JP2016090485A - Power storage control device and vehicle drive system equipped with power storage control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily grasp deterioration state and concrete life of a power storage.SOLUTION: A power storage controller includes a power storage device and a power storage device control unit that manages state information of the battery of the power storage device. The power storage device control unit acquires the minimum value of the voltage value of the power storage device during a predetermined period from the voltage measurement value of the power storage device measured during the predetermined period to calculate history information of the minimum value of the voltage value of the power storage device during the predetermined period and usable information of the power storage device on the basis of the cumulative charging frequency of the power storage device at a time when the voltage value of the power storage device becomes minimum.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power storage control device and a vehicle drive system including the power storage control device, and is suitable for application to a power storage control device that controls the power storage device and a vehicle drive system including the power storage control device.

  As environmental regulations become stronger in various countries around the world, attention is being focused on rail transport, which has a high environmental advantage as a means of transport by land. In recent years, in particular, as a measure to reduce the environmental impact of railway vehicles traveling in non-electrified sections without overhead lines, development of new railway vehicles equipped with storage batteries typified by hybrid trains and storage battery trains, and moves toward practical application have been made. It is becoming active.

  With the recent spread of hybrid vehicles and electric vehicles, high-capacity storage batteries such as lithium ion secondary batteries and nickel metal hydride batteries have been developed as power sources for driving these batteries. Is installed.

  A storage battery changes charge state (SOC: State of Charge) and deterioration state (SOH: State of Health) by repeating charge and discharge. As the deterioration of the storage battery proceeds, the charge / discharge capacity decreases and the internal resistance of the battery increases. Therefore, the output of the battery system gradually decreases as the battery deteriorates.

  Storage batteries used in electric vehicles, railway vehicles, etc. require higher voltage and larger capacity than batteries used in small consumer devices such as mobile phones, notebook PCs, and tablet terminals. The percentage of battery cost is high. Therefore, in order to reduce the system cost, it is necessary to detect and control the battery state in order to optimize the installed battery capacity and to effectively use the battery performance.

  Furthermore, in order to suppress the running cost of the system, it is desirable that the replacement frequency of the storage battery is low. In general, the battery replacement period is often stipulated according to the battery usage period and total charge / discharge amount. However, depending on the battery usage environment and conditions, the battery can be replaced even if it can still be used. It can happen. Therefore, it is desired to suppress the running cost of the system by accurately understanding the deterioration state of the storage battery and replacing the battery at an appropriate timing.

  As a method for detecting the deterioration state of the storage battery, in a hybrid vehicle, for example, as described in Patent Document 1, a technique of measuring the internal resistance of the battery can be cited. In Patent Literature 1, the current and voltage at the time when the state of charge (SOC) of the storage battery is estimated to be the same are measured, and based on the measured values of the voltage and current at the time of discharging and charging, A method for detecting internal resistance is disclosed.

Patent Document 2 discloses a method for detecting a deterioration state of a storage battery particularly for a rail vehicle. In Patent Document 2, the current, surface temperature, voltage, and environmental temperature of the power storage means when traveling on a railroad vehicle whose driving method is determined in advance are recorded, and the difference ΔV between the maximum voltage and the minimum voltage is set as an initial value ΔV _ini In comparison, it is disclosed that the deterioration level of the storage battery is calculated by comparison with a threshold value ΔV _th , control is performed based on the deterioration level, and the deterioration level and an inspection warning are displayed on the cab.

JP 2000-21455 A JP 2012-13472 A

  In the above-mentioned Patent Document 1, the battery voltage during discharging and charging and the corresponding current are utilized by utilizing the feature of the hybrid vehicle that vehicle acceleration / deceleration frequently occurs and switching between charging and discharging of the storage battery occurs frequently. A plurality of values are collected and the internal resistance of the battery is calculated based on the information. However, railcars and electric vehicles are required to have a large current, and the frequency of switching between charging and discharging of batteries is lower than that of hybrid vehicles, and the duration of discharging or charging to storage batteries is long. For this reason, it is difficult to obtain the same amount of data as that of a hybrid vehicle in a railway vehicle or an electric vehicle, and the method of Patent Literature 1 may not be able to accurately determine the deterioration state (SOH) of the battery.

  Further, in Patent Document 2, in a railway vehicle that frequently performs a predetermined operation regularly, deterioration of the storage battery can be grasped from the measurement data of the storage battery obtained during traveling. However, as described above, in a large-scale system such as a railway vehicle, there are inconveniences such as a large number of man-hours for battery replacement and inability to operate the vehicle during the battery replacement period. In addition, it is desired to grasp the specific battery replacement time, that is, the remaining life of the storage battery.

