KR102506089B1 - Motor control apparatus for alternating freewheeling and control method of alternating freewheeling for motor - Google Patents

Abstract

The present invention relates to a motor control device for alternating freewheeling and a method for controlling alternating freewheeling of a motor, comprising four switching elements for driving a motor by configuring a full bridge circuit, and four signals for controlling energization of each switching element. A signal generator for generating (A, A`, B, B`) and an output divider for distributing signals output from the signal generator to respective switching elements, wherein the A` signal is an inverted signal of the A signal. And, the B` signal is an inverted signal of the B signal, and the signal generator is in a high freewheeling operation state in which the A signal and the B signal are high, and the A signal and the B` signal are high. It is characterized in that a signal is generated in one of a motor-on operating state and a low freewheeling operating state in which the signal A′ and the signal B′ are high.

Description

Motor control device for alternating freewheeling and method for controlling alternating freewheeling of a motor

The present invention relates to a motor control device for alternating freewheeling and a method for controlling alternating freewheeling of a motor, and more particularly, to a technique for implementing alternating freewheeling in a device for controlling a motor using a full bridge circuit. .

As the electrification of vehicle parts accelerates, many mechanical devices are being converted into devices controlled by motors.

Among these motors, in the case of a motor controlled using a switching element such as a BLDC motor, it is common to control the driving of the motor through a half-bridge circuit using two FETs or a full bridge circuit using four FETs.

In addition, when the motor is controlled by a method such as pulse width modulation (PWM), freewheeling control is performed while the motor is turned off. Although such a freewheeling operation is usually performed using a freewheeling diode, the freewheeling operation may be performed through an FET of a bridge circuit without using a diode.

However, in the case of the conventional freewheeling control method, since FETs participating in freewheeling are fixed, a lot of imbalance occurs in the conduction time between FETs, which can be a problem.

Meanwhile, the background art of the present invention is disclosed in Korean Patent Publication No. 10-2016-0018752 (2016.02.17).

The present invention is to solve the problems of the conventional motor freewheeling control technology as described above, and a motor control device for alternating freewheeling and alternating motors that can reduce energization imbalance between switching elements through energization control of switching elements An object thereof is to provide a freewheeling control method.

A motor control device for alternating freewheeling according to the present invention comprises four switching elements for driving a motor by configuring a full bridge circuit; a signal generator for generating four signals (A, A', B, B') for controlling the conduction of each switching element; and an output distributor for distributing the signal output from the signal generator to each switching element, wherein the A` signal is an inverted signal of the A signal, and the B` signal is an inverted signal of the B signal. , the signal generating unit, a high freewheeling operating state in which the A signal and the B signal are high, a motor-on operating state in which the A signal and the B′ signal are high, and the A′ signal and the B′ signal and generating a signal in one of the low freewheeling operating states in which the signal is high.

In the present invention, the signal generation unit, two timers for outputting the A signal and the B signal, respectively; and two phase reversal units respectively generating phase inversion signals of signals output from each timer.

In the present invention, the two timers are synchronized with each other, and a high signal or a low signal is output according to whether a timer value in the form of a triangular wave is greater than or equal to a control value for each timer.

The motor control apparatus for alternating freewheeling according to the present invention may further include a controller for controlling the operation duty of the motor by applying the control value for each of the timers to the signal generator.

In the present invention, the signal generator may include four phase delay units for applying phase delays to each of the four signals.

In the present invention, the output distribution unit is characterized in that when the direction of the motor is changed, the A signal and the B signal are switched to each other, and the A' signal and the B' signal are switched to each other.

In the present invention, the output distribution unit is characterized in that it performs signal switching at the point of the maximum value or minimum value of the timer values of the two timers.

The motor control device for alternating freewheeling according to the present invention is characterized by further comprising a timer synchronized with the two timers and generating a trigger signal at the maximum value or minimum value.

