WO2012059061A1

WO2012059061A1 - Method and device for quality-monitoring of high-voltage electrical energy

Info

Publication number: WO2012059061A1
Application number: PCT/CN2011/081740
Authority: WO
Inventors: 侯铁信; 卜正良; 张乐平; 徐芝贵; 胡顺; 李优仪
Original assignee: 武汉国测恒通智能仪器有限公司
Priority date: 2010-11-04
Filing date: 2011-11-03
Publication date: 2012-05-10
Also published as: CN102053203A

Abstract

A method and device for quality-monitoring of high-voltage electrical energy, comprising: acquisition of a voltage measurement signal from a capacitive voltage divider (1) and of a current signal from a low power-consumption, low-voltage current transformer (2); simultaneous transmission to a data collection and processing circuit (4) of the acquired voltage measurement signal and current signal; calculation and analysis of the corresponding electrical energy quality information and transmission thereof via optical fiber (5) to an integrated processing unit (6) for storage and display. The method and device for quality-monitoring of high-voltage electrical energy herein provided is able accurately to measure a voltage harmonics signal and provide powerful data in respect of harmonics monitoring and control, and is also able accurately to measure a current signal when a secondary load is very small while retaining a relatively wide linear working range. Because the present method and device for quality-monitoring of high-voltage electrical energy suspends the data collection and processing circuit (4) on the high-voltage side, cut-off between a first and a second signaling is avoided, device volume and weight are reduced and materials saved. In so far as an installation location can be arranged on an existing power line, the monitoring device can be installed on all types of power line, thus providing a convenient system improvement.

Description

High-voltage power quality detection method and device

TECHNICAL FIELD The present invention relates to the field of power quality monitoring technologies, and more particularly to a method and apparatus for detecting high voltage power quality. BACKGROUND OF THE INVENTION Power quality refers to the extent to which various indicators of voltage and current that are related to the normal operation (or operation) of power supply, power supply systems, and their equipment deviate from the specified range. The detection of power quality is of great significance for improving the quality of power supply. The voltage signal of the existing power quality detection method is mainly taken from the voltage transformer, and the current signal is mainly taken from the current transformer. At present, many countries use capacitive voltage transformers in llOkV and above, but capacitive voltage transformers can only measure power frequency signals and cannot be used for harmonic detection. If the current signal is taken from the current transformer for measurement, the load of the current transformer will change, which may affect the accuracy of the measurement. If the current transformer is used for protection, the secondary signal is small when the system is in normal operation. The accuracy of the current transformer is not high, so the accuracy of the test results cannot be guaranteed.

Power quality includes supply voltage deviation, frequency deviation, three-phase voltage imbalance, voltage fluctuation and flicker, and harmonics. To analyze power quality, it is necessary to comprehensively detect these workloads. It is difficult for existing power quality detection devices to meet these comprehensive tests. Demand. SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a high-voltage power quality detecting method and apparatus capable of accurately measuring voltage harmonic signals and current signals, and having small volume and low cost. In order to solve the above technical problem, the present invention provides a high voltage power quality detecting method, including:

测量 measuring a voltage signal with a capacitive voltage divider, measuring a current signal with a low voltage current transformer; transmitting the voltage signal and the current signal to a data collection and processing circuit, the data The set and processing circuit is suspended on the high voltage side; the data collection and processing circuit calculates and analyzes the power quality information according to the voltage signal and the current signal, and sends the power quality information to the integrated processing unit of the low voltage part. Further, the data collection and processing circuit is supplied with operating energy by an energy dissipating voltage divider. Further, the data collection and processing circuit transmits the power quality information to the integrated processing unit via an optical fiber.

Further, for the three-phase four-wire power system, the voltage signals and current signals of the respective phases are respectively measured and sent to the corresponding data collection and processing circuits; the data collection and processing circuits respectively calculate and analyze the power quality of each phase. And transmitting the power quality information to the integrated processing unit respectively; the integrated processing unit obtains three-phase voltage imbalance information according to the obtained power quality information calculation process of each phase.

