WO2017185226A1 - 基于循环回路的高灵敏度光纤电流传感装置 - Google Patents
基于循环回路的高灵敏度光纤电流传感装置 Download PDFInfo
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- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
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- the invention relates to a technology in the field of photoelectric detection, in particular to a high-performance and high-reliability loop-based high-sensitivity optical fiber current sensing device which can be applied to power transmission, smart grid and substation control.
- Fiber-Optic Current Sensors use magneto-optical effects (Faraday effect) to measure current due to its unique advantages, such as inherent insulation, light weight and immunity to degraded magnetic fields.
- Faraday effect magneto-optical effects
- the two main obstacles that currently limit its practical application are: the sensitivity of the sensor to temperature changes and vibrations, and the insensitivity of the magnetic field of the silicon material as determined by the Feld constant.
- Many studies have improved from improving fiber media to system design. Studies have reported the use of circular birefringent spun fibers to reduce their sensitive environment, using special fibers such as vermiculite glass, rare earth doped glass fibers and large Feld's new magnetic fluid constant to improve sensitivity. However, these specialty fibers are usually very expensive and very difficult to fabricate.
- sensing systems using Sagnac or ring structures have also been reported to increase sensitivity by effectively increasing the length of interaction between the fiber and the magnetic field.
- the invention adopts a low-sensitivity fiber-optic current sensing system based on a loop circuit, which adopts a ring-down structure and thus has a high cycle loss, and can only achieve a small number of Faraday effect accumulation, which leads to limited improvement of sensing sensitivity.
- the device adopts a loop circuit based on fast optical switch, which can realize the Faraday effect accumulation multiple times, and the loss of the system loop is small, and the accumulation times can be more than 10 times, thereby significantly improving the system sensitivity and stability.
- the present invention comprises: a linearly polarized pulse light generating mechanism, a control pulse generating mechanism, a 2 ⁇ 2 optical switch, and a sensing optical fiber, wherein: the first input end and the first output end of the optical switch are respectively coupled to the linearly polarized pulse light generating mechanism and
- the control pulse generating mechanism is connected to receive the linearly polarized pulse light and the control pulse, the control pulse generating mechanism is connected to the linear polarization pulse light generating mechanism and outputs the modulated pulse, and the second input end and the second output end of the optical switch form a loop with the sensing fiber. Loop.
- the linearly polarized pulse light generating mechanism comprises: a light source, a modulator and a polarizer connected in sequence, wherein: a polarizer The linearly polarized pulsed light is output to a first input of the optical switch, and the modulator receives a modulated pulse from the control pulse generating mechanism.
- the control pulse generating mechanism comprises: an analyzer, a photodetector, a signal processing unit and a pulse generator connected in sequence, wherein: the signal processing unit collects and processes the voltage signal obtained by the photodetector, and analyzes the amplitude of the signal. The change obtains polarization change information caused by the influence of the magnetic field on the pulse and outputs it to the pulse generator.
- the pulse generator outputs a modulation pulse to the linearly polarized pulse light generating mechanism to generate a light pulse, and outputs a control pulse to the optical switch to control the light pulse in the circulation loop. Cycle time in .
- the present invention uses a 2 ⁇ 2 optical switch to construct a loop, and uses a special control pulse generating mechanism for signal processing and pulse control, respectively, and the sensitivity and stability of the present invention in terms of test data. Compared with the prior art, there is a big improvement.
- the invention realizes multiple Faraday effect cycle accumulation through innovative design, thereby effectively reducing the use length of the sensing fiber, and the sensing fiber is expensive, especially the special doped high Fidelity constant sensing fiber. Therefore, the present invention can indirectly reduce costs on the basis of improved performance.
- Figure 1 is a schematic structural view of the present invention
- FIG. 2 is a schematic diagram of the on/off of the optical switch
- low level is 1 ⁇ 4, 2 ⁇ 3; high level is 1 ⁇ 3, 2 ⁇ 4;
- Figure 3 is a schematic diagram of a pulse control signal
- Figure 4 is a diagram showing the relationship between the deflection angle and the number of cycles
- Figure 6 is a graph of sensitivity versus cycle number.
- the embodiment includes: a linear polarization pulse light generating mechanism, a control pulse generating mechanism, a 2 ⁇ 2 optical switch, and a sensing optical fiber, wherein: the first input end and the first output end of the optical switch respectively
- the linearly polarized pulse light generating mechanism is connected to the control pulse generating mechanism to receive the linearly polarized pulse light and the control pulse
- the control pulse generating mechanism is connected to the linearly polarized pulse light generating mechanism and outputs the modulated pulse
- the second input end and the second output of the optical switch The end and the sensing fiber form a loop.
