Device for measuring insulation resistance

Abstract

The present invention relates to a device capable of measuring an insulation resistance of a battery. According to the device capable of measuring an insulation resistance according to the present invention, a voltage measuring unit can measure a voltage with respect to a potential of a negative terminal of a battery, rather than a voltage with respect to ground, thus it is possible to measure a parameter requiring high accuracy using one device, thereby reducing costs, and, since a first sensing substrate and a second sensing substrate are separated, it is possible to use different potentials as ground, thereby ensuring better insulation performance between the first sensing substrate as an HV side and the second sensing substrate as an LV side.

Description

[0001] This application is a divisional application of patent application No. 2021103799209, filed on April 9, 2021, entitled "Apparatus for Measuring Insulation Resistance". Technical Field

[0002] This invention relates to a device capable of measuring the insulation resistance of a battery. Background Technology

[0003] Recently, an electric vehicle (EV) that uses a rechargeable and dischargeable battery as its power source has been commercialized, becoming an environmentally friendly vehicle. This EV includes: a battery pack, which serves as a high-voltage (HV) power source to drive motors, inverters, converters, etc., that require high voltage for vehicle operation; and lead-acid batteries, which serve as a low-voltage (LV) power source to the vehicle's electronic equipment.

[0004] At this point, the insulation resistance of the battery pack may decrease, or its insulation may be compromised due to degradation. This is extremely dangerous because anyone touching the chassis could be electrocuted by the high voltage of the battery pack. Therefore, it is necessary to continuously measure and monitor the insulation resistance of the battery pack to ensure that it does not drop below a certain level.

[0005] Meanwhile, existing insulation resistance measurement circuits measure the resistance relative to the low-voltage (LV) side grounded (e.g., the negative terminal or chassis of a lead-acid battery).

[0006] [Related Technical Documents] [Patent Documents] KR 2010-1610921B1 Summary of the Invention

[0007] [Technical Issues] The purpose of this invention is to provide a device for measuring insulation resistance that can reduce costs by minimizing the number of high-precision measuring devices required.

[0008] Another object of the present invention is to provide an apparatus for measuring insulation resistance that can better ensure the insulation performance between the high voltage (HV) side and the low voltage (LV) side of the sensing substrate.

[0009] [Technical Solution] In a general sense, an apparatus for measuring the insulation resistance of a battery includes: a resistance unit comprising a voltage measuring resistor configured to divide and measure the voltage of the battery; a switching unit connected to the resistance unit and including a first switch and a second switch for forming different electrical paths; and a control unit that measures the voltage applied to the voltage measuring resistor and monitors the insulation resistance of the battery, and the control unit can measure the voltage applied to the voltage measuring resistor based on the potential of the negative terminal of the battery.

[0010] The control unit further includes a voltage measurement unit configured to measure the voltage applied to a voltage measuring resistor, which can be connected to the negative terminal of the battery, and the voltage measurement unit can be connected to both the voltage measuring resistor and the negative terminal of the battery.

[0011] The device may further include: a first sensing substrate connected to a battery; and a second sensing substrate connected to a lead-acid battery having a lower voltage than the battery and separate from the first sensing substrate, wherein a resistor unit and a switch unit may be mounted on the first sensing substrate, and a control unit may be mounted on the second sensing substrate.

[0012] The device may further include: a first sensing substrate connected to a battery; and a second sensing substrate connected to a lead-acid battery having a lower voltage than the battery and being separate from the first sensing substrate, and a resistor unit, a switch unit, a voltage measurement unit and a control unit may be mounted on the first sensing substrate.

[0013] The resistor unit may further include: a first resistor connected to the positive terminal of the battery, and a second resistor connected between the first resistor and the voltage measuring resistor, and a first switch may be connected between the first resistor and ground, and a second switch may be connected between the second resistor and ground.

[0014] The control unit can receive the voltage applied to the voltage measuring resistor while operating the first switch in the off state and operating the second switch in the on state, and can also receive the voltage applied to the voltage measuring resistor while operating both the first switch and the second switch in the on state.

