Battery pack voltage measurement circuit and operation method thereof

Abstract

The present invention relates to a battery pack voltage measurement circuit and a method of operation thereof, and more specifically, to a battery pack voltage measurement circuit that measures the voltage of a battery pack and outputs the result value, and a method of operation thereof. According to the present invention, the manufacturing cost of a battery pack voltage measurement circuit can be lowered by providing an environment in which a low-specification relay element can be used through a series connection structure and a parallel connection structure of a plurality of resistors.

Description

Technology Field

[0001] The present invention relates to a battery pack voltage measurement circuit and a method of operation thereof, and more specifically, to a battery pack voltage measurement circuit that measures the voltage of a battery pack and outputs the result value, and a method of operation thereof. Background Technology

[0002] Recently, as the demand for electrical and electronic devices has surged, interest in battery packs has also been increasing. Since battery packs, used as storage batteries or secondary batteries, are an essential component for driving electrical and electronic devices, they are continuously evolving in step with these devices.

[0003] Meanwhile, as global interest in eco-friendly technology intensifies, products related to electric vehicles and solar modules are being mass-produced at an explosive rate. Since electric vehicles and solar modules fundamentally consist of battery packs, the demand for battery packs is steadily increasing. Furthermore, battery packs are being developed to offer longer lifespans and more powerful operation in response to consumer demands. In other words, battery packs are evolving toward high-capacity and high-voltage specifications.

[0004] While high-voltage specifications for battery packs provide more powerful driving force to surrounding circuits under ideal conditions, they can cause serious damage to these circuits in situations where unwanted problems arise. Therefore, measuring and managing the battery pack voltage is considered an essential requirement to prevent abnormal currents. Accordingly, battery packs are configured with a voltage measurement circuit to address this purpose.

[0005] The battery pack voltage measurement circuit includes a relay switch and an ADC (Analog to Digital Converting) output circuit. The relay switch of the battery pack voltage measurement circuit performs an on or off operation based on overcurrent, and the ADC output circuit can measure the voltage of the battery pack according to the current flowing through the relay switch.

[0006] Meanwhile, the voltage of battery packs used in electric vehicles is trending upward from 400V to 800V. Consequently, battery pack voltage measurement circuits must also be designed to accommodate these higher voltages. To achieve this, the relay switches configured in the battery pack voltage measurement circuit must satisfy an allowable voltage of 800V. However, relay switches that operate stably at an allowable voltage of 800V require advanced process technology and the use of high-quality materials, resulting in very high costs; in other words, high-specification relay switches are required. If a low-specification relay switch with an existing allowable voltage of 400V is used to measure the voltage of an 800V battery pack, the switch may be delayed, which can lead to various problems.

[0007] In this regard, Japanese Patent No. 4385640 (Registration Date: Oct. 09, 2009) and Korean Patent No. 1211055 (Registration Date: Dec. 05, 2012) disclose a configuration for detecting the voltage of a battery pack. Both patents disclose a relay switch directly connected to the voltage of the battery pack; in this case, as explained above, if a high-specification relay switch is not used, smooth measurement operation for a high-voltage battery pack is impossible. Prior art literature

[0008] (Patent Document 0001) JP 4385640 B2, 2009.10.09.(Patent Document 0002) KR 1211055 B1, 2012.12.05. The problem to be solved

[0009] Accordingly, the present invention aims to provide a battery pack voltage measurement circuit and a method of operation thereof that enables a low-specification relay element to operate stably even when the voltage of the battery pack is high. means of solving the problem

[0010] According to one aspect for achieving the above-mentioned purpose, the present invention provides a battery pack voltage measurement circuit comprising a first resistor, a relay circuit, a second resistor, and an ADC output circuit sequentially connected in series between a power supply voltage terminal to which the voltage of the battery pack is applied and a ground voltage terminal, wherein the relay circuit is characterized by having a relay element and a relay resistor connected in parallel.

[0011] In addition, when the relay element is turned off, the voltage applied across the relay element may be characterized as being the same as the voltage applied across the relay resistor.