  The present invention has been made in consideration of the above points, and will propose a power storage control device capable of easily grasping a deterioration state and a specific remaining life of a storage battery and a vehicle drive system equipped with the power storage control device. It is what.

  In order to solve this problem, the present invention includes a power storage device and a power storage device control unit that manages battery state information of the power storage device, wherein the power storage device control unit Based on the history information of the minimum value of the voltage value and the cumulative number of charging times of the power storage device at the time when the voltage value of the power storage device is minimum, the usable information of the power storage device is calculated. A power storage control device is provided.

  In order to solve this problem, in the present invention, a power storage device capable of charging / discharging DC power, a power conversion device that converts power supplied from an overhead wire into DC power, and an output from the power storage device or the power conversion device An inverter device that converts the DC power to be converted into AC power, a motor driven by the AC power converted by the inverter device, and a power storage device controller that manages battery state information of the power storage device, The power storage device control unit is configured to store the power storage device based on history information of a minimum value of the voltage value of the power storage device in a predetermined period and a cumulative charge count of the power storage device when the voltage value of the power storage device is minimum. A vehicle drive system equipped with a power storage control device is provided, characterized in that the device availability information is calculated.

  According to the present invention, the deterioration state of the storage battery and the remaining life of the storage battery can be calculated by a simpler method.

1 is a block diagram showing an overall configuration of a storage battery train system according to an embodiment of the present invention. It is a block diagram which shows the function structure of the electrical storage apparatus control part concerning the embodiment. It is the schematic diagram which showed the voltage waveform of the storage battery concerning the embodiment. It is a flowchart which shows the process of the minimum voltage extraction part concerning the embodiment. It is a chart which shows the data table recorded on the 1st data holding part concerning the embodiment. It is a flowchart which shows the process of the 1st data selection part concerning the embodiment. It is a conceptual diagram which shows the relationship between the temperature and internal resistance of the storage battery concerning the embodiment. It is a block diagram which shows the structure of the 2nd data selection part concerning the embodiment. It is a flowchart which shows the process of the employment data selection part concerning the embodiment. It is a conceptual diagram explaining the detail of the process which the adoption data selection part concerning the embodiment performs. It is a graph which shows the data table recorded on the 2nd data holding part concerning the embodiment. It is a flowchart which shows the process of the remaining life calculation part concerning the embodiment. It is a conceptual diagram explaining the calculation content which the remaining life calculation part concerning the embodiment performs.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) Outline of the present embodiment First, the outline of the present embodiment will be described. In Patent Document 1 described above, the internal resistance of the battery is detected while the vehicle is running. Since a hybrid vehicle normally starts running immediately after the engine is started, the detection of the internal resistance of the battery is detected and calculated while the vehicle is running.

  As described above, in a hybrid vehicle, the vehicle is frequently accelerated and decelerated, so that the battery is frequently switched between charging and discharging. Furthermore, since the current rate at which the battery is charged and discharged is as high as, for example, 1 C rate or more, battery voltage fluctuations accompanying current input / output are large. Here, 1C is a current value at which the battery cell having the capacity of the nominal capacity value is subjected to constant current discharge and discharge is completed in one hour. In Patent Document 1, the internal resistance of the battery is detected and calculated while the vehicle is running, and the current and voltage fluctuation characteristics are used to collect a plurality of battery voltages during discharging and charging and corresponding current values. The internal resistance of the battery is calculated based on the information.

  On the other hand, the current flowing through a storage battery mounted on a railway vehicle, an electric vehicle or the like is different in characteristics from the current flowing through the storage battery of the hybrid vehicle described above. Specifically, a railway vehicle or an electric vehicle is required to have a larger current. Further, the frequency of switching between charging and discharging of the battery is lower than that of the hybrid vehicle, and the duration of discharging or charging is long for the storage battery. For this reason, it is difficult to obtain the same amount of data as that of a hybrid vehicle by using a method that calculates the internal resistance of a battery by collecting a large amount of both battery discharge and charge data while the vehicle is running. However, there is a problem that the deterioration state (SOH) of the battery cannot be obtained with high accuracy.

  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 necessarily 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., current measurement error affects the integrated value. Therefore, current measuring means must be highly accurate, and a highly accurate value can be obtained while suppressing costs. There was a problem that was difficult.

