KR20190013257A - Method for controlling ptc heater of mild hybrid electric vehicle - Google Patents

Abstract

A method for controlling a PTC heater of a mild hybrid vehicle comprises the following steps of: allowing a controller to receive a state of charge (SOC) of a first battery and a SOC of a second battery; and controlling one of the first battery and the second battery to be used as power of a positive temperature coefficient (PTC) heater by the controller based on the SOC of the first battery and the SOC of the second battery.

Description

METHOD FOR CONTROLLING PTC HEATER OF MILD HYBRID ELECTRIC VEHICLE FIELD OF THE INVENTION [0001]

The present invention relates to a mild hybrid vehicle, and more particularly, to a PTC heater control method for a mild hybrid vehicle.

A hybrid electric vehicle uses an internal combustion engine and battery power together. That is, the hybrid vehicle uses the power of the internal combustion engine and the power of the motor in an efficient combination.

Hybrid vehicles can be classified into a mild type and a hard type according to the power sharing ratio between the engine and the motor. A mild hybrid vehicle (or a mild hybrid vehicle) includes a mild hybrid starter & generator (MHSG) that starts the engine instead of an alternator or is generated by the output of the engine. The hybrid vehicle of the hard type separately includes a starter generator that starts the engine or generates power by the output of the engine and a drive motor that drives the vehicle.

Mild hybrid vehicles do not have a running mode that only drives the vehicle with MHSG torque, but MHSG can assist the engine torque according to the running condition and charge the battery (for example, 48 V battery) through regenerative braking . As a result, the fuel efficiency of the mild hybrid vehicle can be improved.

In general, diesel hybrid vehicles equipped with direct injection diesel engines use plug heaters or PTC heaters due to the lack of heater heat sources (eg engine coolant). Particularly, the PTC heater is used to heat the air supplied to the room before the engine warm-up after the cold start of the diesel engine vehicle in the winter season.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

SUMMARY OF THE INVENTION The object of the present invention is to provide a method and system for detecting a positive temperature coefficient (PTC) based on the SOC of a first battery (e.g., a 48 volt battery) and the SOC of a second battery A method of controlling a PTC heater of a mild hybrid vehicle capable of selecting a power source to be supplied to a heater.

In order to solve the above problems, a method of controlling a PTC heater of a mild hybrid vehicle according to an embodiment of the present invention includes: a controller for controlling a state of charge of a first battery and a state of charge of a second battery, ; And controlling the controller to use either the first battery or the second battery as a power source of a PTC (positive temperature coefficient) heater based on the SOC of the first battery and the SOC of the second battery .

The voltage charged in the first battery may be greater than the voltage charged in the second battery.

Wherein controlling the first battery or the second battery to be used as a power source of the PTC heater includes controlling the SOC of the first battery to exceed a first reference value and the SOC of the second battery to exceed a fourth reference value Or when the SOC of the first battery exceeds a second reference value that is smaller than the first reference value and the SOC of the second battery exceeds a fifth reference value that is smaller than the fourth reference value, And controlling the power source of the PTC heater to be used.

Wherein controlling the first battery or the second battery to be used as a power source of the PTC heater includes controlling the SOC of the first battery to be lower than the second reference value and the SOC of the second battery being lower than the fourth reference value Or when the SOC of the first battery is equal to or less than a third reference value smaller than the second reference value and the SOC of the second battery is equal to or greater than the fourth reference value or the fifth reference value, As a power source of the power supply.

Wherein controlling the first battery or the second battery to be used as a power source of the PTC heater includes controlling the SOC of the first battery to be lower than the third reference value and the SOC of the second battery being lower than the fifth reference value And controlling the controller not to supply power to the PTC heater when the temperature is less than a sixth reference value.

Wherein the controller controls the first battery and the second battery to be used as a power source for the PTC heater by controlling the controller such that the relay supplying the power of the first battery to the PTC heater is turned on ; And controlling the controller such that the relay supplying the power of the second battery to the PTC heater is in an ON state.

The PTC heater control method of the mild hybrid vehicle further includes the step of the controller determining the state of the engine, wherein when the engine is operated, the controller is controlled by a mild hybrid starter & generator (MHSG) The first battery for storing the developed electric power can be used as the power source of the PTC heater.

The method for controlling the PTC heater of the mild hybrid vehicle may further include the step of the controller determining whether or not the PTC heater is included in the mild hybrid vehicle.

The PTC heater control method of the mild hybrid vehicle may further include the step of confirming whether or not the controller is a mild hybrid vehicle.

