JP2013053884A - Voltage measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage measurement device having a uniform characteristic of filter frequency of each measurement channel while reducing the number of components.SOLUTION: In the voltage measurement device 10, an electrostatic capacitance Cof each capacitor 32 satisfies a relation of C>C, and when τ is expressed as an optionally set filter time constant, a resistance value Rof each resistor 30 has following relations (1) to (3): R=τ/{2(C-C)} (1), R={(2n-1)×τ}/{2(C-C)} (2), and R={(2m-1)×τ}/2C(3).

Description

  The present invention relates to a voltage measuring device that measures the voltage of an assembled battery composed of a plurality of cells connected in series.

  A voltage measuring device for measuring the voltage of an assembled battery composed of a plurality of cells connected in series has been developed (Patent Document 1 and Patent Document 2).

  Patent Document 1 corrects crosstalk (voltage mutual interference) between cells that occurs in the output voltage measured for each cell due to the influence of components that are commonly used when additional components are used in common between cells. Thus, an object of the present invention is to provide a power supply voltage measuring device that accurately measures an output voltage ([0005], summary).

  In order to achieve the object, in Patent Document 1, a capacitor 6a is connected between resistors 5a to 5f connected to both ends of a battery 2 composed of a plurality of cells 2a to 2e and respective contacts of the cells 2a to 2e. The output voltage of each of the cells 2a to 2e is measured through a filter that uses the resistance connected to the contacts of the cells 2a to 2e in common with the cells 2a to 2e. The voltage detection means by the photo MOS relays 7a to 7f and the voltage measurement circuit 8 for detecting the voltage across the capacitors 6a to 6e corresponding to the plurality of cells 2a to 2e, and the voltage across the capacitors 6a to 6e And a high-voltage measurement CPU 1 that calculates the output voltage of each of the cells 2a to 2e before the voltage across the capacitors 6a to 6e changes based on the amount of change per unit time (summary). It is assumed that the resistance values of the resistors 5a to 5f are all the same, and the capacitance values of the capacitors 6a to 6e are all the same ([0019]).

  In Patent Document 2, an object is to provide a battery module voltage detection device capable of reducing a difference in frequency response between battery modules that detect voltage ([0006], summary). In order to solve the problem, in Patent Document 2, a plurality of switches Sw1 to Sw2m connected to both terminals of each of the battery modules E1 to Em constituting the assembled battery 11, and both terminals of the battery modules E1 to Em and a switch Sw1 are used. To R2 (m + 1) having the same resistance value except the one located in the center when m is an even number, and switches of the resistors R1 to R (m + 1). A filter 12 including capacitors C1 to C2m having the same capacitance connected in parallel in the column direction of the assembled battery 11 is provided on the Sw1 to Sw2m side. Capacitors C1 to C2m are divided into a first capacitor group and a second capacitor group in parallel with the first capacitor group, and are symmetrical with respect to the + side terminal and the − side terminal with the center of the assembled battery 11 as the turning point. (Summary).

JP-A-2005-003618 JP 2009-150867 A

  As described above, in the voltage measurement device of Patent Document 1, so-called RC filters can be configured using the resistors 5a to 5f and the capacitors 6a to 6e, but the resistance values of the resistors 5a to 5f are all the same. It is assumed that the capacitance values of the capacitors 6a to 6e are all the same. For this reason, in the RC filter itself of Patent Document 1, the filter frequency characteristics of each measurement channel are different.

  In addition, in the voltage detection device of Patent Document 2, it is possible to match the filter frequency characteristics of each measurement channel from the configuration of the RC filter itself, but a plurality of resistors and a plurality of switches are required for each measurement channel. The score will increase.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a voltage measuring apparatus in which the frequency characteristics of each measurement channel are uniform while reducing the number of parts.

The voltage measuring device according to the present invention measures the voltage of an assembled battery in which an odd number of cells other than 1 are connected in series, and a plurality of voltage detectors are connected to both ends of each voltage detector. Between the plurality of measurement nodes to be measured and the measurement node n located at the nth (n is an integer from 1 to m) counting from the center of the measurement node row and the measurement node n + 1 located at the (n + 1) th. A plurality of capacitors connected to each other and having a capacitance of C _n, and a plurality of cell-side nodes arranged between the cells and at both ends of the cell column, and a measurement node n, respectively, A plurality of resistors whose values are R _n , the capacitance C _n of each capacitor satisfies C _n > C _{n + 1} , and τ is an arbitrarily set filter time constant, the resistance value of each resistor R _n has the following formula (1) - (3 And it satisfies the.
R ₁ = τ / {2 (C ₁ -C ₂ )} (1)
R _n = {(2n−1) · τ} / {2 (C _n −C _{n + 1} )} (2)
R _m = {(2m−1) · τ} / 2C _m (3)

  According to the present invention, it is possible to configure a multistage filter circuit in which the filter frequency characteristics of each odd number of measurement channels are uniform while reducing the number of resistors.

  That is, according to the present invention, the resistance is connected between each cell and between the cell-side node disposed outside the cells at both ends and the measurement node n, so that the required number of resistors is the number of cells. +1. Therefore, the number of resistors can be reduced as compared with the case where two resistors are separately provided for each measurement channel.

Multiple Further, in the present invention, which are respectively connected between the measurement node n and the measuring node n + 1 located at the n + 1 th counted from the center of the measuring node sequence located n-th, is capacitance and C _n, respectively comprising of a capacitor, it is connected between the cell side node and the measuring node n, the resistance value of a plurality of resistors and R _n. These capacitors and resistors form a multistage (odd number) RC filter.

When τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following relationships (1) to (3).
R ₁ = τ / {2 (C ₁ -C ₂ )} (1)
R _n = {(2n−1) · τ} / {2 (C _n −C _{n + 1} )} (2)
R _m = {(2m−1) · τ} / 2C _m (3)

  According to the above formulas (1) to (3), the frequency characteristic (filter time constant) of the RC filter at each stage can be made uniform.

Furthermore, according to the above formulas (1) to (3), the capacitance C _n of each capacitor only needs to satisfy the condition of C _n > C _{n + 1} . For this reason, the capacitance C _n of each capacitor has a relatively high degree of freedom, and it is possible to use a general-purpose product with a low price for each capacitor. On the other hand, there are many choices for the resistance value of the general-purpose resistor as compared with the choice of capacitance for the general-purpose capacitor, and a trimming resistor capable of arbitrarily adjusting the resistance value is generally available. In addition, the resistance value can be easily adjusted by combining the series and the parallel. Therefore, it is possible to reduce the cost of the multistage filter circuit.

  In addition, the cell here means what is regarded as one power generation source on the circuit, and means not only physically one cell but also a combination of a plurality of cells (so-called cell module). (Same below).