  In general, the value of the internal resistance varies depending on the battery temperature even if the deterioration degree of the battery is the same. Therefore, a method of obtaining the deterioration degree information by correcting the internal resistance value based on the temperature information of the battery is considered. It is done. However, in this case, what can actually be measured as temperature information is the surface temperature of the battery. When the battery is charged / discharged, such as when the vehicle is running, the battery itself generates heat, and a temperature distribution is generated inside or on the surface of the battery cell. Therefore, when the surface temperature of the battery is adopted as a value for correcting the internal resistance of the battery, the surface temperature is not always the correct temperature, and an error occurs in the internal resistance calculation based on temperature information during traveling.

In the above-mentioned Patent Document 2, it is assumed that a deterioration state of a storage battery mounted on a hybrid railway vehicle is mainly detected, and an attempt is made to solve the above-described problem that occurs when measuring the internal resistance of the battery while the vehicle is running. A method of measuring the deterioration of the resin by a simple method is disclosed. That is, in a railway vehicle that often performs predetermined driving regularly, the same traveling is obtained from measured data 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. A method is adopted in which the maximum value and the minimum value of the storage means voltage during operation on the route are recorded, and deterioration is determined using the difference ΔV as an index. Furthermore, a method is adopted in which the deterioration of the power storage means is determined by comparing the difference ΔV _ini between the maximum value and the minimum value of the power storage means voltage at the initial stage of travel on a specific route with ΔV during travel.

  However, in the above prior art, only the deterioration state of the storage battery due to the increase in the internal resistance of the storage battery can be determined. The deterioration state of the storage battery needs to be determined in consideration of both the case where the increase in the internal resistance of the storage battery is a factor and the case where the decrease is the storage battery capacity. Moreover, not only the deterioration state of a storage battery but the information regarding the concrete remaining life of how long a storage battery can be used is desired. This is because, in a large-scale system such as a railway vehicle, man-hours required for battery replacement are large, and the vehicle cannot be operated during the battery replacement period, so adjustment such as substituting another vehicle is necessary. Because. If the specific replacement time of the storage battery is known in advance, the railway system can be smoothly operated.

  Therefore, in this embodiment, based on the history information of the minimum value of the storage battery for a predetermined period, the deterioration state of the storage battery due to the internal resistance and capacity reduction of the storage battery is estimated, and further, the history information of the minimum value of the storage battery for the predetermined period In addition, it is possible to more easily calculate a specific remaining life from the cumulative number of charging times.

(2) Configuration of Storage Battery Train System Next, the configuration of the storage battery train system according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the overall configuration of the storage battery train system. The storage battery train system includes a storage battery train 10 and a ground charging facility 30 for charging a storage battery (not shown) in a power storage device 14 mounted on the storage battery train 10.

  The storage battery train 10 includes a power conversion device 11, an inverter 12, a motor 13, and a power storage device 14, and includes an overall control unit 16 and a power storage device control unit 15 as control devices that control these operations.

  The power conversion device 11 is electrically connected to the overhead line 20 via the pantograph 21 at a stop station where the electrified section (overhead section) and the ground charging facility 30 are installed. The power converter 11 receives the power supplied from the overhead wire 20 as input, converts it into DC power corresponding to the command power from the overall control unit 16, and outputs the DC power.

  The inverter 12 receives DC power output from the power conversion device 11 and the power storage device 14 as input, converts this into three-phase AC power, and outputs the converted power. The motor 13 is an induction motor, which receives the three-phase AC power output from the inverter 12 and converts it into shaft torque. The shaft torque is applied to the wheel axle (not shown) to drive the battery train 10. . The inverter 12 controls the variable voltage and the variable frequency so that the output torque of the motor 13 becomes the torque commanded by the overall control unit 16.

  Power storage device 14 is electrically connected to a direct current section between power conversion device 11 and inverter 12. The power storage device 14 is composed of an assembled battery (not shown) in which battery cells are combined in multiple series and multiple parallels in order to obtain a voltage and storage capacity necessary for the system. As a specific example, when a lithium ion secondary battery is used as a battery cell, the voltage of one cell of this battery is about 3.6 V, and for example, a DC voltage of about 720 V can be obtained by connecting 200 cells in series. can get. By further connecting a plurality of assembled batteries connected in series in parallel, the battery capacity of the power storage device can be increased.

  The power storage device 14 includes sensing means (not shown) for acquiring battery voltage information, current information, and temperature information. The power storage device 14 transmits each piece of battery information detected by the sensing means to the power storage device control unit 15.

  Based on the battery voltage information, current information, and temperature information transmitted from the power storage device 14, the power storage device control unit 15 is configured to charge a battery (SOC: State of Charge), internal resistance, Battery state information such as a state of health (SOH) or allowable charge / discharge power is calculated, and the battery state information is transmitted to the overall control unit 16.

