METHOD AND SYSTEM FOR CONTROLLING MOTORS

Abstract

A method for controlling a plurality of motors provided in a vehicle, comprising the following steps: Determining (S11) by means of a controller, a state of charge of a battery suitable for storing power supplied to each motor of a plurality of motors, Calculating (S12) by means of the controller, a current power consumption of each motor of the plurality of motors when the state of charge of the battery is identical to or less than a predetermined reference value; readjusting (S16), by means of the controller, a power supply to each motor of the plurality of motors based on the current power consumption of each motor of the plurality of motors; wherein the step of calculating the current power consumption comprises a step (S13) of setting a first priority for power supply between the plurality of motors based on the current power consumption of each motor of the plurality of motors; the step of calculating the current power consumption further comprises a step (S15) of setting a second priority based on a rating of each motor of the plurality of motors, after the step (S13) of setting the first priority; and the step of readjusting (S16) the power supply further comprises a step of calculating an integrated priority based on the first and second priorities of each motor of the plurality of motors and comparing the integrated priorities, wherein a higher reduction rate of power is employed for a corresponding motor in which the integrated priority is lower than the integrated priority of other motors.

Description

AREA

[0001] The present disclosure relates to a method and system for controlling engines, and more specifically, to a method and system for controlling engines suitable for maintaining a vehicle at a steady speed. BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Generally, vehicles have different types of engines to realize a variety of functions required for their travel. For example, a vehicle having an internal combustion engine has a motor that drives a cooling fan used to circulate coolant for cooling the engine, or a motor that drives an AAF (active air flap) for regulating air intake. Furthermore, in an electric vehicle or a hybrid vehicle powered by motive power generated using a drive motor, a motor is used on an EWP (electric water pump), which circulates coolant to cool highly heated electronic power components used in a power conversion system for supplying electric power to the drive motor.

[0004] To power these motors, the vehicles have a battery that stores electrical energy and supplies the stored electrical energy, which is the power source for the motors. The battery must always be kept charged above a certain level to ensure the vehicle runs smoothly.

[0005] However, the electric power stored in the battery may also be reduced below a desired level due to various reasons when the vehicle is actually operating and driving. In particular, when the electric power stored in the battery decreases while the vehicle is driving, it is desirable to immediately recharge the battery while simultaneously reducing the amount of electric power output from the battery to prevent battery deterioration or prevent the vehicle from shutting down due to excessive discharge.

[0006] The various motors installed in a vehicle have a significant impact on the consumption of electric power stored in the battery. Therefore, when the battery's electric power is reduced below a desired level, it is desirable to reduce the electric power consumed by the motors. However, we have discovered that if the operation of the motors is stopped or the power consumption of each motor is reduced without special consideration when the vehicle is actually running, various functions (e.g., cooling a vehicle's internal combustion engine and electrical power components) realized by driving the motors will deteriorate, which, in severe cases, may lead to an adverse impact on the internal combustion engine or the drive motor.

[0007] Accordingly, the power consumption of the battery must be reduced taking into account various factors that are desired for the vehicle's travel when the electric power stored in the battery is reduced below a certain level during the vehicle's travel.

[0008] The foregoing is intended to aid in understanding the background of the present disclosure and is not intended to indicate that the present invention falls within the scope of related art already known to those skilled in the art.

[0009] DE 10 2016 201 740 A1 discloses a technology of controlling power of a vehicle. More specifically, the present disclosure provides a method and apparatus for controlling power of a vehicle including a main battery, an auxiliary battery, and an electrical load, the apparatus comprising: a state of charge detection unit configured to detect a state of charge, SOC, of ​​the main battery and an SOC of the auxiliary battery; an allowable power calculation unit configured to calculate an allowable power of the main battery based on the SOC of the main battery; a charge / discharge power calculation unit configured to calculate a charge / discharge power of the auxiliary battery performing a charge or discharge operation;a first electric load power calculation unit configured to calculate a first electric load power, which is an electric load power whose execution is requested by a driver; an operation control unit configured to control an electric load operation whose execution has been requested based on the allowable power, the charging / discharging power, and the first electric load power; a second electric load power calculation unit configured to calculate a second electric load power, which is an electric load power executed by the operation control unit;and a charge / discharge control unit configured to control charge or discharge of the auxiliary battery based on the SOC of the auxiliary battery, the allowable power, the charge / discharge power, and the second power of the electrical load; SUMMARY