The voltage measuring apparatus according to the present invention measures the voltage of an assembled battery in which an even number of cells are connected in series, and includes a plurality of voltage detection units and a plurality of voltage detection units connected at both ends. Are connected to the measurement node n located at the nth (n is an integer from 0 to m) and the measurement node n + 1 located at the (n + 1) th, respectively. A plurality of capacitors each having a capacitance of C _n, and a plurality of cell-side nodes arranged between the cells and at both ends of the cell row, and the measurement node n are connected to each other, and the resistance value is R _n. And the capacitance of each capacitor satisfies C _n > C _{n + 1} and when τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor is: Satisfying the equations (4) to (6) And butterflies.
R ₁ = τ / (C ₁ -C ₂ ) (4)
R _n = (n · τ) / (C _n −C _{n + 1} ) (5)
R _m = (m · τ) / C _m (6)

  According to the present invention, it is possible to configure a multistage filter circuit in which the filter frequency characteristics of the even number of measurement channels are uniform while reducing the number of resistors.

  That is, according to the present invention, the resistance is connected between each cell and between the cell-side node disposed outside the cells at both ends and the measurement node n, so that the required number of resistors is the number of cells. +1. Therefore, the number of resistors can be reduced as compared with the case where two resistors are separately provided in each stage.

Multiple Further, in the present invention, which are respectively connected between the measurement node n and the measuring node n + 1 located at the n + 1 th counted from the center of the measuring node sequence located n-th, is capacitance and C _n, respectively comprising of a capacitor, it is connected between the cell side node and the measuring node n, the resistance value of a plurality of resistors and R _n. These capacitors and resistors form a multi-stage (even-numbered stage) RC filter.

When τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following relationships (4) to (6).
R ₁ = τ / (C ₁ -C ₂ ) (4)
R _n = (n · τ) / (C _n −C _{n + 1} ) (5)
R _m = (m · τ) / C _m (6)

  According to the above formulas (4) to (6), the frequency characteristics (filter time constant) of the RC filter at each stage can be made uniform.

Furthermore, according to the above formulas (4) to (6), the capacitance C _n of each capacitor only needs to satisfy the condition of C _n > C _{n + 1} . For this reason, the capacitance C _n of each capacitor has a relatively high degree of freedom, and it is possible to use a general-purpose product with a low price for each capacitor. On the other hand, there are many choices for the resistance value of the general-purpose resistor as compared with the choice of capacitance for the general-purpose capacitor, and a trimming resistor capable of arbitrarily adjusting the resistance value is generally available. In addition, the resistance value can be easily adjusted by combining the series and the parallel. Therefore, the cost of the multistage RC filter can be suppressed.

The voltage measuring apparatus according to the present invention measures the voltage of a battery pack having a cell string in which odd-numbered cells other than 1 are connected in series, and includes a node between cells and nodes at both ends of the cell string. The number of cells connected to each of the cells is connected to the positive electrode side and the negative electrode side of each cell through one wiring, and voltage detecting means for detecting the voltage across each cell, and the number of cells provided on each of the wirings + 1 A plurality of resistors and capacitors of the same number as the number of cells constituting the RC filter in combination with the resistors provided between the adjacent wirings, the positive electrode side of the central cell being a cell located in the center of the cell row, and The electrostatic capacitance of the nth capacitor (n is an integer from 1 to m) counted from the central capacitor that is the capacitor provided between the two wires connecting the negative electrode side and the voltage detection means. capacity When the C _n, the capacitance of each capacitor meets the C _n> C _n + _1, when arbitrarily set the filter time constant tau, resistance R _n of each resistor has the following formula (7) (9) is satisfied.
R ₁ = τ / {2 (C ₁ -C ₂ )} (7)
R _n = {(2n−1) · τ} / {2 (C _n −C _{n + 1} )} (8)
R _m = {(2m−1) · τ} / 2C _m (9)

The voltage measuring device according to the present invention measures a voltage of a battery pack having a cell string in which an even number of cells are connected in series, and is connected to a node between each cell and each of nodes at both ends of the cell string. The number of cells formed is connected to the positive electrode side and the negative electrode side of each cell through one wiring, and voltage detecting means for detecting the voltage across each cell, and the number of cells provided on the wiring plus one resistor And a positive electrode side and a negative electrode of a central cell, which is two cells located in the center of the cell row, and is provided between adjacent wirings and has the same number of capacitors as the number of cells constituting an RC filter in combination with the resistor. The nth capacitor (n is an integer from 1 to m) counted from the central capacitor, which is the two capacitors provided between the three wires connecting the side and the voltage detecting means. Electric When the amount as C _n, the capacitance of each capacitor meets the C _n> C _n + _1, when arbitrarily set the filter time constant tau, resistance R _n of each resistor has the following formula ( 10) to (12) are satisfied.
R ₁ = τ / (C ₁ -C ₂ ) (10)
R _n = (n · τ) / (C _n −C _{n + 1} ) (11)
R _m = (m · τ) / C _m (12)

  According to the present invention, it is possible to configure a multistage filter circuit in which the filter frequency characteristics of the odd or even number of measurement channels are uniform while reducing the number of resistors.

1 is a circuit diagram showing an overall configuration of a voltage measuring apparatus according to a first embodiment of the present invention. It is a circuit diagram which shows the structure of the multistage filter circuit of the 1st voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 1st Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the 2nd voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 1st Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the 3rd voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 1st Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the 4th voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 1st Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the voltage measuring device which concerns on the said 1st Embodiment. FIG. 7 is a diagram illustrating specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit of FIG. 6. It is a figure which shows an example of the frequency characteristic of each RC filter at the time of using the multistage filter circuit of FIG. FIG. 8 is a diagram illustrating specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit according to the first comparative example of the specific example of FIG. 7. It is a figure which shows an example of the frequency characteristic of each RC filter at the time of using the multistage filter circuit of FIG. FIG. 8 is a diagram illustrating specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit according to the second comparative example of the specific example of FIG. 7. It is a figure which shows an example of the frequency characteristic of each filter at the time of using the multistage filter circuit of FIG. It is a circuit diagram which shows the structure of the multistage filter circuit of the 1st voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on 2nd Embodiment of this invention. It is a circuit diagram which shows the structure of the multistage filter circuit of the 2nd voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 2nd Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the 3rd voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 2nd Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the 4th voltage measurement apparatus used in order to demonstrate the structure of the voltage measurement apparatus which concerns on the said 2nd Embodiment. It is a circuit diagram which shows the structure of the multistage filter circuit of the voltage measuring device which concerns on the said 2nd Embodiment. FIG. 18 is a diagram illustrating specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit of FIG. 17. It is a figure which shows an example of the frequency characteristic of each RC filter at the time of using the multistage filter circuit of FIG. FIG. 19 is a diagram showing specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit according to the first comparative example of the specific example of FIG. 18. It is a figure which shows an example of the frequency characteristic of each RC filter at the time of using the multistage filter circuit of FIG. FIG. 19 is a diagram illustrating specific examples of numerical values of resistors and capacitors in the configuration of the multistage filter circuit according to the second comparative example of the specific example of FIG. 18. It is a figure which shows an example of the frequency characteristic of each RC filter at the time of using the multistage filter circuit of FIG. It is a circuit diagram which shows the structure of the multistage filter circuit of the voltage measuring device which concerns on a modification.

