KR20230095491A - Supercap system for vehicle and method for controlling the same - Google Patents

Abstract

Disclosed are a supercap system for a vehicle and a control method thereof. A supercap system includes: a supercap connected to a main bus terminal of a vehicle and composed of a plurality of cells; a load device connected to the main bus terminal of the vehicle; and a control unit which monitors maximum-minimum voltage deviation of supercap cells, and if the voltage deviation is abnormal, determines the necessity of discharging the supercap through the voltage trend and temperature trend of each cell of the supercap, and erases the energy of the supercap through a load device when the supercap needs to be discharged. Therefore, the unnecessary wake-up of a vehicle controller is prevented.

Description

Vehicle supercap system and its control method {SUPERCAP SYSTEM FOR VEHICLE AND METHOD FOR CONTROLLING THE SAME}

The present invention detects the abnormality of the supercap of the vehicle in a relatively simple way, prevents unnecessary wake-up of the vehicle controller by performing the supercap abnormality determination twice, and identifies the internal short of the supercap in advance. It relates to a super cab system of a vehicle that can prevent a fire, etc., and a control method thereof.

Recently, due to the emergence of environmental problems, eco-friendly vehicles such as electric vehicles and fuel cell vehicles are being developed and supplied.

In the case of these eco-friendly vehicles, the vehicle is driven by a motor, and energy is provided through a high-voltage battery or fuel cell. In addition, a method of utilizing a supercapacitor (hereinafter, referred to as a "supercap") in addition or alternatively to a high voltage battery is being reviewed.

The supercap is a device mounted on a vehicle to supply electric energy to the driving motor during acceleration for vehicle driving and to store electric energy generated from the regenerative braking mechanism or fuel cell stack during deceleration. It is equipped with an alternative character.

When the cells of the supercap are in a normal state, they supply electric energy to the motor or prepare to store electric energy.

However, if the cells constituting the supercap are abnormal in the absence of charging and discharging of the supercap (ignition off, stop, etc.), there is a risk of fire due to internal short circuit, etc. There is a need. Therefore, there is a need for a method capable of efficiently detecting such an internal short circuit.

The matters described as the background art above are only for improving understanding of the background of the present invention, and should not be taken as an admission that they correspond to prior art already known to those skilled in the art.

KR 10-2021-0133868 A

The present invention has been proposed to solve this problem. In a relatively simple way, it is possible to determine whether the supercap of the vehicle is abnormal, and to prevent unnecessary wake-up of the vehicle controller by performing the supercap abnormality determination twice. It is intended to provide a vehicle's supercab system and its control method that can prevent fire by identifying the internal short circuit of the supercab in advance.

In order to achieve the above object, a vehicle supercab system according to the present invention includes a supercab connected to a main bus terminal of the vehicle and composed of a plurality of cells; Load device connected to the main bus stage of the vehicle; and monitors the maximum-minimum voltage deviation of the supercap cells, and if the voltage deviation is abnormal, the need to discharge the supercap is determined through the voltage trend and temperature trend of each cell of the supercap, and the load device when the supercap needs to be discharged A control unit that erases the energy of the supercap through

When the output current of the supercap is 0, the control unit may monitor the maximum-minimum voltage deviation of the supercap cells.

The control unit may monitor the maximum-minimum voltage deviation by periodically measuring the voltages of the supercap cells and recording the minimum and maximum values.

When the maximum-minimum voltage deviation of the supercap cells is abnormal, the control unit wakes up the vehicle controller to determine the voltage trend and temperature trend of each cell of the supercap.

When the output current of the supercap is 0, the control unit can determine the voltage trend and temperature trend of each cell of the supercap.

The controller may determine that the supercap needs to be discharged when both the voltage trend and the temperature trend of each cell of the supercap are abnormal.

The control unit may determine that the voltage trend is abnormal when there is a cell having a voltage drop greater than a reference value among the cells of the supercap.

The control unit may determine that the temperature trend is abnormal when there is a cell having a temperature greater than a reference value among the cells of the supercap.

The load device may include at least one of a supercap initial charging device, a heater, and electronic components.

The control unit may select a load device that consumes energy of the supercap according to the charged amount of the supercap.

The control unit can erase the energy of the supercap through all load devices of the vehicle when it is determined that the need to discharge the supercap is above a certain level through the trend of voltage and temperature of each cell of the supercap.

The load device of the vehicle may be connected in parallel with the super cab through the main bus stage.

