KR102432892B1 - Apparatus and method for diagnosing a fault in a relay - Google Patents

Abstract

Disclosed are an apparatus and method for diagnosing a failure of a relay installed between a battery group and an electrical load. The diagnosis method may include: monitoring a relay control command from an external device; allocating a first value or a second value to a control flag according to a monitoring result for the control command; determining whether the current control state of the relay is an open control state; determining whether a first diagnostic condition for diagnosing a short circuit failure of the relay is satisfied when the current control state is the open control state; and diagnosing whether a permanent short-circuit failure has occurred in the relay based on the control flag when the first diagnostic condition is satisfied.

Description

Apparatus and method for diagnosing a fault in a relay

The present invention relates to an apparatus and method for diagnosing a failure of a relay, and more particularly, to an apparatus and method for diagnosing whether a failure of a relay connected between a battery and a load is permanent or temporary.

Recently, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has rapidly increased, and development of electric vehicles, energy storage batteries, robots, satellites, etc. is in full swing, high-performance batteries that can be repeatedly charged and discharged have been developed. Research is actively underway.

Currently commercially available batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium batteries. It is attracting attention due to its low energy density and high energy density.

A relay, which is a kind of switch, is installed between the battery and the load and is used for the purpose of controlling the current flow between the battery and the load. The relay can be largely divided into a monostable type and a bistable type, and becomes any one of at least two control states, ie, an open control state and a short circuit control state, according to a control command from the outside. When the relay is in open control, the current between the battery and the load is cut off. On the other hand, when the relay is in the short-circuit control state, a current between the battery and the load flows through the relay.

However, an open-fault or a short-fault may occur in the relay due to various causes. An open fault is a fault in which a relay is inadvertently opened temporarily or permanently, which causes problems such as abruptly cut off current flow between the battery and the load. A short-circuit fault is a fault in which a relay is unintentionally or permanently closed, and causes problems such as over-discharge, over-charge, and over-current of the battery.

A prior art of diagnosing whether a relay is an open fault or a short fault based on a result of measuring a voltage applied between both ends of a relay and comparing the measured voltage with a predetermined threshold voltage has been disclosed.

However, according to the prior art as described above, it is only possible to diagnose whether the relay is an open failure or a short circuit failure, and it is not possible to distinguish whether the open failure or short circuit failure is temporary or permanent.

The present invention has been devised to solve the above problems, and an object of the present invention is to provide an apparatus and method for diagnosing whether an open failure or a short circuit failure of a relay is temporary or permanent.

Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

Various embodiments of the present invention for achieving the above object are as follows.

A method for diagnosing a failure of a relay installed between a battery group and an electrical load according to an embodiment of the present invention assigns a first value or a second value to a control flag according to whether a control command is received from an external device to do; determining whether the current control state of the relay is an open control state; determining whether a first diagnostic condition for diagnosing a short circuit failure of the relay is satisfied when the current control state is the open control state; and diagnosing whether a permanent short-circuit failure has occurred in the relay based on the control flag when the first diagnostic condition is satisfied.

The first diagnosis condition is that, for a predetermined diagnosis time, a diagnosis voltage corresponding to a voltage applied to both ends of the relay is maintained to be less than a threshold voltage, and a diagnosis current corresponding to a current flowing through the relay is greater than a threshold current. can be satisfied if maintained.

Diagnosing whether a permanent short-circuit failure has occurred in the relay may include: diagnosing that a permanent short-circuit failure has occurred in the relay when the first value is assigned to the control flag; and diagnosing that a temporary short-circuit failure has occurred in the relay when the second value is assigned to the control flag.

The diagnosis method may include, when the current control state is a short-circuit control state, determining whether a second diagnosis condition for diagnosing an open failure of the relay is satisfied; and diagnosing whether a permanent open failure has occurred in the relay based on the control flag when the second diagnostic condition is satisfied.

