CN109733198B - Main contactor sticking detection method and device, power battery system, vehicle - Google Patents

Abstract

The embodiments of the present application disclose a main contactor adhesion detection method and device, a power battery system, and a vehicle, wherein the method includes: acquiring a stable voltage value of a DC bus at both ends of the power battery when the power battery is in a powered-on state; receiving a down Power command, control the main contactor to disconnect according to the power-off command, and obtain the sag voltage value after the voltage on the DC bus drops; obtain the discharge curve of the power battery based on the drop voltage value and the stable voltage value, and the discharge curve represents the voltage on the DC bus. The relationship between the value and time; based on the discharge curve, determine whether the main contactor is stuck, realize the real-time detection of the sticking of the main contactor of the power battery, accurately judge the sticking state of the contactor in the power battery, and improve the safety of the system.

Description

Main contactor sticking detection method and device, power battery system, vehicle

technical field

The present application relates to the technical field of power battery systems, in particular to a main contactor adhesion detection method and device, a power battery system, and a vehicle.

Background technique

In the existing power battery system on the market, the contactor cannot be powered off after sticking, resulting in loss of power control, damage to the electric control in the light, and personal injury in the severe case. Therefore, it is necessary to detect the state of the contactor. However, the state of the contactor, especially the detection of the adhesion state when the main contactor controls the connection and disconnection of the high-voltage circuit, is a technical problem. The main contactor adhesion detection method provided by the prior art cannot effectively determine the adhesion state of the main and negative contactors. When implemented by hardware, it is necessary to increase the detection point of the motor end, and the cost is high. When implemented through software, the high-voltage power-on time needs to be extended, and the experience is poor.

SUMMARY OF THE INVENTION

An embodiment of the present application provides a main contactor adhesion detection technology.

According to an aspect of the embodiments of the present application, a method for detecting adhesion of a main contactor is provided, including:

obtaining the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state;

Receive a power-off command, control the main contactor to disconnect according to the power-off command, and obtain a drop voltage value after the voltage on the DC bus drops;

A discharge curve of the power battery is obtained based on the sag voltage value and the stable voltage value, and the discharge curve represents the variation relationship of the voltage value on the DC bus with time;

Whether the main contactor is stuck is determined based on the discharge curve.

Optionally, in any of the above method embodiments of the present application, before obtaining the discharge curve of the power battery based on the sag voltage value and the stable voltage value, the method further includes:

Acquire the standard discharge curve corresponding to the power battery, the standard discharge curve is a normal discharge curve with the main contactor not sticking, and the standard discharge curve is used to represent the relationship between the stable voltage value and the drop voltage value and time .

Optionally, in any of the above method embodiments of the present application, before obtaining the discharge curve of the power battery based on the sag voltage value and the stable voltage value, the method further includes:

Obtain the drop time from the stable voltage value to the drop voltage value in the standard discharge curve and the duration of the drop voltage value;

The obtaining of the discharge curve of the power battery based on the drop voltage value and the stable voltage value includes:

A discharge curve of the power battery is obtained based on the drop voltage value, the stable voltage value, the drop time, and the duration, and the discharge curve takes time as the horizontal axis and voltage as the vertical axis.

Optionally, in any of the above method embodiments of the present application, the determining whether the main contactor is stuck based on the discharge curve includes:

Comparing the discharge curve with the standard discharge curve to obtain a comparison result;

Whether the main contactor is stuck is determined based on the comparison result.

Optionally, in any of the above method embodiments of the present application, the determining whether the main contactor is stuck based on the comparison result includes:

determining that the main contactor is not stuck in response to the comparison result indicating that the discharge curve coincides with the standard discharge curve;

The main contactor is determined to be stuck in response to the comparison indicating that the discharge curve does not coincide with the standard discharge curve.

Optionally, in any of the above method embodiments of the present application, the comparison of the discharge curve with the standard discharge curve to obtain a comparison result includes:

comparing the curve segment corresponding to the duration in the discharge curve with the standard curve segment corresponding to the duration in the standard discharge curve, and the standard curve segment is represented as a line segment;

A comparison result of whether the curve segment coincides with the standard curve segment is obtained.

