JP2000184785A - Method and device for adjusting current control gain of current control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for setting an initial value by comparing the current command signal of a single-phase AC with a current detection signal waveform for measuring delay phase and time, increasing or decreasing a proportional gain depending on whether a detection delay is large or small, and increasing or decreasing the differential gain of a proportional integration control by increasing or decreasing the command value of the amplitude of the current detection signal waveform. SOLUTION: A current command creation circuit 10 creates and outputs a current command signal Ic. Then, the current command is inputted to a transfer function circuit 14 with primary delay via a comparison circuit 11, a multiplication circuit 12, and an addition circuit 13, thus outputting a current detection signal Id. Then, a control circuit for automatically feeding back to the comparison circuit 11 is formed. The input circuit of the addition circuit 13 is provided for the output of the multiplication circuit 12 via a multiplication circuit 15 and an integration circuit 16. The current command signal Ic and the current detection signal Id are inputted for detecting delay time by a current phase delay detection circuit 17 and a proportional gain Kp is adjusted by a proportional gain adjustment circuit 18 and is sent to the multiplication circuit 12. Output Ki (1/Ti) is inputted to the multiplication circuit 15 by a current amplitude detection circuit 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustment method and an adjustment device for adjusting a current control gain of a current control system when an induction motor is driven by an inverter or the like, and more particularly to a proportional gain and a control system for applying PI control. Related to automatic adjustment of integral gain.

[0002]

2. Description of the Related Art A current control system for controlling an induction motor at a variable speed by an inverter is shown in FIG.
The I (proportional / integral) control is applied, and its adjustment items include a proportional gain K _P and an integration time constant T _i .

FIG. 16 shows a current control system diagram (high response region) of an induction motor, in which 1 is a proportional gain circuit,
Reference numeral 2 denotes an addition circuit that adds the output of the proportional gain circuit 1 and the output of the integration gain circuit 5. Reference numeral 3 denotes a control delay in outputting a voltage, and reference numeral 4 denotes a first-order delay transfer function circuit of a current control system using an induction motor as a control loop element.

The detected current value (Id) of the quantity to be controlled is fed back and compared with the current command value (Ic), and the difference is input to the proportional gain circuit 1 to constitute an automatic control system.

In the figure, σ is the control delay time, Kp is the proportional gain, Ti is the integration time constant (sec), L is the sum (H) of the leakage inductance (L ₁ + L ₂ ), and R is the primary resistance R ₁
+ Secondary resistance R ₂ (Ω), S indicates Laplace operator.

FIG. 17A shows a general T-type equivalent circuit of an induction motor (hereinafter, referred to as a motor). From this equivalent circuit diagram, the current control gains Kp and Ti indicate the motor resistance R and
It can be uniquely determined by the inductance L and the target frequency response ωc.

When the current control system is digitally controlled, if the sampling frequency of the current control operation is high, the effect of the excitation inductance can be neglected as shown in FIG. The transfer function G is given by the following equation (1).

[0008]

G = Kp · (sTi + 1 / sTi) · (1 / sL + R) (1) Assuming that the integral gain Ti is Ti = L / R in the equation (1), the delay term due to the equivalent circuit constant is canceled. In this case, the open-loop transfer function G 'can be represented by the following equation (2).

[0009]

G ′ = Kp · (1 / SL) (2) Therefore, the response of the current control can be uniquely determined by the proportional gain Kp.

The closed-loop transfer function H obtained by using the equation (2) becomes the equation (3).

[0011]

H = 1 / {s (L / Kp) +1} (3) Accordingly, the proportional gain Kp can be determined by the leakage inductance L and the target response ωc, and the current control gain is obtained by the equation (4). .

[0012]

(Equation 1)

When the circuit constant of the motor is known in advance, the current control gain can be obtained by the equation (4).

However, there are motors that do not involve designers,
In many cases, the circuit constant is not known, as in the case of a replacement property. In such a case, generally, a step-like direct current is passed and the frequency response at the current gain is obtained from the response waveform to become the target response. The system is used to increase the gain up to that point.

Further, since the system is a secondary system, overshoot may occur depending on the control gain, making adjustment difficult. In some cases, a system identification method is used. However, the use of a DC step response is still the same, and only the convergence time of the gain is reduced.

