KR20200079939A - Apparatus and Method for controlling power source abnormality of motor - Google Patents

Abstract

Provided is a motor power abnormality control device which can increase power stability by preventing a power overload condition. The motor power abnormality control device comprises: a driving power detection unit detecting a power variable level value when driving a motor; a control unit comparing the power variable level value with a preset standard value to perform a limit driving control; and a power converter supplying driving power for limiting the driving power to the motor or limiting a rotation speed of the motor in accordance with the limit driving control.

Description

Apparatus and Method for controlling power source abnormality of motor}

The present invention relates to a motor control technology for a vehicle, and more particularly, to a motor power abnormality control device and method for changing a driving control of a motor against a power source in a moment when the power becomes unstable due to a battery abnormality.

Recently, eco-friendly vehicles such as electric vehicles and hybrid vehicles have attracted attention due to energy exhaustion and environmental pollution. An eco-friendly vehicle includes a motor that generates driving power using electricity stored in a battery, and generally uses a DC (Direct Current) motor.

In general, a DC motor consists of a stator made of magnet and a rotor made of field winding. The field winding of the rotor is connected to external DC power through a brush. As the rotor rotates, the polarity between the brush and the external power is continuously changed, and the direction of the magnetic field generated in the rotor is also continuously changed. That is, the magnetic field of the rotor is always maintained at a constant polarity with respect to the magnetic field of the stator, thereby generating the rotational force of the motor.

It is common to apply a relay control method to the existing DC (Direct Current) motor. That is, in the case of the existing DC motor, it shows the operation mode according to the state of the power supply in the voltage unstable state (applied current under the power supply ↓). Therefore, in a voltage drop situation in which the power source becomes unstable, the current is also lowered as the voltage is lowered, and there is a problem in that the motor driving torque is lowered.

Conversely, in the case of a BLDC (Brushless Direct Current) motor, when the voltage of the external power supply is low, the current is used as it is regardless of power fluctuation through current control to satisfy conditions such as maintaining RPMs (revolutions per minute). In particular, in the case of PWM (Pulse Width Modulation) control, a control method is shown that increases duty as much as the power drop. In other words, in the case of a BLDC motor, it is controlled so that the applied current does not change through the current control in the voltage unstable state (equal to the applied current in the power ↓ condition, which may cause overlap of loads applied to the power).

In this case, in addition to the cause of the power supply being unstable, there is no difference in the power used by the motor, which may cause a problem of accelerating the voltage drop.

For example, when the sunroof motor DC is driven while the pump motor BLDC of the vehicle is driving, a drop in battery voltage occurs. In this case, the DC motor operates at a lower driving speed as the battery voltage is lowered, whereas the BLDC controls the current to a constant torque generation regardless of the lowered voltage to maintain the RPM and torque of the motor. In this case, a load may be applied to the battery, and an additional voltage drop or a delay in the voltage drop recovery time may occur.

1. Korea Patent Publication No. 10-2010-0111794 2. Korean Patent Publication No. 10-2018-0074213

The present invention has been proposed to solve the problems according to the above background technology, and the driving control of the motor is prepared for power in a moment when the power becomes unstable due to a battery abnormal condition (eg, operation of another stopped power supply product for a vehicle). An object of the present invention is to provide an apparatus and method for controlling a motor power abnormality that can be changed.

In order to achieve the above-described problems, the present invention is a motor power abnormality that can change the driving control of the motor in preparation for the power in a moment when the power becomes unstable due to a battery abnormality situation (eg, operation of another stopped power supply product for a vehicle). Provide a control device.

The motor power abnormality control device,

A driving power sensing unit that senses a power fluctuation level value while driving the motor;

A control unit that performs limit driving control by comparing the power fluctuation level value with a preset reference value; And

It characterized in that it comprises; a power converter for supplying a driving power to limit the driving power to the motor or to limit the motor rotation speed according to the limit driving control.

At this time, the control unit, the output limit control module for performing the limit driving control; And a control signal generation module for generating a control signal according to the limit driving control.

In addition, the power fluctuation level value is a voltage change amount during control, and the reference value is a current control change amount.

In addition, the voltage change amount is a value obtained by dividing a voltage difference by a product of a drive voltage detection period and a stator resistance, and the current control change amount is a value obtained by dividing a preset current output limit by a drive current detection period.

