KR101744374B1 - Apparatus and method for preventing battery using protective circuit - Google Patents

Abstract

In the present invention, when it is not possible to control a relay that energizes or cuts off power supplied to a battery, the protection circuit changes the state of the protection circuit from off to on, Thereby preventing overcharging of the battery and preventing the surge current from flowing into the battery by changing the state of the protection circuit from off to on when a surge current exceeding a predetermined current value flows through the battery And a battery protection device and method using the protection circuit.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and method for protecting a battery using a protection circuit, and more particularly, The battery is prevented from being overcharged by allowing the current flowing into the battery to flow to the protection circuit, and when a surge current exceeding a predetermined current value flows through the battery, the state of the protection circuit To a battery protection device and a method using a protection circuit that prevents a surge current from flowing into a battery by changing the off state of the battery from off to on.

Generally, the secondary battery includes a nickel / cadmium (Ni-Ca) secondary battery, a nickel / hydrogen (Ni-Mh) secondary battery, a sealed lead acid (SLA) secondary battery, a lithium ion secondary battery, A secondary battery, and a reusable alkaline secondary battery. When the secondary battery is overcharged beyond the proper charging condition, gas generation or heat generation due to decomposition of the electrolytic solution may occur, resulting in deterioration or breakage of battery performance. In particular, the lithium ion secondary battery has a degree of deterioration or damage when it is overcharged, and therefore, a relay control technique is provided to protect the lithium ion secondary battery from overcharging.

When the overcurrent flows into the secondary battery, the current sensor senses an overcurrent, and the control unit controls the relay according to the detection result to protect the secondary battery. . However, there is a problem that the circuit is damaged (for example, fusion) due to the delay time until the control unit receives the measurement value from the current sensing sensor and controls the relay.

Further, in the case of a motor which is essentially used in a vehicle (for example, an electric vehicle) using a battery as a main power source, since the relay can not be controlled during the driving of the motor due to a safety problem, the secondary battery can not be protected from an overcurrent I have a problem.

Korean Patent Laid-Open Publication No. 10-2013-0090255 discloses an overcharge preventing circuit. When a secondary battery is overcharged due to a charging voltage exceeding a threshold value (Vmax) So that the current flowing to the secondary battery is introduced into the overcharge prevention circuit by preventing the overcharge of the secondary battery by turning on the chemical switching device.

However, when the secondary battery is overcharged and the charge current value flowing to the overcharge protection circuit is large, the chemical switching device is damaged and the secondary battery can not be prevented from being overcharged. .

In order to solve the problems of the above-described conventional relay control technology and overcharge prevention circuit, the present inventors have found that when the control of the relay for energizing or interrupting the power supplied to the battery is impossible, The battery is prevented from being overcharged by changing the current from the off state to the on state so that the current flowing into the battery flows to the protection circuit and when the surge current exceeding the preset current value flows through the battery, A battery protecting apparatus and method using a protection circuit that prevents a surge current from flowing into a battery by changing the state of a circuit from off to on has been invented.

Korean Patent Publication No. 10-2013-0090255

 SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above-described problems, and an object of the present invention is to provide a method of controlling a relay, The current flowing into the battery is changed to the on state to flow the current to the protection circuit so as to prevent the battery from being overcharged and in the case where a surge current exceeding a predetermined current value flows through the battery, Off state to an on-state, thereby preventing a surge current from flowing into the battery.

More specifically, it is an object of the present invention to provide a power supply control apparatus and a power supply control method of a power supply apparatus, in which, when a relay is abnormally operated (for example, a relay is fixed by fusion) Which is capable of preventing the battery from being damaged due to overheating or swelling by allowing the power supplied from the battery to be supplied to the protection circuit before being supplied to the battery.

It is another object of the present invention to provide a power supply control apparatus and a power supply control method of a power supply apparatus capable of detecting a surge current generated and output from a power supply unit, And preventing the battery from being damaged due to overheating or swelling by allowing the battery to flow into the protection circuit before the battery is protected.

Among the embodiments, a battery protection device using a protection circuit includes a protection circuit provided between a battery that is charged or discharged by receiving power from a power supply unit and a relay unit that energizes or cuts off power supplied from the power supply unit; And a protection circuit control unit for changing the state of the protection circuit to ON or OFF state.

