KR102502715B1 - Apparatus for detecting voltage and current - Google Patents

Abstract

The present invention relates to a voltage and current detection device, and relates to a voltage sensor for detecting voltage and outputting a voltage signal, a current sensor for detecting current and outputting a current signal, and a voltage signal for measurement by amplifying the voltage signal output from the voltage sensor. A voltage signal amplifying unit for outputting a voltage signal amplifying unit for amplifying the current signal output from the current sensor and outputting the current signal for measurement as a current signal for measurement, a voltage signal for measurement and a current for measurement according to a sampling rate determined by the sampling signal Analog-to-digital conversion unit that converts signals into digital data to generate voltage data and current data for measurement, and resamples voltage data and current data for measurement according to the resampling ratio determined based on the sampling rate. The sampling signal is output to the resampling unit and the analog-to-digital conversion unit that samples and outputs the sample, compares the phases of the resampled measurement voltage data and the resampled measurement current data to calculate phase difference data, and an operation control module that corrects and outputs the phase of the current data.

Description

Voltage current detection device {APPARATUS FOR DETECTING VOLTAGE AND CURRENT}

The present invention relates to a voltage current detection device, and more particularly to an electronic voltage current detection device.

A transformer, which is an example of a voltage current detection device, is divided into an electric transformer and an electronic transformer, and an electronic transformer is divided into a transformer that outputs an analog signal or a digital signal.

An electronic transformer that outputs an analog signal has the advantage of using the output as it is or using it after undergoing some signal correction without a special signal converter.

On the other hand, an electronic transformer that outputs a digital signal can transmit and receive data to other remote devices through communication using an optical cable or the like.

These electronic transformers are devices for transforming current and voltage used together with electrical instruments or measuring devices, including current transformers (CT) and transformers (PT) for instruments, and power circuit breakers and control facilities, which are important facilities in power facilities. allow it to function normally.

An electronic transformer is also an electrical device that converts the primary current or voltage into a secondary current or voltage suitable for the connected equipment (e.g. measuring instrument, wattmeter or protection relay). , If extra-high voltage is directly applied to equipment such as a watt-hour meter or protection device, the equipment is damaged. To prevent this, the voltage and current are lowered and supplied to the equipment.

Republic of Korea Patent Registration No. 10-0765344 (Public date: October 10, 2007, title of invention: Electrical and electronic voltage and current detection device) Republic of Korea Patent Registration No. 10-1099953 (Public date: December 28, 2011, title of invention: electronic transformer for composite insulation instrument)

The problem to be solved by the present invention is to perform phase correction of voltage and current to increase the reliability of the operation of the voltage and current detection device.

A voltage current detection device according to one feature of the present invention for solving the above problems is connected to a voltage sensor for detecting voltage and outputting a voltage signal, a current sensor for detecting current and outputting a current signal, and the voltage sensor, A voltage signal amplifying unit that amplifies the voltage signal output from the voltage sensor and outputs the voltage signal for measurement, and is connected to the current sensor, amplifies the current signal output from the current sensor and outputs the current signal for measurement. It is connected to a current signal amplification unit for measurement, a voltage signal amplification unit, and the current signal amplification unit for measurement, and samples the voltage signal for measurement and the current signal for measurement according to a sampling rate determined by the sampling signal to obtain digital data. An analog-to-digital conversion unit that generates voltage data for measurement and current data for measurement by changing the analog-to-digital conversion unit, and is connected to the analog-to-digital conversion unit, and the voltage data for measurement and A resampling unit that resamples and outputs current data for measurement and is connected to the resampling unit, outputs the sampling signal to the analog-to-digital conversion unit, and resamples the voltage data for measurement and the resampled current for measurement and an operation control module that calculates phase difference data by comparing the phases of the data, corrects the phase of the measurement voltage data or current data, and outputs the corrected phase.

The resampling unit delays each phase of the voltage data for measurement and the current data for measurement using a minute delay filter when the sampling rate and the resampling rate are the same, and the resampling rate is higher than the sampling rate. In this case, the interpolation method is applied to each of the voltage data for measurement and the current data for measurement to acquire data, perform a resimplification operation, and then perform phase correction using a minute delay filter, and the resampling When the ratio is low, each of the voltage data for measurement and the current data for measurement may be filtered using a Gaussian filter, and then the phase may be corrected using a minute delay filter.

The operation control module operates according to a synchronization signal and compares the phase of the resampled measurement voltage and the resampled measurement current and outputs phase difference data, a phase comparison unit, an amplitude correction target and an amplitude correction value, and A memory for storing delayed data information, which is information of delayed data among sampled measurement voltage data and resampled measurement current data, connected to the phase comparison unit and using phase difference data applied from the phase comparison unit to The phase of the resampled measurement voltage data or the resampled current data corresponding to the delayed data information is corrected, the phase of the resampled measurement voltage data or the resampled current data is corrected, and stored in the memory a control unit for correcting an amplitude of resampled measurement voltage data or resampled current data using an amplitude correction target and an amplitude correction value; and an oscillation unit that operates under the control of the control unit to generate a synchronization signal and a sampling signal and output them to the analog-to-digital conversion unit and the phase comparison unit, respectively.

