Improved power battery insulation resistance detection device

Abstract

The utility model relates to the technical field of power battery insulation resistance detection, in particular to an improved power battery insulation resistance detection device. The system comprises a positive electrode detection circuit used for accessing a high-voltage positive bus terminal (PACK +) of a power battery (VBAT); the negative electrode detection circuit is used for being connected to a high-voltage negative bus end (PACK-) of the power battery (VBAT); the grounding circuit is used for being connected to a grounding end (GND) of the power battery (VBAT); wherein the positive electrode detection circuit is connected in series with the negative electrode detection circuit, and the grounding circuit is electrically connected with a series connection point of the positive electrode detection circuit and the negative electrode detection circuit; wherein a first sampling circuit (ADC1) is arranged at the positive electrode detection circuit, and a second sampling circuit (ADC2) is arranged at the negative electrode detection circuit. According to the utility model, the circuit design is simplified, the manufacturing efficiency is improved, and the hardware cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to power battery insulation resistance detection technical field, concretely relates to an improved power battery insulation resistance detection device. BACKGROUND

[0002] Through the insulation resistance detection of power battery, when the vehicle system detects insulation fault, the positive terminal and the negative terminal insulation resistance of power system are detected in detail, the detection result is reported to the whole vehicle VCU (vehicle control unit) control system in time, the accuracy and the timeliness of monitoring are improved, the safety management of the whole vehicle is provided with more effective support, and the potential safety hidden danger caused by insulation fault is prevented. UTILITARY MODEL CONTENTS

[0003] The utility model provides a kind of improved power battery insulation resistance detection device, it can overcome certain or some defects of prior art.

[0004] According to the utility model a kind of improved power battery insulation resistance detection device, it includes:

[0005] Positive electrode detection circuit is used to connect the high voltage positive bus end (PACK+) of power battery (VBAT);

[0006] Negative electrode detection circuit is used to connect the high voltage negative bus end (PACK-) of power battery (VBAT);And

[0007] Ground circuit is used to connect the ground end (GND) of power battery (VBAT);

[0008] Among them, positive electrode detection circuit and negative electrode detection circuit are connected in series, ground circuit is electrically connected with the series connection point of positive electrode detection circuit and negative electrode detection circuit;

[0009] Among them, first sampling circuit (ADC1) is arranged at positive electrode detection circuit, second sampling circuit (ADC2) is arranged at negative electrode detection circuit, first sampling circuit (ADC1) is used to obtain the voltage to ground of high voltage positive bus end (PACK+), and second sampling circuit (ADC2) is used to obtain the voltage to ground of high voltage negative bus end (PACK-).

[0010] The improved power battery insulation resistance detection device can be independently arranged on the BMS mainboard of the power battery, the high-voltage part and the low-voltage part in the circuit can be effectively separated in this way, the reliability of hardware control is enhanced, the number of required isolation devices is reduced, and then the circuit design is simplified, the manufacturing efficiency is improved, and the hardware cost is reduced.

[0011] As preferred, the grounding circuit comprises a first switch (K1). Thus, whether to perform the insulation resistance detection function can be selectively realized.

[0012] As preferred, the positive electrode detection circuit comprises a positive electrode switch branch and a positive electrode voltage division branch connected in parallel, and the first sampling circuit (ADC1) is arranged at the positive electrode voltage division branch. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0013] As preferred, the positive electrode switch branch comprises a second switch (K2) and a second switch protection resistor (R2) connected in series. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0014] As preferred, the positive electrode voltage division branch comprises a positive electrode sampling resistor (RX1) and a positive electrode voltage division resistor (R1) connected in series, and the first sampling circuit (ADC1) is used for collecting the voltage across the positive electrode sampling resistor (RX1). Through the arrangement of the positive electrode voltage division resistor (R1), the voltage across the positive electrode sampling resistor (RX1) can be reduced. It can be understood that, after the voltage across the positive electrode sampling resistor (RX1) is acquired, the positive electrode grounding voltage can be preferably realized based on the voltage division ratio of the positive electrode sampling resistor (RX1) and the positive electrode voltage division resistor (R1).

