JP2016220445A - Voltage control device for power storage module, and voltage control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more effectively utilize capacitance that a power storage module has originally.SOLUTION: A voltage control device for a power storage module comprises: a power storage module including (n) (2≤n) pieces of power storage elements B(i) ((i) is an integer from 1 to (n)) that are connected in series; a first control part which controls a voltage of the power storage module equal to or higher than a use lower limit voltage Vuse-ud and equal to or lower than a use upper limit voltage Vuse-up; a second control part which individually controls a voltage of each of the (n) pieces of power storage elements B(i) equal to or higher than an operation guarantee lower limit voltage Vm-ud and equal to or lower than an operation guarantee upper limit voltage Vm-up; a calculation part which individually calculates a preset voltage Vs(i)(Vm≠Vs(i)) of each of the (n) pieces of power storage elements B(i) based on an equalization target voltage Vm (Vm-ud≤Vm≤Vm-up); and a charge/discharge control part which individually charges or discharges at least a part of the (n) pieces of power storage elements B(i). The calculation part calculates Vs(i) in such a manner that the (n) pieces of power storage elements B(i) are equalized by Vm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a voltage control device and a voltage control method for a power storage module including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series.

  Many power storage modules include a plurality of power storage elements connected in series. The plurality of power storage elements do not have exactly the same characteristics, but have their own characteristics. This is based on inevitable causes such as variations in manufacturing conditions and differences in the degree of deterioration. Therefore, for example, a storage element with the smallest capacity among a plurality of storage elements connected in series is likely to be overcharged or overdischarged, and deterioration is likely to proceed. As a result, the variation in characteristics between the power storage elements becomes larger.

  Therefore, Patent Document 1 proposes to equalize the current voltage of the storage element.

JP 2013-226034 A

  Usually, the voltage of a power storage module including a plurality of power storage elements connected in series is controlled to be not less than the use lower limit voltage Vuse-ud and not more than the use upper limit voltage Vuse-up. Even if the current voltage is equalized, the voltage varies in the vicinity of Vuse-ud or Vuse-up. If the power storage module is charged / discharged up to the upper and lower limits of the voltage range to be used without considering such variations, the deterioration of the power storage element having a small capacity proceeds.

  From the viewpoint of suppressing the deterioration as described above, the voltages of the plurality of power storage elements can be individually limited to be not less than the operation guarantee lower limit voltage Vm-ud and not more than the operation guarantee upper limit voltage Vm-up. However, the entire charge / discharge range of the power storage module is limited by the power storage element that first reaches the upper and lower limit voltages. As a result, the capacity originally provided in the power storage module cannot be effectively used.

  Further, equalization of the current voltage is performed by selectively discharging a storage element having a high voltage. Therefore, the equalized voltage is always lower than the current voltage, and the selection range of the equalization target voltage is small.

  In view of the above, one aspect of the present invention is a storage module including n (2 ≦ n) storage elements B (i) (i is an integer from 1 to n) connected in series, and the voltage of the storage module A first control unit for controlling the voltage of the n power storage elements B (i) to be equal to or higher than the use lower limit voltage Vuse-ud and lower than the use upper limit voltage Vuse-up. Based on the second control unit that controls the operation guaranteed upper limit voltage Vm-up or less and the equalization target voltage Vm (where Vm-ud ≦ Vm ≦ Vm-up), the n power storage elements B (i) A calculation unit that individually obtains a set voltage Vs (i) (where Vm ≠ V (i)), and at least a part of the n power storage elements B (i) toward the Vs (i) A charge / discharge control unit that individually charges or discharges, wherein the calculation unit includes the n power storage elements B (i). The present invention relates to a voltage control device for a power storage module that calculates Vs (i) so as to be equalized by Vm.

