KR20180108099A - Apparatus for driving parallel motors and air conditioner including the same - Google Patents

Abstract

The present invention relates to an air conditioner, and more specifically, to a motor driving apparatus and an air conditioner including the same. According to the present invention, the motor driving apparatus includes: a motor unit including a first motor and second motor connected to the first motor in parallel; an inverter which outputs driving signals for driving the motor unit; and an inverter control unit for controlling the inverter. The inverter control unit includes: a sensing unit for sensing the speed and location of the first and second motors; a speed control unit which generates a target speed and target current based on the speed of the first motor sensed by the sensing unit; a current control unit which generates a target voltage based on the target current; a driving signal generation unit which generates the driving signals based on the location of the first motor sensed by the sensing unit and the generated target voltage; and a resonance control unit which estimates the location and speed differences between the first and second motors to generate a correction current which corrects the current control unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a driving apparatus for a parallel operation motor, and an air conditioner including the same.

The present invention relates to an air conditioner, and more particularly, to a driving apparatus for a parallel operation motor and an air conditioner including the same.

Generally, a compressor of an air conditioner uses a motor as a driving source. These motors are supplied with AC power from a power conversion device. In this case, the power conversion device may mean a motor driving device.

Such a power conversion apparatus is generally known to include a rectifying section, a power factor control section, and an inverter.

First, the commercial voltage of the AC output from the commercial power source is rectified by the rectifying part. The rectified voltage at this rectifying part is supplied to the inverter. At this time, the inverter generates AC power for driving the motor by using the voltage outputted from the rectifying section.

The two motors can be simultaneously connected and controlled by the motor driving device including such an inverter. At this time, one of the two motors is controlled by the inverter 140 and the inverter control unit, but in the case of an uncontrolled motor, the operation may become unstable and cause a problem of divergence.

For example, the difference in speed between two motors becomes larger and the phase current of a motor that is not directly controlled may gradually diverge and eventually stop.

Therefore, in the case where two motors are simultaneously connected and controlled by the motor driving apparatus, a method for stably controlling these two motors is required.

SUMMARY OF THE INVENTION The present invention is directed to a driving apparatus for a parallel operation motor capable of suppressing divergence caused by resonance that may occur in a parallel operation in which two motors are simultaneously connected and controlled by a motor driving apparatus and an air conditioner .

The present invention also relates to a driving apparatus for a parallel operation motor and an air conditioner including the same, which can obtain a damping effect in a parallel operation in which two motors are simultaneously connected and controlled by a motor driving apparatus, .

According to a first aspect of the present invention, there is provided a motor control apparatus comprising: a motor unit including a first motor and a second motor connected in parallel with the first motor; An inverter for outputting a drive signal for driving the motor unit; And an inverter control unit for controlling the inverter, wherein the inverter control unit comprises: a sensing unit for sensing a speed and a position of the first motor and the second motor; A speed control unit for generating a target current based on a target speed and a speed of the first motor sensed by the sensing unit; A current controller for generating a target voltage based on the target current; A drive signal generator for generating a drive signal based on the generated target voltage and the position of the first motor sensed by the sensing unit; And a resonance control unit for generating a compensating current by estimating a difference between the speed and the position of the first motor and the second motor and compensating the current to the current control unit.

Here, the compensation current may be a value obtained by multiplying a speed difference between the first motor and the second motor by a difference in position.

In this case, the compensation current may be a value obtained by multiplying the difference between the speeds of the first motor and the second motor by the difference of the position, and a proportional gain.

Here, the compensation current may be a value that generates a damping torque for driving the first motor.

Here, the resonance control unit may include: an estimating unit that estimates a difference between a speed and a position of the first motor and the second motor; And a resonance suppression controller multiplying a difference value between the estimated speed and the position by a proportional gain to generate a compensating current and injecting the compensating current into the current control unit.

Here, the compensation current may be applied to the d-axis current side of the current control unit.

Here, the sensing unit includes: a first phase current detector for sensing a first current that drives the first motor; A second phase current detector for sensing a second current for driving the second motor; And an estimator for estimating a velocity and a position using the first current and the second current.

