KR101127760B1 - A test device for correcting the voltage of a circuit breaker in the distribution line, the method of correcting using a test device - Google Patents

Abstract

PURPOSE: A test device for correcting a measured voltage of a wiring line automatic switch and a test method thereof are provided to enhance the operation efficiency of a system. CONSTITUTION: A test voltage supply unit(110) applies a test voltage to outflow cable of each phase. A part of the test voltage is divided into a reference voltage by a first resistor(113) and a second resistor(114) which are serially connected to an output end of a transformer. A capacitor(120) for constructing voltage divider circuit is serially connected in between a voltage sensor(15-1) installed in a bushing outside the outflow cable and a ground terminal. The capacitor divides a first voltage of each phase applied to the outflow cable.

Description

TEST DEVICE FOR CORRECTING THE VOLTAGE OF A CIRCUIT BREAKER IN THE DISTRIBUTION LINE, THE METHOD OF CORRECTING USING A TEST DEVICE}

The present invention relates to a test apparatus for calibrating the measured voltage of an automatic switchgear of a distribution line, and a test method using the test apparatus, and more particularly, to the measurement of voltage through a switch on a distribution line. The present invention relates to a test apparatus for calibrating the measured voltage of an automatic switchgear for a distribution line that enables the management to increase the operating efficiency of the system, and a test method using the test apparatus.

Switchgear automatic switchgear installed on pole and ground can be classified into switchgear that can be opened and closed as a switch to the line and a control part that processes the signal electrically. The switch is composed of a switch mechanism and a contact point, a voltage and current sensor, a driving device capable of driving the switch mechanism, an insulating medium, and a bushing connected to the distribution line. Voltage and current signals for measurement, drive signals for operating switch mechanisms, and switch status signals are connected to the control unit via control cables.

The control unit generates an electric drive signal for operating (opening and closing) the switch, and has an analog adjustment circuit for the voltage signal. It also includes charging circuits for battery and battery test circuit, switchgear status display and operation button, electric lock / unlock of controller, remote and field control selector switch, etc.

The controller processes the signal associated with the switch and makes it a standard signal, and provides the signal and power through the connector to connect with the Feeder Remote Terminal Unit (FRTU).

Most of the FRTU currently does not implement a function alone, the measurement of voltage and current signals, switch control and acquisition of status through the control unit. FRTU communicates with upper level devices (central server, etc.) and performs control and status monitoring of switchgear, status monitoring of controller and voltage and current measurement of switchgear bushing through contact points provided by controller.

1 is a block diagram showing a connection state of a switchgear automatic switch according to the prior art.

In the distribution automation system, the measurement of the voltage and current of the distribution line 11 is performed through the voltage sensor 15-1 and the current sensor 15-2 embedded in the switch 15 mounted on the columnar or the ground. . In particular, the sensors used in voltage measurement are diverse, but most of them use mutual capacitance by capacitive coupling in terms of economy and stability. In addition, a voltage sensor based on a partial resistance method is also applied. In FIG. 1, only one phase of a processing switch is demonstrated.

Except for the difference in sensor types, the resistance sensor method and the method using mutual capacitance by capacitive coupling have the same circuit configuration and application method. Here, the method using mutual capacitance of capacitive coupling is taken as an example.

Voltage measurement by mutual capacitance of the bushing 14 insulated from the distribution line 11 inside the switch 15 by the electrically inductive voltage sensor 15-1 which does not directly contact the conductors of the distribution line 11. The voltage induced by mutual capacitance between the inner conductor of each bushing 14 and the voltage sensor 15-1 is positioned outside or inside the insulating medium inside the bushing 14. And, a basic voltage signal can be obtained by the voltage dividing circuit through the ground terminal and another capacitor. In general, the partial pressure capacitor may be located in the switch 15 or in the controller 16. The bushing 14 also includes a lead cable 13 for connecting each phase of the switch 15 to the power distribution line 11. The lead cable 13 and the distribution line 11 are electrically connected at the connection point 12.

In the case of overhead switchgear, a conductor such as a teflon wire or a spring is installed outside the bushing 14 in the insulated switchgear 15 to induce a voltage signal, and in the case of a ground switch, a band of metal in the bushing 14 is used. We will use the same method. However, at present, the insulating medium is becoming solid, and as a result, many sensors are installed in the bushing 14 to measure the voltage.

