharged or overdischarged. Also in the present embodiment, when ΔV at the time of deterioration exceeds the threshold value ΔVth, the charge / discharge current of the power storage means can be made smaller than the current threshold value designed in advance. Also, as shown in FIG. 8, in the case of a current threshold value determined from the upper limit V _clim, it is possible to obtain a current value within an allowable range by the current threshold value by lowering the start voltage. Therefore, when the voltage fluctuation width ΔV reaches the threshold value _ΔVth and Vmax reaches V _clim during traveling, the _vehicle travels while reducing the charging current during traveling. By reducing the start voltage at the start of the next run after the end of the run, Vmax can be made equal to or less than V _clim, and the current value can be the original specified current value. When the voltage fluctuation width ΔV reaches the threshold value ΔVth, it is possible to immediately use the power storage means without exchanging the power storage means, and to control the power storage means effectively. The current limit when _ΔV reaches _ΔVth and the maximum voltage Vmax reaches the upper limit voltage V _clim or the minimum voltage Vmin reaches the lower limit voltage V _dlim may be executed when _ΔVth is reached a predetermined number of times. I can do it. As a result, it is possible to prevent wasteful current limitation due to erroneous detection due to noise or the like.

  As another embodiment of the present invention, an example of selecting a measurement time of a voltage measurement value used for calculation of the voltage fluctuation range ΔV will be shown. Parts not mentioned in the present embodiment are assumed to have the same configuration as in the first embodiment.

  In the power storage system of the present invention, the current range before and after a plurality of current values I, where the temperature Tc is equal to or higher than a predetermined temperature, based on recorded data of the current I, voltage V, and temperature Tc of the power storage means when the vehicle travels on a specific route. Using the current value selected by I ± α, select the travel section in the time range t ± t ′ ahead of the time t after the lapse of the predetermined time from the travel start time, and record the route data along with the time From the recorded data, select the calculation location within the predetermined time range where the discharge current and charging current on the selected route are assumed to be the largest, calculate ΔV, and determine the degree of deterioration To do.

  At this time, the temperature range is also limited to a range of T ± t, and further, an average value of a plurality of values is set so as to include deterioration information of the power storage means in a plurality of states.

  According to this embodiment, the measurement condition of the voltage value used for calculating ΔV can be specified, so that the accuracy of the deterioration determination can be further improved.

  As another embodiment of the present invention, an embodiment for calculating the degree of deterioration with higher accuracy will be described. Parts not mentioned in the present embodiment are assumed to have the same configuration as in the first embodiment. A section operated at a constant current is selected as a measurement section for the deterioration degree, and ΔV = (V1−) at a charging voltage V1 at a certain time t and a voltage V2 at a certain time t ′ on the discharge side. V2) is calculated, this ΔV is compared with the initial value ΔVini calculated under the same conditions, and the deterioration degree is calculated from the difference from the threshold value ΔVth.

  According to this embodiment, since the voltage value can be detected under the same current value condition, the deterioration degree can be calculated with high accuracy.

  Averaging is averaged by regular running, and the ΔV at the time of running deterioration is compared with the initial ΔVo as a reference. In the case of an electricity storage device in which the voltage of the electricity storage means changes uniformly with the discharge time (SOC), the maximum voltage and the minimum voltage are determined within the usage range. Furthermore, when the daily operating route is determined, the width of the maximum voltage and the minimum voltage is determined.

  When the power storage means is a lithium ion battery, as shown in FIGS. 9 and 10, the resistance value changes greatly depending on the temperature. However, if the temperature of the power storage means is 25 ° C. or higher, the resistance value is almost constant regardless of the SOC. It is.

  In this system of power storage means operating within the range of SOC and temperature, even if the starting voltage differs by several% and the SOC during traveling is up or down by several% overall, it is possible to estimate the fluctuation of the resistance value by the voltage fluctuation range. Is possible.

  Since the deterioration of the power storage means progresses slowly, the representative value of the initial travel is obtained from the average value when the same route is traveled a plurality of times rather than the comparison between one travel and one travel, and further, for each temperature of the power storage means. Accumulate representative values. For the temperature range that cannot be acquired in the initial running, a conversion table can be created and used from the initial temperature characteristics of the power storage means.

  Comparing the representative value of ΔVini of the initial power storage means with ΔV at the time of running obtained from a moving average obtained by accumulating data for a plurality of runs, for example, 10 days, it is possible to filter the measurement abnormal value and the value of the data conversion abnormality. This makes it possible to perform highly reliable deterioration determination.