The voltage and current detection device according to the above feature cuts off the DC component of each of the voltage signal for measurement and the current signal for measurement output from the voltage signal amplification unit and the measurement current signal amplification unit, and outputs the analog-to-digital conversion unit. A DC component blocking unit may be further included.

The voltage and current detection device according to the above feature is connected to the operation control module, and converts the corrected measurement voltage data and measurement current data output from the operation control module into analog signals and outputs digital-to-analog conversion. Wealth may be further included.

The voltage current detection device according to the above feature is located adjacent to the first temperature sensor and the current sensor for detecting the temperature of the voltage sensor and outputting a first temperature signal to the analog-digital conversion unit. and a second temperature sensor for detecting the temperature of the current sensor and outputting a second temperature signal to the analog-digital converter, wherein the analog-digital converter converts the first temperature signal and the second temperature signal may be converted into digital data and output as first temperature data and second temperature data to the resampling unit, wherein the resampling unit converts the first temperature data and the second temperature data according to a resampling ratio determined based on the sampling ratio. 2 The temperature data may be resampled and outputted to the operation control module, and the operation control module calculates a temperature correction value corresponding to the first temperature data to the phase-corrected voltage data for phase correction. Perform temperature correction of the voltage data for measurement,

Temperature correction of the measurement current data subjected to phase correction may be performed by calculating a temperature correction value corresponding to the second temperature data to the measurement current data subjected to phase correction.

According to this feature, since the phase difference from the capacitive non-contact voltage measurement method and the Rogowski coil current measurement method of the magnetic field non-saturation method is corrected, the precision of power measurement using voltage, current, and phase difference between voltage and current can be improved. .

At this time, since the phase difference correction between the voltage signal and the current signal is performed using a minute delay filter, the accuracy of the phase difference correction is improved.

Furthermore, since the voltage and current signals subjected to phase difference correction are resampled to generate new voltage and current signals, signal accuracy is further improved.

1 is a schematic block diagram of a voltage current detection device according to an embodiment of the present invention.
FIG. 2 is a schematic block diagram of an operation control module shown in FIG. 1 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that adding a detailed description of a technology or configuration already known in the related field may obscure the gist of the present invention, some of them will be omitted from the detailed description. In addition, the terms used in this specification are terms used to properly express the embodiments of the present invention, which may vary depending on people or customs related to the field. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

The terminology used herein is intended only to refer to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of 'comprising' specifies specific characteristics, regions, integers, steps, operations, elements and/or components, and other specific characteristics, regions, integers, steps, operations, elements, components and/or groups. does not exclude the presence or addition of

Hereinafter, a voltage current detection device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

The voltage current detection device of this example can be applied to an electronic transformer, but is not limited thereto.

First, referring to FIG. 1 , the voltage and current detection device of this example includes a voltage signal amplifier connected to a voltage sensor unit 11, a current sensor unit 12, a temperature sensor unit 13, and a voltage sensor unit 11. (21), a current signal amplification unit 22 for measurement connected to the current sensor unit 12, a current signal amplification unit 23 for protection connected to the current sensor unit 12, and amplification units 21-23 And a DC component blocking unit 30 connected to the temperature sensor unit 13, an analog-to-digital conversion unit (A-D conversion unit) 40 connected to the DC component blocking unit 30, an analog-to-digital conversion unit ( 40), a resampling unit 50 connected to the resampling unit 50, an operation control module 60 connected to the operation control module 40, a memory 70 connected to the operation control A digital-analog conversion unit (D-A conversion unit) 80 connected to the module 40 and a communication module 90 connected to the operation control module 40 may be provided.

The voltage sensor unit 11 may include at least one voltage sensor, and each voltage sensor may detect a voltage applied to power equipment installed therein and output the voltage signal as an analog signal.

In this case, the number of voltage sensors may be determined according to at least one of the size, location, and measurement accuracy of the voltage to be sensed.

In this example, the voltage sensor may secure insulation performance by using a capacitive type capacitor sensor. In this case, the voltage sensor 111 may detect capacitance and output a voltage proportional to the detected capacitance.

The current sensor unit 12 may also include at least one current sensor, and each current sensor detects a current flowing in the power equipment installed therein and outputs the current as an analog signal (eg, a current signal).

The number of these current sensors may also be determined according to at least one of the size, position, and measurement accuracy of the current to be sensed.

In this example, each current sensor of the current sensor unit 12 may be a current sensor using a Rogowskii coil.

A current sensor using a Rogowski coil integrates and amplifies the output voltage induced by the current flowing in the conductor (ie, the power medium to measure the current) located inside the circular Rogowski coil made of non-magnetic material using an integrator circuit. Thus, the current value can be calculated.