A method for controlling the alternating freewheeling of a motor according to the present invention is a method for controlling the alternating freewheeling of a motor driven by four switching elements constituting a full bridge circuit. performing wheeling; driving the motor by energizing the first switching element and the fourth switching element; performing low freewheeling by energizing the second switching element and the fourth switching element; and driving the motor by energizing the first switching element and the fourth switching element.

A motor control device for alternating freewheeling and a method for controlling alternating freewheeling of a motor according to the present invention distributes the energization time between switching elements by alternately performing high freewheeling and low freewheeling for energizing different pairs of switching elements. has the effect of enabling

In addition, the motor control device for alternating freewheeling and the method for controlling alternating freewheeling of a motor according to the present invention can be implemented using only hardware resources provided by an MCU used in a vehicle, so that no additional resources are required. It works.

1 is a block diagram showing the configuration of a motor control device for alternating freewheeling according to an embodiment of the present invention.
2 is an exemplary view showing the configuration of a signal generation unit of a motor control device for alternating freewheeling according to an embodiment of the present invention.
3 to 5 are exemplary diagrams for explaining a method of generating a control signal of a motor control device for alternate freewheeling according to an embodiment of the present invention.
6 is an exemplary diagram illustrating a motor control operation of the motor control device for alternate freewheeling according to an embodiment of the present invention.
7 is an exemplary diagram for explaining delay generation of a control signal of a motor control device for alternate freewheeling according to an embodiment of the present invention.
8 is a block diagram showing the configuration of a motor control device for alternate freewheeling according to another embodiment of the present invention.
9 is a flowchart illustrating a method for controlling alternating freewheeling of a motor according to an embodiment of the present invention.

Hereinafter, an embodiment of a motor control device for alternating freewheeling and a method for controlling alternating freewheeling of a motor according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

1 is a block diagram showing the configuration of a motor control device for alternating freewheeling according to an embodiment of the present invention, and FIG. 2 is a signal generating unit of the motor control device for alternating freewheeling according to an embodiment of the present invention. 3 to 5 are exemplary diagrams for explaining a method of generating a control signal of a motor control device for alternating freewheeling according to an embodiment of the present invention, and FIG. 6 is an exemplary view showing an embodiment of the present invention. 7 is an exemplary diagram illustrating a motor control operation of the motor control device for alternating freewheeling according to an embodiment, and FIG. 7 is for explaining delayed generation of a control signal of the motor control device for alternate freewheeling according to an embodiment of the present invention. 8 is a block diagram showing the configuration of a motor control device for alternate freewheeling according to another embodiment of the present invention. Referring to this diagram, a motor control device for alternate freewheeling according to an embodiment of the present invention is shown. The explanation is as follows.

As shown in FIG. 1, a motor control device for alternating freewheeling according to an embodiment of the present invention includes a signal generator 10, an output distribution unit 20, a control unit 30, and FETs 41 to 44 can include

The signal generating unit 10 may generate signals A, A', B, and B' for controlling the conduction of each of the FETs 41 to 44.

The output distribution unit 20 distributes the signal output from the signal generation unit 10 to each of the FETs 41 to 44, but inputs to the FET1(41) and FET3(43) when the motor direction needs to be changed Switching of signals (ie, switching of A and B signals) and switching of signals input to FET2 (42) and FET4 (44) (ie, switching of A' and B' signals) are performed. To this end, the output distribution unit 20 may include a multiplexer (MUX) or the like.

The control unit 30 is composed of a device such as a processor and can control the operation of the signal generator 10 and the output distribution unit 20 . That is, control signals may be applied to the signal generation unit 10 and the output distribution unit 20 to control duty (duty) control for driving the motor, direction change control, and the like.

The FETs 41 to 44 may constitute a full bridge circuit to drive a motor connected thereto.

In this embodiment, it has been described that the FET is used as a switching element for motor control, but other switching elements capable of performing the same function may be used.

On the other hand, basic controls such as duty control and direction change control for driving the motor are implemented according to the characteristics of each device, and are already widely used in the technical field of the present invention, so detailed descriptions will be omitted in the present invention. .