Further, for the three-phase three-wire power system, the current signals of the two phases of C and C and the phase-to-phase voltages of the AB phase and the BC phase are respectively measured and sent to the integrated measuring unit; the integrated measuring unit is based on the phase-to-phase voltage of the AB phase and the BC phase The voltage value of the AC phase is calculated, and the B phase current value is calculated according to the current signals of the two phases A and C, and the power quality information is further calculated and analyzed. The invention also provides a high-voltage power quality detecting device, comprising: a capacitive voltage divider for measuring a voltage signal and outputting; a low-voltage current transformer for measuring a current signal and outputting; a calculation analyzing unit, configured to receive the The voltage signal outputted by the capacitive voltage divider and the current signal output by the low voltage current transformer are calculated and analyzed according to the voltage signal and the current signal to obtain power quality information.

Further, comprising: three capacitive voltage dividers for measuring voltage signals of respective phases of the three-phase four-wire power system and The calculation and analysis unit includes three data collection and processing circuits and an integrated processing unit, wherein

Three data collection and processing circuits are suspended on the high voltage side, respectively connected to a phase capacitive divider and a low voltage current transformer for receiving the voltage signal output by the corresponding capacitive voltage divider and the current output of the corresponding low voltage current transformer a signal, calculating and analyzing the power quality information of each phase according to the voltage signal and the current signal; the integrated processing unit respectively connecting three data collection and processing circuits for receiving power quality information of each phase, and according to the electrical energy The quality information calculates the three-phase voltage imbalance information.

Further, the method includes: two capacitive voltage dividers for measuring the phase-to-phase voltage signals of the AB phase and the BC phase of the three-phase three-wire power system and outputting; two low-voltage current transformers for measuring the three-phase three-wire power system The single-phase current signals of phases A and C are output; the computer analysis unit comprises two single-phase measuring units, one integrated measuring unit and one low-voltage display terminal, wherein: two single-phase measuring units are respectively connected to eight and two C a phase capacitive divider and a low voltage current transformer for receiving the phase-to-phase voltage signal of the AB phase and the BC phase and the single-phase current signals of the two phases A and C, and transmitting the signal to the integrated measuring unit; the integrated measuring unit is respectively connected Two single-phase measuring units are configured to receive a signal output by the single-phase measuring unit, calculate an phase-to-phase voltage and a phase-phase current of the AC phase according to the signal, and further calculate power quality information of each phase;

a low-voltage display terminal is connected to the integrated measuring unit for receiving and displaying the power quality information. Further, it also includes: An energy divider is provided for providing power to the computing analysis unit.

The high-voltage power quality detecting method and device of the invention can accurately measure voltage harmonic signals, solve the problem that the conventional harmonic cannot be measured, provide powerful data for harmonic monitoring, and can accurately measure when the secondary load is small. Current signal and has a wide linear operating range.直接Using the direct measurement method of high-voltage power quality of the invention, the data collection and processing circuit is suspended on the high-voltage side, which can avoid the insulation between the first and second times, significantly reduce the volume and weight of the device, and save a large amount of raw materials; The volume and light weight design enables the detection device of the present invention to be directly mounted on various lines without the reserved installation position of the existing line, thereby facilitating system improvement. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic block diagram of an application embodiment of a high-voltage power quality detecting device of the present invention applied to a three-phase four-wire power system;

Fig. 2 is a block diagram showing the principle of application of the high-voltage power quality detecting device of the present invention to a three-phase three-wire power system. The invention is further described in the following with reference to the accompanying drawings and specific embodiments, which are to be understood by those skilled in the art. The technical solution adopted by the invention is that the voltage signal is measured by a capacitive voltage divider, the current signal is measured by a low-power low-voltage current transformer, and the measured voltage signal and the current signal are simultaneously sent to the data suspended on the high voltage side. The 釆 collecting and processing circuit calculates and analyzes the corresponding power quality information, and sends it to the integrated processing unit of the low voltage part for storage and display through the optical fiber. The high voltage side circuit power supply is provided by an energy dissipating voltage divider.

For the three-phase four-wire power system, the single-phase high-voltage power quality is directly detected. Each phase completes the data collection and calculation on the high-voltage side, completes all power quality calculations except the imbalance, and transmits the data to the integrated processing unit of the low-voltage part through the optical fiber, according to the three-phase data. The integrated processing unit performs the calculation and measurement of the imbalance, and displays the results, remote transmission and statistics. For the three-phase three-wire power system, the three-phase high-voltage power quality direct detection method is adopted. The two phases A and C respectively detect the single-phase power quality, and in the B-phase measurement integrated unit, by calculating the AC phase-to-phase voltage and the B-phase current, all the power quality information can be obtained, and then the B-phase integrated measurement unit The power quality information is transmitted to the low voltage side through the optical fiber for display, remote transmission and statistics. The high voltage power quality detecting device of the invention comprises:

a capacitive voltage divider for measuring a voltage signal and outputting;

a low-voltage current transformer for measuring a current signal and outputting; a calculation analyzing unit, configured to receive a voltage signal output by the capacitive voltage divider and a current signal output by the low-voltage current transformer, according to the voltage signal and the current signal Calculate and analyze the power quality information.

