JPH07155000A - Current vector controller - Google Patents

Abstract

PURPOSE:To improve reliability and operation rate of a control system by enabling operation continuity even when current feedback turns abnormal. CONSTITUTION:A coordinate convertor 10-1 outputs 1d, 1q by making orthogonal rotation coordinate conversion on the basis of 1U, 1W and request position theta*. Comparing operators 1-2A, 2B determines a deviation between direct axis current command 1d* and 1d* and a deviation between 1q* and 1q. Voltage generators 10-3A, 3B output the output of the comparing operators 10-2A, 2B as Vd*, Vq*. Voltage operators 10-8A, 8B output 1d*, 1q* as direct abscissa current calculated value, ordinal axis voltage calculated value according to operations. Bias adders 10-6AL, AU bias the upper and lower sides of the direct abscissa voltage calculated value to set it in a current signal limiter 10-7A, and bias adders 10-6BL, BU those of the ordinal axis voltage calculated value to set it in a current signal limiter 10-7B. A coordinate convertor 10-4 outputs by three-phase conversion with Vd* and Vq*, theta*.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current vector controller for a variable frequency power converter using an inverter for controlling the rotation of a rotating machine.

[0002]

2. Description of the Related Art In recent years, variable frequency power converters such as inverters have been used to control the rotation of rotating machines such as electric motors. In the variable frequency power converters for controlling these rotating machines, vector control has been adopted so that the rotor position of the rotating machine can be detected and a voltage with an optimum frequency and phase can be generated.

FIG. 7 shows a system configuration diagram of a variable frequency power converter using a current vector controller. This system includes a power supply 1, an inverter 2, an electric motor 3, a rotation detector 4, a speed / position detector 5, a speed / torque control device 6, a magnetic flux control device 7, a request vector calculation device 8,
It is composed of current detectors 9A and 9C, a current vector controller 10, and a pulse controller 11.

FIG. 8 is a block diagram of the current vector control device 10 shown in FIG. 7. The current vector control device 10 will be described below with reference to FIGS. 1 and 7. First, the torque request for controlling the target speed by the speed torque control device 6 is calculated from the rotor position detected by the rotation detector 4 and the speed / position detection device 5 in FIG.

The magnetic flux controller 7 is a speed / position detector 5
The magnetic flux request corresponding to the speed is calculated and output according to the rotor position output from. The request vector calculation device 8
The rotor position output from the position detection device 5, the torque request output from the speed torque control device 6, and the magnetic flux control device 7
Direct current demand Id * based on the magnetic flux demand output from
, The horizontal axis current request Iq * and the required position θ * are calculated and output to the current vector control device 10.

The current vector control device 10 outputs the direct-axis current request Id *, the horizontal-axis current request Iq *, the required phase θ *, and the U-phase current detected by the current detectors 9A and 9C from the request vector calculation device 8. And IW which is the W-phase current, the U-phase voltage request VU *, the V-phase voltage request VV *, and the W-phase voltage request VW * are output to the inverter 2.

Next, referring to FIG. 8, a current vector controller
The ten arithmetic processes will be described. The coordinate converter 10-1 performs Cartesian coordinate conversion and rotational coordinate conversion based on IU which is the U-phase current, IW which is the W-phase current, and the required phase θ *, and the vertical axis current component Id which is the current vector component and the horizontal coordinate. The axis current component Iq is calculated and output.

The comparison computing unit 10-2A is a unit for calculating the direct axis current demand Id * output from the demand vector computing unit 8 and the coordinate converter 10.
The deviation of the direct-axis current component Id output from -1 is obtained. The comparison calculator 10-2B obtains a deviation between the horizontal axis current request Iq * output from the request vector calculation device 8 and the horizontal axis current component Iq output from the coordinate converter 10-1.

The voltage calculator 10-3A performs a proportional-integral calculation process on the output from the comparison calculator 10-2A to obtain the direct-axis voltage request V.
Output as d *. The voltage calculator 10-3B is a comparison calculator.
The output from 10-2B is subjected to proportional-plus-integral calculation processing and output as a direct-axis voltage request Vq *.

The coordinate converter 10-4 receives the direct-axis voltage request Vd * output from the voltage calculator 10-3A, the horizontal-axis voltage request Vq * output from the voltage calculator 10-3B, and the requested position θ *. After stationary coordinate conversion and further three-phase conversion processing, U-phase voltage request VU *, V-phase voltage request VV *, W, which is a three-phase AC voltage request
The phase voltage request VW * is output.

