CN107167661B - Device and method for detecting insulation resistance - Google Patents

Abstract

The embodiment of the present application provides a detection device and method for insulation resistance, the device includes: a voltage divider module, a sampling module and a processor; the first output end of the voltage divider module is connected to the first DC side device in the electrochemical energy storage system One input terminal, the second output terminal of the voltage dividing module is connected to the second input terminal of the DC side device, and the third output terminal of the voltage dividing module is connected to the ground wire of the electrochemical energy storage system. The processor is used to control the closing or opening of each switch in the voltage dividing module to trigger the circuit connection in the voltage dividing module to change; the sampling module is used to collect the voltage of the sampling resistor under different circuit connection states in the voltage dividing module; the processor It is also used for: determining the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor. It can be seen that the detection of the insulation resistance of the electrochemical energy storage system has been realized.

Description

Insulation resistance detection device and method

Technical Field

The present application relates to circuit technology, and in particular to a device and method for detecting insulation resistance.

Background Art

Energy storage technology is an important part of energy internet technology, and it is also an important part of distributed energy systems and smart grid systems. Energy storage technology is generally divided into thermal energy storage and electrical energy storage, but in the future, electrical energy storage will be the main application in the global energy internet. Among them, electrical energy storage technology is mainly divided into three categories: physical energy storage, electrochemical energy storage, and electromagnetic energy storage. With the rapid advancement of electrochemical technology, electrochemical energy storage is becoming more and more widely used.

Figure 1 is a schematic diagram of the structure of an electrochemical energy storage system. As shown in Figure 1, the electrochemical energy storage system E includes: an electrochemical energy storage device A, a DC side device B, an AC/DC power conversion device C, and an AC side device D, wherein the AC side device D is connected to a power grid or a load. The electrochemical energy storage system stores the electric energy of the power grid into the electrochemical energy storage device A through the AC/DC power conversion device C, or discharges the electric energy in the electrochemical energy storage device A to the power grid through the AC/DC power conversion device C.

In order to ensure the normal operation of the electrochemical energy storage system and the safety of the operation and maintenance personnel, it is necessary to ensure that the electrochemical energy storage system is well insulated from the ground. However, during the long-term operation of the electrochemical energy storage system, insulation aging, external force damage and other reasons will cause the insulation resistance of the electrochemical energy storage system to the ground to decrease, making the electrochemical energy storage system unable to operate safely and endangering the personal safety of the operation and maintenance personnel. Therefore, it is necessary to conduct long-term detection and monitoring of the insulation resistance of the electrochemical energy storage system.

Therefore, how to detect the insulation resistance of the electrochemical energy storage system has become a technical problem that researchers are currently eager to solve.

Summary of the invention

The present application provides an insulation resistance detection device and method, which realizes the detection of the insulation resistance of an electrochemical energy storage system.

In a first aspect, an embodiment of the present application provides an insulation resistance detection device, comprising: a voltage division module, a sampling module and a processor, wherein the voltage division module is connected to the sampling module and the processor respectively; the voltage division module comprises: at least two switches and at least two sampling resistors;

The first output end of the voltage divider module is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system.

The processor is used to control the closing or opening of each switch in the voltage dividing module to trigger a change in the circuit connection in the voltage dividing module;

The sampling module is used to collect the voltage of the sampling resistor in different circuit connection states in the voltage divider module;

The processor is further used to determine the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor.

The voltage divider module includes: a first sampling unit, a second sampling unit, and a third switch, wherein the first sampling unit includes a first switch and a first sampling resistor, and the second sampling unit includes a second switch and a second sampling resistor; wherein the first end of the first sampling unit is connected to the first input end of the DC side device, the first end of the second sampling unit is connected to the second input end of the DC side device, the second end of the first sampling unit and the second end of the second sampling unit are connected to the first end of the third switch, and the second end of the third switch is connected to the ground wire of the electrochemical energy storage system;

Correspondingly, the sampling module is specifically used to: collect a first voltage across the first sampling resistor when the first switch and the second switch are closed, a second voltage across the first sampling resistor when the first switch and the third switch are closed, and a third voltage across the second sampling resistor when the second switch and the third switch are closed;

The processor is specifically used to determine the insulation resistance of the first input end of the DC side device to the ground and the insulation resistance of the second input end of the DC side device to the ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor and the second sampling resistor.

In a possible design, the voltage dividing module further includes: a fourth switch and a third sampling unit, the third sampling unit includes a fifth switch and a third sampling resistor; wherein the first end of the fourth switch and the first end of the third sampling unit are connected to the first end of the second sampling unit, the second end of the fourth switch is connected to the second end of the third switch, and the second end of the third sampling unit is connected to the first input end of the AC side device in the electrochemical energy storage system;

Correspondingly, the sampling module is further used to: collect a fourth voltage across the third sampling resistor when the fifth switch is closed, and a fifth voltage across the third sampling resistor when the fourth switch and the fifth switch are closed;

The processor is further configured to determine the insulation resistance of the first input terminal of the AC side device to ground according to the fourth voltage, the fifth voltage and the third sampling resistor.

In a possible design, the voltage division module further includes: a fourth sampling unit, the fourth sampling unit including a sixth switch and a fourth sampling resistor; wherein a first end of the fourth sampling unit is connected to a first end of the second sampling unit, and a second end of the fourth sampling unit is connected to a second input end of the AC side device;

Correspondingly, the sampling module is further used to: collect a sixth voltage across the fourth sampling resistor when the sixth switch is closed, and a seventh voltage across the fourth sampling resistor when the fourth switch and the sixth switch are closed;

The processor is further configured to determine an insulation resistance to ground of the second input terminal of the AC side device according to the sixth voltage, the seventh voltage and the fourth sampling resistor.

In a possible design, the voltage division module further includes: a fifth sampling unit, the fifth sampling unit including a seventh switch and a fifth sampling resistor; wherein a first end of the fifth sampling unit is connected to a first end of the second sampling unit, and a second end of the fifth sampling unit is connected to a third input end of the AC side device;

Correspondingly, the sampling module is further used to: collect an eighth voltage across the fifth sampling resistor when the seventh switch is closed, and a ninth voltage across the fifth sampling resistor when the fourth switch and the seventh switch are closed;

The processor is further configured to determine an insulation resistance to ground of a third input terminal of the AC side device according to the eighth voltage, the ninth voltage and the fifth sampling resistor.

In a possible design, the first sampling unit further includes a first voltage-dividing resistor, and the second sampling unit further includes a second voltage-dividing resistor, a first end of the first voltage-dividing resistor is connected to a first input end of the DC side device, a second end of the first voltage-dividing resistor is connected to a first end of the first switch, a second end of the first switch is connected to a first end of the first sampling resistor, a second end of the first sampling resistor is connected to a first end of the third switch, a first end of the second voltage-dividing resistor is connected to a second input end of the DC side device, a second end of the second voltage-dividing resistor is connected to a first end of the second switch, a second end of the second switch is connected to a first end of the second sampling resistor, and a second end of the second sampling resistor is connected to a first end of the third switch;

Correspondingly, the processor is specifically used to determine the insulation resistance of the first input end of the DC side device to ground and the insulation resistance of the second input end of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, the second sampling resistor, the first voltage divider resistor and the second voltage divider resistor.

