KR101541741B1 - Charging cable and Method for charge - Google Patents

Abstract

The present invention relates to a charging cable embedded with a battery management system and an electric vehicle using the same and, more specifically, to the charging cable embedded with the battery management system for using a battery embedded in the electric vehicle efficiently. For this, the charging cable of the present invention is embedded with the battery management system (BMS), and the BMS controls a voltage charged to the battery, and includes at least two charging cable ports connected to the battery at one side, and the number of the charging cable ports is related with the number of cells constituting the battery.

Description

Technical Field [0001] The present invention relates to a charging cable including a battery management system,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a charging cable having a built-in battery management system and a motor vehicle using the charging cable, and more particularly, to a charging cable having a built-in battery management system for efficiently utilizing a battery built in an electric vehicle.

BACKGROUND ART In general, electric vehicles, hybrid electric vehicles, hybrid electric vehicles, electric motorcycles (E-Scooter) and the like are required to generate electric power of tens of kilowatts (KW) A large capacity battery capable of outputting a voltage of about several volts (A) or several hundreds of amperes (A) is used. To do so, a single battery module is formed by connecting a single battery cell in series and / or in parallel.

These electric vehicles were produced before the gasoline car in 1873, but they have not been put to practical use because of the heavy weight of the battery and the time taken to charge the battery.

Such an electric vehicle is slightly different from an internal combustion engine vehicle in addition to an engine replaced by an electric motor. However, the biggest problem is the battery which is the supply source of energy, and the light weight, miniaturization and short charge time of the battery are essential prerequisites for the practical use of the electric vehicle.

In addition, hybrid electric vehicles are equipped with internal combustion engines and electric vehicle battery engines at the same time, minimizing the weight of the vehicle body and minimizing the resistance of the air. To the next generation. Therefore, hybrid electric vehicles are also called environmental vehicles because they can reduce the harmful gas more than 90% compared to existing vehicles, improve the air and surrounding environment of large cities, and meet the traffic control and road planning.

Such an electric vehicle or a hybrid electric vehicle generally uses a secondary battery such as a lithium battery to charge electrical energy.

Korean Patent No. 0949260 entitled " Electric Charging System for Electric Vehicle "

The present invention relates to a battery charging system for an electric vehicle capable of optimizing a set value of a battery charge state amount (SOC [%] (State of Charge)) in a hybrid electric vehicle to extend energy consumption efficiency and battery life of a hybrid electric vehicle, 1. An electric power generating apparatus comprising: an engine that generates power; a generator that generates electricity from the engine; an electric motor; an electric motor that drives the electric motor and is made of any one of a combination of battery, Ultra Capacitor, fuel cell, An electronic storage device, a control unit for controlling the operation of the engine, an electric motor, a generator or an electric energy storage device, and navigation for receiving and displaying information supplied from a position information system (GPS) Wherein the control unit is adapted to monitor the current state of the electrical energy storage device, System, wherein the navigation uses information of acceleration, deceleration, braking, steering and load of the electric vehicle as a function factor from the road and traffic information of the electronic map and the control unit to determine the filling rate of the electric energy storage device And a charging rate management device.

Korean Patent Laid-Open Publication No. 2013-0078352 (entitled "Power Management System for Battery Management System") discloses a power management system in which if an AC power source is not connected to a battery management system (BMS) And provides a power supply system for a battery management system for providing electric energy to the BMS by using AC power only when the AC power is connected to the BMS when the AC power is connected to the BMS. A battery pack for supplying electric energy supplied from a battery to a battery management system (BMS), an AC power source for providing AC power to a battery management system (BMS) 50, And at least one of the AC power supply unit and the BMS, Through ever switching unit including switches for controlling the electric energy and supplying the AC power provided by the BMS characterized by configured.

As described above, the battery in which the conventional BMS is embedded charges the electric energy supplied from the outside via the BMS or discharges the electric energy charged in the battery to the outside. Generally, the BMS is involved in the charging and discharging of the battery, and is always exposed to stress due to heat, overcharge, overdischarge, and the like. When the BMS fails due to such stress, the battery may not be charged with electric energy or the charged electric energy may not be used. Therefore, there is a need for measures to solve such problems.

A problem to be solved by the present invention is to propose a method of using a battery for a long time by remarkably reducing a failure occurrence rate of the battery.

Another problem to be solved by the present invention is to propose a BMS that can monitor the state of a cell constituting a battery in real time.

Another problem to be solved by the present invention is to propose a method of reducing battery failure rate by reducing the battery purchase cost.

To this end, the charging cable of the present invention includes a battery management system (BMS), the BMS controlling at least one of a charging cable terminal connected to the battery on one side, The number of terminals is related to the number of cells constituting the battery.

