JPH05167349A - Signal generator - Google Patents

Abstract

PURPOSE:To obtain an AC signal waveform having an arbitrary amplitude and phase by introducing the amplitude value of a real number component in an AC waveform and the amplitude value of an imaginary number component, respectively generating a real number component waveform and an imaginary number component waveform and synthesizing both waveforms. CONSTITUTION:Based on a frequency set in advance, a reference phase generating means 2 generates the instantaneous value of a phase to be a reference. From the instantaneous value of the above-mentioned phase and the real number component amplitude value from the outside, a real number component waveform generating means 3 generates the real number component AC waveform for which the phase is coincident to the instantaneous value of the phase, when the real number component amplitude value is positive, and the amplitude value is equal to the real number component amplitude value. From the above-mentioned phase instantaneous value and the imaginary number component amplitude value from the outside, an imaginary number component waveform generating means 4 generates the imaginary number component AC waveform for which the phase is different from the real number component AC waveform at 90 deg. and the amplitude value is equal to the absolute value of the imaginary number component amplitude value. A waveform synthesizing means 5 generates an AC signal equal to the vector sum of the real number component AC waveform and the imaginary number component AC waveform by adding both waveforms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal generator, and more particularly to a signal having a function capable of generating an AC signal having an arbitrary amplitude and phase at an arbitrary frequency by introducing a real number amplitude and an imaginary number amplitude. Regarding the generator.

[0002]

2. Description of the Related Art In a test of a protective relay device installed to protect an electric power system, it is common to simulate a phenomenon occurring in the electric power system and verify the reaction under the condition.

As a means for simulating a phenomenon that occurs in a complicated electric power system, an electronic computer is used to simulate and calculate the phenomenon, and as a result, the instantaneous value of the waveform obtained in the form of digital quantity is calculated. A method of converting into an analog quantity and introducing it into a protective relay device through a power amplifier to verify the response is generally performed.

[0004]

The electronic value shown in the prior art is used to calculate the instantaneous value of a waveform in the form of a digital quantity,
The method of converting the instantaneous value into an analog amount requires a large amount of memory to store the instantaneous value data of the waveform obtained as a result of the calculation, and has the drawback that the calculation time becomes long, and it takes a long time. It is not suitable for simulating the phenomenon.

The present invention introduces the real number component and the imaginary number component amplitude value of the AC waveform obtained as a result of simulation and calculation in an electronic computer or the like, so that the real number component waveform and the real number component waveform and the imaginary number component waveform having different 90 ° phases. It is an object of the present invention to provide a signal generator that generates an AC signal having an amplitude and a phase equal to the vector sum of the real number component waveform and the imaginary number component waveform and that has an arbitrarily settable frequency.

[0006]

According to the present invention, a reference phase generating means for generating an instantaneous value of a phase serving as a reference for a preset frequency, an instantaneous value of the phase generated by the reference phase generating means, and an externally introduced value are introduced. The real number component amplitude value, the real number component waveform generating means for generating an AC waveform corresponding to the real number component of the AC signal, the instantaneous value of the phase, and the imaginary number component amplitude value introduced from the outside, the real number The output of the component waveform generating means is different in 90 ° phase, the imaginary number component waveform generating means for generating an AC waveform corresponding to the imaginary number component of the AC signal, the output of the real number component waveform generating means, and the imaginary number component waveform generating means. Waveform combining means for adding the output and the output.

[0007]

The reference phase generating means generates the instantaneous value of the phase which is the reference phase of the preset frequency, and from the instantaneous value of this phase, the amplitude value of the real number and the amplitude value of the imaginary number introduced from the outside. , A real number waveform generating means and an imaginary number waveform generating means generate an alternating current signal whose amplitude is equal to the absolute value of the real number amplitude value and the absolute value of the imaginary number amplitude value, respectively, and synthesize both by a waveform synthesizing means. There is.

[0008]

EXAMPLES Examples will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of the signal generator according to the invention.
The signal generator 1 of this embodiment includes a reference phase generating means 2 and
Real number component waveform generating means 3 and imaginary number component waveform generating means 4
And a waveform synthesizing means 5, and the real number component amplitude value and the imaginary number component amplitude value are introduced with positive and negative polarities, and the amplitude value is equal to the absolute value of the real number component amplitude value. AC waveform and real number component AC waveform and its phase is 90
° Different, the imaginary component AC waveform whose amplitude value is equal to the absolute value of the imaginary component amplitude value is generated respectively, and by combining both, an AC equal to the vector sum of the real component AC waveform and the imaginary component AC waveform Generate a signal.

The reference phase generating means 2 generates an instantaneous value of a reference phase based on a preset frequency. From the instantaneous value of the phase and the amplitude value of the real component introduced from the outside, the real component waveform generating means 3 agrees with the instantaneous value of the phase if the phase is positive, and the amplitude value Generates a real component AC waveform equal to the absolute value of the real component amplitude value. The imaginary number component waveform generating means 4 differs in phase from the real number component AC waveform by 90 ° from the instantaneous value of the phase and the imaginary number component amplitude value introduced from the outside, and the amplitude value is the absolute value of the imaginary number component amplitude value. Generates an AC waveform for an imaginary number equal to the value. The waveform synthesizing means 5 adds the real component AC waveform and the imaginary component AC waveform to generate an AC signal equal to the vector sum of the two.

