KR101323356B1 - Dc digital watt-hour meter and remote meter reading system using the same - Google Patents

Abstract

PURPOSE: A DC digital watt-hour meter and a remote metering system using the same are provided to measure consumption amount of DC accurately and to expect where a current supplied to a consumer is going. CONSTITUTION: A DC digital watt-hour meter (10) comprises a detecting part (11), a metering part (12), and a power line modem (14). The detecting part detects DC voltage at two ends of resistor. Using DC voltage extracted from the detecting part, the metering part produces the amount of voltage after checking the direction of DC. The power line modem, which is connected to angular of the power line, transmits the data including the amount of electric power to a data collecting device. The power line modem receives the data from another DC digital watt-hour meter, relays the same to the DC digital watt-hour meter. In case that a signal is weaker than a predetermined value, the DC digital watt-hour meter compensates the difference and relays the same. [Reference numerals] (11) Detecting part; (12) Metering part; (13) Storage part; (14) Power line modem

Description

DC digital power meter and remote metering system using the same {DC DIGITAL WATT-HOUR METER AND REMOTE METER READING SYSTEM USING THE SAME}

The present invention relates to a DC digital power meter and a remote meter reading system using the same , and more particularly , to a DC digital meter and a remote meter reading system using the same.

With the development of power electronic technology, the distribution system that produces and supplies electricity is evolving into a power system that can integrate various distributed sources and microgrids and provide high power quality and reliability. With the expansion of renewable energy sources, the necessity of measuring the amount of use of DC power produced by various types of distributed power supply systems and DC power distribution systems has been highlighted, and DC digital electricity meters are used for this purpose.

Currently, DC digital wattmeter can measure DC voltage, DC current and power, but due to the characteristics of DC power, it is not possible to perform bidirectional measurement by using current-voltage phase difference like smart grid in AC power field. I couldn't save it.

In addition, the existing DC digital electricity meter has a problem that a separate communication modem should be installed in transmitting the remote meter reading data because it cannot perform power line communication.

The technical problem to be achieved by the present invention is to accurately measure the consumption of the DC power produced by various types of distributed power supply system and DC distribution system, to determine the direction of the power supplied to the customer, and to calculate the maximum demand power The present invention provides a direct-current digital electricity meter capable of transmitting meter reading data using power line communication, and a remote meter reading system using the same.

According to an aspect of the present invention, a detection unit for detecting a DC voltage across the resistance; It provides a direct current digital power meter including a measurement unit for recognizing the direction of the direct current flowing through the resistor using the direct voltage detected by the detection unit, and calculates the amount of power.

The measurement unit may calculate a current value flowing through the resistor by applying Ohm's law to a voltage value across the resistor, and recognize the direction of the current according to the sign of the calculated current value.

The measurement unit may output the number of pulses corresponding to the calculated amount of power.

The apparatus may further include a storage unit which periodically stores the pulse number and LP data calculated from the measurement unit.

The measurement unit may analyze the LP data for a preset period of time stored in the storage unit, and set a large value as the maximum demand power by comparing the LP data value previously stored.

The apparatus may further include a power line modem unit for transmitting the LP data to the data collecting device.

The power line modem unit may amplify and relay the signal when the strength of the signal received from another DC digital power meter is less than the reference value.

According to another aspect of the invention is installed on the customer side to detect the DC voltage generated from the DC distribution system and distributed power supply, and using the detected DC voltage to recognize the direction of the power supplied to the customer to calculate the amount of power DC digital electricity meter; A data collecting device which receives meter reading data including the amount of power periodically by requesting a plurality of DC digital electricity meters; And a remote metering server for receiving and managing the metering data from the data collecting device.

The DC digital wattmeter includes: a detector configured to detect a DC voltage across the resistor; And a measurement unit configured to calculate a current value flowing through the resistor by applying Ohm's law to a voltage value across the resistor, and to recognize a direction of power supplied to the customer according to a sign of the calculated current value.

The DC digital electricity meter further includes a power line modem unit for transmitting the meter reading data to the data collecting device.

The power line modem unit may relay the meter data signal output from the other DC digital electricity meter, and if the intensity of the meter data signal output from the other DC digital meter is less than a predetermined level, it may be amplified and relayed.

