KR20200051307A - Battery management system and operating method thereof - Google Patents

Abstract

The present invention relates to a battery management device comprising: a transistor and a resistor connected in series between a first node of a first channel and a second node of the first channel; a first analog-to-digital converter which outputs a digital value corresponding to a voltage difference between voltage of the first node of the first channel and voltage of the second node of the first channel; and a second analog-to-digital converter which outputs a digital value corresponding to a voltage difference between voltage of the first node of a second channel and voltage of the second node of the second channel.

Description

BATTERY MANAGEMENT SYSTEM AND OPERATING METHOD THEREOF}

The present invention relates to a battery management device and a method of operation thereof.

BMS (battery management system) is a battery applied to an electric vehicle that stores electrical energy and can be used as a power source for a vehicle through a discharge process if necessary, and serves to regenerate and store the energy that is wasted during braking as electrical energy. In charge. It is a system to effectively use various energy flows according to the operation of an electric vehicle. In an electric vehicle, the BMS controls the cooling performance of the battery and manages and controls the information of the battery's state of charge (SOC), maximum charge and discharge power, and various warnings and defects in real time necessary for vehicle operation. The main purpose is to create an optimal operating environment. In addition, it prevents the situation that can damage the battery, such as overcharging and overdischarging, during the charging and discharging operation of the battery. It also functions to extend the state of health of the battery and uses various information collected from the battery. It is also responsible for providing battery information.

Patent registered: 10-1858321, Registration date: December 14, 2015, Title: Fault diagnosis device and method of sal balancing circuit. Patent registration: 10-1679959, Registration date: March 16, 2015, Title: Cell balancing system using a high voltage battery overcharge protection device. Patent: 10-1589198, Registration date: February 19, 2013, Title: A device and method for diagnosing a fault in a cell balancing circuit.

An object of the present invention is to provide a battery management device and an operation method thereof that simultaneously perform cell balancing and sensing.

A battery management apparatus according to an embodiment of the present invention includes a transistor and a resistor connected in series between a first node of a first channel and a second node of the first channel; A first analog-to-digital converter for outputting a digital value corresponding to a voltage difference between the voltage of the first node of the first channel and the voltage of the second node of the first channel; And a second analog-to-digital converter that outputs a digital value corresponding to a voltage difference between the voltage of the first node of the second channel and the voltage of the second node of the second channel.

In an embodiment, the first node of the first channel and the first node of the second channel are commonly connected to a first node connected to a negative voltage terminal of any one battery cell of the battery module, and the first channel It characterized in that the second node and the second node of the second channel are commonly connected to a second node connected to the positive voltage terminal of any one of the battery cells.

In an embodiment, the first analog-to-digital converter is characterized by being used for a balancing operation.

In an embodiment, the second analog-to-digital converter is used for cell sensing operation.

In an embodiment, the cell sensing operation is performed simultaneously while performing the balancing operation.

In an embodiment, the wire connection diagnosis operation is performed using the output values of the first and second analog-to-digital converters.

In an embodiment, when the difference between the output value of the first analog-to-digital converter and the output value of the second analog-to-digital converter is less than a reference value, the wire connection state is determined to be normal.

In an embodiment, when the difference between the output value of the first analog-to-digital converter and the output value of the second analog-to-digital converter is greater than or equal to a reference value, the wire connection state is determined to be a fault condition.

In an embodiment, the wire connection diagnosis operation is performed while performing a balancing operation.

An operation method of a battery management apparatus according to an embodiment of the present invention includes: when the ignition switch is turned on, turning on the battery management apparatus; Performing a balancing operation through a transistor and a resistor connected in series between the first node of the first channel and the second node of the first channel; And performing a cell sensing operation by sensing the voltage between the first node of the second channel and the second node of the second channel while performing the balancing operation, and the first node of the first channel. The first node of the second channel is commonly connected to the first node connected to the negative voltage terminal of any one battery cell of the battery module, and the second node of the first channel and the second node of the second channel are It is characterized in that it is commonly connected to a second node connected to the positive voltage terminal of any one of the battery cells.

