摘要
基于时频复合分析的行波故障定位方法依赖于固有频率法的测距可靠性。为进一步提高该方法的测距精度及可靠性,提出一种改进的时频复合分析行波杆塔故障定位方法。首先分析两侧故障信号,分别得到主固有频率,采用改进的固有频率法初步得到故障点位置;然后利用小波工具对信号进行时域分析,根据固有频率法得到的故障位置推导故障点反射波头到达母线的时间;最后由线路两端故障点反射波与初始行波的时间差之比进行杆塔故障定位。EMTP联合Matlab仿真分析表明,该方法提高了固有频率法测距稳定性,有利于时域分析。同时,对400 km线路的杆塔定位误差在400 m以内,耐受过渡电阻达350?,在线路长度变化3 km情况下不影响故障测距。
Fault location based on time-frequency analysis highly relies on the reliability of natural frequency method. A novel traveling wave fault location by tower based on time-frequency analysis is proposed for improving the fault location reliability and accuracy. First, the fault signals on both sides are analyzed and the natural frequencies are got and the initial fault point is acquired by using improved natural frequencies method. Then, the signal is analyzed by wavelet tools in time-domain. The time of reflection traveling wave from fault point to bus is calculated using the initial fault location result. Finally, the fault is located by the ratio of time spacing between the initial and the reflection wave on both sides. Simulations in EMTP combined with MATLAB show that, the proposed method improves the stability of natural frequency method for time-domain analysis, the error of fault location by tower is less than 400 meters for 400 kilometers line, and it can tolerate transition resistance up to 350 ft. At the same time, the fault location results will not change when the line length varies 3 kilometers.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2015年第20期130-136,共7页
Power System Protection and Control
关键词
固有频率
行波
时频特征
杆塔故障定位
鲁棒性
小波分析
natural frequency
traveling wave
time-frequency characteristics
fault location by tower
robustness
wavelet analysis
