改进SMS孤岛检测方法研究

摘要

滑模频率偏移法(SMS)能够消除特定负载品质因数以下的检测盲区且对电能质量影响较小,是应用较为广泛的主动式孤岛检测方法,但其检测速度受负载品质因数(Qf)的影响显著.本文针对传统SMS算法的这一缺陷,提出了一种改进型SMS算法,将传统SMS算法的正弦型相位偏移曲线修改为圆型相位偏移曲线,该方法避免了传统SMS算法中临界稳定状态的发生,消除了Qf≤2.5下的检测盲区,克服了传统SMS算法检测速度随Qf增大而迅速减慢的缺陷,提高了孤岛检测速度.仿真与实验结果进一步验证了该方法提高孤岛检测速度的有效性.%Slip-mode frequency shift method can eliminate the load detection blindness below the certain quality factor and has small impact on power quality.So the SMS method is widely used.However, the detection speed of the SMS method was significantly affected by load quality factor.Aiming at the defects of traditional SMS algorithm, this paper proposes an improved algorithm of SMS, in which the sinusoidal phase shift curve used by traditional SMS algorithm is replaced by round phase shift curve.The improved SMS algorithm avoids the critical stable state happened in traditional SMS algorithm, eliminates the load detection blindness with Qf≤2.5, overcomes the drawback of the traditional SMS that the islanding detection speed rapidly slowing as the load quality factor increases, and improves the islanding detection speed.Simulation and experimental results further verified the effectiveness of the proposed SMS algorithm in improving the islanding detection speed.