[0016]

When the motor circuit constants are known as described above, the current control gain can be obtained by equation (4). Generally, in the initial stage of adjustment of the current control system, Since the motor circuit constant is unknown, the current control gain cannot be obtained by the equation (4). Therefore, the adjustment is performed with reference to the response waveform such as the step response. However, in order to obtain the response waveform, the current control system must be operated, and the initial value of the current control system is always required.

When the motor circuit constants are known in advance, the target response frequency ωc in the equation (4) is set to a small value to obtain a stable current control gain. Thus, the motor circuit constant may not be known at all. In particular, since a general-purpose inverter does not know what kind of motor is connected, especially when the leakage inductance is small, hunting occurs in the current and the adjustment becomes impossible.

The present invention has been made in view of such a problem, and an object of the present invention is to solve the above-mentioned problem by making it unnecessary to set an initial value.

[0019]

In the above-mentioned conventional method of flowing a step-like direct current, a harmonic component is included in the step response, so that if the current control system is oscillatory, hunting may occur. However, the present invention has been made by paying attention to the fact that when a single-phase alternating current is used, the input frequency has only one frequency component, and the input frequency can be kept low in the initial stage.

Further, according to the present invention, the delay time of the current detection waveform with respect to the current command waveform is determined by a proportional gain, and the amplitude of the current detection waveform is mainly integrated. Focusing on being determined by the gain, based on these findings, adjusting the magnitude of the delay time and the amplitude enables adjustment of the proportional gain and the integral gain.

In the present invention, a means for solving the above-mentioned problem is a current control system for driving an induction motor, wherein
In the current gain adjusting method to which the I control is applied,
The proportional gain of the I control is adjusted by comparing the current command signal of the single-phase AC with the waveform of the current detection signal, measuring the delay phase or delay time of the current detection signal waveform, and setting a preset target delay phase or delay time. It is determined whether or not the detection delay is large. When the detection delay is large, the proportional gain is increased, and when the detection delay is small, the proportional gain is decreased, and adjustment is performed.
Adjustment of the integral gain of the PI control is performed by measuring the amplitude of the current detection signal waveform, determining whether or not the amplitude is large with respect to a preset command value. Adjustment to increase the integral gain is performed.

According to this method, the detected amplitude and the delay time are measured in a half cycle of the output waveform cycle, and it takes time to adjust. To reduce this, each waveform is two-dimensionally represented, expressed as a rotating vector, and the DC coordinate is converted by exchanging the rotating coordinates based on the current command value, and the delay phase angle and amplitude corresponding to the delay time are continuously calculated. And shorten the adjustment time.

The initial value of the proportional gain is roughly determined by the motor capacity which is assumed to be applied. Therefore, if Kp is sufficiently small with respect to the frequency of the current command value, there is a possibility that a step-out occurs due to a delay in following.

In order to prevent this step-out, if the measured delay phase of the current detection signal waveform exceeds a predetermined phase angle, it is determined that the step-out has occurred, and the proportional gain is doubled and readjusted. To prevent loss of synchronism.

The step-out is also caused by the high initial frequency. Therefore, it can also be prevented by setting the initial frequency low and increasing the frequency so as not to lose synchronism. That is, when the delay phase of the current detection signal waveform is larger than a preset phase angle, the frequency of the current command signal is lowered, and when it is smaller than the set angle, the frequency is raised to the target frequency with the set cushion time. To do.

Next, as a current control gain adjusting device for a current control system, a current control system for driving an induction motor, which is a current gain adjusting device to which PI control is applied, wherein a single-phase AC current is applied to the current control system. A current command generation circuit for supplying a command signal, a current command signal of the current command generation circuit,
A current phase delay detection circuit that inputs a current detection signal from a current control system and measures a delay time or a delay phase angle of the current detection signal waveform from the current command signal waveform, and a current that measures the amplitude of the current detection waveform An amplitude detection circuit, a proportional gain adjustment circuit which receives an output of the current phase delay detection circuit, and adjusts a proportional gain so as to fall within a delay time or a delay phase angle determined from a preset target frequency response; and An output of the circuit is input, and an integral gain adjusting circuit for adjusting the integral gain so that the amplitude of the current detection waveform matches the amplitude of the current command signal.