In a second aspect, an embodiment of the present application provides a method for detecting insulation resistance, which is applicable to a detection device, wherein the detection device comprises: a voltage divider module, a sampling module and a processor, wherein the voltage divider module is connected to the sampling module and the processor respectively; the voltage divider module comprises: at least two switches and at least two sampling resistors; a first output end of the voltage divider module is connected to a first input end of a DC side device in an electrochemical energy storage system, a second output end of the voltage divider module is connected to a second input end of the DC side device, and a third output end of the voltage divider module is connected to a ground wire of the electrochemical energy storage system;

The method comprises:

The processor controls the closing or opening of each switch in the voltage dividing module to trigger a change in the circuit connection in the voltage dividing module;

The sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor.

In a possible design, the voltage divider module includes: a first sampling unit, a second sampling unit, and a third switch, wherein the first sampling unit includes a first switch and a first sampling resistor, and the second sampling unit includes a second switch and a second sampling resistor; wherein the first end of the first sampling unit is connected to the first input end of the DC side device, the first end of the second sampling unit is connected to the second input end of the DC side device, the second end of the first sampling unit and the second end of the second sampling unit are connected to the first end of the third switch, and the second end of the third switch is connected to the ground wire of the electrochemical energy storage system;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, including:

The sampling module collects a first voltage across the first sampling resistor when the first switch and the second switch are closed, a second voltage across the first sampling resistor when the first switch and the third switch are closed, and a third voltage across the second sampling resistor when the second switch and the third switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, including:

The processor determines the insulation resistance to ground of the first input terminal of the DC side device and the insulation resistance to ground of the second input terminal of the DC side device according to the first voltage, the second voltage, the third voltage, the first sampling resistor and the second sampling resistor.

In a possible design, the voltage dividing module further includes: a fourth switch and a third sampling unit, the third sampling unit includes a fifth switch and a third sampling resistor; wherein the first end of the fourth switch and the first end of the third sampling unit are connected to the first end of the second sampling unit, the second end of the fourth switch is connected to the second end of the third switch, and the second end of the third sampling unit is connected to the first input end of the AC side device in the electrochemical energy storage system;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects a fourth voltage across the third sampling resistor when the fifth switch is closed, and a fifth voltage across the third sampling resistor when the fourth switch and the fifth switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the first input terminal of the AC side device to the ground according to the fourth voltage, the fifth voltage and the third sampling resistor.

In a possible design, the voltage division module further includes: a fourth sampling unit, the fourth sampling unit including a sixth switch and a fourth sampling resistor; wherein a first end of the fourth sampling unit is connected to a first end of the second sampling unit, and a second end of the fourth sampling unit is connected to a second input end of the AC side device;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects a sixth voltage across the fourth sampling resistor when the sixth switch is closed, and a seventh voltage across the fourth sampling resistor when the fourth switch and the sixth switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the second input terminal of the AC side device to the ground according to the sixth voltage, the seventh voltage and the fourth sampling resistor.

In a possible design, the voltage division module further includes: a fifth sampling unit, the fifth sampling unit including a seventh switch and a fifth sampling resistor; wherein a first end of the fifth sampling unit is connected to a first end of the second sampling unit, and a second end of the fifth sampling unit is connected to a third input end of the AC side device;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects an eighth voltage across the fifth sampling resistor when the seventh switch is closed, and a ninth voltage across the fifth sampling resistor when the fourth switch and the seventh switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the third input terminal of the AC side device to the ground according to the eighth voltage, the ninth voltage and the fifth sampling resistor.

In a possible design, the first sampling unit further includes a first voltage-dividing resistor, and the second sampling unit further includes a second voltage-dividing resistor, a first end of the first voltage-dividing resistor is connected to a first input end of the DC side device, a second end of the first voltage-dividing resistor is connected to a first end of the first switch, a second end of the first switch is connected to a first end of the first sampling resistor, a second end of the first sampling resistor is connected to a first end of the third switch, a first end of the second voltage-dividing resistor is connected to a second input end of the DC side device, a second end of the second voltage-dividing resistor is connected to a first end of the second switch, a second end of the second switch is connected to a first end of the second sampling resistor, and a second end of the second sampling resistor is connected to a first end of the third switch;

Correspondingly, the processor determines the insulation resistance of the first input terminal of the DC side device to ground and the insulation resistance of the second input terminal of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, and the second sampling resistor, including:

The processor determines the insulation resistance to ground of the first input terminal of the DC side device and the insulation resistance to ground of the second input terminal of the DC side device according to the first voltage, the second voltage, the third voltage, the first sampling resistor, the second sampling resistor, the first voltage dividing resistor, and the second voltage dividing resistor.

In the insulation resistance detection device and method provided in the embodiment of the present application, the first output end of the voltage divider module of the insulation resistance detection device is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system. The processor of the insulation resistance detection device controls the closing or opening of each switch in the voltage divider module to trigger a change in the circuit connection in the voltage divider module; further, the sampling module of the detection device collects the voltage of each sampling resistor in different circuit connection states in the voltage divider module; further, the processor determines the insulation resistance of the electrochemical energy storage system based on the voltage of the sampling resistor and the resistance of the sampling resistor. It can be seen that the detection of the insulation resistance of the electrochemical energy storage system is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic diagram of the structure of an electrochemical energy storage system;

FIG2A is a schematic structural diagram of a first embodiment of an insulation resistance detection device of the present application;

FIG2B is a structural schematic diagram 1 of a voltage divider module in an embodiment of the present application;

FIG3A is a second structural diagram of a voltage divider module in an embodiment of the present application;

FIG3B is a third structural diagram of a voltage divider module in an embodiment of the present application;

FIG4A is a fourth structural diagram of a voltage divider module in an embodiment of the present application;

4B is a schematic diagram of the structure of a Thevenin equivalent circuit of a first input terminal of an AC side device of an electrochemical energy storage system through an AC/DC power conversion device to a DC side device in an embodiment of the present application;

FIG4C is a schematic diagram of an equivalent circuit structure of an insulation resistance detection circuit in an embodiment of the present application;

FIG4D is a second schematic diagram of the equivalent circuit structure of the insulation resistance detection circuit in the embodiment of the present application;

FIG5 is a fifth structural diagram of a voltage divider module in an embodiment of the present application;

FIG. 6 is a sixth structural diagram of the voltage divider module in an embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or devices is not necessarily limited to those steps or devices clearly listed, but may include other steps or devices that are not clearly listed or inherent to these processes, methods, products or devices.

First, the electrochemical energy storage system involved in this application is explained:

As shown in FIG1 , the electrochemical energy storage system E includes: an electrochemical energy storage device A, a DC side device B, an AC/DC power conversion device C, and an AC side device D. The first output end of the electrochemical energy storage device A is connected to the first input end of the DC side device B, the second output end of the electrochemical energy storage device A is connected to the second input end of the DC side device B, the first output end of the DC side device B is connected to the first input end of the AC/DC power conversion device C, the second output end of the DC side device B is connected to the second input end of the AC/DC power conversion device C, the first output end of the AC/DC power conversion device C is connected to the first input end of the AC side device D, the second output end of the AC/DC power conversion device C is connected to the second input end of the AC side device D, the third output end of the AC/DC power conversion device C is connected to the third input end of the AC side device D, and the output end of the AC side device D is connected to a power grid or a load.