In this case, a printed circuit board (PCB) Rogowski coil may be used as the Rogowski coil.

In addition, each current sensor of this example may be an air-core coil type current sensor having a structure for shielding an electric field that detects a magnetic field generated when a current flows in a conducting wire, and in this case, the accuracy of current measurement is improved.

The temperature sensor unit 13 may also include at least one temperature sensor 131 or 132, and each temperature sensor 131 or 132 detects the temperature of the mounting position and generates an analog signal (eg, temperature signal) of the corresponding state. can output

When the voltage sensor unit 11 includes a capacitive voltage sensor, the permittivity of a dielectric provided in the voltage sensor changes according to the temperature of each voltage sensor.

In addition, a coil used for a current sensor or the like may be mainly made of copper (Cu), and the resistance value of such copper changes depending on the temperature.

As such, the characteristics of electric and electronic elements used in the voltage and current detection device of the present example, such as a voltage sensor and a current sensor, may change depending on the temperature.

Therefore, in order to compensate for the change in the characteristics of the electric/electronic element that changes with temperature, at least one temperature sensor is required to change the characteristic of the electric/electronic element [eg, current sensor, voltage sensor, amplifier, etc.] or its surroundings. , and may generate a signal (eg, a temperature signal) corresponding to the temperature sensed at the mounting position and output it toward the operation control module 40 . Here, the surroundings may be referred to as within a set range based on the corresponding electric/electronic device.

In this specification, as an example, the voltage sensor unit 11 includes one voltage sensor to output one voltage signal Vs, and the current sensor unit 12 includes one current sensor to output one voltage signal Vs. A current signal (Is) can be output, and the temperature sensor unit 13 includes a first temperature sensor 131 and a second temperature sensor 132 that sense the temperatures of the voltage sensor and the current sensor, respectively. The operation of the voltage current detection device will be described on the assumption that the temperature signal Ts1 and the second temperature signal Ts2 are output, but the present invention is not limited thereto.

The voltage signal amplification unit 21 connected to the voltage sensor unit 11 amplifies the voltage signal Vs output from the voltage sensor unit 11 at a set ratio, and then converts the amplified voltage signal Vt into a voltage signal for measurement. It can be output to the analog-digital conversion unit 40.

At this time, the voltage signal amplifier 21 amplifies the voltage signal Vs output from the voltage sensor so that the magnitude of the voltage signal Vt for measurement is included within the set input range of the analog-to-digital conversion unit 40 located at the rear end. can do.

The current signal amplification unit 22 for measurement and the current signal amplification unit 23 for protection also amplify the current signal Is output from the current sensor at a set ratio and convert the amplified current signals It and Id into analog and digital. It can be output to unit 40.

At this time, the current signal amplification unit 22 for measurement and the current signal amplification unit 23 for protection also include the magnitude of each current signal It and Id within the set input range of the analog-to-digital conversion unit 40 located at the rear end. The current signal output from each current sensor can be amplified.

The measurement current signal amplifier 22 amplifies the current signal Is output from the current sensor within a range of about 1.0 to 1.5 times the normal rating and outputs the corresponding current signal It, and can output the current signal for protection. The amplification unit 23 may amplify the current signal Is output from the current sensor within a range of about 10 to 20 times the normal rating and output the corresponding current signal Id.

As such, the current signal amplification unit 22 for measurement and the current signal amplification unit 23 for protection may amplify the same current signal Is at respective amplification ratios using different amplification ratios.

At this time, the amplified current signal It output from the measurement current signal amplifying unit 22 generates a final measurement current signal Itf output to measurement equipment (not shown) that measures the current and voltage of the power device. The amplified current signal (Id) output from the protection current signal amplification unit 23 may be the current signal for measurement (It) for the final protection current signal output to protection equipment (not shown) that protects the corresponding power device. It may be a protection current signal (Id) for (Idf).

As described above, since the amplification ratio of the current signal amplification unit 23 for protection is greater than that of the current signal amplification unit 22 for measurement, the protection equipment located at the rear end has an instantaneous value (instantaneous value) in each final protection current signal (Idf) input. value), peak value, and current value at the time of short circuit can be easily detected, thereby accurately and easily detecting the abnormal state of the power device to take safety measures such as power-off operation in case of an abnormality. can be taken quickly.

The DC component blocking unit 30 converts the DC component included in the analog signals Vt, It, Id output from each amplification unit 21 to 23 and the signals Ts1 and Ts2 output from the temperature sensor unit 13. As for removing, as an example, a direct current component may be blocked using a high pass filter of 10 Hz to 20 Hz.

As shown in FIG. 1, the DC component blocking unit 30 uses a separate DC component blocking circuit implemented as a circuit to block the DC component included in the analog signals Vt, It, Id, Ts1, and Ts2. However, in an alternative example, the DC component may be implemented as software.

