JP2016010192A - Current distribution control device for parallel power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a large heat loss in the whole parallel power storage system because a method for suppressing a heat loss accompanying charge/discharge considering a large scale parallel power storage system is not provided for the conventional parallel power storage system.SOLUTION: A current distribution controller in a parallel power storage system in which one or more auxiliary batteries are connected in parallel to a main battery evaluates heat losses in the whole parallel power storage system including a DCDC converter and minimizes, on the basis of the evaluation, the sum total of the heat losses in the whole parallel power storage system. The current distribution controller can prevent overcharge/overdischarge or overcurrent in each auxiliary battery, and implement effective use of the auxiliary battery, an energy saving effect, and suppression of battery deterioration.

Description

  The present invention relates to a parallel power storage system, and more specifically, is mounted to determine a current distribution to each battery in a parallel power storage system in which one or more auxiliary batteries are connected in parallel to a main battery via a converter. The present invention relates to a current distribution control device.

Conventionally, for example, in Patent Document 1, in a current distribution control device of a parallel power storage system, current distribution is determined based on a battery temperature based on a technology for equalizing each battery temperature by determining current distribution based on the battery temperature. A technique for making the state of charge of each battery uniform by making a determination is disclosed.
Patent Document 2 proposes a technique of determining current distribution of two batteries so that heat loss is minimized in a current distribution control device of a parallel power storage system.

JP 2008-154302 A JP 2011-50153 A

  However, the current distribution technique for making the battery temperature uniform in Patent Document 1 described above causes a bias in the current distribution when the heat capacity is different for each battery, resulting in a large heat loss when viewed as a whole parallel power storage system. There was a problem that. Furthermore, in general, there is a time lag before the change in the battery internal temperature appears as the change in the battery surface temperature. Therefore, when the measured value of the battery surface temperature is used as the battery temperature, the battery internal temperature may change rapidly. There was also a problem that it could not be handled.

  In addition, the current distribution technique for equalizing the state of charge of the battery in the above-mentioned document 1 is based on a specific battery (for example, a low output) when batteries having different characteristics (for example, a low output battery and a high output battery) are connected in parallel. There is a problem that the burden on the battery) is increased, leading to deterioration, and heat loss of the entire parallel power storage system is increased.

  On the other hand, the technique of Patent Document 2 determines the current distribution so as to minimize the heat loss generated in the two batteries at the time of discharging, but the current flows only to the large-capacity battery at the time of charging. That does not consider the heat loss that occurs in the DCDC converter, does not consider that the internal resistance of the battery fluctuates over time, and when three or more batteries are connected in parallel The problem is that it is not taken into consideration.

  The present invention has been made to solve the above-described problems. In a parallel power storage system in which one or more auxiliary batteries are connected in parallel to a main battery, a parallel power storage including a DCDC converter is provided. A current distribution control device that prevents overcharging / discharging and overcurrent of each auxiliary battery while minimizing the heat loss of the entire system, and realizes effective use of the auxiliary battery, energy saving effect, and suppression of battery deterioration. The purpose is to provide.

  A current distribution control device for a parallel power storage system according to the present invention includes a main battery, at least one auxiliary battery electrically connected in parallel with the main battery, and at least one connected between the main battery and the auxiliary battery. This is a current distribution control device used in a parallel power storage system having a DCDC converter of more than one unit, a voltage detector for detecting the voltage of the auxiliary battery, and a load device. The current distribution control device also corrects the current to satisfy a predetermined constraint, a charge amount estimation unit that estimates the charge amount of the auxiliary battery, an optimization unit that determines current distribution between the main battery and the auxiliary battery, and A correction unit is provided. In addition, the optimization unit, based on the current command value sent from the load device and the detection voltage of the voltage detector, for a certain time from the current time of the main battery, the auxiliary battery and the DCDC converter. The optimum current distribution value that minimizes the total heat loss is determined. Further, the correcting unit is configured to generate a predetermined target charge amount based on the current command value sent from the load device, the detected voltage of the voltage detector 104, and the charge amount estimated value sent from the charge amount estimating unit. The optimal current distribution value determined by the optimization unit is corrected so as to satisfy a predetermined charge amount restriction and a predetermined chargeable / dischargeable current value restriction.

  Since the current distribution control device for a parallel power storage system according to the present invention is configured as described above, it is possible to minimize heat loss within a predetermined time of the entire parallel power storage system including all the storage batteries and the converter. Therefore, energy saving and deterioration suppression can be realized simultaneously regardless of the number of auxiliary batteries. In addition, by considering the charge amount, chargeable / dischargeable current value, target charge amount, etc., each auxiliary battery can be used effectively while preventing overcurrent, overcharge and overdischarge of each high output LIB. Furthermore, even if the number of auxiliary batteries is large, the current distribution can be calculated in a short time, so that high accuracy and high expandability can be realized.

It is a block diagram which shows the structure of the parallel electrical storage system of this invention. 1 is a configuration diagram of a current distribution control device according to Embodiment 1. FIG. 3 is an internal configuration diagram of an optimization unit according to Embodiment 1. FIG. 3 is an internal configuration diagram of a correction unit according to Embodiment 1. FIG. FIG. 3 is a flowchart representing the operation of the current distribution control device according to the first embodiment. It is an equivalent circuit diagram of LIB. 3 is an internal configuration diagram of a LIB0 heat loss coefficient calculation unit according to Embodiment 1. FIG. 3 is an internal configuration diagram of a LIBi heat loss coefficient calculation unit according to Embodiment 1. FIG. 3 is an internal configuration diagram of converter i heat loss coefficient calculating means according to Embodiment 1. FIG. FIG. 3 is an internal configuration diagram of optimum current distribution calculation means according to the first embodiment. FIG. 3 is an internal configuration diagram of a LIBi current correction parameter calculation unit according to the first embodiment. FIG. 3 is an internal configuration diagram of a LIBi current distribution command value determining unit according to the first embodiment. FIG. 6 is a configuration diagram of a current distribution control device according to a second embodiment. FIG. 10 is a flowchart representing the operation of the current distribution control device according to the second embodiment. FIG. 6 is an internal configuration diagram of a LIBi constraint value calculation unit according to a second embodiment. FIG. 6 is an internal configuration diagram of optimum current calculation means according to Embodiment 2. FIG. 10 is a flowchart showing the operation of a constraint determination storage unit according to the second embodiment. FIG. 10 is an internal configuration diagram of a constraint determining unit according to Embodiment 2. FIG. 5 is an internal configuration diagram of an optimization unit according to Embodiment 2.

Embodiment 1 FIG.
First, a configuration of a current distribution control device for a parallel power storage system according to the present invention and a control method thereof will be described with reference to the drawings. The drawings are schematic and conceptually illustrate functions and structures. Further, the present invention is not limited to the embodiments described below. Unless otherwise specified, the basic configurations of the parallel power storage system and the current distribution control device are common to all the embodiments. Moreover, what attached | subjected the same code | symbol is the same or equivalent, and this is common in the whole text of a specification.

