保护用数据同步系统失效场景下线路主保护应急方案研究

Research on Emergency Scheme for Main Protection of Transmission Line Under Time Synchronization System for Protection Become Invalid

随着变电站的数字化和智能化,电量信息由点对点的模拟量传输逐步转变为网络化的数字量传输,因此数字信息的同步变得尤为重要。保护用数据同步系统失效后,不仅线路两侧的电气量无法准确比相,即使完全依赖本侧信息的测量量,如距离/方向信息,因其依赖电压电流之间进行比相,也会输出错误结果。在此场景下,只能依赖电流速断和其他站的远后备保护实现对管辖区域内故障的保护,保护范围和动作速度都将显著变差。针对这一问题,基于拥有抗高阻故障能力且无需两侧信息同步的和阻抗继电器原理,提出无需相位信息的和阻抗模量保护判据和中段保护判据,结合电流速断保护,通过纵联通道的模量信息交互,形成保护用数据同步系统失效场景下的线路主保护应急方案,显著改善上述场景下的线路主保护性能。仿真算例验证所提方法的有效性和优越性。

With the digitalization and intellectualization trend of substation, dependence on the time synchronization system of relay protection is increasing. When time synchronization system collapses, not only the protection rely on both sides electrical quantity of the line cannot use phase-comparison, even the protection based on local electrical quantity such as impedance/directional information will lose effectiveness. Under such condition, the existing protection principle will fail, only the quick-break over current protection and the remote backup protection of other substation can bedependent on, range and action speed of protection will be significantly worse. Aiming at this problem, based on a resistance-type protection with high-resistance earth fault detection ability, and do not need time synchronization, a modulus summation impedance protection criterion without phase information synchronization was proposed, combined with quickbreak over current protection and proposed mid-part modulus protection criterion, which significantly improved the protection performance of when time synchronization system collapses.The effectiveness has been validated with simulation tests.