KR102308492B1 - Motor operating device and method for the same - Google Patents

Abstract

A motor driving apparatus according to an aspect of the disclosed invention includes a rectifier for rectifying an AC voltage and an AC current supplied from a power supply into a DC voltage and a DC current, a smoothing unit for removing ripples included in the DC voltage and DC current, and a smoothing unit from the a power conversion unit that receives a DC current and converts it into an AC current to provide a driving current to the motor; And it may include a control unit for controlling the power converter to change the phase of the driving current according to the rotational speed and torque load of the motor.

Description

Motor driving device and its control method

The disclosed invention relates to a motor driving apparatus and a method for controlling the same.

In order to operate the motor, it is necessary to control the magnetic flux of the stator so that it is electrically perpendicular to the magnetic flux of the permanent magnet generated in the rotor or at an arbitrary angle. To this end, it is necessary to determine the switching state of the switching elements of the inverter so as to always detect which denture the rotor is in and determine the magnetic flux generation position of the stator according to the position of the rotor. At this time, a resolver, an encoder, a Hall sensor, etc. are used to detect the position of the rotor, or a sensorless that detects the position of the rotor from the voltage or current applied to the motor. By using a (sensorless) method, the position of the rotor may be detected by the Back ElectroMotive Force (Back-EMF) of the motor detected through the position detection circuit.

However, when the rotational speed of the motor increases, the load increases together, so that the driving current applied to the motor is not synchronized with the induced current according to the position of the rotor and a delay occurs. In addition, when an additional torque such as reluctance torque exists, it is affected by the load due to the additional torque as well as the load effect due to the rotational speed of the motor, which causes an additional current delay.

An aspect of the disclosed invention is to provide a motor driving apparatus and a control method for controlling the motor driving in consideration of the load generated by the motor.

A motor driving apparatus according to an aspect of the disclosed invention includes a rectifier for rectifying an AC voltage and an AC current supplied from a power supply into a DC voltage and a DC current, a smoothing unit for removing ripples included in the DC voltage and DC current, and a smoothing unit from the It includes a power converter that receives the DC current and converts it into an alternating current to provide a driving current to the motor, and a controller that controls the power converter so that the phase of the driving current changes according to the rotational speed and torque load of the motor.

In addition, according to an embodiment, the controller may control the phase of the driving current to change based on a change value of a lead angle of the driving current according to an increase in the torque load.

In addition, according to an embodiment, the controller may control the phase of the driving current to change according to a torque load due to the reluctance torque of the motor.

In addition, according to the embodiment, the control unit may receive a change value of the lead angle according to the torque load, and multiply the change value by the torque load of the motor.

In addition, according to the embodiment, the lead angle change value may be different depending on the type of the motor.

In addition, according to an embodiment, the control unit may control the power conversion unit based on a load according to the rotational speed of the motor and a torque load according to the reluctance torque of the motor.

Also, according to an embodiment, the controller may add and calculate a phase delayed according to the rotation speed of the motor with a phase of the driving current.

In addition, according to an embodiment, the controller may control the phase of the driving current to advance by a phase delayed according to the rotation speed of the motor.

In addition, according to the embodiment, the control unit receives the lead angle input and controls the first phase shifter to control the phase of the driving current to change, and to receive the lead angle change value according to the increase in the torque load of the motor to change the phase of the driving current and a second phase shifter.

In addition, according to an embodiment, the second phase shifter may receive a different lead angle change value according to the type of the motor.

A motor driving apparatus according to another aspect of the disclosed invention includes a rectifier for rectifying an AC voltage and an AC current supplied from a power supply into a DC voltage and a DC current, a smoothing unit for removing ripples included in the DC voltage and DC current, and a smoothing unit from the It includes a power converter that receives the DC current and converts it into an alternating current to provide a driving current to the motor, and a controller that controls the power converter to change the phase of the driving current according to the reluctance torque of the motor.

In addition, according to the embodiment, the control unit may control the power conversion unit to apply a lead angle corresponding to the torque load due to the reluctance torque of the motor to the driving current.

In addition, according to an embodiment, the control unit may receive a change value of the lead angle according to the reluctance torque of the motor, and multiply the change value by the torque load of the motor.

