KR20030062951A - An apparatus for a trouble wire display of voltameter - Google Patents

Abstract

PURPOSE: An apparatus for diagnosing the line failure of an electronic measuring instrument is provided to output a failure signal so that the user recognizes the failure when the line is failed. CONSTITUTION: An apparatus for diagnosing the line failure of an electronic measuring instrument includes a voltage input block(10), a current input block(20), a plurality of noise filters(30(a) - 30(c)), a plurality of analog-to-digital(AD) convertor(40(a) - 40(c)), a power circuit(50), a signal processing block(60), a micro computer(70), a backup memory(80), a front display block(90), a communication block(100) and a monitoring system(110). In the apparatus, the backup memory(80) stores the reference value to determine the failure of the power circuit(50) and the front display block(90) displays the failure if the failure information is generated at the failure information generator. And, the communication block(100) transmits the failure information to outside when the failure information is generated at the failure information generator.

Description

An apparatus for diagnosing line failure of an electronic meter

The present invention relates to an apparatus for diagnosing line faults in an electronic meter, and more particularly, to an apparatus for diagnosing line faults in an electronic meter that can inform a user of line fault information when a line fault occurs.

Hereinafter, a general meter will be described.

1 is a configuration diagram of a general electricity meter and an earth leakage breaker.

As shown in the drawing, a power meter generally provided to a user's consumer is supplied with a single-phase two-wire power supply. In the distribution panel to which the power is connected, an electric power meter (4) for measuring the amount of electric power, an earth leakage circuit breaker (5) for quickly shutting off the power when a failure occurs due to short circuit, overload, short circuit, etc. in the customer; It comprises a load 1, 2 (1, 2) driven by the supplied power, and the switch 1, 2 (SW1, SW2) for switching control by separating the load 1, 2 (1, 2).

As shown in the installation configuration, the conventional power meter (4) is mostly used induction disc type analog type, but due to the development of digital technology, a more precise electronic electricity meter is introduced.

Hereinafter, a description of the configuration according to the prior art will be described based on the electronic meter which is a recent technology.

2 is a control block diagram of an electronic meter according to the prior art.

As shown in the figure, the electronic power meter includes a signal input unit 3 for receiving current and voltage signals from a single-phase two-wire power system, a power circuit 7 for supplying operation power, and an input from the signal input unit 6. Noise filters (8a, 8b) for removing noise components of the signal, AD converters (9a, 9b) for converting the analog value input to the wattmeter into a digital signal, and a signal processor for calculating the amount of power from the digital conversion signal 10, a microcomputer 11 for controlling the operation of the electricity meter 4 according to the amount of power processed by the signal processing unit 10, and a front display unit 12 for displaying the amount of power calculated by the signal processing unit 10. It is configured to include).

The front display unit 12 includes a pulsed LED 12 (a) for displaying a power amount using a light emitting diode element, a display LCD 12 (b) for displaying a power amount to a user through an LCD screen, and a power meter setting. Button 12 (c).

Looking at the connection relationship of the control configuration in detail as follows.

The signal input unit 3 mentioned above is composed of two resistors and one transformer. That is, resistor 1 (R1) and resistor 2 (R2) are connected in series, resistor 1 (R1) is connected to the N-phase input port, and resistor 2 (R2) is connected to the P-phase input port. In addition, the resistor 2 (R2) is connected to the first stage of the transformer (CT). The primary end ① of the transformer is also connected to the P-phase input terminal.

In addition, the N-phase and P-phase input terminals are respectively connected to the power supply circuit 7. That is, the first stage ② and the N-phase input terminal of the transformer CT are connected to the power supply circuit 7. Then, the second cut-off ② of the transformer CT is grounded.

Meanwhile, the noise filter 1 (8 (a)) is connected between the resistor 1 (R1) and the resistor 2 (R2). The second stage ① of the transformer CT is connected to the noise filter 2 (8 (b)).

The noise filter 1 (8 (a)) and the AD converter 1 (9 (a)) are connected to the noise filter 2 (8 (b)) and the AD converter 2 (9 (b)). The noise filters 1 and 2 are connected to the signal processor 10, and the signal processor 10 is connected to the microcomputer 11. The microcomputer 11 is connected to a pulsed LED 12 (a), a display LCD 12 (b), and a button 12 (c), which are configured in the front display unit 12, respectively.

