基于Labwindows/CVI的高压隔离开关主回路微电阻测量的研究

摘要

高压隔离开关质量是影响工程实践、电网安全稳定运行的重要因素,其主回路微电阻是反映隔离开关和运行状态的重要指标.针对主回路微电阻测量较难等问题,设计了一种基于Labwindows/CVI的高压隔离开关主回路的高精度直流微电阻测量系统.该测量采用四线法以PIC 16F873A为核心外接AD7705为控制处理器,由恒流源发生装置,电压、电流调理电路、高精度A/D转换器等搭建而成,测量范围由几十微欧到几百微欧.通过测试表明系统测量方法安全、有效,测量结果精度高、稳定、可靠,测量误差为0.96％.%High-vohage disconnector is a very important control and security device in power systems,whose main loop resistance is a significant parameter to reflect its performance and running state.In order to measure the micro-ohm resistance,a micro main loop resistance measuring instrument is presented for high-voltage disconnector based on Labwindows/CVI in this paper.The measuring instrument based on four-line method is designed taking PIC16F873A and AD7705as the core control processor,which is consist of a constant current source device,current and voltage conditioning circuit,high precision A/D converter module.The measuring range is from dozens to hundreds of micro ohm.The experiment shows that the measurement method is safe and effective,and the measurement results are accurate,stable and reliable.In addition,the maximum error of measurement is 0.96％.