FIG. 1 is a diagram illustrating a configuration example of a parallel power storage system according to the present embodiment. As illustrated in FIG. 1, a parallel power storage system 1 according to the present embodiment includes one large-capacity LIB 101 that can be charged and discharged. (Hereinafter, this is simply referred to as “LIB0”. Note that “LIB0” is a storage battery.) And n high-output LIBs 102-i (where i∈ {1, 2,... , N}) (hereinafter simply referred to as “LIBi”, where “LIBi” is an auxiliary battery) and a DCDC converter 103 for performing voltage conversion between the large-capacity LIB and each high-output LIB. −i (where i∈ {1, 2,..., N}) and a voltage detector 104-j (where j∈ {0,1, n}) that detects the voltage of the large-capacity LIB and each high-output LIB. 2,..., N}) and the voltage detection value of each voltage detector and at least In addition, based on a predetermined signal including only the current command value to the parallel power storage system (only the current command value in FIG. 1), the DCDC converter outputs the current command value sent from the load device 106 at regular time intervals. And a current distribution control device 105 that controls the operation.

  The components of the load device 106 are not shown, but include, for example, a smoothing capacitor that stores DC power, an inverter device that converts DC power into AC power, an electric motor that drives the vehicle, and the like.

  FIG. 2 is a diagram illustrating a configuration example of the current distribution control device according to the present embodiment. As shown in FIG. 2, the current distribution control device 105 includes a charge amount estimation unit 201 that estimates the charge amount of each high-output LIB, and an optimum current distribution that minimizes the heat loss of the entire parallel power storage system. And a correction unit 203 that corrects the current distribution obtained by the optimization unit based on predetermined information including the charge amount of each high-output LIB.

  The current distribution control device 105 outputs a current command value Iref [A] (a charging current when Iref> 0 and a discharging current when Iref <0) sent from the load device 106 at regular time intervals Δ [s]. ., 104-n, the detection voltages Vdet0, Vdet1,..., Vdetn [V] obtained by the voltage detectors 104-0, 104-1,. And based on these information, the charge amount estimation part 201, the optimization part 202, and the correction | amendment part 203 perform the below-mentioned process, The electric current distribution command value to each LIBi after (DELTA) second progress from the present time I1, I2,..., In [A] (constant values) are calculated and transmitted to the DCDC converter 103-i (i = 1, 2,..., N).

  Of the components of the current distribution control device 105, the charge amount estimation unit 201 estimates the charge amount of each LIBi, for example, by a current integration method based on the immediately preceding current command value.

Optimization unit 202, the current time _t k: = to the current command value Iref in kΔ [s], the heat loss caused by the entire parallel power storage system during the Δ seconds from _{t k} to _{t k + 1,} DCDC converter 103-i (i = 1, 2,..., N) is minimized by utilizing the fact that it can be expressed by a quadratic function of the currents I1, I2,. The optimal current distribution I1 ^* , I2 ^* ,..., In ^* for Δ seconds is calculated.

  FIG. 3 is a configuration diagram illustrating an internal functional configuration of the optimization unit 202. The optimization unit 202 includes LIB heat loss coefficient calculation means 301, converter heat loss coefficient calculation means 302, and optimum current distribution calculation means 303. The LIB heat loss coefficient calculation means 301 includes a LIB0 heat loss coefficient calculation means 701 and a plurality of LIBi heat loss coefficient calculation means 801 (i = 1,..., N), and converter heat loss coefficient calculation means. 302 includes a plurality of converter i heat loss coefficient calculating means 901 (901-i; i = 1,..., N).

The correction unit 203 includes a detection voltage obtained by the voltage detector 104, a charge amount estimation value obtained by the charge amount estimation unit 201, and optimum current distributions I1 ^* , I2 ^* ,. Based on In ^* , the optimal current distribution is corrected in consideration of the LIBi charge amount, the maximum charge / discharge current, and the target charge amount. Thereby, final current distributions I1, I2,..., In are determined, and these are transmitted to each DCDC converter 103 as command values for current distribution.

  FIG. 4 is a configuration diagram illustrating an internal functional configuration of the correction unit 203. The correction unit 203 includes a correction parameter calculation unit 401 that determines a correction parameter for each LIBi for correcting the optimal current distribution obtained by the optimization unit 202 in consideration of the target charge amount, and a correction parameter calculation unit 401. Current distribution command value calculation means 402 for determining a current distribution command value for the DCDC converter 103 based on the correction parameters obtained in step S3 and the restrictions on the charge amount / current value. The correction parameter calculation unit 401 includes a plurality of correction parameter i calculation units 1101 (1101-i; i = 1,..., N), and the current distribution command value calculation unit 402 includes a plurality of current distribution command values. i calculation means 1201 (1201-i; i = 1,..., n) is provided.

  Below, operation | movement of the electric current distribution control apparatus 105 is demonstrated in detail using the flowchart of FIG.

  First, in step s501, the current distribution control device 105 acquires the current command value Iref sent from the load device.

  Next, in step s502, the current distribution control device 105 receives each detection voltage Vdetj acquired by each voltage detector 104-j.

  Then, in step s503, the charge amount estimation unit 201 estimates the charge amount Qi [C] of each LIBi using, for example, the current integration method, using the current distribution command value Ii immediately before output from the current distribution control device.

  In step s504, the LIB heat loss coefficient calculation unit 301 of the optimization unit 202 determines coefficients μj and νj related to the heat loss amount of each LIBj in Δ seconds. This can be obtained, for example, by using an LIB equivalent circuit.

FIG. 6 is an equivalent circuit model of LIBj. Rsj [Ω], Rdj [Ω], Cdj [F], qj [C], Ej [V], and Vj [V] are the solution resistance, charge transfer resistance, electric double layer capacitance, and electric double layer of LIBj, respectively. The amount of electricity stored, the open circuit voltage (OCV), and the battery voltage. However, it is assumed that Rsj, Rdj, and Cdj have values obtained in advance by the AC impedance method or the like, or values are estimated online. The measured value Vdetj obtained by the voltage detector 104-j can be used as the value of Vj. Although q0 cannot be obtained directly, assuming that the initial value is zero, if current distribution I0 ⁻ and electric double layer electric quantity q0 ⁻ one step before are used, it is calculated as shown in equation (1) from FIG. be able to. Also for qi, if the value Ii ′ ⁻ one step before the current Ii ′ for LIBi is used, it can be calculated as in equation (2) in the same way as for q0.

（１）

(1)

（２）

(2)

Hereinafter, a method of calculating the heat loss coefficient using such values obtained from FIG. 6 will be described.

First, a method of calculating the heat loss coefficients μ0 and ν0 of LIB0 will be described.
In lib0, heat loss F0 [J] generated by Δ seconds from the current time _{t k} until _{t k + 1,} in the equivalent circuit of FIG. 5, the heat loss caused by Rs0 and Rd0, in the interval from _{t k} to _{t k + 1} Since it only has to be integrated, (5) as in the first formula. If this is calculated using equation (1) and equation (3) which is a relational expression between Iref and each Ij, the heat loss coefficients μ0, ν0, and σ0 defined by equation (4) are used. (5) can be expressed as the second equation. When the calculation of μ0 and ν0 is realized inside the current distribution control device, it is as shown in FIG.

