JP2827792B2 - Feedback control device and control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and a control method for controlling a control target such as an inverter and a converter.

[0002]

2. Description of the Related Art FIG. 1 shows a feedback control device in a system for supplying power from a variable voltage source 2 comprising a PWM converter or the like to a load 1 comprising a reactor having an inductance value L. This system is configured to supply a load current I corresponding to a digital command current value Ir generated from a digital command value (reference value or target value) generator 3 from a variable voltage source 2 to a load 1. The load current I is a control amount in the feedback control system, and is detected by a current detector (control amount detector) 4 and an ADC (analog-digital converter) 5 connected thereto. AD
C5 samples the analog detection current detected by the current detector 4 at a constant sampling cycle, converts the sample into a digital signal, and outputs the digital signal. Here ADC
Let I denote both the input and output of 5 by I. The digital subtractor 6 as a comparison means forms an output (error output) of a difference between the command value Ir and the detection value I. The digital controller 7 connected to the subtractor 6 is a control element including a proportional integrator or a proportional compensator in the feedback control system, and is constituted by a microcomputer (microcomputer or microprocessor). A digital operation amount V for operating the variable voltage source 2 so as to make the signal zero is formed. Note that the command value generator 3, the ADC 5, and the subtractor 6 can be included in the microcomputer together with the digital controller 7. Between the digital controller 7 and the variable voltage source 2, there is connected a hold circuit 8 which forms an analog manipulated variable corresponding to the digital manipulated variable V, holds it for one sample period, and outputs it. The hold circuit 8 includes a DAC (digital-to-analog converter) and forms an analog manipulated variable corresponding to the digital manipulated variable V. Therefore, the hold circuit 8 can also be called an analog manipulated variable generator. Here, both the digital operation amount and the analog operation amount are indicated by V. The variable voltage source 2 includes a circuit that generates, for example, a PWM control pulse in response to the analog manipulated variable V and a switching element that responds to the PWM control pulse, performs an operation corresponding to the analog manipulated variable V, and obtains an output current I. Output voltage for Here,
In FIG. 1, the hold circuit 8, the variable voltage source 2, and the load 1 are collectively called a control target. However, load 1
Only the control target may be called a control target, and the digital controller 7, the hold circuit 8, and the variable voltage source 2 may be collectively called a control element. In this case, the output voltage kV (where k is a constant) of the variable voltage source 2 becomes the manipulated variable.

In FIG. 1, reference numeral 1a denotes a current Il based on a disturbance.
Is a disturbance current source that schematically indicates the occurrence of
Includes the disturbance current Il.

When the load shown in FIG. 1 is replaced with an inductance L and a resistor R, the same control system as that shown in FIG. 1 can be formed. The load 1 in FIG. 1 is a capacitor C, and a current is supplied from a variable current source to the load
Is basically controlled in the same manner as in FIG.

When the transfer function for the controlled object is obtained with reference to FIG. 1 using the operation amount as input and the control amount as output, the following equation (1) is obtained. G _A (s) = 1 / Ls (1) Also, in the case where a capacitor C is provided instead of L in FIG. 1 and a variable current source is connected thereto, a transfer function is similarly obtained. Becomes _{G B (s) = 1 /} Cs (2) Equation (1), is simulated by the control object integral element both from the L load and C load (2) (element that increases the output of Indiana emissions Shall response time), also Both the operation amount and the control amount are similar circuits except that the voltage and the current are switched. Therefore, only the case of the L load in FIG. 1 will be described below.

FIG. 2 shows a transfer function in the control system of FIG.
It is represented in a discrete time domain by conversion. Here, the digital controller 7 including the proportional integrator is ki / (z−
The element 7a of 1), the element 7b of Kp, and the adder 7c are shown. Further, the hold circuit 8, the variable voltage source 2, and the load 1 of FIG. 1 are (kTs / L) ｛(m (z−1) +1) /
This is shown as a controlled object 10 including an element 10a of (z-1)} and an element 10b of Z- ¹ . Further, the control amount I of the control target 10 is shown to include the disturbance component Il.

