JP2003194905A - Test-power-separate type standard power generating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test-power-separate type standard power generating apparatus of a simple constitution for precisely performing the various performance of a watt(-hour) meter such as frequency characteristics, power-factor characteristics, high-frequency characteristics, etc. <P>SOLUTION: The test-power-separate type standard power generating apparatus is comprised of a multi-phase A.C. signal generator for generating a sinusoidal wave signal to be a fundamental wave signal, an in-phase signal in phase with the fundamental wave signal, and a perpendicular phase signal with a phase angle advanced by an angle of 90° or delayed by an angle of 90° to the fundamental wave signal or the in-phase signal, a voltage amplifier for amplifying the fundamental wave signal to a fundamental wave voltage, a predetermined voltage, a transconductance amplifier for in-phase signals for generating an in-phase current, a current in phase with the fundamental wave voltage, from the in-phase signal, and a transconductance amplifier for perpendicular phase signals for generating a perpendicular phase current, a current in a phase perpendicular to the fundamental wave voltage, from the perpendicular phase signal. The test-power-separate type standard power generating apparatus is provided with both an effective power generating part for a standard for generating effective power from the fundamental wave voltage and the in-phase current and a test power generating part for a device under test for generating test power from the fundamental wave voltage and a test current in which the in-phase current is superposed on the perpendicular phase current. The generation of power for the standard is separated from the generation of power for the device under test. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power generation device capable of evaluating an electric power (quantity) meter under necessary test conditions.

[0002]

2. Description of the Related Art In a test of a standard power (quantity) meter, a precision imaginary load test power source capable of precisely setting a test power has been widely used. FIG. 4 is a configuration diagram of a conventional precision virtual load test power supply device. The precision virtual load test power supply device consists of a multi-phase oscillator, an AC voltage amplifier, and a transconductance amplifier. The voltage signal of the polyphase oscillator is input to the standard power (quantity) meter and the power under test (quantity) meter via the voltage amplifier. The current signal of the multi-phase oscillator in which a predetermined phase difference is set with respect to the voltage signal is input as a current output through the transconductance amplifier to the required number of tested electric power (quantity) meters. .

The operation method of this power supply device is such that the output signal of the synthesizer type multi-phase oscillator having excellent stability is stable,
It amplifies by a precise voltage amplifier and transconductance amplifier and generates a predetermined test voltage and current. The precision of the test power and the amount of power directly depend on the performance of the oscillator, voltage amplifier, and transconductance amplifier as the signal generator, which makes the device complicated and extremely expensive. If the setting accuracy of the test power generated by the imaginary load test power supply is insufficient compared to the required test accuracy,
Replace one of the power meters under test with a standard power meter that has been tested or inspected in advance, input the same power to all power meters, and use the standard power meter and others. Power under test
A comparative test is conducted to compare the differences in the (quantity) meter response. The standard electricity meter used must be calibrated to a higher standard. This chain of calibration tests requires a higher accuracy or performance standard power meter.

The time-division type watt-hour meter, thermoelectric type watt-hour meter, and digital multiplication type watt-hour meter have been extremely widely used, especially from precision national standards to industrial and field measuring instruments. In the background to this, the performance of the main electronic components that make up these wattmeters has been dramatically improved due to the recent sophistication of electronic circuit integration technology. However, in a test using a power meter that strongly depends on the performance of these electronic components as a standard,
The items to be evaluated in order to estimate the magnitude of the uncertainty contained in the test results are electronic parts, which is extremely complicated and difficult.

For example, a time division type power meter will be described. FIG. 5 is a block diagram of a conventional time division type wattmeter. The time division type power meter includes a pulse width modulation circuit, an analog switch, a low pass filter and an analog pulse converter,
It consists of equipment such as a / D converter. The test current is input to the analog switch. The test voltage is input to the pulse width modulation circuit and a pulse signal whose pulse width is proportional to the instantaneous value of the test voltage is output. The analog signal is switched by this pulse signal. The output signal of the analog switch outputs a pulsed signal whose amplitude is proportional to the instantaneous value of the input test current and whose width is proportional to the instantaneous value of the test voltage. Since the AC power is a quantity defined by averaging over one cycle of the test voltage or test current, the output of the analog switch is selected as the DC signal component through the low-pass filter and displayed as the detected power.