（３）

(3)

（４）

(4)

（５）

(5)

FIG. 7 shows the LIB0 heat loss coefficient calculation means 701 inside the LIB heat loss coefficient calculation means 301. In the LIB0 heat loss coefficient calculating means 701, first, the current I0 ⁻ one step before stored in the LIB0 current storage means 702 is sent to the LIB0 electric double layer electric quantity calculating means 703. The LIB0 electric double layer electric quantity calculation means 703 uses this I0 ⁻ and the electric double layer electric quantity q0 ⁻ one step before sent from the LIB0 electric double layer electric quantity storage means 704 according to the equation (1). q0 is calculated. However, the initial value of q0 is zero. The LIB0 electric double layer electric quantity storage means 704 receives q0 and stores it. The multiplying unit 706 multiplies the quantity of electricity q0 and the value stored in the value storage unit 705 to obtain (0) the value of ν0 defined by the second equation, and outputs this to the outside. The value storage unit 707 stores the value of μ0 defined by (4) the first equation, and outputs this to the outside. When the current distributions I1, I2,... In at the current time are determined and sent from the correction unit, the summation unit 708 calculates I1 + I2 +... + In and sends it to the subtraction unit 709. The subtraction unit 709 subtracts the value sent from the subtraction unit 708 from the value of Iref sent from the load device 106, and sends this to the LIB0 current storage means 702 as the value of I0. The LIB0 current storage means 702 stores this until the next step.

Next, a method for calculating the heat loss coefficients μi and νi of LIBi will be described.
Considering the conversion of the current Ii by the DCDC converter 103-i, the current Ii ′ flowing through LIBi can be expressed by the equation (7) using fηi defined by the equation (6). However, ηci and ηdi in the equation (6) are conversion efficiencies of the DCDC converter 103-i during charging and discharging, respectively.

（６）

(6)

（７）

(7)

  The heat loss Fi generated in LIBi can be expressed as (9) as shown in the first equation. Therefore, if calculated using equations (2) and (7), it is defined by equation (8) as in LIB0. By using μi, νi, and σi to be expressed, (9) can be expressed as shown in the second equation. When the calculation of μi and νi is realized in the current distribution control device, it is as shown in FIG.

（８）

(8)

（９）

(9)

FIG. 8 shows the LIBi heat loss coefficient calculation means 801 inside the LIB heat loss coefficient calculation means 301.
The LIBi heat loss coefficient calculation means 801 first sends Ii ′ ⁻ stored in the LIBi current conversion coefficient storage means to the LIBi electric double layer electric quantity calculation means 803. The description of the LIBi electric double layer electric quantity calculation means 803, the LIBi electric double layer electric quantity storage means 804, the value storage section 805, and the multiplication section 806 is as follows: LIBi electric double layer electric quantity calculation means 703, LIBi electric double layer electric quantity calculation means Since it is the same as the description about the quantity storage means 704, the value storage part 705, and the multiplication part 706, it abbreviate | omits. The conditional branching unit 807 determines whether the current command value Iref sent from the load device 106 is positive or negative, and outputs ηci when positive and 1 / ηdi when negative. The division unit 808 divides Vdet0 and Vdeti sent from the voltage detectors 0 and i. The multiplication unit 809 multiplies the outputs of the conditional branching unit 807 and the division unit 808, thereby generating Ii ′ and Ii conversion coefficient fηi defined by the equation (6). The multiplication unit 810 multiplies the output of the multiplication unit 806 and the output of the multiplication unit 809, and outputs (8) νi defined by the second equation to the outside. The multiplication unit 811 multiplies the value stored in the value storage unit 812 by the square of the output of the multiplication unit 809, and outputs (8) μi defined by the first equation to the outside. When the current distribution I1, I2,... In at the current time is determined and Ii is sent from the correction unit, the multiplication unit 813 multiplies this by the output of the multiplication unit 809, (7) A value of Ii ′ defined by the expression is generated. The LIBi current conversion coefficient storage means 802 stores this until the next step.

  In step s505, the converter heat loss coefficient calculation means 302 of the optimization unit 202 determines a coefficient ρi related to the heat loss amount in Δ seconds of each converter i.

The heat loss Gi [J] generated in the DCDC converter in Δ seconds is expressed by gηi defined by the equation (10) using the conversion efficiencies ηci and ηdi at the time of charging and discharging, the detected voltage Vdet0 [V] of LIB0, the sample Using the time Δ and the current Ii to the converter i, it can be expressed as, for example, equation (11).

（１０）

(10)

（１１）

(11)

When the calculation of ρi is realized in the current distribution control device, it is as shown in FIG.
FIG. 9 is a diagram showing converter i heat loss coefficient calculation means 900 inside converter heat loss coefficient calculation means 302.

  In converter i heat loss coefficient calculation means 900, first, conditional branching section 901 generates gηi defined by equation (10) based on the value of Iref sent from load device 106. Next, the multiplication unit 902 multiplies gηi by Vdet0 sent from the voltage detector 104-0 and outputs this value. Then, the multiplication unit 903 multiplies the output of the multiplication unit 902 and Δ stored in the value storage unit 904, generates ρi, and outputs it to the outside.

In step s506, the optimum current distribution calculation unit 303 in the optimization unit 202 optimizes the current distribution I1 ^* , I2 ^* ,..., In that minimizes the heat loss of the entire parallel power storage system in Δ seconds. ^{* Is} determined. First, after explaining the calculation method of the optimal current distribution, a method of realizing this derivation inside the current distribution control device 105 will be described.

  The heat loss Ploss [J] of the entire parallel power storage system that occurs during Δsec is the heat loss F0 of LIB0 expressed by the equation (5), the heat loss Fi of LIBi expressed by the equation (9), and (11) The heat loss Gi of the converter i expressed by the equation can be added and expressed as the equation (12).

（１２）

(12)

The optimal current distributions I1 ^* , I2 ^* ,..., In ^* that minimize the loss are such that the partial differential values at each Ii of the loss are all zero. That is, I1 ^* , I2 ^* ,..., In ^* are I1, I2,.

（１３）

(13)

  The value of the partial differentiation due to the loss Ii is expressed by the equation (14) from the equations (5), (9), (11), and (12).

（１４）

(14)

  Therefore, using current vector I, vector b, and matrix A defined by equations (15), (16), and (17), equation (13) can be expressed as equation (18).

（１５）

(15)

（１６）

(16)

（１７）

(17)

（１８）

(18)

After that, in order to obtain the optimal current distribution vector I ^* : = [I1 ^* I2 ^* ... In ^* ] ^T , both sides of equation (18) may be multiplied by A ⁻¹ from the left.