A method for controlling a supercap system of a vehicle of the present invention includes monitoring a maximum-minimum voltage deviation of supercap cells in a control unit; If the voltage deviation is abnormal, determining the voltage trend and temperature trend of each cell of the supercap by the control unit; and erasing energy of the supercap through a load device in a control unit when the voltage trend and temperature trend of each cell of the supercap are abnormal.

According to the vehicle supercap system and its control method of the present invention, it is relatively simple to determine whether the vehicle's supercap is abnormal, and to prevent unnecessary wake-up of the vehicle controller by performing the supercap abnormality determination twice. And, by identifying the internal short of the supercap in advance, it is possible to prevent fire.

1 is a block diagram of a supercab system of a vehicle according to an embodiment of the present invention.
2 and 3 are diagrams related to cell monitoring for explanation of a supercap system of a vehicle and a control method thereof according to an embodiment of the present invention.
4 and 5 are graphs showing voltage and charging amount of a supercap for explanation of a supercap system of a vehicle and a control method thereof according to an embodiment of the present invention.
6 is a flowchart of a method for controlling a supercap system of a vehicle according to an embodiment of the present invention.

1 is a block diagram of a supercap system of a vehicle according to an embodiment of the present invention, and FIGS. 2 and 3 are cell monitoring diagrams for explaining a supercap system of a vehicle and a control method thereof according to an embodiment of the present invention. 4 and 5 are graphs showing the voltage and charge amount of the supercap for explaining the supercap system of a vehicle and its control method according to an embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. It is a flowchart of the supercap system control method of a vehicle according to.

In the embodiment of the present invention, a supercap (supercapacitor) applied to a fuel cell vehicle is taken as an example. A supercap is an alternative to a battery and uses capacitor technology to store electrical energy. As the supercap, a double layer capacitor (also referred to as a supercap, ultracap, or supercapacitor) is mainly used. It has a structure in which porous electrodes and ions are dissolved in an organic electrolyte, and belongs to an electrochemical energy storage device similar to the structure of a storage battery.

No electrochemical reaction occurs in the capacitor during charging or discharging of the supercap, and the chemical reaction proceeds only to a very limited extent. Supercaps are useful energy storage devices for applications that require high power and many cycles. However, it is expensive and difficult to use widely in many applications.

Supercaps can replace batteries because of their long cycle life when the number of cycles is very high (possibly more than one cycle per minute). Recently, the capacitance of capacitors is getting bigger and bigger (maximum capacitance of 5000F), while the internal resistance is getting very low (less than 1mΩ). Supercaps have much smaller internal resistance than batteries, so they can release the large current required to start a motor in a short time of seconds.

Therefore, the supercap is also very suitable as an energy buffer that supports peak output when starting or accelerating in a hybrid vehicle, electric vehicle, or fuel cell vehicle.

1 is a block diagram of a supercap system of a vehicle according to an embodiment of the present invention. In the case of a fuel cell vehicle, a fuel cell stack (F), a motor (M), and a motor controller (I) are connected to a main bus stage. , To this, the load device (E2), the COD heater (E3), the supercap (S), the low voltage battery (L) and the LDC (D), the air conditioner system (A), and the air conditioning heater system (E4) are connected in parallel. In addition, the supercap (S) may be connected to the main bus stage through the initial charging device (E1). Although not shown separately in the case of the control unit, it may be composed of a processor and a memory that control the overall system of the present invention.

A supercab system for a vehicle according to the present invention includes a supercab (S) connected to a main bus terminal of the vehicle and composed of a plurality of cells; Load devices (E1 to E4) connected to the main bus terminal of the vehicle; And monitoring the maximum-minimum voltage deviation of the cells of the supercap (S), and determining the need to discharge the supercap (S) through the voltage trend and temperature trend of each cell of the supercap (S) when the voltage deviation is abnormal , A control unit that erases the energy of the supercap (S) through the load devices (E1 to E4) when the supercap (S) needs to be discharged.

The supercap (S) is connected to the main bus terminal through an initial charging unit (E1), and is composed of a plurality of cells to form a pack. In addition, various load devices E1 to E4 capable of consuming electrical energy are provided at the main bus stage. The load device includes the aforementioned heaters E3 and E4, the initial charging unit E1, and the like.

And the control unit manages the energy of the supercap (S). The control unit monitors the maximum-minimum voltage deviation of supercap (S) cells in normal times. And if the voltage deviation is abnormal as a result of the monitoring, the voltage trend and temperature trend of each cell of the supercap (S) is grasped to determine whether the supercap (S) is abnormal again. Through this process, the control unit can relatively simply and accurately verify whether or not the supercap (S) is abnormal, in particular, the possibility of an internal short circuit.