This time division type wattmeter outputs a DC signal proportional to the input power, but when pulse width modulating the test voltage, there is a problem in that information about the absolute value corresponding to the proportional constant is lost. there were. In a imaginary load test power supply equipped with a synthesizer-type multi-phase oscillator that uses a D / A converter, etc., a precision sampling power meter that is synchronized with the operation clock of the base that synthesizes the waveform can be realized. Although it was developed for the purpose of measuring the power consumption, it has been widely used in recent years to establish a national standard for electric power and to evaluate the power consumption of industrial equipment.

FIG. 6 shows a power-source-synchronized sampling power (quantity) meter which uses a clock of a virtual load test power supply equipped with a conventional synthesizer type multi-phase oscillator. The imaginary load test power supply section retrieves data from the reference pulse generator and the memory in which the waveform pattern is stored in the form of digital data D
It is composed of a synthesized multi-phase AC voltage generator for converting into an analog signal by A / A conversion and outputting it, a voltage amplifier, and a transconductance amplifier. The clock from the reference pulse generator is used as a trigger for D / A conversion of the synthesized multi-phase AC voltage generator, and at the same time is used as a sampling signal of a power supply synchronous sampling power (quantity) meter.

The test voltage from the AC voltage amplifier and the test current from the transconductance current amplifier are sampled by the voltage signal sampler and the current signal sampler in synchronization with the clock. The sampled voltage output and current output are A / D converted by the A / D converter, the product is calculated by the digital multiplier, and displayed or output as test power. According to this power meter, the ambiguity of the phase is removed because the sampled test voltage and test current are synchronized with the test voltage and current. However, it is difficult to evaluate the performance and uncertainty of the A / D converter used in the sampling power (quantity) meter, and in order to follow the switching frequency used in industrial equipment, A / D conversion is required. The equipment has to be operated at higher speed, making its evaluation more difficult.

[0009]

Each of the conventional power meters described above has problems in practical use. In recent years, it has been attempted to supply electric power more efficiently and cheaply by generating power in various forms and scales. As a result, the power transfer is measured accurately, the quality of the supplied power is evaluated, the load power factor is evaluated accurately, and the power and the amount of power under the condition that the test current is greatly distorted by harmonic current are accurately measured. It is required to test. Further, in recent years, switching regulators have been widely used in industrial equipment and home appliances for the purpose of more efficient use of electric power, and the harmonic content rate of the current flowing into the equipment has increased, and its order has also increased. . The development objectives of switching regulators are high efficiency and miniaturization, and it is important to test their efficiency and power consumption. Various types of electric power / watt hour meters have been selected and used to support this evaluation test. However, in order to ensure the reliability of the evaluation results, these electric power / watt hour meters themselves are tested more precisely. Is essential.

That is, the use of electric power at a higher frequency and the use of electric power at a load in which higher order harmonic currents flow make use of the electric power (quantity) meter itself for precisely evaluating the electric power (quantity). It is required to evaluate under the necessary test conditions. However, a great deal of cost and development time are required for the development and research of more advanced standards. In addition, when measuring the power generation, receiving power, designing industrial equipment and consumer equipment, evaluating the power consumption in manufacturing, and verifying the power specifications associated with the purchase and sale of products, we used standard equipment in accordance with national standards. Tests by accredited test providers are required in various situations. These test operators purchase or develop standard equipment to realize tests with the required uncertainty and perform testing and inspection work, but there is a need for a reasonable evaluation of the uncertainty.

Although a wide variety of test conditions are set and tested / inspected in an electric power (quantity) meter, a standard device used for the test / inspection has higher performance, higher reliability, and precise uncertainty. Evaluation is required. For example, in the test of a power (quantity) meter at a predetermined power factor under a test current containing harmonics,
The standard to be used must accurately measure only the test quantity to be measured under such test conditions, but it is a standard that satisfies various characteristics such as frequency characteristics, power factor characteristics, and harmonic characteristics. The development of the container requires enormous development cost and period. In the comparative test method in which the same electric power is input to the electric power (quantity) meter that serves as a standard and the electric power (quantity) under test, the standard must have better performance than the electric power (quantity) under test. However, it is extremely difficult to develop a standard device that satisfies these conditions under various test conditions. In view of the above problems, an object of the present invention is to provide a frequency characteristic, a power factor characteristic,
Electric power (quantity) meter test that satisfies various characteristics such as harmonic characteristics
An object is to provide a test power separation type standard power generation device for inspection.