In an embodiment, converting the difference value between the voltage of the first node of the first channel and the voltage of the second node of the first channel in a first analog-to-digital converter into a first digital value; And converting a difference value between the voltage of the first node of the second channel and the voltage of the second node of the second channel into a second digital value in the second analog-to-digital converter.

In an embodiment, the method may further include determining whether a difference between the first digital value and the second digital value is less than a reference value.

In an embodiment, when the difference between the first digital value and the second digital value is less than the reference value, the wire connection state is a normal range state.

In an embodiment, when the difference between the first digital value and the second digital value is greater than or equal to the reference value, the wire connection state is a fault condition.

The battery management apparatus and its operation method according to an embodiment of the present invention can minimize the voltage drop generated during cell balancing by advancing the branching point of the cell sensing circuit and the balancing circuit at the closest position of the actual cell.

In addition, the battery management apparatus and its operation method according to an embodiment of the present invention minimizes the voltage drop, thereby performing cell sensing during cell balancing, and as a result, further balancing time can be secured.

The accompanying drawings are provided to help understand the present embodiment, and provide embodiments with detailed description. However, the technical features of the present embodiment are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form a new embodiment.
1 is a view showing a general battery management device 10.
2 is a view exemplarily showing a battery management apparatus 100 according to an embodiment of the present invention.
3 is a flowchart illustrating an operation method of the battery management apparatus 100 according to an embodiment of the present invention.

Hereinafter, the contents of the present invention will be described clearly and in detail so that those skilled in the art of the present invention can easily implement the drawings using the drawings.

The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms.

The terms may be used for the purpose of distinguishing one component from other components. For example, the first component may be referred to as the second component without departing from the scope of the present invention, and similarly, the second component may also be referred to as the first component. When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

Other expressions describing the relationship between the components, such as “between” and “just between” or “neighboring to” and “directly neighboring to” should be interpreted similarly. Terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "include" or "have" are intended to indicate the presence of a feature, number, step, action, component, part or combination thereof carried out, one or more other features or numbers. It should be understood that it does not preclude the existence or addition possibilities of, steps, actions, components, parts or combinations thereof. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in the commonly used dictionary, should be interpreted as meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. .

1 is a view showing a general battery management device 10. The battery management device 10 may include a cell balancing / sensing device. The battery management device 10 may include an analog-to-digital converter (ADC2), a transistor (T), and a resistor (R). The sensing circuit includes an analog-to-digital converter ADC2, and the balancing circuit includes a transistor T and a resistor R. As shown in FIG. 1, a cell sensing circuit and a balancing circuit are configured in parallel.

The branch points C1 and C0 of the battery module 20 exist inside the controller or sensing integrated circuit (IC). In this case, a resistance component generated on the conducting wire up to the actual cell and the branch point is generated. This resistance component generates cell balancing current * resistance = voltage drop when performing cell balancing. Since voltage drop occurs during cell balancing, inaccurate values may be sensed if sensing is performed during balancing. Therefore, the general battery management apparatus 10 cannot use the sensed voltage value during the balancing to calculate the state of charge (SOC).

In a typical passive type cell balancing device, if cell voltage sensing is performed while cell balancing is in progress, since the dropped voltage is sensed due to the resistance component of the sensing wire, cell balancing and sensing can be performed simultaneously. none. For this reason, the time to perform balancing is limited.

2 is a view exemplarily showing a battery management apparatus 100 according to an embodiment of the present invention. Referring to FIG. 2, the battery management apparatus 100 may include a first analog-to-digital converter ADC1, a second analog-to-digital converter ADC2, a transistor T, and a resistor R.

The balancing circuit includes a transistor T and a resistor R connected in series between the first node B0 of the first channel and the second node B1 of the first channel, and the first node B0 of the first channel B0 of the first channel. It may include a first analog-to-digital converter (ADC1) for converting the difference between the voltage and the voltage of the second node (B1) of the first channel to a digital value.

