KR20220119236A - Power generating system for driving EWP of 48V mild hybrid system, and control method thereof - Google Patents

Abstract

The present invention relates to a mild hybrid vehicle, and more specifically, to a power generation control system and method for driving an EWP in a 48V mild hybrid system, which can secure a SOC of a battery for EWP operation, prevent damage to a urea solution injector due to the residual heat of the engine, and promote efficient operation of the EWP. The method for driving an EWP in a 48V mild hybrid system according to the present invention comprises: a step of determining whether ignition of a vehicle is off; if it is confirmed that the ignition of the vehicle is off, a step of determining whether power generation is necessary after restarting the vehicle; if power generation for the vehicle is deemed necessary, a step of restarting the vehicle and setting a target voltage of an LDC to the maximum to charge the battery; and, after confirming whether a sufficient SOC of the battery has been secured, a step of turning off the ignition if a sufficient SOC of the battery has been confirmed.

Description

Power generating system for driving EWP of 48V mild hybrid system, and control method thereof

The present invention relates to a power generation control system and method for driving an Electric Water Pump (EWP) in a hybrid vehicle, and more particularly, by securing sufficient SOC of a 12V battery for EWP driving in a 48V mild hybrid system, factors caused by engine residual heat The present invention relates to a power generation control system and method for driving an electric water pump of a 48V mild hybrid system capable of preventing burnout of a single water injector and efficiently driving an EWP.

In general, internal combustion engines using fossil fuels such as gasoline or diesel cause environmental pollution by exhaust gas. Hazardous substances such as (HC), particulate matter, and nitrogen oxides (NOx) may be included.

Accordingly, in the exhaust system of a vehicle equipped with a diesel engine, exhaust gases such as Diesel Oxidation Catalyst (DOC), Diesel Particulate Matter Filter (DPF), Selective Catalyst Reduction (SCR) and Lean NOx Trap (LNT) to reduce harmful substances A post-processing device is provided.

Among them, in the exhaust gas post-treatment device to which SCR (hereinafter referred to as 'selective catalytic reduction system') is applied, a reducing agent such as urea water is injected into the exhaust pipe through a urea water injector module to reduce nitrogen oxides and ammonia in the exhaust gas. Nitrogen oxide is reduced to nitrogen gas (N2) and water (H2O) by a catalytic reaction.

Such a urea water injector module is generally mounted on an exhaust pipe to inject urea water into the exhaust gas. Continuous cooling is required as this may occur. For this purpose, in a vehicle equipped with a selective catalytic reduction system, an electric water pump (EWP; hereinafter referred to as 'EWP') for cooling the urea water injector module is mounted.

This EWP needs to be driven even when the vehicle is running, but in order to prevent the urea injector module from overheating due to engine residual heat even when the engine is turned off after the vehicle has been driven, up to 30 minutes after the vehicle is turned off. additional driving is required.

As described above, in the prior art, the EWP had to be driven for a certain period of time to cool the urea injector module even after the vehicle has been driven. There was a problem of generating exhaust gas and causing a reduction in fuel efficiency of the vehicle. In addition, in the case of a hybrid vehicle, the power of the 12V battery is used to drive the EWP after the ignition is turned off. If the water injector module cannot be cooled, there is a problem in that the urea water injector module is damaged due to engine residual heat.

Republic of Korea Patent Registration No. 10-1988603 (2019.06.05)

The present invention has been devised to solve the above problems, and the technical problem to be solved in the present invention is to control the charging voltage of the 12V battery through the 48V battery in a vehicle equipped with a 48V mild hybrid system to drive the EWP even after the ignition is OFF. By ensuring that the necessary 12V battery SOC is sufficiently secured, it is possible to prevent the burnout of the urea water injector module due to engine residual heat, and a power generation control system for driving the electric water pump of the 48V mild hybrid system that can promote the efficient operation of the EWP; to provide a way.