Optionally, in any of the above method embodiments of the present application, the main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, and the positive curve segment corresponds to The judgment time of the main positive contactor, and the negative curve segment corresponds to the judgment time of the main negative contactor;

The standard curve segment includes a positive standard curve segment and a negative standard curve segment, the positive standard curve segment corresponds to the judgment time of the main positive contactor, and the negative standard curve segment corresponds to the judgment time of the main negative contactor.

Optionally, in any of the above method embodiments of the present application, comparing the discharge curve with a standard discharge curve to obtain a comparison result, and determining whether the main contactor is stuck based on the comparison result, includes:

Comparing the positive curve segment with the positive standard curve segment, and determining whether the main positive contactor is stuck according to whether the positive curve segment and the positive standard curve segment overlap;

The negative curve segment is compared with the negative standard curve segment, and it is determined whether the main negative contactor is stuck according to whether the negative curve segment and the negative standard curve segment overlap.

Optionally, in any of the above method embodiments of the present application, the obtaining the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state includes:

Obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is powered on by using a voltage sensor in the battery management system;

The acquiring the sag voltage value after the voltage on the DC bus has dropped, includes:

The sag voltage value after the voltage drop on the DC bus is obtained by using the voltage sensor in the battery management system.

Optionally, in any of the above method embodiments of the present application, the method further includes:

The discharge curve is displayed by a display device.

According to another aspect of the embodiments of the present application, a device for detecting adhesion of a main contactor is provided, comprising:

a voltage sensor, configured to obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state, and obtain the drop voltage value after the voltage on the DC bus drops;

The controller is used to receive the power-off command, and control the main contactor to disconnect according to the power-off command;

a curve determination unit, configured to obtain a discharge curve of the power battery based on the sag voltage value and the stable voltage value, where the discharge curve represents a time-varying relationship of the voltage value on the DC bus;

A determination unit, which determines whether the main contactor is stuck based on the discharge curve.

Optionally, in any of the above device embodiments of the present application, the device further includes:

A standard curve unit, used to obtain a standard discharge curve corresponding to the power battery, the standard discharge curve is a normal discharge curve without adhesion of the main contactor, and the standard discharge curve is used to represent the stable voltage value and the drop The relationship between voltage value and time.

Optionally, in any of the above device embodiments of the present application, the device further includes:

a time obtaining unit, configured to obtain the drop time from the stable voltage value to the drop voltage value in the standard discharge curve and the duration of the drop voltage value;

The curve determination unit is specifically configured to obtain a discharge curve of the power battery based on the drop voltage value, the stable voltage value, the drop time and the duration, where the discharge curve takes time as the horizontal axis, Take the voltage as the vertical axis.

Optionally, in any of the above device embodiments of the present application, the judgment unit is specifically configured to compare the discharge curve with the standard discharge curve to obtain a comparison result; determine the main discharge curve based on the comparison result. Whether the contactor is stuck.

Optionally, in any of the above device embodiments of the present application, when determining whether the main contactor is stuck based on the comparison result, the judgment unit is specifically configured to indicate that the discharge curve is different from the discharge curve in response to the comparison result. The standard discharge curves overlap, and it is determined that the main contactor is not stuck; in response to the comparison result indicating that the discharge curve does not overlap with the standard discharge curve, it is determined that the main contactor is stuck.

Optionally, in any of the above device embodiments of the present application, when comparing the discharge curve with the standard discharge curve and obtaining a comparison result, the judgment unit is specifically configured to compare the discharge curve with the standard discharge curve. The curve segment corresponding to the duration in the discharge curve is compared with the standard curve segment corresponding to the duration in the standard discharge curve, and the standard curve segment is represented as a line segment; obtaining the curve segment and the standard curve segment The comparison result of whether the curve segments overlap.

Optionally, in any of the above device embodiments of the present application, the main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, and the positive curve segment corresponds to The judgment time of the main positive contactor, and the negative curve segment corresponds to the judgment time of the main negative contactor;

The standard curve segment includes a positive standard curve segment and a negative standard curve segment, the positive standard curve segment corresponds to the judgment time of the main positive contactor, and the negative standard curve segment corresponds to the judgment time of the main negative contactor.

