CN115166432A

CN115166432A - Automobile high-voltage power supply loop insulation detection method, circuit and system and automobile

Info

Publication number: CN115166432A
Application number: CN202210741283.XA
Authority: CN
Inventors: 邓磊; 郭洪江; 谢哲锋
Original assignee: Zhaoqing Xiaopeng Automobile Co Ltd
Current assignee: Zhaoqing Xiaopeng Automobile Co Ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-10-11
Anticipated expiration: 2042-06-28
Also published as: CN115166432B

Abstract

The application relates to an automobile high-voltage power supply loop insulation detection method, circuit and system and an automobile. The high-voltage power supply loop comprises a power supply positive end interface, a power battery pack and a power supply negative end interface, electrodes at two ends of the power battery pack are respectively connected with the power supply positive end interface and the power supply negative end interface, the center point of the power battery pack is connected with one end of a measuring resistor, and the other end of the measuring resistor is grounded; the method comprises the following steps: acquiring a first leakage current measured by a first leakage current sensor and a second leakage current measured by a second leakage current sensor; the first leakage current sensor is respectively connected with the power supply anode end interface and the central point, and the second leakage current sensor is respectively connected with the power supply cathode end interface and the central point; and obtaining the high-voltage insulation state condition of the high-voltage power supply loop according to the first leakage current and the second leakage current. The scheme that this application provided can be used for carrying out high voltage insulation state and detect and need not to pour into detected signal into, can ensure high voltage power supply circuit normal operating.

Description

Automobile high-voltage power supply loop insulation detection method, circuit and system and automobile

Technical Field

The application relates to the technical field of insulation detection, in particular to an automobile high-voltage power supply loop insulation detection method, circuit and system and an automobile.

Background

A high-voltage power supply loop in the new energy electric automobile comprises a power battery pack, wherein the power battery pack is formed by connecting a large number of battery cells in series and in parallel. The internal connection of a high-voltage power supply loop of an automobile is complicated and complicated, and an insulation fault is easy to occur. In order to ensure safety of automobiles and users, it is necessary to detect a high-voltage insulation state of a high-voltage power supply circuit.

In the related art, an injection type insulation detection scheme is used for detecting the high-voltage insulation state of a high-voltage power supply loop by injecting detection signals (such as voltage and current) into the high-voltage power supply loop where a power battery pack is located.

However, the injection insulation detection scheme may affect the operation of the high-voltage power supply circuit and even cause safety risks.

Disclosure of Invention

In order to solve or partially solve the problems in the related art, the application provides the method, the circuit, the system and the automobile for detecting the insulation of the high-voltage power supply loop of the automobile, the high-voltage insulation state of the high-voltage power supply loop can be detected, a detection signal does not need to be injected, and the normal operation of the high-voltage power supply loop can be guaranteed.

The application provides a car high voltage power supply circuit insulation detection method in the first aspect, high voltage power supply circuit includes power supply positive terminal interface, power battery group and power supply negative terminal interface, the both ends electrode of power battery group respectively with power supply positive terminal interface reaches power supply negative terminal interface connection, the central point and the measuring resistor one end of power battery group are connected, measuring resistor's other end ground connection, the method includes:

acquiring a first leakage current measured by a first leakage current sensor and a second leakage current measured by a second leakage current sensor; the first leakage current sensor is respectively connected with the power supply positive terminal interface and the central point, and the second leakage current sensor is respectively connected with the power supply negative terminal interface and the central point;

and obtaining the high-voltage insulation state condition of the high-voltage power supply loop according to the first leakage current and the second leakage current.

In one embodiment, the method for detecting insulation of the high-voltage power supply loop of the automobile further comprises the following steps:

acquiring a third leakage current measured by a third leakage current sensor; the third leakage current sensor is respectively connected with the power supply positive end interface and the power supply negative end interface;

and obtaining the high-voltage insulation state condition of the high-voltage power supply loop according to the first leakage current, the second leakage current and the third leakage current.

In one embodiment, the obtaining a high-voltage insulation state of the high-voltage power supply circuit according to the first leakage current and the second leakage current includes:

and when the first leakage current is not equal to zero or the second leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in the internal circuit of the high-voltage power supply loop.

In one embodiment, the obtaining a high-voltage insulation state of the high-voltage power supply circuit according to the first leakage current, the second leakage current, and the third leakage current includes:

and under the condition that the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, judging that the external line of the high-voltage power supply loop has high-voltage insulation abnormity.

In one embodiment, the determining that there is a high-voltage insulation abnormality in the internal line of the high-voltage power supply circuit when the first leakage current is not equal to zero or the second leakage current is not equal to zero includes:

after a first pair of external power supply switches connected to the power supply anode end interface and a second pair of external power supply switches connected to the power supply cathode end interface are respectively disconnected, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in the internal circuit of the high-voltage power supply loop; or the like, or a combination thereof,

after a first pair of outer power supply switches connected to the power supply anode end interface and a second pair of outer power supply switches connected to the power supply cathode end interface are respectively closed, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it is judged that high-voltage insulation abnormality exists in an internal line of the high-voltage power supply loop.

when the first leakage current is not equal to zero, judging that the high-voltage insulation of an internal line of the high-voltage power supply loop is abnormal, and judging that the high-voltage insulation of the high-voltage power supply loop between the power supply anode end interface and the central point is abnormal; or the like, or a combination thereof,

and when the second leakage current is not equal to zero, judging that the high-voltage insulation of the internal line of the high-voltage power supply loop is abnormal, and judging that the high-voltage insulation of the high-voltage power supply loop between the power supply negative terminal interface and the central point is abnormal.

In one embodiment, the power battery pack includes a first battery pack and a second battery pack; the positive electrode of the first battery pack is connected with the power supply positive electrode end interface, the negative electrode of the first battery pack is connected with the positive electrode of the second battery pack, and the negative electrode of the second battery pack is connected with the power supply negative electrode end interface; the connection point between the cathode of the first battery pack and the anode of the second battery pack is the central point;

the insulation detection method for the high-voltage power supply loop of the automobile further comprises the following steps:

after judging that the high-voltage insulation abnormality exists in a line of the high-voltage power supply loop between the power supply anode end interface and the central point, calculating a first insulation resistor according to the voltage of the measuring resistor, the voltage of the first battery pack and the first leakage current; or the like, or, alternatively,

and calculating a second insulation resistance according to the voltage of the measuring resistance, the voltage of the second battery pack and the second leakage current after judging that the high-voltage insulation abnormality exists in the line of the high-voltage power supply loop between the power supply negative terminal interface and the central point.