A power generation control method for driving an EWP of a 48V mild hybrid system according to the present invention for solving the above technical problem includes the steps of: (a) determining whether the vehicle's ignition is OFF; (b) determining whether power generation is required after restarting the vehicle when it is confirmed that the vehicle's ignition is off; (c) when it is determined that power generation of the vehicle is necessary, restarting the vehicle and setting a low-side target voltage of a low voltage DC-DC converter (LDC) to a maximum value to charge a 12V battery; (d) after checking whether the SOC of the 12V battery is sufficiently secured, and then turning off the ignition when the battery SOC is sufficiently secured.

Here, in step (b), the remaining time required to drive the EWP (Electric Water Pump) is greater than or equal to the threshold value, the SOC of the 12V battery is less than or equal to the threshold, or the SOC of the 48V battery is less than or equal to the threshold. When one or more conditions are satisfied, it may be determined that power generation is necessary after restarting the vehicle.

And, when it is determined from step (b) that power generation is necessary after restarting the vehicle, a message informing of this may be output on the cluster.

In addition, in step (d), when the difference between the SOC of the current 12V battery and the SOC of the 12V battery required for EWP driving is greater than a preset minimum battery SOC, it may be determined that the SOC of the current battery is sufficiently secured.

In addition, when it is confirmed that the ignition is not turned off in step (a), determining whether EWP driving is required, and calculating the target 12V battery SOC required for EWP driving if EWP driving is required (e) may be additionally performed.

At this time, the target 12V battery SOC calculation in step (e) is calculated by calculating the time required for driving the EWP, multiplying the calculated time by the EWP power consumption to convert the 12V battery SOC, and then adding the battery SOC of the set level can do.

In this case, the battery SOC of the set level may be the battery SOC of the 50% level.

On the other hand, when the target 12V battery SOC is calculated from step (e), the current 12V battery SOC and the calculated target 12V battery SOC are compared, and if the current battery SOC is smaller than the target battery SOC, the low side of the LDC The step (f) of increasing the target voltage may be additionally performed.

And, after increasing the low-side target voltage of the LDC in step (f), the step (g) of strengthening the 12V battery SOC condition for entering the SSC (Start-Stop Coasting) may be additionally performed. have.

In this case, the method of strengthening the 12V battery SOC condition for SSC entry in step (g) may be performed by replacing the 12V battery SOC condition with the target 12V battery SOC condition calculated in step (e).

In addition, after the 12V battery SOC condition for SSC entry is strengthened from step (g), it is possible to control to prohibit assisting the torque of the Mild Hybrid Starter & Generator (MHSG) through the battery.

On the other hand, in the power generation control system for driving the EWP of the 48V mild hybrid system according to the present invention, information on ignition on/off detected through a starting sensor mounted on the vehicle is transmitted to the control unit, and the control unit When it is confirmed that the ignition is off, it is determined whether power generation is required after restarting the vehicle. to charge the 12V battery, and control to turn off the ignition when it is determined that the SOC of the 12V battery is sufficiently secured.

According to the present invention having the above configuration, by controlling the charging voltage of the 12V battery through the 48V battery in the vehicle to which the 48V mild hybrid system is applied, the 12V battery SOC required for driving the EWP is sufficiently secured even after the vehicle is turned off. It is possible to prevent the burnout of the injector module due to the urea number and to ensure the efficient operation of the EWP.

In addition, in the prior art, in order to secure power required to drive the EWP for a certain time for cooling the urea injector module in a state in which the engine is turned off after driving the vehicle, the engine is maintained in an idle state. Although there was a problem of generating additional exhaust gas and reducing fuel efficiency, in the present invention, the SOC of the 12V battery required for EWP driving can be sufficiently secured through the control of the charging voltage of the 12V battery through the 48V battery. There is an advantage that exhaust gas emission can be reduced and fuel efficiency can be reduced by eliminating the need to operate the engine for this purpose.

1 is a configuration diagram showing the peripheral configuration of a selective catalytic reduction system (SCR) mounted on a vehicle.
2 is a block diagram showing the configuration of a main part of a power generation control system for a vehicle equipped with a 48V mild hybrid system according to the present invention.
3 is a flowchart sequentially illustrating a power generation control method for EWP driving of a 48V mild hybrid system according to the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention.

