KR101744713B1 - Diagnosis method of battery management system - Google Patents

Abstract

According to an embodiment of the present invention, a fault diagnosis method of a battery management system includes a plurality of batteries including at least two first battery cells and a second battery cell connected in series, A method of diagnosing a fault in a battery management system including a cell and a battery controller, the method comprising: measuring a voltage of the plurality of battery cells; A failure recognition step of recognizing a failure of the battery management system when a voltage of the plurality of battery cells measured in the voltage measurement step is outside a predetermined range; Comparing the voltage of the first battery cell measured in the voltage measuring step and the minimum voltage value measurable by the battery controller when the failure of the battery management system is recognized in the failure recognition step, And diagnosing whether the failure of the battery management system is a failure inside or outside the battery controller by comparing the voltage of the second battery cell measured at the battery controller with the maximum voltage value measurable by the battery controller do.

Description

{DIAGNOSIS METHOD OF BATTERY MANAGEMENT SYSTEM}

The present invention relates to a method for diagnosing a failure of a battery management system. Specifically, the present invention relates to a technique for identifying a precise cause of failure of a battery management system for managing a high voltage battery used in a hybrid vehicle, a plug-in hybrid vehicle, and an electric vehicle.

In recent years, various devices such as industrial devices, home appliances and automobiles using high-voltage batteries have appeared, and especially in the field of automobile technology, the use of high-voltage batteries is becoming more active.

Automobiles that use internal combustion engines that use fossil fuels such as gasoline or heavy oil as the main fuel have a serious impact on pollution such as air pollution. Therefore, in recent years, efforts have been made to develop an electric vehicle or a hybrid vehicle in order to reduce pollution.

Electric vehicles (EVs) are cars that do not use petroleum fuels and engines but that use electric batteries and electric motors. In other words, although an electric vehicle that drives a car by rotating an electric motor that is stored in a battery has been developed before a gasoline car, it has not been put into practical use due to problems such as a heavy weight of a battery and a time required for charging. Recently, And research for commercialization began in the 1990s.

On the other hand, hybrid technology (HEV) that uses electric vehicles, fossil fuels and electric energy adaptively is being commercialized as battery technology has been developed remarkably.

Since HEV uses both gasoline and electricity as power sources, it is receiving positive reviews in terms of fuel efficiency improvement and emission reduction. It is expected that HEV will play an intermediate role in evolving into a full electric vehicle because it is important to overcome the price difference with gasoline automobile by reducing the amount of secondary battery to one third of that of electric cars.

Since HEV and EV vehicles using such electric energy use a battery in which a plurality of rechargeable secondary cells are packed as a main power source, there is no exhaust gas and noise is small. have.

Since the performance of a battery using the electric energy directly affects the performance of the vehicle, it is necessary to measure the voltage of each battery cell, the voltage and current of the entire battery, and to efficiently manage charge and discharge of each battery cell However, a battery management system (BMS) is required to monitor the state of a cell sensing IC that senses each battery cell, thereby enabling stable control of the corresponding cell.

On the other hand, the battery management system includes a battery cell and a battery controller connected through a wire. Inside the battery controller, a sensing IC and a fuse for protecting the sensing IC from an overcurrent are provided.

The sensing IC performs a function of measuring a voltage of a battery cell, and an abnormal voltage may be measured in the sensing IC. In this case, there is no way to determine whether the fuse inside the battery controller is open or the wire connected to the battery controller is disconnected or the connector of the battery controller is in bad contact. Therefore, the battery management system itself needs to be replaced in such a case.

U.S. Patent Application Publication No. 2014-0070772

It is an object of the present invention to provide a diagnostic method that accurately discriminates whether an open failure occurs in a battery management system or whether a failure occurs inside a battery controller or outside a battery controller.

According to an embodiment of the present invention, a fault diagnosis method of a battery management system includes a fault diagnosis of a battery management system including a plurality of battery cells and a battery controller including at least two first battery cells and a second battery cell connected in series, The method comprising: measuring a voltage of the plurality of battery cells; A failure recognition step of recognizing a failure of the battery management system when a voltage of the plurality of battery cells measured in the voltage measurement step is outside a predetermined range; Comparing the voltage of the first battery cell measured in the voltage measuring step and the minimum voltage value measurable by the battery controller when the failure of the battery management system is recognized in the failure recognition step, And diagnosing whether the failure of the battery management system is a failure inside or outside the battery controller by comparing the voltage of the second battery cell measured at the battery controller with the maximum voltage value measurable by the battery controller do.

In addition, if the voltage of the first battery cell is the minimum voltage value that can be measured by the battery controller and the voltage of the second battery cell is the maximum voltage value that can be measured by the battery controller An external fault diagnosis step of diagnosing a fault outside the battery controller.