  The overall control unit 16 charges and discharges the power storage device 14 based on a driving command from the vehicle driver and battery state information (such as a charged state, a deteriorated state, or chargeable / dischargeable power) from the power storage device control unit 15. To decide. The overall control unit 16 issues an operation command to each of the power conversion device 11 and the inverter 12 so that the power storage device 14 performs desired charging / discharging.

  The ground charging facility 30 includes a transformer, a converter, and the like (not shown). The ground charging facility 30 converts power from a distribution line (not shown) into desired AC power or DC power and supplies it to the overhead line 20.

  The operation of the storage battery train system having the above-described configuration will be described below by dividing it into an electrified section (overhead section) and a non-electrified section (non-overhead section).

  In the electrified section, that is, the overhead line section, the electric power supplied from the overhead line 20 via the pantograph 21 is stepped down by the power converter 11 and supplied to the inverter 12 as the traveling power of the storage battery train 10. Moreover, when SOC of a storage battery is low, a part of electric power supplied from the overhead wire 20 is utilized for charge of a storage battery. In addition, the regenerative power during braking is used for charging the storage battery, but when the SOC of the storage battery is high, it is used for regeneration to the overhead line 20.

  When charging the storage battery of the power storage device 14 at a station where the ground charging facility 30 is installed, as shown in FIG. 1, the pantograph 21 is raised to electrically connect the ground charging facility 30 via the overhead line 20. Then, the power storage device 14 is charged.

  On the other hand, since there is no overhead line 20 in the non-electrified section, that is, the non-overhead section, the overall control unit 16 stops the operation of the power converter 11. At this time, only DC power from the power storage device 14 is supplied to the inverter 12 as traveling power. In addition, regenerative power during braking is used for charging the storage battery, but when the SOC of the storage battery is high, the regenerative energy is discharged as heat.

  Next, the operation and function of the power storage device control unit 15 according to the present invention will be described in detail. As a premise for the following explanation, it is assumed that the storage battery train 10 continuously operates on a specific route section every day.

  FIG. 2 is a block diagram showing a functional configuration of the power storage device control unit 15 and a signal flow. The power storage device control unit 15 includes an input processing unit 100, an output processing unit 200, a minimum voltage extraction unit 300, a first data holding unit 400, a first data selection unit 500, a second data selection unit 600, and second data. A holding unit 700 and a remaining life calculation unit 800 are provided. In addition to these, calculation units for calculating battery state information such as battery SOC and allowable charge / discharge power may be included, but these calculation units are omitted below.

  The input processing unit 100 receives sensing information such as battery voltage, temperature, or current transmitted from the power storage device 14, performs necessary processing such as A / D conversion, and sends the information to other processing units. send. Further, the input processing unit 100 receives a charging start signal and a charging end signal when the power storage device 14 is charged by the ground charging facility 30 from the overall control unit 16, and sends this signal to other processing units.

  The output processing unit 200 transmits battery state information calculated by each processing unit in the power storage device control unit 15 to the overall control unit 16 via necessary means such as communication means.

  The minimum voltage extraction unit 300, the first data holding unit 400, the first data selection unit 500, the second data selection unit 600, the second data holding unit 700, and the remaining life calculation unit 800 are stored in the storage battery 14. In order to calculate the deterioration state and the remaining life, it has a function of sequentially performing various calculations. Hereinafter, each part will be described in detail.

  The minimum voltage extraction unit 300 extracts the minimum value of the storage battery voltage output from the power storage device 14 while the storage battery train 10 travels on a specific route section. A specific operation of the minimum voltage extraction unit 300 will be described with reference to FIGS.

FIG. 3 is a schematic diagram illustrating a voltage waveform of the storage battery output from the power storage device 14 to the power storage device control unit 15. In the example of FIG. 3, the power storage device 14 is charged while the storage battery train 10 is stopped at the charging station where the ground charging facility 30 is installed. After the charging is completed, the storage battery train 10 travels between non-electrified routes between the stations. The voltage waveform of the storage battery until it returns to and is charged is shown. During running between multiple stations, power running and regeneration are repeated, so the voltage of the storage battery fluctuates up and down, but since the storage battery is not charged from the overhead line during traveling, the voltage of the storage battery gradually decreases . Further, FIG. 3 shows that the storage battery voltage is minimum (V _min ) in the traveling period between the stations at time t.