However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. In addition, it is to be noted that throughout the detailed description, parts denoted by the same reference numerals mean the same components.

Hereinafter, a power generation control system and method for driving an EWP in a vehicle equipped with a 48V mild hybrid system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a peripheral part of an SCR system, which is an exhaust gas post-treatment device according to the present invention, and FIG. 2 is a main part of a power generation control system for driving an EWP in a vehicle equipped with a 48V mild hybrid system according to the present invention. A block diagram showing the configuration.

1 and 2, in a vehicle equipped with a selective catalyst reduction system (SCR, hereinafter referred to as "SCR"), which is an exhaust gas after-treatment device, the urea water injector module is introduced into the exhaust pipe 10 . (20) by injecting urea water (reducing agent) through the catalytic reaction of nitrogen oxides (NOx) and urea water contained in the exhaust gas to reduce nitrogen oxides into nitrogen gas (N ₂ ) and water (H2O) It purifies and treats harmful substances contained in the gas.

In this case, the urea water injector module 20 mounted on the exhaust pipe 10 injects urea water as a reducing agent to the exhaust gas moving along the exhaust pipe 10 so that a reduction reaction with nitrogen oxide is made. In the process, the urea water injector module 20 is easily exposed to high temperature exhaust gas, and thus damage or failure may occur due to high temperature heat.

For this reason, in a vehicle equipped with an SCR system, an Electric Water Pump (EWP) 106 is mounted to continuously cool the urea water injector module 20, and the EWP 106 is a control transmitted from the control unit 107. The driving is controlled by the signal.

On the other hand, the EWP 106 requires driving even when the vehicle is running, but prevents the urea injector module 20 from overheating due to residual heat of the engine 101 in a state in which the engine is turned OFF after the vehicle is driven. To do this, additional driving is required for up to 30 minutes even after the vehicle is turned off.

As such, even after the vehicle has been driven, the EWP 106 must be driven for a certain period of time to prevent overheating of the urea injector module 20 due to residual heat of the engine 101, so even after the vehicle is turned off, the EWP (106) In order to secure power for driving the engine 101, it is necessary to maintain the engine 101 in an idle state for a certain period of time, which causes additional exhaust gas generation and reduction in fuel efficiency of the vehicle.

In addition, in the case of a hybrid vehicle equipped with a motor assisting the engine 101, 12V battery power is used to drive the EWP 106 even after the engine is turned off. In this case, there is a problem in that the EWP 106 fails to cool the urea water injector module 20 and eventually causes damage to the urea water injector module 20 due to engine residual heat.

In order to solve this problem, the present invention provides an LDC ( By controlling the low-side target voltage of the Low voltage DC-DC Converter; It is possible to efficiently drive the EWP 106 even without operation, thereby preventing the burnout of the urea water injector module due to engine residual heat, and implementing additional exhaust gas generation and fuel economy reduction due to engine operation.

For this purpose, in a vehicle equipped with a 48V mild hybrid system of the present invention, a 12V battery ( 105) is mounted, and an LDC 104 for output conversion between a high voltage (48V) and a low voltage (12V) is connected to the 12V battery 105 .

Here, the LDC 104 is a device that variably controls the voltage to efficiently manage power in the vehicle and operates to charge or discharge the battery according to the driving mode of the vehicle, and in the 48V mild hybrid system vehicle of the present invention, 48V By charging the 12V battery 105 by converting the DC high voltage from the battery 103 into a DC low voltage, sufficient SOC of the 12V battery 105 for smooth driving of the EWP 106 can be secured.