The leakage of electric wires or electrical equipment (for example, deterioration, aging, carbonization, mechanical loss, etc.) and leakage of current through the conductive material such as metal is called leakage. As a result, when the leakage current flows in the vicinity of building materials such as wood or other combustible materials, the earth leakage material is generated by ignition of the combustible materials by the joule heat of the current leakage.

As shown in FIG. 1, when a short circuit as described above occurs in the load 1 (1), the earth leakage breaker operates in a short time, and a switch for switching and controlling the voltage / current supplied to the load 1 (1). Open 1 (SW1). At this time, voltage and current are supplied to the load 2 (2), and the load 2 (2) is driven. At the same time, it finds and repairs the power supply of the load 1 (1).

In the operation control as described above, it is necessary to periodically check to ensure the operation reliability of the closed earth leakage breaker under normal conditions. Therefore, press the test button of the earth leakage breaker to perform the operation test several times, and check periodically.

Hereinafter, the operation control process of the above-described control configuration will be described.

The voltage and current input to the electricity meter are transmitted to the signal input unit 6, and the signal input unit 6 transmits the voltage / current signals to the noise filters 8 (a) and 8 (b), respectively. Then, the noise filters 8 (a) and 8 (b) extract noises included in the input signal through the noise filters 8 (a) and 8 (b). At this time, the DC voltage and the like are removed together with the high frequency component from the voltage / current signal. In this way, the signal from which the noise is extracted is converted into a digital signal through the AD converters 9 (a) and 9 (b), and the signal converted into the digital signal is input to the signal processor 10.

The signal processor 10 transmits the digital signal to the microcomputer 11, and the microcomputer 11 controls the power meter 4 to be driven and to display the power amount according to the input signal. . Accordingly, the amount of power is displayed to the user of the consumer through the front display 12.

In the control process as described above, the digital signal passed through the AD converters 9 (a) and 9 (b) is transferred to the signal processor 10 through high speed sampling. At this time, the signal processor 10 calculates the amount of power using the following equation using the sampled voltage / current values.

[Equation]

The signal processing unit 10 calculates the amount of power using the above equation and transfers the amount of power to the microcomputer 11. Accordingly, the microcomputer 11 outputs pulses to the front display unit 12 according to the transferred amount of power data according to the number of pulses per KW / H, and also displays the amount of power on the front display LCD 12 (b).

Therefore, the prior art operating as described above has the following problems.

First, if a circuit breaker does not operate even if a failure occurs in a line in a consumer, this may cause a fire after a predetermined time elapses.

Second, when the leakage current flows below the non-operating current leakage for a long time, the user may not know, and in this case, a situation may later occur due to degradation of the leakage point.

Third, the earth leakage breaker operation due to the overload of the line and the earth leakage breaker operation due to the earth leakage of the line are not distinguished.

Accordingly, an object of the present invention is to provide an apparatus for diagnosing a line failure of an electronic meter that outputs a failure signal so that the user can recognize the failure of the track.

1 is a configuration diagram of a typical power meter and an earth leakage breaker.

2 is a control block diagram of an electronic meter according to the prior art.

3 is a control configuration diagram of the electronic meter in accordance with the present invention.

Figure 4 is a waveform diagram showing the current difference according to the leakage of the electronic meter in accordance with the present invention.

Explanation of symbols on the main parts of the drawings

10: voltage input unit 20: current input unit

30 (a) ~ 30 (c): Noise filter 40 (a) ~ 40 (c): AD converter

50: power supply circuit 60: signal processing unit

70: microcomputer 80: backup memory

90: front display unit 90 (a): pulse LED

90 (b): Display LCD90 (c): Button

100: communication unit 110: monitoring system

An apparatus for diagnosing a line failure of an electronic meter according to the present invention for achieving the above object is a power meter that detects a voltage and a current, calculates an amount of power, and displays the same, and is connected to an input terminal of a P phase to detect a current of the P phase. Current detecting means 1; Current detecting means 2 connected to an input terminal of the N phase and detecting a return current of the N phase; Memory means for storing a reference value for determining a failure of the electricity meter; The P phase current and the N phase current detected by the current detection means 1 and 2 are used to calculate a value for determining whether the fault is generated, and the fault value is generated by comparing the calculated value with a reference value stored in the memory means. Fault information generating means; Display means for displaying, when fault information is generated in the fault information generating means; When the fault information is generated in the fault information generating means, it comprises a communication means for transmitting this signal to the outside.