Secondly, the application background of the embodiment of the present application is introduced:

Generally, during the long-term operation of the electrochemical energy storage system E, insulation aging, external force damage and other reasons will cause the insulation resistance of the electrochemical energy storage system E to the ground to decrease, making the electrochemical energy storage system E unable to operate safely and endangering the personal safety of the operation and maintenance personnel. Therefore, it is necessary to perform long-term detection and monitoring of the insulation resistance of the electrochemical energy storage system E (such as the insulation resistance to the ground on the DC side and/or the insulation resistance to the ground on the AC side).

The insulation resistance detection device and method provided in the embodiments of the present disclosure are intended to detect the insulation resistance of the electrochemical energy storage system E. For specific implementation methods, see the following embodiments:

The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

FIG2A is a schematic diagram of the structure of the first embodiment of the detection device of the insulation resistance of the present application, and FIG2B is a schematic diagram of the structure of the voltage divider module in the embodiment of the present application. In combination with FIG1, FIG2A and FIG2B, the detection device 20 of the insulation resistance includes: a voltage divider module 201, a sampling module 202 and a processor 203. Optionally, the voltage divider module 201 is connected to the sampling module 202 and the processor 203 respectively, and the processor 203 is connected to the sampling module 202; the voltage divider module includes: at least two switches and at least two sampling resistors. Optionally, the at least two switches in the voltage divider module 201 are in different states (such as closed or open), and the circuit connection in the voltage divider module 201 is different. Optionally, the switch in the voltage divider module 201 can be a switch with a physical breakpoint. Of course, the switch in the voltage divider module 201 can also be a switch in other forms, which is not limited in the embodiment of the present application.

Among them, the first output end ① of the voltage divider module 201 is connected to the first input end of the DC side device B in the electrochemical energy storage system E, the second output end ② of the voltage divider module 201 is connected to the second input end of the DC side device B, and the third output end ③ of the voltage divider module 201 is connected to the ground wire of the electrochemical energy storage system E.

Optionally, the processor 203 is used to control the closing or opening of each switch in the voltage divider module 201 to trigger a change in the circuit connection in the voltage divider module 201. The sampling module 202 is used to collect the voltage of the sampling resistor in different circuit connection states in the voltage divider module 201. Optionally, the sampling module 202 transmits the collected voltages of each sampling resistor in different circuit connection states in the voltage divider module 201 to the processor 203. Further, the processor 203 is also used to: determine the insulation resistance of the electrochemical energy storage system E according to the voltage of each sampling resistor and the resistance of each sampling resistor transmitted by the sampling module 202. Optionally, the insulation resistance can be the insulation resistance to ground of the DC side (for example, the insulation resistance to ground _Rgp of the first input end of the DC side device and the insulation resistance to ground _Rgn of the second input end of the DC side device in FIG. 1). Of course, the insulation resistance of the electrochemical energy storage system E can also include other insulation resistances to ground, which is not limited in the embodiment of the present application.

Optionally, the sampling module 202 may first convert the collected voltages of the sampling resistors in different circuit connection states in the voltage divider module 201 into digital voltage signals, and transmit the digital voltage signals to the processor 203, so that the processor 203 determines the insulation resistance of the electrochemical energy storage system E according to the digital voltage signals (i.e., the voltages of the sampling resistors transmitted by the sampling module 202) and the resistances of the sampling resistors. Optionally, the sampling module 202 converts the voltages of the sampling resistors into digital voltage signals through analog-to-digital conversion (Analog-to-Digital Convert, A/D) so that the processor can calculate. Optionally, the A/D conversion method may adopt the A/D conversion method in the prior art, which is not limited in the embodiments of the present application.

In this embodiment, the first output end of the voltage divider module of the insulation resistance detection device is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system; the processor of the insulation resistance detection device is used to control the closing or opening of each switch in the voltage divider module to trigger the change of the circuit connection in the voltage divider module; the sampling module of the insulation resistance detection device is used to collect the voltage of each sampling resistor in different circuit connection states in the voltage divider module; the processor is also used to: determine the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor. It can be seen that the detection of the insulation resistance of the electrochemical energy storage system is realized.

FIG3A is a second structural schematic diagram of the voltage divider module in the embodiment of the present application. In combination with FIG1 , FIG2B and FIG3A , on the basis of the embodiment, the voltage divider module 201 includes: a first sampling unit 201A, a second sampling unit 201B, and a third switch K _g1 , wherein the first sampling unit 201A includes a first switch K _p and a first sampling resistor R _p2 , and the second sampling unit 201B includes a second switch K _n and a second sampling resistor R _n2 . Wherein, the first end of the first sampling unit 201A (i.e., the first output end ① of the voltage divider module 201) is connected to the first input end of the DC side device B, the first end of the second sampling unit 201B (i.e., the second output end ② of the voltage divider module 201) is connected to the second input end of the DC side device B, the second end of the first sampling unit 201A and the second end of the second sampling unit 201B are connected to the first end of the third switch K _g1 , and the second end of the third switch K _g1 (i.e., the third output end ③ of the voltage divider module 201) is connected to the ground wire of the electrochemical energy storage system E.

Optionally, in this embodiment, the connection relationship between the first switch _Kp and the first sampling resistor _Rp2 in the first sampling unit 201A, and the connection relationship between the second switch _Kn and the second sampling resistor _Rn2 in the second sampling unit 201B are not limited. For example, the first end of the first switch _Kp can be used as the first end of the first sampling unit 201A, the second end of the first switch _Kp is connected to the first end of the first sampling resistor _Rp2 , and the second end of the first sampling resistor _Rp2 is used as the second end of the first sampling unit 201A (not shown in the figure); or, the first end of the first sampling resistor _Rp2 can be used as the first end of the first sampling unit 201A, the second end of the first sampling resistor _Rp2 is connected to the first end of the first switch _Kp , and the second end of the first switch _Kp is used as the second end of the first sampling unit 201A (as shown in FIG. 3A). Of course, the first sampling unit 201A and the second sampling unit 201B can also include other devices, which are not limited in this embodiment.

Optionally, the first detection terminal and the second detection terminal of the sampling module 202 are respectively connected to the two ends of the first sampling resistor R _p2 , so as to collect the voltage across the two ends of the first sampling resistor R _p2 , and the third detection terminal and the fourth detection terminal of the sampling module 202 are respectively connected to the two ends of the second sampling resistor R _n2 , so as to collect the voltage across the two ends of the second sampling resistor R _n2 . Optionally, the specific circuit structure of the sampling module 202 can adopt the structure of the sampling circuit in the prior art, which is not limited in this embodiment.