In order to change the output voltage from a voltage induced by mutual capacitance or a resistance type sensor to an appropriate magnitude, it passes through a voltage dividing circuit of the switch 15 or the controller 16. This voltage signal is minute in intensity and requires an amplification and adjusting circuit to amplify to a prescribed voltage magnitude. The amplification and adjustment circuit is located inside the control unit 16, and amplifies through a variable resistor to match the original signal to which the magnitude and phase are applied and the purpose for amplifying the signal strength of the voltage signal itself induced by the switch 15. Adjust the ratio and phase.

Power sources for driving the control unit 16 include an AC 220V and a storage battery 17, and the storage battery 17 is located in a container in which the control unit 16 is installed. Transformer 20 for supplying AC 220V power is connected separately.

The amplified voltage signal is supplied to the FRTU 18 through the insulated measuring transformer, and the FRTU 18 measures 13,200V when the magnitude of the input signal is 4V.

The FRTU 18 measures voltage and current signals provided by the controller 16 to determine whether a failure occurs on the distribution line 11, and the switch drive circuit of the controller 16 is controlled by a remote command of the central server 19. An electrical signal is applied to drive the switch mechanism. Accordingly, the contact of the switch 15-3 of the switch 15 is opened and closed. The operation information and the collected data of the FRTU 18, the magnitude of the voltage and current of the measured distribution line 11 may be made remotely by a central server 19 connected through a communication network.

In order to increase the measurement accuracy of measuring the magnitude of the voltage signal in the FRTU 18 and the controller 16, the most important thing is to increase the accuracy of the sensor. Increasing precision, however, should not only be considered a technical problem, but also a cost / economic issue.

In this respect, voltage measurement based on mutual capacitance currently used is the most efficient. But the biggest problem is that there is a big variation in each product. This is due to the error generated when the voltage sensor 15-1 is fixed to the bushing 14 inside the switch 15, the mutual capacitance of each phase, and the precision of the capacitor constituting the voltage divider circuit. You need a circuit for it.

In addition, the adjustment of the size and phase through the variable resistor has the disadvantage that it is impossible to replace the device with the same characteristics during repair or replacement due to the failure of the device.

Visually adjusting the variable resistance and checking the magnitude and phase has many problems in securing precision. Although the voltage value displayed on the LCD of the FRTU 18 is visually checked to confirm that the voltage adjustment is appropriate, the voltage value displayed on the FRTU 18 is not an instantaneous value of one cycle but an instant of several to several cycles. Since the value is averaged, the source of the actual voltage does not reflect that part even if it moves over time.

Currently, a method of applying a test voltage to the lead-out cable 13 on each phase of the switch 15 can be classified into three types.

First, a commercial power source (AC 220V) is used, and Slidacs (Slidacs) that can adjust 220V at the first stage, and withdrawal cable 13 of each phase of the switchgear 15 through a transformer of 220: 13,200 ratio This is a method of applying a voltage to the.

The second method is to use a commercial power source (AC 220V), install Slidacs that can adjust 220V in the first phase, and apply voltage to the lead-out cable 13 of each phase through the MOF transformer of 220: 13,200 ratio. That's how.

Third, a voltage is directly applied to the lead cable 13 through the withstand voltage tester at a commercial frequency.

FIG. 2 is a circuit diagram illustrating a detailed structure of a test apparatus for correcting a measured voltage in the automatic switch of FIG. 1.

The configuration of the test apparatus is largely associated with the control unit 16, the test voltage supply unit 21, and the voltage sensor 15-1, and the mutual capacitance and voltage dividing circuit between the inner conductor of each phase of the bushing 14 and the voltage sensor 15-1. Capacitor 22 is composed of.

The controller 16 includes a portion for adjusting the magnitude of the applied voltage and a portion for adjusting the phase delay of the voltage signal.

In FIG. 2, Vs 21-1 is a commercial power source of AC 220V, Slidax 21-2 is for 220V, and transformer 21-3 is for 220: 13.2kV. A VM (Volt Meter) 21-4 is connected in parallel to the secondary side of the transformer 21-3. The VM 21-4 measures the magnitude of the voltage so that it can be visually confirmed.

