WO2020078156A1

WO2020078156A1 - Voltage transformer and method for using same to meter voltage

Info

Publication number: WO2020078156A1
Application number: PCT/CN2019/105701
Authority: WO
Inventors: 李璿; 吴士普; 汪本进; 陈江波; 余春雨; 冯宇; 杜砚; 毛安澜; 邱进; 陈晓明; 王玲; 徐思恩; 邵苠峰
Original assignee: 中国电力科学研究院有限公司; 国家电网有限公司
Priority date: 2018-10-18
Filing date: 2019-09-12
Publication date: 2020-04-23

Abstract

Disclosed are a voltage transformer (100) and a method for metering a voltage. The voltage transformer (100) comprises: a first component (101), configured to receive a first voltage; a power output unit (1021), configured to output a second voltage; a voltage metering unit (1022), which is the voltage transformer (100) converting the second voltage into a third voltage or has a mutual inductance with the first component (101), and is configured to meter a voltage; a current transformer (1023), configured to measure a load current; and a compensate impedance (1024), which is connected in series to a winding of the voltage metering unit (1022), is connected in parallel to the current transformer (1023), and is configured to compensate for a voltage drop generated by the load current on the leakage reactance of the voltage metering unit (1022) when a user load changes, so as to compensate for an error of voltage metering.

Description

Voltage transformer and method for voltage measurement using the same

This application requires the priority of the Chinese patent application filed on October 18, 2018 with the Chinese Patent Office, application number 201811215537.4, and the Chinese patent application filed with the Chinese Patent Office on October 18, 2018, application number 201811216310.1, the application The entire content of is incorporated by reference in this application.

Technical field

The present application relates to the field of measurement calibration, for example, to a voltage transformer and a method for voltage measurement using the same.

Background technique

Both the transformer and the voltage transformer use the principle of electromagnetic induction, which converts the electrical energy of one AC voltage into the electrical energy of another AC voltage at the same frequency. Transformers mainly transfer large-capacity or super-large-capacity electrical energy, and transformers are mainly used for voltage measurement, which is a special transformer specially used for voltage conversion, and this difference affects the main design parameters of transformers and transformers.

Since the main concern of the transformer is the output capacity, the requirements for the output voltage value of the transformer can be varied within the range of ± 5% to 10% depending on the voltage level. Due to the leakage reactance, when the output capacity changes greatly, the output voltage will fluctuate widely. For the power supply transformer that supplies power to the load center, in order to ensure the stability of the power supply voltage, it is usually necessary to be equipped with a load regulating transformer. This is why the transformer cannot be used as a voltage transformer. The voltage transformer is a specially designed transformer. Due to the small load and stability, the high accuracy limit can be achieved by design.

Therefore, for a voltage transformer that realizes the functions of voltage measurement and power output at the same time, how to design the voltage transformer to accurately measure the voltage to meet the accuracy requirements is a problem to be solved.

Summary of the invention

The present application proposes a voltage transformer and a method for voltage measurement using the same to solve the problem of how to use the voltage transformer to accurately perform voltage measurement to meet the accuracy requirements.

The present application provides a voltage transformer. The voltage transformer includes:

The first component is configured to be connected to the voltage input terminal and receive the first voltage from the voltage input terminal;

The power output unit is mutually inductive with the first component, and is configured to be connected to the voltage output terminal and output the second voltage;

A voltage metering unit configured to be connected to the voltage output terminal to achieve parallel connection with the power output unit. The voltage metering unit is a voltage transformer configured to convert the second voltage to a third voltage. Voltage measurement; or, the mutual inductance between the voltage measurement unit and the first component is set to achieve voltage measurement and obtain a third voltage;

The current transformer is set in series with the winding of the power output unit to measure the load current;

The compensation impedance is connected in series with the winding of the voltage measurement unit and in parallel with the current transformer. It is set to compensate for the voltage drop generated by the load current on the leakage reactance of the voltage measurement unit when the user load changes. Realize the compensation for the error of voltage measurement.

In an embodiment, in the case where the voltage metering unit and the power output unit are connected in parallel, the compensation impedance is connected in series with the secondary winding of the voltage metering unit.

In an embodiment, the second voltage is in the range of 110V-1000V.

In an embodiment, the second voltage is 220V power frequency voltage.

In an embodiment, the third voltage is within a preset range threshold of a standard voltage threshold, the standard voltage threshold is 57.7V, and the preset range threshold is set according to system requirements of the power grid.