In one embodiment, the determining that there is a high-voltage insulation abnormality in the external line of the high-voltage power supply circuit when the third leakage current is not equal to zero when the first leakage current and the second leakage current are respectively equal to zero includes:

after a first pair of outer power supply switches connected to the power supply anode end interface is closed and a second pair of outer power supply switches connected to the power supply cathode end interface is opened, or the first pair of outer power supply switches connected to the power supply anode end interface is opened and the second pair of outer power supply switches connected to the power supply cathode end interface is closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, it is judged that a high-voltage insulation abnormality exists in an external line of the high-voltage power supply loop; or the like, or, alternatively,

after a first pair of outer power supply switches connected to the power supply anode end interface and a second pair of outer power supply switches connected to the power supply cathode end interface are respectively closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, it is judged that the high-voltage insulation abnormality exists in the external circuit of the high-voltage power supply loop.

and under the condition that the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, judging that the external circuit connected with the power supply positive end interface in the high-voltage power supply loop has high-voltage insulation abnormity or the external circuit connected with the power supply negative end interface in the high-voltage power supply loop has high-voltage insulation abnormity according to the positive and negative value conditions of the third leakage current.

after judging that the external circuit connected with the power supply positive terminal interface in the high-voltage power supply loop has high-voltage insulation abnormity, calculating a third insulation resistance according to the voltage of the measuring resistance, the voltage of the first battery pack and the third leakage current; or the like, or, alternatively,

and after judging that the external line connected with the power supply negative end interface in the high-voltage power supply loop has high-voltage insulation abnormity, calculating a fourth insulation resistance according to the voltage of the measuring resistance, the voltage of the second battery pack and the third leakage current.

The second aspect of the application provides an insulating detection circuitry in car high voltage power supply circuit, high voltage power supply circuit includes power supply positive terminal interface, power battery group and power supply negative terminal interface, power battery group's both ends electrode respectively with power supply positive terminal interface reaches power supply negative terminal interface connection, insulating detection circuitry includes: the device comprises a measuring resistor, a first leakage current sensor, a second leakage current sensor and a signal measuring module;

one end of the measuring resistor is connected with the central point of the power battery pack, and the other end of the measuring resistor is grounded;

the first leakage current sensor is respectively connected with the power supply positive terminal interface and the central point;

the second leakage current sensor is respectively connected with the power supply negative terminal interface and the central point;

the signal measuring module is respectively connected with the measuring resistor, the first leakage current sensor and the second leakage current sensor; the signal measurement module is configured to perform the method as described above.

In one embodiment, the insulation detection circuit of the high-voltage power supply loop of the automobile further includes a third leakage current sensor, and the third leakage current sensor is respectively connected to the positive power supply terminal interface and the negative power supply terminal interface;

the signal measuring module is also connected with the third leakage current sensor.

In one embodiment, the insulation detection circuit of the high-voltage power supply loop of the automobile further comprises a measurement switch, and the measurement resistor is connected with the central point of the power battery pack through the measurement switch;

the signal measurement module is also used for controlling the on and off of the measurement switch.

The third aspect of the present application provides an insulating detecting system of car high voltage supply circuit, including: a high voltage power supply circuit and a circuit as described above;

the high-voltage power supply loop comprises a power supply positive end interface, a power battery pack and a power supply negative end interface, and two end electrodes of the power battery pack are respectively connected with the power supply positive end interface and the power supply negative end interface.

The present application provides in a fourth aspect an automobile comprising: a system as described above.

A fifth aspect of the present application provides an electronic device, comprising:

a processor; and

a memory having executable code stored thereon, which when executed by the processor, causes the processor to perform the method as described above.

A sixth aspect of the present application provides a computer-readable storage medium having stored thereon executable code, which, when executed by a processor of an electronic device, causes the processor to perform the method as described above.

The technical scheme provided by the application can comprise the following beneficial effects:

according to the method, the high-voltage insulation state condition of the high-voltage power supply loop is obtained according to the first leakage current and the second leakage current by obtaining the first leakage current measured by the first leakage current sensor and the second leakage current measured by the second leakage current sensor. Therefore, the high-voltage insulation state of the high-voltage power supply loop can be detected without injecting a detection signal, and the normal operation of the high-voltage power supply loop can be guaranteed.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The foregoing and other objects, features and advantages of the application will be apparent from the following more particular descriptions of exemplary embodiments of the application as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the application.

Fig. 1 is a schematic flow chart of an insulation detection method for a high-voltage power supply loop of an automobile according to an embodiment of the present application;

FIG. 2 is another schematic flow chart of a method for detecting insulation of a high-voltage power supply circuit of an automobile according to an embodiment of the present application;

FIG. 3 is another schematic flow chart of a method for detecting insulation of a high-voltage power supply circuit of an automobile according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of an insulation detection system of a high-voltage power supply loop of an automobile according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of an insulation detection circuit of a high-voltage power supply loop of an automobile according to an embodiment of the present application;

FIG. 6 is another schematic structural diagram of an insulation detection system of a high-voltage power supply circuit of an automobile according to an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an automobile according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of an electronic device shown in an embodiment of the present application.

Detailed Description

Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While embodiments of the present application are illustrated in the accompanying drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The injection type insulation detection scheme in the related art can influence the operation of a high-voltage power supply loop and even cause safety risks.

In order to solve the above problem, an embodiment of the application provides an insulation detection method for an automobile high-voltage power supply loop, which can detect a high-voltage insulation state of the high-voltage power supply loop without injecting a detection signal, and can ensure normal operation of the high-voltage power supply loop.