As shown in FIG. 2, the signal generating unit 10 includes two timers 11 and 15, two upper inverting units 12 and 16 for generating a phase inversion signal of a signal output from each timer, and a short circuit. It may include four upper delay portions 13, 14, 17, and 18 to prevent this.

3 to 5 show the generation of a control signal in a situation where the operating duty of the motor is 50%, and the signal generation using the two timers 11 and 15 will be described with reference to this.

As shown in FIGS. 3 and 4 , each of the timers 11 and 15 may have a triangular wave shape in which a value increases and then decreases again from a maximum value. Also, the two timers 11 and 15 may be synchronized.

Each of the timers 11 and 15 may be configured to output a high signal when the value is equal to or less than the reference control value. Alternatively, it may be configured to output a low signal when the value is less than the control value according to design. In this embodiment, it will be described assuming that a high signal is output when the value is less than the control value.

At this time, a control value serving as a reference for comparison may be transmitted from the control unit 30, and the duty applied to the motor may be adjusted by adjusting the control value.

In a situation where the operating duty of the motor is 50%, the control value of Timer A (11) may be 75% of the maximum value, and the control value of Timer B (15) may be 25% of the maximum value. ), signal A may be output, and signal B may be output from timer B 15.

A' signal, which is a phase inversion signal of signal A, and signal B', which is a phase inversion signal of signal B, can be output by the phase reversal units 12 and 16 provided one by one for each timer 11 and 15.

Accordingly, signals A, A', B, and B' may have a form as shown in FIG. 5 .

If the operation of the upper delay units 13, 14, 17, and 18 is omitted, signals A, A', B, and B' are sequentially applied to FET1 to FET4 (41 to 44) when the motor rotates in the forward direction.

In this case, looking at the operation of the motor with reference to FIG. 6, since the FET1 (41) and the FET3 (43) are energized in the period where the A and B signals are high, a freewheeling operation using the high-side FET is implemented.

Next, since the FET1 (41) and the FET4 (44) are energized during the period in which the A and B′ signals are high, power is applied to the motor and becomes an on state.

In addition, since the FET2 (42) and the FET4 (44) are energized in the period where the A' and B' signals are high, a freewheeling operation using a low-side FET is implemented.

Accordingly, based on the 50% duty, FET1 (41) can distribute the conduction time as 75%, FET2 (42) and FET (43) as 25%, and FET4 (44) as 50%. This can evenly distribute the conduction time of the FETs compared to the conventional method using only high freewheeling.

The upper delay units 13, 14, 17 and 18 can delay signals to prevent short circuits. For example, as shown in FIG. 7, FET1 (41) and FET2 (42) are energized between ON -> low freewheeling and low freewheeling -> ON state transitions for the A signal and the A' signal, respectively. There is a possibility of a short circuit.

Accordingly, it is possible to prevent a short circuit by applying a phase delay to the signal A′ in the ON-> low freewheeling state transition and applying a phase delay to the A signal in the low freewheeling->ON state transition.

Similarly, there is a possibility that FET3 (43) and FET4 (44) are energized and short-circuited between high freewheeling -> ON and ON -> high freewheeling state transitions for the B signal and the B' signal.

Accordingly, it is possible to prevent a short circuit by applying a phase delay to signal B' in the high freewheeling -> ON state transition and applying a phase delay to the B signal in the ON -> high freewheeling state transition.

To this end, the upper delay units 13, 14, 17, and 18 may be configured to apply an upper delay when the signal changes from low to high.

Meanwhile, as described above, the output distributor 20 may convert the distribution of the signal output from the signal generator 10 in order to control the direction of the motor. However, even in the case of such a conversion, a short circuit may occur depending on whether each of the FETs 41 to 44 are energized.

Accordingly, in order to prevent a short circuit, the output distributor 20 may be configured to perform switching of the output signal only in a specific state.

For example, the output distributor 20 may be configured to switch signals at the maximum and minimum values of the timers 11 and 15 .