In general, in order to obtain an inverse matrix of an n × n matrix, it is known that a calculation amount of the order of n ³ is required. However, if the form is A in Equation (17), Sherman-Morrison- By developing A ⁻¹ using Woodbury's formula, the value of A ⁻¹ can be directly obtained as shown in equation (19) (Non-patent Document 1 below; p. 87-89). However, all off-diagonal components of the first term on the right side of equation (19) are zero.

（１９）

(19)

  Thereby, even when the number of high-output LIBs is large (n is large), it is possible to significantly reduce the delay due to the calculation of the controller.

Non-Patent Document 1 is the following document.
W. H. Press, S.M. A. Teukolsky, W .; T.A. Vetterling, B.W. P. Franner, Tankeikatsu City, Haruhiko Okumura, Toshiro Sato, Makoto Kobayashi, “Numeric Recipes in C [Japanese Version] Recipe for Numerical Computation in C Language”, First Edition, Technical Review, Inc., November 1, 2001

When the calculation of I ^* that can be obtained by the above method is realized in the current distribution control device, it is as shown in FIG.

FIG. 10 is a block diagram showing the internal configuration of the optimum current distribution calculation means 303.
In the optimum current distribution calculating means 303, first, the inverse matrix calculating means 1001 calculates A ⁻¹ represented by the equation (19) based on all μj sent from the LIB heat loss coefficient calculating means 301. Next, the b calculating means 1002 receives Iref sent from the load device 106, μ0 and all νj sent from the LIB heat loss coefficient calculating means 301, and all sent from the converter heat loss coefficient calculating means 302. Based on ρi, equation (16) is calculated. Then, the matrix multiplication unit 1003 multiplies the output A ⁻¹ of the inverse matrix calculation unit 1001 and the output b of the b calculation unit 1002 to calculate A ⁻¹ b, and uses this as the optimum current distribution vector I ^* to the outside. Output.

  In step s507, the correction parameter calculation unit 401, which is a component in the correction unit 203, determines a correction parameter βi for correcting the optimum current distribution determined in step s506 based on the target charge amount of each LIBi.

  βi is calculated using the estimated charge amount Qi of LIBi, the target charge amount Qiref [C], the allowable maximum charge amount Qimax [C], and the allowable minimum charge amount Qimin [C], for example, as shown in Equation (20). decide. However, p and q are both natural numbers or infinite. βi always satisfies 0 ≦ βi ≦ 1, and when Qi is larger (smaller) than Qiref and Iref is positive (negative), the larger the difference between Qi and Qiref, the larger the value. . That is, βi takes a large value when the current command value is such that Qi moves away from Qiref.

（２０）

(20)

When the calculation of βi is realized inside the current distribution control device, it is as shown in FIG.
FIG. 11 is a diagram showing the internal configuration of the correction parameter i calculation unit 1101 inside the correction parameter calculation unit 401.

  In correction parameter i calculation means 1101, first, subtraction unit 1103 calculates Qi−Qiref based on estimated charge amount Qi sent from charge amount estimation unit 201 and Qiref stored in value storage unit 1102. To do. The subtraction unit 1104 calculates Qimax−Qiref based on Qimax stored in the value storage unit 1105 and Qiref stored in the value storage unit 1102. The division unit 1106 calculates (Qi−Qiref) / (Qimax−Qiref) based on the outputs of the subtraction unit 1103 and the subtraction unit 1105. The summation unit 1107 calculates the p-th power of the output of the division unit 1106. On the other hand, the division unit 1108 calculates Qiref−Qi based on Qiref and the charge amount estimated value Qi stored in the value storage unit. The division unit 1109 calculates Qiref−Qimin based on Qiref stored in the value storage unit 1102 and Qimin stored in the value storage unit 1110. The division unit 1111 calculates (Qiref−Qi) / (Qiref−Qimin) based on the output of the subtraction unit 1108 and the output of the subtraction unit 1109. The summation unit 1112 calculates the qth power of the output of the division 1111. The conditional branching unit 1113 stores the value of the output of the summation unit 1107, the output of the synergy unit 1112 and the value based on the sign of the output Qi-Qiref of the subtraction unit 1103 and the sign of Iref sent from the load device 106. One of 0 stored in the unit 1114 is selected as shown in the equation (20) and output to the outside.

In step s508, the current command value calculation unit 402 sets restrictions on the charge amount and charge / discharge current of each LIB based on I ^* determined in step s506, each βi determined in step s507, and the current command value Iref. The current command value Ii to each converter i is determined in consideration.

In order to prevent the charge amount of LIBi from exceeding the upper limit and the lower limit, the charge amount should not exceed the allowable maximum value Qimax [C] and the allowable minimum value Qimin [C] after Δ seconds. Correct the current distribution. That is, the final current distributions I1, I2,..., In after correcting I1 ^* , I2 ^* ,..., In ^* are made to satisfy the inequality (21).

（２１）

(21)

  Qimax may be a full charge amount (FCC: Full Charge State) of LIBi, or may be a value slightly smaller than FCC. Qimin may also be zero, or may be a value slightly larger than zero.

  Then, the current value Ii of LIBi must satisfy Equation (22) so that it does not exceed the allowable maximum charging current Iimax [A] during charging and does not decrease below the allowable maximum discharging current Iimin [A] during discharging. . The values of Iimax and Iimin may be determined from the specifications of LIBi, or may be values that vary depending on time or the state of LIB if possible.

（２２）

(22)

Furthermore, in order to prepare for future charge / discharge or to suppress LIB degradation, it is desirable to bring the charge amount of LIBi (i = 1, 2,..., N) closer to the target charge amount Qiref [C]. In order to satisfy this requirement, Ii ^* is corrected to (1-βi) Ii ^* using βi determined in step s507. If correction is made using this βi, the current value is calculated from the equation (20) when the charge amount Qi is far from the target charge amount Qiref and further away from Qiref by flowing the current Ii ^*. Is limited to a small absolute value.

In order to satisfy the constraints of equations (20) and (21) while correcting Ii ^* using the correction term βi, the final current distribution may be determined by equation (23).

（２３）

(23)

When the calculation of Ii is realized inside the current distribution control device, it is as shown in FIG.
FIG. 12 is a diagram showing the internal configuration of the LIBi current command value calculation means 1201 inside the current command value calculation means 402.