In one embodiment, the protection circuit control unit changes the state of the protection circuit from OFF to ON based on at least one of the charging voltage value of the battery, the current value of the current flowing into the battery, and the state of the relay unit So that the current flowing into the battery flows to the protection circuit.

In one embodiment, the battery protection apparatus using the protection circuit may further include a relay control unit for changing the state of the relay unit to an on state or an off state.

In one embodiment, the battery protection device using the protection circuit may further include a voltage measurement unit for measuring a charging voltage value of the battery.

In one embodiment, the relay control unit may change the state of the relay unit from on to off when the charge voltage measured through the voltage measurement unit corresponds to a predetermined voltage value or more.

In one embodiment, when the relay control unit can not change the state of the relay unit from the on state to the off state, the protection circuit control unit may change the state of the protection circuit from off to on.

In one embodiment, the battery protection apparatus using the protection circuit may further include a current measuring unit measuring a current value of a current flowing into the battery and transmitting the measured current value to the protection circuit controller.

In one embodiment, the protection circuit control unit may change the state of the protection circuit from off to on when the current value of the current measured through the current measurement unit corresponds to a predetermined current value or more.

In one embodiment, the protection circuit comprises a protection circuit switch; And a protection circuit resistor.

In one embodiment, the protection circuit switch is changed to an on or off state through the control of the protection circuit control section, and when the protection circuit switch is turned on, a current flowing into the battery flows to the protection circuit resistance have.

In one embodiment, the resistance value of the protection circuit resistance may be determined according to the capacity of the battery.

In one embodiment, the protection resistor may be a variable resistor.

Among other embodiments, a battery protection method using a protection circuit includes: (a) a battery that is charged or discharged by receiving power from a power supply unit; and a protection circuit provided between relay units that energize or cut off power supplied from the power supply unit ; (b) checking at least one of a charging voltage value of the battery, a current value of a current flowing into the battery, and a state of the relay unit; And (c) changing the state of the protection circuit from off to on based on at least one of a charging voltage value of the battery, a current value of a current flowing into the battery, and a state of the relay unit, And allowing the current to flow to the protection circuit.

In one embodiment, the step (b) may include the step of the voltage measuring unit measuring the charging voltage value of the battery.

In one embodiment, the step (c) may include changing a state of the relay unit from on to off when the charge voltage measured through the voltage measuring unit corresponds to a predetermined voltage value or more have

In one embodiment, the step (c) may further include changing the state of the protection circuit from off to on when the state of the relay unit can not be changed from on to off.

In one embodiment, the step (b) may include measuring a current value of a current flowing into the battery by the current measuring unit.

In one embodiment, the step (c) includes the steps of changing the state of the protection circuit from off to on when the current value of the current flowing into the battery measured through the current measuring unit is equal to or greater than a predetermined current value ; ≪ / RTI >

An apparatus and method for protecting a battery using a protection circuit according to an exemplary embodiment of the present invention can change a state of a protection circuit from off to on when a relay is abnormally operated to overcharge the battery, Into the protection circuit. Therefore, the current flows to the protection circuit through the control of the protection circuit, thereby preventing the battery from being damaged due to overheating or swelling of the battery due to overcharging, thereby prolonging the life of the battery.

Further, the present invention is applicable to a case where a short-circuit of the main relay is not permitted (for example, when a surge current is temporarily output from the motor in a situation where the battery is charged by electric power generated during driving of the electric automobile motor If the main relay is short-circuited, the main relay may be in an off-state, but if the main relay is short-circuited, the motor may suddenly stop during operation of the electric vehicle, so that the BMS (Battery Management System) The state of the protection circuit is changed from off to on in order to prevent the surge current from flowing into the battery regardless of whether the main relay is short-circuited.

Fig. 1 is a block diagram showing a configuration of a conventional electric vehicle 1; Fig.
2 is a block diagram showing the configuration of a battery protection apparatus 100 using a protection circuit according to an embodiment of the present invention.
3 is a circuit diagram showing a circuit of a battery protection device 100 using a protection circuit according to an embodiment of the present invention.
4 is a circuit diagram showing a circuit of a battery protection device 100 using a protection circuit according to another embodiment of the present invention.
5 is a flowchart showing an operation procedure according to an embodiment of the battery protecting apparatus 100 using a protection circuit.
6 is a flowchart showing an operation procedure according to another embodiment of the battery protecting apparatus 100 using the protection circuit.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Further, the term "part" in the description means a unit for processing one or more functions or operations, which may be implemented by hardware, software, or a combination of hardware and software.

