Study on LC Detuning Failure Protection for the Static Blocking Filters
The static blocking filters (SBF) are selected as a key solution to eliminate the torsional interaction, which turbine-generators are connected to the series compensated network and it is at risk of sub-synchronous oscillation.To detect LC (reactor and capacitor) detuning failure for the SBF, the current amplitude ratio (CR) between the parallel reactor and capacitor currents are calculated.However, the CR is easily affected with the sub-synchronous oscillation or non-period current, which can leads to the fluctuations of current amplitudes.The fluctuation reason is analyzed, and an improved algorithm is proposed, which uses second-order difference equation to transform the reactor current to an equivalent capacitive current and get a new CR.By the novel method, it is improved the stability of CR.The effect of the method is verified by some RTDS experiment cases.The LC detuning protection could be improved in two aspects: one is higher sensitivity because of the smaller range between the upper and lower limit settings, and another is that the time-delay settings could be shorten to 0.5~2.0s from10~20s.Further more, the novel LC detuning protection method can also be widely applied to other LC tuned circuit, for instance,the three-tuned DC filter for HVDC transmission.
Detuning Failure Protection Difference Equation LC Detuning Static Blocking Fitter (SBF) Sub-synchronous Oscillation (SSO) Sub-synchronous Resonance(SSR) Turbine Generator
Qixue Zhang BaoliXu KaiWang Guang Wang Jun Chen Xicai Zhao
NR Electric Co.,Ltd., Nanjing,China
国际会议
南京
英文
97-101
2015-09-21（万方平台首次上网日期，不代表论文的发表时间）