At the rear end of the VM 21-4, a drawing cable 13 is drawn out from the bushing 14 to connect each phase of the switch 15 and the distribution line 11. The secondary side of the transformer 21-3 is connected to each phase of the switchgear 15 through an outgoing cable 13, and a voltage sensor 15-1 is installed in the bushing 14 of each phase inside the switchgear 15. do.

The mutual capacitance represents the magnitude of the geometric capacitance of the inner conductor of the switch bushing 14 on the A phase and the voltage sensor 15-1, and the partial voltage capacitance represents the size of the capacitor 22 constituting the voltage divider circuit.

The amplification ratio adjusting resistor 16-2 is a variable resistor for adjusting the magnitude of the A-phase voltage by adjusting the magnitude of the current fed back from the first amplifier 16-1.

The power output from the first amplifier 16-1 is input to the inverting terminal of the second amplifier 16-4 through the phase adjusting resistor 16-3 which is a variable resistor.

The insulated voltage signal Va, which has been adjusted for phase delay while passing through the second amplifier 16-4, is applied to the FRTU 18 via the measuring transformer 16-5.

In the method of applying a signal, as shown in FIG. 2, the switch 15-3 is closed by using a single-phase device, and any one of three phases is shorted, and then A / B / C phase and R / S / T phase are applied. There may be a method of applying a batch, there may be a method to apply separately to each phase by using a three-phase equipment. Here, an example of a single phase application method that can be configured relatively simply is given.

Adjust the Slidax 21-2 and visually apply the VM 21-4 to the secondary cable of the transformer 21-3 and the draw cable 13 of each phase of the switch 15 to be 13,200V. Check it. When the VM 21-4 instructs 13,200 V, the adjustment is stopped, and the A-phase voltage displayed on the LCD of the FRTU 18 becomes 13.2 kV by adjusting the variable resistance of the amplification ratio adjusting resistor 16-2, or VM Adjust to 4V using (21-4). In Fig. 2, only the circuit for phase A is shown, but the same circuit is also configured for the remaining phases B / C and R / S / T. Thereafter, the width ratio adjustment resistor 16-2 is sequentially adjusted for the remaining phases so that the voltage of the phase is 13.2kV on the LCD of the FRTU 18 or 4V using the VM 21-4.

In the phase adjustment method, the voltage signal Van applied to the lead-out cable 13 on each switch 15 is visually checked through a screen of an oscilloscope using a device such as a high-pressure probe, and then the FRTU (18). The phase adjustment resistor 16-3 is adjusted to be equal to the phase of the voltage signal Va applied to the side. If the phase of the voltage has a phase difference within a prescribed error, the adjustment is completed, and the same adjustment is performed for the remaining phases.

As a problem with this adjustment method,

First, the method of displaying the value measured by the VM 21-4 or FRTU 18 cannot be confirmed that the actual fluctuation is made by using the method of averaging the value of several to several tens of cycles instead of the instantaneous value.

Second, the human error (Human Error) caused by manually adjusting the variable resistance through visual confirmation,

Third, the voltage actually applied is not stable, which lowers the overall reliability. In some cases, waveform distortion may occur at an applied voltage, and there is a problem of continuous fluctuation when using a commercially available 220V.

If a test voltage is applied by using a device that outputs high-precision voltage, many problems can be solved, but the proper equipment is not yet applied.

These adjustments are possible in factories and laboratories with certain equipment, but when they are used in the actual field, there is a problem that the same adjustment values cannot be obtained when replacing or repairing the equipment. Is the reality.

The present invention for solving the above-described problems, after applying the commercial power to the inner conductor of the switchgear bushing, the distribution line to calculate the factor for voltage correction in an automated manner according to the magnitude and phase of the voltage measured by the measuring means It is an object of the present invention to provide a test apparatus for calibrating the measured voltage of an automatic switchgear and a test method using the test apparatus.

In addition, the present invention stores the factor for voltage correction in the internal or external memory, and provides the FRTU (18) to measure the magnitude of the voltage more precisely by providing to the FRTU (18) through a serial or parallel bus method, such as a controller It is an object of the present invention to provide a test apparatus for calibrating the measured voltage of an automatic switchgear for a distribution line that can maintain the existing accuracy even when replacing or repairing a device caused by a fault.