The inventors of the present invention, the DC digital electricity meter and the remote meter reading system using the same, can accurately measure the amount of DC power produced by various types of distributed power supply systems and DC power distribution systems, and determine the direction of power supplied to customers. Demand power can be calculated and meter reading data can be transmitted using power line communication.

1 is a conceptual diagram of a remote meter reading system using a DC digital electricity meter according to an embodiment of the present invention,
2 is a configuration diagram of a DC digital power meter according to an embodiment of the present invention;
3 is a conceptual view for explaining that the measurement unit recognizes the direction of the current according to an embodiment of the present invention,
4 is a conceptual view illustrating that the measurement unit recognizes the direction of the current according to another embodiment of the present invention.
5 is a conceptual diagram of a remote meter reading system using a DC digital electricity meter according to another embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

1 is a conceptual diagram of a remote meter reading system using a DC digital electricity meter according to an embodiment of the present invention, Figure 2 is a block diagram of a DC digital electricity meter according to an embodiment of the present invention.

Referring to Figure 1, the remote meter reading system using a DC digital electricity meter 10 according to an embodiment of the present invention is installed on the customer side and detects the DC voltage generated from the DC distribution system and distributed power supply, and the detected DC A direct current digital electricity meter (10) for recognizing the direction of power supplied to the customer using a voltage and calculating an amount of power; A data collecting device 20 which receives a plurality of DC digital electricity meters 10 and periodically receives meter reading data including the amount of power; And it may be configured to include a remote meter reading server 30 to receive and manage the meter data from the data collection device 20.

Referring to FIG. 2, the DC digital power meter 10 according to an embodiment of the present invention includes a detector 11 that detects a DC voltage across the resistor; A measurement unit 12 for recognizing the direction of the DC current flowing through the resistance by using the DC voltage detected by the detection unit 11 and calculating a power amount; A storage unit 13 periodically storing the number of pulses and LP (Load Profile) data calculated from the measurement unit 12; And a power line modem unit 14 for transmitting the number of pulses and the LP data to the data collecting device 20.

The detector 11 may detect the DC voltage generated from the DC distribution system and the distributed power supply by measuring the voltage across the resistor. The detector 11 may use a shunt resistor to detect a voltage.

The measurement unit 12 may recognize the direction of the DC current flowing through the resistor by using the DC voltage detected by the detector 11, and may recognize the direction of the power supplied to the customer through the measurement.

As shown in FIG. 3, the detector 11 may detect a voltage across the shunt resistor, and the measurement unit 12 may calculate a value of the DC current flowing through the shunt resistor by applying a law of Ohm. The sign of the direct current is determined by the sign of the voltage across the shunt resistor, and the direction of the direct current can be recognized through the sign of the direct current. For example, in FIG. 3, when the voltage across the shunt resistor is +0.015 V and the value of the shunt resistor is 3 mΩ, the measurement unit 12 recognizes the power receiving direction (forward direction) because the current flowing through the shunt resistor is +5 A. can do.

In addition, as shown in FIG. 4, when the voltage across the shunt resistor is -0.015 V and the value of the shunt resistor is 3 mΩ, the current flowing through the shunt resistor is -5 A. Therefore, the measurement unit 12 moves in the power transmission direction (reverse direction). I can recognize it.

The measurement unit 12 may calculate the amount of power using the DC voltage value detected by the detector 11 and the calculated current value. The amount of power detected by the measurement unit 12 may be calculated as a product of a voltage value and a current value, and may be generated by generating a pulse number corresponding to the calculated amount of power. The measurement unit 12 may accumulate and output the pulse number according to the amount of power calculated by using a pre-stored processing program and a system clock from a crystal oscillator (by a predetermined time unit).

The measurement unit 12 may periodically store the calculated power in the storage unit 13 by including the directional information in the power receiving direction or the power transmitting direction. The measurement unit 12 may store the number of pulses and the LP data every predetermined time by using the RTC (Real Time Clock) built in the DC digital power meter 10, and may store the data for 90 days at intervals of 15 minutes, for example. LP (Loaf Profile) data may refer to the amount of power used per hour of a certain period, the electricity supplier or remote meter reading server 30 can analyze the load usage patterns and predict the load of the customer using the LP data, power failure and restoration You can see the timing and use it when other problems occur.