[0012]

The present invention adopts the following means in order to solve the above problems. When testing a watt-hour meter under test at an arbitrary power factor, the watt-hour meter as standard equipment and the watt-hour meter as test equipment must indicate the input power It is an active ingredient. Therefore, only active power is input to the standard device, and reactive power of a required magnitude is superimposed on the active power in order to set the power factor as a test condition in the device under test. When testing a reactive power (quantity) meter under test at an arbitrary power factor, it is input that the reactive power (quantity) meter as a standard device and the reactive power (quantity) meter as a device under test shall indicate. It is a reactive component of electric power. Therefore, only the reactive power is input to the standard device, and in order to set the power factor as the test condition to the device under test, a large amount of active power is superposed on the reactive power. When the test electric power (quantity) meter is tested under the condition that the test current is distorted,
The electric power (quantity) meter as the (quantity) meter and the UUT must indicate the fundamental wave component of the input power. Therefore, the active power based on the test current of the fundamental wave component is input to the standard device, and a harmonic current of a magnitude required as a test condition is superimposed on the active power to perform the test.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The test power separation type standard power generator of the present invention separates a quantity to be tested from a quantity for setting a test condition, and tests only a quantity to be tested with a standard device,
The quantity as the test condition is characterized in that it is configured so as to be input to the device under test while being superposed on the quantity to be tested.

(First Embodiment) FIG. 1 is a configuration diagram for explaining a test state of a power meter at an arbitrary power factor by a test power separation type standard power generator of a first embodiment of the present invention. The test power separation type standard power generator of the first embodiment comprises a multi-phase AC signal generator 1, a voltage amplifier 2, a transconductance amplifier 3-1, and a transconductance amplifier 3-2. The standard power (quantity) meter is connected to the active power generator for the standard unit, and the power under test (quantity) meter is connected to the test power generator for the unit under test. The multi-phase AC voltage generator 1 is for sequentially D / A converting waveform data stored in a memory based on an internal clock, and can set arbitrary amplitudes and phases for multi-phase signals. It is possible to generate harmonics of different frequencies simultaneously. In the figure, a fundamental wave signal, an in-phase signal having substantially the same phase as the fundamental wave signal, and a quadrature phase signal having a substantially quadrature phase with respect to the fundamental wave signal are generated. The voltage amplifier 2 amplifies the fundamental wave signal of the multi-phase AC signal generator 1 to generate a fundamental wave voltage of a predetermined magnitude.

The transconductance amplifier 3-1 is
It is a transconductance type amplifier for generating a predetermined test current from the in-phase signal of the multi-phase AC signal generator 1. The transconductance amplifier 3-2 is a transconductance amplifier that outputs a predetermined quadrature current from the quadrature signal of the multiphase AC voltage generator 1. The fundamental voltage output by the amplifier 1 and the common-mode current output by the transconductance amplifier 3-1 generate active power for a standard device based on the imaginary load test method. The current of the transconductance amplifier 3-1 is the power to be tested (quantity).
The in-phase current is superimposed on the quadrature current by connecting in parallel to the current input circuit of the meter. The transconductance amplifier 3-1 is added to the fundamental wave voltage output from the amplifier 1 and the quadrature current output from the transconductance amplifier 3-2.
The common-mode current output by is superimposed and generates test power for the UUT based on the imaginary load test method.

(Effect of First Embodiment) The standard device is required to be tested and evaluated in advance with a power factor of 1, but the standard device is not supplied with a test current containing a quadrature component. Therefore, the errors for various test power factors required for the UUT do not affect the test errors. Therefore, it is required to prepare an electric power (quantity) meter that has excellent linearity and long-term stability only in a very limited range near the power factor 1 where the test voltage and test current are in phase with each other. To be Since the required performance is limited, the range of model selection such as the operating principle of the electric power (quantity) meter is expanded, and it becomes possible to use a higher performance reactive electric power (quantity) meter with narrowed requirements. The accuracy and uncertainty of are improved.

(Second Embodiment) FIG. 2 is a configuration diagram for explaining a test state of a reactive power meter using a test power separation type standard power generator according to a second embodiment of the present invention. The second embodiment is different from the first embodiment of FIG. 1 in that the imaginary load test power generation unit for standard equipment outputs a fundamental wave voltage and a quadrature current, and the other configurations are the same. .