In addition, according to an embodiment, the controller may additionally control the phase of the driving current to change according to the degree of delay of the driving current according to an increase in the rotational speed of the motor.

In addition, according to the embodiment, the control unit includes a phase control unit that calculates a reference current based on a delay degree of a driving current according to the rotational speed of the motor and a change value of a lead angle due to a reluctance torque, based on the driving current and the reference current It may include a current controller for calculating a reference voltage, an output signal generator for calculating a driving voltage for driving the motor based on the reference voltage, and outputting a control signal for controlling the power converter by pulse width modulation of the driving voltage.

A control method of a motor driving apparatus including a power converter for converting a motor DC current into an AC current to provide a driving current to the motor according to another aspect of the disclosed invention, detecting the rotational speed and the driving current of the motor, and the rotational speed and generating a reference current having a different phase according to a load of the motor based on the and driving current, and driving the motor based on the generated reference current.

In addition, in generating the reference current according to the embodiment, the phase delay value of the driving current according to the rotation speed is added to the phase of the driving current, and the reference current is calculated based on the change value of the lead angle of the driving current according to the torque load of the motor. It may include creating

In addition, generating the reference current according to the embodiment may include receiving a change value of a lead angle according to a torque load and multiplying the change value with the torque load of the motor to generate the reference current.

In addition, generating the reference current according to the embodiment may generate the reference current having a different phase according to the reluctance torque of the motor.

In addition, the input of the change value of the lead angle according to the torque load according to the embodiment may include receiving the input of the change value of the lead angle that is different according to the type of the motor.

According to one aspect of the disclosed invention, it is possible to provide a motor driving device for efficiently controlling the motor in consideration of the rotational speed and load of the motor.

According to another aspect of the disclosed invention, it is possible to provide a motor driving apparatus for controlling a motor based on a current phase changed by a torque load of a rotor, and a method for controlling the same.

1 is a diagram illustrating a power supply device, a motor, and a motor driving device according to an embodiment of the disclosed invention.
2 is a view showing a rectifier according to an embodiment of the disclosed invention.
3 is a view showing a power conversion unit employing a smoothing unit and a two-level inverter according to an embodiment of the disclosed invention.
4 is a diagram illustrating a power conversion unit employing a smoothing unit and a 3-level diode clamped inverter according to an embodiment of the disclosed invention.
5 is a diagram illustrating a power conversion unit employing a smoothing unit and a 3-level direct switching inverter according to an embodiment of the disclosed invention.
6 is a diagram illustrating a configuration of a control unit of a motor driving apparatus according to an embodiment of the disclosed invention.
7 is a flowchart illustrating a method for controlling a motor driving apparatus according to an embodiment of the disclosed invention.
8 is a block diagram of a phase controller according to an exemplary embodiment.
9 is a graph of a load characteristic of a motor.
10 is a graph of the phase delay according to an increase in the rotational speed of the motor.
11 is a control flowchart of a phase controller according to an exemplary embodiment.
12 is a schematic view of the appearance of a surface-mounted permanent magnet synchronous motor and an embedded permanent magnet synchronous motor.
13 is a graph of a magnetic flux path of an embedded permanent magnet synchronous motor.
14 is a characteristic graph of a lead angle according to a type of a motor.

The embodiments described herein and the configurations shown in the drawings are the spirit of the disclosed invention.

It is merely a direct example, and it should be noted that there are various modifications that can be substituted for the embodiments and drawings of the present specification.

Hereinafter, an embodiment of the disclosed invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a power supply device, a motor, and a motor driving device according to an embodiment of the disclosed invention.

Referring to FIG. 1 , the motor driving apparatus 1 according to an embodiment of the disclosed invention drives the motor 3 by receiving electric energy from a power source 2 and supplying a driving current to the motor 3 .

The power supply device 2 may be 110V/220V commercial AC power used for home use or high voltage AC power used for industrial purposes, and DC power supplied through a solar generator or the like may be employed.

The motor 3 may be a motor used for industrial purposes as well as a motor used for home appliances such as a washing machine, a refrigerator, or an air conditioner.