[0010] The present disclosure provides a method and system for controlling motors capable of maintaining a vehicle at a steady speed in such a manner that when the state of charge of a battery for supplying electric power stored therein to a plurality of motors provided in the vehicle is low, the consumption of the battery is reduced by lowering the electric power supplied to each of the motors.

[0011] A method according to the invention for controlling a plurality of motors provided in a vehicle is defined by claim 1. The method comprises: determining, by means of a controller, a state of charge of a battery capable of storing power supplied to each motor of a plurality of motors; calculating, by means of the controller, a current consumption of each motor of the plurality of motors when the state of charge of the battery is identical to or less than a predetermined reference value; and readjusting, by means of the controller, a power supply to each motor of the plurality of motors based on the current power consumption of each motor of the plurality of motors.

[0012] Calculating the current power consumption includes: setting a first priority for power supply between the plurality of motors based on the current power consumption for each motor of the plurality of motors.

[0013] The readjusting step further includes a step of allocating a lower current supply to a motor whose current power consumption is lower than the current power consumption of other motors in the plurality of motors. Calculating a current power consumption further includes setting a second priority based on a rating of each of the motors after setting the first priority. The power supply readjusting step further includes a step of calculating an integrated priority based on the first and second priorities of each motor in the plurality of motors and comparing the integrated priorities, wherein a higher current reduction rate is applied to a corresponding motor whose integrated priority is lower than the integrated priority of other motors.

[0014] Subclaims relate to preferred embodiments. An electric current or electric power can be supplied to each of the motors by applying a drive voltage or control voltage using a pulse-width modulation (PWM) method in which a load is adjusted.

[0015] When re-adjusting a current supply, a higher current reduction rate is used for a motor where the first priority is low if motors with the same built-in priority exist.

[0016] Both the first and second priorities can be set so that priority values ​​from 1 to n (where n denotes a natural number corresponding to the number of motors) are assigned starting from a motor with the highest priority in sequential order, and when readjusting the power supply based on a result obtained by combining priority values ​​depending on the first priority and priority values ​​according to the second priority, a larger reduction rate for power is applied to a corresponding motor in which the integrated priority is greater than an integrated priority of other motors.

[0017] When resetting a current supply, if the same combined priority value is found for different motors, a higher reduction rate for the current is used for a motor where the priority value of the first priority is greater than the priority value of the first priority assigned to other motors.

[0018] A system for controlling motors according to the invention is defined by claim 7. The system comprises a battery, a plurality of motors driven by electric power stored in the battery, and a controller adapted to control a drive voltage applied to each of the motors by means of a PWM method in which a load is adjusted, wherein, when a state of charge of the battery is equal to or less than a predetermined reference value, the controller is adapted to calculate a current power consumption of each of the motors and readjust a power supply to each of the motors based on the current power consumption of each of the motors.

[0019] The controller sets a first priority for the power supply between the motors based on the current power consumption of each of the motors, and a motor whose current power consumption is lower than the current power consumption of other motors is assigned a lower power supply by the controller.

[0020] The controller sets a second priority based on an evaluation of each of the motors, and the controller is adapted to calculate an integrated priority based on the first and second priorities and compare the integrated priorities, wherein a higher reduction rate for the current supply is applied by the controller to a corresponding motor for which the integrated priority is lower than the integrated priority of other motors.

[0021] If motors with the same built-in priority exist, the controller will apply a higher current reduction rate to a motor where the first priority is low.

[0022] Subclaims relate to preferred embodiments. Each of the first and second priorities can be set such that priority values ​​from 1 to n (where n is a natural number corresponding to the number of motors) are assigned, starting from a motor with the highest priority, in sequential order by means of the controller. The controller is adapted to combine priority values ​​according to the first priority and priority values ​​according to the second priority to apply a higher reduction rate for the current supply to a corresponding motor for which a combined priority value is higher than a combined value for other motors.

