超导磁储能装置对输电线路多边形特性距离保护的影响分析

超导磁储能(SMES)装置响应速度快,能够对有功、无功进行独立控制,在电力系统中将得到越来越广泛的应用。SMES并入系统后的充放电过程会与电网双向交换功率,可能会对输电线路的继电保护产生影响,造成保护装置的不正确动作。在建立SMES电磁暂态仿真模型的基础上,在PSCAD环境下研究了含SMES的单机无穷大系统(SMIB)输电线路多边形距离保护的动作特性,针对不同短路故障类型和SMES的不同安装位置分析了多边形距离保护的动作结果。仿真结果表明,SMES并入电网后多边形距离保护的测量阻抗发生了变化,在某些情况下会对保护的动作结果产生影响。最后提出了一个保护动作特性曲线的改进方案,并通过仿真试验验证了其可行性。

Effects analysis of SMES device on polygon distance relay of transmission line

Superconductor magnetic energy storage (SMES) system has rapid response and controls active and reactive power independently, so it is applied more broadly. But its charge or discharge processes will exchange power with the power system and may affect relay protection of transmission line. This paper builds an electromagnetic transient simulation model for SMES and studies characteristics of the polygon distance relay of transmission line in one-machine-infinite-bus (OMIB) system with SMES in PSCAD. The simulation on the polygon distance relay is conducted under different faults and at different installation sites of SMES. Results show that when the SMES is connected to the power grid, the measured impedance is changed and the relay action is affected. At last, a scheme for improving the relay protection characteristic curve is proposed and proved to be feasible by simulation.