In this case, the DC component blocking unit 30 is implemented as a digital filter in which calculation is performed by the operation of the processor, and after removing the DC component included in each analog signal (Vt, It, Id, Ts1, Ts2), analog-digital It can be output to the conversion unit 40. In this case, the digital filter may be a finite impulse response filter (FIR), an infinite impulse response filter (IIR), or an FFT filter.

However, this DC component blocking unit 30 may be omitted if necessary.

The analog-to-digital converter 40 includes an amplified voltage signal for measurement (Vt) from which the DC component is removed, an amplified current signal for measurement (It) and an amplified current signal for protection (Id) and each of the temperature sensors 131 and 132 The first temperature signal Ts1 and the second temperature signal Ts2 output from ) may be received and converted into a digital state having a corresponding value, and then output to the operation control module 40 .

Therefore, the analog-to-digital conversion unit 40 synchronizes with the sampling signal applied from the operation control module 40 to generate a voltage signal for measurement (Vt), a current signal for measurement (It), a current signal for protection (Id), and each Sampling operation is performed on the temperature signals (Ts1, Ts2) to extract sampling data for each signal (Vs, It, Id, Ts2, Ts2), quantization is performed on each sampling data, and decoding operation is performed to The resampling unit 50 converts digital data of the number of bits into measurement voltage data (Vtd), measurement current data (Itd), protection current data (Idd), and first and second temperature data (Ts1d, Ts2d) can be output as

Therefore, the analog-to-digital conversion unit 40 transmits the voltage signal for measurement (Vt), the current signal for measurement (It), the current signal for protection (Id) and the temperature signals Ts1 and Ts2 in real time for each period of the sampling signal. It generates digital data (Vtd, Itd, Idd, Ts1d, Ts2d) for the corresponding measurement voltage signal (Vt), measurement current signal (It), and protection current signal (Id) at the sampling rate determined according to the sampling signal cycle. ) and the temperature signals Ts1 and Ts2 can be sampled and converted into digital data.

At this time, each data (Vtd, Itd, Idd, Ts1d, Ts2d) converted by the analog-to-digital converter 40 may be 16 bits, 24 bits, or 32 bits.

The resampling unit 50 compensates for data lost by a sampling operation performed when an analog signal is converted into a digital signal so that the digital signal waveform has a waveform similar to that of the original signals Vs, Is, Ts1, and Ts1. This is to increase the accuracy of the operation.

The resampling operation of the resampling unit 50 may be performed at the same resampling rate as the sampling rate, at a resampling rate higher than the sampling rate, or at a resampling rate lower than the sampling rate, depending on the resampling rate. cases may exist.

At this time, as the resampling rate is higher than the sampling rate, the similarity with the waveform of the original signal increases, but a distorted portion may occur in the shape of the low waveform.

When resampling is performed at a higher sampling rate than the analog-to-digital conversion, the resampling unit 50 may use an interpolation method.

That is, when the sampling rate is higher than the analog-to-digital conversion, the resampling unit 50 applies an interpolation method to each of the measurement voltage data (Vtd), measurement current data (Itd), and protection current data (Idd) to obtain data. can be obtained to perform a resimplification operation.

At this time, the resampling unit 50 varies the slope value according to the size of the signal so that the distortion rate of the waveform is equal to or close to the distortion rate of the original signals VT, IoS, Ts1, and Ts2 so as to be as close to the original signal as possible. can Since the interpolation coefficient for this can already be stored in the memory 70 by applying a reference signal during mass production and calculating this value, the resampling unit 50 uses the interpolation coefficient stored in the memory 70 to determine the corresponding interpolation coefficient. Interpolation can be performed on the signals Vtd, Itd, Ts1d, and Ts2d.

In this way, after the resampling operation is performed using the interpolation method, the resampling unit 50 corrects the phase of the generated data, that is, the resampled data, using the delay filter provided therein, and then the operation control module 60 ) can be output.

When resampling is performed at the same rate as the sampling rate during analog-to-digital conversion, there is no need to readjust the sampling rate, so the resampling unit 50 uses only the minute delay filter provided inside to measure voltage data (Vtd ), each phase of the current data for measurement Itd and the current data for protection Idd can be delayed to correct only the phase.

Finally, when the next resampling is performed at a rate lower than the sampling rate during analog-to-digital conversion, the resampling unit 50 may use a Gaussian filter.

Accordingly, the resimpler 50 may filter each of the voltage data for measurement (Vtd), the current data for measurement (Itd), and the current data for protection (Idd) with a Gaussian filter.

At this time, the resampling unit 50 may set a range in which the representative value is to be taken, and discard a portion larger or smaller than the value automatically determined by the resampling unit 50 or the value determined by the user based on the representative value. Therefore, the value of the down-resampled data can approach the distortion of the original signal.

In this way, after the resampling operation is performed using the Gaussian filter, the resampling unit 50 may correct the phase of the resampled signal using a small delay filter and then output the signal to the operation control module 60. .