To this end, a method of charging a battery using a charging cable with a built-in battery management system (BMS) according to the present invention includes the steps of connecting a charging cable constituting a charger to a battery, Charging a cell having a relatively low charging voltage when the difference between the charging voltages of the cells exceeds a set range; charging the cell having the relatively low voltage within a set range; And charging each cell constituting the battery. If the number of cells of the battery is n (n: natural number), the number of the terminals is greater than 2n + 1.

The charging cable having the battery management system according to the present invention and the battery charging method using the same can remarkably reduce the failure occurrence rate of the battery and can use the battery for a long time, thereby reducing the battery purchase cost.

In addition, each pin constituting the charge cable is connected to the battery, whereby the state of the cell constituting the battery can be monitored in real time, and only the cell in which the failure has occurred can be replaced.

1 illustrates a battery and a charger according to an embodiment of the present invention.
FIG. 2 illustrates a charger incorporating a BMS according to an embodiment of the present invention.
FIG. 3 illustrates a process of performing charging using a charger having a built-in BMS according to an embodiment of the present invention.
FIG. 4 shows a configuration of a train according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

1 illustrates a battery and a charger according to an embodiment of the present invention.

Hereinafter, a structure of a battery and a charger according to an embodiment of the present invention will be described in detail with reference to FIG.

1, the BMS 120 is not built in a battery, but is built in a charger. That is, in relation to the present invention, the battery includes a cell, and a battery management system (BMS) for managing the charging of the battery is embedded in the charger.

The battery charges the electric energy provided under the control of the BMS 120 when the electric energy is supplied from the outside. However, when the electric energy charged in the battery is discharged, the discharge is performed without controlling the BMS. In accordance with the present invention, an electric vehicle provides electric energy charged in a battery to a motor controller and a motor, and the electric motor drives the electric energy using the supplied electric energy. However, the motor controller stops supplying the electric energy stored in the battery when the electric energy stored (charged) in the battery is less than the set value. That is, when the battery is completely discharged, the corresponding battery can not be used. Therefore, the motor controller stops supplying the electric energy when the electric energy stored in the battery is less than the set value. To this end, a motor controller (not shown) is included between the battery and the motor.

The motor controller measures the current value of the electric energy supplied from the battery and cuts off the electric energy supplied from the battery to the driving motor when the measured current value is less than the set value. As described above, in the case of charging electric energy with a battery, the electric energy is charged via the BMS formed in the charging device. However, when electric energy charged in the battery is discharged, the electric energy Lt; / RTI >

As described above, the BMS has been involved in the charging and discharging processes of the battery. However, the present invention has an advantage that the failure probability of the BMS is reduced by involving the BMS only when the battery is charged with electric energy.

In addition, when the existing BMS fails, the electric energy charged in the battery can not be efficiently used. However, the present invention does not use a separate BMS at the time of discharging but uses only the electric current value of the discharged electric energy, Therefore, there is an advantage that the electric energy charged in the battery can be efficiently used.

A battery cell for an electric vehicle has a relatively high capacity and voltage, and a large number of battery cells are combined to form one battery module. An electric vehicle employs one or two battery modules, which ultimately consists of hundreds or thousands of cells. Therefore, the BMS must be used to manage hundreds or thousands of cells, and the present invention mounts the BMS on the charger.

BMS manages a single cell, a battery module, and a battery pack, and consists of several types of actuators, sensors, control devices, and connecting wires.

The input signals of BMS are ① main current and main voltage measured by main circuit current sensor and voltage sensor ② cell temperature measured by temperature sensor, battery external temperature and battery coolant inlet and outlet temperature ③ accelerator pedal and brake pedal sensor Measured analog signal ④ Start switch and digital signal transmitted from charge enable / disable switch.

The BMS output signal and its role first control the cooling and heating by operating a thermal management module such as a fan and an electric heater and operate a balance module such as a capacitor, a switch and a loss resistor to maintain parallelism of the battery, Maintain battery voltage safety through operation of battery module contacts.

In addition, the BMS instructs charging by a digital signal, alerts the coupling, and controls and manages the communication module, the internal power supply module, the time indication module, and the charging system.

The battery management system improves mileage and stability by optimizing electric car battery control. The functions of the battery management system can be roughly classified into two types. (SOC) control technology that determines the state of each battery and operates at the optimum efficiency point, and a heat management control technology that can uniformly cool the weak battery even when the temperature is weak.