FIG. 3 shows a control amount (load current) I detected for each Ts and its detected value and a digital value when both the sampling period (interval) of the controller of FIG. 1 and the control interval of the controller 7 are Ts. Alternatively, the relationship of the analog operation amount V is shown. Note that n-2, n-1, n, and n + 1 indicate sampling points, and I (n-2), I (n-1), I (n), and I (n
+1) indicates a control value (sample) detection value at each sampling point, and V (n-2), V (n-1), V (n), and V (n + 1) are operation amounts at each sampling interval. Is shown. Assuming that the sampling time point n is the current time point, the manipulated variable V (n) output at the current time point n
Is the control amount detection value I at the previous sampling time point n-1.
(n-1). Therefore, in the feedback control system including the digital controller 7, a control delay of one sampling time interval Ts and a control error occur.

The problems related to the control delay and the control error are problems peculiar to a control system constituted by a digital controller, and it is known to use a control amount predictor as shown in FIG. FIG. 4 is a block diagram in which a control amount predictor 9 is added to the control system of FIG. In FIG. 1, the transfer function of the hold circuit 38 can be expressed by the following equation (3). G _H (s) = (1−e− ^{s · Ts} ) / s (3) The variable voltage source 2 can be represented by a proportional element k. Further, since the transfer function of the controlled load 1 is represented by the equation (1), the total transfer function G (s) from the hold circuit 8 to the controlled load 1 is represented by the following equation (4). _{G (s) = G H (} s) · k · G A (s) = ((1-e -s · Ts) / s) · k · (1 / Ls) = k · (1-e -s · ^{ts) / (s 2 L)} (4) where, expressed G (s) is the discrete time domain by Z conversion by formula Z transform becomes the following expression (5). G (z) = (k · Ts / L) · (1 / (Z−1)) · Z ⁻¹ (5) In FIG. 4, 7 is a digital controller represented in a discrete time domain, and 10 is an equation ( 5) a transfer function from the hold circuit 8 to the controlled load 1 represented by 5), 11 is a one-sample delay element, 9 is a control amount predictor, 12 is an adder, 6 is a subtractor,
3 is a command value for the control amount. The line 13 corresponds to the output of the ADC 5 in FIG. 1, and the control amount detection value is obtained here. One input terminal of the adder 12 is connected to the line 13, and the other input terminal is connected to the predictor 9. The predictor 9 is connected to the digital controller 7 via the delay element 11 and calculates a predicted value Δi (n−1) based on the digital manipulated variable V.
Occurs.

More specifically, the predictor 9 calculates and predicts only an increase (change) of the control amount when a certain operation amount V is given to the control target. Therefore, since the control object of this example is the reactor 4, the function for obtaining the increase can be represented by (k / Ln) · Ts (where Ln represents the nominal value of L). FIG. 5 shows a state of the control. (N-1)
At the time, the control amount I (n-1) is detected on the line 13.
Also, the manipulated variable v (n-1) output at the time (n-1) is obtained by the delay element 11 and input to the predictor 9 to obtain T
The control amount increase predicted value Δi (n-1) at time s is obtained. The control amount predicted value i (n) at the time point n is added by adding the control amount increase predicted value and the detected control amount by the adder 12.
Is obtained. A control error is obtained by the subtractor 6 from the obtained control amount predicted value and command value at the time point n, and the control error is output by the digital controller 7 in one sample period from the time point n so that the control error converges to zero. The operation amount V (n) is determined, and is output to the control target in a period from n to n + 1. This technique compensates for control errors due to one sample time. However, when a constant (for example, L) to be controlled changes, an error occurs. The error is larger as the prediction time is longer. Here, the variation of the constant of the controlled object means that the inductance value L varies in the example of FIG. 1 and that the load 1 has a resistance component together with the inductance L.