The driving device 1 includes a rectifier 10 that rectifies the AC voltage and AC current supplied from the power supply 2 into DC voltage and DC current, and a smoothing unit 20 that removes ripples included in the DC voltage and DC current. , a power conversion unit 30 that receives a direct current from the smoothing unit 20 and converts it into an alternating current to provide a driving current to the motor 3, a current sensing unit 50 for sensing the driving current of the motor 3 , a position sensing unit 50 for detecting the position of a rotor (not shown) included in the motor 3 , and a control unit 100 for controlling the overall operation of the driving device 1 , a control signal of the control unit 100 . and a switching signal generating unit 60 for generating a switching signal for controlling the power converting unit 30 in response.

2 is a view showing a rectifier according to an embodiment of the disclosed invention.

As shown in Figures 2 (a) and 2 (b), the rectifying unit 10 is a power supply device

The configuration may vary depending on the power supplied from (2). For example, when the power supplied from the power supply device 2 is a two-phase AC power supply, a diode bridge arranged so that a current conducts in one direction through two pairs of diodes as shown in FIG. 2(a) may be employed. , when the power supplied from the power supply device 2 is a three-phase AC power supply, a three-phase diode bridge arranged so that a current conducts in one direction through three pairs of diodes as shown in FIG. 2(b) may be employed.

However, when the power supply 2 shown in FIG. 1 supplies DC power, the rectifying unit 10 may be omitted, and the rectifying unit 10 further includes a PFC (Power Factor Correction) circuit for improving the power factor. can do.

3 is a diagram showing a power conversion unit employing a smoothing unit and a 2-level inverter according to an embodiment of the disclosed invention, and FIG. 4 is a smoothing unit and a 3-level diode clamped inverter according to an embodiment of the disclosed invention. It is a view showing a power conversion unit, Figure 5 is a view showing a power conversion unit employing a smoothing unit and a 3-level direct switching inverter according to an embodiment of the disclosed invention.

3 to 5, since the configuration of the smoothing unit 20 is changed according to the configuration of the power converting unit 30, the smoothing unit 20 and the power converting unit 30 will be described together.

Referring to FIG. 3 , when a two-level inverter is employed as the power conversion unit 30 , the smoothing unit 20 may include a capacitor C21 disposed between the output nodes of the rectifying unit 10 . Specifically, the smoothing unit 20 receives the DC voltage including the ripple from the rectifying unit 10, removes the ripple through the capacitor C21, and outputs Vdc/2 (V) through the upper output node Nh, -Vdc/2(V) is output through the lower output node Nl.

In addition, the two-level inverter includes three pairs of switches (S21 and S22, S23 and S24, S25 and S26) connected in series between the output nodes Nh and Nl of the smoothing unit 20, and the three pairs of switches (S21 and S21) According to the conduction or interruption of S22, S23 and S24, and S25 and S26), the 2-level inverter outputs Vdc/2(V) or -Vdc/2(V) through the output nodes U, V and W.

Referring to FIG. 4 , when a three-level diode clamped inverter is employed as the power conversion unit 30 , the smoothing unit 30 is disposed in series between the output nodes of the rectifying unit 10 and a pair of capacitors having the same capacity (C41, C42). Specifically, the smoothing unit 20 receives a DC voltage including a ripple from the rectifying unit 10, removes the ripple through a pair of capacitors C41 and C42, and Vdc/2 (V) through the upper output node Nh. ) and output 0(V) through the central output node Nc and -Vdc/2(V) through the lower output node Nl.

In addition, the 3-level diode clamped inverter is a pair of switches S41 and S42, S43 and S44, S45 and S46, S47 and S48, respectively connected in series between the output nodes Nh and Nc, Nc and Nl of the smoothing unit 20, 6 diodes D42, D43, D46, D47, D50, and D51 provided between the node to which the above-described pair of switches are connected and the output node Nc of the smoothing unit 20, including S49 and S50, S51 and S52 include The 3-level diode clad inverter outputs Vdc/2(V), 0(V), and -Vdc/2(V) through the output nodes U, V, and W according to the opening and closing of the 12 switches described above.

