KR102529389B1 - System and method for low voltage dc-dc converter control of environmentally friendly vehicles - Google Patents

Abstract

A converter control system and method for an eco-friendly vehicle are disclosed.
According to an embodiment of the present invention, a converter control system for an eco-friendly vehicle boosts a drive motor that generates driving force of the vehicle, a high-voltage battery that supplies power to the drive motor, and AC power supplied from the outside and then converts it into DC power. A vehicle charger that charges a battery with the high-voltage power, a converter that converts the high-voltage power input from the high-voltage battery or the vehicle charger into a low voltage and supplies it to the electric load and auxiliary battery, and the state information of the eco-friendly vehicle and the input voltage of the converter and a control unit for selectively operating the converter as a full-bridge or half-bridge with reference to the state information and a state detection unit that detects the state information.

Description

Converter control system and method for eco-friendly vehicles {SYSTEM AND METHOD FOR LOW VOLTAGE DC-DC CONVERTER CONTROL OF ENVIRONMENTALLY FRIENDLY VEHICLES}

The present invention relates to a converter control system and method for an eco-friendly vehicle, and more particularly, to a converter control system and method for an eco-friendly vehicle for improving the efficiency of a converter that converts high voltage to low voltage during slow charging of an eco-friendly vehicle. will be.

In general, eco-friendly vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid vehicles (PHEVs) are driven by motor power using batteries, unlike internal combustion engine vehicles.

Since these eco-friendly vehicles move with the power of a motor, a high-capacity high-voltage battery and the voltage of the high-voltage battery (eg, 200 ~ 400V) are converted into a low voltage (eg, 12V) that can be used by the electric load of the vehicle, and the alternator of the internal combustion engine As shown, a low voltage DC-DC Converter (LDC) is installed to charge the auxiliary battery.

For example, FIG. 1 compares and shows operating states of LDCs during driving and charging in a conventional eco-friendly vehicle.

Referring to FIG. 1 attached, the LDC receives high voltage energy from a high voltage battery while an eco-friendly vehicle is driving, converts it to low voltage, and then supplies it to an auxiliary battery and various electrical loads of the vehicle.

In addition, LDC can receive high-voltage energy from an on-board charger (OBC) that converts external AC power to DC power during slow charging of an eco-friendly vehicle, convert it to low voltage, and then supply it to auxiliary batteries and electric loads. there is.

At this time, the operating range of the LDC during driving of the eco-friendly vehicle and during slow charging is different from each other as shown in the graph of FIG. 1 .

First, to explain why the LDC input voltage range is different, the voltage during driving has a wide voltage range reflecting the characteristics of a high-voltage battery according to temperature and driving/regeneration of the motor. Because the scope is narrow.

In addition, to explain the reason why the LDC input power is different, a lot of 12V electric loads are used while driving, so almost all controllers operate and loads such as fans and lamps according to control conditions operate, but charging This is because only some of the controllers for charging operate during operation, so the 12V electric load consumption is relatively small.

On the other hand, since the operating range of the LDC during driving of an eco-friendly vehicle and during slow charging are different from each other, a clear difference occurs in LDC efficiency.

2 shows an LDC circuit diagram applied to a conventional eco-friendly vehicle.

3 is a graph showing LDC efficiency during driving and charging of a conventional eco-friendly vehicle.

First, referring to attached FIG. 2, the LDC circuit applied to a conventional eco-friendly vehicle is a Phase Shift Full-Bridge Converter, and when converting from high voltage (300V) to low voltage (12V), four FETs Conduction loss and switching loss are the main loss factors. Therefore, conventionally, zero voltage switching of the LDC is controlled to prevent the switching loss from occurring.

However, as shown in the graph curve of the LDC efficiency of FIG. 3, there is a clear difference in the LDC efficiency between driving and charging, and the problem is that the LDC efficiency at a low load (50 to 150 W) level is rapidly reduced during charging. The reason why the low-load efficiency drops sharply is that zero-voltage switching is not performed in the low-load operating range during slow charging due to the characteristics of the LDC.

That is, since the currently applied LDC does not perform zero voltage switching under a low load condition of 200 W or less, there is a problem in that switching loss increases during slow charging.

Matters described in this background art section are prepared to enhance understanding of the background of the invention, and may include matters that are not prior art already known to those skilled in the art to which this technique belongs.