  According to another aspect of the present invention, (I) the voltage of a power storage module including n (2 ≦ n) power storage elements B (i) connected in series (i is an integer from 1 to n) A step of controlling the voltage to Vuse-ud or more and the use upper limit voltage Vuse-up or less; and (II) the voltage of the n power storage elements B (i) is individually set to the operation guarantee lower limit voltage Vm-ud or more and the operation guarantee upper limit voltage. And (III) a set voltage Vs (n) of the n power storage elements B (i) based on the equalization target voltage Vm (where Vm-ud ≦ Vm ≦ Vm-up). i) (however, Vm ≠ Vs (i)) is obtained individually, and (IV) at least a part of the n power storage elements B (i) is individually provided toward Vs (i). Charging or discharging, and the Vs (i) is calculated so that the n power storage elements B (i) are equalized by the Vm. The present invention relates to a voltage control method for a storage module.

  According to the above aspect of the present invention, the overall voltage of the power storage module is controlled to be not less than the use lower limit voltage Vuse-ud and not more than the use upper limit voltage Vuse-up, and the voltages of the plurality of power storage elements are individually set to the operation guarantee lower limit. The capacity originally provided in the power storage module can be utilized more effectively while limiting the voltage to be not less than the voltage Vm-ud and not more than the operation guarantee upper limit voltage Vm-up.

It is a circuit block diagram of an example of the voltage control apparatus which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the use lower limit voltage Vuse-ud and the use upper limit voltage Vuse-up of the voltage of an electrical storage module. It is a conceptual diagram which shows the operation | movement guarantee lower limit voltage Vm-ud and the operation | movement guarantee upper limit voltage Vm-up of the voltage of n electrical storage element B (i). It is a conceptual diagram which shows equalization of the voltage of n electrical storage element B (i) by the conventional control. It is a conceptual diagram which shows the use range of the whole voltage of the electrical storage module equalized by the conventional control. It is a conceptual diagram which shows equalization of the voltage of n electrical storage element B (i) by control which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the use range of the whole voltage of the electrical storage module equalized by control which concerns on one Embodiment of this invention. It is a flowchart of an example of the voltage control method which concerns on one Embodiment of this invention. It is an image figure which shows an example of the relationship between the charge condition (SOC) of an electrical storage element, and the electrostatic capacitance C. It is an image figure which shows an example of the conversion table which determines the electrostatic capacitance of an electrical storage element from temperature and SOC.

[Description of Embodiment of the Invention]
First, the contents of the embodiments of the invention will be listed and described.
A voltage control device for a power storage module according to the present embodiment includes a power storage module including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series, The first control unit that controls the voltage to the use lower limit voltage Vuse-ud or more and the use upper limit voltage Vuse-up or less, and the voltages of the n power storage elements individually to the operation guarantee lower limit voltage Vm-ud and the operation guarantee upper limit voltage, respectively. Based on the second control unit that controls Vm-up or less and the equalization target voltage Vm (where Vm-ud ≦ Vm ≦ Vm-up), the set voltage Vs (i) of n power storage elements (however, Vm ≠ Vs (i)) are individually calculated, and a charging / discharging control unit that individually charges or discharges at least a part of the n power storage elements toward Vs (i) is provided.

  The calculation unit calculates Vs (i) so that n power storage elements are equalized by Vm. Here, the n power storage elements being equalized by Vm means that, for example, the voltages of the n power storage elements simultaneously become Vm (or a voltage in the vicinity of Vm).

  For example, Vm is set to Vm-ud (or a voltage near Vm-ud) or Vm-up (or a voltage near Vm-up). As a result, the voltages of the n power storage elements are equalized by Vm-ud or Vm-up without greatly varying. Therefore, it becomes difficult to be restricted by the second control unit in the high voltage region or the low voltage region, and the voltage range of Vuse-ud or more and Vuse-up or less of the power storage module can be used more effectively.

  However, for example, when Vm is set to Vm-up, there is a possibility that the voltage variation becomes large in the low voltage region. On the other hand, when Vm is set to Vm-ud, there is a possibility that the voltage variation becomes large in the high voltage region. Therefore, Vm is selected so as to be suitable for the use of the power storage module and the purpose of control. For example, when there is a great demand for preventing overdischarge, Vm may be set to Vm-ud (or a voltage in the vicinity of Vm-ud).

  The voltage in the vicinity of Vx (= Vm, Vm-up or Vm-ud) is, for example, a voltage range of Vx ± Vx / 100 (that is, 0.99 Vx to 1.01 Vx). That is, when the equalization target voltage Vm is set to 2 V, for example, a variation in the equalization voltage of about ± 20 mV is allowed.