Fig. 1 is a block diagram showing a configuration of a conventional electric vehicle 1; Fig.

1, an electric vehicle 1 may include a battery 10, a battery management system (BMS) 20, an ECU (Electronic Control Unit) 30, an inverter 40 and a motor 50 have.

The battery 10 is an electric energy source that drives the electric vehicle 1 by providing a driving force to the motor 50. [ The battery 10 can be charged or discharged by the inverter 40 in accordance with the driving of the motor 50 and the internal combustion engine (not shown).

Here, the type of the battery 10 is not particularly limited and may be a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, or the like.

The battery 10 is formed of a battery pack in which a plurality of battery cells are connected in series and in parallel. At least one such battery pack may be provided to form the battery 10.

The BMS 20 estimates the state of the battery 10 and manages the battery 10 using the estimated state information. For example, estimates and manages state information of the battery 10 such as a state of charge (SOC) of the battery 10, a state of health (SOH), a maximum input / output power allowable amount, and an output voltage. By using this state information, it is possible to control the charging or discharging of the battery 10, and furthermore, to estimate the replacement time of the battery 10.

The BMS 20 may correspond to or include any one or more of the relay control unit 130 and the protection circuit control unit 160 described later with reference to FIGS. 2 to 6. The BMS 20 may measure the voltage The relay 110, the relay 120, the current measuring unit 140 and the protection circuit 150 are controlled so that the current stability between the battery 10 and the motor 50 can be enhanced.

The ECU 30 is an electronic control device for controlling the state of the electric vehicle 1. [ For example, it determines the degree of torque based on information such as an accelerator, a break, and a speed, and controls the output of the motor 50 to match the torque information.

The ECU 30 also sends a control signal to the inverter 40 so that the battery 10 can be charged or discharged based on state information of the SOC, SOH, etc. of the battery 10 transmitted by the BMS 20 .

The inverter 40 causes the battery 10 to be charged or discharged based on the control signal of the ECU 30. [

The motor 50 drives the electric vehicle 1 based on control information (for example, torque information) transmitted from the ECU 30 using the electric energy of the battery 10.

Since the electric vehicle 1 is driven using the electric energy of the battery 10, the battery 10 and the motor 50 are connected through various circuits. At this time, a current having a different potential difference may flow from the microcurrent to the high current in the circuit. In order to protect the battery 10 and the motor 50 from such a current, it is preferable to provide a circuit protection device such as a relay.

FIG. 2 is a block diagram illustrating a configuration of a battery protection apparatus 100 using a protection circuit according to an embodiment of the present invention. FIG. 3 is a block diagram of a battery protection apparatus 100 using a protection circuit according to an embodiment of the present invention. 4 is a circuit diagram showing a circuit of a battery protection device 100 using a protection circuit according to another embodiment of the present invention.

2 to 4, a battery protection device 100 using a protection circuit includes a voltage measurement unit 110, a relay unit 120, a relay control unit 130, a current measurement unit 140, a protection circuit 150 And a protection circuit control unit 160. [

At this time, the battery protecting apparatus 100 using the protection circuit may be connected to the power supply unit 60 and the battery 70.

Here, the power supply unit 60 may include a converter 61 and an AC voltage source 62. The converter 61 converts the AC input voltage supplied from the AC voltage source 62 into a DC output voltage. Accordingly, the power supply unit 60 can serve to charge the battery 70 by supplying the converted DC output voltage to both ends of the battery 70.

Meanwhile, the power supply unit 60 may be configured in a manner different from that of FIG. 2, which will be described in more detail with reference to FIG.

4, the power supply 60 'shown in FIG. 4 may take a different form from the power supply 60 shown in FIGS. 2 and 3, and the power supply 60' includes an inverter 61 ' And may include a motor 62 '.

The inverter 61 'may be included in the inverter 40 shown in FIG. 1 described above. When the electric vehicle 1 shown in FIG. 1 travels through the charging electric power of the battery 70 to be described later, The inverter 61 'can convert the DC voltage output from the battery 70 into an AC voltage, and drive the motor 62' through the converted AC voltage.

On the other hand, when the electric vehicle 1 shown in Fig. 1 travels by the power of the internal combustion engine (not shown) or decelerates by using the decelerator during traveling, the inverter 61 ' And the battery 70 can be charged through the converted DC voltage.