A. First embodiment (odd-stage RC filter)
[A-1. Overall configuration]
FIG. 1 is a circuit diagram showing an overall configuration of a voltage measuring apparatus 10 according to the first embodiment. As shown in FIG. 1, the voltage measuring apparatus 10 includes an assembled battery 12 having a cell row 14 in which an odd number of cells 16 other than 1 are connected in series, and a voltage between both ends of each cell 16 (hereinafter referred to as “cell voltage Vcell”). The voltage measuring circuit 18 to which the cell voltage Vcell is detected based on the output of the voltage measuring circuit 18.

  Between the node between the cells 16 and the cell side node 22 which is a node at both ends of the cell row 14, and the + side input terminal 26 and the − side input terminal 28 of the voltage measurement circuit 18, the number of cells + 1 wiring 24 Is arranged. Thereby, the positive electrode side and the negative electrode side of each cell 16 are connected to the + side input terminal 26 or the − side input terminal 28 of the voltage measurement circuit 18.

  More specifically, the positive side of a certain cell 16 {eg, the central cell 16 in FIG. 1 (hereinafter also referred to as “central cell 16 mid”)} is connected to the + side input terminal 26 of the voltage measurement circuit 18. The negative side of the central cell 16mid is connected to the negative input terminal 28 of the voltage measurement circuit 18. Further, the positive side of the cell 16 adjacent to the central cell 16mid (for example, the cell 16 that is one or one lower than the central cell 16mid in FIG. 1) is connected to the negative input terminal 28 of the voltage measuring circuit 18. The negative electrode side of the cell 16 is connected to the + side input terminal 26 of the voltage measurement circuit 18.

  A resistor 30 is provided on each wiring 24, and a capacitor 32 is provided between each adjacent wiring 24. Therefore, a so-called RC filter 34 is formed for each combination of one capacitor 32 and two resistors 30. Hereinafter, a combination of the RC filters 34 is referred to as a multistage filter circuit 36.

  Further, a switch 38 is disposed on each wiring 24 on the voltage measurement circuit 18 side with respect to each capacitor 32. Each switch 38 is, for example, a semiconductor switch, and is turned on / off according to a control signal from the control unit 40.

  The control unit 40 turns each switch 38 on and off so that each cell 16 is connected to the voltage measurement circuit 18 in order. For example, when the central cell 16mid and the voltage measurement circuit 18 are connected, the two switches 38 on the two wires 24 connecting the central cell 16mid and the voltage measurement circuit 18 are turned on and the other switches 38 are turned off. To do. As a result, a measurement channel CH that connects each cell 16 and the voltage measurement circuit 18 is formed, and the output of the voltage measurement circuit 18 indicates the cell voltage Vcell of each cell 16. The number of measurement channels CH is the same as the number of cells 16 (number of cells).

  The assembled battery 12 in this embodiment can be either a primary battery or a secondary battery, for example. The primary battery here includes a fuel cell. The secondary battery mentioned here includes a lithium ion battery, a nickel metal hydride battery, and a capacitor.

  For example, the basic configuration of the voltage measuring apparatus 10 can be the one described in Patent Document 1.

  Since the voltage measuring apparatus 10 according to the first embodiment has the configuration as described above, the odd number of cells 16 is provided with an even number (number of cells + 1) of resistors 30 and an odd number of cells (the same number as the number of cells). Capacitor 32 and an even number (number of cells + 1) of switches 38.

For convenience of explanation, in FIG. 1, the middle two resistors 30 (that is, the resistors 30 connected to both ends of the center cell 16mid) are referred to as “center resistors 30mid”. The resistance value of each resistor 30 is expressed as R _10n . The subscript n is an integer from 1 to m, and indicates the number counted from the central resistance 30 mid. For example, the two central resistor 30mid resistance value itself is _{R 101,} respectively. Resistance values of the two resistors 30 adjacent to each central resistor 30mid is _{R 102,} respectively. Here, m is an integer of (number of cells + 1) / 2. Accordingly, the total number of cells 16 (number of cells) is 2m−1, and the total number of resistors 30 is 2 m.

Similarly, for convenience of explanation, in FIG. 1, one capacitor 32 located in the middle (that is, the capacitor 32 corresponding to the center cell 16mid is referred to as “center capacitor 32mid”). In addition, the capacitance of each capacitor 32 is expressed as C _10n . The subscript “n” is the same as above. In other words, n indicates the number from the central capacitor 32mid. For example, the capacitance of the central capacitor 32mid itself is _{C 101.} The capacitance of the two capacitors 32 adjacent to the central capacitor 32mid are _{C 102,} respectively. The total number of capacitors 32 is 2m-1, which is the same as the number of cells.

  Further, nodes at both ends of each capacitor 32 are referred to as “measurement nodes 44”. Two adjacent measurement nodes 44 form a measurement channel CH corresponding to a single cell 16 with the voltage measurement circuit 18.

[A-2. Basic concept of resistance and capacitance]
Next, a method for setting the resistance value R _10n of the resistor 30 and the capacitance C _10n of the capacitor 32 in the first embodiment will be described.

  2 to 5 are first to fourth voltage measuring devices 100A to 100D (hereinafter also referred to as “voltage measuring devices 100A to 100D”) used to describe the configuration of the voltage measuring device 10 according to the first embodiment. It is a circuit diagram which shows the structure of these multistage filter circuits 136a-136d. FIG. 6 is a circuit diagram showing a configuration of the multistage filter circuit 36 of the voltage measuring apparatus 10 according to the first embodiment. In the following, the same components as those shown in FIG.

  As described above, FIGS. 2 to 5 are for explaining the configuration of the voltage measurement device 10 according to the first embodiment, and do not show the configuration of the voltage measurement device 10 itself. Note that the structure of itself is shown in FIG. In addition, in the voltage measurement devices 100A to 100D for explanation and the voltage measurement device 10 according to the first embodiment, the number of measurement channels CH is an odd number (odd number) of multistage filter circuits 36, 136a to 136d ( (Hereinafter also referred to as “filter circuits 36, 136a to 136d”).

  The voltage measurement devices 10 and 100A to 100D include the voltage measurement circuit 18, the calculation unit 20, the switch 38, the control unit 40, and the like, as in FIG. 1, but are omitted in FIGS.

  The multistage filter circuit 136a of the voltage measuring apparatus 100A of FIG. 2 includes an assembled battery 12 including a cell array 14 in which odd (five) cells 16 are connected in series, an even (six) resistors 30, and an odd number. And three (three) capacitors 132a to 132c. The capacitor 132a is connected to the positive electrode side and the negative electrode side of the central cell 16mid. The capacitor 132b is connected to the positive electrode side and the negative electrode side of the cell row including the central cell 16mid and the two cells 16 on both sides thereof. The capacitor 132c is connected to the positive electrode side and the negative electrode side of the cell row in which the central cell 16mid and the two cells 16 on both sides thereof are combined.