  For example, if the calculation unit calculates Vs (i) such that the difference ΔQr in the storage amount at the current voltage Vr (i) of the n storage elements B (i) approaches the difference ΔQm in the storage amount at Vm. Good. That is, due to equalization, the difference in the amount of power stored in the n power storage elements B (i) at Vs (i) approaches (or becomes equal to) ΔQm. ΔQr and ΔQm are, for example, the difference in the amount of electricity stored in each voltage between one reference storage element B (base) and the other storage element among n storage elements, and each is (n−1). ΔQr and ΔQm are calculated.

  The difference ΔQm in the storage amount at Vm of the n storage elements B (i) and the difference in the storage amount at Vs (i) are not significantly different. That is, the subsequent charging / discharging is performed in a state in which the difference in the storage amount in Vs (i) is substantially maintained. Since the same current flows through each of the n power storage elements B (i) connected in series, the increase or decrease in the amount of power stored during charge / discharge is the same. Therefore, the reliability of the equalization process based on the difference in the charged amount is high.

  The voltage control device is particularly effective when n power storage elements are each capacitors. When each of the n power storage elements is a capacitor, the calculation unit can calculate ΔQr and ΔQm using the correlation between the voltage (or SOC) of the n power storage elements and the capacitance. . A capacitor can derive its capacitance relatively accurately from its voltage (or SOC).

  Note that the actual storage amount at Vm of the storage element is, for example, about ± 2% with respect to the storage amount Qm at Vm obtained using the correlation between the voltage (or SOC) of the storage element and the capacitance. Variations are allowed.

  Next, the voltage control method of the power storage module according to the present embodiment includes (I) power storage including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series. The step of controlling the voltage of the module between the use lower limit voltage Vuse-ud and the use upper limit voltage Vuse-up, and (II) the voltage of the n power storage elements B (i) individually for the operation guarantee lower limit voltage Vm- Based on the step of controlling ud to the operation guarantee upper limit voltage Vm-up and below (III) equalization target voltage Vm (where Vm-ud ≦ Vm ≦ Vm-up), n power storage elements B (i ) Of the set voltage Vs (i) (where Vm ≠ Vs (i)), and (IV) at least part of the n power storage elements B (i) toward Vs (i) And charging or discharging each of them individually. Again, Vs (i) is calculated so that n power storage elements B (i) are equalized by Vm. According to the above method, the capacity originally provided in the power storage module can be utilized more effectively. In step (III), an appropriate Vm may be set when Vs (i) is calculated, or a preset Vm may be used.

  In step (III), for example, a step of calculating a difference ΔQm in the amount of electricity stored in Vm of n power storage elements B (i) and a current voltage Vr (i) of n power storage elements B (i) are measured. And a step of calculating the difference ΔQr in the amount of electricity stored in Vr (i) of n power storage elements B (i) and a step of calculating Vs (i) so that ΔQr approaches ΔQm.

  When n power storage elements B (i) are each capacitors, step (III) uses ΔVr and the relationship between the voltage or SOC of the n power storage elements B (i) and the capacitance. It is preferable to include a step of calculating ΔQm.

  Depending on the deterioration state of the n power storage elements B (i), the relationship between the voltage or the SOC and the capacitance may be reset in a timely manner, and Vm may be reset in a timely manner. Thereby, the reliability of the equalization process based on the difference in the charged amount can be further increased.

[Details of the embodiment of the invention]
Embodiments of the present invention will be described below with reference to the drawings as appropriate. In addition, this invention is not limited to these illustrations, is shown by the attached claim, and is intended that all the changes within the meaning and range equivalent to the claim are included. .

FIG. 1 shows a circuit configuration diagram of an example of a voltage control apparatus according to the present embodiment.
The voltage control apparatus 100 includes a power storage module 101 including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series. Resistors R (1) to R (n) and switches S (1) to S (n) for equalization processing are connected in parallel to the storage elements B (1) to B (n), respectively. .