The present application also provides a method for voltage measurement using the voltage transformer as described above. The method includes:

The first component receives the first voltage from the voltage input;

The mutual output of the power output unit and the first component performs power output and outputs a second voltage;

The current transformer measures the load current;

When the user load changes, the compensation impedance compensates the voltage drop generated by the load current on the primary side leakage reactance and the secondary side leakage reactance of the voltage measurement unit, and compensates the error of the voltage measurement; the voltage measurement unit converts the first The second voltage is converted into a third voltage, and voltage measurement is performed to obtain a third voltage, or the voltage measurement and the first component have mutual inductance, voltage measurement is performed to obtain a third voltage.

In an embodiment, the second voltage is 220V power frequency voltage.

The present application provides a voltage transformer. The output voltage of the power output unit of the voltage transformer supplies power to the user. The voltage measurement unit is a voltage transformer or a voltage measurement unit directly connected in parallel with the winding of the power output unit. Component mutual inductance, through error compensation of the winding of the voltage measurement unit, to achieve the voltage measurement function; a current transformer is connected in series with the winding of the power output unit to monitor the load current, and a certain value of compensation impedance is connected in parallel with the current transformer. And the compensation impedance is connected in series on the loop of the voltage measurement unit winding to perform error compensation. When the power is output from 0 to full load, the error meets the measurement level error limit requirements.

BRIEF DESCRIPTION

FIG. 1 is a schematic structural diagram of a voltage transformer provided by an embodiment of the present application;

2 is a schematic diagram of a voltage transformer provided by an embodiment of the present application;

3 is a schematic diagram of a voltage transformer provided by an embodiment of the present application;

4 is a flowchart of a voltage measurement method using a voltage transformer provided by an embodiment of the present application;

5 is a schematic structural diagram of another voltage transformer provided by an embodiment of the present application;

6 is a schematic diagram of another voltage transformer provided by an embodiment of the present application;

7 is a schematic diagram of another voltage transformer provided by an embodiment of the present application;

8 is a flowchart of another method for voltage measurement using a voltage transformer provided by an embodiment of the present application.

detailed description

Exemplary embodiments of the present application will now be described with reference to the drawings, however, the present application can be implemented in many different forms and is not limited to the embodiments described herein. The terminology shown in the exemplary embodiments in the drawings does not limit the present application. In the drawings, the same units / elements use the same reference numerals.

Unless otherwise stated, the terms (including scientific and technical terms) used herein have the ordinary meaning to those skilled in the art. In addition, it is understandable that terms defined in commonly used dictionaries should be understood to have a consistent meaning with the context of their related fields, and should not be interpreted as an idealized or excessively formal meaning.

FIG. 1 is a schematic structural diagram of a voltage transformer provided by an embodiment of the present application. As shown in FIG. 1, the output voltage of the power output unit 1021 of the voltage transformer 100 provided in this embodiment is 220V, which can directly supply power to the user. The voltage measurement unit 1022 is a device directly connected in parallel with the winding of the power output unit 1021

Small electromagnetic voltage transformer, through error compensation for the secondary winding of the small electromagnetic voltage transformer, to achieve the voltage measurement function; a current transformer 1023 is connected in series with the winding of the power output unit 1021, which is set to monitor the load current, pass A certain amount of compensation impedance 1024 is connected in parallel to the load current, and the compensation impedance 1024 is connected in series on the loop of the voltage measurement unit 1022 winding to perform error compensation. When the power is output from 0 to full load, the error meets the measurement level error limit Claim. The voltage transformer 100 provided in this embodiment includes a first component 101 and a second component 102. In an embodiment, the first component 101 is configured to be connected to a voltage input terminal, and inductance with the second component 102 to receive a first voltage from the voltage input terminal.

In an embodiment, the second component 102 is configured to be connected to a voltage output terminal and output a second voltage to the voltage output terminal, so as to realize power output and voltage measurement.

The second component 102 includes a power output unit 1021, a voltage metering unit 1022, a current transformer 1023, and a compensation impedance 1024.

In an embodiment, the power output unit 1021 is mutually inductance with the first component 101 and is connected to the voltage output terminal to perform power output and output the second voltage.

In an embodiment, the second voltage is a 220V power frequency voltage provided to the user.

In an embodiment, the voltage measuring unit 1022 is configured to be connected to the voltage output terminal to achieve parallel connection with the power output unit 1021, and the voltage measuring unit 1022 is configured to convert the second voltage to The voltage transformer of the third voltage is set to perform voltage measurement.

In an embodiment, the current transformer 1023 is set in series with the voltage output terminal to measure the load current.

In an embodiment, the compensation impedance 1024 is connected in series with the secondary winding of the voltage metering unit 1022, and is connected in parallel with the current transformer 1023. The voltage drop generated on the primary side leakage reactance and the secondary side leakage reactance of the voltage measurement unit 1022 is to compensate for the error of the voltage measurement.

