KR102301019B1 - Charging/discharging device and method for electric vehicle - Google Patents

Abstract

The present invention relates to a charging/discharging control device and method for an electric vehicle. The present invention provides a charging/discharging control device for controlling charging and discharging of a battery of an electric vehicle, comprising: a first power supply line and a second power supply line respectively connected to both ends of a battery; a charge/discharge control line disposed in parallel with the second power supply line; a back-to-back IGBT provided in the charge/discharge control line; and an MCU for controlling the operation of the back-to-back IGBT.

Description

Charging/discharging control device and method for electric vehicle {CHARGING/DISCHARGING DEVICE AND METHOD FOR ELECTRIC VEHICLE}

The present invention relates to a charging/discharging control device and method for an electric vehicle. More particularly, the present invention relates to a charge/discharge control apparatus and method for an electric vehicle capable of stably charging and discharging a battery.

As interest in the environment and energy increases, the development and mass production of electric vehicles using electricity as an energy source are increasing. These electric vehicles include a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and an electric vehicle in which an engine is removed and power is supplied only by a motor (Electric Vehicle: EV), and a fuel cell electric vehicle (FCEV) using a fuel cell. Among them, the PHEV and EV charge the high voltage battery provided inside the vehicle using power supplied from the outside, and supply power to the driving motor for driving the vehicle through discharge control of the power charged in the high voltage battery.

In controlling the charging and discharging of high voltage batteries, there are some using a mechanical relay as a switch. However, when a mechanical relay is used, there is a problem in that it increases the size and weight of vehicle electrical components because it is bulky and heavy, and there is a problem in that the mechanical relay is fused due to an inrush current due to a switch contact. In addition, when the charging and discharging lines are configured as one line, there is a problem in that the charging efficiency is lowered because heat is not distributed due to the single charging/discharging line.

Republic of Korea Patent Publication No. 10-2018-0113338 (published on October 16, 2018)

An object of the present invention is to provide a charge/discharge control device and method for an electric vehicle capable of stably charging and discharging a battery by effectively blocking the inrush current and preventing relay fusion by reducing the load borne by the relay. The purpose.

The present invention provides a charging/discharging control device for controlling charging and discharging of a battery of an electric vehicle, comprising: a first power supply line and a second power supply line respectively connected to both ends of a battery; a charge/discharge control line disposed in parallel with the second power supply line; a back-to-back IGBT provided in the charge/discharge control line; and an MCU for controlling the operation of the back-to-back IGBT.

In an embodiment, the back-to-back IGBT includes a first IGBT and a second IGBT in which an emitter or a collector is connected to each other.

In addition, the charging/discharging control device for the electric vehicle further includes a gate driving IC for applying a PWM control signal for driving to the first IGBT or the second IGBT, and the charging/discharging is performed according to the duty of the PWM control signal. Current flow through the control line may be controlled.

In addition, a first relay may be provided in the first power supply line.

In addition, a relay may be provided in the second power supply line at a position parallel to the charge/discharge control line.

In an embodiment, the second power supply line may further include a charging line and a discharging line disposed in parallel with the charging/discharging control line.

In addition, a second relay may be provided in the charging line, and a third relay may be provided in the discharge line.

In an embodiment, the MCU may control the back-to-back IGBT before turning on the relay of the second power supply line to perform precharging when charging or discharging the battery.

In addition, when the relay of the second power supply line is in an on state and the temperature or current of the relay is greater than a reference value, the MCU controls the back-to-back IGBT to allow current flow through the charge/discharge control line can do it

The present invention provides at least one of a low-speed charging unit and a fast charging unit, an inverter, a battery, a first power supply line and a second power supply line respectively connected to both ends of the battery, and the second power supply line in parallel An electric vehicle comprising a charge/discharge control line disposed on the charge/discharge control line, a back-to-back IGBT configured by interconnecting emitters or collectors of at least two IGBTs, and an MCU for controlling the operation of the back-to-back IGBT In the battery charging/discharging control method, in the initial stage of controlling the charging or discharging of the battery, the relay provided in the second power supply line is turned off, and the back-to-back IGBT is controlled to perform precharging through the charging/discharging control line. It provides a charging/discharging control method for an electric vehicle comprising;

In an embodiment, a charging line is provided in the second power supply line in parallel with the charge/discharge control line, and a second relay is provided in the charging line, and the control method includes: The method may further include turning on a second relay to charge the battery through the charging line.