Also, the output of the current phase delay detection circuit is input, and when the detection delay phase exceeds a predetermined phase angle, a signal is output to a proportional gain adjustment circuit so that the proportional gain is doubled. A step-out prevention circuit is provided.

As a device for shortening the adjustment time, a current command generation circuit for supplying a single-phase AC current command signal to the current control system, a current command signal of the current command generation circuit, and a current control system , A two-dimensional current detection signal, a rotation coordinate conversion circuit that performs rotation coordinate conversion by a current command signal, and an output of the rotation coordinate conversion circuit. The output of the current phase delay detection circuit and the current amplitude detection circuit for measuring the delay phase angle and the amplitude, and the output of the current phase delay detection circuit are input so that the delay time or the delay phase angle determined from the target frequency response set in advance is within. The output of the current amplitude circuit and the proportional gain adjustment circuit that adjusts the proportional gain are input to each other, and the product is adjusted so that the amplitude of the current detection waveform matches the amplitude of the current command signal. Providing an integral gain adjustment circuit for adjusting the gain.

Further, a proportional gain and an integral gain are calculated in advance when circuit constants are known, and an initial value calculating / setting circuit for setting initial values of a proportional gain adjusting circuit and an integrating buffer of the integral gain adjusting circuit is provided. To reduce adjustment time.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described in the prior art, in a method in which a step-like DC current is supplied to obtain a frequency response of a current gain from a response waveform thereof and adjust a gain until a target response is obtained, the step Since the response contains a high frequency component, hunting may occur if the current control system is vibratory.

Accordingly, the present invention is to stably adjust the current control gain using a single-phase alternating current.

That is, when the single-phase AC is used, the input frequency has only one frequency component, and the input frequency can be suppressed low at the initial value stage. The control gain can be adjusted.

Hereinafter, the adjustment of the current control system using the single-phase alternating current will be described in detail.

FIG. 1 shows a current command waveform and a current detection waveform when a single-phase AC is applied to a current control system such as an induction motor. In the figure, the horizontal axis indicates time, the vertical axis indicates current value, the current command waveform Ic is indicated by a dotted line, and the current detection waveform Id is indicated by a solid line. The current detection waveform Id is generated with a delay time Td behind the current command waveform Ic.

The delay time Td is determined by the proportional gain, and the detected amplitude Ip of the current detection waveform is mainly determined by the integral gain. That is, when the proportional gain is small, the delay time Td increases, and when the proportional gain is large, the delay time Td decreases.

When the integral gain is small, the detection amplitude Ip becomes small due to the following error. When the integral gain is large, the detection width becomes large due to overshoot.

The target response frequency is defined as ωc (rad / s
ec), when the gain can be adjusted to the expression shown in the above equation (4), the delay time Td (sec) becomes Td
The proportional gain may be adjusted so that d = 1 / ωc and the delay time becomes Tdelay.

Therefore, the control gain of the current control system can be adjusted using these phenomena.

FIG. 2 is a block diagram of the current control gain adjusting circuit. In FIG. 2, reference numeral 10 denotes a current command generating circuit which generates and outputs a current command signal (value) (current command waveform Ic in FIG. 1). I do. This current command signal Ic is input to a first-order lag transfer function circuit 14 via a comparison circuit 11, a multiplication circuit 12, and an addition circuit 13, and the transfer function circuit 14 outputs a current detection signal (current detection waveform Id in FIG. 1). ) Is output.
This current detection signal (value) is fed back to the comparison circuit 11 to form an automatic control circuit.

The output circuit of the multiplication circuit 12 is provided with a circuit for inputting the signal to the addition circuit 13 via the multiplication circuit 15 and the integration circuit 16.

Reference numeral 17 denotes a current phase delay detection circuit which receives a current command signal (Ic) and a current detection signal (Id) from the current command creation circuit 10 and detects a current phase delay time Id.
Input to the proportional gain adjustment circuit 18. The proportional gain (Kp) is adjusted and output by the proportional gain adjusting circuit 18 and sent to the multiplying circuit 12.

Reference numeral 19 denotes a current amplitude detection circuit, which receives the current command signal (Ic) from the current command creation circuit 10 and the transfer function circuit 1
The current Ki (1 / Ti) is input to the multiplication circuit 15 via the integral gain adjustment circuit 20 by inputting the current detection signal (Id) from the P. 4 and the current detection signal (Id).

