KR102726817B1 - Power control method for electrical device of electric vehicle - Google Patents

Abstract

The present invention relates to a method for controlling the output of an electric device of a vehicle, and its main purpose is to provide a method for controlling the output of an electric device of a vehicle, which can prevent problems such as short-circuiting or disconnection due to current from occurring in a component or location having a low allowable standard value in an electric device of an electric vehicle. In order to achieve the above-mentioned purpose, a method for limiting the output of an electric device of a vehicle is disclosed, which includes: a step in which a controller acquires a predetermined value among the power and current of an electric device in a vehicle and determines a driver's required power according to a driver's driving input; a step in which the controller determines a current vehicle state based on the determined driver's required power; a step in which the controller determines whether an output state of an electric device satisfies a predetermined allowable condition according to the current vehicle state using the acquired power or current value information; a step in which the controller determines that the output state of the electric device does not satisfy the predetermined allowable condition, and a step in which the controller limits the output of the electric device if the controller determines that the output state of the electric device is abnormal.

Description

{Power control method for electrical device of electric vehicle}

The present invention relates to a method for controlling the output of an electric device of a vehicle, and more specifically, to a method for controlling the output of an electric device of a vehicle capable of preventing problems such as short circuits or disconnection due to current from occurring in components or locations having low tolerances in the electric device of an electric vehicle.

Today, the spread of electric vehicles driven by motors is becoming more active worldwide due to environmental regulations.

Electric vehicles include hybrid electric vehicles (HEV), battery electric vehicles (BEV), and fuel cell electric vehicles (FCEV).

The above-mentioned electric vehicles have in common that they use a motor as a driving device to drive the vehicle and have a battery that supplies electricity to the motor.

Also known as hybrid vehicles are plug-in hybrid vehicles (PHEVs), and plug-in hybrid vehicles (PHEVs) and battery electric vehicles (BEVs) are plug-in electric vehicles that charge their batteries by receiving electricity from an external source.

To charge the battery that powers the vehicle in a plug-in electric vehicle, a direct current (DC) power source (rapid charging equipment) can be directly connected to the battery for rapid charging, or an alternating current (AC) power source can be connected to the vehicle for slow charging.

In rapid charging, rapid charging equipment that uses direct current (DC) power is designed to convert alternating current power into direct current power and supply it to the vehicle. Since it is directly connected to the vehicle battery and provides high current, it can complete charging of the vehicle battery in a short period of time.

On the other hand, in the slow charging method, AC power is supplied to the vehicle using a commercial AC power source connected to the distribution system, and the AC power is converted to DC power within the vehicle to charge the battery.

When applying the slow charging method, the AC power supplied by the commercial AC power source must be converted into DC power in terms of form and size, so a charger (On-Board Charger, OBC) with a circuit configuration of a power conversion system is installed in the vehicle.

When the above vehicle charger is connected to an AC power source, the charger converts AC power into DC power and simultaneously converts it into a current and voltage suitable for charging a high-voltage battery, thereby charging the high-voltage battery.

In addition, the vehicle is equipped with a battery management system (BMS) that monitors and manages the status and operation of the battery, and the battery controller collects battery status information through sensors and circuits, and performs various controls for battery management, such as charge and discharge control.

For example, a battery management system collects and acquires battery status information such as battery voltage, current, temperature, and state of charge (SOC), and provides the collected battery status information to other controllers inside and outside the vehicle so that it can be used for vehicle control or charging control.

FIG. 1 is a block diagram illustrating electric devices mounted on an electric vehicle. As illustrated, a battery (11) that serves as a power source (electric power source) within the vehicle, a motor (13) that drives the vehicle, an inverter (12) for operating and controlling the motor (13), an air conditioner (A/C) or heater (15) that is a high-voltage electrical component, a DC-DC converter (16) that converts electric power from the battery (11) and supplies it to other electric devices within the vehicle, and an on-board charger (17) for charging the battery are illustrated.

