阅读说明：本技术 一种集群式和链式光学电流传感器及测量电流的方法 (Cluster type and chain type optical current sensor and method for measuring current ) 是由 李岩松 刘君 赵晓君 于 2021-08-02 设计创作，主要内容包括：本发明公开了一种集群式和链式光学电流传感器及测量电流的方法,所述光学电流传感器包括信号处理系统和多个传感器系统。在进行光学电流传感时,所述的集群式光学电流传感器的多个传感器系统位于待测导体周围,可控电流源控制可控发光源发出可控光并转变为线偏振光,线偏转光在导体周围的磁场中,根据法拉第旋光效应产生不同的旋光角,光信号经过光电探测器输出的电信号及光电转速传感器输出的转速分别送到信号处理系统,经过求解非线性方程组的迭代算法,从而求解出被测电流的大小和集群式光学电流传感器的位置信息。(The invention discloses a cluster and chain type optical current sensor and a method for measuring current. When optical current sensing is carried out, a plurality of sensor systems of the cluster type optical current sensor are positioned around a conductor to be measured, a controllable light source is controlled by a controllable current source to emit controllable light and convert the controllable light into linearly polarized light, the linearly polarized light generates different optical rotation angles in a magnetic field around the conductor according to the Faraday optical rotation effect, optical signals are respectively transmitted to a signal processing system through electric signals output by a photoelectric detector and rotating speeds output by a photoelectric rotating speed sensor, and the magnitude of the measured current and the position information of the cluster type optical current sensor are solved through an iterative algorithm for solving a nonlinear equation set.)

1. A clustered optical current sensor, characterized by comprising a plurality of sensor systems (15) and 1 clustered optical current sensor real-time signal processing system (20);

the sensor system (15) is sequentially connected with a high-stability controllable current source (6), a controlled luminous source (7), a sensing magneto-optical light path structure (9), a photoelectric detector (10) and an analog/digital converter (11) along the light path transmission direction;

the sensing magneto-optical light path structure (9) comprises an input collimator (1), a polarizer (2), magneto-optical materials (3), an analyzer (4) and a parallel output collimator (5);

the cluster-type optical current sensor real-time signal processing system (20) comprises a cluster-type optical current sensor data processing unit (16), a three-phase current signal output unit (17), a mutual inductor position signal output unit (18) and a signal output comprehensive unit (19).

2. The clustered optical current sensor according to claim 1, wherein the sensing magneto-optical circuit structures (9) are disposed around the conductor to be measured, 2-10 magneto-optical circuit structures are in one group, the arrangement mode between each group of sensing magneto-optical circuit structures (9) is any shape and is perpendicular to the conductor to be measured, and the distance between the sensing magneto-optical circuit structures (9) and the conductor to be measured is in a range of 0.001mm-1000 mm; multiple groups of sensing magneto-optical light path structures (9) are laminated together in the same axis.

3. A clustered optical current sensor as claimed in claim 1, characterized in that the controlled light emitting source (7) and the sensing magneto-optical path structure (9) in the sensor system (15) are connected by optical fibers, and the sensing magneto-optical path structure (9) and the photodetector (10) are connected by optical fibers.

4. The clustered optical current sensor as claimed in claim 2, wherein the conductors to be measured include an a-phase conductor (12), a B-phase conductor (13), and a C-phase conductor (14), and the a-phase conductor (12), the B-phase conductor (13), and the C-phase conductor (14) are arranged horizontally or in a regular triangle.

5. A clustered optical current sensor as claimed in claim 1, characterized in that the analog/digital converter (11) of the electrical signal outputted from the photodetector (10) finally inputs the digital signal to the clustered optical current sensor real-time signal processing system (20); the digital signals enter a cluster type optical current sensor data processing unit (16) for data processing, three-phase current information and mutual inductor position information are output by a three-phase current signal output unit (17) and a mutual inductor position signal output unit (18) respectively after the data processing, and finally a signal output comprehensive unit (19) outputs the information.

6. A clustered optical current sensor as claimed in claim 1, wherein the multidimensional digital signals entering the clustered optical current sensor data processing unit (16) form corresponding multidimensional nonlinear equations according to faraday rotation effect, the data processing unit (16) solves the multidimensional nonlinear equations by using an iterative method, and the solved three-phase current instantaneous values and transformer position signals are outputted from the three-phase current signal output unit (17) and the transformer position signal output unit (18), respectively.