  The power storage module 101 communicates with the module control unit 102. The module control unit 102 controls the voltage of the power storage module B (1) to B (n) and the first control unit 11 that controls the voltage of the power storage module to the use lower limit voltage Vuse-ud or more and the use upper limit voltage Vuse-up or less. A second control unit 12 that individually controls the operation guarantee lower limit voltage Vm-ud to be equal to or higher than the operation guarantee upper limit voltage Vm-up and a switch control unit 13 that individually operates the switches S (1) to S (n). It comprises. The first control unit 11 includes a first voltage sensor (not shown) that detects the voltage of the power storage module. The second control unit 12 includes a second voltage sensor that individually detects the voltages of the storage elements B (1) to B (n). The switch control unit (SW control unit) 13 individually charges the storage elements B (1) to B (n) for an arbitrary time by individually operating the switches S (1) to S (n). Or it is comprised so that it can discharge.

  The number of resistors and switches and the connection method are not limited to the example in FIG. The power storage elements B (1) to B (n) may be configured to be charged or discharged individually. The power storage elements B (1) to B (n) are devices such as capacitors and secondary batteries. The capacitor may be an electric double layer capacitor, a lithium ion capacitor, or the like. The secondary battery may be a sodium ion secondary battery, a lithium ion secondary battery, a nickel hydride storage battery, or the like. The types of the switches S (1) to S (n) are not particularly limited, and can be configured with transistors, FETs, diodes, relay switches, and the like.

  The module control unit 102 communicates with the arithmetic processing device 103, and the arithmetic processing device 103 communicates with the power storage module 101. The arithmetic processing unit 103 includes a central processing unit (CPU) and a memory unit 16. The memory unit 16 can be configured by a random access memory (RAM), a read only memory (ROM) in which an arithmetic processing program is stored, or the like. The arithmetic processing unit 103 calculates, based on Vm, a calculation unit 14 that individually obtains Vs (i) of n power storage elements B (i), and at least a part of the n power storage elements B (i), A charge / discharge control unit (or equalization processing unit) 15 that controls the charging and discharging of the power storage module 101 while individually charging or discharging each of these voltages until the current voltage Vr (i) changes to Vs (i). It comprises.

  Communication between the module control unit 102 and the arithmetic processing unit 103 is performed by a communication unit 104 capable of bidirectional communication. For example, the communication unit 104 is responsible for transmitting a control command from the arithmetic processing unit 103 to the module control unit 102 and transmitting a detected voltage value from the module control unit 102 to the arithmetic processing unit 103.

  FIG. 2 is a conceptual diagram showing the use lower limit voltage Vuse-ud and the use upper limit voltage Vuse-up of the voltage of the power storage module 101. FIG. 3 is a conceptual diagram showing the operation guarantee lower limit voltage Vm-ud and the operation guarantee upper limit voltage Vm-up of the voltages of n power storage elements. As understood from the conceptual diagrams, the voltage Vuse (Module_V) of the power storage module 101 corresponds to an integrated value of the voltages of n power storage elements.

  The n power storage elements are all regulated by the same operation guarantee lower limit voltage Vm-ud and operation guarantee upper limit voltage Vm-up. However, in practice, the performance of the n power storage elements is not the same. Therefore, when the current voltages of the n power storage elements are equalized as in the conventional case, as shown in FIG. 4, variations occur in the upper and lower limits of the voltage use range. For example, when any one of the storage elements (storage element Bmax) reaches the operation guarantee upper limit voltage Vm-up, it is considered that all n storage elements simultaneously reach the operation guarantee upper limit voltage Vm-up. The charging of the power storage module 101 is stopped. At this time, as shown in FIG. 5, the voltage Vuse of the power storage module 101 can be considerably lower than Vuse-up due to the influence of the power storage element having a voltage lower than that of the power storage element Bmax. As a result, a voltage range of Vuse-ud or more and Vuse-up or less is not fully utilized, and the power storage module 101 cannot sufficiently exhibit its performance.

  On the other hand, in FIG. 6, equalization is performed when all n power storage elements reach Vm-up. In this case, the voltages of the n power storage elements are set to Vs (i) independently and then charged to Vm, whereby equalization is performed with Vm. However, Vs (i) is calculated by the calculation unit 14 so that n power storage elements are equalized by Vm. Thereby, as shown in FIG. 7, the voltage Vuse of the power storage module 101 can be increased to Vuse-up.