The pulse controller 11 controls the inverter 2 in accordance with the U-phase voltage request VU *, the V-phase voltage request VV *, and the W-phase voltage request VW * output from the current vector controller 10. Generate. The inverter 2 outputs a desired AC power based on this pulse to control the rotation of the electric motor 3.

[0012]

However, in such a current vector control device, since the output voltage is controlled by feeding back the detected current, an abnormality such as loss of the current feedback signal occurs. However, there was a problem that the output voltage became excessively high at the same time, and as a result, the output current became excessively large, causing the inverter to make an emergency stop.

The operation when the detected current signal is lost is shown in FIG.
Shown in. In FIG. 9, B is the detected current and D is the output voltage. On the left side of the point A, the detected current is normal, so the current vector control is controlled by the value of a.

When the detected current is lost at point A and changes from a to a-3, the output voltage which was like a becomes large like a-2, and as a result, the current actually flowing in the controlled object. Is
It becomes too large like a-2 and the inverter stops.

Further, even if it is desired to increase the proportional-integral gain for the vertical axis and the horizontal axis, which are vector components, there is a problem that the output voltage waveform is disturbed by the ripple component of the detected current. There was a problem that could not be raised. Therefore, there was a problem in responsiveness.

The present invention has been made in order to solve the above-mentioned problems in the conventional control device, and is a current source.
It is an object of the present invention to provide a control device that enables continuous operation even if the feedback becomes abnormal and improves the reliability and operating rate of the control system. Another object of the present invention is to provide a control device having responsiveness that cannot be obtained by the conventional control device.

[0017]

In order to achieve the above object, first conversion means for converting and outputting a direct axis current component and a horizontal axis current component based on a detected current of a controlled object and a required phase,
A first calculating means for calculating a deviation amount between the direct-axis current component and the direct-axis current request component and outputting a direct-axis voltage request signal according to a predetermined control characteristic, and a deviation amount between the horizontal-axis current component and the horizontal-axis current request component. To output a horizontal axis voltage request signal according to a predetermined control characteristic, the signals output from the first and second operation means, and the three-phase required voltages based on the required phases. In the current vector control device having the second converting means, the invention described in [claim 1] calculates the direct-axis voltage request signal output from the first calculating means into a current component and subtracts the set bias. A first subtracting means, a first adding means for calculating a direct axis voltage request signal output from the first calculating means into a current component, and adding a set bias, and a horizontal axis voltage output from the second calculating means. Calculate the request signal into current component and set via A second subtracting means for subtracting the second
Of the horizontal axis voltage request signal output from the calculating means of (1) to the current component and adding the set bias, and the signal output from the first subtracting means is output from the lower limit value and the first adding means. Which is the upper limit value, the first limiting means for limiting the direct-axis current component output from the first converting means and outputting it to the first calculating means, and the lower limit for the signal output from the second subtracting means. And a second limiting means for limiting the direct-axis current component output from the first converting means and outputting the value to the second calculating means with the value and the signal output from the second adding means as the upper limit value.

According to a second aspect of the present invention, a voltage component is calculated from the direct-axis current demand component and the set bias is subtracted.
Subtracting means, first adding means for calculating a voltage component from the direct axis current request component and adding the setting bias, second subtracting means for calculating a voltage component from the horizontal axis current request component and subtracting the setting bias, and the horizontal axis The second addition means for calculating the voltage component from the current request component and adding the set bias, the signal output from the first subtraction means as the lower limit value, and the signal output from the first addition means as the upper limit value, First limiting means for limiting the direct-axis current component output from the converting means to output to the first computing means, and a signal output from the second subtracting means from the lower limit value and the second adding means. And a first limiting means for limiting the direct-axis current component output from the first converting means and outputting the signal to the second computing means.

According to a third aspect of the present invention, the signal output from the first and second calculating means, the signal output from the first converting means, and the phase advanced from the required phase obtained based on the required phase. Second, which outputs the required voltage of three phases based on
It has a conversion means of.

The invention according to [claim 4] is [claim 1].
A current vector control device, wherein the second conversion means according to claim 3 is applied instead of the second conversion means described.

The invention as defined in [Claim 5] is [Claim 2].
A current vector control device, wherein the second conversion means according to claim 3 is applied instead of the second conversion means described.

