发电机负序电流高精度频域算法的实现

Realization of Generator Negative Sequence Current High Precision Frequency Domain Algorithm

发电机负序电流作为不平衡负荷的判据是关系到发电机安全稳定运行的一个重要参数,对负序电流进行监测、报警以及故障处理都是非常重要的工作。本文剖析了目前负序电流监测仪表主要采用的算法存在的不足,给出了一种高精度的负序电流频域算法,通过相关运算和数字滤波技术实现了对信号的均值去噪,对处理后的信号进行频域运算可精确求出负序电流值。详细介绍了算法的原理,并给出了具体的实现方法。应用此算法的负序电流监测仪实时性好,精度高,在现场运行稳定可靠。

Generator imbalance load is judged by negative sequence current,thus negative sequence current is an important parameter related to safe and stable running of generator. Negative sequence current monitoring, alarm and fault handling are very important work. The paper analyzes shortcomings of main algorithm used by the current monitoring instrument, introduces high precision frequency domain algorithm. In the algorithm, signal denoising is realized with correlation and digital filtering. Negative sequence current can be calculated by transforming signal to frequency domain. The principle of algorithm is described in detail and practical realization is given. Using the algorithm, negative sequence current monitoring instruments work reliably in power plants. Precision of monitoring and real-time response is high.