Optionally, the processor 203 is used to: respectively control the first switch _Kp and the second switch _Kn in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the first switch _Kp and the second switch _Kn are in an open state, the first switch _Kp and the third switch _Kg1 in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the first switch _Kp and the third switch _Kg1 are in an open state, and the second switch _Kn and the third switch _Kg1 in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the second switch _Kn and the third switch _Kg1 are in an open state.

Optionally, the sampling module 202 is specifically used to collect a first voltage U p21 across the first sampling resistor R p2 when the first switch K _p and the second switch K _n are closed (all switches except the first switch K _p and the second switch K _n in the voltage dividing module 201 are in an open state), a second voltage U _p22 across the first sampling resistor R _p2 when the first switch K _p and the third switch K _g1 are closed (all switches except the first switch K _p and the third switch K _g1 in the voltage dividing module 201 are in an open state), and a third voltage _{U n2} across the second sampling resistor R _n2 when the second switch K _n and the third switch K _g1 are closed (all switches except the second switch K _n and the third switch K _g1 in the voltage dividing module ₂₀₁ are in an open state).

Further _, the processor 203 is specifically used to determine the insulation resistance R _{gp of the first input end of the DC side device and the insulation resistance R gn of the second input end of the DC side device according to the first voltage Up21, the second voltage Up22 , the third} voltage Un2, the first sampling resistor R _p2 and the second sampling resistor R _n2 .

Optionally, the processor determines the R _gp and the R _gn according to the following formula 1, formula 2 and formula 3.

Wherein, the U _dc represents the DC side voltage of the electrochemical energy storage system E (or the voltage between the first input terminal of the DC side device B and the second input terminal of the DC side device B).

Since the other parameters except the U _dc , the R _gp and the R _gn in the above three formulas are known, the processor can determine the U _dc , the R _gp and the R _gn according to the above three formulas.

Of course, the processor may also determine the R _gp and the R _gn according to other equivalent or modified formulas of the above formula 1, other equivalent or modified formulas of the above formula 2, and other equivalent or modified formulas of the above formula 3, which is not limited in the embodiments of the present application.

In summary, in this embodiment, the sampling module collects the first voltage U _p21 across the first sampling resistor in the voltage dividing module when the first switch and the second switch in the voltage dividing module are closed, the second voltage U _p22 across the first sampling resistor when the first switch and the third switch in the voltage dividing module are closed, and the third voltage U _n2 across the second sampling resistor in the voltage dividing module when the second switch and the third switch in the voltage dividing module are closed; further, the processor determines the insulation resistance R _gp of the first input end of the DC side device and the insulation resistance R _gn of the second input end of the DC side device according to the first voltage U _p21 , the second voltage U _p22 , the third voltage U _n2 , the first sampling resistor R _p2 and the second sampling resistor R _n2 . It can be seen that the detection of the insulation resistance to ground of the DC side of the electrochemical energy storage system is achieved.

FIG3B is a third structural diagram of the voltage divider module in the embodiment of the present application. Optionally, as shown in FIG3B , the first sampling unit 201A further includes a first voltage divider resistor R _p1 , and the second sampling unit further includes a second voltage divider resistor R _n1 . Optionally, the first end of the first voltage divider resistor R _p1 (i.e., the first end of the first sampling unit 201A) is connected to the first input end of the DC side device B, the second end of the first voltage divider resistor R _p1 is connected to the first end of the first switch K _p , the second end of the first switch K _p is connected to the first end of the first sampling resistor R _p2 , and the second end of the first sampling resistor R _p2 (i.e., the second end of the first sampling unit 201A) is connected to the first end of the third switch K _g1 . Optionally, the first end of the second voltage-dividing resistor _Rn1 (i.e., the first end of the second sampling unit 201B) is connected to the second input end of the DC side device B, the second end of the second voltage-dividing resistor _Rn1 is connected to the first end of the second switch _Kn , the second end of the second switch _Kn is connected to the first end of the second sampling resistor _Rn2 , and the second end of the second sampling resistor _Rn2 (i.e., the second end of the second sampling unit 201B) is connected to the first end of the third switch _Kg1 .

Of course, the connection relationship between the first switch _Kp , the first voltage-dividing resistor _Rp1 and the first sampling resistor _Rp2 in the first sampling unit 201A, and/or the connection relationship between the second switch _Kn , the second voltage-dividing resistor _Rn1 and the second sampling resistor _Rn2 in the second sampling unit 201B may also be other connection modes. In this embodiment, the connection relationship between the first switch _Kp , the first voltage-dividing resistor _Rp1 and the first sampling resistor _Rp2 in the first sampling unit 201A, and the connection relationship between the second switch _Kn , the second voltage-dividing resistor _Rn1 and the second sampling resistor _Rn2 in the second sampling unit 201B are not limited.

Correspondingly, the processor 203 is specifically used to determine the insulation resistance R _gp of the first input end of the DC side device and the insulation resistance _{R gn of} the second input end of the DC side device according to the first voltage _Up21 , the second voltage _Up22 , the third voltage _Un2 , the first sampling resistor R _p2 , the second sampling resistor R _n2 , the first voltage dividing resistor R p1 and the second voltage dividing resistor R _n1 .

Optionally, the processor determines the R _gp and the R _gn according to the following Formula 4, Formula 5 and Formula 6.

Wherein, the U _dc represents the DC side voltage of the electrochemical energy storage system E (or the voltage between the first input terminal of the DC side device B and the second input terminal of the DC side device B).

Since all parameters except the U _dc , the R _gp and the R _gn in the above formulas 4 to 6 are known, the processor can determine the U _dc , the R _gp and the R _gn according to the above formulas 4 to 6.

Of course, the processor may also determine the R _gp and the R _gn according to other equivalent or modified formulas of Formula 4, other equivalent or modified formulas of Formula 5, and other equivalent or modified formulas of Formula 6, which is not limited in the embodiments of the present application.

Optionally, when the sampling module of the insulation resistance detection device collects the first voltage U _p21 across the first sampling resistor R _p2 when the first switch K _p and the second switch K _n are closed, the second voltage U p22 across the first sampling resistor R _p2 when the first switch K _p and the third switch K _g1 are closed, and the third voltage U _n2 across the second sampling resistor R _n2 when the second switch K _n and the third switch K _g1 are closed, as shown in FIG1 , 1) if the switch _S1 and the switch S2 of the electrochemical energy storage device A of the electrochemical energy storage system E are closed, the R gp and the R _{gn calculated by the processor of the insulation resistance detection device according to the above formulas 1 to 3 or the above formulas 4 to 6 include the insulation resistance of the electrochemical energy storage device A to the ground; 2) if the switch S1 and the switch S2 of the electrochemical energy storage device A of the electrochemical energy storage system E are disconnected, the R gp and the R gn calculated} by the processor of the insulation resistance detection device according to the above formulas 1 to ₃ or the above formulas 4 to 6 include the insulation resistance of the electrochemical energy storage device A to the ground. _gn does not include the insulation resistance of the electrochemical energy storage device A to ground.