- the linearly polarized pulse light generating mechanism comprises: a light source, a modulator and a polarizer connected in sequence, wherein: the polarizer outputs linearly polarized pulse light to the first input end of the optical switch, and the modulator receives the control pulse generating mechanism Modulation pulse.
- the control pulse generating mechanism comprises: an analyzer, a photodetector, a signal processing unit and a pulse generator connected in sequence, wherein: the signal processing unit collects and processes the voltage signal obtained by the photodetector, and analyzes the amplitude of the signal. The change obtains the polarization change information caused by the pulse affected by the magnetic field and outputs it to the pulse generator, and the pulse generator respectively linearly polarizes
- the pulsed light generating mechanism outputs a modulated pulse to generate a light pulse, and outputs a control pulse to the optical switch to control the cycle time of the light pulse in the circulation loop.
- the polarization change information includes: a control pulse and synchronization information.
- the sensing fiber is disposed in a circulation loop, and the length of the sensing fiber is greater than or equal to the length of the modulation pulse.
- the signal processing unit includes: an arbitrary waveform generation module and a data acquisition module.
- the embodiment relates to a method for sensing a fiber current of the device, which specifically includes the following steps:
- the first input end and the first output end of the optical switch are respectively connected to the linear polarization pulse light generating mechanism and the control pulse generating mechanism, and the second input end and the second output end of the optical switch form a circulation loop
- the sensing fiber is disposed in the circulation loop
- the fiber length of 1km is set in the circulation loop system, and as the delay fiber and the sensing fiber, the effect of the delay is that the pulse length is completely contained in the circulation loop, thereby ensuring system stability;
- the bias voltage and current are set for the laser.
- the output laser power is 25 mW.
- the bias voltage and current are set to the photodetector so that the received optical signal can be converted into a voltage amplitude signal output.
- the switch controls the cycle time of the light pulse in the loop.
- a modulation pulse width of 5 microseconds is used, and the length of the control pulse is selected according to the number of cycles required. In the case of 10 cycles, the control pulse length is selected to be 55 microseconds.
