KR20150022110A - 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 an apparatus for preventing battery discharge and detecting whether discharging of the low voltage battery according to an error of an electric device load is forecast.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery discharge prevention device,

The present invention relates to an electric vehicle, and more particularly, to an electric vehicle, and more particularly, to an electric vehicle, which prevents discharge of a low-voltage battery that may occur in the case of an unpleasant operation of a vehicle, prevents battery discharge when a discharge of a low- And an abnormality detecting device.

The present invention also relates to a method for preventing discharge of a low-voltage battery and detecting a discharge of a low-voltage battery according to an abnormality of the electric-field load.

Generally, gasoline and diesel vehicles convert the rotational energy from the engine to electric energy through the alternator, and charge the battery in the vehicle.

This system has a low voltage battery natural discharge which occurs when a vehicle is long-term mischievous, and many loads connected to the battery are erroneous or obsolete, so that when the battery voltage is continuously consumed, the battery is discharged and the start-up is difficult .

The driver also has a disadvantage in that it is difficult to determine whether the discharge problem is due to the battery or 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 regulation of the enhanced exhaust gas against the vehicles and to provide fuel economy improvement.

The eco-friendly vehicle supplies the main battery's high voltage to the auxiliary battery (Aux Battery) that stores the low voltage for the electric load by lowering the high voltage of the main battery to the low voltage by using the electric load power supply device, do.

A diagram showing this is shown in Fig. Referring to FIG. 1, a battery system 110 for supplying power, an inverter 120 that receives power from the battery system 110 and converts the battery into a three-phase alternating current to supply the battery to the electric motor 130, And a DC power converter 140 for supplying DC power to the low voltage battery 150.

In the case of an electric vehicle, there is a low voltage DC-DC converter (DCC) that charges a low-voltage battery using a BMS and a high-voltage battery that can go into a sleep mode in case of an unpleasant operation. It is possible to charge the low-voltage battery through the LDC, and it is possible to check the problem caused by the abnormality of the electric field load by using the output current check logic by the LDC.

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

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

It is an object of the present invention to provide a battery discharge prevention device and a method thereof, which are capable of preventing a complete discharge of a low-voltage battery and extending the service life of the battery.

It is another object of the present invention to provide a battery discharge preventing device and a method thereof that can determine whether or not a problem of a different electric field load is discriminated.

It is another object of the present invention to provide a battery discharge preventing device and a method thereof, which can detect an electric field load which becomes a problem in A / S easily by recording an abnormality of electric load.

The present invention provides a battery discharge prevention device capable of preventing a complete discharge of a low voltage battery and extending the life of the battery.

The battery discharge preventing device includes:

High voltage battery;

A power converter for converting the power of the high voltage battery and supplying power to the electric field load;

A switching unit for shutting off or passing the power flowing from the high voltage battery to the power conversion apparatus;

A low voltage battery for receiving and charging the converted power from the power conversion device; And

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

At this time, the power conversion apparatus senses the output power supplied to the electrical load and compares the sensed value with a predetermined electrical load output power supply reference value to determine whether the electrical load is abnormal.

In addition, the periodic wakeup and monitoring may be performed when the start-up is off.

In addition, the battery management unit operates in a sleep mode when the vehicle is in an unpleasant situation, and has a long wake-up period to reduce the discharge effect of the low-voltage battery.

Also, the charging time for the low-voltage battery is within a preset charging reference value, and the electric field load output reference value and the charging reference value are learned and analyzed using an SOC (State Of Charge) value of the high-voltage battery and an IBS (Intelligent Battery Sensor) Value. ≪ / RTI >

The determination of the abnormal discharge of the electric field load may be made by comparing the number of times of charging the low voltage battery with the reference value of the number of times of charging the battery.

On the other hand, another embodiment of the present invention includes 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 reference value of the battery power source to turn off or pass the power flowing from the high-voltage battery to the power conversion unit as the switching unit is turned on or off; A charging step of charging the low-voltage battery with the power converted by the power converter when the power is passed; And turning off the battery management unit when the power is turned off.

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

The switching may further include comparing the SOC of the high voltage battery with a reference SOC value; And turning off the switching unit if the comparison result is less than the reference SOC value.

The method may further include the step of sensing an output power supplied to the electrical load and comparing the sensed value with a predetermined electrical load output power supply reference value to determine whether the electrical load has been abnormally discharged.

According to the present invention, low-voltage battery monitoring can be performed in a non-operating condition of the vehicle, and the BMS can be turned off by turning off or on using a switch as necessary to prevent additional battery consumption.