As shown in FIG. 1, as an embodiment applied to a three-phase four-wire power system, the detecting apparatus of the present invention includes:

Three capacitive voltage dividers 1 for measuring the voltage signals of each phase of the three-phase four-wire power system

Three low-voltage current transformers 3 for measuring the current signals of the phases of the three-phase four-wire power system and outputting them;

The calculation analysis unit includes three data collection and processing circuits 4 and an integrated processing unit 6, wherein

Three data collection and processing circuits 4 are suspended on the high voltage side, respectively connected to a phase capacitive divider 1 and a low voltage current transformer 3 for receiving the voltage signal outputted by the corresponding capacitive voltage divider 1 and the corresponding low voltage current mutual inductance The current signal output by the device 3 is calculated and analyzed according to the voltage signal and the current signal to obtain power quality information such as voltage deviation, frequency deviation, voltage fluctuation, flicker and harmonics of each phase;

The integrated processing unit 6 is connected to three data collection and processing circuits 4 for receiving power quality information of each phase, and calculating three-phase voltage imbalance information according to the power quality information, and Display results, remote transmissions and statistics. Preferably, the data collection and processing circuit and the integrated processing unit 6 are connected by an optical fiber 5. In addition, each phase further includes an energy dissipating voltage divider 2 coupled to the data collection and processing circuit 4 of the phase for obtaining electrical energy from the power supply line for powering the corresponding data collection and processing circuit 4. As shown in FIG. 2, as another embodiment applied to a three-phase three-wire power system, the detecting apparatus of the present invention includes:

A capacitive voltage divider 7, a low voltage current transformer 9 and a single phase measuring unit 10 are respectively arranged on the high voltage side of the A phase and the high voltage side of the C phase, wherein a capacitive voltage divider of the high phase side of the A phase is used to measure the phase of the AB phase. Voltage, and the capacitive divider of the high-voltage side of the C-phase is used to measure the phase-to-phase voltage signal of the BC phase, and the low-voltage current transformer 9 of the high-voltage side of the A-phase and the high-voltage side of the C-phase are used to measure the current signals of the A-phase and the C-phase, respectively. The voltage divider 7 and the current transformer 9 respectively transmit the measured phase-to-phase voltage signal and the single-phase current signal to the corresponding single-phase measuring unit 10; the single-phase measuring unit 10 transmits the corresponding phase-to-phase voltage signal and the single-phase current signal to Integrated measurement unit 11 on the B phase high side;

The B-phase high-voltage side includes an integrated measuring unit 11, and the integrated measuring unit 11 receives the signals output by the single-phase measuring units 10, and calculates the phase-to-phase voltage signal and the B-phase current of the AC phase based on the signals, and further calculates the electric energy of each phase. Quality information, including supply voltage deviation, frequency deviation, voltage fluctuations and flicker, harmonics, and three-phase voltage imbalance. The integrated measurement unit 11 can transmit the calculated power quality information to the low-voltage display terminal 13 for display, and the low-voltage display terminal 13 can further transmit and count the power quality information. An energy dissipating voltage divider 8 is provided on the high-pressure side of the A-phase, the high-pressure side of the B-phase, and the high-pressure side of the C-phase, respectively for supplying power to the single-phase measuring unit 10 and the combined measuring unit 11. Preferably, each of the single-phase measuring unit 10 and the integrated measuring unit 11 and the combined measuring unit 11 and the low-voltage display terminal 13 are connected by an optical fiber 12. The invention uses a capacitive voltage divider to accurately measure voltage harmonic signals, solve the problem that the conventional harmonics cannot be measured, and provide powerful data for harmonic monitoring; use low-power low-voltage current transformers, twice The current signal can be accurately measured under a small load, and has a wide linear operating range. 直接 The data of the high-voltage power quality direct measurement method of the present invention is used to collect data. Suspended on the high voltage side with the processing circuit, it can avoid the insulation between the first and second, significantly reduce the size and weight of the device, and save a lot of raw materials; Small size and light weight design, can be installed in the existing line without reservation In the case of position, it is directly installed on various lines to facilitate system improvement.

