JPH0638371A - Power system simulator - Google Patents

Abstract

PURPOSE:To make waveforms smooth even when frequencies, etc., abruptly change so as to always actuate a power system simulator synchronously with an analog device by providing a frequency correcting arithmetic section which corrects the current frequency based on the variation of a phase angle, current frequency, and calculating time interval. CONSTITUTION:When the current frequency outputted from the simulating arithmetic section 2 of a computer 9 is deviated from the frequency of one calculating interval before, a frequency correcting arithmetic section 8 finds the current phase angle based on an assumption that no deviation occurs in the frequency from the phase angle of one calculating time interval before. In addition, the section 8 finds the phase angle variation from the found phase angle and the current phase angle outputted from the section 2 and corrects the current frequency based on the phase angle variation, current frequency, and calculating time interval. Therefore, even when frequencies or phase angles abruptly change, waveforms become smooth and this power system simulator can be actuated synchronously with an analog device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power system simulator for simulating a large-scale power system and outputting sinusoidal AC voltage and current.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a conventional power system simulating device. In the figure, 1 is an input section for inputting data indicating the state of a power system, and 2 is an input condition from the input section 1. And the state of the power system is calculated by a predetermined calculation time interval Δ
This is a computer that performs a simulated calculation for each t and outputs the effective value of the voltage or current, the frequency, and the phase angle, and constitutes a simulated calculation unit.

Reference numeral 3 is an instantaneous value data conversion section for converting the effective value, frequency and phase angle of the voltage or current output from the simulation operation section 2 into instantaneous value data of the voltage or current, and 4 is an instantaneous value data conversion section 3. D / A conversion section (digital / analog conversion section) for converting the converted instantaneous value data to digital / analog and outputting a sine wave AC voltage or current, 5 is an input section 1, a simulation calculation section 2, an instantaneous value data conversion It is an electric power system simulation device including a unit 3 and a D / A conversion unit 4.

Reference numeral 6 is an amplifier for amplifying the sinusoidal AC voltage or current output from the D / A converter 4, and 7 is an analog device constituting a power system.

Next, the operation will be described. First, the simulation calculation unit 2 receives the input condition from the input unit 1 (input data D1).
And the output data D6 of the analog device 7 are input to simulate the phenomenon of the power system at every predetermined calculation time interval Δt, and as a result, the effective value of the voltage or current, the frequency and the phase angle are output as the digital data D2. .

Next, the instantaneous value data conversion unit 3 inputs the digital data D2 output by the simulation calculation unit 2,
The digital data D2 is converted into 360 ° instantaneous value data D3, and an instantaneous value data table is created. That is, since the digital data D2 has information on the effective value of the voltage or current, the frequency, and the phase angle at the present time, it is possible to infer a sine wave starting from the current time from the digital data D2. Therefore, 36 from the current phase angle
Up to the phase angle after 0 °, for example, the phase angle 10
Interval (0 °, 10 °, 20 °, ..., 360 °)
Then, the instantaneous value of the voltage or current at that phase angle is obtained, and the instantaneous value data table is created.

Here, as shown in FIG. 11, if the frequency was f1 before the time point B (current time point), that is, between the time points A and B, if the frequency becomes f2 at the time point B. , The waveform changes abruptly at time B as shown in FIG. Therefore, conventionally, the instantaneous value data converter 3
In, the waveform is smoothed by using a correction method called 2-point smoothing.

That is, after outputting the final output data Edata based on the frequency f1 at time B, the average value Hdata of the final output data Edata and the second data data2 is obtained, and this average value Hdata is calculated as the average value Hdata of the first data data1. Instead, it is corrected by outputting. Hdata = (Edata + data2) / 2 As a result, the waveform becomes as shown in FIG.

Next, the D / A converter 4 digital-analog converts the instantaneous value data D3 converted by the instantaneous value data converter 3 to output a sine wave AC voltage or current D4. Then, the amplifier 6 amplifies the sine wave AC voltage or current D4 to a level required for the analog device 7, and outputs amplified data D5 to the analog device 7. Then, the analog device 7 consumes the voltage or current of the amplified data D5 and ends the series of processes.