The memory means stores an electric leakage fault setting value at which an electric leakage breaker connected to the electricity meter is operated, and an electric leakage failure setting time, and wherein the fault information generating means has a leakage current calculated from a difference between the P phase current and the N phase current. And when the leakage fault of the leakage current is larger than the leakage fault set value stored in the memory means, the leakage fault alarm is generated.

The memory means stores a ground fault check set value set to a value relatively smaller than the ground fault fault set value and a ground fault check set time, and wherein the fault information generating means leaks calculated from a difference between the P-phase current and the N-phase current. An electric leak inspection alarm is generated when the current is larger than the electric leakage inspection set value and the leakage time of the leakage current is larger than the electric leakage inspection set time.

The memory means stores an overload set value for detecting an overload fault and an overcurrent alarm time, and wherein the fault information generating means, when the P-phase current is greater than the overload set value, and such a state has passed the alarm time, It is characterized by generating an overload failure alarm.

The memory means stores a short circuit fault setting value for detecting a short circuit fault, and the fault information generating means generates a short circuit fault alarm when the P-phase current is larger than the short circuit fault set value.

The stored value of the memory means can be changed by user adjustment.

The current detecting means 1, 2 includes a current transformer connected to the P-phase input terminal and the N-phase input terminal; A noise filter for removing noise from a current detected through the current transformer; And an analog / digital converter for converting the value of the noise filter into a digital signal.

The fault information generating means includes signal processing means for calculating a leakage current from an output of the analog / digital converter, and a microcomputer for comparing the value of the signal processing means with a value of the memory means to determine whether there is a fault. It is composed.

Hereinafter, the electronic meter according to the present invention will be described.

3 is a control block diagram of the electronic meter in accordance with the present invention.

As shown in the drawing, the control configuration of the electronic meter according to the present invention includes a voltage input unit 10 for receiving a voltage signal from a single-phase two-wire power system and a current input unit 20 for receiving a current signal from a single-phase two-wire power system. And a noise filter 1, 2, 3 (30 (a), for removing noise components of a signal input from the voltage input unit 10 and the current input unit 20) and a power supply circuit 50 for supplying operating power. 30 (b), 30 (c), AD converters 1, 2, and 3 (40 (a), 40 (b), 40 (c)) for converting analog values inputted into the electricity meter into digital signals, A signal processor 60 for calculating the amount of power from the digital conversion signal, a microcomputer 70 for controlling the power meter operation according to the amount of power processed by the signal processor 60, and the amount of power calculated by the signal processor 60 Front display unit 90 for displaying a fault signal and a back for storing setting information and cause of failure Up memory 80 and the communication unit 100 for connecting to the failure monitoring system 110 according to the failure signal is configured.

Here, the front display unit 90 includes a pulsed LED 90 (a) for displaying a power amount using a light emitting diode device, a display LCD 90 (b) for displaying a power amount to a user through an LCD screen, and a user. Includes a button 90 (c) for changing the set value. In addition, the power meter is configured to further include a monitoring system 110 for transmitting this through the communication unit 100, if a line failure occurs.

Looking at the connection relationship of the control configuration according to the invention shown in the drawings in more detail as follows.

The voltage and current of the N and P phases are input to the voltage input unit 10 and the current input unit 20, respectively. The voltage input unit 10 includes a resistor 1 (R1) and a resistor 2 (R2). The current input unit 20 includes a transformer 1 (CT1) and a transformer 2 (CT2).

The resistor 1 '(R1') and the resistor 2 '(R2') are connected in series, and between the resistor 1 '(R1') and the resistor 2 '(R2') is a noise filter 1 (30 (a)). Connected with The resistor 1 '(R1') is connected to the N-phase input terminal, and the resistor 2 '(R2') is connected to the P-phase input terminal.

The connection point of the resistor 2 '(R2') and the P-phase input terminal is connected to the first stage of the transformer 1 (CT1). ① of the second stage of the transformer 1 (CT1) is connected to the noise filter 2 (30 (b)), and ② of the second stage of the transformer 1 (CT1) is grounded. And the first stage ② of the transformer 1 (CT1) is connected to the power supply circuit (50).

In addition, the connection point of the resistor 1 '(R1') and the N-phase input terminal is connected to the first stage of the transformer 2 (CT2). The second stage ① of the transformer 2 (CT2) is connected to the noise filter 3 (30 (c)), and ② of the second stage of the transformer 2 (CT2) is grounded. And the first stage ② of the transformer 2 (CT2) is connected to the power supply circuit (50).

The noise filter 1 (30 (a) mentioned above is connected to the AD converter 1 (40 (a)), and the noise filter 2 (30 (b) is connected to the AD converter 2 (40 (b)). The noise filter 3 (30 (c)) is connected to the AD converter 3 (40 (c)), respectively. The noise filters 1, 2, and 3 are connected to the signal processor 60. The signal processor 60 is connected to the microcomputer 70, and the backup memory 80 is also connected to the microcomputer 70. In addition, the front display unit 90 constituted by the pulse LED 90 (a), the display LCD 90 (b), the button 90 (c), and the communication unit 100 also include the microcomputer 70 and the like. Connected. The communication unit 100 is connected to an external failure monitoring system 110.

Hereinafter, an operation control process that operates according to the control configuration of the electricity meter according to the present invention will be described.

As shown in FIG. 3, a voltage signal is detected while the signals input through the input terminals of the N and P phases pass through the resistors R1 'and R2'. The voltage detected by the voltage input unit 10 is sampled as a digital signal through an AD converter 1 (40 (a)) through a noise filter 1 (30 (a)) for removing high frequency noise and DC voltage. Is input to the signal processing unit 60.

The current signal is detected while the signal input through the input terminal of the P phase passes through the current transformer CT1. The detected P-phase current is sampled as a digital signal through the noise filter 2 (30 (b)) and through the AD converter 2 (40 (b)). The sampled data is input to the signal processor 60.

On the other hand, the signal input through the N-phase input terminal is passed through the current transformer 2 (CT2) of the current input unit 20, the current signal is detected. The detected N-phase current is sampled as a digital signal through the noise filter 3 (30 (c)) and through the AD converter 3 (40 (c)). The sampled data is input to the signal processor 60. The N-phase current is a value obtained by detecting a current value used and returned according to the driving of the system.

The voltage, the P-phase current, and the N-phase current thus detected are calculated by the signal processor 60 using the following equations to calculate the current, voltage, and power amount.

[Equation 2]

The data value calculated by the above equation is transferred to the microcomputer 70. The microcomputer 70 determines a failure through the transferred power, current, and voltage data, and controls the operation of the electricity meter. The operation result controlled by the microcomputer 70 is then displayed through the display LED 90 (a) and the display LCD 90 (b).

As the data value calculated by the signal processor 60 is transmitted to the microcomputer 70 in the control process as described above, the microcomputer 70 not only measures and displays the amount of power through the data, but also By detecting abnormal operation of the line of the electricity meter 4 as described above, the electricity meter 4 may be controlled and the line fault information may be notified to the user.

At this time, the operation control process for the microcomputer to recognize the abnormal operation of the electricity meter is as follows.

First, the microcomputer 70 may detect a failure of the electronic electricity meter according to the leakage current and control the notification to the user through the leakage current failure processing method.

That is, the magnitude of the current transmitted to the microcomputer 70 through the current transformer 1 (CT1) and the current transformer 2 (CT2) configured in the current input unit 20 returns to the P phase current in calculating the amount of power in the steady state. The difference of the N-phase current that comes is small compared to the rated current. When a short circuit occurs, as shown in FIG. 4, a current difference between the P phase current and the N phase current occurs. This is because the magnitude of the current returning to the N phase is reduced by the leakage current as shown in the following equation.

The leakage current may be expressed as follows.

Leakage current = P phase current-N phase current

Accordingly, the electronic watt-hour meter 4 processes the ground fault inspection alarm and the ground fault alarm in two steps according to the magnitude of the leakage current value to inform the user. In the microcomputer 70, a check alarm time and a fault alarm time which are generated in accordance with the leakage current value during the duration of the electric leakage of the electronic watt-hour meter are preset. Thus, a ground fault inspection alarm occurs when the leakage current is a value between two set points.

In the ground fault fault alarm, the ground fault breaker 5 operates. However, the ground fault interrupter does not operate in the ground fault check alarm. Therefore, the leakage current value detected in the ground fault fault alarm is such that the ground fault breaker 5 can be operated, and the leak current check alarm is smaller than this.

The ground fault inspection alarm time is determined when the leakage current value is continuously detected for a predetermined time, and the ground fault failure time is determined immediately after the leakage current value for the operation of the ground fault breaker is detected.

That is, the earth leakage check set point <leakage current <earth fault set point, (leakage current time> check alarm time)

When the overload failure alarm occurs, it is stored in the backup memory 80 of the electronic electricity meter 4 for alarm history management, and the microcomputer 70 displays the alarm through the front display unit 90 and controls the buzzer to sound. do. In addition, the alarm content is transmitted to the failure monitoring system 110 for communication. The alarm contents transmitted to the failure monitoring system 110 are stored in a hard disk and generate an alarm to a manager or a user through a screen or a buzzer, and notify the alarm contents through the Internet.

On the other hand, a failure occurs due to a short circuit of the electronic watt-hour meter 4, which occurs when the leakage current is higher than the ground fault setting value and the ground fault state is maintained for the ground fault failure time or more.

That is, leakage current> leakage fault alarm set value, (leakage current duration> fixed alarm time)

And when the leakage fault alarm is generated, it is stored in the backup memory 80 of the electronic electricity meter for the alarm history management, the microcomputer 70 controls to display an alarm and sound a buzzer through the front display unit (90) do. It also transmits the alarm content to the failure monitoring system 110 for communication. The alarm contents transmitted to the failure monitoring system 110 are stored in the hard disk and generate an alarm to the administrator or the user through a screen or a buzzer, and notify the alarm contents through the Internet.

The fault handling notification process according to the leakage current flowing through the electronic power meter has been described.

Second, the microcomputer may detect a failure due to an overload of the electronic electricity meter and notify the user of the failure through an overload failure processing method.

In case of an overload failure, unlike a ground fault, it is generated by using more load than expected load in the customer, so it must be classified and alarmed. The electronic electricity meter generates an overload alarm when the P-phase current value is larger than the overload setting value (about 1.2 times of the maximum operating current value) as shown below, and maintained over the overload setting time.

That is, phase current> overload alarm set value, (overcurrent duration time> overcurrent alarm time)

When the overload failure alarm occurs, it is stored in the backup memory 80 of the electronic electricity meter 4 for alarm history management, and the microcomputer 70 displays the alarm through the front display unit 90 and controls the buzzer to sound. do. It also transmits the alarm content to the failure monitoring system 110 for communication. The alarm contents transmitted to the failure monitoring system 110 are stored in a hard disk and generate an alarm to a manager or a user through a screen or a buzzer, and notify the alarm contents through the Internet.

Third, the microcomputer 70 controls the electronic power meter 4 to detect a short circuit failure of the line and notify the user of the short circuit failure process.

In the case of a short circuit, it is several times the normal operating current. As a result, a large current may occur, and if the cause of the failure is not solved, it may spread to a large failure. Therefore, it should be known to the administrator or user in a short time.

Accordingly, the processing of the short circuit failure in the electronic power meter 4 controls the microcomputer 70 to generate a short circuit failure alarm if the input P-phase current value is larger than the preset short circuit failure set value. At this time, the short circuit fault alarm is determined and executed immediately after detecting the short circuit fault set value.

In summary, the magnitude of the current value is in the order of short circuit failure set point> overload set point> ground fault check set point> ground fault check alarm set point, and the short circuit fault set point and overload set point are measured through P phase current, and the ground fault check set point And earth leakage check alarm set point are measured by leakage current. The short circuit fault setting time and the short circuit fault setting time can be determined immediately after detection, and the overload setting time and the short circuit checking alarm time are determined after a predetermined time elapses.

As described above, in order for the microcomputer to recognize whether the state of the electronic electricity meter is in a normal state or an abnormal state, a predetermined reference value should be set. Therefore, a reference value should be set for comparison with the measurement value generated according to each state (eg, ground fault alarm, ground fault, overload failure, short circuit failure, etc.). To do this, the reference value is input and set using a button configured on the front display unit. The reference value at this time is set to an optimal value based on the experimental value.