The present invention devised to solve the above-described problem is applied to the test cable (Vs2) to the lead-out cable 13 of each phase of the automatic switchgear 15 of the distribution line 11, the magnitude of the voltage measured by the measuring means And a test device for calculating a factor for correcting the phase and the phase, wherein a test voltage (Vs2) is applied to the lead cable (13) of each phase, and the first resistor (113) and the second resistor ( A test voltage supply unit (110) for branching a part of the test voltage (Vs2) to a reference voltage (Vref) by 114; Primary voltages Van, Vbn, Vcn of each phase applied to the lead cable 13 by being connected in series between the voltage sensor 15-1 installed on the bushing 14 outside the lead cable 13 and the ground terminal. Capacitor 120 for configuring a voltage divider circuit for branching, Vrn, Vsn, Vtn; Receives and amplifies the input divided voltages (Vac, Vbc, Vcc, Vrc, Vsc, Vtc) input by being divided by the voltage dividing circuit constituting capacitor 120 as an input value and input voltages (Vai, Vbi) of each amplified phase. A voltage signal linker 130 for outputting Vci, Vri, Vsi, and Vti; It is determined by the input voltages (Vai, Vbi, Vci, Vri, Vsi, Vti) of each phase output from the voltage signal connection unit 130, and the first resistor 113 and the second resistor 114. The divided voltage ratio X, the reference voltage Vref branched by the first resistor 113 and the second resistor 114, and the primary voltages Van, Vbn, Vcn, and Vrn of each phase are input. And a factor generator 140 for generating a factor for correcting the magnitude and phase of the voltage signal based on Vsn and Vtn).

의 식으로 정의되는 것을 특징으로 한다.The partial pressure ratio (X) is

It is characterized by the formula.

The factor generator 140 has a primary voltage (Van, Vbn) of each phase with respect to magnitudes of the input voltages Va, Vbi, Vci, Vri, Vsi, Vti inputted from the voltage signal linker 130. , Vcn, Vrn, Vsn, Vtn) is characterized by defining the ratio of each phase factor.

After applying the test voltage (Vs2) to the lead-out cable 13 of each phase of the automatic switchgear 15 of the distribution line 11 by using the test apparatus of any one of claims 1 to 3, the measurement means A test method for calculating a factor for correcting the magnitude and phase of a voltage, comprising: a first step of applying, by a test voltage supply unit 110, a test voltage Vs2 to the lead cables 13 of each phase; A second step of shorting one side of the switch (15-3) of each phase and maintaining a closed state while applying the test voltage (Vs2); The divided voltage ratio X of the test voltage Vs2 is obtained by using the magnitudes of the first resistor 113 and the second resistor 114 included in the test voltage supply unit 110, and the factor generator 140 determines the reference voltage ( A third step of measuring Vref) and multiplying the partial pressure ratio X to obtain a magnitude of a test voltage Vs2; A fourth step of measuring magnitudes of the input voltages Vai, Vbi, Vci, Vri, Vsi, and Vti inputted to the impedance matching circuit 140-2 of the voltage size adjusting factor generator 140; And a fifth step of the factor generator 140 dividing the magnitude of the test voltage Vs2 by the magnitude of the input voltages Va, Vbi, Vci, Vri, Vsi, and Vti of each phase.

의 식으로 정의되는 것을 특징으로 한다.The partial pressure ratio (X) is

It is characterized by the formula.

The factor generator 140 is applied to the draw cable 13 for the magnitude of the input voltages Vai, Vbi, Vci, Vri, Vsi, Vti inputted from the voltage signal linker 130. The ratio of the magnitudes of the primary voltages Van, Vbn, Vcn, Vrn, Vsn, and Vtn is characterized by being defined as a factor of each phase.

According to the present invention there is an effect that the manufacturer who manufactures and installs the measuring device and the switching device does not have to maintain human precision and precision of the test equipment generated during the testing of the equipment.

In addition, it is possible to solve the difficulty of securing accuracy by manually adjusting the magnitude and phase difference of the voltage, and the same adjustment effect can be obtained even when replacing the device due to maintenance, which is advantageous in terms of management of the device.