5, when a three-level direct switching inverter is employed as the power conversion unit 30, the smoothing unit 30 is disposed in series between the output nodes of the rectifying unit 10 and a pair of capacitors having the same capacity ( C1, C2). Specifically, the smoothing unit 20 receives a DC voltage including a ripple from the rectifying unit 10 and removes the ripple through a pair of capacitors C1 and C2 to Vdc/2 (V) through the output node Nh. and outputs 0(V) through the output node Nc and -Vdc/2(V) through the output node Nl.

In addition, the 3-level direct switching inverter includes three switches S1, S5, and S9 provided between the output node Nh of the smoothing unit 20 and the output nodes U, V, and W, and the output node Nc of the smoothing unit 20 and A pair of switches S2 and S3, S6 and S7, S10 and S11 arranged in series between the output terminals U, V, and W, and the output node Nl of the smoothing unit 20 and the output terminals U, V, W provided between It includes three switches S4, S8, and S12. In addition, in each switch, one transistor and one diode are arranged in parallel.

Specifically with respect to the output node U, the switch S1 is disposed between the output node U and the node Nh, the switch S2 and the switch S3 are disposed between the output node U and the node Nc in series, and the switch S4 is disposed between the output node U and the node Nl. is placed

In addition, when the switch S1 conducts, a voltage of Vdc/2 (V) is output through the output node U, and when the switches S2 and S3 become conductive, a voltage of 0 (V) is output through the output node U, and the switch S4 conducts Then, a voltage of -Vdc/2(V) is output through the output node U. Also, the output node V and the output node W have the same structure.

Hereinafter, it is assumed that the power conversion unit 30 employs a 3-level direct switching inverter.

Referring back to FIG. 1 , the current sensing unit 40 senses the three-phase driving current Iabc supplied from the power conversion unit 30 to the motor 3 . The current sensing unit 40 connects a shunt resistor (not shown) in series on a wire for supplying a driving current from the power conversion unit 30 to the motor 3 , and a shunt resistor (not shown) The driving current of the motor 3 can be sensed by detecting the voltage applied to both ends.

The position sensing unit 50 detects a position of a rotor (not shown) of the motor 3 . The position sensing unit 50 may employ a resolver, a hall sensor, or an encoder. Although the motor driving apparatus 1 according to an embodiment of the disclosed invention has the current sensing unit 40 and the position sensing unit 50 as separate components, the present invention is not limited thereto. When estimating the position of the rotor of the motor 3 based on the current (eg, counter electromotive force), the position sensing unit 50 may be omitted.

The switching signal generation unit 60 generates a switching signal for opening and closing each switch of the power conversion unit 30 according to the control signal of the control unit 100 . There is a difference between the voltage of the control signal output from the control unit 100 and the voltage for opening and closing the switch of the power conversion unit 30 . For example, when the power supply device 1 supplies 220V AC power, since 310V DC power is supplied from the smoothing unit 20 to the power conversion unit 30 , a signal for opening and closing the switch of the power conversion unit 30 . A switching signal for opening and closing the switch of the power conversion unit 60 according to the control signal of the control unit 100 because a voltage of at least several tens of V is required, whereas the control unit 100 normally outputs a control signal of 3.3V to 5V. A generator 60 is required.

Hereinafter, the control unit 100 will be described with reference to FIG. 6 showing the configuration of the control unit 100 of the motor driving apparatus 1 according to an embodiment of the disclosed invention.

Referring to FIG. 6 , the control unit 100 includes a speed calculation unit 110 , a first coordinate conversion unit 120 , a phase control unit 130 , a current control unit 140 , a second coordinate conversion unit 150 , an offset calculation unit ( 160 ), an output voltage generator 170 , and a pulse width modulator 180 .

The speed calculating unit 110 calculates the rotational speed ωrm of the rotor (not shown) based on the position of the rotor (not shown) of the motor 3 sensed by the above-described position detecting unit 50 . Specifically, the speed calculator 110 may calculate the rotational speed ωrm of the rotor (not shown) by differentiating the position of the rotor (not shown) with respect to time.

The first coordinate change unit 120 includes three-phase driving currents Ia, Ib, Ic sensed by the current sensing unit 40 based on the position of the rotor (not shown) sensed by the position sensing unit 50 . ) (Hereinafter, Ia, Ib, and Ic are collectively referred to as Iabc. ) is converted into dq-axis driving currents (Id, Iq) in the Cartesian coordinate system (hereinafter, Id and Iq are collectively referred to as Idq).