The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Fig. 1 is a schematic flow chart of an insulation detection method for a high-voltage power supply circuit of an automobile according to an embodiment of the present application. The high-voltage power supply circuit in the embodiment of fig. 1 may include a power supply positive terminal interface, a power battery pack and a power supply negative terminal interface, electrodes at two ends of the power battery pack are respectively connected to the power supply positive terminal interface and the power supply negative terminal interface, a center point of the power battery pack is connected to one end of a measuring resistor, and the other end of the measuring resistor is grounded.

Referring to fig. 1, the method includes:

step S101, a first leakage current measured by the first leakage current sensor and a second leakage current measured by the second leakage current sensor are obtained.

The first leakage current sensor is connected with the power supply anode end interface and the central point respectively, and the second leakage current sensor is connected with the power supply cathode end interface and the central point respectively.

The first leakage current sensor and the second leakage current sensor may be dc leakage current sensors. A dc leakage current sensor is a measuring module that converts a measured dc current into a dc current or voltage signal that is output in proportion to the current using the fluxgate principle.

It should be noted that the dc leakage current sensor is used to be installed on the positive and negative output lines of the dc loop in a surrounding manner, when the insulation condition of the dc loop is normal, the currents flowing through the dc leakage current sensor are equal in magnitude and opposite in direction, and the output signal value is zero; when the insulation condition of the direct current loop is abnormal (such as short circuit of the ground), the direct current leakage current sensor has differential current flowing through, and the output signal value is not zero.

In one embodiment, the power battery pack comprises a first battery pack and a second battery pack; the positive electrode of the first battery pack is connected with the power supply positive electrode end interface, the negative electrode of the first battery pack is connected with the positive electrode of the second battery pack, and the negative electrode of the second battery pack is connected with the power supply negative electrode end interface; the connection point between the negative electrode of the first battery pack and the positive electrode of the second battery pack is a central point. It can be seen that the first leakage current sensor may measure a first leakage current of a dc loop in which the first battery pack is located, and the second leakage current sensor may measure a second leakage current of a dc loop in which the second battery pack is located.

In this step, the acquired first leak current may be a signal value output by the first leak current sensor for the measurement result, and the acquired second leak current may be a signal value output by the second leak current sensor for the measurement result.

And S102, obtaining the high-voltage insulation state condition of the high-voltage power supply loop according to the first leakage current and the second leakage current.

In one embodiment, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it is determined that the high-voltage insulation abnormality exists in the internal line of the high-voltage power supply loop. That is to say, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it indicates that there is a high-voltage insulation abnormality in a line between the power supply positive terminal interface and the power supply negative terminal interface in the high-voltage power supply loop.

It can be seen from this embodiment that, in the method provided in this embodiment of the present application, the high-voltage insulation state condition of the high-voltage power supply circuit is obtained according to the first leakage current and the second leakage current by obtaining the first leakage current measured by the first leakage current sensor and the second leakage current measured by the second leakage current sensor. Therefore, the high-voltage insulation state of the high-voltage power supply loop can be detected without injecting a detection signal, and the normal operation of the high-voltage power supply loop can be guaranteed.

Fig. 2 is another schematic flow chart of the method for detecting insulation of the high-voltage power supply circuit of the vehicle according to the embodiment of the application. Fig. 2 depicts the solution of the present application in more detail with respect to fig. 1. The high-voltage power supply circuit in the embodiment of fig. 2 may include a power supply positive terminal interface, a power battery pack and a power supply negative terminal interface, electrodes at two ends of the power battery pack are respectively connected to the power supply positive terminal interface and the power supply negative terminal interface, a center point of the power battery pack is connected to one end of a measuring resistor, and the other end of the measuring resistor is grounded.

Referring to fig. 2, the method includes:

step S201, a first leakage current measured by the first leakage current sensor and a second leakage current measured by the second leakage current sensor are obtained.

This step can be referred to the description in step S101, and is not described herein again.

Step S202, according to the first leakage current and the second leakage current, a high-voltage insulation state condition of the high-voltage power supply loop is obtained.

This step can be referred to the description in step S102, and is not described herein again.

And step S203, acquiring a third leakage current measured by the third leakage current sensor.

And the third leakage current sensor is respectively connected with the power supply anode end interface and the power supply cathode end interface. The third leakage current sensor may be a dc leakage current sensor, and the second leakage current sensor may measure a third leakage current of a dc loop in which the power battery pack is located.

In this step, the acquired third leak current may be a signal value output to the measurement result by the third leak current sensor.

And S204, obtaining the high-voltage insulation state condition of the high-voltage power supply loop according to the first leakage current, the second leakage current and the third leakage current.

In one embodiment, when the first leakage current and the second leakage current are respectively equal to zero and the third leakage current is not equal to zero, it is determined that the high-voltage insulation abnormality exists in the external line of the high-voltage power supply circuit. That is, it can be determined that there is a high-voltage insulation abnormality in the external line connected to the power supply positive terminal interface in the high-voltage power supply circuit, or that there is a high-voltage insulation abnormality in the external line connected to the power supply negative terminal interface in the high-voltage power supply circuit.

It can be seen from this embodiment that, in the method provided in the embodiment of the present application, the condition of the high-voltage insulation state of the high-voltage power supply circuit is obtained according to the first leakage current, the second leakage current, and the third leakage current by obtaining the first leakage current measured by the first leakage current sensor, the second leakage current measured by the second leakage current sensor, and the third leakage current measured by the third leakage current sensor. Therefore, the high-voltage insulation state of the high-voltage power supply loop can be detected without injecting a detection signal, and the normal operation of the high-voltage power supply loop can be guaranteed.

Fig. 3 is another schematic flow chart of the method for detecting insulation of the high-voltage power supply circuit of the automobile according to the embodiment of the application. Fig. 3 describes the solution of the present application in more detail with respect to fig. 2. The high-voltage power supply circuit in the embodiment of fig. 3 may include a power supply positive terminal interface, a power battery pack and a power supply negative terminal interface, electrodes at two ends of the power battery pack are respectively connected to the power supply positive terminal interface and the power supply negative terminal interface, a center point of the power battery pack is connected to one end of a measuring resistor, and the other end of the measuring resistor is grounded.