  Next, the voltage control method according to the present embodiment will be described with reference to FIG. Below, the case where a capacitor is used as an electrical storage element is demonstrated. Note that the flow in FIG. 8 is merely an example, and the order of the steps, the number of steps, and the like are not limited to those in FIG. 8 and the following description.

  The starting point of the voltage control method is not particularly limited. For example, it may be started when the voltage control device is activated. When the voltage control device is activated, the current voltage Vr (i) of each power storage element is measured by the second voltage sensor of the second control unit 12 (S10). The measured Vr (i) is transmitted from the module control unit 102 to the arithmetic processing unit 103 through the communication unit 104.

  On the other hand, the calculation unit 14 sets Vm (S20). Vm is set to an appropriate value in a timely manner depending on the use and usage of the power storage module 101. Note that Vm may be set arbitrarily, and a predetermined Vm may be simply read from the memory unit 16 of the arithmetic processing unit 103.

  Next, one storage element B (base) serving as a reference is selected from the n storage elements (S11). The criteria for selecting the storage element B (base) are not particularly limited. For example, when Vm is set to the operation guarantee upper limit voltage Vm-up, it is desirable to select the storage element having the lowest current voltage. In this case, the equalization process can be normally performed by an operation of discharging power storage elements other than the power storage element B (base). The storage element B (base) is selected only when the storage element B (base) is not determined in advance or when the storage element B (base) is determined in advance but needs to be changed. Just do it.

  Next, the charged amount Qr (i) is calculated from Vr (i) (S12). In the case of a capacitor, since the current SOC and capacitance Cr (i) are derived from Vr (i), the current charged amount is calculated by Qr (i) = Cr (i) × Vr (i). The relationship between the voltage and the capacitance may be measured in advance and stored in the memory unit 16 of the arithmetic processing unit 103.

  FIG. 9 shows an example of the relationship between Cr (i) and SOC. Vr (i) and SOC are approximately proportional. However, since the relationship between the voltage and the capacitance also depends on the temperature, when the operating environment temperature range of the power storage module 101 is wide, the relationship between the SOC, the temperature, and the capacitance as shown in FIG. It is desirable to store the conversion table shown in the memory unit 16 of the arithmetic processing unit 103 and use this to calculate the storage amount Qr (i) from Vr (i). In this case, the voltage control device 100 may be provided with a temperature sensor that measures the temperature of the power storage module 101 so as to communicate with the arithmetic processing device 103.

  Next, from the calculated value of the n power storage amounts Qr (i), a difference ΔQr () between the power storage amounts of (n−1) power storage elements other than the power storage element B (base) and the power storage element B (base). i) is obtained (S13).

  On the other hand, similarly to the above, the storage amount Qm (i) at Vm of the n storage elements B (i) is calculated (S21). The SOC and the capacitance Cm (i) of the electricity storage element at Vm can be obtained from the conversion table. The amount of electricity stored Qm (i) at Vm is calculated by Qm (i) = Cm (i) × Vm. Then, similarly to the above, from the calculated value of the n power storage amount Qm (i), the power storage amount of (n−1) power storage elements other than the power storage device B (base) and the power storage device B (base) A difference ΔQm (i) is obtained (S22). If Vm and power storage element B (base) are determined in advance, ΔQm (i) can also be calculated in advance and stored in memory unit 16 of arithmetic processing unit 103.

  Next, Vs (i) is calculated so that ΔQr (i) approaches ΔQm (i) (S30). Vs (i) is calculated for (n−1) power storage elements other than the power storage element B (base). Vs (i) of the storage element B (base) may remain at the current voltage Vr (i). However, when the current consumption of the entire circuit is taken into account, Vr (i) decreases with time. Accordingly, Vs (i) may be set low.