7. A chained optical current sensor for a single pair of polarizers, wherein a plurality of magneto-optical materials are used to serially connect the clustered optical current sensor according to any one of claims 1 to 6 in a chained manner, only the first segment of the first magneto-optical material is provided with a polarizer, and the tail end of the last magneto-optical material is provided with an analyzer; the first section and the tail end of each magneto-optical material are respectively provided with a polarization-maintaining collimator, and the tail end of the upper magneto-optical material is connected with the polarization-maintaining collimator of the first section of the lower magneto-optical material by a polarization-maintaining optical fiber (8).

8. The single pair of polarizer chain optical current sensors of claim 7, wherein the single pair of polarizer chain optical current sensors are formed by chain connecting the clustered optical current sensors in series with a plurality of magneto-optical materials; a polarizer and an analyzer are arranged at the first section and the tail end of each magneto-optical material; the analyzer at the tail end of the upper strip of magneto-optical material is connected with the polarizer at the first section of the lower strip of magneto-optical material by optical fibers.

9. A method of calculating optical current and transformer position using a clustered optical current sensor according to any of claims 1-6, comprising the steps of:

step 1, arranging the optical current sensors around a conductor to be detected, wherein a group of optical current sensors are arranged around a wire, and a sensing magneto-optical light path structure (9) in the group of optical current sensors is perpendicular to the wire;

step 2: the high-stability controllable current source (6) is turned on, the high-stability controllable current source (6) works in a constant current or constant power mode, and the controlled luminous source (2) is driven to output high-stability direct current light intensity;

and step 3: opening a switch of the photodetector (10) and a switch of the analog/digital converter (11);

and 4, step 4: turning on a power supply of a cluster type optical current sensor real-time signal processing system (21), and inputting a data processing program and parameters into a cluster type optical current sensor data processing unit (16);

and 5: the signal output integration unit (19) outputs three-phase current information and mutual inductor position information.

10. A method of measuring current and sensor position using a clustered optical current sensor according to any of claims 1-6, comprising the steps of:

step S1: the high-stability controllable current source (6) works in a constant current or constant power mode to drive the controlled luminous source (7) to output high-stability direct current light intensity, and an optical signal reaches the photoelectric detector (10) after passing through the sensing magneto-optical light path structure (9);

step S2: the cluster type optical current sensor induces the magnetic field intensity of the magneto-optical material (3) in a magneto-optical light path structure (9) through the Faraday optical rotation effect;

step S3: the analog/digital converter (11) receives an analog signal transmitted from the photoelectric detector (10), converts the analog signal into a digital signal and transmits the digital signal to a clustered optical current sensor data processing unit (16) in a clustered optical current sensor real-time signal processing system (20);

step S4: the cluster type optical current sensor data processing unit (16) measures three-phase current signals and mutual inductor position signals through arithmetic operation, and a signal output integration unit (19) outputs the measured signals.

Technical Field

The invention belongs to the technical field of current measurement in an electric power system, relates to a current measurement sensor taking magneto-optical materials as a main sensing device, and particularly relates to a cluster type and chain type optical current sensor and a current measurement method

Background

In recent years, with the great improvement of the operating voltage level of a power grid, electric field measurement has wider application in a power system. The current transformer is an important device for metering and protection control of an electric power system, a serious magnetic saturation phenomenon occurs in the traditional electromagnetic current transformer under the condition of short-circuit fault, and besides, the electromagnetic current transformer has the defects of large volume, difficult insulation, narrow response frequency band, small dynamic range and the like, and the modern electric power measurement requirement is difficult to meet. A novel optical current transformer based on faraday magneto-optical effect is produced, and particularly, the development of a block-shaped optical current transformer is more emphasized. The optical current transformer adopts magneto-optic materials as sensing media, and realizes the measurement of current by utilizing the characteristic that the angle of change of the polarization direction is in direct proportion to an external magnetic field when linearly polarized light passes through the magneto-optic materials in the external magnetic field.

Object of the Invention

The invention aims to solve the problems in the prior art, and provides a cluster type optical current sensor and a chain type optical current sensor which are simple in manufacturing process, low in manufacturing cost and more beneficial to batch production, so that the influence of magnetic field interference on a block type magneto-optical glass mutual inductor can be avoided, the measurement accuracy of the sensor is effectively improved, and the influence of the position change factor of the mutual inductor on the long-term operation stability of the sensor is eliminated.

