KR20180066606A - Apparatus and method for diagnosing deterioration of battery in eco-vehicle - Google Patents

Abstract

The present invention relates to an apparatus for diagnosing deterioration of a battery of an eco-friendly vehicle and a method thereof. The apparatus of the present invention comprises: a battery including a plurality of battery cells; a charger for charging the battery using power applied from the outside; and a battery controller for entering a deterioration degree calculation mode when a charge start signal is received from the charger, collecting an initial charge voltage of each of the battery cells, measuring a charge consumption time consumed to reach a specific voltage within a deterioration degree calculation voltage section from the initial charge voltage, calculating a slope of the charge consumption time within the deterioration degree calculation voltage section, comparing the calculated slope of the charge consumption time with a charge consumption time of a new battery cell, and estimating the degree of deterioration of the battery.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and a method for diagnosing a battery deterioration of an environment-

The present invention relates to an apparatus and method for diagnosing a battery deterioration of an environmentally friendly vehicle that detects the deterioration degree of a battery in an environmentally friendly vehicle by utilizing the charging time required for each degree of deterioration.

Eco-friendly vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) are equipped with high-voltage batteries.

The deterioration characteristics are apparent in the state of charge (SOC) of the high-voltage battery for environment-friendly vehicles, and the degradation degree is calculated at the level of SOC 30% (cell voltage less than about 3.6 V, AEEV standard). The total deterioration calculation range is about 30% to 90% of the SOC, but the frequency of SOC over 90% is small and the charge time per charge power (6.6 kW standard: about 3 Time, ICCB 110V standard: about 20 hours), the deterioration degree calculation frequency is decreased, and if the calculation is not performed for a long time, the reliability of the stored deterioration value becomes poor.

The calculated degree of deterioration is utilized in Distance To Empty (DTE) and available energy calculations, and if the reliability of the degradation degree is lowered, there is a possibility that the battery is overdischarged / overcharged during the vehicle running, which may cause dissatisfaction of the customer.

Conventionally, a high voltage battery for EV and PHEV is charged at 90% or more, and battery deterioration is detected using the battery voltage characteristic at that time. Such conventional technology utilizes a characteristic that a charging amount within a certain voltage decreases linearly as the deterioration progresses, and detects the deterioration degree of the battery during a slow charging, which is a low current charging mode in which the resistance is less influenced. However, the conventional technique has a drawback in that it takes a long time to detect the deterioration degree of the battery.

KR 101526641 B1 (2015.06.01)

An object of the present invention is to provide an apparatus and method for diagnosing battery deterioration of an environmentally friendly vehicle that detects the deterioration degree of a battery in an environmentally friendly vehicle by utilizing the charging time required for each degree of deterioration.

According to an aspect of the present invention, there is provided an apparatus for diagnosing a battery deterioration of an environmentally friendly vehicle, comprising: a battery configured by a plurality of battery cells; a charger for charging the battery using an external power source; And a charging start time determining unit for calculating a charging time required to reach a specific voltage in the deterioration calculating voltage range at the initial charging voltage, And a battery controller for calculating a slope of the required charging time in the deterioration calculation voltage section and estimating a deterioration degree of the battery by comparing the calculated charging time elapsed time with a required charging time of the new battery cell, .

The battery deterioration diagnosis apparatus includes a voltage detector for measuring a charging voltage of the battery, a current detector for measuring a charging current of the battery, and a temperature detector for measuring a temperature of the battery.

Wherein the battery controller measures a charging voltage, a charging current and a temperature of the battery through the voltage detector, the current detector and the temperature detector upon receiving the charging start signal, Is satisfied with the deterioration degree calculation condition.

The battery controller is characterized in that after collecting the initial charging voltage of each battery cell, the battery controller checks whether the charging current of the battery changes, whether charging is stopped, and whether charging is completed, .

Wherein the calculated slope of the required charging time is a ratio of a variation amount of charging time to a variation amount of the charging voltage of each battery cell.

The battery controller calculates a ratio of a slope of a required time for charging the new battery cell to a slope of the calculated required charging time and calculates a deterioration degree of the battery using the calculated ratio.

Meanwhile, the method for diagnosing degradation of an environmentally friendly vehicle according to an embodiment of the present invention includes: collecting an initial charge voltage of each battery cell when a charge start signal is received; Calculating a slope of the charging time required for the deterioration calculation voltage section by using the measured charging time; and calculating the calculated charging time period And estimating the degree of deterioration of the battery by comparing the slope of the battery with the time required to charge the new battery cell.

