CN114236456A - Double-loop single-phase electric energy meter calibrating device and method - Google Patents
Double-loop single-phase electric energy meter calibrating device and method Download PDFInfo
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Abstract
The invention relates to a double-loop single-phase electric energy meter calibrating device and a method, wherein the device comprises: a plurality of parallel certification stations; the current loop switching unit is arranged at each verification station, and the switching circuit is connected into a channel of the detected electric energy meter; a master control unit and a control computer; isolating a plurality of paths PT; single-phase standard power electric energy meter. The invention has smart design, can detect two current measurement loops including an L loop and an N loop, and can detect double current loops besides the function of detecting the traditional single-loop single-phase electric energy meter.
Description
Technical Field
The invention relates to the technical field of electric energy meter verification, in particular to a double-loop single-phase electric energy meter verification device and method.
Background
The electric energy meter calibrating device is a special standard metering device, a test power supply provides standard test signal voltage, current and the like to a calibrated meter and a standard electric energy meter to simultaneously meter electric energy, the standard electric energy meter sends high-frequency standard electric energy pulses, the electric energy meter to be tested sends low-frequency electric energy pulses to be tested, and an error calculator synchronously receives the standard pulses and the pulses to be tested and calculates electric energy errors.
The traditional single-phase electric energy meter calibrating device is designed aiming at the original electromechanical single-phase electric energy meter, a current metering loop of the electric energy meter is accessed from a live wire (L loop), voltage is accessed from a live wire (L) and a zero line (N), a plurality of epitopes are connected in series when calibrating, each epitope of current is connected in series, and each epitope of voltage is connected in parallel;
however, after an electronic electric energy meter comprehensively replaces an electromechanical electric energy meter, particularly after an intelligent electric energy meter and an intelligent gateway electric energy meter appear in recent years, a single-phase electric energy meter is provided with current metering units in a live line (L) loop and a zero line (N) loop, the L loop and the N loop can be used for metering, and the abnormal electricity utilization state can be recorded and reported through the current difference value of the L loop and the N loop, so that the metering accuracy and the electricity utilization management level are improved.
The invention relates to a double-loop single-phase electric energy meter calibrating device, which is designed for meeting the calibration of a double-loop single-phase electric energy meter.
Disclosure of Invention
In order to solve the problems, the invention designs a double-loop single-phase electric energy meter calibrating device and a method thereof, and a group of switching devices are arranged on the basis of each epitope test unit of the traditional single-phase electric energy meter calibrating device and can be switched between an L loop and an N loop, thereby realizing the calibration of the double-loop electric energy meter.
The technical scheme of the invention is as follows:
a kind of dual-circuit single-phase electric energy meter calibrating installation, including:
a plurality of parallel verification stations, wherein each station is provided with a single-phase electric energy meter to be detected for parallel verification; each verification station is provided with an error calculator for calculating the error of the electric energy meter to be detected;
the current loop switching unit is arranged at each verification station, and the switching circuit is connected into a channel of the detected electric energy meter;
the general control unit is communicated with the control computer through the LAN port, and the control computer sends a control command to the general control unit, collects detection data and uploads the detection data to the control computer;
the utility model discloses a PT is kept apart to multichannel, keeps apart the primary input termination of PT and tests power supply voltage output, and the secondary has a plurality of isolated winding each other, and the winding quantity is device table digit +1 way, and the voltage transformation ratio between the primary and secondary winding is 1: 1, providing mutually isolated test voltage signals for a standard electric energy meter and a tested electric energy meter by an isolated PT secondary side;
the single-phase standard power electric energy meter is connected with voltage and current signals output by a three-phase test power supply, measures real-time electric parameters such as voltage, current and power and the like as standard values, sends out electric energy pulses in direct proportion to the power, and provides the electric energy pulses to the electric energy meter error calculation unit for calculating errors.
Furthermore, the device also comprises a single-phase test power supply which is communicated with the master control unit through an RS232 port, is controlled by the master control unit and outputs voltage signals and current signals required by verification.
Furthermore, the device also comprises a standard clock source module which provides a standard high-frequency clock signal for calibrating the daily timing error of the electric energy meter clock.