An embodiment of the present invention provides a converter control system and method for an eco-friendly vehicle that can operate a low-voltage DC converter as a half-bridge and improve LDC efficiency through zero-voltage switching control under a low load condition during slow charging of the vehicle. are doing

According to one aspect of the present invention, a converter control system for an eco-friendly vehicle includes a driving motor generating driving force of the vehicle; a high voltage battery supplying power to the driving motor; an inverter converting power supplied from the high voltage battery into three-phase AC power to drive the driving motor; a vehicle charging unit that steps up AC power supplied from the outside and converts it into DC power to charge the battery with the high voltage power; a converter that converts the high voltage power input from the high voltage battery or the vehicle charging unit into a low voltage and supplies it to the electric load and the auxiliary battery; a state detector detecting the state information of the eco-friendly vehicle and the input voltage of the converter; and a control unit for selectively operating the converter in full-bridge or half-bridge mode with reference to the status information.

In addition, the converter is a low voltage DC-DC converter (LDC) and may include four switches.

In addition, the control unit may control the first switch and the second switch of the converter to perform a PWM operation and turn off the third switch and the fourth switch when operating as the half bridge.

In addition, the control unit may control zero voltage switching in a half-bridge operating state of the converter.

In addition, the control unit sets a reference input voltage of the converter during the charging, controls the full bridge when the input voltage is less than the reference input voltage, and controls the half bridge when the input voltage exceeds the reference input voltage. You can control it.

In addition, the reference input voltage may be set to an input voltage value corresponding to a load amount of the converter at a point in time when the amount of conduction loss of the converter becomes equal to the amount of switching loss.

Also, the control unit may control zero voltage switching in a full bridge operating state of the converter.

On the other hand, according to one aspect of the present invention, the converter control system of the eco-friendly vehicle converts the input high voltage power into a low voltage when the vehicle is charged with an external power source and supplies it to the electric load and battery (Low Voltage DC-DC Converter, LDC) A method for controlling the a) detecting the input voltage of the converter by collecting state information when the start of charging of the eco-friendly vehicle is detected; b) controlling the converter to operate as a full bridge when the detected input voltage is less than or equal to a preset reference input voltage; and c) controlling the converter to operate as a half bridge when the detected input voltage exceeds the reference input voltage.

In addition, prior to the step a), the step of setting the reference input voltage to an input voltage value corresponding to the load amount of the converter at the time when the amount of conduction loss of the converter generated during charging becomes equal to the amount of switching loss may further include the step of setting the reference input voltage. can

In addition, step b) may include determining a PWM duty range according to a design factor of the converter as a basic duty, and PWM operation of all switches of the converter.

Also, step c) may include determining a PWM duty range according to a design factor of the converter to be twice the basic duty.

In addition, step c) may include controlling the first switch and the second switch of the converter to perform a PWM operation, and turning off the third switch and the fourth switch.

Further, step c) may include controlling zero voltage switching in a half-bridge operating state of the converter.

Further, step c) may include switching the converter to a full bridge operation when a start of the eco-friendly vehicle or an IG ON signal is detected.

The method may further include terminating charging of the auxiliary battery after step c) when the detected input voltage reaches an upper limit input voltage during charging set in a converter design factor.

According to an embodiment of the present invention, switching loss compared to full-bridge can be reduced by half by operating the converter as a half-bridge during slow charging of an eco-friendly vehicle.

In addition, since zero voltage switching is possible through a half-bridge operation of the converter during charging, switching loss can be additionally reduced and fuel efficiency can be improved accordingly.

In addition, if the converter input voltage during charging is below the standard input voltage at a level at which the target voltage output for battery charging is impossible, it is operated as a full bridge, and when it exceeds the standard input voltage, it is converted to a half bridge, thereby improving LDC charging efficiency and stable battery charging. There are possible effects.

1 shows a comparison between operating states of LDCs during driving and charging in a conventional eco-friendly vehicle.
2 shows an LDC circuit diagram applied to a conventional eco-friendly vehicle.
3 is a graph showing LDC efficiency during driving and charging of a conventional eco-friendly vehicle.
4 is a block diagram schematically showing the configuration of a charging control system for an eco-friendly vehicle according to an embodiment of the present invention.
5 schematically shows the configuration of a converter (LDC) according to an embodiment of the present invention.
6 shows an LDC design factor and an output voltage equation for each circuit of a PHEV vehicle according to an embodiment of the present invention.
7 is a graph showing an LDC control state (A) and LDC efficiency (B) during slow charging according to an embodiment of the present invention.
8 is a graph showing a method for setting an input reference voltage considering LDC loss during slow charging according to an embodiment of the present invention.
9 is a flowchart schematically illustrating a method for controlling a converter of an eco-friendly vehicle according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated. In addition, terms such as “… unit”, “… unit”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. there is.