Wherein the step of collecting the initial charging voltage of each battery cell comprises the steps of: confirming whether the charging state of the battery satisfies the deterioration degree calculation condition upon receipt of the charging start signal; determining whether the charging state of the battery satisfies the deterioration degree calculation condition The method comprising the steps of: entering the deterioration degree calculation mode; and collecting the charging voltage of each battery cell when entering the deterioration degree calculation mode.

Determining whether the state of charge of the battery satisfies the continuity condition of the deterioration degree calculation after the initial charge voltage of each battery cell is collected, And measuring the charging time at a predetermined voltage interval within the deterioration calculation voltage range if the condition is satisfied.

Calculating the slope of the required charging time within the deterioration calculation voltage section calculates a ratio of a variation amount of the measured charging time to the variation amount of the charging voltage of each battery cell.

Wherein the step of estimating the degree of deterioration of the battery includes the steps of calculating a ratio of the time required for charging the new battery cell to the slope of the required charging time and calculating the degree of deterioration of the battery using the calculated ratio And a control unit.

Since the deterioration degree of the battery in the environmentally friendly vehicle is detected by utilizing the correlation between the deterioration and the required charging time, the deterioration estimation reliability can be improved by increasing the number of times of entering the deterioration calculation.

1 is a block diagram showing an apparatus for diagnosing a battery deterioration of an environmentally friendly vehicle according to an embodiment of the present invention;
FIG. 2 is a graph showing test data for measuring charging time for a charging voltage according to the degree of deterioration according to the present invention. FIG.
Fig. 3 is a graph showing the time required to charge the charging voltage for the experimental data of Fig. 2; Fig.
4 is a diagram illustrating a method of calculating a deterioration degree using a charge time slope related to the present invention.
5 is a graph comparing actual deterioration degree estimation results and actual test data according to the present invention.
6 is a flowchart illustrating a method for diagnosing a battery deterioration of an environmentally friendly vehicle according to an embodiment of the present invention.

The terms "comprises", "comprising", "having", and the like are used herein to mean that a component can be implanted unless otherwise specifically stated, Quot; element ".

Also, the terms " part, "" module, " and" module ", as used herein, refer to a unit that processes at least one function or operation and may be implemented as hardware or software or a combination of hardware and software . It is also to be understood that the articles "a", "an", "an" and "the" Can be used.

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

The present invention relates to a technology for diagnosing a state of health (SOH) of a battery by using a correlation between deterioration in which the resistance in the battery cell increases as the deterioration progresses, Is used to detect the degree of deterioration of the battery. Therefore, the present invention can improve the reliability of estimation of deterioration degree by increasing the frequency of detecting deterioration degree.

FIG. 1 is a block diagram showing an apparatus for diagnosing a battery deterioration of an environmentally friendly vehicle according to an embodiment of the present invention. FIG. 2 is test data for measuring a charging time for a charging voltage according to the present invention, FIG. 3 is a graph showing the time required to charge the charging voltage with respect to the experimental data of FIG. 2, FIG. 4 is a diagram illustrating a method of calculating the deterioration degree using the charging time slope according to the present invention, And comparing the actual deterioration degree estimation result with the actual test data.

1, the battery deterioration diagnosis apparatus includes a charger 110, a battery 120, a voltage detector 130, a current detector 140, a temperature detector 150, and a battery controller 160. As shown in FIG.

The charger 110 charges the battery 120 using a power source that is mounted in the vehicle and supplied from the outside. The charger 110 performs a fast charge of the battery 120 from a power source applied from an EVSE (electric vehicle supply equipment). Also, the charger 110 receives commercial power from an external source and performs a continuous charging of the battery 120. [

The charger 110 informs the battery controller 160 of the start of charging or the end of charging. When the power supply for charging the battery is started, the charger 110 transmits to the battery controller 160 a signal for notifying the start of charging (charging start notification). When the power supply for charging the battery is stopped or the charging of the battery is completed, the charger 110 transmits to the battery controller 160 a signal for notifying the completion of charging (charging end notification).

The battery 120 is a high-voltage battery, and supplies power necessary for driving the vehicle. The battery 120 is charged by the power supplied through the charger 110 or the regenerative power generated during regenerative braking.

The battery 120 is composed of a plurality of battery cells. For example, the battery 120 may be composed of 96 to 120 battery cells.