Furthermore, 4 current relays are arranged in the current loop switching unit, the two relays are in a group, when the switches of the two relays are closed, the current loop of each epitope is switched to be connected to the L loop of the electric energy meter to be detected, the current loop of each epitope is switched to be connected to the N loop of the electric energy meter to be detected, the group of relays are controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the error calculation unit performs switching control according to a loop state instruction sent by the upper computer.
Furthermore, in the current switching unit, a first relay switch is connected with an Lin1 interface of the tested electric meter, a second relay switch is connected with a Lout2 interface of the tested electric meter, a third relay switch is connected with a Min1 interface of the tested electric meter, and a fourth relay switch is connected with a Mout2 interface of the tested electric meter;
in the first current switching unit, a first relay switch and a third relay switch are connected with a single-phase standard power electric energy meter, a second relay switch and a fourth relay switch are connected with the first relay switch and the third relay switch of the second current switching unit, and so on, the second relay switch and the fourth relay switch of the n-1 current switching unit are connected with the first relay switch and the third relay switch of the n current switching unit, and the second relay switch and the fourth relay switch of the n current switching unit are connected with a single-phase test power supply.
The invention also relates to a double-loop single-phase electric energy meter calibration method which is carried out based on the device and comprises the following steps:
each station is provided with a single-phase electric energy meter to be detected for parallel detection; the error calculator of each verification station calculates the error of the detected electric energy meter;
the current loop switching unit of each verification station is connected with a channel of the detected electric energy meter through a switching circuit;
the current loop switching unit is internally provided with 4 current relays which are in a group, when the switches of the two relays are closed, the current loop of each epitope is switched to be connected to the L loop of the electric energy meter to be detected, the current loop of each epitope is switched to be connected to the N loop of the electric energy meter to be detected, the group of relays is controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the error calculation unit performs switching control according to loop state instructions sent by an upper computer;
the master control unit is communicated with the control computer through the LAN port, and the control computer sends a control command to the master control unit, collects detection data and uploads the detection data to the control computer;
the primary input end of isolation PT is connected with the voltage output of a test power supply, the secondary is provided with a plurality of mutually isolated independent windings, the number of the windings is +1 path of the meter digit of the device, and the voltage transformation ratio between the primary winding and the secondary winding is 1: 1, providing mutually isolated test voltage signals for a standard electric energy meter and a tested electric energy meter by an isolated PT secondary side;
the single-phase standard power electric energy meter is connected with voltage and current signals output by the three-phase test power supply, measures real-time electric parameters such as voltage, current and power and the like as standard values, sends out electric energy pulses in direct proportion to the power, and provides the electric energy pulses to the electric energy meter error calculation unit for calculating errors.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention has smart design, can detect two current measurement loops including an L loop and an N loop, and can detect double current loops besides the function of detecting the traditional single-loop single-phase electric energy meter.
2. In the invention, each meter position is switched and controlled by a current loop switching module; each meter position provides mutually isolated test voltage through an isolation PT; the number of epitopes can be selected from 2-120 epitopes according to implementation requirements.
Drawings
Fig. 1 is a working principle block diagram of the double-loop single-phase electric energy meter calibrating device of the invention.
Detailed Description
The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples without making any creative effort, shall fall within the protection scope of the present application.
Unless otherwise defined, technical or scientific terms used in the embodiments of the present application should have the ordinary meaning as understood by those having ordinary skill in the art. The use of "first," "second," and similar terms in the present embodiments does not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. "mounted," "connected," and "coupled" are to be construed broadly and may, for example, be fixedly coupled, detachably coupled, or integrally coupled; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. "Upper," "lower," "left," "right," "lateral," "vertical," and the like are used solely in relation to the orientation of the components in the figures, and these directional terms are relative terms that are used for descriptive and clarity purposes and that can vary accordingly depending on the orientation in which the components in the figures are placed.