The output of the multiplication circuit 15 is input to the addition circuit 13 via the integration circuit 16.

The proportional gain adjustment circuit 18 adjusts the proportional gain by measuring the delay time at the time of the zero crossing of the current as a means for measuring the delay time of the waveform.

The integral gain adjusting circuit adjusts the integral gain by measuring the maximum value of the waveform.

Next, a method of adjusting the proportional gain and the integral gain will be described with reference to the flowchart of FIG.

FIG. 3 shows a flowchart of the control gain (proportional gain and integral gain) adjustment. Initially, the current command creation circuit 10 initializes the control (S1), and outputs a single-phase AC current command signal (S2). From the single-phase AC output and the current detection signal, the delay of the detection waveform is measured by the current phase delay detection circuit 17 (S3), and the proportional gain adjustment circuit 18 determines whether the detection delay is larger than the target delay. Judge (S
4) When the value is large, the proportional gain is increased (S5), and when the value is small, the proportional gain is decreased, and adjustment is performed so as to fall within a preset phase delay target value (S6).

Next, the amplitude of the detected waveform is measured by the current amplitude detecting circuit 19 (S7), and whether or not the amplitude is larger than the command value is determined by the integral gain adjusting circuit 20 (S8). The integral gain is decreased (S9), and when it is smaller, the integral gain is increased, and the amplitude of the detected waveform is adjusted to match the amplitude of the current command value (S10).

In step S11, it is determined whether or not each gain has converged. When the gains have converged, the adjustment is terminated (S1).
2) If not converged, return to step S3 and repeat until converged.

It should be noted that since the amplitude is small even if the response speed is low, it is necessary to make the adjustment speed of the proportional gain faster than the adjustment speed of the integral gain.

In the above method, the delay time and the detected amplitude shown in FIG. 1 are measured in a half cycle of the output waveform cycle, and it takes some time to adjust. The means for shortening the adjustment time is the second embodiment.

This means converts each waveform into a two-dimensional form and expresses it as a rotation vector, and performs DC conversion by performing rotation coordinate conversion based on the current command value, and continuously converts the delay phase angle and amplitude corresponding to the delay time. To be able to get to.
However, two-dimensionalization is performed by setting the current command to sin (ωt) and arranging its differential value in a phase advanced by 90 ° in time.

FIG. 4 shows the two-dimensional rotation vector diagram, and FIG. 5 shows the current vector diagram after the rotation coordinate conversion.

FIG. 6 is a block diagram of a current control gain adjustment circuit using rotation coordinate conversion. The current control gain adjustment circuit of FIG. 2 is provided with a rotation coordinate conversion circuit. Therefore, the same functional portions or corresponding portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 6, reference numeral 21 denotes a rotation coordinate conversion circuit which receives the current command signal (Ic) and the current detection signal (Id) from the current command creation circuit 10 and converts the rotation coordinate based on the current command value. Perform DC conversion.

FIG. 7 shows an example of the rotation coordinate conversion circuit 21.
The current command signal is assumed to be sin (ωt), its differential value is arranged in a phase advanced by 90 ° in time, two-dimensionalization is performed, a current phase delay detection circuit 17 detects a current phase delay from the X axis, and The current amplitude value is detected by the current amplitude detecting circuit 19, and the proportional gain is adjusted by the proportional gain adjusting circuit 18 and the integral gain is adjusted by the integral gain adjusting circuit 20, as in FIG.

Next, embodiments of the proportional gain adjustment circuit 18 and the integral gain adjustment circuit 20 will be described in detail.

FIG. 8 shows an example of the configuration of the proportional gain adjusting circuit 18, in which a phase delay target value determined from a target frequency response is set, and the phase delay target value and phase delay information (time or angle) are set.
Is compared by the comparison circuit 18a, and the difference is input to the adjustment gain circuit 18c via the excessive response prevention limiter 18b, and the proportional gain is output through the integration circuit 18d.

As described above, the proportional gain adjuster is configured by the integral control, and the limiter is provided in the input stage, thereby stabilizing the adjustment.