Optionally, in any of the above device embodiments of the present application, the judging unit is specifically configured to compare the positive curve segment with the positive standard curve segment, according to the positive curve segment and the positive standard curve segment. Whether the curve segments overlap, determine whether the main positive contactor is stuck; compare the negative curve segment with the negative standard curve segment, and determine the negative curve segment according to whether the negative curve segment and the negative standard curve segment overlap. Whether the main and negative contactors are stuck.

Optionally, in any of the above device embodiments of the present application, the voltage sensor adopts a voltage sensor in a battery management system.

Optionally, in any of the above device embodiments of the present application, the device further includes:

a display device for displaying the discharge curve.

According to yet another aspect of the embodiments of the present application, a power battery system is provided, comprising: a power battery and the main contactor adhesion detection device according to any one of the above.

According to yet another aspect of the embodiments of the present application, a vehicle is provided, comprising: the main contactor sticking detection device as described in any one of the above or the power battery system as described above.

Based on the method and device for detecting adhesion of a main contactor, a power battery system, and a vehicle provided by the above-mentioned embodiments of the present application, the stable voltage value of the DC bus at both ends of the power battery when the power battery is in the power-on state is obtained; Control the main contactor to disconnect according to the power-off command, and obtain the sag voltage value after the voltage on the DC bus drops; obtain the discharge curve of the power battery based on the sag voltage value and the stable voltage value. The discharge curve represents the voltage value on the DC bus with time. Based on the discharge curve to determine whether the main contactor is stuck, to realize real-time detection of the sticking of the main contactor of the power battery, accurately determine the sticking state of the contactor in the power battery, and improve the safety of the system.

The technical solutions of the present application will be described in further detail below through the accompanying drawings and embodiments.

Description of drawings

The accompanying drawings, which form a part of the specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

The present application may be more clearly understood from the following detailed description with reference to the accompanying drawings, wherein:

FIG. 1 is a flowchart of a method for detecting adhesion of a main contactor provided by an embodiment of the present application.

FIG. 2 is a schematic diagram of a standard discharge curve in another embodiment of the main contactor adhesion detection method provided by the embodiment of the present application.

FIG. 3 is a schematic structural diagram of a main contactor adhesion detection device provided in an embodiment of the present application.

Detailed ways

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise.

Meanwhile, it should be understood that, for the convenience of description, the dimensions of various parts shown in the accompanying drawings are not drawn in an actual proportional relationship.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

Contactor is a passive actuator, in practical application, except for its own design and manufacturing quality problems. The main reasons that may cause bonding are: the contactor (such as: relay, etc.) has a large current at the moment of closing, which is generally a capacitive load without pre-charging or insufficient pre-charging (motor controller, DCDC, air conditioning compressor, Charger, etc.); the contactor has a large current when it is disconnected, usually when the motor does not stop working, it is abnormally powered off; when the battery pack is short-circuited, a large current is generated, and the relay contacts may be affected by the electric repulsion in the closed state. Bounce off to draw the arc.

FIG. 1 is a flowchart of a method for detecting adhesion of a main contactor provided by an embodiment of the present application. The method can be performed by any electronic device, such as a terminal device, a server, a mobile device, a vehicle-mounted device, and the like. As shown in Figure 1, the method of this embodiment includes:

Step 110: Obtain a stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state.

Optionally, the power battery may be a power battery in a vehicle, and the power battery may be a lithium battery pack or other battery packs, and the present application does not limit the specific form of the power battery. Optionally, in this embodiment of the present application, the voltage on the DC bus is collected by a voltage sensor to obtain a stable voltage value of the DC bus when the DC bus is powered on. The voltage sensor may be a voltage sensor in the battery management system, or may be set separately. voltage sensor.

Step 120: Receive a power-off command, control the main contactor to disconnect according to the power-off command, and obtain a sag voltage value after the voltage on the DC bus drops.

When the power-off command is received, the power-off of the power battery is performed, and the main contactor needs to be disconnected. In the embodiment of the present application, the voltage change on the DC bus during the disconnection process and the sag voltage value after the power-off is obtained are obtained. When the main contactor is stuck, the sag voltage value will be different from the sag voltage value of normal power off. In this embodiment of the present application, the obtained sag voltage value can be compared with the sag voltage value of normal power off to determine whether the contactor is Adhesion.

Step 130, obtaining a discharge curve of the power battery based on the drop voltage value and the stable voltage value.