[0010]

Since the conventional power system simulating device is configured as described above, the waveform is corrected using a correction method called 2-point smoothing, but the correction is local (first Since only the data is corrected), if the frequency and phase angle change suddenly, the waveform cannot be made smooth enough, and as a result, unnecessary harmonics are generated and synchronization with analog equipment cannot be performed. There was a problem.

The present invention has been made in order to solve the above problems, and provides a power system simulating device that can be always synchronized with an analog device so that the waveform becomes smooth even if the frequency or the like changes suddenly. The purpose is to get.

[0012]

According to a first aspect of the present invention, there is provided a power system simulating device, wherein when there is a deviation between the current frequency output by the simulation calculating section and the frequency one calculation time interval before, one calculation time interval is set. The phase angle at the present time is calculated assuming that there is no frequency deviation from the previous phase angle, and the calculated phase angle and the amount of change in the phase angle from the current phase angle output by the simulation calculation unit are calculated. The present frequency is corrected based on the calculated amount of change in the phase angle, the current frequency, and the calculation time interval.

In the power system simulator according to the second aspect of the present invention, there is a difference between the current frequency output by the simulation calculator and the frequency one calculation time interval before, and the current voltage or current effective value. If there is a deviation in the effective value of the voltage or current one calculation time interval before and, the current frequency and the current voltage or current are calculated based on the effective value, frequency and phase angle of the voltage or current output by the simulation calculation unit. The effective value of is corrected.

Further, in the power system simulator according to the third aspect of the present invention, when there is a deviation between the current frequency output by the simulation calculator and the frequency one calculation time interval before, and the effective value of the voltage or current at the current time. If there is a deviation between the effective value of the current and the effective value of the current one calculation time interval before, the effective value of the current frequency and the effective value of the current voltage or current are calculated based on the effective value of the voltage or current, the frequency and the phase angle output by the simulation calculation unit. The value is corrected, and the change in the frequency at the time of rising and at the time of stopping the output is corrected in a sine wave shape.

[0015]

The power system simulation device according to the invention of claim 1 is
By providing the frequency correction calculation unit that corrects the current frequency based on the change amount of the phase angle, the current frequency, and the calculation time interval, the waveform becomes smooth even if the frequency and the phase angle change suddenly.

In the power system simulator according to the second aspect of the present invention, the effective value of the voltage or current, the effective value of the frequency or the phase angle and the effective value of the voltage or current at the present time are output based on the effective value of the voltage or the current. By providing the data abrupt change correction unit for correcting, the waveform becomes smooth even if the effective value of the voltage or current, the frequency, or the phase angle changes suddenly.

Further, in the power system simulator according to the invention of claim 3, the current frequency and the current voltage or current effective value are calculated based on the voltage or current effective value, frequency and phase angle output by the simulation calculator. In addition to compensating for the above, and by providing a data sudden change correction unit that corrects the frequency change at the time of rising and output stop in a sinusoidal waveform, even if the effective value of the voltage or current, the frequency, or the phase angle suddenly changes, the waveform It also becomes smooth, and the frequency change at the time of rising and at the time of output stop becomes sinusoidal.

[0018]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an electric power system simulating device according to an embodiment of the present invention. In the figure, the same reference numerals as those of the conventional one indicate the same or corresponding portions, and the explanation thereof will be omitted. 8 indicates the phase angle θ at the time point A when there is a deviation between the frequency f2 at the time point B (current time) and the frequency f1 at the time point A (one calculation time interval before) output by the simulation calculator 2.
The phase angle θ1 at time B is calculated on the assumption that the frequency does not deviate from 0, and the phase angle θ1 obtained and the change in phase angle from the phase angle θ2 at time B output by the simulation calculator 2 are calculated. A frequency correction calculation unit that calculates the amount Δθ and corrects the frequency f2 at the time point B based on the amount of change Δθ in the phase angle, the frequency f2 at the time point B, and the calculation time interval Δt, and 9 is the simulation calculation unit 2 and the frequency correction calculation unit. The computer 10 is composed of an input unit 1, a computer 9, an instantaneous value data conversion unit 3 and a D / A conversion unit 4, and is a power system simulation device.