[0022]

In the current vector control device of the present invention having the above-mentioned structure, the feedback current is processed as a stationary vector on the rotating coordinates, so that the alternating current is controlled. However, it can be treated as if it were a direct current. Therefore, it was possible to limit the AC signal to a specific range, which was impossible to limit to a certain range, and it became possible to limit it to a specific range. By limiting the detected direct-axis current with the calculated direct-axis current calculated from the request, runaway of the direct-axis voltage can be prevented. Similarly, by limiting the detected horizontal axis current with the calculated horizontal axis current calculated from the horizontal axis voltage request,
It is possible to prevent runaway of the horizontal axis voltage.

In the current vector control device according to the second aspect of the present invention configured as described above, when the abnormality such as the loss of the feedback current occurs, the direct axis voltage request calculated from the direct axis current request is used. The output voltage runaway can be prevented by limiting the direct-axis voltage requirement by feedback control. Similarly, the horizontal axis voltage request calculated from the horizontal axis current request
Since the horizontal axis voltage request by the feedback control is limited, runaway of the output voltage can be prevented.

In the current vector controller according to the present invention, which is configured as described above, when the required voltage on the rotating coordinates is returned to the original coordinates, the voltage phase is made slightly smaller than the current. By proceeding, the torque of the electric motor can be easily generated and the responsiveness can be greatly improved.

In the current vector control device of [claim 4] and [claim 4] configured as above, runaway of the output voltage is prevented when an abnormality such as loss of feedback current occurs. , The responsiveness can be improved.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. An embodiment of the current vector control device according to the present invention will be described with reference to FIGS. 1, 2 and 7.

FIG. 1 is a block diagram of the current vector control device 10 of this embodiment shown in FIG. 7, and the current vector control device 10 of this embodiment will be described with reference to this drawing and FIG.
Will be described below.

First, from the rotor position detected by the rotation detector 4 and the speed / position detection device 5 of FIG. 7, a torque request for controlling the target speed by the speed torque control device 6 is calculated.

The magnetic flux controller 7 includes a speed / position detector 5
The magnetic flux request corresponding to the speed is calculated and output according to the rotor position output from. The request vector calculation device 8
The rotor position output from the position detection device 5, the torque request output from the speed torque control device 6, and the magnetic flux control device 7
Direct current demand Id * based on the magnetic flux demand output from
, The horizontal axis current request Iq * and the required position θ * are calculated and output to the current vector control device 10.

The current vector control device 10 includes the U-phase detected by the direct-axis current request Id *, the horizontal-axis current request Iq *, the required position θ *, and the current detectors 9A and 9C output from the request vector calculation device 8. Based on the current IU and the W-phase current IW, the U-phase voltage request VU *, the V-phase voltage request VV *, W
The phase voltage request VW * is output to the inverter 2.

Next, referring to FIG. 1, a current vector controller
The ten arithmetic processes will be described. The coordinate converter 10-1 performs Cartesian coordinate conversion and rotational coordinate conversion based on IU which is a U-phase current, IW which is a W-phase current and a required position θ *, and a direct-axis current component Id which is a current vector component and a horizontal coordinate. The axis current component Iq is calculated and output.

The current calculator 10-5A outputs a direct-axis voltage request Vd *, which will be described later, as a direct-axis current calculation value according to a predetermined calculation. The current calculator 10-5B has a horizontal axis voltage request Vq described later.
Output * as a horizontal axis current calculation value according to a predetermined calculation.

It should be noted that a first-order lag time constant calculator (*) having a proportional gain is used as one calculation of the current calculators 10-5A and 5B. As the proportional gain and the time constant of the first-order lag, values that match the characteristics of the controlled object are appropriately selected.

[0034]

[Equation 1] The bias adder 10-6AU applies a bias of about 5% to the upper side of the calculated direct-axis current value output from the current calculator 10-5A.

The bias adder 10-6BU is a current calculator 10-5.
A bias of about 5% is applied to the upper side of the horizontal axis current calculation value output from B. The bias adder 10-6AL is 5% below the calculated value of the direct-axis current output from the current calculator 10-5A.
Apply a degree of bias.