In the power generation control system for driving the EWP of the present invention as described above, the starting on/off information of the current vehicle is detected through the starting detection sensor 108 mounted on the vehicle and transmitted to the control unit 107, and the The control unit 107 determines whether the vehicle is started ON/OFF based on the information detected by the start detection sensor 108, and when it is confirmed that the vehicle is in the OFF state, after restarting the vehicle (starting ON), It is determined whether power generation is required to drive the EWP 106, and when it is determined that power generation is required because the state of charge (SOC) of the battery is insufficient, the vehicle is started and turned on and low voltage DC-DC (LDC) is turned on. The converter; Control to turn off the ignition can be performed.

Meanwhile, FIG. 3 is a flowchart for sequentially explaining a power generation control method for driving the EWP 106 in a vehicle equipped with a 48V mild hybrid system according to the present invention.

Referring to FIG. 3 , in the power generation control method for driving the EWP of a 48V mild hybrid system according to the present invention, first, the control unit 107 starts on/off the vehicle through the information detected from the start sensor 108 ( ON/OFF) or not. (S201)

Here, if it is confirmed that the vehicle's ignition is OFF, it is determined whether or not power generation for charging the 12V battery 105 is required after the vehicle's ignition is turned ON. (S202) )

In this case, the following several conditions may be considered as a criterion (condition) for determining that power generation is necessary after restarting the vehicle in step S202.

① Remaining time required for EWP operation > Threshold

② 12V battery SOC < threshold

③ 48V battery SOC < threshold

That is, in a situation in which the SOC of the 12V battery 105 is not sufficiently secured while the vehicle is driving, a situation in which the 12V battery 105 is completely discharged due to the EWP 106 driving after the engine is turned off may occur, to prevent this. To this end, the control unit 107 determines whether power generation is required to secure the SOC of the battery 105 .

In this case, any one or more of the conditions under which the remaining time required for driving the EWP 106 is equal to or greater than the threshold value, the SOC of the 12V battery 105 is less than or equal to the threshold, or the SOC of the 48V battery 103 is less than or equal to the threshold. When the condition is satisfied, it may be determined that power generation is necessary after restarting the vehicle.

At this time, the reason for checking the SOC of the 48V battery 103 is that if the SOC of the 48V battery 103 is sufficient, the 12V battery 105 can be charged through the SOC secured in the 48V battery 103 without a separate start. to be.

Next, if it is determined from step S202 that power generation is necessary after restarting the vehicle, the control unit 107 transmits a signal to the cluster 109 located on the dashboard to output a phrase informing the restart of the vehicle (S203) , after turning on the vehicle's ignition (S204), the target voltage of the low side of the LDC 104 is set to the maximum value to perform the charging operation of the 12V battery 105 (S205).

Here, when starting the charging of the battery after turning on the vehicle to secure the SOC of the 12V battery for driving the EWP 106, the control unit 107 sends a signal to the cluster 109, for example, By outputting the message “I keep the engine in the starting state to operate the hardware to prevent damage to the system”, it is possible to prevent the engine from causing discomfort to the driver by turning the engine off regardless of the driver’s will. can

In addition, as described above, the reason for setting the target voltage of the low side of the LDC 104 to the maximum is by setting the target voltage to the maximum value in consideration of the allowable current for preventing damage to the mild hybrid system, the EWP 106 This is to quickly secure the SOC of the 12V battery 105 necessary for driving to quickly end the ignition-on situation regardless of the driver's will.

On the other hand, the reason for not setting the low-side target voltage of the LDC 104 to the maximum in the driving state of the vehicle is to suppress power generation by consuming fuel in a normal driving situation, and to generate regenerative power as much as possible. This is in order to be able to generate electricity using the energy obtained without consuming fuel.

Subsequently, after the charging operation of the 12V battery 105 is performed through the step S205, the controller 107 determines whether the SOC of the 12V battery 105 is sufficiently secured (S206), and the 12V battery 105 When it is determined that the SOC of the vehicle is sufficiently secured, the vehicle is turned off (S207), and a signal is transmitted to the EWP 106 to drive the EWP 106 .