In an embodiment, a discharge line is provided in the second power supply line in parallel with the charge/discharge control line, and a third relay is provided in the discharge line, and the control method includes: The method may further include turning on the third relay to discharge the inverter through the discharge line.

The method may further include, when charging of the battery is performed by the low-speed charging unit, controlling the back-to-back IGBT to perform low-speed charging of the battery through the charge/discharge control line.

In addition, the present invention provides at least one of a low-speed charging unit and a high-speed charging unit, an inverter, a battery, a first power supply line and a second power supply line respectively connected to both ends of the battery, and the second power supply line. Electricity comprising a charge/discharge control line disposed in parallel, a back-to-back IGBT provided on the charge/discharge control line and configured by interconnecting at least two IGBT emitters or collectors, and an MCU controlling the operation of the back-to-back IGBT A method for controlling charging and discharging a battery of a vehicle, the method comprising: at least one relay provided in a second power supply line in parallel with the charging/discharging control line, and measuring a temperature of the relay or a current value flowing through the relay; determining whether the temperature or the current value is greater than a reference value; and permitting current flow through the charge/discharge control line by switching the back-to-back IGBT when the temperature or the current value is greater than a reference value as a result of the determination.

In one embodiment, in the second power supply line, a charging line and a discharging line are provided in parallel with the charge/discharge control line, and a second relay and a third relay are respectively provided in the charging line and the discharging line, , the second relay may be turned on during discharging, and the third relay may be turned on during charging.

According to the present invention, it is possible to block the inrush current by using the back-to-back IGBT configuration, and to reduce the load applied to the relay during charge/discharge control of the battery to prevent fusion of the relay and to control excessive heat generation.

Accordingly, the charge/discharge control apparatus and method for an electric vehicle according to the present invention can minimize the risk of failure and perform stable and efficient charge/discharge control of a high voltage battery.

1 is a view showing a schematic configuration of a power system of an electric vehicle having a charge/discharge control device for an electric vehicle according to a preferred embodiment of the present invention.
2 is a diagram illustrating a back-to-back IGBT module in a charge/discharge control device for an electric vehicle according to a preferred embodiment of the present invention.
3 is a flowchart illustrating a charging control method according to a preferred embodiment of the present invention.
4 is a flowchart illustrating a discharge control method according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, preferred embodiments of the present invention will be described below, but the technical spirit of the present invention is not limited thereto and may be variously implemented by those skilled in the art without being limited thereto.

Power system including charge/discharge control device 200

1 is a view showing a schematic configuration of a power system of an electric vehicle having a charge/discharge control device for an electric vehicle according to a preferred embodiment of the present invention. 2 is a diagram illustrating a back-to-back IGBT module in a charge/discharge control device for an electric vehicle according to a preferred embodiment of the present invention.

Referring to FIG. 1 , a power system of an electric vehicle is connected to a plurality of power supply/supply devices 20 , 30 , 40 , 50 and power supply/supply devices 20 , 30 , 40 , and 50 to supply power. It includes a power distribution unit 10 that distributes (PDU) and a battery unit 100 connected to the power distribution unit 10 . The battery unit 100 includes a battery 110 that stores power, a power management unit 120 that manages the state of a vehicle or battery and instructs charging or discharging of the battery, and according to a request of the power management unit 120 . and a charge/discharge control device 200 for controlling charging or discharging of the battery 110 . The power management unit 120 and the charge/discharge control device 200 may be connected through a signal connector 130 for signal connection.

The power distribution unit 10 selectively controls the connection between the plurality of power supply/supply devices 20 , 30 , 40 , 50 and the charge/discharge control device 200 . The charging/discharging control device 200 is connected to at least one of the plurality of power supply/supply devices 20 , 30 , 40 , and 50 by the power distribution unit 10 to receive or supply power.