In addition, the operator of the automatic switchgear improves the efficiency and management of the system operation by securing the accuracy of the voltage signal, reduces the voltage signal management factor due to the maintenance and replacement of the device, and adjusts the voltage adjustment correction factor (Factor). By managing in the upper system, it is effective to effectively manage the validity of the voltage signal.

In addition, it is possible to operate the distribution automation system based on the voltage signal through the measurement of voltage signal more precisely than the existing device, and it is possible to operate the high reliability system by improving the reliability of information, thereby reducing the loss of the distribution line and disconnection / phase loss. There is an effect that can improve the reliability of the failure.

1 is a block diagram showing a connection state of a switchgear automatic switch according to the prior art.
Figure 2 is a circuit diagram showing the configuration and structure of a test apparatus for adjusting the voltage signal in the automatic switch of Figure 1;
Figure 3 is a circuit diagram showing the configuration and structure of a measurement voltage test apparatus according to an embodiment of the present invention.
4 is a block diagram showing the internal structure of a factor generator.
Figure 5 is a flow chart showing the process of the test method for the measurement voltage correction according to an embodiment of the present invention.

Hereinafter, with reference to the drawings will be described "voltage measuring apparatus and voltage measuring method for automatic switchgear distribution line" according to an embodiment of the present invention.

Figure 3 is a circuit diagram showing the structure of the measurement voltage test apparatus according to an embodiment of the present invention, Figure 4 is a block diagram showing the internal structure of the factor generator, Figure 5 is a test for the measurement voltage correction according to an embodiment of the present invention A flowchart showing the process of the method.

3 to 5, a test apparatus (hereinafter, referred to as a “test apparatus”) for calibrating a measured voltage of an automatic switchgear of a distribution line of the present invention will be described.

Unlike in the prior art, in order to adjust the magnitude and phase of a voltage signal, a method of generating and storing digitized information (correction factor) in a memory without using a variable resistor is used.

3 is a circuit diagram of the components and the connection state of the measurement voltage test apparatus 100 according to a new embodiment.

In the configuration of the test apparatus 100 according to the new embodiment, the slip voltage is excluded from the test voltage supply unit 110, and the voltage supplied by the test voltage Vs 111, which is a commercial power supply, is serially passed through the boosting transformer 112. It is applied to the voltage divider circuit by two resistors 113 and 114 connected to the ground terminal. In addition, the internal conductor of the bushing 14 and the mutual capacitance by the voltage sensor 15-1 and branched by the voltage dividing capacitor 120 are applied to the voltage signal connection unit 130.

The first resistor 113 and the second resistor 114 are resistors for configuring a voltage divider circuit for creating a divided reference voltage Vref. The first resistor 113 and the second resistor 114 are composed of high-precision elements and precisely measure a voltage of 13,200 V applied to the distribution line 11. To allow for partial pressure. In a practical configuration, the test voltage is high and it is necessary to secure the insulation distance. Therefore, it is preferable that the first resistor 113 and the second resistor 114 are made of several to several tens of resistors instead of a single resistor.

The reference voltage Vref is a reference for allowing the factor generator 140 to generate a factor for adjusting the magnitude and phase of the voltage. By measuring the magnitude and phase of the reference voltage Vref, a factor (correction factor) for correcting an error occurring in the coupling structure between the internal conductor of the bushing 14 and the voltage sensor 15-1 and the voltage application characteristic is measured. Create

The factor generated by the factor generator 140 is stored in the storage means existing inside the factor generator 140 and in an external memory 150 connected to the outside. The factor stored in the external memory 150 may be transmitted to the central server 19 using a protocol defined through the FRTU 18 or the FRTU 18 through a separate interface or slot.

The test apparatus 100 of the present invention differs from the measuring apparatus in the related art in that the slips 21-2 are omitted, and a commercial 220V power supply is directly connected to the boosting transformer 112, and the VM 21 -4) is changed to the voltage divider circuit by the resistors 113 and 114 to apply the reference voltage Vref to the voltage regulation factor generator 140, and also by applying the voltage regulation factor generator 140 The digitization correction factor was applied in the adjustment method. In the conventional adjustment circuit, the phase delay adjustment circuit was removed, and the variable resistor for magnitude amplification was changed to a fixed resistor.