Disclosure of Invention

According to an aspect of the present invention, a clustered optical current sensor is provided, comprising a plurality of sensor systems (15) and 1 clustered optical current sensor real-time signal processing system (20); the sensor system (15) is sequentially connected with a high-stability controllable current source (6), a controlled luminous source (7), a sensing magneto-optical light path structure (9), a photoelectric detector (10) and an analog/digital converter (11) along the light path transmission direction; the sensing magneto-optical light path structure (9) comprises an input collimator (1), a polarizer (2), magneto-optical materials (3), an analyzer (4) and a parallel output collimator (5); the cluster-type optical current sensor real-time signal processing system (20) comprises a cluster-type optical current sensor data processing unit (16), a three-phase current signal output unit (17), a mutual inductor position signal output unit (18) and a signal output comprehensive unit (19).

Preferably, the sensing magneto-optical light path structures (9) are placed around the conductor to be detected, 2-10 sensing magneto-optical light path structures form a group, the arrangement mode among each group of sensing magneto-optical light path structures (9) is any shape and is perpendicular to the conductor to be detected, and the distance range between the sensing magneto-optical light path structures (9) and the conductor to be detected is 0.001mm-1000 mm. Multiple groups of sensing magneto-optical light path structures (9) are laminated together in the same axis. Preferably, the controlled light emitting source (7) and the sensing magneto-optical path structure (9) in the sensor system (15) are connected by an optical fiber, and the sensing magneto-optical path structure (9) and the photodetector (10) are connected by an optical fiber.

Preferably, the conductor to be tested comprises an A-phase conductor (12), a B-phase conductor (13) and a C-phase conductor (14), and the A-phase conductor (12), the B-phase conductor (13) and the C-phase conductor (14) are arranged horizontally or in a regular triangle.

Preferably, the digital signal is finally input into a clustered optical current sensor real-time signal processing system (20) in an analog/digital converter (11) of the electric signal output by the photoelectric detector (10); the digital signals enter a cluster type optical current sensor data processing unit (16) for data processing, three-phase current information and mutual inductor position information are output by a three-phase current signal output unit (17) and a mutual inductor position signal output unit (18) respectively after the data processing, and finally a signal output comprehensive unit (19) outputs the information.

Preferably, multidimensional digital signals entering the cluster type optical current sensor data processing unit (16) form corresponding multidimensional nonlinear equations according to the Faraday rotation effect, the data processing unit (16) solves the multidimensional nonlinear equations by using an iteration method, and the solved three-phase current instantaneous values and mutual inductor position signals are output by a three-phase current signal output unit (17) and a mutual inductor position signal output unit (18) respectively.

According to another aspect of the present invention, there is provided a chain type optical current sensor for a single pair of polarizers, which is formed by connecting a plurality of magneto-optical materials in series in a chain manner, wherein a polarizer is disposed at a first segment of a first magneto-optical material, and an analyzer is disposed at a tail end of a last magneto-optical material; the first section and the tail end of each magneto-optical material are respectively provided with a polarization-maintaining collimator, and the tail end of the upper magneto-optical material is connected with the polarization-maintaining collimator of the first section of the lower magneto-optical material by a polarization-maintaining optical fiber (8).

Preferably, the chain type optical current sensor of the single pair of polarizing plates is formed by connecting a plurality of magneto-optical materials in series in a chain manner with the cluster type optical current sensor, and a polarizer and an analyzer are arranged at the head section and the tail end of each magneto-optical material; the analyzer at the tail end of the upper strip of magneto-optical material is connected with the polarizer at the first section of the lower strip of magneto-optical material by optical fibers.

According to another aspect of the present invention, there is provided a method for measuring current by using the above-mentioned clustered optical current sensor, comprising the steps of:

step 1, placing a sensor structure (21) around a conductor to be detected, wherein a group of sensor structures (21) are arranged around a wire, and a sensing magneto-optical light path structure (9) in the group of sensor structures (21) is perpendicular to the wire;

step 2: the high-stability controllable current source (6) is turned on, the high-stability controllable current source (6) works in a constant current or constant power mode, and the controlled luminous source (2) is driven to output high-stability direct current light intensity;

and step 3: opening a switch of the photodetector (10) and a switch of the analog/digital converter (11);

and 4, step 4: turning on a power supply of a cluster type optical current sensor real-time signal processing system (21), and inputting a data processing program and parameters into a cluster type optical current sensor data processing unit (16);

and 5: the signal output integration unit (19) outputs three-phase current information and mutual inductor position information.