The method for controlling the PTC heater of the mild hybrid vehicle according to the embodiment of the present invention uses a 12 / 48V battery, which is the first / second battery included in the mild hybrid vehicle, to control the PTC heater coefficient heater can be selected to suit the source of the PTC heater, thus optimizing the control of the PTC heater.

Further, in the embodiment of the present invention, when the power source of the PTC heater is changed to the 48V battery which is the first battery, the PTC heater can utilize high power, so that the heating performance of the PTC heater can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the drawings used in the detailed description of the present invention, a brief description of each drawing is provided.
1 is a view for explaining a PTC heater control method of a mild hybrid vehicle according to the related art.
2 is a view for explaining a PTC heater control apparatus of a mild hybrid vehicle according to an embodiment of the present invention.
3 is a flowchart illustrating a method of controlling a PTC heater of a mild hybrid vehicle according to an embodiment of the present invention.
FIG. 4 is a view for explaining reference values relating to the state of charge (SOC) of the first battery and the second battery shown in FIG. 2. FIG.
5 is a block diagram illustrating a mild hybrid vehicle including the PTC heater control apparatus shown in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, and the objects attained by the practice of the invention, reference should be made to the accompanying drawings, which illustrate embodiments of the invention, and to the description in the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Like reference numerals in the drawings denote like elements.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having", etc., are used to specify that a feature, a number, a step, an operation, an element, a component, or a combination thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Throughout the specification, when a part is referred to as being "connected" to another part, it is not necessarily the case that it is "directly connected", but also "electrically or mechanically connected" .

Unless defined otherwise, 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 this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and, unless expressly defined herein, are to be construed as either ideal or overly formal Do not.

When the blower blows, the air heated by the PTC heater, which is air conditioning (air conditioner or air conditioner), is supplied to the inside of the vehicle and the interior of the vehicle is heated.

The 48V battery of a mild hybrid vehicle is used as the power source of the MHSG, the power source of the 12V battery, and the power source of the PTC heater, so the SOC of the 48V battery may be lowered. Therefore, the heating function of the PTC heater can be limited.

In the related art, although the operating condition of the PTC heater is low, the battery power is low or the power consumed by the PTC heater is excessive, so that the air conditioning heating by the PTC heater may not be possible during the winter time have.

1 is a view for explaining a PTC heater control method of a mild hybrid vehicle according to the related art.

Referring to FIG. 1, an ECU (Electronic Control Unit) of the mild hybrid vehicle operates a PTC heater in response to an operating condition of a PTC heater such as a blower ON condition.

The operating conditions of the PTC heater include a blower on condition, a glow off condition, a condition without a failure of a coolant temperature sensor, a condition without a failure of an outside air temperature sensor (or an air flow sensor) The condition that the RPM (revolutions per minute) is equal to or more than the reference set value (e.g. idle RPM), the condition that the battery voltage is not discharged, the condition that the ambient temperature measured by the outside temperature sensor is equal to or higher than the reference temperature value, The condition that the cooling water and inlet air temperature (intake air temperature of the engine) is higher than the preset temperature value, the delay time until the PTC heater starts to operate after the initial engine operation, And the condition that the duration after PTC heater operation is less than or equal to the preset minimum operating time.

The operating condition of the PTC heater can be detected by a sensor included in the mild hybrid vehicle.

The Blower On condition condition may mean that the operation switch provided on the center fascia of the mild hybrid vehicle is in the air conditioning operation state (blower (blower switch) ON state).

The Glow Off condition condition may indicate a condition that the operation of Glow (glow plug), which is in transient current consumption in the vehicle, is terminated.

The condition without the failure of the coolant temperature sensor may indicate a condition in which there is no failure of the corresponding sensor as a reference for the operation of the PTC heater.

The condition without the failure of the outside temperature sensor may indicate a condition in which the corresponding sensor serving as a reference of the operation of the PTC heater does not fail.

The condition that the battery voltage is equal to or higher than the set value at which the battery voltage is not discharged may indicate a condition that the battery voltage is equal to or higher than a minimum set voltage at which the battery voltage is discharged.

The condition that the outside air temperature measured by the outside air temperature sensor is higher than the reference temperature value may indicate a condition that the actual outside air temperature is not the engine room temperature but is equal to or higher than the preset temperature value.

The condition that the duration after the operation of the PTC heater is equal to or less than the predetermined minimum operation time may be a condition for setting the reference time for preventing the side effect that may occur in the infinite operation of the PTC heater.