According to such a configuration, even if the controller 16 of FIG. 1 is replaced or repaired, the same performance and characteristics may be guaranteed.

In FIG. 3, only one phase (A phase) is shown as in FIG. 2, but the other phases are connected to the same circuit, and voltage signals of the respective phases are also applied to the voltage adjusting factor generator 140.

As the test voltage (Vs; 111), a commercially available 220V power supply is used as before, and a method of applying voltages to all phases in a single phase by shorting any one of three phases with the switch 15-3 closed. .

The reference voltage Vref divided by the two voltage divider resistors 113 and 114 is configured to be within a range that is easy to use in the voltage regulation factor generator 140. In addition, the voltage adjusting factor generator 140 applies a signal using a voltage generator having a high precision to the port into which the reference voltage (Vref) signal and the voltage of each phase are input, and must be calibrated very precisely.

When a voltage is applied to all phases, a voltage signal is supplied to the voltage adjusting factor generator 140 through the voltage sensor 15-1 of each phase, and the reference voltage Vref is within a predetermined voltage range. The adjustment request calculates the adjustment factor for the magnitude and phase of the voltage.

On the other hand, as shown in Figure 4, the Factor generator 140 is a microprocessor unit (MPU) 140-1 capable of high-speed operation on a variety of data and the input voltage (Vai, Vbi, Vci, Vri, Vsi, Vti) for each phase A / D converter / MUX for selectively converting the voltage signal and the reference voltage (Vref) for each phase applied from the impedance matching circuit 140-2 and the voltage signal linking unit 130 to match the impedance with respect to the digital signal (140-3), the display unit (140-4) for displaying the status and the generated factor, the progress of the factor generator 140, and transmits data to the console port for the user connection to check the test start progress and transmission progress command It consists of a communication port 140-5 ROM 140-6, an internal memory 140-7, and an external memory interface 140-8 for storing a factor.

The external memory 150 may be installed in any one of the inside of the control unit, the inside of the enclosure in which the control unit is installed, the switch body, or the FRTU 18.

The ROM 140-6 may be used for storing a program, and the internal memory 140-7 may be used to store a generated factor.

The voltage measuring circuit into which the input voltages (Vai, Vbi, Vci, Vri, Vsi, Vti) and the reference voltage (Vref) are input to each phase is configured so that the measurement PT is not used so as not to affect phase delay or precision. The element used is also configured to have a minimum delay characteristic. The A / D converter 140-3 to be used uses a device capable of high-speed conversion to have a sufficient sampling rate, and the A / D converter 140-3 performs control, measurement value calculation, and FFT to perform actual voltage adjustment factor. MPU (140-1) that performs the function of generating a is also composed of elements that can exhibit sufficient performance.

FIG. 5 is a flowchart illustrating a process of obtaining a voltage adjustment factor and a phase adjustment factor. The magnitude and phase of a voltage signal applied to a power distribution line using a circuit of such a configuration is obtained, and an appropriate factor is obtained to correct the operation of the automatic switch. The process of doing this will be described with reference to FIG.

First, upon receiving a factor adjustment request, the test voltage supply unit 110 applies a test voltage Vs2 to the lead cable 13 of each phase of the switch 15. (S102) A test voltage applied to the lead cable 13 ( Vs2) becomes the primary voltages Van, Vbn, Vcn, Vrn, Vsn, and Vtn of each phase.

The input divided voltages Vac, Vbc, Vcc, Vrc, Vsc, and Vtc branched from the voltage sensor 15-1 installed in the bushings 14 of each phase are connected to the amplifier 131 included in the voltage signal connection unit 130. It is input as non-inverting terminal (+).

The factor generator 140 measures instantaneous values of the reference voltage Vref and the voltage signals Vai, Vbi, Vci, Vri, Vsi, and Vti at the same time, and measures the phase difference with respect to the reference voltage Vref. do.

First, the measurement process for phase A is described, and the same for all other B, C, R, S, and T phases.

While applying the test voltage Vs2, one of the phase A switches 15-3 is short-circuited and kept closed so that the voltage is applied to phase A. (S104)

In order to calculate the voltage regulation factor, first, the ratio of the resistors 113 and 114 for the voltage divider circuit is calculated, and the reference voltage Vref is measured to calculate the test voltage Vs2 multiplied by the voltage divider ratio X. The divided voltage ratio X is a ratio of the test voltage Vs2 to the reference voltage Vref. The test voltage Vs2 is obtained by the following equation.