Here, the sensing unit may include: a first position sensor for sensing a position of the first motor; A second position sensor for sensing a position of the second motor; And a speed calculator for calculating speed using a value sensed by the first position sensor and the second position sensor.

According to a second aspect of the present invention, there is provided a method of driving a motor unit including a first motor and a second motor connected in parallel with the first motor, Sensing the speed and position of the motor; Generating a target current based on the target speed and the sensed speed of the first motor; Generating a target voltage based on the target current; Generating a drive signal based on the generated target voltage and the sensed position of the first motor; And compensating for the target current by generating a compensation current by estimating the difference between the speed and the position of the first motor and the second motor.

The air conditioner may include the driving device or may be driven by the driving method.

The present invention has the following effects.

First, it is possible to suppress divergence caused by resonance that may occur in parallel operation in which two motors are simultaneously connected and controlled by the motor driving device.

In addition, a damping effect can be obtained in a parallel operation in which two motors are simultaneously connected and controlled by a motor driving device, thereby stabilizing the entire system.

1 is a block diagram showing a power conversion apparatus according to an embodiment of the present invention.
2 is a circuit diagram showing a power conversion apparatus according to an embodiment of the present invention.
3 is a block diagram showing details of an inverter control unit according to an embodiment of the present invention.
4 is a block diagram showing details of an inverter control unit according to another embodiment of the present invention.
5 is a graph showing the damping current, the damping torque, and the damping coefficient of the system shown in Fig.
6 shows waveforms when the resonance control of the present invention is not performed.
7 shows waveforms when the resonance control of the present invention is performed.
8 shows waveforms of the load variation characteristic at the time of application of the resonance control of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

FIG. 1 is a block diagram showing a motor driving apparatus according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a motor driving apparatus according to an embodiment of the present invention.

1 and 2, the power inverter 100 includes a rectifier 110 for rectifying an AC power source 10, a converter 120 for controlling the power factor of the DC voltage rectified by the rectifier 110, A converter control unit 130 for controlling the converter 120, an inverter 140 for outputting a three-phase AC current, an inverter control unit 150 for controlling the inverter 140 and a converter 120 and an inverter 140, And a DC-link capacitor C between the DC-link capacitors.

This inverter 140 outputs a three-phase alternating current, and this output current is supplied to the motor 200. Here, the motor 200 may be a compressor motor for driving the air conditioner. Hereinafter, the motor 200 is a compressor motor that drives the air conditioner, and the power inverter 100 is a motor driving device that drives such a compressor motor.

However, the motor 200 is not limited to a compressor motor and can be used in various applications using frequency-varying alternating voltages, for example, AC motors such as refrigerators, washing machines, electric trains, automobiles, and vacuum cleaners.

Further, as shown in FIG. 2, the motor 200 may include two motors 210 and 220. In this manner, the two motors 210 and 220 can be driven by one inverter 140.

The two motors 210 and 220 may be motors other than compressors such as fan motors.

The motor driving apparatus 100 may further include a DC voltage detection unit B, an input voltage detection unit A, an input current detection unit D, and an output current detection unit E.

The motor drive apparatus 100 receives the AC power from the system, converts the power, and supplies the converted power to the motor 200.

The converter 120 converts the input AC power supply 10 into a DC power supply. The converter 120 may use a DC-DC converter operating as a power factor control (PFC) unit. In addition, such a DC-DC converter can use a boost converter. Optionally, the converter 120 may be a concept that includes the rectifier 110. Hereinafter, the converter 120 will be described by way of example using a step-up converter.

The rectifying unit 110 receives and rectifies the single-phase AC power supply 10 and outputs the rectified power to the converter 120 side. For this purpose, the rectifying part 110 can use a full-wave rectifying circuit using a bridge diode.

In this way, the converter 120 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifier 110.

The converter 120 includes an inductor L1 connected to the rectifying section 110, a switching element Q1 connected to the inductor L1, and a switching element Q1 connected between the switching element Q1 and the DC- And a diode D1.

The boost converter 120 can obtain an output voltage higher than the input voltage. When the switching device Q1 is turned on, the diode D1 is cut off and energy is stored in the inductor L1, and the DC-link capacitor C ) Discharges and generates an output voltage at the output terminal.