The second diagnostic condition may be satisfied when a diagnostic voltage corresponding to a potential difference between both ends of the relay is greater than a threshold voltage and a diagnostic current corresponding to a current flowing through the relay is less than a threshold current.

Diagnosing whether a permanent open failure has occurred in the relay may include: when the first value is assigned to the control flag, diagnosing that a permanent open failure has occurred in the relay; and diagnosing that a temporary open failure has occurred in the relay when the second value is assigned to the control flag.

The diagnosis method may further include determining the current control state according to the control command.

According to another embodiment of the present invention, there is provided an apparatus for diagnosing a failure of a relay installed between a battery group and an electrical load, comprising: a voltage measuring unit configured to measure a diagnostic voltage corresponding to a voltage applied to both ends of the relay; a current measuring unit configured to measure a diagnostic current corresponding to a current flowing through the relay; and a control unit operatively coupled to the voltage measurement unit and the current measurement unit. The control unit assigns a first value or a second value to the control flag according to whether a control command is received from an external device. The control unit determines whether the current control state of the relay is an open control state. When the current control state is the open control state, the controller determines whether a first diagnostic condition for diagnosing a short circuit failure of the relay is satisfied based on the diagnostic voltage or the diagnostic current. When the first diagnostic condition is satisfied, the control unit diagnoses whether a permanent short-circuit failure has occurred in the relay based on the control flag.

When the first value is assigned to the control flag when the first diagnostic condition is satisfied, the controller may diagnose that a permanent short-circuit failure has occurred in the relay. When the second value is assigned to the control flag when the first diagnostic condition is satisfied, the controller may diagnose that a temporary short-circuit failure has occurred in the relay.

When the current control state is a short-circuit control state, the controller may determine whether a second diagnostic condition for diagnosing an open failure of the relay is satisfied based on the diagnostic voltage or the diagnostic current. When the second diagnosis condition is satisfied, the controller may diagnose whether the relay is a permanent open failure based on the control flag.

When the first value is assigned to the control flag when the second diagnosis condition is satisfied, the controller may diagnose that a permanent open failure has occurred in the relay. When the second value is assigned to the control flag when the second diagnostic condition is satisfied, the controller may diagnose that a temporary open failure has occurred in the relay.

A battery pack according to another embodiment of the present invention includes the diagnostic device.

The electric device according to another embodiment of the present invention includes the battery pack.

According to at least one of the embodiments of the present invention, it is possible to selectively diagnose an open failure and a short circuit failure of a relay.

In addition, according to at least one of the embodiments of the present invention, it is possible to diagnose whether the relay open failure is temporary or permanent.

In addition, according to at least one of the embodiments of the present invention, it is possible to diagnose whether the short circuit failure of the relay is temporary or permanent.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the detailed description of the present invention to be described later, so the present invention is described in such drawings should not be construed as being limited only to
1 is a view showing the configuration of an electric device including a battery pack according to an embodiment of the present invention.
2 and 3 are flowcharts illustrating a method for diagnosing a failure of a relay according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the configuration shown in the embodiments and drawings described in the present specification is merely the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms including an ordinal number such as 1st, 2nd, etc. are used for the purpose of distinguishing any one of various components from the others, and are not used to limit the components by such terms.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, a term such as <control unit> described in the specification means a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

In addition, throughout the specification, when a part is "connected" with another part, it is not only "directly connected" but also "indirectly connected" with another element interposed therebetween. include

1 is a view showing the configuration of a transmission device 1 including a battery pack 10 according to an embodiment of the present invention.

Referring to FIG. 1 , the electric device 1 includes a main controller 2 , a battery pack 10 , and an electric load 40 . For example, the transmission 1 may be an electric vehicle, and in this case, the main controller 2 may be referred to as a vehicle controller. The motor controller 44 and the controller 130, which will be described later, may operate in response to a command from the main controller 2 . The motor controller 44 , the controller 130 , and the main controller 2 may communicate with each other through, for example, a controller area network (CAN). Each of the motor controller 44 and the controller 130 may be activated in response to a start command from the main controller 2 .

