KR102088893B1 - Apparatus and method for protection of bi-directional dc-dc converter - Google Patents

Abstract

Disclosed is a protection device and method for a bidirectional DC-DC converter. A protection device and method for a bidirectional DC-DC converter of the present invention include a power conversion unit having a plurality of switches to perform voltage conversion in both directions between a low voltage battery and a high voltage battery; And detecting the current value flowing through the power conversion unit to determine whether an overcurrent has occurred through comparison with the reference current value, and if the detected current value is greater than or equal to the reference current value, it is determined that an overcurrent has occurred and all switches of the power conversion unit are turned off. (Turn Off) a control unit; includes, the power conversion unit, when an overcurrent occurs, a protection switch unit for blocking the flow of current; And a protection circuit unit for stopping the operation of the power conversion unit by turning off the protection switch unit when all switches of the power conversion unit are not turned off when an overcurrent occurs.

Description

Protective device and method of bi-directional DC-DC converter {APPARATUS AND METHOD FOR PROTECTION OF BI-DIRECTIONAL DC-DC CONVERTER}

The present invention relates to a protection device and method of a bi-directional DC-DC converter, and more specifically, to protect a bi-directional DC-DC converter operating in hardware by applying a secondary protection circuit to the input / output terminal of the bi-directional DC-DC converter. It relates to a device and method.

In general, a power system of a vehicle is a system that supplies electric power for operating electronic components, safety components, or various accessories in a vehicle. In general, a DC voltage is supplied to operate electronic components in a vehicle. In the past, a 12V power system was used as a vehicle power system, but recently, a 48V power system has been widely used to increase energy capacity and improve power efficiency using high-power electronic components.

However, when a 48V power system is applied, there is a problem in that all electronic components of a vehicle operated with a conventional 12V voltage need to be replaced for 48V, and a 12V-48V power conversion system capable of supplying voltages of 12V and 48V together As a result, parts with low power consumption can be operated at a voltage of 12V as before, and parts with high power consumption, such as electric steering or air conditioning systems, can be operated at 48V to efficiently utilize power. . The 12V-48V power conversion system is usually a bi-directional DC-DC converter, and the bi-directional DC-DC converter adopts a multi-phase structure to improve efficiency by accommodating high capacity, securing fast response of power conversion, and sharing current. Is being used. In addition, the bi-directional DC-DC converter has an interleaved structure to distribute the current to each phase to reduce stress applied to the device. That is, the bi-directional DC-DC converter is mounted between 12V and 48V batteries and converts power through step-up and step-down operations.

On the other hand, the bi-directional DC-DC converter can perform power conversion by switching and controlling the power conversion unit including a microcontroller unit (MCU), and when the MCU detects the current value and abnormal operation such as overcurrent occurs, the switching operation is turned OFF. It can be controlled and stopped. However, if a malfunction occurs in the MCU itself, an overcurrent cannot be detected, which may cause a problem that causes a fatal error in which the converter malfunctions.

Background art of the present invention is the Republic of Korea Patent Registration No. 0774673 (2007.11.08. Announcement), "a transformer heat dissipation structure of the DC / DC converter".

According to an aspect of the present invention, the present invention was devised to improve the above problems, and a secondary protection circuit is applied to an input / output terminal of a bidirectional DC-DC converter to turn off a switching operation in hardware when an error occurs. An object of the present invention is to provide a protection device and method for a bidirectional DC-DC converter (Turn OFF).

A protection device for a bi-directional DC-DC converter according to an aspect of the present invention includes a power conversion unit having a plurality of switches to perform voltage conversion in both directions between a low voltage battery and a high voltage battery; And detecting the current value flowing through the power conversion unit to determine whether an overcurrent has occurred through comparison with a reference current value. If the detected current value is greater than or equal to the reference current value, it is determined that overcurrent has occurred and all switches of the power conversion unit Includes; Turn off (Turn Off) control unit; including, the power conversion unit, when the overcurrent occurs, the protection switch unit for blocking the flow of current; And a protection circuit unit for stopping the operation of the power conversion unit by turning off the protection switch unit when all the switches of the power conversion unit are not turned off when the overcurrent occurs.

In the present invention, the protection circuit unit, a signal amplifying unit for amplifying the voltage of the current measuring unit for measuring the current of the power conversion unit; A comparator comparing the output voltage of the signal amplifying unit with a preset reference voltage; A latch circuit configured to output an output signal that enables an enable signal of the power supply IC to be changed according to the comparison result of the comparator; And a protection switch unit driver for turning on or off the protection switch unit using the power of the power supply IC.