Therefore, the partial pressure ratio X is as follows.

If the first resistance is 13,196 mA and the second resistance is 4 mA, the partial pressure ratio X is 3,300. And if the measured reference voltage (Vref) is 4.0V, the test voltage (Vs2) will be 13.2kV.

Next, the primary voltage Van to be applied to the lead cable 13 on the A phase must be obtained, which is the same as the test voltage Vs2. Therefore, the primary voltage Van of phase A is as follows (S108).

If it is assumed that the reference voltage Vref is divided by the ratio of the divided voltage ratio X 3,300, the factor generator 140 multiplies the measured reference voltage Vref value by the divided voltage ratio 3,300 to take out the cable of the A phase of the switch. The primary voltage Van applied to 13) is calculated. The voltage size adjustment factor of the phase A is determined so that the value of measuring the input voltage Va of the phase A input to the impedance matching circuit 140-2 of the factor generator 140 is equal to the primary voltage Van of the phase A. (S110)

For example, if the primary voltage Van of phase A is 13,200V and the input voltage Va of phase A is measured at 4V, the voltage resizing factor of phase A is 13,200 / 4.

On the other hand, the phase adjustment factor is obtained by calculating the phase difference of each phase compared to the reference voltage (Vref) by performing a fast fourier transform (FFT) on the reference voltage (Vref) and the voltage waveform of each phase measured at the same time (S112). That is, the phase of the reference voltage Vref becomes 0 °, and the phase adjustment factor has a negative or positive sign as the phase advances and reverses.

For each phase (power-side three-phase A, B, C and load-side three-phase R, S, T) phase adjustment factors, the sign code is included according to the leading and trailing edges. The phase adjustment factor calculates a phase difference with each phase by using the reference voltage Vref as a reference phase. The factor generator 140 measures the reference voltage (Vref) and voltage signals of the three phases of the power supply side and the load side at the same time to perform a discrete fourier transform (DFT) to obtain magnitude and phase (S114).

In the test with the single-phase power supply and the switch 15 closed, the phase adjustment factor for each phase is calculated so that the phase of the reference voltage (Vref) and the phase of each phase are the same.

The actual phase adjustment for the phase with the phase earlier (faster) than the phase of the reference voltage Vref should be subtracted from the corresponding value, and the actual phase adjustment for the phase with the phase later than the phase of the reference voltage Vref Adjust by adding the value.

The same method is applied to the remaining phases (B, C, R, S, and T) to calculate and obtain a voltage scaling factor and a phase adjustment factor for all phases (S116).

The factor generator 140 displays a progress status externally through the display unit 140-4 so that the user can check each step that proceeds, and when the calculation of all factors is completed, the factor generator 140 displays the corresponding factor in the internal memory 140-7 or The recording method is recorded in the external memory 150 (S118). The recording method may be linked by various data communication methods and data buses.

When the device is used in the field, the FRTU 18 is connected to the external memory 150 to read the voltage scaling factor and the phase adjustment factor for each phase and move them to its own area. For the magnitude of the voltage, the voltage of each phase is obtained by multiplying the measured voltage signal by the voltage scaling factor. In addition, the FRTU 18 calculates a phase for each phase with respect to the voltage input signal, and determines the phase value by adding the phase adjustment factor to the calculated value.

The factor adjustment memory can be configured in the controller or as a separate device. In addition, the voltage adjusting factor generator 140 may be included in an RTU or an IED such as the FRTU 18, and in this case, the factor adjusting memory may be embedded in the same device.