FIG4A is a fourth structural schematic diagram of the voltage divider module in the embodiment of the present application. In combination with FIG1, FIG2B, FIG3A, FIG3B and FIG4A, on the basis of the embodiment, the voltage divider module 201 further includes: a fourth switch K _g2 and a third sampling unit 201C, and the third sampling unit 201C includes a fifth switch _Ka and a third sampling resistor _Ra . Wherein, the first end of the fourth switch K _g2 and the first end of the third sampling unit 201C are connected to the first end of the second sampling unit 201B (i.e., the second output end ② of the voltage divider module 201), the second end of the fourth switch K _g2 is connected to the second end of the third switch K _g1 (i.e., the third output end ③ of the voltage divider module 201), and the second end of the third sampling unit 201C (i.e., the fourth output end ④ of the voltage divider module 201) is connected to the first input end of the AC side device D in the electrochemical energy storage system E. Optionally, the first input end of the AC side device may be the A phase line, the B phase line or the C phase line of the AC side device. For the convenience of illustration, FIG1 takes the example that the first input end of the AC side device may be the A phase line.

Optionally, in this embodiment, the connection relationship between the fifth switch _Ka and the third sampling resistor _Ra in the third sampling unit 201C is not limited. For example, the first end of the fifth switch _Ka can be used as the first end of the third sampling unit 201C, the second end of the fifth switch _Ka is connected to the first end of the third sampling resistor _Ra , and the second end of the third sampling resistor _Ra is used as the second end of the third sampling unit 201C (not shown in the figure); or, the first end of the third sampling resistor _Ra can be used as the first end of the third sampling unit 201C, the second end of the third sampling resistor _Ra is connected to the first end of the fifth switch _Ka , and the second end of the fifth switch _Ka is used as the second end of the third sampling unit 201C (as shown in FIG. 4A). Of course, the third sampling unit 201C can also include other devices, which are not limited in this embodiment.

Optionally, the fifth detection terminal and the sixth detection terminal of the sampling module 202 are respectively connected to two ends of the third sampling resistor _Ra , so as to collect the voltage across the two ends of the third sampling resistor _Ra .

Optionally, the processor 203 is further used to: respectively control the fifth switch _Ka in the voltage divider module 201 to be closed and the remaining switches in the voltage divider module 201 except the fifth switch _Ka are in an open state, and the fourth switch _Kg2 and the fifth switch _Ka in the voltage divider module 201 to be closed and the remaining switches in the voltage divider module 201 except the fourth switch _Kg2 and the fifth switch _Ka are in an open state.

Optionally, the sampling module 202 is further used to collect a fourth voltage U a1 across the third sampling resistor _{Ra when the fifth switch Ka is closed (all switches except the fifth switch Ka in the voltage dividing module 201 are in an open state), and a fifth voltage U a2 across the third sampling resistor Ra when the fourth} switch K _g2 and the fifth switch _Ka are closed (all switches except the fourth switch K _g2 and the fifth switch _Ka in the voltage _dividing module ₂₀₁ are in an open state).

Further, the processor 203 is further configured to determine the insulation resistance _Rga of the first input terminal of the AC side device to ground (the insulation resistance of the AC side of the electrochemical energy storage system to ground) according to the fourth voltage _Ua1 , the fifth voltage _Ua2 and the third sampling resistor _Ra .

FIG4B is a schematic diagram of the structure of the Thevenin equivalent circuit of the first input terminal of the AC side device of the DC side device of the electrochemical energy storage system through the AC-DC power conversion device in the embodiment of the present application, FIG4C is a schematic diagram of the equivalent circuit structure of the insulation resistance detection circuit in the embodiment of the present application, and FIG4D is a schematic diagram of the equivalent circuit structure of the insulation resistance detection circuit in the embodiment of the present application. Wherein, FIG4C is the equivalent circuit corresponding to when the fifth switch _Ka in the voltage divider module is closed and the remaining switches except the fifth switch _Ka in the voltage divider module 201 are in an open state, and FIG4D is the equivalent circuit corresponding to when the fourth switch _Kg2 and the fifth switch _Ka in the voltage divider module are closed and the remaining switches except the fourth switch _Kg2 and the fifth switch _Ka in the voltage divider module 201 are in an open state. _{The Udc} in FIG4B-FIG4D represents the DC side voltage of the electrochemical energy storage system (or the voltage between the first input terminal of the DC side device B and the second input terminal of the DC side device B), _{and R0a} represents the internal resistance of the Thevenin equivalent circuit.

Optionally, the processor determines the R _ga according to the following formula 7 and formula 8.

Since all parameters except the R _0a and the R _ga in the above formulas 7 and 8 are known (U _dc may adopt the value determined in the above embodiment), the processor may determine the R _0a and the R _ga according to the above formulas 7 and 8.

Of course, the processor may also determine the R _ga according to other equivalent or modified formulas of the above formula 7 and other equivalent or modified formulas of the above formula 8, which is not limited in the embodiment of the present application.

FIG5 is a structural schematic diagram 5 of the voltage divider module in the embodiment of the present application. In combination with FIG1, FIG2B, FIG3A, FIG3B, FIG4A and FIG5, on the basis of the embodiment, the voltage divider module 201 further includes: a fourth sampling unit 201D, and the fourth sampling unit 201D includes a sixth switch K _b and a fourth sampling resistor R _b . Wherein, the first end of the fourth sampling unit 201D is connected to the first end of the second sampling unit 201B (i.e., the second output end ② of the voltage divider module 201), and the second end of the fourth sampling unit 201D (i.e., the fifth output end ⑤ of the voltage divider module 201) is connected to the second input end of the AC side device D. Optionally, the second input end of the AC side device D can be the A phase line, the B phase line or the C phase line of the AC side device. For the convenience of illustration, FIG1 takes the second input end of the AC side device as the B phase line as an example.

Optionally, in this embodiment, the connection relationship between the sixth switch K _b and the fourth sampling resistor R _b in the fourth sampling unit 201D is not limited. For example, the first end of the sixth switch K _b can be used as the first end of the fourth sampling unit 201D, the second end of the sixth switch K _b is connected to the first end of the fourth sampling resistor R _b , and the second end of the fourth sampling resistor R _b is used as the second end of the fourth sampling unit 201D (not shown in the figure); or, the first end of the fourth sampling resistor R _b can be used as the first end of the fourth sampling unit 201D, the second end of the fourth sampling resistor R _b is connected to the first end of the sixth switch K _b , and the second end of the sixth switch K _b is used as the second end of the fourth sampling unit 201D (as shown in FIG. 5). Of course, the fourth sampling unit 201D can also include other devices, which are not limited in this embodiment.

Optionally, the seventh detection terminal and the eighth detection terminal of the sampling module 202 are respectively connected to the two ends of the fourth sampling resistor R _b , so as to collect the voltage across the two ends of the fourth sampling resistor R _b .

Optionally, the processor 203 is further used to: respectively control the sixth switch K _b in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the sixth switch K _b to be in an open state, and the fourth switch K _g2 and the sixth switch K _b in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the fourth switch K _g2 and the sixth switch K _b to be in an open state.

Optionally, the sampling module 202 is further used to collect a sixth voltage U b1 across the fourth sampling resistor R _b when the sixth switch K _b is closed (all switches except the sixth switch K _b in the voltage dividing module 201 are in an open state), and a seventh voltage U _b2 across the fourth sampling resistor R b when the fourth switch K _g2 and the sixth switch K _b are closed (all switches except the fourth switch K _g2 and the sixth switch K _b in the voltage dividing module ₂₀₁ are in an open state ₎ .

