基于有源电子互感器的输电线路等传变差动保护

罗氏线圈电子式电流互感器的积分环节会放大传变误差，可能造成电流传变严重失真，导致保护误动。针对此问题，提出了线路保护直接采用罗氏线圈微分电流信号输出的改进思路。并以差动保护为例，提出了一种基于有源电子互感器的输电线路等传变差动保护方法。该方法直接采用罗氏线圈输出的电流微分信号进行计算，将用于电容电流补偿计算的电压信号经虚拟罗氏线圈数字传变处理，保证电压电流信号经过相同的传变环节。仿真和试验结果表明，新方法在区内故障时可快速动作，且消除了积分环节引入的传变误差对差动保护的影响，降低了电压电流传变差异对保护精度的影响，性能优于现有差动保护方法。

Current differential relay of a transmission line based on an active electronic transformer using value after an equal transfer processes

The integrator of a Rogowski coil current transformer will amplify the error of current transfer and probably cause serious distortion of the current transfer. This will lead to protection mal-operation. To this end, an improved idea for a line relay directly using the differential current output of Rogowski coil is put forward. Taking the differential relay as an example, a current differential relay of the transmission line based on an active electronic transformer using value after equal transfer processes is proposed. In the scheme, the differential current output from the Rogowski coil is directly used for protection calculation, and the voltage signal used for capacitance current compensation calculation is transformed by a virtual Rogowski coil to ensure that the voltage and current signals have the same transfer process. Simulation and experimental results demonstrate that the novel relay has high operational speed in the case of internal faults, the influence of the transmission error introduced by the integral link is eliminated, the impacts of voltage and current signal transmission difference on protection accuracy are mitigated and the performance is superior to the existing differential protection methods. This work is supported by the National Natural Science Foundation of China (No. 51877090).