In an embodiment, the first node B0 of the first channel and the first node C0 of the second channel may be commonly connected to the first node N0 connected to the negative voltage terminal of the battery cell. In an embodiment, the second node B1 of the first channel and the second node C1 of the second channel may be commonly connected to the second node N1 connected to the positive voltage terminal of the battery cell.

The cell sensing circuit may include a second analog-to-digital converter ADC2 that converts a difference value between the voltage of the first node C0 of the second channel and the voltage of the second node C1 of the second channel into a digital value. have.

In an embodiment, the first channel and the second channel may be implemented as a wire between the battery management device 100 and the battery module 200.

The battery management apparatus 100 according to an exemplary embodiment of the present invention may proceed to the branching point of the cell sensing circuit and the balancing circuit at the nearest position (N0 or N1) of the actual cell inside the battery module 200. Accordingly, the battery management apparatus 100 according to the embodiment of the present invention can minimize the voltage drop occurring during cell balancing. When the voltage drop is minimized, cell sensing can be performed while cell balancing is in progress, and the balancing time can be secured more than before.

In order to check the wire connection problem, a general cell balancing / sensing device compares cell voltage values before and during balancing, and it is determined that there is a problem in wire connection due to a voltage drop above a set reference value during balancing.

On the other hand, the battery management apparatus 100 according to an embodiment of the present invention may compare the voltage values sensed by the first and second analog-to-digital converters ADC1 / ADC2, respectively, and determine the wire connection state. If it is a normal wire connection state, the difference between the two conversion values is the same value within a margin of error. On the other hand, if a difference more than the set error occurs, it may be determined that there is a problem with the wire state.

3 is a flowchart illustrating an operation method of the battery management apparatus 100 according to an embodiment of the present invention. 1 to 3, the operation of the battery management apparatus 100 may proceed as follows.

The ignition switch is turned on (IG ON) (S110). The battery management device (BMS, 100) may be turned on (S120). The BMS may perform a sensing operation, perform a balancing operation, or diagnose whether or not a failure occurs in a battery cell of the battery module 200 according to a predetermined method (S130).

The battery management apparatus 100 may check the normal range of the wire by determining whether the difference between the output values of the first and second analog-to-digital converters ADC1 and ADC2 is less than a reference value (S140). If the difference between the output values is a normal range that is less than the reference value, a normal wire connection state may be notified (S150). On the other hand, when the difference between the output values is greater than or equal to the reference value, a fault diagnosis may be notified as a wire connection state (S160).

The operation method of the battery management apparatus according to the embodiment of the present invention is through a transistor T and a resistor R connected in series between the first node B0 of the first channel and the second node B1 of the first channel. The cell sensing operation is performed by sensing a voltage between the first node C0 of the second channel and the second node C1 of the second channel while performing the balancing operation and performing the balancing operation. The first node B0 and the first node C0 of the second channel are commonly connected to the first node N0 connected to the negative voltage terminal of any one battery cell of the battery module, and the first node B0 The second node B1 and the second node C1 of the second channel may be commonly connected to the second node N1 connected to the positive voltage terminal of any one battery cell.

In an embodiment, the first analog-to-digital converter ADC1 may convert a difference value between the voltage of the first node B0 of the first channel and the voltage of the second node of the first channel into a first digital value. . In an embodiment, the second analog-to-digital converter ADC2 converts a difference value between the voltage of the first node C0 of the second channel and the voltage of the second node C1 of the second channel into a second digital value. Can be. Here, when the difference between the first digital value and the second digital value is less than the reference value, the wire connection state is a normal range state. On the other hand, when the difference between the first digital value and the second digital value is greater than or equal to a reference value, the wire connection state is a failure state.

In the battery management apparatus 100 according to an embodiment of the present invention, a fault diagnosis operation is possible during balancing, and a separate sequence is not required for diagnosis. As a result, the battery management apparatus 100 according to an embodiment of the present invention can secure a sufficient balancing time.

The steps and / or operations according to the present invention may occur simultaneously in other embodiments, in different order, or in parallel, or in different embodiments for different epochs, etc., as can be understood by one skilled in the art. Can be.