The operation control module 40 includes resampled measurement voltage data (Vtd), resampled measurement current data (Itd), resampled protection current data (Idd) applied from the connected resampling unit 50, and Resampled first and second temperature data Ts1d and Ts2d are input.

The operation control module 60 determines the phases of the resampled measurement voltage data (Vtd) and each resampled current data (ie, the resampled measurement current data (Itd) and the resampled protection current data (Idd)). It is possible to calculate phase difference data by comparing each, and store the calculated phase difference data in the memory 70 .

Using the stored phase difference data, the operation control module 60 may correct the phase of at least one of the resampled measurement voltage data Vtd and the resampled current data Itd and Idd.

In addition, the operation control module 60 may perform temperature error correction on the measurement voltage data Vtd and current data Vtd and Vdd using the resampled first and second temperature data Ts1d and Ts2d. there is.

In addition, the operation control module 60 uses the amplitude correction value stored in the memory 70 to generate at least one of corresponding data (ie, measurement voltage data Vtd and current data Itd and Idd). Amplitude correction can also be performed.

This operation control module 60 will be described in detail next.

The memory 70 may be a storage medium in which data or commands necessary for the operation of the voltage and current detection device are stored.

In the memory 70, a temperature correction value, which is a correction value for a corresponding electric/electronic element for temperature, may be stored in the form of a table, and the voltage signal Vs output from the voltage sensor unit 11 and the current sensor unit ( At least one amplitude correction value, which is a correction value for the amplitude difference between the current signals Is output in 12), may be set and stored.

In this example, since the temperature sensor includes the first temperature sensor 131 for one voltage sensor and the second temperature sensor 132 for one current sensor, the memory 70 has voltage data for temperature ( A temperature correction value (eg, a first temperature compensation value) of Vd) and a temperature compensation value (eg, a second temperature compensation value) of each current data (Itd and Idd) for temperature may be stored.

Therefore, the operation control module 60 checks the temperature sensed by the operation of each of the temperature sensors 131 and 132 using the first temperature correction value and the second temperature correction value of the memory 70 to determine the detected temperature. Each corresponding temperature correction value corresponding to the temperature is read and the measurement voltage data (Vtd) and current data (ie, measurement current data (Itd) and correction current data (Idd)) output from the corresponding electric/electronic device are corrected. can do.

In addition, the memory 70 may store not only the amplitude correction value but also the type of data to be subjected to amplitude correction, that is, the name of at least one of voltage data Vd and current data Itd and Idd. For this reason, the operation control module 60 may perform amplitude correction on the corresponding data by using the type of data stored in the memory 70 and the corresponding amplitude correction value.

The digital-to-analog conversion unit 80 is used for measurement voltage data (Vtd'), measurement current data (Itd'), and protection for measurement, in which phase compensation, amplitude compensation, and temperature compensation are performed by the operation of the operation control module 60. The current data Idd' may be converted into corresponding analog signals and output as a final measurement voltage signal Vtf, a final measurement current signal Itf, and a final protection current signal Idf, respectively.

In this example, a digital signal output from the motion control module 60 may have a step shape due to quantized digital data.

Accordingly, the digital-to-analog converter 80 of this example may include a smoothing filter or an anti-aliasing filter, and in this case, the waveform of the output signal is complemented by these filters. can

The final measurement voltage signal (Vtf) and the final measurement current signal (Itf) in an analog state may be output to the measurement equipment, and the final protection current signal (Idf) may be output to the protection equipment.

The communication module 90 is connected to the operation control module 60 and is for wireless or wired communication with external equipment.

Accordingly, the operation control module 60 may transmit the corrected voltage data Ttd' and current data Itd' and Idd' to an external device through the communication module 90.

In this example, the communication module 90 may use at least one communication method among RS-232, RS-485, CAN, ETHERNET, FIBER OPTIC, and WIFI.

Next, with reference to FIG. 2, the operation control module 60 will be described in detail.

As shown in FIG. 2, the operation control module 60 of this example includes a phase comparator 61, a control unit 62 connected to the phase comparator 61, a phase comparator 61 and a control unit 62 ) may be provided with an oscillation unit 63 connected to.

The phase comparator 61 may generate phase difference data by comparing phases of the voltage data Vtd for measurement applied from the resampling unit 50 and the current data for measurement (at least one of Itd and Idd).

At this time, the phase comparator 61 calculates the phase difference between the voltage data for measurement (Vtd) and the current data for measurement (Itd) and between the voltage data for measurement (Vtd) and the current data for protection (Idd), or A phase difference between the voltage data (Vtd) and one current data (Itd or Idd) may be calculated.

In this example, the phase comparator 61 calculates the phase difference between the measurement voltage data Vtd and the measurement current data Itd and the phase difference between the measurement voltage data Vtd and the protection current data Idd. By calculating all of them, corresponding phase difference data can be generated.

