Regenerative braking control system for a motor vehicle

Abstract

The present invention provides a regenerative braking control system for a motor vehicle configured to enable easy conversion of excess electric energy generated by an electric motor into heat energy during the process of regenerative braking by converting the electric energy into heat energy using both a brake resistor and a heater, thereby providing a continuous auxiliary braking force by continuous reverse torque of the electric motor, and to obtain an interior heating effect by using the heat energy converted by the brake resistor and the heater as a heat source for interior heating, without discharging the heat energy to the outside.

Description

TECHNICAL FIELD

[0001] The present application relates to a regenerative braking control system for a motor vehicle, and more particularly, to a regenerative braking control system capable of performing not only regenerative braking but also internal heating using a brake resistor and a heater. BACKGROUND

[0002] As is well known in the art, an eco-friendly vehicle (e.g., a hybrid vehicle, an electric vehicle, and a fuel cell electric vehicle) is driven by an electric motor.

[0003] The electric motor not only drives the vehicle, but also functions as a generator that performs regenerative braking to assist braking when the vehicle is decelerating or coasting down a downhill road, and charges a battery by converting kinetic energy of the vehicle into electric energy.

[0004] However, when charging according to the regenerative braking of the electric motor is not possible due to the battery being fully charged, or when the regenerative braking force of the electric motor is insufficient, a specific auxiliary brake is required to meet the braking assistance requirement.

[0005] The auxiliary brake refers to a device capable of reducing the load of a main brake (e.g., a hydraulic brake) and capable of maintaining the braking effect for a long time, and is generally classified into three types: an exhaust brake, an engine brake, and a retarder brake.

[0006] The exhaust brake is a device that obtains a deceleration effect by blocking an exhaust path to reduce the RPM of the engine. The engine brake is a device that reduces the compression pressure by forcibly opening an exhaust valve at the end of compression in the engine and obtains a deceleration effect by reducing the power from the engine. The retarder brake is a device that decelerates the vehicle by applying resistance (e.g., hydraulic resistance or electromagnetic resistance) to the torque of the transmission shaft.

[0007] However, when the eco-friendly vehicle is equipped with an auxiliary brake such as an exhaust brake, an engine brake, or a retarder brake, there are problems such as an increase in the number of components, an increase in cost, deterioration in assembly convenience of the overall arrangement, etc.

[0008] Therefore, a brake resistor has been applied to meet the braking assistance requirement, which performs regenerative braking using the electric motor and discharges electric energy generated by the electric motor in the form of heat energy.

[0009] Figure 1 (PRIOR ART) is a circuit diagram showing a charging / discharging and cooling system for a fuel cell vehicle, Figure 2 (PRIOR ART) is a schematic diagram showing a brake resistor.

[0010] As in Figure 1As shown in the middle, the fuel cell 10 is connected to the motor 13 through the inverter 11 to be able to supply electric power, and the fuel cell 10 and the motor 13 are connected to the battery 16 through the inverter 12 to be able to charge and discharge the battery 16.

[0011] In particular, a braking resistor 15 that converts electric energy generated by the motor 13 into heat energy is connected to the motor 13 through a high-voltage connector.

[0012] Reference Figure 2 The high-voltage connector 15-1 connected to the motor 13 is formed at one side of the braking resistor 15, and a cooling water inlet 15-2 and a cooling water outlet 15-3 connected to the cooling water circulation line 20 are formed at the other side of the braking resistor 15 to circulate cooling water through the braking resistor 15.

[0013] The fuel cell 10, the inverter 11, the inverter 12, the motor 13, and the braking resistor 15 generate heat while operating, and thus they need to be cooled to obtain thermal protection and need to ensure sufficient performance.

[0014] To this end, the cooling water circulation line 20 is connected to the fuel cell 10, the inverter 11, the inverter 12, the motor 13, and the braking resistor 15, and a water pump 17 for circulating cooling water and a radiator 18 for cooling high-temperature cooling water that has completed cooling are provided in the cooling water circulation line 20.

[0015] Cooling water passages (not shown) that communicate with the cooling water circulation line 20 are formed in the fuel cell 10, the inverter 11, the inverter 12, the motor 13, and the braking resistor 15.

[0016] Therefore, when electric energy generated by the fuel cell 10 is converted through the inverter 11 and then directly supplied to the motor 13, the motor 13 operates and the vehicle can be driven.

[0017] Alternatively, when electric energy generated by the fuel cell 10 is accumulated in the battery 16 through the inverter 12 and then supplied from the battery 16 to the motor 13 through the inverter 11, the motor 13 operates and the vehicle can be driven.