FIG. 9 shows an example of the configuration of the integral gain adjusting circuit 20, in which a current command amplitude value and a current detection amplitude value are compared by a comparison circuit 2.
0a, and inputs the difference to an adjustment gain circuit 20c via an excessive response prevention limiter 20b.
The integrated gain Ki is output through 0d.

As described above, the integration gain adjuster is configured by the integral control, and the limiter is provided in the input stage, so that the adjustment can be stabilized.

Since the adjustment speed of the integral gain must be lower than the adjustment speed of the proportional gain for stabilization in the adjustment stage, as described above, the adjustment gain cannot be increased.

However, when the current amplitude of the current detection signal exceeds the current amplitude of the current command signal, an overshoot clearly occurs, and the integral gain must be reduced promptly. From this, it was found that more stable and prompt convergence can be expected by using different gains for the adjustment gain when increasing the integration gain and the adjustment gain when decreasing the integration gain.

FIG. 10 is a circuit diagram for varying the adjustment gain by increasing or decreasing the integral gain.

In the figure, reference numeral 30 denotes an adjustment gain adjusting circuit for making the adjustment gain variable by increasing or decreasing the integral gain. As shown in the figure, a current command amplitude value and a current detection amplitude value are compared by a comparison circuit 30a. , The difference is input to a plus excessive response prevention limiter 30b (0 to + upper limit) and a negative excess response prevention limiter 30c (0 to −upper limit), and the output is added via adjustment gains 30d and 30e, respectively. 3
0f, and integrated by the composite circuit 30g to obtain an integral gain K
i.

When this circuit is used, the circuit is replaced with an integral gain adjusting circuit 20 shown in FIG. With this configuration, the convergence speed of the integral gain can be increased and the integration gain can be stabilized by making the integral gain variable on the increasing side and the decreasing side.

The current detection includes noise due to a discretization error and a detection offset. Therefore, when trying to completely match the target value, there is a possibility that divergence may occur due to the relationship with the adjustment gain of the proportional gain.

Therefore, in order to prevent this, a dead zone is provided near the target value so that the convergence can be achieved more stably.

FIG. 11 shows an example of the configuration of an integral gain adjusting circuit provided with this dead zone. The comparing circuit 30h is added to the input side of the plus excess response preventing limiter 30b shown in FIG. Each of the circuits 30i is provided. The comparison circuit 30h inputs the deviation value and the dead band offset value of the preceding comparison circuit 30a and inputs the difference to the plus excess response limiter 30b. The deviation value of the arithmetic circuit 30a and the offset value for the dead zone are input and added, and input to the minus excess prevention limiter 30e. By providing a dead zone of about 10% in the adjustment width of the integral gain, stability during adjustment can be achieved.

The initial value of the proportional gain is roughly determined by the motor capacity assumed to be applied. Therefore, if the proportional gain Kp is sufficiently small with respect to the frequency of the current command value, there is a possibility that a step-out occurs due to a delay in following. If the step-out occurs, the proportional gain adjustment circuit
Since the adjustment is performed in a direction opposite to the original direction, the proportional gain diverges.

The third embodiment of the present invention is provided with this step-out prevention function.

FIG. 12 is a block diagram of a current control gain adjustment block circuit having a step-out prevention function. In the figure, the same or corresponding parts as those described above are denoted by the same reference numerals, and detailed description is omitted. A step-out prevention circuit 40 receives the output of the current phase delay detection circuit 17 and inputs the output to the proportional gain adjustment circuit 18.

The step-out prevention circuit 40 has a function of determining that step-out has occurred when the detection delay phase angle exceeds a preset phase angle, for example, 180 °, and performing a readjustment by doubling the proportional gain. . FIG. 13 shows a current vector diagram when this step-out occurs.

Since step-out occurs also due to the high initial frequency, step-out prevention can be realized by setting the initial frequency low and increasing the frequency so that step-out does not occur. The fourth embodiment is an adjusting means provided with this step-out prevention circuit. FIG. 14 is a block diagram of a current control gain adjustment block provided with this step-out prevention frequency setting circuit.

In the figure, reference numeral 41 denotes a step-out preventing frequency setting circuit, which inputs the output of the current phase delay detecting circuit 17 and sends the output to the current command generating circuit 10. Then, for example, when the detection delay phase becomes larger than a preset phase angle, for example, 120 °, the frequency is lowered,
If the angle is smaller than 120 °, the target frequency is raised to the target frequency in the set cushion time.