[0023] If the same combined priority value is found for different motors, the controller is capable of applying a higher current reduction rate to a corresponding motor where the priority value of the first priority is higher than the priority value of the first priority assigned to other motors.

[0024] As apparent from the above description, the method and system for controlling motors can actively control the driving of motors taking into account the running state of a vehicle and an effect of power consumption of each of the motors when it is desired to reduce the power consumption of the motor due to the low state of charge of a battery.

[0025] Therefore, the method and system for controlling motors can prevent the vehicle from turning off due to excessive battery discharge by reducing the consumption of the battery while causing a reduced influence on the vehicle's running even when the battery's charge level is reduced, and can prevent an internal combustion engine or electric power parts thereof from being damaged due to insufficient drive of the motors and resulting deterioration of a cooling performance of the vehicle.

[0026] Further areas of applicability will become apparent from the description provided herein. It is to be understood that the description and specific examples are provided for purposes of illustration only and are not intended to limit the scope of the present disclosure. FIGURES

[0027] In order that the disclosure may be readily understood, various embodiments of the same exemplary nature will now be described, with reference to the accompanying drawings, in which: Fig. 1 is a block diagram showing a system for controlling according to an embodiment of the present disclosure; Fig. 2 is a flowchart illustrating a method for controlling motors according to another embodiment of the present disclosure; and Fig. 3A to 3C are views for explaining a concept of calculating current consumptions of engines in the method and system for controlling engines according to an embodiment of the present disclosure.

[0028] The drawings described herein are for illustrative purposes only and are not intended to limit the present disclosure in any way. DETAILED DESCRIPTION

[0029] This description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that reference characters refer to the same or corresponding parts and features throughout the figures.

[0030] A method and system for controlling engines according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings.

[0031] Fig. 1 is a block diagram showing a system for controlling motors according to an embodiment of the present invention.

[0032] As in Fig. 1, the system for controlling motors may include a battery 20 that stores electrical energy, a plurality of motors 30, 40, and 50 that are driven by the electrical power supplied from the battery 20, and a controller 10 that allows the electrical energy stored in the battery 20 to be supplied to the motors 30, 40, and 50.

[0033] The battery 20 is a component provided for storing electrical energy, and it can be used as a power source for a plurality of electronic parts provided in the vehicle, and also for the motors 30, 40 and 50, as shown in Fig. 1 shown.

[0034] The motors 30, 40 and 50 are some of the electronic components of the vehicle and may include a motor 30 that rotates a cooling fan of a radiator of the vehicle, a motor 40 that drives an AAF (active air flap), and a motor 50 that is provided in an EWP (electric water pump) for circulating coolant.

[0035] The controller 10 is a unit for controlling the drive power supplied from the battery 20 to the motors 30, 40 and 50. Fig. 1 shows that the controller 10 includes an EMS (engine management system) 11 that controls the motor 30 provided in the cooling fan and the motor 40 provided in the AAF, and an MCU (motor control unit) 12 that controls the motor 50 provided in the EWP. However, these components represent only some of the components of the controller 10, and the present disclosure is not limited thereto. The present disclosure may be embodied in various ways without departing from the spirit and scope of the present disclosure.

[0036] As in Fig. 1, the EMS 11 may control the motor 30 provided in the cooling fan and the motor 40 provided in the AAF, which are components related to cooling an internal combustion engine, and the MCU 12 may control the motor 50 provided in the EWP used to circulate coolant for cooling a power electric part used to activate a drive motor used to drive an electric vehicle or a hybrid vehicle.

[0037] According to the Fig. 1, the motors can be controlled by cooperative control of the EMS 11 and the MCU 12, which are two components of the controller.

[0038] Specifically, the controller 10 may control the motors 30, 40, and 50 by applying a drive voltage to each of the motors using a PWM (pulse width modulation) method in which a load is adjusted. Typically, a motor may be controlled using a PWM method or using CAN (controller area network) communication. In the embodiment of the present disclosure, the motors are controlled using the PWM method to eliminate the disadvantages of CAN communication (a limitation on the number of controllers for preventing or preventing communication delay and failure, and the high cost required to implement the same) and similarly calculate the power consumption of the motors.