As in FIG. 1, the resistance value R _10n of each resistor 30 is R ₁₀₁ , R ₁₀₁ , R ₁₀₂ , R ₁₀₂ , R ₁₀₃ , R ₁₀₃ from the two central resistors 30 mid toward the outside (vertical direction in FIG. 2). And The resistance values C _11n of the capacitors 132a to 132c are C ₁₁₁ , C ₁₁₂ , and C ₁₁₃ , respectively.

In the multistage filter circuit 136a of FIG. 2, the RC product (R _10n · C _11n ) (where n is an integer of 1 to 3) of each RC filter 34 is equal, and the voltage of each cell 16 (cell voltage) Assume that Vcell) is uniform. In this case, the voltage across the capacitor 132b is three times the voltage across the capacitor 132a, and the voltage across the capacitor 132c is five times the voltage across the capacitor 132a. For this reason, the output voltages V ₁ , V ₂ , V ₃ of each RC filter 34 are uniform.

As shown in FIG. 3, the capacitor 132b shown in FIG. 2 can be replaced with a series connection of three capacitors 132d having a capacitance C ₁₁₂ × 3 that is three times as large. Since the voltage between both ends of the capacitor 132d is equally divided into three, the voltage at the point B in FIG.

Similarly, as shown in FIG. 3, the capacitor 132c shown in FIG. 2 can be replaced with a series connection of five capacitors 132e having a capacitance C ₁₁₃ × 5 that is five times as large. Since the voltage across the capacitor 132e is equally divided into five, the voltage at point C in FIG. 3 is equal to the voltage at point A and point B. Similarly, the voltage at point D is equal to the voltage at point E.

From the above, the capacitors 132d divided, the midpoint of 132e (adjacent capacitor 132d, the intermediate portion of 132e) be connected to the wiring 24 as shown in FIG. 4, the output voltage _V 1, _{V 2} of the RC filter 34 , _{V 3} does not change the configuration of FIG. 2.

Here, as shown in FIG. 5, each capacitor group connected in parallel in FIG. 4 is replaced with one capacitor. That is, the capacitors 132a, 132d, and 132e between the wirings 24 connected to the positive electrode side and the negative electrode side of the central cell 16mid are replaced with one capacitor 132f. The capacitors 132d and 132e between the wirings 24 connected to the positive electrode side and the negative electrode side of each of the two cells 16 adjacent to the central cell 16mid are replaced with one capacitor 132g. The capacitor 132e between the wirings 24 connected to the positive electrode side and the negative electrode side of the cell 16 at both ends of the cell row 14 is replaced with one capacitor 132h. Here, assuming that the capacitances of the capacitors 132f, 132g, and 132h are C ₁₀₁ , C ₁₀₂ , and C ₁₀₃ , respectively, the capacitances C ₁₀₁ , C ₁₀₂ , and C ₁₀₃ are represented by the relationship between FIG. 4 and FIG. It is calculated | required by following Formula (1)-(3), respectively.
C ₁₀₁ = C ₁₁₁ + 3 × C ₁₁₂ + 5 × C ₁₁₃ (1)
C ₁₀₂ = 3 × C ₁₁₂ + 5 × C ₁₁₃ (2)
C ₁₀₃ = 5 × C ₁₁₃ (3)

Here, when the filter time constant in the multistage filter circuit 136a of FIG. 2 is τ, the relationship of the following expression (4) is established in FIG.
τ = 2 × R ₁₀₁ × C ₁₁₁ (4)

As described above, since the configuration of FIG. 2 can be replaced as shown in FIG. 5, the following equation (5) is established.
τ = 2 × R ₁₀₁ × (C ₁₀₁ −C ₁₀₂ ) (5)

Similarly, when the filter time constant in the multistage filter circuit 136a of FIG. 2 is τ, the relationship of the following equation (6) is established in FIG.
τ = 2 × R ₁₀₂ × C ₁₁₂ (6)

As described above, since the configuration of FIG. 2 can be replaced as shown in FIG. 5, the following equation (7) is established.
τ = 2 × R ₁₀₂ × (C ₁₀₂ −C ₁₀₃ ) / 3 (7)

Similarly, when the filter time constant in the multistage filter circuit 136a of FIG. 2 is τ, the relationship of the following equation (8) is established in FIG.
τ = 2 × R ₁₀₃ × C ₁₁₃ (8)

Here, as described above, since the configuration of FIG. 2 can be replaced as shown in FIG. 5, the following equation (9) is established.
τ = 2 × R ₁₀₃ × C _103/5 (9)

  Based on the above, the odd number stage (2m−1) {m is an integer of (number of cells + 1) / 2 in the voltage measurement apparatus 10 according to the first embodiment. } Has a configuration as shown in FIG. Specifically, the filter circuit 36 includes an odd number (2m−1) of cells 16, an even number (2m) of resistors 30, and an odd number (2m−1) of capacitors 32.

The resistor 30 and the capacitor 32 constituting the RC filter 34 are arranged vertically symmetrically about the center cell 16mid or the center capacitor 32mid, and the capacitance C of the capacitor 32 at any n (where 1 ≦ n ≦ m−1). _{10n is} arbitrarily set from _{C 101} to _{C 10 m} so as to satisfy _{C 10n>} C _{10n + 1.}

Further, the resistance value R _10n of each resistor 30 is set so that the following equations (10) to (12) are satisfied when the filter time constant of the RC filter 34 is τ.

By setting the capacitance C _10n and the resistance value R _10n as described above, it is possible to make the filter time constant τ uniform by the RC filters 34 themselves of the multistage filter circuit 36.

[A-3. Specific Examples and First and Second Comparative Examples]
FIG. 7 is a diagram showing a specific example (first embodiment) of the numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 36 of FIG. FIG. 8 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 36 of FIG. 7 is used. In FIG. 8, the horizontal axis represents the frequency [Hz] (however, logarithmic notation) of the input signal to the RC filter 34, and the vertical axis represents the gain [dB]. 8 shows the filter characteristics when the input signals of the cell voltages Vcell (V ₁ , V ₂ , V ₃ , V ₄ ) of the _four cells 16 from the bottom in FIG. 7 are input to the RC filter 34. (The same applies to FIGS. 10, 12, 19, 21, and 23).

  FIG. 9 is a diagram showing a specific example of the numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 536a according to the first comparative example. FIG. 10 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 536a of FIG. 9 is used. FIG. 11 is a diagram illustrating a specific example of numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 536b according to the second comparative example. FIG. 12 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 536b of FIG. 11 is used.

  7, 9, and 11, the cell 16 is indicated by an AC symbol, which indicates that the cell 16 is a battery cell, and the voltage fluctuates due to charging and discharging.