Although the above-described method is used when the motor circuit constant is not known at all, there are cases where the motor circuit constant is known in advance. In such a case, the adjustment time can be short-circuited. The fifth embodiment is an adjusting means when the number of motor circuits is known. FIG. 15 shows a block diagram of a current control gain adjusting block including the initial value calculating and setting circuit. The circuit shown in FIG.
Are input to the proportional gain adjustment circuit 18 and the integral gain adjustment circuit 20, and the proportional gain and the integral gain are calculated in advance by the above equation (4), and the initial values of the integration buffers of the gain adjustment circuits 18 and 20 are set. Set to.

[0077]

As described above, according to the present invention, the proportional gain can be started from 1 and the integral gain can be started from 0 in any induction motor, so that there is no need to set an initial value. This is an effective means especially when the motor constant is unknown such as in the case of a replacement property, or when the wiring length from the inverter to the induction motor is long, or when the filter is connected to the output and the leakage inductance is unknown. . Further, since the gain adjustment is configured as an adaptive type, it is possible to continuously adjust the gain and obtain a quick convergence value.

[Brief description of the drawings]

FIG. 1 is a diagram showing a current command waveform and a current detection waveform when a single-phase alternating current flows.

FIG. 2 is an adjustment block diagram of a current control gain according to the present invention.

FIG. 3 is a control gain adjustment flowchart of the present invention.

FIG. 4 is a two-dimensional rotation vector diagram.

FIG. 5 is a current vector diagram obtained by performing rotation coordinate conversion.

FIG. 6 is a current control gain adjustment block diagram using the rotational coordinate transformation of the present invention.

FIG. 7 is an example of a current phase delay detection and amplitude detection circuit using rotational coordinate conversion.

FIG. 8 is a configuration example of a proportional gain adjustment circuit.

FIG. 9 is a configuration example of an integral gain adjustment circuit.

FIG. 10 is a configuration example of a circuit that varies an adjustment gain by increasing or decreasing an integral gain.

FIG. 11 is a configuration example of an integral gain adjustment circuit when a dead zone is provided.

FIG. 12 is a current control gain adjustment block diagram including a step-out prevention circuit according to the present invention.

FIG. 13 is a current vector diagram when step-out occurs.

FIG. 14 is a current control gain adjustment block diagram including a step-out prevention frequency setting circuit according to the present invention.

FIG. 15 is a current control gain adjustment block diagram including an initial value calculation / setting circuit of the present invention.

FIG. 16 is a diagram of a current control system when driving an induction motor.

FIG. 17 is an equivalent circuit diagram at the time of current response of the induction motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Current command creation circuit 11 ... Comparison circuit 12, 15 ... Multiplication circuit 13 ... Addition circuit 14 ... First-order lag transfer function circuit 16 ... Integration circuit 17 ... Current phase delay detection circuit 18 ... Proportional gain adjustment circuit 19 ... Current amplitude Detection circuit 20 ... Integral gain adjustment circuit 21 ... Rotation coordinate conversion circuit 30 ... Adjustment gain adjustment circuit 40 ... Step-out prevention circuit 41 ... Step-out prevention frequency setting circuit 42 ... Initial value calculation / setting circuit

Continued on front page F-term (reference)

Claims (11)

