摘要
针对输电线路电流互感器(current transformer,CT)感应取能的方式,存在小电流时难以取到最大功率,大电流时磁芯易饱和,输电线路电流波动导致取能不稳定等问题,提出一种基于电压型整流器(voltage source rectifier,VSR)等效阻抗在线匹配取能方法。首先建立VSR取能等效电路模型,推导电路模型各参数与CT输出功率之间的关系,进而针对CT具有电流源的特性(其端口电压幅值由输电线路电流、励磁参数和负载特性确定),提出定d轴电流、定直流电压外环q轴电流内环的控制策略,实时控制VSR端口电压电流幅值与相位,将其等效为可调阻抗与CT励磁阻抗进行动态匹配,间接控制CT端口电压为定值。为验证所提方法的有效性,搭建仿真和实验系统,结果表明在输电线路电流较小时,VSR等效阻抗表现为容性,可实现输电线路小电流时CT输出最大功率,输电线路大电流时,VSR等效阻抗表现为感性,可抑制CT磁芯饱和,满足输电线路上一些低功耗设备的供能需求。
To solve the problems of current transformer(CT)inductive energy harvesting mode in transmission lines,such as difficulty in obtaining maximum power at low current,easy saturation of magnetic core at high current and unstable energy harvesting caused by current fluctuation of transmission line,this paper proposes an online energy harvesting method based on equivalent impedance matching of voltage source rectifier(VSR)was proposed.First,a VSR energy harvesting equivalent circuit model is constructed,and the relationship between the parameters of the circuit model and the output power of CT is deduced.Then,considering the characteristic of CT as a current source(the port voltage amplitude is determined by the transmission line current,excitation parameters and load characteristics),a control strategy of constant d-axis current,constant DC voltage outer loop and q-axis current inner loop is proposed.The amplitude and phase of VSR port voltage and current are controlled in real time,VSR is equivalent to the adjustable impedance to dynamically match with CT excitation impedance,and then the CT port voltage is indirectly controlled to a fixed value.With the aim of verifying the effectiveness of the method in this paper,simulation and experimental systems are built.The results show that the equivalent impedance of VSR is capacitive when the transmission line current is low,which can achieve the maximum power output of CT at low current of the transmission line,and the equivalent impedance of VSR is inductive when the transmission line current is high,which can inhibit the saturation of CT magnetic core.It can meet the power supply requirements of some low-power devices on transmission lines.
作者
唐欣
唐凯璇
李珍
肖超凡
李泽宇
TANG Xin;TANG Kaixuan;LI Zhen;XIAO Chaofan;LI Zeyu(State Key Laboratory of Disaster Prevention&Reduction for Power Grid(Changsha University of Science and Technology),Changsha 410114,Hunan Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2024年第24期9811-9819,I0025,共10页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国家自然科学基金项目(52377167)。
关键词
感应取能
电压型整流器
等效阻抗
动态匹配
inductive energy harvesting
voltage source rectifier
equivalent impedance
dynamic matching