[0039] In more detail, the controller 10 may determine a state of charge (SOC) of the battery 20 and readjust the drive power supplied to the motors 30, 40, and 50 when the state of charge of the battery 20 is equal to or less than a predetermined reference value. The controller 10 may readjust the drive power supplied to the motors 30, 40, and 50 by controlling the PWM loads of the drive power.

[0040] For example, when the state of charge of the battery 20 is equal to or lower than the reference value, the controller 10 may reduce the drive power applied to the motors 30, 40, and 50 to reduce a discharge amount of the battery 20, and may reduce the PWM loads of the drive power applied to the motors 30, 40, and 50 to thereby delay a discharge rate of the battery 20. In the process of reducing the PWM loads of the drive power applied to the motors 30, 40, and 50, the controller 10 controls the drive powers of the motors 30, 40, and 50 at different reduction rates for each of the motors, taking into account the driving state of the vehicle and the effect of battery consumption by the motors, instead of using the same reduction rate for all the motors.

[0041] Hereinafter, a method for controlling motors will be described in detail to help understand the operation and effect of the system for controlling motors having the above configuration according to the embodiment of the present disclosure.

[0042] Fig. Figure 2 is a flowchart illustrating a method for controlling motors according to an embodiment of the present disclosure. In this embodiment, the same reference numerals are used to denote the same or corresponding parts as the previous embodiment.

[0043] First, the controller 10 determines whether the state of charge of the battery 20 is equal to or lower than a predetermined reference value A (S11). Fig. 1 shows that the controller 10 determines the state of charge of the battery 20 by the voltage supplied directly thereto. However, the controller 10 may receive information about the state of charge of the battery, or may be informed that the state of charge of the battery is equal to or lower than a predetermined reference value A, from a BMS (Battery Management System), which is a separate controller provided for managing the battery 20.

[0044] Next, the controller 10 may calculate the current consumption of each of the motors 30, 40, and 50 (S12 and S13). Since the controller 10 controls the motors 30, 40, and 50 depending on the vehicle's driving state, such as the temperature of an engine coolant or the temperature of the electronic power unit, the current current consumption of the motors 30, 40, and 50 may reflect the vehicle's current driving state.

[0045] Since the motors 30, 40 and 50 are driven by PWM control as described above, the controller 10 can easily calculate the current consumptions taking into account a duty and a time period for maintaining the duty load in the PWM control.

[0046] Fig. 3A to 3C are views for explaining a concept of calculating current consumption of engines in the method and system for controlling engines according to the embodiment of the present disclosure.

[0047] As in Fig. 3A, the signal for controlling each of the motors 30, 40, and 50 may be applied as a square wave with an on / off load by means of the control by the controller 10. In response to the PWM control signal, a current is applied to each of the motors 30, 40, and 50. As shown in Fig. 3B, the current may increase slightly, rather than suddenly (“instantaneous”) during the on-load. As shown in Fig. As shown in Figure 3C, the current can decrease slightly by means of a regenerative component when the off-load is initiated.

[0048] The drive current of each of the motors 30, 40, and 50 has a specific pattern corresponding to the on / off state of the PWM control signal. The slightly reduced current during the off-load condition can compensate for the slightly increased current during the on-load condition. As shown in Fig. As shown in Figure 3C, the current consumption for one cycle of the PWM control signal can be calculated by multiplying a time duration of the on-load and a maximum current value at the on-load.

[0049] If it is determined that the controller 10 is capable of calculating the current power consumption of the motors 30, 40 and 50 in step S12, the controller 10 can calculate the current power consumptions of the respective motors 30, 40 and 50 using the method described with reference to Fig. 3a to 3C above and can set a first priority in the order in which the current power consumptions are high in step S13.

[0050] Next, if it is determined that the controller 10 is capable of readjusting the power consumptions of the motors 30, 40, and 50 using only the first priority (S14), the controller 10 may readjust the power supply to the motors 30, 40, and 50 using the first priority (S16).