In addition, the voltage adjustment factor is transmitted to the upper system through the communication protocol so that the upper system can manage the factor, so that the same measurement performance can be maintained by reapplying the factor when replacing or repairing the equipment, and the factor and the measured value are valid. Can be determined systematically.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the above-described technical configuration of the present invention may be embodied by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

11: distribution line 12: connection point
13: outgoing cable 14: bushing
15: switch 16: control unit
17 storage battery 18 FRTU
19: central server 20: transformer
21: test voltage supply unit 22: capacitor
100: test apparatus 110: test voltage supply unit
120: Capacitor 130: voltage signal connection unit
140: Factor generator 150: External memory

Claims (6)

Test device for applying the test voltage (Vs2) to the lead-out cable 13 of each phase of the automatic switchgear 15 of the distribution line 11, and then calculate the factor for correcting the magnitude and phase of the voltage measured by the measuring means as,
The test voltage Vs2 is applied to the lead-out cable 13 of each phase, and a part of the test voltage Vs2 is referenced by the first resistor 113 and the second resistor 114 connected in series to the output side of the transformer. A test voltage supply unit 110 branching to a voltage Vref;
Primary voltages Van, Vbn, Vcn of each phase applied to the lead cable 13 by being connected in series between the voltage sensor 15-1 installed on the bushing 14 outside the lead cable 13 and the ground terminal. Capacitor 120 for configuring a voltage divider circuit for branching, Vrn, Vsn, Vtn;
Receives and amplifies the input divided voltages (Vac, Vbc, Vcc, Vrc, Vsc, Vtc) input by being divided by the voltage dividing circuit constituting capacitor 120 as an input value and input voltages (Vai, Vbi) of each amplified phase. A voltage signal linker 130 for outputting Vci, Vri, Vsi, and Vti;
It is determined by the input voltages (Vai, Vbi, Vci, Vri, Vsi, Vti) of each phase output from the voltage signal connection unit 130, and the first resistor 113 and the second resistor 114. The divided voltage ratio X, the reference voltage Vref branched by the first resistor 113 and the second resistor 114, and the primary voltages Van, Vbn, Vcn, and Vrn of each phase are input. And a factor generator (140) for generating a factor for correcting the magnitude and phase of the voltage signal based on Vsn and Vtn). The method of claim 1,
The partial pressure ratio (X) is

Test apparatus for correcting the measured voltage of the automatic switchgear of the distribution line, characterized in that defined by the equation. The method of claim 2,
The factor generator 140 has a primary voltage (Van, Vbn) of each phase with respect to magnitudes of the input voltages Va, Vbi, Vci, Vri, Vsi, Vti inputted from the voltage signal linker 130. , Vcn, Vrn, Vsn, Vtn) The ratio of the size of each phase of the phase characterized in that the test device for calibrating the measured voltage of the automatic switchgear distribution line. After applying the test voltage (Vs2) to the lead-out cable 13 of each phase of the automatic switchgear 15 of the distribution line 11 by using the test apparatus of any one of claims 1 to 3, the measurement means As a test method for calculating the factor to correct the magnitude and phase of the voltage,
A first step of the test voltage supplying unit (110) applying a test voltage (Vs2) to the lead-out cable (13) of each phase;
A second step of shorting one side of the switch (15-3) of each phase and maintaining a closed state while applying the test voltage (Vs2);
The divided voltage ratio X of the test voltage Vs2 is obtained by using the magnitudes of the first resistor 113 and the second resistor 114 included in the test voltage supply unit 110, and the factor generator 140 determines the reference voltage ( A third step of measuring Vref) and multiplying the partial pressure ratio X to obtain a magnitude of a test voltage Vs2;
A fourth step of measuring magnitudes of the input voltages Vai, Vbi, Vci, Vri, Vsi, and Vti inputted to the impedance matching circuit 140-2 of the voltage size adjusting factor generator 140;
And a fifth step of the factor generator 140 dividing the magnitude of the test voltage Vs2 by the magnitude of the input voltages Vai, Vbi, Vci, Vri, Vsi, and Vti of each phase. Test method using test equipment to calibrate measured voltage of automatic switchgear of distribution line. The method of claim 4, wherein
The partial pressure ratio (X) is

A test method using a test apparatus for correcting the measured voltage of the automatic switchgear of the distribution line, characterized in that defined by the equation. The method of claim 5,
The factor generator 140 is applied to the draw cable 13 for the magnitude of the input voltages Vai, Vbi, Vci, Vri, Vsi, Vti inputted from the voltage signal linker 130. A test method using a test apparatus for correcting the measured voltage of an automatic switchgear of a distribution line, characterized in that the ratio of the magnitude of the primary voltage (Van, Vbn, Vcn, Vrn, Vsn, Vtn) is defined as a factor of each phase. .

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