KR100587526B1 - Cell voltage monitoring apparatus and method of a rechargeable battery - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cell voltage measurement of rechargeable batteries, wherein when one or both measurement points exceed the voltage range allowed by conventional differential amplifiers in cell voltage measurement of a battery composed of a plurality of series-connected cells It measures the differential voltage of and aims to measure the voltage of which both ends of cell are reversed by over discharge of battery.

The apparatus for measuring cell voltage of a rechargeable battery according to the present invention includes a battery 100 including a plurality of series-connected cells, a cell voltage divider 120 for reducing a cell voltage to a voltage that a differential amplifier can accommodate, A cell voltage multiplexer 140 for selecting a differential voltage of a battery cell, a cell voltage multiplexer controller 160 for controlling the cell voltage multiplexer, a multiplexer synchronization command unit 180 input to the cell voltage multiplexer controller, and the cell A differential amplifier 200 for amplifying a battery cell differential voltage input from a voltage multiplexer, an offset unit 240 for setting an offset of the differential amplifier to measure a cell voltage at which both voltages are reversed, and an offset unit for controlling the offset unit The offset address control unit 260 converts the battery voltage output from the differential amplifier into digital data. A data processing unit 220 to. The data processor may include a sample and hold unit 225 and an analog-digital converter 230.

Cell Voltage Measurement, Rechargeable Battery, Inverted Cell Voltage Measurement, Differential Amplifier, Offset

Description

Cell voltage measuring apparatus of rechargeable battery and method thereof

1 is a block diagram showing the configuration of a cell voltage measuring apparatus of a rechargeable battery according to the prior art.

FIG. 2 is a circuit diagram illustrating a dual output multiplexer for explaining the basic principle of FIG. 1.

FIG. 3 is a block diagram illustrating an embodiment of a cell voltage multiplexer, a cell voltage multiplexer controller, and a multiplexer synchronization command unit configured with an 8-channel dual output multiplexer for the battery of 32 cells of FIG. 1; FIG.

4 is a block diagram illustrating an embodiment of a cell voltage multiplexer, a cell voltage multiplexer control unit, and a multiplexer synchronization command unit configured with an 8-channel single output multiplexer for the battery of 32 cells of FIG. 1;

5 is a block diagram showing the configuration of an apparatus for measuring cell voltage of a rechargeable battery according to the present invention;

6 is a block diagram illustrating a detailed configuration of an offset unit of FIG. 5.

FIG. 7 is a circuit diagram illustrating an example configuration of a reference voltage generator, a reference voltage divider, and an offset voltage multiplexer of FIG. 6.

8 is a flowchart illustrating a process of performing a cell voltage measuring method of a rechargeable battery according to the present invention;

<Description of Signs of Major Parts of Drawings>

100: battery 120: cell voltage divider

140: cell voltage multiplexer 160: cell voltage multiplexer controller

165: ripple counter 170: decoder

180: multiplexer synchronization command unit 185: minor synchronization command

190: main synchronization command 200: differential amplifier

220: data processing unit 225: sample and hold unit

230: analog-to-digital conversion unit 240: offset unit

245: reference voltage generator 250: reference voltage divider

255: offset voltage multiplexer 260: offset address control unit

The present invention relates to an apparatus and method for measuring a cell voltage of a rechargeable battery, and more particularly, that the measuring points of one or both of the battery consisting of a plurality of series-connected cells exceeds the voltage range allowed in conventional differential amplifiers. The present invention relates to a cell voltage measuring device of a rechargeable battery capable of measuring the voltage of a cell even if the voltage across the cell is reversed by over discharge.

1 is a block diagram showing the configuration of a cell voltage measuring apparatus of a rechargeable battery according to the prior art. As shown in FIG. 1, a cell voltage measuring apparatus of a conventional rechargeable battery includes a battery 100 including a plurality of series-connected cells, a cell voltage divider for lowering a cell voltage to a voltage that a differential amplifier can accommodate. 120, a cell voltage multiplexer 140 for selecting a differential voltage of the divided battery cell, a cell voltage multiplexer controller 160 for controlling the cell voltage multiplexer, and a multiplexer synchronization command unit input to the cell voltage multiplexer controller ( 180, a differential amplifier 200 for amplifying the battery cell differential voltage input from the cell voltage multiplexer, and a data processor 220 for converting the battery voltage output from the differential amplifier into digital data.