In addition, the output limit control module, the first proportional integral control block for controlling by gradually reducing the difference value minus the required motor rotation speed from the actual motor rotation speed; And a second proportional integral control block for gradually reducing and controlling the difference value obtained by subtracting the current current output limit from the driving bus phase current.

In addition, the current output limit is characterized in that it is calculated by multiplying a unit current by a sum of a preset integral gain and a proportional gain.

In addition, the driving power is characterized by being generated through PWM (Pulse Width Modulation).

In addition, the PWM is characterized in that it is based on a duty cycle.

In addition, the driving power sensing unit is characterized in that it detects by adding the fluctuation width to the absolute value of the power fluctuation level.

In addition, the limited driving control is characterized in that it is made using an anti-windup PI (Proportional Integral) control method.

In addition, the limited driving control is characterized in that it is executed only within a preset reference time.

On the other hand, another embodiment of the present invention, the sensing step of detecting the power fluctuation level value while the driving power sensor is driving the motor; A comparison step of the control unit comparing the power fluctuation level value with a preset reference value; A driving control step in which the control unit performs limited driving control according to the comparison result; And a supply step of supplying, by the power converter, drive power to the motor to limit the drive power or to limit the motor rotation speed according to the limit drive control.

According to the present invention, when the power enters the unstable state, the power return time can be shortened by removing a load portion that the motor can supply to the power.

In addition, another effect of the present invention is that it is possible to increase the stability to the power supply by preventing the power supply overload condition.

In addition, another effect of the present invention is that it is possible to minimize the possibility of motor control divergence due to power supply instability.

In addition, another effect of the present invention is that it enables the controller to minimize the impact on other products using power due to the power consumed (for example, a sunroof <-> pump motor).

In addition, another effect of the present invention is that the limit level can be limited to a few ms ~ hundreds of ms.

1 is a block diagram of a motor power abnormality control device according to an embodiment of the present invention.
2 is a graph showing a typical motor initial driving waveform.
FIG. 3 is a block diagram showing the concept of output limitation among the motor power anomaly control devices illustrated in FIG. 1.
4 is a graph illustrating the current output limit of the motor according to an embodiment of the present invention.
5 is a flowchart showing a motor power drop control process according to an embodiment of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals are used for similar components. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components.

For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. The term “and/or” includes a combination of a plurality of related described items or any of a plurality of related described items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains.

Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Should not.

Hereinafter, an apparatus and method for controlling a motor power failure according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a motor power abnormality control device 100 according to an embodiment of the present invention. Referring to FIG. 1, the motor power abnormality control device 100 compares the motor 10, the driving power detection unit 110 that detects the power fluctuation level value while driving the motor 10, and the power fluctuation level value with a reference value It may be configured to include a control unit 101 for performing the limit driving control, a power converter 160 for supplying power to the motor 10 in accordance with the limit driving control.

The motor 10 may be a brushless direct current (BLDC) motor, but is not limited thereto, and a general DC motor may also be used. The motor is composed of a stator (not shown) and a rotor (not shown) that rotates within or outside the stator.

In other words, the BLDC motor has a winding that has a three-phase coil for generating an inductance component. That is, the BLDC motor has a structure without an insulator such as a carbon brush for transmitting electric power, and there is a magnet on the motor shaft and a coil on the inner wall of the motor case, so that the supply of electric power for the motor to rotate does not rotate. It is a structure that does not require a brush as it is supplied to a coil attached to a wall.

The control unit 101 performs a function of performing limit driving control by comparing the power fluctuation level value with a reference value. To this end, the control unit 101, the rotation cycle of the motor rotor, the position information about the rotor of the motor, the recognition module 120 for recognizing power (that is, the motor driving voltage (Vdc) of DC power), rotation A speed calculation module 121 for calculating a motor rotation speed using a cycle, an output limit control module 140 for controlling an output controlling a duty cycle, and determining an instability level of a voltage change amount based on a unit current control level, Configuration including a power control module 130 that performs limited drive control, a control signal generation module 150 that generates a drive control signal for controlling a power switching element (not shown) configured in the power converter 160, and the like Can be.

The power converter 160 functions to supply power to the motor 10. In other words, the power converter 160 converts the DC power into a pulse-shaped three-phase AC power supply U, V, W having an arbitrary variable frequency and supplies driving power to the motor 10. That is, the power converter 160 converts the DC voltage into a three-phase AC voltage and supplies it to the motor 10.