[0051] For example, in step S16, if the motor 30 provided in the cooling fan has the first highest priority, the motor 50 provided in the EWP has the first intermediate priority, and the motor 40 provided in the AAF has the first lowest priority, the controller 10 determines that the drive of the motor 30 provided in the cooling fan is most desired during vehicle travel. Therefore, the controller 10 may allow the current power consumption of the motor 30 provided in the cooling fan to be maintained (there is no reduction in drive power), allow the drive power of the motor 50 provided in the EWP to be reduced to a power level of 70%, and allow the drive power of the motor 40 provided in the AAF to be reduced to a power level of 50%.

[0052] The reduction rate of the driving power according to the first priority may be set in advance and may be varied differently depending on the driving environment or a continuous state of the vehicle.

[0053] However, if it is determined that the controller 10 is unable to calculate the current power consumptions of the motors 30, 40 and 50 to set the first priority in step S12, or if it is determined that it is desirable to consider a second priority (there is a small difference between the current power consumptions of the motors 30, 40 and 50) in step S14, the controller 10 may set a second priority.

[0054] The second priority may be set taking into account an effect of the current consumption of the vehicle by the motors 30, 40, and 50 in step S15, and the controller 10 may set the second priority depending on the evaluation of the motors 30, 40, and 50. For example, if it is desired to reduce the consumed battery 20 to as low a level as possible due to the low state of charge of the battery 20, the controller 10 may set the second priority in the order in which the evaluated power consumptions of the motors 30, 40, and 50 are low in step S15.

[0055] When both the first and second priorities are set, the controller 10 may set a final integrated priority taking the first and second priorities into consideration together in step S16.

[0056] To set the final priority, the controller 10 may set both the first and second priorities by assigning priority values ​​from 1 to n (where n is a natural number corresponding to the number of a plurality of motors) in sequential order, starting from a motor with the highest priority. Next, the controller 10 may set the final integrated priority by adding priority values ​​depending on the first priority and priority values ​​depending on the second priority. Here, the integrated priority is set so that the motor with the added lowest priority has the highest priority.

[0057] In order for the integrated priority to be high (the added priority values ​​are low), the current reduction rate supplied to a corresponding motor can be set larger by means of the controller 10.

[0058] Meanwhile, in step S16, if there are motors with the same integrated priority, the controller 10 may determine the current reduction rate supplied to each of the motors 30, 40, and 50 based on the first priority. That is, if the result obtained by adding priority values ​​according to the first priority and priority values ​​according to the second priority is the same, the current reduction rate supplied to a corresponding motor may be adjusted by the controller 10 so that the higher the priority values ​​according to the first priority (the lower the priority), the higher the current reduction rate supplied to a corresponding motor.

[0059] Next, the controller 10 may reduce the power consumptions of the motors 30, 40, and 50 by considering the power reduction rate determined in step S16 and by changing the load of the PWM signal for controlling each of the motors 30, 40, and 50.

[0060] As described above, the method and system for controlling motors according to embodiments of the present disclosure can actively control the drive of the motors taking into account the running state of the vehicle and the effect of power consumption of each of the motors when it is desired to reduce the power consumption of the motor due to the low state of charge of the battery.

[0061] Therefore, the method and system for controlling motors can reduce or prevent the vehicle from turning off or shutting down due to excessive battery discharge by reducing the consumption of the battery while exerting a reduced influence on the vehicle's travel even though the battery's state of charge is reduced, and can prevent or reduce damage to the internal combustion engine or the electronic power parts thereof due to insufficient drive of the motors and therefore deterioration of a cooling performance of the vehicle.

