Bently 3500应用于300 MW机组TSI系统中信号失真的问题研究

针对某电厂300 MW机组轴振信号频繁中断的故障,通过轴电流、轴电压测试分析以及振动信号检测、热工回路测试分析,判定汽轮机安全监视系统(TSI)接地不良导致较大的干扰信号通过电缆或地网进入信号中,使得电涡流传感器工作电压超出正常范围(-2.75~-16.75 V),导致板卡处于NOT OK状态,引起振动信号中断。重新搭建了TSI接地网络,方案实施完成后应用至今,轴振信号未出现异常,显著提高了机组安全性。

Research on Bently 3500 Signal Distortion in the TSI System of 300-MW Power Generation Units

Aiming at the fault of frequent bearing vibration signal interruption in a 300-MW power generation unit, through the analysis on bearing current and voltage testing, vibration signal detection and control loop testing, it is verified that a clear interference signal is added to the bearing vibration signal through the cables or the network due to the ill TSI system grounding, which makes the working voltage of the eddy current sensor exceed the normal range (-2.75~-16.75 V), causing the card staying at NOT OK status and the bearing vibration signal being interrupted. Therefore, the TSI grounding network is reconstructed. Since the completion and application of the network no abnormal bearing vibration signals have ever appeared. Thus, the unit security has been greatly improved.