Here, the battery (11) is connected to the motor (13) via an inverter (12) so that it can be charged and discharged, and the inverter (12) converts the direct current of the battery (13) into a three-phase alternating current and applies it to the motor (13) to drive the motor (13).

The above motor (13) is connected to the driving wheel (14) to drive the vehicle, and when the vehicle is braking or coasting due to inertia, the motor (13) receives rotational power from the driving wheel (14) and operates to generate electricity and charge the battery (11).

The above air conditioner or heater (15) and DC-DC converter (16) are high-voltage electrical devices that operate by receiving high-voltage power from the battery (11), just like the inverter (12) and motor (13).

Meanwhile, in an electric vehicle equipped with a battery (11), a motor (13), and other high-voltage electrical devices, a protective device is required to protect the electrical devices.

In an electric vehicle, a protective device may include a fuse (18) installed in each electric device, and the fuse (18) protects the electric device by cutting off the current by short-circuiting the circuit when a current exceeding the allowable value flows.

In addition, in order to protect each electrical device installed in an electric vehicle, safety control such as power cut-off is performed when a current or voltage exceeding the set value is observed in the electrical device.

As described above, conventionally, a protection element (a fuse or an element with a function similar to a fuse) is installed in each individual electrical device, and when a current exceeding the allowable value occurs, the current is cut off by the protection element, thereby protecting the individual device.

However, in this case, problems such as open circuits or short circuits may occur in parts or locations with lower allowable standards within each unit before the allowable current limit is reached.

For example, if a 50A fuse is installed in the air conditioner as a protective device, and a current of 40A continuously flows to the air conditioner, the protective device will not block the current because the 40A current is within the allowable standard, but even if the current is within the allowable standard, it can cause a problem in a vulnerable location within the air conditioner.

Accordingly, the present invention has been created to solve the above problems, and its purpose is to provide a method for controlling the output of an electric device of an electric vehicle, which can prevent problems such as short circuits or disconnection due to current from occurring in components or locations with low allowable standards in the electric devices of an electric vehicle.

In order to achieve the above object, according to an embodiment of the present invention, a method for limiting output of an electric device of a vehicle is provided, including: a step in which a controller acquires a predetermined value among power and current of an electric device in a vehicle and determines a driver's required power according to a driver's driving input; a step in which the controller determines a current vehicle state based on the determined driver's required power; a step in which the controller determines whether an output state of an electric device satisfies a predetermined allowable condition according to the current vehicle state using the acquired power or current value information; a step in which the controller determines that the electric device is in an abnormal output state if the controller determines that the output state of the electric device does not satisfy the predetermined allowable condition; and a step in which the controller limits the output of the electric device if the controller determines that the electric device is in an abnormal output state.

Accordingly, according to the method for controlling the output of an electric device of a vehicle according to the present invention, when the output of each electric device in an electric vehicle is determined to be abnormal, the electric device and the vehicle system can be effectively protected by limiting the output of the corresponding electric device.

Figure 1 is a block diagram illustrating electric devices mounted on an electric vehicle.
Figure 2 is a flowchart showing an example of how to limit the output of an electric device when the vehicle is in a driving state.
FIG. 3 is a flowchart showing a method for controlling the output of an electric device of an electric vehicle according to an embodiment of the present invention.
Figure 4 is a diagram showing an example of normal battery output according to each vehicle status of driving, regeneration, stop, and charging in an electric vehicle.
FIG. 5 is a drawing showing an example of applying the control method of the present invention when there is an abnormal output situation of battery power in each vehicle state of driving, regeneration, stop, and charging in an electric vehicle.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

When a part of a specification is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

The present invention relates to a method for controlling the output of an electric device of an electric vehicle. The main feature of the present invention is that the power or current of each electric device mounted on the vehicle is estimated or measured through calculation to obtain the power or current, and then, based on the obtained power value or current value information, it is determined whether a set allowable condition according to the current vehicle state is satisfied, and if the allowable condition is not satisfied, the output (power) of the corresponding electric device is limited.

In the following description, electrical devices, individual components, parts, and electrical components may be interpreted with the same meaning unless specifically defined otherwise.