The electrical load 40 is configured to supply DC power from the battery pack 10 or to supply DC power to the battery pack 10 . The electrical load 40 may include a smoothing capacitor 41 , an inverter 42 , a motor 43 , and a motor controller 44 . The smoothing capacitor 41 is connected in parallel between the first pack terminal P+ and the second pack terminal P- of the battery pack 10 to suppress a sudden change in DC power. The inverter 42 converts DC power supplied from the battery pack 10 into AC power and provides it to the motor 43 . The motor 43 operates using AC power provided from the inverter 42 .

The battery pack 10 includes a battery group 20 , a relay 30 , and a diagnostic device 100 . The battery group 20 includes at least one battery cell 21 . Each battery cell may be, for example, a lithium ion battery. Of course, the type of the battery cell 21 is not limited to the lithium ion battery, and is not particularly limited as long as it can be repeatedly charged and discharged. When the plurality of battery cells 21 are included in the battery group 20 , the plurality of battery cells 21 may be connected in series or series-parallel.

The relay 30 is installed on at least one of the high voltage line HL and the low voltage line LL of the battery pack 10 . As shown, when the relay 30 is installed on the high voltage line HL, one end of the relay 30 is connected to the positive terminal of the battery group 20 , and the other end of the relay 30 is the electric load 40 . ) can be connected to The relay 30 may be of a monostable type or a bistable type. The relay 30 may be controlled to an open control state or a short control state according to a switching signal output by the diagnostic apparatus 100 .

The diagnostic apparatus 100 is operatively coupled to the relay 30 and the main controller 2 , and includes a voltage measurement unit 110 , a current measurement unit 120 , and a control unit 130 .

The voltage measuring unit 110 includes a first voltage sensor 111 and a second voltage sensor 112 . The first voltage sensor 111 may be connected between one end of the relay 30 and a reference node (eg, the negative terminal of the battery group 20 ). For example, the first voltage sensor 111 is connected in parallel to the battery group 20 and is configured to measure a voltage between the positive terminal and the negative terminal of the battery group 20 (hereinafter referred to as a 'first voltage'). do. The second voltage sensor 112 may be connected between the other end of the relay 30 and the reference node. As an example, the second voltage sensor 112 is connected in parallel to the smoothing capacitor 41, and is applied to a voltage (hereinafter, 'second voltage') applied between the first pack terminal P+ and the second pack terminal P-. ) is configured to measure. The voltage measuring unit 110 may output a voltage signal representing the first voltage and a voltage signal representing the second voltage to the controller 130 .

The current measuring unit 120 is installed in the high voltage line HL or the low voltage line LL of the battery pack 10 and is configured to measure the current flowing through the relay 30 . The current measurement unit 120 may output a current signal representing the measured current to the control unit 130 .

The control unit 130 is operatively coupled to the voltage measurement unit 110 , the current measurement unit 120 , the relay 30 , and the main controller 2 . The controller 130 is hardware, ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), microprocessors ( microprocessors) and may be implemented using at least one of electrical units for performing other functions.

The control unit 130 determines a diagnostic voltage corresponding to the voltage applied to both ends of the relay 30 based on the voltage signal output from the voltage measuring unit 110 . For example, the diagnostic voltage may represent an absolute value of a difference between the first voltage and the second voltage.

The control unit 130 also determines a diagnosis current corresponding to the current flowing through the relay 30 based on the current signal from the current measuring unit 120 . For example, the diagnostic current may represent an absolute value of a current flowing through the relay 30 .

A memory device may be embedded in the controller 130 , and as the memory device, for example, a RAM, ROM, register, hard disk, optical recording medium, or magnetic recording medium may be used. The memory device may store, update, and/or erase a program including various control logic executed by the controller 130 and/or data generated when the control logic is executed.

The controller 130 monitors a control command from an external device every predetermined time (eg, 1 second). The external device may be, for example, the main controller 2 . The control command may be a signal requesting the controller 130 to change the control state of the relay 30 .