2 is a view for explaining a PTC heater control apparatus of a mild hybrid vehicle according to an embodiment of the present invention. 3 is a flowchart illustrating a method of controlling a PTC heater of a mild hybrid vehicle according to an embodiment of the present invention. FIG. 4 is a view for explaining reference values relating to the state of charge (SOC) of the first battery and the second battery shown in FIG. 2. FIG. 5 is a block diagram illustrating a mild hybrid vehicle including the PTC heater control apparatus shown in FIG. The method of controlling the PTC heater of the above mild hybrid vehicle can be applied to the cold start of the mild hybrid vehicle during the cold season (at the low temperature start).

Referring to FIGS. 2, 3, 4, and 5, in the verification step 200, the controller 80 such as an ECU (Electronic Control Unit) confirms whether the vehicle including the controller is a mild hybrid vehicle (Judgment). For example, the controller 80 may be connected to a communication network (e.g., LIN (Local Interconnect Network) or CAN (Controller Area Network) communication, which is a vehicle network (MHSG) ) Message to recognize whether the vehicle including the controller is a mild hybrid vehicle.

The controller 80 may be, for example, one or more microprocessors operated by a program or hardware including the microprocessor, and the program may be executed by a PTC heater of a mild hybrid vehicle according to an embodiment of the present invention. And a series of instructions for performing the control method. The controller 80 may control the overall operation of the mild hybrid vehicle.

The mild hybrid vehicle includes an engine 10, a transmission 20, a mild hybrid starter & generator (MHSG) 30, a battery 40, a differential gear device 50, a wheel 60, And a controller (80).

The engine 10 is, for example, a diesel engine, which combusts fuel and air to convert chemical energy into mechanical energy. The power transmission of the mild hybrid vehicle is carried out when the torque of the engine 10 is transmitted to the input shaft of the transmission 20 and the torque output from the output shaft of the transmission 20 is transmitted to the axle via the differential gear device 50 do. The mild hybrid vehicle is driven by the torque of the engine 10 by rotating the wheel 60 with the axle.

The MHSG 30 converts electrical energy into mechanical energy or mechanical energy into electrical energy. That is, the MHSG 30 can start the engine 10 or generate electricity by the output of the engine 10. [ In addition, the MHSG 30 may assist the torque of the engine 10. [ The mild hybrid vehicle can use the torque of the MHSG 30 as an auxiliary power while making the combustion torque of the engine 10 the main driving force. The engine 10 and the MHSG 30 may be connected via a belt 32 (or pulleys and belts).

The first battery 40 may be charged via electricity supplied to the MHSG 30 or recovered through the MHSG 30 in the regenerative braking mode. The first battery 40 may be a 48 V battery. The mild hybrid vehicle includes a low voltage DC-DC converter (LDC) for converting a voltage supplied from the battery 40 to a low voltage, and a second battery 105 for supplying a low voltage to a battery load using a low voltage. As shown in FIG.

In a mild hybrid system, the MHSG (Mild Hybrid Starter & Generator) can be a major component that functions as an alternator, engine torque assist, or regenerative braking. Particularly, the mild hybrid system can avoid the reliance on the torque generating function of the existing internal combustion engine through the engine torque assist function.

In the above mild hybrid vehicle, such as the 48V MHSG system (mild hybrid system), the alternator is replaced by a Mild Hybrid Starter & Generator (MHSG) and an additional 48V battery (main battery) and LDC (Low Voltage DC / DC Converter) Can be applied.

The MHSG can drive (start) control the engine of the vehicle in the cranking and torque control mode of the vehicle (or engine), and can generate electricity by the output of the engine 10 to charge the 48V battery have. In accordance with the running state of the vehicle, the MHSG is provided with an engine starting mode, an engine torque assist mode which operates with the motor to assist the torque of the engine 10, a power supply of the vehicle (electric load) ) Mode that charges the 12 (volt) battery connected to the battery, a mode that charges the 48 (volt) battery that charges the battery, a regenerative braking mode that can charge the battery by 48 (volts), an inertial mode that can extend the mileage, Or an idle stop mode in which the engine 10 is started in the idle period of the engine 10. The MHSG is optimally controlled in accordance with the running state of the vehicle to reduce the fuel consumption of the vehicle The effect can be maximized. An example of a mild hybrid vehicle may be disclosed in Korean Patent Publication No. 10-2016-0057084.

According to the verification step 205, when the vehicle including the controller 80 is a mild hybrid vehicle, the controller 80 can determine whether the mild hybrid vehicle includes the PTC heater 125 have. For example, the mounting (application) presence information of the pre-factory PTC heater of the mild hybrid vehicle may be provided to the controller 80 in the factory line. The presence / absence information of the PTC heater may be written (created) in the PTC heater application variable value of the software included in the controller 80.