If the voltage of the first battery cell exceeds the minimum voltage value and falls below the predetermined range and the voltage of the second battery cell exceeds the predetermined range and falls below the maximum voltage value, The system may further include an internal failure diagnosis step of diagnosing a failure in the battery controller.

In the external fault diagnosis step, a failure outside the battery controller may mean that a wire connected to the battery controller is opened.

In the external fault diagnosis step, a failure outside the battery controller may mean that the connector connected to the battery controller has a poor contact.

In the internal fault diagnosis step, a failure inside the battery controller may mean that the fuse included in the battery controller is opened.

The system may further include an external failure notifying step of informing the user that the failure is outside the battery controller, when the failure is determined to be outside the battery controller.

In addition, if it is determined that there is a failure in the battery controller, it may further include an internal failure notifying step of informing the user that the failure has occurred in the battery controller.

The battery controller may include a fuse and a resistor connected in parallel with the fuse.

The present invention has the effect of accurately discriminating whether an open failure occurs in the battery management system, whether it is a failure inside the battery controller or a failure outside the battery controller.

In addition, the present invention has an effect of reducing the repairing cost by detecting the exact cause of the failure and replacing the failed part only when a failure occurs in the battery management system.

1 is a block diagram of a battery management system.
2 is a flowchart illustrating a failure diagnosis method of the battery management system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the embodiments of the present invention, descriptions of techniques which are well known in the technical field of the present invention and are not directly related to the present invention will be omitted. This is for the sake of clarity of the present invention without omitting the unnecessary explanation.

For the same reason, some of the components in the drawings are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In the drawings, the same or corresponding components are denoted by the same reference numerals.

Hereinafter, a fault diagnosis method of the battery management system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

1 is a block diagram of a battery management system.

Referring to FIG. 1, a battery management system 100 includes a plurality of battery cells 11 and 12, wires 21, 22 and 23, and a battery controller 70. At this time, the number of the battery cells 11, 12 and the wires 21, 22, 23 is not limited to the number shown in FIG.

The battery controller 70 includes a connector 30, fuses 41, 42 and 43, resistors 51, 52 and 53 and a sensing IC 60. At this time, the number of the fuses 41, 42, 43 and the resistors 51, 52, 53 is not limited to the number shown in FIG.

The battery controller 70 measures the voltages of the plurality of battery cells 11 and 12, determines an overdischarge state or an overcharge state, and performs inter-battery-cell balancing or the like.

The connector 30 functions to connect the battery controller 70 to the plurality of battery cells 11 and 12 through the wires 21, 22, and 23.

The fuses 41, 42, and 43 serve to protect the sensing IC 60 from an overcurrent. That is, when the overcurrent flows into the battery controller 70, the fuses 41, 42 and 43 are opened to protect the sensing IC 60.

The resistors 51, 52, 53 are connected in parallel with the fuses 41, 42, 43. Therefore, the resistors 51, 52, and 53 allow the current to flow to the sensing IC 60 even when the fuses 41, 42, and 43 are opened. At this time, the resistors 51, 52, and 53 are connected to the fuses 41, 42, and 43 so as not to affect the currents flowing through the fuses 41, It is preferable to have a very large value as compared with the internal resistance.

The sensing IC (60) measures the voltages of the plurality of battery cells (11, 12).

A fault diagnosis method of a battery management system according to an embodiment of the present invention is implemented through a battery management system having the above configuration. Hereinafter, this will be described in detail.

2 is a flowchart illustrating a failure diagnosis method of the battery management system according to an embodiment of the present invention.

Hereinafter, a fault diagnosis method of the battery management system according to an embodiment of the present invention will be described with reference to a case where the second wire 22 or the second fuse 42 is opened or not. The first battery cell 11 and the second battery cell 12 connected to the upper and lower ends of the second wire 22 and the second fuse 42 will be mainly described.

First, the voltages of the plurality of battery cells 11 and 12 are measured (S101). Hereinafter, the voltage of the first battery cell 11 measured in step S101 is assumed to be V1, and the voltage of the second battery cell 12 is assumed to be V2.

Then, it is determined whether the voltage measured in step S101 is within a predetermined range (S103). When Vn_min? V1 and V2? Vn_max, the voltages of the plurality of battery cells 11 and 12 fall within a predetermined range. The predetermined range is a range in which the voltage of the battery cell is sensed as a normal value. That is, this means that there is no failure of the battery management system 100. For example, 3 V ≤ V1 and V2 ≤ 4 V can be considered. However, the voltage value may vary depending on the performance of the sensing IC 60 of the battery controller 70, and the value is not necessarily limited thereto.

Thereafter, when it is determined in step S103 that the voltage measured in step S101 is outside the predetermined range, V1 is the minimum voltage value Vmax measurable by the battery controller 70 and V2 is the minimum voltage value Vmax that can be measured by the battery controller 70 (Vmin) (S105). For example, Vmax = 5 V and Vmin = 0 V. [ However, the maximum voltage value and the minimum voltage value may vary depending on the performance of the sensing IC 60 of the battery controller 70, and the value is not necessarily limited thereto.