Among them, the discharge curve represents the change relationship of the voltage value on the DC bus with time; optionally, the main contactor will have a voltage drop process during the disconnection process, which is reflected in the discharge curve, and a drop curve will appear. This application In the embodiment, by identifying the change of the discharge curve, the change of the voltage value on the DC bus during the power-off process can be determined, and whether the main contactor is stuck can be determined by the change of the voltage value during the power-off process.

Step 140, determining whether the main contactor is stuck based on the discharge curve.

The method for detecting the adhesion of a main contactor provided by the above-mentioned embodiments of the present application is to obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is in the power-on state; receive a power-off command, and control the main contactor to cut off according to the power-off command Open, obtain the sag voltage value after the voltage on the DC bus drops; obtain the discharge curve of the power battery based on the sag voltage value and the stable voltage value, and the discharge curve represents the change relationship of the voltage value on the DC bus with time; Whether the contactor is stuck or not can realize the real-time detection of the sticking of the main contactor of the power battery, accurately judge the sticking state of the contactor in the power battery, and improve the safety of the system.

In one or more optional embodiments, before obtaining the discharge curve of the power battery based on the drop voltage value and the stable voltage value, the method further includes:

Obtain the standard discharge curve corresponding to the power battery. The standard discharge curve is the normal discharge curve of the main contactor without adhesion, and the standard discharge curve is used to represent the relationship between the stable voltage value and the drop voltage value and time.

Optionally, in order to determine whether the main contactor is normally disconnected, it is first necessary to know the discharge curve when the main contactor is normally disconnected. Since the discharge curves of different power batteries may be different, the embodiment of the present application can ensure In the case that the main contactor is not stuck (for example, when the power battery is initially shipped from the factory), the standard discharge curve of the power battery under normal conditions is collected to ensure that the main contactor can be identified.

Optionally, before obtaining the discharge curve of the power battery based on the drop voltage value and the stable voltage value, the method further includes:

Obtain the drop time from the stable voltage value to the drop voltage value and the duration of the drop voltage value in the standard discharge curve;

Based on the drop voltage value and the stable voltage value, the discharge curve of the power battery is obtained, including:

The discharge curve of the power battery is obtained based on the drop voltage value, the stable voltage value, the drop time and the duration. The discharge curve takes time as the horizontal axis and voltage as the vertical axis.

FIG. 2 is a schematic diagram of a standard discharge curve in another embodiment of the main contactor adhesion detection method provided by the embodiment of the present application. As shown in Figure 2, in the closed state of the main contactor, the voltage of the battery DC bus is maintained at a stable voltage value of X volts. When the power-off command is received, the main contactor is controlled to disconnect, and the voltage on the battery DC bus begins to drop. The curve reflected in the time period a (corresponding to the drop time in the above-mentioned embodiment) in the figure indicates that the DC bus voltage drops Y volts from X volts in the time period a, and the obtained drop voltage value is X-Y volts at this time; After the drop, the drop voltage value will last for b time period (corresponding to the duration in the above embodiment), and the b time period is the voltage smoothing time after the drop voltage, and the voltage value on the DC bus does not change. This application implements For example, by comparing the discharge curves in the b time period, it can be determined whether the main contactor is stuck, that is, the main contactor state in the b time period is the diagnosis state. Optionally, Y in FIG. 2 is 20% of the battery pack voltage, a is the drop time of 300ms, b is the adhesion detection time, and X is the maximum detection voltage range of 350V-400V.

In one or more optional embodiments, determining whether the main contactor is stuck based on the discharge curve includes:

Compare the discharge curve with the standard discharge curve to obtain the comparison result;

Determine whether the main contactor is stuck based on the comparison results.

In the embodiment of the present application, when the standard discharge curve and the currently obtained discharge curve are known, the curves are compared to determine whether the main contactor is stuck, the judgment method is simple and easy to implement, and can be realized without complicated equipment, which improves the accuracy of judgment sex and speed.

Optionally, determining whether the main contactor is stuck based on the comparison result, including:

In response to the comparison result indicating that the discharge curve coincides with the standard discharge curve, it is determined that the main contactor is not stuck;

The main contactor is determined to be stuck in response to the comparison indicating that the discharge curve does not coincide with the standard discharge curve.