The PTC heater 125 is an electric heater that can be used as a heat source for an auxiliary heating device of a diesel vehicle and has a low specific resistance at room temperature and a high specific resistance at a transition temperature of the ferroelectric, An electric heating element capable of improving the cooling, heating and ventilation quality of the vehicle by improving the damping and heating effect in winter due to the rapid heating performance of cooling water and extending the durability life can be used as a heating source, The engine can be used to heat the air supplied into the vehicle before the engine warm-up after the cold start of the winter.

According to the determination step 210, the controller 80 can determine the state of the engine 10 based on the number of revolutions (e.g., RPM) of the engine. For example, the number of revolutions of the engine may be detected by the RPM sensor and provided to the controller 80.

When it is determined that the state of the engine 10 is the engine running, the PTC heater control method of the mild hybrid vehicle, which is a process, can proceed to the decision step 215. [ When it is determined that the state of the engine 10 is an On state (i.e., the engine is not operating), an IG (ignition device) for igniting the engine is judged as a judgment step 235 You can proceed.

According to the determination step 215, the controller 80 can determine whether the operating condition (operating entry condition) of the PTC heater 125 such as the blower on condition is satisfied or not. The determination step 215 may be performed in a manner similar to the PTC heater control method of the mild hybrid vehicle described above with reference to Fig.

According to the operation state determination step 220, when the operating condition of the PTC heater 125 is satisfied, the controller 80 can determine the operating state of the PTC heater. In another embodiment of the present invention, the operation state determination step 220 may be omitted from the PTC heater control method of the mild hybrid vehicle, which is a process.

According to the selection step 230, the controller 80 controls the 48V battery 40, which is the first battery charged by the generated power of the mild hybrid starter & generator (MHSG) 30, as the power source of the PTC heater 125 Can be selected. For example, the controller 80 can control the relay 120 that supplies the power of the first battery 40 to the PTC heater 125 to be in the ON-state (turn-on state) have.

As described above, when the engine 10 is operated, the controller 80 controls the 48V battery 40, which is the first battery storing the electric power generated by the mild hybrid starter & generator (MHSG) 30 connected to the engine It can be controlled to be used as the power source of the PTC heater 125. [

According to the determination step 235, the controller 80 can determine whether the operating condition (operating entry condition) of the PTC heater 125 such as the blower on condition is satisfied or not. The determination step 215 may be performed in a manner similar to the PTC heater control method of the mild hybrid vehicle described above with reference to Fig.

According to the first comparison step 240, the controller 80 determines whether the SOC of the 48V battery, which is the first battery 40, exceeds the first reference value A1 and the SOC of the 12V battery, which is the second battery 105, When the SOC of the first battery 40 exceeds the second reference value B1 and the SOC of the second battery 105 is less than the fourth reference value A2, It is possible to judge whether or not it exceeds the small fifth reference value B2. The voltage charged in the first battery 40 may be greater than the voltage charged in the second battery 105.

According to the selection step 245, when the SOC of the 48V battery of the first battery 40 exceeds the first reference value A1 and the SOC of the 12V battery of the second battery 105 exceeds the fourth reference value A2 Or when the SOC of the first battery 40 exceeds the second reference value B1 and the SOC of the second battery 105 exceeds the fifth reference value B2, Can be controlled to be used as the power source of the PTC heater (125). For example, the controller 80 controls the PTC heater 125 so that the relay 120 that supplies the power of the first battery 40 is switched from the OFF state to the ON state .

According to the second comparison step 250, the controller 80 determines whether the SOC of the first battery 40 is equal to or less than the second reference value B1 and the SOC of the second battery 105 is equal to or less than the fourth reference value A2, Or whether the SOC of the first battery 40 is equal to or less than the third reference value C1 and the SOC of the second battery 105 is equal to or greater than the fourth reference value A2 or the fifth reference value B2.

According to the selection step 255, when the SOC of the first battery 40 is lower than the second reference value B1 and the SOC of the second battery 105 is lower than the fourth reference value A2, When the SOC is equal to or less than the third reference value C1 smaller than the second reference value B1 and the SOC of the second battery 105 is equal to or greater than the fourth reference value A2 or the fifth reference value B2, The battery 105 can be controlled to be used as the power source of the PTC heater 125. [ For example, the controller 80 controls the relay 115 that supplies the power of the second battery 105 to the PTC heater 125 to be switched from the OFF state to the ON state . The PTC heater control apparatus may include a controller 80, a relay 115, and a relay 115.