Next, the operation will be described. First, similarly to the conventional one, the simulation calculation unit 2 causes the predetermined calculation time interval Δ
The phenomenon of the power system is simulated every t, and as a result, the effective value of the voltage or current, the frequency and the phase angle are output as digital data D2.

Next, when there is a deviation between the frequency f2 at the time point B and the frequency f1 at the time point A, the frequency correction calculation unit 8 corrects the frequency f2 at the time point B as follows, but as shown in FIG. It can be seen that the corrected frequency fn has a smooth waveform if the frequency has the phase angle θ1 at the time point B and the phase angle θ3 at the time point C.

First, it is assumed that the frequency does not deviate from the phase angle θ0 at time A (the frequency at time B is also assumed to be f1).
In this case, the phase angle θ1 at time B is calculated. θ1 = θ0 + (Δt * 360 °) * f1 (1) Here, in the calculation time interval Δt, the frequency f is calculated.
The change amounts θx and θn of the phase angle when changing at 2 and fn can be shown as follows. θx = 2πf2Δt (2) θn = 2πfnΔt (3) Further, the following can be shown. θx = θ3−θ2 (4) θn = θ3−θ1 (5) Furthermore, the phase angle change amount Δθ at the time point B can be expressed as follows. Δθ = θ2-θ1 (6)

Subtracting the equation (4) from the equation (5), θn-θx = θ2-θ1 (7) Therefore, 2πfnΔt-2πf2Δt = Δθ (8) Solving for fn, fn = f2 + Δθ / 2πΔt (9)

In this way, the frequency fn at which the waveform becomes smooth can be obtained from the frequency f2 at time B, the phase angle variation Δθ, and the calculation time interval Δt.

Thereafter, similarly to the conventional one, the instantaneous value data conversion unit 3 converts the instantaneous value data D3 of 360 ° into an instantaneous value data table, and then the D / A conversion unit 4
Outputs the sine wave AC voltage or current D4 by digital-analog converting the instantaneous value data D3.

Example 2. FIG. 3 is a block diagram showing an electric power system simulating device according to another embodiment of the present invention. In FIG. 3, 11 is a frequency f2 at time B (current time) output by the simulating operation unit 2 and time A (1 calculation time). If there is a deviation in the frequency f1 (before the interval) and there is a deviation in the effective value of the voltage or current at the time B and the effective value of the voltage or current at the time A, the voltage or current output by the simulation calculator 2 It is a data sudden change correction unit that corrects the effective value of the frequency at time B and the voltage or current at time B based on the effective value, frequency, and phase angle.

Next, the operation will be described. However, except for the data sudden change correction unit 11, since it is the same as the conventional one,
Only the operation of the data sudden change correction unit 11 will be described.

When there is a deviation between the frequency f1 (for example, 50 Hz) at the time point A and the frequency f2 (for example, 51 Hz) at the time point B, and the amplitude at the time point A (for example, 1.0 KV) and the amplitude at the time point B (for example, 0.5 KV). If there is a deviation, the frequency f2 and the amplitude at time B are corrected as follows.
As shown in, it is understood that the corrected frequency fn has a smooth waveform if the frequency has the phase angle θ1 at the time point B and the phase angle θ3 at the time point C.

To obtain a waveform like the frequency fn in FIG. 4, it is necessary to perform phase difference correction and amplitude correction. First, the phase difference correction will be described. First, using Expression (1), the phase angle θ3 at time C when the frequency f2 is changed is obtained (however, the calculation time interval Δt is 0.01 seconds). θ3 = θ2 + (Δt * 360 °) * f2 = 90 ° + (0.01 * 360 °) * 51 = 273.6 °

As described above, the phase angle θ3 is 273.6 °.
Therefore, as shown in FIG. 5, data having a phase angle of 273.6 ° on the frequency f1, that is, data (phase angle 27
Correct by moving so that (3.6 °) comes to point C (d
(data1, data2, data3, ... Are also moved in the same manner as data). This correction is a phase difference correction, and the corrected data is output to Hdata1, Hdata2, and Hdata for each output step width ΔT.
3, ..., Hdatam can be shown as follows. Hdata (m) = data (n) + K * (data (n + 1) -data (n)) (10) where K is a complement coefficient 0 ≦ K ≦ 1 m maximum value = one cycle of frequency fn The maximum value of m is the maximum value of integers smaller than 1 / fn * Δt Δt is the set calculation step width.