The power supply/supply device 20 , 30 , 40 , and 50 includes a low-speed charging unit 20 performing low-speed charging of the battery, a fast charging unit 30 performing high-speed charging of the battery 110 , and the battery 110 . It may include an inverter 40 that receives power and supplies power to a driving motor (not shown) for driving the vehicle. In addition, the ACCM 54 (Air Conditioning Control Module) for controlling an air conditioner such as a heater 52 for heating a specific part, an air conditioner, etc., or the temperature inside the vehicle cabin, which consumes power for the operation of the electric vehicle A power consuming unit 50 such as a CHCM 56 (Coolant Heater Control Module) for controlling the , may be included as the power supply/supply device 20 , 30 , 40 , 50 .

The power management unit 120 is a vehicle control module (VCM: Vehicle Control Module) that controls the driving and operation of the electric vehicle and / and a battery management system (BMS: Battery Monitoring System) for monitoring and controlling the state of the battery 110 . can be The power management unit 120 may transmit an instruction for charging or discharging the battery 110 to the charging/discharging control device 200 .

The charging/discharging control device 200 is respectively connected to both ends of the battery 110 to connect the battery 110 and the power distribution unit 10 to the first power supply line 202 and the second power supply line 204 . includes In one embodiment, the second power supply line 204 is provided with a charge/discharge control line 208 in parallel. In addition, the second power supply line 204 may further include a charging line 206a and a discharging line 206b disposed in parallel with the charging/discharging control line 208 . Further, in one embodiment, the first power supply line 202 is connected to the positive (+) pole of the battery 110 and the second power supply line 204 is connected to the negative (-) pole of the battery 110 . can be connected

In addition, the charging/discharging control device 200 is provided in the first power supply line 202 to connect or block the first power supply line 202 to the first relay 210 and the charging line 206a. The second relay 220 for connecting or blocking the charging line 206a, the third relay 230 provided on the discharging line 206b to connect or blocking the discharging line 206b, and the charging/discharging control line 208 It may include a back-to-back IGBT 240 provided, and an MCU 250 for controlling the operation of these relays 210 , 220 , 230 and the back-to-back IGBT 240 . Meanwhile, in an embodiment, the second power supply line 204 may be provided with a shunt resistor 222 to sense the current of the battery 110 .

The back-to-back IGBT 240 connects two IGBTs 242 and 244 to face each other. An Insulated-Gate Bipolar Transistor (IGBT) is an electrical device having a composite in which an input part has a MOSFET structure and an output part has a bipolar structure. In the case of IGBT, current blocking is possible in the _{I CE direction, but in the I EC} direction, it operates as a short circuit like a general circuit. In the present invention, there is a feature in applying the back-to-back IGBT 240 of the back-to-back connection method configured by connecting two IGBTs 242 and 244 opposite to each other. In an embodiment, emitters of the first IGBT 240a and the second IGBT 240b may be connected to each other. The back-to-back IGBT 240 configured in this way may be capable of blocking current in both directions. In addition, the first IGBT 240a and the second IGBT 240b may have collectors connected to each other, and in this case, the control may be performed in the opposite way to the case where the emitters are connected to each other. have.

In order to control the back-to-back IGBT 240 , the charging/discharging control device 200 includes a gate driving IC 242 for gate driving of the first IGBT 240a and the second IGBT 240b, and a voltage for supplying a voltage. A regulator 244 may be further included. The gate driving IC 242 may transmit a gate driving signal to the first IGBT 240a and the second IGBT 240b under the control of the MCU 250 . The back-to-back IGBT 204 controls by supplying a PMW driving signal to at least one of the first IGBT 240a and the second IGBT 240b, thereby supplying current in the right or left direction based on FIG. 2 . can make it possible

Pre-Charge

Pre-charge at the time of discharge control using the charge/discharge control device 200 according to the present invention will be described. For example, when electric power is supplied from the battery 110 to the inverter 40 , if the potentials between the battery 110 and the inverter 40 do not match, the relay may be fused by the inrush current. In order to prevent this, the electric potential of the battery 110 and the inverter 40 is equalized by controlling the back-to-back IGBT 240 during discharge control.