Further, when the switching element Q1 is interrupted, the energy stored in the inductor L1 at the time of the switching element Q1 is added and is transferred to the output terminal.

Here, the switching device Q1 may perform a switching operation by a separate pulse width modulation (PWM) signal. That is, the PWM signal transmitted from the converter control unit 130 is connected to the gate (or base) terminal of the switching element Q1, and the switching operation can be performed by the PWM signal.

The converter control unit 130 may include a gate driver for transmitting a PWM signal to a gate terminal of the switching element Q1 and a controller for transmitting a driving signal to the gate driver.

The switching element Q1 may use a power transistor, for example, an insulated gate bipolar mode transistor (IGBT).

The IGBT is a switching device having a structure of a metal oxide semi-conductor field effect transistor (MOSFET) and a bipolar transistor. The IGBT has a small driving power and is capable of high-speed switching, high-voltage conversion, and high current density.

In this manner, the converter control unit 130 can control the turn-on timing of the switching element Q1 in the converter 120. [ Thus, the converter control signal Sc for the turn-on timing of the switching element Q1 can be output.

The converter controller 130 may receive the input voltage Vs and the input current Is from the input voltage detector A and the input current detector D, respectively.

Optionally, such converter 120 and converter control 130 may be omitted. That is, the output voltage through the rectifying unit 110 can be charged to the DC-link capacitor C without passing through the converter 120, or the inverter 140 can be driven.

The input voltage detecting section A can detect the input voltage Vs from the input AC power supply 10. [ For example, at the front end of the rectifying part 110. [

The input voltage detecting section A may include a resistance element, an OP AMP, or the like for voltage detection. The detected input voltage Vs can be applied to the converter control unit 130 to generate a converter control signal Sc as a discrete signal in the form of a pulse.

Next, the input current detection unit D can detect the input current Is from the input AC power supply 10. [ Specifically, it may be located at the front end of the rectifying section 110. [

The input current detection unit D may include a current sensor, a current transformer (CT), a shunt resistor, or the like, for current detection. The detected input voltage Is may be applied to the converter control unit 130 to generate the converter control signal Sc as a discrete signal in the form of a pulse.

The DC voltage detecting section B detects the pulsating voltage Vdc of the DC-link capacitor C. For such power detection, a resistance element, OP AMP, or the like can be used. The voltage Vdc of the detected DC-link capacitor C may be applied to the inverter control unit 150 as a discrete signal in the form of a pulse, and the DC voltage Vdc of the DC-link capacitor C The inverter control signal Si can be generated.

On the other hand, unlike the drawing, the detected DC voltage is applied to the converter control unit 130 and may be used for generating the converter control signal Sc.

The inverter 140 includes a plurality of inverter switching elements Qa, Qb, Qc, Qa ', Qb', and Qc ', and is turned on and off by the switching element Q1 of the converter 120 It is possible to convert the direct-current power supply Vdc into a three-phase alternating-current power supply having a predetermined frequency, and output it to the three-phase motor 200.

Specifically, the inverter 140 is a pair of the upper switching elements Qa, Qb, and Qc and the lower switching elements Qa ', Qb', and Qc 'that are serially connected to each other, and a total of three pairs of upper and lower switching The devices can be connected in parallel with each other.

The switching elements Qa, Qb, Qc, Qa ', Qb', and Qc 'of the inverter 140 may be power transistors, for example, an insulated gate bipolar transistor bipolar mode transistor (IGBT)).

The inverter control unit 150 can output the inverter control signal Si to the inverter 140 in order to control the switching operation of the inverter 140. [ The inverter control signal Si is a switching control signal of the pulse width modulation method PWM and is based on the output current io flowing through the motor 200 and the DC- link voltage Vdc across the DC- Can be generated and output. The output current io at this time can be detected from the output current detecting portion E and the DC-link voltage Vdc can be detected from the DC-link voltage detecting portion B.

The inverter controller 150 includes a gate driver for transmitting a PWM signal to the gate of the switching elements Qa, Qb, Qc, Qa ', Qb' and Qc 'included in the inverter 140, And a control unit for transmitting a driving signal to the driving unit.