Through this, the control unit determines the need to discharge the supercap (S), and if the supercap (S) needs to be discharged, the energy of the supercap is erased through the load devices (E1 to E4).

In the case of the supercap (S), the amount of energy remaining compared to the battery can be determined by the “voltage” value of the supercap, and cell defects can also be easily identified. The voltage of each cell of the supercap (S) is data that is basically read by the control unit, and can be determined through the normally used in-vehicle control unit.

Vehicle batteries need to evaluate not only the voltage but also the resistance of the cell when aging or defectiveness is judged. Therefore, it is impossible for a user to visit a vehicle repair shop and determine defects in a cell without monitoring equipment while the cell is mounted on the vehicle. On the other hand, in the case of the supercap, it is possible to identify the internal short circuit through the voltage or temperature of the cell. In the present invention, the intentional energy consumption of the supercap is performed by monitoring the voltage and temperature of the supercap.

Specifically, FIGS. 2 and 3 are diagrams related to cell monitoring for explanation of a supercap system of a vehicle and a control method thereof according to an embodiment of the present invention.

When the output current of the supercap is 0, the control unit may monitor the maximum-minimum voltage deviation of the cells of the supercap (S). That is, accurate verification is performed by measuring the OCV in the absence of energy charging and discharging of the supercap (S).

First, as shown in FIG. 2 , the control unit may monitor the maximum-minimum voltage deviation by periodically measuring the voltages of the supercap (S) cells and recording the minimum and maximum values. The control unit monitors the voltage of each cell of the supercap (S) at regular intervals. However, in a normal case, analysis is not performed through such voltage data, but only the minimum and maximum values of the cell voltage are stored in the memory, and only the voltage deviation between the stored minimum and maximum values is analyzed. As this primary analysis is performed simply, it is possible to effectively use the resources of the control unit, and if there is an abnormality in the primary analysis result, the supercap is accurately verified through the secondary analysis as described below.

In the case of FIG. 3, as a result of the first analysis of FIG. 2, a specific verification is shown when the supercap (S) is abnormal. When the maximum-minimum voltage deviation of the cells of the supercap (S) is abnormal, the control unit wakes up the vehicle controller to determine the voltage trend and temperature trend of each cell of the supercap (S). When the control unit wakes up various controllers of the vehicle, it is possible to grasp the voltage trend of each cell and to grasp the temperature.

In the case of the temperature sensor, the temperature of various points of the supercap (S) can be measured, or it is possible to indirectly reflect the temperature of the supercap (S) by measuring the temperature of various points around it.

Also, when the output current of the supercap (S) is 0, the controller determines the voltage trend and temperature trend of each cell of the supercap (S).

In addition, the control unit may determine that the supercap needs to be discharged when both the voltage trend and the temperature trend of each cell of the supercap (S) are abnormal.

Specifically, the control unit may determine that the voltage trend is abnormal when there is a cell having a voltage drop greater than a reference value among the cells of the supercap (S). In addition, the control unit may determine that the temperature trend is abnormal when there is a cell having a temperature greater than a reference value among each cell of the supercap (S).

In the case of FIG. 3, it is known that cells 2-3 and 2-5 deviate from the average voltage trend. And in the case of temperature, it can be seen that the case of cells 2-5 is out of the way. Therefore, the control unit can predict that there is an internal short circuit due to unstable voltage and temperature in the case of cells 2 to 5, and proceeds with energy consumption of the entire supercap or the corresponding cell to prevent the resulting fire.

4 and 5 are graphs showing voltage and charging amount of a supercap for explanation of a supercap system and a control method for a vehicle according to an embodiment of the present invention. As shown in FIG. 4, it can be seen that a normal supercap corresponding to a good product shows a gradual voltage drop over time, but a defective supercap, that is, a rapid voltage drop when there is an internal short circuit. Therefore, in the case of a supercap, it is possible to determine the defect or deterioration of a cell through the trend of voltage.

Meanwhile, the load devices E1 to E4 may include at least one of a supercap initial charging device E1, heaters E3 and E4, and electronic parts E2. In addition, the control unit may select a load device that consumes energy of the supercap S according to the amount of charge of the supercap S.

Various load devices are all connected in parallel to the main bus stage. Therefore, as the number of load devices to be operated increases, total circuit resistance decreases and energy consumed increases. This can be seen by referring to the graph of FIG. 5 . As shown in FIG. 5 , it can be seen that as the number of load devices connected increases, the resistance decreases, and the charging amount of the supercap decreases more rapidly as the resistance decreases.