In the present invention, when the output voltage of the signal amplification unit is greater than or equal to the reference voltage as a result of the comparison of the comparator, the latch circuit occurs in the latch circuit unit so that the enable signal of the power supply IC becomes low. It is characterized by.

In the present invention, the protection circuit unit is characterized in that when the enable signal of the power supply IC is low, the power supply of the power supply IC is cut off so that the protection switch unit driver turns off the protection switch unit.

In the present invention, the latch circuit portion, it characterized in that it comprises a D- flip-flop (FlipFlop) circuit.

In the present invention, the control unit detects the states of the low-voltage battery and the high-voltage battery, and based on the state of the low-voltage battery and the high-voltage battery, a Buck mode for step-down from a high-voltage battery to a low-voltage battery and a high voltage in the low-voltage battery In order to perform a boost mode for boosting to a battery, the plurality of switches of the power converter are turned on or off, respectively, so that the voltages of the low voltage batteries and the high voltage batteries reach the target voltage. .

A method of protecting a bi-directional DC-DC converter according to another aspect of the present invention includes the steps of: performing a voltage conversion in both directions between a low-voltage battery and a high-voltage battery by providing a plurality of switches; A step in which a control unit senses a current value flowing in the power conversion unit and determines whether an overcurrent occurs through comparison with a reference current value; Determining that overcurrent has occurred if the current value sensed by the control unit is greater than or equal to a reference current value, turning off all switches of the power conversion unit; And when all the switches of the power converter are not turned off when the overcurrent occurs, the protection circuit part included in the power converter is turned off to stop the operation of the power converter. It characterized in that it comprises a step.

The present invention, the signal amplifying step of amplifying the voltage of the current measuring unit measuring the current of the power conversion unit; A comparator comparing the output voltage of the signal amplifying unit with a preset reference voltage; Outputting an output signal to enable the enable signal of the power supply IC to be changed according to the comparison result of the comparator; And a step in which the driver of the protection switch turns on or off the protection switch using the power of the power IC.

In the step of turning off the protection switch unit of the present invention, when the output voltage of the signal amplification unit is greater than or equal to a reference voltage as a result of comparison of the comparator, a latch operation occurs in the latch circuit unit to enable the power supply IC. Characterized in that the signal to be low (Low).

In the step of turning off the protection switch unit of the present invention, the protection circuit unit, when the enable signal of the power IC is low, the power of the power IC is cut off and the protection switch unit driver turns the protection switch unit It is characterized by being turned off.

The present invention comprises the steps of the control unit to grasp the state of the low voltage battery and the high voltage battery; And the control unit performing a buck mode for step-down from a high voltage battery to a low voltage battery and a boost mode for boosting from a low voltage battery to a high voltage battery based on the state of the low voltage battery and the high voltage battery. It characterized in that it further comprises the step of turning on or off each of the plurality of switches of the power conversion unit so that the voltage of each low-voltage battery and the high-voltage battery reaches the target voltage.

The protection device and method of a bidirectional DC-DC converter according to an embodiment of the present invention apply a secondary protection circuit to the input / output terminal of the bidirectional DC-DC converter to turn off the switching operation in hardware when an error occurs (Turn OFF) By doing so, it is possible to improve the stability by allowing the switching operation to be turned off even when the primary protection fails due to a software malfunction.

1 is a view schematically showing a protection device of a bidirectional DC-DC converter according to an embodiment of the present invention.
2 is a view showing a protection circuit in the protection device of the bi-directional DC-DC converter according to an embodiment of the present invention.
3 is a flowchart illustrating a method of protecting a bi-directional DC-DC converter according to an embodiment of the present invention.

Hereinafter, a protection device and method of a bidirectional DC-DC converter according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition of these terms should be made based on the contents throughout the present specification.

1 is a view schematically showing a protection device of a bidirectional DC-DC converter according to an embodiment of the present invention, and FIG. 2 shows a protection circuit part in a protection device of a bidirectional DC-DC converter according to an embodiment of the present invention As a drawing, the protection device of the bidirectional DC-DC converter will be described with reference to the following.

As shown in FIG. 1, a protection device of a bidirectional DC-DC converter according to an embodiment of the present invention performs voltage conversion in both directions between a low voltage battery (eg 12V) and a high voltage battery (eg 48V). A power conversion unit 200 and a control unit 100 for controlling the power conversion unit 200 may be included.