Referring to fig. 3, the method includes:

step S301, a first leakage current measured by the first leakage current sensor, a second leakage current measured by the second leakage current sensor, and a third leakage current measured by the third leakage current sensor are obtained.

This step may refer to the descriptions in step S201 and step S203, and will not be described herein.

Further, the high voltage power supply circuit of the embodiment of fig. 3 can be seen in fig. 4, and in the embodiment shown in fig. 4, the power battery pack includes a first battery pack B1 and a second battery pack B2. The positive electrode of the first battery pack B1 is connected with a power supply positive electrode end interface B +, the negative electrode of the first battery pack B1 is connected with the positive electrode of the second battery pack B2, and the negative electrode of the second battery pack B2 is connected with a power supply negative electrode end interface B-; a connection point between the negative electrode of the first battery B1 and the positive electrode of the second battery B2 is a center point M.

The high-voltage line between the power supply positive terminal interface B + and the positive electrode of the first battery pack B1 is a first cable Z1, the high-voltage line between the negative electrode of the second battery pack B2 and the power supply negative terminal interface B-is a second cable Z2, the high-voltage line between the negative electrode of the first battery pack B1 and the central point M is a third cable Z3, and the high-voltage line between the central point M and the positive electrode of the second battery pack B2 is a fourth cable Z4.

In the embodiment shown in fig. 4, the first leakage current IL1 measured by the first leakage current sensor L1 is equal to the difference between the current I1 in the first cable Z1 and the current I3 in the third cable Z3, and in one embodiment, the first leakage current IL1= I1-I3. The first leakage current sensor L1 may be installed between the first cable Z1 and the third cable Z3.

The second leakage current IL2 measured by the second leakage current sensor L2 is equal to the difference between the current I2 in the second cable Z2 and the current I4 in the fourth cable Z4, in an embodiment, the second leakage current IL2= I2-I4. The second leakage current sensor L2 may be installed between the second cable Z2 and the fourth cable Z4.

The third leakage current IL3 measured by the third leakage current sensor L3 is equal to the difference between the current I2 in the second cable Z2 and the current I1 in the first cable Z1, in one embodiment, the third leakage current IL3= I2-I1. The third leakage current sensor L3 may be installed between the first cable Z1 and the second cable Z2.

Step S302, after the first pair of external power supply switches connected to the power supply anode terminal interface and the second pair of external power supply switches connected to the power supply cathode terminal interface are respectively disconnected, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it is determined that the high-voltage insulation abnormality exists in the internal circuit of the high-voltage power supply loop.

It should be noted that, in the embodiment shown in fig. 4, the power supply positive terminal interface B + is connected to a first pair of external power supply switches (not shown), the power supply negative terminal interface B-is connected to a second pair of external power supply switches (not shown), the power supply positive terminal interface B + and the power supply negative terminal interface B-are connected to load devices (for example, driving motors) through the first pair of external power supply switches and the second pair of external power supply switches, and when the first pair of external power supply switches and the second pair of external power supply switches are respectively closed, the power battery pack supplies power to the load devices to supply power. Under the condition that the first pair of external power supply switches and the second pair of external power supply switches are respectively disconnected, namely, the high-voltage power supply loop where the power battery pack is located does not supply power to the outside. Before the high-voltage power supply loop supplies power to the outside, insulation detection can be carried out on the high-voltage power supply loop. Before the high-voltage power supply loop supplies power outwards, the method and the device realize the insulation detection of the high-voltage power supply loop by executing the step 302, and discover the insulation problem of the high-voltage power supply loop in time, thereby avoiding the occurrence of the insulation abnormal condition in the process of supplying power outwards and influencing the safety.

In one embodiment, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, determining that the high-voltage insulation abnormality exists in the internal line of the high-voltage power supply circuit may include:

and step S302-1, when the first leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in the line of the high-voltage power supply loop between the power supply positive terminal interface and the central point.

That is to say, the first leakage current IL1 ≠ 0, which indicates that there is a high-voltage insulation abnormality in the line of the high-voltage power supply loop between the power supply positive terminal interface B + and the central point M, i.e. there is a high-voltage insulation abnormality point in the first cable Z1, the first battery B1, and the third cable Z3.

Further, in one embodiment, after it is determined that the high voltage insulation abnormality exists in the line of the high voltage power supply loop between the power supply positive terminal interface and the central point, the first insulation resistance may be calculated according to the voltage of the measurement resistance, the voltage of the first battery pack, and the first leakage current.

It should be noted that, since the center point M is the center point of the power battery pack, the length of the third cable Z3 is short, and the first insulation resistance can be regarded as equivalent to the insulation resistance on the first cable Z1. The first insulation resistance Rp1= (UR + UB 1)/IL 1. The UR is a voltage of the measuring resistor R, that is, a measuring voltage, and the measuring voltage UR can be obtained by measuring the voltage of the measuring resistor R. The voltage of the first battery stack of UB1, IL1, is a first leakage current.

And S302-2, when the second leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in a line of the high-voltage power supply loop between the power supply negative terminal interface and the central point.

That is to say, the second leakage current IL2 ≠ 0, which indicates that there is a high-voltage insulation abnormality in the line of the high-voltage power supply loop between the power supply negative terminal interface B-and the central point M, i.e. there is a high-voltage insulation abnormality point in the second cable Z2, the second battery B2, and the fourth cable Z4.

Further, in one embodiment, after it is determined that the high voltage insulation abnormality exists in the line of the high voltage power supply loop between the power supply negative terminal interface and the central point, the second insulation resistance may be calculated according to the voltage of the measurement resistance, the voltage of the second battery pack, and the second leakage current.

It should be noted that, since the center point M is the center point of the power battery pack, the length of the fourth cable Z4 is short, and the second insulation resistance can be regarded as equivalent to the insulation resistance on the second cable Z2. Second insulation resistance Rn1= (UR + UB 2)/IL 2. Where UR is a voltage of the measurement resistor R, that is, a measurement voltage, and the measurement voltage UR may be obtained by performing voltage measurement on the measurement resistor R. The voltage of the second battery of UB2, IL2 is a second leakage current.