The voltage detector 130 measures an output voltage (hereinafter referred to as battery voltage) output from the battery 120 using a voltage sensor connected to the output terminal of the battery 120. [ The voltage detector 130 transmits the measured battery voltage to the battery controller 140.

The voltage detector 130 measures a charging voltage of each battery cell through a voltage sensor connected to an input terminal of each battery cell.

The current detector 140 is connected to the negative terminal of the battery 120 to measure the battery current. Also, the current detector 140 may measure the charging current supplied to each battery cell using a current sensor. Here, the current sensor can be implemented as a hall sensor.

The temperature detector 150 includes an outside temperature sensor mounted on the top of the battery pack and sensing an ambient temperature of the battery 120 and an internal temperature sensor measuring an inside temperature of the battery 120. The ambient temperature sensor is mounted on the top of the battery pack and can be implemented with a negative temperature coefficient thermistor (NTC). The internal temperature sensors are mounted on the internal module of the battery, and a plurality of internal temperature sensors are installed at regular intervals.

The battery controller 160 is a battery management system (BMS) that measures the state of charge (SOC), the degree of deterioration (SOH), voltage, temperature, current, Time and other information. The battery controller 160 prevents the battery 120 from overcharging or overdischarging.

The battery controller 160 exchanges information with the charger 110 via the vehicle network. The vehicle network is implemented in a Controller Area Network (CAN), a Media Oriented Systems Transport (MOST) network, a Local Interconnect Network (LIN), or an X-by-Wire (Flexray).

The battery controller 160 computes the degree of deterioration utilizing the characteristics of variation in charge time required for each degree of deterioration. The battery controller 160 includes a processor 161, a memory 162, and a time recorder 163.

The processor 161 controls the overall operation of the battery controller 160. The memory 162 may store programs and input / output data for operation of the battery controller 160. [

In addition, the memory 162 stores a rate of change in charge required time with respect to a fresh battery cell and a rate of change in charge required time with respect to the degree of degradation.

The memory 162 may be a flash memory, a hard disk, an SD card (Secure Digital Card), a RAM (Random Access Memory), a ROM (Read Only Memory) web storage), or the like.

The time counter 163 measures the elapsed time of a specific event. In this embodiment, the time meter 163 is used to measure the charging time.

When the processor 161 receives the charge start signal (charge start notification) informing the start of charge from the charger 110, it confirms whether the battery state satisfies the deterioration calculation condition. The processor 161 measures the charging voltage, the charging current and the temperature of the battery 120 at the start of charging through the voltage detector 130, the current detector 140 and the temperature detector 150 and measures the measured charging voltage, Check if the temperature meets the set conditions. At this time, the processor 161 prohibits entry into the degradation degree calculation mode unless any of the measured charge voltage, charge current, and temperature satisfies the deterioration calculation condition.

For example, when the deterioration calculation starting voltage is 3.5 V and the deterioration calculation start temperature is 0 DEG C, the processor 161 determines that the measured charging voltage of the battery 120 exceeds 3.5 V or the measured battery temperature Is 0 DEG C or more, the entry into the degradation degree calculation mode is inhibited. On the other hand, when the measured charge voltage is 3.5 V or less and the battery temperature is less than 0 캜, the processor 161 enters the deterioration calculation mode.

When the battery charge state satisfies the degradation degree calculation condition, the processor 161 enters the degradation degree calculation mode and collects the deterioration calculation start voltage of each battery cell. The processor 161 measures the charging voltage (charging start voltage) of each battery cell at the start of the deterioration calculation through the voltage detector 130. [

The processor 161 collects the deterioration calculation start voltage of each battery cell and confirms whether the battery charge state satisfies the deterioration calculation continuation condition. For example, the processor 161 stops the deterioration calculation when the charging current during charging fluctuates or when charging is stopped or completed.