  Railway vehicles have a predetermined route, service pattern, and charging method at the charging station. Therefore, a certain vehicle repeatedly travels on the same route section, and the battery is charged by the same charging method every time at the charging station. Therefore, it is expected that the voltage waveform of the storage battery has a similar voltage waveform. It is expected that the voltage value is minimized at the same timing every time. In the present embodiment, the above-mentioned property unique to the railway vehicle, that is, the fact that the voltage waveform of the storage battery has the same shape every time is used.

  In the above, the minimum value of the voltage of the storage battery in the predetermined section or the predetermined period is recorded, but the present invention is not limited to this example. As described above, in the predetermined section, the voltage waveform of the storage battery has a similar shape. For example, the minimum value of the voltage in a predetermined section may be calculated from the voltage value at a certain timing based on a voltage waveform that can be grasped in advance. For example, a minimum value in a section with little variation in voltage value may be acquired based on an operation pattern of a railway vehicle, and the voltage in a predetermined section may be estimated from the minimum value.

  FIG. 4 is an example of a flowchart showing processing of the minimum voltage extraction unit 300. As illustrated in FIG. 4, when the minimum voltage extraction unit 300 receives a charge end signal from the input processing unit 200 (S301), the voltage V, current I, and temperature T of the storage battery output by the power storage device 14 are time-series data. (S302). In step S302, the minimum voltage extraction unit 300 may record time-series data every second, for example.

When the minimum voltage extraction unit 300 receives a travel end or charge start signal from the input processing unit 200 (S303), the minimum voltage extraction unit 300 extracts the minimum voltage value (minimum value _Vmin ) from the voltage data recorded in step S302. (S304). For example, when the minimum value V _min is recorded at time t, the current I (t) and temperature T (t) at the same time t are extracted together. Then, the minimum voltage extraction unit 300 transmits and outputs the minimum voltage V _min extracted in step S304, the current I (t) and the temperature T (t) at the same time to the first data holding unit 400 (S305).

The minimum voltage extraction unit 300 performs the processing from step S301 to step S305 every time the vehicle is in operation, and each time the minimum voltage V _min , current I, and temperature T are extracted, the first data holding unit 400 described below. Send to.

The first data holding unit 400 has a function of recording the minimum voltage V _min , current I (t), and temperature T (t) output from the minimum voltage extraction unit 300. The first data holding unit 400 includes a RAM (Random Access Memory) that performs temporary recording, and a ROM (Read that records operation data).
Only Memory) and at least one rewritable large-capacity recording medium.

FIG. 5 shows an example of a data table recorded in the first data holding unit 400. The first data holding unit 400 sets a set of the minimum voltage V _min 412, the current I (t) 413, and the temperature T (t) 414 output from the minimum voltage extraction unit 300 described above for each data acquisition, and sets the data No 411. Then, the data is stored in the data table 410.

  Next, the function of the first data selection unit 500 will be described. The first data selection unit 500 has a role of a filter that passes only data that is equal to or higher than a preset temperature threshold.

FIG. 6 is an example of a flowchart showing processing of the first data selection unit 500. First, the first data selection unit 500 reads the nth minimum voltage V _min (n), current I (n), and temperature T (n) from the data table recorded in the first data holding unit 400 ( S501). Next, the preset temperature threshold value _Tth is compared with the read temperature T (n) (S502).

When it is determined in step S502 that T (n) is equal to or higher than the temperature threshold T _th , the first data selection unit 500 selects the minimum voltage V _min (n) and the current I (n) as the second data selection. To the unit 600. On the other hand, if it is determined in step S502 that T (n) is less than the temperature threshold T _th , the first data selection unit 500 ends the process for the nth data.

Here, the reason why the determination process of step S502 is provided in the process of FIG. 6 will be described. In the present embodiment, the power storage device control unit 15 _pays attention to the minimum voltage _Vmin in the information obtained from the power storage device 14, and calculates the deterioration state and remaining life of the storage battery based on this. A method for calculating the deterioration state and remaining life of the storage battery will be described in detail later.

V _min is a battery voltage when the battery is discharged, and this voltage value is a value obtained by subtracting a potential difference applied to the internal resistance of the battery when energized from the open circuit voltage (OCV) of the battery. As the battery deteriorates, this internal resistance increases. Therefore, even if the same current flows through the battery, the potential difference applied to the internal resistance increases and _Vmin decreases. Therefore it is possible to grasp the deteriorated state of the battery from lowering properties of V _min.