At this time, as a criterion for determining whether the SOC of the 12V battery 105 is sufficiently secured in the step S206, the difference between the SOC of the current 12V battery 105 and the SOC of the 12V battery 105 required for driving the EWP 106 is the difference When it is greater than the set minimum battery SOC, it may be determined that the SOC of the current 12V battery 105 is sufficiently secured. That is, when the current battery SOC - the battery SOC required for the EWP driving > the minimum battery SOC is satisfied, it can be determined that the current battery SOC is sufficiently secured.

At this time, the calculation of the 12V battery SOC required for driving the EWP 106 is,

It can be calculated by converting (EWP power consumption * remaining time required for EWP operation) to battery SOC.

In addition, the 'minimum battery SOC' refers to a battery SOC of a level capable of stably starting the vehicle when the next driving starts, and may be, for example, a 12V battery SOC of 20%. In this case, the reason for using the minimum battery SOC as a reference is to quickly end the current starting situation that has been carried out regardless of the driver's will.

On the other hand, when it is determined that the current vehicle ignition is not turned OFF in step S201, that is, when the ignition ON state is confirmed, it is determined whether the driving of the EWP 106 is required after the vehicle ignition is OFF ( S208), here, if it is determined that the current SOC of the 12V battery 105 is insufficient and thus the EWP 106 needs to be driven, a task of calculating the target 12V battery SOC required for the EWP 106 driving is performed. ( S209)

At this time, in the step S209, the calculation of the target 12V battery SOC required for driving the EWP 106 is calculated by first calculating the time required for driving the EWP, and multiplying the calculated time by the EWP power consumption is converted into 12V battery SOC. Then, it may be calculated by adding the battery SOC of the set level (the battery SOC of the 50% level).

That is, the target battery (12V) SOC calculation method is,

It can be calculated by converting (EWP driving time required * EWP power consumption) to 12V battery SOC and adding it to the set (appropriate) 50% level of battery SOC.

In this case, the 'set appropriate level of battery SOC' refers to a level of battery SOC capable of stably and efficiently operating a vehicle, and may be set to a battery SOC of 50% level.

In addition, the time required for driving the EWP may be output from a map using the temperature of the urea water injector module 20 as input information, and in this map, through a driving test, various urea injector modules 20 It can be obtained by mapping the EWP time driven to maintain the temperature of the urea number injector module 20 at an appropriate level after Key Off in the temperature condition.

Then, when the calculation of the target battery (12V) SOC required for driving the EWP 106 from step S209 is all completed, the current 12V battery SOC and the calculated target 12V battery SOC are compared next (S210), and if If the current 12V battery SOC is less than the target 12V battery SOC, the low-side target voltage of the LDC 104 is increased so that the 12V battery can be charged quickly within a short time (S211).

Here, in the 48V mild hybrid system of the present invention, the 12V battery 105 is charged by the LDC 104 and the 48V battery 103, and the target LDC 104 Low Side voltage and the 12V battery ( 105) It is controlled so that the amount of charge can be adjusted by the difference in voltage.

In addition, in the present invention, in order to reach the target 12V battery SOC level before the driving of the vehicle is completed, unlike the general charging situation, the LDC 104 Low Side target voltage is increased by increasing the target voltage before the driving of the vehicle is finished. A sufficient level of battery SOC required for driving the EWP 106 can be secured within a short time.

At this time, as a method of increasing the low-side target voltage of the LDC 104, a map using the ratio of the target 12V battery SOC and the current 12V battery SOC and the remaining driving time received from the vehicle's navigation as input information ( Map) by multiplying the output correction value by the LDC Low Side target voltage.

Next, after increasing the low-side target voltage of the LDC 104 in the step S211, the SOC condition of the 12V battery 105 for starting SSC (Start-Stop Coasting) is strengthened. (S212)

In general, in the case of a 48V mild hybrid system, one of SSC (Start-Stop Coasting) or Coasting Regen is selected and controlled during coasting. In order to secure the battery SOC for driving the EWP in the future, fuel consumption according to the operation of the engine is required, which may adversely affect fuel efficiency.