That is, the set values which are the criteria for determining the line fault of the customer include the leakage inspection set value, the leakage inspection set time, the leakage failure set value, the leakage failure set time, the overload set value, the overcurrent alarm time and the short circuit failure set value. These settings are set using the buttons provided on the front display at the site where the electronic wattmeter is installed.

As described above, according to the present invention, when a line fault, that is, a short circuit check, a short circuit failure, an overload failure, a short circuit failure, or the like is detected in the electronic watt-hour meter, it is a basic technical idea to notify the user of the failure.

In addition, it is possible to set / reset the default setting value for detecting the failure through a button provided on the front display or to change the setting value through a communication device at a long distance.

The rights of the present invention are not limited to the embodiments described above, but are defined by the claims, and those skilled in the art can make various modifications and adaptations within the scope of the claims. It is self-evident.

Therefore, the following effects can be expected due to the present invention.

First, the leakage current which is not detected by the ground fault interrupter may be prevented from being deteriorated due to a failure in the future by preventing deterioration of the wire which may occur when the leakage current lasts for a long time.

Second, if the earth leakage breaker detects a short circuit but does not operate due to a mechanical defect, it may notify the administrator or user of the short circuit failure.

Third, the earth leakage breaker generates an alarm by distinguishing an overload fault that is difficult to distinguish and handle, and thus serves as a criterion for determining the cause of operation when the earth leakage breaker is operated by an overload.

Fourth, it is a standard for judging the cause of operation when operating the circuit breaker by short circuit because it generates alarm by classifying short circuit failure which is difficult to classify and handles the circuit breaker.

Accordingly, as a result, the user using the product according to the present invention having the above effects can maximize satisfaction with the product.

Claims (8)

In the electricity meter that detects the voltage and current to calculate the amount of power and displays it, Current detecting means 1 connected to an input terminal of the P phase and detecting a current of the P phase; Current detecting means 2 connected to an input terminal of the N phase and detecting a return current of the N phase; Memory means for storing a reference value for determining a failure of the electricity meter; The P phase current and the N phase current detected by the current detecting means 1 and 2 are used to calculate a value for determining whether the fault is generated, and the fault value is generated by comparing the calculated value with a reference value stored in the memory means. Fault information generating means; Display means for displaying, when fault information is generated in the fault information generating means; And a communication means for transmitting this signal to the outside when the failure information is generated in the failure information generating means. The method of claim 1, The memory means stores a ground fault setting value and a ground fault setting time at which the ground fault breaker connected to the electricity meter is operated. The fault information generating means, when the leakage current calculated from the difference between the P-phase current and the N-phase current is larger than the leakage fault setting value stored in the memory means, the leakage fault is greater than the leakage fault setting time. An apparatus for diagnosing line failure of an electronic meter, comprising generating an alarm. The method of claim 2, The memory means stores a ground fault check set value and a ground fault check set time set to a value relatively smaller than the ground fault fault set value, The fault information generating means generates a ground fault inspection alarm when the leakage current calculated from the difference between the P-phase current and the N-phase current is larger than the leakage current check set value, and the leakage time of the leakage current is larger than the ground fault check set time. A device for diagnosing line failure of an electronic meter. The method of claim 1, The memory means stores an overload setpoint and an overcurrent alarm time for detecting an overload fault, And wherein the fault information generating means generates an overload fault alarm when the P-phase current is greater than the overload set value and this state has elapsed the alarm time. The method of claim 1, The memory means stores a short circuit fault setting value for detecting a short circuit fault. And the fault information generating means generates a short circuit fault alarm when the P-phase current is larger than the short circuit fault set value. The method of claim 1, And a stored value of the memory means is changeable by user control. The method of claim 1, The current detecting means 1, 2, A current transformer connected to the P-phase input terminal and the N-phase input terminal; A noise filter for removing noise from a current detected through the current transformer; And an analog / digital converter for converting a value of the noise filter into a digital signal. The method of claim 7, wherein The fault information generating means, Signal processing means for calculating a leakage current from an output of the analog / digital converter; And a microcomputer for comparing a value of the signal processing means and a value of the memory means to determine whether there is a failure.