Another advantage of the present invention is that the cause of failure of the electric field load can be easily identified by storing information on the cause of failure of the electric field load.

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

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed 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 this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a battery discharge prevention device 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 a battery discharge preventing device 200 for preventing low-voltage battery discharge and abnormal detection of electric load according to an embodiment of the present invention. 2, the battery discharge prevention device 200 includes a high voltage battery 210, a power conversion device 240 for converting the power of the high voltage battery 210 and supplying power to the electric field load 280, A switching unit 270 for shutting off or passing the power flowing from the high voltage battery 210 to the power conversion apparatus 240, a low voltage battery 250 for receiving and charging the power converted from the power conversion apparatus 240, And a battery management unit 260 that monitors the low-voltage battery through wake-up and turns on or off the switching unit 270. [

The high-voltage battery 210 is an energy source for supplying electricity of the drive motor in the electric vehicle. Electric vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (EVs), low-speed electric vehicles (NEVs) FCV (Fuel-Cell Vehicle), and Clean Diesel Vehicle (CDV).

The low-voltage battery 250 is an energy source that supplies electricity to the electrical components of the electric load 280, and is usually a 12-volt low-voltage battery.

The battery management unit 260 controls the status monitoring, cell balancing, and / or charging / discharging of the high voltage battery 250. It operates in sleep mode even when the vehicle is in a haphazard mode, and wake-up is possible according to the setting. Therefore, the power supply of the low-voltage battery 250 is always supplied. Monitoring of the low-voltage battery 250 and the on signal of the power converter 240 and / or the on signal of the switching unit 270 via additional wake-up.

The power conversion apparatus 240 down-converts the high-voltage direct current (DC) to the low-voltage DC to supply the low-voltage battery charging and / or the electric load 280.

As the switching unit 270, a high voltage relay is used, but the present invention is not limited thereto, and a power semiconductor device, TRIAC, or the like may be used. The switching unit 270 is turned on or off under the control of the battery management unit 260. The power from the high voltage battery 210 flows to the power inverter 240, and when the power is off, the power from the high voltage battery 210 is cut off.

The electric field load 280 is an electrical load in the vehicle such as a lamp, a heater, an air conditioner, and various ECUs (Electronic Control Unit). This electric field load 280 generates an excessive discharge effect depending on the deterioration and abnormality of the parts.

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

1. Performed when the vehicle is not in operation (various ECUs off).

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

3. The reference value (c, d) is determined by learning when driving. In addition, it is a learned analysis value using an SOC (State Of Charge) value of the high voltage battery and an IBS (Intelligent Battery Sensor).

4. The lower the reference value (e), the higher the battery consumption.

Referring first to FIG. 3, the battery management unit 260 (FIG. 2) enters a wake up mode and monitors the state of the low-voltage battery 250 (steps S310 and S320). The battery management unit 260 operates in a sleep mode at the time of the vehicle's unpleasant operation and lengthens the wake-up period in order to reduce the discharge effect of the low-voltage battery 250, .

The voltage of the monitored low-voltage battery 250 is compared with the charge demand voltage (step S330). In addition, if the voltage of the low voltage battery 250 is lower than the battery power supply reference value (a: a voltage when the low voltage battery is discharged and charged), the battery management unit 260 proceeds to the sleep mode because no charging is required.

Otherwise, the switching unit 270 is turned on and enters the SOC (State Of Charge) check mode of the high voltage battery 210 (steps S331 and S333).

If the SOC of the high voltage battery 210 is compared with the reference SOC value b in the SOC check mode and the reference SOC value b is greater than the reference SOC value b, the power converter 240 is turned on and the charging time is compared with the charging reference value S335, and S337). In addition, a process is performed to verify that the SOC of the high voltage battery is sufficient to charge the low voltage battery.

Alternatively, if the SOC of the high voltage battery is lower than the reference SOC value b in step S333, the battery capacity for charging the low voltage battery is insufficient, so that the switching unit 270 is turned off, the battery discharge failure is stored, (260) is turned off (S340, S350). That is, the battery management unit OFF process 301 proceeds.

In step S337, if the charging time is larger than the charging reference value c, the low-voltage battery 250 is charged (step S339). Of course, in this case, an iterative loop 302 for charging through the iterative execution of steps S337 and S339 proceeds.

On the other hand, in step S337, if the charging time is less than the charging reference value c, the flow chart of FIG. 4 proceeds.