The phase current detector E can detect the output current io flowing between the inverter 140 and the motor 200. [ That is, the current flowing in the motor 200 is detected. The phase current detector E may detect all the output currents ia, ib, ic of each phase or may detect the output currents of the two phases using a three-phase balance.

The phase current detector E may be located between the inverter 140 and the motor 200. For current detection of each phase, a current transformer (CT), a shunt resistor, or the like may be used.

As mentioned above, the two motors including the first motor (motor 1) 210 and the second motor (motor 2) 220 can be simultaneously driven by the inverter 140. At this time, the first motor 210 may be a main motor controlled by the inverter control unit 150.

The second motor 220 may be an auxiliary motor that is driven by the inverter control unit 150 but is not under the control of the inverter. That is, the first motor 210 may be a master motor, and the second motor 220 may be a slave motor connected thereto.

Accordingly, the first motor 210 and the second motor 220 are simultaneously driven by the output currents ia, ib, ic. At this time, the output currents ia, ib, It can be used as a control element for driving.

The inverter control unit 150 controls the first motor 210 as a master motor and the second motor 220 as a slave motor by using one inverter 140 And these motors are referred to as parallel operation motors), it is possible to perform control (hereinafter, referred to as resonance control) for suppressing divergence caused by resonance that may occur in parallel operation.

According to the present invention, the inverter controller 150 controls the slave motor (second motor) 220, which is generated while controlling the parallel operation motor in the master-slave manner, as the master motor (first motor; 210 can be directly compensated for the d-axis control current value of the master motor 210 by multiplying the difference between the position angles of the rotor and the speed difference. A detailed description thereof will be described later.

3 is a block diagram showing details of an inverter control unit according to an embodiment of the present invention.

3, a detailed configuration of the inverter control unit 150 is shown and includes a first motor 210 and a second motor 220 connected in parallel with the first motor 210 And the motor unit 200 are shown together.

In addition, a first phase current detector E and a second phase current detector E 'for detecting a current flowing through the first motor 210 and the second motor 220 are represented, respectively. The difference between the position (position angle) and the speed of the first motor 210 and the second motor 220 is detected by a sensorless method through the first phase current detector E and the second phase current detector E ' Can be detected.

The inverter control unit 150 may mainly use a proportional integral control (PWM) motor control method.

That is, the inverter control unit 150 of the proportional plus integral control system includes a speed control unit 151, a current control unit 152, a drive signal PWM generation unit 153, a sensing unit 154, and a resonance control unit 157 .

Hereinafter, such a configuration will be described in detail.

First, the sensing unit 154 senses the speed and position of the first motor 210 and the second motor 220 and outputs the speed and position value of the first motor 210 have.

The speed controller 151 can generate the target current based on the target speed (speed command value) and the speed of the first motor 210 sensed by the sensing unit 154. [

The current controller 152 can generate the target voltage V ^* (voltage command value) based on the target current I ^* (current command value) output from the speed controller 151.

The driving signal generating unit 153 generates a driving signal PWM signal based on the target voltage V ^* generated by the current controller 152 and the position of the first motor 210 sensed by the sensing unit 154 can do.

The drive voltage Vabc is generated in the inverter 140 by the drive signal (PWM signal), and the first motor 210 and the second motor 220 can be driven by the drive voltage V _abc .

The resonance controller 157 can estimate the difference between the speed and the position of the first motor 210 and the second motor 220 and generate a compensation current to compensate the current controller 152.

At this time, the compensation current may be a value obtained by multiplying the difference between the speeds of the first motor 210 and the second motor 220 and the difference in position.

On the other hand, the compensation current may be a value obtained by multiplying the difference between the speeds of the first motor 210 and the second motor 220 by the difference of the position and the proportional gain K.

Here, the compensation current may be a value that generates a damping torque for driving the first motor 210. [

The resonance control unit 157 includes an estimation unit 159 for estimating the difference between the speed and the position of the first motor 210 and the second motor 220, And a resonance suppression control unit 158 for multiplying the difference value by a proportional gain K to generate a compensation current and inject it into the current control unit 152 side.