The multistage filter circuit 536a according to the first comparative example shown in FIG. 9 has the same circuit arrangement as the multistage filter circuit 36 according to the first embodiment shown in FIG. 7, but each resistance value R _10n of each resistor 30 and each Each capacitance C _10n of the capacitor 32 is different from that of the first embodiment. More specifically, in the multi-stage filter circuit 536a, the resistance values R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , and R _{104 of the} resistors 30 are all the same at 5 kΩ, and the capacitances C ₁₀₁ and C _{102 of the} capacitors 32 are the same. , C ₁₀₃ , and C ₁₀₄ are the same at 1 μF.

  As shown in FIG. 10, according to the multistage filter circuit 536a of FIG. 9, the variation in the frequency characteristics of the RC filter 34 of each stage (each measurement channel CH) becomes large.

A multistage filter circuit 536b according to the second comparative example shown in FIG. 11 has a circuit arrangement different from that of the multistage filter circuit 36 according to the first embodiment shown in FIG. 7, and for example, the configuration shown in Patent Document 1 is applied. is there. More specifically, the multistage filter circuit 536b includes two resistors 30 and one capacitor 32 for each RC filter 34 (or cell 16). The resistance values R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , and R _{104 of the} resistors 30 are the same at 5 kΩ, and the capacitances C ₁₀₁ , C ₁₀₂ , C ₁₀₃ , and C _{104 of the} capacitors 32 are the same at 1 μF. is there.

  As shown in FIG. 12, according to the multistage filter circuit 536b of FIG. 11, the frequency characteristics of the RC filter 34 of each stage (each measurement channel CH) are uniform, but the number of resistors 30 increases. In addition, the number of switches 38 (not shown) disposed between the multistage filter circuit 536b and the voltage measurement circuit 18 (not shown) also increases.

On the other hand, in the multi-stage filter circuit 36 according to the first embodiment, although what the circuit configuration is the same as the first comparative example, as shown in FIG. 7, the the highest capacitance C _10n of the capacitor 32, a central The capacitance C _10n of the capacitor 32 decreases from the center toward the outside (upper side and lower side in FIG. 7). That is, C ₁₀₂ is smaller than C ₁₀₁ , C ₁₀₃ is smaller than C ₁₀₂ , and C ₁₀₄ is smaller than C ₁₀₃ . Each resistor 30 in FIG. 7 is set so as to satisfy the relationships of the above formulas (10) to (12).

  The multistage filter circuit 36 shown in FIG. 7 is designed in the following order, for example. That is, a required filter time constant τ is set. In the first embodiment, τ = 10 msec.

Next, the capacitance C _10n of the capacitor 32 is determined. As described above, in the first embodiment, the capacitance C _10n of each capacitor 32 only needs to satisfy C _10n > C _{10n + 1} . For this reason, each capacitance C _10n can be set relatively freely. In the first embodiment, C ₁₀₁ = 1 uF, C ₁₀₂ = 0.68 uF, C ₁₀₃ = 0.47 uF, and C ₁₀₄ = 0.33 uF.

  In general, the capacitance of a capacitor is often manufactured in accordance with a standard (for example, E6 series or E12 series), and a special order product is required to realize an intermediate capacitance.

However, in the first embodiment, since the capacitance C _10n of each capacitor 32 only needs to satisfy C _10n > C _{10n + 1} , it is possible to select a commercially available product or a general-purpose product. In addition, it is preferable that the specification of each capacitor | condenser 32 considers other elements (for example, the pressure | voltage resistant limit of the capacitor | condenser 32).

After setting the capacitance C _10n of each capacitor 32, the resistance value R _10n of the resistor 30 is calculated so as to satisfy the above equations (10) to (12). That is, each resistance value R _10n is set to R ₁₀₁ = 15.6 kΩ, R ₁₀₂ = 71.4 kΩ, R ₁₀₃ = 179 kΩ, and R ₁₀₄ = 106 kΩ.

  As shown in FIG. 8, according to the multistage filter circuit 36 of FIG. 7, the frequency characteristics of the RC filter 34 of each stage (each measurement channel CH) are uniform.

[A-4. Effect of First Embodiment]
As described above, according to the first embodiment, it is possible to configure the multistage filter circuit 36 in which the filter frequency characteristics of the odd number of measurement channels CH are uniform while reducing the number of resistors 30.

  That is, according to the first embodiment, the resistor 30 is connected between each cell 16 and between the cell-side node 22 and the measurement node 44 arranged outside the cells 16 at both ends. The number of resistors 30 is the number of cells + 1. Therefore, the number of resistors 30 and switches 38 can be reduced as compared with the case where two resistors 30 are separately provided for each measurement channel CH.

In the first embodiment, the nth measurement node n and the (n + 1) th measurement node n + 1 are respectively connected from the center of the column of the measurement nodes 44, and the capacitance is C _10n. A plurality of capacitors 32, and a plurality of resistors 30 connected between the cell side node 22 and the measurement node 44 and having a resistance value of R _10n . These capacitors 32 and resistors 30 form a multistage RC filter 34.

When τ is an arbitrarily set filter time constant, the resistance value R _10n of each resistor 30 satisfies the relationship of the above formulas (10) to (12).

  According to the above formulas (10) to (12), the frequency characteristics (filter time constant τ) of the RC filter 34 at each stage can be made uniform.

Furthermore, according to the above formulas (10) to (12), the capacitance C _10n of each capacitor 32 only needs to satisfy the condition of C _10n > C _{10n + 1} . For this reason, the capacitance C _10n of each capacitor 32 has a relatively high degree of freedom, and it is possible to use a low-cost general-purpose product for each capacitor 32. On the other hand, there are many choices for the resistance value _R10n of the general-purpose resistor 30 compared to the choice of the capacitance _C10n for the general-purpose capacitor 32, and there are also trimming resistors and the like that can arbitrarily adjust the resistance value _R10n. Generally available. In addition, the resistance value R _10n can be easily adjusted by _combining the series and the parallel. Therefore, the cost of the multistage filter circuit 36 can be reduced.

B. Second Embodiment (Even-numbered RC filter)
[B-1. Overall configuration]
The voltage measuring apparatus 10A (FIG. 17) according to the second embodiment has basically the same configuration as the voltage measuring apparatus 10 according to the first embodiment. The difference between the two is that the voltage measuring apparatus 10 according to the first embodiment has an odd number of cells 16 and capacitors 32, and an even number of resistors 30 and switches 38, whereas the voltage measuring apparatus 10 according to the first embodiment is different. The voltage measuring apparatus 10A is that the number of cells 16 and capacitors 32 is an even number, and the number of resistors 30 and switches 38 is an odd number. In addition, in the second embodiment, the setting method of the resistance value of the resistor 30 and the capacitance of the capacitor 32 is different from that of the first embodiment.