In particular, the control unit can erase the energy of the supercap through all load devices of the vehicle when it is determined that the need to discharge the supercap is above a certain level through the trend of voltage and temperature of each cell of the supercap. That is, when the amount of charge of the supercap is small, energy is consumed by connecting only some load devices, and when the amount of charge is large, energy is consumed quickly by connecting multiple load devices as much as necessary to quickly erase energy. In particular, when the difference in voltage or temperature is very large, it is determined that it is an emergency situation and the energy of the supercap can be erased through all load devices.

6 is a flowchart of a method for controlling a supercap system of a vehicle according to an embodiment of the present invention. The method for controlling a supercap system of a vehicle according to the present invention includes monitoring a maximum-minimum voltage deviation of supercap cells in a controller (S200); If the voltage deviation is abnormal, the controller determines the voltage trend and temperature trend of each cell of the supercap (S400); and erasing energy of the supercap through a load device in a control unit when the voltage trend and temperature trend of each cell of the supercap are abnormal (S500).

Specifically, the control unit first verifies the primary internal short circuit by monitoring the maximum-minimum voltage deviation of the supercap cells only when the output current of the supercap is 0 (S100, S200).

And if the voltage deviation is abnormal, the control unit identifies the voltage trend and temperature trend of each cell of the supercap, and performs secondary detailed verification through this (S300, S400).

As a result of the second verification, if the voltage trend and temperature trend of each cell of the supercap are abnormal, the control unit erases the energy of the supercap through the load device to prevent an internal short circuit (S500, S600). In addition, a warning is issued to the vehicle to notify the need for inspection (S600).

According to the vehicle supercap system and its control method of the present invention, it is relatively simple to determine whether the vehicle's supercap is abnormal, and to prevent unnecessary wake-up of the vehicle controller by performing the supercap abnormality determination twice. And, by identifying the internal short of the supercap in advance, it is possible to prevent fire.

Although shown and described in relation to specific embodiments of the present invention, it is known in the art that the present invention can be variously improved and changed without departing from the technical spirit of the present invention provided by the claims below. It will be self-evident to those skilled in the art.

F: fuel cell stack E1, E2, E3, E4: load device
S: Supercap

Claims (13)

A super cab connected to the main bus terminal of the vehicle and composed of a plurality of cells;
Load device connected to the main bus stage of the vehicle; and
The maximum-minimum voltage deviation of the supercap cells is monitored, and if the voltage deviation is abnormal, the need to discharge the supercap is determined through the voltage trend and temperature trend of each cell of the supercap, and the load device is operated when the supercap needs to be discharged. A control unit that erases energy of the supercap through the vehicle's supercap system. The method of claim 1,
The control unit monitors the maximum-minimum voltage deviation of the supercap cells when the output current of the supercap is 0. The method of claim 1,
The control unit monitors the maximum-minimum voltage deviation by periodically measuring the voltages of the supercap cells and recording the minimum and maximum values. The method of claim 1,
The control unit wakes up the vehicle controller when the maximum-minimum voltage deviation of the supercap cells is abnormal to grasp the voltage trend and temperature trend of each cell of the supercap. The method of claim 1,
Wherein the controller determines the voltage trend and temperature trend of each cell of the supercap when the output current of the supercap is 0. The method of claim 1,
The control unit determines that the supercap needs to be discharged when the voltage trend and temperature trend of each cell of the supercap are both abnormal. The method of claim 1,
The control unit determines that the voltage trend is abnormal when there is a cell with a voltage drop greater than a reference value among each cell of the supercap. The method of claim 1,
The control unit determines that the temperature trend is abnormal when there is a cell having a temperature greater than a reference value among each cell of the supercap. The method of claim 1,
The supercap system of a vehicle, characterized in that the load device includes at least one or more of a supercap initial charging device, a heater, and electronic parts. The method of claim 1,
The supercap system of a vehicle, characterized in that the control unit selects a load device that consumes energy of the supercap according to the charged amount of the supercap. The method of claim 1,
The control unit erases the energy of the supercap through all load devices of the vehicle when it is determined that the need to discharge the supercap is above a certain level through the voltage trend and temperature trend of each cell of the supercap. system. The method of claim 1,
The vehicle's load device is a supercap system of a vehicle, characterized in that connected in parallel with the supercap through the main bus stage. A method for controlling the supercap system of the vehicle of claim 1,
Monitoring the maximum-minimum voltage deviation of supercap cells in a controller;
If the voltage deviation is abnormal, determining the voltage trend and temperature trend of each cell of the supercap by the control unit; and
A method for controlling a supercap system of a vehicle, comprising: erasing energy of the supercap through a load device in a control unit when the voltage trend and temperature trend of each cell of the supercap are abnormal.

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