In addition, the bi-directional DC-DC converter according to an embodiment of the present invention is composed of an interleaved structure and can distribute current to each phase to reduce stress applied to the device.

Referring to FIG. 1, the circuit configuration of the power converter 200 in the bi-directional DC-DC converter according to this embodiment will be described in detail. The power converter 200 includes a first switch SW1 and a second switch ( SW2), an inductor L, a protection circuit unit I, an LV protection switch unit 20 and an HV protection switch unit 21, and may also include a first switch SW1 and a second switch SW2. A switch driver (SW DRV) for turning on / off may be included.

The first switch SW1 is connected to the HV protection switch unit 21 and one terminal thereof. In addition, the second switch SW2 is connected between the other terminal of the first switch SW1 and the ground. In addition, although not shown in the drawing, the HV protection switch unit 21 may be connected to a high voltage battery (not shown) via BUSBAR. The inductor L is connected to a connection node of the first switch SW1 and the second switch SW2 and one terminal thereof. And the other terminal of the inductor (L) is connected to the current measuring unit 24 for measuring the large current flowing in the power conversion unit 200, the current measuring unit 24 is LV protection switch unit 20 and its one terminal Is connected. In addition, although not shown in the drawing, the LV protection switch unit 20 may be connected to a low voltage battery (not shown) via BUSBAR. In addition, the first switch SW1, the second switch SW2, the LV protection switch unit 20, and the HV protection switch unit 21 may be configured as a field effect transistor (FET), but are not limited thereto. A switch can be employed.

On the other hand, referring to Figure 1, the above-described circuit configuration can be configured by connecting a plurality of parallel according to the capacity of the bidirectional DC-DC converter, each circuit configuration LV protection switch unit 20 and HV protection switch Although shown as being integrally connected to the unit 21, the LV protection switch unit 20 and the HV protection switch unit 21 may be provided in each circuit configuration.

Based on the above-described circuit configuration, the control unit 100 includes a power supply unit 11, a voltage sensing unit 12, a microcontroller unit (MCU) 13, a communication unit 14, and a current sensing unit 15. At least one of the switch SW1, the second switch SW2, the LV protection switch unit 20, and the HV protection switch unit 21 may be turned on or off. At this time, the control unit 100 controls the switching of the first switch SW1, the second switch SW2, the LV protection switch unit 20, and the HV protection switch unit 21 through the MCU 13 or PWM IC ( Pulse Width Modulation Integrated Circuit).

Meanwhile, in the present embodiment, the control unit 100 may mean an integrated control means including components necessary for the MCU 13 to entirely control the protection device of the bidirectional DC-DC converter.

The power supply unit 11 is an electric energy source for supplying power to the control unit 100.

The voltage detection unit 12 detects the voltages of the low voltage battery and the high voltage battery and transmits them to the MCU 13, and through this, the MCU 13 can grasp the state of the low voltage battery and the high voltage battery.

The communication unit 13 is a control signal of the MCU 13 to the first switch SW1, the second switch SW2, the LV protection switch unit 20 and the HV protection switch unit 21 and other elements for control To send. The communication unit 13 may transmit a control signal through a CAN (Controller Area Network) method, a 1 wire method, or a 2 wire method, but the communication method of the communication unit described above is only exemplary and is not limited.

The current detection unit 15 senses the current flowing through the power conversion unit 200 and transmits it to the MCU 13. Through this, the MCU 13 can grasp an error such as occurrence of overcurrent. At this time, the current detection unit 15 and the current measurement unit 24, which will be described later, may be configured identically.

That is, the MCU 13 may grasp the states of the low voltage battery and the high voltage battery through the voltage detection unit 12 and perform bidirectional power conversion based on the states of the low voltage battery and the high voltage battery. More specifically, the MCU 13 may perform a buck mode for step-down from a high voltage battery to a low voltage battery, and may perform a boost mode for boosting from a low voltage battery to a high voltage battery. . At this time, the MCU 13 may turn on or off each of a plurality of switches of the power converter 200 so that the voltages of the low voltage batteries and the high voltage batteries reach the target voltage. Meanwhile, a technique for converting power by performing a buck-boost mode between a low voltage battery and a high voltage battery is a well-known technique, so a detailed method will be omitted. In addition, since this embodiment discloses a protection device for a bidirectional DC-DC converter, the circuit configuration for performing the buck-boost mode has been schematically shown.