The processor 161 measures the charging time required for reaching a specific voltage within the deterioration calculation voltage range by using the voltage detector 130 and the time detector 163 when the battery charge state satisfies the deterioration calculation continuation condition do. The processor 161 measures the voltage of each battery cell and measures a charging time required for reaching a specific voltage from a deterioration calculation start voltage of the battery cell. The deterioration calculation voltage section is a voltage section (for example, 3.5V to 3.8V) used for the deterioration calculation in the charge voltage section (for example, 3.3V to 4.1V). The specific voltage is a point for measuring the charging time, and is determined at constant intervals in the deterioration calculation voltage range. For example, as shown in FIG. 2, when the deterioration calculation voltage range is 3725 mV to 3950 mV and the charging time is measured at 25 mV intervals, the processor 161 sets the specific voltage to 3725 mV, 3750 mV, 3775 mV, 3800 mV, , 3850 mV, 3875 mV, 3900 mV, 3925 mV, and 3950 mV, respectively. The processor 161 measures the charging time required for charging the battery 120 to reach the charging voltage SOC of 2.5% and reaching the charging voltage of 3725 mV. The processor 161 changes the specific voltage to 3950 mV in increments of 25 mV, and measures the charging time required for reaching a specific voltage.

)을 연산한다. 여기서, △전압은 열화도 연산 시작 전압(열화도 연산 전압 구간의 시작 전압)과 열화도 연산 종료 전압(열화도 연산 전압 구간의 종료 전압)의 차이를 의미한다. 예를 들어, 열화도 연산 시작 전압이 3.5V이고, 열화도 연산 종료 전압이 3.8V이면 △전압은 0.3V이 된다.The processor 161 calculates the rate of change of the charging required time with respect to the voltage DELTA in the deterioration-

). Here, the? Voltage means the difference between the deterioration calculation start voltage (the start voltage of the deterioration calculation voltage section) and the deterioration calculation end voltage (the end voltage of the deterioration calculation voltage section). For example, when the deterioration degree calculation starting voltage is 3.5 V and the deterioration degree calculation end voltage is 3.8 V, the? Voltage becomes 0.3 V.

As shown in FIG. 3, the amount of increase in charge time with respect to the increase amount of the charge voltage by the degree of deterioration can be represented by a linear function. Therefore, the rate of change of the charge required time with respect to the voltage DELTA is the slope of the linear function.

The processor 161 compares the rate of change (slope) a _n of the calculated required charging time with the rate of change a of the charging time of the new battery cell to estimate the degree of deterioration D. [ Here, the rate of change of the charging time of the new battery cell is a rate of change of the charging time required for 100% charging of the new battery cell whose SOC is 2.5%.

Processor 161 is the rate of change of the calculated charging time _n and a ratio of a rate of change of the charging time of the new battery cell (gradient ratio) to compute the a / a _n. The processor 161 calculates (estimates) the deterioration degree D of the battery 120 using the calculated ratio a / a _n . In other words, the processor 161 calculates the deterioration degree D of the battery 120 using the following equation (1).

Here, f is a characteristic value derived from the test result and is an arbitrary constant value.

For example, the processor 161 calculates a ratio (a slope ratio) a / a _n of the rate of change a _n of charge required time calculated as shown in FIG. 4 and the rate of change a of the charge time of the new battery cell, The degree of deterioration of the battery 120 is calculated.

As a result of estimating the degree of deterioration of the battery 120 according to the embodiment of the present invention as described above, it can be understood that the error of the estimated deterioration is almost the same as the actual experimental data, as shown in FIG.

6 is a flowchart illustrating a method for diagnosing battery deterioration of an environmentally friendly vehicle according to an embodiment of the present invention.

First, the battery controller 160 receives a signal indicating the start of charging from the charger 110 (S110). The battery controller 160 recognizes the start of charging through the charge start notification transmitted from the charger 110. [

The battery controller 160 checks whether the charged state of the battery 120 satisfies the deterioration calculation condition (S120). The battery controller 160 measures the charging voltage, the charging current, and the temperature of the battery through the voltage detector 130, the current detector 140, and the temperature detector 150.

When the charged state of the battery 120 satisfies the deterioration calculation condition, the battery controller 160 enters the deterioration calculation mode and acquires the deterioration calculation start voltage of each battery cell (S130). That is, the battery controller 160 measures the charging voltage (initial charging voltage) of each battery cell at the start of the deterioration calculation.

The battery controller 160 measures the deterioration calculation start voltage of each battery cell and then checks whether the charge state of the battery 120 satisfies the deterioration calculation continuation condition (S140). The battery controller 160 confirms whether the charging current is fluctuated, the charging is stopped, and the charging is completed.

The battery controller 160 measures the charging time in the deterioration calculation voltage section when the charging state of the battery 120 satisfies the deterioration calculation continuation condition (S150). The battery controller 160 measures the charging time required to reach a specific voltage in the deterioration calculation voltage range from the deterioration calculation starting voltage of each battery cell. At this time, the battery controller 160 measures the charging time at a constant voltage interval within the deterioration calculation voltage period. For example, the battery controller 160 measures the charging time from an interval of 3725 mV to 3950 mV at 25 mV intervals.