Furthermore, the processor 203 is further configured to determine the insulation resistance _Rgb of the second input terminal of the AC side device to ground (the insulation resistance of the AC side of the electrochemical energy storage system to ground) according to the sixth voltage _Ub1 , the seventh voltage _Ub2 and the fourth sampling resistor _Rb .

Optionally, for an implementation manner in which the processor 203 determines the insulation resistance R _gb to ground of the second input terminal of the AC side device according to the sixth voltage U _b1 , the seventh voltage U _b2 and the fourth sampling resistor R _b , reference may be made to the relevant content regarding “the processor 203 determines the insulation resistance R ga to ground of the first input terminal of the AC side device according to the fourth voltage U _a1 , the fifth voltage U _a2 and the third sampling resistor R _{a ”} in the above embodiment of the present application (for example, U _a1 in the above formula 7 and the above formula 8 may be replaced by U _b1 , U _a2 may be replaced by U _b2 , _Ra may be replaced by R _b , R _0a may be replaced by R _0b , and R _ga may be replaced by R _gb ), which will not be described in detail in the embodiments of the present application.

FIG6 is a sixth structural schematic diagram of the voltage divider module in the embodiment of the present application. In combination with FIG1 , FIG2B , FIG3A , FIG3B , FIG4A , FIG5 and FIG6 , on the basis of the embodiment, the voltage divider module 201 further includes: a fifth sampling unit 201E, the fifth sampling unit 201E includes a seventh switch K _c and a fifth sampling resistor R _c . Wherein, the first end of the fifth sampling unit 201E is connected to the first end of the second sampling unit 201B (i.e., the second output end ② of the voltage divider module 201), and the second end of the fifth sampling unit 201E (i.e., the sixth output end ⑥ of the voltage divider module 201) is connected to the third input end of the AC side device D. Optionally, the third input end of the AC side device D can be the A phase line, the B phase line or the C phase line of the AC side device. For the convenience of illustration, FIG1 takes the third input end of the AC side device as the C phase line as an example.

Optionally, in this embodiment, the connection relationship between the seventh switch K _c and the fifth sampling resistor R _c in the fifth sampling unit 201E is not limited. For example, the first end of the seventh switch K _c can be used as the first end of the fifth sampling unit 201E, the second end of the seventh switch K _c is connected to the first end of the fifth sampling resistor R _c , and the second end of the fifth sampling resistor R _c is used as the second end of the fifth sampling unit 201E (not shown in the figure); or, the first end of the fifth sampling resistor R _c can be used as the first end of the fifth sampling unit 201E, the second end of the fifth sampling resistor R _c is connected to the first end of the seventh switch K _c , and the second end of the seventh switch K _c is used as the second end of the fifth sampling unit 201E (as shown in FIG. 6). Of course, the fifth sampling unit 201E can also include other devices, which are not limited in this embodiment.

Optionally, the ninth detection terminal and the tenth detection terminal of the sampling module 202 are respectively connected to the two ends of the fifth sampling resistor R _c , so as to collect the voltage across the two ends of the fifth sampling resistor R _c .

Optionally, the processor 203 is further used to: respectively control the seventh switch K _c in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the seventh switch K _c to be in an open state, and the fourth switch K _g2 and the seventh switch K _c in the voltage dividing module 201 to be closed and the remaining switches in the voltage dividing module 201 except the fourth switch K _g2 and the seventh switch K _c to be in an open state.

Optionally, the sampling module 202 is further used to collect an eighth voltage U c1 across the fifth sampling resistor R _c when the seventh switch K _c is closed (all switches except the seventh switch K _c in the voltage dividing module 201 are in an open state), and a ninth voltage U _c2 across the fifth sampling resistor R c when the fourth switch K _g2 and the seventh switch K _c are closed (all switches except the fourth switch K _g2 and the seventh switch K _c in the voltage dividing module ₂₀₁ are in an open state ₎ .

Furthermore, the processor 203 is further configured to determine an insulation resistance _Rgc to ground of the third input terminal of the AC side device (an insulation resistance to ground of the AC side of the electrochemical energy storage system) according to the eighth voltage _Uc1 , the ninth voltage _Uc2 and the fifth sampling resistor _Rc .

Optionally, for an implementation manner in which the processor 203 determines the insulation resistance R _gc to ground of the third input terminal of the AC side device according to the eighth voltage U _c1 , the ninth voltage U _c2 and the fifth sampling resistor R _c , reference may be made to the relevant content regarding “the processor 203 determines the insulation resistance R ga to ground of the first input terminal of the AC side device according to the fourth voltage U _a1 , the fifth voltage U _a2 and the third sampling resistor R _{a ”} in the above embodiment of the present application (for example, U _a1 in the above formula 7 and the above formula 8 may be replaced by U _c1 , U _a2 may be replaced by U _c2 , _Ra may be replaced by R _c , R _0a may be replaced by R _0c , and R _ga may be replaced by R _gc ), which will not be described in detail in the embodiments of the present application.

In summary, the insulation resistance detection device provided by the present application determines, through the processor, the insulation resistance Rgp of the first input end of the DC side device and the insulation resistance _Rgn of the second input end of the DC side device to ground according to the first voltage U _p21 , the second voltage U _p22 , the third voltage U _n2 , the first sampling resistor _{R p2} and the second sampling resistor R _n2 collected by the collection module; determines the insulation resistance R ga of the first input end of the AC side device to ground according to the fourth voltage U _a1 , the fifth voltage U _a2 and the third sampling resistor R _a collected by the collection module; determines the insulation resistance R _gb of the second input end of the AC side device to ground according to the sixth voltage U _b1 , the seventh voltage U _b2 and the fourth sampling resistor R _b collected by the collection _{module; and determines the insulation resistance R gc of} the third input end of the AC side device to ground according to the eighth voltage U _c1 , the ninth voltage U _c2 and the fifth sampling resistor R _c collected by the collection module. It can be seen that the insulation resistance to ground on the DC side (including the R _gp and R _gn ) and the insulation resistance to ground on the AC side (including the R _ga , the R _gb and the R _gc ) of the electrochemical energy storage system are detected, thereby ensuring the safe operation of the electrochemical energy storage system and the personal safety of the operation and maintenance personnel.

Optionally, in the above embodiments, when the sampling module of the insulation resistance detection device collects the voltage of each sampling resistor under different circuit connection states in the voltage divider module, as shown in Figure 1, the AC-DC power conversion device D of the electrochemical energy storage system E should stop working, and the switch group S3 of the AC side device D should be disconnected.

The embodiment of the present application also provides an embodiment of a method for detecting insulation resistance. Optionally, the method for detecting insulation resistance can be applied to the detection device for insulation resistance provided in the above embodiment of the present application. Optionally, the detection device includes: a voltage divider module, a sampling module and a processor, the voltage divider module is connected to the sampling module and the processor respectively; the voltage divider module includes: at least two switches and at least two sampling resistors; the first output end of the voltage divider module is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system.