Next, the amplitude correction will be described. In the amplitude correction, the result of frequency correction as shown in FIG. 5 is further corrected in the amplitude direction (vertical direction), and the corrected data is Sdata1, S for each output step width ΔT.
Data2, Sdata3, ..., Sdatam can be expressed as follows. Sdata (m) = 1 + ((amplitude after change)-(amplitude before change)) / m * (amplitude before change) * Hdata (m)
(11) As a result of the correction, a smooth amplitude change is obtained as shown in FIG.

Example 3. FIG. 6 is a block diagram showing an electric power system simulating device according to another embodiment of the present invention. In FIG. 6, reference numeral 12 denotes a frequency f2 at time B (current time) output by the simulating operation unit 2 and time A (1 calculation time). If there is a deviation in the frequency f1 (before the interval) and there is a deviation in the effective value of the current at time B and the effective value of the current at time A, then the effective value, frequency and phase of the current output by the simulation calculator 2 It is a data sudden change correction unit that corrects the frequency at time B and the effective value of the current at time B based on the angle, and corrects the change in frequency at the time of rising and at the time of output stop in a sine wave shape.

Next, the operation will be described. This Example 3
Then, the change in the frequency at the time of rising and at the time of stopping the output is corrected. That is, the characteristic of the current does not change sharply as shown by the solid line in FIG. 7 at the time of rising and when the output is stopped, but gradually increases and decreases as shown by the dotted line. Therefore, it is corrected according to this characteristic. It is a thing.

The calculation of the correction at the time of rising from zero amplitude is as follows. The corrected data is output for each output step width ΔT, and Tdata1 and Tdata are output.
2, Tdata3, ..., Tdatam, Tdata = (m / (maximum value of m)) * Hdata
(M) ... (12)

Further, in the output stop correction, even if a signal indicating that a certain portion is cut off is received from the power system during the output of data, the current of that portion is not immediately reduced to zero but is sequentially set to 360. Output the data for ° deg until it crosses the zero point.

Example 4. It should be noted that in the above-described embodiment, the case where either the frequency correction calculation unit 8 or the data sudden change correction units 11 and 12 is used has been described, but as shown in FIG. 8, the frequency correction calculation unit 8 and the data sudden change correction unit 11 are used. Alternatively, both 12 may be used.

In the above embodiment, the instantaneous value data converter 3 converts digital data for the calculation time interval Δt into instantaneous value data at one time. However, as shown in FIG. The conversion may be performed in a divided manner, which has the effect that D / A conversion output can be performed at a higher speed than in the above embodiment.

[0037]

As described above, according to the first aspect of the present invention, when there is a deviation between the current frequency output by the simulation calculation unit and the frequency one calculation time interval before, the phase one calculation time interval before The phase angle at the present time is calculated assuming that there is no deviation from the angle to the frequency, and the change amount of the phase angle is calculated from the calculated phase angle and the current phase angle output by the simulation calculation unit, Since it is configured to correct the current frequency based on the change amount of the phase angle, the current frequency, and the calculation time interval, the waveform becomes smooth even if the frequency and the phase angle change suddenly, and it can be always synchronized with the analog device. And so on.

According to the second aspect of the present invention, when there is a deviation between the current frequency output by the simulation calculator and the frequency one calculation time interval before, and the effective value of the current voltage or current and one calculation time. If there is a deviation in the effective value of the voltage or current before the interval, the effective value of the current frequency and the effective value of the current voltage or current are calculated based on the effective value of the voltage or current, the frequency, and the phase angle output by the simulation calculator. Since it is configured to correct, the effective value of voltage or current,
Even if the frequency and the phase angle change suddenly, the waveform becomes smooth, and there is an effect that it can always be synchronized with the analog device.