As shown in fig. 1, the calibration apparatus for a dual-circuit single-phase electric energy meter of the present embodiment includes:
n parallel verification stations, wherein each station is provided with a single-phase electric energy meter to be detected for parallel verification; each verification station is provided with an error calculator for calculating the error of the electric energy meter to be detected;
the current loop switching unit is arranged at each verification station, and the switching circuit is connected into a channel of the detected electric energy meter; the current loop switching unit is internally provided with 4 current relays which are in a group, when the switches of the two relays are closed, the current loop of each epitope is switched to be connected to the L loop of the electric energy meter to be detected, the current loop of each epitope is switched to be connected to the N loop of the electric energy meter to be detected, the group of relays is controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the error calculation unit performs switching control according to loop state instructions sent by the upper computer.
In the current switching unit, a first relay switch is connected with an Lin1 interface of the tested electric meter, a second relay switch is connected with a Lout2 interface of the tested electric meter, a third relay switch is connected with a Min1 interface of the tested electric meter, and a fourth relay switch is connected with a Mout2 interface of the tested electric meter;
in the first current switching unit, a first relay switch and a third relay switch are connected with a single-phase standard power electric energy meter, a second relay switch and a fourth relay switch are connected with the first relay switch and the third relay switch of the second current switching unit, and so on, the second relay switch and the fourth relay switch of the n-1 current switching unit are connected with the first relay switch and the third relay switch of the n current switching unit, and the second relay switch and the fourth relay switch of the n current switching unit are connected with a single-phase test power supply.
The general control unit is communicated with the control computer through the LAN port, and the control computer sends a control command to the general control unit, collects detection data and uploads the detection data to the control computer;
the utility model discloses a PT is kept apart to multichannel, keeps apart the primary input termination of PT and tests power supply voltage output, and the secondary has a plurality of isolated winding each other, and the winding quantity is device table digit +1 way, and the voltage transformation ratio between the primary and secondary winding is 1: 1, the isolated PT secondary side provides mutually isolated test voltage signals for the standard electric energy meter and the tested electric energy meter.
The single-phase standard power electric energy meter is connected with voltage and current signals output by a three-phase test power supply, measures real-time electric parameters such as voltage, current and power and the like as standard values, sends out electric energy pulses in direct proportion to the power, and provides the electric energy pulses to the electric energy meter error calculation unit for calculating errors.
The single-phase test power supply is communicated with the master control unit through the RS232 port, is controlled by the master control unit and outputs voltage signals and current signals required by verification.
And the standard clock source module provides a standard high-frequency clock signal for verifying the daily timing error of the clock of the electric energy meter.
In this embodiment, the epitope can be selected from 2 to 120 epitopes according to actual requirements.
Each verification station is provided with an error calculator for calculating the error of the electric energy meter to be detected; the error calculator carries out high-speed data communication with a master control unit of the device through a CAN bus, and accesses a standard electric energy pulse of a standard electric energy meter, a standard clock pulse of a standard clock source, an electric energy pulse of a detected electric energy meter, a clock pulse and RS485 communication, each meter position calculates the electric energy error and the daily timing error of the detected electric energy meter of each meter position in parallel, and CAN carry out RS485 communication with the detected electric energy meter.
The switching circuit is connected to a channel of the detected electric energy meter; the current loop switching unit is internally provided with 4 current relays (K1-K4), the nominal working current of the group of relays can reach 120A at most, the two relays form a group, when K1 and K2 are closed, the current loop of each epitope is switched to be connected to the L loop (1-Lin, 2-Lout) of the detected electric energy meter, when K1 and K2 are closed, the current loop of each epitope is switched to be connected to the N loop (3-Nin, 4-Nout) of the detected electric energy meter, the group of relays are controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the switching control is carried out by the error calculation unit according to loop state instructions sent by an upper computer.
The general control unit is communicated with the control computer through the LAN port, the verification software runs on the control computer, the control command is sent to the general control unit through the LAN port, the general control unit forwards the control command to the device and the unit module, and the detection data is collected and uploaded to the control computer. The standard clock source, the single-phase standard power electric energy meter, the single-phase test power supply, the error calculator, the isolation PT, the control computer and the master control unit are all existing devices.