When describing the procedure for precharging, first, all the relays 210 , 220 , 230 and the back-to-back IGBT 240 are in an open (that is, off) state.

Next, the first relay 210 is turned on to prepare for discharge.

The back-to-back IGBT 240 is controlled by PWM (Pulse Width Modulation) so that current is supplied to the inverter 40 through the charge/discharge control line 208 . When a driving signal is applied to the gate of the back-to-back IGBT 240 in a PWM manner, current is sequentially supplied to the inverter 40 through the charge/discharge control line 208, and the potential of the battery 110 and the inverter 40 is equal to the potential becomes

Thereafter, the back-to-back IGBT 240 is opened and the third relay 230 provided in the discharge line 206b is turned on to start discharging.

Meanwhile, this precharge control may be performed even when the battery 110 is being charged. That is, in order to prevent damage to the relays 210 and 220 due to inrush current when the battery 110 is charged, the first relay 210 is turned on and before the second relay 220 is turned on, the back-to-back IGBT ( 240) can be PWM-controlled so that current from the low-speed charging unit 20 or the high-speed charging unit 30 is pre-supplied to the battery 110 through the charge/discharge control line 208 . After a predetermined time or a predetermined voltage is reached, the back-to-back IGBT 240 is opened and the second relay 220 is turned on to continue charging the battery 110 .

Heat control during charging and discharging

First, relay heating control at the time of discharge will be described.

The first relay 210 is on, the back-to-back IGBT 240 is open, the second relay 220 is off, and the third relay 230 is on. / or it is assumed that the power is being supplied to the power consuming unit 50 .

In an embodiment, the MCU 250 may detect a load applied to at least one of the first or third relays 210 and 230 or detect the temperature of the first or third relays 210 and 230 . have. To this end, the MCU 250 may monitor the current flowing through the first or third relays 210 and 230 . Alternatively, a sensor for measuring the temperature of the first or third relays 210 and 230 or the temperature of the housing (not shown) of the charge/discharge control device 200 may be provided.

When an excessive load is applied to the first or third relays 210 and 230, or when the temperature of the first or third relays 210 and 230 rises above a predetermined value, the MCU 250 performs the back-to-back IGBT ( 240) is controlled by PMW to allow a current to partially flow to the charge/discharge control line 208.

Accordingly, the current supplied through the discharge line 206b is reduced, thereby reducing the load applied to at least the third relay 230 or reducing the temperature.

Next, relay heating control during charging will be described.

The first relay 210 is on, the back-to-back IGBT 240 is open, the second relay 220 is on, and the third relay 230 is off. It is assumed that charging of the battery 110 is performed through the

In an embodiment, the MCU 250 may detect a load applied to at least one of the first or second relays 210 and 220 or sense the temperature of the first or second relays 210 and 220 . have. To this end, the MCU 250 may monitor the current flowing through the first or second relays 210 and 220 . Alternatively, a sensor for measuring the temperature of the first or second relays 210 and 220 or the temperature of the housing (not shown) of the charge/discharge control device 200 may be provided.

When an excessive load is applied to the first or third relays 210 and 230, or when the temperature of the first or third relays 210 and 230 rises above a predetermined value, the MCU 250 performs the back-to-back IGBT ( 240) is controlled by PMW to allow a current to partially flow to the charge/discharge control line 208.

Accordingly, the current supplied through the charging line 206a is reduced, thereby reducing the load applied to at least the second relay 220 or reducing the temperature.

Slow charge control

Meanwhile, the charging/discharging control device 200 according to the present invention may provide a charging path through the charging/discharging control line 208 when the battery 110 is charged through the low-speed charging unit 20 .

The first relay 210 is on, the back-to-back IGBT 240 is open, the second relay 220 is off, and the third relay 230 is off. Assume that charging is in progress.

