JP2017147793A - Control device for ac motor and control method for ac motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an AC motor and a control method for an AC motor capable of setting a torque boost voltage value while preventing a type of an AC motor to be controlled from being limited.SOLUTION: A control device 100 of an AC motor 102 includes a torque boost voltage value setting unit 6 that sets a torque boost voltage value V, which is a voltage value for raising a voltage value of an AC voltage applied from a power conversion unit 101 to the AC motor 102. The torque boost voltage value setting unit 6 sets, before operating the AC motor 102, a multiplication value of a calculated value Rof the AC motor 102 and a preset set current value Ias the torque boost voltage value V.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an AC motor control device and an AC motor control method, and more particularly, to an AC motor control device including a torque boost voltage value setting unit for setting a torque boost voltage value and an AC motor control method.

  2. Description of the Related Art Conventionally, an AC motor control device and an AC motor control method including a torque boost voltage value setting unit that sets a torque boost voltage value are known (see, for example, Patent Document 1).

  Patent Document 1 discloses a torque boost control device for an induction motor including a central processing unit that sets a torque boost voltage. In this torque boost control device, the central processing unit increases the torque boost voltage stepwise while supplying an alternating current to the induction motor, detects the output current, and the detected output current is a predetermined excitation current. The torque boost voltage at the time when the value exceeds the design value is automatically set as the torque boost voltage when the output frequency is 0 (0 Hz).

JP-A-7-163188

  However, the torque boost control device for an induction motor described in Patent Document 1 is configured to set a torque boost voltage at an output frequency of 0 while supplying an alternating current to the induction motor. For this reason, even if the induction motor to be controlled is in a state where an alternating current is supplied, the induction motor is in a stationary state (a state where the output frequency is 0) in order to set a torque boost voltage at an output frequency of 0. Or the induction motor needs to be in an unloaded state in order to compare the output current with a predetermined excitation current design value. In this case, there is an inconvenience that an induction motor (AC motor) that generates a load from the start of operation (with an output frequency of 0) such as a fan or a pump cannot be used as an induction motor to be controlled. . That is, the torque boost control device of Patent Document 1 has a problem that the type (application) of the AC motor to be controlled is limited.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to prevent a torque boost voltage value while preventing the types of AC motors to be controlled from being limited. It is providing the control apparatus and control method of an AC motor which can set automatically.

  In order to achieve the above object, a control device for an AC motor according to a first aspect of the present invention increases a voltage value of an AC voltage applied to an AC motor from a variable voltage and variable frequency power converter. A torque boost voltage value setting unit that sets a torque boost voltage value that is a value, and the torque boost voltage value setting unit sets a primary resistance value of the AC motor and a preset set current value before operating the AC motor. Is set as a torque boost voltage value. In the specification of the present application, “operating an AC motor” is described as meaning that an AC current is supplied to the AC motor to drive the AC motor. In the present specification, the “primary resistance value” means the resistance value of the primary winding of the AC motor, the wiring resistance value from the power conversion unit to the AC motor, and the resistance component of the power conversion unit. It is described as a concept including at least the resistance value of the primary winding of the AC motor.

  In the control apparatus for an AC motor according to the first aspect of the present invention, as described above, the torque boost voltage value setting unit calculates the primary resistance value of the AC motor calculated or stored in advance before the AC motor is operated. A multiplication value with a preset current value is set as a torque boost voltage value. Thereby, since the torque boost voltage value is set based on the multiplication value of the primary resistance value of the AC motor and a preset current value, the AC motor is driven by supplying the AC current to the AC motor. Without setting the torque boost voltage value. As a result, even when using an AC motor that generates a load from the start of operation (with a frequency of 0), the torque boost voltage value at a frequency of 0 can be set without driving the AC motor. The torque boost voltage value can be set (automatically set) while preventing the type (application) of the AC motor to be controlled from being limited.

  The control apparatus for an AC motor according to the first aspect preferably further includes a storage unit in which a set current value is stored, and the torque boost voltage value setting unit is configured in advance of the AC motor before operating the AC motor. The primary resistance value is calculated, and the storage unit is configured to store the primary resistance value of the AC motor. If comprised in this way, since a torque boost voltage value can be set based on the primary resistance value and setting current value which were previously memorize | stored in the memory | storage part, a torque boost voltage value can be set, without driving | operating an AC motor. Can be set.