The above-described embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the scope of the present invention. The scope of the invention is defined by the claims.

Claims

Claim

A high-voltage power quality detecting method, characterized in that:

测量 measuring a voltage signal by using a capacitive voltage divider, measuring a current signal by using a low voltage current transformer; transmitting the voltage signal and the current signal to a data collection and processing circuit, wherein the data collection and processing circuit is suspended on the high voltage side;

The data collection and processing circuit calculates and analyzes the power quality information based on the voltage signal and the current signal, and transmits the information to the integrated processing unit of the low voltage portion.

2. The high voltage power quality detecting method according to claim 1, wherein the data collecting and processing circuit supplies operating power from the energy dissipating voltage divider.

The high-voltage power quality detecting method according to claim 1, wherein the data collection and processing circuit transmits the power quality information to the integrated processing unit via an optical fiber.

The high-voltage power quality detecting method according to claim 1, wherein, for the three-phase four-wire power system, the voltage signals and current signals of the respective phases are respectively measured and sent to the corresponding data collecting and processing circuits;

The data collection and processing circuit respectively calculates and analyzes the power quality information of each phase, and respectively sends the power quality information to the integrated processing unit;

The integrated processing unit obtains three-phase voltage imbalance information based on the obtained power quality information calculation processing of each phase.

The high-voltage power quality detecting method according to claim 1, wherein, for the three-phase three-wire power system, the current signals of the eight and C phases and the phase-to-phase voltages of the AB phase and the BC phase are respectively measured and sent to the integrated measuring unit. ;

The integrated measuring unit calculates the voltage value of the AC phase according to the phase-to-phase voltage of the AB phase and the BC phase, calculates the B-phase current value according to the A and C phase currents, and further calculates and analyzes the power quality information.

6. A high-voltage power quality detecting device, comprising:

a capacitive voltage divider for measuring a voltage signal and outputting;

Low-voltage current transformer for measuring current signals and outputting;

And a calculation analyzing unit, configured to receive a voltage signal output by the capacitive voltage divider and a current signal output by the low voltage current transformer, and calculate and obtain power quality information according to the voltage signal and the current signal.

7. The high-voltage power quality detecting apparatus according to claim 6, comprising: three capacitive voltage dividers for measuring voltage signals of each phase of the three-phase four-wire power system and three current transformers, And respectively for measuring a current signal of each phase of the three-phase four-wire power system, and the calculation and analysis unit comprises three data collection and processing circuits and an integrated processing unit, wherein

Three data collection and processing circuits are suspended on the high voltage side, respectively connected to a phase capacitive divider and a low voltage current transformer for receiving the voltage signal output by the corresponding capacitive voltage divider and the current output of the corresponding low voltage current transformer a signal, calculating and analyzing the power quality information of each phase according to the voltage signal and the current signal;

The integrated processing unit is respectively connected with three data collection and processing circuits for receiving power quality information of each phase, and calculating three-phase voltage imbalance information according to the power quality information.

8. The high-voltage power quality detecting apparatus according to claim 6, comprising: two capacitive voltage dividers for measuring and outputting phase-to-phase voltage signals of the AB phase and the BC phase of the three-phase three-wire power system;

Two low-voltage current transformers for measuring single-phase current signals of phase A and phase C of a three-phase three-wire power system and outputting them;

The computer analysis unit includes two single-phase measurement units, one integrated measurement unit, and one Low voltage display terminals, where:

Two single-phase measuring units respectively connecting the eight-phase and two-phase capacitive voltage dividers and the low-voltage current transformers for receiving the phase-to-phase voltage signals of the AB phase and the BC phase and the single-phase current signals of the two phases of A and C , sent to the integrated measurement unit;

The integrated measuring unit is respectively connected to two single-phase measuring units for receiving signals output by the single-phase measuring unit, calculating phase-to-phase voltage and phase B current of the AC phase according to the signals, and further calculating electrical energy of each phase Quality information;

a low-voltage display terminal is connected to the integrated measuring unit for receiving and displaying the power quality information.

9. The device of claim 6, further comprising:

An energy divider is provided for providing power to the computing analysis unit.