FIG. 2 is a circuit diagram illustrating a dual output multiplexer for explaining the basic principle of FIG. 1. The battery 100 is composed of a plurality of cells connected in series (cell 1, cell 2 cell 3, and cell 4). The negative electrode 102 of Cell 1 located at the bottom of the battery is connected to the reference potential 109. The measuring points A, B, C and D of the respective cells are connected to the cell voltage dividers 122, 124, 126 and 128. The cell voltage dividers lower the cell voltage to a voltage that the differential amplifier 200 can accommodate by the same voltage division ratio by the precisely matched resistors R1 and R2. The cell voltage dividers are referenced to a reference potential 109. The reference potential and the cell voltages divided by the cell voltage dividers are connected to the respective switches S0, S1, S2, S3, and S4 of the cell voltage multiplexer 140. The switches of the cell voltage multiplexer have dual output characteristics. Lower terminals 142, 144, 146, 148, and 150 of the multiplexer switches are commonly connected to the differential amplifier inverting terminal 202, and upper terminals 152, 154, 156, and 158 are commonly connected. And to the differential amplifier non-inverting terminal 204. The cell voltages selected by the sequential opening and shorting of the switches of the multiplexer are amplified by the differential amplifier 200. The differential amplifier is referenced to a reference potential 109. The voltage Vout output from the differential amplifier 200 is calculated as in Equation 1 below. The voltage output from the differential amplifier (Vout) is related to the gain (G) of the differential amplifier and the differential voltage (Vmp) between the two measuring points of the battery cell and the voltage division ratio (Ratio) of the precisely matched cell voltage divider connected to the measuring points. do.

Vout = G × Vmp × Ratio

3 is a block illustrating an embodiment of a cell voltage multiplexer 140, a cell voltage multiplexer controller 160, and a multiplexer synchronization command unit 180 configured as an 8-channel dual output multiplexer for the battery of 32 cells of FIG. 1. It is also. The voltage divided by the battery voltage dividers from the battery cells 1 to the cell 8 is input to the multiplexer D1, the voltage divided by the battery cells 9 to the cell 16 is input to the multiplexer D2, and the voltage divided from the battery cells 17 to the cell 24 is divided. Is input to multiplexer D3, and the voltage divided from battery cell 25 to cell 32 is input to multiplexer D4. Multiplexers D1, D2, D3, and D4 have one functional operation ("EN") input and three address ("ADD") inputs. The outputs of multiplexers D1, D2, D3, and D4 are input to D5. The multiplexer D5 is always active so the output is input to the differential amplifier 200 and amplified. The multiplexers D1, D2, D3, D4, and D5 have eight input channels and have dual output characteristics. In order to operate the cell voltage multiplexer 140, the cell voltage multiplexer controller 160 includes a ripple counter 165 and a decoder 170. The lower three of the five outputs of the ripple counter control the addresses of the multiplexers D1, D2, D3, and D4, and the upper two outputs control the addresses of the multiplexer D5 and are simultaneously input to the decoder 170. Four outputs of the decoder control the functional operation of multiplexers D1, D2, D3 and D4. The multiplexer synchronization command unit 180 includes a sub-synchronization command 185 and a main synchronization command 190. The sub-synchronization command is provided in a continuous pulse and increments the ripple counter 165 to measure the cell voltage sequentially. The main synchronization command is provided with one pulse for every 32 sub-synchronization commands to initiate cell voltage measurements.

