KR102255321B1 - Apparatus for preventing battery discharge and detecting fault of electric field load, and Method thereof - Google Patents

Abstract

The present invention relates to an electric vehicle, and more particularly, to prevent discharge of a low voltage battery that may occur when the vehicle is not operated, and to detect when discharge of a low voltage battery is expected due to an abnormality in the electric load. It relates to an abnormality detection device.

Description

TECHNICAL FIELD [0001] Apparatus for preventing battery discharge and detecting fault of electric field load, and method thereof

The present invention relates to an electric vehicle, and more particularly, to prevent discharge of a low voltage battery that may occur when the vehicle is not operated, and to detect when discharge of a low voltage battery is expected due to an abnormality in the electric load. It relates to an abnormality detection device.

In addition, the present invention relates to a method of preventing discharge of a low voltage battery and detecting a discharge of a low voltage battery due to an abnormality in an electric load.

In general, gasoline and diesel vehicles use an alternator to change rotational energy by an engine into electric energy, and charge and use a battery in the vehicle.

In this system, when the vehicle is not operated for a long period of time, the natural discharge of the low-voltage battery occurs, and when the voltage of the battery is continuously consumed due to the faulty or deterioration of many loads connected to the battery, the battery is discharged and the start-up is not possible. .

In addition, there is a disadvantage in that it is difficult for the driver to determine whether the discharge problem is due to the battery or the electronic load.

On the other hand, eco-friendly vehicles such as hybrid vehicles, electric vehicles, and fuel cell vehicles have been developed and operated in order to satisfy the reinforced exhaust gas regulations for vehicles and to provide improved fuel efficiency.

In eco-friendly vehicles, the high voltage of the main battery is stepped down to a low voltage using the electric load power supply device, and is supplied as a charging voltage to the auxiliary battery, which stores the low voltage for the electric load, and at the same time supplied as power to the electric load. do.

A view showing this is shown in FIG. 1. Referring to FIG. 1, a battery system 110 that supplies power, an inverter 120 that receives power from the battery system 110 and converts it to 3-phase AC to supply the electric motor 130, and a battery system 110. ), and a DC power conversion device 140 for supplying DC power to the low voltage battery 150 and the like.

In the case of electric vehicles, there is a low-voltage DC-DC converter (LDC) that charges low-voltage batteries using BMS and high-voltage batteries that can be operated in sleep mode when not in operation. It has the advantage that it is possible to charge a low voltage battery through the LDC, and a problem due to an abnormal occurrence of the electric load can be checked using the output current check logic with the LDC.

However, in spite of these advantages, there is a problem that natural discharge of the battery occurs, discharge still occurs due to all electric loads, and the battery life is shortened due to such discharge.

1. Korean Patent Registration No. 10-1220389 2. Korean Patent Publication No. 10-2005-0092920 3. Korean Patent Publication No. 10-2005-0048012

The present invention has been proposed in order to solve the above problems related to the background art, and an object thereof is to provide a battery discharge prevention apparatus and a method thereof capable of prolonging the life of the battery by preventing complete discharge of a low voltage battery.

In addition, another object of the present invention is to provide an apparatus for preventing discharge of a battery and a method thereof capable of determining whether other electric loads are problematic.

In addition, another object of the present invention is to provide an apparatus for preventing discharge of a battery and a method for preventing discharge of a battery so that an electric load that is a problem can be easily identified during A/S by recording an abnormality of the electric load.

The present invention provides a battery discharge prevention device capable of prolonging the life of the battery by preventing complete discharge of a low voltage battery in order to achieve the above-described problem.

The battery discharge preventing device,

High voltage battery;

A power conversion device that converts power of the high voltage battery and supplies power to an electric load;

A switching unit that cuts off or passes power flowing from the high voltage battery to the power conversion device;

A low voltage battery that receives and charges the converted power from the power conversion device; And

And a battery management unit configured to turn on or off the switching unit by monitoring a low voltage battery through periodic wake-up.