In addition, in the description below, the electric device that is the target of the output control according to the present invention may be a battery and an electrical component that consumes power from the battery, which is mounted on a typical electric vehicle.

In addition, in the following description, an electric device that is a target of output control according to the present invention will be described with reference to Fig. 1.

Specifically, the electric device that is the target of output control in the present invention may be a high-voltage component that consumes power of a high-voltage main battery (11) in an electric vehicle, and more specifically, may include a motor (13) that drives the vehicle, an inverter (12) for operating and controlling the motor (13), a power-consuming device (15) that operates while consuming power of the battery (11), and a DC-DC converter (16) that converts power of the battery (11) and supplies it to other electrical loads in the vehicle.

Among the above-mentioned electric devices, the motor (13) is connected to the battery (11), which is the power source of the vehicle, through the inverter (12) so that it can be charged and discharged, and the DC-DC converter (16) is also connected to the battery (11) so that it can convert the power of the battery (11) and supply it to an auxiliary battery or other electric devices.

The above power consumption device (15) may include an air conditioner or heater (15) connected to a battery (11) so that it can operate by receiving power from the battery (11).

In addition, as described below, since output (power) limitation is performed during charging, the electric device in the present invention does not consume power from the battery (11), but may include an on-board charger (OBC) (17) for charging the battery.

Figure 2 is a flowchart showing an example in which the output of each electric device (component) can be limited when the vehicle state is in a driving state by dividing the vehicle state into a driving state and a non-driving state.

As illustrated, when the vehicle is in a driving state at step (S1), the power or current of each electric device (part) is estimated or measured through calculation (S2), the estimated or measured value is compared with an allowable value (S3), and if it is higher than the allowable value, the output or power of the electric device is limited (S4).

As described above, it is necessary to differentiate control according to the vehicle status by distinguishing the vehicle status, because the expected system output value is different depending on the vehicle status.

For example, while driving, the power output can be 100%, but when the vehicle is stopped, the power consumption of the vehicle itself is small, so if it is limited to 100% while driving, precise and fine protection control is impossible.

On the other hand, if the expected power consumption when the vehicle is stopped is assumed to be 10% of the power consumption while driving, and the power allowance while the vehicle is stopped is set to 8 to 12% of the power allowance while driving, abnormal output of the vehicle can be monitored even when the vehicle is stopped.

Therefore, it is desirable to distinguish vehicle states in more detail rather than simply dividing them into driving and non-driving states. For example, even in the case of a driving state where there is vehicle speed, there are cases of motor driving and motor regeneration, so it is necessary to distinguish vehicle states in more detail.

Accordingly, in the present invention, the vehicle status is classified in more detail, and the output of each electric device is controlled according to the vehicle status. When a current signal exceeding or below the allowable value is detected in each vehicle unit, the allowable current is limited in each individual unit to protect the vehicle, thereby protecting the entire system so that no abnormality occurs in the vehicle.

Here, an example of abnormal current generation in a vehicle is an abnormal current application that may occur due to a failure of an electrical device component, which may lead to damage to the component or to the entire vehicle.

In addition, if a leakage occurs in a single component due to external leakage or submersion, abnormal current may be applied, which may also lead to damage to the single component or to the entire vehicle.

In addition, during vehicle maintenance, abnormal current may be applied to equipment outside the vehicle or an external power source due to various reasons such as a breakdown of a component, which may result in damage to the component, damage to the entire vehicle, or even injury to the vehicle mechanic.

Therefore, in the present invention, power of each electric device is monitored and, if necessary, the output of the electric device that exceeds the allowable range condition is limited, and the power usage estimate for the power-consuming components of the vehicle is classified and predicted according to each vehicle state, and the allowable current according to each vehicle state is identified so that the system can be protected, thereby enabling detailed and precise protection control for each electric device.

Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings, and FIG. 3 is a flowchart showing a method for controlling the output of an electric device of an electric vehicle according to an embodiment of the present invention.