It should be further noted that, when a double-point fault occurs (i.e., there is a high-voltage insulation abnormality in the line between the positive power supply terminal interface B + and the central point M, and there is also a high-voltage insulation abnormality in the line between the negative power supply terminal interface B-and the central point M), the first insulation resistance Rp1 and the second insulation resistance Rn1 may be calculated respectively.

It can be understood that, under normal conditions of insulation of the high-voltage power supply circuit, the load current of the power battery pack is I0, where I1= I2= I3= I4= I0, and therefore IL1= IL2= IL3=0, and the measurement voltage UR =0 of the measurement resistor connected at this time.

Before the high-voltage power supply loop supplies power to the outside, namely after a first pair of outer power supply switches connected to the power supply anode end interface and a second pair of outer power supply switches connected to the power supply cathode end interface are disconnected respectively, when a first leakage current IL1 is equal to zero and a second leakage current IL2 is equal to zero, it can be judged that an internal line (namely a line between the power supply anode end interface B + and the power supply cathode end interface B-) of the high-voltage power supply loop is normal in insulation.

Step S303, after a first pair of outer power supply switches connected to the power supply anode terminal interface is closed and connected to a second pair of outer power supply switches connected to the power supply cathode terminal interface is opened, or a first pair of outer power supply switches connected to the power supply anode terminal interface is opened and connected to a second pair of outer power supply switches connected to the power supply cathode terminal interface is closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, it is judged that a high-voltage insulation abnormality exists in an external circuit of a high-voltage power supply loop.

In one embodiment, when the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, it is determined that there is a high-voltage insulation abnormality in the external line connected to the power supply positive terminal interface in the high-voltage power supply circuit or the external line connected to the power supply negative terminal interface in the high-voltage power supply circuit according to the positive and negative values of the third leakage current.

Further, step S303 may include step S303-1 and step S303-2.

Step S303-1, after a first pair of external power supply switches connected to the power supply positive terminal interface is closed and a second pair of external power supply switches connected to the power supply negative terminal interface is opened, under the condition that the first leakage current and the second leakage current are respectively equal to zero and when the third leakage current is not equal to zero, judging that the external line connected with the power supply positive terminal interface in the high-voltage power supply loop has high-voltage insulation abnormity according to the condition that the third leakage current is a negative value.

In the embodiment shown in fig. 4, after the first pair of external power supply switches connected to the power supply positive terminal interface B + is closed and the second pair of external power supply switches connected to the power supply negative terminal interface B-is opened, the first pair of external power supply switches is closed and the second pair of external power supply switches is opened. That is, the high-voltage power supply loop in which the power battery pack is located does not supply power to the outside. Before the high-voltage power supply loop supplies power outwards, the method realizes the insulation detection of the high-voltage power supply loop by executing the step 303-1, finds the insulation problem of the high-voltage power supply loop in time, and avoids the insulation abnormal condition in the process of supplying power outwards to influence the safety.

In this step, IL1= IL2=0, the third leakage current IL3 is a negative value, and the third leakage current IL3= UR/R. Wherein UR is the voltage of the measuring resistor R, UR is a negative value, and R is the resistance of the measuring resistor R. It indicates that there is a high-voltage insulation abnormality in the external line connected to the positive terminal interface B + of the power supply in the high-voltage power supply loop.

Further, in one embodiment, after it is determined that the high-voltage insulation abnormality exists in the external line connected to the positive power supply terminal interface B + in the high-voltage power supply loop, the third insulation resistance may be calculated according to the voltage of the measurement resistance, the voltage of the first battery pack, and the third leakage current.

The third insulation resistor is an insulation resistor of an external line connected with a power supply positive terminal interface B + in the high-voltage power supply loop, and the third insulation resistor Rp2= (UR + UB 1)/IL 3. Where UR is the voltage of the measurement resistor R, i.e. the measurement voltage. The voltage of the first battery of UB1, IL3 is the third leakage current.

It can be understood that after the first pair of external power supply switches connected to the power supply positive terminal interface B + is closed and the second pair of external power supply switches connected to the power supply negative terminal interface B-is opened, that is, the first pair of external power supply switches is closed, and after the second pair of external power supply switches is opened, when the third leakage current IL3 is equal to zero, it is determined that the external line connected to the power supply positive terminal interface B + in the high-voltage power supply loop is normally insulated.

Step S303-2, after the first pair of external power supply switches connected to the power supply positive terminal interface is disconnected and the second pair of external power supply switches connected to the power supply negative terminal interface is closed, under the condition that the first leakage current and the second leakage current are respectively equal to zero and when the third leakage current is not equal to zero, judging that the external line connected with the power supply negative terminal interface in the high-voltage power supply loop has high-voltage insulation abnormity according to the condition that the third leakage current is a positive value.

In the embodiment shown in fig. 4, after the first pair of external power supply switches connected to the power supply positive terminal interface B + is turned off and the second pair of external power supply switches connected to the power supply negative terminal interface B-is turned on, the first pair of external power supply switches is turned off and the second pair of external power supply switches is turned on. That is, the high-voltage power supply loop in which the power battery pack is located does not supply power to the outside. Before the high-voltage power supply loop supplies power outwards, the method and the device realize insulation detection on the high-voltage power supply loop by executing the step 303-2, and find the insulation problem of the high-voltage power supply loop in time, thereby avoiding the occurrence of insulation abnormal conditions in the process of supplying power outwards and influencing safety.

In this step, IL1= IL2=0, the third leakage current IL3 is positive, and the third leakage current IL3= UR/R. Where UR is the voltage of the measurement resistor R, UR is a positive value, and R is the resistance of the measurement resistor R. It indicates that there is a high voltage insulation abnormality in the external line connected to the power supply negative terminal interface B-in the high voltage power supply loop.

Further, in one embodiment, after it is determined that there is a high-voltage insulation abnormality in the external line connected to the power supply negative terminal interface in the high-voltage power supply loop, the fourth insulation resistance may be calculated according to the voltage of the measurement resistance, the voltage of the second battery pack, and the third leakage current.