The battery controller 160 calculates the ratio (rate of change) of the amount of charge required time to the amount of change (voltage) of the charge voltage in the deterioration-factor calculation voltage section (S160). In other words, the battery controller 160 calculates the slope of the required charging time with respect to the charging voltage, which is a ratio of the variation amount of the charging time to the increase amount of the charging voltage.

The battery controller 160 calculates a ratio (slope ratio) of the rate of change of the required charging time of the new battery cell to the rate of change of the calculated required charging time (S170).

The battery controller 160 calculates the final deterioration degree using the calculated ratio (S180). The battery controller 160 calculates the degree of deterioration of the battery 120 using Equation (1).

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program can be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing an embodiment of the present invention.

110: Charger
120: Battery
130: Voltage detector
140: Current detector
150: Temperature detector
160: Battery controller
161: Processor
162: Memory
163: Timer

Claims (11)

A battery composed of a plurality of battery cells,
A charger for charging the battery using an external power source, and
And when the charging start signal is received from the charger, it enters the deterioration degree calculation mode, collects the initial charging voltage of each battery cell, measures the charging time required to reach a specific voltage within the deterioration calculation voltage range at the initial charging voltage And a battery controller for calculating a slope of the charge required time in the deterioration calculation voltage section and estimating a deterioration degree of the battery by comparing the calculated slope of the required charge time with the charging time of the new battery cell The battery deterioration diagnosis device of the eco-friendly vehicle is characterized in that The method according to claim 1,
A voltage detector for measuring a charging voltage of the battery,
A current detector for measuring the charging current of the battery, and
And a temperature detector for measuring the temperature of the battery. 3. The method of claim 2,
The battery controller includes:
And a temperature detector for measuring a charging voltage, a charging current, and a temperature of the battery through the voltage detector, the current detector, and the temperature detector, Of the vehicle is satisfied. The method according to claim 1,
The battery controller includes:
Wherein the controller determines whether the charging current of the battery is fluctuated, whether the charging is stopped, whether charging is completed, and whether the charging is completed after the initial charging voltage of each battery cell is collected. Diagnostic device. The method according to claim 1,
The slope of the computed required charging time is calculated as follows:
Wherein the ratio of the amount of change in the charging time to the amount of change in the charging voltage of each battery cell is a ratio of the amount of change in charging time to the charging voltage of each battery cell. The method according to claim 1,
The battery controller includes:
Calculating a ratio of a slope of a required charging time of the new battery cell to a slope of the calculated required charging time, and calculating a deterioration degree of the battery using the calculated ratio, Device. Upon receipt of a charge start signal, entering a degradation mode of operation and collecting an initial charge voltage of each battery cell,
Measuring a charging time required to reach a specific voltage within the deterioration calculation voltage range at the initial charging voltage,
Calculating a slope of the required charging time in the deterioration calculation voltage section using the measured charging time; and
And estimating a deterioration degree of the battery by comparing a calculated slope of the required charging time with a required charging time of the new battery cell. 8. The method of claim 7,
The step of collecting the initial charging voltage of each battery cell comprises:
Upon receipt of the charge start signal, confirming whether the charge state of the battery satisfies the degradation degree calculation condition,
Entering the deterioration degree calculation mode if the state of charge of the battery satisfies the deterioration degree calculation condition, and
And collecting a charging voltage of each battery cell when entering the deterioration degree calculation mode. 8. The method of claim 7,
Measuring the charging time,
After collecting the initial charging voltage of each battery cell, confirming whether the state of charge of the battery satisfies the continuity condition of the deterioration calculation, and
And measuring the charging time at a predetermined voltage interval within the deterioration calculation voltage range when the charged state of the battery satisfies the deterioration calculation continuation condition. 8. The method of claim 7,
Wherein the step of calculating the slope of the required charging time in the deterioration-
And calculating a ratio of a change amount of the measured required charging time to a variation amount of the charging voltage of each battery cell. 8. The method of claim 7,
The step of estimating the degree of deterioration of the battery includes:
Calculating a ratio of the required time for charging the new battery cell to the slope of the required charging time, and
And calculating the degree of deterioration of the battery using the calculated ratio.

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