The bias adder 10-6BL is a current calculator 10-5.
A bias of about 5% is applied to the lower side of the horizontal axis current calculation value output from B. In the current signal limiter 10-7A, the value obtained by the bias adder 10-6AU is set as the upper limit value, and the value obtained by the bias adder 10-6AL is set as the lower limit value. When the direct-axis current component Id output from the coordinate converter 10-1 is within the set upper and lower limit values, that is, when the current is normally detected from the controlled object, the limiting operation is not performed, and the direct-axis current component Id is not performed. When the deviation exceeds the set upper and lower limit values, the direct-axis current component Id limited to the upper and lower limit values is output.

The current signal limiter 10-7B is a bias adder.
10-6 BU upper limit value, and bias adder 10-6
The value calculated by BL is set as the lower limit. Coordinate converter
If the horizontal axis current component Iq output from 10-1 is within the set upper and lower limit values, that is, if the current is normally detected from the control target, the limiting operation is not performed and the horizontal axis current component Iq is set. When the upper and lower limit values are exceeded, the horizontal axis current component Iq limited to the upper and lower limit values is output.

The comparison computing unit 10-2A is a unit for calculating the direct axis current demand Id * output from the demand vector computing unit 8 and the coordinate converter 10.
The deviation of the direct-axis current component Id output from -1 is obtained. The comparison calculator 10-2B obtains a deviation between the horizontal axis current request Iq * output from the request vector calculation device 8 and the horizontal axis current component Iq output from the coordinate converter 10-1.

The voltage calculator 10-3A performs a proportional-integral calculation process on the output from the comparison calculator 10-2A to obtain the direct-axis voltage request V.
Output as d *. The voltage calculator 10-3B is a comparison calculator.
The output from 10-2B is subjected to proportional-plus-integral calculation processing and output as a horizontal axis voltage request Vq *.

The coordinate converter 10-4 receives the direct-axis voltage request Vd * output from the voltage calculator 10-3A, the horizontal-axis voltage request Vq * output from the voltage calculator 10-3B, and the required phase θ *. After stationary coordinate conversion and further three-phase conversion processing, U-phase voltage request VU *, V-phase voltage request VV *, W, which is a three-phase AC voltage request
The phase voltage request VW * is output.

The pulse controller 11 controls the inverter 2 according to the U-phase voltage request VU *, the V-phase voltage request VV *, and the W-phase voltage request VW * output from the current vector controller 10. Generate.

The inverter 2 outputs a desired AC power based on this pulse to control the rotation of the electric motor 3. Next, the operation of this embodiment will be described with reference to the operation diagram of FIG.

FIG. 2A shows an operation diagram of the detected current, and FIG. 2B shows an operation diagram of the output voltage. Also, t
= 0 to tA indicates a normal time, and t = tA to indicates an abnormal time. The alternate long and short dash line a indicates the upper limit value of the current signal limiter, the alternate long and short dash line c indicates the lower limit value, and the solid line a indicates the detected current.

At t = 0 to tA, since the detected current detected is normal, the detected current is controlled by the detected current shown by the solid line B in the current vector control regardless of the limitation.
As a result, the output voltage is also shown as a solid line d in FIG.

When an abnormality occurs at t = tA and the detected current is lost, the solid line a changes to the solid line a-3, and accordingly, the solid line d, which is the output voltage, changes like a dotted line d-2. Due to the lower limit value of the one-dot chain line c shown in (A) of 2, the detection current cannot be lowered below that.

However, since the lower limit value of the one-dot chain line c is set to be about 5% lower than the solid line a, the comparison calculator
10-2A, 10-2B and voltage calculators 10-3A, 10-3B increase the output voltage by about 5% to the value of the solid line d-1. As a result, the output of the current signal limiter is shown by the solid line c-1. Like

As a result, the current actually flowing in the controlled object is as shown by the two-dot chain line a-1 and does not run away like the dotted line a-2. From the above, even if the detected current from the controlled object is lost due to an abnormality or the like, the output voltage and current of the inverter do not run away, so the inverter can prevent an emergency stop due to excessive current. Improves reliability and availability.

Although the bias applied to each bias adder has been described as 5% in this embodiment, the present invention is not limited to this, and may be any value at which the current signal limiter does not operate during normal control. Further, the current calculators 10-5A and 5B of the present embodiment may be operated by any calculation formula capable of calculating the current, for example, a primary delay / primary advance time constant circuit (*).

[0049]

[Equation 2] Further, since the output frequency is proportional to the number of revolutions, the speed signal may be input to the current calculators 10-5A and 10-5B to correct the signal.