Further, according to the third aspect of the present invention, when there is a deviation between the current frequency output by the simulation calculation section and the frequency one calculation time interval before, and the effective value of the current voltage or current and one calculation time. If there is a deviation in the effective value of the voltage or current before the interval, the effective value of the current frequency and the effective value of the current voltage or current are calculated based on the effective value of the voltage or current, the frequency, and the phase angle output by the simulation calculator. Since it is configured to correct the changes in the frequency at the time of rising and stopping the output in a sine wave shape as well as the correction, even if the effective value of the voltage or current, the frequency, or the phase angle suddenly changes,
The waveform becomes smooth, and the frequency changes at the time of rising and at the time of stopping the output are sinusoidal, and there is an effect that it can always be synchronized with the analog device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a power system simulator according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing frequency correction.

FIG. 3 is a block diagram showing a power system simulator according to another embodiment of the present invention.

FIG. 4 is a waveform diagram showing correction of sudden change in data.

FIG. 5 is a waveform diagram showing phase difference correction.

FIG. 6 is a block diagram showing a power system simulator according to another embodiment of the present invention.

FIG. 7 is a waveform diagram showing correction at the time of rising and at the time of stopping output.

FIG. 8 is a block diagram showing a power system simulation device according to another embodiment of the present invention.

FIG. 9 is a waveform diagram showing correction by division.

FIG. 10 is a block diagram showing a conventional power system simulator.

FIG. 11 is a waveform diagram showing 2-point smoothing correction.

FIG. 12 is a waveform diagram before correction.

FIG. 13 is a waveform diagram after correction.

[Explanation of symbols]

 1 Input Part 2 Simulated Calculation Part 3 Instantaneous Value Data Conversion Part 4 D / A Conversion Part (Digital / Analog Conversion Part) 8 Frequency Correction Calculation Part 11, 12 Data Sudden Correction Part

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Further, in the power system simulator according to the third aspect of the present invention, when there is a deviation between the current frequency output by the simulation calculator and the frequency one calculation time interval before, and the effective value of the voltage or current at the current time. And the power before one calculation time interval
If there is a deviation in the effective value of the pressure or current, correct the effective value of the current frequency and the effective value of the voltage or current based on the effective value of the voltage or current, the frequency and the phase angle output by the simulation calculator. The frequency changes at the time of rising and at the time of stopping the output are corrected in a sine wave shape.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

As described above, the phase angle θ3 is 273.6 °.
Therefore, as shown in FIG. 5, data having a phase angle of 273.6 ° on the frequency f1, that is, data (phase angle 27
Correct by moving so that (3.6 °) comes to point C (d
(data1, data2, data3, ... Are also moved in the same manner as data). This correction is a phase difference correction, and the corrected data is output to Hdata1, Hdata2, and Hdata for each output step width ΔT.
3, ..., Hdatam can be shown as follows. Hdata (m) = data (n) + K * (data (n + 1) -data (n)) (10) where K is a complement coefficient 0 ≦ K ≦ 1 m maximum value = one cycle of frequency fn The maximum value of m is the maximum value Δt of integers smaller than 1 / fn * Δt, which is the set calculation step width .

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

Next, the amplitude correction will be described. In the amplitude correction, the result of the phase angle correction as shown in FIG. 5 is further corrected in the amplitude direction (vertical direction), and the corrected data is Sdata1, S for each output step width ΔT.
Data2, Sdata3, ..., Sdatam can be expressed as follows. Sdata (m) = 1 + ((amplitude after change)-(amplitude before change)) / ( m * (amplitude before change) ) * Hdata
(M) (11) As a result of the correction, a smooth amplitude change is obtained as shown in FIG.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