[0015] The control unit can calculate the positive and negative insulation resistance by combining the following equations 1 and 2: [Equation 1] [Equation 2] (Where VRmes_SW2 represents the voltage applied to the voltage measuring resistor when the first switch is in the off state and the second switch is in the on state, VRmes_SW1_SW2 represents the voltage applied to the voltage measuring resistor when both the first and second switches are in the on state, Pack V represents the battery voltage, Rmes represents the value of the voltage measuring resistor, R1 represents the value of the first resistor, R2 represents the value of the second resistor, RLeak+ represents the value of the positive insulation resistance, and RLeak- represents the value of the negative insulation resistance).

[0016] The resistor unit may further include a third resistor connected between the switching unit and ground.

[0017] The control unit can receive the voltage applied to the voltage measuring resistor while operating the first switch in the off state and operating the second switch in the on state, and can also receive the voltage applied to the voltage measuring resistor while operating both the first switch and the second switch in the on state.

[0018] The control unit can calculate the positive insulation resistance and the negative insulation resistance by combining Equations 3 and 4 below.

[0019] [Equation 3] [Equation 4] (where equation 4 satisfies:) V Rmes_ SW2 represents the voltage applied to the voltage measuring resistor when the first switch is in the open state and the second switch is in the closed state, in V. Rmes_SW1_SW2 This indicates the voltage applied to the voltage measuring resistor when both the first and second switches are in the ON state. Pack V represents the battery voltage, and R... mes This indicates the value of the voltage measuring resistors. R1 represents the value of the first resistor, R2 represents the value of the second resistor, and R3 represents the value of the third resistor. Leak+ This represents the value of the positive insulation resistance, and R Leak - indicates the value of negative insulation resistance).

[0020] [Beneficial Effects] According to the device for measuring insulation resistance of the present invention, the voltage measuring unit can measure the voltage relative to the potential of the negative terminal of the battery rather than the voltage relative to ground, thus allowing a single device to measure parameters requiring high precision, thereby reducing costs.

[0021] Furthermore, in the device for measuring insulation resistance according to the present invention, since the first sensing substrate and the second sensing substrate are separate, different potentials can be used as ground, thereby ensuring better insulation performance between the first sensing substrate as the HV side and the second sensing substrate as the LV side. Attached Figure Description

[0022] Figure 1 This is a block diagram schematically illustrating the apparatus of the present invention for measuring insulation resistance.

[0023] Figure 2 This is a circuit diagram of the first circuit formed in the device for measuring insulation resistance according to the present invention.

[0024] Figure 3 This is a circuit diagram of the second circuit formed in the device for measuring insulation resistance according to the present invention.

[0025] Figure 4 This is a view showing in more detail the connection structure of the device for measuring insulation resistance according to the present invention.

[0026] Figure 5 This is a block diagram illustrating a situation where the position of the control unit, which is another embodiment of the device for measuring insulation resistance according to the present invention, is changed.

[0027] Figure 6 This is a circuit diagram illustrating a case where a resistor device is added as another embodiment of the apparatus for measuring insulation resistance according to the present invention.

[0028] Explanation of reference numerals in the attached figures 10: Battery 11: Battery positive terminal 12: Battery negative terminal 20: Lead-acid batteries 100: Resistor unit 110: Voltage measuring resistor 120: First resistor 130: Second resistor 140: Third resistor 200: Switching unit 210: First Switch 220: Second switch 300: Voltage Measurement Unit 400: Control Unit 500: First sensing substrate 600: Second sensing substrate: Detailed Implementation

[0029] The invention will now be described in detail with reference to the accompanying drawings. Detailed descriptions of known functions and structures that may unnecessarily obscure the subject matter of the invention will be omitted. Furthermore, terms such as “…unit” and “module” mean a unit that performs at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

[0030] Figure 1 This is a schematic block diagram illustrating the apparatus of the present invention for measuring insulation resistance. Figure 2 and Figure 3 These are circuit diagrams of the first circuit and the second circuit formed in the device for measuring insulation resistance according to the present invention, respectively. Figure 4 This is a view showing in more detail the connection structure of the device for measuring insulation resistance according to the present invention.

[0031] Reference Figures 1 to 3 The device for measuring insulation resistance according to the present invention includes a resistance unit 100, a switching unit 200, a voltage measuring unit 300, and a control unit 400. The control unit 400 may include the voltage measuring unit 300.