Next, the operation will be described. Reference phase generating means 2
The instantaneous value of the phase generated in 1) and the component whose phase coincides with each other are generated by the real number component waveform generating means 3, and the component having a 90 ° phase difference is generated by the imaginary number component waveform generating means 4, and the two are added. The output is output from the waveform synthesizing means 5. The angular frequency ω, the peak value Em, and the AC signal Em · sin (ωt + θ) whose phase is advanced by θ from the reference signal are (1)
It can be expanded like a formula. Em · sin (ωt + θ) = Em (cosθ · sinωt + sinθ · cosωt) (1)

In the equation (1), Em · cos θ is the real number component amplitude value Er, and Em · sin θ is the imaginary number component amplitude value Ei.
In other words, equation (1) can be rewritten as equation (2). Em · sin (ωt + θ) = Er · sinωt + Ei · cosωt (2)

Therefore, if the instantaneous value of the phase which is the output of the reference phase generating means 2 is ωt and Er and Ei are introduced from the outside in the form of positive and negative polarities as the real component amplitude value and the imaginary component amplitude value, respectively. The output of the signal generator according to the present embodiment completely matches the equation (2). Therefore, by varying the amplitude value of the real number component and the amplitude value of the imaginary component introduced from the outside, an AC signal waveform having an arbitrary amplitude and an arbitrary phase can be obtained.

As described above, by varying the amplitude value of the real number component and the amplitude value of the imaginary number component introduced from the outside, an AC signal waveform having an arbitrary phase with an arbitrary phase can be obtained. By simulating the phenomenon that occurs in the power system and introducing the amplitude values of the real number component and the imaginary number component of the waveforms of the voltage, current, etc., obtained as a result into the signal generator of this embodiment, a failure etc. occurs in the power system. Voltage when
The current waveform can be accurately simulated.

FIG. 2 shows a second embodiment specifically showing the signal generator according to the present invention. The signal generator of the second embodiment includes a reference phase generating circuit 21, a real number component waveform generating circuit 22,
An imaginary component waveform generation circuit 23 and a waveform synthesis circuit 24 are provided. The reference phase generation circuit 21 includes a frequency setter 21a for setting the frequency of the output signal, a frequency pulse generation circuit 21b,
It is composed of an N-ary counter circuit 21c that generates an instantaneous value ωt of a reference phase. The real number component waveform generation circuit 22 converts the data output of the storage element 22a, such as a read-only memory, which stores the instantaneous value of the sine waveform in the form of positive and negative digital quantities, into an analog quantity, and uses it as a reference voltage. It is composed of a four-quadrant multiplication type D / A conversion circuit 22b for multiplying the introduced real number component amplitude value. The imaginary number component waveform generation circuit 23 is a storage element such as a read-only memory that stores the instantaneous value of a cosine (cos) waveform that leads the sine waveform by 90 ° and has a positive and negative digital amount.
23b, a four-quadrant operation type D / A conversion circuit 23b for converting the data output of the storage element 23b into an analog quantity and multiplying it by the imaginary number component amplitude value introduced as a reference voltage. The waveform synthesis circuit 24 is a real number component waveform generation circuit 22.
Is an analog adder circuit for synthesizing the output of the above and the output of the imaginary component waveform generation circuit 23. In addition, the storage element 22b,
The reference phase generating circuit 21b is used as address data in 23b.
The instantaneous value ωt of the phase which is the output of is input. Next, the operation of the above embodiment will be described with reference to FIG.

First, the frequency setter 21a sets a predetermined frequency f.
Set to ₀ . This set value f ₀ serves as a reference for frequency and phase, and a pulse signal having the frequency f = Nf ₀ (Hz) is generated by the frequency pulse generation circuit 21b and input to the N-ary counting circuit 21c. Since this counter circuit is N-ary, 0-N-1 is repeatedly counted and output, and f
/ N = Nf ₀ / N = f ₀ That is, _{0 to} N-1 are repeatedly counted the same number of times as the frequency f ₀ set by the frequency setter 21a. Here, assuming that N = 3600, for example, this count output has an instantaneous value ωt of the reference phase of 0.1.
Will be given in steps. This output ωt is input to the storage elements 22a and 23a as address data.
Since the address data, that is, a sine waveform corresponding to the instantaneous value of the phase, is written in the memory element 22a in the form of a positive and negative digital amount, this output data and the real component amplitude value introduced from the outside Multiplying Er and D / A
The output that is converted into an analog amount by multiplication in the conversion circuit 22b becomes Er · sin ωt.