Since the standard discharge curve represents the discharge curve when the main contactor is not stuck, if the obtained discharge curve coincides with the standard discharge curve, it means that the main contactor is not stuck.

Optionally, compare the discharge curve with the standard discharge curve to obtain a comparison result, including:

Compare the curve segment corresponding to the duration in the discharge curve with the standard curve segment corresponding to the duration in the standard discharge curve, and the standard curve segment is represented as a line segment;

Obtain the comparison result of whether the curve segment coincides with the standard curve segment.

No matter whether the main contactor is stuck, its DC bus voltage is the same in the closed state and when it starts to open. Therefore, the obtained discharge curve in the closed state and the drop time coincide with the standard discharge curve. For these two The segment curves do not need to be compared, and the embodiment of the present application mainly determines whether the main contactor is stuck by comparing the curve segment corresponding to the duration with the standard curve segment.

Optionally, the main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, the positive curve segment corresponds to the judgment time of the main positive contactor, and the negative curve segment corresponds to the main negative contactor. judgment time;

The standard curve segment includes a positive standard curve segment and a negative standard curve segment. The positive standard curve segment corresponds to the judgment time of the main positive contactor, and the negative standard curve segment corresponds to the judgment time of the main negative contactor.

Compare the discharge curve with the standard discharge curve, obtain the comparison result, and determine whether the main contactor is stuck based on the comparison result, including:

Compare the positive curve segment with the positive standard curve segment, and determine whether the main positive contactor is stuck according to whether the positive curve segment and the positive standard curve segment overlap;

Compare the negative curve segment with the negative standard curve segment, and determine whether the main negative contactor is stuck according to whether the negative curve segment and the negative standard curve segment overlap.

Optionally, through the sequence of the contactor disconnection when the power battery system is powered off, the voltage is extracted for cross-comparison, and the detection condition of the contactor sticking is established. During the power-off process of the power battery, the disconnection of the main positive contactor and the main negative contactor will have a sequence. When the sequence of disconnection is known, according to the comparison of the corresponding positive curve segment and the positive standard curve segment, the negative curve Compare the segment with the negative standard curve segment to determine whether the main positive contactor is stuck or the main negative contactor is stuck. Optionally, when the main positive contactor is normally disconnected, the positive terminal voltage of the inverter is approximately equal to the value of the slope voltage discharged by the motor controller within milliseconds after subtracting the entire battery voltage; when the main negative contactor is normally disconnected, due to the reference If the ground is lost, the positive terminal voltage of the inverter is a floating voltage, and the reference ground voltage is a floating voltage. When the main positive contactor is stuck, the positive terminal voltage of the inverter is approximately equal to the entire battery voltage; when the main negative contactor is stuck, the inverter positive terminal voltage is approximately equal to the entire battery voltage. The reference ground voltage is close to zero potential and the DC loop has a small current; the detection method of the present application can directly detect the adhesion of the main contactor when the power battery is powered off; and the test has high accuracy and low cost.

In one or more optional embodiments, step 110 includes:

Use the voltage sensor in the battery management system to obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is powered on;

Step 120 includes:

Use the voltage sensor in the battery management system to obtain the drop voltage value after the voltage on the DC bus has dropped.

In the embodiment of the present application, the voltage value on the DC bus is acquired by the voltage sensor in the battery management system (BATTERY MANAGEMENT SYSTEM, BMS). Since the power battery is usually equipped with a corresponding battery management system when in use, the embodiment of the present application The original equipment is used, the equipment cost does not need to be increased, and the testability is improved.

In one or more optional embodiments, the methods provided in the embodiments of the present application further include:

The discharge curve is displayed by the display device.

In the embodiment of the present application, the display device is like a discharge curve, and the discharge curve and the standard discharge curve can also be overlapped and compared in the display device, so that the adhesion identification of the main contactor is more intuitive.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by program instructions related to hardware, the aforementioned program can be stored in a computer-readable storage medium, and when the program is executed, execute It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

FIG. 3 is a schematic structural diagram of a main contactor adhesion detection device provided in an embodiment of the present application. The apparatus in this embodiment can be used to implement the above method embodiments of the present application. As shown in Figure 3, the device of this embodiment includes:

The voltage sensor 31 is used to obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is in the power-on state, and obtain the drop voltage value after the voltage on the DC bus drops.