In the present invention, in order to prevent the fuel efficiency reduction problem of the vehicle, the amount of power generation can be increased by reinforcing the entry condition of the SSC to replace the section where the SSC would have been used in a general situation with a coasting regen.

At this time, as the 12V battery condition to strengthen the SSC entry condition, in the case of SSC, the 12V & 48V battery SOC is generally sufficient to enter. In the present invention, the 12V battery SOC condition is calculated as the target 12V battery SOC condition calculated in step S209. Instead, the problem of reduced fuel economy can be solved by strengthening the SSC entry condition.

In addition, in a situation in which it is necessary to secure the 12V battery SOC for driving the EWP 106, consuming the battery SOC as power to assist the torque of the MHSG (Mild Hybrid Starter &Generator; 102) is disadvantageous to fuel efficiency, In order to prevent this problem, after the 12V battery SOC condition for SSC entry is strengthened from the step S212, it is controlled to prohibit assisting the torque of the MHSG 102 through the battery (S213), and to the EWP (106). A signal may be sent to drive the EWP 106 .

As described above, in a vehicle equipped with a 48V mild hybrid system, the charging voltage of the 12V battery is controlled through the 48V battery according to the control logic of the present invention. As before, the EWP cannot be driven due to the discharge of the 12V battery after the ignition is turned off as before, so it is possible to prevent the damage of the urea injector module single unit from being burned out due to the residual heat of the engine, and the vehicle starting ON/OFF Regardless of the situation, it is possible to secure a sufficient 12V battery SOC for driving the EWP, which has the advantage of implementing efficient driving of the pump.

In addition, as the engine is maintained in the idle state to secure the power required to drive the EWP for a certain period of time for cooling the urea injector module in the state that the engine is turned off after driving the vehicle, additional exhaust exhaust Although there was a problem of gas generation and reduction of fuel efficiency, in the present invention, the SOC of the 12V battery required for EWP driving can be sufficiently secured through the control of the charging voltage of the 12V battery through the 48V battery. Since there is no need to operate the engine, exhaust gas emission can be reduced and fuel efficiency can be reduced.

Although preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to these specific embodiments, and those skilled in the art will appropriately change within the scope described in the claims of the present invention. this will be possible

10: exhaust gas pipe 20: urea water injector module
40: SCR 101: engine
102: MHSG 103: 48V battery
104: LDC 105: 12V battery
106: EWP 107: control unit
108: start detection sensor 109: cluster

Claims (18)