In order to solve the above-mentioned drawbacks, the present applicant shortens the prediction time and makes it difficult for errors to occur, and when a prediction error occurs, calculates the value obtained by integrating the error between the predicted value and the actual value. A method of converging a prediction error to 0 by adding to the input or output of a predictor is disclosed in Japanese Patent Application No. Hei 4-26436.
No. 3 proposed. Next, a feedback control device according to this method will be described with reference to FIGS. However, in FIGS. 6 and 7, portions common to FIGS. 1 to 5 are denoted by the same reference numerals, and description thereof is omitted. As is clear from the comparison between FIG. 6 and FIG. 4, the method of FIG. 6 is obtained by adding a prediction error detector 14, a prediction error compensator 15, and an adder 16 to the method of FIG. That is, this compensation means is provided in addition to the control amount change prediction means 9b . The newly provided adder 16 adds the output V (n-1) of the delay element 11 and the prediction error compensation amount obtained from the prediction error compensator 15 and sends the result to the change (increase) predictor 9b. Prediction error detector 14
Is the delay element 17 of one sample period and exp (−mT
s) and a subtractor 19. Delay element 17
Is connected to the output line of the adder 12, and the control amount prediction value i
The control amount prediction value i (n-1) at (n-1) one sample period Ts before (n) is output. The circuit 18 outputs the control amount detection value I (n-1) at the time of (n-1). Therefore, the output Δie (n−1) of the difference between the predicted value i (n−1) and the detected value I (n−1) is obtained from the subtracter 19 as a prediction error. The prediction error compensator 15 calculates kz / (z
-1), and sends the prediction error compensation amount to the adder 16. In FIG. 6, the control amount predictor 9a and the prediction error detector 1
4. Although the prediction error compensator 15 and the adders 12 and 16 are functionally shown as blocks, they are actually formed of a DSP (digital signal processor) or a microcomputer, and are processed by software according to a predetermined program.

In this embodiment, as shown in FIG. 7, m points are provided between each sampling time interval Ts, and the detection timing of the control amount and the output timing of the operation amount are as follows. The description will be made by taking an example between the points (n-1) and (n).
The control amount I (n-1, m) at the point m (n-1, m) Ts from n-1 to n is detected and output at the point n. Here, m takes a value between 0 and 1. When m = 1, there is no control delay. When m = 0, a control delay of one sample occurs. Therefore, the predicted time is (1-m) Ts
It becomes less than one sample time.

Next, the transfer function in the discrete time domain of the controlled object at the above timing can be expressed by equation (6) by extended Z-transform. G (z, m) = (k · Ts / L) · (m (Z−1) +1) / (Z−1)) · Z ⁻¹ (6) Further, the control amount increase is calculated by the predictor 9b. The function to be found is (1
-M) To predict after the time Ts: (K / Ln) · (1-m) Ts

By introducing the timing m, FIG.
Is controlled by (kTs / L) ｛[m (z-1) +1] /
A control amount detection value indicated by I (n-1, m) is obtained as an output of the block 10a indicated by (z-1)} and the delay element 10b of one sample. Further, the predictor 9b calculates (k /
Ln) expressed by (1-m) Ts, and the predicted value Δi (n-1, m) of the (1-m) Ts time control amount increase from (n-1, m) Ts to (n) Ts. Is output.

In FIGS. 6 and 7, the manipulated variables v (n-1) and (n-1) Ts output to the control object at the time of (n-1) Ts are shown.
The value obtained by adding the output value of the prediction error compensator 15 at the time by the adder 16 is input to the predictor 9b to calculate the control amount increase predicted value Δi (n-1, m) after (1-m) Ts. . Also, (n-1,
m) The control amount I (n-1, m) at the time of Ts is detected, and the value of Δi (n
−1, m) is added by the adder 12 to calculate the control amount predicted value i (n) at the time of (n) Ts. Also, (n-1) Ts
Control value i (n-1) and (n-1, m) Ts
MTs time delay element of the control amount detection value at the time, that is, (n
-1) Difference Δie (n-1) from control amount detection value I (n-1) at Ts
Is the prediction error of the control amount at the time of (n-1) Ts.
In order to converge the prediction error to 0, the prediction error is input to the prediction error compensator 15 composed of an integral element, and the output, which is the prediction error compensation amount, is input to the operation amount V, which is the input value of the predictor 9b. By adding to (n-1), the control value increase predicted value is compensated. The control amount predicted value i at (n) Ts
(n) is compared with the command value Ir (n) to obtain a control error. Based on this error, the digital controller 7 determines an operation amount v (n) such that the error converges to 0, and ) Output at Ts.