[0032] The resistor unit 100 may include multiple resistors to distribute the voltage of the battery 10. In this case, the multiple resistors include a voltage measuring resistor 110, a first resistor 120, and a second resistor 130. The first resistor 120 is connected to the positive terminal 11 of the battery 10, and the second resistor 130 is connected between the first resistor 120 and the voltage measuring resistor 110. Here, the battery 10 can be formed by connecting multiple battery cells in series or parallel.

[0033] The switching unit 200 is connected to the resistor unit 100 and includes a first switch 210 and a second switch 220, and can form circuits with different paths according to the on-off operation of the first switch 210 and the second switch 220. That is, the switching unit 200 is connected to the resistor unit 100 and includes a first switch 210 and a second switch 220 for forming different electrical paths.

[0034] Next, the voltage measurement unit 300 is configured to measure the voltage applied to the voltage measuring resistor 110, and may include an analog-to-digital converter (ADC) that receives an analog voltage signal and converts the analog voltage signal into digital data. In this case, the operating power of the voltage measurement unit 300 may be provided by the battery pack 10, or by an isolated DC-DC converter from the lead-acid battery 20.

[0035] Meanwhile, in the device for measuring insulation resistance of the present invention, the voltage measuring unit 300 measures the voltage applied to the voltage measuring resistor 110 relative to the potential of the negative terminal 12 of the battery 10.

[0036] Next, the control unit 400 measures the voltage applied to the voltage measuring resistor 110 and monitors the battery's insulation resistance. The control unit 400 controls the switching unit 200 and simultaneously receives the voltage applied to the voltage measuring resistor 110 measured by the voltage measuring unit 300 to calculate the configuration of the positive and negative insulation resistances.

[0037] More specifically, the control unit 400 can receive the voltage applied to the voltage measuring resistor 110 as measured by the voltage measuring unit 300 while the first switch 210 is in the open state and the second switch 220 is in the closed state, and can also receive the voltage applied to the voltage measuring resistor 110 as measured by the voltage measuring unit 300 while both the first switch 210 and the second switch 220 are in the closed state. Here, the control unit 400 may be a microcontroller unit (MCU).

[0038] In this context, positive insulation resistance refers to the resistance between the positive terminal 11 of battery 10 and ground, and negative insulation resistance refers to the resistance between the negative terminal 12 of battery 10 and ground. Grounding is low-voltage (LV) grounding and is typically the chassis of the vehicle.

[0039] The specific connection structure of the device for measuring insulation resistance according to the present invention will be described below.

[0040] Reference Figure 2 and Figure 3 One end of the first resistor 120 is connected to the positive terminal 11 of the battery 10, and the other end is connected to one end of the first switch 210. One end of the second resistor 130 is connected to the voltage measuring resistor 110, and the other end is connected to one end of the second switch 220. The other ends of the first switch 210 and the second switch 220 are grounded.

[0041] At this time, one end of the voltage measuring resistor 110 is connected to the negative terminal 12 of the battery 10, and the other end is connected to the second resistor 130. In addition, the voltage measuring unit 300 is connected to each of the voltage measuring resistor 110 and the negative terminal 12 of the battery 10, thereby measuring the voltage applied to the voltage measuring resistor 110 relative to the potential of the negative terminal 12 of the battery 10.

[0042] Simultaneously, the battery voltage and current, as well as the inverter voltage (hereinafter referred to as high voltage (HV) measurement parameters), are measured relative to the potential of the battery's negative terminal. HV measurement parameters are used for battery diagnostics and are related to the safe operation of the vehicle, therefore requiring high-precision measurements, similar to insulation resistance measurements.

[0043] However, as mentioned above, the insulation resistance measurement circuits of the prior art measure the resistance relative to ground. To illustrate this more specifically, one end of the voltage measuring resistor is grounded; therefore, the voltage measuring unit is configured to measure the voltage applied to the voltage measuring resistor relative to the ground potential.

[0044] Therefore, in the prior art, since different potentials are used as reference points to measure HV measurement parameters and insulation resistance, the device used to measure insulation resistance needs to be a different device than the device used to measure the HV measurement parameters.