The single-phase test power supply communicates with the master control unit through the RS232 port, is controlled by the master control unit, and outputs a voltage signal and a current signal required by verification, in the embodiment, the main indexes of a typical single-phase test power supply are as follows:
a) voltage range: 220V
b) Current range: 0.001A, 0.005A, 0.01A, 0.025A, 0.05A, 0.1A, 0.25A, 0.5A, 1A, 2.5A, 5A, 10A, 25A, 50A, 100A;
c) frequency range: 45 Hz-65 Hz; resolution ratio: 0.01 Hz;
d) phase adjustment: 0-359.99 degrees; adjusting the fineness: 0.01 degree;
e) stability: 0.05%/3 min;
f) output waveform distortion degree: 0.5 percent.
The primary input end of the multi-path isolation PT is connected with the voltage output of a test power supply, a plurality of mutually isolated independent windings are arranged at the secondary side, the number of the windings is +1 path of the meter digit of the device, and the voltage transformation ratio between the primary winding and the secondary winding is 1: 1, the isolated PT secondary side provides mutually isolated test voltage signals for the standard electric energy meter and the tested electric energy meter.
The main criteria for a typical isolated PT of this embodiment are as follows:
a) accuracy grade: grade 0.01;
b) output power per loop: 3-10 VA;
c) voltage range: 220V +/-15%.
The single-phase standard power electric energy meter is connected to voltage and current signals output by a three-phase test power supply, real-time electric parameters such as voltage, current and power are measured to serve as standard values, electric energy pulses in direct proportion to power are sent out and provided to an electric energy meter error calculation unit to be used for calculating errors, and a typical single-phase electric energy meter of the embodiment has the following main indexes:
a) accuracy grade: grade 0.05;
b) voltage range: 240V;
c) current measurement range: 0.3 mA-100A;
d) frequency range: 40Hz-70 Hz; accuracy: 0.01 Hz;
e) phase measurement 0-359.999 °; resolution ratio: 0.001 degree; accuracy: 0.02.
the standard clock source module of this embodiment provides a standard high-frequency clock signal for verifying the daily timing error of the clock of the electric energy meter, and the main indexes of a typical clock source of this embodiment are as follows:
a) output frequency: 500 kHz;
b) frequency output accuracy: 2X 10-7；
c) Frequency output stability: not more than 5X 10-8。
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (6)
1. The utility model provides a single-phase electric energy meter calibrating installation of two return circuits which characterized in that: the method comprises the following steps:
a plurality of parallel verification stations, wherein each station is provided with a single-phase electric energy meter to be detected for parallel verification; each verification station is provided with an error calculator for calculating the error of the electric energy meter to be detected;
the current loop switching unit is arranged at each verification station, and the switching circuit is connected into a channel of the detected electric energy meter;
the general control unit is communicated with the control computer through the LAN port, and the control computer sends a control command to the general control unit, collects detection data and uploads the detection data to the control computer;
the utility model discloses a PT is kept apart to multichannel, keeps apart the primary input termination of PT and tests power supply voltage output, and the secondary has a plurality of isolated winding each other, and the winding quantity is device table digit +1 way, and the voltage transformation ratio between the primary and secondary winding is 1: 1, providing mutually isolated test voltage signals for a standard electric energy meter and a tested electric energy meter by an isolated PT secondary side;
the single-phase standard power electric energy meter is connected with voltage and current signals output by a three-phase test power supply, measures real-time electric parameters such as voltage, current and power and the like as standard values, sends out electric energy pulses in direct proportion to the power, and provides the electric energy pulses to the electric energy meter error calculation unit for calculating errors.
2. The apparatus of claim 1, wherein: the device also comprises a single-phase test power supply, which is communicated with the master control unit through an RS232 port, is controlled by the master control unit and outputs voltage signals and current signals required by verification.
3. The apparatus of claim 1, wherein: the device also comprises a standard clock source module which provides a standard high-frequency clock signal for detecting the daily timing error of the electric energy meter clock.
4. The apparatus of claim 1, wherein: the current loop switching unit is internally provided with 4 current relays which are in a group, when the switches of the two relays are closed, the current loop of each epitope is switched to be connected to the L loop of the electric energy meter to be detected, the current loop of each epitope is switched to be connected to the N loop of the electric energy meter to be detected, the group of relays is controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the error calculation unit performs switching control according to loop state instructions sent by the upper computer.