At this time, when the current value of the current generated during the driving of the motor 62 is equal to or greater than a predetermined current value and the current flows to the battery 70, the protection circuit control unit 160, which will be described later, 150 is changed from off to on, the battery 70 can be prevented from overcharging. Here, the predetermined current value is a value that can be set by the user or can be initially set to a range in which the current does not damage the battery. For example, the preset current value may be 50A.

Finally, the motor 62 'may be included in the motor 50 shown in Fig. 1 described above.

The battery 70 may be charged or discharged by receiving power from the power supply unit 60. In one embodiment, the battery 70 may be included in the battery 10 shown in FIG. 1 described above, and the battery 70 will not be described in detail because it uses existing known techniques. Is not limited as long as the battery 70 is charged with electric power through the power supply unit 60, the type of the battery 70 and the charging capacity are not limited.

The voltage measuring unit 110 may be positioned adjacent to both ends of the battery 70 to measure the potential difference of the battery 70. [ Meanwhile, the voltage measuring unit 110 may include at least one switch element, a capacitor, a lead, and the like to measure the voltage of the battery 70. The charging voltage value measured through the voltage measuring unit 110 may be transmitted to the relay controller 130, which will be described later.

The relay unit 120 may energize or shut off the power supplied from the power supply unit 60 and may include a first main relay 121, a second main relay 122, a precharge resistor 123, 124).

First, the first main relay 121 may be connected to the positive (+) pole of the battery 70 and the second main relay 122 may be connected to the negative (-) pole of the battery 70. Power can be supplied from the power supply unit 60 to the battery 70 when the states of the first main relay 121 and the second main relay 122 are changed from the off state to the on state.

The precharge resistor 123 and the precharge relay 124 may be connected in parallel with the first main relay 121 and the state of the precharge relay 124 is changed to the on state, The current value of the corresponding electric power may be reduced during the charging start (for example, time corresponding to 20 ms or less) of the battery 70. Accordingly, the precharge relay 124 reduces the current value of the overcurrent that may occur in the step of starting charging, and causes the overcurrent to flow through the pre-charge resistor 123 so that the first main relay 121 is over- And the battery 70 can be protected from the overcurrent. The state of the precharge relay 124 is changed from the on state to the off state and the state of the first main relay 121 is changed from the off state to the on state, so that the battery 70 is disconnected from the power supply unit 60 The power can be supplied to continue charging.

The relay control unit 130 may be connected to the voltage measurement unit 110, the relay unit 120 and a protection circuit control unit 160 to be described later. The relay control unit 130 may be connected to the battery 70, and when the measured charge voltage value through the voltage measuring unit 110 corresponds to a predetermined voltage value or more, the relay unit 120 is changed from on to off state Can play a role. Here, the predetermined voltage value is initially set to a range in which the corresponding voltage does not damage the battery, or may be set by a user. For example, the preset voltage value may be 400V.

The relay control unit 130 may control the first main switch 110 included in the relay unit 120 when the charge voltage of the battery 70 measured by the voltage measuring unit 110 is equal to or greater than a preset voltage value. The state of the relay 121 and the second main relay 122 can be changed from the on state to the off state so that the power supplied from the power supply unit 60 to the battery 70 can be cut off.

If the charging voltage of the battery 70 measured through the voltage measuring unit 110 does not correspond to a preset voltage value or more, the relay controller 130 controls the first main relay The state of the first main relay 121 and the second main relay 122 is not changed from ON to OFF, so that the charging of the battery 70 can be maintained.

The relay controller 130 controls the first main relay 121 and the second main relay 122. The first main relay 121 and the second main relay 122 are connected to each other, The relay control unit 130 can not change the state of the first main relay 121 and the second main relay 122 from the on state to the off state in spite of the fact that the state of the first main relay 121 and the second main relay 122 are changed from on to off, The control unit 130 can transmit a switch change disable signal to the protection circuit control unit 160, which will be described later. For example, when the first main relay 121 and the second main relay 122 are overheated and fused due to an overcurrent flowing to the relay unit 120, or when the relay control unit 130 is connected to the first main relay 121 and / If the state of the second main relay 122 can not be controlled, the relay control unit 130 may transmit a switch change disable signal to the protection circuit control unit 160.