(a) determining whether the ignition of the vehicle is off (OFF);
(b) determining whether power generation is required after restarting the vehicle when it is confirmed that the vehicle's ignition is off;
(c) when it is determined that power generation of the vehicle is required, restarting the vehicle and setting a low-side target voltage of a low voltage DC-DC converter (LDC) to a maximum value to charge a 12V battery;
(d) checking whether the state of charge (SOC) of the 12V battery is sufficiently secured, and then turning off the ignition if the 12V battery SOC is sufficiently secured;
A power generation control method for EWP driving of a 48V mild hybrid system comprising a.
According to claim 1, wherein the step (b),
When any one or more of the following conditions are satisfied: the remaining time required to drive the EWP (Electric Water Pump) is greater than or equal to the threshold value, the SOC of the 12V battery is less than or equal to the threshold, or the SOC of the 48V battery is less than or equal to the threshold A power generation control method for EWP driving of a 48V mild hybrid system, characterized in that it is determined that power generation is necessary after restarting the.
The method according to claim 1, wherein when it is determined that power generation is required after restarting the vehicle from step (b), a message notifying this is output on a cluster. power generation control method.
According to claim 1, In step (d),
When the difference between the current 12V battery SOC and the 12V battery SOC required for EWP driving is greater than the preset minimum 12V battery SOC, it is determined that the current 12V battery SOC is sufficiently secured. power generation control method.
The method of claim 1, wherein when it is confirmed that the engine is not turned off in step (a), it is determined whether EWP driving is required, and if EWP driving is required, calculating the target 12V battery SOC required for EWP driving. Power generation control method for EWP driving of a 48V mild hybrid system, characterized in that it further comprises step (e).
The method of claim 5, wherein the target 12V battery SOC calculation in step (e) calculates the time required to drive the EWP, multiplies the calculated time by the EWP power consumption to convert the battery SOC, and then calculates the battery SOC of the set level. Power generation control method for EWP driving of a 48V mild hybrid system, characterized in that it is calculated by adding
[Claim 7] The method of claim 6, wherein the set level of battery SOC is 50% level of battery SOC.
The method of claim 5, wherein when the target 12V battery SOC is calculated from step (e), the current 12V battery SOC and the calculated target 12V battery SOC are compared, and if the current 12V battery SOC is less than the target 12V battery SOC, the LDC Power generation control method for EWP driving of a 48V mild hybrid system, characterized in that it further comprises the step (f) of increasing the low-side target voltage.
The method of claim 8, wherein after increasing the low-side target voltage of the LDC in step (f), strengthening the 12V battery SOC condition for SSC (Start-Stop Coasting) entry (g) Power generation control method for EWP driving of the 48V mild hybrid system, characterized in that it further comprises.
The 48V mild, characterized in that in step (g), the 12V battery SOC condition for SSC entry is reinforced by replacing the 12V battery SOC condition with the target 12V battery SOC condition calculated in step (e). Power generation control method for EWP driving of hybrid system.
10. The method of claim 9, wherein after the 12V battery SOC condition for SSC entry is strengthened from step (g), it is characterized in that it is prohibited to assist the torque of the MHSG (Mild Hybrid Starter & Generator) through the battery. Power generation control method for EWP driving of 48V mild hybrid system.
Information on ignition on/off (ON/OFF) detected through the ignition sensor mounted on the vehicle is transmitted to the control unit, and when it is confirmed that the ignition is off, the control unit determines whether power generation is required after restarting the vehicle, If power generation is required, restart the vehicle and set the low-side target voltage of the LDC (Low voltage DC-DC converter) to the maximum to charge the 12V battery, and when it is determined that the SOC of the 12V battery is sufficiently secured Power generation control system for EWP driving of 48V mild hybrid system that turns off the ignition.
13. The method of claim 12, wherein the control unit, EWP (Electric Water Pump) of the remaining time required to drive the threshold value or more, the SOC of the 12V battery is less than the threshold value, or the SOC of the 48V battery is less than the threshold value. A power generation control system for EWP driving of a 48V mild hybrid system, characterized in that it is determined that power generation is required after restarting the vehicle when any one or more conditions are satisfied.
The method according to claim 12, wherein the controller determines that the SOC of the current 12V battery is sufficiently secured when a difference between the SOC of the current 12V battery and the SOC of the 12V battery required for EWP driving is greater than a preset minimum battery SOC. Power generation control system for EWP driving of 48V mild hybrid system.
The EWP driving of the 48V mild hybrid system according to claim 12, wherein the control unit calculates the target 12V battery SOC required for the EWP driving when it is determined that the EWP driving is required when it is confirmed that the ignition is not turned off. for power generation control systems.
The method of claim 15, wherein the controller compares the current 12V battery SOC and the calculated target 12V battery SOC, and if the current 12V battery SOC is less than the target 12V battery SOC, increases the low-side target voltage of the LDC. A power generation control system for EWP driving of a 48V mild hybrid system, characterized in that it controls to make it happen.
The method of claim 16, wherein the controller increases the low-side target voltage of the LDC and then replaces the 12V battery SOC condition with the calculated target 12V battery SOC condition to enter Start-Stop Coasting (SSC) Power generation control system for EWP driving of 48V mild hybrid system, characterized in that it controls to strengthen the 12V battery SOC condition for
18. The method of claim 17, wherein the control unit controls to prohibit assisting the torque of the MHSG (Mild Hybrid Starter & Generator) through the battery after the 12V battery SOC condition for entering the SSC is strengthened. Power generation control system for EWP driving of a 48V mild hybrid system, characterized in that.

Images