  However, it is generally known that the value of the internal resistance changes depending on the battery temperature even if the deterioration state of the battery is the same. FIG. 7 is a characteristic example showing the relationship between the temperature of the storage battery mounted on the power storage device 14 and the internal resistance. Here, the vertical axis represents the resistance ratio based on the internal resistance at a temperature of 25 ° C. Generally, the lower the battery temperature, the higher the internal resistance, and conversely, the higher the battery temperature, the lower the internal resistance. In addition, as shown in FIG. 7, the amount of change in internal resistance with respect to temperature change in the low temperature region is large, whereas in the region of 25 ° C. or more, the value of internal resistance changes almost even when the temperature changes. It is known not to.

As described above, when the battery is at a low temperature, the value of the internal resistance greatly changes due to the temperature change. Therefore, it is determined whether the internal resistance changes due to the deterioration of the battery or whether the internal resistance changes due to the temperature change. It becomes difficult. As shown in FIG. 7, when the battery temperature is 25 ° C. or higher, the internal resistance change due to the temperature change is small. Therefore, in order to reduce the influence of changes in internal resistance due to temperature changes as much as possible, it is desirable that the battery temperature be high. Therefore, the threshold value _Tth in step S502 in the flowchart shown in FIG.

Next, the function of the second data selection unit 600 will be described. While the first data selection unit 500 selects data according to the battery temperature condition, the second data selection unit 600 selects data according to the current value and calculates the minimum voltage calculation value V _b used in the subsequent processing. Is output to the second data holding unit 700.

The purpose of the data selection process by the second data selection unit 600 is to reduce the variation error of the minimum voltage V _min used in the calculation by the remaining life calculation unit 800 described later. The magnitude of the current value at the timing when the minimum voltage V _min is obtained is expected to vary within a certain range. This is because even if a battery train repeatedly travels on the same route section, the load on the battery changes due to various factors such as differences in driving methods by drivers, differences in weather conditions, differences in boarding rates, etc. Because. By excluding the minimum voltage when the current value is extremely large or small by the calculation in the subsequent processing unit, it is possible to improve the accuracy of the battery deterioration information obtained from _Vmin .

  FIG. 8 is a block diagram showing a configuration of the second data selection unit 600 and a signal flow. The second data selection unit 600 includes an adopted data selection unit 610 and a minimum voltage calculation unit 620 therein. Hereinafter, functions of each unit will be described.

  The adopted data selection unit 610 has a function of reading the current value information I (n) transmitted from the first data selection unit 500 and testing whether there is a jump value. An example of a specific process is demonstrated with reference to FIG.9 and FIG.10.

  FIG. 9 is an example of a flowchart showing processing of the employment data selection unit 610. In the present embodiment, an operation of receiving the past 10 measurement data I (1) to I (10) from the first data selection unit 500 will be described as an example, but the number of data to be referred to is the past 5 times or the past 20 times. Etc. may be appropriately changed.

  The adopted data selection unit 610 reads the values of measurement data I (1) to I (10) for the past 10 times in a predetermined section (S611), and calculates an average value μ of I (1) to I (10). (S612). Further, the adopted data selection unit 610 calculates the standard deviation σ of I (1) to I (10) from the calculated average value μ and the read ten current values (S613). Then, the adopted data selection unit 610 transmits the data number in which the current value I (n) is between μ−σ and μ + σ to the minimum voltage calculation unit 620 (S614).

  Details of processing executed by the employment data selection unit 610 shown in FIG. 9 will be described with reference to FIG. Assume that ten pieces of current value data I (1) to I (10) have a magnitude relationship as shown in FIG. The average value μ of the current value data I (1) to I (10) is the position of the dotted line B, the standard deviation is σ, μ + σ is the position of the dotted line A, and μ−σ is the position of the dotted line C. . At this time, the adopted data selection unit 610 has a data number in a range between the dotted line A and the dotted line C, that is, I (1), I (2), I (3), I (4), I (6). , I (8), I (9), I (10) are transmitted to the minimum voltage calculation unit 620. The current data I (5) and I (7) above the dotted line A or below the dotted line C are excluded from the selection data as outliers compared to other data.

The minimum voltage calculation unit 620 is the minimum corresponding to the data number selected by the adopted data selection unit 610 among the ten minimum voltages V _min (1) to V _min (10) read from the first data selection unit. These average values are calculated using only the voltage value data, and this average value is output to the second data holding unit 700.

In the example shown in FIG. 10, since the current values I (5) and I (7) are excluded as outliers, only 8 data excluding data numbers 5 and 7 are valid. That is, V _min (1), V _min (2), V _min (3), V _min (4), V _min (6), V _min (8), V _min (9), and V _min (10) a total of eight voltage data becomes valid and calculates an average value V _b of the eight voltage data. Then, V _b is output to the second data holding unit 700 described later.