The phase control unit 130 integrates the dq-axis reference currents Id*, Iq* (hereinafter Id*, Iq*) based on the rotor (not shown) rotational speed ωrm calculated by the speed calculating unit 110 . is called Idq*. ) is calculated. Specifically, the phase control unit 130 outputs the dq-axis reference current Idq* for minimizing the current delay of the motor 3 due to the rotational speed ωrm. The reference current (idq*) is different depending on the load characteristics of the motor, and the method of calculating the reference current (idq*) will be described in detail below.

The current control unit 140 is a dq-axis reference voltage based on the dq-axis reference current (Idq*) calculated by the phase control unit 130 and the dq-axis driving current (Idq) calculated by the first coordinate conversion unit 130 . (Vd*, Vq*) (hereinafter, Vd* and Vq* are collectively referred to as Vdq*) is calculated. Specifically, the current controller 140 outputs a dq-axis reference voltage Vdq* for minimizing the difference between the dq-axis reference current Idq* and the dq-axis driving current Idq.

The second coordinate conversion unit 150 converts the dq-axis reference voltage Vdq* calculated by the current control unit 140 based on the position of the rotor (not shown) sensed by the position detection unit 50 into three phases. Converts to reference voltages (Vas*, Vbs*, Vcs*) (hereinafter, Vas*, Vbs*, and Vcs* are collectively referred to as Vabcs*).

The offset calculating unit 160 calculates the offset voltage Vsn based on the dq-axis reference current Idq* calculated by the phase control unit 130 and the dq-axis reference voltage Vdq* calculated by the current control unit 140 . print out

The output voltage generating unit 170 adds the three-phase reference voltage Vabcs* calculated by the second coordinate conversion unit 150 and the offset voltage Vsn calculated by the offset calculating unit 160 to the three-phase driving voltage ( Van*, Vbn*, Vcn*) (Hereinafter, Van*, Vbn*, and Vcn* are collectively referred to as Vabcn).

In addition, the output voltage generator 170 pulse width modulates the three-phase driving voltage Vabcn to generate a control signal for opening and closing each switch of the power converter 30 , and output it to the switching signal generator 60 . do.

7 is a flowchart illustrating a method of controlling a motor driving apparatus according to an embodiment of the disclosed invention.

Referring to FIG. 7 , the motor driving device 1 includes a three-phase driving current of the motor 3 .

(iabc) and detects the position of the rotor (210).

Next, the motor driving device 1 converts the three-phase driving current iabc into the dq-axis driving current idq based on the position of the rotor ( 215 ).

Next, the motor driving device 1 calculates the rotational speed ωrm of the rotor based on the sensed position of the rotor of the motor ( 220 ).

Next, the motor driving apparatus 1 calculates the dq-axis reference current Idq* based on the rotational speed ωrm of the motor and the torque load of the motor (230). The reference current (idq*) is different depending on the load characteristics of the motor, and the method of calculating the reference current (idq*) will be described in detail below.

Next, the motor driving device 1 calculates the dq-axis reference voltage Vdq* based on the difference between the dq-axis reference current Idq* and the dq-axis driving current Idq (240).

Next, the motor driving device 1 converts the dq-axis reference voltage (Vdq*) into a three-phase reference voltage (Vabcs*) based on the position of the rotor ( 245 ).

Next, the motor driving device 1 calculates the offset voltage Vsn based on the dq-axis reference current Idq* and the dq-axis reference voltage Vdq* (250).

Next, the motor driving device 1 calculates the three-phase driving voltage Vabcn by adding the three-phase reference voltage Vabcs* and the offset voltage Vsn ( 260 ).

Next, the motor driving apparatus 1 generates a control signal for controlling the power converter 30 by pulse width modulation of the three-phase driving voltage Vabcn ( 270 ).

Next, the motor driving device 1 generates a three-phase driving current Iabc for driving the motor 3 by controlling the power conversion unit 30 according to the control signal ( 280 ).