  In the control apparatus for an AC motor according to the first aspect, preferably, the torque boost voltage value setting unit is configured to perform control to set a no-load current value of the AC motor as a set current value. With this configuration, when the AC motor is driven with the set torque boost voltage value, the no-load current value is relatively small (for example, smaller than the rated current value), so the load of the AC motor is compared. Even when the target is small, it is possible to suppress an excessive current from flowing through the AC motor. That is, when an AC motor having a relatively small load is used, the AC motor can be appropriately controlled.

  In the control apparatus for an AC motor according to the first aspect, preferably, the torque boost voltage value setting unit is configured to perform control to set a rated current value of the AC motor as a set current value. If comprised in this way, when an alternating current motor is driven with the set torque boost voltage value, even when the frequency (rotational frequency) of the alternating current motor is relatively small, a torque having a magnitude close to the rated torque is generated. be able to. As a result, when an AC motor having a load that requires a rated torque at the time when the frequency of the AC motor is relatively small is controlled, it is possible to suppress a shortage of the generated torque.

  In the control apparatus for an AC motor according to the first aspect, preferably, the torque boost voltage value setting unit supplies a predetermined DC current from the power conversion unit to the AC motor and a current value flowing through the AC motor and a predetermined DC current. The primary resistance value is either the deviation from the command current value or the calculated value of the induced voltage value of the AC motor generated by applying a predetermined voltage from the power converter to the AC motor. It is configured to calculate in advance. With this configuration, it is possible to easily calculate (measure) the primary resistance value before setting the torque boost voltage value. In addition, when a predetermined direct current is supplied to the AC motor, the AC motor is not driven. Therefore, the primary resistance value is easily calculated in advance without driving the AC motor (with the frequency being 0). be able to.

  In the control method for an AC motor according to the second aspect of the present invention, before the AC motor is operated, a multiplication value of the primary resistance value of the AC motor and a preset set current value is set to a variable voltage and a frequency. The torque boost voltage value, which is a voltage value that raises the voltage value of the AC voltage applied to the AC motor from the variable power conversion unit, is set.

  In the control method for an AC motor according to the second aspect of the present invention, as described above, the product of the primary resistance value of the AC motor calculated or stored in advance and the preset set current value is set to a variable voltage. In addition, the voltage value of the AC voltage applied to the AC motor from the frequency variable power converter is set as a torque boost voltage value that is a voltage value for raising the voltage value. Thus, even when an AC motor that generates a load from the start of operation (in a state where the frequency is 0) is used as the AC motor, the torque boost voltage value at the frequency of 0 can be set, and thus the control target. An AC motor control method capable of setting a torque boost voltage value while preventing the types of AC motors from being limited can be provided.

  According to the present invention, as described above, the torque boost voltage value can be set while preventing the type of the AC motor to be controlled from being limited.

It is a block diagram which shows the whole structure of the control apparatus of the alternating current motor by 1st Embodiment and 2nd Embodiment of this invention. It is a figure for demonstrating V / f control of the control apparatus of the AC motor by 1st Embodiment and 2nd Embodiment of this invention. It is a block diagram which shows the structure of the torque boost value setting part of the control apparatus of the AC motor by 1st Embodiment and 2nd Embodiment of this invention. It is a block diagram which shows the whole structure of the control apparatus of the alternating current motor by the modification of 1st Embodiment of this invention and 2nd Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

[First Embodiment]
With reference to FIGS. 1-3, the structure of the control apparatus 100 (henceforth "control apparatus 100") of the AC motor by 1st Embodiment is demonstrated.

(Overall configuration of the first embodiment)
As shown in FIG. 1, the control device 100 is configured to control the driving of the AC motor 102 via the power converter 101. That is, the control device 100, the power conversion unit 101, and the AC motor 102 are configured as a drive system for the AC motor 102.

The power conversion unit 101 includes a plurality of switching elements, drives the plurality of switching elements based on a command (command voltage V ₁ ^* or the like) from the control device 100, and causes the AC motor 102 to generate power (AC current or DC). Current).

Specifically, the power conversion unit 101 is configured to output power so that the voltage value can be changed (voltage variable) and the output frequency can be changed (frequency variable). Then, the command voltage V ₁ ^* (command voltage value V ^* and command frequency ω ^* ) is transmitted from the control device 100 to the power conversion unit 101, whereby the command voltage value V ^* and the command frequency ω ^* (V (voltage Value) / f (frequency) pattern (see FIG. 2)) is configured to supply AC power to the AC motor 102. That is, the control device 100 is configured to control the AC motor 102 by V / f control (so-called simple V / f control).

  The AC motor 102 is configured as a three-phase AC induction motor, and is configured to be rotationally driven by AC power supplied from the power conversion unit 101. The AC motor 102 is configured to drive a load such as a fan or a pump, for example.