In the case of low-speed charging, the current is tens of amperes (A) or less, and since the IGBT can operate for high voltage and high current, in the case of low-speed charging, it may be possible to provide a charging path using a back-to-back IGBT.

During low-speed charging, the back-to-back IGBT 240 is PMW-controlled so that current can be supplied from the low-speed charging unit 20 to the battery 110 through the charge/discharge control line 208 .

Next, a charge/discharge control method according to a preferred embodiment of the present invention will be described.

How to control charging

3 is a flowchart illustrating a charging control method according to a preferred embodiment of the present invention.

A charging port is connected for charging (S100). The charging port may be connected to the low-speed charging unit 20 or the fast charging unit 30 according to a charging method.

At the start of charging, a precharge process may be performed (S102). In the precharging process, after the first relay 210 is turned on by the MCU 250 and before the second relay 220 is turned on, the back-to-back IGBT 240 is PWM controlled to control the charge/discharge control line 208 . ) may be performed by allowing the battery 110 to be connected through. In one embodiment, precharge controls the back-to-back IGBT 240 to a predetermined high duty, for example, a PWM duty of 95% (S104), and then controls the back-to-back IGBT 240 to a low duty, For example, it may be performed by controlling the PMW duty of 5% (S106). In some cases, it may be possible to open the back-to-back IGBT 240 .

After the pre-charging process ( S102 ) is completed, according to the charging method ( S108 ), in the case of fast charging, the second relay 220 is turned on to charge the battery 110 through the charging line 206a.

When charging the battery, the temperature of the first relay 210 or the second relay 220 may be measured (S112). When the temperature is greater than the reference value, the temperature of the relay can be lowered by switching the back-to-back IGBT 240 to a predetermined duty so that a portion of the battery charging current flows through the charge/discharge control line 208 ( S116 ). If the temperature is less than the reference value, it is also possible to turn off the back-to-back IGBT 240 (S118).

Steps S112 to S116 may also be performed by comparing the current flowing through the first relay 210 or the second relay 220 with a reference value.

Meanwhile, in step S108 , in the case of low-speed charging, the second relay 220 may be kept in an off state and the back-to-back IGBT 240 may be switched to charge the battery 110 through the charge/discharge control line.

Also, even in the case of low-speed charging, it may be possible to charge the battery 110 through steps S110 to S118 instead of step S120 .

Discharge control method

4 is a flowchart illustrating a discharge control method according to a preferred embodiment of the present invention.

During discharge control, for example, when discharging to the inverter 40 , a precharge process may be performed first ( S220 ). As described above, in the precharge process, all the relays 210 , 220 , 230 and the back-to-back IGBT 240 are opened (that is, off), and the first relay 210 is turned on to discharge discharge. Prepare, PWM control the back-to-back IGBT 240 so that current is supplied to the inverter 40 through the charge/discharge control line 208 to match the potentials of the battery 110 and the inverter 40 .

Next, the third relay 230 is turned on and the discharge line 206b is connected (S202).

During discharge control, temperature measurement or current measurement of the third relay 230 and the like may be performed (S204 and S206).

If the temperature is greater than the reference value (S208) or the current is greater than the reference value (S210), PWM control the back-to-back IGBT 240 to flow some current through the charge/discharge control line 208, so that the third relay 230, etc. It can prevent overheating.

If the temperature is not greater than the reference value, the back-to-back IGBT 240 is maintained in an off state.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains may make various modifications, changes and substitutions within the scope without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are intended to explain, not to limit the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings. . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

10: power distribution unit 20: low-speed charging unit
30: fast charging unit 40: inverter
50: power consumption unit 100: battery unit
110: battery 120: power management unit
130: signal connector 200: charge and discharge control device
202: first power supply line 204: second power supply line
206a: charging line 206b: discharging line
208: charge/discharge control line 210: first relay
220: second relay 230: third relay
240: back-to-back IGBT 242: gate driving IC
244: voltage regulator 250: MCU

Claims (15)