(Effect of the Second Embodiment) It is required that the standard device has a power factor of zero and its error is tested and evaluated in advance. However, since the standard device is not supplied with a test current containing an in-phase component. , The errors of various test power factors required for the UUT do not affect the test error. Therefore, it is required to prepare a power meter with excellent linearity and long-term stability only in a very limited range around zero power factor, where the test voltage and test current are in a phase at right angles to each other. To be Since the required performance is limited, the range of model selection such as the operating principle of the electric power (quantity) meter is expanded, and it becomes possible to use a higher performance reactive electric power (quantity) meter with narrowed requirements. The accuracy and uncertainty of are improved.

(Third Embodiment) FIG. 3 is a configuration diagram for explaining a test state of a power meter at a test current containing harmonics by a test power separation type standard power generator according to a third embodiment of the present invention. . Compared to the first embodiment of FIG. 1, the third embodiment uses a multi-frequency multi-phase AC signal generator 4 instead of the multi-phase AC signal generator 1, and uses a transconductance amplifier 3-for harmonics. The difference is that 3 is used. However, a synthesizer-type multi-phase signal generator that uses a D / A converter has an arbitrary amplitude, phase angle,
In such a case, it is possible to use the multi-phase AC signal generator as the multi-frequency multi-phase AC signal generator since it is possible to generate signals of frequencies. Further, as for the in-phase transconductance amplifier, the quadrature-phase transconductance amplifier, and the harmonic transconductance amplifier, if the performance is satisfied in a necessary frequency band, the same model can be used. is there.

The multi-frequency multi-phase AC signal generator 4 generates a fundamental wave signal, an in-phase signal, and a harmonic signal having a frequency different from those of the fundamental wave and the in-phase signal. The harmonic transconductance amplifier 3-3 generates a harmonic current of a required magnitude from the harmonic signal. First
Similar to the embodiment, in the active power generator for standard device, the fundamental wave voltage and the in-phase current output the power based on the imaginary load test method and supply the standard power (quantity) meter with the standard power. The test current, in which the harmonic current is superimposed on the same current as the fundamental voltage, outputs the power based on the imaginary load test method and supplies the test power to the power under test (quantity) meter. This embodiment describes a case where the active current (quantity) meter is tested under the condition that the test current contains harmonics. However, when a similar test is required at an arbitrary power factor, the first embodiment is performed. As in the example, prepare a quadrature phase transconductance amplifier and set the quadrature current to the power under test.
It is realized by superimposing and inputting on the (quantity) meter.

(Effect of Third Embodiment) The standard device is required to be tested and evaluated in advance for its error with the fundamental wave. However, since the standard device is not supplied with the test current containing harmonics, The error in the case of the test current containing various harmonics required for the device under test does not affect the test error. Therefore, it is necessary to prepare a power meter that has excellent linearity and long-term stability only in a very limited frequency range. Since the required performance is limited, the range of model selection such as the operating principle of the electric power (quantity) meter is widened, and the reactive power (quantity) with higher performance is narrowed down to the necessary conditions.
It becomes possible to use a meter, and the accuracy and uncertainty of the test are improved. Although the respective embodiments of the present invention have been described above, the test power separation type standard power generator of the present invention supplies the fundamental wave power when testing the power or the reactive wattmeter at the test current including the harmonic current. The test voltage source to generate, the in-phase or quadrature-phase current source with the same frequency, the higher-order current source with the required frequency, and the circuit connection that superimposes the fundamental current and the higher-order current By separating (quantity) from other power components, it becomes possible to evaluate the test quantity precisely. It also makes it possible to test an AC active wattmeter, reactive wattmeter, active and / or reactive watthour meter at a test current of arbitrary load power factor and arbitrary harmonic content.

The present invention is not limited to the above-mentioned embodiment, and the test power separation type standard power generator, which is the gist of the present invention, separates the quantity to be tested from the quantity to set the test condition, and conducts the test. Any embodiment is possible as long as it is configured such that only the target amount is tested by the standard device and the amount as the test condition is input to the device under test in superposition with the previous test target amount. In addition, when a certified tester introduces the electric power standard system based on the present invention, the uncertainty that is described in the calibration certificate, etc. as a result of separating the relevant test amount and other components for setting the test conditions. Since the calibration value and the test condition that accompany the evaluation result of the length are separated, the uncertainty can be easily evaluated, and the standard control and the device for setting the test condition can be separated. The ratio of standard equipment management and test / calibration equipment management has been streamlined.
This also simplifies and streamlines the creation of quality control manuals and technical manuals that describe test procedures.