The MCU 13 can sense the current flowing through the power conversion unit 200 through the current detection unit 15, and generates overcurrent through comparison of the sensed current value with a reference current value set in advance for overcurrent detection. You can judge whether or not. At this time, the MCU 13 may determine that an overcurrent has occurred if the sensed current value is greater than or equal to a reference current value. If it is determined that an overcurrent has occurred, turn off all switches of the power conversion unit 200 to turn off. The converter operation can be stopped.

However, when a malfunction occurs in the MCU 13 itself, the converter operation is not stopped because all switches are not turned off even in the event of overcurrent. As a result, a fatal error can occur that causes the converter to fail. In addition, in the case of the 12V-48V bidirectional converter as in this embodiment, detection of overcurrent is more important because the current range is large depending on the capacity.

Therefore, in the present embodiment, the protection circuit unit I is provided so that the secondary protection can be performed in hardware despite the malfunction of the MCU 13 itself.

That is, the power conversion unit 200 includes an LV protection switch unit 20 and an HV protection switch unit 21 to block the flow of current when an overcurrent occurs, and when the overcurrent occurs, all switches of the power conversion unit When it is not turned off, that is, when the switching control is not performed due to a malfunction of the MCU 13, the operation of the power conversion unit 20 is performed by causing the LV protection switch unit 20 and the HV protection switch unit 21 to be turned off. And a protection circuit portion (I) for stopping.

The protection circuit unit I may include a current measurement unit 24, a signal amplification unit 25, a comparator 26, a latch circuit unit 27, a power supply IC 28, and a protection switch unit driver 29. At this time, in this embodiment, the protection switch unit driver 29 is described as being included in the protection circuit unit I, but may be included in the LV protection switch unit 20 and the HV protection switch unit 21, respectively.

The current measuring unit 24 measures a large current flowing through the power conversion unit 200, and may be configured as a shunt resistor.

The signal amplifying unit 25 may be input to the comparator 26 by amplifying the voltage input from the current measuring unit 24, the input terminal being connected to the current measuring unit 24, and the output terminal being connected to the comparator 26. .

The comparator 26 may compare the output voltage of the signal amplifying unit 25 with a preset reference voltage. That is, the comparator 26 may use the reference voltage that is the output of the reference voltage generator (not shown) as a plus terminal input, and may use the output voltage of the signal amplification unit 25 as a negative terminal input. The comparator 26 may compare the reference voltage with the output voltage of the signal amplifying unit 25 and output a signal for the comparison result to the latch circuit unit 27.

At this time, the comparator 26 may output a Hi signal when the reference voltage is higher than the output voltage of the signal amplifying unit 25, and when the reference voltage is lower than the output voltage of the signal amplifying unit 25, A low signal can be output.

The latch circuit unit 27 may be configured to output an output signal that enables the enable signal of the power supply IC 28 to be changed according to the comparison result of the comparator 26.

At this time, a NOT gate (Inverter) may be provided between the comparator 26 and the latch circuit part 27. That is, a value opposite to the signal output from the comparator 26 is output.

Therefore, when the comparison result from the comparator 26, the reference voltage is higher than the output voltage of the signal amplification section 25, a low signal is input to the latch circuit section 27, and the reference voltage is the output of the signal amplification section 25. When it is lower than the voltage, a high signal may be input to the latch circuit portion 27.

Meanwhile, the latch circuit part 27 may include a D-FlipFlop circuit. The D-flip-flop circuit operates according to the clock signal CLK, and a control signal input to the D stage is not shown in the drawing, but a control signal input to the D stage synchronized with the clock signal may be output.

Accordingly, the latch circuit unit 27 may enable the switching element to be turned on when the high signal is input, so that the enable signal of the power supply IC 28 is low, and when the low signal is input, the switching element is turned on. By turning it off, the enable signal of the power supply IC 28 can be made high.

The power supply IC 28 receives and outputs power from a battery. When the enable signal is low, the power supply may be cut off.

The protection switch unit driver 29 turns on or off the LV protection switch unit 20 and the HV protection switch unit 21 using the power of the power supply IC 28. That is, when the power of the power supply IC 28 is cut off, the protection switch unit driver 29 turns off the LV protection switch unit 20 and the HV protection switch unit 21 so that the operation of the power conversion unit 200 is performed. It can be stopped.