Throughout the specification, terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The above terms are only for the purpose of distinguishing one component from another component, e.g., without departing from the scope of rights according to the concept of the present invention, a first component may be termed a second component, and similarly The second component may also be referred to as the first component.

Throughout the specification, when a component is referred to as being 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but there may be other components in the middle. It should be understood that it may be On the other hand, when a component is referred to as 'directly connected' or 'directly connected' to another component, it should be understood that no other component exists in the middle.

Throughout the specification, terms used are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

Throughout the specification, terms related to 'comprise', 'have', etc. are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features. It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless otherwise defined herein, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as consistent with the meaning in the context of the related art, and are not interpreted in an ideal or overly formal sense unless explicitly defined herein.

Now, a low voltage DC converter control system and method for an eco-friendly vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram schematically showing the configuration of a charging control system for an eco-friendly vehicle according to an embodiment of the present invention.

Referring to FIG. 4 attached, the converter control system 100 of an eco-friendly vehicle according to an embodiment of the present invention includes a high voltage battery 110, an auxiliary battery 120, an inverter 130, a drive motor 140, and a vehicle charging unit. 150, a converter 160, a state detection unit 170 and a control unit 180.

The high voltage battery 110 is composed of a battery pack in which a plurality of battery cells are connected in series to store energy and supplies the stored energy to drive the driving motor 140 .

Hereinafter, it will be described assuming that the target supply voltage of the high voltage battery 110 is 410V, but the embodiment of the present invention is not limited thereto and may be designed differently. The number of cells may also vary.

The auxiliary battery 120 refers to a vehicle battery that supplies 12V power to various electrical loads of the vehicle.

The inverter 130 converts power supplied from the high voltage battery 110 into three-phase AC power according to a control signal applied from the controller 180 to drive the driving motor 140 .

The driving motor 140 generates a driving force of the eco-friendly vehicle with high voltage power supplied from the inverter 130 .

The vehicle charger 150 is an on-board charger (OBC) that boosts AC power supplied from the outside and then converts it into DC power to charge the high-voltage battery 110. do

The converter (Low Voltage DC-DC Converter, LDC) 160 varies and supplies the high voltage power input from the high voltage battery 110 according to the voltage (eg 12V) used in the electric load of the vehicle when the eco-friendly vehicle is driving. At this time, the converter 160 performs the same function as an alternator of an internal combustion engine charging the auxiliary battery 120 with a variable voltage.

In addition, the converter 160 may change the high voltage power input from the vehicle charging unit 150 to a low voltage (eg, 12V) during slow charging of the eco-friendly vehicle, and supply it to the electric load of the vehicle and the auxiliary battery 120.

5 schematically shows the configuration of a converter (LDC) according to an embodiment of the present invention.

Referring to FIG. 5 attached, a full-bridge converter is applied to the converter 160 according to an embodiment of the present invention.

The converter 160 is composed of a full-bridge converter including four switches (FET1 to FET4).

The converter 160 removes the noise of the high voltage power supply through the input filter, converts the direct current (DC) property into the alternating current (AC) property through high-speed switching of four switches (FET1 to FET4), and reduces the voltage through the transformer. It converts alternating current (AC) properties into direct current (DC) properties by smoothing through an output filter.

The converter 160 may operate as a full-bridge under a high load condition in which an eco-friendly vehicle is running, and may operate as a half-bridge under a relatively low load condition during slow charging. When operating as the half-bridge, the first switch FET1 and the second switch FET2 of the converter 160 are driven to be ON, and the third switch FET3 and the fourth switch FET4 are turned on. ) can be turned off. Alternatively, on/off driving in the opposite combination is also possible.

In addition, the converter 160 may operate as a full-bridge during driving under a relatively high load condition and as a half-bridge during slow charging under a relatively low load condition. Here, during driving may mean a state in which power is connected to various electrical loads due to starting or IG ON as well as driving the vehicle on the road.

The state detection unit 170 detects state information from various sensors and controllers according to driving or charging of the eco-friendly vehicle. The state detection unit 170 may detect the converter input voltage according to the state information of the eco-friendly vehicle.

The control unit 180 is a power control unit of an eco-friendly vehicle, includes at least one processor, and controls the overall operation of each of the above components for power control of the eco-friendly vehicle.