The controller 130 may selectively output the first switching signal or the second switching signal to the relay 30 in response to the control command. The first switching signal is a signal for guiding the relay 30 to the open control state, and the second switching signal is a signal for guiding the relay 30 to the short control state. The controller 130 may include a relay control circuit configured to selectively output the first switching signal and the second switching signal.

When the relay 30 is a bistable type, the relay 30 may include a coil, an electromagnet, and a contact. In this case, when a current in the first direction flows through the coil of the relay 30 by the first switching signal, the electromagnet moves the contact to the open position, so that the relay 30 enters the open control state. On the other hand, when a current opposite to the first direction flows in the coil of the relay 30 by the second switching signal, the electromagnet moves the contact to the closed position, so that the relay 30 is in a short-circuit control state. In addition, when the controller 130 outputs neither the first switching signal nor the second switching signal to the relay 30 , the relay 30 is maintained in the previous control state.

The controller 130 assigns a first value (eg, 1) or a second value (eg, 0) to the control flag according to the monitoring result for the control command. Specifically, when a control command from an external device is received, the controller 130 assigns a first value to the control flag. On the other hand, when the control command is not received within a predetermined time, the controller 130 assigns a second value to the control flag.

The controller 130 may determine the current control state according to the monitoring result for the control command. Specifically, when the control command is received, the controller 130 determines a control state opposite to the previous control state as the current control state. For example, when the previous control state is the short-circuit control state, the open control state is determined as the current control state. On the other hand, when the control command is not received, the controller 130 determines the same control state as the previous control state as the current control state. For example, when the previous control state is the short-circuit control state, the short-circuit control state is determined as the current control state.

In other words, the assignment of the first value to the control flag means that the current control state of the relay 30 is different from the previous control state. On the other hand, that the second value is assigned to the control flag means that the current control state is the same as the previous control state.

After determining the value of the control flag and the current control state, the controller 130 determines whether the first diagnostic condition or the second diagnostic condition is satisfied based on the diagnostic voltage or the diagnostic current. Specifically, when the current control state is the open control state, the controller 130 determines whether the first diagnostic condition is satisfied. The first diagnosis condition is for diagnosing an open failure of the relay 30 . On the other hand, when the current control state is the short-circuit control state, the controller 130 determines whether the second diagnostic condition is satisfied. The second diagnosis condition is for diagnosing an open failure of the relay 30 .

The first diagnosis condition may be satisfied when the diagnosis voltage is maintained to be less than a threshold voltage (eg, 0.5V) for a predetermined diagnosis time (eg, 0.1 second). Alternatively, the first diagnostic condition may be satisfied when the diagnostic current is maintained to be greater than the threshold current (eg, 0.5A) during the diagnostic time. Alternatively, the first diagnosis condition may be satisfied when, during the diagnosis time, the diagnosis voltage is maintained less than the threshold voltage and the diagnosis current is maintained greater than the threshold current during the diagnosis time. Since the current flow between the battery and the electrical load 40 is blocked while the relay 30 is normally operated in the open control state, the diagnostic voltage must be greater than or equal to the threshold voltage or the diagnostic current must be less than or equal to the threshold current. If not (that is, if the first diagnostic condition is satisfied), it indicates that the relay 30 is a short-circuit failure in which the relay 30 does not operate normally in the open control state.

The second diagnosis condition may be satisfied when the diagnosis voltage is maintained to be greater than the threshold voltage during the diagnosis time. Alternatively, the second diagnostic condition may be satisfied when the diagnostic current is maintained less than the threshold current during the diagnostic time. Alternatively, the second diagnosis condition may be satisfied when, during the diagnosis time, the diagnosis voltage is maintained greater than the threshold voltage and the diagnosis current is maintained less than the threshold current during the diagnosis time. Since a current flows between the battery and the electrical load 40 while the relay 30 is normally operated in the short-circuit control state, the diagnostic voltage must be less than or equal to the threshold voltage or the diagnostic current must be greater than or equal to the threshold current. If not (that is, if the second diagnostic condition is satisfied), it indicates that the relay 30 is an open fault in which the relay 30 does not operate normally in the short-circuit control state.