The controller 32 is configured to receive a power-off instruction, and control the main contactor to disconnect according to the power-off instruction.

The curve determination unit 33 is configured to obtain the discharge curve of the power battery based on the sag voltage value and the stable voltage value, and the discharge curve represents the variation relationship of the voltage value on the DC bus with time;

The determination unit 34 determines whether the main contactor is stuck based on the discharge curve.

The main contactor adhesion detection device provided by the above-mentioned embodiments of the present application obtains the stable voltage value of the DC bus at both ends of the power battery when the power battery is in the power-on state; receives a power-off command, and controls the main contactor to cut off according to the power-off command. Open, obtain the sag voltage value after the voltage on the DC bus drops; obtain the discharge curve of the power battery based on the sag voltage value and the stable voltage value, and the discharge curve represents the change relationship of the voltage value on the DC bus with time; Whether the contactor is stuck or not can realize the real-time detection of the sticking of the main contactor of the power battery, accurately judge the sticking state of the contactor in the power battery, and improve the safety of the system.

In one or more optional embodiments, the device provided in the embodiment of the present application further includes:

The standard curve unit is used to obtain the standard discharge curve corresponding to the power battery. The standard discharge curve is the normal discharge curve of the main contactor without adhesion, and the standard discharge curve is used to express the relationship between the stable voltage value and the drop voltage value and time.

Optionally, in order to determine whether the main contactor is normally disconnected, it is first necessary to know the discharge curve when the main contactor is normally disconnected. Since the discharge curves of different power batteries may be different, the embodiment of the present application can ensure In the case that the main contactor is not stuck (for example, when the power battery is initially shipped from the factory), the standard discharge curve of the power battery under normal conditions is collected to ensure that the main contactor can be identified.

Optionally, the device provided in the embodiment of the present application further includes:

The time acquisition unit is used to acquire the drop time from the stable voltage value to the drop voltage value and the duration of the drop voltage value in the standard discharge curve;

The curve determination unit 33 is specifically configured to obtain a discharge curve of the power battery based on the sag voltage value, the stable voltage value, the sag time and the duration. The discharge curve takes time as the horizontal axis and voltage as the vertical axis.

In one or more optional embodiments, the determination unit 34 is specifically configured to compare the discharge curve with the standard discharge curve to obtain a comparison result; and determine whether the main contactor is stuck based on the comparison result.

In the embodiment of the present application, when the standard discharge curve and the currently obtained discharge curve are known, the curves are compared to determine whether the main contactor is stuck, the judgment method is simple and easy to implement, and can be realized without complicated equipment, which improves the accuracy of judgment sex and speed.

Optionally, when determining whether the main contactor is stuck based on the comparison result, the judgment unit 34 is specifically configured to determine that the main contactor is not stuck in response to the comparison result indicating that the discharge curve coincides with the standard discharge curve; The standard discharge curves do not overlap, and it is determined that the main contactor is stuck.

Optionally, when the judgment unit 34 compares the discharge curve with the standard discharge curve and obtains the comparison result, it is specifically configured to compare the curve segment corresponding to the duration in the discharge curve and the curve segment corresponding to the duration in the standard discharge curve. The standard curve segment is compared, and the standard curve segment is represented as a line segment; the comparison result of whether the curve segment and the standard curve segment overlap is obtained.

Optionally, the main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, the positive curve segment corresponds to the judgment time of the main positive contactor, and the negative curve segment corresponds to the main negative contactor. judgment time;

The standard curve segment includes a positive standard curve segment and a negative standard curve segment. The positive standard curve segment corresponds to the judgment time of the main positive contactor, and the negative standard curve segment corresponds to the judgment time of the main negative contactor.

Optionally, the judgment unit is specifically configured to compare the positive curve segment with the positive standard curve segment, and determine whether the main positive contactor is stuck according to whether the positive curve segment and the positive standard curve segment overlap; compare the negative curve segment with the negative standard curve segment. Compare the main negative contactor and determine whether the main negative contactor is stuck according to whether the negative curve segment coincides with the negative standard curve segment.

In one or more optional embodiments, the voltage sensor is a voltage sensor in a battery management system.