The control unit 180 detects state information of the eco-friendly vehicle during driving or charging through the state detection unit 170 .

The control unit 180 refers to the status information and selectively operates the converter in full-bridge or half-bridge.

For example, the control unit 180 refers to the state information to determine that the eco-friendly vehicle is operating, operates the converter 160 in full-bridge, and controls zero-voltage switching in the full-bridge operation state. Thus, switching loss can be reduced. Here, the zero voltage switching (ZVS) is turned on when the voltage is zero, so that the switching loss becomes zero, and when turned off, the voltage rise slope is reduced to turn off ( OFF) means to reduce switching loss.

However, as described above with reference to FIG. 3, conventionally, due to the characteristics of the LDC, zero voltage switching is not performed in the low-load operating range during slow charging, so switching loss occurs and the LDC efficiency is lowered compared to the operating state. I have presented a problem. .

To solve this problem, the control unit 180 according to an embodiment of the present invention determines that the eco-friendly vehicle is in slow charging according to the status information, the first switch (FET1) and the second switch (FET2) of the converter 160 Operates as a Half-Bridge driven only by ON. That is, since only two switches of the converter 160 perform a PWM operation, switching loss compared to a full-bridge can be reduced by half.

In addition, since the control unit 180 can control the zero voltage switching when the converter 160 is operated as a half-bridge, switching loss can be additionally reduced by performing the zero voltage control.

However, since the LDC design is based on the operating range in the driving conditions of an eco-friendly vehicle, the controller 180 cannot control the half-bridge operation in the entire voltage range during slow charging.

For example, FIG. 6 shows an LDC design factor and an output voltage equation for each circuit of a PHEV vehicle according to an embodiment of the present invention.

Referring to FIG. 6 attached, <Table 1> shows LDC design factors of a plug-in hybrid vehicle (PHEV), and <Table 2> shows output voltage equations for each full-bridge and half-bridge circuit according to the LDC design factors.

Referring to <Table 1> and <Table 2>, it is impossible to output the LDC target voltage of 12.8V up to the reference input voltage of 340 to 350V when charging the PHEV vehicle.

Therefore, the control unit 180 sets 350V as the reference input voltage for slow charging, controls the converter 160 as a full-bridge up to the reference input voltage or less, and after exceeding the reference input voltage can be controlled by half-bridge.

For example, FIG. 7 is a graph showing an LDC control state (A) and LDC efficiency (B) during slow charging according to an embodiment of the present invention.

Referring to FIG. 7, the control unit 180, assuming the PHEV vehicle in <Table 1>, starts slow charging and then switches the converter 160 to full bridge when the input voltage is below the reference input voltage (eg 350V). (Full-Bridge) operation. In addition, when the reference input voltage (eg, 350V) is exceeded, a half-bridge operation may be controlled.

Referring to the graph of the LDC control state (A), of the total slow charging time (100%), the full-bridge operation time of the converter 160 is 15%, and the half-bridge operation The time appears to be 85%.

Therefore, LDC efficiency during slow charging according to an embodiment of the present invention may increase by 5 to 10%, thereby increasing fuel consumption by up to 0.4%. Considering that when the LDC efficiency increases by 1% during slow charging, the fuel efficiency of the vehicle increases by 0.04%, according to an embodiment of the present invention, there is an effect of increasing the LDC efficiency during slow charging to the level of LDC efficiency during driving. there is.

Meanwhile, the input reference voltage 350V described in the previous embodiment can be changed and set according to the LDC design factor of the eco-friendly vehicle as an example, and the input reference voltage setting method will be described with reference to FIG. 8 below.

8 is a graph showing a method of setting an input reference voltage during slow charging in consideration of LDC loss according to an embodiment of the present invention.

Referring to FIG. 8 attached, the loss during high voltage-to-low voltage conversion in the full bridge converter is basically divided into conduction loss and switching loss of the four switches (FET1 to FET4) configured in the converter 160. At this time, the switching loss according to the load of the converter has little change, but the conduction loss increases.

The control unit 180 converts the converter 160 from full-bridge operation to half-bridge operation during slow charging. The reference input voltage is the amount of conduction loss of the converter 160. It can be set as an input voltage value corresponding to the converter load amount (ie, output amount) at the time when (a) becomes equal to the amount of switching loss (b).

At this time, as shown in FIG. 8, when the low load section and the high load section of the converter load are divided based on the reference input voltage during slow charging, the switching loss is relatively higher than the conduction loss in the low load section, and switching in the high load section. It can be seen that the loss is relatively low compared to the conduction loss.