[0018] However, when the vehicle is decelerated or coasting, regenerative braking is performed in which the motor 13 operates as a generator. In addition, during the regenerative braking, electric energy generated by the motor 13 is accumulated in the battery 16 through the inverter 12, and an auxiliary braking force is generated by the reverse torque of the motor 13.

[0019] According to the above-described process, the motor 13 performs an auxiliary brake function of generating an auxiliary braking force by generating a reverse torque, however, the reverse torque can be continuously generated only when the generated electric energy is consumed.

[0020] However, in the case where the battery 16 is fully charged, the electric energy generated by the motor 13 becomes excess electric energy that cannot be further accumulated in the process of regenerative braking, and the auxiliary braking force can be continuously generated by the continuous reverse torque of the motor 13 only when the excess electric energy is consumed.

[0021] Therefore, the braking resistor 15 consumes the excess electric energy generated by the motor 13 by converting the excess electric energy into heat energy to satisfy the braking auxiliary requirement, so that the auxiliary braking force can be continuously generated by the continuous reverse torque of the motor 13.

[0022] However, it is limited to convert the excess electric energy generated by the motor 13 into heat energy only by the braking resistor 15, and there is a problem that the converted heat energy is discharged to the outside and consumed without being used for any purpose. SUMMARY

[0023] The present application provides a regenerative braking control system for a motor vehicle, which enables excess electric energy generated by a motor to be easily converted into heat energy in the process of regenerative braking by converting electric energy into heat energy using both a braking resistor and a heater, so that continuous auxiliary braking force can be provided by the continuous reverse torque of the motor.

[0024] Another object of the present application is to obtain an internal heating effect by using the heat energy converted by the braking resistor and the heater as a heat source for internal heating, without discharging the heat energy to the outside.

[0025] To achieve the object of the present application, a regenerative braking control system for a motor vehicle includes a motor configured to operate as a generator to charge a battery with electric energy in the process of regenerative braking, a braking resistor configured to convert excess electric energy generated by the motor into heat energy in the process of regenerative braking, a heater configured to convert excess electric energy generated by the motor into heat energy together with the braking resistor, a cooling water circulation line connected to the braking resistor and the heater so that cooling water can circulate, and a controller configured to control the turning on and off of the braking resistor and the heater based on state of charge information of the battery, thereby executing a heating mode, a regenerative braking mode, a heating and regenerative braking mode, and a maximum regenerative braking mode.

[0026] The cooling water circulation line can include a heating line extending from the heater and connected to a heater blower for internal heating, a first cooling water return line extending from the heating line and connected to a radiator through the braking resistor, a second cooling water return line extending from the heater blower and connected to the radiator, and a cooling water supply line extending from the radiator and connected to the heater.

[0027] A three-way valve can be provided at a junction of the heating line and the first cooling water return line, controlled to be opened and closed to deliver cooling water to the heater blower or the braking resistor, and an electric water pump can be provided in the cooling water supply line.

[0028] In the heating mode, in response to a control signal from the controller, the heater, the electric water pump, and the heater blower can be operated, the three-way valve can be operated to be opened to the heating line and closed to the first cooling water return line, and the braking resistor can be kept closed.

[0029] When the medium-temperature cooling water heated by the heater flows through the heating line and the heater blower, the air to be blown by the heater blower to the interior can be heated by the medium-temperature cooling water, so that the interior heating can be performed.

[0030] In the regenerative braking mode, in response to a control signal from the controller, the braking resistor and the electric water pump can be operated, the three-way valve can be operated to be closed to the heating line and opened to the first cooling water return line, and the heater and the heater blower can be kept closed.

[0031] In the regenerative braking mode, the excess electric energy generated by the motor can be converted into heat energy and consumed by the braking resistor, so that the auxiliary braking force can be continuously generated by the continuous reverse torque of the motor.

[0032] In the regenerative braking mode, the low-temperature cooling water flowing from the radiator through the cooling water supply line can flow through the first cooling water return line and cool the braking resistor by the operation of the electric water pump, and after cooling the braking resistor, the high-temperature cooling water flowing out of the braking resistor can flow back to the radiator.

[0033] In the heating and regenerative braking mode, in response to a control signal from the controller, the braking resistor, the electric water pump, the heater, and the heater blower can be turned on and operated, and the three-way valve can be operated to an angle to be opened to both the heating line and the first cooling water return line.