In the LIBi current command value calculation unit 1201, the subtraction unit 1202 performs subtraction between 1 stored in the value storage unit 1203 and βi sent from the correction parameter calculation unit 401 to generate 1−βi. The multiplier 1204 multiplies the output of the subtractor 1202 and the output Ii ^* of the optimizer 202 to generate (1-βi) Ii ^* . The subtraction unit 1205 subtracts Qimax stored in the value storage unit 1206 from the charge amount estimation value Qi sent from the charge amount estimation unit 201 to generate Qimax−Qi.
The fηi calculating unit 12071 generates fηi based on Vdet0, Vdeti, and Iref sent from the voltage detectors 104-0, 104-i and the load device 106. The specific method for calculating fηi is as described above. Multiplier 12072 multiplies Δ stored in fηi calculating means 12071 and value storage unit 12073. The division unit 1208 divides the output values of the subtraction unit 1205 and the multiplication unit 12072, and generates (Qimax−Qi) / fηiΔ.
The minimum value output unit 1209 outputs the minimum value among the three values of the output value of the multiplication unit 1204, the output value of the division unit 1208, and Iimax stored in the value storage unit 1210. On the other hand, the subtraction unit 1211 subtracts the charge amount estimated value Qi sent from the charge amount estimation unit 201 and Qimin stored in the value storage unit 1212 to generate Qimin-Qi. The division unit 1213 divides the output of the subtraction unit 1211 and the output value of the multiplication unit 12072 to generate (Qimin−Qi) / fηiΔ.
The maximum value output unit 1214 outputs the maximum value among the output value of the multiplication unit 1204, the output value of the division unit 1213, and Iimin stored in the value storage unit 1215. The conditional branching unit 1216 includes a minimum value output unit 1209, a maximum value output unit 1214, and a positive / negative sign of Ii ^* sent from the optimization unit 202 and a positive / negative sign of Iref sent from the load device 106. Then, Ii is determined from the value storage unit 1217 as shown in equation (23). The current distribution command values I1, I2,..., In determined as described above are sent as command values from the current distribution control device to the DCDC converter i.

The above-described embodiment can be summarized as follows. The current distribution control device 105 for the parallel power storage system of this embodiment includes a main battery 101, at least one auxiliary battery 102 electrically connected to the main battery 101 in parallel, and between the main battery 101 and the auxiliary battery 102. Current distribution control device 105 for use in a parallel power storage system having at least one DCDC converter 103 connected to, voltage detector 104 for detecting the voltage of auxiliary battery 102, and load device 106.
Then, the current distribution control device 105 includes a charge amount estimation unit 201 that estimates a charge amount of the auxiliary battery 102, an optimization unit 202 that determines current distribution between the main battery 101 and the auxiliary battery 102, and predetermined constraints. A correction unit 203 is provided to correct the current so as to satisfy.
In addition, the optimization unit 202 determines the main battery 101, the auxiliary battery 102, and the DCDC converter 103 from the current time based on the current command value sent from the load device 106 and the detection voltage of the voltage detector 104. The optimum current distribution value that minimizes the sum of heat loss during a certain time is determined.
Further, the correction unit 203 performs a predetermined operation based on the detection voltage of the voltage detector 104, the current command value sent from the load device 106, and the charge amount estimation value sent from the charge amount estimation unit 201. The optimum current distribution value determined by the optimization unit 202 is corrected so as to satisfy the target charge amount, the predetermined charge amount restriction, and the predetermined chargeable / dischargeable current value restriction.

  According to the current distribution control device according to the present embodiment as described above, since the current distribution is determined based on the current distribution that minimizes the heat loss of the entire parallel power storage system, the energy saving and the deterioration of the high output LIB are suppressed. Leads to. Furthermore, since the current distribution is determined in consideration of the constraint conditions related to charging / discharging of each high-power LIB, the battery can be used with reduced load, leading to a longer life. Moreover, even if the number of high output LIBs is large, current distribution can be determined in a short time.

In the first embodiment, in the current distribution control device 105 for the parallel power storage system, the charge amount estimation unit 201 uses each optimum current distribution value sent from the optimization unit 202 at the previous time. The estimated charge amount of the auxiliary battery 102 is calculated.
Further, in the optimization unit 202, based on the current command value sent from the load device 106 and the detection voltage of the voltage detector 104, the heat loss of all the auxiliary batteries 102 is performed by the LIB heat loss coefficient calculation means 301. The coefficients are calculated, the converter heat loss calculation means 302 calculates the heat loss coefficients of all the DCDC converters 103, and the optimum current distribution calculation means 303 calculates and outputs the optimum current distribution value.
Further, the correction unit 203 uses the correction parameter calculation unit 401 to charge each auxiliary battery 102 based on the detected voltage value, the estimated charge amount, the optimum current distribution value, and the current command value from the load device 106. The correction parameter is calculated using the estimated amount of charge, the allowable maximum charge amount, the allowable minimum charge amount and the target charge amount, and the allowable maximum charge amount and the allowable minimum charge amount of each auxiliary battery 102 are calculated by the current distribution command value calculation means 402. The current distribution command value to the DCDC converter 103 is calculated and output by correcting the optimum current distribution using the allowable maximum charge / discharge current value and the correction parameter.

  According to the current distribution control device according to the present embodiment as described above, while limiting the charge amount and the maximum charge / discharge current, based on the current distribution that minimizes the heat loss of the entire parallel power storage system, The current distribution command value to the DCDC converter can be determined in consideration of the charge amount target value and the like. In addition, when obtaining the optimum current distribution in the optimization unit, instead of calculating the inverse matrix, it is only necessary to substitute a value, and when correcting the current distribution in consideration of the constraints of the high output LIB, Since iterative calculation is not required, current distribution can be determined in a short time even if the number of high output LIBs is large.

Embodiment 2. FIG.
FIG. 13 is a diagram illustrating a configuration example of the current distribution control device according to the second embodiment of the present invention. In addition, since the structure of the parallel electrical storage system which concerns on this Embodiment 2 is the same as the parallel electrical storage system which concerns on Embodiment 1, description is abbreviate | omitted here.

  As illustrated in FIG. 13, the current distribution control device according to the second embodiment includes a charge amount estimation unit 1301 that estimates the charge amount of each high-output LIB, a charge amount estimate value of each high-output LIB, and a maximum charge amount. In consideration of the discharge current and the target charge amount, the constraint determination unit 1302 that determines the constraint condition that gives the upper limit and the lower limit of the current value of each high-output LIB, and parallel storage under the constraint condition determined by the constraint determination unit And an optimization unit 1303 that determines a current distribution that minimizes the heat loss of the entire system.

  FIG. 18 shows an internal configuration of the constraint determination unit 1302, and the constraint determination unit 1302 includes a correction parameter calculation unit 13020 and a LIB constraint value calculation unit 1500. The correction parameter calculation unit 1302 includes a correction parameter i calculation unit 13021 (i = 1,..., N) therein, and the LIB constraint value calculation unit 1500 includes a LIBi constraint value calculation unit 1501 (inside). i = 1,..., n).

In the following, a method of determining the current distribution command values I1 ^* , I2 ^* ,..., In ^* by the current distribution control device and sending them as command values to each DCDC converter will be specifically described with reference to the flowchart of FIG. Explained.

  In step s1401, the current distribution control device 105 acquires the current command value Iref sent from the load device.

  In step s1402, the current distribution control device 105 receives each detection voltage Vdetj acquired by each voltage detector 104-j.

  In step s1403, the charge amount estimation unit 1301 estimates the charge amount Qi [C] of each LIBi based on the current distribution command value acquired from the optimization unit 1303 at the immediately preceding time, for example, by a current integration method.