Since it is difficult for the control unit 180 to meet the LDC target voltage (e.g., 12.8V) in a low load section where the input voltage is low, the converter 160 is switched off when the converter input voltage detected by the state detection unit 170 is less than or equal to the reference input voltage. It is driven by Full-Bridge.

In addition, the controller 180 drives the converter 160 as a half-bridge when the converter input voltage exceeds the reference input voltage.

In this case, since the switching loss is a value obtained by multiplying each switch loss by the number of switches, switching loss can be reduced as much as the number of switches driven is reduced when driving with a half-bridge in which only half the number of switches is operated.

Here, the converter 160 according to an embodiment of the present invention operates as a full-bridge under a high load condition of an electric load in which an eco-friendly vehicle is running, and has LDC efficiency under a relatively low load condition during slow charging. Its main feature is that it operates as a half-bridge for

This low load condition of electric load makes it clear that the LDC efficiency is different from that which can simply control a full-bridge converter with a half-bridge.

For example, when the converter performs a half-bridge operation under a high load condition (i.e., normal driving condition) where a load is applied due to the operation of an eco-friendly vehicle or an electronic device using a full bridge converter, twice the current is required even for the same voltage operation. Therefore, there is a disadvantage in that the conduction loss is greatly increased. Therefore, it is common for full bridge to be more advantageous than half bridge for converter operation when the load is high, and it is differentiated in that a large conduction loss must be endured when operating with half bridge unreasonably.

Meanwhile, based on the configuration of the above-described converter control system 100 for an eco-friendly vehicle, a converter control method for an eco-friendly vehicle according to an embodiment of the present invention will be described with reference to FIG. 9 below. However, since the detailed configuration of the converter control system 100 of the eco-friendly vehicle can be subdivided by function or integrated into one system, the subject of the converter control system 100 in the description of the converter control method of the eco-friendly vehicle through FIG. ) to explain.

9 is a flowchart schematically illustrating a method for controlling a converter of an eco-friendly vehicle according to an embodiment of the present invention.

Referring to FIG. 9 , the converter control system 100 according to an embodiment of the present invention collects state information and detects a converter input voltage when charging start of an eco-friendly vehicle is detected through the state detection unit 170 ( S1).

The converter control system 100 compares the detected converter input voltage with a preset reference input voltage and determines the half-bridge or full-bridge operation of the converter 160 according to whether the input voltage is exceeded (S2).

In the step S2, the converter control system 100 controls the converter 160 to operate as a full bridge when the detected input voltage is equal to or less than a preset reference input voltage (S2; No) (S3).

At this time, the converter control system 100 determines the PWM duty range (D) according to the LDC design factor as the basic duty (S4), and turns on all the switches (FET1 to FET4) of the converter 160 to operate PWM to be performed (S5). The full bridge operation according to steps S3 to S5 is repeated until the converter input voltage exceeds the reference input voltage.

On the other hand, in step S2, if the detected input voltage exceeds the reference input voltage (S2; Yes), the converter control system 100 controls the converter 160 to operate as a half bridge (S6).

At this time, the converter control system 100 determines the PWM duty range (D) according to the LDC design factor to be twice the basic duty (S4), and operates only half of the switches provided in the converter 160 (S7). For example, the converter control system 100 turns on the first and second switches FET1 and FET2 to perform a PWM operation, and turns off the third and fourth switches FET3 and FET4. (OFF) can be turned on.

The converter control system 100 returns to the step S1 and repeats the half bridge control when the converter input voltage is less than the upper limit input voltage during charging set in the LDC design factor (S9; No).

Thereafter, the converter control system 100 terminates the charging of the auxiliary battery when the converter input voltage reaches the upper limit input voltage during charging (S9; Yes).

In addition, preferably, start may be restricted for safety during charging of the eco-friendly vehicle, but depending on the manufacturer or vehicle model, allowing use of the electric load during charging by starting or IG ON cannot be completely ruled out.

Therefore, although omitted in FIG. 9, the converter control system 100 operates the converter 160 when the start or IG ON signal is detected from the state detection unit 170 during the half-bridge operation of the converter 160. A conversion step may be further included.

This means that if power is constantly supplied to the electric load by starting/IG ON during the half bridge operation of the converter 160 during charging, the load of the electric load is increased accordingly, and the half bridge operation at a high load generates double current This is to prevent this because the conduction loss greatly increases due to the need for

As such, according to an embodiment of the present invention, switching loss compared to full-bridge can be reduced by half by operating the converter as a half-bridge during slow charging of an eco-friendly vehicle.