<Process when the first diagnosis condition is satisfied>

When the first diagnostic condition is satisfied, the control unit 130 determines whether the short-circuit failure is temporary or permanent, based on the control flag.

Specifically, when the first value is assigned to the control flag, the control unit 130 determines that the short-circuit failure is permanent. That the current control state is the open control state and the first value is assigned to the control flag means that the previous control state was the short control state. Even though the relay 30 is induced to the open control state by the first switching signal output by the controller 130 , the relay 30 is maintained in the short circuit control state that is the previous control state is a permanent short circuit failure in the relay 30 . means that this has occurred.

On the other hand, when the second value is assigned to the control flag, the controller 130 determines that the short-circuit failure is temporary. That the current control state is the open control state and the second value is assigned to the control flag means that the previous control state was the open control state. Even though the control unit 130 does not output the first switching signal to the relay 30 , the relay 30 is changed from the previous control state (ie, open control state) to the short-circuit control state due to an external shock or the like. ) means that a temporary short-circuit failure has occurred.

<Process when the second diagnosis condition is satisfied>

When the second diagnostic condition is satisfied, the control unit 130 determines whether the open failure is temporary or permanent, based on the control flag.

Specifically, when the first value is assigned to the control flag, the control unit 130 determines that the open failure is permanent. That the current control state is a short control state and the first value is assigned to the control flag means that the previous control state was an open control state. Even though the relay 30 is induced to the short-circuit control state by the second switching signal output from the controller 130, the relay 30 is maintained in the open control state, which is the previous control state, a permanent open failure in the relay 30 means that this has occurred.

On the other hand, when the second value is assigned to the control flag, the control unit 130 determines that the open failure is temporary. That the current control state is the short-circuit control state and the second value is assigned to the control flag means that the previous control state was the short-circuit control state. Even though the control unit 130 does not output the first switching signal to the relay 30 , the relay 30 is in the open control state from the previous control state (that is, the short-circuit control state), the relay 30 due to an external shock, etc. ) means that a temporary open failure has occurred.

2 and 3 are flowcharts showing a method for diagnosing a failure of the relay 30 according to another embodiment of the present invention. The methods shown in FIGS. 2 and 3 may be repeatedly executed every predetermined time (eg, 1 second).

1 to 3 , in step S200 , the controller 130 determines whether a control command from an external device has been received. The control command may be a signal requesting the controller 130 to change the control state of the relay 30 . If the result of step S200 is "YES", step S210 proceeds. When the result of step S200 is "NO", step S220 proceeds.

In step S210, the control unit 130 assigns a first value to the control flag.

In step S215 , the controller 130 outputs a switching signal corresponding to the control command to the relay 30 . For example, when the control command requests an open control state, the controller 130 outputs the first switching signal to the relay 30 . As another example, when the control command requests a short-circuit control state, the controller 130 outputs the second switching signal to the relay 30 .

In step S220, the control unit 130 assigns the second value to the control flag.

In step S230 , the control unit 130 determines the current control state of the relay 30 . When the first value is assigned to the control flag, the previous control state and the current control state of the relay 30 are reversed. For example, when the previous control state is the open control state, the current control state is determined to be the short control state. On the other hand, the previous control state and the current control state of the relay 30 are the same.

In step S240 , the control unit 130 determines whether the current control state of the relay 30 is an open control state. If the result of step S240 is "YES", step S250 proceeds. If the result of step S240 is "NO", step S300 proceeds. The result of step S240 of "NO" indicates that the current control state of the relay 30 is a short-circuit control state.

