KR102537874B1 - Motor system of vehicle and method for controlling low efficiency thereof - Google Patents

Abstract

A motor system of a vehicle capable of performing low-efficiency control of the motor system using driving prediction information and a low-efficiency control method thereof. A battery charging electric energy generated by a motor, and a control unit performing low-efficiency control of the motor according to regenerative braking of the vehicle, wherein the control unit obtains driving prediction information of the vehicle and converts the obtained driving prediction information to the vehicle. Based on this, it is confirmed whether low-efficiency control of the motor is required, and if low-efficiency control of the motor is required, the motor control factor corresponding to the low-efficiency control is calculated based on the obtained driving prediction information of the vehicle, and the low-efficiency control factor for the motor is calculated according to the calculated motor control factor. control can be performed.

Description

Motor system of vehicle and low-efficiency control method thereof

The present invention relates to a motor system of a vehicle, and more particularly, to a motor system of a vehicle capable of performing low-efficiency control of a motor system using driving prediction information and a low-efficiency control method thereof.

In general, in an eco-friendly vehicle, depending on the characteristics and state of the high voltage battery, the time available for charging the battery may vary due to continuous regenerative braking.

In addition, when performing regenerative braking in an eco-friendly vehicle, battery protection is particularly important.

If the vehicle continuously performs regenerative braking when the battery is fully charged, the battery may be overcharged, causing serious problems in durability of the battery.

In addition, when the battery is fully charged while the vehicle is performing regenerative braking, and regenerative braking is stopped and switching to the disc brake is performed, a sense of heterogeneity in drivability may occur.

In order to reduce such heterogeneity in drivability, continuous regenerative braking should not be maintained, but battery charging should not be performed.

Therefore, there is a need for a low-efficiency control method capable of maintaining regenerative braking without affecting the battery and drivability even when the vehicle performs regenerative braking.

However, when performing low-efficiency control, heat may be generated in the motor system due to increased loss of the motor system.

Such overheating of the motor may result in a reduction in output and efficiency of the motor, as well as irreversible demagnetization, resulting in a permanent reduction in output.

Here, if the amount of energy required for low-efficiency control is controlled with high power in a short time, a sudden temperature rise may occur in the motor system. However, if the motor system is treated with low power for a long time, the temperature rise can be controlled.

However, when the vehicle goes on a steep slope or goes downhill for a long time, if the amount of sacrificial power increases and low-efficiency control is performed to prevent overcharging of the battery, the low-efficiency control amount rapidly increases in a short time and the motor temperature may rise rapidly.

Therefore, there is a demand for the development of low-efficiency control technology for motor systems that can optimize the low-efficiency control of the motor system to prevent overcharging of the battery, prevention of overheating of the motor system, and prevention of heterogeneity in driving even in steep slopes or long-term downhill environments in the future. .

The present invention performs low-efficiency control of the motor according to the motor control voltage value calculated based on the driving prediction information of the vehicle, thereby preventing battery overcharging, preventing motor system overheating, and driving heterogeneity even in a steep slope or long-term downhill environment. It is to provide a motor system of a vehicle that can prevent and a low efficiency control method thereof.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

In order to solve the above technical problem, a motor system of a vehicle according to an embodiment of the present invention includes a motor that generates driving force of the vehicle and operates as a generator during coasting, and supplies power to the motor and generates electricity from the motor. A battery charging energy, and a controller that performs low-efficiency control of a motor according to regenerative braking of the vehicle, wherein the controller obtains driving prediction information of the vehicle and controls low-efficiency motor based on the obtained driving prediction information of the vehicle. It is possible to check whether the motor is necessary, and if low-efficiency control of the motor is required, a motor control factor corresponding to the low-efficiency control is calculated based on the obtained driving prediction information of the vehicle, and low-efficiency control for the motor can be performed according to the calculated motor control factor. there is.

Here, the motor control factor may be a voltage value applied for motor control.

The control unit includes an acquisition unit that acquires driving prediction information of the vehicle, a first calculator that calculates an amount of energy required for low-efficiency control based on the vehicle driving prediction information obtained from the acquisition unit, and A second calculation unit that calculates a motor control voltage value corresponding to low efficiency control based on the amount of energy required for low efficiency control and the obtained driving prediction information of the vehicle; and a motor that performs low efficiency control for the motor according to the calculated motor control voltage value. A controller may be included.