The calculation of the correction at the time of rising from zero amplitude is as follows. The corrected data is output for each output step width ΔT, and Tdata1 and Tdata are output.
2, Tdata3, ..., Tdatam, Tdata (m) = (m / (maximum value of m)) * Hdat
a (m) ・ ・ ・ (12)

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

Further, in the output stop correction, even if a signal indicating that a certain portion is cut off is received from the power system during the output of data, the current of that portion is not immediately reduced to zero but is sequentially set to 360. Output data for ° minutes until it crosses the zero point.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yama ▲ Zaki ▼ Akira 2-4-1, Nishi-Atsuji-oka, Chofu-shi, Tokyo Inside the TEPCO Technical Research Institute (72) Inventor Toshiyuki Sakurai 6-1, Hamayama-dori, Hyogo-ku, Kobe No. 1 Mitsubishi Electric Engineering Co., Ltd. Kobe Office (72) Inventor Hideo Noguchi 1-2 1-2 Wadazakicho, Hyogo-ku, Kobe Sanritsu Electric Co., Ltd. Control Works (72) Inventor Hisao Taoka Tsukaguchi Amagasaki Honcho 8-1-1 Mitsubishi Electric Corporation Industrial Systems Laboratory (72) Inventor Isao Iyoda 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (3)

[Claims] 1. A simulation calculation unit for performing a simulation calculation of a state of a power system at predetermined calculation time intervals under an input condition from an input unit and outputting an effective value of voltage or current, a frequency and a phase angle. , If there is a deviation between the current frequency output by the simulation calculation section and the frequency one calculation time interval before, the current phase on the assumption that there is no frequency deviation from the phase angle one calculation time interval before The angle is obtained, and the amount of change in the phase angle is obtained from the obtained phase angle and the current phase angle output by the simulation calculation unit, based on the amount of change in the phase angle, the current frequency, and the calculation time interval. A frequency correction calculator that corrects the current frequency,
An instantaneous value data conversion unit for converting the frequency corrected by the frequency correction operation unit and the effective value and phase angle of the voltage or current output by the simulation operation unit into instantaneous value data of voltage or current; and the instantaneous value data Digital / analog conversion of the instantaneous value data converted by the converter to output a sine wave AC voltage or current
A power system simulation device including an analog conversion unit. 2. A simulation calculation unit for performing a simulation calculation of a state of a power system at predetermined calculation time intervals under an input condition from the input unit and outputting an effective value of voltage or current, a frequency and a phase angle. , When there is a deviation between the current frequency output by the simulation calculation unit and the frequency before one calculation time interval, and when there is a deviation between the effective value of the current voltage or current and the effective value of the voltage or current before one calculation time interval. If there is, a data sudden change correction unit that corrects the current frequency and the current voltage or current RMS value based on the effective value of the voltage or current, the frequency, and the phase angle output by the simulated calculation unit; The instantaneous value data conversion unit for converting the frequency and the effective value of the voltage or current corrected by the unit into the instantaneous value data of the voltage or current, and the instantaneous value data converted by the instantaneous value data conversion unit. A power system simulating device comprising a digital-analog converter that converts time value data to digital-analog and outputs a sine wave AC voltage or current. 3. A simulation calculation section for performing a simulation calculation of the state of the power system at predetermined calculation time intervals under an input condition from the input section and outputting an effective value of voltage or current, a frequency and a phase angle. , When there is a deviation between the current frequency output by the simulation calculation unit and the frequency before one calculation time interval, and when there is a deviation between the effective value of the current voltage or current and the effective value of the voltage or current before one calculation time interval. If there is, corrects the current frequency and the current voltage or current RMS value based on the voltage or current RMS value, frequency and phase angle output by the simulated operation unit, and also determines the frequency at the time of rising and stopping the output. Data abrupt change compensator that corrects the change in sine wave, and from the frequency and voltage or current effective value corrected by the data abrupt change compensator to instantaneous voltage or current value data. Electric power system simulation provided with an instantaneous value data conversion unit for conversion and a digital / analog conversion unit for digital-analog converting the instantaneous value data converted by the instantaneous value data conversion unit and outputting a sine wave AC voltage or current apparatus.