If the relay control unit 130 fails to change the state of the first main relay 121 and the second main relay 122 from the on state to the off state, the switch unchangeable signal is transmitted from the relay control unit 130 to the protection circuit control unit 130. [ The first main relay 121 and the second main relay 122 are not changed from the ON state to the OFF state.

The current measuring unit 140 is connected in series with the battery 70 to measure a current value of power flowing from the power supplying unit 60 to the battery 70. [

The current measuring unit 140 performing such a function may include a current sensor corresponding to at least one of a current transformer method, a Hall element method, and a fuse method.

Here, the current sensor may mean a sensor for measuring the amount of current flowing in the direct current.

In one embodiment, the current measuring unit 140 may include a ballast (e.g., a resistor having a high resistance value) capable of protecting internal elements from fire due to an overcurrent (for example, current corresponding to 50 A or more) (Not shown).

The current measured by the current measuring unit 140 may be transmitted to the protection circuit controller 160 to be described later. The current measuring unit 140 may measure the current value through the current measuring unit 140 as long as the current measuring unit 140 performs the above- It should be noted that the kind of the compound is not limited.

The protection circuit 150 is provided between the battery 70 that is charged or discharged by receiving power from the power supply unit 60 and the relay unit 120 that energizes or cuts off the power supplied from the power supply unit 60, A circuit switch 151 and a protection circuit resistor 152.

The state of the protection circuit switch 151 may correspond to either a short-circuit state in which a pair of conductors are spaced from each other or a contact state in which a pair of conductors are in contact with each other. Current flows into the battery 70. When the state of the protection circuit switch 151 corresponds to the contact state, current does not flow into the battery 70 and current Can be supplied.

The protection circuit switch 151 may be turned on or off through the control of the protection circuit controller 160 to be described later. When the protection circuit switch 151 is turned on, Current can flow to the protection circuit resistor 152.

The resistance value of the protection circuit resistor 152 can be varied according to the charging capacity of the battery 70, and accordingly, the power value of the corresponding incoming current can be reduced.

As a result, when the state of the protection circuit switch 151 corresponds to the ON state, a current flows due to the contact of the protection circuit switch 151, and the current value of the current flowing at this time is reduced by the protection circuit resistor 152 .

The protection circuit control unit 160 may be connected to the relay control unit 130, the current measurement unit 140, and the protection circuit 150.

The protection circuit control unit 160 may change the state of the protection circuit 150 from off to on when the current value of the current measured through the current measurement unit 140 corresponds to a predetermined current value or more. More specifically, the protection circuit control unit 160 compares the current value of the current flowing into the battery 70 with the predetermined current value received from the current measurement unit 140, The state of the protection circuit switch 151 can be changed from the off state to the on state so that the power supplied from the power supply unit 60 can be supplied to the protection circuit 150. [

In addition, the protection circuit control unit 160 can receive the switch changeover signal from the relay control unit 130 and change the state of the protection circuit switch 151 from off to on. When the relay unit 120 fails The battery 70 can be prevented from being overcharged by cutting off the power supplied to the battery 70 through the protection circuit 150. [

The components of the battery protection device 100 using the protection circuit according to the embodiment of the present invention have been described above and the embodiments of the operation of the battery protection device 100 using the protection circuit including these components Will be described in detail with reference to Figs. 5 and 6 below.

5 is a flowchart showing an operation procedure according to an embodiment of the battery protecting apparatus 100 using a protection circuit.

5, the voltage measuring unit 110 measures the charging voltage value of the battery 70 which is currently being charged (S501), and transmits the measured charging voltage value to the relay control unit 130 (S502 ).

Next, the relay control unit 130 compares and determines whether the charge voltage value transmitted through the voltage measurement unit 110 corresponds to a predetermined voltage value or more (S503). Here, the predetermined voltage value is initially set to a range in which the corresponding voltage does not damage the battery, or may be set by a user. For example, the preset voltage value may be 400V.

The relay controller 130 changes the states of the first main relay 121 and the second main relay 122 from the on state to the off state when the determined result value is equal to or greater than a preset voltage value S504).

On the contrary, when the determined result value does not correspond to a predetermined voltage value or more, the relay control unit 130 keeps the states of the first main relay 121 and the second main relay 122 on.

The relay control unit 130 determines whether the states of the first main relay 121 and the second main relay 122 are changed from the on state to the off state in step S505. If the first main relay 121 and the second main relay 122 are turned off, When the state of the relay 122 does not change from the on state to the off state, the relay control unit 130 transmits a switch change impossibility signal to the protection circuit control unit 160 (S506).