In addition, a low-efficiency control method of a motor system of a vehicle according to an embodiment of the present invention includes a controller that performs low-efficiency control of a motor, a battery, and a motor according to regenerative braking of the vehicle, wherein the controller performs driving of the vehicle. Obtaining prediction information; determining, by a controller, whether low-efficiency control of the motor is required based on the obtained vehicle driving prediction information; Calculating a motor control factor corresponding to the low-efficiency control based on the calculated motor control factor, and performing, by the controller, the low-efficiency control for the motor according to the calculated motor control factor.

The motor system of a vehicle and the low-efficiency control method thereof according to at least one embodiment of the present invention configured as described above performs low-efficiency control of a motor according to a motor control voltage value calculated based on driving prediction information of a vehicle, Even in steep slopes or long downhill environments, it provides effects that can prevent battery overcharging, motor system overheating, and driving discomfort.

That is, in the present invention, when the road condition is steep or downhill for a long period of time, the amount of regenerative power of the vehicle increases and overcharging of the battery may occur, which may have a weak effect on the durability of the battery. By starting the low-efficiency control of the motor before entering the front downhill, overcharging of the battery can be prevented.

In addition, in the present invention, when the battery is fully charged before the end of the steep slope, if the low efficiency control amount is increased to offset the high amount of regenerative power at the steep slope, high heat generation occurs in a short time, which can cause a rapid rise in motor temperature. By pre-distributing the predicted low-efficiency control energy amount and using the same low-efficiency control amount for a long time, a cooling effect can be obtained and the motor temperature rise can be prevented.

Accordingly, the present invention can operate with higher efficiency when the low-efficiency control ends by preventing the motor temperature from rising.

In addition, according to the present invention, by preventing overcharging of the battery or rapid temperature rise through pre-distribution of the low efficiency control to prevent switching to the disc brake, it is possible to prevent a sense of heterogeneity in drivability.

The effects obtainable in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 is a block diagram illustrating a motor system of a vehicle according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a method of controlling low efficiency of a motor of the controller of FIG. 1 .
FIG. 3 is a block configuration diagram for explaining the configuration of a control unit of FIG. 1 .
4 is a flowchart illustrating a low-efficiency control process of a motor system of a vehicle according to an embodiment of the present invention.
5 is a graph for explaining a low efficiency control method according to a state of charge of a battery.
6 is a graph for explaining changes in SOC, low efficiency control amount, and motor temperature according to low efficiency control of a motor system.

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

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

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated. In addition, parts denoted with the same reference numerals throughout the specification mean the same components.

Hereinafter, a motor system of a vehicle and a low-efficiency control method thereof applicable to embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6 .

1 is a block diagram illustrating a motor system of a vehicle according to an embodiment of the present invention.

As shown in FIG. 1, the motor system 100 of the vehicle generates driving force of the vehicle and supplies power to the motor 110, which operates as a generator during coasting and supplies power to the motor 110, It may include a battery 120 that charges electric energy, and a controller 130 that performs low-efficiency control of the motor 110 according to regenerative braking of the vehicle.

Here, the control unit 130 obtains driving prediction information of the vehicle, checks whether low-efficiency control of the motor is required based on the obtained driving prediction information of the vehicle, and if low-efficiency control of the motor is required, the obtained driving prediction information of the vehicle It is possible to calculate a motor control voltage value corresponding to the low efficiency control based on , and perform the low efficiency control for the motor according to the calculated motor control voltage value.

For example, when acquiring driving prediction information of the vehicle, the controller 130 may include first information predicting regenerative energy according to road conditions, second information predicting chargeable battery energy, and third predicting driving time. Driving prediction information including 3 information may be obtained.

Here, the first information may be information that predicts regenerative energy when the road condition is downhill, but is not limited thereto.

And, the second information may be battery energy information that can be charged at the time of predicting regenerative energy, but is not limited thereto.

In addition, the third information may be travel time information from the time when the regenerative energy is predicted to the time when the downhill of the road ends, but is not limited thereto.

Next, when determining whether low-efficiency control of the motor 110 is required, the control unit 130, among the obtained driving prediction information of the vehicle, predicts the regenerative energy value predicted when the road is going downhill and the regenerative energy value predicted when predicting it. It is possible to determine whether low-efficiency control of the motor 110 is required by comparing the energy value of the rechargeable battery.

Here, the controller 130 compares the regenerative energy value predicted when the road is going downhill and the chargeable battery energy value predicted when the regenerative energy value is predicted, and if the regenerative energy value is greater than the battery energy value, the motor 110 ) can be judged to require low-efficiency control.

In addition, when the controller 130 compares the regenerative energy value predicted when the road is going downhill ahead and the rechargeable battery energy value predicted when the regenerative energy value is predicted, if the regenerative energy value is smaller than or equal to the battery energy value, the motor It may be determined that the low efficiency control of 130 is not necessary.