[Embodiment 2] An embodiment of the current vector control device according to the present invention will be described with reference to FIGS. 3, 4 and 7. FIG. 3 is a block diagram of the current vector control device 10 of the present embodiment shown in FIG. 7, and the current vector control device 10 of the present embodiment will be described below with reference to this drawing and FIG. . FIG. 7 refers to the description of the embodiment based on the invention described in [Claim 1], and the description is omitted here.

The calculation process of the current vector control device 10 will be described with reference to FIG. The coordinate converter 10-1 performs Cartesian coordinate conversion and rotational coordinate conversion based on IU which is the U-phase current, IW which is the W-phase current, and the required phase θ *, and the vertical axis current component Id which is the current vector component and the horizontal coordinate. The axis current component Iq is calculated and output.

The comparison computing unit 10-2A is a unit for calculating the direct axis current demand Id * output from the demand vector computing unit 8 and the coordinate converter 10.
The deviation of the direct-axis current component Id output from -1 is obtained. The comparison calculator 10-2B obtains a deviation between the horizontal axis current request Iq * output from the request vector calculation device 8 and the horizontal axis current component Iq output from the coordinate converter 10-1.

The voltage calculator 10-3A performs a proportional-integral calculation process on the output from the comparison calculator 10-2A to obtain the direct-axis voltage request V.
Output as d *. The voltage calculator 10-3B is a comparison calculator.
The output from 10-2B is subjected to proportional-plus-integral calculation processing and output as a horizontal axis voltage request Vq *.

The voltage calculator 10-8A has a direct-axis current demand Id *.
Is output as a direct-axis voltage calculated value according to a predetermined calculation. The voltage calculator 10-8B outputs the horizontal axis current request Iq * as a horizontal axis voltage calculation value according to a predetermined calculation.

An incomplete differentiator having an incomplete differential having a proportional gain and a differential gain is used as one operation of the voltage calculators 10-8A and 10-8B. For the incomplete differential calculator constant having the proportional gain and the differential gain, a value is appropriately selected according to the characteristics of the control target.

The bias adder 10-9AU is a voltage calculator 10-8.
A bias of about 5% is applied to the upper side of the calculated direct-axis voltage output from A. The bias adder 10-9BU is 5% above the horizontal axis voltage calculation value output from the current calculator 10-8B.
Apply a degree of bias.

The bias adder 10-9AL is a voltage calculator 10-8.
A bias of about 5% is applied to the lower side of the calculated direct axis current output from A. The bias adder 10-9BL is 5% below the horizontal axis current calculation value output from the voltage calculator 10-8B.
Apply a degree of bias.

The voltage signal limiter 10-10A is a bias adder.
10-8 AU value is the upper limit value, and bias adder 10-8
The value obtained by AL is set as the lower limit. When the direct axis voltage request Vd * output from the voltage calculator 10-3A is within the set upper and lower limit values, that is, when the current is normally detected from the controlled object, the limiting operation is not performed and the direct axis When the voltage component Vd * deviates from the set upper and lower limit values, the direct-axis voltage request Vd * limited to the upper and lower limit values is output.

The voltage signal limiter 10-10B is a bias adder.
10-8 BU upper limit value, and bias adder 10-6
The value calculated by BL is set as the lower limit. Then, when the horizontal axis voltage request Vq * output from the voltage calculator 10-3B is within the set upper and lower limit values, that is, when the voltage is normally detected from the control target, the limiting operation is not performed and the horizontal axis is set. When the voltage request Iq * deviates from the set upper and lower limit values, the horizontal axis voltage request Vq * limited to the upper and lower limit values is output.

The coordinate converter 10-4 receives the direct-axis voltage request Vd * output from the voltage calculator 10-3A, the horizontal-axis voltage request Vq * output from the voltage calculator 10-3B, and the required position θ *. After stationary coordinate conversion and further three-phase conversion processing, U-phase voltage request VU *, V-phase voltage request VV *, W, which is a three-phase AC voltage request
The phase voltage request VW * is output.

The pulse controller 11 controls the inverter 2 in accordance with the U-phase voltage request VU *, the V-phase voltage request VV *, and the W-phase voltage request VW * output from the current vector controller 10. Generate.

The inverter 2 outputs a desired AC power based on this pulse to control the rotation of the electric motor 3. Next, the operation of this embodiment will be described with reference to the operation diagram of FIG.

