基于光纤布拉格光栅和压电转换器的电功率传感器

摘要

针对传统功率计测量电功率存在线圈电感、电容与金属部分的涡流感应等限制,本文基于布拉格光纤光栅与压电转换器设计了电功率传感器来测量实功率与虚功率.将布拉格光纤光栅粘贴于压电转换器上,构建了动态应变模拟装置.负载电压与负载电流的乘积形成的等效电压施加在压电转换器上使布拉格光纤光栅动态变化,由此测量光栅动态变化所造成的波长改变量即可得到等效负载功率.相位检测电路用于测量负载电压与负载电流的相位差,由该相位差即可求得功率因数.所研究的传感器可以取代传统功率计用于实功率和虚功率的测量.%The measurement of power by conventional meters has some limitations due to the inductance and capacitance of coils and the eddy current induction in the metal parts of the meters.Optical fiber gratings are currently being used as sensors for a number of physical quantities such as temperature,strain and pressure;other quantities,such as current and electrical power measurements can be detected by fiber gratings using appropriate transducers.This paper demonstrates an optical fiber sensor using a Fiber Bragg Grating(FBG)and a piezo-electrical transducer(PZT)to measure real and reactive powers.Mounting an FBG on a PZT bar,a dynamic strain simulator is constructed.The voltage equivalent to the product of load voltage and load current applied on PZT is converted to the dynamic variation of the FBG Bragg wavelength.The load power will be achieved by measuring the changing value of the wavelength.A phase detector circuit is used to measure the phase angle between voltage and current signals.The power factor can be obtained from the phase angle.Thus,the sensor can be used to measure real and reactive powers without the use of a traditional power meter.