The operation at the time of measurement according to the present invention will be described with reference to FIG. The initial voltage Vini is measured when the system is started (S1), the initial state SOC _ini of the power storage means is calculated from information on the voltage V, current I, and temperature T (S2), and then the start voltage V _ini and SOC _ini are stored in the data recording unit. After recording (S3), traveling is started (S5). The voltage, current, and temperature at the time of execution are recorded as data (S6), and ΔV is calculated for the selected voltage and current data (S8). SOH is calculated from ΔV (from the resistance value obtained using the current data used) (S10) and displayed on the operator confirmation screen (S11). Further, the calculated SOH is compared with a threshold value of ΔSOH as a variation ΔSOH from the reference SOH (S12). S13), the history is recorded (S14). If ΔSOH ≦ threshold value in S12, only the history is recorded and not reflected in the parameter.

Further, the data storage device for recording the storage means voltage, current, temperature, etc. for each run is preferably in the state detection calculation unit of the secondary battery system in the vehicle, but any data storage device in the vehicle, Or you may exist in the vehicle base outside a vehicle using communication, such as LAN.

  Record the date and time of travel, the current of the storage means, the voltage, the temperature of the storage means, and the environmental temperature for each route or section, and select the route selection and temperature range on the visual operation panel in the cab as shown in FIG. By selecting and specifying the date and time, ΔV of the power storage means in a desired period can be calculated, an arbitrary degree of deterioration can be confirmed, and it can be confirmed whether there is an abnormality during maintenance of the power storage means.

  FIG. 12 shows an example of a driver's cab visual operation panel. The operation display panel includes a part for displaying an inspection warning display and a replacement display, and includes at least one of a first power storage means state display device and an arbitrary measurement SOH display device. The temperature range selection unit and the route selection unit The condition is set, the state of the power storage means is calculated by the deterioration check processing switch of the power storage means, and the result is displayed on the display device. The inspection warning display may be arranged on each power storage means in addition to the operation panel of the cab.

  As described above, the state of the power storage unit is detected from the information on the current I, the voltage V, and the temperature T of the power storage unit, and the deterioration state (SOH) of the power storage unit is calculated. The calculated SOH is reflected in the control parameters, the allowable current / allowable power calculation of the detected state of the power storage means is performed, and stable output is obtained by charging / discharging the power storage means according to the input / output command based on this As a result, the life of the power storage system can be extended, and the system can be maintained stably.

  The power storage means 2 in the present embodiment is an element constituting the system of the power storage means, and can be applied as a single battery, or may be an assembled battery combining the single batteries.

  Furthermore, when there is a data storage area, for example, in a built-in control circuit or the like in the battery pack housing of the power storage means by communication, the history can be stored and used during maintenance.

  The power storage means in the present invention is not limited to a lithium secondary battery, and can be applied to all battery systems including chargeable / dischargeable power storage elements such as nickel metal hydride batteries, NAS batteries, lead batteries, and electric double layer capacitors. These battery systems can be used, and the current input / output pattern is almost fixed. It is effective for stable maintenance of large-scale battery systems such as rail vehicles, ground power supply facilities, power storage systems, etc. is there. In the system and method for controlling the battery, it is possible to accurately determine the degree of deterioration of the battery, contributing to the manufacture, sale, and maintenance of the battery control system, and improving the reliability of the battery system.

DESCRIPTION OF SYMBOLS 10 Data recording part 20, 211, 212 Electric storage means 30, 31, 32 Voltage measurement means 40 Current detection means 50 State detection means 60 Charging / discharging means 70 Control command generation means

Claims (15)