In an embodiment of the present invention, the vehicle state can be divided into a driving state in which the vehicle is moving and a non-driving state in which the vehicle is stopped without moving.

In addition, the driving state of the vehicle can be subdivided into a driving state and a regenerative state as illustrated, where the driving state is a state in which the vehicle is driving by driving the motor to satisfy the driver's demand torque determined according to the driver's driving input.

In addition, the regenerative state is a state in which the known regenerative mode is being performed in which the motor receives rotational power from the driving wheels and generates power to charge the battery when the vehicle is braking or coasting due to inertia.

Additionally, the non-driving state can be subdivided into a stationary state where the vehicle is stopped without charging, and a charging state where the battery is charged through an on-board charger (OBC) using an external power source while the vehicle is stopped.

And, in an embodiment of the present invention, the electric device may be an electric device in an electric vehicle that is predetermined for output control, and may be at least one or two or more of a battery (11), an inverter (12), a motor (13), a power consumption device (15), a DC-DC converter (16), and a charger (OBC) (17).

Here, the motor (13) is a vehicle driving source, i.e., a driving device that drives the vehicle, and is a motor (i.e., a driving motor) that is connected to the driving wheel (14) so as to be able to transmit power, and may be a single or multiple motors.

In addition, the power consumption device (15) may be a known high-voltage electrical component that consumes battery power in a typical electric vehicle, for example, an air conditioner (A/C) or a heater, and the air conditioner may specifically be an air conditioner compressor.

In this way, in the embodiment of the present invention, the power-consuming device may be an air conditioner or a heater (15), but this is merely exemplary and the present invention is not limited thereto. In addition to the air conditioner or heater (15), any device that is mounted on an electric vehicle and consumes battery power may be one of the power-consuming devices subject to output control.

In addition, although it has been described above that the electric device includes at least one or two or more of a battery (11), an inverter (12), a motor (13), a power consumption device (15), a DC-DC converter (16), and a charger (17), the types of these electric devices are also exemplary, and the present invention is not limited thereto, and in addition to these, other electric devices mounted on an electric vehicle may be added.

Below, an example will be explained in which the electric device is a battery (11), an inverter (12), two motors (first motor and second motor) (13), an air conditioner or heater (15), and a charger (OBC) (17).

The output control process of the present invention can be performed by a controller in a vehicle, and the controller calculates or measures and acquires a predetermined value among the power and current of each electric device (part) as shown in Fig. 3, while the vehicle is powered on, and further calculates the driver's required power (or vehicle power) according to the driver's driving input (S11).

Here, the power value of each electric device may be a power value estimated or measured for each electric device (part) in the vehicle, and for example, may be a power value obtained based on voltage and current information detected through detection elements such as sensors or circuits for each electric device.

In the present invention, the power value or current value can be acquired for each electric device set as the output limitation target, and in the case of a vehicle equipped with two or more motors, the power value or current value can be acquired for each motor.

In an embodiment of the present invention, the power (W) of the battery can be calculated as the product of the battery current (A) and the battery voltage (V).

Additionally, the power (W) of the inverter can be calculated as the product of the inverter input current (A) and the inverter input voltage (V) or the product of the inverter output current (A) and the inverter output voltage (V).

Additionally, the power (W) of the first motor can be calculated as the product of the first motor applied current (A) and the first motor voltage (V), or as the value of 'output torque of the first motor × output speed of the first motor (rpm) × 2π/60'.

Additionally, the power (W) of the second motor can be calculated as the product of the second motor applied current (A) and the second motor voltage (V), or as the value of 'second motor output torque × second motor output speed (rpm) × 2π/60'.

Additionally, the power (W) of the air conditioner can be calculated by the product of the air conditioner current (A) and the air conditioner voltage (V), and the heater power (W) can be calculated by the product of the heater current (A) and the heater voltage (V).

Additionally, the power (W) of the DC-DC converter can be calculated by multiplying the current (A) and voltage (V) of the DC-DC converter.

Next, the controller determines the current vehicle status (S12, S15), and at this time, one of the four modes, i.e., driving, regeneration, stopping, and charging, can be determined to represent the current vehicle status.