FIG. 2 is a schematic diagram of a voltage transformer provided by an embodiment of the present application. As shown in Fig. 2, U1 is a high-voltage voltage, and a voltage transformer (Potential transformer, PT) for voltage measurement is a voltage transformer that converts a low-voltage voltage to 57.7V, and a PT load for voltage measurement is a compensation winding. The output voltage of the power output winding is a voltage in the range of 100V-1000V, such as 220V, which can directly supply power to the user. The voltage measurement unit is a direct connection with the power output unit winding in parallel.

Of the small electromagnetic voltage transformer, the load error of the voltage transformer for voltage measurement changes with the change of the load current when the user load changes, and the voltage measurement is realized by adopting the method of no-load error compensation and load error compensation Winding error compensation.

FIG. 3 is a schematic diagram of a voltage transformer provided by an embodiment of the present application. As shown in Figure 3, AN is the high-voltage terminal on the primary side, T is the voltage transformer, an is the power output terminal, PT1 is the voltage measurement unit, and is the voltage transformer that converts the low voltage of the voltage transformer to 57.7V, CT is Current transformer for monitoring load current, Z is compensation impedance, 1a1n is voltage measurement terminal. By connecting PT1 with high accuracy to the winding of the power output unit, the voltage is converted to the one required for measurement

Voltage, when the load connected to an changes, the error of 1a1n will increase due to the change of the load current. By connecting Z in series in the loop, the leakage current of the primary side and the secondary side of the PT1 due to the load current will be compensated. The voltage drop generated in the above, thus achieving error compensation, can simultaneously achieve the functions of power output and voltage measurement.

FIG. 4 is a flowchart of a method for voltage measurement using a voltage transformer provided by an embodiment of the present application. As shown in FIG. 4, the method for voltage measurement provided by this embodiment starts at step 4010. In step 4010, the first component receives the first voltage from the voltage input terminal.

In step 4020, the power output unit and the first component perform mutual power output to output a second voltage.

In an embodiment, the second voltage is in the range of 100V-1000V.

In step 4030, the current transformer measures the load current.

In step 4040, when the user load changes, the compensation impedance compensates the voltage drop generated by the load current on the primary side leakage reactance and the secondary side leakage reactance of the voltage measurement unit, and compensates the error of the voltage measurement, and the voltage The measurement unit performs voltage measurement to obtain the third voltage.

The method for voltage measurement using the voltage transformer provided in this embodiment corresponds to the voltage transformer 100 provided in the above embodiment, and will not be repeated here.

FIG. 5 is a schematic structural diagram of another voltage transformer provided by an embodiment of the present application. As shown in FIG. 5, the voltage transformer 200 provided in this embodiment includes: a first component 201 configured to receive a first voltage from a voltage input terminal; a power output unit 202 that senses the first component 201 and the output voltage is 220V , In order to achieve power output and directly supply power to users; current transformer 204, which is connected in series with the winding of power output unit 303, is set to monitor the load current; The compensation winding 205 is connected in series on the winding of the parallel winding, and the compensation winding 205 is connected in parallel with the current transformer 204, and a certain value of the compensation impedance 205 is connected in parallel to the current transformer 204, and the compensation impedance 205 is connected in series on the loop of the winding of the voltage metering unit 203. Error compensation, when the power is output from 0 to full load, the error meets the measurement level error limit requirements. The voltage transformer 200 provided in this embodiment includes: a first component 201, a power output unit 202, a voltage measurement unit 203, a current transformer 204, and a compensation impedance 205. In an embodiment, the first component 201 is configured to be connected to a voltage input terminal and receive a first voltage from the voltage input terminal.

In an embodiment, the power output unit 202, mutual inductance with the first component 201, is configured to output a second voltage to a voltage output terminal to achieve power output.

In an embodiment, the second voltage is in the range of 100V-1000V.

In an embodiment, the voltage measuring unit 203 and the first component 201 have mutual inductance, and are configured to implement voltage measurement and obtain a third voltage.

In an embodiment, the current transformer 204 is connected in series with the winding of the power output unit 202 and is configured to measure the load current.

In an embodiment, the compensation impedance 205 is connected in series with the winding of the voltage metering unit 203 and in parallel with the current transformer 204, and is set to compensate the load current at the voltage metering when the user load changes The voltage drop generated by the leakage reactance of the unit 203 can compensate the error of the voltage measurement.