When the constant L of the controlled load 1 shown in FIG. 1 changes from the nominal value Ln by the above operation, the command value Ir is accurately followed even when the load 1 includes the resistance R together with L. Control is realized.

The disturbance current Il shown in FIG. 6 is converted into a voltage Vl, which is supplied to an adder 20 on the input side of the controlled object 10 as shown in FIG. 8 to add the manipulated variable V (n) to this. It can be shown as follows. The control amount I is the disturbance voltage Vl
Or, the prediction error compensator 15
The compensated prediction error obtained from (1) contains a disturbance component.

[0017]

By the way, in the method shown in FIG. 6 or FIG. 8, the control value predicted value including the disturbance component flows from the adder 12 to the subtractor 6, and the control value further includes the proportional integral element or the proportional element. Passes through the vessel 7. The time constant of the integral element in the controller 7 is set to a time several times longer than the time (estimated time constant) in which the predicted value (estimated value) is determined by the control amount predicting means 9a in order to enhance the stability of the control system. You. Therefore, it has been difficult to satisfactorily compensate for a fast-changing disturbance (disturbance that changes at a high frequency).

An object of the present invention is to provide a feedback control device and method capable of favorably compensating for a fast-changing disturbance.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for detecting a control amount of a digital object by detecting a control amount of a control object or an amount corresponding thereto at a predetermined sampling time interval. a digital control amount detection means for obtaining a value, and the digital command value generating means for the control amount detection value is generated by a digital quantity command value to be followed, it compares the hand
A stage, a proportional-integral compensation means or a proportional compensation means,
And a second and third addition means, a delay element, a control amount variation <br/> predicting means and the prediction error detection and compensation means, wherein
The first adding means controls the control detected by the control amount detecting means.
By adding the output of the control amount change amount predicting means to the amount detection value.
And outputs a control amount prediction value, wherein the comparison means serves to generate an output corresponding to the difference between the command value and the control amount predicted value obtained al a from said first addition means, wherein The proportional-integral compensation means or the proportional compensation means compensates for the output obtained from the comparing means by proportional-integral compensation or proportional compensation, and the second adding means adds the output of the proportional-integral compensation means or the proportional compensation means to the output. and it outputs a manipulated variable for controlling the controlled object by adding the prediction error compensation amount obtained from the prediction error detection and compensation means, wherein
The delay element is the manipulated variable obtained from the second adding means.
Signal with a delay of a predetermined sampling time interval
And the third adding means outputs the delay.
The prediction signal obtained from the prediction error detection and compensation means is added to the extended signal.
The control amount change predicting means includes an output of the third adding means and the control object.
Are those which based in on the constant is calculated by calculating a predicted value of change in the control amount of the control amount and the next sampling time point of the current sampling time, the prediction error detection and compensation means, the control amount obtains a prediction error by a difference between the actual control amount detection value and the prediction value, calculated the prediction error compensation amount to compensate for this prediction error to converge to 0, the
The present invention relates to a digital feedback control device, wherein the prediction error compensation amount is sent to the third adding means . It should be noted that the prediction error compensation value can be added to the output of the control amount change predicting means as described in claim 2. Claim 3 corresponds to the apparatus of Claims 1 and 2.
And 4 can be adopted.

[0020]

According to the invention of each claim, the prediction error compensation amount indicating the disturbance component is determined by the control amount prediction value and the command value.
In addition to value proportional compensating the output of the difference of the proportional integral complement 償Ma other
Is Runode, can be performed without accompanied delay compensation of the disturbance component of the rapid changes, it is possible to obtain good control characteristics.

[0021]

Next, a feedback control device according to a first embodiment of the present invention will be described with reference to FIG. However, in FIG. 9, portions common to FIGS. 1 to 8 are denoted by the same reference numerals, and description thereof is omitted. FIG. 9 shows a circuit obtained by adding an adder 21 to the circuit of FIG. That is, in FIG. 9, the adder 21 is connected to the output stage of the controller 7 as the proportional integral compensation means or the proportional compensation means.
The output of the controller 7 and the compensated prediction error obtained from the prediction error compensator 15 are added, and the manipulated variable V
(N) is formed.