In addition, when calculating the motor control value corresponding to the low-efficiency control, the control unit 130 calculates the amount of energy required for the low-efficiency control based on the obtained driving prediction information of the vehicle, and the optimal power for the low-efficiency control based on the amount of energy required for the low-efficiency control. value can be calculated.

Here, the controller 130, when calculating the amount of energy required for low-efficiency control, among the obtained driving prediction information of the vehicle, the regenerative energy value predicted when the road is going downhill and the chargeable energy value predicted when the regenerative energy value is predicted Based on the battery energy value, the amount of energy required for low-efficiency control can be calculated.

For example, the amount of energy required for low efficiency control may be a difference between a regenerative energy value predicted when the road is going downhill and a chargeable battery energy value predicted when the regenerative energy value is predicted, but is not limited thereto.

That is, the amount of energy required for low-efficiency control may be the amount of energy to be charged in the battery 120 when the low-efficiency control for the motor is performed.

In addition, when calculating the low-efficiency control optimal power value, the control unit 130 determines the low-efficiency control based on the calculated amount of energy required for the low-efficiency control and the travel time from the time point at which the regenerative energy is predicted to the time when the front downhill of the road ends. An optimal power value can be calculated.

For example, the optimal power value for low-efficiency control may be a value obtained by dividing the driving time by the amount of energy required for low-efficiency control.

That is, the low-efficiency control optimum power value may be a motor control voltage value applied to the motor when the low-efficiency control is performed on the motor.

Next, when the low efficiency control for the motor 110 is performed according to the calculated motor control voltage value, the control unit 130 counts the low efficiency control time when the low efficiency control for the motor 110 starts, and the counted low efficiency The control time and the driving time from the time when the regenerative energy is predicted to the time when the downhill of the road ends is compared, and low efficiency control of the motor 110 can be performed according to the comparison result.

Here, the controller 130 may end the low-efficiency control of the motor 110 if the low-efficiency control time is greater than or equal to the travel time when comparing the low-efficiency control time and the travel time.

In addition, when comparing the low-efficiency control time and the travel time, the controller 130 checks whether the motor temperature and the inverter temperature exceed the reference temperature if the low-efficiency control time is smaller than the travel time, and as a result of the check, the motor temperature and the inverter temperature When the reference temperature is exceeded, low efficiency control of the motor 110 may be terminated.

Here, when checking whether the motor temperature and the inverter temperature exceed the reference temperature, the control unit 130 checks whether the state of charge of the battery 120 is more than full, if the motor temperature and the inverter temperature do not exceed the reference temperature, and as a result of the check When the state of charge of the battery 120 is not less than full, the low efficiency control of the motor 110 may be maintained by comparing the low efficiency control time with the travel time.

Next, the controller 130 checks whether the state of charge of the battery 120 is full or higher, and if the state of charge of the battery is higher than full as a result of the check, the controller 130 checks the discharge current value discharged from the battery 120, and the checked discharge current value. Based on this, low-efficiency control for the motor 110 may be strengthened or relaxed.

For example, when checking the discharge current value discharged from the battery 120, the control unit 130 performs low-efficiency control reinforcement for the motor 110 if the discharge current value is less than 0, and if the discharge current value is greater than 0 Low efficiency control relaxation for motor 110 may be performed.

That is, the reinforcement of the low efficiency control of the motor 110 may reduce the motor control voltage value corresponding to the low efficiency control, and perform the low efficiency control of the motor based on the reduced motor control voltage value.

In addition, the low-efficiency control relaxation of the motor 110 may increase a motor control voltage value corresponding to the low-efficiency control, and perform the low-efficiency control of the motor 110 based on the increased motor control voltage value.

As such, when performing low-efficiency control of the motor 110, the controller 130 may control the motor 110 with low power so that the battery 120 is regeneratively charged for a long time during regenerative braking of the vehicle. .

FIG. 2 is a diagram for explaining a method of controlling low efficiency of a motor of the controller of FIG. 1 .

As shown in FIG. 2 , the present invention is a technique of utilizing driving prediction information 300 of a vehicle and reflecting it to motor current control, and the control unit 130, which is a motor controller (MCU), includes a VCU, HCU, FCU, etc. A torque command necessary for the vehicle may be received from the vehicle controller 200 including the.

In addition, the control unit 130 may calculate a current command reflecting the low efficiency control amount calculated from the driving prediction information 300 in the current command curve, which is a torque curve such as to output the received torque command.

