KR20150120037A - Structure for Sensing Current of Battery of Vehicle Using a Shunt Resistence Type Current Sensor - Google Patents

Abstract

The present invention relates to a structure for sensing a current of a battery of a vehicle using a shunt resistor-type current sensor. More specifically, a high current blocking system for blocking a high current generated when a battery of a vehicle is abnormal comprises a shunt resistor-type current sensor disposed on a positive (+) terminal of the battery. When the shunt resistor-type current sensor measures a current, a voltage changing circuit to change a voltage to prevent an error caused by a voltage difference between both ends of a shunt resistor and a current value amplifying circuit to measure a current are applied to accurately measure the voltage and the current to construct the high current blocking system.

Description

[0001] The present invention relates to a current sensing structure for a vehicle battery using a shunt resistor type current sensor,

The present invention relates to a current sensing structure for a vehicle battery using a shunt resistor type current sensor, and more particularly, to a current sensing structure for a vehicle battery using a shunt resistor type current sensor. More particularly, the present invention relates to a current sensing structure for preventing over- A voltage changing circuit for changing a voltage to prevent an error caused by a voltage difference between both ends of the shunt resistor when measuring a current of the shunt resistor type current sensor, The present invention relates to a technique for constructing a large current blocking system by accurately measuring a current and a voltage by applying a value amplifying circuit.

2. Description of the Related Art Generally, known vehicles are provided with various electric devices used in a driving system of a vehicle or for convenience of a user, and electric devices provided in the vehicle are powered by a battery .

Generally, a battery installed in a vehicle is installed in an engine room of an automobile. Power is output from (+) and (-) terminals provided in the battery, and various electronic devices installed in a vehicle interior Also, since the power source is supplied, the role of the battery plays an important role in known vehicles.

Therefore, if the battery is discharged, a problem that the vehicle can not be started may occur, and in order to prevent the battery from being discharged, continuous management is required to prevent the battery from discharging. The power management of the battery automatically determines the battery state of charge (state of charge) charged in the battery, and when the charged power below the predetermined level falls, the power of the power source is cut off, And a power supply cut-off means that can be operated.

On the other hand, the vehicle battery deteriorates in resistance and capacity depending on the use environment or the use period, and the available capacity decreases or the resistance increases. As a result, the state of health (SOH) do.

Therefore, when the SOH degradation of the battery occurs, the remaining capacity of the battery may be different from the initial production state. To manage the SOH, the remaining capacity of the battery is measured through accurate estimation of the SOH of the battery, So as to increase the efficiency.

Also, the vehicle battery is configured to detect the state of function (SOF) of the battery and adjust the output of the battery in accordance with the detected function state of the battery.

The SOH and SOF are based on an accurate measurement of the current output from the battery, and a current sensor is provided in the battery.

On the other hand, Hall type current sensors and shunt resistor type current sensors are commonly used as current sensors for current measurement of automobile batteries.

FIG. 1 is a block diagram showing the principle of measurement of a known shunt resistor type current sensor, and FIG. 2 shows a principle of measurement of a known Hall type current sensor.

The shunt resistor type current sensor amplifies the voltage output signal of the resistor, performs A / D conversion and signal processing, and converts the voltage output signal into a current in the microcontroller unit (MCU). The current measurement method is based on the Ohm's law (V = IR), and the accurate current value can be measured by using the law that the voltage changes in proportion to the current. The shunt resistor type current sensor has a high response speed and it is capable of precise measurement of various current ranges with one sensor, but it has a disadvantage that a microcomputer (MCU) is required and the price is high.

A known shunt resistor type current sensor applied to a battery of a vehicle is generally configured to be mounted on the negative (-) terminal of the battery. If the shunt type current sensor is mounted on the battery (+) terminal, It is not applicable because of the disadvantage that the voltage range is different and the error becomes too large.

The Hall type current sensor is a sensor using a Hall element having a current magnetic effect in which the output changes when a magnetic field is applied perpendicularly to the direction of current, and is used to check the rotation direction, rotation angle and rotation number of the shaft.

The Hall-type current sensor is basically provided with a Hall element and an amplifier, which are semiconductors in which a signal is generated when a conductor approaches the circuit board inside the sensor, and an A / D converter and a voltage regulator.