To this end, the power converter 160 may include a DC-DC (Direct Current-Direct Current) converter, an inverter, and the like. The inverter may be a VSI (Voltage Source Inverter). Inverters generally include a three-phase power switching element, for example, an upper three-phase field effect transistor (FET) and a lower three-phase FET may be configured. The power switching element may be a power metal-oxide-semiconductor FET (MOSFET), an insulated gate bipolar transistor (IGBT), or the like.

The driving power detecting unit 110 detects a driving bus phase current (I _DCBus ), a driving bus power (U _DCBus ), and a back electro-motive force (BEMF) generated in the power converter 160. To this end, a current sensor, a voltage sensor, and the like can be configured. As the current sensor, a hall sensor, an optical fiber current sensor, or a current transformer (CT) type current sensor may be used.

In other words, the driving power sensing unit 110 senses the DC link power in real time since the DC link power is basically necessary information for motor control. Here, in order to detect the unstable state of the DC link power supply, it is also possible to detect the fluctuation width in addition to the absolute value of the sensed power supply value. The DC link power is the voltage flowing between the converter and the inverter.

The driving power detector 110 is configured with an analog-digital converter (ADC) 111 to convert the detected analog signal into a digital signal. The driving power detection unit 110 transmits a digital signal (I _DCBus , BEMF) to the control unit 101.

The output limit control module 140 has a function of generating a duty cycle using the actual motor actual speed, the required motor rotation speed, the driving bus phase current (I _DCBus ), and the current limit. Perform. The modulation module 150 implements pulse width modulation (PWM) control using this duty cycle. That is, the pulse width becomes the duty cycle.

The output limit control module 140 is composed of a first proportional integral control block 140-1 for limiting the motor rotation speed and a second integral control block 140-2 for limiting the current.

Particularly, the first proportional integral control block 140-1 performs a function of gradually reducing and controlling a difference value obtained by subtracting a required motor rotation speed from an actual motor rotation speed.

On the other hand, the second proportional integral control block 140-2 performs a function of gradually reducing and controlling a difference value obtained by subtracting the current limit current from the driving bus phase current I _DCBus .

In other words, the motor driving voltage Vdc supplied to the motor 10 is detected through the power sensing unit 110. When the motor driving voltage is detected, the recognition module 120 checks the voltage drop level generation condition for the motor driving voltage.

In order to determine the reference of the voltage drop level, the current limit (I(limit)) is defined as in the following equation.

Here, k _p is a proportional gain, k _i is an integral gain, and I(unit) represents a unit current. Here, the unit current is different according to states such as PWM (Pulse Width Modulation), motor, and excitation current.

That is, the instability level of the voltage change amount is determined based on the unit current control level of the gain among the PI (Proportional Integral) controllers.

At this time, the transfer function C(s) and the control input signal u(t) of the PI controller are as follows.

Here, e is a control error, τ is a time constant, k _p is a proportional gain, and k _i is an integral gain. k _p and k _i can be design values.

e is as follows.

Here, r is a desired reference value, and y is a system output value.

Therefore, in general, the larger the value of k _p is, the larger the input u of the system for the same error is, so the output value is faster, which follows the reference. If k _p is too small, the response speed is slow and the steady state cannot be reached. Conversely, if k _p is too large, the response speed is fast, but an overshoot occurs, resulting in oscillation.

The term “…module” described in FIG. 1 means a unit that processes at least one function or operation, which may be implemented in software and/or hardware. In hardware implementation, application specific integrated circuit (ASIC), digital signal processing (DSP), programmable logic device (PLD), field programmable gate array (FPGA), processor, microprocessor, and others designed to perform the functions described above It may be implemented as an electronic unit or a combination thereof. In the software implementation, it may be implemented as a module that performs the functions described above. Software can be stored in a memory unit and executed by a processor. The memory unit or processor may employ various means well known to those skilled in the art.

2 is a graph showing a typical motor initial driving waveform. 2, the driving voltage waveform and the driving current waveform appear to cross each other. In general, the driving voltage waveform is a curve shape that maintains a constant value at a high point in the initial stage and then recovers rapidly after falling sharply and then changes its height finely. On the other hand, the driving current waveform is in the form of a curve that maintains a constant value at the initial low point, then rises rapidly, then recovers rapidly downwards and changes constantly.