In this case, the power conversion device may sense output power supplied to the electric load and compare the sensing value with a preset electric load output power reference value to determine whether the electric load is abnormal.

In addition, the periodic wake-up and monitoring may be performed when the engine is turned off.

In addition, the battery manager may operate in a sleep mode when the vehicle is not in operation, and a wake-up period may be long in order to reduce a discharge effect of a low voltage battery.

In addition, the charging time for the low voltage battery is within a preset charging reference value, and the electric load output reference value and the charging reference value are learned and analyzed using the SOC (State Of Charge) value and IBS (Intelligent Battery Sensor) of the high voltage battery. It can be characterized as a value.

In addition, the determination of whether the electric load is abnormal may be performed by comparing the number of times of charging the low-voltage battery with a reference value of the number of times of charging the battery.

On the other hand, another embodiment of the present invention, a monitoring step of monitoring a low voltage battery through periodic wake-up; A switching step of comparing the power of the low voltage battery with a battery power reference value and turning on or off the switching unit to cut off or pass power flowing from the high voltage battery to the power conversion device; A charging step of charging the low voltage battery with power converted by the power conversion device when power is passed; And an off step of turning off the battery management unit when the power is cut off.

In this case, when the power of the low-voltage battery is greater than a battery power reference value or charging is completed, the switching unit is turned off and the battery management unit enters a sleep mode.

In addition, the switching step may include comparing the SOC of the high voltage battery with a reference SOC value; And turning off the switching unit when the comparison result is smaller than the reference SOC value.

In addition, it may further include the step of determining whether the electric load is abnormal by sensing the output power supplied to the electric load and comparing the sensing value with a preset electric load output power reference value.

According to the present invention, it is possible to prevent additional battery consumption by turning off the BMS by performing low-voltage battery monitoring when the vehicle is not in operation and turning off or on using a switch as necessary.

In addition, as another effect of the present invention, it is possible to easily identify the cause of failure of the electric load by storing information on the cause of failure of the electric load.

1 is a conceptual diagram of supplying power to an electric load in a general electric vehicle.
2 is a conceptual diagram of an apparatus 200 for preventing discharge of a battery for preventing discharge of a low voltage battery and detecting an abnormality in an electric load according to an embodiment of the present invention.
3 and 4 are flowcharts illustrating a process of preventing discharge of a low voltage battery and detecting an abnormality in an electric load according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals are used for similar elements.

Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term “and/or” includes a combination of a plurality of related stated items or any of a plurality of related stated items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Shouldn't.

Hereinafter, an apparatus for preventing discharge of a battery and a method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a conceptual diagram of an apparatus 200 for preventing discharge of a battery for preventing discharge of a low voltage battery and detecting an abnormality in an electric load according to an embodiment of the present invention. Referring to FIG. 2, the battery discharge prevention device 200 includes a high voltage battery 210, a power conversion device 240 for converting power of the high voltage battery 210 and supplying power to the electric load 280, A switching unit 270 that cuts off or passes power flowing from the high voltage battery 210 to the power conversion device 240, a low voltage battery 250 that receives and charges the converted power from the power conversion device 240, a cycle It is configured to include a battery management unit 260 for turning on or off the switching unit 270 by monitoring the low voltage battery through a normal wake-up.

The high voltage battery 210 is an energy source that supplies electricity to a driving motor in an electric vehicle. Electric vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (EVs), neighborhood electric vehicles (NEVs), and fuel cell vehicles. FCV: Fuel-Cell Vehicle) and CDV: Clean Diesel Vehicle.

The low voltage battery 250 is an energy source for supplying electricity to the electric equipment of the electric load 280 and is usually a 12V low voltage battery.

The battery management unit 260 controls the state monitoring, cell balancing, and/or charging/discharging of the high voltage battery 250. Even when the vehicle is not in operation, it operates in a sleep mode, and wake-up is possible according to the setting. Therefore, power to the low voltage battery 250 is always supplied. An on signal of the monitoring and power conversion device 240 of the low voltage battery 250 and/or an on signal of the switching unit 270 is generated through additional wake-up.