FIG. 4A shows the operation diagram of the detection current, and FIG. 4B shows the operation diagram of the detection voltage. Also, t
= 0 to tA indicates a normal time, and t = tA to indicates an abnormal time. The alternate long and short dash line E indicates the upper limit value of the voltage signal limiter, the alternate long and short dash line curve C shown in FIG. 4B indicates the lower limit value, and the solid line D indicates the output voltage.

At t = 0 to tA, the detected output voltage is normal, so the current vector control is controlled by the solid line B shown in FIG. 4A regardless of the limit of the output voltage. t
When an abnormality occurs at t = A and the detected current is lost, the solid line a changes to the solid line a-3, and accordingly, the solid line d, which is the output voltage, tends to change like the dotted line d-2. The output voltage cannot rise higher than that due to the lower limit value of the alternate long and short dash line (e).

As a result, since the value of the one-dot chain line E is about 5% higher than the value of the solid line D, the current actually flowing in the controlled object is as shown by the two-dot chain line A-1 and the dotted line A-2.
There is no runaway like.

From the above, even if the detected current from the controlled object is lost due to an abnormality or the like, the output voltage and current of the inverter do not run away, so the inverter can prevent an emergency stop due to an excessive current. The reliability and the operating rate are further improved.

Although the bias applied to each bias adder has been described as 5% in the present embodiment, the present invention is not limited to this and may be any value at which the current signal limiter does not operate during normal control.

Further, the voltage calculators 10-8A and 10-8 of this embodiment are also provided.
B may be an arithmetic expression that can calculate the voltage. For example, since the output frequency is proportional to the rotation speed, the voltage calculator 10-8A,
The speed signal may be input to the 10-8B to correct the signal.

An embodiment of the current vector control device according to the present invention will be described with reference to FIGS. 5, 6 and 7. FIG. 5 is a configuration diagram of the current vector control device 10 of the present embodiment shown in FIG. 7, and the current vector control device 10 of the present embodiment will be described below with reference to this drawing and FIG. 7. . FIG. 7 refers to the description of the embodiment based on the invention described in [Claim 1], and the description is omitted here.

The arithmetic processing of the current vector control device 10 will be described with reference to FIG. The coordinate converter 10-1 performs Cartesian coordinate conversion and rotational coordinate conversion based on IU which is the U-phase current, IW which is the W-phase current and the required phase θ *, and the direct-axis current component Id which is the current vector component and the horizontal coordinate. The axis current component Iq is calculated and output.

The comparison calculator 10-2A determines the direct axis current demand Id *.
And the deviation of the direct-axis current component Id output from the coordinate converter 10-1 is obtained. The comparison calculator 10-2B has a horizontal axis current request Iq *
And the deviation of the horizontal axis current component Iq output from the coordinate converter 10-1 is obtained.

The voltage calculator 10-3A performs the proportional-integral calculation processing on the output from the comparison calculator 10-2A, and the direct-axis voltage request V
Output as d *. The voltage calculator 10-3B is a comparison calculator.
The output from 10-2B is subjected to proportional-plus-integral calculation processing and output as a horizontal axis voltage request Vq *.

The phase calculation unit 10-11 uses the horizontal axis current component Iq output from the coordinate converter 10-1 and the required position θ * to calculate
The phase angle advanced from this required phase θ * is calculated and output to the coordinate converter. The following is an example of one operation (*
) Is shown.

[0074]

[Formula 3] −K × (dθ / dt) × Iq + θ ... (*) The coordinate converter 10-4 uses the direct-axis voltage request Vd * and the voltage calculator 10 output from the voltage calculator 10-3A. The horizontal axis voltage request Vq * output from -3B is a three-phase AC voltage request after stationary coordinate conversion and further three-phase conversion processing based on the required phase θ * output from the phase calculator 10-11. U-phase voltage demand VU
*, V-phase voltage request VV *, W-phase voltage request VW * are output.

The pulse controller 11 controls the inverter 2 according to the U-phase voltage request VU *, the V-phase voltage request VV *, and the W-phase voltage request VW * output from the current vector controller 10. Generate.

The inverter 2 outputs a desired AC power based on this pulse to control the rotation of the electric motor 3. Figure 6
The conversion process in the coordinate converter 10-4 will be described using.