[0034] In the heating and regenerative braking mode, for the regenerative braking mode, the braking resistor and the heater convert the excess electric energy generated by the motor into heat energy, so that the auxiliary braking force can be continuously generated by the continuous reverse torque of the motor.

[0035] When in the heating and regenerative braking mode, for the heating mode, the medium-temperature cooling water heated by the heater flows through the heating line and the heater blower, the air to be blown by the heater blower to the interior can be heated by the medium-temperature cooling water, so that the interior heating can be performed.

[0036] The medium temperature cooling water heated by the heater can flow to the brake resistor via the first cooling water return line by the operation of the electric water pump, and the high temperature cooling water after cooling the brake resistor can flow to the radiator for cooling.

[0037] In the maximum regenerative braking mode, the brake resistor, the electric water pump, and the heater can be turned on and operated in response to a control signal from the controller, the three-way valve can be operated to close to the heating line and open to the first cooling water return line, and the heater blower can be kept off.

[0038] In the maximum regenerative braking mode, the brake resistor and the heater can convert the excess electric energy generated by the motor into heat energy, so that the auxiliary braking force can be continuously generated by the continuous reverse torque of the motor. In addition, when the state of charge (SOC) of the battery is 100%, the electric energy generated by the motor can all be excess electric energy, which can be converted into heat energy by the brake resistor and the heater and consumed, so that the auxiliary braking force can be maximized by the continuous reverse torque of the motor.

[0039] The low temperature cooling water flowing through the cooling water supply line from the radiator by the operation of the electric water pump can sequentially cool the heater and the brake resistor while passing through the cooling water passages of the heater and the brake resistor, and the high temperature cooling water flowing out of the brake resistor after cooling the brake resistor can flow back to the radiator.

[0040] The present application provides the following effects from the above-mentioned purposes.

[0041] First, since in the process of regenerative braking, in addition to the brake resistor, the excess electric energy generated by the motor can also be converted into heat energy by the heater, the auxiliary braking force can be continuously obtained by the continuous reverse torque of the motor.

[0042] Second, since in the process of regenerative braking, the excess electric energy generated by the motor is converted into heat energy by the brake resistor and the heater, and then used as a heat source for internal heating without being discharged to the outside, the internal heating effect can also be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0043] The above and other objects, features and other advantages of the present application will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0044] Figure 1 ( Prior art) is a diagram showing a charging / discharging and cooling system for a fuel cell vehicle;

[0045] Figure 2 ( Prior art) is a schematic diagram showing a brake resistor;

[0046] Figure 3 A diagram is shown of a regenerative braking control system for a motor vehicle according to the present invention;

[0047] Figure 4 A schematic diagram showing the arrangement of the brake resistor and heater in a regenerative braking control system for a motor vehicle according to the present invention is provided.

[0048] Figure 5 A circuit diagram showing the flow of cooling water when the regenerative braking control system for a motor vehicle according to the present invention is operated for heating, wherein the heater is on, the heater blower is on, and the braking resistor is off;

[0049] Figure 6 A circuit diagram showing the flow of cooling water when the regenerative braking control system for a motor vehicle according to the present invention is operated to perform regenerative braking, wherein the heater is off, the heater blower is off, and the braking resistor is on.

[0050] Figure 7 This diagram illustrates the flow of cooling water when the regenerative braking control system for a motor vehicle according to the present invention operates to perform heating and regenerative braking, wherein: heater: on, heater blower: on, braking resistor: on; and

[0051] Figure 8 The diagram shows the flow of cooling water when the regenerative braking control system for a motor vehicle according to the present invention is operated to perform maximum regenerative braking, wherein the heater is on, the heater blower is off, and the braking resistor is on. Detailed Implementation

[0052] It should be understood that, as used herein, the terms “vehicle” or “of a vehicle” or other similar terms generally include motor vehicles, such as passenger vehicles including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, vessels including various boats and ships, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from non-petroleum energy sources). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle that is powered by both gasoline and electricity.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items. Throughout this specification, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising" will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms "unit", "member", "device" and "module" described in the specification mean a unit for performing at least one function and operation, and can be implemented by a hardware component or a software component and combinations thereof.

[0054] Further, the control logic of the present application can be implemented as a non-volatile computer readable medium on a computer readable medium, which contains executable program instructions executed by a processor, a controller, etc. Examples of the computer readable medium include, but are not limited to, ROM, RAM, compact disc (CD)-ROM, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable medium is stored and executed in a distributed fashion via, for example, a remote information processing server or a controller area network (CAN).