- the optical signal obtained by the photodetector will be converted into a voltage signal input to the data acquisition module of the signal processing unit.
- Figure 5 shows the amplitude of the acquired time domain signal after 8 cycles of the time domain signal under different current conditions. Variety.
- the present invention innovatively uses a laser, a modulator, a polarizer, a 2 ⁇ 2 optical switch, an analyzer, and a photodetector to construct a loop, and employs a specially designed signal processing unit and pulse. Signal control unit.
- the resulting fiber-optic current sensing system has the performance advantages of high stability and high sensitivity, and the sensitivity increases with the number of cycles, and the sensing fiber portion can be replaced with the fiber type as needed.
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Abstract
一种基于循环回路的高灵敏度光纤电流传感装置，包括：线偏振脉冲光发生机构、控制脉冲发生机构、2×2的光开关以及传感光纤，其中：光开关的第一输入端和第一输出端分别与线偏振脉冲光发生机构和控制脉冲发生机构相连以接收线偏振脉冲光和控制脉冲，控制脉冲发生机构与线偏振脉冲光发生机构相连并输出调制脉冲，光开关的第二输入端和第二输出端与传感光纤组成循环回路。
Description
本发明涉及的是一种光电检测领域的技术，具体是一种可以应用于电力传输、智能电网、变电控制的高性能、高可靠性的基于循环回路的高灵敏度光纤电流传感装置。
光纤电流传感器(Fiber-Optic Current Sensors,FOCS)，利用磁光效应(法拉第效应)测量电流，由于其独特的优点，如固有的绝缘性，重量轻和对退化磁场免疫。但目前限制其实际应用技术的两个主要的障碍包括：该传感器对于温度变化和振动的敏感性，以及由费尔德常数决定的硅材料磁场的不敏感性。许多研究已经从改善光纤传媒到系统设计方面进行了改进。有研究报道使用圆双折射纺纤维降低其敏感性环境，采用特殊纤维如燧石玻璃、稀土掺杂玻璃纤维和大费尔德新型磁流体常数提高灵敏度。然而，这些特种纤维通常非常昂贵，非常困难捏造。另一方面，传感系统利用Sagnac或环状结构也有报道通过有效地提高光纤和磁场的相互作用长度，提高了灵敏度。
经过对现有技术的检索发现，Z Hao等在“High-current-sensitivity all-fiber current sensor based on fiber loop architecture.”(《Optics Express》,2012,20(17):18591-9)中公开了一种用普通石英光纤实现的新型全光纤电流传感器。但该现有技术衰荡腔结构存在较严重的损耗问题，只能实现很少数量的脉冲循环，因此能够提高的灵敏度很有限，同时现有方法还会出现系统不稳定，容易受外界稳定振动影响的问题。
发明内容
本发明针对现有技术采用衰荡结构因此循环损耗较高，只能实现少量次数的法拉第效应积累从而导致对传感灵敏度的提高有限等不足，提出一种基于循环回路的高灵敏度光纤电流传感装置，采用基于快速光开关的循环回路，可以多次实现法拉第效应积累，并且系统环路的损耗较小，可以实现的积累次数超过10次以上，因此显著提高系统灵敏度和稳定性。
本发明是通过以下技术方案实现的：
本发明包括：线偏振脉冲光发生机构、控制脉冲发生机构、2×2的光开关以及传感光纤，其中：光开关的第一输入端和第一输出端分别与线偏振脉冲光发生机构和控制脉冲发生机构相连以接收线偏振脉冲光和控制脉冲，控制脉冲发生机构与线偏振脉冲光发生机构相连并输出调制脉冲，光开关的第二输入端和第二输出端与传感光纤组成循环回路。
所述的线偏振脉冲光发生机构包括：依次相连的光源、调制器和起偏器，其中：起偏器
输出线偏振脉冲光至光开关的第一输入端，调制器接收来自控制脉冲发生机构的调制脉冲。
所述的控制脉冲发生机构包括：依次相连的检偏器、光电探测器、信号处理单元和脉冲发生器，其中：信号处理单元对光电探测器得到的电压信号进行采集和处理，解析信号幅度的变化得到脉冲受磁场影响导致的偏振变化信息并输出至脉冲发生器，脉冲发生器分别向线偏振脉冲光发生机构输出调制脉冲以产生光脉冲，向光开关输出控制脉冲以控制光脉冲在循环回路中的循环时间。
技术效果
与现有技术相比，本发明使用了2×2光开关来构建环路，同时用了专门的控制脉冲发生机构分别用于信号处理和脉冲控制，在检验数据方面，本发明灵敏度和稳定性较已有技术相比有较大提升。
本发明通过创新设计实现多次法拉第效应循环积累，从而有效降低传感光纤的使用长度，由于传感光纤昂贵，特别是特种掺杂的高菲德尔常数传感光纤。因此，本发明可以在提高性能的基础上间接降低成本。
图1为本发明结构示意图；
图2为光开关通断示意图；
图中：低电平为1→4、2→3；高电平为1→3、2→4；
图3为脉冲控制信号示意图；
图4为偏转角度与循环次数关系图；