  In step s1404, the correction parameter i calculation unit 13021 in the constraint determination unit 1302 has the same configuration as the correction parameter i calculation unit 1101 in the first embodiment, and based on the target charge amount Qiref of each LIBi, the next step s1404. In order to correct the current constraint, the correction parameter βi expressed by the equation (20) is calculated.

In step s1405, the LIBi constraint value calculation means 1501 in the constraint determination unit 1302 detects the detected voltages Vdet0 and Vdeti sent from the voltage detectors 104-0 and 104-i, and the current command sent from the load device 106. Based on the value Iref and the charge amount estimation value Qi estimated by the charge amount estimation unit 1301, the constraint condition regarding the current Ii of LIBi is determined. Specifically, for example, the maximum value Iimax ^* and the minimum value Iimin ^* that Ii can take are determined from Expressions (20), (21), and (22) as shown in Expression (24).

（２４）

(24)

When the calculation of Iimax ^* and Iimin ^* is realized in the current distribution control device, it is as shown in FIG.
FIG. 15 is a diagram showing the configuration of the LIBi constraint value calculation unit 1501 inside the constraint determination unit 1302.

In the LIBi constraint value calculation unit 1501, the subtraction unit 1502 subtracts the βi that is calculated and transmitted by the correction parameter i calculation unit inside the correction parameter calculation unit 1302 and the value 1 stored in the value storage unit 1503. 1-βi is generated. The subtraction unit 1504 subtracts the allowable maximum charge amount Qimax stored in the value storage unit 1505 and the charge amount estimated value Qi sent from the charge amount estimation unit 1301 to generate Qimax-Qi.
The fηi calculating unit 15061 generates fηi based on Vdet0, Vdeti, and Iref sent from the voltage detectors 104-0, 104-i and the load device 106. A specific calculation method of fηi is as described in the first embodiment. The multiplier 15062 multiplies Δ stored in the fηi calculating means 15061 and the value storage 15063, and the divider 1507 divides the output values of the subtractor 1504 and the multiplier 15062, and (Qimax−Qi) / fηiΔ is generated.
The minimum value output unit 1508 compares the output of the division unit 1507 with Iimax stored in the value storage unit 1509, and outputs the smaller value. Multiplier 1510 outputs a value obtained by multiplying the output of subtractor 1502 and the output of minimum value output unit 1508. The subtraction unit 1511 subtracts Qi and Qimin stored in the value storage unit 1512 to generate Qimin−Qi. The division unit 1513 divides the output of the division unit 1511 and the output value of the multiplication unit 15062 to generate (Qimin−Qi) / fηiΔ.
Maximum value output unit 1514 compares division unit 1513 with Iimin stored in value storage unit 1515 and outputs the larger value. Multiplier 1516 outputs a value obtained by multiplying the output of subtractor 1502 and the output of maximum value output unit 1514. The conditional branching unit 1517 obtains Iimax ^* based on the value of Iref sent from the load device 106, the output of the multiplication unit 1510, the value 0 stored in the value storage unit 1518, and the output of the multiplication unit 1516 ^. And Iimin ^* are output. Specifically, when Iref> 0, selects the output of the multiplying unit 1510 as the value of limax ^*, 0 is selected as the value of Iimin ^*. When Iref <0, 0 is selected as the value of Iimax ^* , and the output of the multiplier 1516 is selected as the value of Iimin ^* . In this way, the constraint value calculation means 1501 outputs Iimax ^* and Iimin ^* according to the equation (24) to the outside.

  In step s1406, the LIB heat loss coefficient calculation means in the optimization unit 1303 calculates coefficients μj and νj related to the heat loss amount of each LIBj in Δ seconds.

  FIG. 19 is a configuration diagram showing the internal configuration of the optimization unit 1303. The optimization unit 1303 includes LIB heat loss coefficient calculation means 13031, converter heat loss coefficient calculation means 13032, and optimum current distribution calculation means 1600. The LIB heat loss coefficient calculation means 13031 includes LIB0 heat loss coefficient calculation means 130311 and LIBi heat loss coefficient calculation means 130312 (i = 1,..., N), and the converter heat loss coefficient calculation means 13032 includes It is constituted by converter i heat loss coefficient calculation means 130321 (i = 1,..., N).

  The method of calculating μj and νj by the LIB0 heat loss coefficient calculation means and the LIBi heat loss coefficient calculation means is as described in the first embodiment.

  In step s1407, the converter heat loss coefficient calculation means 13032 inside the optimization unit 1303 calculates a coefficient ρi related to the heat loss amount in Δ seconds of each converter i inside. The calculation method of ρi by converter i heat loss coefficient calculation means 130321 is as described in the first embodiment.

  In step s1408, the optimum current distribution calculation unit 1600 in the optimization unit 1303 calculates a value that is a candidate for optimum current distribution that minimizes the heat loss Ploss of the entire composite power supply system. This calculation will be described in detail with reference to FIG.

（２５）

(25)

FIG. 16 is a block diagram showing the internal configuration of optimum current distribution calculation means 1600.
Inside the optimum current distribution calculating means 1600, the inverse matrix calculating means 1601 includes μj calculated inside the LIB heat loss coefficient calculating means 13031 and outputs p1, p2,. Based on the above, A _par ⁻¹ represented by the equation (26) is calculated and output. In the initial state, it is assumed that pi = i and m = n.

（２６）

(26)

The subtracting unit 1602 subtracts Iref sent from the load device 106 and r sent from the constraint determination storage unit 1605 to calculate Iref-r, and outputs this as Irefpar. In the initial state, r = 0. The b _par calculation means 1603 outputs p1, p2,..., pm of the constraint determination storage means 1605, the output Irefpar of the subtraction unit 1602, and μ0 and νj (j = j calculated by the LIB heat loss coefficient calculation means 13031). 0, 1,..., N) and ρi (i = 1,..., N) calculated inside the converter heat loss coefficient calculating means 13032, b defined by the equation (27) Calculate and output _par .

（２７）

(27)

The multiplication unit 1604 multiplies the output of the inverse matrix calculation unit 1601 and the output of the b _par calculation unit 1603 and outputs A _par ⁻¹ b _par as I _par .

In step s1409, the optimum current distribution calculation means 1600 determines whether or not I (−) obtained in s1408 satisfies the constraint. If it satisfies, the process ends, and the stored current distribution command values I1 ^* and I2 ^* , ..., In ^* are sent to converters 1, 2, ..., n, respectively. If the constraint is not satisfied, the parameter is updated in step s1410 and the process returns to step s1408.

Steps s1409 and s1410 will be described in detail with reference to FIG.
The constraint determination storage unit 1605 outputs the output I _par of the multiplication unit 1604, the constraint values Iimax ^* and Iimin ^{* of} each LIBi sent from the constraint determination unit 1302, and r and p1 obtained immediately before by the constraint determination storage unit itself. , P2,..., Pm, and r and p1, p2,. This part will be specifically described with reference to the flowchart of FIG.