In an embodiment of the present invention, the controller may be set to determine that the vehicle state is in a driving state if the driver demand power (W) is greater than 0 and the vehicle speed is not 0.

Additionally, the controller can be configured to determine that the vehicle condition is regenerative if the driver demand power is less than zero and the vehicle speed is not zero.

Additionally, the controller may be set to determine that the vehicle state is stopped if the driver demand power, vehicle speed, and charger input power are all 0, and may be set to determine that the vehicle state is charged if the driver demand power and vehicle speed are 0 but the charger input power is greater than 0.

Here, the driver demand power (W) can be determined from vehicle driving information, where the vehicle driving information can include driver pedal input information and vehicle speed, and where the driver pedal input information can be an accelerator pedal input value and a brake pedal input value.

The above accelerator pedal input value may be a value (i.e., an APS value) obtained from a signal of an accelerator pedal sensor (APS) installed in the accelerator pedal, and the above brake pedal input value may be a value (i.e., a BPS value) obtained from a signal of a brake pedal sensor (BPS) installed in the brake pedal.

The driver demand power (W) can be obtained from the driving power map based on the current accelerator pedal input value (APS value) and vehicle speed, or from the braking power map based on the current brake pedal input value (BPS value) and vehicle speed.

As described above, the current vehicle state is determined as one of driving, regeneration, stop, and charging. However, the vehicle state is not limited to driving, regeneration, stop, and charging. In addition to driving, regeneration, stop, and charging, other driving modes in which output limitation of the electric device can be performed as needed in the present invention may be added as vehicle states.

Next, using the acquired power value or current value information, it is determined whether the output status of the electric device and system satisfies the set allowable conditions according to the current vehicle status (S13.S18), and if the allowable conditions are not satisfied, it is determined that the output of the electric device is abnormal.

At this time, the system tolerance based on the power or current value is determined according to the current vehicle status, and the tolerance information according to the determined current vehicle status is used to determine whether the current output status of the electric device and system indicated by the acquired power value or current value information satisfies the tolerance condition.

Additionally, in an embodiment of the present invention, the allowable value information can be determined from the driver demand power or the vehicle power, and when the vehicle state is a charging state, the allowable value of the charging state can be determined from the charger output power or the charger input power.

Here, the vehicle power (W) can be obtained as the change in vehicle kinetic energy (ΔE _k ), and the vehicle kinetic energy (E _k ) can be calculated by the equation 'E _k = (1/2) × m × v ² + m × g × sinθ'.

Here, m is the vehicle weight, v is the vehicle speed, g is the acceleration due to gravity, and θ is the incline angle of the road.

The vehicle weight (m) can be pre-input into the controller as a vehicle specification value and used, and the vehicle speed (v) and inclination angle (θ) can be obtained from sensor signals within the vehicle.

The above charger input power (W) can be calculated as the product of the charger input current (A) and the charger input voltage (V), and the above charger output power (W) can be calculated as the product of the charger output current (A) and the charger output voltage (V).

When the vehicle state is a driving state, the allowable value can be obtained from the driver demand power and the driving safety upper limit coefficient or the vehicle power and the driving safety upper limit coefficient, and specifically, it can be calculated as the value of 'driver demand power × (1 + α _d )' or 'vehicle power × (1 + β _d )'.

Here, α _d and β _d represent the driving safety upper limit coefficients, and these values are preset to the controller as positive values.

Alternatively, instead of the driving safety upper limit coefficient, a driving safety lower limit coefficient can be used, in which case the allowable value of the driving state can be calculated as the value of 'driver demand power × (1 - γ _d )' or 'vehicle power × (1 - δ _d )'.

Here, γ _d and δ _d represent the driving safety lower limit coefficients, and these values are preset to the controller as positive values.

Ultimately, the allowable condition when the vehicle is in the driving state can be set as the condition of 'Driver demand power × (1 + α _d ) or vehicle power × (1 + β _d ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)'.

