KR100443824B1 - Watt-hour meter that having electronic and mechanical display device - Google Patents

Abstract

PURPOSE: A power meter comprising an electronic and mechanical display unit is provided, which checks power metering data using a mechanical digit display when power failure occurs a voltage is not supplied. CONSTITUTION: A current transformer(2) is installed on a low voltage power line(1) and is connected to a current detector of a signal detection unit(10). The signal detection unit detects signals from the current transformer and the low voltage power line. A controller(20) includes an A/D conversion unit converting signals from the signal detection unit into digital signals, and a calculation and memory unit calculating and storing converted data, and a serial communication interface exchanging data with a microprocessor unit(40). The micro processor unit controls a system with an embedded data communication program, and controls to display data by being connected to a display unit(50) and a mechanical digit display(60). The display unit displays data to the external. And a power line communication modem unit(30) transmits and receives a transmission command and the stored data through the low voltage power line by power line communication.

Description

Watt-hour meter that having electronic and mechanical display device

SUMMARY OF THE INVENTION The present invention provides an electronic watt-hour meter incorporating a power line communication modem installed in a consumer, comprising an electronic and mechanical display device including a mechanical numeric display to read data on electricity usage even in the event of a power failure or fire. It relates to a meter.

In general, the electricity supplier installs a electricity meter in the customer's building to quantify the amount of electric energy used by the consumer, and the meter of the electricity supplier periodically reads the electricity meter.

The above-mentioned electricity meter has mainly used a mechanical electricity meter, but in recent years, as the power generation of the industry and electricity consumption increase, the electricity meter can calculate information such as power factor and effective power amount, store metering information for each time zone, and also remotely Electronic meter is used with various functions such as meter reading.

In the conventional mechanical wattmeter, when a power is supplied, a moving magnetic field is generated by a magnetic flux generated in a coil, and when a vortex is formed through a rotating disk, the rotating disc rotates by a magnetic force generated by the combination of magnetic flux and vortex. As a result, the mechanical counter is linked to display the amount of power consumed.

However, if the center of rotation is deflected due to the wrong installation of the rotating disc, the mechanical precision is easily degraded, so that accurate measurement values are not transmitted to the mechanical counter.

An inverted watt-hour meter has been proposed to solve this problem, and the driving unit for measuring the amount of power is made electronically, and a numerical indicator indicating the measured amount of power is configured mechanically. This eliminates the need for a separate memory device or power failure compensation battery to store the measured values.

However, since the numeric display is mechanical, there is a problem in that it cannot collect or display multiple information related to the electricity meter and the transformer.

In addition, in the conventional electronic watt-hour meter, the amount of power consumed is measured and calculated by a digital circuit and displayed numerically on the liquid crystal display.

However, since the number displayed on the LCD is black, it is difficult to find out easily when the meter is installed in the dark or at night, and when the electricity is not supplied due to a power failure or accident, the meter is weighed on the LCD. There is a problem that cannot be read because the value does not appear.

Therefore, in order to solve the above problems, an electronic watt-hour meter having a check function of weighing data at the time of power failure as shown in FIG. 1 has been proposed.

The configuration and operation of the electronic watt-hour meter having the measurement data checking function at the time of power failure will be described in detail with reference to FIG. 1 as follows.

The electronic wattmeter uses a battery for power failure compensation to provide a switch input circuit, a power monitoring circuit, and a program that can display the weighing data on the liquid crystal display even in the event of a power failure, so that the measured value can be checked at the time of reading even in the event of a power failure. Can be.

The electronic electricity meter is largely comprised of a power circuit unit 120, a power / frequency conversion unit 130, a digital circuit unit 140, an external output unit 150.

The power circuit unit includes a power transformer 121, a power circuit 122, and a power failure compensator 123. The power transformer 121 receives power from the low voltage power line 1 and drops an AC voltage to output the power. Power supply circuit 122, the power supply circuit 122 rectifies the input AC voltage to supply power to each circuit, the power failure compensation unit 123 to maintain various data and electronic clock of the meter during power failure It is an auxiliary power supply circuit.

The power / frequency converter 130 includes a voltage signal converter 131, a current signal converter 132, a multiplier 133, and a frequency converter 134. Detects the voltage and the current through the multiplier 133 and the frequency converter 134 and converts it into an electrical signal that can be used in the central processing unit 141.