[B-2. basic way of thinking]
13 to 16 are first to fourth voltage measuring devices 200A to 200D (hereinafter also referred to as “voltage measuring devices 200A to 200D”) used for explaining the configuration of the voltage measuring device 10A according to the second embodiment. It is a circuit diagram which shows the structure of these multistage filter circuits 236a-236d. FIG. 17 is a circuit diagram showing a configuration of the multistage filter circuit 36a of the voltage measuring apparatus 10A according to the second embodiment. In the following, the same components as those shown in the first embodiment (FIG. 1 and the like) are denoted by the same reference numerals.

  As described above, FIGS. 13 to 16 are for explaining the configuration of the voltage measuring apparatus 10A according to the second embodiment, and do not show the configuration of the voltage measuring apparatus 10A itself, but the voltage measuring apparatus 10A. Note that the structure of itself is shown in FIG. In addition, in the voltage measurement devices 200A to 200D for explanation and the voltage measurement device 10A according to the second embodiment, the multistage filter circuits 36a, 236a to 236d (the number of the even number) of the measurement channels CH are even numbers (even stages). (Hereinafter also referred to as “filter circuits 36a, 236a to 236d”).

  The voltage measuring devices 10A and 200A to 200D include the voltage measuring circuit 18, the arithmetic unit 20, the switch 38, the control unit 40, and the like, as in the first embodiment (FIG. 1), but are omitted in FIGS. Yes.

  The multistage filter circuit 236a of the voltage measuring apparatus 200A of FIG. 13 includes an assembled battery 12 including a cell array 14 in which an even number (six) cells 16 are connected in series, an odd number (seven) resistors 30, and an even number. And six (six) capacitors 232a to 232c. In the second embodiment, the two cells 16 located in the center of the cell row 14 are referred to as “central cell 16 mid”, and the resistor 30 disposed on the wiring 24 between the two central cells 16 mid is referred to as “central resistance”. 30mid ".

  Each capacitor 232a is connected to the positive side and the negative side of each central cell 16mid. Each capacitor 232b is connected to the positive electrode side and the negative electrode side of each cell row composed of two cells 16 including the central cell 16mid and the cells 16 adjacent thereto. Each capacitor 232c is connected to a positive electrode side and a negative electrode side of a cell row composed of three cells 16 including one central cell 16mid and two cells 16 on one side thereof.

The resistance value R _20n of each resistor 30 is R ₂₀₀ , R ₂₀₁ , R ₂₀₁ , R ₂₀₂ , R ₂₀₂ , R ₂₀₃ , R ₂₀₃ from one central resistor 30 mid toward the outside (in the vertical direction in FIG. 13). (The same applies to FIGS. 14 to 17.) The resistance values C _21n of the capacitors 232a to _232c are C ₂₁₁ , C ₂₁₂ , and C ₂₁₃ , respectively.

In the multistage filter circuit 236a of FIG. 13, the RC product (R _20n · C _21n ) of each RC filter 34 (where n is an integer of 0 to 3 for R _20n and 1 to 3 for C _21n. Are assumed to be equal) and the voltage of each cell 16 (cell voltage Vcell) is uniform. In this case, the voltage across the capacitor 232b is twice the voltage across the capacitor 232a, and the voltage across the capacitor 232c is four times the voltage across the capacitor 232a. For this reason, the output voltages V ₁ , V ₂ , V ₃ of each RC filter 34 are uniform.

As shown in FIG. 14, the capacitor 232b of FIG. 13 can be replaced with two capacitors 232d having a double capacitance C ₂₁₂ × 2 connected in series. Since the voltage across the capacitor 232d is equally divided into two, the voltage at point B in FIG. 14 is equal to the voltage at point A.

Similarly, as shown in FIG. 14, the capacitor 232 c of FIG. 13 can be replaced with three capacitors 232 e having a capacitance C ₂₁₃ × 3 that is three times as many as those connected in series. Since the voltage across the capacitor 232e is equally divided into three, the voltage at point C in FIG. 14 is equal to the voltage at point A and point B. Similarly, the voltage at point D is equal to the voltage at point E.

As described above, even if the middle points of the divided capacitors 232d and 232e (intermediate portions of adjacent capacitors 232d and 232e) are connected as shown in FIG. 15, the output voltages V ₁ , V ₂ , and V _{3 of the} RC filters 34 are connected. Is the same as the configuration of FIG.

Here, as shown in FIG. 16, each capacitor group connected in parallel in FIG. 15 is replaced with one capacitor. That is, the capacitors 232a, 232d, and 232e between the wirings 24 connected to the positive electrode side and the negative electrode side of each central cell 16mid are replaced with one capacitor 232f. The capacitors 232d and 232e between the wirings 24 connected to the positive electrode side and the negative electrode side of each of the two cells 16 adjacent to the central cell 16mid are replaced with one capacitor 232g. The capacitor 232e between the wirings 24 connected to the positive electrode side and the negative electrode side of the cell 16 at both ends of the cell row 14 is replaced with one capacitor 232h. Here, assuming that the capacitances of the capacitors 232f, 232g, and 232h are C ₂₀₁ , C ₂₀₂ , and C ₂₀₃ , respectively, the capacitances C ₂₀₁ , C ₂₀₂ , and C ₂₀₃ are expressed by the relationship between FIG. 15 and FIG. It is calculated | required by following Formula (13)-(15), respectively.
C ₂₀₁ = C ₂₁₁ + 2 × C ₂₁₂ + 3 × C ₂₁₃ (13)
C ₂₀₂ = 2 × C ₂₁₂ + 3 × C ₂₁₃ (14)
C ₂₀₃ = 3 × C ₂₁₃ (15)

Here, if the filter time constant in the multistage filter circuit 236a of FIG. 13 is τ, the relationship of the following equation (16) is established in FIG.
τ = R ₂₀₁ × C ₂₁₁ (16)

Since the configuration of FIG. 13 can be replaced as shown in FIG. 16 as described above, the following equation (17) is established.
τ = R ₂₀₁ × (C ₂₀₁ −C ₂₀₂ ) (17)

Similarly, when the filter time constant in the multistage filter circuit 236a of FIG. 13 is τ, the relationship of the following equation (18) is established in FIG.
τ = R ₂₀₂ × C ₂₁₂ (18)

As described above, since the configuration of FIG. 13 can be replaced as shown in FIG. 16, the following equation (19) is established.
τ = R ₂₀₂ × (C ₂₀₂ −C ₂₀₃ ) / 2 (19)

Similarly, when the filter time constant in the multistage filter circuit 236a of FIG. 13 is τ, the relationship of the following equation (20) is established in FIG.
τ = R ₂₀₃ × C ₂₁₃ (20)

Here, as described above, since the configuration of FIG. 13 can be replaced as shown in FIG. 16, the following equation (21) is established.
τ = R ₂₀₃ × C _203/3 (21)

  Based on the above, the even number stage (2m) {m is an integer of the number of cells / 2 in the voltage measuring apparatus 10A according to the second embodiment. } Has a configuration as shown in FIG. Specifically, the filter circuit 36a includes an even number (2m) of cells 16, an odd number (2m + 1) of resistors 30, and an even number (2m) of capacitors 32.