In the power storage means deterioration estimation method for estimating the deterioration of chargeable / dischargeable power storage means connected to the charge / discharge means for controlling charge / discharge of the power storage means,
Measure the voltage of the power storage means,
Record the measured voltage measurement value,
Calculate the voltage fluctuation range from the maximum and minimum values of the voltage measurement values recorded in the specified period,
A method for estimating deterioration of power storage means, wherein the deterioration state of power storage means is estimated by comparing the calculated voltage fluctuation width with a reference voltage fluctuation width. The power storage means deterioration estimation method according to claim 1,
When measuring the voltage of the power storage means, measure at least one of the current flowing through the power storage means, the operating temperature of the power storage means, and the environmental temperature,
Recording the voltage measurement value in association with at least one of the current measurement value, the operating temperature measurement value, and the environmental temperature measurement value;
The voltage fluctuation range is calculated from the maximum and minimum values of the voltage measurement values stored in association with the measurement values that do not deviate from the predetermined range, and is compared with the reference voltage fluctuation range, thereby deteriorating the storage means. A method for estimating deterioration of power storage means, characterized in that The power storage means deterioration estimation method according to claim 1,
Detecting the temperature of the power storage means;
Store the voltage measurement value in association with the temperature detection value,
A method for estimating deterioration of power storage means, comprising: calculating a voltage fluctuation range from a maximum value and a minimum value of voltage measurement values associated with a temperature detection value in a predetermined temperature range. In the storage means deterioration estimation method according to any one of claims 1 to 3,
The method for estimating deterioration of power storage means, wherein the reference voltage fluctuation width is a voltage fluctuation width calculated from a maximum value and a minimum value of voltage measurement values in an initial state of the power storage means. In the electrical storage means deterioration estimation method in any one of Claims 1 thru | or 4,
When the maximum value of the voltage measurement value is greater than or equal to the maximum allowable voltage and the minimum value of the voltage measurement value is greater than the minimum allowable voltage value, the voltage of the power storage means at the next start of traveling is reduced. A method for estimating deterioration of power storage means. The power storage means deterioration estimation method according to claim 5,
A method for estimating deterioration of power storage means, comprising: reducing an allowable current value of the power storage means when the voltage fluctuation width becomes equal to or greater than the reference voltage fluctuation width by a predetermined number of operations. In a power supply device comprising a chargeable / dischargeable power storage means, a charge / discharge means for controlling charge / discharge of the power storage means,
Voltage measuring means for measuring a voltage value of the power storage means;
Recording means for recording the voltage measurement value;
A voltage fluctuation range is calculated based on the maximum and minimum voltage measurement values recorded in the recording unit during a predetermined period, and the calculated voltage fluctuation range is compared with a reference voltage fluctuation range to determine the deterioration state of the power storage unit. A power supply apparatus comprising: a deterioration determining means for determining. The power supply device according to claim 7, wherein
Current measuring means for measuring a current flowing through the power storage means;
Temperature measuring means for measuring an operating temperature of the power storage means;
An environmental temperature measuring means for measuring the environmental temperature and at least one of the measuring means;
The measurement value of the measurement unit is recorded in the recording unit in association with the voltage measurement value measured by the voltage measurement unit,
The degradation determination unit calculates a voltage fluctuation range from the maximum value and the minimum value of the voltage measurement value recorded in association with the measurement value of the measurement unit that does not deviate from a predetermined temperature range. apparatus. The power supply device according to claim 7 or 8,
It is equipped with condition specifying means that can specify the condition for judging deterioration,
The deterioration determination means extracts a voltage measurement value that matches the condition input by the condition specifying means from the recording means, calculates a voltage fluctuation range using the voltage measurement value, and determines the deterioration state of the power storage means. A power supply device characterized by determining. The power supply device according to claim 9, wherein
A power supply apparatus comprising: a display device that displays a deterioration state determined based on a condition input by the condition designating unit using a resistance increase rate or a capacity maintenance rate. The power supply device according to claim 7 or 8,
A power supply apparatus comprising: a display device that displays a warning when the deterioration state determined by the deterioration determination means exceeds a predetermined deterioration degree. The power supply device according to claim 11, wherein
The display device displays a deterioration state by a resistance increase rate or a capacity maintenance rate. In a railway vehicle provided with chargeable / dischargeable power storage means, an inverter device that receives supply of electric power from the power storage means, and an electric motor driven by the inverter device,
Voltage measuring means for measuring a voltage value of the power storage means;
Recording means for recording the voltage measurement value;
A voltage fluctuation range is calculated based on the maximum and minimum voltage measurement values recorded in the recording unit during a predetermined period, and the calculated voltage fluctuation range is compared with a reference voltage fluctuation range to determine the deterioration state of the power storage unit. A deterioration determining means for determining;
A control unit that controls the inverter device using information of the determined deterioration state;
A railway vehicle characterized by comprising: The railway vehicle according to claim 13,
Temperature detecting means for detecting the temperature of the power storage means,
The recording means records the temperature detection value in association with the voltage measurement value,
The degradation determination means is a voltage measurement value recorded in association with the temperature detection value in a predetermined temperature range, and the voltage fluctuation is caused by the maximum value and the minimum value of the voltage measurement value recorded in the recording means during a predetermined period. A railway vehicle characterized by calculating a width. The railway vehicle according to claim 13,
Current measuring means for measuring a current flowing through the power storage means;
Temperature measuring means for measuring an operating temperature of the power storage means;
Environmental temperature measuring means for measuring environmental temperature;
In addition to the voltage measurement value, the recording means for recording route information, current measurement value, power storage means temperature measurement value, environmental temperature measurement value,
The deterioration determining means extracts a voltage measurement value from the recording means within a specified range of a route, current value, power storage means temperature, and environmental temperature, and a voltage fluctuation range according to the maximum value and the minimum value of the voltage measurement value. And the ratio between the calculated voltage fluctuation width and the reference voltage fluctuation width as a deterioration index,
When the maximum value of the voltage measurement value reaches a predetermined maximum allowable voltage value and the voltage fluctuation range reaches the predetermined maximum allowable voltage value a plurality of times, the predetermined allowable current value is decreased. Railway vehicle characterized by letting

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