Alternatively, the allowable condition when the vehicle is in the driving state can be set as the condition of 'Driver demand power × (1 - γ _d ) or vehicle power × (1 - δ _d ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)'.

Accordingly, if the controller determines that the electric device is in an abnormal output state when the vehicle state is in a driving state and does not satisfy the above-mentioned allowable conditions, it restricts the output as described below (S14).

Next, when the vehicle state is a regenerative state, the allowable value can be obtained from the driver demand power and the regenerative safety upper limit coefficient or the vehicle power and the regenerative safety upper limit coefficient, and specifically, it can be calculated as the value of 'driver demand power × (1 + α _r )' or 'vehicle power × (1 + β _r )'.

Here, α _r and β _r represent the regenerative safety upper limit coefficients, and these values are preset to the controller as positive values.

Alternatively, instead of the regenerative safety upper limit coefficient, a regenerative safety lower limit coefficient can be used, in which case the allowable value of the regenerative state can be calculated as the value of 'driver demand power × (1 - γ _r )' or 'vehicle power × (1 - δ _r )'.

Here, γ _r and δ _r represent the regenerative safety lower limit coefficients, and these values are preset to the controller as positive values.

Ultimately, the allowable condition when the vehicle is in a regenerative state can be set as the condition of 'Driver demand power × (1 + α _r ) or vehicle power × (1 + β _r ) < (battery power or inverter power or motor power) + (air conditioner power or heater power + DC-DC converter power)'.

Alternatively, the allowable condition when the vehicle is in a regenerative state can be set as the condition of 'Driver demand power × (1 - γ _r ) or vehicle power × (1 - δ _r ) < (battery power or inverter power or motor power) + (air conditioner power or heater power + DC-DC converter power)'.

Accordingly, if the controller determines that the electric device is in an abnormal output state when the above allowable conditions are not satisfied when the vehicle is in a regenerative state, it limits the output as described below (S19).

Next, when the vehicle status is stationary, the allowable value can be obtained from the driver demand power and the stationary safety upper limit coefficient or the vehicle power and the stationary safety upper limit coefficient, and specifically, it can be calculated as the value of 'driver demand power × (1 + α _S )' or 'vehicle power × (1 + β _S )'.

Here, α _S and β _S represent the upper limit safety coefficients of the stopping power, and they are preset to the controller as positive values.

Alternatively, instead of the upper stall safety limit coefficient, a lower stall safety limit coefficient can be used, in which case the allowable value of the stall state can be calculated as the value of 'driver demand power × (1 - γ _S )' or 'vehicle power × (1 - δ _S )'.

Here, γ _S and δ _S represent the stopping safety lower limit coefficients, which are preset to the controller as positive values.

Finally, the allowable condition when the vehicle is stationary can be set as the condition of 'Driver demand power × (1 + α _S ) or vehicle power × (1 + β _S ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)'.

Alternatively, the allowable condition when the vehicle is stationary can be set as the condition of 'Driver demand power × (1 - γ _S ) or vehicle power × (1 - δ _S ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)'.

Accordingly, if the controller determines that the electrical device is in an abnormal output state when the above allowable conditions are not satisfied while the vehicle is stopped, it limits the output as described below (S16).

Next, when the vehicle status is a charging status, the allowable value can be obtained from the charger output power and the charging output safety upper limit coefficient or the charger input power and the charging input safety upper limit coefficient, and specifically, it can be calculated as the value of 'charger output power × (1 + α _c )' or 'charger input power × (1 + β _c )'.

Here, α _c represents the charging output safety upper limit coefficient, and β _c represents the charging input safety upper limit coefficient, and these values are preset to the controller as positive values.

Alternatively, instead of the charging output safety upper limit factor and the charging input safety upper limit factor, the charging output safety lower limit factor and the charging input safety lower limit factor can be used, in which case the allowable value of the charging state can be calculated as the value of 'charger output power × (1 - γ _c )' or 'charger input power × (1 - δ _c )'.

Here, γ _c represents the charging output safety lower limit coefficient, and δ _c represents the charging input safety lower limit coefficient, and these values are preset to the controller as positive values.