The thermal management control technology monitors the voltage, current and temperature of the system and maintains it in an optimum condition, and can take alarm and advance safety precautions for safe operation of the system. In addition, overcharge and overdischarge of the battery are suppressed to uniformly control the voltage between the cells, thereby prolonging the energy efficiency and the life of the battery. It is possible to save the alarm history status and to preserve the data and to diagnose the system through external diagnosis system or monitoring PC.

The technology of controlling the charge state is realized by the cell balance which keeps all the cells always in an equally charged state. Furthermore, the battery management system comprehensively analyzes various change factors, predicts the remaining travelable distance, and provides the information to an upper electronic control unit (ECU).

The software that supports the functions of the battery management system includes measurement algorithms for voltage, current and temperature, state of charge (SOC), and state of health (SOH) estimation, Cell balancing algorithm, Thermal management, Diagnostic algorithm, Protection algorithm and Communication with vehicle.

Hereinafter, a method of predicting the battery state among functions of the BMS will be described.

The battery state refers to the correlation between SOC, SOH and SOF, and in particular, SOH is determined by the expected service life and the output of the fault diagnosis result. The SOF is determined in consideration of the influence of the aging effect, the range of the SOC, the temperature range and the defect level.

SOC refers to the ratio of the amount of charge remaining in the battery (chargeable amount) to the total charge amount (battery capacity) when the battery is charged under the standard state. The unit of SOC is expressed in%, where 100% is the maximum charge state and 0% is the maximum discharge state. In the case of one battery cell, it is clear as described above, but in the case of a battery module or a battery pack composed of a plurality of battery cells, it becomes somewhat complicated. If a plurality of cells are connected in parallel, they are regarded as one large capacity cell. In case of connecting in series, an equilibrating device for maintaining the state and capacity of each cell should be additionally considered. The method of predicting the SOC of a battery includes a current integration method (a method using time integration of a current), an internal resistance measurement method of estimating the SOC by measuring the internal physical characteristics of the battery, a method of finding a function related to input / And current starch method.

The SOH compares the current state of the battery based on the ideal state of the battery and displays the value as a percentage. SOH is derived from capacitance and initial resistance, or derived from AC impedance, self-discharge rate and power density.

[Equation 1]

C (t): Capacity at time t

C _E : Final capacity

C _R : Initial capacity

&Quot; (2) "

SOF indicates how well the battery performance meets the actual requirements while using the battery and is determined by the SOC, SOH, operating temperature and charge / discharge history.

FIG. 2 illustrates a charger incorporating a BMS according to an embodiment of the present invention. Hereinafter, a charger having a built-in BMS according to an embodiment of the present invention will be described in detail with reference to FIG.

According to Fig. 2, the charger forms a plurality of terminals. The number of charging cable terminals formed in the charger is related to the number of cells constituting the battery. That is, the number of cells constituting the battery is proportional to the number of the charging cable terminals formed in the charger.

For example, when the number of cells constituting the battery is 13, the number of the charging cable terminals includes at least 27. That is, one terminal is connected to the (+) terminal and the (-) terminal of each cell, and one terminal is grounded. Thus, the number of charging cable terminals constituting the charger constituting the present invention is related to the number of cells constituting the battery.

As described above, according to the present invention, the charging time can be remarkably reduced compared with the conventional case by forming the BMS on the charger instead of forming the battery on the battery.

FIG. 3 illustrates a process of performing charging using a charger having a built-in BMS according to an embodiment of the present invention. Hereinafter, a process of performing charging using a charger having a built-in BMS will be described in detail with reference to FIG.

In step S300, the charger connects the charging cable terminal of the charger to each cell of the battery to charge the battery. As described above, the number of charging cable terminals of the charger is related to the number of cells of the battery.

In step S310, the BMS of the charger measures the voltage of each cell. That is, the voltage of each cell is measured by using the charging cable terminal formed on the charger.

In step S320, the charger verifies whether the voltage of each cell is within the set range. The charger performs charging when the voltage of each cell is within the set range.

In step S330, if the difference in voltage between the cells is not within the set range, the charger performs charging for the cell having a relatively low voltage so that the difference in voltage of each cell can be included within the set range.

In step S340, the charger charges each cell when the voltage of each cell is within the set range. As described above, according to the present invention, a cell having a relatively low voltage is charged first so that the voltage of each cell can maintain the same voltage, and then all cells are charged if the voltages of the cells have the same voltage.

Also, the charger may have a display window and can display the voltage or abnormality of each cell. The user can confirm the abnormality of each cell by using the information displayed on the display window and replace the cell if necessary. By replacing only the cell in which the abnormality has occurred as described above, the replacement cost of the battery can be reduced.