  In this embodiment, as an example of the processing of the second data selection unit 600, the outlier of the current value is tested using the average value μ and the standard deviation σ of the current value. The data may be selected by another method as long as the method reduces the error.

Next, the function of the second data holding unit 700 will be described. Second data holding unit 700, the minimum voltage calculation value V _b output from the second data selection unit 600 described above, is recorded together with the cumulative operation times of the data acquisition date and initial. Here, the cumulative number of operations is equivalent to the cumulative number of charges in the power storage device 14.

FIG. 11 shows an example of a data table recorded in the second data holding unit 700. As illustrated in FIG. 7, the second data holding unit 700 includes the date 511 of the data acquisition date, the cumulative operation count 512 from the initial stage to the data acquisition date, and the minimum voltage calculation value V _b output from the second data selection unit 600. The set of 513 is stored in the data table 510.

  In general, the deterioration of a storage battery is not a one-time operation of a storage battery train, i.e., running between a plurality of stations after the storage battery is charged, and a difference can not be clearly detected in a short period until the next charging, Deterioration gradually progresses in several tens of times. Therefore, the addition of data to the second data holding unit 700 is not necessarily performed every day, and may be performed once a week, for example.

  Next, the function of the remaining life calculation unit 800 will be described. The remaining life calculation unit 800 refers to the data table 510 recorded in the second data holding unit 700 described above, calculates the deterioration state of the storage battery of the power storage device 14 and the estimated remaining life, and outputs the information. Output to the unit 200.

FIG. 12 is an example of a flowchart showing processing of the remaining life calculation unit 800. As shown in FIG. 12, the remaining life calculation unit 800 first reads data stored in the second data holding unit 700 (S801). The data read in step S801 is all of the data table shown in FIG. 11 or data of the cumulative number of past operations and the minimum voltage calculation value corresponding thereto from the latest date. Hereinafter, as the latest value of the data read from the second data holding unit 700 by the remaining life calculation unit 800, the cumulative number of operations is expressed as n _c and the corresponding minimum voltage calculation value is expressed as V _bc .

  Next, the remaining life calculation unit 800 calculates a linear regression equation based on the m variables of the cumulative operation count and the minimum voltage calculation value, which are the two variables read in step S801 (S802). Specifically, the regression line is expressed by equation (1), and the constant term α and the regression coefficient β are calculated.

Then, the remaining life calculation unit 800 calculates the maximum number of use N _{max according} to the equation (2) based on the constant term α, the regression coefficient β, and the end-of-use voltage V _EOL calculated in step S802 (S803).

Incidentally, the end voltage V _EOL has a maximum power P _max which battery train is required mainly during powering is calculated from the maximum permissible current I _max which can be energized to the battery by the equation (3).

Note that P _max and I _max are both predetermined values depending on the specifications of the vehicle and the storage battery. Therefore, _VEOL is set as a specified value.

Then, the remaining life calculation unit 800 calculates the estimated remaining life value N _{L according} to the following expression (4) from the maximum use number N _max obtained by the above expression (2) and the latest cumulative operation number n _c ( S804).

Here, with reference to FIG. 13, the values calculated in steps S801 to S803 by the remaining life calculation unit 800 will be described. FIG. 13 is a graph in which the horizontal axis represents the cumulative number of operations and the vertical axis represents the minimum voltage calculation value, and the data read from the second data holding unit 700 by the remaining life calculation unit 800 is plotted with diamond marks. . Further, it is assumed that the regression line (the above formula (1)) obtained based on the plotted values is a straight line indicated by a dotted line in the figure. At this time, the above maximum number of uses N _max is the value of the x coordinate when the y coordinate of the regression line becomes _VEOL . Further, the remaining life estimated value N _L is the length of the bidirectional arrow described in FIG. 13, that is, a value corresponding to the above equation (4).

Returning to FIG. 12, in step S <b> 804, the remaining life calculation unit 800 outputs to the output processing unit 200 the minimum voltage calculation value _Vbc in the latest data, together with the estimated remaining life value N _L calculated by the above equation (4). To do.

Then, the output processing unit 200 transmits the minimum voltage calculated value V _bc and the remaining life estimated value N _L calculated by the calculation in each processing unit of the power storage device control unit 15 to the overall control unit 16.

(3) Effects of this Embodiment The operations and processes executed by the power storage device control unit 15 have been described above. By the above processing, the overall control unit 16 grasps how long (or the number of times) the storage battery mounted on the storage battery train 10 can be used, that is, the remaining life when it continues operating on the same route. be able to. In addition, the deterioration state of the battery can be grasped by seeing how much the minimum voltage calculation value has decreased compared to the initial use.