[0012] In addition, the resistance value Rr of the above relay resistor may be characterized as being determined to satisfy [Equation 1] below.

[0013] In addition, the resistance value Rr of the above relay resistor may be characterized as being determined to satisfy [Equation 2] below.

[0014] In addition, according to another aspect for achieving the above-mentioned purpose, the present invention provides a method of operation of a battery pack voltage measuring circuit comprising: a process of reducing a battery pack voltage applied to measure the voltage of the battery pack; a process of determining the ON state of a relay element according to the battery pack voltage; a process of setting the voltage across the relay element to be equal to the voltage across the relay resistor based on the result of the determining process; and a process of detecting the battery pack voltage.

[0015] In addition, according to another aspect for achieving the above-mentioned purpose, the present invention provides a battery pack voltage measurement circuit comprising a voltage drop circuit, a relay circuit, and an ADC output circuit sequentially connected in series between a power supply voltage terminal to which the voltage of the battery pack is applied and a ground voltage terminal, wherein the relay circuit is characterized by being configured such that a relay element and a relay resistor are connected in parallel.

[0016] In addition, the voltage drop circuit may include a resistor connected between the power supply voltage terminal and the relay circuit, which reduces the voltage applied to the power supply voltage terminal.

[0017] In addition, it may include a resistor connected between the relay circuit and the ADC output circuit, which reduces and distributes the voltage applied to the relay circuit. Effects of the invention

[0018] As explained above, according to the present invention, by lowering the voltage of the battery pack applied to the relay circuit, a low-specification relay element with a low allowable voltage value can be used.

[0019] That is, the present invention includes a first resistor, a relay circuit, a second resistor, and an ADC output circuit sequentially connected in series between a power supply voltage terminal to which the voltage of the battery pack is applied and a ground voltage terminal, wherein the relay circuit detects the voltage of the battery pack by connecting a relay element and a relay resistor in parallel.

[0020] In this case, the relay element configured in the relay circuit can be a low-specification relay element through the series connection structure of the first and second resistors and the parallel connection structure of the relay resistor. Therefore, even if the voltage of the battery pack to be detected increases, the manufacturing cost of the battery pack voltage measurement circuit can be lowered by using a low-specification relay element with a low cost instead of a high-specification relay element with an expensive cost. Brief explanation of the drawing

[0021] FIG. 1 is a diagram illustrating a battery pack voltage measurement circuit according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating the operation method of the battery pack voltage measurement circuit of FIG. 1. FIG. 3 is a diagram illustrating a battery pack voltage measurement circuit according to another embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and the embodiments of the present invention are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In the drawings, like reference numerals refer to like elements.

[0023] FIG. 1 is a diagram illustrating a battery pack voltage measurement circuit (10) according to an embodiment of the present invention.

[0024] Referring to FIG. 1, a battery pack voltage measurement circuit (10) according to an embodiment of the present invention includes a first resistor (C_R1), a relay circuit (11), a second resistor (C_R2), and an ADC output circuit (12). Here, the first resistor (C_R1), the relay circuit (11), the second resistor (C_R2), and the ADC output circuit (12) are sequentially connected in series between a power supply voltage terminal (V_BP) to which the voltage of a battery pack (not shown) is applied and a ground voltage terminal (GND).

[0025] The first resistor (C_R1) is connected between the power supply voltage terminal (V_BP) and the relay circuit (11). The first resistor (C_R1) reduces the voltage of the battery pack applied from the power supply voltage terminal (V_BP) and provides it to the relay circuit (11). Therefore, even if, for example, a voltage of 800V of the battery pack is applied to the power supply voltage terminal (V_BP), the voltage reduced by the first resistor (C_R1) is applied to the relay circuit (11).

[0026] The relay circuit (11) includes a relay element (C_RS) and a relay resistor (C_RR). Here, the relay element (C_RS) and the relay resistor (C_RR) are configured by connecting them in parallel between a first resistor (C_R1) and a second resistor (C_R2).