In FIG. 9, the relationship between the disturbance Vl and the control amount Il is expressed by the following equation. Vl = (L / kTs) (z-1) Il / {m (z-1) +1} When i (n-1) and I (n-1) are matched by the action of the prediction error compensator 15. The output Vl '(n) of the prediction error compensator 15 corresponds to the disturbance component Vl (n) in the control target because the predictor 9a is a model of the control target 10. Therefore, the output Vl 'of the prediction error compensator 15
(N) is added to or subtracted from the output of the controller 7 so that the disturbance Vl (n) cancels out. This makes it possible to compensate for a fast-changing disturbance regardless of the delay in the controller 7 as the proportional-integral compensation means.

[0023]

Second Embodiment Next, referring to FIG. 10, a second embodiment of the present invention will be described.
The feedback control device of the embodiment will be described. However, in FIG. 10, portions common to FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the output of the prediction error compensator 15 is added to the output of the predictor 9b using the adder 12. The other parts are the same as those in FIG. 9, and thus the same operation and effect can be obtained.

[0024]

FIG. 11 shows a three-phase UPS to which the present invention is applied.
1 shows an inverter device for use. This device is configured by connecting a bridge type three-phase inverter circuit 31 to a DC power supply 30 and connecting the inverter circuit 31 to a load 34 via a reactor 32 and a transformer 33.
The switching elements (not shown) of the inverter circuit 31 are controlled by the PWM control circuit 35. This PWM control is performed so that the voltage applied to the load 34 becomes a constant value.

In this embodiment, the inverter circuit 31, the reactor 32, the transformer 33, and the load 34 can be regarded as the controlled object 10 in FIG. PW of inverter 31
Means for controlling the M control circuit 35 includes an output voltage detection transformer 36, an AD converter or ADC 37, a filter capacitor 38, a current detector 39, an ADC 40, a clock signal generator 41, a 1/4 frequency divider, And a digital signal processor or DSP 43.

As shown in FIG. 11, the DSP 43 includes a reference voltage generator 44, first and second prediction means 45 and 46,
First and second comparators 47 and 48, first and second proportional compensators 49 and 50, and third and fourth comparators 51 and 5
2, first and second proportional-integral compensators or proportional compensators 53 and 54, first and second adders 55 and 56, proportional gain circuits 57 and 58, and a subtractor 59, U, V, and W phase control data are output to output lines 60, 61, and 62, and are supplied to a PWM control circuit 35. FIG.
The correspondence between FIG. 11 and FIG.
4 and the first and second comparators 47 and 48 and the first and second proportional compensators 49 and 50 correspond to the command value generator 3 in FIG. The third and fourth comparators 51 and 52 correspond to the subtractor 6 in FIG. First and second prediction means 45,
Reference numeral 46 corresponds to the prediction means 9a, the prediction error detector 14, and the prediction error compensator 15 of FIG. The first and second adders 55 and 56 correspond to the adder 21 of FIG.

As a counterpart to the command value generator 3 shown in FIG. 9, the digital reference voltage generator 44 comprises a ROM in which sine wave data is stored, and generates a reference signal for two phases consisting of digital sine wave data. In order to form a major loop for constant voltage control, U-phase and W-phase inverter output voltages are detected by a transformer 36 and an ADC 37 and sent to first and second comparators (error amplifiers) 47 and 48. An error output between the reference voltage and the detected voltage is obtained from the comparators 47 and 48, and this is passed through the proportional compensators 49 and 50 to become the command value Ir (n). The comparators 51 and 52 receive the command value Ir.
(N) and control predicted value i obtained from prediction means 45 and 46
The value of the difference from (n) is obtained. The proportional integral compensators or proportional compensators 53 and 54 are the same as the controller 7 in FIGS. The adders 55 and 56 add the operation error V (n) by adding the prediction error Vl '(n) as a disturbance component obtained from the prediction means 45 and 46 to the output of the proportional integral compensator or the proportional compensator 53 or 54. And the operation amounts Vu and Vw of the U phase and the W phase are sent to the lines 60 and 62. The subtractor 59 is provided for the U phase and the W phase.
Based on the operation amount of the phase, the operation amount Vv of the V phase is created and transmitted to the line 61.