Here, in the first embodiment, before operating the AC motor 102, the control device 100 increases the torque boost voltage value V _b that is the increase amount of the command voltage value V ^* when the command frequency ω ^* is 0 (FIG. 2). Browse) is configured. In the specification of the present application, “operating the AC motor 102” means that the AC motor 102 is rotated by applying an AC voltage (AC current) to the AC motor 102, and the AC motor 102 is driven. It is described as a concept that does not include the case of supplying a current that is not allowed to be supplied (for example, a predetermined direct current I ₁ or a no-load current I ₀ described later).

Specifically, in the first embodiment, control device 100 includes a primary resistance calculation value R ₁ ^# (hereinafter referred to as “calculation value R ₁ ^# ”) of AC motor 102 calculated in advance and a preset set current. A multiplication value with the value Is is set as the torque boost voltage value _Vb . The control device 100 is configured to control the drive of the AC motor 102 (start operation) based on the V / f pattern (see FIG. 2) in which the set torque boost voltage value V _b is taken into consideration. Has been.

(Configuration of each part of the control device)
As shown in FIG. 1, the control device 100 includes a command value generator 1, a command voltage value calculator 2, an integrator 3, a coordinate converter 4, a primary resistance value calculator 5, and a torque boost value. A setting unit 6, a current vector rotator 7, a current detector 8, and an operation unit 9 are provided. The command value generator 1, the primary resistance value calculator 5, and the torque boost value setting unit 6 are examples of the “torque boost voltage value setting unit” in the claims. In FIG. 1, each unit of the control device 100 is illustrated as a functional block. However, each unit may be configured as separate hardware (for example, a CPU (Central Processing Unit)) or a plurality of functional blocks. It may be configured as hardware including.

The command value generator 1 is configured to generate (generate) a command signal for controlling the AC motor 102. The command value generator 1 is connected to a command voltage value calculator 2, an integrator 3, and a primary resistance value calculator 5. The command value generating unit 1 is configured to transmit the command frequency ω ^* to the command voltage value calculating unit 2 and the integrator 3. In addition, command value generation unit 1 is configured to transmit command current value i _1d ^* to primary resistance value calculation unit 5 when calculating calculation value R ₁ ^# .

As shown in FIG. 2, the command voltage value calculation unit 2 generates a command based on the command frequency ω ^* acquired from the command value generation unit 1 and the torque boost voltage value V _b acquired from the torque boost value setting unit 6. The voltage value V ^* is set. The command voltage value calculation unit 2 is connected to the coordinate converter 4 and is configured to transmit the set command voltage value V ^* to the coordinate converter 4.

FIG. 2 shows an example of a graph (V / f pattern) indicating the command voltage value V ^* corresponding to the command frequency ω ^* , where the horizontal axis is the command frequency ω ^* and the vertical axis is the command voltage value V ^* . . And the command voltage value calculating part 2 is comprised so that command voltage value V ^* may be output with respect to the input of command frequency ω ^* based on said V / f pattern.

Here, the dotted line in FIG. 2 shows a basic V / f pattern (when the torque boost voltage value _Vb is 0). In the basic V / f pattern, when the command frequency ω ^* is less than the base frequency ω _b ^* of the AC motor 102, control (calculation) is performed so that the command voltage value V ^* is proportional to the command frequency ω ^* . In other words, the command voltage value calculation unit 2 performs control so that the value of V / f is constant (for example, rated voltage value V _rate / base frequency ω _b ^* ). The command voltage value calculation unit 2 is configured to set the rated voltage value V _rate as the command voltage value V ^* when the command frequency ω ^* is equal to or higher than the base frequency ω _b ^* .

Here, since AC motor 102 is configured as an induction motor, a voltage drop occurs due to resistance of the stator windings (primary resistance) and leakage inductance. For this reason, when the control is performed based on the basic V / f pattern, the generated torque may be insufficient due to this voltage drop. In particular, the lower the frequency (command frequency ω ^* ) that the AC motor 102 drives, the greater the influence of the voltage drop due to the primary resistance and leakage inductance, making it difficult to generate the required torque.

Therefore, as shown by the solid line in FIG. 2, the command voltage value calculation unit 2 is configured to perform (control) a calculation to raise the command voltage value V ^* by the torque boost voltage value _Vb . Specifically, the command voltage value calculation unit 2 is configured to set the torque boost voltage value _Vb as the command voltage value V ^* when the command frequency ω ^* is zero.