The insulation resistance detection method comprises:

The processor controls the closing or opening of each switch in the voltage dividing module to trigger a change in the circuit connection in the voltage dividing module;

The sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor.

Optionally, the voltage divider module includes: a first sampling unit, a second sampling unit, and a third switch, wherein the first sampling unit includes a first switch and a first sampling resistor, and the second sampling unit includes a second switch and a second sampling resistor; wherein the first end of the first sampling unit is connected to the first input end of the DC side device, the first end of the second sampling unit is connected to the second input end of the DC side device, the second end of the first sampling unit and the second end of the second sampling unit are connected to the first end of the third switch, and the second end of the third switch is connected to the ground wire of the electrochemical energy storage system;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, including:

The sampling module collects a first voltage across the first sampling resistor when the first switch and the second switch are closed, a second voltage across the first sampling resistor when the first switch and the third switch are closed, and a third voltage across the second sampling resistor when the second switch and the third switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, including:

The processor determines the insulation resistance to ground of the first input terminal of the DC side device and the insulation resistance to ground of the second input terminal of the DC side device according to the first voltage, the second voltage, the third voltage, the first sampling resistor and the second sampling resistor.

Optionally, the voltage dividing module further includes: a fourth switch and a third sampling unit, the third sampling unit includes a fifth switch and a third sampling resistor; wherein the first end of the fourth switch and the first end of the third sampling unit are connected to the first end of the second sampling unit, the second end of the fourth switch is connected to the second end of the third switch, and the second end of the third sampling unit is connected to the first input end of the AC side device in the electrochemical energy storage system;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects a fourth voltage across the third sampling resistor when the fifth switch is closed, and a fifth voltage across the third sampling resistor when the fourth switch and the fifth switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the first input terminal of the AC side device to the ground according to the fourth voltage, the fifth voltage and the third sampling resistor.

Optionally, the voltage dividing module further includes: a fourth sampling unit, the fourth sampling unit including a sixth switch and a fourth sampling resistor; wherein a first end of the fourth sampling unit is connected to a first end of the second sampling unit, and a second end of the fourth sampling unit is connected to a second input end of the AC side device;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects a sixth voltage across the fourth sampling resistor when the sixth switch is closed, and a seventh voltage across the fourth sampling resistor when the fourth switch and the sixth switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the second input terminal of the AC side device to the ground according to the sixth voltage, the seventh voltage and the fourth sampling resistor.

Optionally, the voltage division module further includes: a fifth sampling unit, the fifth sampling unit including a seventh switch and a fifth sampling resistor; wherein a first end of the fifth sampling unit is connected to a first end of the second sampling unit, and a second end of the fifth sampling unit is connected to a third input end of the AC side device;

Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes:

The sampling module collects an eighth voltage across the fifth sampling resistor when the seventh switch is closed, and a ninth voltage across the fifth sampling resistor when the fourth switch and the seventh switch are closed;

The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes:

The processor determines the insulation resistance of the third input terminal of the AC side device to the ground according to the eighth voltage, the ninth voltage and the fifth sampling resistor.

Optionally, the first sampling unit further includes a first voltage-dividing resistor, and the second sampling unit further includes a second voltage-dividing resistor, a first end of the first voltage-dividing resistor is connected to the first input end of the DC side device, a second end of the first voltage-dividing resistor is connected to the first end of the first switch, a second end of the first switch is connected to the first end of the first sampling resistor, a second end of the first sampling resistor is connected to the first end of the third switch, a first end of the second voltage-dividing resistor is connected to the second input end of the DC side device, a second end of the second voltage-dividing resistor is connected to the first end of the second switch, a second end of the second switch is connected to the first end of the second sampling resistor, and a second end of the second sampling resistor is connected to the first end of the third switch;

Correspondingly, the processor determines the insulation resistance of the first input terminal of the DC side device to ground and the insulation resistance of the second input terminal of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, and the second sampling resistor, including:

The processor determines the insulation resistance of the first input terminal of the DC side device to ground and the insulation resistance of the second input terminal of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, the second sampling resistor, the first voltage dividing resistor and the second voltage dividing resistor.

The insulation resistance detection method of the embodiment of the present application can adopt the technical solution of any embodiment of the insulation resistance detection device of the present application. The implementation principle and technical effect are similar and will not be repeated here.

In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units or modules is only a logical function division. There may be other division methods in actual implementation, such as multiple units or modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims (8)