FIG. 4 is a block diagram of an embodiment of a cell voltage multiplexer 140, a cell voltage multiplexer controller 160, and a multiplexer synchronization command unit 180 configured as an 8-channel single output multiplexer for the battery of 32 cells of FIG. 1. It is also. The voltage divided at the positive pole from battery cell 1 to cell 8 by the cell voltage dividers is input to multiplexer S1 and the voltage divided at the negative pole is input to multiplexer S5, and the voltage divided at the positive pole from battery cell 9 to cell 16 is multiplexer. The voltage inputted to S2 and the divided voltage at the negative pole is input to the multiplexer S6, the voltage divided at the positive pole from the battery cells 17 to the cell 24 is input to the multiplexer S3, and the voltage divided at the negative pole is input to the multiplexer S7, and the battery cell 25 at The voltage divided at the anode up to cell 32 is input to multiplexer S4 and the voltage divided at the cathode is input to multiplexer S8. The outputs of the multiplexers S1, S2, S3 and S4 are input to the multiplexer S9, and the outputs of the multiplexers S5, S6, S7 and S8 are input to the multiplexer S10. The output of the multiplexer S9 is input to the non-inverting terminal of the differential amplifier 200, and the output of the multiplexer S10 is input to the inverting terminal of the differential amplifier. The multiplexers S1, S2, S3, S4, S5, S6, S7, S8, S9 and S10 have eight input channels and have a single output characteristic. In order to operate the cell voltage multiplexer 140, the cell voltage multiplexer controller 160 and the multiplexer synchronization command unit 180 have the same characteristics as those of FIG. 3. The lower three of the five outputs of the ripple counter 165 simultaneously control the addresses of the multiplexers S1 and S5, S2 and S6, S3 and S7, S4 and S8, and the upper two outputs control the addresses of the multiplexers S9 and S10. It is controlled and simultaneously input to the decoder 170. The four outputs of the decoder simultaneously control the functional operations ("EN") of multiplexers S1 and S5, S2 and S6, S3 and S7, S4 and S8. The multiplexer synchronization command unit 180 is configured and operated in the same manner as in FIG. 3.

The cell voltage measuring device of a rechargeable battery according to the prior art has a range of input voltages and common mode voltages in which one or both measuring points of a battery composed of a plurality of series-connected cells are unacceptable in the conventional differential amplifier 200. The battery cell voltage can be measured. In this case, the differential amplifier 200 is designed based on the reference potential 109 connected to the negative electrode 102 of the cell located at the bottom of the battery 100 so that the inverted cell is reversed when the voltage across the cell is reversed by the overdischarge of the battery. There is a problem that can not measure the voltage of.

Thus, overcoming the absurdity of the cell voltage measuring device of such a conventional rechargeable battery, the measuring points of one or both of the battery composed of a plurality of series-connected cells exceed the voltage range allowed by the conventional differential amplifier and are overcharged. There is an increasing demand for a cell voltage measuring device of a rechargeable battery capable of measuring the voltage of the cell even when the voltage across the cell is reversed.

Accordingly, the present invention has been made to solve the above problems, and a first object of the present invention is a voltage range in which one or both measurement points of a battery composed of a plurality of series-connected cells are allowed in a conventional differential amplifier. It is to provide a cell voltage measuring device of a rechargeable battery that exceeds and can measure the reverse voltage of the cell even if the voltage across the cell is reversed by over discharge.

A second object of the present invention for solving the above problems is to provide a function to adjust the different offset voltage to adjust the reference voltage of the differential amplifier according to the degree of the reverse voltage of the cell by the battery over-discharge battery cell voltage It is to provide a cell voltage measuring device of a rechargeable battery that can improve the measurement accuracy by widening the measurement range of.

According to a first aspect of the present invention for achieving the above object, in the cell voltage measuring apparatus of a rechargeable battery, an offset unit for setting the offset of the reference voltage of the differential amplifier, an offset address control unit for controlling the offset unit An apparatus for measuring cell voltage of a rechargeable battery may be provided.