[Claims] 1. A current control system for driving an induction motor, wherein a current gain adjustment method to which PI control is applied, wherein the proportional gain of the PI control is adjusted by controlling a single-phase AC current command signal and a current detection signal. Compare the waveforms and measure the delay phase or delay time of the current detection signal waveform, determine whether the detection delay is large relative to the preset target delay phase or delay time, and if the detection delay is large, proportional gain A current control gain adjustment method for a current control system, wherein an adjustment is made to increase the proportional gain when it is small. 2. A current control system for driving an induction motor, wherein a current gain adjustment method to which PI control is applied is characterized in that the adjustment of the integral gain of the PI control is performed by measuring the amplitude of a current detection signal waveform and presetting the amplitude. The current control gain of the current control system is characterized in that it is determined whether or not the amplitude is large relative to the command value, and when the amplitude is large, the integral gain is decreased, and when the amplitude is small, the integral gain is increased. Adjustment method. 3. A method for adjusting a proportional gain of a PI control, wherein the proportional gain of the PI control is a single-phase AC current command signal and a current detection signal of a current detection signal. Compare the waveforms and measure the delay phase or delay time of the current detection signal waveform, determine whether the detection delay is large relative to the preset target delay phase or delay time, and if the detection delay is large, proportional gain Is increased, and when it is smaller, the proportional gain is decreased. The integral gain of the PI control is adjusted by measuring the amplitude of the current detection signal waveform and determining whether the amplitude is larger than a preset command value. A current control gain adjustment method for a current control system, wherein an adjustment is made to decrease the integration gain when it is large and to increase the integration gain when it is small. 4. The current control gain adjusting method for a current control system according to claim 3, wherein the lag phase or lag time and amplitude of the current detection signal waveform are measured by a rotating coordinate conversion means. 5. When the measured lag phase of the current detection signal waveform exceeds a preset phase angle, it is determined that the step-out occurs, and the step-out is prevented by re-adjusting by doubling the proportional gain. 4. The current control gain adjusting method for a current control system according to claim 1, wherein: 6. The frequency of the current command signal is reduced when the delay phase of the current detection signal waveform is larger than a preset phase angle, and when the delay phase is smaller than the preset angle, the target is set at a set cushion time. 4. The current control gain adjusting method for a current control system according to claim 1, wherein the frequency is increased to a frequency. 7. A current control system for driving an induction motor, wherein a current gain adjusting device to which PI control is applied includes: a current command generation circuit for supplying a single-phase AC current command signal to the current control system; A current phase delay detection circuit for inputting a current command signal of a command generation circuit and a current detection signal from a current control system, and measuring a delay time or a delay phase angle of the current detection signal waveform from the current command signal waveform; A current amplitude detection circuit for measuring an amplitude of a current detection waveform and an output of the current phase delay detection circuit are input, and a proportional gain is adjusted so as to fall within a delay time or a delay phase angle determined from a preset target frequency response. The outputs of the proportional gain adjustment circuit and the current amplitude circuit are input, and the integral gain is adjusted so that the amplitude of the current detection waveform matches the amplitude of the current command signal. Min gain control circuit and a current control gain regulator of the current control system, characterized in that it comprises a. 8. An input of an output of the current phase delay detection circuit,
8. A step-out prevention circuit for outputting a signal to a proportional gain adjusting circuit when the detection delay phase exceeds a preset phase angle to readjust the proportional gain twice. A current control gain adjusting device for a current control system according to claim 1. 9. It has a function of adjusting the frequency of the current command generation circuit, inputs the output of the current phase delay detection circuit, sets the initial frequency of the current command generation circuit low, and gradually increases the frequency to detect the detection delay. 8. The current control according to claim 7, further comprising a frequency setting circuit for preventing a turbulence, which lowers the frequency when the phase is larger than a preset phase angle, and raises the frequency when the phase is smaller than the preset phase angle to a target frequency in a cushion time. System current control gain adjustment device. 10. A current control system for driving an induction motor, wherein the current gain adjusting device to which PI control is applied includes: a current command generation circuit for supplying a single-phase AC current command signal to the current control system; A rotation command conversion circuit that inputs a current command signal of a command generation circuit and a current detection signal from a current control system, converts the current detection signal into a two-dimensional form, and performs rotation coordinate conversion based on the current command signal; A current phase delay detection circuit and a current amplitude detection circuit for inputting an output of the circuit and measuring a delay phase angle and an amplitude from a current command signal; and an output of the current phase delay detection circuit, and a preset target frequency response. A proportional gain adjusting circuit for adjusting a proportional gain so as to fall within a delay time or a delay phase angle determined by Current control gain regulator of the current control system characterized in that a integral gain adjustment circuit whose amplitude is adjusted integral gain to match the amplitude of the current command signal. 11. An initial value calculating / setting circuit for calculating a proportional gain and an integral gain in advance when circuit constants are known, and setting initial values of an integral buffer of the proportional gain adjusting circuit and the integral gain adjusting circuit. The current control gain adjusting device for a current control system according to any one of claims 7, 8, 9, and 10, wherein: