KR20100048736A - Electric power meter having function for sensing mis-wiring and control method thereof - Google Patents

Abstract

PURPOSE: By preventing the error of operator and rapidly dealing with the error wiring and trouble occurrence the electronic type watt-hour-meter and control method can seclude the civil application induction. CONSTITUTION: It is connected to the voltage signal and the power supply unit(1) offers the electronic type watt-hour-meter drive power. It is connected to the voltage signal and current signal and the wattmeter side(2) changes the micro voltage and current signal. Whether according to the watt hour meter rating the normal range or not CPU decides.

Description

Electric power meter having function for sensing mis-wiring and control method

The present invention relates to the field of wattmeters, and more specifically, in order to prevent erroneous metering or instrument failure due to erroneous wiring between the electrical wiring and the wattmeter terminal block inadvertently due to the operator's carelessness when installing or replacing the wattmeter. The present invention relates to an electronic wattmeter having a miswiring detection function and a control method thereof.

Currently, 17.5 million electricity meters are installed in Korea. Among them, about 148,000 high-voltage electricity meters are mostly installed as electronic electricity meters, and about 400,000 of the remaining low-voltage electricity meters are installed as electronic electricity meters. More than 1.7 million units are installed as mechanical meters. KEPCO plans to replace all of the low-voltage mechanical meters by 2015.

Currently, the electricity meter installed / installed in KEPCO uses unidirectional electricity meter to measure power received from the customer's point of view. In order to install the electricity meter, it is structured to connect to the electricity meter input terminal through the inlet distribution line and to the load of the customer side at the electricity meter output terminal. All of the electricity meter installation is performed manually by the field worker.

In the process of laying the electricity meter, the wiring connection is not made correctly and the wiring is incorrect or remains open due to the carelessness of the worker and the deterioration of concentration due to the poor environment of the field environment where the electricity meter is located. . In particular, there is a high possibility of incorrect wiring in the electricity meter installed in a three-phase four-wire receiving customer using relatively high power rather than a single-phase two-wire type.

Conventional electricity meters do not display information about incorrect wiring, so it is not easy to check even if such a wiring error occurs during the wiring of the site worker.

This misleading effect can lead to 'under-weigh' or 'over-weigh', even when the weighing value is 'zero'. In the single-phase two-wire type, in the case of reverse connection where the wiring between input terminal and output terminal is changed, it has [-] power value. When the meter is integrating the power amount, the relevant regulations such as production purchase specification [-] Since the power value is not included as the amount of power, it is not measured. In the three-phase four-wire system, when one phase of the power meter output unit is inversely connected to the symmetrical phase of the input unit, as in the single-phase two-wire system, it has a [-] power value to perform non-metering. Due to the cross wiring between wires, the power value of each phase has a [-] value or a lead value, which leads to incorrect metering.

In this case, if the measurement of power generation usage is abnormal or not measured due to the wiring error, under- or non-measurement causes not only large economic loss from the perspective of KEPCO, which is a utility company, but also many cases of customer dissatisfaction in the rate calculation. There is a problem that complaints frequently occur.

Therefore, the miswiring problem of the electricity meter is a major issue of the installation and management department of the electricity meter, and preventive measures are urgently required.

An object of the present invention is to solve the conventional problems as described above, by comparing the phase of the voltage and current from the power meter's own input terminal terminal by the wattmeter rating, such as single-phase, three-phase, three-wire, three-phase four-wire wattmeter Determination of wiring status and instrument breakdown, and the error and fault information is stored in the internal memory and displayed on the LCD attached to the electricity meter and the alarm is triggered by the alarm speaker. It is to provide a power meter and a control method thereof.

Another object of the present invention, in the initial installation of the electricity meter according to the new electricity supply of the customer side and to prevent the malfunction of the electricity meter due to the incorrect wiring of the wiring when replacing the electricity meter to determine the miswiring function by rating and rating The present invention provides an electronic power meter having a miswiring detection function and a method of controlling the same, informing a field worker of error information, such as displaying an LCD display device and generating an alarm to an alarm device.

As a means for achieving the above object, the configuration of the apparatus of the present invention is connected to a voltage signal and provides a power supply unit for providing an electric power meter driving power source, and is connected to a voltage signal and a current signal, and provides a small voltage and current signal. Power measuring unit converts analog signal to digital signal using D converter and outputs it, and whether it is normal range (single phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less) In case of abnormal state through judging and comparing with phase discrimination, CPU for displaying incorrect wiring information by judging incorrect wiring by rating of power meter, and outputting control signal to generate alarm, LCD connected to the CPU and And a speaker connected to the CPU and a memory connected to the CPU.

The configuration of the apparatus of the present invention is preferred if it further comprises an operation switch for stopping the alarm sound.

In the configuration of the apparatus of the present invention, it is preferable that the CPU stores the miswiring information related to the occurrence time of the miswiring, the phase difference associated with the miswiring, the magnitude of each current vector, and the like in the memory.

It is preferable that the configuration of the device of the present invention is that the CPU has a function of setting an alarm generation time for alarm generation.

As a means for achieving the above object, the configuration of the method of the present invention comprises the steps of determining and comparing the phases of each phase by measuring the phases of each phase in the CPU of the electricity meter when the operation is started, and the normal range (single phase 2) Wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less), and if it is determined to be normal, display 'normal' through the LCD, and If it is determined, store the wiring information in the memory and generate an abnormal alarm and display 'unusual status' through the LCD, and if the alarm sound is recognized by the on-site worker and the alarm stop switch is operated. Judging; determining whether the alarm sound setting time has been exceeded when the alarm is not recognized; and stopping the alarm sound when the alarm is recognized or the alarm setting time is exceeded. It comprise.

This invention prevents workers' errors when connecting electricity meters, and promptly responds to incorrect wiring and failures to block civil complaints caused by incorrect or unmetered measures, and unnecessary manpower and waste of work occur according to the rate agreement for employees in the company. It is effective to avoid.

In addition, the present invention has the effect of contributing to the improvement of the inefficiency of not receiving a proper electricity bill when calculating the electricity bill by the rate agreement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings in order to describe in detail enough to enable those skilled in the art to easily carry out the present invention. . Other objects, features, and operational advantages, including the object, operation, and effect of the present invention will become more apparent from the description of the preferred embodiment.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred embodiment in order to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment Rather, various changes, additions, and changes are possible within the scope without departing from the spirit of the present invention, as well as other equivalent embodiments.

1 is a block diagram of an electronic wattmeter with a miswiring detection function according to an embodiment of the present invention.

As shown in FIG. 1, the configuration of an electronic wattmeter having a miswiring detection function according to an embodiment of the present invention includes: a power supply unit 1 connected to a voltage signal and providing an electronic wattmeter driving power supply; A power measurement unit (2) connected to a signal and a current signal and converting a minute voltage and current signal from an analog signal to a digital signal using an A / D converter, and an operation switch (3) for stopping an alarm sound; In case of abnormal state by comparing with phase discrimination by determining whether it is the normal range (single-phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less) by power meter rating, CPU 4 for outputting a control signal for generating an alarm by judging the connection and displaying an incorrect wiring information, an LCD 5 connected to the CPU 4 described above, and a connection to the CPU 4 described above. Speaker 6 and CPU 4 described above It comprises a memory (8) connected to.

The CPU 4 has a structure having a function of setting an alarm generation time for alarm generation.

2 is a flowchart illustrating a method of controlling an electronic wattmeter having a miswiring detection function according to an embodiment of the present invention.

As shown in FIG. 2, the control method of the electronic wattmeter with a miswiring detection function according to an embodiment of the present invention includes a step S1 at which operation is started and phases of phases in the CPU of the wattmeter. Step (S2) of measuring the phase, and determining and comparing phases of each phase (S3), and the normal range (single-phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° by power meter rating) Step (S4), and if it is within the phase range set for each wattmeter rating (S5), the step of displaying a 'normal state' through the LCD (S6), and for each wattmeter rating If it is out of the set phase range is determined as a miswiring (S7), storing the miswiring information in the memory (S8), generating a 'abnormal alarm' (S9), and 'abnormal through the LCD State (S10) and the alarm sound by the on-site worker Determining whether the alarm sound stop switch has been operated (S11), determining whether the alarm sound setting time has been exceeded when the alarm is not recognized (S12), and when the alarm is recognized or the alarm setting time has been exceeded. And stopping the alarm sound (S13), and terminating the operation (S14).

According to the above configuration, the operation of the electronic wattmeter with a miswiring detection function according to an embodiment of the present invention and a control method thereof are as follows.

The voltage and current signals are supplied to the CPU 4 through the power supply unit 1, and the voltage and current signals are converted into digital values through the power measurement unit 2 and transmitted to the CPU 4 as pulse values.

When power is applied and operation starts (S1), the CPU 4 of the electricity meter measures phases for each phase by using a signal input from the power measurement unit 2 (S2).

While determining and comparing the measured phases of each phase (S3), the CPU 4 judges whether the normal range (single-phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less) for each power meter rating. (S4). At the same time, the CPU 4 performs processing such as power amount calculation, power factor calculation, pulse accumulation, and the like, and displays the power amount, the accumulated power amount, and the power factor value through the LCD 5.

Next, the CPU 4 determines to be normal when it is within a phase range set for each power meter rating (S5), and displays the 'normal state' through the LCD 5 (S6).

However, when the phase range set for each wattmeter rating is out of range, the CPU 4 determines that it is a miswiring (S7), and displays miswiring information related to the occurrence time of the miswiring, the phase difference with respect to the miswiring, and the magnitude of each current vector. The memory 8 is stored in the memory 8 for a specific time (S8) and the 'abnormal alarm' is generated through the speaker 6 (S9), and the 'abnormal state' is displayed on the LCD 5 (S10).

The range of phase angle in normal connection when comparing and discriminating the phase of voltage and current for each power meter rating is as follows.

① Single phase, three phase four wire power meter: 0 ° <phase angle <± 90 °

② 3-phase 3-wire power meter: 0 ° <phase angle <± 60 °

This will be described in more detail with reference to the drawings.

Figure 3 shows a vector diagram for each phase in the normal measurement of the three-phase four-wire watt-hour meter. In FIG. 3, all three phases such as a phase (10, 13), b phase (11, 14), and c phase (12, 15) are determined as normal measurements because the phase difference (θ1, θ2, θ3) is within 90 °. . It can be seen that all three phases show the ground lagging of the current phase, and that the angle (120 °) of each phase current vector is constant and the size is uniform to form a phase equilibrium. That is, when the imaginary line 17 is drawn at a position of ± 90 ° with respect to U1 (10), if it is located within ± 90 ° of the left and right sides of U1 (10), it may be determined as a normal measurement. In addition, in the case of U2 (11), since the phase difference is within ± 90 ° based on U2 (11), it can be determined as a normal connection. However, when the phase difference is 90 ° or more, it occurs when the wiring is incorrect. In other words, the region 18 located within ± 90 ° of the left and right sides of the U1 10 with respect to the phase a becomes the normal measurement range. In addition, when the phase of the current is within ± 90 ° (18) with respect to the imaginary line 17 located at ± 90 ° with respect to U1 (10), the apparent power value (kVA) is [+] power value (10). In other words, it means that the power is integrated with the power receiving power. On the contrary, when it is out of the range of ± 90 °, it has a [-] power value 16, which means transmission power. That is, quadrant I and quadrant IV represent a power reception state, and quadrant II and III represent a power transmission state. However, the electronic electricity meter actually used does not count because the [-] value, which is the state of transmission, is not integrated. In the case of the single-phase two-wire watt-hour meter, as in the three-phase four-wire type, when the phase difference is within ± 90 °, it is a normal connection.

Figure 4 shows the phase vector diagram during normal metering of the three-phase three-wire watt-hour meter. In FIG. 4, all three phases such as a phase (20, 23), b phase (21, 24), and c phase (22, 25) are determined as normal measurements because the phase difference (θ1, θ2, θ3) is within 60 °. . All three phases show the Lag that the phase of current is inferior, and when the imaginary line 27 is drawn at a position of ± 60 ° based on the voltage vector U1 (20) of a phase, the left and right ± If it is located within 60 ° (28), it can be judged as normal measurement. Also, in the case of phase b, since the phase difference is within 60 ° based on the voltage vector U2 (21), it can be determined as a normal connection. However, when the phase difference is 60 ° or more, it occurs when the wiring is incorrect.

FIG. 5 shows a vector diagram of each phase in which the electricity meter is abnormally operated when the load side output terminals L1 and L2 of the electricity meter are cross-wired. In FIG. 5, when the output terminals L1 and L2 of the electricity meter are cross-connected, that is, incorrectly connected, the current vectors of the voltage vector U1 (30) and the voltage vector U2 (31) of the phase A are interchanged with each other. I1 33 is close to U2 31, and current vector I2 34 on b is close to U1 30. Accordingly, when the wiring on the load side is incorrectly cross-connected, as shown in FIG. 5, the I1 33 has an angle θ1 greater than 60 ° with the U1 30, so that it may be determined to be an abnormal situation. Since I2 34 also has a lead current at a phase angle θ2 of [-] as well as exceeding 60 °, an abnormal situation can be easily determined. On the other hand, it can be seen that the phase vector θ3 of the voltage vector 32 and the current vector 35 of the c phase that is normally connected is normal within 60 °.