FIG. 6 is a schematic diagram of another voltage transformer provided by an embodiment of the present application. As shown in Figure 6, U1 is a high voltage, the PT load for voltage measurement is the compensation winding, and the voltage transformer has two secondary windings, including: power output winding (ie power output unit), the output voltage is 220V, can be directly To achieve power supply to users; the voltage measurement winding (ie, voltage measurement unit), the output voltage is / 100 /, under the condition that the user load changes, the load error of the voltage transformer for voltage measurement changes with the change of the load current, by adopting The methods of no-load error compensation and load error compensation realize the error compensation of the voltage measurement winding.

7 is a schematic diagram of another voltage transformer provided by an embodiment of the present application. As shown in Figure 7, AN is the high-voltage terminal on the primary side, T is the voltage transformer, an is the power output terminal, CT is the current transformer that monitors the load current, Z is the compensation impedance, and 1a1n is the voltage measurement terminal. When the load connected to an changes, the error of 1a1n will change due to the change of the load current. By connecting Z in the loop, the voltage drop caused by the leakage reactance of the load current and voltage measurement unit is compensated, so To achieve error compensation, the functions of power output and voltage measurement can be realized at the same time.

8 is a flowchart of another method for voltage measurement using a voltage transformer provided by an embodiment of the present application. As shown in FIG. 8, the method for voltage measurement provided by this embodiment starts at step 8010. In step 8010, the first component receives the first voltage from the voltage input terminal.

In step 8020, the power output unit outputs a second voltage to the voltage output terminal to achieve power output. In an embodiment, the second voltage is a 220V power frequency voltage provided to the user.

In step 8030, the current transformer measures the load current.

In step 8040, when the user load changes, the compensation impedance compensates the voltage drop generated by the load current on the leakage reactance of the voltage measurement unit, compensates the error of the voltage measurement, and the voltage measurement unit performs voltage measurement to obtain the first Three voltages.

The voltage measurement method provided in this embodiment corresponds to the voltage transformer 200 provided in the above embodiment, and will not be repeated here.

Generally, all terms used in the claims are interpreted according to their ordinary meanings in the technical field, unless explicitly defined otherwise therein. All references to "a / said / the [device, component, etc.]" are openly interpreted as at least one example of the device, component, etc. unless explicitly stated otherwise. The steps of any method disclosed herein are not necessarily performed in the exact order disclosed, unless explicitly stated.

Claims

A voltage transformer, including:

The first component is configured to be connected to the voltage input terminal and receive the first voltage from the voltage input terminal;

The power output unit is mutually inductive with the first component, and is configured to be connected to the voltage output terminal and output the second voltage;

A voltage measurement unit is connected in parallel with the power output unit, the voltage measurement unit is a voltage transformer configured to convert the second voltage to a third voltage, and is configured to perform voltage measurement; or, the voltage measurement unit and The mutual inductance of the first component is set to realize voltage measurement and obtain a third voltage;

The current transformer is connected in series with the winding of the power output unit to measure the load current;

The compensation impedance is connected in series with the winding of the voltage measurement unit and in parallel with the current transformer, and is set to compensate the voltage drop generated by the load current on the leakage reactance of the voltage measurement unit when the user load changes , In order to compensate for the error of voltage measurement.
The voltage transformer according to claim 1, wherein, in the case where the voltage metering unit and the power output unit are connected in parallel, the compensation impedance is connected in series with the secondary winding of the voltage metering unit.
The voltage transformer according to claim 1 or 2, wherein the second voltage is in the range of 110V-1000V.
The voltage transformer according to claim 3, wherein the second voltage is 220V.
The voltage transformer according to any one of claims 1 to 4, wherein the third voltage is within a preset range threshold of a standard voltage threshold, the standard voltage threshold is 57.7V, and the preset range threshold is based on The system requirements of the power grid are set.
A method for voltage measurement using the voltage transformer according to claim 1, comprising:

The first component receives the first voltage from the voltage input;

The power output unit and the first component have mutual inductance and output a second voltage;

The current transformer measures the load current;

When the user load changes, the compensation impedance compensates the voltage drop generated by the load current on the leakage reactance of the voltage metering unit, and compensates the error of the voltage metering; the voltage metering unit converts the second voltage to the third Voltage, perform voltage measurement, and obtain a third voltage, or the voltage measurement unit and the first component have mutual inductance, perform voltage measurement, and obtain a third voltage.
The method according to claim 6, wherein the second voltage is in the range of 110V-1000V.
The method according to claim 7, wherein the second voltage is 220V.
The method according to any one of claims 6-8, wherein the third voltage is within a preset range threshold of a standard voltage threshold, the standard voltage threshold is 57.7V, and the preset range threshold is based on System requirements are set.