The Hall type current sensor is widely used for measuring the current of a battery due to its excellent linearity, small size, and low cost. However, it is impossible to measure currents of various ranges with one sensor, , A constant power source) is required and the accuracy is low. In addition, the Hall-type current sensor has a problem that it can not be applied to a vehicle to which the ISG specification is applied because the current measurement range is limited and the SOH and SOF functions can not be implemented. In other words, in the case of the Hall type current sensor, the maximum measurable current is 130 A, so it is impossible to measure the starting current ranging from 600 A to 700 A at the start of the vehicle, so that the SOF and SOH functions can not be performed, There is a disadvantage that it is not possible to prevent a fire caused by an overcurrent for a long time at startup.

Therefore, it is required to develop a technology that can be applied to a positive terminal of a vehicle battery and can measure an accurate current, and has an accurate current and voltage measurement capability equivalent to that of the shunt resistor type current sensor.

The present invention has been made to solve the above problems,

A high-current cut-off system for cutting off an overcurrent generated when a vehicle battery abnormality occurs in a vehicular battery includes a shunt resistor type current sensor disposed at a positive (+) terminal of the battery, and the voltage difference between both ends of the shunt resistor type current sensor And a current value amplifying circuit for measuring the current are applied to prevent the error caused by the voltage difference between the current and the voltage of the shunt resistor type current sensor, do.

According to an aspect of the present invention,

A shunt resistor placed between the battery post plus (+) stage of the vehicle battery and the load; A voltage gradient lowering the voltage across both ends of the shunt resistor; A current measuring unit for calculating a voltage difference measured at both ends of the shunt resistor through a voltage signal dropped below the voltage rake and calculating a current through the calculated voltage difference; And an MCU unit for calculating an algorithm for estimating a battery state by receiving the current measured by the current measuring unit.

The MCU unit may further include an amplifier unit connected to the current measuring unit and amplifying and outputting a voltage signal input from the lower portion of the voltage ramp, gain is changed.

The MCU unit may be configured to match and preset at least two predetermined current ranges and a gain range to be changed by the amplifier unit and to set the gains of the amplifiers so as to correspond to gain ranges corresponding to the current values received from the current measurement unit and the gain is changed.

In addition, the algorithm for predicting the battery condition of the MCU unit may control the output of the battery to be cut off if the current measured by the current measuring unit exceeds a predetermined first current value.

The MCU unit is connected to the vehicle body control unit to receive a collision signal, and the algorithm for predicting the battery condition of the MCU unit includes: determining a current value measured by the current measuring unit at a predetermined second current The control unit controls the output of the battery to be cut off.

The algorithm for predicting the battery condition of the MCU unit may include counting a reception time of the current value measured by the current measuring unit and comparing the measured current value with a preset arbitrary third current value, And controls the output of the battery to be cut off when the predetermined limit time is exceeded.

The present invention having the above-described configuration provides the following advantages.

1. In the battery (+) stage, only the Hall sensor type current sensor was applicable, but according to the present invention, the shunt type current sensor can be applied to the battery (+) stage, thereby improving the current measurement range.

: Hall sensor Maximum current measurement range 250A Shunt type Maximum current measurement range 1,200A

The Hall type battery sensor can measure up to battery charge rate (SOC) because of low accuracy of current and voltage measurement, but it can be applied to shunt type so that SOF and SOH functions can be measured in addition to SOC. Can be enlarged.

2. The current measurement range can be extended up to 1,200A, which can realize various kinds of large current shutdown logic.

- Blocking logic 1: Blocking when current over 300A after receiving collision signal (blocking logic in case of collision)

- Blocking logic 2: Blocking when current exceeding 1,000A (Blocking logic when there is no collision but abnormal current is generated)

- Blocking logic 3: 500A or more current is blocked for 30 seconds (block logic in cold start)

1 is a block diagram showing a principle of measurement of a known shunt resistor type current sensor.
Fig. 2 shows the principle of measurement of a known Hall-type current sensor.
3 shows a preferred embodiment of a current sensing structure of a vehicle battery using a shunt resistor type current sensor of the present invention.
FIG. 4 is a block diagram showing a circuit of an embodiment in which the block diagram of FIG. 3 is specifically embodied.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

3 shows a preferred embodiment of a current sensing structure of a vehicle battery using a shunt resistor type current sensor of the present invention.

As shown in the figure, the present invention includes a current sensor for measuring a current and a voltage of a battery 100 provided in a vehicle, and the current sensor is formed of a shunt resistor type current sensor.