That is, when the signal amplifying unit 25 amplifies the voltage input from the current measuring unit 24 and outputs it to the comparator 26, the comparator 26 compares the output voltage of the signal amplifying unit 25 with the reference voltage. , When an overcurrent occurs, the reference voltage is lower than the output voltage of the signal amplifier 25. Therefore, a low signal is output from the comparator 26, and a high signal is input to the latch circuit 27 through the NOT gate. At this time, in the latch circuit unit 27, a high signal is input to the clock stage, a high signal is output, and the switching element is turned on so that most of the current flows to the ground, so that the enable signal of the power supply IC 28 is low. That is, the power supply of the power supply IC 28 is cut off, the operation of the power conversion unit 200 is stopped, and the converter can be protected by preventing a failure due to overcurrent.

Accordingly, when the output voltage of the signal amplification unit 25 is greater than or equal to the reference voltage as a result of the comparison of the comparator 26, the protection circuit unit I generates a latch operation in the latch circuit unit 27 so that the enable signal of the power supply IC 28 is generated. Make it low. In addition, when the enable signal of the power supply IC 28 is low, the protection circuit unit I is cut off from the power supply of the power supply IC 28, so that the protection switch unit driver 29 receives the LV protection switch unit 20 and the HV. Turn off the protection switch unit 21.

3 is a flowchart illustrating a method of protecting a bi-directional DC-DC converter according to an embodiment of the present invention. Referring to this, a method of protecting a bi-directional DC-DC converter will be described below.

As shown in FIG. 3, in the method of protecting the bi-directional DC-DC converter according to an embodiment of the present invention, the controller 100 first checks the battery state (S10).

That is, the control unit 100 may receive the voltage detection values of the low voltage battery and the high voltage battery from the voltage detection unit 12 to grasp the state of the low voltage battery and the high voltage battery.

Next, the control unit 100 turns on the protection switch units 20 and 21 (S20).

In this case, the protection switch units 20 and 21 may include the LV protection switch unit 20 on the low voltage battery side and the HV protection switch unit 21 on the high voltage battery side.

Then, the control unit 100 drives the power conversion unit 200 by turning on or off a plurality of switches of the power conversion unit 200 based on the battery state identified in step S10 (S30).

That is, the control unit 100 can grasp the state of the high voltage battery and the low voltage battery to perform a buck mode for step-down from the high voltage battery to the low voltage battery, and boost for boosting from the low voltage battery to the high voltage battery ( Boost) mode, wherein at least one of the first switch SW1 and the second switch SW2 may be turned on.

In this case, when at least one of the first switch SW1 and the second switch SW2 is not turned on, the controller 100 may determine that power conversion between the high voltage battery and the low voltage battery is not necessary, and may end.

In step S20, when at least one of the first switch SW1 and the second switch SW2 is turned on, the controller 100 determines whether an error such as overcurrent occurs (S40).

The control unit 100 may receive the current detection value from the current detection unit 15 to determine the occurrence of overcurrent.

In step S40, if no error occurs, the controller 100 determines whether the voltage of the high voltage battery or the low voltage battery has reached the target voltage as a result of performing the buck mode or the boost mode (S50).

If the target voltage is not reached in step S50, the process returns to step S40 until the target voltage is reached to determine whether an error has occurred, and power conversion in buck mode or boost mode can be continuously performed.

On the other hand, in step S40, when an error occurs, the operation of the protection circuit unit I varies depending on whether all of the switches of the power conversion unit 200 are turned off and stopped (S60).

That is, when the driving of the power conversion unit 200 is stopped in step S60, it may end.

However, when all the switches are not turned off even when an overcurrent occurs (when the driving of the power converter 200 is not stopped), the overcurrent is detected in hardware through the protection circuit unit I (S70), and the LV protection switch The secondary protection is performed by allowing the unit 20 and the HV protection switch unit 21 to be turned off (S80).

That is, when a malfunction occurs in the control unit 100 itself, the converter operation is not stopped because all switches are not turned off even in the event of overcurrent. Accordingly, in the present embodiment, the protection circuit unit I is provided to enable secondary protection in hardware even in the case of malfunction of the control unit 100 itself.

Here, the protection circuit unit I may include a current measurement unit 24, a signal amplification unit 25, a comparator 26, a latch circuit unit 27, a power supply IC 28, and a protection switch unit driver 29. have.

The signal amplification unit 25 may amplify the voltage input from the current measurement unit 24 and output it to the comparator 26, and the comparator 26 outputs the output voltage of the signal amplification unit 25 and a preset reference voltage. Can be compared. In addition, the comparator 26 may compare the reference voltage and the output voltage of the signal amplifying unit 25 and output a signal for the comparison result to the latch circuit unit 27.