The power conversion device 240 steps down a high voltage direct current (DC) to a low voltage DC to charge a low voltage battery and/or supply power to the electric load 280.

A high voltage relay is used as the switching unit 270, but is not limited thereto, and a power semiconductor device, a TRIAC, or the like may be used. The switching unit 270 is turned on or off according to the control of the battery management unit 260. When turned on, power flows from the high voltage battery 210 toward the power conversion device 240, and when turned off, power from the high voltage battery 210 is cut off.

The electric load 280 becomes an electric load in a vehicle such as a lamp, a heater, an air conditioner, and various electronic control units (ECUs). This electric load 280 generates an excessive discharge effect according to the aging and abnormality of the parts.

3 and 4 are flowcharts illustrating a process of preventing discharge of a low voltage battery and detecting an abnormality in an electric load according to an embodiment of the present invention. Prior to describing FIGS. 3 and 4, setting of conditions and reference values of an algorithm is as follows.

1. Executed when the vehicle is not operated (various ECUs are off).

2. The reference values (a,b) are determined according to the battery type and/or vehicle conditions.

3. The reference values (c,d) are determined by learning when driving the vehicle. In other words, it is a learning analysis value using a state of charge (SOC) value and an intelligent battery sensor (IBS) of the high voltage battery.

4. The smaller the reference value (e), the lower the high voltage battery consumption.

First, referring to FIG. 3, the battery manager (260 of FIG. 2) enters a wake-up mode and monitors the state of the low-voltage battery 250 (steps S310 and S320). In other words, the battery management unit 260 operates in a sleep mode when the vehicle is not in operation, and the discharge effect of the low voltage battery 250 by extending the wake-up period to reduce the discharge effect of the low voltage battery 250 Is reduced.

The monitored voltage of the low-voltage battery 250 is compared with the required charging voltage (step S330). In other words, if the voltage of the low-voltage battery 250 is less than the battery power reference value (a: voltage when the low-voltage battery is discharged and charging is required), charging is not required, and the battery manager 260 proceeds to the sleep mode.

In contrast, if the battery power is greater than the reference value, since charging is required, the switching unit 270 is turned on, and the high voltage battery 210 enters a state of charge (SOC) check mode (steps S331 and S333).

In the SOC check mode, the SOC of the high voltage battery 210 is compared with the reference SOC value (b), and if it is greater than the reference SOC value (b), the power conversion device 240 is turned on and the charging time is compared with the charging reference value (step S335, S337). In other words, a process of checking whether the SOC of the high voltage battery is sufficient to charge the low voltage battery is performed.

On the contrary, if the SOC of the high voltage battery is less than the reference SOC value (b) in step S333, this is because the amount of battery for charging the low voltage battery is insufficient, so that the switching unit 270 is turned off and the battery discharge fault is stored, and the battery management unit 260 is off (S340, S350). That is, the battery management unit off process 301 proceeds.

In step S337, when the charging time is greater than the charging reference value c, the low voltage battery 250 is charged (step S339). Of course, in this case, the repetition loop 302 for charging through the repetition of steps S337 and S339 proceeds.

Alternatively, in step S337, if the charging time is less than the charging reference value c, the flowchart of FIG. 4 proceeds.

4, the output current of the power conversion device 240 is compared with the electric load output reference value d (step S410). This step refers to a process of checking whether the electric load 280 is abnormal.

In step S410, if the output current is less than the electric load output reference value d, charging is completed, the power conversion device 240 is turned off, and the battery manager 260 enters the sleep mode (step S430). That is, the sleep mode entry process 401 of the battery management system (BMS) proceeds.

In contrast, in step S410, if the output current of the power conversion device 240 is greater than the electric load output reference value d, the number of times of charging the low voltage battery and the number of times of charging reference value e are compared (step S411). In other words, this process is a process of determining a failure of the electric load 280 by determining a discharge that excessively flows into the electric load 280.