That is, the control unit 130 may obtain driving prediction information using a precision map from the driving prediction system of the vehicle, and use the predicted information to control the motor with low efficiency.

As such, the present invention includes the regeneration amount, section distance, section average gradient, section average vehicle speed, etc. when a vehicle having a motor system including a motor, inverter, and battery as a driving source performs low-efficiency control of the motor system. Receives the driving prediction information that is needed, and monitors the battery status based on the received driving prediction information. Through the optimization of low-efficiency control, the purpose is to prevent overcharging of the battery, overheating of the motor system, and prevention of heterogeneity in drivability.

For example, in the present invention, if the predicted amount of regenerative braking energy on the forward downhill is greater than the amount of energy that can be charged in the battery at the start of the forward downhill, it means that low-efficiency control is required, and the amount of regenerative braking energy and the amount of energy that can be charged in the battery The difference in the amount becomes the amount of low-efficiency control energy required.

Therefore, the present invention can optimize low-efficiency control by distributing the required amount of low-efficiency control energy with appropriate power for an appropriate time during downhill driving, thereby preventing overcharging of the battery, preventing overheating of the motor system, and preventing heterogeneity in driving performance. effect can be obtained.

FIG. 3 is a block configuration diagram for explaining the configuration of a control unit of FIG. 1 .

As shown in FIG. 3 , the control unit 130 of the present invention includes an acquisition unit 132 that acquires vehicle driving prediction information and low efficiency control required energy based on the vehicle driving prediction information obtained from the acquisition unit 132. A first calculation unit 134 that calculates the amount of energy required for low-efficiency control calculated from the first calculation unit 134 and the obtained driving prediction information of the vehicle to calculate a motor control voltage value corresponding to low-efficiency control 2 may include a calculator 136 and a motor controller 138 that performs low-efficiency control of the motor according to the calculated motor control voltage value.

Here, the acquisition unit 132 obtains driving prediction information including first information predicting regenerative energy according to road conditions, second information predicting chargeable battery energy, and third information predicting driving time. can do.

In this case, the first information may be information obtained by predicting regenerative energy when the road condition is downhill ahead, the second information may be battery energy information that can be charged at the time of predicting the regenerative energy, and the third information may be , may be driving time information from the time of predicting the regenerative energy to the time when the downhill of the road ends.

Then, the motor controller 138 compares the regenerative energy value predicted when the road is downhill ahead and the rechargeable battery energy value predicted when the regenerative energy value is predicted among the obtained driving prediction information of the vehicle, thereby reducing the efficiency of the motor. You can check whether you need control.

That is, when the motor controller 138 compares the regenerative energy value predicted when the road is going downhill and the rechargeable battery energy value predicted when the regenerative energy value is predicted, if the regenerative energy value is greater than the battery energy value, the motor If it is determined that low-efficiency control is required, and the regenerative energy value is less than or equal to the battery energy value, it may be determined that low-efficiency control of the motor is not required.

Next, the first calculation unit 134 may calculate the amount of energy required for low-efficiency control based on the obtained driving prediction information of the vehicle.

That is, when calculating the amount of energy required for low-efficiency control, the first calculation unit 134, among the obtained driving prediction information of the vehicle, predicts the regenerative energy value predicted when the road is going downhill and the regenerative energy value predicted when predicting it. The amount of energy required for low-efficiency control can be calculated based on the energy value of the rechargeable battery.

Here, the amount of energy required for low-efficiency control may be a difference between a regenerative energy value predicted when the road is going downhill and a chargeable battery energy value predicted when the regenerative energy value is predicted.

In this case, the amount of energy required for the low-efficiency control may be the amount of energy to be charged in the battery when performing the low-efficiency control for the motor.

Subsequently, the second calculator 136 may calculate an optimum power value for low efficiency control based on the amount of energy required for low efficiency control.

That is, the second calculation unit 136 calculates the low-efficiency control optimal power value based on the calculated amount of energy required for low-efficiency control and the travel time from the time when the regenerative energy is predicted to the time when the forward downhill of the road ends. , it is possible to calculate the optimal power value for low efficiency control.

Here, the optimal power value for low-efficiency control may be a value obtained by dividing the driving time by the amount of energy required for low-efficiency control.

In this case, the low-efficiency control optimum power value may be a motor control voltage value applied to the motor when the low-efficiency control is performed on the motor.

Next, the motor controller 138, when performing the low-efficiency control of the motor according to the calculated motor control voltage value, counts the low-efficiency control time when the low-efficiency control of the motor starts, and calculates the counted low-efficiency control time and regenerative energy The driving time from the time of predicting the forward downhill of the road to the end of the road downhill is compared, and low efficiency control for the motor can be performed according to the comparison result.