The protection circuit controller 160 receives the switch changeover signal and changes the state of the protection circuit 150 from off to on (S507). The protection circuit control unit 160 causes the current flowing into the battery 70 to flow to the protection circuit 150 in step S508 and consequently the power supplied from the power supply unit 60 to the battery 70 is shut off S509).

On the contrary, when the relay control unit 130 changes the state of the first main relay 121 and the second main relay 122 from the on state to the off state, the electric power supplied to the battery 70 is cut off, (S509). ≪ / RTI >

6 is a flowchart showing an operation procedure according to another embodiment of the battery protecting apparatus 100 using the protection circuit.

6, the current measuring unit 140 measures the current value of the current flowing into the battery 70 (S601), and transmits the measured current value to the protection circuit controller 150 (S602) .

Next, the protection circuit controller 160 compares and determines whether the measured current value transmitted through the current measuring unit 140 is equal to or greater than a preset current value (S603). Here, the predetermined current value is a value that can be set by the user or can be initially set to a range in which the current does not damage the battery. For example, the preset current value may be 50A.

If the determined result value is equal to or greater than a preset current value, the protection circuit controller 160 changes the state of the protection circuit 150 from off to on (S604).

On the contrary, if the determined result value does not correspond to the preset current value or more, the operation returns to the start.

The protection circuit control unit 160 causes the current flowing into the battery 70 to flow to the protection circuit in step S605 and consequently the power supplied from the power supply unit 60 to the battery 70 is shut off in step S606.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

1: Electric vehicle
10: Battery 20: BMS
30: ECU 40: Inverter
50: Motor
60: Power supply
61: converter 62: AC voltage source
60 ': Power supply
61 ': inverter 62': motor
70: Battery
100: Battery protection device using protection circuit
110: voltage measuring unit
120: relay part
121: first main relay 122: second main relay
123: pre-charge resistor 124: pre-charge relay
130: Relay controller
140: current measuring unit
150: Protection circuit
151: Protection circuit switch 152: Protection circuit resistance
160: Protection circuit control section

Claims (16)

A protection circuit provided between a battery that is charged or discharged by receiving power from the power supply unit and a relay unit that energizes or cuts off power supplied from the power supply unit;
A protection circuit control unit for changing the state of the protection circuit to ON or OFF state;
A relay controller for changing the state of the relay unit to an on state or an off state;
A voltage measuring unit for measuring a charged voltage value of the battery; And
And a current measuring unit for measuring a current value of a current flowing into the battery,
The relay control unit,
And changing the state of the relay unit from the on state to the off state when the charge voltage measured through the voltage measurement unit corresponds to a predetermined voltage value or more,
The protection circuit control unit,
When the relay control unit can not change the state of the relay unit from the on state to the off state or when the current value of the current measured through the current measurement unit corresponds to a predetermined current value or more, State,
The protection circuit comprising:
Protection circuit switches; And
A protective circuit resistor,
Wherein the protection circuit switch is changed to an on or off state through the control of the protection circuit control unit and a current flowing into the battery flows to the protection circuit resistance when the protection circuit switch is turned on, Characterized in that the resistance value of the resistance is a variable resistance determined according to the capacity of the battery.
Battery protection device using protection circuit.
delete delete delete delete delete delete delete delete delete (a) a protection circuit provided between a battery that is charged or discharged by receiving power from a power supply unit and a relay unit that energizes or cuts off power supplied from the power supply unit;
(b) measuring a charging voltage value of the battery and a current value of a current flowing into the battery, respectively; And
(c) when the charge voltage measured by the voltage measuring unit is greater than or equal to a preset voltage value, the relay unit changes its state from on to off and fails to change the state of the relay unit from on to off And changing the state of the protection circuit from off to on when the current value of the current flowing into the battery measured by the current measuring unit is equal to or greater than a preset current value,
The protection circuit comprising:
Protection circuit switches; And
A protective circuit resistor,
The step (c)
(C) flowing the current flowing into the battery to the protection circuit resistor whose resistance value is determined according to the capacity of the battery when the protection circuit switch which is changed to the on or off state is turned on through the step ≪ / RTI >
A method of protecting a battery using a protection circuit. delete delete delete delete delete

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