In step S411, if the number of times of charging the battery is less than the reference value e of the number of charging, the number of times of charging is updated (step S413).

On the contrary, in step S411, if the number of times of charging the battery is greater than the reference value e of the number of charging, charging is completed, the power conversion device 240 is turned off, and the abnormality of the electric load 280 is stored (step S441). That is, the process 404 of storing whether the electric load is abnormal is performed.

Periodic wake-up and monitoring shown in FIGS. 3 and 4 are performed assuming that the engine is turned off.

200: battery discharge prevention device
210: high voltage battery 240: power conversion device
250: low voltage battery 260: battery management unit
270: switching unit 280: electric load

Claims (14)

High voltage battery;
A power conversion device that converts power of the high voltage battery and supplies power to an electric load;
A switching unit that cuts off or passes power flowing from the high voltage battery to the power conversion device;
A low voltage battery that receives and charges the converted power from the power conversion device; And
Includes; a battery management unit that monitors the low voltage battery through periodic wake-up to turn on or off the switching unit, and
The periodic wake-up and monitoring are performed when the engine is turned off,
The battery management unit operates in a sleep mode when the vehicle is not in operation, and has a long wake-up cycle to reduce the discharge effect of the low-voltage battery,
When the battery management unit enters the wake-up mode and monitors the low voltage battery power, if the power of the low voltage battery is less than a preset battery power reference value, the battery management unit does not require charging to proceed to the sleep mode. Battery discharge prevention device, characterized in that.
The method of claim 1,
Wherein the power conversion device determines whether the electric load is abnormal by comparing a sensed value of the output power supplied to the electric load with a preset electric load output power reference value.
delete delete The method of claim 2,
The charging time for the low voltage battery is within a preset charging reference value, and the electric load output reference value and the charging reference value are values that are learned and analyzed using the SOC (State Of Charge) value and IBS (Intelligent Battery Sensor) of the high voltage battery. Battery discharge prevention device, characterized in that.
The method of claim 2,
The battery discharge preventing device, characterized in that the determination of whether the electric load is abnormal is made by comparing the number of times of charging the low-voltage battery with a reference value of the number of times of charging the battery.
A monitoring step of monitoring the low voltage battery through periodic wake-up;
A switching step of comparing the power of the low voltage battery with a battery power reference value and turning on or off the switching unit so that power flowing from the high voltage battery to the power conversion device is cut off or passed;
A charging step of charging the low voltage battery with power converted by the power conversion device when power is passed; And
When the power is cut off, an off step of turning off the battery management unit; and the periodic wake-up and monitoring are performed when the ignition is turned off,
The battery management unit operates in a sleep mode when the vehicle is not in operation, and has a long wake-up cycle to reduce the discharge effect of the low-voltage battery,
When the battery management unit enters the wake-up mode and monitors the low voltage battery power, if the power of the low voltage battery is less than a preset battery power reference value, the battery management unit does not require charging to proceed to the sleep mode. Battery discharge prevention method characterized in that.
The method of claim 7,
When the power of the low voltage battery is greater than the battery power reference value or when charging is completed, the switching unit is turned off and the battery management unit enters a sleep mode.
The method of claim 7,
The switching step,
Comparing the SOC of the high voltage battery with a reference SOC value; And
As a result of the comparison, turning off the switching unit if it is smaller than the reference SOC value.
The method of claim 7,
And determining whether the electric load is abnormal by sensing the output power supplied to the electric load and comparing the sensing value with a preset electric load output power reference value.
delete delete The method of claim 10,
The charging time for the low voltage battery is within a preset charging reference value, and the electric load output reference value and the charging reference value are values that are learned and analyzed using the SOC (State Of Charge) value and IBS (Intelligent Battery Sensor) of the high voltage battery. Battery discharge prevention method characterized in that.
The method of claim 10,
The method of preventing discharge of a battery, characterized in that the determination of whether the electric load is abnormal is made by comparing the number of times of charging the low voltage battery with a reference value of the number of times of charging the battery.

Images