Here, the motor controller 138 may end the low-efficiency control of the motor when the low-efficiency control time is greater than or equal to the travel time when comparing the low-efficiency control time and the travel time.

In addition, when comparing the low-efficiency control time and the travel time, the motor controller 138 checks whether the motor temperature and the inverter temperature exceed the reference temperature if the low-efficiency control time is smaller than the travel time, and as a result of the check, the motor temperature and the inverter temperature When the temperature exceeds the reference temperature, the low-efficiency control for the motor can be terminated.

And, when checking whether the motor temperature and the inverter temperature exceed the reference temperature, the motor controller 138 checks whether the battery charge state is full or higher if the motor temperature and the inverter temperature do not exceed the reference temperature, and as a result of the check, the battery is charged. If the state is more than full, the low-efficiency control of the motor can be maintained by comparing the low-efficiency control time with the running time.

In addition, the motor controller 138 checks whether the state of charge of the battery is full or higher, and if the state of charge of the battery is higher than full as a result of the check, checks the discharge current value discharged from the battery, and determines the value of the discharge current for the motor based on the checked discharge current value. Inefficient control can be strengthened or relaxed.

Next, the motor controller 138 may terminate the low-efficiency control and maintain the battery charge state at full charge when the road condition ends with a forward downhill.

Therefore, the present invention performs low-efficiency control on the motor according to the motor control voltage value calculated based on the driving prediction information of the vehicle, thereby preventing overcharging of the battery, preventing overheating of the motor system, and driving Gender heterogeneity can be avoided.

4 is a flowchart for explaining a low efficiency control process of a motor system of a vehicle according to an embodiment of the present invention, and FIG. 5 is a graph for explaining a low efficiency control method according to a state of charge of a battery.

As shown in FIG. 4 , first, the control unit of the present invention may obtain vehicle driving prediction information from the vehicle driving prediction system (S110).

Here, the controller may obtain driving prediction information including first information predicting regenerative energy according to road conditions, second information predicting chargeable battery energy, and third information predicting driving time.

Then, the control unit may determine whether low-efficiency control of the motor is required based on the obtained driving prediction information of the vehicle (S120).

Here, the control unit compares the regenerative energy value predicted when the road is going downhill ahead of the obtained driving prediction information of the vehicle and the rechargeable battery energy value predicted when the regenerative energy value is predicted, and as a result of the comparison, the regenerative energy value If the battery energy value is greater than the battery energy value, it is determined that low-efficiency control of the motor is required, and if the regenerative energy value is smaller than or equal to the battery energy value, it is determined that the low-efficiency control of the motor is not required.

Subsequently, if it is determined that the low-efficiency control of the motor is necessary as a result of the check, the control unit may calculate a motor control voltage value corresponding to the low-efficiency control based on the obtained driving prediction information of the vehicle.

That is, the controller may calculate the motor control voltage value as follows.

First, the control unit calculates the amount of energy required for low-efficiency control based on a regenerative energy value predicted when the road is going downhill ahead and a chargeable battery energy value predicted when the regenerative energy value is predicted among the obtained driving prediction information of the vehicle. It can (S130).

Here, the amount of energy required for low-efficiency control may be a difference between a regenerative energy value predicted when the road is going downhill and a chargeable battery energy value predicted when the regenerative energy value is predicted.

Next, the controller may calculate an optimal power value for low-efficiency control based on the calculated amount of energy required for low-efficiency control and a driving time from the time when regenerative energy is predicted to the time when the downhill of the road ends (S140).

Here, the low-efficiency control optimum power value is a motor control voltage value, and may be a value obtained by dividing the driving time by the amount of energy required for the low-efficiency control.

In addition, the control unit may perform low-efficiency control of the motor according to the calculated motor control voltage value.

That is, the control unit may perform low efficiency control of the motor according to the calculated motor control voltage value as follows.

First, the controller starts low-efficiency control of the motor (S150).

Then, when the low efficiency control for the motor starts, the controller counts the low efficiency control time (S150).

Next, the control unit compares the counted low-efficiency control time with the driving time from the time when the regenerative energy is predicted to the time when the front downhill of the road ends (S160).

Here, the control unit may terminate the low efficiency control for the motor when the low efficiency control time is greater than or equal to the travel time as a result of the comparison (S170).

However, as a result of the comparison, if the low-efficiency control time is shorter than the driving time, the control unit checks whether the motor temperature and the inverter temperature exceed the reference temperature (S180).