图5为本发明选择第8次脉冲循环时得到的时域脉冲随电流的变化；
图6为灵敏度随循环次数关系图。
如图1所示，本实施例包括：线偏振脉冲光发生机构、控制脉冲发生机构、2×2的光开关以及传感光纤，其中：光开关的第一输入端和第一输出端分别与线偏振脉冲光发生机构和控制脉冲发生机构相连以接收线偏振脉冲光和控制脉冲，控制脉冲发生机构与线偏振脉冲光发生机构相连并输出调制脉冲，光开关的第二输入端和第二输出端与传感光纤组成循环回路。
所述的线偏振脉冲光发生机构包括：依次相连的光源、调制器和起偏器，其中：起偏器输出线偏振脉冲光至光开关的第一输入端，调制器接收来自控制脉冲发生机构的调制脉冲。
所述的控制脉冲发生机构包括：依次相连的检偏器、光电探测器、信号处理单元和脉冲发生器，其中：信号处理单元对光电探测器得到的电压信号进行采集和处理，解析信号幅度的变化得到脉冲受磁场影响导致的偏振变化信息并输出至脉冲发生器，脉冲发生器分别向线偏振
脉冲光发生机构输出调制脉冲以产生光脉冲，向光开关输出控制脉冲以控制光脉冲在循环回路中的循环时间。
所述的偏振变化信息包括：控制脉冲和同步信息。
所述的传感光纤设置于循环回路中，该传感光纤的长度大于等于调制脉冲的长度。
所述的信号处理单元包括：任意波形发生模块和数据采集模块。
如图2～图4所示，本实施例涉及上述装置的光纤电流传感方法，具体包括以下步骤：
步骤1)系统组装：
1.1将激光器通过光纤连接到调制器，将调制器通过光纤连接到起偏器，将起偏器通过光纤连接到光开关一个输入端口，基于光开关构建循环回路系统；
1.2对于循环回路系统：光开关的第一输入端和第一输出端分别与线偏振脉冲光发生机构和控制脉冲发生机构相连，光开关的第二输入端和第二输出端组成循环回路，传感光纤设置于循环回路中；
1.3采用1km长度的光纤设置于循环回路系统，同时作为延迟光纤和传感光纤，作为延迟的作用是指脉冲长度整个被包含在循环回路中，从而保证系统稳定性；
1.4将循环回路输出端通过光纤连接到检偏器，通过光纤将检偏器连接至光电探测器，通过电连接线将光电探测器连接至信号处理单元中的数据采集模块。
步骤2)系统初始化：
2.1对激光器设置偏置电压和电流，本实施例中输出激光功率为25mW。对光电探测器设置偏置电压和电流，使得接收到的光信号可以转换为电压幅度信号输出。
2.2通过命令控制信号处理单元中的任意波形发生模块产生所需的调制脉冲和控制脉冲，输出调制电脉冲信号至调制器对激光器输出的连续激光进行脉冲调制以产生光脉冲，输出控制脉冲至光开关以控制光脉冲在循环回路中的循环时间。
本实施例采用了5微秒的调制脉冲宽度，而控制脉冲的长度根据所需的循环次数选取，在10次循环的情况下，选取控制脉冲长度为55微秒。
2.3)光电探测器得到的光信号将转换为电压信号输入到信号处理单元的数据采集模块，图5显示了所采集到的脉冲幅度在8次循环之后的时域信号在不同电流情况下的幅度变化。
如图6所示，本发明创新地使用了激光器、调制器、起偏器、2×2光开关、检偏器和光电探测器来构建循环回路，并且采用了专门设计的信号处理单元和脉冲信号控制单元。图中所示，最终得到的光纤电流传感系统具有高稳定性和高灵敏度的性能优势，灵敏度随循环次数提升，其中传感光纤部分可以根据需要更换光纤类型。
上述具体实施可由本领域技术人员在不背离本发明原理和宗旨的前提下以不同的方式
对其进行局部调整，本发明的保护范围以权利要求书为准且不由上述具体实施所限，在其范围内的各个实现方案均受本发明之约束。
Claims (7)
- 一种基于循环回路的高灵敏度光纤电流传感装置，其特征在于，包括：线偏振脉冲光发生机构、控制脉冲发生机构、2×2的光开关以及传感光纤，其中：光开关的第一输入端和第一输出端分别与线偏振脉冲光发生机构和控制脉冲发生机构相连以接收线偏振脉冲光和控制脉冲，控制脉冲发生机构与线偏振脉冲光发生机构相连并输出调制脉冲，光开关的第二输入端和第二输出端与传感光纤组成循环回路。
- 根据权利要求1所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，所述的线偏振脉冲光发生机构包括：依次相连的光源、调制器和起偏器，其中：起偏器输出线偏振脉冲光至光开关的第一输入端，调制器接收来自控制脉冲发生机构的调制脉冲。
- 根据权利要求1所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，所述的控制脉冲发生机构包括：依次相连的检偏器、光电探测器、信号处理单元和脉冲发生器，其中：信号处理单元对光电探测器得到的电压信号进行采集和处理，解析信号幅度的变化得到脉冲受磁场影响导致的偏振变化信息并输出至脉冲发生器，脉冲发生器分别向线偏振脉冲光发生机构输出调制脉冲以产生光脉冲，向光开关输出控制脉冲以控制光脉冲在循环回路中的循环时间。
- 根据权利要求3所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，所述的偏振变化信息包括：控制脉冲和同步信息。
- 根据权利要求1所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，所述的传感光纤的长度大于等于调制脉冲的长度。
- 根据权利要求1或5所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，所述的传感光纤具体为：采用1km长度的光纤设置于循环回路系统，同时作为延迟光纤和传感光纤。
- 根据权利要求1或2或3或5所述的基于循环回路的高灵敏度光纤电流传感装置，其特征是，在10次循环的情况下，所述的调制脉冲的长度为5微秒，所述的控制脉冲的长度为55微秒。
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| CN112578173A (zh) * | 2019-09-27 | 2021-03-30 | 上海康阔光智能技术有限公司 | 光学雷电流测量系统及测量方法 |
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