Depending on the embodiment, some or all of the steps and / or actions drive instructions, programs, interactive data structures, clients and / or servers stored in one or more non-transitory computer-readable media. At least some may be implemented or performed using one or more processors. The one or more non-transitory computer-readable media may illustratively be software, firmware, hardware, and / or any combination thereof. In addition, the functionality of the “module” discussed herein may be implemented in software, firmware, hardware, and / or any combination thereof.

One or more non-transitory computer-readable media and / or means for implementing / performing one or more operations / steps / modules of embodiments of the present invention include application-specific integrated circuits (ASICs), standard integrated circuits, Controllers that perform appropriate instructions, including microcontrollers, and / or embedded controllers, field-programmable gate arrays (FPGAs), complex programmable logic devices (CPLDs), and the like. Does not.

Meanwhile, the above-described contents of the present invention are only specific embodiments for carrying out the invention. The present invention will include technical ideas that are abstract and conceptual ideas that can be utilized as future technologies, as well as specific and practically available means themselves.

10, 100: battery management device
ADC1, ADC2: Analog to digital converter
R: resistance
T: Transistor

Claims (14)

A transistor and a resistor connected in series between the first node of the first channel and the second node of the first channel;
A first analog-to-digital converter for outputting a digital value corresponding to a voltage difference between the voltage of the first node of the first channel and the voltage of the second node of the first channel;
And a second analog-to-digital converter that outputs a digital value corresponding to a voltage difference between the voltage of the first node of the second channel and the voltage of the second node of the second channel. According to claim 1,
The first node of the first channel and the first node of the second channel are commonly connected to a first node connected to a negative voltage terminal of any one battery cell of the battery module,
And a second node of the first channel and a second node of the second channel are commonly connected to a second node connected to a positive voltage terminal of the one battery cell. According to claim 1,
The first analog-to-digital converter is a battery management device, characterized in that used in the balancing operation. According to claim 1,
The second analog-to-digital converter is a battery management device, characterized in that used in the cell sensing operation. According to claim 1,
Battery management device, characterized in that the cell sensing operation is performed simultaneously while performing a balancing operation. According to claim 1,
A battery management device, characterized in that a wire connection diagnosis operation is performed using the output values of the first and second analog-to-digital converters. The method of claim 6,
A battery management device characterized in that the wire connection state is determined to be normal when the difference between the output value of the first analog-to-digital converter and the output value of the second analog-to-digital converter is less than a reference value. The method of claim 6,
And a difference between the output value of the first analog-to-digital converter and the output value of the second analog-to-digital converter is greater than or equal to a reference value. The method of claim 6,
The battery management apparatus, characterized in that the wire connection diagnosis operation is performed while performing a balancing operation. In the operation method of the battery management device:
When the ignition switch is turned on, turning on the battery management device;
Performing a balancing operation through a transistor and a resistor connected in series between the first node of the first channel and the second node of the first channel; And
And performing the cell sensing operation by sensing the voltage between the first node of the second channel and the second node of the second channel while performing the balancing operation,
The first node of the first channel and the first node of the second channel are commonly connected to a first node connected to a negative voltage terminal of any one battery cell of the battery module,
The method of claim 1, wherein the second node of the first channel and the second node of the second channel are commonly connected to a second node connected to a positive voltage terminal of the one battery cell. The method of claim 10,
Converting a difference value between a voltage of a first node of the first channel and a voltage of a second node of the first channel in a first analog-to-digital converter to a first digital value; And
And converting the difference value between the voltage of the first node of the second channel and the voltage of the second node of the second channel into a second digital value in the second analog-to-digital converter. The method of claim 11,
And determining whether the difference between the first digital value and the second digital value is less than a reference value. The method of claim 12,
When the difference between the first digital value and the second digital value is less than the reference value, the wire connection state is a normal range state. The method of claim 12,
When the difference between the first digital value and the second digital value is greater than or equal to the reference value, the wire connection state is a failure state.

Images