[0045] In this invention, the voltage measurement unit 300 is connected to the negative terminal 12 of the battery 10 instead of grounding, so that the potential of the negative terminal 12 of the battery 10 is used as a reference potential when measuring the voltage applied to the voltage measuring resistor 110. Therefore, the voltage measurement unit 300 can be configured by adding voltage measurement functionality to a device (e.g., an ADC) used when measuring HV measurement parameters. That is, by utilizing a single device to measure parameters related to the safe driving of electric vehicles, the number of devices requiring high-precision measurements can be reduced. Furthermore, since high precision is a cost-increasing factor, the cost reduction effect increases as the number of devices requiring high precision decreases.

[0046] Therefore, by connecting the voltage measurement unit 300 to the negative terminal 12 of the battery 10 instead of grounding, the manufacturing cost of configuring the battery system is reduced.

[0047] Reference Figure 4 This makes it easier to understand. The potential of the negative terminal 12 of the battery 10 serves as the reference input for the voltage measurement unit 300 of the device for measuring insulation resistance according to the present invention. Therefore, the voltage measurement circuit of the battery 10, the current measurement circuit of the battery 10, and the voltage measurement resistor 110 of the device for measuring insulation resistance can all be connected to a single voltage measurement unit 300. Thus, other measurement units besides the measuring device included in the voltage measurement unit 300 do not need to have high precision.

[0048] The following will describe in detail the method of measuring insulation resistance using the apparatus for measuring insulation resistance of the present invention.

[0049] First, the control unit 400 can form a first circuit by operating the first switch 210 in the off state and the second switch 220 in the on state, such as... Figure 2 As shown. Here, operating the switch in the ON state means that the switch is electrically conductive, while operating the switch in the OFF state means that the switch is not electrically conductive but is disconnected.

[0050] The first circuit includes a closed circuit connecting the battery 10, the positive insulation resistor, the second resistor 130, and the voltage measuring resistor 110, as well as a closed circuit connecting the second resistor 130, the voltage measuring resistor 110, and the negative insulation resistor.

[0051] When the first circuit is formed, the voltage measuring unit 300 measures the voltage applied to the voltage measuring resistor 110 and transmits the voltage to the control unit 400. Simultaneously, when the voltage distribution principle is applied to the first circuit, Equation 1 below is calculated.

[0052] [Equation 1] Here, VRmes_SW2 represents the voltage applied to the voltage measuring resistor 110 when the first switch 210 is in the off state and the second switch 220 is in the on state, Pack V represents the voltage of the battery 10, Rmes represents the value of the voltage measuring resistor 110, R1 represents the value of the first resistor 120, R2 represents the value of the second resistor 130, RLeak+ represents the value of the positive insulation resistance, and RLeak- represents the value of the negative insulation resistance.

[0053] Next, as Figure 3 As shown, the control unit 400 can form a second circuit by operating both the first switch 210 and the second switch 220 in the ON state.

[0054] The second circuit includes a closed circuit connecting the battery 10, the first resistor 120, the second resistor 130 and the voltage measuring resistor 110, a closed circuit connecting the positive insulation resistor and the first resistor 120, and a closed circuit connecting the second resistor 130, the voltage measuring resistor 110 and the negative insulation resistor.

[0055] When forming the second circuit, the voltage measuring unit 300 measures the voltage applied to the voltage measuring resistor 110 and transmits this voltage to the control unit 400. Simultaneously, when the voltage distribution principle is applied to the second circuit, Equation 2 below is calculated.

[0056] [Equation 2] Here, VRmes_SW1_SW2 represents the voltage applied to the voltage measuring resistor 110 when both the first switch 210 and the second switch 220 are in the ON state, Pack V represents the voltage of the battery 10, Rmes represents the value of the voltage measuring resistor 110, R1 represents the value of the first resistor 120, R2 represents the value of the second resistor 130, RLeak+ represents the value of the positive insulation resistance, and RLeak- represents the value of the negative insulation resistance.

[0057] Regarding this, in Equations 1 and 2, || denotes the symbol indicating that the resistors are connected in parallel. Furthermore, VRmes_SW2 and VRmes_SW1_SW2 are values ​​measured by the voltage measuring unit 300, and the values ​​of the voltage measuring resistor 110 (Rmes), the first resistor 120 (R1), and the second resistor 130 (R2) are known resistance values ​​and can be stored in the control unit 400. Therefore, since there are two unknowns, RLeak+ and RLeak-, and Equations 1 and 2 include these unknowns, the positive and negative insulation resistances can be calculated by solving the simultaneous equations.