[0027] The relay element (C_RS) may be composed of a solenoid and a switch, although it is not shown in detail in the drawing. The relay element (C_RS) can control the on or off operation of the switch based on the magnetic force generated in the solenoid. And the relay resistor (C_RR) is connected in parallel with the relay element (C_RS). Therefore, when the relay element (C_RS) is turned off, the voltage applied across the relay element (C_RS) is the same as the voltage applied across the relay resistor (C_RR).

[0028] Here, since one side of the relay element (C_RS) is supplied with a voltage that has been lowered by the first resistor (C_R1), the relay element (C_RS) can be designed as a low-spec relay element. And since the other side of the relay element (C_RS) is supplied with a voltage that has been lowered by the first resistor (C_R1) and the relay resistor (C_RR), stable on or off operation can be guaranteed even if the relay element (C_RS) is used as a low-spec relay element.

[0029] The second resistor (C_R2) is connected between the relay circuit (11) and the ADC output circuit (12). The second resistor (C_R2) is configured to increase and distribute the voltage applied to the relay circuit (11), and as will be explained later through mathematical formulas, a more stable voltage can be applied across the relay element (C_RS) through the second resistor (C_R2).

[0030] The ADC output circuit (12) includes a third resistor (R3) and a capacitor (C). Here, the third resistor (R3) and the capacitor (C) are configured to be connected in parallel between the second resistor (C_R2) and the ground voltage terminal (GND). The ADC output circuit (12) converts the analog voltage transmitted through the second resistor (C_R2) into a digital voltage to generate a detection signal (DET) corresponding to the voltage of the battery pack. Since the circuit operation of the ADC output circuit (12) is already known, a detailed description will be omitted.

[0031] Meanwhile, the resistance value (Rr) of the relay resistor (C_RR) is determined to satisfy [Equation 1] below.

[0032] [Mathematical Formula 1]

[0033]

[0034] [Mathematical Equation 1] is a formula that excludes the ADC output circuit (12) for convenience of explanation. Here, R1 and R2 are the resistance values ​​of the first and second resistors (C_R1, C_R2), respectively, and V limis the allowable voltage value of the relay element (C_RS), and Vo represents the voltage value of the battery pack.

[0035] In [Equation 1], the allowable voltage value (V) of the relay element (C_RS) lim ) may be smaller than the voltage value (Vo) of the battery pack. This is because the voltage of the battery pack (Vo) is subject to a voltage drop caused by the resistance values ​​R1, R2, and Rr of the first and second resistors (C_R1, C_R2) and the relay resistor (C_RR), respectively. Therefore, even if the voltage value (Vo) of the battery pack increases from, for example, 400V to 800V, if the resistance values ​​(R1, R2, Rr) of the first and second resistors (C_R1, C_R2) and the relay resistor (C_RR) are designed appropriately, the allowable voltage value (V) of the relay element (C_RS) lim ...can satisfy ). Here, even if the voltage value (Vo) of the battery pack becomes 800V, the allowable voltage value (V) of the relay element (C_RS) lim The fact that ) is satisfied means that even when using a low-spec relay element (C_RS), the voltage (Vo) of a battery pack with a high voltage can be measured stably.

[0036] In addition, when the relay element (C_RS) is turned off, a voltage that has been lowered by the first resistor (R1) is applied to one end of the relay element (C_RS), and a voltage equal to the voltage applied to both ends of the relay resistor (C_RR) is applied to both ends of the relay element (C_RS). Therefore, even if the relay element (C_RS) is used at a low specification, the off operation of the relay element (C_RS) can be performed stably.

[0037] As described above, through this configuration and operation, the battery pack voltage measurement circuit (10) according to the embodiment of the present invention provides an environment in which a relay element (C_RS) can be used at a low specification.

[0038] On the other hand, the resistance value (Rr) of the relay resistor (C_RR) is determined to satisfy [Equation 2] below.

[0039] [Mathematical Formula 2]

[0040]

[0041] [Mathematical Equation 2] is a formula including an ADC output circuit (12). Here, R1, R2, and Rc are the resistance values ​​of the first and second resistors (C_R1, C_R2) and the ADC output circuit (12), respectively, and V lim is the allowable voltage value of the relay element (C_RS), and Vo represents the voltage value of the battery pack.