The prediction means 45 and 46 are provided in the minor loop. U phase and W of Y-connected capacitor 38
After the phase current is detected by the current detector 39, the ADC 40
And is sent to the prediction means 45 and 46 as a control amount detection value I (n-1, m). The prediction means 45 and 46 also receive Vu and Vw as the manipulated variables V (n), and the prediction means 9a, the prediction error detector 14, and the prediction error compensator 1 of FIG.
5 and outputs the control amount prediction value i (n) and the prediction error (disturbance component) Vl '(n).

The PWM control circuit 35 operates the manipulated variables Vu, Vv,
The data indicating Vw is converted into a PWM pulse and sent to the switching element of the inverter circuit 31. The clock pulse generator 41 includes a PWM control circuit 35, a DSP 43,
A frequency divider 42, which is connected to the DC 40 and divides the output of the clock pulse generator 41 by 1/4, comprises a DSP 43 and an A
Connected to DC37. The clock pulse is DSP4
The interrupt signal of No. 3 starts and executes a program for detecting a control amount and performing arithmetic processing by the interrupt signal.

The operation of this device is indicated by a DSP
43 is realized by software. FIG. 12 shows a flowchart for one phase of only the portion related to the present invention of the software. A, C, E, and G in the figure are working registers. Note that the register values are A, C,
E and G will be shown. k, Ln, m, and Ts are constants. V, I, i, Δi, and Ir are variables. D (z)
Is a function. The flowchart will be described below.

Initial settings are made in the first step 70 after the start. This initialization is a reset of working registers and variables. Next, in step 71, the process waits for an interrupt. Next, in step 72, the manipulated variable V calculated in the previous process is output. Next, in step 73, the control amount I is read from the ADC 40. Next, at step 74, the ADC
The control amount predicted value calculated in the previous process is subtracted from the control amount read from 40 and stored in the register A. That is, the control amount prediction error detection value is stored in the register A. Next, at step 75, the value of the register C is added to the value obtained by multiplying the value of the register A by the constant k, and the result is stored in the register C again. Thereby, the prediction error compensation amount is stored in the register C.
Next, in step 76, the predicted error compensation amount C of the register C is added to the manipulated variable V output in step 72, and the result is stored in the register E. Next, as shown in step 77, the value obtained by multiplying the value of the register E by the constant K, further multiplying by (1−m) Ts and dividing by Ln is stored as the control amount excess prediction value Δi. Next, as shown in step 78, the control amount I
Read from 40. Next, as shown in step 79,
The control amount I read from the ADC 40 is added with the control amount increase predicted value Δi to obtain a control amount predicted value i, which is stored in a register. Next, as shown in step 80, the command value ir
Is subtracted from the control amount prediction value i and stored in the register G.
Next, as shown in step 81, the manipulated variable V is obtained from the value of the register G and the function D (z), and this is stored in the register. Next, as shown in step 82, the value of register C is added to V in step 81 and stored in the register. Thereafter, the process returns to step 71. Here, the time from step 71 to step 78 is started is mTs time. This program is started and executed by interruption at time intervals of Ts.

From the above, if there is no sudden change in the constant of the control target between the sampling points (such as a change in L in this example), the prediction error converges to 0 with the time constant of the integral element. As a result, even when there is an approximation error or variation in the model (modeled with Ln in this example) for the control object in the control amount predictor, the control amount is accurately predicted, and the sampling interval and control interval specific to digital control are set. It is possible to compensate for the deterioration of the control performance due to this. This method is a method in the case of one sample delay if m is set to 0. Therefore, it can be applied to the conventional prediction method. Also, the disturbance is compensated without delay of the proportional integral compensator or the proportional compensators 53 and 54.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a conventional feedback control device.