[0058] In other words, the control unit 400 can calculate the value of the positive insulation resistance RLeak+ and the value of the negative insulation resistance RLeak- by combining Equations 1 and 2 calculated from the first circuit and the second circuit.

[0059] Furthermore, the control unit 400 can determine whether the battery 10 has insulation breakdown based on the positive insulation resistance value RLeak+ and the negative insulation resistance value RLeak- calculated as described above. In this regard, the control unit 400 can store a threshold value for the insulation resistance as a reference for determining whether the battery 10 has insulation breakdown. Additionally, when it is determined that the battery 10 has insulation breakdown, the control unit 400 can generate a warning signal or a signal to cut off the main relay power supply to the battery 10 as a follow-up measure.

[0060] Meanwhile, the device for measuring insulation resistance of the present invention may further include a first sensing substrate 500 and a second sensing substrate 600.

[0061] Here, the first sensing substrate 500 is connected to the battery 10 with a high voltage to sense the voltage and current of the battery 10, and the second sensing substrate 600 is a substrate with an MCU and communication components and connected to a lead-acid battery 20 with a relatively low voltage compared to the battery 10. The sensing substrate may be a printed circuit board (PCB).

[0062] In the device for measuring insulation resistance according to the present invention, the first sensing substrate 500 may be a substrate separate from the second sensing substrate 600. Here, separation means not only that the first sensing substrate 500 and the second sensing substrate 600 are insulated by an insulating device (e.g., a DC-DC converter including a transformer, an isolated (not shown) communication line, etc.), but also that the first sensing substrate 500 and the second sensing substrate 600 are spatially separated different substrates.

[0063] At this time, as Figure 1As shown, the resistor unit 100, the switch unit 200, and the voltage measurement unit 300 can be mounted on the first sensing substrate 500, and the control unit 400 can be mounted on the second sensing substrate 600. In this case, the control unit 400 can send an on / off control signal to the switch unit 200 through an isolated communication line, and receive the voltage applied to the voltage measuring resistor 110 by the voltage measurement unit 300 through an isolated communication line.

[0064] Optionally, in the device for measuring insulation resistance of the present invention, the resistance unit 100, the switching unit 200, the voltage measuring unit 300, and the control unit 400 can all be mounted on the first sensing substrate 500, such as... Figure 5 As shown. In this case, the control unit 400 may be an MCU additionally disposed on the first sensing substrate 500. As described above, when the control unit 400 is disposed on the first sensing substrate 500 in other configurations, the control unit 400 may control other measurement circuits in addition to the device for measuring insulation resistance. For example, in addition to controlling the switching unit 200, the control unit 400 may also control the switching signal of the battery voltage measurement circuit or the switching signal of the battery current measurement circuit. Therefore, the second sensing substrate 600, which is the LV side, does not need to isolate the above signals and transmit the above signals to the first sensing substrate 500, which is the HV side, and the components are configured to exchange communication signals only between the HV side and the LV side, thereby reducing costs.

[0065] Refer again Figure 4 The voltage measurement circuit of battery 10, the current measurement circuit of battery 10, and the voltage measurement unit 300 for measuring insulation resistance are mounted on the first sensing substrate 500. The voltage measurement unit 300 uses the negative terminal 12 of battery 10 as a reference potential to measure voltage. Therefore, the negative terminal 12 of battery 10 can be used as the ground (HV ground) of the first sensing substrate 500.

[0066] Alternatively, a second sensing board 600 that is equipped with a device (MCU, communication component, etc.) that uses the negative terminal of the lead-acid battery 20 as ground can use the negative terminal of the lead-acid battery 20 as the ground (LV ground) of the second sensing board 600.

[0067] In other words, since the first sensing substrate 500 and the second sensing substrate 600 are divided into different substrates, different potentials (HV ground and LV ground) can be used as grounds, and since the voltage measuring unit 300 is mounted on the first sensing substrate 500, the voltage of the battery 10 with high voltage is not applied to the second sensing substrate 600, thereby ensuring better insulation performance between the sensing substrate 500 as the HV side and the second sensing substrate 600 as the LV side.

[0068] In addition, as mentioned above, the device requiring relatively high measurement accuracy is mounted on the first sensing substrate 500, and the first sensing substrate 500 and the second sensing substrate 600 are spatially separated, so the device protecting the first sensing substrate 500 (e.g., a cover for impact protection) can be made of a more robust material.