Ultimately, the allowable condition when the vehicle is in a charging state can be set as the condition of 'charger output power × (1 + α _c ) or charger input power × (1 + β _c ) < (battery power + air conditioner power or heater power + DC-DC converter power)'.

Alternatively, the allowable condition when the vehicle is in a charging state can be set as the condition of 'charger output power × (1 - γ _c ) or charger input power × (1 - δ _c ) < (battery power + air conditioner power or heater power + DC-DC converter power)'.

Accordingly, if the controller determines that the electric device is in an abnormal output state when the vehicle status is in a charging state and does not satisfy the above-mentioned allowable conditions, it restricts the output as described below (S17).

Meanwhile, if the output status from the acquired power value or current value information does not satisfy the allowable conditions according to the current vehicle status, control is performed to limit the output of each electric device according to the current vehicle status, which will be described in detail below.

First, when the output (power) limit is not applied while the vehicle is driving, the power of the electric device can be output within a set first percentage of the total allowable power, for example, 100%, where the total allowable power can be the maximum output value of the entire electric system of the vehicle preset in the controller.

On the other hand, when output limitation is implemented, the output is limited to a value corresponding to a set second percentage of the total allowable power.

For example, it limits the output of electrical devices to 20% of the total allowable power while driving, allowing emergency evacuation while the vehicle is in motion.

Next, when the output (power) is not limited during vehicle regeneration (braking), the power of the electric device can be output up to a set third percentage of the total allowable power, for example, 50%, where 50% of the total allowable power is set as the maximum output of the electric device during regeneration.

On the other hand, when power limitation is implemented, the output of the electric device is limited to 0% of the total permissible power at a level where the hydraulic brakes can operate while driving.

Next, when the output (power) limit is not applied while the vehicle is stopped, the power of the electric device can be output up to a predetermined fourth percentage of the total allowable power, for example, 20%, where 20% of the total allowable power is determined as the maximum output of the electric device while the vehicle is stopped.

On the other hand, when output limitation is implemented, the output of the electrical device is limited to 0% of the total allowable power.

Next, when the output (power) limit is not applied during charging of the vehicle, the power of the electric device can be output up to a set fifth percentage of the total allowable power, for example, 30%, where 30% of the total allowable power is set as the maximum output of the electric device during charging of the vehicle.

On the other hand, when output limitation is implemented, the output of the electrical device is limited to 0% of the total allowable power.

Meanwhile, Fig. 4 is a drawing showing an example of normal battery output according to each vehicle state of driving, regeneration, stop, and charging in an electric vehicle. As shown, when the output of battery power is normally controlled, it can be seen that the battery power is maintained and controlled within the allowable output range (allowable required power range).

On the other hand, FIG. 5 is a drawing showing an example of applying the control method of the present invention when there is an abnormal output situation of battery power in each vehicle state of driving, regeneration, stop, and charging in an electric vehicle.

As illustrated, even if the battery power reaches an abnormal state momentarily in each vehicle state, it can be seen that the battery power is recovered and maintained within the allowable output range (required power allowable range) by limiting the output when it is determined that the battery power is in an abnormal output state according to the control method of the present invention (see the diagram of 'Output when power is limited' in FIG. 5).

In this way, in the present invention, when the output of each electric device in an electric vehicle is determined to be abnormal, output restriction is performed on the corresponding electric device, thereby effectively protecting the electric device and vehicle system.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also included in the scope of the present invention.