FIG. 2 is a block diagram equivalently showing the feedback control device of FIG. 1;

FIG. 3 is a diagram showing a relationship between a control amount and an operation amount in FIG. 1;

FIG. 4 is a block diagram showing another conventional feedback control device.

FIG. 5 is a diagram illustrating a control amount, a control amount prediction value, and an operation amount in FIG. 4;

FIG. 6 is a block diagram showing another conventional feedback control device.

FIG. 7 is a diagram showing a control amount, a control amount prediction value, and an operation amount in FIG. 6;

FIG. 8 is a functional block diagram showing a modified form of the feedback control device of FIG. 6;

FIG. 9 is a block diagram showing a feedback control device according to the first embodiment of the present invention.

FIG. 10 is a block diagram illustrating a feedback control device according to a second embodiment.

FIG. 11 is a block diagram showing a three-phase inverter device according to a third embodiment.

FIG. 12 is a flowchart for determining an operation amount in the apparatus of FIG. 11;

[Explanation of symbols]

 3 Command value generator 7 Digital controller 10 Control object 9a Control amount prediction means 14 Prediction error detector 15 Prediction error compensator 21 Disturbance adder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G05B 11/00-13/04 G05B 21/00-21/02 G05F 1/10 302 H02M 7/48

Claims (4)