That is, when an abnormality occurs in the battery, the entire battery is replaced without replacing only the corresponding cell. That is, it is possible to know whether or not an abnormality has occurred in a certain cell constituting the battery, and the entire battery is replaced without replacing the cell constituting the battery.

In the conventional BMS, when any one of the cells constituting the battery is abnormal, it is determined that an abnormality has occurred in the entire battery. However, according to the present invention, It is possible to judge whether or not an abnormality exists in units of cells by judging whether there is an abnormality.

FIG. 4 shows a configuration of a train according to an embodiment of the present invention. Hereinafter, the configuration of a train according to an embodiment of the present invention will be described in detail with reference to FIG.

According to Fig. 4, the electric train includes a fuel tank, an engine, a generator, a converter, a battery, an engine / motor speed control unit, a control unit, and a motor. Of course, other configurations than those described above may be included in the electric vehicle proposed in the present invention.

The fuel tank 402 stores fuel therein.

The engine 404 uses the fuel supplied from the fuel tank 402 to produce kinetic energy under the control of the engine / motor speed control unit 406. [ The generator 408 converts the kinetic energy produced by the engine 404 into electric energy under the control of the engine / motor speed controller 406. The electric energy converted at the generator 408 is provided to the motor 416. [ Of course, in this case, the converter 410 converts the electric energy generated by the generator 408 to have a set voltage and current. The converter 410 of the present invention converts the produced electric energy so as to have energy suitable for the use of the electric motor vehicle. Of course, the energy converted by the converter 410 may vary depending on the setting.

The electric energy converted in the converter 410 is supplied to the motor 416 under the control of the control unit 414. [

The motor 416 generates energy (kinetic energy) for driving the wheel motor using the supplied electric energy. Of course, some of the electrical energy converted by the converter 410 is supplied to the battery 412 to be charged. That is, when the magnitude of the electric energy converted in the converter 410 is larger than the electric energy necessary for driving the motor, the surplus electric energy is supplied to the battery 412 under the control of the control unit.

As described above, the battery 412 does not have a BMS therein.

4, the engine / motor speed control unit 406 is connected to the control unit 414, and the engine / motor speed control unit 406 controls the generator / motor speed control unit 406 according to the speed control command of the motor 416, 408) and the magnitude of the rotational energy produced by the motor. Of course, the engine / motor speed control unit 406 may directly control the magnitude of the rotational energy produced by the motor 416, or may control it using the control unit 414. [ 4, the control unit 414 controls the motor 416 in accordance with the control command received from the engine / motor speed control unit 406. As shown in FIG.

In addition, the control unit 414 of the present invention grasps the voltage charged in the battery in real time. The control unit 414 cuts off the voltage (power) supplied from the battery when the voltage charged in the battery is equal to or less than the set voltage. As described above, the battery of the present invention does not incorporate a separate BMS therein, but uses the control unit 414 to control whether the battery is discharged.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention .

100: Charger 110: Charging cable terminal
120: BMS 402: Fuel tank
404: engine 406: engine / motor speed control section
408: generator 410: converter
200: battery 414:
416: Motor

Claims (5)

An engine connected to the fuel tank and producing kinetic energy using the fuel stored in the fuel tank;
A generator for converting kinetic energy produced by the engine into electric energy;
A motor directly receiving the converted electric energy from the generator or receiving electric energy stored in the battery;
A converter that provides excess electrical energy remaining to be supplied to the motor among the converted electrical energy from the generator;
A battery that receives electrical energy from a charger, is connected to the converter and stores surplus electrical energy provided from the converter;
A control unit for shutting off the supply of electric energy from the battery to the motor when the voltage of the electric energy stored in the battery is equal to or less than a set voltage;
And an engine / motor speed control unit for controlling the magnitude of rotational energy produced by the motor according to a control command received from the outside,
The battery charger includes a battery management system (BMS), which controls a voltage charged by the battery, and includes at least two charging cable terminals connected to the battery at one side thereof, The BMS calculates a life prediction (SOH) representing a current state of the battery based on a state of charge (SOC) and an ideal state of the battery, Wherein the SOH is calculated by the following equation (3).
&Quot; (3) "

C (t): Capacity at time t
C _E : Final capacity
C _R : Initial capacity.
The electric vehicle according to claim 1, wherein, when the number of cells of the battery is n (n: natural number), the number of the charging cable terminals is greater than 2n + 1.
3. The electric vehicle according to claim 2, wherein the BMS receives a charging voltage charged in each cell from a charging cable terminal connected to each cell.
The battery charger according to claim 3, wherein the charger includes a display unit,
Wherein the display unit displays an abnormality of each cell or a charging voltage of each cell from the BMS. delete

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