[0069] Figure 6 This is a circuit diagram illustrating an embodiment of the apparatus for measuring insulation resistance of the present invention, in which a resistive device is added.

[0070] Reference Figure 6 The resistor unit 100 may further include a third resistor 140 connected to the other end of the first switch 210 and the other end of the second switch 220.

[0071] In this regard, the control unit 400 can form a third circuit by operating the first switch 210 in the off state and the second switch 220 in the on state, and can form a fourth circuit by operating both the first switch 210 and the second switch 220 in the on state.

[0072] Here, the third circuit includes a closed circuit connecting the battery 10, the positive insulation resistor, the third resistor 140, the second resistor 130, and the voltage measuring resistor 110, as well as a closed circuit connecting the third resistor 140, the second resistor 130, the voltage measuring resistor 110, and the negative insulation resistor.

[0073] Additionally, the fourth circuit includes a closed circuit connecting the battery 10, the first resistor 120, the third resistor 140, the second resistor 130, and the voltage measuring resistor 110; a closed circuit connecting the first resistor 120, the positive insulation resistor, and the third resistor 140; and a closed circuit connecting the third resistor 140, the second resistor 130, the voltage measuring resistor 110, and the negative insulation resistor.

[0074] When forming the third circuit, the voltage measuring unit 300 measures the voltage applied to the voltage measuring resistor 110 and transmits this voltage to the control unit 400. When the voltage distribution principle is applied to the third circuit, the following equation 3 is calculated.

[0075] [Equation 3] Subsequently, when the fourth circuit is formed, the voltage measuring unit 300 measures the voltage applied to the voltage measuring resistor 110 and transmits the voltage to the control unit 400. The following equation 4 is calculated through the fourth circuit.

[0076] [Equation 4] Here, equation 4 satisfies: VRmes_SW2 represents the voltage applied to the voltage measuring resistor 110 when the first switch 210 is in the off state and the second switch 220 is in the on state. VRmes_SW1_SW2 represents the voltage applied to the voltage measuring resistor 110 when both the first switch 210 and the second switch 220 are in the on state. Pack V represents the voltage of the battery 10. Rmes represents the value of the voltage measuring resistor 110. R1 represents the value of the first resistor 120. R2 represents the value of the second resistor 130. R3 represents the value of the third resistor 140. RLeak+ represents the value of the positive insulation resistance, and RLeak- represents the value of the negative insulation resistance.

[0077] In other words, besides adding a third resistor 140, based on... Figure 2 and Figure 3 The same principle is used to calculate the insulation resistance in the embodiments.

[0078] As described above, in the device for measuring insulation resistance according to the present invention, the voltage measuring unit can measure the voltage relative to the potential of the negative terminal of the battery, rather than the voltage relative to ground, so that a single device can be used to measure parameters requiring high accuracy, thereby reducing costs.

[0079] Furthermore, since the first sensing substrate and the second sensing substrate are separate, different potentials can be used as grounding, thereby ensuring better insulation performance between the first sensing substrate as the HV side and the second sensing substrate as the LV side.

[0080] at the same time, Figure 2 and Figure 3 Examples of calculations of equations 1 and 2, and Figure 6 The embodiments of calculations in Equations 3 and 4 are exemplary. Although the present invention has been described with reference to the above embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which this invention pertains can make various modifications and variations based on these descriptions. Therefore, the technical concept of the present invention is understood only by the claims, and all equivalent or equivalent modifications thereof fall within the scope of the technical concept of the present invention.

Claims

1. An apparatus for measuring the insulation resistance of a battery, the apparatus comprising: A switching unit includes at least one switch, and forms circuits with different paths according to the on and off operation of the switch; A voltage measuring resistor is connected between the negative terminal of the battery and ground. A voltage measuring unit measures the insulation voltage applied to the voltage measuring resistor; as well as The control unit receives the insulation voltage measured by the voltage measuring unit and calculates the positive insulation resistance between the positive terminal of the battery and ground, and the negative insulation resistance between the negative terminal of the battery and ground.

2. The device according to claim 1, in, The voltage measuring unit is connected to each of the negative terminal of the battery and the voltage measuring resistor, and measures the insulation voltage applied to the voltage measuring resistor based on the potential of the negative terminal of the battery.