1. An insulation resistance detection device, characterized in that it comprises: a voltage dividing module, a sampling module and a processor, wherein the voltage dividing module is connected to the sampling module and the processor respectively; the voltage dividing module comprises: at least two switches and at least two sampling resistors; The first output end of the voltage divider module is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system. The processor is used to control the closing or opening of each switch in the voltage dividing module to trigger a change in the circuit connection in the voltage dividing module; The sampling module is used to collect the voltage of the sampling resistor in different circuit connection states in the voltage divider module; The processor is also used to: determine the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor; The voltage divider module includes: a first sampling unit, a second sampling unit, and a third switch, wherein the first sampling unit includes a first switch and a first sampling resistor, and the second sampling unit includes a second switch and a second sampling resistor; wherein the first end of the first sampling unit is connected to the first input end of the DC side device, the first end of the second sampling unit is connected to the second input end of the DC side device, the second end of the first sampling unit and the second end of the second sampling unit are connected to the first end of the third switch, and the second end of the third switch is connected to the ground wire of the electrochemical energy storage system; Correspondingly, the sampling module is specifically used to: collect a first voltage across the first sampling resistor when the first switch and the second switch are closed, a second voltage across the first sampling resistor when the first switch and the third switch are closed, and a third voltage across the second sampling resistor when the second switch and the third switch are closed; The processor is specifically configured to: determine the insulation resistance of the first input terminal of the DC side device to ground and the insulation resistance of the second input terminal of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor and the second sampling resistor; Wherein, the voltage dividing module further includes: a fourth switch and a third sampling unit, wherein the third sampling unit includes a fifth switch and a third sampling resistor; wherein the first end of the fourth switch and the first end of the third sampling unit are connected to the first end of the second sampling unit, the second end of the fourth switch is connected to the second end of the third switch, and the second end of the third sampling unit is connected to the first input end of the AC side device in the electrochemical energy storage system; Correspondingly, the sampling module is further used to: collect a fourth voltage across the third sampling resistor when the fifth switch is closed, and a fifth voltage across the third sampling resistor when the fourth switch and the fifth switch are closed; The processor is further configured to: determine the insulation resistance of the first input terminal of the AC side device to the ground according to the fourth voltage, the fifth voltage and the third sampling resistor; The voltage divider module further includes: a fourth sampling unit, the fourth sampling unit including a sixth switch and a fourth sampling resistor; wherein the first end of the fourth sampling unit is connected to the first end of the second sampling unit, and the second end of the fourth sampling unit is connected to the second input end of the AC side device; Correspondingly, the sampling module is further used to: collect a sixth voltage across the fourth sampling resistor when the sixth switch is closed, and a seventh voltage across the fourth sampling resistor when the fourth switch and the sixth switch are closed; The processor is further configured to: determine the insulation resistance of the second input terminal of the AC side device to the ground according to the sixth voltage, the seventh voltage and the fourth sampling resistor; The voltage dividing module further includes: a fifth sampling unit, the fifth sampling unit including a seventh switch and a fifth sampling resistor; wherein the first end of the fifth sampling unit is connected to the first end of the second sampling unit, and the second end of the fifth sampling unit is connected to the third input end of the AC side device; Correspondingly, the sampling module is further used to: collect an eighth voltage across the fifth sampling resistor when the seventh switch is closed, and a ninth voltage across the fifth sampling resistor when the fourth switch and the seventh switch are closed; The processor is further configured to determine an insulation resistance to ground of a third input terminal of the AC side device according to the eighth voltage, the ninth voltage and the fifth sampling resistor. 2. The detection device according to claim 1, characterized in that the first sampling unit further comprises a first voltage-dividing resistor, the second sampling unit further comprises a second voltage-dividing resistor, a first end of the first voltage-dividing resistor is connected to the first input end of the DC side device, a second end of the first voltage-dividing resistor is connected to the first end of the first switch, a second end of the first switch is connected to the first end of the first sampling resistor, a second end of the first sampling resistor is connected to the first end of the third switch, a first end of the second voltage-dividing resistor is connected to the second input end of the DC side device, a second end of the second voltage-dividing resistor is connected to the first end of the second switch, a second end of the second switch is connected to the first end of the second sampling resistor, and a second end of the second sampling resistor is connected to the first end of the third switch; Correspondingly, the processor is specifically used to determine the insulation resistance of the first input end of the DC side device to ground and the insulation resistance of the second input end of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, the second sampling resistor, the first voltage divider resistor and the second voltage divider resistor. 3. A method for detecting insulation resistance, applicable to the detection device according to claim 1, characterized in that the detection device comprises: a voltage divider module, a sampling module and a processor, the voltage divider module is connected to the sampling module and the processor respectively; the voltage divider module comprises: at least two switches and at least two sampling resistors; the first output end of the voltage divider module is connected to the first input end of the DC side device in the electrochemical energy storage system, the second output end of the voltage divider module is connected to the second input end of the DC side device, and the third output end of the voltage divider module is connected to the ground wire of the electrochemical energy storage system; The method comprises: The processor controls the closing or opening of each switch in the voltage dividing module to trigger a change in the circuit connection in the voltage dividing module; The sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module; The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor. 4. The detection method according to claim 3, characterized in that the voltage divider module comprises: a first sampling unit, a second sampling unit, and a third switch, the first sampling unit comprises a first switch and a first sampling resistor, and the second sampling unit comprises a second switch and a second sampling resistor; wherein the first end of the first sampling unit is connected to the first input end of the DC side device, the first end of the second sampling unit is connected to the second input end of the DC side device, the second end of the first sampling unit and the second end of the second sampling unit are connected to the first end of the third switch, and the second end of the third switch is connected to the ground wire of the electrochemical energy storage system; Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, including: The sampling module collects a first voltage across the first sampling resistor when the first switch and the second switch are closed, a second voltage across the first sampling resistor when the first switch and the third switch are closed, and a third voltage across the second sampling resistor when the second switch and the third switch are closed; The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, including: The processor determines the insulation resistance to ground of the first input terminal of the DC side device and the insulation resistance to ground of the second input terminal of the DC side device according to the first voltage, the second voltage, the third voltage, the first sampling resistor and the second sampling resistor. 5. The detection method according to claim 4, characterized in that the voltage dividing module further comprises: a fourth switch and a third sampling unit, the third sampling unit comprising a fifth switch and a third sampling resistor; wherein the first end of the fourth switch and the first end of the third sampling unit are connected to the first end of the second sampling unit, the second end of the fourth switch is connected to the second end of the third switch, and the second end of the third sampling unit is connected to the first input end of the AC side device in the electrochemical energy storage system; Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes: The sampling module collects a fourth voltage across the third sampling resistor when the fifth switch is closed, and a fifth voltage across the third sampling resistor when the fourth switch and the fifth switch are closed; The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes: The processor determines the insulation resistance of the first input terminal of the AC side device to the ground according to the fourth voltage, the fifth voltage and the third sampling resistor. 6. The detection method according to claim 5, characterized in that the voltage division module further comprises: a fourth sampling unit, the fourth sampling unit comprising a sixth switch and a fourth sampling resistor; wherein the first end of the fourth sampling unit is connected to the first end of the second sampling unit, and the second end of the fourth sampling unit is connected to the second input end of the AC side device; Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes: The sampling module collects a sixth voltage across the fourth sampling resistor when the sixth switch is closed, and a seventh voltage across the fourth sampling resistor when the fourth switch and the sixth switch are closed; The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes: The processor determines the insulation resistance of the second input terminal of the AC side device to the ground according to the sixth voltage, the seventh voltage and the fourth sampling resistor. 7. The detection method according to claim 5, characterized in that the voltage division module further comprises: a fifth sampling unit, the fifth sampling unit comprising a seventh switch and a fifth sampling resistor; wherein the first end of the fifth sampling unit is connected to the first end of the second sampling unit, and the second end of the fifth sampling unit is connected to the third input end of the AC side device; Correspondingly, the sampling module collects the voltage of the sampling resistor in different circuit connection states in the voltage divider module, and further includes: The sampling module collects an eighth voltage across the fifth sampling resistor when the seventh switch is closed, and a ninth voltage across the fifth sampling resistor when the fourth switch and the seventh switch are closed; The processor determines the insulation resistance of the electrochemical energy storage system according to the voltage of the sampling resistor and the resistance of the sampling resistor, and further includes: The processor determines the insulation resistance of the third input terminal of the AC side device to the ground according to the eighth voltage, the ninth voltage and the fifth sampling resistor. 8. The detection method according to any one of claims 3 to 7, characterized in that the first sampling unit further comprises a first voltage-dividing resistor, the second sampling unit further comprises a second voltage-dividing resistor, a first end of the first voltage-dividing resistor is connected to a first input end of the DC side device, a second end of the first voltage-dividing resistor is connected to a first end of the first switch, a second end of the first switch is connected to a first end of the first sampling resistor, a second end of the first sampling resistor is connected to a first end of the third switch, a first end of the second voltage-dividing resistor is connected to a second input end of the DC side device, a second end of the second voltage-dividing resistor is connected to a first end of the second switch, a second end of the second switch is connected to a first end of the second sampling resistor, and a second end of the second sampling resistor is connected to a first end of the third switch; Correspondingly, the processor determines the insulation resistance of the first input terminal of the DC side device to ground and the insulation resistance of the second input terminal of the DC side device to ground according to the first voltage, the second voltage, the third voltage, the first sampling resistor, and the second sampling resistor, including: The processor determines the insulation resistance to ground of the first input terminal of the DC side device and the insulation resistance to ground of the second input terminal of the DC side device according to the first voltage, the second voltage, the third voltage, the first sampling resistor, the second sampling resistor, the first voltage dividing resistor, and the second voltage dividing resistor.

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