The compensation current generated in this process can be applied to the d-axis current side of the current controller 152. [

Here, the d-axis means one axis in the rotation synchronous coordinate system. In the rotation synchronous coordinate system, the three-phase information is represented by two orthogonal coordinates (d-axis and q-axis).

Thus, the compensation current (current reference) applied to the current control unit 152 is directly compensated for the d-axis of the drive control value for driving the first motor 210, which is the master motor, to obtain a damping effect, The entire system can be stabilized.

Meanwhile, the sensing unit 154 for sensing the speed and position of the first motor 210 and the second motor 220 may be realized by a sensorless method or a sensor method.

First, in the case of a sensorless method that does not include a sensor, the velocity and position can be estimated using the current sensed by the phase current detector E.

That is, the sensing unit 154 includes a first phase current detector E for sensing a first current for driving the first motor 210, a second phase current detector E for sensing a second current for driving the second motor 220, And a estimating unit 155 estimating a velocity and a position using the detecting unit E 'and the first current and the second current.

As shown in the figure, among the speed and position (position angle) values of the first motor 210 estimated by the sensing unit 154 through the estimating unit 155, the speed values are added to the speed command values, And the position value may be fed back to the driving signal generation unit 153. [

Meanwhile, as described above, the sensing unit 154 may be implemented in a sensor manner.

4 is a block diagram showing details of an inverter control unit according to another embodiment of the present invention.

Referring to FIG. 4, the sensing unit 154 includes a sensor.

That is, the sensing unit 154 includes a first position sensor F for sensing the position angle of the first motor 210 and a second position sensor F 'for sensing the position angle of the second motor 220, And a speed calculator 156 for calculating the speed using the sensed values from the first position sensor F and the second position sensor F '.

As shown in the figure, the velocity values of the first motor 210 computed by the sensing unit 154 through the velocity computation unit 156 are applied to the speed control unit 151 in addition to the speed command values, respectively, F and the second position sensor F 'may be fed back to the drive signal generator 153. [

The remaining parts are the same as those described with reference to FIG. 3, and therefore repeated description will be omitted.

As described above, when the two motors 210 and 220 are simultaneously driven by one inverter 140, the position of the two motors 210 and 220 on the d axis of the motor (first motor 210) Resonance can be suppressed by injecting a current proportional to a value obtained by multiplying the difference between the angles and the speed difference to the current reference. Accordingly, the two motors 210 and 220 can be stably controlled by using one inverter 140. FIG.

Hereinafter, the process of deriving the principle of resonance suppression and the effect thereof will be described in detail.

As shown in FIG. 2, when two motors 210 and 220 are operated using one inverter 140, resonance may occur due to inherent characteristics of the entire system.

At this time, the master motor 210 (the first motor) of the two motors 210 and 220 is controlled by the inverter 140 and the inverter control unit 150, but in the case of the slave motor 220 (the second motor) There may arise a problem that the operation of the second motor 220 becomes unstable and divergence occurs.

For example, the difference in speed between the two motors 210 and 220 gradually increases, and the phase current of the second motor 220, which is a slave motor, gradually diverges and eventually stops.

When the two motors 210 and 220 are operated by one inverter 140, the dynamic characteristics of the entire system are expressed by Equation (1).

In Equation 1, J ₂ is the moment of inertia of the second motor 220, and B ₂ is the damping coefficient of the overall system connected to the second motor 220. Here, J ₂ denotes the moment of inertia of the entire motor including the entire system connected to the second motor 220, that is, the fan, the rotary shaft, and the like.

Further, ω _md denotes ω _{m 2} - ω _m1 , that is, a difference between angular velocities of two motors, and p denotes a pole pair (pole number / 2) of the motor.

And, ω _r means the electrical rotation speed, which is the angular speed in the electrical position. That is, the electric frequency and the pole number of the motor are considered. For example, if the mechanical frequency of a four-pole motor is 60 Hz, the electrical frequency is 120 Hz (ω _r = ω _m * number of motor poles / 2).