[0055] Hereinafter, exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0056] In the drawings, Figure 3 and Figure 4 a regenerative braking control system for a motor vehicle according to the present application is shown, Figures 5 to 8 a cooling circuit diagram for a regenerative braking control system for a motor vehicle according to the present application.

[0057] Referring to Figure 3 The fuel cell 10 is connected to the motor 13 through a converter 11 to be able to supply electric power, and the fuel cell 10 and the motor 13 are connected to the battery 16 through an inverter 12 to be able to charge and discharge the battery 16.

[0058] A braking resistor 15 that converts electric energy generated by the motor 13 into heat energy is connected to the motor 13 through a high-voltage connector.

[0059] Accordingly, when the electric power generated by the fuel cell 10 is converted by the inverter 11 and then directly supplied to the motor 13, or when the electric power generated by the fuel cell 10 is accumulated in the battery 16 by the inverter 12 and then supplied from the battery 16 to the motor 13 by the inverter 11, the motor 13 operates and the vehicle can be driven.

[0060] However, when the vehicle is decelerated or coasting, the regenerative braking in which the motor 13 operates as a generator is performed. Further, during the regenerative braking, the electric power generated by the motor 13 is accumulated in the battery 16 by the inverter 12, and the assist braking force is generated by the reverse torque of the motor 13.

[0061] However, in the case where the battery 16 is fully charged, the electric power generated by the motor 13 becomes the excess electric power which cannot be further accumulated during the regenerative braking, and the assist braking force can be generated by the continuous reverse torque of the motor 13 only when the excess electric power is consumed.

[0062] Accordingly, during the regenerative braking, the brake resistor 15 consumes the excess electric power generated by the motor 13 by converting the excess electric power into heat energy, so that the assist braking force can be continuously generated by the continuous reverse torque of the motor 13.

[0063] The regenerative braking control system for a motor vehicle includes a brake resistor 15 and a heater 30, and the brake resistor 15 and the heater 30 are controlled to be turned on / off by a controller based on the state of charge information of the battery to convert the excess electric power generated by the motor 13 into heat energy.

[0064] Accordingly, during the regenerative braking, the excess electric power generated by the motor 13 is converted into heat energy not only by the brake resistor 15 but also by the heater 30, so that the working load of the brake resistor 15 can be reduced, and the excess electric power can be completely converted into heat energy and consumed. Therefore, the assist braking force can be continuously generated by the continuous reverse torque of the motor 13.

[0065] In the above description, the excess electric power generated by the motor 13 is converted into heat energy by the heater 30 in addition to the brake resistor 1. However, as shown in Figure 5 in which the electric water pump 42 and the electric cooling fan 18-1 of the radiator 18 are sequentially operated before the heater 30 is operated, the excess electric power generated by the motor 13 can be consumed, so that the assist braking force can be ensured by the continuous reverse torque of the motor 13.

[0066] According to the present application, the heat energy converted by the brake resistor 15 and the heater is not discharged to the outside for consumption without being used for any purpose, but is used as a heat source for internal heating, so that an internal heating effect can be achieved.

[0067] To this end, in addition to the brake resistor 15 and the heater 30, a heater blower 32 for internal heating, a three-way valve 40, and the like are connected, so that the cooling water can be circulated through the cooling water circulation line.

[0068] Obviously, a cooling water passage (not shown) through which the cooling water is circulated is formed in the brake resistor 15, the heater 30, the heater blower 32, and the like.

[0069] Reference Figures 5 to 8 The cooling water circulation line is composed of a heating line 21 extending from the heater 30 and connected to the heater blower 32 for internal heating, a first cooling water return line 22 extending from the heating line 21 and connected to the inlet of the radiator 18 through the brake resistor 15, a second cooling water return line 23 extending from the heater blower 32 and connected to the inlet of the radiator 18, and a cooling water supply line 24 extending from the outlet of the radiator 18 and connected to the heater 30.

[0070] A three-way valve 40 is provided at the junction of the heating line 21 and the first cooling water return line 22, and is opened / closed to deliver the cooling water to the heater blower 32 or the brake resistor 15, controlled by the controller.

[0071] An electric water pump 42 controlled to operate by the controller 50 is provided in the cooling water supply line 24.

[0072] During internal heating and regenerative braking, the controller 50 controls the opening / closing of the brake resistor 15, the heater 30, the heater blower 32, the electric water pump 42, and the like (which are connected to each other by the cooling water circulation line so that the cooling water can be circulated) based on the battery charge information.

[0073] The operation flow when the regenerative braking control system for a motor vehicle according to the present application operates to perform heating and regenerative braking will be described in each mode.