Therefore, both the driving voltage waveform and the driving current waveform appear at the time of power supply instability. The driving voltage waveform and the driving current waveform shown in FIG. 2 are root mean squares (RMS) in CHA (channel A).

FIG. 3 is a block diagram showing the concept of output limitation among the motor power anomaly control devices illustrated in FIG. 1. Referring to FIG. 3, when control is unstable, current output limitation is applied using an anti-windup PI control method.

The miter 330 uses an anti-windup PI control method. In other words, the miter 330 inputs a difference value between the actual motor rotation speed (Actual speed) and the required motor rotation speed (w _r ^* ) of the motor 10 calculated by the summer 310. It receives and generates the output value which is the control amount by proportional integration. In this output value, the integral component is subtracted according to the difference to generate a q-axis current command value (i _qs ^* ). If the integral component is not subtracted, the output value continues to increase and increases to an almost infinite value. At this time, if you try to control in the reverse direction, the integral component will be resolved without moving in the opposite direction by the integrated almost infinite value. It will continue to move in the forward direction.

Therefore, the limiter 330 functions to stop the integration of the Anti-Windup PI control method by limiting the output values to the preset limit areas I _max and -I _max .

The output control module 340 receives the q-axis current command value (i _qs ^* ) and the d-axis magnetic flux command value (λ _dr ^* ) and PWM for phase conversion of the DC voltage into a three-phase AC voltage through magnetic flux vector control and current control. Generate a signal. This PWM signal has a duty cycle based on the q-axis current command value (i _qs ^* ) and the d-axis magnetic flux command value (λ _dr ^* ). This duty cycle is generally determined by the ratio of the setpoint and the driving power.

The current control converts the current command according to the d/q axis current command into a voltage command for the motor stator d/q axis to perform the control function. The magnetic flux vector control converts three-phase currents (i _as ,i _bs ,i _cs ) into two dq-axis signals having an orthogonal relationship through dq conversion, and controls them using the two signals.

Accordingly, the output control module 340 generates a gate signal, which is a pulse width modulation (PWM) signal, using this duty cycle to control a switching element configured in the power converter 160.

The power converter 160 supplies driving power for driving the motor 10, and this driving power is a product of a duty cycle and a DC power. That is, it may be a product of the duty cycle and the driving voltage (V _DC ) of the DC power supply.

4 is a graph illustrating a current limit of a motor (10 in FIG. 1) according to an embodiment of the present invention. Referring to FIG. 4, when a current limit is applied, a current graph curve 410 and a current graph curve 420 without a current output limit are shown. That is, when the current output limit (current limit) is applied, the current graph curve 410 may be reduced in current by about 30A (160A-130A) within a predetermined time (about 0.2 seconds to 0.7 seconds).

In addition, for motors in operation, a limit of up to about -10% of max RPM or torque can be applied.

5 is a flowchart showing a motor power drop control process according to an embodiment of the present invention. Referring to FIG. 5, the controller (101 in FIG. 1) determines whether a motor driving signal is generated in an initializing and waiting state (steps S510 and S520).

As a result of the determination, if a motor driving signal is generated in step S520, the controller 101 performs normal motor driving (step S530). Of course, the control unit 101 simultaneously or previously detects the driving voltage V _DC and the three-phase currents i _as ,i _bs ,i _cs (step S531 ).

Thereafter, the control unit 101 detects the driving voltage fluctuation width (ΔV _DC ) and performs a determination operation on the current control effect of the voltage change amount (step S550). The current control influence degree is expressed as follows.

Here, Rs is a motor stator resistance, T ₁ is a driving voltage sensing period, I (limit) is a current output limit, and T ₂ is a driving current sensing period.

Thereafter, the control unit 101 determines a level at which the voltage fluctuation affects the current control using the equation calculated above (step S560).

As a result of the determination, in step S560, if the voltage fluctuation is greater than the reference level, the control unit 101 drives the motor with a current limit or a speed limit, and an operation time for driving the current limit or the speed limit has passed a preset reference time. It is determined whether or not (steps S570, S580).

As a result of the determination, in step S580, when the operating time passes the reference time, that is, when the operating time is greater than the reference time, the control unit 101 executes steps S530 to S580 again.

