考虑频变参数的高压直流输电线路距离保护

提出了一种基于频变参数模型的高压直流输电线路距离保护方法。该方法的主要原理是将线路的频变参数特性用补偿矩阵表征,从而将频变参数模型传输矩阵分解为理想分布参数模型传输矩阵与补偿矩阵的级联,并在实际应用中将该补偿矩阵用有限冲激响应(FIR)滤波器实现。在此基础上,用保护安装处的电压电流准确地计算保护整定点处的电压电流;然后,以整定点为观测点,通过解时域微分方程求得故障距离。所述算法提高了直流线路末端故障的测距精度,容易在时域实现且动作快速,显著改善了高压直流输电线路距离保护的动作性能。

Distance Protection for HVDC Transmission Line Considering Frequency-dependent Parameters

A distance protection method considering frequency-dependent parameters is proposed for high voltage direct current(HVDC) transmission line.The main principle is that the frequency-dependent parameter characteristic of line is represented by a compensation matrix,so that transfer matrix of frequency-dependent parameter model is separated into ideal distributed parameter model and plus compensation matrix.And in practical application,the compensation matrix is implemented with finite impulse response(FIR) filters.Based on this,the voltage and current at the setting point are calculated accurately using local sampling data,and the fault distance is obtained by solving differential equations in time-domain.The proposed algorithm is able to enhance the calculation accuracy of fault distance greatly at remote end faults.In addition,it is easy to implement in time-domain and quick acting so that it significantly improves the action performance of HVDC transmission line distance protection.