Specifically, the command voltage value calculating unit 2, when the command frequency omega ^* is 0, the command voltage value V ^* as the torque boost voltage V _b, when command frequency omega ^* is the base frequency omega _b ^* of Control is performed so as to have a linear function relationship in which the command voltage value V ^{* is set} to the rated voltage value _Vrate .

The integrator 3 is configured to acquire the command frequency ω ^* from the command value generator 1 and calculate the command phase value θ ^* based on the command frequency ω ^* . The integrator 3 is connected to the coordinate converter 4 and is configured to transmit the calculated command phase value θ ^* .

The coordinate converter 4 acquires the command voltage value V ^* from the command voltage value calculation unit 2 and the command phase value θ ^* from the integrator 3, and based on the command voltage value V ^* and the command phase value θ ^*. Thus, the command voltage V ₁ ^* (V _u ^* , V _v ^* , V _w ^* ) is calculated. The coordinate converter 4 is configured to transmit the command voltage V ₁ ^* to the power conversion unit 101. Further, the coordinate converter 4 generates a command voltage V ₁ ^** for primary resistance value calculation based on the command voltage value V _1d ^* from the primary resistance value calculation unit 5 and transmits the command voltage V ₁ ^** to the power conversion device 101. Is configured to do.

The current vector rotator 7 detects the three-phase detected current value i ^# (primary current value of the AC motor 102) detected by the current detector 8 (see FIG. 1) and the detected current value i for calculating the primary resistance value. ₁ ^# is configured to be dq converted. That is, the current vector rotator 7 converts the detected current value i ^# (i ₁ ^# ) into a d-axis (magnetization) detected current value i _d ^# component (i _1d ^# component) and a q-axis (torque) detected current. It is configured to be decomposed into values i _q ^# (components of i _1d ^# ).

The current detector 8 is disposed in the vicinity of the wiring connecting the power conversion unit 101 and the AC motor 102, and calculates the current value (primary current value) of the current supplied from the power conversion unit 101 to the AC motor 102. It is configured to detect (acquire the detected current value i ^# ). Current detector 8 is configured to transmit detected current value i ^# to current vector rotator 7.

The operation unit 9 is configured to accept a setting operation from an operator, and is configured by, for example, a keyboard. And the operation part 9 is connected with each part of the control apparatus 100, and is comprised so that setting operation from an operator may be transmitted to each part. For example, the operation unit 9, the operator, the operation for executing a mode to set the torque boost voltage value V _b, the operation for executing a mode for calculating the calculated value R ₁ ^♯, and to set the set current value I _s It is configured to accept an operation for executing the mode.

<Configuration for primary resistance calculation>
Here, in the first embodiment, the primary resistance value calculation unit 5 sets the calculation value R ₁ ^# in advance (for example, based on an operation for executing a mode for calculating the calculation value R ₁ ^# from the operation unit 9 ( It is configured to calculate (before setting the torque boost voltage value _Vb ). For example, when the control device 100 is deployed (introduced), the control device 100 executes this mode, calculates the calculated value R ₁ ^#, and stores the storage unit 61 of the torque boost value setting unit 6 (see FIG. 3). ) As a primary resistance convergence value R ₁ ^# (0).

Specifically, for example, the primary resistance value calculation unit 5 supplies a predetermined DC current I ₁ (see FIG. 1) from the power conversion unit 101 to the AC motor 102 and the current value i _1d ^# flowing in the AC motor 102 And an integrated calculation value of a deviation (i _1d ^# −i _1d ^* ) between a command current value i _1d ^* of a predetermined DC current and a calculation value R ₁ ^# (primary resistance convergence value R ₁ ^# (0)) in advance. It is comprised so that it may calculate.

That is, the primary resistance value calculation unit 5 supplies the predetermined DC current I ₁ and calculates the calculation value R ₁ ^# based on the current value i _1d ^# flowing in the AC motor 102 to thereby change the AC motor 102. The calculation value R ₁ ^# is calculated in a stationary state.

Specifically, the command value generating unit 1, and generates a command current value i _1d ^*, is configured to transmit the generated command current value i _1d ^* to the primary resistance value calculation unit 5.