On the other hand, when the field operator recognizes the alarm sound generated from the speaker 6 to stop the alarm through the alarm sound stop operation switch 3 to stop the alarm sound.

The CPU 4 uses the signal input from the operation switch 3 to determine whether the alarm sound is recognized by the field operator and the alarm sound stop switch is operated (S11).

If the alarm is not recognized, the CPU 4 judges whether the alarm sound setting time has been exceeded (S12), and maintains the alarm operation when the alarm sound setting time is not exceeded.

However, when the alarm is recognized by the field operator or the alarm setting time is exceeded, the alarm sound is stopped (S13) and the operation is terminated (S14).

By receiving incorrect wiring information from the electricity meter itself, the operator can greatly reduce the inspection time and reduce the number of equipment to be prepared by the on-site worker, so the work efficiency is very excellent and much more than the inspection cost by the separate inspection device. It can be implemented at low cost.

In addition, the present invention can be implemented in all KEPCO low-voltage and high-voltage electronic electricity meter and civilian electricity meter, thereby preventing the occurrence of civil complaints due to incorrect wiring early and economic value in terms of improving work efficiency of the relevant staff and related departments. Is very high. In addition, the incorrect wiring information is displayed through the LCD attached to the electricity meter and an alarm is generated through the alarm speaker so that the on-site worker rechecks the incorrect wiring to promote the normal operation of the metering device. Can be blocked early.

1 is a block diagram of an electronic wattmeter with a miswiring detection function according to an embodiment of the present invention.

2 is a flowchart illustrating a method of controlling an electronic wattmeter having a miswiring detection function according to an embodiment of the present invention.

Figure 3 shows a vector diagram for each phase in the normal measurement of the three-phase four-wire watt-hour meter.

Figure 4 shows the phase vector diagram during normal metering of the three-phase three-wire watt-hour meter.

FIG. 5 shows a vector diagram of each phase in which the electricity meter is abnormally operated when the load side output terminals L1 and L2 of the electricity meter are cross-wired.

Explanation of symbols on the main parts of the drawings

1: power supply unit 2: power measurement unit

3: switch for operation 4: CPU

5: LCD 6: Speaker

8: main memory

Claims (6)

A power supply unit connected to the voltage signal and providing an electric power meter driving power source; A power measurement unit connected to a voltage signal and a current signal and converting a minute voltage and current signal from an analog signal to a digital signal using an A / D converter; Operation switch for stopping the alarm sound, Determination of the normal range (single-phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less) by power meter rating. A CPU for judging the error information, indicating incorrect wiring information, and outputting a control signal for generating an alarm; LCD connected to the above CPU, A speaker connected to the above CPU, An electronic power meter having a miswiring detection function, comprising a memory connected to the CPU. The method of claim 1, Electronic electricity meter with a mis-wiring detection function characterized in that it further comprises a switch for operation for stopping the alarm sound. Electronic electricity meter with a mis-connection detection function, characterized in that comprises. The method according to claim 1 or 2, The CPU is an electronic power meter having a misconnection detection function, characterized in that for storing the misconnection information related to the occurrence time of the misconnection, the phase difference related to the misconnection, the magnitude of each current vector, and the like. The method according to claim 1 or 2, The CPU is an electronic power meter having a mis-wiring detection function, characterized in that it has a function to set the alarm occurrence time for the alarm. When the operation is started to determine the phase of each phase by measuring the phase of each phase in the CPU of the electricity meter, and Determining whether the power meter is in the normal range (single-phase 2-wire and 3-phase 4-wire: ± 90 ° or less, 3-phase 3-wire: ± 60 ° or less); If it is determined to be normal, displaying the "normal state" through the LCD; If it is determined that the wiring is incorrect, store the wiring information in memory and generate an abnormal alarm, and at the same time, display the abnormal status on the LCD. Determining whether an alarm sound stop switch is activated by an on-site worker, Determining whether the alarm sound setting time has been exceeded when the alarm is not recognized; The control method of the electronic watt-hour meter with a mis-wiring detection function comprising the step of stopping the alarm sound when the alarm is recognized or the alarm setting time is exceeded. The method of claim 5, The miswiring information includes a generation time of the miswiring, a phase difference related to the miswiring, and a magnitude of each current vector.

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