FIG. 17 is a flowchart for explaining the operation of the constraint determination storage unit 1605.
First, block 1701 and block 1702 represent both ends of the loop, and the operation between the two blocks is performed m times from i = 1 to m. Block 1703 determines whether or not I _par pi ≧ Ipimax ^* holds. If yes, proceed to block 1704, otherwise go to block 1706. In block 1704, Ipi ^* = Ipimax ^* is sent to the definite current storage means 1606. In block 1705, r + Ipimax ^* is substituted for r. In block 1706, it is determined whether or not I _par pi ≦ Ipimin ^* is established ^{. If} yes, the process proceeds to block 1707, and if not, the process proceeds to block 1709. In block 1707, Ipi ^* = Ipimin ^* is sent to the definite current storage means 1606. In block 1708, r + Ipimin ^* is substituted for r. Block 1709 stores pi throughout the loop. After the end of the loop, block 1710 outputs r and p1, p2,..., Pm, and thereafter resets the storage of p1, p2,. The operation of the constraint determination storage unit 1605 has been described above.

The definite current storage unit 1606 stores the value every time Ipi ^* is sent from the constraint determination storage unit 1605. i = 1,2, · · ·, where all the current distribution command value of n has been ^sent, I1 ^*, I2 *, · · ·, outputs an In ^*, respectively converters 1, 2,・ Send to n. The end determination unit 1607 closes the switch when p1, p2,... Pm are no longer output from the constraint determination storage unit 1605 (that is, when there is no more current distribution exceeding the constraint), and the multiplication unit 1604 The output I _par is sent to the deterministic current storage means 1606. The deterministic current storage means 1606 stores each element as an optimum current, and together with the remaining elements stored so far, I1 ^* , I2 ^* ,. • Output as In ^* .

  As a specific example, the operation of the optimum current distribution calculation unit 1600 when n = 4 will be described with reference to FIG.

First, at first, m = 4, p1 = 1, p2 = 2, p3 = 3, p4 = 4,
Irefpar = Iref, and in the inverse matrix calculation means 1601,
Calculate A _par ⁻¹ in the equation (28).

（２８）

(28)

Next, in b _par calculating unit 1603 calculates the b _par of (29).

（２９）

(29)

From here, the multiplication unit 1604 calculates A _par ⁻¹ b _par and sends it to the constraint determination storage unit 1605 as I _par . When the constraint determination storage unit 1605 follows the flowchart of FIG. 17, for example, currents that do not satisfy the constraints are I _par 1 and I _par 3, and when I _par 1> I1max ^* and I _par 3> I3max ^* , I1 ^* = I1max ^* and I3 ^* = I3max ^* are transmitted to the fixed current storage unit 1606, and the fixed current storage unit 1606 stores them. When the loop of FIG. 17 ends, r = I1max ^* + I3max ^* , p1 = 2, and p2 = 4 (m = 2) are output. Then, when returning to the multiplication unit 1602, the multiplication unit 1602 calculates Irefpar = Iref−r. Since p1 = 2 and p2 = 4, the output of the inverse matrix calculation means 1601 is given by equation (30).

（３０）

(30)

Further, the output of the b _par calculating means 1603 calculates b _par of the equation (31).

（３１）

(31)

Then, again from here, the multiplication unit 1604 calculates A _par ⁻¹ b _par and sends it to the constraint determination storage unit 1605 as I _par . If there is no element that violates the constraint at this time, p1, p2,..., Pm do not exist (m = 0), the end determination unit 1607 closes the switch, and the I _par element remains as I2 ^* , I4. ^* Is sent to the fixed current distribution 1606. Since all of I1 ^* , I2 ^* , I3 ^* , and I4 ^* are provided in the fixed current distribution 1606, these are output and each is sent to the converter i as a current distribution command value.

The above method efficiently solves the problem of minimizing Ploss under the constraint of equation (25) by the same method as the effective constraint method. Number of times of the repetition of the result calculated in step s1408 is at most n times, and calculates also the usual A _par ^-1 is the place takes time on the order of n ^3, is calculated using equation (26) Therefore, the solution can be obtained in a short time as a whole.

The above-described second embodiment is summarized as follows. The current distribution control device 105 for the parallel power storage system of this embodiment includes a main battery 101, at least one auxiliary battery 102 electrically connected to the main battery 101 in parallel, and between the main battery 101 and the auxiliary battery 102. Current distribution control device 105 for use in a parallel power storage system having at least one DCDC converter 103 connected to, voltage detector 104 for detecting the voltage of auxiliary battery 102, and load device 106.
The current distribution control device 105 includes a charge amount estimation unit 201 that estimates a charge amount of the auxiliary battery 102, an optimization unit 1303 that determines a current distribution between the main battery 101 and the auxiliary battery 102, and the auxiliary battery 102. A constraint determination unit 1302 that determines upper and lower limit constraints on the current value flowing through the auxiliary battery 102 in consideration of predetermined constraints.
Further, the constraint determination unit 1302 includes a detection voltage value sent from the voltage detector 104, a current command value sent from the load device 106, and a charge amount estimation value sent from the charge amount estimation unit 1301. To determine the upper and lower limits of the current distribution command value for each auxiliary battery 102 so that the predetermined target charge amount, the predetermined charge amount constraint, and the predetermined chargeable / dischargeable current value constraint are satisfied. Sent to the conversion unit 1303.
In addition, the optimization unit 1303 generates a current distribution command for each auxiliary battery 102 determined by the constraint determination unit 1302 based on the current command value sent from the load device 106 and the detection voltage of the voltage detector 104. Determine the optimal current distribution value that minimizes the total heat loss of the main battery 101, auxiliary battery 102, and DCDC converter 103 for a certain period of time from the current time so that the upper and lower limits of the value are not exceeded. To do.

  As described above, according to the current distribution control device according to the second embodiment, the upper limit and the lower limit of the current value of each high output LIB are set based on restrictions on the charge amount and charge / discharge current, consideration of the target charge amount, and the like. After the determination, the optimum current distribution is determined so as to minimize the heat loss within a certain time of the parallel power storage system under this constraint. Therefore, in addition to the same effect as in the first embodiment, the heat loss is minimized. There is an effect that the optimum current distribution can be directly used as a command value for the DCDC converter.

In the second embodiment, in the current distribution control device 105 for the parallel power storage system, the charge amount estimating unit 1301 is based on the optimum current distribution value sent from the optimization unit 1303 at the immediately preceding time. The estimated charge amount of the auxiliary battery 102 is calculated.
In addition, the constraint determination unit 1302 uses the correction parameter calculation unit 13021 to calculate the estimated charge amount, the allowable maximum charge amount, the allowable minimum value based on the detection voltage of the voltage detector 104, the current command value, and the charge amount estimated value. The correction parameter is calculated using the charge amount and the target charge amount, and the allowable maximum charge amount, the allowable minimum charge amount, the allowable maximum charge / discharge current value, and the correction parameter of each auxiliary battery 102 are calculated by the LIB constraint value calculation unit 1501. Thus, the upper limit and lower limit constraints on the current value of each LIB are determined.
Further, the optimization unit 1303 uses the LIB heat loss coefficient calculation unit 13031 based on the current command value sent from the load device 106, the detection voltage of the voltage detector 104, and the predetermined constraint of the auxiliary battery 102. The heat loss coefficients of all the auxiliary batteries 102 are calculated, the heat loss coefficients of all the DCDC converters 103 are calculated by the converter heat loss calculation means 13032, and the upper limit of the current value of the auxiliary battery 102 is calculated by the optimum current distribution calculation means 1600. And the optimal current distribution value under the lower limit constraint is calculated and output.