The fourth insulation resistor is an insulation resistor of an external line connected with a power supply negative terminal interface B-in the high-voltage power supply loop, and the fourth insulation resistor Rn2= (-UR + UB 2)/IL 3. Where UR is the voltage of the measurement resistor R, i.e. the measurement voltage. The voltage of the second battery pack of UB2, IL3, is a third leakage current.

It can be understood that after the first pair of external power supply switches connected to the power supply positive terminal interface B + is turned off and the second pair of external power supply switches connected to the power supply negative terminal interface B-is turned on, that is, the first pair of external power supply switches is turned off, and after the second pair of external power supply switches is turned on, when the third leakage current IL3 is equal to zero, it is determined that the external line connected to the power supply negative terminal interface B-in the high-voltage power supply loop is normally insulated.

It should be noted that, in the embodiment shown in fig. 4, when the first pair of external power supply switches and the second pair of external power supply switches are closed respectively, that is, the high-voltage power supply circuit in which the power battery pack is located is supplying power to the outside. In the process of supplying power to the outside by the high-voltage power supply loop, the present application implements insulation detection on the high-voltage power supply loop by executing step 304 and step S305, and finds an insulation problem of the high-voltage power supply loop in time.

Step S304, after the first pair of external power supply switches connected to the power supply anode terminal interface and the second pair of external power supply switches connected to the power supply cathode terminal interface are respectively closed, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it is determined that the high-voltage insulation abnormality exists in the internal circuit of the high-voltage power supply loop.

step S304-1, when the first leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in the line of the high-voltage power supply loop between the power supply positive terminal interface and the central point, and calculating the first insulation resistance according to the voltage of the measuring resistor, the voltage of the first battery pack and the first leakage current.

And S304-2, when the second leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in the line of the high-voltage power supply loop between the power supply negative terminal interface and the central point, and calculating a second insulation resistance according to the voltage of the measuring resistance, the voltage of the second battery pack and the second leakage current.

The description about step S304-1 can refer to step S302-1, and the description about step S304-2 can refer to step S302-2, which is not described herein again.

Step S305, after the first pair of external power supply switches connected to the power supply positive terminal interface and the second pair of external power supply switches connected to the power supply negative terminal interface are respectively closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, it is determined that the high-voltage insulation abnormality exists in the external circuit of the high-voltage power supply loop.

In one embodiment, when the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, determining that the high-voltage insulation abnormality exists in the external line of the high-voltage power supply circuit may include:

step S305-1, under the condition that the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, judging that the external circuit connected with the power supply positive terminal interface in the high-voltage power supply loop has high-voltage insulation abnormity according to the condition that the third leakage current is a negative value, and calculating a third insulation resistor according to the voltage of the measuring resistor, the voltage of the first battery pack and the third leakage current.

And S305-2, under the condition that the first leakage current and the second leakage current are respectively equal to zero and the third leakage current is not equal to zero, judging that the high-voltage insulation abnormality exists in an external circuit connected with the power supply negative end interface in the high-voltage power supply loop according to the condition that the third leakage current is a positive value, and calculating a fourth insulation resistor according to the voltage of the measuring resistor, the voltage of the second battery pack and the third leakage current.

The description of step S305-1 can refer to step S303-1, and the description of step S305-2 can refer to step S303-2, which is not repeated herein.

It can be understood that, under the condition that the first pair of external power supply switches and the second pair of external power supply switches are respectively closed, that is, in the process of supplying power to the outside by the high-voltage power supply loop, if a single-point fault occurs (that is, there is an insulation fault in the line between the power supply positive terminal interface B + and the central point M, the line between the power supply negative terminal interface B-and the central point M, the external line connected to the power supply positive terminal interface B +, or the external line connected to the power supply negative terminal interface B-), the insulation abnormality may be detected by executing step S304 or step S305. In addition, if multi-point faults occur, the faults at different positions are in chronological order, so that the positions of the insulation abnormity can be respectively detected. For example, when the first insulation resistance Rp1 and the second insulation resistance Rn1 exist simultaneously, they may be detected and calculated separately. However, if the third insulation resistance Rp2 and the fourth insulation resistance Rn2 coexist, the respective results cannot be detected and calculated. The third insulation resistance Rp2 and the fourth insulation resistance Rn2 may be detected and calculated by performing step 302 and step S303 before the high-voltage power supply loop supplies power to the outside.

It should be noted that, in consideration of the fact that the measurement error is difficult to be completely avoided, in the present application, being equal to zero may mean being completely equal to zero or being close to zero, and being close to zero may mean that a difference value from zero is smaller than a preset value. For example, the first leakage current is equal to 0.1A, and if the predetermined value is 0.2A, the first leakage current is considered to be equal to zero.

Further, in one embodiment, one end of the measuring resistor R is connected to the central point M of the power battery pack through the measuring switch S, and the other end of the measuring resistor R is grounded through the body of the automobile. In this way, whether insulation detection is carried out on the high-voltage power supply loop or not is controlled by controlling the on and off of the measuring switch S. And the insulation detection of the high-voltage power supply loop is carried out by controlling the measurement switch S to be closed. And the insulation detection of the high-voltage power supply loop is finished by controlling the measurement switch S to be switched off.

It can be seen from this embodiment that the method provided in the embodiment of the present application can perform high-voltage insulation state detection on a high-voltage power supply circuit without injecting a detection signal, and implements an injection-free insulation detection method for a high-voltage power supply circuit of an automobile, thereby ensuring normal operation of the high-voltage power supply circuit, i.e., not affecting use and state detection functions of the high-voltage power supply circuit. Secondly, the insulation detection method is simple and reliable in steps. In addition, the high-voltage power supply circuit has the capacity of capturing the abnormal sudden change of the insulation, the abnormal change of the insulation of the high-voltage power supply circuit can be captured, the position where the insulation is abnormal can be determined according to the detected first leakage current, the detected second leakage current and the detected second leakage current, and the corresponding insulation resistance value can be calculated.

The application also provides an insulating detection circuitry of car high voltage power supply return circuit.