[0015] As preferred, the negative electrode detection circuit comprises a negative electrode switch branch and a negative electrode voltage division branch, and the second sampling circuit (ADC2) is arranged at the negative electrode voltage division branch. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0016] As preferred, the negative electrode switch branch comprises a third switch (K3) and a third switch protection resistor (R4) connected in series. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0017] As preferred, the negative electrode voltage division branch comprises a negative electrode sampling resistor (RX2) and a negative electrode voltage division resistor (R3) connected in series, and the second sampling circuit (ADC2) is used for collecting the voltage across the negative electrode sampling resistor (RX2). Through the arrangement of the negative electrode voltage division resistor (R3), the voltage across the negative electrode sampling resistor (RX2) can be reduced. It can be understood that, after the voltage across the negative electrode sampling resistor (RX2) is acquired, the positive electrode grounding voltage can be preferably realized based on the voltage division ratio of the negative electrode sampling resistor (RX2) and the negative electrode voltage division resistor (R3). BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A circuit diagram of an improved type of power battery insulation resistance detection device in Example 1;

[0019] Figure 2 A data flow direction schematic diagram of an improved type of power battery insulation resistance detection method in Example 2. DETAILED DESCRIPTION

[0020] In order to further understand the content of the present application, the present application will be described in detail in conjunction with examples. It should be understood that the examples are merely an explanation of the present application and not a limitation.

[0021] Example 1

[0022] As shown in Figure 1 The present embodiment provides an improved type of power battery insulation resistance detection device, which comprises:

[0023] A positive electrode detection circuit for connecting to a high-voltage positive bus end (PACK+) of a power battery (VBAT);

[0024] A negative electrode detection circuit for connecting to a high-voltage negative bus end (PACK-) of the power battery (VBAT); and

[0025] A grounding circuit for connecting to a ground end (GND) of the power battery (VBAT);

[0026] Wherein, the positive electrode detection circuit and the negative electrode detection circuit are connected in series, and the grounding circuit is electrically connected to the series connection point of the positive electrode detection circuit and the negative electrode detection circuit;

[0027] Wherein, a first sampling circuit (ADC1) is arranged at the positive electrode detection circuit, and a second sampling circuit (ADC2) is arranged at the negative electrode detection circuit, the first sampling circuit (ADC1) is used to obtain the voltage of the high-voltage positive bus end (PACK+) to ground, and the second sampling circuit (ADC2) is used to obtain the voltage of the high-voltage negative bus end (PACK-) to ground.

[0028] The improved type of power battery insulation resistance detection device in the present embodiment can be independently set to the ground of the BMS mainboard of the power battery. This way can effectively separate the high-voltage part and the low-voltage part in the circuit, enhance the reliability of hardware control, reduce the number of required isolation devices, and thus simplify the circuit design, improve the manufacturing efficiency and reduce the hardware cost.

[0029] In the present embodiment, the grounding circuit comprises a first switch (K1). Thus, it can be selectively realized whether to perform the insulation resistance detection function.

[0030] In the embodiment, the positive electrode detection circuit includes a positive electrode switch branch and a positive electrode voltage division branch connected in parallel, and the first sampling circuit (ADC1) is arranged at the positive electrode voltage division branch. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0031] In the embodiment, the positive electrode switch branch includes a second switch (K2) and a second switch protection resistor (R2) connected in series. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0032] In the embodiment, the positive electrode voltage division branch includes a positive electrode sampling resistor (RX1) and a positive electrode voltage division resistor (R1) connected in series, and the first sampling circuit (ADC1) is configured to acquire the voltage across the positive electrode sampling resistor (RX1). By setting the positive electrode voltage division resistor (R1), the voltage across the positive electrode sampling resistor (RX1) can be reduced. It can be understood that, after the voltage across the positive electrode sampling resistor (RX1) is acquired, the acquisition of the positive electrode ground voltage can be preferably realized based on the voltage division ratio of the positive electrode sampling resistor (RX1) and the positive electrode voltage division resistor (R1).

[0033] In the embodiment, the negative electrode detection circuit includes a negative electrode switch branch and a negative electrode voltage division branch, and the second sampling circuit (ADC2) is arranged at the negative electrode voltage division branch. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0034] In the embodiment, the negative electrode switch branch includes a third switch (K3) and a third switch protection resistor (R4) connected in series. Thus, the acquisition of multiple groups of required calculation parameters can be preferably realized.

[0035] In the embodiment, the negative electrode voltage division branch includes a negative electrode sampling resistor (RX2) and a negative electrode voltage division resistor (R3) connected in series, and the second sampling circuit (ADC2) is configured to acquire the voltage across the negative electrode sampling resistor (RX2). By setting the negative electrode voltage division resistor (R3), the voltage across the negative electrode sampling resistor (RX2) can be reduced. It can be understood that, after the voltage across the negative electrode sampling resistor (RX2) is acquired, the acquisition of the positive electrode ground voltage can be preferably realized based on the voltage division ratio of the negative electrode sampling resistor (RX2) and the negative electrode voltage division resistor (R3).