I is a vector of detected current, V * is a voltage request vector, and V * 'is a voltage obtained by applying a three-phase AC voltage converted by the phase calculator 10-11 so that the phase advances in the coordinate system of θ *. It is a request vector.

Since the controlled object generally has a reactance component, the phase of the current lags the phase of the inverter output voltage, so that the voltage of V * becomes the current vector of I'and it lags behind the necessary current vector I. It will be.

Therefore, in the phase calculator 10-11, the voltage vector of I can be obtained by advancing the phase and advancing the phase like V * '. From the above, in the conventional current vector control, the phase of the voltage vector is not rotated by the horizontal axis current component Iq. Therefore, during the current feedback, it is not necessary to wait for the phase of the voltage vector to gradually converge to the forward side. Although the response is slow, the voltage vector is advanced by the horizontal axis current component Iq, which is a torque component, when the required voltage on the rotating coordinate is returned to the original coordinate as in the present embodiment. The forward speed of the battery is significantly faster, and the response of the current feedback is improved.

In the above embodiment, the signal input to the phase calculator 10-11 has been described as the horizontal axis current component Iq, but instead of the horizontal axis current component Iq, the direct axis current request Id * or the horizontal axis current request Iq. The calculation may be performed using Iq *. Furthermore, the calculation may be performed using the signal output from the comparison calculator 10-2B.

In the above embodiment, the phase change (dθ / d
The case where t) is calculated by the phase calculator 10-11 has been described.
The calculation may be performed using the speed obtained from the speed / position detector 5 shown in FIG.

In FIGS. 1, 3 and 5, the U-phase current IU and the V-phase current IV are used as the signals input to the coordinate converter 10-1, but the W-phase current IW may be used. Further, the configuration of the current vector control device shown in FIGS. 1 and 3 may be a configuration in which the phase calculator described in FIG. 5 is applied.

That is, in FIG. 1, based on at least one signal of the direct-axis current component Id and the horizontal-axis current component Iq and the required phase θ *, the phase angle advanced from the required phase θ * is calculated to calculate the coordinate converter 10-. The phase calculator 10-11 provided to 4 is provided.

Similarly, in FIG. 3, the direct-axis current component Id is similarly generated.
Further, there is provided a phase calculator 10-11 for calculating a phase angle advanced from the required phase θ * on the basis of at least one signal of the horizontal axis current component Iq and the required phase θ * and giving it to the coordinate converter 10-4.

Although the above embodiments have been described in the case of the electric motor,
In the case of the generator, the direction of the current is only opposite to that of the electric motor, and the same effect can be obtained even when applied to the generator system.

Although the rotary machine has been described, the same effect can be obtained even if the linear motion of a linear motor or the like is used and the current vector control is performed by detecting the position of the moving part.

[0087]

According to the inventions of [Claim 1] and [Claim 2], the output voltage and current of the inverter runaway even if the detected current from the controlled object is lost due to an abnormality or the like. By eliminating this, the inverter can be prevented from an emergency stop due to an excessive current, and the reliability and operating rate are further improved. Further, according to the invention of [Claim 3], since the voltage phase is advanced by the horizontal axis current component Iq which is the torque component, the advance of the voltage vector is significantly accelerated, and the responsiveness of the current feedback is improved. Further, according to the inventions of [Claim 4] and [Claim 5], the reliability and the operating rate can be improved, and the responsiveness can also be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a current vector control device according to an embodiment of the present invention.

FIG. 2 is an operation diagram of the current vector control device according to the first embodiment of the invention.

FIG. 3 is a configuration diagram of a current vector control device according to an embodiment of the present invention.

FIG. 4 is an operation diagram of a current vector control device according to an embodiment of the present invention.

FIG. 5 is a configuration diagram of a current vector control device according to an embodiment of the present invention.

FIG. 6 is an operation diagram of a current vector control device according to an embodiment of the present invention.

FIG. 7 is a system configuration diagram of a variable frequency power conversion device using a current vector control device.