Fig. 5 is a schematic structural diagram of an insulation detection circuit of an automotive high-voltage power supply loop according to an embodiment of the present application.

Referring to fig. 4 and 5 together, an insulation detection circuit 50 for a high-voltage power supply circuit of an automobile includes a positive power supply terminal interface B +, a power battery pack, and a negative power supply terminal interface B-, where two terminal electrodes of the power battery pack are connected to the positive power supply terminal interface B + and the negative power supply terminal interface B-, respectively. The power battery pack comprises a first battery pack B1 and a second battery pack B2. The positive pole of the first battery pack B1 is connected with the power supply positive terminal interface B +, the negative pole of the first battery pack B1 is connected with the positive pole of the second battery pack B2, and the negative pole of the second battery pack B2 is connected with the power supply negative terminal interface B-. A connection point between the negative electrode of the first battery B1 and the positive electrode of the second battery B2 is a center point M.

The insulation detection circuit 50 of the high-voltage power supply loop of the automobile comprises: a measuring resistor R, a first leakage current sensor L1, a second leakage current sensor L2, and a signal measuring module 510.

One end of the measuring resistor R is connected with the central point M of the power battery pack, and the other end of the measuring resistor R is grounded.

The first leakage current sensor L1 is respectively connected with the power supply positive terminal interface B + and the central point M.

And the second leakage current sensor L2 is respectively connected with the power supply negative terminal interface B-and the central point M.

The signal measurement module 510 is connected to the measurement resistor R, the first leakage current sensor L1, and the second leakage current sensor L2, respectively. The signal measurement module 510 is configured to perform a method as in the embodiment of fig. 1-3.

It can be seen from this embodiment that the circuit 50 provided in the embodiment of the present application can detect the high-voltage insulation state of the high-voltage power supply circuit without injecting a detection signal, and can ensure the normal operation of the high-voltage power supply circuit.

Further, the insulation detection circuit 50 of the high-voltage power supply loop of the automobile further comprises a third leakage current sensor L3, and the third leakage current sensor L3 is respectively connected with the positive terminal interface B + of the power supply and the negative terminal interface B-of the power supply.

The signal measurement module 510 is also connected to a third leakage current sensor L3.

Further, the insulation detection circuit 50 of the high-voltage power supply loop of the automobile further comprises a measurement switch S, and the measurement resistor R is connected with the central point M of the power battery pack through the measurement switch S.

The signal measurement module 510 is also used to control the closing and opening of the measurement switch S.

The application also provides an insulating detecting system of car high voltage power supply circuit.

Fig. 6 is a schematic structural diagram of an insulation detection system 60 of a high-voltage power supply loop of an automobile according to an embodiment of the present application.

Referring to fig. 4 and fig. 6, an insulation detecting system 60 for a high voltage power supply circuit of an automobile is characterized by comprising: the high voltage power supply circuit 610 and the vehicle high voltage power supply circuit insulation detection circuit 620.

The high-voltage power supply loop comprises a power supply positive end interface B +, a power battery pack and a power supply negative end interface B-, and electrodes at two ends of the power battery pack are respectively connected with the power supply positive end interface B + and the power supply negative end interface B-.

Further, the power battery pack comprises a first battery pack B1 and a second battery pack B2. The positive pole of the first battery pack B1 is connected with the power supply positive terminal interface B +, the negative pole of the first battery pack B1 is connected with the positive pole of the second battery pack B2, and the negative pole of the second battery pack B2 is connected with the power supply negative terminal interface B-. A connection point between the negative electrode of the first battery B1 and the positive electrode of the second battery B2 is a center point M.

The automotive high voltage supply loop insulation detection circuit 620 may be the circuit 50 of the embodiment of fig. 5.

It can be seen from this embodiment that, the system 60 provided in the embodiment of the present application can detect the high-voltage insulation state of the high-voltage power supply circuit 610 through the insulation detection circuit 620 of the high-voltage power supply circuit of the vehicle without injecting a detection signal, and can ensure the normal operation of the high-voltage power supply circuit 610.

The application also provides an automobile.

Fig. 7 is a schematic structural diagram of an automobile according to an embodiment of the present application.

Referring to fig. 7, an automobile 70 includes an automobile high voltage supply loop insulation detection system 710.

The system 710 for detecting the insulation of the high-voltage power supply loop of the vehicle may be the system 60 according to the embodiment in fig. 6.

It can be seen from this embodiment that, the automobile 70 provided in the embodiment of the present application can implement the high-voltage insulation state detection on the high-voltage power supply loop through the automobile high-voltage power supply loop insulation detection system 710, and does not need to inject a detection signal, which can ensure the normal operation of the high-voltage power supply loop.

Referring to fig. 8, an electronic device 800 includes a memory 810 and a processor 820.

The Processor 820 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 810 may include various types of storage units, such as a system memory, a Read Only Memory (ROM), and a permanent storage device. Wherein the ROM may store static data or instructions for the processor 820 or other modules of the computer. The persistent storage device may be a read-write storage device. The persistent storage may be a non-volatile storage device that does not lose stored instructions and data even after the computer is powered off. In some embodiments, the persistent storage device employs a mass storage device (e.g., magnetic or optical disk, flash memory) as the persistent storage device. In other embodiments, the permanent storage may be a removable storage device (e.g., floppy disk, optical drive). The system memory may be a read-write memory device or a volatile read-write memory device, such as a dynamic random access memory. The system memory may store instructions and data that some or all of the processors require at run-time. Further, the memory 810 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (e.g., DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), magnetic and/or optical disks, may also be employed. In some embodiments, memory 810 may include a removable storage device that is readable and/or writable, such as a Compact Disc (CD), a digital versatile disc read only (e.g., DVD-ROM, dual layer DVD-ROM), a Blu-ray disc read only, an ultra-dense optical disc, flash memory cards (e.g., SD, min SD, micro-SD, etc.), magnetic floppy disks, and the like. Computer-readable storage media do not contain carrier waves or transitory electronic signals transmitted by wireless or wired means.

The memory 810 has stored thereon executable code that, when processed by the processor 820, may cause the processor 820 to perform some or all of the methods described above.