In addition, zero voltage switching is possible through a half-bridge operation of the converter during charging, so that switching loss can be additionally reduced.

In addition, when the converter input voltage during charging is below the standard input voltage at a level where the target voltage (12.8V) cannot be output, it operates as a full bridge, and when it exceeds the standard input voltage, it converts to a half bridge to ensure stable battery charging along with LDC charging efficiency. This is a possible effect.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also included in the scope of the present invention. that fall within the scope of the right.

100: converter control system
110: high voltage battery
120: auxiliary battery
130: inverter
140: drive motor
150: vehicle charging unit
160: converter (LDC)
170: state detection unit
180: control unit

Claims (16)

a drive motor that generates a driving force for an eco-friendly vehicle;
a high voltage battery supplying power to the driving motor;
A vehicle charging unit that boosts AC power supplied from the outside and converts it into DC power to charge the battery with high voltage power;
a converter that converts the high voltage power input from the high voltage battery or the vehicle charging unit into a low voltage and supplies it to an electric load and an auxiliary battery;
a state detector detecting the state information of the eco-friendly vehicle and the input voltage of the converter; and
A control unit for selectively operating the converter in full-bridge or half-bridge with reference to the status information;
The converter control system of an eco-friendly vehicle, wherein the control unit operates the converter as a full bridge while driving the vehicle and operates the converter as a half bridge during charging by referring to the status information. According to claim 1,
The converter
An eco-friendly vehicle converter control system that includes 4 switches as LDC (Low Voltage DC-DC Converter). delete According to claim 1 or 2,
The control unit
A converter control system for an eco-friendly vehicle that controls the first switch and the second switch of the converter to perform a PWM operation and turns off the third switch and the fourth switch when operating as the half bridge. According to claim 4,
The control unit
A converter control system for an eco-friendly vehicle that controls zero-voltage switching in a half-bridge operating state of the converter. According to claim 4,
The control unit
An eco-friendly vehicle that sets a reference input voltage of the converter during the charging, controls the full bridge when the input voltage is less than or equal to the reference input voltage, and controls the half bridge when the input voltage exceeds the reference input voltage. converter control system. According to claim 6,
The reference input voltage is
A converter control system for an eco-friendly vehicle, characterized in that the input voltage value corresponding to the converter load amount at the time when the amount of conduction loss of the converter is equal to the amount of switching loss. According to claim 1,
The control unit
A converter control system of an eco-friendly vehicle that controls zero-voltage switching of the converter in a full-bridge operating state. A method for controlling a converter (Low Voltage DC-DC Converter, LDC) that converts input high voltage power into low voltage when the converter control system of an eco-friendly vehicle is charged with external power and supplies it to an electric load and a battery,
a) detecting an input voltage of the converter by collecting state information when the start of charging of the eco-friendly vehicle is detected;
b) controlling the converter to operate as a full bridge when the detected input voltage is less than or equal to a preset reference input voltage; and
c) controlling the converter to operate as a half bridge when the detected input voltage exceeds the reference input voltage;
Converter control method of an eco-friendly vehicle comprising a. According to claim 9,
Before step a) above,
Setting the reference input voltage to an input voltage value corresponding to the load of the converter at a time when the amount of conduction loss of the converter generated during charging is equal to the amount of switching loss. The method of claim 9 or 10,
In step b),
A method for controlling a converter of an eco-friendly vehicle comprising determining a PWM duty range according to a design factor of the converter as a basic duty and PWM operation of all switches of the converter. The method of claim 9 or 10,
In step c),
A converter control method for an eco-friendly vehicle comprising the step of determining a PWM duty range according to a design factor of the converter to be twice the basic duty. According to claim 12,
In step c),
Controlling the first switch and the second switch of the converter to perform a PWM operation and turning off the third switch and the fourth switch. According to claim 9,
In step c),
A method of controlling a converter of an eco-friendly vehicle comprising the step of controlling zero-voltage switching in a half-bridge operating state of the converter. According to claim 9,
In step c),
and converting the converter to a full bridge operation when a start or IG ON signal of the eco-friendly vehicle is detected. According to claim 9,
After step c),
The method of controlling the converter of an eco-friendly vehicle further comprising terminating charging of the auxiliary battery when the detected input voltage reaches an upper limit input voltage during charging set in a converter design factor.

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