[0036] Embodiment 2

[0037] In combination Figure 2As shown, based on the improved power battery insulation resistance detection device of embodiment 1, the embodiment provides an improved power battery insulation resistance detection method, which is based on the insulation monitoring module for monitoring the insulation resistance of the power battery (VBAT), wherein the insulation monitoring module includes the improved power battery insulation resistance detection device, and the improved power battery insulation resistance detection device at least has a positive electrode detection circuit, a negative electrode detection circuit and a grounding circuit, the positive electrode detection circuit is used for accessing the high-voltage positive bus end (PACK+) of the power battery (VBAT), the negative electrode detection circuit is used for accessing the high-voltage negative bus end (PACK-) of the power battery (VBAT), and the grounding circuit is used for accessing the ground end (GND) of the power battery (VBAT); it includes:

[0038] Based on the positive electrode detection circuit and the grounding circuit, the positive electrode ground voltage and the equivalent resistance of the positive electrode to the ground of the high-voltage positive bus end (PACK+) of the power battery (VBAT) are obtained;

[0039] Based on the negative electrode detection circuit and the grounding circuit, the negative electrode ground voltage and the equivalent resistance of the negative electrode to the ground of the high-voltage negative bus end (PACK-) of the power battery (VBAT) are obtained;

[0040] Based on the positive electrode ground voltage, the equivalent resistance of the positive electrode to the ground, the negative electrode ground voltage and the equivalent resistance of the negative electrode to the ground, the positive electrode insulation resistance (Rp) and the negative electrode insulation resistance (Rn) of the power battery (VBAT) are obtained.

[0041] Wherein, the positive electrode detection circuit and the negative electrode detection circuit are connected in series, and the grounding circuit is electrically connected with the series connection point of the positive electrode detection circuit and the negative electrode detection circuit;

[0042] The positive electrode ground voltage and the equivalent resistance of the positive electrode to the ground of the high-voltage positive bus end (PACK+) of the power battery (VBAT) are obtained based on the positive electrode detection circuit and the grounding circuit, which includes,

[0043] The positive electrode detection circuit accesses the ground end (GND) of the power battery (VBAT) through the grounding circuit;

[0044] The negative electrode ground voltage and the equivalent resistance of the negative electrode to the ground of the high-voltage negative bus end (PACK-) of the power battery (VBAT) are obtained based on the negative electrode detection circuit and the grounding circuit, which includes,

[0045] The negative electrode detection circuit accesses the ground end (GND) of the power battery (VBAT) through the grounding circuit.

[0046] Wherein, the positive electrode detection circuit includes a positive electrode switch branch and a positive electrode voltage division branch connected in parallel;

[0047] The positive electrode detection circuit and the grounding circuit are used to obtain the positive electrode grounding voltage and the equivalent resistance of the positive electrode to the ground of the high-voltage positive bus end (PACK+) of the power battery (VBAT), and comprise,

[0048] The positive electrode switch branch is controlled to be disconnected, and the positive electrode grounding voltage U1 and the positive electrode equivalent resistance are obtained ;

[0049] The positive electrode switch branch is controlled to be turned on, and the positive electrode grounding voltage U2 and the positive electrode equivalent resistance are obtained .

[0050] The positive electrode voltage dividing branch comprises a positive electrode sampling resistor (RX1) and a positive electrode voltage dividing resistor (R1) connected in series, and the positive electrode equivalent resistance is,

[0051] .

[0052] The positive electrode switch branch comprises a second switch (K2) and a second switch protection resistor (R2) connected in series, and the positive electrode equivalent resistance is,

[0053] .

[0054] A first sampling circuit (ADC1) is used to collect the voltage across the positive electrode sampling resistor (RX1), and then the positive electrode grounding voltage U1 or the positive electrode grounding voltage U2 is obtained.

[0055] The negative electrode detection circuit comprises a negative electrode switch branch and a negative electrode voltage dividing branch.

[0056] The negative electrode detection circuit and the grounding circuit are used to obtain the negative electrode grounding voltage and the equivalent resistance of the negative electrode to the ground of the high-voltage negative bus end (PACK-) of the power battery (VBAT), and comprise,

[0057] The negative electrode switch branch is controlled to be disconnected, and the negative electrode grounding voltage and the negative electrode equivalent resistance are obtained.

[0058] The negative electrode switch branch is controlled to be turned on, and the negative electrode grounding voltage and the negative electrode equivalent resistance are obtained.

[0059] The negative electrode voltage dividing branch comprises a negative electrode sampling resistor (RX2) and a negative electrode voltage dividing resistor (R3) connected in series, and the negative electrode equivalent resistance is,

[0060] .