Hereinafter, a method of calculating the reference current idq* by the motor driving apparatus 1 through the phase control unit 130 according to an embodiment of the disclosed invention will be described.

8 is a block diagram of the phase control unit 130 according to an embodiment.

Referring to FIG. 8 , the phase control unit 130 includes a first phase shifter 130 - 1 and a second phase shifter 130 - 2 that change the phase of the driving current idq.

The first phase shifter 130-1 converts the phase of the driving current idq based on the rotation speed wrm and the lead angle of the motor.

Specifically, the first phase shifter 130-1 adds a lead angle for changing the phase of the driving current to the phase of the driving current in consideration of the delayed phase, and calculates the result by adding the result to the first reference current It can be implemented as an addition operator outputting as .

The read angle is an input value of the first phase shifter for changing the phase of the driving current, may be a value stored in advance by a separate storage unit (not shown), and received by a user or a manufacturer through an input unit (not shown) can be a value. Also, it may be a value calculated by a separate lead angle calculator (not shown). In this regard, it will be described later.

9 is a graph of the load characteristics of the motor, and FIG. 10 is a graph of phase delay according to an increase in the rotational speed of the motor.

Referring to FIG. 9 , due to the load characteristics of the motor, when the rotation speed of the motor is gradually increased in a no-load state, a load L is generated in the motor, and the load is proportional to the rotation speed of the motor. In this case, the load L generated in the motor may be an inductance L[H] proportional to the rotation speed.

In addition, referring to FIG. 10A , a phase difference between the induced current (eg, counter electromotive force) and the driving current idq of the motor does not occur in the no-load state. However, referring to FIG. 10B , when the load increases, the motor A phase difference occurs between the induced current (eg, counter electromotive force) and the driving current idq.

As such, when the load L increases, the phase delay of the driving current idq applied to the motor increases. When the load is an inductance L[H], the driving current ( idq) is not synchronized to the rotor and a phase delay occurs.

Therefore, it is necessary to apply a lead angle that advances the phase of the driving current in advance according to the rotational speed wrm of the rotor (not shown) to the driving current, and the first phase shifter is the speed calculating unit 110 as shown in FIG. 10C . The lead angle a corresponding to the rotation speed wrm of the motor calculated by is added to the phase of the driving current, and the result is output as the first reference current.

Referring back to FIG. 8 , the second phase shifter changes the phase of the first reference current output from the first phase shifter in consideration of load characteristics of different motors depending on the type of the motor, and outputs the result as the second reference current. It can be implemented as a multiplication operator. A description related to a method of controlling the first phase shifter and the second phase shifter will be described later with reference to FIG. 11 .

11 is a control flowchart of a phase controller according to an exemplary embodiment.

Referring to FIG. 11 , the first phase shifter controls the phase of the driving current idq to advance by the read angle ( 310 ). That is, the first phase shifter outputs the first reference current by adding the phase and the read angle of the driving current idq.

Referring back to FIGS. 9 and 10B , when the rotation speed of the motor increases in a no-load state, a load (eg, inductance) is generated in the motor due to the increase in the rotation speed, and the driving current due to the increase in the load is generated. delay occurs.

That is, the delayed phase of the driving current increases in proportion to the rotation speed wrm of the motor.

Referring to FIG. 10C , the first phase shifter according to an exemplary embodiment may calculate a lead angle a based on an inductance induced by an increase in the rotation speed wrm of the motor, and convert the lead angle a to a driving current. It can be added to the phase of (idq). Meanwhile, the lead angle a may be calculated by an external separate lead angle calculator (not shown), and may be a predetermined value proportional to the inductance.

Meanwhile, the cause of the phase delay may be different depending on the type of the motor, and for example, a current delay due to a reluctance torque may also occur in addition to the current delay due to an increase in the rotational speed.

There are generally widely used induction motors and synchronous motors that are increasingly being introduced for the purpose of saving energy. There are two types: a Surface Permanent Magnet Synchronous Motor (SPMSM) and an Interior Permanent Magnet Synchronous Motor (IPMSM) with a permanent magnet embedded in the rotor.

The embedded permanent magnet synchronous motor in which the permanent magnet is inserted into the rotor has magnetic torque and reluctance torque due to its structural characteristics.