In step S250 , the controller 130 determines whether the first diagnosis condition is satisfied. To this end, the controller 130 monitors the diagnosis voltage and the diagnosis current for a diagnosis time (eg, 0.1 second) between the start time and the end time of step S240 . The first diagnosis condition may be satisfied when the diagnosis voltage is maintained to be less than a threshold voltage (eg, 0.5V) for a predetermined diagnosis time (eg, 0.1 second). Alternatively, the first diagnostic condition may be satisfied when the diagnostic current is maintained to be greater than the threshold current (eg, 0.5A) during the diagnostic time. Alternatively, the first diagnosis condition may be satisfied when, during the diagnosis time, the diagnosis voltage is maintained less than the threshold voltage and the diagnosis current is maintained greater than the threshold current during the diagnosis time. If the result of step S250 is "YES", step S260 proceeds. If the result of step S250 is "NO", step S280 proceeds.

In step S260, the control unit 130 determines whether the first value is assigned to the control flag. If the result of step S260 is "YES", step S272 proceeds. If the result of step S260 is "NO", step S274 proceeds. The result of step S260 being "NO" indicates that the second value is assigned to the control flag.

In step S272 , the controller 130 diagnoses that a permanent short-circuit failure has occurred in the relay 30 .

In step S274 , the controller 130 diagnoses that the controller 130 has a temporary short-circuit failure in the relay 30 .

In step S280 , the controller 130 diagnoses that a short circuit failure does not occur in the relay 30 .

In step S300, the controller 130 determines whether the second diagnosis condition is satisfied. To this end, the control unit 130 monitors the diagnosis voltage and the diagnosis current for a diagnosis time (eg, 0.1 second) between the start time and the end time of step S3000. The second diagnosis condition may be satisfied when the diagnosis voltage is maintained to be greater than the threshold voltage during the diagnosis time. Alternatively, the second diagnostic condition may be satisfied when the diagnostic current is maintained less than the threshold current during the diagnostic time. Alternatively, the second diagnosis condition may be satisfied when, during the diagnosis time, the diagnosis voltage is maintained greater than the threshold voltage and the diagnosis current is maintained less than the threshold current during the diagnosis time. If the result of step S300 is "YES", step S310 proceeds. If the result of step S300 is "NO", step S330 proceeds.

In step S310, the control unit 130 determines whether the first value is assigned to the control flag. If the result of step S310 is "YES", step S322 proceeds. If the result of step S310 is "NO", step S324 proceeds. The result of step S310 being "NO" indicates that the second value is assigned to the control flag.

In step S322 , the controller 130 diagnoses that a permanent open failure has occurred in the relay 30 .

In step S324 , the controller 130 diagnoses that the controller 130 has a temporary open failure in the relay 30 .

In step S330 , the controller 130 diagnoses that an open failure has not occurred in the relay 30 .

Step S272, S274, S280, S322, S324 or S330 may be executed, and then step S290 may be executed. In step S290 , the control unit 130 transmits a diagnosis message indicating a result of diagnosis of the relay 30 to the external device.

The embodiment of the present invention described above is not implemented only through the apparatus and method, and may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded. The implementation can be easily implemented by those skilled in the art to which the present invention pertains from the description of the above-described embodiments.

In the above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto and will be described below with the technical idea of the present invention by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims.

In addition, since the present invention described above is capable of various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention for those of ordinary skill in the art to which the present invention pertains, the above-described embodiments and attachments It is not limited by the drawings, and all or part of each embodiment may be selectively combined so that various modifications may be made.