[0061] The negative electrode switch branch includes a third switch (K3) and a third switch protection resistor (R4) connected in series, and the negative electrode equivalent resistance For,

[0062] .

[0063] The second sampling circuit (ADC2) is used to collect the voltage across the negative electrode sampling resistor (RX2), and then the negative electrode ground voltage or the negative electrode ground voltage .

[0064] In this example, " / / " represents parallel connection, which is only used to express the connection mode of the resistor device, and is not a calculation symbol.

[0065] In this embodiment, the BMS mainboard can send an insulation resistance detection instruction to the insulation detection module through the communication module, and then the insulation detection module can realize the acquisition of the following four groups of data based on the on-off control of the first switch (K1), the second switch (K2) and the third switch (K3):

[0066] (1) The positive electrode ground voltage U1 and the positive electrode equivalent resistance ;

[0067] (2) The positive electrode ground voltage U2 and the positive electrode equivalent resistance ;

[0068] (3) The negative electrode ground voltage and the negative electrode equivalent resistance ;

[0069] (4) The negative electrode ground voltage and the negative electrode equivalent resistance .

[0070] Based on the above two groups of data, the following equation group can be constructed, for example:

[0071] ;

[0072] .

[0073] Then, the positive electrode insulation resistance Rp and the negative electrode insulation resistance Rn can be preferably obtained.

[0074] It is easy to understand that those skilled in the art can combine, split, recombine, etc. the embodiments of the present application on the basis of one or more embodiments provided in the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0075] The above describes the utility model and its embodiments in a schematic manner, and the description is not restrictive, and the embodiments shown are only part of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired thereby, without departing from the creative concept of the utility model, similar structural modes and embodiments are designed without creativity, and all should belong to the protection scope of the utility model.

Claims

1. An improved device for detecting the insulation resistance of a power cell, characterized in that, The application relates to a battery voltage detection circuit. The battery voltage detection circuit comprises: a positive electrode detection circuit for connecting to a high-voltage positive bus end (PACK+) of a power battery (VBAT); a negative electrode detection circuit for connecting to a high-voltage negative bus end (PACK-) of the power battery (VBAT); and a grounding circuit for connecting to a grounding end (GND) of the power battery (VBAT); wherein the positive electrode detection circuit and the negative electrode detection circuit are connected in series, and the grounding circuit is electrically connected to the series connection point of the positive electrode detection circuit and the negative electrode detection circuit; wherein a first sampling circuit (ADC1) is arranged at the positive electrode detection circuit, and a second sampling circuit (ADC2) is arranged at the negative electrode detection circuit, the first sampling circuit (ADC1) is used for acquiring the voltage between the high-voltage positive bus end (PACK+) and the ground, and the second sampling circuit (ADC2) is used for acquiring the voltage between the high-voltage negative bus end (PACK-) and the ground.

2. The improved power battery insulation resistance detection device according to claim 1, characterized in that: The grounding circuit comprises a first switch (K1).

3. The improved power battery insulation resistance detection device according to claim 1, characterized in that: The positive electrode detection circuit comprises a positive electrode switch branch and a positive electrode voltage division branch connected in parallel, and the first sampling circuit (ADC1) is arranged at the positive electrode voltage division branch.

4. The improved power battery insulation resistance detection device according to claim 3, characterized in that: The positive electrode switch branch comprises a second switch (K2) and a second switch protection resistor (R2) connected in series.

5. The improved power battery insulation resistance detection device according to claim 3, characterized in that: The positive electrode voltage division branch comprises a positive electrode sampling resistor (RX1) and a positive electrode voltage division resistor (R1) connected in series, and the first sampling circuit (ADC1) is used for collecting the voltage between the positive electrode sampling resistor (RX1).

6. The improved power battery insulation resistance detection device according to claim 1, characterized in that: The negative electrode detection circuit comprises a negative electrode switch branch and a negative electrode voltage division branch, and the second sampling circuit (ADC2) is arranged at the negative electrode voltage division branch.

7. The improved power battery insulation resistance detection device according to claim 6, characterized in that: The negative electrode switch branch comprises a third switch (K3) and a third switch protection resistor (R4) connected in series.

8. The improved power battery insulation resistance detection device according to claim 6, characterized in that: The negative electrode voltage division branch comprises a negative electrode sampling resistor (RX2) and a negative electrode voltage division resistor (R3) connected in series, and the second sampling circuit (ADC2) is used for collecting the voltage between the negative electrode sampling resistor (RX2).

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