In the embodiment of the present application, the voltage value on the DC bus is acquired by the voltage sensor in the battery management system (BATTERY MANAGEMENT SYSTEM, BMS). Since the power battery is usually equipped with a corresponding battery management system when in use, the embodiment of the present application The original equipment is used, the equipment cost does not need to be increased, and the testability is improved.

In one or more optional embodiments, the apparatus further includes:

The display device is used to display the discharge curve.

In the embodiment of the present application, the display device is like a discharge curve, and the discharge curve and the standard discharge curve can also be overlapped and compared in the display device, so that the adhesion identification of the main contactor is more intuitive.

According to yet another aspect of the embodiments of the present application, a power battery system is provided, comprising: a power battery and the main contactor adhesion detection device provided by any one of the above embodiments.

According to yet another aspect of the embodiments of the present application, a vehicle is provided, including: the main contactor adhesion detection device provided in any of the above embodiments or the power battery system provided by the above embodiments.

The methods and apparatus of the present application may be implemented in many ways. For example, the methods and apparatus of the present application may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present application are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present application can also be implemented as programs recorded in a recording medium, the programs comprising machine-readable instructions for implementing methods according to the present application. Thus, the present application also covers a recording medium storing a program for executing the method according to the present application.

The description of the present application is presented for the purpose of illustration and description, and is not intended to be exhaustive or to limit the application to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better explain the principles of the application and the practical application, and to enable others of ordinary skill in the art to understand the application for various embodiments with various modifications as are suited to the particular use.

Claims (16)