Then, as a result of the confirmation, the control unit may terminate the low efficiency control of the motor when the temperature of the motor and the inverter exceeds the reference temperature (S170).

However, the controller may check whether the battery charge state is full or higher when the motor temperature and the inverter temperature do not exceed the reference temperature (S190).

And, as a result of checking, if the state of charge of the battery is more than full, the control unit may maintain the low efficiency control of the motor by comparing the low efficiency control time with the traveling time.

However, as a result of checking, if the state of charge of the battery is more than full, the control unit may check the discharge current value discharged from the battery (S200).

Next, as a result of checking, if the discharge current value is less than 0, the control unit may perform low-efficiency control enhancement for the motor (S210).

Here, the reinforcement of the low-efficiency control of the motor may reduce the motor control voltage value corresponding to the low-efficiency control, and perform the low-efficiency control of the motor based on the reduced motor control voltage value.

Then, as a result of the check, if the discharge current value is 0 or more, the control unit may perform low efficiency control relaxation for the motor (S220).

Here, the low-efficiency control relaxation of the motor may increase the motor control voltage value corresponding to the low-efficiency control, and perform the low-efficiency control of the motor based on the increased motor control voltage value (S230).

As such, when the SOC of the battery is 100%, the control unit may maintain the SOC of the battery at 100% by monitoring the DC current.

That is, as shown in FIG. 5 , when the SOC of the battery is 100% and the DC current of the battery is less than 0, the control unit may perform low efficiency control enhancement for the motor.

Here, the reinforcement of the low-efficiency control of the motor may reduce the motor control voltage value corresponding to the low-efficiency control, and perform the low-efficiency control of the motor based on the reduced motor control voltage value.

In addition, as shown in FIG. 5 , when the SOC of the battery is 100% and the DC current of the battery is 0 or more, the control unit may perform low efficiency control relaxation of the motor.

Here, the low-efficiency control relaxation of the motor may increase the motor control voltage value corresponding to the low-efficiency control, and perform the low-efficiency control of the motor based on the increased motor control voltage value.

As such, the present invention performs low-efficiency control of the motor according to the motor control voltage value calculated based on the driving prediction information of the vehicle, thereby preventing battery overcharging, preventing motor system overheating, and driving Gender heterogeneity can be avoided.

That is, in the present invention, when the road condition is steep or downhill for a long period of time, the amount of regenerative power of the vehicle increases and overcharging of the battery may occur, which may have a weak effect on the durability of the battery. By starting the low-efficiency control of the motor before entering the front downhill, overcharging of the battery can be prevented.

In addition, in the present invention, when the battery is fully charged before the end of the steep slope, if the low efficiency control amount is increased to offset the high amount of regenerative power at the steep slope, high heat generation occurs in a short time, which can cause a rapid rise in motor temperature. By pre-distributing the predicted low-efficiency control energy amount and using the same low-efficiency control amount for a long time, a cooling effect can be obtained and the motor temperature rise can be prevented.

Accordingly, the present invention can operate with higher efficiency when the low-efficiency control ends by preventing the motor temperature from rising.

In addition, the present invention prevents overcharging of the battery or rapid temperature rise by pre-distribution of the low efficiency control to prevent switching to disc brakes, thereby preventing a sense of heterogeneity in drivability.

6 is a graph for explaining changes in SOC, low efficiency control amount, and motor temperature according to low efficiency control of a motor system.

As shown in FIG. 6 , before the road condition is steep or the road is downhill for a long period of time, the motor system of the vehicle may obtain driving prediction information of the vehicle in advance and start low-efficiency control of the motor.

That is, the vehicle determines whether the driving prediction low efficiency control is controlled by comparing the amount of energy that can be charged in the battery at the prediction time from the driving prediction information and the amount of regenerative charging energy generated on the downhill.

In addition, when low efficiency control is required, the vehicle calculates equal power required for low efficiency control by dividing the required low efficiency control energy by the predicted time until the end of the downhill section.

Next, the vehicle distributes power evenly and performs low-efficiency control at low power for a long time, thereby stably controlling battery SOC, low-efficiency control amount, and motor temperature change to prevent battery overcharge, motor system overheating, and drivability. can prevent

That is, the present invention prevents overcharging of the battery and prevents the use of unnecessary disc brakes by obtaining and controlling low-efficiency control energy to prevent heterogeneity in driving performance.

In addition, the present invention, by distributing the low-efficiency control power evenly, can prevent the motor temperature rise caused by controlling with high power in a short time and extend the life of the motor.