3. The device according to claim 2, further comprising: The first resistor is connected between the positive terminal of the battery and ground; as well as The second resistor is connected between the negative terminal of the battery and ground. The voltage measuring resistor is connected between the negative terminal of the battery and the second resistor.

4. The device according to claim 3, in, One end of the voltage measuring unit is connected between the negative terminal of the battery and the voltage measuring resistor, and the other end of the voltage measuring unit is connected between the voltage measuring resistor and the second resistor.

5. The device according to claim 3, in, The switching unit includes a first switch and a second switch, wherein the first switch is connected between the first resistor and ground, and the second switch is connected between the second resistor and ground.

6. The device according to claim 5, further comprising: The third resistor is connected between the first switch, the second switch, and ground.

7. The device according to claim 1, further comprising: A first sensing substrate is connected to the battery; as well as The second sensing substrate is connected to a low-voltage source having a voltage lower than that of the battery. The first sensing substrate and the second sensing substrate are spatially separated and insulated from each other.

8. The device according to claim 7, in, The switching unit, the voltage measuring resistor, and the voltage measuring unit are mounted on the first sensing substrate, and the control unit is mounted on the second sensing substrate.

9. The device according to claim 1, in, The battery comprises multiple battery cells connected in series or in parallel.

10. A method for measuring insulation resistance, wherein the method employs a device for measuring the insulation resistance of a battery. in, The device includes: The first resistor is connected between the positive terminal of the battery and ground; The first switch is connected between the first resistor and ground; The second resistor is connected between the negative terminal of the battery and ground. The second switch is connected between the second resistor and ground; A voltage measuring resistor is connected between the negative terminal of the battery and the second resistor; The voltage measuring unit measures the insulation voltage applied to the voltage measuring resistor; and The control unit receives the insulation voltage measured by the voltage measuring unit and calculates the positive insulation resistance between the positive terminal of the battery and ground, and the negative insulation resistance between the negative terminal of the battery and ground. The method uses the control unit to calculate the positive insulation resistance and the negative insulation resistance.

11. The insulation resistance measurement method according to claim 10, comprising: While operating the first switch in the open state and the second switch in the closed state, the insulation voltage measured by the voltage measuring unit is received; as well as While operating both the first switch and the second switch in the ON state, the insulation voltage measured by the voltage measurement unit is received.

12. The insulation resistance measurement method according to claim 11, further comprising: The positive insulation resistance and the negative insulation resistance are calculated by combining Equations 1 and 2 below: [Equation 1] [Equation 2] Among them, V Rmes_SW2 This represents the voltage applied to the voltage measuring resistor when the first switch is in the open state and the second switch is in the closed state, in V. Rmes_SW1_SW2 This indicates the voltage applied to the voltage measuring resistor when both the first and second switches are in the ON state. Pack V represents the battery voltage, and R... mes This indicates the value of the voltage measuring resistor, R1 represents the value of the first resistor, R2 represents the value of the second resistor, and R... Leak+ This represents the value of the positive insulation resistance, and R Leak - indicates the value of negative insulation resistance.

13. The insulation resistance measurement method according to claim 10, in, The device further includes a third resistor connected between the first switch, the second switch, and ground.

14. The insulation resistance measurement method according to claim 13, comprising: While operating the first switch in the open state and the second switch in the closed state, the insulation voltage measured by the voltage measuring unit is received; as well as While operating both the first switch and the second switch in the ON state, the insulation voltage measured by the voltage measurement unit is received.

15. The insulation resistance measurement method according to claim 14, further comprising: The positive and negative insulation resistances are calculated by combining Equations 3 and 4 below: [Equation 3] [Equation 4] Equation 4 satisfies: Where V Rmes_SW2 This represents the voltage applied to the voltage measuring resistor when the first switch is in the open state and the second switch is in the closed state, in V. Rmes_SW1_SW2 This indicates the voltage applied to the voltage measuring resistor when both the first and second switches are in the ON state. Pack V represents the battery voltage, and R... mes This indicates the value of the voltage measuring resistors. R1 represents the value of the first resistor, R2 represents the value of the second resistor, and R3 represents the value of the third resistor. Leak+ This represents the value of the positive insulation resistance, and R Leak - indicates the value of negative insulation resistance.

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