The digital circuit unit 140 includes a central processing unit 141, an oscillation circuit 142, an EEPROM 143, an operation switch 144, an external control signal output unit 145, and a power monitor. And a frequency output from the frequency converter 134 is applied to the central processing unit 141, and the oscillating circuit 142 is used as an oscillator necessary for the central processing unit 141 to operate. 143 is used to store the weighing data calculated and calculated in the central processing unit 141, the operation switch 144 is used as the input of information required by the instrument, such as time, date, external control signal output unit 145 Is a signal output unit for remote meter reading or blocking of load. The power monitoring circuit 146 monitors the state of AC power so that the central processing unit 141 can operate in a power saving mode during a power failure. Extends life

The external control signal output unit 145 is configured as a liquid crystal display, and is controlled by the central processing unit 141 and displays the operation state and metering data of the electronic power meter.

However, the electronic wattmeter has a problem in that the meter reading data cannot still be checked when the LCD breaks or becomes inoperable due to an accident such as a fire or a natural disaster such as flooding.

In addition, a battery for power failure compensation should be provided, and accordingly, the structure is complicated, and thus a manufacturing cost is high and it is difficult to be commercialized.

Accordingly, the present invention has been proposed to solve the problems of the above-mentioned prior arts, and enhances the function of the electronic wattmeter, which is a built-in power line communication modem, so that the measured value is not supplied when a power failure or voltage is not supplied. It is an object of the present invention to provide a watt-hour meter that can check meter reading data even when it cannot be confirmed.

In particular, the present invention has the advantage that even if the liquid crystal display breaks down due to fire or natural disaster, or the state cannot be identified, the weighing data can be read by a mechanical numeric display.

In addition, the present invention does not use a separate memory device or a battery for compensating for power failure to maintain the measured value during power failure to provide a power meter having an electronic and mechanical display device that can reduce the manufacturing cost and facilitate the design will be.

1 is a block diagram of a conventional electronic wattmeter with a measurement data check function during a power failure.

2 is a block diagram of a wattmeter having an electronic and mechanical display device to which the present invention is applied.

※ Explanation of code about main part of drawing ※

1: low voltage power line 2: current transformer

3: Current transformer 4: Load switch

5: switching power unit 10: signal detection unit

11: breaker / switchgear open / closed state detection unit 12: zero cross detector

13: voltage detector 14: current detector

15: leakage / conduction detector 20: control unit

21: A / D converter 22: operation and memory

23: central processing unit 24: serial communication interface

30: power line communication modem unit 31: line coupler

32: power amplifier 33: carrier amplifier

34: Carrier Controller 35: Filter and Amplifier

40: microprocessor unit 41: central processing unit

42: carrier oscillator 43: serial communication interface

50: display unit 51: LCD driver

52 LCD display 120 power circuit

130: power / frequency converter 140: digital circuit

150: external output unit

In order to solve the above technical problem, the present invention provides an electric power meter having a built-in power line communication modem and receiving a signal from an image current transformer to detect a short circuit / conduction. The present invention relates to a watt-hour meter having an electronic and mechanical display device having a function of reading and checking.

The present invention is installed on a low voltage power line and an image transformer connected to the leakage / conduction detector of the signal detection unit, a current transformer installed on the low voltage power line and connected to the current detector of the signal detection unit, a low voltage power line is installed on the breaker / switchgear open state detection unit A load switch connected to the controller, a signal detector for detecting various electrical signals, converts the signal value output from the signal detector into a digital signal, and calculates, calculates, and stores the converted data. A microprocessor unit for controlling the system and controlling the display of the various data connected to the display unit and the mechanical number display device by a built-in control unit connected to the control unit, and a data communication program for data communication in both directions. The data processed by the processor unit And a display unit for displaying the data, a mechanical numeric display unit for displaying the above data externally, and a power line communication modem unit for transmitting and receiving the data transmission command of the upper data concentrator and the stored data through power line communication through a low voltage power line. It is characterized by.

In particular, the core of the present invention by connecting a mechanical numeric display in addition to the LCD display unit to the central processing unit of the microprocessor unit mechanically displays the measured amount of power even when the LCD display device does not operate due to an accident such as a power outage or fire It is in the configuration which can read and confirm the amount of electricity.

The mechanical number display generates a moving magnetic field by the magnetic flux generated from the coil when the power is supplied, and the moving magnetic field is rotated by the magnetic force generated by the combination of the magnetic flux and the vortex when the vortex is formed through the rotating disk. The mechanical counter is linked to display the amount of power consumed.