Claims

[1] A method for controlling a plurality of motors provided in a vehicle, comprising the steps of: Determining (S11) by means of a controller, a state of charge of a battery suitable for storing power supplied to each motor of a plurality of motors, Calculating (S12) by means of the controller, a current power consumption of each motor of the plurality of motors when the state of charge of the battery is identical to or less than a predetermined reference value; readjusting (S16), by means of the controller, a power supply to each motor of the plurality of motors based on the current power consumption of each motor of the plurality of motors; wherein the step of calculating the current power consumption comprises a step (S13) of setting a first priority for power supply between the plurality of motors based on the current power consumption of each motor of the plurality of motors; the step of calculating the current power consumption further comprises a step (S15) of setting a second priority based on a rating of each motor of the plurality of motors, after the step (S13) of setting the first priority; and the step of readjusting (S16) the power supply further comprises a step of calculating an integrated priority based on the first and second priorities of each motor of the plurality of motors and comparing the integrated priorities, wherein a higher reduction rate of power is employed for a corresponding motor in which the integrated priority is lower than the integrated priority of other motors. [2] The method according to claim 1, wherein an electric power is supplied to each motor of the plurality of motors by applying a drive voltage by a PWM method in which a load is adjusted. [3] A method according to any one of the preceding claims, wherein the step of readjusting (S16) the power supply comprises a step of allocating a lower power supply to a motor whose current power consumption is lower than the current power consumption of other motors of the plurality of motors. [4] The method according to claim 1, wherein in the step of readjusting (S16) the current supply, when motors with the same integrated priority exist, a higher reduction rate of current is applied to a motor for which the first priority is low. [5] A method according to claim 1, wherein: both the first and second priorities are set (S13, S15) so that priority values ​​from 1 to n are assigned, starting from a motor with the highest priority, in sequential order; and in the step of readjusting (S16) the current supply, based on a result determined by combining priority values ​​depending on the first priority and priority values ​​depending on the second priority, a higher reduction rate of current is used for a corresponding motor for which the integrated priority is higher than an integrated priority of other motors, where n is a natural number corresponding to the number of motors. [6] The method according to claim 5, wherein in the step of readjusting (S16) the current supply, when the same combined priority value is found for different motors, a higher reduction rate of current is applied to a motor for which the priority value of the first priority is higher than the priority value of the first priority assigned to other motors. [7] System for controlling engines, comprising: a battery (20); a plurality of motors (30, 40, 50) driven by electrical power stored in the battery (20); and a controller (10) adapted to allow the electric power stored in the battery (20) to be supplied to each of the motors (30, 40, 50) depending on a driving condition of a vehicle, and to control a drive voltage applied to the motors (30, 40, 50), wherein, when a state of charge of the battery (20) is identical to or less than a predetermined reference value, the controller is adapted to calculate a current power consumption of each of the motors (30, 40, 50) and to readjust a power supply to each of the motors (30, 40, 50) based on the current power consumption of each of the motors (30, 40, 50), wherein the controller (10) is adapted to set a first priority for power supply between the motors (30, 40, 50) based on the current power consumption of each of the motors (30, 40, 50), and a lower power supply is assigned by the controller to a motor (30, 40, 50) whose current power consumption is lower than the current power consumption of other motors (30, 40, 50), and the controller (10) is adapted to set a second priority based on an evaluation of each of the motors, and the controller is adapted to calculate an integrated priority based on the first and second priorities and to compare the integrated priorities, wherein the controller assigns a higher reduction rate of current supply to a corresponding motor for which the integrated priority is lower than the integrated priorities of other motors. [8] A system according to claim 7, wherein, when motors with the same integrated priority exist, the controller (10) applies a higher reduction rate of current supply to a motor for which the first priority is low. [9] A system according to claim 7 or 8, wherein both the first and second priorities are set so that priority values ​​from 1 to n are assigned, starting from a motor with the highest priority, in sequential order, by means of the controller (10), and the controller (10) is adapted to combine priority values ​​depending on the first priority and priority values ​​depending on the second priority, and to apply a higher reduction rate of current supply to a corresponding motor for which a combined priority value is greater than a combined value of other motors, where n is a natural number corresponding to the number of motors. [10] A system according to claim 9, wherein, when the same combined priority value is found for different motors, the controller (10) is adapted to apply a higher reduction rate of current supply to a corresponding motor for which the priority value of the first priority is greater than the priority value of the first priority assigned to other motors.

Images