To this end, the output distributor 20 may be configured to receive trigger signals generated at the maximum and minimum values of the timers 11 and 15 . This trigger signal may be input from the control unit 30 .

However, in some hardware specifications, since the output distribution unit 20 may not be able to receive information about the maximum and minimum value points of the timers 11 and 15, timer A 11 and timer B as in the embodiment shown in FIG. A timer C 50 synchronized with (15) may be further provided, and the timer C 50 may be configured to generate a trigger at the maximum and minimum value points.

Configurations such as the signal generation unit 10, the output distribution unit 20, the control unit 30, and the timer C 50 can be implemented with hardware support specifications of the MCU installed in the vehicle, so additional resources are not required. may not be

9 is a flowchart illustrating a method for controlling alternating freewheeling of a motor according to an embodiment of the present invention.

As shown in FIG. 9, the method for controlling alternating freewheeling of a motor according to an embodiment of the present invention includes the steps of performing high freewheeling by energizing FET1 (41) and FET3 (43) (S100), FET1 (41) ), driving the motor by energizing FET4 (44) (S200), performing low freewheeling by energizing FET2 (42) and FET4 (44) (S300), and FET1 (41), FET4 (44 ) to drive the motor (S400), but these steps can be performed repeatedly, and the specific operation of each step is the same as the operation of the motor control device for alternating freewheeling described above. can be performed with

The present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. will understand Therefore, the technical protection scope of the present invention should be determined by the claims below.

10: signal generator
11, 15, 50: timer
12, 16: first half
13, 14, 17, 18: upper limb part
20: output distribution unit
30: control unit
41, 42, 43, 44: FET

Claims (9)

Four switching elements configured to drive a motor by configuring a full bridge circuit;
a signal generator for generating four signals (A, A', B, B') for controlling the conduction of each switching element; and
An output distribution unit for distributing the signal output from the signal generation unit to each switching element,
The A′ signal is an inverted signal of the A signal, and the B′ signal is an inverted signal of the B signal;
The signal generating unit may include a high freewheeling operation state in which the A signal and the B signal are high, a motor-on operation state in which the A signal and the B' signal are high, and the A' signal and the B' signal. Generating a signal in one of the low freewheeling operating states in which is high, wherein the signal is generated in the order of the high freewheeling operating state, the motor-on operating state, the low freewheeling operating state, and the motor-on operating state. Motor control unit for alternating freewheeling.
According to claim 1,
The signal generator,
two timers respectively outputting the A signal and the B signal; and
A motor control device for alternating freewheeling, characterized in that it comprises: two phase-reversal units each generating a phase-reversal signal of a signal output from each timer.
According to claim 2,
The two timers are synchronized with each other and output a high signal or a low signal depending on whether the timer value in the form of a triangular wave is greater than or equal to the control value for each timer.
According to claim 3,
and a control unit controlling the operation duty of the motor by applying the control value for each of the timers to the signal generator.
According to claim 1,
The signal generator,
A motor control device for alternating freewheeling comprising: four phase delay units for applying a phase delay to each of the four signals.
According to claim 2,
Wherein the output distribution unit switches the A signal and the B signal to each other, and switches the A' signal and the B' signal to each other when the direction of the motor is changed.
According to claim 6,
The motor control device for alternating freewheeling, characterized in that the output distribution unit performs switching of signals at the maximum or minimum value of the timer values of the two timers.
According to claim 7,
A motor control device for alternating freewheeling, characterized in that it further comprises; a timer synchronized with the two timers and generating a trigger signal at the maximum value or minimum value point.
A method for controlling alternating freewheeling of a motor driven by four switching elements constituting a full bridge circuit,
performing high freewheeling by energizing the first switching element and the third switching element;
driving the motor by energizing the first switching element and the fourth switching element;
performing low freewheeling by energizing the second switching element and the fourth switching element; and
and driving the motor by energizing the first switching element and the fourth switching element.

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