A method for measuring current and sensor position by using the cluster type optical current sensor comprises the following steps:

step S1: the high-stability controllable current source (6) works in a constant current or constant power mode to drive the controlled luminous source (7) to output high-stability direct current light intensity, and an optical signal reaches the photoelectric detector (10) after passing through the sensing magneto-optical light path structure (9);

step S2: the cluster type optical current sensor induces the magnetic field intensity of the magneto-optical material (3) in a magneto-optical light path structure (9) through the Faraday optical rotation effect;

step S3: the analog/digital converter (11) receives an analog signal transmitted from the optical detector (10), converts the analog signal into a digital signal and transmits the digital signal to a clustered optical current sensor data processing unit (16) in a clustered optical current sensor real-time signal processing system (20);

step S4: the cluster type optical current sensor data processing unit (16) measures three-phase current signals and mutual inductor position signals through arithmetic operation, and a signal output integration unit (19) outputs the measured signals.

Drawings

FIG. 1 is a schematic diagram of a cluster-type optical current sensor and a signal processing device thereof;

FIG. 2 is a schematic diagram of a single pair of polarizer chain type optical current sensor and a signal processing device thereof;

fig. 3 and 4 are schematic diagrams of two different types of chain type optical current sensors with pairs of polarizing plates and signal processing devices thereof.

Reference numerals: 1-an input collimator; 2-a polarizer; 3-a magneto-optical material; 4-an analyzer; 5-parallel output collimator; 6-high stability controllable current source; 7-a controlled light emitting source; 8-polarization maintaining fiber; 9-sensing a magneto-optical light path structure; 10-a photodetector; 11-an analog/digital converter; 12-current conductor to be tested a; 13-current conductor to be tested B; 14-current conductor C to be measured; 15-a sensor system; 16-a clustered optical current sensor data processing unit; 17-a three-phase current signal output unit; 18-a transformer position signal output unit; 19-a signal output synthesis unit; 20-a cluster type optical current sensor real-time signal processing system.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The attached drawing is a schematic diagram of a cluster type optical current sensor and a signal processing device thereof, as shown in the figure, an A-phase conductor (12), a B-phase conductor (13) and a C-phase conductor (14) are horizontally arranged in a parallel mode, the distance between the adjacent conductors is a fixed value, and the cluster type optical current sensor comprises 6 sensor systems (15) and 1 cluster type optical current sensor real-time signal processing system (20); the system comprises 6 sensor systems (15), a high-stability controllable current source (6), a controlled light source (7), an optical splitting path (8), a sensing magneto-optical path structure (9), a photoelectric detector (10) and an analog/digital converter (11), wherein the high-stability controllable current source, the controlled light source (7), the optical splitting path (8), the sensing magneto-optical path structure (9) and the photoelectric detector are sequentially connected along the optical path transmission direction; the sensing magneto-optical light path structure (9) comprises an input collimator (1), a polarizer (2), magneto-optical materials (3), an analyzer (4) and a parallel output collimator (5); the cluster-type optical current sensor real-time signal processing system (20) comprises a cluster-type optical current sensor data processing unit (16), a three-phase current signal output unit (17), a mutual inductor position signal output unit (18) and a signal output comprehensive unit (19).

The cluster type optical current sensor measures the magnetic field intensity through the Faraday magneto-optical effect so as to reflect the current in a conductor to be measured, a sensor structure (21) is arranged around the conductor to be measured, a group of sensor structures (21) (the number of the sensor structures is 2-10) are arranged around one conductor, and sensing magneto-optical light path structures (9) in the group of sensor structures (21) are parallel to each other and are perpendicular to the measured current conductor; the high-stability controllable current source (6) is turned on, the high-stability controllable current source (6) works in a constant current or constant power mode, and the controlled luminous source (2) is driven to output high-stability direct current light intensity; opening a switch of the photodetector (10) and a switch of the analog/digital converter (11); turning on a power supply of a cluster type optical current sensor real-time signal processing system (21), and inputting a data processing program and parameters into a cluster type optical current sensor data processing unit (16); the signal output integration unit (19) outputs three-phase current information and mutual inductor position information.

The specific calculation process of the clustered optical current sensor data processing unit (16) is as follows:

I_a、I_b、I_cthree-phase current, a, b and c are distances between the magneto-optical glass on the left side of the mutual inductor and the nearest conductor, I₁～I₆A digital signal output by the analog/digital converter; d is the distance between adjacent conductors and M is half the length of the magneto-optical glass.

Giving initial values of variables as I_a ⁽⁰⁾，I_b ⁽⁰⁾，I_c ⁽⁰⁾，a⁽⁰⁾，b⁽⁰⁾And c⁽⁰⁾And let the correction amounts be respectively Delta I_a ⁽⁰⁾，ΔI_b ⁽⁰⁾，ΔI_c ⁽⁰⁾，Δa⁽⁰⁾，Δb⁽⁰⁾And Δ c⁽⁰⁾。

Let the iteration number k equal to 0 and start the iteration.

