计及分布式电源发电出力的自适应反时限保护

Adaptive Inverse-time Protection Based on Output from Distributed Generation

随着分布式电源在配电网中的渗透率不断提高,为解决其发电出力间歇性变化对配网保护可靠性影响的问题,本文提出一种计及分布式电源发电出力的自适应反时限保护新方法。首先,基于分布式电源发电出力对反时限保护的影响特征,对新的保护原理与方法进行分析整定。然后,针对分布式电源发电出力对测量阻抗变化特性的影响,利用过渡电阻偏移角和阻抗修正系数对反时限动作特性曲线进行修正;以实时发电出力作为判据,选定保护整定值,实现上、下级保护的动作延时。最后,通过MATLAB/Simulink仿真实验,验证了该方法能够在分布式电源发电出力间歇性变化的情况下,保证保护动作的速率,同时,最大程度确保上、下级保护间的配合关系,具有一定的工程实际意义。

With the increasing permeability of distributed generation(DG)in distribution network,a novel adaptive in-verse-time protection method which takes into account the output from DG is proposed to solve the problem of the influ-ence of intermittent variation in DG output on the protection reliability of distribution network.First,based on the influ-ence characteristics of DG output on the inverse-time protection,the novel protection principle and method are ana-lyzed and adjusted.At the same time,in view of the influence of DG output on the changing characteristics of measur-ing impedance,the transition resistance offset angle and impedance correction coefficient are used to correct the in-verse-time action characteristic curve.The real-time power output is taken as a criterion,and the protection setting val-ue is selected to realize the action delay of upper and lower protections.Finally,MATLAB/Simulink simulations verify that the proposed method can ensure the cooperation between the upper and lower protections to a maximum extent while maintaining the protection rate under the condition of intermittent variation in DG output,which is of certain sig-nificance to engineering practices.