模拟退火-牛顿法在高压输电线路故障定位中的应用

Application of Simulated Annealing-Newton Method in Fault Location for High-voltage Transmission Lines

故障排除是高压输电线路运行维护的重中之重,而随着电力技术的不断发展,智能故障定位技术已取代人工巡线查询故障点的方式。牛顿法是求解故障定位方程组的有效方法,但对初始值的选取要求较高,同时二阶收敛的特性降低了计算速度。因此将牛顿法与模拟退火算法相结合,利用模拟退火算法求取低精度解作为牛顿法的初始值,同时对牛顿法作出改进,使其具有三阶收敛特性。弥补了牛顿法初始值选取以及收敛速度慢,同时避免了模拟退火算法易陷入局部最优解和求解时间长的弊端,进而有效提高了故障定位计算准确率。通过搭建线路故障模型,以单相接地短路故障和两相相间短路故障为例利用PSCAD和MATLAB进行仿真验证。仿真结果表明,可以有效确定故障点位置,计算精度高,能够满足实际要求。

Trouble shooting is the top priority in the operating maintenance of high-voltage transmission lines.Along with continuous development of electric power technology,intelligent fault location has taken the place of artificial line inspection.The Newton method is an effective approach for solving the fault location equation set,but it poses a strict requirement on the selection of initial value,and second-order convergence characteristics reduce calculation speed.Therefore,the Newton method was combined with the simulated annealing algorithm so that a low-precision solution could be obtained through the simulated annealing algorithm as the initial value for the Newton method.On the other hand,the Newton method was modified to obtain third-order convergence characteristics.The proposed approach could not only make up for the selection of the initial value of the Newton method and slow convergence speed,but also prevent the simulated annealing algorithm from falling into partial optimal solution and avoid long resolving time,thus improving the accuracy rate of fault location calculation to a great extent.PSCAD and MATLAB simulation was completed for single-phase grounding short circuit and for short circuit fault between two phases,based on a model set up for line fault.Simulation results indicated that the proposed approach could effectively locate the fault point with high calculation accuracy and satisfy practical requirements.