  For example, when the difference ΔQr (j) in the storage amount between the storage element B (j) and the storage element B (base) is greater than ΔQm (j), the storage element B (base) is not discharged and the storage element B ( By discharging only j) for a certain time, ΔQr (j) approaches ΔQm (j). At this time, a charge amount represented by ΔQr (j) −ΔQm (j) = Δq (j), a relational expression of Δq (j) = Cr (j) × ΔV, and Vs (j) = Vr (j) −ΔV From the relational expression, Vs (j) can be obtained.

  However, Vs (j) may be updated with the passage of time in consideration of the current consumption of the entire circuit, the time required for equalization is estimated in advance, and Vs (j) after the lapse of time is calculated. Also good. At that time, the voltage drop of each power storage element may be calculated and reflected in Vs (j) on the assumption that the current consumption of the entire circuit flows through each power storage element.

  The current consumption of the entire circuit (hereinafter referred to as Ik) includes current consumption for equalization (hereinafter referred to as I), current consumption necessary for the operation of the module control unit 102 and the operation of the arithmetic processing unit 103, and the like. When Vs (j) is updated over time, the charge amount Δqk = Ik × Δt is obtained from Ik after every start of individual discharge for equalization, and Δqk = Cr (j) × Using the relational expression of ΔVk and the relational expression of Vs ′ (j) = Vs (j) −ΔVk, the updated Vs ′ (j) can be obtained.

  The current consumption I for equalization is the current consumption of the individual discharge means. In the case of FIG. 1, it is configured when only the switch S (j) is turned on and the other switches are turned off by the switch control unit 13. This is a current flowing through a circuit (equalized discharge circuit) including the storage element B (j), the resistor R (j), and the switch S (j). When estimating the time required for equalization before the start of individual discharge, I is calculated from the resistance of the equalization discharge circuit and Vr (j), and current I is calculated from the relational expression of Δq (j) = I × T (time). What is necessary is just to calculate time T which flows. Next, the amount of charge Δqk = Ik × T used by Ik at time T is obtained, and the relational expression of Δqk = Cr (j) × ΔVk and the relational expression of Vs ″ (j) = Vs (j) −ΔVk are obtained. By using this, it is possible to estimate Vs ″ (j) in consideration of current consumption of the entire circuit.

  Next, charge / discharge for equalization of power storage elements other than the power storage element B (base) is performed (S31). Charge / discharge for equalization is a process of charging or discharging (n−1) power storage elements B (i) to Vs (i) set to each.

  When equalization charge / discharge is performed, after that, when normal charge / discharge of the power storage module 101 is performed (S32), the n power storage elements become Vm at almost the same timing, and the voltage is equalized by Vm. The

  In normal charging / discharging, the voltage Vr (i) of n power storage elements B (i) is measured every predetermined time and compared with Vm-up (S33). If Vr (i) <Vm-up (Y), charging is continued, and then Vr (i) and Vm-ud are compared (S34). If Vr (i)> Vm-ud (Y), the discharge is continued. On the other hand, if Vr (i) ≧ Vm-up (N) in S33, charging is stopped when charging is in progress. If Vr (i) ≦ Vm−ud in S34 (N), the discharge is stopped when discharging is in progress. The same comparison is performed for all the power storage elements B (1) to B (n). Therefore, if any one of them satisfies Vr (i) ≧ Vm-up or Vr (i) ≦ Vm-ud, charging is stopped during charging and discharging is stopped when discharging. Such control is performed by the second control unit 12.

  On the other hand, the 1st control part 11 measures the voltage Vuse of the electrical storage module 101 for every predetermined time, and contrasts with Vuse-up (S35). If Vuse <Vuse-up (Y), charging is continued, and then Vuse and Vuse-ud are compared (S36). If Vuse> Vuse-ud (Y), the discharge is continued. If Vuse ≧ Vuse-up or Vuse ≦ Vuse-ud, charging is stopped when charging, and discharging is stopped when discharging.

  When the use of the power storage module is continued, the power storage element gradually deteriorates. The degree of progress of deterioration differs depending on the storage element. Therefore, it is desirable to perform reset after correcting the correlation between the voltage of the power storage element or the SOC and the capacitance (for example, the conversion table) after using the power storage module for a predetermined period. The correction method is not particularly limited, but in the case of a capacitor, the electrostatic capacity can be estimated from the voltage change (ΔV / I) of the capacitor when a current is passed for a very short time. Therefore, the correlation can be corrected and updated in a timely manner.