According to the present invention, a signal required by a power meter is detected using a signal detector, and then the signal detected by the signal detector is input to an A / D converter of the controller, converted into a digital signal, and then calculated through the serial communication interface of the controller. The memory unit calculates, calculates and stores the operation data of the low voltage power line and the transformer using the received signals and transmits the data to the microprocessor unit using the serial communication interface.

The microprocessor sends the data transmitted from the control unit to the central processing unit through the serial communication interface, and the central processing unit drives the LCD driving unit of the display unit to display the data on the LCD display unit. It is also sent to the indicator for external verification, and it makes data suitable for data communication and transmits it to the power line communication modem unit.

The power line communication modem unit transmits data received from the microprocessor unit by a transmission command of an upper data concentrator.

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention configured and operated as described above are as follows.

FIG. 2 is a block diagram of an electronic power meter capable of detecting a conductivity to which the present invention is applied.

The present invention includes a current transformer 2 and an associative current transformer 3 installed on the low voltage power line 1 to measure a signal, a signal detector 10 to detect a signal measured on the low voltage power line 1, and the signal. A control unit 20 which calculates, calculates and stores a signal value output from the detection unit 10, and transmits the signal value to the microprocessor unit 40, and transmits commands and stored data of a higher data concentrator (not shown) to the low voltage line. (1) is connected to transmit and receive power line communication modem unit 30, which transmits and receives power line communication via power line communication, and transmits and receives data to and from power line communication modem unit 30 and control unit 20. A microprocessor unit 40 having a communication program for data communication by embedding data therein, a display unit 50 connected to the microprocessor unit 40 to display meter reading data from the outside using an LCD display unit; side It consists of a number of mechanical energy to the indicator 60 to display the number.

The low voltage power line (1) has a current transformer (2) for measuring the current, an image current transformer (3) for detecting the change in the value of the current due to a short circuit and a conduction, and a load switch that can open and close the acceptance of electricity ( 4) is installed,

The signal detector 10 includes a current detector 14 for detecting a current from the current transformer 2, a voltage detector 13 for detecting a voltage in the low voltage power line 1, and a short circuit from the image current transformer 3. / An earth leakage / conduction detector 15 for detecting a signal generated by the conduction, a circuit breaker / switchgear open and close state detection unit 11 connected to the load switch 4 to detect the open / closed state of the breaker / switchgear, low-voltage power line ( It is composed of a zero cross detector 12 connected to 1) detects a zero cross point by detecting a phase difference between voltage and current.

The control unit 20 and the A / D conversion unit 21 for converting the analog signal output from the signal detection unit 10 into a digital signal that can be used in the serial communication interface 24 and the calculation and memory unit 22 and And a serial communication interface 24 for transmitting data between the A / D converter 21 and the calculation and memory unit 22, and an operation of calculating, calculating and storing operating data of the transformer by calculating an input digital signal. And a memory unit 22 and a serial communication interface 24 which is a communication port for transmitting these data.

The A / D conversion unit 21 and the operation and memory unit 22 are bundled to form the central processing unit 23 of the control unit.

The microprocessor unit 40 includes a carrier oscillator 42 for generating a synchronization signal for transmitting various types of information transmitted to the power line communication modem unit 30, and a program for data communication to control a system. A central processing unit 41 programmed to drive the LCD driver 51 so that information can be output from the display unit 50 to the outside, and to display the measured power amount on the mechanical numeric display 60; 20) and a serial communication interface 43 for communicating in both directions and sending data to the central processing unit 41.

The power line communication modem unit 30 is output from the carrier controller 34 and the carrier amplifier 33 for controlling and transmitting various data output on the oscillation frequency of the carrier oscillator 42 of the microprocessor unit 40. A power amplifier 32 for power amplifying a carrier signal and transmitting the power signal to a line coupler connected to the low voltage power line 1 and a control signal received from a data concentrator (not shown) connected to the low voltage power line 1 include a line coupler ( 31) and through the filter and the amplifier 35 to the serial communication interface 43 of the microprocessor unit 40.

The display unit 50 is operated by the LCD driver 51 and the LCD driver 51 operating by receiving a drive signal from the microprocessor unit 40 so that the external state of the electricity meter can be known from the outside. It consists of an LCD display unit 52 that outputs,

The mechanical number display 60 is connected to the central processing unit 41 of the microprocessor unit 40, and is configured to display the amount of power consumed by the mechanical counter interlocked by rotating the rotating disc.