At this time, the phase difference data between the measurement voltage data (Vtd) and the measurement current data (Itd) is referred to as first phase difference data, and the phase difference data between the measurement voltage data (Vtd) and the protection current data (Idd) is It may be referred to as second phase difference data.

As shown in FIG. 2 , the control unit 62 may include a control unit 621 and a phase difference correction unit 622 connected to the control unit 621 .

The control unit 621 is a part that controls the overall operation of the operation control unit 60 and may be a processor made of a chip.

The controller 621 controls the operation of the phase difference compensator 622 and the amplitude compensator 423, and at least one of the voltage data for measurement (Vtd), the current data for measurement (Itd), and the current data for protection (Idd). It is possible to control the operation of correcting the phase of, and at least one of the voltage data for measurement (Vtd), the current data for measurement (Itd) and the current data for protection (Idd) using the amplitude correction value stored in the memory 70. A single amplitude can also be calibrated.

As described above, the phase difference correction unit 622 operates under the control of the control unit 621, and uses the first phase difference data and the second phase difference data to generate measurement voltage data (Vtd), measurement current data (Itd), and A phase of at least one of the protection current data Idd may be corrected.

In this example, the phase difference correction unit 622 may correct the phase difference of corresponding data using a fractional delay filter.

In this way, when phase difference correction and amplitude difference correction are performed on at least one of the voltage data for measurement (Vtd), the current data for measurement (Itd), and the current data for protection (Idd), the controller 621 performs phase difference correction and amplitude difference correction. Voltage data for measurement (Vtd'), current data for measurement (Itd') and current data for correction (Idd') for which correction has been performed can be generated and output.

The oscillation unit 63 performs an oscillation operation under the control of the control unit 621 to generate a sampling signal and a synchronization signal, which are pulse signals having a predetermined pulse width, respectively, and output the sampling signal to the analog-to-digital conversion unit 40. A synchronization signal may be output to the phase comparator 61 .

The oscillator 63 may include a crystal oscillator.

Next, the operation of the controller 621 will be described in detail.

First, when the operation of the control unit 621 starts, the control unit 621 operates the oscillation unit 63 so that the oscillation unit 63 can generate a sampling signal and a synchronization signal.

Therefore, the oscillation unit 63 starts operating according to the driving signal applied by the control unit 621 to generate a sampling signal and a synchronization signal having a predetermined pulse width and frequency, and then the analog-to-digital conversion unit 40 and It can be output to the phase comparator 61.

In this way, when the sampling signal is applied from the oscillation unit 63, the analog-to-digital converter 40 generates a voltage signal Vt and current signals It and Id input for each period of the sampling signal applied from the oscillation unit 63. And the first and second temperature signals Ts1 and Ts2 may be converted into digital data Vtd, Itd, Idd, Ts1d, and Ts2d, respectively, and applied to the phase comparator 61 and the control unit 621.

Therefore, the phase comparator 61 calculates the phase difference between the input measurement voltage data Vtd and the measurement current data Itd and the input measurement voltage data Vtd and the protection current data Idd. Thus, first phase difference data and second phase difference data, which are phase difference data for each calculated phase difference, may be generated and output to the control unit 621 .

Due to this, the control unit 621 may store the input first phase difference data and second phase difference data in the memory 70, respectively. At this time, the control unit 621 determines which data is delayed among the voltage data for measurement (Vtd), the current data for measurement (Itd), and the current data for protection (Idd) by using the states of the first phase difference data and the second phase difference data. Since this can be known, information about this can also be stored correspondingly to the first phase difference data and the second phase difference data.

In addition, the controller 621 may store the data Vtd, Itd, Idd, Ts1d, and Ts2d input from the resampling unit 50 in the memory 70, respectively.

In this way, when the first phase difference data and the second phase difference data are input from the phase comparator 61, the control unit 621 operates the phase difference correction unit 622 to obtain measurement voltage data Vtd and measurement current data ( Itd) and at least one of the protection current data Idd may be corrected for phase difference.

Therefore, the control unit 621 reads the first phase difference data and the second phase difference data, measurement voltage data (Vtd), measurement current data (Itd), and protection current data (Idd) stored in the memory 70. It can be input to the phase difference correction unit 622.

The phase difference correction unit 622 calculates the value of at least one of the measurement voltage data Vtd and the measurement current data Itd using the input first phase difference data, and calculates the measurement voltage data Vtd and the measurement voltage data Vtd. A phase difference between the current data Itd can be corrected.

In addition, the phase difference correction unit 622 calculates the value of at least one of the voltage data for measurement (Vtd) and the current data for protection (Idd) using the input second phase difference data, and calculates the value of the voltage data for measurement (Vtd) and the current data for protection (Idd). A phase difference between protection current data Idd can be corrected.

As already described, the memory 70 includes delayed data information (Vtd or Itd), which is information of delayed data among voltage data (Vtd) for measurement and current data (Itd) for measurement, voltage data (Vtd) for measurement, and current for protection. Since delayed data information (Vtd or Idd), which is information of delayed data, is stored in the data Idd, the controller 621 may output the delayed data information to the phase difference compensator 622.