Referring to FIG. 4, the output current of the power converter 240 is compared with the electric field load output reference value d (step S410). This step is a process for checking whether or not the electric field load 280 is abnormal.

In step S410, if the output current is smaller than the electric field load output reference value d, the charging is completed, the power converter 240 is turned off, and the battery management unit 260 enters the sleep mode (step S430). That is, the sleep mode entering process 401 of the battery management unit (BMS) proceeds.

Alternatively, if the output current of the power conversion apparatus 240 is greater than the electric field load output reference value d in step S410, the number of times of charging the low-voltage battery is compared with the reference number of charging times e (step S411). In other words, this process is a process of checking a fault of the electric field load 280 by judging a discharge which is excessively flowing to the electric field load 280.

In step S411, if the battery charging count is smaller than the charging count reference value e, the charging count is updated (step S413).

On the other hand, if it is determined in step S411 that the battery charge count is greater than the charge count reference value e, charging is completed, the power converter 240 is turned off, and an abnormality in the electric field load 280 is stored (step S441). In other words, a process 404 for storing the abnormality of the electric field load storing the abnormality of the electric field load is performed.

The periodic wakeup and monitoring shown in FIGS. 3 and 4 are performed assuming that the start-up is 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 field load

Claims (14)

High voltage battery;
A power converter for converting the power of the high voltage battery and supplying power to the electric field load;
A switching unit for shutting off or passing the power flowing from the high voltage battery to the power conversion apparatus;
A low voltage battery for receiving and charging the converted power from the power conversion device; And
A battery management unit monitoring the low-voltage battery through periodic wake-up to turn on or off the switching unit;
Wherein the battery discharge prevention device comprises:
The method according to claim 1,
Wherein the power conversion device senses an output power supplied to the electric field load and compares the sensed value with a preset electric field load output power reference value to determine whether the electric field load is abnormal or not.
The method according to claim 1,
Wherein the periodic wake-up and monitoring is performed when the start-up is turned off.
The method according to claim 1,
Wherein the battery management unit operates in a sleep mode when the vehicle is in an unfavorable state and has a longer wake-up period to reduce a discharge effect of the low-voltage battery.
3. The method of claim 2,
The charging time of the low-voltage battery is within a predetermined charging reference value, and the electric field load output reference value and the charging reference value are values obtained by performing a learning analysis using an SOC (State Of Charge) value of the high-voltage battery and an IBS (Intelligent Battery Sensor) A device for preventing battery discharge.
3. The method of claim 2,
Wherein the determination as to whether or not the abnormal discharge of the electric field load is performed is made by comparing the number of times of charging the low voltage battery with the reference value of the number of times of charging the battery.
Monitoring the low voltage battery through periodic wakeup;
A switching step of comparing the power of the low-voltage battery with a reference value of the battery power source to turn off or pass the power flowing from the high-voltage battery to the power conversion unit as the switching unit is turned on or off;
A charging step of charging the low-voltage battery with the power converted by the power converter when the power is passed; And
An off step of turning off the battery management unit when the power supply is interrupted;
Wherein the battery discharge prevention method comprises:
8. The method of claim 7,
Wherein the switching unit is turned off and the battery management unit enters a sleep mode when the power of the low-voltage battery is higher than the battery power reference value or the charging is completed.
8. The method of claim 7,
Wherein the switching comprises:
Comparing the SOC of the high voltage battery with a reference SOC value; And
And turning off the switching unit if the comparison result is smaller than the reference SOC value.
8. The method of claim 7,
Further comprising the step of sensing an output power supplied to the electrical load and comparing the sensed value with a preset electrical load output power reference value to determine whether the electrical load is abnormal or not.
8. The method of claim 7,
Wherein the periodic wakeup and monitoring is performed when the start-up is off.
8. The method of claim 7,
Wherein the battery management unit is operated in a sleep mode in the case of a vehicle malfunction and the cycle of wake-up is long in order to reduce the discharge effect of the low voltage battery.
9. The method of claim 8,
The charging time of the low-voltage battery is within a predetermined charging reference value, and the electric field load output reference value and the charging reference value are values obtained by performing a learning analysis using an SOC (State Of Charge) value of the high-voltage battery and an IBS (Intelligent Battery Sensor) Thereby preventing battery discharge.
9. The method of claim 8,
Wherein the determination as to whether or not an abnormal discharge of the electric field load is made is made by comparing the number of times of charging the low voltage battery with the reference value of the number of times of charging the battery.

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