Further, in the state in which the motor 10 is normally driven, the control unit 101 determines whether a motor driving stop signal is input (step S533).

As a result of the determination, if there is a motor driving stop signal, the control unit 101 starts step S510, and if there is no motor driving stop signal, the control unit 101 proceeds to step S540.

In addition, the steps of the method or algorithm described in connection with the embodiments disclosed herein are implemented in the form of program instructions that can be executed through various computer means, such as a microprocessor, processor, central processing unit (CPU), and the like, to read a computer. It can be recorded on a possible medium. The computer-readable medium may include program (instruction) codes, data files, data structures, or the like alone or in combination.

The program (instruction) code recorded on the medium may be specially designed and configured for the present invention or may be known and usable by those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, Blu-rays, and ROMs, and RAMs (ROMs). RAM), a flash memory, etc., may include a semiconductor memory element specifically configured to store and execute program (instruction) code.

Here, examples of the program (instruction) code include high-level language code that can be executed by a computer using an interpreter or the like, as well as machine language codes made by a compiler. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

10: motor
100: motor power failure control device
101: control
110: driving power detection unit
160: power converter

Claims (19)

A driving power sensing unit that senses a power fluctuation level value while driving the motor;
A control unit that performs limit driving control by comparing the power fluctuation level value with a preset reference value; And
A power converter supplying driving power to limit the driving power to the motor or to limit the motor rotation speed according to the limit driving control;
Motor power abnormality control device comprising a.
According to claim 1,
The control unit,
An output limit control module that performs the limit drive control; And
And a control signal generating module for generating a control signal according to the limit driving control.
According to claim 2,
The power supply fluctuation level value is a voltage change amount during control, and the reference value is a current power change amount control device. The method of claim 3,
The voltage variation is a value obtained by dividing the voltage difference by the product of the driving voltage detection period and the stator resistance, and the current control variation is a motor power abnormality characterized in that the preset current limit is divided by the driving current detection period. controller.
The method of claim 4,
The output limit control module,
A first proportional integral control block for gradually reducing and controlling a difference value obtained by subtracting the required motor rotation speed from the actual motor rotation speed; And
And a second proportional integral control block for gradually reducing and controlling a difference value obtained by subtracting the current current output limit from the driving bus phase current.
The method of claim 4,
The current output limit is calculated by multiplying a unit current by a sum of a preset integral gain and a proportional gain. According to claim 1,
The driving power is a motor power abnormality control device, characterized in that generated through PWM (Pulse Width Modulation).
The method of claim 7,
The PWM is a motor power abnormality control device, characterized in that based on the duty cycle.
According to claim 1,
The driving power sensing unit detects the power fluctuation level value by adding a fluctuation width to an absolute value.
According to claim 1,
The limit driving control is a motor power failure control device characterized in that it is made using an anti-windup PI (Proportional Integral) control method.
According to claim 1,
The limit driving control is a motor power abnormality control device, characterized in that executed only within a preset reference time.
A sensing step in which the driving power sensing unit detects a power fluctuation level value while driving the motor;
A comparison step of the control unit comparing the power fluctuation level value with a preset reference value;
A driving control step in which the control unit performs limited driving control according to the comparison result; And
A supply step in which a power converter supplies driving power to the motor to limit the driving power or to limit the motor rotation speed according to the limited driving control;
Motor power abnormality control method comprising a.
The method of claim 12,
The power fluctuation level value is a voltage change amount during control, and the reference value is a current power change amount control method.
The method of claim 13,
The voltage variation is a value obtained by dividing the voltage difference by the product of the driving voltage detection period and the stator resistance, and the current control variation is a motor power abnormality characterized in that the preset current limit is divided by the driving current detection period. Control method.
The method of claim 14,
The current output limit is calculated by multiplying a unit current by a sum of a preset integral gain and a proportional gain.
The method of claim 12,
The driving power is a motor power abnormality control method characterized in that generated through PWM (Pulse Width Modulation).
The method of claim 16,
The PWM is a power cycle abnormality control method, characterized in that based on the duty cycle.
The method of claim 12,
The limit driving control is a motor power abnormality control method characterized in that it is made using an anti-windup PI (Proportional Integral) control method.
The method of claim 12,
The limit driving control is a motor power abnormality control method characterized in that it is executed only within a preset reference time.

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