一种新的频率测量与报警系统的研制

频率是电能质量的重要指标之一，针对电网调度运行的特点和频率测量的目的，研制开发了电力系统频率测量与报警系统。分析研究了DFT和参考点两种高性能的频率测量方法，并通过反复试验对其分别进行了改进，将它们综合到一个系统中以适应不同的现场条件和测量要求。同时结合测量过程又对频率变化率的测量计算进行了初步分析，增加了自动报警功能，能有效提高运行人员和自动化装置的反应速度，减少频率越限时间，使频率监控由被动走向主动。本系统基于虚拟仪器平台开发，可进一步拓展基于Internet和GPS的实时同步广域频率监控网。

Development of a new power system frequency measurement and alarm system

Frequencyis one of the most important indexes of power quality.In this paper,according to the characteristics of power networkdispatching and runningand the purpose of frequency measurement,a power system frequency measurement and alarm system is developed.The advanced DFT group and reference point detection algorithms are adopted to measure frequency and rate of frequency change in this system,by which harmonic,direct current and random interferential signals can be inhibited effectively.Alarm can be given with different form whenever frequency exceeds limit or the change of frequency appears abnormal.The system is designed using Virtual Instrument,which can further expand the wide area real-time and synchronizing frequency monitoring network based on Internet and GPS.