The above-described present invention can be implemented as computer readable code on a medium on which a program is recorded. The computer-readable medium includes all types of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable media include Hard Disk Drive (HDD), Solid State Disk (SSD), Silicon Disk Drive (SDD), ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc. , and also includes those implemented in the form of a carrier wave (eg, transmission over the Internet).

Accordingly, the above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

100: motor system
110: motor
120: battery
130: control unit
200: vehicle control unit
300: driving prediction information

Claims (21)

A motor that generates driving force of the vehicle and operates as a generator during coasting;
a battery supplying power to the motor and charging electrical energy generated by the motor; and,
A control unit for performing low-efficiency control of the motor according to regenerative braking of the vehicle;
The control unit,
Driving prediction information of the vehicle is obtained, and based on the obtained driving prediction information of the vehicle, it is determined whether low-efficiency control of the motor is necessary, and if low-efficiency control of the motor is required, the driving prediction information of the obtained vehicle is determined. A motor system of a vehicle, characterized in that calculating a motor control factor corresponding to low efficiency control, and performing low efficiency control for the motor according to the calculated motor control factor. The method of claim 1, wherein the control unit,
When driving prediction information of the vehicle is acquired, driving prediction information including first information predicting regenerative energy according to road conditions, second information predicting chargeable battery energy, and third information predicting driving time. A motor system of a vehicle, characterized in that for obtaining. The method of claim 1, wherein the control unit,
When determining whether the low-efficiency control of the motor is required, among the obtained driving prediction information of the vehicle, a regenerative energy value predicted when the road is going downhill is compared with a chargeable battery energy value predicted when the regenerative energy value is predicted. A motor system of a vehicle, characterized in that for determining whether the low-efficiency control of the motor is required. The method of claim 3, wherein the control unit,
When comparing the regenerative energy value predicted when the road is downhill ahead and the rechargeable battery energy value predicted when the regenerative energy value is predicted, if the regenerative energy value is greater than the battery energy value, low efficiency control of the motor is required. The motor system of the vehicle, characterized in that for determining that. The method of claim 3, wherein the control unit,
When comparing the regenerative energy value predicted when the road is downhill ahead and the rechargeable battery energy value predicted when the regenerative energy value is predicted, if the regenerative energy value is smaller than or equal to the battery energy value, low efficiency control of the motor A motor system of a vehicle, characterized in that for determining that is not necessary. The method of claim 1, wherein the control unit,
When calculating the motor control factor corresponding to the low-efficiency control, the amount of energy required for low-efficiency control is calculated based on the obtained driving prediction information of the vehicle, and the optimum power value for low-efficiency control is calculated based on the amount of energy required for low-efficiency control. The motor system of the characterized vehicle. The method of claim 6, wherein the control unit,
When calculating the amount of energy required for the low-efficiency control, based on the predicted regenerative energy value when the road is downhill ahead and the energy value of the rechargeable battery predicted when the regenerative energy value is predicted, among the obtained driving prediction information of the vehicle. The motor system of a vehicle, characterized in that for calculating the amount of energy required for the low efficiency control. The method of claim 7, wherein the control unit,
When the low-efficiency control optimal power value is calculated, the low-efficiency control optimal power is based on the calculated amount of energy required for the low-efficiency control and the driving time from the time when the regenerative energy value is predicted to the time when the front downhill of the road ends. A motor system of a vehicle, characterized in that for calculating a value. The method of claim 8, wherein the control unit,
When the low-efficiency control for the motor is performed according to the calculated motor control factor, when the low-efficiency control for the motor starts, the low-efficiency control time is counted, and the counted low-efficiency control time and the regenerative energy value are predicted. The motor system of a vehicle, characterized in that the driving time is compared from the time from the start to the end of the forward downhill of the road, and low efficiency control of the motor is performed according to the comparison result. The method of claim 9, wherein the control unit,
When comparing the low-efficiency control time with the travel time, if the low-efficiency control time is greater than or equal to the travel time, the low-efficiency control for the motor is terminated. The method of claim 9, wherein the control unit,
When comparing the low-efficiency control time and the running time, if the low-efficiency control time is shorter than the running time, it is checked whether the motor temperature and the inverter temperature exceed the reference temperature, and as a result of the check, the motor temperature and the inverter temperature are the reference temperature Exceeding the motor system of the vehicle, characterized in that to end the low efficiency control for the motor. The method of claim 11, wherein the control unit,