At this time, the comparator 26 may output a Hi signal when the reference voltage is higher than the output voltage of the signal amplifying unit 25, and when the reference voltage is lower than the output voltage of the signal amplifying unit 25, A low signal may be output. When an overcurrent occurs, a low signal is output because the reference voltage is lower than the output voltage of the signal amplifier 25.

The latch circuit part 27 is configured to output an output signal that enables the enable signal of the power supply IC 28 to change according to the comparison result of the comparator 26. That is, when a low signal is output from the comparator 26 and a high signal is input to the latch circuit 27 through the NOT gate, the switching element is turned on and the enable signal of the power supply IC 28 goes low. That is, the power supply of the power supply IC 28 is cut off, the operation of the power conversion unit 200 is stopped, and the converter can be protected by preventing a failure due to overcurrent.

Accordingly, when the output voltage of the signal amplification unit 25 is greater than or equal to the reference voltage as a result of the comparison of the comparator 26, the protection circuit unit I generates a latch operation in the latch circuit unit 27 so that the enable signal of the power supply IC 28 is generated. Make it low. In addition, when the enable signal of the power supply IC 28 is low, the protection circuit unit I is cut off from the power supply of the power supply IC 28, so that the protection switch unit driver 29 receives the LV protection switch unit 20 and the HV. Turn off the protection switch unit 21.

As described above, the protection device and method of the bidirectional DC-DC converter according to an embodiment of the present invention apply a secondary protection circuit to the input / output terminal of the bidirectional DC-DC converter to turn the switching operation in hardware when an error occurs By turning it OFF, it is possible to improve stability by enabling the switching operation to be turned off even when the primary protection fails due to a software malfunction.

The present invention has been described with reference to the embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art to which the art belongs can various modifications and equivalent other embodiments from this. Will understand.

Therefore, the true technical protection scope of the present invention should be defined by the following claims.

100: control unit 11: power supply unit
12: voltage detection unit 13: MCU
14: communication unit 15: current sensing unit
200: power conversion unit 20: LV protection switch unit
21: HV protection switch 24: current measurement
25: signal amplifier 26: comparator
27: latch circuit 28: power supply IC
29: protection switch driver I: protection circuit
SW1: First switch SW2: Second switch
SW DRV: 1st switch and 2nd switch driver

Claims (1)

A power conversion unit having a plurality of switches to perform voltage conversion in both directions between a low voltage battery and a high voltage battery; And
The current value flowing through the power conversion unit is sensed to determine whether an overcurrent has occurred through comparison with a reference current value. Includes a control unit for turning off (Turn Off),
The power conversion unit,
A protection switch unit for blocking the flow of current when an overcurrent occurs; And
When the overcurrent occurs, when all the switches including the protection switch unit of the power conversion unit is not turned off, the protection circuit unit to stop the operation of the power conversion unit by turning off the protection switch unit; includes,
The protection circuit unit,
A signal amplifying unit for amplifying the voltage of the current measuring unit measuring the current of the power conversion unit;
A comparator comparing the output voltage of the signal amplifying unit with a preset reference voltage;
A latch circuit unit configured to output an output signal that enables an enable signal of a power supply IC to be changed according to a comparison result of the comparator; And
It includes; a protection switch driver for turning on or off the protection switch using the power of the power supply IC;
The circuit configuration of the power conversion unit is an interleaved structure configured by connecting a plurality of them in parallel according to the capacity of a bidirectional DC-DC converter,
The protection circuit unit,
When the output voltage of the signal amplification unit is higher than the reference voltage as a result of the comparison of the comparator, a latch operation occurs in the latch circuit unit so that the enable signal of the power supply IC becomes low,
The protection circuit unit,
When the enable signal of the power IC is low, the power of the power IC is cut off so that the driver of the protection switch turns off the protection switch,
The power conversion unit further includes a first switch, a second switch and an inductor, and the protection switch unit includes a first protection switch unit and a second protection switch unit,
The first switch is connected to the first protection switch unit and one terminal thereof, the second switch is connected between the other terminal and the ground of the first switch, and the first protection switch unit busbar ( BUSBAR) to connect to the high voltage battery,
The inductor is connected to a connection node of the first switch and the second switch and one terminal thereof, and to the other terminal of the inductor, the current measurement unit for measuring a current flowing through the power conversion unit is connected, and the current measurement The protection device of the bi-directional DC-DC converter, characterized in that the second protection switch part and one terminal thereof are connected, and the second protection switch part is connected to a low voltage battery through a busbar.

Images