The shunt resistor type current sensor of the present invention is disposed at the positive (+) terminal of the battery 100 of the battery 100 at the post. The present invention aims at constructing a high current power shutdown system by measuring the current and voltage of the battery 100 and enabling SOH and SOF functions. For the SOH and SOF functions, an overcurrent The shunt resistor type current sensor is disposed at the positive (+) terminal of the battery 100 in place of the conventional Hall type current sensor.

More specifically, the current sensor of the shunt resistor type needs to measure the voltage and current at the positive (+) terminal of the battery 100, and the current measurement range is larger than that of the conventionally used Hall type current sensor Should have. Therefore, the present invention is configured to achieve the above-described object by connecting the shunt resistor 10 to the positive (+) terminal of the battery 100.

However, when the current sensor of the shunt resistor type is mounted on the positive (+) terminal of the battery 100 as it is, the current sensor of the shunt resistor type included in the current mass production vehicle is directly connected to the post + There is a problem that an error occurs in measurement of the current and the voltage due to the high voltage difference between the both ends of the shunt resistor 10 connected thereto.

Therefore, in order to measure the current and the voltage by mounting the current sensor of the shunt resistor type on the positive (+) terminal of the battery 100, the present invention includes a circuit including the following components, Even if a shunt resistor type current sensor is applied to the positive (+) stage, accurate current and voltage can be measured.

1) stabilizing means for stabilizing the measurement signal of the voltage difference across the shunt resistor 10 when measuring the current flowing through the positive (+) terminal of the battery 100;

2) current conversion means for measuring the voltage difference of the shunt resistor 10 and converting it into a current

3) calculating means for calculating an algorithm for predicting the state of the battery 100 using the measured current and voltage;

In the present invention, a current sensor of a shunt resistor type is applied to the positive (+) terminal of the battery 100 post through the above-described components to enable accurate current measurement.

The above-described structure of the present invention will be described more specifically with reference to the drawings with reference to Figs. 3 and 4. Fig.

FIG. 4 is a block diagram showing a circuit of an embodiment in which the block diagram of FIG. 3 is specifically embodied.

The current sensing structure of the vehicle battery using the shunt resistor type current sensor according to the present invention includes a shunt resistor connected between the positive (+) terminal of the battery 100 of the vehicle battery 100 and the load 200 The voltage difference measured at both ends of the shunt resistor 10 is calculated through a voltage signal lowering the voltage applied to both ends of the shunt resistor 10 and a voltage signal lowered from the voltage lower portion 20 An amplifier unit 40 connected to the current measuring unit 30 and amplifying a voltage signal inputted from the voltage lower portion 20 and outputting the amplified voltage signal, And an MCU unit 50 for receiving an electric current measured by the current measuring unit 30 and calculating an algorithm for predicting the state of the battery 100.

As described above, a known shunt resistor 10 type current sensor can be used because the potential difference is low and the voltage level is low at the post (-) terminal of the battery 100 where the shunt resistor 10 is disposed, Unlike the post (-) stage of the battery 100, the voltage level at the post (+) terminal of the battery 100 is high (typically 14V). Therefore, if a known shunt resistor type current sensor is applied as it is, measurement by high voltage difference may not be possible.

The present invention solves this problem by lowering the high voltage across the shunt resistor 10, which is connected to the positive (+) terminal of the battery 100, through the voltage lower portion 20, And the known shunt resistor type current sensor manufactured is also applicable to the positive (+) stage of the battery 100.

The voltage lower portion 20 as described above can be implemented through a chopping circuit (chop) provided in, for example, a known IC, AS8525, as shown in Fig.

On the other hand, the current whose voltage has dropped through the voltage lower portion 20 is measured through the current measuring portion 30. The current measuring unit 30 measures the voltage difference across the shunt resistor 10 and measures the current flowing through the shunt resistor 10. At this time, The current is calculated using the Ohm's law through the voltage difference across the opposite ends. The current measurement principle of the current measuring unit 30 is a known matter, and a further explanation will be omitted. As shown in FIG. 4, the current measuring unit 30 may be realized by a 16-bit ADC provided in a known ASIC, for example, AS8510.

The current measured by the current measuring unit 30 is transmitted to the MCU unit 50 as described above. The MCU unit 50 receives the current measured by the current measuring unit 30 and calculates an algorithm for predicting the state of the battery 100,

For example, if the current measured by the current measuring unit 30 exceeds a predetermined first current value, for example, the MCU unit 50 indicates a current value of 1000 A or more, 100 can be expected to generate an abnormal current, and in this case, the output of the battery 100 can be controlled to be shut off.