More specifically, the controller 80 receives the SOC of the first battery 40 and the SOC of the second battery 105, and the controller 80 determines the SOC of the first battery 40 and the SOC of the second battery 105, The first battery and the second battery may be selectively used as the power source of the PTC heater 125. [

According to the third comparison step 260, the controller 80 determines whether the SOC of the first battery 40 is equal to or less than the third reference value C1 and the SOC of the second battery 105 is equal to or less than the sixth reference value C2 Can be determined.

The SOC of the first battery 40 is equal to or less than the third reference value C1 and the SOC of the second battery 105 is equal to or less than the sixth reference value C2 less than the fifth reference value B2, The controller 80 controls the PTC heater 125 so that power is not supplied to the PTC heater 125 so that the PTC heater 125 is not finally operated.

As described above, since the mild hybrid system includes the 48V battery and the 12V battery, it is advantageous in terms of the control of the PTC heater and it is possible to select an appropriate battery supply source for each control situation. In addition, when the engine is running, the 48V battery can be charged through the development of the MHSG, thereby solving the problem of lowering the battery SOC during heating of the PTC heater.

The components or " units " or blocks or modules used in the embodiments of the present invention may be implemented in software, such as a task, a class, a subroutine, a process, an object, an execution thread, ), A hardware such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), or a combination of the above software and hardware. The components or parts may be included in a computer-readable storage medium, or a part of the components may be dispersed in a plurality of computers.

As described above, the embodiments have been disclosed in the drawings and specification. Although specific terms are used herein, they are used for the purpose of describing the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. It is therefore to be understood by those skilled in the art that various modifications and equivalent embodiments may be made without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: Engine
30: MHSG
40: First battery
80:
105: Second battery
115: Relay
120: Relay
125: PCT heater

Claims (9)

A method of controlling a PTC heater of a mild hybrid vehicle,
Receiving a state of charge (SOC) of the first battery and a state of charge (SOC) of the second battery; And
Controlling the controller to use either the first battery or the second battery as a power source of a PTC (positive temperature coefficient) heater based on the SOC of the first battery and the SOC of the second battery;
Wherein the PTC heater control method comprises the steps of:
The method according to claim 1,
Wherein the voltage charged in the first battery is greater than the voltage charged in the second battery.
The method as claimed in claim 2, wherein the step of controlling one of the first battery and the second battery to be used as a power source of the PTC heater includes:
When the SOC of the first battery exceeds a first reference value and the SOC of the second battery exceeds a fourth reference value or the SOC of the first battery exceeds a second reference value that is smaller than the first reference value, And controlling the controller to use the first battery as a power source of the PTC heater when the SOC of the PTC heater exceeds a fifth reference value that is smaller than the fourth reference value Way.
4. The method of claim 3, wherein the step of controlling one of the first battery and the second battery to be used as a power source of the PTC heater includes:
Wherein when the SOC of the first battery is lower than the second reference value and the SOC of the second battery is lower than the fourth reference value or the SOC of the first battery is lower than a third reference value lower than the second reference value, And controlling the controller to use the second battery as a power source of the PTC heater when the SOC is equal to or greater than the fourth reference value or the fifth reference value.
5. The method of claim 4, wherein the step of controlling one of the first battery and the second battery to be used as a power source of the PTC heater includes:
Controlling the controller such that power is not supplied to the PTC heater when the SOC of the first battery is less than the third reference value and the SOC of the second battery is less than or equal to a sixth reference value smaller than the fifth reference value Wherein the PTC heater control method comprises the steps of:
The method as claimed in claim 1, wherein the step of controlling one of the first battery and the second battery to be used as a power source of the PTC heater includes:
Controlling the controller such that the relay supplying power to the first battery is turned on to the PTC heater; And
Controlling the controller such that the relay supplying the power of the second battery to the PTC heater is turned on;
And controlling the PTC heater according to the detected temperature.
The method of controlling a PTC heater of a mild hybrid vehicle according to claim 1,
Further comprising the step of the controller determining the state of the engine,
Wherein the controller controls the first battery, which stores electric power generated by a mild hybrid starter & generator (MHSG) connected to the engine, to be used as a power source of the PTC heater when the engine is operated. A method for controlling a PTC heater of a vehicle.
The method of controlling a PTC heater of a mild hybrid vehicle according to claim 7,
Further comprising the step of the controller determining whether the PTC heater is included in the mild hybrid vehicle.
9. The method of controlling a PTC heater of a mild hybrid vehicle according to claim 8,
Further comprising checking whether the controller is a mild hybrid vehicle if the vehicle including the controller is a mild hybrid vehicle.

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