11 : Battery
12 : Inverter
13 : Motor
14 : Drive wheel
15: Air conditioning (A/C) or heater
16: DC-DC converter
17: In-vehicle charger (OBC)

Claims (14)

A step in which the controller acquires a predetermined value among the power and current of an electric device in the vehicle and determines the driver's required power according to the driver's driving input;
A step in which the controller determines the current vehicle status based on the determined driver demand power;
A step in which the controller determines whether the output status of the electric device satisfies a set allowable condition according to the current vehicle status using the acquired power or current value information;
A step for determining that the output state of the electric device is abnormal when the controller determines that the output state of the electric device does not satisfy the set allowable condition; and
A method for limiting output of an electrical device of a vehicle, comprising a step of limiting output of the electrical device when the controller determines that the electrical device is in an abnormal output state.
In claim 1,
The above electrical device,
Battery mounted on the vehicle;
Inverter connected to the above battery;
A motor for driving a vehicle, said motor being rechargeably connected to said battery via said inverter;
A power-consuming device connected to the above battery and operating while consuming power from the battery;
a DC-DC converter connected to the above battery; and
A method for limiting the output of an electric device of a vehicle, characterized in that at least one or two on-board chargers (OBCs) connected to the battery are present.
In claim 2,
A method for limiting the output of an electric device of a vehicle, characterized in that when the electric device comprises two or more of the battery, inverter, motor, power consumption device, DC-DC converter, and charger, the steps are individually performed for each electric device by the controller.
In claim 1,
At the step of judging the current vehicle status,
The above controller,
A driving state in which the vehicle is driven by a motor powered by battery power;
A regenerative state in which the battery is charged by the above motor;
vehicle stopped; and
A method for limiting the output of an electric device of a vehicle, characterized in that one of the charging states in which a battery is charged through an in-vehicle charger by power from an external power source of the vehicle is determined as the current vehicle state.
In claim 4,
The above controller,
By further utilizing the vehicle speed along with the above driver demand power, the driving state and the regenerative state are distinguished and judged,
A method for limiting the output of an electric device of a vehicle, characterized in that the charger input power is further used together with the driver demand power and vehicle speed to distinguish and determine the vehicle stationary state and the charging state.

In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is in driving state,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 + α _d ) or vehicle power × (1 + β _d ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)' (wherein α _d and β _d are driving safety upper limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is in driving state,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 - γ _d ) or vehicle power × (1 - δ _d ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)' (wherein γ _d and δ _d are driving safety lower limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle condition is in regeneration state,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 + α _r ) or vehicle power × (1 + β _r ) < (battery power or inverter power or motor power) + (air conditioner power or heater power + DC-DC converter power)' (wherein α _r and β _r are regenerative safety upper limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle condition is in regeneration state,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 - γ _r ) or vehicle power × (1 - δ _r ) < (battery power or inverter power or motor power) + (air conditioner power or heater power + DC-DC converter power)' (wherein γ _r and δ _r are regenerative safety lower limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is stopped,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 + α _S ) or vehicle power × (1 + β _S ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)' (wherein α _S and β _S are stop safety upper limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is stopped,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that it is determined as 'Driver demand power × (1 - γ _S ) or vehicle power × (1 - δ _S ) < (battery power or inverter power or motor power) - (air conditioner power or heater power + DC-DC converter power)' (where γ _S and δ _S are stop safety lower limit coefficients preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is charging,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that the output power of the charger is determined as 'charger output power × (1 + α _c ) or charger input power × (1 + β _c ) < (battery power + air conditioner power or heater power + DC-DC converter power)' (wherein α _c is a charging output safety upper limit coefficient preset in the controller, and β _c is a charging input safety upper limit coefficient preset in the controller).
In claim 4,
At the stage of determining whether the above-mentioned allowable conditions are satisfied,
If the above vehicle status is charging,
The above conditions of acceptance are:
A method for limiting the output of an electric device of a vehicle, characterized in that the output power of the charger is determined as 'charger output power × (1 - γ _c ) or charger input power × (1 - δ _c ) < (battery power + air conditioner power or heater power + DC-DC converter power)' (wherein γ _c is a charging output safety lower limit coefficient preset in the controller, and δ _c is a charging input safety lower limit coefficient preset in the controller).
In claim 1,
In the step of limiting the output for the above electric device,
The above controller limits the output of the electrical device to a set percentage of the preset total allowable power,
A method for limiting the output of an electric device of a vehicle, characterized in that the value of the above-described set ratio is set in the controller as a value for each vehicle status.