5. The apparatus of claim 4, wherein: in the current switching unit, a first relay switch is connected with an Lin1 interface of the tested electric meter, a second relay switch is connected with a Lout2 interface of the tested electric meter, a third relay switch is connected with a Min1 interface of the tested electric meter, and a fourth relay switch is connected with a Mout2 interface of the tested electric meter;
in the first current switching unit, a first relay switch and a third relay switch are connected with a single-phase standard power electric energy meter, a second relay switch and a fourth relay switch are connected with the first relay switch and the third relay switch of the second current switching unit, and so on, the second relay switch and the fourth relay switch of the n-1 current switching unit are connected with the first relay switch and the third relay switch of the n current switching unit, and the second relay switch and the fourth relay switch of the n current switching unit are connected with a single-phase test power supply.
6. A method for calibrating a double-loop single-phase electric energy meter is characterized by comprising the following steps: the method is carried out based on the device of any one of claims 1 to 5, and comprises the following steps:
each station is provided with a single-phase electric energy meter to be detected for parallel detection; the error calculator of each verification station calculates the error of the detected electric energy meter;
the current loop switching unit of each verification station is connected with a channel of the detected electric energy meter through a switching circuit;
the current loop switching unit is internally provided with 4 current relays which are in a group, when the switches of the two relays are closed, the current loop of each epitope is switched to be connected to the L loop of the electric energy meter to be detected, the current loop of each epitope is switched to be connected to the N loop of the electric energy meter to be detected, the group of relays is controlled by the error calculation unit of the epitope, and when the test of different loops is selected, the error calculation unit performs switching control according to loop state instructions sent by an upper computer;
the master control unit is communicated with the control computer through the LAN port, and the control computer sends a control command to the master control unit, collects detection data and uploads the detection data to the control computer;
the primary input end of isolation PT is connected with the voltage output of a test power supply, the secondary is provided with a plurality of mutually isolated independent windings, the number of the windings is +1 path of the meter digit of the device, and the voltage transformation ratio between the primary winding and the secondary winding is 1: 1, providing mutually isolated test voltage signals for a standard electric energy meter and a tested electric energy meter by an isolated PT secondary side;
the single-phase standard power electric energy meter is connected with voltage and current signals output by the three-phase test power supply, measures real-time electric parameters such as voltage, current and power and the like as standard values, sends out electric energy pulses in direct proportion to the power, and provides the electric energy pulses to the electric energy meter error calculation unit for calculating errors.
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| CN101718853A (en) * | 2009-11-20 | 2010-06-02 | 深圳市科陆电子科技股份有限公司 | Detecting device and detecting method of single-phase double-loop metering electric energy meter |
| CN203658571U (en) * | 2013-12-31 | 2014-06-18 | 郑州三晖电气股份有限公司 | Switching wiring circuit for double-loop ammeter detection instrument |
| CN108845286A (en) * | 2018-09-03 | 2018-11-20 | 海盐星创电子有限公司 | Calibration equipment while a kind of two current loops of single-phase electric energy meter |
| CN111722101A (en) * | 2020-05-29 | 2020-09-29 | 宁波三星医疗电气股份有限公司 | Detection circuit and protection method of double-loop relay |
| CN112305491A (en) * | 2020-10-30 | 2021-02-02 | 海南电网有限责任公司 | Multi-loop switching method |
-
2021
- 2021-11-11 CN CN202111335672.4A patent/CN114236456A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101718853A (en) * | 2009-11-20 | 2010-06-02 | 深圳市科陆电子科技股份有限公司 | Detecting device and detecting method of single-phase double-loop metering electric energy meter |
| CN203658571U (en) * | 2013-12-31 | 2014-06-18 | 郑州三晖电气股份有限公司 | Switching wiring circuit for double-loop ammeter detection instrument |
| CN108845286A (en) * | 2018-09-03 | 2018-11-20 | 海盐星创电子有限公司 | Calibration equipment while a kind of two current loops of single-phase electric energy meter |
| CN111722101A (en) * | 2020-05-29 | 2020-09-29 | 宁波三星医疗电气股份有限公司 | Detection circuit and protection method of double-loop relay |
| CN112305491A (en) * | 2020-10-30 | 2021-02-02 | 海南电网有限责任公司 | Multi-loop switching method |
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Application publication date: 20220325 |