According to a second aspect of the present invention for achieving the above object, in the cell voltage measuring apparatus of a rechargeable battery, a reference voltage generator for generating a predetermined reference voltage, dividing the reference voltage from the generated reference voltage An apparatus for measuring a cell voltage of a rechargeable battery, comprising: a reference voltage divider, an offset voltage multiplexer for selecting one differential amplifier offset voltage from a divided reference voltage, and an offset address controller for controlling an offset voltage multiplexer Can be provided.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention;

5 is a block diagram showing the configuration of an apparatus for measuring cell voltage of a rechargeable battery according to the present invention. As shown in FIG. 5, a cell voltage measuring apparatus of a rechargeable battery according to the present invention includes a battery 100, a cell voltage divider 120, a cell voltage multiplexer 140, a cell voltage multiplexer controller 160, and a multiplexer. The synchronization command unit 180, the differential amplifier 200, the data processing unit 220 for converting the battery voltage output from the differential amplifier into digital data, and to set the offset of the differential amplifier to measure the cell voltage reversed voltage The offset unit 240 and an offset address control unit 260 for controlling the offset unit are included. Here, the battery 100, the cell voltage divider 120, the cell voltage multiplexer 140, the cell voltage multiplexer controller 160, the multiplexer synchronization command unit 180, the differential amplifier 200, and the data processor 220 are provided. It is the same as the configuration of the cell voltage measuring device of the conventional rechargeable battery.

The data processor 220 includes a sample and hold unit 225 and an analog to digital converter 230, which is the same as the conventional analog and digital data processing.

The voltage Vout output from the differential amplifier 200 is calculated as in Equation 2 below. The voltage (Vout) output from the differential amplifier is set at the gain (G) of the differential amplifier and the differential voltage (Vmp) between the two measuring points, the division ratio (Ratio) and the offset of the precisely matched cell voltage divider connected to the measuring points. It is related to the voltage Voffset.

Vout = G × Vmp × Ratio + Voffset

FIG. 6 is a block diagram illustrating a detailed configuration of an offset unit of FIG. 5, which is a block diagram showing a configuration of an apparatus for measuring a cell voltage of a rechargeable battery according to the present disclosure.

The offset unit 240 includes a reference voltage generator 245 for generating a predetermined reference voltage, a reference voltage divider 250 for dividing the reference voltage from the generated reference voltage, and one differential amplifier offset voltage from the divided reference voltage. And an offset voltage multiplexer 255 for selecting.

FIG. 7 is a circuit diagram illustrating an example configuration of a reference voltage generator, a reference voltage divider, and an offset voltage multiplexer of FIG. 6. In the exemplary embodiment of FIG. 7, the reference voltage Vref is divided to eight, and the multiplexer has eight input channels and has a dual output characteristic.

The reference voltage generator 245 includes a reference voltage 242 and a precision reference voltage generator 244.

The precision reference voltage 244 receives the reference voltage Vcc to generate the precision reference voltage Vref.

The reference voltage divider 250 divides the precision reference voltage Vref by the same voltage difference with the precisely matched resistors R. FIG.

The offset voltage multiplexer 255 switches the voltages divided by the reference voltage divider. The multiplexer has one functional operation ("EN") input and three address ("ADD") inputs. The multiplexer is always designed to be functional.

The offset address controller 260 controls the address of the multiplexer.

8 is a flowchart illustrating a process of measuring a cell voltage of a rechargeable battery according to the present invention.

Referring to FIG. 8, first, the cell voltage multiplexer controller 160 selects a battery cell according to the sub-synchronization command 190 of the multiplexer synchronization command unit 180 (S310). As described above, the function operation terminal "EN" and the address terminal "ADD" of the cell voltage multiplexer are controlled according to the ripple counter 165 of the cell voltage multiplexer controller 160 and the output signals of the decoder 170. Select the cell voltage multiplexer channel corresponding to the signal.

Next, one offset initial value voltage is selected from the voltage divided by the reference voltage (S320). As described above, the offset address controller 260 selects a channel corresponding to the address of the offset voltage multiplexer 255.

The generating of the offset signal may include generating a precision reference voltage preset from the reference voltage 242 of the reference voltage generator 245 to the precision reference voltage generator 244, and precisely matching the reference voltage divider 250. Dividing the precision reference voltage with the same resistors by the same voltage difference and selecting a channel corresponding to the address of the offset voltage multiplexer 255 according to the control signal of the offset address controller 260.