Referring to the operation of the wattmeter provided with electronic and mechanical display device using the device configured as described above are as follows.

The electrical signals generated by the current transformer 2, the image current transformer 3, the load switch 4, and the like installed on the low voltage power line 1 supplied to the customer are various detectors 11, 12, 13, 14, and 15, and the analog signal output from the signal detector 10 is input to the A / D converter 21 of the controller 20, converted into a digital signal, and then the It is transmitted to the operation and memory unit 22 of the control unit 20 via the serial communication interface 24, and the operation and memory unit 22 transmits the instructions such as the previous month's instructions, the current instructions, the effective power amount, the reactive power amount, and the like by the set program. The value is calculated and then stored, and the stored data is transmitted to the microprocessor unit 40 through the serial communication interface 24.

The data stored in the calculation and memory unit 22 of the control unit 20 is transmitted to the microprocessor unit 40 to connect the data combined with the unique number of the facility to the low-voltage power line (1) The transmission command transmitted from the shorthand (not shown) is transmitted through the power line communication modem unit 30.

In addition, the microprocessor unit 40 operates to drive the LCD driver 51 to display the data received from the controller 20 on the LCD display device 50, and the amount of power measured is a mechanical numeric display ( 60).

In the process of transmitting data by the power line communication modem unit 30, when a command for transmitting data stored in the microprocessor unit 40 is received from a data concentrator (not shown) connected to the low voltage power line 1, the power line communication modem unit 30 receives the data. As the data concentrator (not shown) and the electronic electricity meter are made of power line communication, the transmission command is received by the line coupler 31 of the power line communication modem unit 30 through the low voltage power line 1 to correspond to the transmission command. Only the communication signal is extracted, and the extracted communication signal passes through the filter and the amplifier 35 to filter only a specific frequency band, and the synchronously amplifies the filtered signal through the serial communication interface 43 of the microprocessor unit 40. The received command is transmitted to the central processing unit 41 of the microprocessor unit 40.

When the data transmission command is received from the power line communication modem unit 30, the data stored by the program set in the central processing unit 41 of the microprocessor unit 40 is transmitted.

As the data is applied to the carrier controller 34 of the power line communication modem unit 30, data information is loaded on a carrier signal generated by the carrier oscillator 42, and the signal is output to the carrier amplifier 33. After amplifying the voltage and power through the power amplifier 32, and then to the low-voltage power line 1 via the line coupler 31, the data information transmitted through the low-voltage power line 1 is a power line communication It is transmitted to a data collector (not shown).

Therefore, the present invention has a built-in power line communication modem and the electronic power meter that can detect a short circuit / conduction by receiving a signal from the video current transformer, by installing a mechanical numeric display to read and check the measured power amount during power failure as described above It works.

As described above, the present invention includes a mechanical numeric indicator in addition to an electronic wattmeter incorporating a conventional power line communication modem, even when the measured power value cannot be confirmed when a power failure or power is not supplied. It is effective to check meter reading data by using indicator.

In addition, since the present invention does not use a separate memory device or a battery for compensating for power failure to maintain the measured value during power failure, there is an effect of reducing the manufacturing cost and facilitating the design.

In particular, in the present invention, even if the liquid crystal display breaks due to fire or natural disaster, or the state cannot be identified, the effect of reading the amount of power data by the mechanical numeric display can be expected.

Claims (3)

A current transformer installed in the low voltage power line and connected to the current detector of the signal detector; A signal detector for detecting various electrical signals from the current transformer and the low voltage power line; An A / D converter for converting the signal value output from the signal detector into a digital signal, an arithmetic and memory unit for calculating, calculating and storing the converted data, and a serial communication interface for exchanging data with the microprocessor unit. A control unit; A microprocessor unit which bidirectionally communicates with the control unit and includes a program for data communication to control the system and to control the display of data by being connected to a display unit and a mechanical number display; A display unit which displays data processed by the microprocessor unit to the outside; An electric power meter having an electronic and mechanical display device including a command to send an upper data concentrator and a power line communication modem unit for transmitting and receiving the stored data through power line communication through a low voltage power line. The method of claim 1, A power meter having an electronic and mechanical display device, characterized in that it further comprises a video current transformer installed in the low-voltage power line for detecting a leakage current and connected to the leakage / conduction detector of the signal detection unit. The method according to claim 1 or 2, A power meter having an electronic and mechanical display device further comprising a load switch installed on the low voltage power line and connected to the breaker / switch switch state detection unit of the signal detector.