Accordingly, the phase difference correction unit 622 may correct data corresponding to the delayed data information applied from the control unit 621 using the first phase difference data and the second phase difference data, respectively.

Due to the operation of the phase difference correction unit 622, the voltage data for measurement (Vtd), the current data for measurement (Itd), and the current data for protection (Idd) may have the same phase without a phase difference.

Unlike this example, in an alternative example, only one phase difference data related to the phase difference between the measurement voltage data (Vtd) and one current data (Itd or Idd) is calculated, and the object of phase correction (ie, delay When the generated data) is current data, the phases of both the current data Itd for measurement and the current data Idd for protection can be corrected using one phase difference data.

On the other hand, when only one phase difference data is calculated and the phase correction target is the measurement voltage data (Vtd), the phase of only the measurement voltage data (Vtd) is corrected using the phase difference data, of course, and all data (Vtd, Itd, Idd) can be identically matched.

As described above, the phase correction unit 622 may correct a phase difference between corresponding voltage data Vtd and current data Itd and Idd using a fractional delay filter.

When the phase difference correction using the fractional delay filter is completed, the phase correction unit 622 may input the phase difference correction completed voltage data (Vtd) and current data (Itd and Idd) to the control unit 621. . Accordingly, the controller 621 may store the voltage data Vtd and the current data Itd and Idd for which phase difference correction has been completed in the memory 70 .

Next, the control unit 621 applies an amplitude correction value to one of the voltage data (Vtd) and current data (Itd and Idd) by using the amplitude correction value stored in the memory 70 to determine the voltage data (Vtd) and the current data (Vtd). Amplitude deviation between data Itd and Idd can be corrected.

At this time, the amplitude correction target is voltage data (Vtd) or current data (Itd and Idd) for which amplitude correction is performed, and since they are already stored in the memory 70 to correspond to the amplitude correction values, the control unit 621 controls the memory 70 ) is read and the amplitude correction value is applied to the voltage data (Vtd) to correct the amplitude of the voltage data (Vtd), or the amplitude correction value is applied to both the measurement current data (Itd) and protection current data (Idd). Thus, the amplitudes of the current data Itd and Idd can be corrected.

Next, the control unit 621 controls temperature correction for the voltage sensor unit 11 and the current sensor unit 12 using the temperatures detected by the first temperature sensor 131 and the second temperature sensor 132. can

Therefore, the control unit 621 determines the temperature correction value corresponding to the first temperature data Ts1d, that is, the first temperature sensor 131 by using the first temperature data Ts1d related to the temperature of the voltage sensor unit 11. The temperature correction value corresponding to the temperature sensed by the temperature correction is read from the memory 70, and the temperature correction value is calculated on the measurement voltage data (Vt1) for which phase correction and amplitude correction are completed, and the temperature correction is performed for measurement voltage data (Vtd ') can be calculated and stored in the memory 70.

Similarly, in the case of the current data Itd and Idd, the control unit 621 generates a temperature correction value corresponding to the second temperature data Ts2d related to the temperature of the current sensor unit 12, that is, the second temperature sensor 132 A temperature correction value corresponding to the temperature sensed by is read from the memory 70 . Then, the control unit 621 calculates a temperature correction value corresponding to each of the current data for measurement (Itd) and current data for protection (Idd) for which phase correction and amplitude correction have been completed, thereby obtaining measurement current data (Itd' for which temperature correction has been performed). and protection current data Idd' may be calculated and stored in the memory 70 .

In this way, a method of calculating the corrected voltage data (Vtd) and current data (Itd, Idd) as the corresponding temperature correction value may be adding or subtracting the corresponding temperature correction value. In this example, such temperature correction is performed. Although the operation is performed after the phase correction and amplitude correction are completed, alternatively, it may be performed even before at least one of the phase correction and amplitude correction is performed.

Orders of the phase difference correction control operation, amplitude correction operation, and temperature correction operation of the control unit 621 may be changed, and at least one of them may be omitted.

Then, the controller 621 outputs the temperature-corrected measurement voltage data (Vtd') and current data (Itd', Idd') to the digital-to-analog conversion unit 80, and outputs them in analog form with corresponding waveforms. A voltage signal (Vtf) for measurement, a current signal (Itf) for measurement, and a current signal (Idf) for protection may be generated and output to measurement equipment and protection equipment, respectively.

The technical features disclosed in each embodiment of the present invention are not limited to the corresponding embodiment, and unless incompatible with each other, the technical features disclosed in each embodiment may be merged and applied to other embodiments.

In the above, the embodiments of the present invention have been described. The present invention is not limited to the above-described embodiments and accompanying drawings, and various modifications and variations will be possible from the viewpoint of those skilled in the art to which the present invention belongs. Therefore, the scope of the present invention should be defined by not only the claims of this specification but also those equivalent to these claims.