12A is a surface-mounted permanent magnet synchronous motor, and FIG. 12B is a simplified view of the exterior of the embedded permanent magnet synchronous motor.

Since the surface-attached permanent magnet synchronous motor has the same magnetic permeability as the vacuum permeability of the permanent magnet attached to the surface, the magnetic resistance of the part where the permanent magnet is present is the same as the air gap. Therefore, in the surface-mounted permanent magnet synchronous motor, there is no reluctance torque and only magnetic torque is generated.

On the other hand, referring to FIG. 13 , in the embedded permanent magnet synchronous motor of FIG. 12B in which the permanent magnet is embedded in the iron core of the rotor, a permanent magnet magnetically equivalent to the air gap is placed in the magnetic flux path in the d-axis direction made by the armature winding. Therefore, the magnetic resistance is large, and in the magnetic flux path in the q-axis direction, the magnetic flux penetrates only the iron core, so the magnetic resistance is small.

This difference in magnetoresistance is a factor that generates reluctance torque in addition to magnetic torque in the embedded permanent magnet synchronous motor.

Accordingly, the embedded permanent magnet synchronous motor can generate maximum output torque because the reluctance torque generated from the magnetoresistance difference according to the rotor position is added to the magnetic torque resulting from the permanent magnet.

The torque of the embedded permanent magnet synchronous motor can be expressed as Equation (1).

는 영구자석에 의한 전기자쇄교자속 실효치,

, ie는 상전류 실효치,

, β는 전류 위상각, Ld는 d축 인덕턴스, Lq는 q축 인덕턴스, Tm은 마그네틱 토크, Tr은 릴럭턴스 토크를 의미한다. where Pn is an even number,

is the effective value of the magnetic flux linkage by the permanent magnet,

, ie is the rms phase current,

, β is the current phase angle, Ld is the d-axis inductance, Lq is the q-axis inductance, Tm is the magnetic torque, and Tr is the reluctance torque.

Referring to Equation 1, the magnetic torque is proportional to the amount of armature flux linkage by the permanent magnet to the current, the reluctance torque is proportional to the inductance difference between the d-axis and the q-axis, and is proportional to the square of the driving current Ia.

That is, the generated torque of the embedded permanent magnet synchronous motor is generated by adding the magnetic torque component and the reluctance torque. There is a need.

14 is a characteristic graph of a lead angle according to a type of a motor.

14A is a surface mounted permanent magnet synchronous motor, and a driving current idq may be applied in consideration of only a lead angle by a magnetic torque component. However, the embedded permanent magnet synchronous motor of FIG. 13B has a reluctance torque. The driving current idq must be applied in consideration of the change in the read angle caused by this.

Accordingly, the second phase shifter according to an exemplary embodiment may change the phase of the driving current idq based on a change value of a lead angle according to an increase in torque load of the motor ( 320 ).

Specifically, the second phase shifter receives the change value of the lead angle according to the torque load according to the motor type as the slope, multiplies the slope with the current torque load to calculate the lead angle of the driving current idq, and the driving current ( The second reference current idq* in which the phase of idq) is changed may be calculated.

On the other hand, the lead angle change value according to the increase in the torque load of the motor is an input value of the second phase shifter for changing the phase of the driving current idq, and may be previously stored in a storage unit (not shown), and may be a user or a manufacturer. It may have been input from the input unit (not shown). Also, it may be a value calculated by a separate lead angle calculator (not shown).

The lead angle calculator (not shown) may be implemented as, for example, a phase difference detection torque sensor, and the phase difference detection torque sensor detects a lead angle (phase difference) caused by a torque load, and there are magnetic and optical detection methods. It is not necessarily limited thereto.

According to this embodiment of the motor driving apparatus and its control method, it is possible to efficiently control the motor in consideration of the rotational speed and load of the motor, and to control the motor based on the current phase changed by the torque load of the rotor. have.

In the above, one embodiment of the disclosed invention has been illustrated and described, but the disclosed invention is not limited to the specific embodiments described above, and those of ordinary skill in the art to which the disclosed invention belongs without departing from the gist of the claims Various modifications are possible, of course, and these modifications cannot be individually understood from the disclosed invention.