[0042] [Equation 2] is also, just like [Equation 1], the allowable voltage value (V) of the relay element (C_RS). lim ) can be smaller than the voltage value (Vo) of the battery pack, and this is also because the voltage value (Vo) of the battery pack is subject to a voltage drop due to the resistance values ​​R1, R2, Rc, and Rr of the first and second resistors (C_R1, C_R2), the resistance of the ADC output circuit (12), and the relay resistor (C_RR), respectively. In particular, [Equation 2] can control the voltage value (Vo) of the battery pack to be lower by the resistance value (Rc) of the ADC output circuit (12), which means that even if the voltage value (Vo) of the battery pack increases, the allowable voltage value (V) of the relay element (C_RS) lim It means that it can be included in ).

[0043] As described above, since the battery pack voltage measurement circuit (10) according to the embodiment of the present invention can use a low-spec relay element (C_RS), the battery pack voltage measurement circuit (10) can be mass-produced at a lower manufacturing cost.

[0044] FIG. 2 is a flowchart illustrating the operation method of the battery pack voltage measurement circuit (10) of FIG. 1.

[0045] Referring to FIGS. 1 and 2, the operation method of the battery pack voltage measurement circuit (10) includes a process of lowering the battery pack voltage (S1), a process of determining the ON state of the relay element (S2), a process of setting the voltage across the relay element (S3), and a process of detecting the battery pack voltage (S4).

[0046] The process of reducing the battery pack voltage (S1) is a process of reducing the battery pack voltage applied from the power supply voltage terminal (V_BP) to measure the voltage of the battery pack. The process of reducing the battery pack voltage (S1) can be performed by the first to third resistors (C_R1, C_R2, C_R3) of FIG. 1.

[0047] The process of determining the ON state of the relay element (S2) is a process of determining the ON state of the relay element (C_RS, see FIG. 1) according to the battery pack voltage. If the relay element (C_RS) is in the OFF state (No), the process S3, which will be explained later, is performed, and if the relay element (C_RS) is in the ON state (Yes), the process S4, which will be explained later, is performed.

[0048] The process of setting the voltage across the relay element (S3) is a process of setting the voltage across the relay element (C_RS) to be equal to the voltage across the relay resistor (C_RR) when the relay element (C_RS) is in an off state (No) based on the result of the judgment process (S2). The process of setting the voltage across the relay element (S3) can be performed by the relay resistor (C_RR) of FIG. 1.

[0049] The process of detecting the battery pack voltage (S4) is a process of detecting an analog type battery pack voltage applied from the power supply voltage terminal (V_BP) and outputting it as a digital type detection signal (DET). The process of detecting the battery pack voltage (S4) can be performed in the ADC output circuit (12) of FIG. 1.

[0050] FIG. 3 is a diagram illustrating a battery pack voltage measurement circuit (30) according to another embodiment of the present invention.

[0051] Referring to FIG. 3, a battery pack voltage measurement circuit (30) according to another embodiment of the present invention includes a voltage drop circuit (31), a relay circuit (32), and an ADC output circuit (33). Here, the voltage drop circuit (31), the relay circuit (32), and the ADC output circuit (33) are sequentially connected in series between a power supply voltage terminal (V_BP) to which the voltage of a battery pack (not shown) is applied and a ground voltage terminal (GND).

[0052] The voltage drop circuit (31) is connected between the power supply voltage terminal (V_BP) and the relay circuit (22) and is configured to reduce the voltage applied to the power supply voltage terminal (V_BP). The voltage drop circuit (31) may correspond to the first resistor (C_R1) of FIG. 1. As already explained in FIG. 1, the voltage drop circuit (31) reduces the voltage of the battery pack applied to the power supply voltage terminal (V_BP) through the first resistor (C_R1) and provides it to the relay circuit (32).

[0053] The relay circuit (32) is composed of the relay element (C_RS) and relay resistor (C_RR) of FIG. 1. The ADC output circuit (33) is composed of the third resistor (C_R3) and capacitor (C_C) of FIG. 1. Since the configuration and operation of the relay circuit (32) and the ADC output circuit (33) have been sufficiently explained in FIG. 1, a more detailed explanation will be omitted.