A charge/discharge control device for controlling charging and discharging of a battery of an electric vehicle, comprising:
a first power supply line and a second power supply line respectively connected to both ends of the battery;
a charge/discharge control line disposed in parallel with the second power supply line;
a back-to-back IGBT provided in the charge/discharge control line; and
MCU for controlling the operation of the back-to-back IGBT;
including,
A relay is provided in the second power supply line at a position parallel to the charge/discharge control line,
The MCU controls the back-to-back IGBT when the temperature or current of the relay is greater than a reference value to prevent overheating of the relay when the relay of the second power supply line is in an on state to control the charge/discharge control line A charge/discharge control device for an electric vehicle, characterized in that it enables the flow of current through the The method of claim 1,
The back-to-back IGBT includes a first IGBT and a second IGBT connected to an emitter or a collector. 3. The method of claim 2,
Further comprising a gate driving IC for applying a PWM control signal for driving to the first IGBT or the second IGBT, wherein the current flow through the charge/discharge control line is controlled by the duty of the PWM control signal A charge/discharge control device for electric vehicles. The method of claim 1,
A charging/discharging control device for an electric vehicle, characterized in that a first relay is provided in the first power supply line. delete 5. The method according to any one of claims 1 to 4,
and the second power supply line further includes a charging line and a discharging line arranged in parallel with the charging/discharging control line. 7. The method of claim 6,
The charging/discharging control device for an electric vehicle, wherein a second relay is provided in the charging line, and a third relay is provided in the discharge line. The method of claim 1,
wherein the MCU controls the back-to-back IGBT before turning on the relay of the second power supply line to perform pre-charging during charging or discharging of the battery. . delete At least one of a low-speed charging unit and a high-speed charging unit, an inverter, a battery, a first power supply line and a second power supply line respectively connected to both ends of the battery, and charging/discharging arranged in parallel to the second power supply line Battery charge/discharge control of an electric vehicle comprising a control line, a back-to-back IGBT provided in the charge/discharge control line and configured by interconnecting at least two emitters or collectors of the IGBT, and an MCU for controlling the operation of the back-to-back IGBT In the method,
performing precharging through the charge/discharge control line by turning off a relay provided in the second power supply line and controlling the back-to-back IGBT in the initial stage of controlling the charging or discharging of the battery; and
and controlling the back-to-back IGBT to perform low-speed charging of the battery through the charge/discharge control line when the battery is charged by the low-speed charging unit. 11. The method of claim 10,
A charging line is provided in the second power supply line in parallel with the charge/discharge control line, and a second relay is provided in the charging line,
After the pre-charging is completed, the charging/discharging control method for an electric vehicle further comprising the step of turning on the second relay to charge the battery through the charging line. 11. The method of claim 10,
A discharge line is provided in the second power supply line in parallel with the charge/discharge control line, and a third relay is provided in the discharge line,
After the pre-charging is completed, the charging/discharging control method for an electric vehicle further comprising the step of turning on the third relay to discharge the inverter through the discharge line. delete At least one of a low-speed charging unit and a high-speed charging unit, an inverter, a battery, a first power supply line and a second power supply line respectively connected to both ends of the battery, and charging/discharging arranged in parallel to the second power supply line Battery charge/discharge control of an electric vehicle comprising a control line, a back-to-back IGBT provided in the charge/discharge control line and configured by interconnecting at least two emitters or collectors of the IGBT, and an MCU for controlling the operation of the back-to-back IGBT In the method,
At least one relay is provided in the second power supply line in parallel with the charge/discharge control line,
measuring the temperature of the relay or a current value flowing through the relay;
determining whether the temperature or the current value is greater than a reference value; and
When the temperature or the current value is greater than the reference value as a result of the determination, the back-to-back IGBT is switched and controlled to prevent overheating of the relay when the relay is on, allowing current flow through the charge/discharge control line to do;
A charging/discharging control method for an electric vehicle comprising a. 15. The method of claim 14,
In the second power supply line, a charging line and a discharging line are provided in parallel with the charging/discharging control line, and a second relay and a third relay are respectively provided in the charging line and the discharging line,
The charging/discharging control method for an electric vehicle, wherein the second relay is turned on during discharging, and the third relay is turned on during charging.

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