(57) [Claims] 1. A digital control amount detecting means for detecting a control amount of a control object or a corresponding amount at a predetermined sampling time interval to obtain a control amount detection value of a digital amount; a digital command value generating means but which generates a digital quantity command value to be followed, comparison
Means, proportional integral compensation means or proportional compensation means,
1, second and third adding means, a delay element,
And a prediction error detection and compensation means , wherein the first addition means is detected by the control amount detection means.
Add the output of the control amount change predicting means to the control amount detection value
And and outputs a control amount predicted value, an output said comparison means corresponding to the difference between the command value and the system <br/> control amount predicted value obtained al a from said first addition means The proportional-integral compensating means or the proportional compensating means is for compensating for the output obtained from the comparing means. The second adding means is the proportional-integral compensating means or the proportional The prediction error compensation amount obtained from the prediction error detection and compensation means is added to the output of the compensation means to output an operation amount for controlling the controlled object, and the delay element is the second addition Said operation obtained from the means
Delay that gives a delay of a predetermined sampling time interval to the production
And the third adding means outputs the prediction error detection signal to the delayed signal.
And the prediction error compensation amount obtained from the compensation means
And the control amount change predicting means outputs the output of the third adding means .
Force and based on the constant of the control target of the current sampling
A prediction value of a change between the control amount at the time of sampling and the control amount at the next sampling time is calculated , and the prediction error detection and compensation means calculates the control amount prediction value and the actual control amount detection value. , The prediction error is compensated so as to converge to 0, the prediction error compensation amount is obtained , and the prediction error compensation amount is calculated by the third addition.
A digital feedback control device for sending to a means . 2. A digital control amount detecting means for detecting a control amount of a control target or a corresponding amount at a predetermined sampling time interval to obtain a control amount detection value of a digital amount, and said control amount detection value. a digital command value generating means but which generates a digital quantity command value to be followed, comparison
Means, proportional integral compensation means or proportional compensation means,
And second adding means, delay element, control amount change amount prediction
Means, a prediction error detection and compensation means, wherein the first addition means is detected by the control amount detection means.
The control amount detection value and the output of the control amount change
The control amount is predicted by adding the prediction error detection and the output of the compensation means.
A measurement value, wherein the comparing means obtains the control value obtained from the first adding means.
Generates an output corresponding to the difference between the control value predicted value and the command value.
The proportional-integral compensating means or the proportional compensating means is
Compensates the output from the stage for proportional integral or proportional
It is those, wherein the second addition means the proportional integral compensation means or proportional
The output of the compensation means is obtained from the prediction error detection and compensation means.
The control target is controlled by adding the calculated prediction error compensation amount.
The delay element is used to output an operation amount for the operation, and the delay element is output from the second addition means.
Delay that gives a delay of a predetermined sampling time interval to the production
A signal, and the control amount change predicting means includes the delay signal and the control signal.
Control of the current sampling point based on the constant of interest
The amount and change amount of the pre and control amount in the next sampling time
The measurement value is calculated by calculation, and the prediction error detection and compensation means includes the control amount prediction value and
The prediction error is calculated based on the difference from the actual control amount detection value.
Is compensated so that the prediction error of
A difference compensation amount is obtained, and the prediction error compensation amount is added to the first addition.
Digital feedback characterized by sending to means
Control device. 3. A control amount of a control object or a control amount corresponding thereto.
At a predetermined sampling time interval.
Digital control variable detection to obtain digital variable control variable detection value
Output means and a command value to be followed by the control amount detection value in digital quantity.
The digital command value generating means and the digital control amount detecting means correspond to the command value.
The operation amount for obtaining the control amount detection value
The control pair is determined by digital operation at
Digital control means for controlling an elephant
A method of controlling the controlled object by a feedback control device.
Therefore, the digital control means determines the operation amount.
The comparison step, the compensation step, the first, second and
Third addition step, delay step, and control amount change
The prediction step and the step of calculating the prediction error compensation amount
The control amount detecting means in the first adding step.
The control amount change amount prediction value is added to the control amount detection value detected in
The control amount prediction is performed by adding the control amount change prediction value obtained in step.
A measurement value, and in the comparing step, in the first adding step,
The difference between the created control amount predicted value and the command value
Output in the compensating step and the output in the comparing step.
A value obtained by proportionally integrating or proportionally compensating the output, and in the second adding step, calculating the proportional and integral compensation value.
Or by adding the prediction error compensation amount to the proportional compensation value,
An operation amount for controlling the control target is created, and in the delaying step, in the second adding step,
Apply the created operation amount for a predetermined sampling time interval
A delayed signal is created, and the third signal is added to the delayed signal in the third adding step.
A value obtained by adding the prediction error compensation amount is created, and in the control amount change amount prediction step, the third addition is performed.
Between the added value created in the calculation step and the constant to be controlled
Based on the control amount at the current sampling time and the next
By calculating the predicted value of the change from the control amount at the time of pulling
Calculating and calculating the prediction error compensation amount,
The prediction error is determined by the difference between the control amount prediction value and the control amount detection value.
And compensated to make this prediction error converge to 0.
A feedback control method, wherein the prediction error compensation amount is created . 4. A control amount of a control object or a control amount corresponding to the control amount.
At a predetermined sampling time interval.
Digital control variable detection to obtain digital variable control variable detection value
Output means and a command value to be followed by the control amount detection value in digital quantity.
The digital command value generating means and the digital control amount detecting means correspond to the command value.
The operation amount for obtaining the control amount detection value
The control pair is determined by digital operation at
Digital control means for controlling an elephant
A method of controlling the controlled object by a feedback control device.
Therefore, the digital control means determines the operation amount.
The comparing step, the compensating step, and the first and second
Addition step, delay step, control amount change prediction
And a step of obtaining a prediction error compensation amount . In the first adding step, the control amount detection means
The control amount detection value detected in step (a) and the control amount
Predicted value of control amount change obtained in step and compensation of the prediction error
By adding the amount to create a controlled amount predicted value, in said comparison step, in the first adding step
The difference between the created control amount predicted value and the command value
Output in the compensating step and the output in the comparing step.
The output obtained is proportional-integral compensation or proportional-compensated value is created, and in the second addition step, the proportional-integral compensation or
Or by adding the prediction error compensation amount to the proportional compensation value,
An operation amount for controlling the control target is created, and in the delaying step, in the second adding step,
Apply the created operation amount for a predetermined sampling time interval
Creating a delayed delay signal, and in the control amount change amount prediction step, the delay signal
Current sampling based on the
Change between the control amount at the time and the control amount at the next sampling time
Calculating the predicted value of the compound by calculation and obtaining the predicted error compensation amount,
The prediction error is determined by the difference between the control amount prediction value and the control amount detection value.
And compensated to make this prediction error converge to 0.
A feedback control method, wherein the prediction error compensation amount is created .