[0074] Normal mode

[0075] The normal mode is a mode in which it is checked whether the components are operating and the components are initialized when the vehicle is started.

[0076] For example, when the vehicle is started, the controller 50 checks for an abnormal signal indicating that the display member including the brake resistor 15 is disconnected, a short circuit, and the like, and checks whether the valve diaphragm of the three-way valve 40 is at an initial neutral angle (for example, a 45° angle at which the cooling line can flow to the heating line 21 and the first cooling water return line 22), so that the cooling level is stably injected into the heating line 21, the first cooling water return line 22, the second cooling water return line 23, and the cooling water supply line 24 of the cooling water circulation line.

[0077] Heating mode

[0078] The heating mode is a mode in which the interior of the vehicle is heated by the heater.

[0079] To this end, as shown in Figure 5 , in response to a control signal from the controller 50, when the heater switch is operated, the heater 30, the electric water pump 42, and the heater blower 32 are operated and the brake resistor 15 is kept off.

[0080] Further, in response to a control signal from the controller 50, the three-way valve 40 is operated to an angle at which the heating line 21 is opened and the first cooling water return line 22 is closed.

[0081] Accordingly, the cooling water flowing from the radiator 18 to the cooling water supply line 24 is passed through the heater 30 by the operation of the electric water pump 42, and is heated by the heater 30.

[0082] Further, when the medium-temperature cooling water heated by the heater 30 passes through the heating line 21 and the heater blower 32, the air to be blown into the interior by the heater blower 32 is heated by the medium-temperature cooling water, and the heated air is blown into the interior, so that the interior can be easily heated.

[0083] For example, a cooling water passage (not shown) of the heater blower 32 through which the medium-temperature cooling water passes is located in front of the blowing fan of the heater blower 32, so that the air to be blown into the interior by the blowing fan of the heater blower can be heated. Further, the heated air is blown into the interior, so that the interior can be easily heated.

[0084] Meanwhile, as shown in Figure 5 , the cooling water that has been cooled, that is, the medium-temperature cooling water that has passed through the heater blower 32, flows to the radiator 18 through the second cooling water return line 23.

[0085] Regenerative braking mode

[0086] The regenerative braking mode is a mode in which, when the environmental vehicle is decelerated or coasting, the electric motor 13 operates as a generator, the electric energy generated by the electric motor 13 is accumulated in the battery 16 through the inverter 12, and an auxiliary braking force is generated by the reverse torque of the electric motor 13.

[0087] To this end, as shown in Figure 6 , in response to a control signal from the controller 50, the brake resistor 15 is turned on and operated, the electric water pump 42 is also operated, but the heater 30 and the heater blower 32 are kept off.

[0088] Further, in response to a control signal from the controller 50, the three-way valve 40 is operated to an angle that closes to the heating line 21 and opens to the first cooling water return line 22.

[0089] Accordingly, in the process of regenerative braking, the brake resistor 15 consumes the excess electric energy generated by the electric motor 13 by converting the excess electric energy into heat energy in the process of regenerative braking, so that the auxiliary braking force can be continuously generated by the continuous reverse torque of the electric motor 13.

[0090] For example, when the battery temperature is 15℃, the state of charge (SOC) of the battery is 80%, and the chargeable capacity of the battery is 68kW in the process of regenerative braking, it can be necessary to generate a total of 91kW of power, which includes an additional power (e.g., 23kW) for generating a continuous reverse torque to meet the required braking force of the vehicle, in addition to the 68kW of power generated by the electric motor 13 to charge the battery. Accordingly, in this case, the brake resistor 15 converts and consumes the additional power (e.g., 23kW) of the excess electric energy into heat energy.

[0091] As described above, in the process of regenerative braking, the brake resistor 15 consumes the excess electric energy generated by the electric motor 13 by converting the excess electric energy into heat energy in the process of regenerative braking, so that the auxiliary braking force can be continuously obtained by the continuous reverse torque of the electric motor 13.

[0092] On the other hand, as shown in Figure 6 , the low-temperature cooling water flowing through the cooling water supply line 24 from the radiator is flowed through the first cooling water return line 22 by the operation of the electric water pump 42, and cools the brake resistor 15 while flowing through the cooling water passage of the brake resistor 15. Further, the high-temperature cooling water flowing out of the brake resistor 15 after cooling the brake resistor 15 flows back to the radiator 18.

[0093] Heating and regenerative braking mode

[0094] The heating and regenerative braking mode is a mode in which the heating mode and the regenerative braking mode are simultaneously performed.

[0095] To this end, as shown in Figure 7 the brake resistor 15 is caused to be turned on and operate, the electric water pump 42 is caused to operate, and the heater 30 and the heater blower 32 are caused to be turned on in response to a control signal from the controller 50.

[0096] For example, since the SOC of the battery is 80%, the battery needs to be charged for regenerative braking, but when the temperature of the battery is 0°C, it is lower than the temperature of the outside air, it is determined that internal heating is needed. Accordingly, in addition to the brake resistor 15, the controller 50 causes the heater 30 and the heater blower 32 to be turned on.

[0097] Accordingly, during regenerative braking, not only the brake resistor 15 but also the heater 30 converts the excess electric energy generated by the electric motor 13 into heat energy, so the operating load of the brake resistor 15 can be reduced, and the excess electric energy can be completely converted into heat energy and consumed. Therefore, the assist braking force can be continuously generated by the continuous reverse torque of the electric motor 13.

[0098] For example, when the battery temperature is 0°C, the state of charge (SOC) of the battery is 80%, and the chargeable capacity of the battery is 33 kW during regenerative braking, it can be necessary to generate a total of 91 kW of power, which includes additional power (e.g., 58 kW) for generating a continuous reverse torque to satisfy the required braking force of the vehicle in addition to 33 kW of power generated by charging the battery with the electric motor 13. Accordingly, in this case, the brake resistor 15 is limited in converting and consuming the additional power (e.g., 58 kW) as excess electric energy into heat energy.

[0099] Accordingly, not only the brake resistor 15 but also the heater 30 converts the additional power (e.g., 58 kW) as excess electric energy into heat energy, so the operating load of the brake resistor 15 can be reduced, and the excess electric energy can be completely converted into heat energy and consumed. Therefore, the assist braking force can be continuously generated by the continuous reverse torque of the electric motor 13.

[0100] Meanwhile, the three-way valve 40 is operated to an angle at which the heating line 21 and the first cooling water return line 22 are simultaneously opened in response to a control signal from the controller 50.

[0101] For example, the valve diaphragm of the three-way valve is controlled to 75°, so the cooling water flows to the heating line 21 at 15% and to the first cooling water return line 22 at 75%.

[0102] Accordingly, as shown in Figure 7As shown, medium-temperature cooling water heated by heater 30 passes through heating pipe 21 and heater blower 32. The medium-temperature cooling water heats the air that heater blower 32 is to blow into the interior, and the heated air is blown into the interior, thereby easily heating the interior.

[0103] Furthermore, the operation of the electric water pump 42 causes the medium-temperature cooling water heated by the heater 30 to flow to the braking resistor 15 via the first cooling water return line 22, and the high-temperature cooling water that has cooled the braking resistor 15 flows into the radiator 18 for cooling. In addition, the medium-temperature cooling water that has passed through the heater blower 32 also flows into the radiator 18 via the second cooling water return line 23.

[0104] According to the heating and regenerative braking mode, since both the braking resistor 15 and the heater 30 convert excess electrical energy into heat energy, the auxiliary braking force is continuously provided by the continuous reverse torque of the motor 13, thereby meeting the required braking force. Furthermore, the operation of the heater 30 can achieve an internal heating effect.

[0105] Maximum regenerative braking mode

[0106] Maximum regenerative braking mode is a mode that provides extreme auxiliary braking force to meet the braking force required by the vehicle during regenerative braking.

[0107] Therefore, as in Figure 8 As shown, in response to a control signal from controller 50, brake resistor 15 is turned on and operates, electric water pump 42 is also turned on, and heater 30 is also turned on.

[0108] In addition, in response to a control signal from the controller 50, the three-way valve 40 is operated to an angle that closes to the heating line 21 and opens to the first cooling water return line 22.

[0109] Accordingly, during regenerative braking, excess electrical energy generated by the motor 13 is converted into heat energy not only through the braking resistor 15 but also through the heater 30, thereby continuously generating auxiliary braking force through the continuous reverse torque of the motor 13.

[0110] That is, when the battery's SOC is 100% and regenerative braking is performed in this state, since the braking resistor 15 and heater 30 are activated in response to the control signal from the controller 50, and all the electrical energy generated by the motor 13 during regenerative braking becomes excess electrical energy, the excess electrical energy is converted into heat energy and consumed by the braking heater 15 and heater 30 to obtain auxiliary braking force through the continuous reverse torque of the motor 13. Accordingly, the maximum auxiliary braking force can be generated by the continuous reverse torque of the motor 13.

[0111] For example, when the battery temperature is 25°C, the battery is fully charged and has an SOC of 100%, and the chargeable capacity of the battery is not more than 7 kW during regenerative braking, it can be necessary to generate a total of 91 kW of power, including additional power (e.g., 84 kW) for generating continuous reverse torque to satisfy the required braking force of the vehicle, in addition to 7 kW of power generated by charging the battery with the motor 13. Accordingly, in this case, there is a limitation in terms of converting and consuming the additional power (e.g., 84 kW) as excess electric energy using only the brake resistor 15.

[0112] Accordingly, since not only the brake resistor 15 but also the heater 30 are operated, and the additional power (e.g., 84 kW) as excess electric energy is converted into heat energy by the brake resistor 15 and the heater 30, the excess electric energy can be completely converted into heat energy and consumed. Therefore, it is possible to maximize the auxiliary braking force by the continuous reverse torque of the motor 13.

[0113] In another aspect, as shown in Figure 8 When the low-temperature cooling water flowing through the first cooling water return line 22 from the radiator flows through the cooling water supply line 24 by the operation of the electric water pump 42, the low-temperature cooling water cools the heater 30 and the brake resistor 15 while sequentially flowing through the cooling water passages of the heater 30 and the brake resistor 15. In addition, the high-temperature cooling water flowing out of the brake resistor 15 after cooling the brake resistor 15 flows back to the radiator 18.

[0114] As described above, since the excess electric energy generated by the motor 13 can be converted into heat energy by the heater 30 in addition to the brake resistor 15 during regenerative braking, it is possible to obtain the auxiliary braking force satisfying the required braking force by the continuous reverse torque of the motor according to the SOC of the battery. In addition, the heat energy converted by the brake resistor and the heater is used as a heat source for interior heating, so that the interior heating effect can be achieved.

Claims

1. A regenerative braking control system for a motor vehicle, the regenerative braking control system comprising: an electric motor configured to operate as a generator to charge a battery with electric energy during regenerative braking; a braking resistor configured to convert excess electric energy generated by the electric motor into heat energy during regenerative braking; a radiator; a heater configured to convert, together with the braking resistor, the excess electric energy generated by the electric motor into heat energy; a heater blower configured to blow air heated by the heater to an interior; a cooling water circulation line connected to the braking resistor and the heater so that cooling water can circulate; and a controller configured to control the braking resistor and the heater to be turned on and off based on state of charge information of the battery so that a heating mode, a regenerative braking mode, a heating and regenerative braking mode, and a maximum regenerative braking mode are executed; wherein the cooling water circulation line comprises: a cooling water supply line extending from the radiator and connected to the heater; a heating line extending from the heater and connected to the heater blower; a three-way valve provided in the heating line, a first port of the three-way valve connected to the heating line connected to the heater, a second port of the three-way valve connected to the heating line connected to the heater blower; a first cooling water return line connected to a third port of the three-way valve, extending from the heating line and connected to the radiator through the braking resistor; and a second cooling water return line extending from the heater blower and connected to the radiator; wherein the controller is configured to control the three-way valve to be turned on / closed to selectively supply cooling water flowing through the heater to the heater blower, or to the braking resistor, or to both the heater blower and the braking resistor, according to the heating mode, the regenerative braking mode, the heating and regenerative braking mode, and the maximum regenerative braking mode. An electric water pump is provided in the cooling water supply line.

2. The regenerative braking control system for a motor vehicle according to claim 1, wherein, In the heating mode, in response to a control signal from the controller, the heater, the electric water pump, and the heater blower are operated, the three-way valve is operated to be turned on to the heating line and closed to the first cooling water return line, and the braking resistor is kept off.

3. The regenerative braking control system for a motor vehicle according to claim 1, wherein, When the medium-temperature cooling water heated by the heater flows through the heating line and the heater blower, the air to be blown by the heater blower to the interior is heated by the medium-temperature cooling water, thereby performing interior heating.

4. The regenerative braking control system for a motor vehicle according to claim 3, wherein, In the regenerative braking mode, in response to a control signal from the controller, the braking resistor and the electric water pump are operated, the three-way valve is operated to be closed to the heating line and turned on to the first cooling water return line, and the heater and the heater blower are kept off.

5. The regenerative braking control system for a motor vehicle according to claim 1, wherein, In the regenerative braking mode, the excess electric energy generated by the electric motor is converted into heat energy by the braking resistor and consumed, thereby continuously generating an auxiliary braking force by the continuous reverse torque of the electric motor.

6. The regenerative braking control system for a motor vehicle according to claim 5, wherein, The low-temperature cooling water flowing through the cooling water supply line from the radiator is circulated through the first cooling water return line by the operation of the electric water pump and cools the braking resistor, and the high-temperature cooling water flowing out from the braking resistor after cooling the braking resistor flows back to the radiator.

7. The regenerative braking control system for a motor vehicle according to claim 5, wherein, ​ 8. The regenerative braking control system for a motor vehicle according to claim 1, wherein, In the heating and regenerative braking mode, the brake resistor, the electric water pump, the heater, and the heater blower are turned on and operated in response to a control signal from the controller, and the three-way valve is operated to an angle to open to the heating line and the first cooling water return line at the same time.

9. The regenerative braking control system for a motor vehicle according to claim 8, wherein, For the regenerative braking mode, the brake resistor and the heater convert the excess electric energy generated by the electric motor into heat energy, thereby continuously generating an auxiliary braking force through continuous reverse torque of the electric motor.

10. The regenerative braking control system for a motor vehicle according to claim 8, wherein, For the heating mode, when the medium temperature cooling water heated by the heater flows through the heating line and the heater blower, the air to be blown into the interior by the heater blower is heated by the medium temperature cooling water, thereby performing interior heating.

11. The regenerative braking control system for a motor vehicle according to claim 8, wherein, The medium temperature cooling water heated by the heater flows to the brake resistor via the first cooling water return line through the operation of the electric water pump, and the high temperature cooling water after cooling the brake resistor flows to the radiator to be cooled.

12. The regenerative braking control system for a motor vehicle according to claim 1, wherein, In the maximum regenerative braking mode, the brake resistor, the electric water pump, and the heater are turned on and operated in response to a control signal from the controller, the three-way valve is operated to close to the heating line and open to the first cooling water return line, and the heater blower is kept closed.

13. A regenerative braking control system for a motor vehicle according to claim 12 wherein, In the maximum regenerative braking mode, the brake resistor and the heater convert the excess electric energy generated by the electric motor into heat energy, thereby continuously generating an auxiliary braking force through continuous reverse torque of the electric motor.

14. The regenerative braking control system for a motor vehicle according to claim 13, wherein, When the state of charge of the battery is 100%, all of the electric energy generated by the electric motor becomes excess electric energy, which is converted into heat energy by the brake resistor and the heater and consumed, thereby maximally generating an auxiliary braking force through continuous reverse torque of the electric motor.

15. The regenerative braking control system for a motor vehicle of claim 12, wherein, The low temperature cooling water flowing through the cooling water supply line from the radiator through the operation of the electric water pump sequentially cools the heater and the brake resistor while passing through the cooling water passages of the heater and the brake resistor, and the high temperature cooling water flowing out of the brake resistor after cooling the brake resistor flows back to the radiator. In the heating and regenerative braking mode, the brake resistor, the electric water pump, the heater, and the heater blower are turned on and operated in response to a control signal from the controller, and the three-way valve is operated to an angle to open to the heating line and the first cooling water return line at the same time. For the regenerative braking mode, the brake resistor and the heater convert the excess electric energy generated by the electric motor into heat energy, thereby continuously generating an auxiliary braking force through continuous reverse torque of the electric motor. For the heating mode, when the medium temperature cooling water heated by the heater flows through the heating line and the heater blower, the air to be blown into the interior by the heater blower is heated by the medium temperature cooling water, thereby performing interior heating. The medium temperature cooling water heated by the heater flows to the brake resistor via the first cooling water return line through the operation of the electric water pump, and the high temperature cooling water after cooling the brake resistor flows to the radiator to be cooled. In the maximum regenerative braking mode, the brake resistor, the electric water pump, and the heater are turned on and operated in response to a control signal from the controller, the three-way valve is operated to close to the heating line and open to the first cooling water return line, and the heater blower is kept closed. In the maximum regenerative braking mode, the brake resistor and the heater convert the excess electric energy generated by the electric motor into heat energy, thereby continuously generating an auxiliary braking force through continuous reverse torque of the electric motor. When the state of charge of the battery is 100%, all of the electric energy generated by the electric motor becomes excess electric energy, which is converted into heat energy by the brake resistor and the heater and consumed, thereby maximally generating an auxiliary braking force through continuous reverse torque of the electric motor. The low temperature cooling water flowing through the cooling water supply line from the radiator through the operation of the electric water pump sequentially cools the heater and the brake resistor while passing through the cooling water passages of the heater and the brake resistor, and the high temperature cooling water flowing out of the brake resistor after cooling the brake resistor flows back to the radiator.

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