(1) Calculating the amount of unbalance f₁ ^(k)，f₂ ^(k)，f₃ ^(k)，f₄ ^(k)，f₅ ^(k)And f₆ ^(k)

(2) Calculate its Jacobian matrix J

Wherein the content of the first and second substances,

(3) solving a correction equation, and calculating the correction quantity delta I obtained by the k iteration_a ^(k)，ΔI_b ^(k)，ΔI_c ^(k)，Δa^(k)，Δb^(k)And Δ c^(k)

(4) Correcting variables

a^(k+1)＝a^(k)-△a^(k)

b^(k+1)＝b^(k)-△b^(k)

c^(k+1)＝c^(k)-△c^(k)

(5) Will be delta I_a ^(k+1)，ΔI_b ^(k+1)，ΔI_c ^(k+1)，Δa^(k+1)，Δb^(k+1)And Δ c^(k+1)As new variable initial values, the next iteration is carried out again according to (1), (2), (3) and (4) until the new variables are metThe iteration ends. Wherein epsilon is iteration precision;

a method of using a clustered optical current sensor, comprising the steps of:

step 1, arranging sensor structures (21) around a conductor to be detected, wherein 6 sensor structures (21) (the number of the sensor structures is 2-10) are arranged around one wire, and sensing magneto-optical light path structures (9) in the sensor structures (21) are parallel to each other and are perpendicular to a current wire to be detected;

step 2: the high-stability controllable current source (6) is turned on, the high-stability controllable current source (6) works in a constant current or constant power mode, and the controlled luminous source (2) is driven to output high-stability direct current light intensity;

and step 3: opening a switch of the photodetector (10) and a switch of the analog/digital converter (11);

and 4, step 4: turning on a power supply of a cluster type optical current sensor real-time signal processing system (20), inputting the data processing program and basic parameters into a cluster type optical current sensor data processing unit (16), taking three-phase currents IA (100), IB (100) and IC (200) as examples for verification, inputting basic parameters a (50), b (50) and c (50) to initialize LABVIEW, obtaining data I1 (23.23), I2 (21.634), I3 (12.953), I4 (73.566), I5 (77.914) and I6 (35.445), and calculating by utilizing the processing process to obtain three-phase current instantaneous values I (24)_a、I_b、I_cAnd the final results of the transformer position signals a, b and c are shown in the following table:

actual value and measured value comparison table

	IA	IB	IC	a	b	c
							Measured value	99.9723	99.9449	-199.949	49.9903	49.9872	49.9845
Actual value	100	100	-200	50	50	50

And 5: the signal output integrated unit (19) outputs three-phase current information I_a、I_b、I_cAnd mutual inductor position information a, b, c.

The invention is mainly suitable for measuring the current of a power system, and provides a method for measuring the current and the sensor position by a cluster type optical current sensor on the basis of the traditional current measurement, wherein the method comprises the following steps:

1) the high-stability controllable current source (6) works in a constant current or constant power mode, the controlled luminous source (7) is driven to output high-stability direct current light intensity, and an optical signal reaches the photoelectric detector (10) after passing through the sensing magneto-optical light path structure (9);

2) the cluster type optical current sensor induces the magnetic field intensity of the magneto-optical material (3) in a magneto-optical light path structure (9) through the Faraday optical rotation effect;

3) the analog/digital converter (11) receives the analog signal transmitted from the photoelectric detector (10), converts the analog signal into a digital signal and transmits the digital signal to a cluster type optical current sensor data processing unit (16) in a cluster type optical current sensor real-time signal processing system (20);

4) the cluster type optical current sensor data processing unit (16) measures three-phase current signals and mutual inductor position signals through arithmetic operation, and a signal output integration unit (19) outputs the measured signals.

Compared with the prior art, the invention has the beneficial effects that:

1. when the three-phase current is measured, the sensing heads on each phase of conductor are mutually coupled, so that the output result of the sensor simultaneously contains the three-phase current result, the influence of magnetic field interference on the block magneto-optical glass mutual inductor is avoided, and the measurement precision of the sensor is effectively improved.

2. The invention can simultaneously measure the position relation between the mutual inductor and the conductor when measuring the three-phase current, and can eliminate the influence on the long-term operation stability of the sensor due to the position change factor of the mutual inductor.

3. The mutual inductor provided by the invention is a plurality of block magneto-optical glass mutual inductors, has simple manufacturing process and low manufacturing cost, and is more beneficial to batch production.

It should be understood by those skilled in the art that the above embodiments are only preferred embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.