The MCU unit 50 is connected to the vehicle body control unit and receives the collision signal from the vehicle body control unit. When the collision signal is received from the vehicle body control unit, the current value measured by the current measurement unit 30 is preset If the current value exceeds a certain second current value, for example, a current value of 300 A or more, the battery 100 can be predicted to generate an abnormal current in a vehicle collision state. In this case, It is possible to control the output of the battery 100 to be cut off.

The MCU unit 50 counts a time at which the current value is received when the current value measured by the current measuring unit 30 is received. If the current value measured by the current measuring unit 30 is a dictionary If the reception time of the current value counted by the MCU unit 50 exceeds a predetermined limit time, for example, 30 seconds, for example, , It can be predicted that the state of the battery 100 is in the cold start state, and in this case, the output of the battery 100 can be controlled to be shut off.

The control of the battery 100 of the MCU unit 50 is not limited to the control method described above and the same control method as that used in the control module of any known large current shutdown system may be applied.

The MCU unit 50 also performs control to change the gain of the amplifier so as to correspond to the current value received from the current measuring unit 30. [ Preferably, the MCU unit 50 matches and pre-sets at least two preset current measurement ranges and a gain range to be changed by the amplifier unit 40, The gain of the amplifier is changed so as to correspond to the gain range corresponding to the current value.

For example, the current measuring range measured at the post + (+) terminal of the known battery 100 is usually measured within the range of 1 A to 1800 A. However, since the current measuring range is a wide range, The MCU unit 50 of the present invention divides the current measurement range into a plurality of sections, matches the current values to the respective divided current measurement ranges, and sets the gain range .

Thereafter, the MCU unit 50 controls the amplifier unit 40 to be described later in accordance with the gain range corresponding to the current value received from the current measuring unit 30.

The amplifier unit 40 is connected to the current measuring unit 30 and is configured to amplify a voltage signal input from the voltage lower portion 20 and apply the amplified voltage signal to the current measuring unit 30. The amplifier unit 40 changes the amplified value of the current according to the gain value. At this time, the gain unit is controlled by the MCU unit 50, and since the process is described above, do.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed embodiments, And the like. It will be apparent to 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.

10: Shunt resistance
20: Voltage lower part
30: current measuring unit
40:
50: MCU unit
100: Battery
200: Load

Claims (6)

A shunt resistor placed between the battery post plus (+) stage of the vehicle battery and the load;
A voltage gradient lowering the voltage across both ends of the shunt resistor;
A current measuring unit for calculating a voltage difference measured at both ends of the shunt resistor through a voltage signal dropped below the voltage rake and calculating a current through the calculated voltage difference; And
An MCU unit for receiving an electric current measured by the current measuring unit and calculating an algorithm for predicting a battery state;
And a current sensing structure for a vehicle battery using the shunt resistor type current sensor.
The method according to claim 1,
Connected to the current measuring unit,
Further comprising an amplifier unit for amplifying and outputting a voltage signal input from the lower portion of the voltage,
Wherein the MCU unit changes a gain of the amplifier to correspond to a current value received from the current measuring unit.
3. The method of claim 2,
The MCU unit
Matching and presetting at least two preset current ranges and a gain range to be changed in the amplifier section,
Wherein a gain of the amplifier is changed so as to correspond to a gain range corresponding to a current value received from the current measuring unit.
The method according to claim 1,
An algorithm for predicting the battery condition of the MCU unit includes:
And controls the output of the battery to be cut off when the current measured by the current measuring unit exceeds a preset arbitrary first current value.
The method according to claim 1,
Wherein the MCU unit is connected to the vehicle body control unit to receive the collision signal,
An algorithm for predicting the battery condition of the MCU unit includes:
And controls the output of the battery to be cut off when the current value measured by the current measuring unit exceeds a preset arbitrary second current value when the collision signal is received. The current sensing of the vehicle battery using the shunt resistor type current sensor rescue
The method according to claim 1,
An algorithm for predicting the battery condition of the MCU unit includes:
Counts the reception time of the current value measured by the current measuring unit,
And controls the output of the battery to be cut off when the measured current value exceeds a preset arbitrary third current value and the counted time exceeds a predetermined limit time. Current sensing structure.

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