Thereafter, if it is determined in step S105 that V1 = Vmin and V2 = Vmax, it is determined that there is a failure outside the battery controller 70 (S107). Failure outside the battery controller 70 may mean that the wire connected to the battery controller 70 is open. Specifically, it may mean that the second wire 22 is opened. Or failure outside the battery controller 70 may mean that the connector 30 connected to the battery controller 70 is in poor contact.

Thereafter, the user can be notified of the failure outside the battery controller 70 (S109). For example, a warning message may be displayed on a video device such as an AVN (Audio Video Navigation) of a vehicle, or a warning sound may be emitted through audio equipment of a vehicle. At this time, a warning message or a warning sound indicating failure outside the battery controller 70 is distinguished from an internal failure of the battery controller 70, which will be described later.

On the other hand, if it is determined in step S105 that V1? Vmin or V2? Vmax, it is diagnosed as a failure in the battery controller 70 (S111). That is, when Vmin < V1 < Vn_min and Vn_max < V2 < Vmax, it is determined that there is a failure in the battery controller 70. [ For example, it can be assumed that 0 V <V1 <3 V and 4 V <V2 <5 V. However, the voltage value may vary depending on the performance of the sensing IC 60 of the battery controller 70, and the value is not necessarily limited thereto.

The failure in the battery controller 70 may mean that the fuses 41, 42, and 43 included in the battery controller 70 are open. Specifically, it may mean that the second fuse 42 is opened. When an overcurrent flows to the battery controller 70, the fuses 41, 42, and 43 are opened. 1, the resistors 51, 52 and 53 are connected in parallel with the fuses 51, 52 and 53, and the sensing IC 60 senses the voltages of the battery cells 11 and 12 . However, since an internal failure occurs in the battery controller 70, the voltage of the battery cells 11 and 12 sensed by the sensing IC 60 deviates from a normal value. At this time, the error depends on the performance of the sensing IC.

Thereafter, the user can be notified of the failure in the battery controller 70 (S113). For example, a warning message may be displayed on a video device such as an AVN (Audio Video Navigation) of a vehicle, or a warning sound may be emitted through audio equipment of a vehicle. At this time, a warning message or a warning sound indicating failure in the battery controller 70 is distinguished from an external failure of the battery controller 70 described above.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalents thereof are included in the scope of the present invention Should be interpreted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And is not intended to limit the scope of the invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: Battery management system `11, 12: Battery cell
21, 22, 23: wire 30: connector
41, 42, 43: Fuse 51, 52, 53:
60: sensing IC 70: battery controller

Claims (9)

A method for diagnosing a fault in a battery management system including a plurality of battery cells and a battery controller including at least two serially connected first and second battery cells,
A voltage measurement step of measuring a voltage of the plurality of battery cells;
A failure recognition step of recognizing a failure of the battery management system when a voltage of the plurality of battery cells measured in the voltage measurement step is outside a predetermined range;
Comparing the voltage of the first battery cell measured in the voltage measuring step and the minimum voltage value measurable by the battery controller when the failure of the battery management system is recognized in the failure recognition step, A failure diagnosis step of diagnosing whether a failure of the battery management system is a failure inside or outside the battery controller by comparing a voltage of the second battery cell measured by the battery controller with a maximum voltage value measurable by the battery controller; And
When the voltage of the first battery cell exceeds the minimum voltage value and is less than the predetermined range and the voltage of the second battery cell exceeds the predetermined range and is less than the maximum voltage value, And an internal failure diagnosis step of diagnosing a failure in the battery controller. The method according to claim 1,
When the voltage of the first battery cell is the minimum voltage value that can be measured by the battery controller and the voltage of the second battery cell is the maximum voltage value that can be measured by the battery controller And an external fault diagnosis step of diagnosing a fault outside the battery controller. delete 3. The method of claim 2,
And a wire connected to the battery controller is opened when a failure occurs in the outside of the battery controller in the external fault diagnosis step. 3. The method of claim 2,
Wherein a failure outside the battery controller in the external fault diagnosis step is a contact failure of a connector connected to the battery controller. The method according to claim 1,
Wherein the failure in the battery controller in the internal failure diagnosis step is a case where a fuse included in the battery controller is opened. 3. The method according to claim 1 or 2,
Further comprising an external failure notifying step of notifying a user of a failure outside the battery controller when it is determined that there is a failure outside the battery controller. The method according to claim 1,
Further comprising an internal failure notifying step of notifying a user of a failure in the battery controller when it is determined that the failure has occurred in the battery controller. The method according to any one of claims 1, 2, and 4 to 6,
Wherein the battery controller includes a fuse and a resistor connected in parallel with the fuse.

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