  As the deterioration of the storage element progresses, the guaranteed operating voltage range also changes. Therefore, after using the power storage module for a predetermined period, Vuse-ud and Vuse-up of the power storage module, Vm-ud and Vm-up of the power storage element, and Vm may be reset after being corrected and reset. desirable.

  According to the embodiment of the present invention, the capacity originally provided in the power storage module can be utilized more effectively.

  100: voltage control device, 101: power storage module, 102: module control unit, 103: arithmetic processing unit, 104: communication means, 11: first control unit, 12: second control unit, 13: SW control unit, 14: Calculation unit, 15: charge / discharge control unit, 16: memory

Claims (10)

A power storage module including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series;
A first control unit for controlling the voltage of the power storage module to be not less than the use lower limit voltage Vuse-ud and not more than the use upper limit voltage Vuse-up;
A second controller for individually controlling the voltages of the n power storage elements B (i) to be not less than the operation guarantee lower limit voltage Vm-ud and not more than the operation guarantee upper limit voltage Vm-up;
Based on the equalization target voltage Vm (where Vm−ud ≦ Vm ≦ Vm−up), the set voltage Vs (i) (where Vm ≠ Vs (i)) of the n power storage elements B (i) A calculation part to be obtained individually,
A charge / discharge control unit that individually charges or discharges at least a part of the n power storage elements B (i) toward the Vs (i),
The voltage calculation device for a power storage module, wherein the calculation unit calculates the Vs (i) so that the n power storage elements B (i) are equalized with the Vm. The calculator is
The Vs (i) is calculated so that the difference ΔQr in the storage amount at the current voltage Vr (i) of the n storage elements B (i) approaches the difference ΔQm in the storage amount at the equalization target voltage Vm. The voltage control device for a power storage module according to claim 1.   The voltage control device for a power storage module according to claim 2, wherein each of the n power storage elements B (i) is a capacitor. The calculator is
The voltage control of the power storage module according to claim 3, wherein ΔQr and ΔQm are calculated using a correlation between a voltage or a charged state of the n power storage elements B (i) and a capacitance. apparatus. (I) The voltage of a power storage module including n (2 ≦ n) power storage elements B (i) (i is an integer from 1 to n) connected in series is equal to or higher than the use lower limit voltage Vuse-ud and the use upper limit voltage. A process of controlling to below Vuse-up;
(II) controlling the voltages of the n power storage elements B (i) individually to be not less than the operation guarantee lower limit voltage Vm-ud and not more than the operation guarantee upper limit voltage Vm-up;
(III) Based on the equalization target voltage Vm (where Vm−ud ≦ Vm ≦ Vm−up), the set voltage Vs (i) of the n power storage elements B (i) (where Vm ≠ Vs (i )) For each process,
(IV) charging or discharging each of at least a part of the n power storage elements B (i) toward Vs (i),
The voltage control method for the power storage module, wherein the Vs (i) is calculated so that the n power storage elements B (i) are equalized with the Vm. The step (III)
Calculating a difference ΔQm in the amount of electricity stored in the Vm of the n power storage elements B (i);
Measuring a current voltage Vr (i) of each of the n power storage elements B (i), and calculating a storage amount difference ΔQr in the Vr (i) of the n power storage elements B (i);
The voltage control method for a power storage module according to claim 5, further comprising: calculating the Vs (i) so that the ΔQr approaches the ΔQm.   The voltage control method for a power storage module according to claim 5 or 6, wherein each of the n power storage elements B (i) is a capacitor. The step (III)
The power storage module according to claim 7, comprising a step of calculating the ΔQr and the ΔQm using a correlation between a voltage or a charged state of the n power storage elements B (i) and a capacitance. Voltage control method.   The voltage control method for a power storage module according to claim 8, further comprising a step of resetting the correlation according to a deterioration state of the n power storage elements B (i). The voltage control method for a power storage module according to claim 9, further comprising a step of resetting the Vm in accordance with a deterioration state of the n power storage elements B (i).

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