Furthermore, the method according to the present application may also be implemented as a computer program or computer program product comprising computer program code instructions for performing some or all of the steps of the above-described method of the present application.

Alternatively, the present application may also be embodied as a computer-readable storage medium (or non-transitory machine-readable storage medium or machine-readable storage medium) having executable code (or a computer program or computer instruction code) stored thereon, which, when executed by a processor of an electronic device (or server, etc.), causes the processor to perform part or all of the steps of the above-described methods according to the present application.

The foregoing description of the embodiments of the present application has been presented for purposes of illustration and description and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The method for detecting the insulation of the high-voltage power supply loop of the automobile is characterized in that the high-voltage power supply loop comprises a power supply positive electrode end interface, a power battery pack and a power supply negative electrode end interface, electrodes at two ends of the power battery pack are respectively connected with the power supply positive electrode end interface and the power supply negative electrode end interface, a center point of the power battery pack is connected with one end of a measuring resistor, the other end of the measuring resistor is grounded, and the method comprises the following steps:

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein obtaining the high voltage isolation condition of the high voltage power supply circuit according to the first leakage current and the second leakage current comprises:

4. The method of claim 2, wherein obtaining the high voltage isolation status of the high voltage power supply circuit according to the first leakage current, the second leakage current, and the third leakage current comprises:

and under the condition that the first leakage current and the second leakage current are respectively equal to zero, and when the third leakage current is not equal to zero, judging that the external circuit of the high-voltage power supply loop has high-voltage insulation abnormity.

5. The method according to claim 3, wherein the determining that the high voltage insulation abnormality exists in the internal line of the high voltage power supply loop when the first leakage current is not equal to zero or the second leakage current is not equal to zero comprises:

after a first pair of outer power supply switches connected to the power supply anode end interface and a second pair of outer power supply switches connected to the power supply cathode end interface are respectively closed, when the first leakage current is not equal to zero or the second leakage current is not equal to zero, it is judged that the high-voltage insulation abnormality exists in the internal circuit of the high-voltage power supply loop.

6. The method according to claim 3, wherein the determining that the high voltage insulation abnormality exists in the internal line of the high voltage power supply loop when the first leakage current is not equal to zero or the second leakage current is not equal to zero comprises:

when the first leakage current is not equal to zero, judging that the high-voltage insulation of an internal line of the high-voltage power supply loop is abnormal, and judging that the high-voltage insulation of the high-voltage power supply loop between the power supply anode end interface and the central point is abnormal; or the like, or, alternatively,

7. The method of claim 6, wherein: the power battery pack comprises a first battery pack and a second battery pack; the positive electrode of the first battery pack is connected with the power supply positive electrode end interface, the negative electrode of the first battery pack is connected with the positive electrode of the second battery pack, and the negative electrode of the second battery pack is connected with the power supply negative electrode end interface; the connection point between the cathode of the first battery pack and the anode of the second battery pack is the central point;

the method further comprises the following steps:

8. The method according to claim 4, wherein the determining that there is a high-voltage insulation abnormality in the external line of the high-voltage power supply loop when the third leakage current is not equal to zero under the condition that the first leakage current and the second leakage current are respectively equal to zero comprises:

after a first pair of outer power supply switches connected to the power supply anode end interface is closed and a second pair of outer power supply switches connected to the power supply cathode end interface is opened, or the first pair of outer power supply switches connected to the power supply anode end interface is opened and the second pair of outer power supply switches connected to the power supply cathode end interface is closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, judging that a high-voltage insulation abnormality exists in an external circuit of the high-voltage power supply loop; or the like, or, alternatively,

and after a first pair of outer power supply switches connected with the power supply anode end interface and a second pair of outer power supply switches connected with the power supply cathode end interface are respectively closed, and under the condition that the first leakage current and the second leakage current are respectively equal to zero, when the third leakage current is not equal to zero, judging that the external circuit of the high-voltage power supply loop has high-voltage insulation abnormity.

9. The method according to claim 4, wherein the determining that there is a high-voltage insulation abnormality in the external line of the high-voltage power supply loop when the third leakage current is not equal to zero under the condition that the first leakage current and the second leakage current are respectively equal to zero comprises:

10. The method of claim 9, wherein: the power battery pack comprises a first battery pack and a second battery pack; the positive electrode of the first battery pack is connected with the power supply positive electrode end interface, the negative electrode of the first battery pack is connected with the positive electrode of the second battery pack, and the negative electrode of the second battery pack is connected with the power supply negative electrode end interface; a connection point between the cathode of the first battery pack and the anode of the second battery pack is the central point;

the method further comprises the following steps:

and after judging that the high-voltage insulation abnormality exists in an external line connected with the power supply cathode end interface in the high-voltage power supply loop, calculating a fourth insulation resistance according to the voltage of the measuring resistance, the voltage of the second battery pack and the third leakage current.

11. The utility model provides an insulating detection circuitry in car high voltage power supply return circuit, its characterized in that, high voltage power supply return circuit includes power supply positive terminal interface, power battery group and power supply negative terminal interface, the both ends electrode of power battery group respectively with power supply positive terminal interface reaches power supply negative terminal interface connection, insulating detection circuitry includes: the device comprises a measuring resistor, a first leakage current sensor, a second leakage current sensor and a signal measuring module;

the signal measuring module is respectively connected with the measuring resistor, the first leakage current sensor and the second leakage current sensor; the signal measurement module is configured to perform the method of any one of claims 1-10.

12. The circuit of claim 11, wherein:

the circuit further comprises a third leakage current sensor, and the third leakage current sensor is respectively connected with the power supply positive electrode end interface and the power supply negative electrode end interface;

the signal measurement module is also connected with the third leakage current sensor.

13. The circuit of claim 11, wherein:

the circuit further comprises a measuring switch, and the measuring resistor is connected with the central point of the power battery pack through the measuring switch;

14. The utility model provides an insulating detecting system of car high voltage supply return circuit which characterized in that includes: a high voltage supply loop and a circuit as claimed in any one of claims 11 to 13;

15. An automobile, comprising: the system of claim 14.