The primary resistance value calculation unit 5 adds the command current value i _1d ^* and the d-axis detected current value i _1d ^# (negative value) from the current vector rotator 7 so as to calculate the deviation. It is configured. The primary resistance value calculation unit 5 includes an integration calculation circuit or a proportional integration calculation circuit, and calculates (calculates) the calculation value R ₁ ^# based on the deviation (i _1d ^* −i _1d ^# ). It is configured. Specifically, using the proportional gain K _{p of} the proportional integral arithmetic circuit and the integral gain K _i of the integral arithmetic circuit (proportional integral arithmetic circuit), for example, the computation shown in the following formula (1) or (2) The value R ₁ ^# is configured to be calculated. If the primary resistance value calculation unit 5 is provided with an integral calculation circuit, the calculation value R ₁ ^# is calculated by the equation (1), and the primary resistance value calculation unit 5 includes the proportional integration calculation circuit. Is provided, the calculated value R ₁ ^# is calculated according to equation (2).

Then, the primary resistance value calculation unit 5 is in a state where the deviation between the DC current command value i _1d ^* and the d-axis detected current value i _1d ^# from the current vector rotator 7 is 0 (substantially 0). In a steady state), the primary resistance convergence value R ₁ ^# (0) (hereinafter, convergence value R ₁ ^# (0)) is transmitted to the torque boost value setting unit 6 (the storage unit 61). .

<Configuration for torque boost voltage setting>
With reference to FIG. 3, a configuration (torque boost voltage value _Vb setting mode) of a configuration related to setting of torque boost voltage value _Vb (torque boost value setting unit 6) will be described.

In the first embodiment, the torque boost voltage value setting unit 6 calculates the calculation value R ₁ ^# of the AC motor 102 calculated in advance before the AC motor 102 is operated (normal operation) (V / f control is performed). a preset set multiplied value between the current value I _s, is configured to set as torque boost voltage V _b (set automatically). The torque boost voltage value setting unit 6 is configured to set the torque boost voltage value V _b while the AC motor 102 is stationary. For example, the torque boost voltage setting unit 6 in response to an operation of executing a mode to set the torque boost voltage V _b from the operation unit 9 is configured to set the torque boost voltage V _b.

Here, the voltage equation of AC motor 102 is as follows: V ₁ is a primary voltage value, i ₁ is a primary current value, φ ₂ is a secondary magnetic flux, R ₁ is a primary resistance value, Lσ is a leakage inductance, and ω ₁ is The following equations (3) and (4) can be used, where the primary frequency, p is the differential operator, and d and q are the d-axis and q-axis of the rotational coordinates.

Here, when the primary frequency ω ₁ is 0, the voltage values shown in the above equations (3) and (4) are as shown in the following equations (5) and (6).

From the above equations (5) and (6), the following equation (7) is established.

That is, since the magnitude of V ₁ shown in the equation (7) is a voltage value in consideration of the primary resistance value and the leakage inductance when the primary frequency ω ₁ is 0, the magnitude of V ₁ is the torque. by setting the boost voltage value V _b, the appropriate torque boost voltage value V _b for the AC motor 102. Specifically, the calculated value R ₁ ^# , which is the calculated value of the primary resistance value R ₁ , and the set current value I corresponding to the current value to be _passed (current value components (i _1d and i _1q ) of equation (7)). a multiplication value between _s), by setting the torque boost voltage V _b, it is possible to set an appropriate torque boost voltage V _b.

In the first embodiment, (a mode to set the set current value I _s) torque boost voltage setting unit 6, a control for setting the no-load current value I ₀ ^♯ the AC motor 102 as a set current value I _s Is configured to do.

Specifically, as shown in FIG. 3, the torque boost value setting unit 6 is provided with a storage unit 61. Storage unit 61, for example, a non-volatile memory, the storage unit 61, information of the information of the calculated value R ₁ ^♯ (convergence value R ₁ ^♯ (0)) and the set current value I _s is stored. The storage unit 61 is an example of the “storage unit” in the claims.

Here, in advance (before the torque boost voltage value V _b is set by the torque boost value setting unit 6, for example, as a value of design data at the time of manufacturing the control device 100), the control device 100 determines the AC motor 102. to obtain the no-load current value I ₀ ^♯, and is configured to store in the storage unit 61 a no-load current value I ₀ ^♯ as set current value I _s. The present invention is not limited to the time of manufacture, control unit 100, in response to an operation to perform the mode for setting the set current value I _s from the operation unit 9, and configured to acquire a no-load current value I ₀ ^♯ of may be, in accordance with an operation to execute a mode for calculating the calculated value R ₁ ^♯, it may be configured to sequentially perform a calculating operation values R ₁ ^♯ and measurement of the no-load current value I ₀ ^♯ .