Next, the differential voltage of the cell selected by the cell voltage multiplexer 140 is differentially amplified by the differential amplifier 140 (S330).

Next, the differentially amplified battery cell voltage is converted into digital data through the sample and hold unit 225 and the analog-to-digital converter 230 of the data processor 220 (S340).

Next, it is determined whether the value converted into digital data by the data processor 220 exceeds the battery cell voltage range (S350).

If the value converted into digital data exceeds the battery cell voltage range, the offset voltage is changed (S360).

If the value converted into digital data does not exceed the battery cell voltage range, the battery cell selected according to the sub-synchronization command 190 of the multiplexer synchronization command unit 180 increases (S370). As described above, the ripple counter 165 of the cell voltage multiplexer controller 160 is increased according to the sub-synchronization command 190 of the synchronization command unit 180, and the address of the function operation terminal “EN” and the address of the cell voltage multiplexer is increased. The cell voltage multiplexer channel corresponding to the control signal of the terminal "ADD" is selected.

Although the detailed circuit configuration of the cell voltage measuring apparatus of the rechargeable battery is illustrated and described in the present embodiment, the present invention is not limited to the detailed circuit configuration, and various modifications or modified circuit configurations are of course possible.

According to the present invention as described above, by providing the offset function of the differential amplifier, one or both measurement points of the battery consisting of a plurality of series-connected cells exceed the voltage range allowed by the conventional differential amplifier and It is possible to provide an apparatus for measuring cell voltage of a rechargeable battery that can measure the voltage of a cell even when the voltage at both ends is reversed.

In addition, by providing the function of adjusting the different offset voltage through the control of the reference voltage divider and the offset voltage multiplexer to measure the battery cell voltage by adjusting the reference voltage of the differential amplifier according to the degree of reverse of the voltage across the cell by battery over-discharge By widening the range, it is possible to provide an apparatus for measuring cell voltage of a rechargeable battery that can improve measurement accuracy.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (6)

A device for measuring cell voltage of a rechargeable battery, A battery composed of a plurality of series-connected cells; A cell voltage divider for lowering the cell voltage to a voltage that the differential amplifier can accommodate; A cell voltage multiplexer for selecting a differential voltage of the divided battery cells; A cell voltage multiplexer controller for controlling the cell voltage multiplexer; A multiplexer synchronization command unit input to the cell voltage multiplexer control unit; A differential amplifier for amplifying a battery cell differential voltage input from the cell voltage multiplexer; An offset unit configured to set an offset of the differential amplifier to measure a cell voltage in which both ends of the voltage are inverted; An offset address control unit for controlling the offset unit; And a data processor converting the battery voltage output from the differential amplifier into digital data. The method of claim 1, And the offset unit sets an offset voltage of the differential amplifier corresponding to the control signal of the offset address control unit. The method of claim 2, A device for measuring cell voltage of a rechargeable battery, characterized in that it provides a function of adjusting different offset voltages through address control of a reference voltage divider and an offset voltage multiplexer. The method of claim 3, wherein The reference voltage divided voltage divides the precision reference voltage by the same voltage difference with the resistors that are precisely matched in the previously generated reference voltage. In the cell voltage measuring method of a rechargeable battery, Selecting a battery cell according to a sub-synchronization command of the multiplexer synchronization command unit in the cell voltage multiplexer controller; Selecting an offset initial voltage of the differential amplifier; Amplifying the differential voltage of the selected cell in the cell voltage multiplexer; Converting the differentially amplified battery cell voltage into digital data through a sample and hold unit and an analog-digital converter of the data processor; Determining whether a value converted into digital data exceeds a battery cell voltage range; Changing the offset voltage if the value converted into digital data exceeds the battery cell voltage range; And If the value converted into digital data does not exceed the battery cell voltage range, increasing the battery cell selected according to the multiplexer synchronization command. The method of claim 5, The selecting of the offset voltage may include selecting an offset voltage by selecting a channel corresponding to an address of an offset voltage multiplexer from a voltage divided by a reference voltage.

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