1. a main contactor adhesion detection method, is characterized in that, comprises: obtaining the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state; Receive a power-off command, control the main contactor to disconnect according to the power-off command, and obtain a drop voltage value after the voltage on the DC bus drops; A discharge curve of the power battery is obtained based on the sag voltage value and the stable voltage value, and the discharge curve represents the variation relationship of the voltage value on the DC bus with time; Comparing the discharge curve with the standard discharge curve, obtaining a comparison result, and determining whether the main contactor is stuck based on the comparison result; Wherein, comparing the discharge curve with the standard discharge curve, and obtaining a comparison result includes: Comparing the curve segment corresponding to the duration of the drop voltage value in the discharge curve with the standard curve segment corresponding to the duration in the standard discharge curve, the standard curve segment expresses is a line segment; obtain the comparison result of whether the curve segment coincides with the standard curve segment; The main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, the positive curve segment corresponds to the judgment time of the main positive contactor, and the negative curve segment corresponds to the judgment time of the main positive contactor. The curve segment corresponds to the judgment time of the main negative contactor; The standard curve segment includes a positive standard curve segment and a negative standard curve segment, the positive standard curve segment corresponds to the judgment time of the main positive contactor, and the negative standard curve segment corresponds to the judgment time of the main negative contactor. 2 . The method according to claim 1 , wherein before obtaining the discharge curve of the power battery based on the sag voltage value and the stable voltage value, the method further comprises: 3 . Acquire the standard discharge curve corresponding to the power battery, the standard discharge curve is a normal discharge curve with the main contactor not sticking, and the standard discharge curve is used to represent the relationship between the stable voltage value and the drop voltage value and time . 3 . The method according to claim 2 , wherein before obtaining the discharge curve of the power battery based on the sag voltage value and the stable voltage value, the method further comprises: 4 . Obtain the drop time from the stable voltage value to the drop voltage value in the standard discharge curve and the duration of the drop voltage value; The obtaining of the discharge curve of the power battery based on the drop voltage value and the stable voltage value includes: A discharge curve of the power battery is obtained based on the drop voltage value, the stable voltage value, the drop time, and the duration, and the discharge curve takes time as the horizontal axis and voltage as the vertical axis. 4. The method according to any one of claims 1-3, wherein the determining whether the main contactor is stuck based on the comparison result comprises: determining that the main contactor is not stuck in response to the comparison result indicating that the discharge curve coincides with the standard discharge curve; The main contactor is determined to be stuck in response to the comparison indicating that the discharge curve does not coincide with the standard discharge curve. 5. The method according to claim 4, wherein, comparing the discharge curve with a standard discharge curve, obtaining a comparison result, and determining whether the main contactor is stuck based on the comparison result, comprising: Comparing the positive curve segment with the positive standard curve segment, and determining whether the main positive contactor is stuck according to whether the positive curve segment and the positive standard curve segment overlap; The negative curve segment is compared with the negative standard curve segment, and it is determined whether the main negative contactor is stuck according to whether the negative curve segment and the negative standard curve segment overlap. 6. The method according to any one of claims 1-3, wherein the obtaining the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state comprises: Obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is powered on by using a voltage sensor in the battery management system; The acquiring the sag voltage value after the voltage on the DC bus has dropped, includes: The sag voltage value after the voltage drop on the DC bus is obtained by using the voltage sensor in the battery management system. 7. The method according to any one of claims 1-3, wherein the method further comprises: The discharge curve is displayed by a display device. 8. A main contactor adhesion detection device, characterized in that, comprising: a voltage sensor, configured to obtain the stable voltage value of the DC bus at both ends of the power battery when the power battery is in a powered-on state, and obtain the drop voltage value after the voltage on the DC bus drops; The controller is used to receive the power-off command, and control the main contactor to disconnect according to the power-off command; a curve determination unit, configured to obtain a discharge curve of the power battery based on the sag voltage value and the stable voltage value, where the discharge curve represents a time-varying relationship of the voltage value on the DC bus; a judgment unit, configured to compare the discharge curve with a standard discharge curve to obtain a comparison result; determine whether the main contactor is stuck based on the comparison result; wherein the discharge curve is compared with the standard discharge curve , when the comparison result is obtained, compare the curve segment corresponding to the duration of the drop voltage value in the discharge curve with the standard curve segment corresponding to the duration in the standard discharge curve, The standard curve segment is represented as a line segment; a comparison result of whether the curve segment and the standard curve segment overlap is obtained; The main contactor includes a main positive contactor and a main negative contactor; the curve segment includes a positive curve segment and a negative curve segment, the positive curve segment corresponds to the judgment time of the main positive contactor, and the negative curve segment corresponds to the judgment time of the main positive contactor. The curve section corresponds to the judgment time of the main negative contactor; the standard curve section includes a positive standard curve section and a negative standard curve section, the positive standard curve section corresponds to the judgment time of the main positive contactor, and the negative standard curve section corresponds to the judgment time of the main positive contactor. The curve segment corresponds to the judgment time of the main negative contactor. 9. The device according to claim 8, wherein the device further comprises: A standard curve unit, used to obtain a standard discharge curve corresponding to the power battery, the standard discharge curve is a normal discharge curve without adhesion of the main contactor, and the standard discharge curve is used to represent the stable voltage value and the drop The relationship between voltage value and time. 10. The device according to claim 9, wherein the device further comprises: a time obtaining unit, configured to obtain the drop time from the stable voltage value to the drop voltage value in the standard discharge curve and the duration of the drop voltage value; The curve determination unit is specifically configured to obtain a discharge curve of the power battery based on the drop voltage value, the stable voltage value, the drop time and the duration, where the discharge curve takes time as the horizontal axis, Take the voltage as the vertical axis. 11. The device according to any one of claims 8-10, wherein, when determining whether the main contactor is stuck based on the comparison result, the judgment unit is specifically configured to indicate that the main contactor is stuck in response to the comparison result. The discharge curve coincides with the standard discharge curve, and it is determined that the main contactor is not stuck; in response to the comparison result indicating that the discharge curve and the standard discharge curve do not overlap, it is determined that the main contactor is stuck. 12. The device according to claim 11, wherein the judging unit is specifically configured to compare the positive curve segment with the positive standard curve segment, and according to the positive curve segment and the positive standard curve Whether the curve segments overlap, determine whether the main positive contactor is stuck; compare the negative curve segment with the negative standard curve segment, and determine the negative curve segment according to whether the negative curve segment and the negative standard curve segment overlap. Whether the main and negative contactors are stuck. 13. The device according to any one of claims 8-10, wherein the voltage sensor is a voltage sensor in a battery management system. 14. The device according to any one of claims 8-10, wherein the device further comprises: a display device for displaying the discharge curve. 15. A power battery system, comprising: a power battery and the main contactor adhesion detection device according to any one of the above claims 8-14. 16 . A vehicle, characterized by comprising: the main contactor sticking detection device according to any one of claims 8 to 14 or the power battery system according to claim 15 .

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