Specifically, as shown in FIG. 1, the control device 100 sends a predetermined primary frequency from the power conversion device 101 to the AC motor 102 in a no-load state (not connected to a load (not shown)). Control is performed to supply electric power (no-load current I ₀ ) having ω ^** and a predetermined primary voltage V ^** . Then, the control unit 100, configured to obtain the detected current value i ^♯ from the current detector 8, so as to store the detected current value i ^♯ at this time as a no-load current value I ₀ ^♯, the storage unit 61 Has been. The no-load current value I ₀ ^# is smaller than the rated current value I _rate of the AC motor 102.

As shown in FIG. 3, the torque boost value setting unit 6 includes a calculation unit 62, and the calculation unit 62 calculates the calculation value R ₁ ^# (convergence value R ₁ ^#) stored in the storage unit 61. (0)) and the set current value I _s (no-load current value I ₀ ^# ), the torque boost voltage value V _b is calculated. That is, the calculation unit 62 is configured to set the torque boost voltage value V _b using the following equation (8).

2, the control device 100 is configured to control the drive of the AC motor 102 via the power conversion unit 101 based on the set torque boost voltage value V _b. ing.

(Control method of AC motor)
<Operation for setting torque boost voltage value _Vb >
With reference to FIG. 3, an operation (mode) for setting the torque boost voltage value V _b of the control device 100 in the first embodiment will be described. The operation for setting the torque boost voltage value _Vb is performed before the AC motor 102 is operated (V / f control is performed). In this example, the storage unit 61 of the torque boost value setting unit 6, the no-load current value I ₀ ^♯ is stored as a preset current value I _s.

First, in the first embodiment, before the torque boost voltage value V _b is set (in advance), the primary resistance value calculation unit 5 calculates the calculated value R ₁ ^# (convergence value R ₁ ^# (0)). Done. Specifically, in accordance with an operation for executing a mode for calculating the calculated value R ₁ ^# from the operation unit 9, the primary resistance value calculation unit 5 causes the power conversion unit 101 to transfer the AC motor 102 to a predetermined DC current I. deviation of ₁ and a d-axis detected current value i _1d of the detected current value i ₁ ^♯ flowing to the AC motor 102 by supplying ^♯, and the command current value i ₁ ^* of predetermined direct current (i ₁ ^* -i _1d ^♯) the integral calculation value, calculation of the calculated value R ₁ ^♯ (the above formula (1) or (2) refer) is performed. Then, a convergence value R ₁ ^# (0) that is a convergence value of the calculated value R ₁ ^# is stored in the storage unit 61.

Then, the torque boost value setting unit 6 performs the calculation value R ₁ ^# and the set current from the storage unit 61 by the calculation unit 62 according to an operation for executing the mode for setting the torque boost voltage value V _b from the operation unit 9. The value I _s is read, and a multiplication value of the calculated value R ₁ ^# and the set current value I _s (no-load current value I ₀ ^# ) is set as the torque boost voltage value V _b . Then, the operation for setting the torque boost voltage value _Vb is ended.

[Effect of the first embodiment]
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, the torque boost value setting unit 6 sets the convergence value R ₁ ^# (0) of the AC motor 102 calculated in advance before the AC motor 102 is operated. a multiplication value between the current value I _s, configured to set a torque boost voltage V _b. Thus, based on the multiplication value of the pre-convergence value R ₁ ^♯ (0) and a preset current value I _s of the computed AC motor 102, since the torque boost voltage V _b is set, AC The torque boost voltage value _Vb can be set without supplying the AC current to the motor 102 to drive the AC motor 102. Further, the calculated value R ₁ ^# is calculated in advance by supplying a predetermined DC current I ₁ to the AC motor 102. Therefore, the calculated value R ₁ ^# is calculated in advance without driving the AC motor 102. Is done. As a result, even when using the AC motor 102 that generates a load from the start of operation (in the state where the command frequency ω ^* is 0), the calculation value R ₁ ^# is calculated without driving the AC motor 102, and the command can be frequency omega ^* sets the torque boost voltage value V _b at 0. As a result, the torque boost voltage value _Vb can be set while preventing the type (application) of the AC motor 102 to be controlled from being limited.

Further, in the first embodiment, as described above, the torque boost value setting unit 6 calculates the calculation value R ₁ ^# of the AC motor 102 in advance before operating the AC motor 102 and stores the AC value in the storage unit 61. The calculation value R ₁ ^# of the electric motor 102 is configured to be stored. Thus, based on the previously calculated value stored in the storage unit 61 R ₁ ^♯ and set current value I _s, it is possible to set the torque boost voltage value V _b, without operating the AC motor 102, torque The boost voltage value _Vb can be set.