는 모터 1의 동기 좌표계(synchronous reference frame)에서의 모터 1의 d축 전류, 그리고 α는 아래 수학식 2와 같다.In Equation 1, θ _md is the difference in position angles of two motors, R _s is the resistance of the stator, T _d is the disturbance torque externally applied, L _s is the phase inductance of the motor ), λ _f is the flux linkage from the permanent magnet,

Is the d-axis current of the motor 1 in the synchronous reference frame of the motor 1, and?

Equation (1) is a formula representing the behavior of two typical motors including mass, damper, and the like. When damping is not sufficient,? _D (difference in position angles of two motors) is amplified by disturbance.

항이 댐핑 토크(damping torque)를 발생시키도록 제어할 수 있다.At this time, in order to ensure that the system does not diverge and has stability, in Equation (1)

So as to generate a damping torque.

That is, if the d-axis current (i _d ) is controlled as shown in Equations (3) to (5) below to provide a damping effect of the system, an effect of adding a damper to the system can be obtained, Do.

As described above, the torque of the slave motor (second motor) generated by the d-axis current of the master motor (first motor) can be used to generate additional damping torque as shown in Equations 3 to 5. [

That is, the command value of the damping torque (T ^* damp) is an equivalent damping coefficient (B _eq; as a function of the position difference) and the difference in speed; inde product of (the speed of the first motor speed of the second motor ω _d), At the motor, this damping torque can be represented by K _T * position difference * i _d .

Where K _T is the torque constant of the motor (a value determined when the motor is designed).

From this equation, the damping current, damping torque and damping coefficient of the system can be interpreted as shown in FIG. 5 below.

5 is a graph showing the damping current, the damping torque, and the damping coefficient of the system shown in Fig.

In FIG. 5, T _L1 and T _L2 represent load torques 1 and 2, respectively. This means the load torque applied to each motor. In addition, (a) of Figure 5 when the T T _L1 and _L2 be the same, (b) if a T _L1 is greater than _L2 T, (c) shows a case where T is greater than T _{L1 L2.}

Here, an average difference of the position angles of the motors may occur depending on the load difference, and the average value may be positive or negative depending on the load. That is, if T _L1 is larger, θ _d moves in the + direction in FIG. 5, and if T _L2 is larger, θ _d moves in the minus direction.

If also the pulsation in the first graph, the system pulse wave sine wave of 5, since θ _d is a view of the pulsation cycle of the resonance of the ω _n (sin function type), and the third graph form of a fine powder of θ _d them cos ( cos) function.

5, the command value (i ^* _d1 ) of the d-axis current (i _d1 ) of the first motor is in the form of sin * cos from the equation (5) have.

As shown in the graph at the bottom of Fig. 5, the damping effect in the case of injecting the current command value as described above implies that the damping torque of the form in which the damping coefficient also changes with time is expressed by Equation (4).

As described above, when the d-axis current of the motor (the motor 1) 210 to be controlled is applied as a product of the difference in speed and the difference in position angle, it can be seen that the torque always acts in the same direction as the direction of the speed. The torque is proportional to the speed and can act as a damping force. Also, this damping force always agrees with the sign of speed, even if there is a difference in load between the two motors.

Figs. 6 to 8 show the resonance reduction effect according to the control according to the present invention described above. Specifically, FIG. 6 shows waveforms when the resonance control of the present invention is not performed, and FIG. 7 shows waveforms when the resonance control of the present invention is performed. 8 shows the waveform of the load variation characteristic at the time of application of the resonance control of the present invention.

First, referring to FIG. 6, it is assumed that a disturbance torque of a delta function type is applied as shown in the graph (a).

At this time, it can be seen that the speed difference between the two motors becomes gradually larger as shown in the graph (b) from when the disturbance torque is applied.

6C shows the phase current of the master motor (first motor) 210. It can be seen that the current is constantly controlled even after the disturbance knocking is applied.

6 (d), it can be seen that the phase current of the slave motor (second motor) 220 gradually increases and diverges from the moment the disturbance torque is applied.

Referring to FIG. 7, when the disturbance torque is applied as in FIG. 6 (a), the speed difference between the two motors 210 and 220 is gradually decreased as shown in (b) .