On the other hand, the storage element 23a has a sine
Since a cosine (cos) waveform with a 90 ° phase advance from the waveform is written and the imaginary number component amplitude value Ei is input as the reference voltage to the multiplication D / A conversion circuit 23b, the multiplication D / A conversion is performed. The output of the circuit 23b is Ei · cosωt.

Therefore, the output Er · sinωt of the multiplication type D / A conversion circuit 22b and the output E of the multiplication type D / A conversion circuit 23b.
Waveform synthesis circuit 21 that adds i · cosωt in an analog manner
The output of is completely in agreement with the equation (2). Therefore, as described above, the real component amplitude value Er = Em ·
cos θ, Ei = Em · sin θ as the imaginary component amplitude value
If a DC voltage equal to is input, Em · sin (ωt
Not only can the AC signal waveform of + θ) be completely simulated, but when the real number component amplitude value Er and the imaginary number component amplitude value Ei change, the output waveform also changes without a time delay.
An AC signal waveform with a sudden change in amplitude or phase can be easily extracted.

FIG. 3 shows an application example in which the second embodiment is expanded to a signal generator having a plurality of elements. The signal generator of this application example includes a reference phase generation circuit 21, a real number component waveform generation circuit 22A, an imaginary number component waveform generation circuit 23A, and a waveform synthesis circuit 24A. The real number component waveform generation circuit 22A includes a storage element 22a in which a sine waveform is written and a plurality of multiplication type D / A conversion circuits 22 for inputting output data of the storage element 22a as digital inputs.
b-1, 22b-2, ..., 22b-n,
The corresponding real number component amplitude values Er1, Er2, ..., Ern are input to the respective multiplication D / A conversion circuits as reference voltages. Imaginary component waveform generator 23A
Similarly, a storage element 23a in which a cosine waveform is written and a plurality of multiplication type D / A conversion circuits 23b-1, 23b-2, ..., In which the output data of the storage element 23a is input as a digital input.
23b-n, and each D / A conversion circuit has a corresponding imaginary component amplitude value Ei1, E
i2, ..., Ein are input as reference voltages. Similarly, the waveform synthesizing circuit 24A also includes a plurality of analog adding circuits 24−.
, 24-2, ..., 24-n, and 24-1 is the output of the multiplication type D / A conversion circuit 22b-1 and the output of 23b-1.
24-2 outputs 22b-2 and 23b-2, 24-n
It is configured to add the outputs of 22b-n and 23b-n. With this configuration, it is possible to simultaneously extract a plurality of AC signal waveforms having different amplitudes and phases.

As described above, since the signal generator of this application example can simultaneously generate a large number of AC signal waveforms having different amplitudes and phases, the electric power system is simulated using an electronic computer or the like, and the result is obtained. Introduce the real and imaginary component amplitude values of voltage and current into the signal generator of this application example, convert them into AC signal waveforms, amplify the output with a power amplifier, and input to the protective relay device. Then, the response of the protective relay device when a failure occurs in the power system can be accurately verified.

[0020]

As described above, according to the present invention,
Not only the amplitude value of the real number component and the amplitude value of the imaginary number component of the AC waveform can be introduced to extract the AC signal waveform having the arbitrary amplitude and phase at the arbitrary frequency, but also the amplitude value and the imaginary number component of the real number component. When the amplitude value of changes, the output waveform also changes without a time delay, so an AC signal waveform with a sudden change in amplitude or phase can be easily extracted.
Further, since it can be easily expanded to a plurality of elements, it is possible to simultaneously extract a plurality of AC signal waveforms having different amplitudes and phases. Thereby, using a computer or the like to simulate the power system, the amplitude value of the real number component of each of the voltage and current waveforms obtained as a result, the amplitude value of the imaginary number component is introduced into the signal generator of the present invention, By converting the waveform into an AC waveform, amplifying its output with a power amplifier, and inputting it to a protective relay device, it is possible to accurately verify the response of the protective relay device when a failure occurs in the power system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a signal generator according to the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing an application example of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Signal generator, 2 ... Reference phase generation means, 3 ... Real number component waveform generation means, 4 ... Imaginary number component waveform generation means, 5 ... Waveform synthesis circuit, 21 ... Reference phase generation circuit, 22 ... Real number component waveform generation circuit, 23 ... Imaginary component waveform generation circuit, 24 ... Waveform synthesis circuit

Claims (1)

[Claims] 1. A reference phase generating means for generating an instantaneous value of a phase serving as a reference of a preset frequency in a signal generator for generating an AC signal having an amplitude and a phase that can be controlled arbitrarily at an arbitrary frequency. And a real number component waveform generating means for generating an AC waveform corresponding to the real number component of the AC signal from the instantaneous value of the phase generated by the reference phase generating means and the real number component amplitude value introduced from the outside, and the instant of the phase. From the value and the imaginary number component amplitude value introduced from the outside, the output of the real number component waveform generating means is different in 90 ° phase, and an imaginary number component waveform generating means for generating an AC waveform corresponding to the imaginary number component of the AC signal. A signal generator comprising: a waveform synthesizer for adding the output of the real number component waveform generator and the output of the imaginary component waveform generator.