The resistor 30 and the capacitor 32 constituting the RC filter 34 are arranged vertically symmetrically around the wiring 24 connected between the two central cells 16mid or the central resistor 30mid formed thereon, and any n (however, In 1 ≦ n ≦ m−1), the capacitance C _20n of the capacitor 32 is arbitrarily set from C ₂₀₁ to C _20m so as to satisfy C _20n > C _{20n + 1} .

Further, the resistance value R _20n of each resistor 30 is set so that the following formulas (22) to (24) are satisfied when the filter time constant of the RC filter 34 is τ.

The resistance value _{R 200} of central resistor 30mid may be any value. Further, as will be described later, a configuration in which the central resistor 30mid is not provided is also possible.

By satisfying the capacitance C _20n and the resistance value R _20n as described above, it is possible to make the filter time constant τ uniform by the RC filters 34 themselves of the multistage filter circuit 36a.

[B-3. Specific Examples and First and Second Comparative Examples]
FIG. 18 is a diagram showing a specific example (second embodiment) of numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 36a of FIG. FIG. 19 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 36a of FIG. 18 is used. FIG. 20 is a diagram illustrating a specific example of the numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 636a according to the first comparative example. FIG. 21 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 636a of FIG. 20 is used. FIG. 22 is a diagram illustrating a specific example of numerical values of the resistor 30 and the capacitor 32 in the configuration of the multistage filter circuit 636b according to the second comparative example. FIG. 23 shows an example of the frequency characteristic of each RC filter 34 when the multistage filter circuit 636b of FIG. 22 is used.

  18, 20, and 22, the cell 16 is indicated by an AC symbol, which indicates that the cell 16 is a battery cell, and the voltage fluctuates due to charging and discharging.

The multistage filter circuit 636a according to the first comparative example shown in FIG. 20 has the same circuit arrangement as the multistage filter circuit 36a according to the second embodiment shown in FIG. 18, but the resistance value _R20n of each resistor 30 and each capacitor. The capacitance C _{20n of} 32 is different from that of the second embodiment. More specifically, in the multi-stage filter circuit 636a, the resistance values R ₂₀₀ , R ₂₀₁ , R ₂₀₂ , R ₂₀₃ , and R _{204 of the} resistors 30 are the same at 5 kΩ, and the capacitances C ₂₀₁ , C of the capacitors 32 are the same. ₂₀₂ , C ₂₀₃ , and C ₂₀₄ are the same at 1 μF.

  As shown in FIG. 21, according to the multistage filter circuit 636a of FIG. 20, the variation in frequency characteristics of the RC filter 34 of each stage (each measurement channel CH) becomes large.

A multi-stage filter circuit 636b according to the second comparative example shown in FIG. 22 has a circuit arrangement different from that of the multi-stage filter circuit 36a according to the second embodiment shown in FIG. 18, for example, to which the configuration shown in Patent Document 1 is applied. is there. More specifically, the multistage filter circuit 636b includes two resistors 30 and one capacitor 32 for each RC filter 34 (or cell 16). Further, the resistance values R ₂₀₁ , R ₂₀₂ , R ₂₀₃ , and R _{204 of} each resistor 30 are the same at 5 kΩ, and the capacitances C ₂₀₁ , C ₂₀₂ , C ₂₀₃ , and C _{204 of} each capacitor 32 are the same at 1 μF. .

  As shown in FIG. 23, according to the multistage filter circuit 636b of FIG. 22, the frequency characteristics of the RC filter 34 at each stage (each measurement channel CH) are uniform, but the number of resistors 30 and switches 38 is increased. End up.

On the other hand, in the multi-stage filter circuit 36a according to the second embodiment, although the circuit configuration is the same as that of the first comparative example, as shown in FIG. The capacitance C _20n of the capacitor 32 decreases from the center toward the outside (upper side and lower side in FIG. 18). That is, C ₂₀₂ is smaller than C ₂₀₁ , C ₂₀₃ is smaller than C ₂₀₂ , and C ₂₀₄ is smaller than C ₂₀₃ . Each resistor 30 in FIG. 18 is set so as to satisfy the relationships of the above equations (22) to (24).

  The multi-stage filter circuit 36a shown in FIG. 18 is designed in the following order, for example. That is, a required filter time constant τ is set. In the second embodiment, τ = 10 msec.

Next, the capacitance C _20n of the capacitor 32 is determined. As described above, in the second embodiment, the capacitance C _20n of each capacitor 32 only needs to satisfy C _20n > C _{20n + 1} . For this reason, each electrostatic capacity C _20n can be set relatively freely. In the second embodiment, C ₂₀₁ = 1 uF, C ₂₀₂ = 0.68 uF, C ₂₀₃ = 0.47 uF, and C ₂₀₄ = 0.33 uF.

  In general, the capacitance of a capacitor is often manufactured in accordance with a standard (for example, E6 series or E12 series), and a special order product is required to realize an intermediate capacitance.

However, in the second embodiment, since the capacitance C _20n of each capacitor 32 only needs to satisfy C _20n > C _{20n + 1} , a commercially available product or a general-purpose product can be selected. In addition, it is preferable that the specification of each capacitor | condenser 32 considers other elements (for example, the pressure | voltage resistant limit of the capacitor | condenser 32).

After setting the capacitance C _20n of each capacitor 32, the resistance value R _20n of the resistor 30 is calculated so as to satisfy the above equations (22) to (24). That is, let each resistance value R _20n be R ₂₀₁ = 31.3 kΩ, R ₂₀₂ = 95.2 kΩ, R ₂₀₃ = 214 kΩ, and R ₂₀₄ = 121 kΩ.

  As shown in FIG. 19, according to the multistage filter circuit 36a of FIG. 18, the frequency characteristics of the RC filter 34 of each stage (each measurement channel CH) are uniform.

[B-4. Effect of Second Embodiment]
As described above, according to the second embodiment, it is possible to configure the multistage filter circuit 36a in which the filter frequency characteristics of the even number of measurement channels CH are uniform while reducing the number of resistors 30.

  That is, according to the second embodiment, the resistor 30 is connected between each cell 16 and between the cell-side node 22 and the measurement node 44 arranged outside the cells 16 at both ends. The number of resistors 30 is the number of cells + 1. Therefore, the number of resistors 30 and switches 38 can be reduced as compared with the case where two resistors 30 are separately provided for each measurement channel CH.

In the second embodiment, the nth measurement node 44 and the (n + 1) th measurement node 44 are respectively connected from the center of the column of the measurement nodes 44, and the capacitance is C _20n. A plurality of capacitors 32, and a plurality of resistors 30 connected between the cell side node 22 and the measurement node 44 and having a resistance value of R _20n . These capacitors 32 and resistors 30 form a multistage RC filter 34.

When τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor 30 satisfies the relationship of the above equations (22) to (24).

  According to the above formulas (22) to (24), the frequency characteristics (filter time constant τ) of the RC filter 34 at each stage can be made uniform.

Furthermore, according to the above formulas (22) to (24), the capacitance C _20n of each capacitor 32 only needs to satisfy the condition of C _20n > C _{20n + 1} . For this reason, the capacitance C _20n of each capacitor 32 has a relatively high degree of freedom, and it is possible to use a low-cost general-purpose product for each capacitor 32. On the other hand, there are many options for the resistance value R _20n of the general-purpose resistor 30 compared with the options of the capacitance C _20n for the general-purpose capacitor 32, and there are also trimming resistors and the like that can arbitrarily adjust the resistance value R _20n. Generally available. In addition, the resistance value R _20n can be easily adjusted by _combining the series and the parallel. Therefore, the cost of the multistage filter circuit 36a can be reduced.

C. Modifications It should be noted that the present invention is not limited to the above-described embodiments, and it is needless to say that various configurations can be adopted based on the description in the specification, claims, or drawings. For example, the following configuration can be adopted.

  In each of the above embodiments, each cell 16 and one voltage measurement circuit 18 are connected. However, the voltage measurement circuit 18 is not limited to this as long as it is two or more and not more than the number of cells.

  In each of the above-described embodiments, it has been described that a general-purpose product can be used as the capacitor 32 as an effect. However, the capacitor 32 does not necessarily have to be a general-purpose product, and may be a custom-made product.

  In the second embodiment (FIG. 17), the central resistor 30mid is provided on the wiring 24 connected between the two central cells 16mid. However, a configuration in which the central resistor 30mid is not provided is also possible.

  FIG. 24 is a circuit diagram showing a partial configuration of a voltage measuring device 10B according to a modification. The voltage measuring device 10B includes a multistage filter circuit 36b that does not have a central resistance 30mid. In the multistage filter circuit 36b, the wiring 24 connected between the two central cells 16mid is connected to the ground.

  Note that, as described above, each cell 16 can be configured not only when each cell 16 is configured by one physical cell but also by a module including two or more equal numbers of physical cells.

DESCRIPTION OF SYMBOLS 10, 10A, 10B ... Voltage measuring device 12 ... Battery assembly 14 ... Cell train 16 ... Cell 16mid ... Central cell 18 ... Voltage measuring circuit (voltage detection means)
22 ... Cell side node 24 ... Wiring 30 ... Resistance 30mid ... Central resistor 32 ... Capacitor 32mid ... Central capacitor 34 ... RC filter 36, 36a, 36b ... Multi-stage filter circuit 44 ... Measurement node CH ... Measurement channel (voltage detection unit)

Claims (4)

A voltage measuring device for measuring a voltage of an assembled battery in which an odd number of cells other than 1 are connected in series,
A plurality of voltage detectors;
A plurality of measurement nodes to which both ends of each voltage detection unit are respectively connected;
A capacitance is respectively connected between a measurement node n located at the nth (n is an integer from 1 to m) counting from the center of the measurement node row and a measurement node n + 1 located at the (n + 1) th. A plurality of capacitors with C _n ,
Are respectively connected between the plurality of cells side node disposed at both ends of and between the cell columns of each cell and the measuring node n, the resistance value and a plurality of resistors and R _n,
The capacitance C _n of each capacitor satisfies C _n > C _{n + 1} ,
A voltage measuring device characterized in that when τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following equations (1) to (3).
R ₁ = τ / {2 (C ₁ -C ₂ )} (1)
R _n = {(2n−1) · τ} / {2 (C _n −C _{n + 1} )} (2)
R _m = {(2m−1) · τ} / 2C _m (3) A voltage measuring device that measures the voltage of an assembled battery in which an even number of cells are connected in series,
A plurality of voltage detectors;
A plurality of measurement nodes to which both ends of each voltage detection unit are respectively connected;
A capacitance is respectively connected between a measurement node n located at the nth (n is an integer from 0 to m) counting from the center of the measurement node row and a measurement node n + 1 located at the (n + 1) th. A plurality of capacitors _denoted C _n ;
Are respectively connected between the plurality of cells side node disposed at both ends of and between the cell columns of each cell and the measuring node n, the resistance value and a plurality of resistors and R _n,
The capacitance of each capacitor satisfies C _n > C _{n + 1} ,
A voltage measuring device characterized in that when τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following equations (4) to (6).
R ₁ = τ / (C ₁ -C ₂ ) (4)
R _n = (n · τ) / (C _n −C _{n + 1} ) (5)
R _m = (m · τ) / C _m (6) A voltage measuring device for measuring a voltage of a battery pack having a cell string in which an odd number of cells other than 1 are connected in series,
Voltage detection means for detecting the voltage across each cell, connected to the positive and negative sides of each cell via the number of cells connected to the node between each cell and each node at both ends of the cell column + 1 wire When,
The number of cells provided on each of the wirings plus one resistor;
Including the same number of capacitors as the number of cells constituting the RC filter in combination with the resistor provided between the adjacent wirings;
The nth (nth (n) th nth counting from the central capacitor which is the capacitor provided between the two wirings connecting the positive electrode side and the negative electrode side of the central cell, which is a cell located in the center of the cell row, and the voltage detecting means) Is an integer from 1 to m), where C _n is the capacitance of the capacitor, the capacitance of each capacitor satisfies C _n > C _{n + 1} ,
A voltage measuring device characterized in that when τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following equations (7) to (9).
R ₁ = τ / {2 (C ₁ -C ₂ )} (7)
R _n = {(2n−1) · τ} / {2 (C _n −C _{n + 1} )} (8)
R _m = {(2m−1) · τ} / 2C _m (9) A voltage measuring device for measuring a voltage of a battery pack having a cell row in which an even number of cells are connected in series,
Voltage detection means for detecting the voltage across each cell, connected to the positive and negative sides of each cell via the number of cells connected to the node between each cell and each node at both ends of the cell column + 1 wire When,
The number of cells provided on each of the wirings plus one resistor;
Including the same number of capacitors as the number of cells constituting the RC filter in combination with the resistor provided between the adjacent wirings;
Counting from the central capacitor that is the two capacitors provided between the three wirings that connect the positive and negative sides of the central cell, which is the two cells located in the center of the cell row, and the voltage detection means. When the capacitance of the _n-th capacitor (n is an integer from 1 to m) is C _{n, the} capacitance of each capacitor satisfies C _n > C _{n + 1} ,
A voltage measuring device characterized in that when τ is an arbitrarily set filter time constant, the resistance value R _n of each resistor satisfies the following equations (10) to (12).
R ₁ = τ / (C ₁ -C ₂ ) (10)
R _n = (n · τ) / (C _n −C _{n + 1} ) (11)
R _m = (m · τ) / C _m (12)

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