When checking whether the motor temperature and the inverter temperature exceed the reference temperature, if the motor temperature and the inverter temperature do not exceed the reference temperature, it is checked whether the battery SOC is full or more, and as a result of the check, the battery SOC is more than full. or comparing the low-efficiency control time with the running time to maintain the low-efficiency control of the motor. The method of claim 12, wherein the control unit,
It is checked whether the state of charge of the battery is more than full, and as a result of the check, if the state of charge of the battery is more than full, a discharge current value discharged from the battery is checked, and low efficiency control for the motor is strengthened based on the confirmed discharge current value. Or a motor system of a vehicle, characterized in that mitigating. The method of claim 1, wherein the control unit,
an acquisition unit acquiring driving prediction information of the vehicle;
a first calculation unit that calculates an amount of energy required for low-efficiency control based on the vehicle driving prediction information acquired from the acquisition unit;
a second calculator that calculates a motor control voltage value corresponding to the low-efficiency control based on the amount of energy required for the low-efficiency control calculated from the first calculator and the obtained driving prediction information of the vehicle; and,
and a motor controller that performs low-efficiency control of the motor according to the calculated motor control voltage value. The method of claim 1, wherein the motor control factor,
A motor system of a vehicle, characterized in that it is a voltage value applied for motor control. A low-efficiency control method of a vehicle motor system including a motor, a battery, and a control unit that performs low-efficiency control of the motor according to regenerative braking of the vehicle,
obtaining, by the control unit, driving prediction information of the vehicle;
determining, by the control unit, whether or not low-efficiency control of the motor is required based on the obtained driving prediction information of the vehicle;
calculating, by the control unit, a motor control factor corresponding to the low-efficiency control based on the obtained driving prediction information of the vehicle when low-efficiency control of the motor is required; and,
The low-efficiency control method of a motor system of a vehicle comprising the step of performing, by the control unit, low-efficiency control for the motor according to the calculated motor control factor. The method of claim 16, wherein the step of determining whether low-efficiency control of the motor is required based on the obtained driving prediction information of the vehicle comprises:
Among the obtained driving prediction information of the vehicle, a regenerative energy value predicted when the road is going downhill is compared with a chargeable battery energy value predicted when the regenerative energy value is predicted, and as a result of the comparison, the regenerative energy value is If it is greater than the battery energy value, it is determined that low efficiency control of the motor is required, and if the regenerative energy value is smaller than or equal to the battery energy value, it is determined that low efficiency control of the motor is not required. Low-efficiency control method of 17. The method of claim 16, wherein calculating a motor control factor corresponding to the low efficiency control based on the obtained driving prediction information of the vehicle comprises:
Calculating the required amount of energy for low-efficiency control based on a regenerative energy value predicted when the road is going downhill ahead and a chargeable battery energy value predicted when the regenerative energy value is predicted among the obtained driving prediction information of the vehicle; and,
Calculating the optimal power value for low-efficiency control based on the calculated amount of energy required for low-efficiency control and a driving time from the time of estimating the regenerative energy to the end of the downward slope of the road Low-efficiency control method of motor system of vehicle. The method of claim 18, wherein performing the low-efficiency control for the motor according to the calculated motor control factor comprises:
starting low-efficiency control for the motor;
counting a low-efficiency control time when the low-efficiency control for the motor starts;
comparing the counted low-efficiency control time with the driving time from a time point at which the regenerative energy value is predicted to a time when a downhill front of the road ends;
The low-efficiency control method of a motor system of a vehicle comprising the step of performing low-efficiency control on the motor according to the comparison result. The method of claim 19, wherein comparing the low efficiency control time and the driving time,
The low-efficiency control method of a motor system of a vehicle, characterized in that ending the low-efficiency control for the motor when the low-efficiency control time is greater than or equal to the running time. The method of claim 19, wherein performing low-efficiency control on the motor according to the comparison result comprises:
checking whether the motor temperature and the inverter temperature exceed reference temperatures when the low-efficiency control time is shorter than the running time;
As a result of the check, if the motor temperature and the inverter temperature exceed the reference temperature, terminating the low-efficiency control for the motor, and if the motor temperature and the inverter temperature do not exceed the reference temperature, checking whether the battery charge state is full or more. ;
As a result of the check, if the state of charge of the battery is more than full, the low efficiency control time and the running time are compared to maintain the low efficiency control of the motor, and if the state of charge of the battery is more than full, the discharge current value discharged from the battery checking; and,
As a result of the check, if the discharge current value is less than 0, low efficiency control reinforcement for the motor is performed, and if the discharge current value is 0 or more, low efficiency control relaxation for the motor is performed. Low-efficiency control method.

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