That is, it can be seen that the phase current d of the slave motor (the second motor) 220 is also controlled to be constant as the phase current c of the master motor (the first motor 210).

Here, FIG. 7E shows the d-axis compensation current of the master motor 210, which is applied largely at the time of application of the disturbance torque, and can be seen to be gradually reduced.

Thus, even if the disturbance torque is applied by injecting the d-axis compensation current as described above into the control of the master motor 210, the speed difference between the two motors 210 and 220 is controlled not to be increased, Able to know.

8 (a) shows the torque response difference due to the asynchronous load change. That is, it shows the torque response difference resulting from the fact that different loads are added to or subtracted from two motors 210 and 220 at substantially different times.

In this way, when the load is changed between the two motors 210 and 220, a speed difference between the two motors 210 and 220 may occur as in (b).

At this time, the phase current of the master motor 210 appears as (c), and the phase current of the slave motor 220 appears as (d).

According to the resonance control according to the present invention, the d-axis compensation current of the master motor 210 can be injected as shown in (e) of FIG. 8, , 220) is controlled and becomes smaller.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: power converter 110: rectifying part
120: converter 130: converter control unit
140: inverter 150: inverter controller
151: speed control unit 152: current control unit
153: drive signal PWM generation unit 154:
157 resonance control section 200:
210: first motor (master motor) 220: second motor (slave motor)

Claims (12)

A motor unit including a first motor and a second motor connected in parallel with the first motor;
An inverter for outputting a drive signal for driving the motor unit; And
And an inverter control unit for controlling the inverter,
The inverter control unit includes:
A sensing unit sensing a speed and a position of the first motor and the second motor;
A speed control unit for generating a target current based on a target speed and a speed of the first motor sensed by the sensing unit;
A current controller for generating a target voltage based on the target current;
A drive signal generator for generating a drive signal based on the generated target voltage and the position of the first motor sensed by the sensing unit; And
And a resonance controller for generating a compensation current by estimating the difference between the speed and the position of the first motor and the second motor and compensating the generated current to the current control unit. The driving apparatus for a parallel driving motor according to claim 1, wherein the compensation current is a value obtained by multiplying a speed difference between the first motor and the second motor by a difference in position. 3. The driving apparatus for a parallel driving motor according to claim 2, wherein the compensation current is a value obtained by multiplying a difference between a speed difference between the first motor and the second motor by a position difference and a proportional gain. The driving apparatus for a parallel running motor according to claim 1, wherein the compensation current is a value for generating a damping torque in driving the first motor. The resonator according to claim 1,
An estimator for estimating a difference between a speed and a position of the first motor and the second motor; And
And a resonance suppression control unit for multiplying a difference between the estimated speed and the position by a proportional gain to generate a compensation current and injecting the compensation current into the current control unit. The driving apparatus for a parallel operation motor according to claim 1, wherein the compensation current is applied to the d-axis current side of the current control section. The apparatus according to claim 1,
A first phase current detector for sensing a first current for driving the first motor;
A second phase current detector for sensing a second current for driving the second motor; And
And estimating a speed and a position using the first current and the second current. The apparatus according to claim 1,
A first position sensor for sensing a position of the first motor;
A second position sensor for sensing a position of the second motor; And
And a speed calculator for calculating a speed using a value sensed by the first position sensor and the second position sensor. A method of driving a motor unit including a first motor and a second motor connected in parallel with the first motor,
Sensing a speed and a position of the first motor and the second motor;
Generating a target current based on the target speed and the sensed speed of the first motor;
Generating a target voltage based on the target current;
Generating a drive signal based on the generated target voltage and the sensed position of the first motor; And
And compensating for the target current by generating a compensation current by estimating the difference between the speed and the position of the first motor and the second motor. 10. The driving method of a parallel driving motor according to claim 9, wherein the compensation current is a value obtained by multiplying a difference between a speed difference between the first motor and the second motor by a position difference and a proportional gain. The driving method of a parallel operation motor according to claim 10, wherein the compensation current is compensated for a d-axis current of the target current. An air conditioner comprising the driving device according to any one of claims 1 to 8 or driven by the driving method according to any one of claims 9 to 11.

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