极控系统触发角差保护软件设计缺陷分析

Difference Firing Angle Protection Function of Pole Control System Software

为找出贵广Ⅰ回直流工程安顺换流站多次收到极控系统报触发角差告警的原因利用西门子SIMADYND系统在线诊断软件PM5/EP3.IBS,结合录波采样,按照极控软件流程图逐一排查,发现是从控的极控系统接收来自直流保护的接地极电流时有长时间的正向误差(相对于主控的极控系统)的积累,从而启动电流平衡控制功能调节控制触发角的输出。由于两套系统冗余配置,当其中一套作为从控系统时,仅仅作为热备用系统而不参与实际控制,自身控制调节量不出口调节触发角,其闭环控制的反馈量实际为主控极控系统的控制量,在系统设计时没有考虑到这一点。因此根据工程实际情况,采用最简单适用的方法修改了极控软件,屏蔽了从控系统的电流平衡控制功能,消除了极控系统存在的隐患,提高了直流输电系统的可靠性。

The pole control system of Guiguang Ⅰ HVDC; project had given the difference firing angle warning signals. The maintenance engineers have found that in the slave pole control system the current of electrode line at normal bipolar balance operation has the accumulation of the error which was caused by that the data transmission between the DC protection systems to pole control systems was not actually same. So the slave pole control system tried to change the firing angle caused by the current balance control function, but it could not only because the active system ean change the firing angle. Then the current balance control function has been canceled when the system is slave system. The modification of the software improved the reliability of the HVDC system.