FIG. 8 is a configuration diagram of a conventional current vector control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply 2 ... Inverter 3 ... Electric motor 4 ... Rotation detector 5 ... Speed / position detection device 6 ... Speed torque control device 7 ... Flux control device 8 ... Request vector calculation device 9 ... Current detector 10 ... Current vector control Device 11… Pulse control device 10-1… Coordinate converter 10-2A, 10-2B… Comparison calculator 10-3A, 10-3B… Voltage calculator 10-4… Coordinate converter 10-5A, 10-5B… Current calculator 10-6AU, 10-6BU ... Bias adder 10-6AL, 10-6BL ... Bias subtractor 10-7A, 10-7B ... Current signal limiter 10-8A, 10-8B ... Voltage calculator 10- 9AU, 10-9BU ... Bias adder 10-9AL, 10-9BL ... Bias subtractor 10-10A, 10-10B ... Voltage signal limiter 10-11 ... Phase calculator

[Procedure amendment]

[Submission date] June 9, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Figure 9

[Correction method] Added

[Correction content]

FIG. 9 is an operation diagram of a conventional current vector control device.

Claims (5)

[Claims] 1. A first conversion means for converting and outputting a direct axis current component and a horizontal axis current component based on a detected current to be controlled and a required phase, and a deviation amount between the direct axis current component and the direct axis current request component. For calculating the deviation between the horizontal axis current component and the horizontal axis current request component, and calculating the difference between the horizontal axis current request component and the horizontal axis voltage request signal according to a predetermined control characteristic. A current vector control having a second arithmetic means for outputting a demand signal, a signal outputted from the first and second arithmetic means, and a second conversion means for outputting a demand voltage of three phases based on a demand phase. In the apparatus, a first subtraction unit that calculates a direct-axis voltage request signal output from the first calculation unit into a current component and subtracts a set bias, and a direct-axis voltage request output from the first calculation unit. Calculates the signal as a current component and A first addition means for adding astigmatism, a second subtraction means for calculating a horizontal axis voltage request signal output from the second calculation means into a current component, and subtracting the set bias, and the second calculation means A second adder that calculates the horizontal axis voltage request signal that is output as a current component and subtracts the set bias, a signal that is output from the first subtractor and a lower limit value, and a signal that is output from the first adder The upper limit, the first
First limiting means for limiting the direct-axis current component output from the converting means to output to the first computing means, and a signal output from the second subtracting means from the lower limit value and the second adding means. With the output signal as the upper limit value, the first
Second limiting means for limiting the direct-axis current component output from the converting means to output the current component to the second computing means, the current vector control device. 2. A first conversion means for converting and outputting a direct axis current component and a horizontal axis current component based on a detected current to be controlled and a required phase, and a deviation amount between the direct axis current component and the direct axis current request component. For calculating the deviation between the horizontal axis current component and the horizontal axis current request component, and calculating the difference between the horizontal axis current request component and the horizontal axis voltage request signal according to a predetermined control characteristic. A current vector control having a second arithmetic means for outputting a demand signal, a signal outputted from the first and second arithmetic means, and a second conversion means for outputting a demand voltage of three phases based on a demand phase. In the device, a first subtraction unit that calculates a voltage component from the direct-axis required current component and subtracts a setting bias; and a first addition unit that calculates a voltage component from the direct-axis required current component and add a setting bias. , The horizontal axis demand current component Output from the first subtracting means; second subtracting means for computing a voltage component from the set bias and subtracting the setting bias; second adding means for computing a voltage component from the horizontal axis required current component and adding the set bias; The lower limit value as the lower limit value and the signal output from the first adding means as the upper limit value.
First limiting means for limiting the direct-axis voltage component output from the calculating means to output to the second converting means, and a signal output from the second subtracting means from the lower limit value and the second adding means. With the output signal as the upper limit value, the first
Second limiting means for limiting the horizontal axis voltage component output from the converting means and outputting the voltage component to the second converting means. 3. A first conversion means for converting and outputting a direct axis current component and a horizontal axis current component based on a detected current to be controlled and a required phase, and a deviation amount between the direct axis current component and the direct axis current request component. For calculating the deviation between the horizontal axis current component and the horizontal axis current request component, and calculating the difference between the horizontal axis current request component and the horizontal axis voltage request signal according to a predetermined control characteristic. From the request phase obtained based on the request phase, the second operation means outputting a request signal, the signals output from the first and second operation means, and the signal output from the first conversion means. 3 based on advanced phase
A current vector control device comprising a second conversion means for outputting a required voltage of a phase. 4. A current vector control device in which the second conversion means according to [claim 3] is applied instead of the second conversion means according to [claim 1]. 5. A current vector control device, characterized in that the second conversion means according to [claim 3] is applied instead of the second conversion means according to [claim 2].