[0023]

According to the present invention, the power to be tested can be tested and inspected more accurately and more easily by separating the power to be tested from other power components for setting the test conditions. become. No special development is required as a standard device. Furthermore, because the amount of the test object for which uncertainty evaluation is required is separated, related tasks are dramatically simplified.
As a result, conventional techniques and ideas have had strong restrictions on harmonics, but these technical issues have been eliminated, and it is easier to maintain uncertainty and to maintain the quality of testing and inspection laboratories. .

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a test state of a power meter at an arbitrary power factor by a test power separation type standard power generation device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a test state of a reactive power meter at an arbitrary power factor by a test power separation type standard power generation device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a test state of a power meter at a test current containing harmonics by a test power separation type standard power generator according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional precision virtual load test power supply device.

FIG. 5 is a configuration diagram of a conventional time division type wattmeter.

FIG. 6 is a power-source-synchronized sampling power (quantity) meter that uses an operation clock from a virtual load test power supply including a conventional synthesizer-type multi-phase oscillator.

[Explanation of symbols]

1 Multi-phase AC signal generator 2 voltage amplifier 3-1, 3-2, 3-3 transconductance amplifier 4 Multi-frequency multi-phase AC signal generator

Claims (3)

[Claims] 1. A sine wave signal as a fundamental wave signal, an in-phase signal in phase with the fundamental wave signal, and a phase angle of 90 degrees or 90 degrees with respect to the fundamental wave signal or the in-phase signal. A multi-phase AC signal generator that generates a quadrature-phase signal, a voltage amplifier that amplifies the fundamental wave signal to a fundamental wave voltage that is a predetermined voltage, and a current that is in phase with the fundamental wave voltage from the in-phase signal And a quadrature-phase transconductance amplifier that generates a quadrature-phase current that is a quadrature-phase current from the quadrature-phase signal from the quadrature-phase signal. For an active power generator for a standard device that generates active power from the in-phase current, and for a device under test that generates test power from a test current in which the fundamental wave voltage and the in-phase current and the quadrature current are superimposed. A test power separation type standard power generator, which is equipped with a test power generator and separates the generation of power for the standard device and the device under test. 2. A sine wave signal serving as a fundamental wave signal, an in-phase signal having the same phase as the fundamental wave signal, and a phase angle of 90 degrees or a lag 9 with respect to the fundamental wave signal or the in-phase signal.
The multi-phase AC signal generator that generates a quadrature signal of 0 degree, the voltage amplifier that amplifies the fundamental wave signal to a fundamental wave voltage that is a predetermined voltage, and the in-phase signal with respect to the fundamental wave voltage. An in-phase transconductance amplifier that generates an in-phase current that is an in-phase current; and a quadrature-phase transconductance amplifier that generates a quadrature-phase current that is a quadrature-phase current with respect to the fundamental wave voltage from the quadrature-phase signal. And a test power generated from a reactive current generator for a standard device that generates reactive power from the fundamental wave voltage and the quadrature current, and a test current obtained by superimposing the fundamental wave voltage and the in-phase current and the quadrature current. A test power separation type standard power generator characterized in that the test power generation unit for the device under test is provided, and the power generation for the standard device and the power for the device under test are separated. 3. A multi-frequency multi-phase AC signal generator for generating a sine wave signal as a fundamental wave signal, an in-phase signal having the same phase as the fundamental wave signal, and a harmonic signal having a frequency different from these signals, A voltage amplifier that generates a predetermined voltage from a fundamental wave signal, an in-phase transconductance amplifier that generates a current in phase with the fundamental wave signal from the in-phase signal, and a current proportional to the same signal from the harmonic signal. An active power generator for a standard device, which comprises a harmonic transconductance amplifier that generates a harmonic current, and that generates active power from a fundamental voltage and a common-mode current, and the fundamental voltage, the common-mode current, and the harmonic current. A test power separation type characterized by having a power generation part for the device under test that generates test power from the test current that superimposes the test current and separating the generation of power for the standard device and the power under test. Quasi-power generator.