[0054] Meanwhile, the battery pack voltage measurement circuit (30) further includes a second resistor (C_R2) of FIG. 1 connected between the relay circuit (32) and the ADC output circuit (33). As described in FIG. 1, the second resistor (C_R2) is configured to reduce and distribute the voltage applied to the relay circuit (32).

[0055] As described above, since the battery pack voltage measurement circuit (30) according to the embodiment of the present invention can use a low-spec relay element (C_RS), the battery pack voltage measurement circuit (30) can be mass-produced at a lower manufacturing cost.

[0056] In the foregoing, preferred embodiments of the present invention have been described and illustrated using specific terms, but such terms are intended solely to clarify the present invention, and it is obvious that various modifications and changes may be made to the embodiments and described terms of the present invention without departing from the technical spirit and scope of the following claims. Such modified embodiments should not be understood separately from the spirit and scope of the present invention, but should be considered to fall within the scope of the claims of the present invention. Explanation of the symbols

[0057] C_R1 : First resistor C_R2 : Second resistor C_R3 : Third resistor C_RS : Relay element C_RR : Relay resistor C_C : Capacitor 10: Battery pack voltage measurement circuit 11: Relay circuit 12: ADC Output Circuit

Claims

Claim 1 A battery pack voltage measurement circuit comprising a first resistor, a relay circuit, a second resistor, and an ADC output circuit sequentially connected in series between a power supply voltage terminal to which the voltage of the battery pack is applied and a ground voltage terminal, wherein the relay circuit is configured such that a relay element and a relay resistor are connected in parallel, the relay element has an allowable voltage lower than the voltage of the battery pack, and the resistance values ​​of the first resistor, the second resistor, and the relay resistor are set such that the voltage applied across the relay resistor is smaller than the allowable voltage of the relay element. Claim 2 delete Claim 3 A battery pack voltage measurement circuit according to claim 1, characterized in that the resistance value Rr of the relay resistor is determined to satisfy the following [Equation 1]. [Equation 1] (Here, R1 and R2 are the resistance values ​​of the first and second resistors, respectively, V lim is the allowable voltage value of the relay element, and Vo is the voltage value of the battery pack) Claim 4 A battery pack voltage measurement circuit according to claim 1, characterized in that the resistance value Rr of the relay resistor is determined to satisfy the following [Equation 2]. [Equation 2] (R1, R2, and Rc are the first and second resistors, the resistance value of the ADC output circuit, V, respectively. lim is the allowable voltage value of the relay element, and Vo is the voltage value of the battery pack) Claim 5 A method for measuring a battery pack voltage in a battery pack voltage measuring circuit according to any one of claim 1, claim 3, or claim 4, comprising: a process of reducing a battery pack voltage applied to measure the voltage of the battery pack; a process of determining the ON state of a relay element according to the battery pack voltage; a process of setting the voltage across the relay element to be equal to the voltage across the relay resistor when the result of determining the ON state of the relay element is that the relay element is in an OFF state; and a process of detecting the battery pack voltage when the result of determining the ON state of the relay element is that the relay element is in an ON state. Claim 6 A battery pack voltage measurement circuit comprising a voltage drop circuit, a relay circuit, and an ADC output circuit sequentially connected in series between a power supply voltage terminal to which the voltage of the battery pack is applied and a ground voltage terminal, wherein the relay circuit is configured such that a relay element and a relay resistor are connected in parallel, the relay element has an allowable voltage lower than the voltage of the battery pack, and the voltage applied across the relay resistor is set to be smaller than the allowable voltage of the relay element by means of the voltage drop circuit and the relay resistor. Claim 7 In claim 6, the voltage drop circuit comprises a resistor connected between the power supply voltage terminal and the relay circuit, which reduces the voltage applied to the power supply voltage terminal; a battery pack voltage measurement circuit. Claim 8 A battery pack voltage measurement circuit according to claim 6, further comprising a resistor connected between the relay circuit and the ADC output circuit, which reduces and distributes the voltage applied to the relay circuit.

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