1: Motor drive
2: Power
3: Motor
10: rectification unit
20: smooth part
30: power conversion unit
40: current sensing unit
50: position detection unit
60: switching signal generator
100: control unit

Claims (20)

a rectifier for rectifying the AC voltage and AC current supplied from the power supply into DC voltage and DC current;
a smoothing unit for removing ripples included in the DC voltage and the DC current;
a power conversion unit receiving a direct current from the smoothing unit and converting it into an alternating current to provide a driving current to the motor; and
A control unit for controlling the power conversion unit to change the phase of the driving current according to the rotational speed and torque load of the motor,
The control unit receives a change value of the lead angle according to the torque load, and multiplies the change value by the torque load of the motor. The method of claim 1,
The controller is configured to control the phase of the driving current to change based on a change value of a lead angle of the driving current according to the increase in the torque load. The method of claim 1,
The controller is a motor driving device for controlling the phase of the driving current to change according to a torque load due to the reluctance torque of the motor. delete 3. The method of claim 1 or 2,
The lead angle change value is different depending on the type of motor. The method of claim 1,
The control unit is a motor driving device for controlling the power conversion unit based on a load according to the rotational speed of the motor and a torque load according to the reluctance torque of the motor. The method of claim 1,
The controller is a motor driving device for calculating the phase delayed according to the rotational speed of the motor by adding the phase of the driving current. The method of claim 1,
The controller is a motor driving device for controlling the phase of the driving current to advance by a phase delayed according to the rotation speed of the motor. The method of claim 1,
The control unit receives a lead angle and controls a first phase shifter to change the phase of the driving current, and a second phase shifter for controlling the phase of the driving current to change by receiving a lead angle change value according to an increase in torque load of the motor. A motor driving device including a phase shifter. 10. The method of claim 9,
The second phase shifter is a motor driving device that receives a different lead angle change value according to the type of the motor. a rectifier for rectifying the AC voltage and AC current supplied from the power supply into DC voltage and DC current;
a smoothing unit for removing ripples included in the DC voltage and the DC current;
a power conversion unit receiving a direct current from the smoothing unit and converting it into an alternating current to provide a driving current to the motor; and
a control unit for controlling the power conversion unit to change the phase of the driving current according to the reluctance torque of the motor;
The control unit receives a change value of the lead angle according to the reluctance torque of the motor, and multiplies the change value by the torque load of the motor. 12. The method of claim 11,
The control unit controls the power conversion unit to apply a lead angle corresponding to a torque load due to the reluctance torque of the motor to the driving current. delete 12. The method of claim 11,
The controller additionally controls a phase of the driving current to change according to a delay degree of the driving current according to an increase in the rotation speed of the motor. 12. The method of claim 11,
The control unit is
a phase control unit configured to calculate a reference current based on a delay degree of the driving current according to the rotation speed of the motor and a change value of a lead angle due to the reluctance torque;
a current control unit for calculating a reference voltage based on the driving current and the reference current;
and an output signal generator for calculating a driving voltage for driving the motor based on the reference voltage, and outputting a control signal for controlling the power converter by pulse width modulation of the driving voltage. In the control method of a motor driving device comprising a power converter for converting a DC current into an AC current to provide a driving current to the motor,
detecting the rotation speed of the motor and the driving current;
generating a reference current having a different phase according to a load of the motor based on the rotation speed and the driving current;
Comprising driving the motor based on the generated reference current,
To generate the reference current,
receiving a change value of the lead angle according to the torque load of the motor;
A control method of a motor driving apparatus to generate a reference current by multiplying the change value with the torque load of the motor. 17. The method of claim 16,
To generate the reference current,
adding a phase delay value of the driving current according to the rotation speed to the phase of the driving current;
and generating a reference current based on a lead angle change value of the driving current according to the torque load of the motor. delete 17. The method of claim 16,
To generate the reference current,
A method of controlling a motor driving apparatus to generate a reference current having different phases according to the reluctance torque of the motor. 17. The method of claim 16,
The receiving of the change value of the lead angle according to the load is a control method of a motor driving apparatus that receives a different lead angle change value according to the type of the motor.

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