  In the system and method for controlling the battery, it is possible to accurately obtain the deterioration state of the battery, contribute to the manufacture, sale and maintenance of the battery control system, and improve the reliability of the battery system.

(4) Other Embodiments The storage battery according to the present invention is not limited to a lithium ion secondary battery, but is composed of chargeable / dischargeable storage elements such as a nickel metal hydride battery, a lead storage battery, an electric double layer capacitor, and a lithium ion capacitor. Applicable to all battery systems. By applying the present invention, these battery systems can be used, and in a system that travels on a route in which current input / output patterns are almost determined, such as a large-scale railway vehicle, ground power supply facility, power storage system, etc. The battery system can be stably maintained.

DESCRIPTION OF SYMBOLS 10 Storage battery train 11 Power conversion device 12 Inverter 13 Motor 14 Power storage device 15 Power storage device control part 16 General control part 20 Overhead wire 21 Pantograph 30 Ground charging equipment 100 Input processing part 200 Output processing part 300 Minimum voltage extraction part 400 1st data holding part 500 First data selection unit 600 Second data selection unit 700 Second data holding unit 800 Remaining life calculation unit

Claims (10)

A power storage device;
A power storage device controller that manages battery state information of the power storage device;
With
The power storage device controller is
Based on the history information of the minimum value of the voltage value of the power storage device for a predetermined period and the accumulated number of times of charging of the power storage device at the time when the voltage value of the power storage device becomes the minimum, the availability information of the power storage device is calculated A power storage control device comprising: The power storage device controller is
2. The minimum value of the voltage value of the power storage device is used as history information when the temperature of the power storage device at the time when the voltage value of the power storage device is minimum is within a predetermined temperature range. The power storage control device described in 1. The power storage device controller is
The minimum value of the voltage value of the power storage device is used as history information when the current value of the power storage device at the time when the voltage value of the power storage device is minimum is within a predetermined current range. The power storage control device according to any one of 1 and 2. The power storage device controller is
The minimum value of the measured voltage value of the power storage device measured during the predetermined period and the temperature and current value of the power storage device at the time when the voltage value of the power storage device is minimized are recorded as the history information. The electrical storage control apparatus in any one of Claims 1-3 characterized by these. The power storage device controller is
From the voltage measurement value of the power storage device measured during the predetermined period, obtain the minimum value of the voltage value of the power storage device during the predetermined period,
Based on the history information of the minimum value of the voltage value of the power storage device and the cumulative number of charging times of the power storage device at the time when the voltage value of the power storage device is minimum, the usable period or the usable amount of the power storage device is determined. The power storage control device according to claim 1, wherein the power storage control device is estimated. A power storage device capable of charging and discharging DC power; and
A power conversion device that converts the power supplied from the overhead line into DC power;
An inverter device for converting direct current power output from the power storage device or the power conversion device into alternating current power;
A motor driven by AC power converted by the inverter device;
A power storage device controller that manages battery state information of the power storage device;
With
The power storage device controller is
Based on the history information of the minimum value of the voltage value of the power storage device for a predetermined period and the accumulated number of times of charging of the power storage device at the time when the voltage value of the power storage device becomes the minimum, the availability information of the power storage device is calculated A vehicle drive system equipped with a power storage control device. The power storage device controller is
The minimum value of the voltage value of the power storage device is used as history information when the temperature of the power storage device at the time when the voltage value of the power storage device is minimum is within a predetermined temperature range. The vehicle drive system which mounts the electrical storage control apparatus of description. The power storage device controller is
The minimum value of the voltage value of the power storage device is used as history information when the current value of the power storage device at the time when the voltage value of the power storage device is minimum is within a predetermined current range. A vehicle drive system equipped with the power storage control device according to any one of 6 and 7. The power storage device controller is
The minimum value of the measured voltage value of the power storage device measured during the predetermined period and the temperature and current value of the power storage device at the time when the voltage value of the power storage device is minimized are recorded as the history information. A vehicle drive system equipped with the power storage control device according to any one of claims 6 to 8. The power storage device controller is
From the voltage measurement value of the power storage device measured during the predetermined period, obtain the minimum value of the voltage value of the power storage device during the predetermined period,
Based on the history information of the minimum value of the voltage value of the power storage device and the cumulative number of charging times of the power storage device at the time when the voltage value of the power storage device is minimum, the usable period or the usable amount of the power storage device is determined. A vehicle drive system equipped with the power storage control device according to claim 6.