The measurement unit 12 may calculate the maximum demand power using the LP data stored in the storage unit 13. The measurement unit 12 may analyze the LP data stored in the storage unit 13 for a predetermined period of time and compare the LP data with previously stored LP data values to calculate a large value as the maximum demand power during the preset period. For example, the measurement unit 12 stores LP data for one month, compares the old LP data with the current LP data and stores the updated LP data to a large value, and calculates the updated LP data value as the maximum demand power. Can be.

The storage unit 13 may periodically accumulate and store the pulse number and LP data calculated by the measurement unit 12. The storage unit 13 may be configured as a nonvolatile memory device such that there is no loss of information even during a power failure.

The power line modem unit 14 may transmit the number of pulses and the LP data calculated by the measurement unit 12 to the data collection device 20. The power line modem unit 14 may perform power line communication by connecting to two signal lines and two neutral lines in a single phase, and to R, S, T lines, and a neutral line in a three-phase four line. The power line modem unit 14 may be implemented in the form of an integrated circuit chip or module that may be embedded in the DC digital power meter 10.

The power line modem unit 14 may perform a role of relaying a signal transmitted from another DC digital power meter 10. For example, as shown in FIG. 5, the power line modem unit 14 (10 (b)) receives a signal transmitted from a DC digital power meter 10 (a) that is physically remote from the data collection device 20. When the intensity of the received signal is below a predetermined level, the signal may be amplified (10 (b) and 10 (c) of FIG. 5) and transmitted to the data collection device 20.

The data collection device 20 may request a plurality of DC digital electricity meters 10 and periodically receive meter reading data and transmit the meter reading data to the remote meter reading server 30. The remote meter reading server 30 can analyze the load and the power usage pattern of the customer through the received data and can determine the time point of power failure and recovery.

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

10: DC digital electricity meter
11: detector
12: measuring unit
13:
14: power line modem unit
20: data collection device
30: remote meter reading server

Claims (11)

A detector detecting a DC voltage across the resistor;
A measuring unit for recognizing the direction of the DC current flowing through the resistance using the DC voltage detected by the detection unit, and calculates the amount of power
A power line modem unit connected to each phase of a power line and transmitting meter reading data including the amount of power to a data collection device;
The power line modem unit receives a reading data from another DC digital electricity meter and transmits the reading data to a DC digital electricity meter located in the data collection device side direction, and the intensity of the reading data signal received from the other DC digital electricity meter is constant. DC digital watt-hour meter to compensate for this if less than.
The method of claim 1,
And the measurement unit calculates a current value flowing through the resistor by applying Ohm's law to a voltage value across the resistor, and recognizes the direction of the current according to the sign of the calculated current value.
The method of claim 1,
The measuring unit is a DC digital power meter for generating and outputting the number of pulses corresponding to the calculated amount of power.
The method of claim 3, wherein
And a storage unit for periodically storing the pulse number and LP data calculated from the measurement unit.
5. The method of claim 4,
And the measuring unit analyzes the LP data for a preset period of time stored in the storage unit, and sets a large value as the maximum demand power by comparing with the LP data value previously stored.
5. The method of claim 4,
And the power line modem unit transmits the pulse number and the LP data to the data collection device.
delete A DC digital watt-hour meter installed at a customer side and detecting a DC voltage generated from a DC distribution system and a distributed power supply, and recognizing a direction of power supplied to the customer by using a DC current measurement resistance;
A data collecting device which receives meter reading data including the amount of power periodically by requesting a plurality of DC digital electricity meters; And
It includes a remote meter reading server for receiving and managing the meter data from the data collection device,
The direct current digital electricity meter includes a power line modem unit connected to each phase of a power line to transmit the meter reading data to the data collection device.
The power line modem unit receives a reading data from another DC digital electricity meter and transmits the reading data to a DC digital electricity meter located in the data collection device side direction, and the intensity of the reading data signal received from the other DC digital electricity meter is constant. Remote metering system using a DC digital electricity meter to compensate for this if less than.
The method of claim 8,
The DC digital wattmeter is
A detector detecting a DC voltage across the resistor;
A measurement unit for calculating a current value flowing through the resistor by applying Ohm's law to a voltage value across the resistor, and recognizing a direction of power supplied to the customer according to a sign of the calculated current value
Remote metering system using a DC digital electricity meter including a.
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