  In the first and second embodiments, the control method using the minimum components has been described. However, when more detailed information can be obtained, these may be used. For example, if the current value can be detected, the charge amount may be estimated using the detected current value instead of estimating the charge amount from the current command value as in the present embodiment.

  Also, if LIB temperature information can be obtained, heat loss can be calculated more accurately by preparing the values of the parameters of the equivalent circuit shown in FIG. 3 for each temperature as a map, and the voltage of each LIBi. The equivalent circuit parameter value may be calculated from the current value and the current value, and the degree of LIBi deterioration may be determined from the difference between this value and the parameter value held as a map, and reflected when determining the current distribution. .

  Furthermore, when information about the use of the future or past parallel power storage system is known to some extent, these may be used. For example, when the usage history of the parallel power storage system or usage information in the near future is obtained, these may be reflected when determining the current distribution.

  Moreover, although the large capacity LIB and the high output LIB have been considered as the batteries so far, other storage batteries, large capacity capacitors, or the like may be used. Further, a plurality of main batteries may be used.

  It should be understood that the above-described embodiment is illustrative in all respects and not restrictive. The scope of the present invention is shown not by the scope of the above-described embodiment but by the scope of claims, and includes all modifications within the meaning and scope equivalent to the scope of claims.

101 Large-capacity LIB,
102-i (where i = 1, 2,..., N) high output LIB,
103-i (where i = 1, 2,..., N) DCDC converter,
104-j (where j = 0, 1, 2,..., N) voltage detector,
105 Current distribution control device 106 Load device.

Claims (4)

Main battery, at least one auxiliary battery electrically connected in parallel with the main battery, at least one DCDC converter connected between the main battery and the auxiliary battery, voltage of the auxiliary battery A current distribution control device used in a parallel power storage system having a voltage detector and a load device for detecting
The current distribution control device includes:
A charge amount estimating unit for estimating a charge amount of the auxiliary battery,
An optimization unit for determining a current distribution between the main battery and the auxiliary battery;
And a correction unit that corrects the current so as to satisfy a predetermined constraint,
The optimization unit, based on the current command value sent from the load device and the detection voltage of the voltage detector, for a predetermined time from the current time of the main battery, the auxiliary battery, and the DCDC converter. The optimal current distribution value that minimizes the total heat loss during
The correction unit is a predetermined target based on a current command value sent from the load device, a detection voltage of the voltage detector 104, and a charge amount estimation value sent from the charge amount estimation unit. Correcting the optimum current distribution value determined by the optimization unit so as to satisfy a charge amount, a predetermined charge amount constraint, and a predetermined chargeable / dischargeable current value constraint;
Current distribution control device for parallel power storage system. The charge amount estimation unit calculates the charge amount estimation value of each auxiliary battery based on the optimum current distribution value sent from the optimization unit at the immediately preceding time,
The optimization unit, based on the current command value sent from the load device and the detection voltage of the voltage detector,
Calculate the heat loss coefficient of all auxiliary batteries by the LIB heat loss coefficient calculation means,
Calculate the heat loss coefficient of all DCDC converters by the converter heat loss calculation means,
The optimal current distribution calculation means calculates and outputs the optimal current distribution value,
The correction unit
Based on the estimated charge amount, the optimum current distribution value, the detection voltage of the voltage detector, and the current command value from the load device,
The correction parameter calculation means calculates the correction parameter using the estimated charge amount of each auxiliary battery, the allowable maximum charge amount, the allowable minimum charge amount and the target charge amount,
The current distribution command value calculation means corrects the optimum current distribution using the allowable maximum charge amount, allowable minimum charge amount, allowable maximum charge / discharge current value and correction parameter of each auxiliary battery, thereby providing a current distribution command to the DCDC converter. Calculate and output values,
The current distribution control device for a parallel power storage system according to claim 1. Main battery, at least one auxiliary battery electrically connected in parallel with the main battery, at least one DCDC converter connected between the main battery and the auxiliary battery, voltage of the auxiliary battery A current distribution control device used in a parallel power storage system having a voltage detector and a load device for detecting
The current distribution control device includes:
A charge amount estimation unit for estimating a charge amount of the auxiliary battery 102,
An optimization unit for determining a current distribution between the main battery and the auxiliary battery;
And a constraint determining unit that determines the upper limit and the lower limit of the current value flowing through the auxiliary battery in consideration of predetermined restrictions of the auxiliary battery,
The constraint determination unit is configured to generate a predetermined target charge amount based on a current command value sent from a load device, a detection voltage of the voltage detector, and a charge amount estimation value sent from a charge amount estimation unit. The upper limit and the lower limit of the current distribution command value for each auxiliary battery are determined and sent to the optimization unit so as to satisfy the predetermined charge amount constraint and the predetermined chargeable / dischargeable current value constraint,
The optimization unit, based on the current command value sent from the load device and the detection voltage of the voltage detector, the upper limit of the current distribution command value for each auxiliary battery determined by the constraint determination unit, An optimal current distribution value is determined so as to minimize the total heat loss of the main battery, the auxiliary battery, and the DCDC converter for a certain period from the current time without exceeding the lower limit.
Current distribution control device for parallel power storage system. The charge amount estimation unit calculates the charge amount estimation value of each auxiliary battery based on the optimum current distribution value sent from the optimization unit at the immediately preceding time,
Based on the detection voltage of the voltage detector, the current command value, and the charge amount estimation value, the constraint determination unit
The correction parameter calculation means calculates the correction parameter using the estimated charge amount, the maximum allowable charge amount, the minimum allowable charge amount, and the target charge amount,
Using the LIB constraint value calculation means, the upper limit and lower limit constraints on the current value of each LIB are determined using the allowable maximum charge amount, allowable minimum charge amount, allowable maximum charge / discharge current value, and correction parameter of each auxiliary battery,
The optimization unit, based on the current command value sent from the load device, the detection voltage of the voltage detector, and the predetermined constraint of the auxiliary battery,
Calculate the heat loss coefficient of all auxiliary batteries by the LIB heat loss coefficient calculation means,
Calculate the heat loss coefficient of all DCDC converters by the converter heat loss calculation means,
The optimal current distribution calculation means calculates and outputs an optimal current distribution value under the constraints of the upper limit and the lower limit of the current value of the auxiliary battery,
The current distribution control device for a parallel power storage system according to claim 3.

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