In the first embodiment, as described above, the torque boost voltage setting unit 6, configured to perform control to set the no-load current value I ₀ ^♯ the AC motor 102 as a set current value I _s. Thereby, when AC motor 102 is driven by set torque boost voltage value V _b , no-load current value I ₀ ^# is relatively small (for example, compared to rated current value I _rate (see the second embodiment)). Therefore, even when the load on the AC motor 102 is relatively small, it is possible to suppress an excessive current from flowing through the AC motor 102. That is, when the AC motor 102 having a relatively small load is used as the AC motor 102, the AC motor 102 can be appropriately controlled.

In the first embodiment, as described above, the torque boost voltage value setting unit 6 supplies the predetermined DC current I ₁ from the power conversion unit 101 to the AC motor 102 and flows to the AC motor 102. The integral calculation value of the deviation between _1d ^# and the command current value i _1d ^* of the predetermined direct current I ₁ is calculated in advance as the calculation value R ₁ ^# (see the above formula (1) or (2)). . As a result, when the predetermined DC current I ₁ is supplied to the AC motor 102, the AC motor 102 is not driven. Therefore, the AC motor 102 is not easily driven (in the state where the command frequency ω ^* is 0). The primary resistance value (calculated value R ₁ ^# ) can be calculated in advance.

[Second Embodiment]
Next, the configuration of the control device 200 for the AC motor 102 according to the second embodiment will be described with reference to FIG. In the second embodiment, unlike the control device 100 according to the first embodiment is configured to set the no-load current value I ₀ ^♯ as set current value I _s, the rating of the AC motor 102 as a set current value I _s The current value I _rate is set. In addition, about the structure same as the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

(Configuration of Control Device according to Second Embodiment)
As shown in FIG. 1, a torque boost value setting unit 206 is provided in the control device 200 according to the second embodiment. As shown in FIG. 3, the rated current value I _rate of the AC motor 102 is stored in advance in the storage unit 261 of the torque boost value setting unit 206 (for example, from the time of manufacture of the control device 200). The rated current value I _rate is a value larger than the no-load current value I ₀ ^# . The storage unit 261 stores a calculation value R ₁ ^# (convergence value R ₁ ^# (0)) of the AC motor 102 calculated in advance.

In the second embodiment, the torque boost value setting unit 206 sets a rated current value I _rate stored in the storage unit 261 as the set current value I _s, the calculated value R ₁ ^♯ (convergence value R ₁ ^# (0)) and the set current value I _s (rated current value I _rate ) are set as the torque boost voltage value V _b . That is, the torque boost value setting unit 206 is configured to calculate the torque boost voltage value V _b using the following equation (9).

  Moreover, the other structure of the control apparatus 200 by 2nd Embodiment is the same as that of the control apparatus 100 in 1st Embodiment.

[Effects of Second Embodiment]
In the second embodiment, the following effects can be obtained.

In the second embodiment, as hereinabove described, the torque boost voltage value setting unit 206, configured to perform control to set the rated current value I _rate of the AC motor 102 as a set current value I _s. Thereby, when the AC motor 102 is driven by the set torque boost voltage value V _b , the frequency (rotation frequency) of the AC motor 102 is relatively small (the command frequency ω ^* is smaller than the base frequency ω _b ^*. Even at the time, a torque close to the rated torque can be generated. As a result, when the AC motor 102 having a load that requires a rated torque is controlled at a time when the frequency (command frequency ω ^* ) of the AC motor 102 is relatively small, it is possible to suppress the shortage of the generated torque. .

  The other effects of the control device 200 according to the second embodiment are the same as those of the control device 100 according to the first embodiment.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

For example, the first embodiment and the second embodiment show an example in which the convergence value R ₁ ^# (0) of the calculated value R ₁ ^# is used as the primary resistance value for calculating the torque boost voltage value V _b. However, the present invention is not limited to this. For example, the primary resistance value may be used as a primary resistance value for calculating the torque boost voltage value V _b as a value estimated as the primary resistance value, and the calculated value R ₁ ^# before convergence. However, when the primary resistance value of the AC motor 102 is known, the primary resistance value may be stored in the storage unit 61 in advance and used without calculating the primary resistance value again.

In the first embodiment and the second embodiment, the no-load current value I ₀ ^♯ or rated current I _rate shows an example in which the set current value I _s, the present invention is not limited thereto. That is, the set current value I _s may be an appropriate current value according to the magnitude of the load of the AC motor 102. For example, an intermediate value between the no-load current value I ₀ ^# and the rated current value I _rate is set. The set current value I _s may be set, and the torque boost value setting unit 6 or 206 can be set to switch between the no-load current value I ₀ ^# and the rated current value I _rate according to the setting operation from the operation unit 9. It may be configured.