11: voltage sensor unit 12: current sensor unit
13: temperature sensor unit 21: voltage signal amplification unit
22: current signal amplifier for measurement 23: current signal amplifier for protection
30: DC component blocking unit 40: analog-digital conversion unit
6: motion control module 61: phase comparison unit
62: control unit 621: control unit
622: phase difference correction unit 63: oscillation unit
70: memory 80: digital analog-conversion unit
Vs: voltage signal Is: current signal
Ts1: first temperature signal Ts2: second temperature signal
Vt: voltage signal for measurement It: current signal for measurement
Id: voltage signal for protection Vtd: voltage data for resampled measurement
Vtd: Resampled current data for measurement Idd: Resampled current data for protection
Ts1d: resampled first temperature data Ts2d: resampled second temperature data
Vtf: voltage signal for final measurement Itf: current signal for final measurement
Idf: current signal for final protection

Claims (6)

a voltage sensor that detects voltage and outputs a voltage signal;
a current sensor that detects current and outputs a current signal;
a voltage signal amplifier connected to the voltage sensor and amplifying the voltage signal output from the voltage sensor and outputting the amplified voltage signal for measurement;
a current signal amplifier for measurement connected to the current sensor and amplifying the current signal output from the current sensor and outputting the amplified current signal for measurement;
It is connected to the voltage signal amplifier and the current signal amplifier for measurement, and samples the voltage signal for measurement and the current signal for measurement according to a sampling rate determined by the sampling signal and converts them into digital data to obtain measurement voltage data and an analog-to-digital conversion unit generating current data for measurement;
a resampling unit that is connected to the analog-to-digital conversion unit and resamples and outputs measurement voltage data and measurement current data according to a resampling rate determined based on the sampling rate;
A memory for storing delayed data information, which is information of delayed data among an amplitude correction target, an amplitude correction value, resampled measurement data, and resampled measurement current data; and
It is connected to the resampling unit and the memory, outputs the sampling signal to the analog-to-digital conversion unit, compares the phases of the resampled measurement voltage data and the resampled measurement current data to calculate phase difference data, , Operation control module that corrects and outputs the phase of voltage data for measurement or current data for measurement
including,
The motion control module,
a phase comparator operating according to a synchronization signal to compare phases of the resampled measurement voltage and the resampled measurement current to output phase difference data;
It is connected to the phase comparator and corrects the phase of resampled measurement voltage data or resampled current data corresponding to the delayed data information using phase difference data applied from the phase comparator, and stores the data in the memory. a control unit for correcting the amplitude of resampled measurement voltage data or resampled current data using stored amplitude correction targets and amplitude correction values; and
An oscillation unit that operates under the control of the control unit to generate a synchronization signal and a sampling signal and output them to the analog-to-digital conversion unit and the phase comparison unit, respectively.
Voltage current detection device comprising a. According to claim 1,
The resampling unit,
If the sampling rate and the resampling rate are the same, each phase of the voltage data for measurement and the current data for measurement is delayed using a minute delay filter,
When the re-sampling rate is higher than the sampling rate, interpolation is applied to each of the voltage data for measurement and the current data for measurement to acquire data, perform a re-simplification operation, and then perform phase correction using a minute delay filter. conducted,
When the resampling rate is lower than the sampling rate, the voltage data for measurement and the current data for measurement are filtered using a Gaussian filter, and then the phase is corrected using a minute delay filter. Voltage current detection device. delete According to claim 1,
The voltage signal amplifier further comprising a DC component blocker for blocking the DC component of each of the measurement voltage signal and the measurement current signal output from the voltage signal amplifier and the measurement current signal amplifier and outputting the DC component to the analog-to-digital conversion unit. detection device. According to claim 1,
Further comprising a digital-to-analog conversion unit connected to the operation control module and converting the corrected measurement voltage data and measurement current data output from the operation control module into analog signals and outputting the voltage current detection device. According to claim 1,
a first temperature sensor positioned adjacent to the voltage sensor to detect a temperature of the voltage sensor and output a first temperature signal to the analog-to-digital converter; and
A second temperature sensor located adjacent to the current sensor detects the temperature of the current sensor and outputs a second temperature signal to the analog-to-digital converter.
Including more,
The analog-to-digital conversion unit converts the first temperature signal and the second temperature signal into digital data, respectively, and outputs the first temperature data and the second temperature data to the resampling unit;
The resampling unit resamples the first temperature data and the second temperature data according to a resampling rate determined based on the sampling rate and outputs the resampled data to the operation control module;
The operation control module calculates a temperature correction value corresponding to the first temperature data to the measurement voltage data subjected to phase correction, performs temperature correction of the measurement voltage data subjected to phase correction, and the second temperature data A voltage-current detection device that calculates a temperature correction value corresponding to the phase-corrected measurement current data to perform temperature correction on the measurement current data subjected to phase correction.

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