1: powertrain
2: main controller
10: battery pack
20: battery group
30: relay
40: electrical load
100: diagnostic device
110: voltage measuring unit
120: current measuring unit
130: control unit

Claims (13)

A method for diagnosing a failure of a relay installed between a battery group and an electrical load, the method comprising:
Depending on whether a control command is received from an external device, a first value indicating that the current control state of the relay has changed or a second value indicating that the current control state of the relay maintains the previous control state is assigned to the control flag to do;
determining whether the current control state of the relay is an open control state;
determining whether a first diagnostic condition for diagnosing a short circuit failure of the relay is satisfied when the current control state is the open control state; and
diagnosing whether a permanent short circuit failure has occurred in the relay based on the control flag when the first diagnostic condition is satisfied;
Including, relay fault diagnosis method.
According to claim 1,
The first diagnostic condition is
Satisfied when, for a predetermined diagnostic time, a diagnostic voltage corresponding to the voltage applied to both ends of the relay is maintained less than a threshold voltage, and a diagnostic current corresponding to a current flowing through the relay is maintained greater than the threshold current, How to diagnose relay failure.
According to claim 1,
Diagnosing whether a permanent short-circuit failure has occurred in the relay comprises:
diagnosing that a permanent short circuit failure has occurred in the relay when the first value is assigned to the control flag; and
diagnosing that a temporary short-circuit failure has occurred in the relay when the second value is assigned to the control flag;
Including, relay fault diagnosis method.
According to claim 1,
determining whether a second diagnostic condition for diagnosing an open failure of the relay is satisfied when the current control state is a short circuit control state; and
diagnosing whether a permanent open failure has occurred in the relay based on the control flag when the second diagnostic condition is satisfied;
Further comprising, relay failure diagnosis method.
5. The method of claim 4,
The second diagnostic condition is
It is satisfied when a diagnostic voltage corresponding to a potential difference between both ends of the relay is greater than a threshold voltage, and a diagnostic current corresponding to a current flowing through the relay is less than the threshold current.
5. The method of claim 4,
Diagnosing whether a permanent open failure has occurred in the relay comprises:
diagnosing that a permanent open failure has occurred in the relay when the first value is assigned to the control flag; and
diagnosing that a temporary open failure has occurred in the relay when the second value is assigned to the control flag;
Including, relay fault diagnosis method.
According to claim 1,
determining the current control state according to the control command;
Further comprising, relay failure diagnosis method.
An apparatus for diagnosing a failure of a relay installed between a battery group and an electrical load, comprising:
a voltage measuring unit configured to measure a diagnostic voltage corresponding to a voltage applied to both ends of the relay;
a current measuring unit configured to measure a diagnostic current corresponding to a current flowing through the relay; and
Including; a control unit operatively coupled to the voltage measuring unit and the current measuring unit;
The control unit is
Depending on whether a control command is received from an external device, a first value indicating that the current control state of the relay has changed or a second value indicating that the current control state of the relay maintains the previous control state is assigned to the control flag do,
determine whether the current control state of the relay is an open control state;
when the current control state is the open control state, determine whether a first diagnostic condition for diagnosing a short circuit failure of the relay is satisfied based on the diagnostic voltage or the diagnostic current;
and diagnosing whether a permanent short-circuit failure has occurred in the relay based on the control flag when the first diagnostic condition is satisfied.
9. The method of claim 8,
The control unit is
When the first diagnostic condition is satisfied, if the first value is assigned to the control flag, it is diagnosed that a permanent short circuit failure has occurred in the relay,
and when the second value is assigned to the control flag when the first diagnostic condition is satisfied, diagnosing that a temporary short-circuit failure has occurred in the relay.
9. The method of claim 8,
The control unit is
when the current control state is a short-circuit control state, determine whether a second diagnostic condition for diagnosing an open failure of the relay is satisfied based on the diagnostic voltage or the diagnostic current;
and diagnosing whether the relay is a permanent open failure based on the control flag when the second diagnostic condition is satisfied.
11. The method of claim 10,
The control unit is
When the second diagnostic condition is satisfied, when the first value is assigned to the control flag, it is diagnosed that a permanent open failure has occurred in the relay,
and when the second value is assigned to the control flag when the second diagnosis condition is satisfied, diagnosing that a temporary open failure has occurred in the relay.
The relay failure diagnosis device according to any one of claims 8 to 11;
comprising, a battery pack.
The battery pack according to claim 12;
Including, a powertrain.

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