Further, in the first embodiment and the second embodiment, the control device 100 supplies the predetermined DC current I ₁ from the power conversion unit 101 to the AC motor 102 and the detected current value i _1d ^# flowing in the AC motor 102 An example has been shown in which the integral calculation value of the deviation of the predetermined direct current I _{1 from} the command current value i _1d ^* is calculated in advance as the calculation value R ₁ ^#. Not limited. That is, like the control device 300 according to the modification of the first embodiment and the second embodiment shown in FIG. 4, the AC motor 102 generated by applying a predetermined voltage V ₁₀ from the power conversion unit 101 to the AC motor 102. The integral calculation value of the magnetic flux axis voltage value E _M that is the calculation value of the induced voltage value E may be calculated in advance as the calculation value R ₁ ^# .

Here, as shown in FIG. 4, the control device 300 according to the modification includes a primary resistance value calculation unit 305, a voltage vector rotator 307, and a voltage detector 310. Control device 300, before setting the torque boost voltage value V _b, advance (for example, based on an operation to execute a mode for calculating the calculated value R ₁ ^♯ from the operation unit 9), the calculated value R ₁ ^♯ It is comprised so that it may calculate. Specifically, the control device 300 is configured to perform control to apply a predetermined voltage V ₁₀ from the power conversion unit 101 to the AC motor 102. The voltage detector 310 is configured to acquire an induced voltage value E of the AC motor 102 generated by applying a predetermined voltage V ₁₀ to the AC motor 102. The voltage detector 310 transmits the induced voltage value E to the voltage vector rotator 307, and the voltage vector rotator 307 is an operation value of the M-axis component (component parallel to the magnetic flux axis) of the induced voltage value E. The magnetic flux axis voltage value E _M is transmitted to the primary resistance value calculation unit 305.

Primary resistance value calculation unit 305 calculates in advance an integration calculation value of magnetic flux axis voltage value E _M of AC electric motor 102 generated by applying predetermined voltage V ₁₀ as calculation value R ₁ ^#. It is configured. In detail, the primary resistance value calculation unit 305 integrates the magnetic flux axis voltage value E _M (hereinafter, expression (10)) or proportionally integrates E _M (hereinafter, expression (11)), thereby obtaining the resistance value R _1. It is configured to calculate ^# .

1 Command value generator (torque boost voltage value setting unit)
5,305 Primary resistance value calculation unit (torque boost voltage value setting unit)
61, 261 Storage unit 6, 206 Torque boost value setting unit (torque boost voltage value setting unit)
100, 200, 300 Control device (AC motor control device)
101 Power converter 102 AC motor

Claims (6)

A torque boost voltage value setting unit that sets a torque boost voltage value that is a voltage value that raises the voltage value of the AC voltage applied to the AC motor from the voltage variable and frequency variable power conversion unit,
The torque boost voltage value setting unit sets a multiplication value of a primary resistance value of the AC motor and a preset set current value as the torque boost voltage value before operating the AC motor. The control apparatus of the alternating current motor comprised. A storage unit storing the set current value;
The torque boost voltage value setting unit is configured to calculate a primary resistance value of the AC motor in advance before operating the AC motor and store the primary resistance value of the AC motor in the storage unit. The control apparatus for an AC motor according to claim 1, wherein   The control device for an AC motor according to claim 1, wherein the torque boost voltage value setting unit is configured to perform control to set a no-load current value of the AC motor as the set current value.   The control device for an AC motor according to claim 1, wherein the torque boost voltage value setting unit is configured to perform control to set a rated current value of the AC motor as the set current value.   The torque boost voltage value setting unit supplies a predetermined DC current from the power conversion unit to the AC motor, and a deviation between a current value flowing through the AC motor and a command current value of the predetermined DC current, or the Any integral calculation value of the calculated value of the induced voltage value of the AC motor generated by applying a predetermined voltage from the power conversion unit to the AC motor is preliminarily calculated as the primary resistance value. The control apparatus of the alternating current motor according to any one of claims 1 to 4.   Before operating the AC motor, an alternating current applied to the AC motor from a power conversion unit having a variable voltage and a variable frequency by multiplying a primary resistance value of the AC motor by a preset current value. A method for controlling an AC motor, wherein the method is set as a torque boost voltage value that is a voltage value that raises the voltage value of the voltage.

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