应用CT和ECT的变压器差动保护仿真研究与对比分析

为了分析电磁式电流互感器(current transformer,CT)和电子式电流互感器(electronic current transformer,ECT)对继电保护的适应性,基于PSCAD和MATLAB软件搭建了采用CT和ECT的变压器差动保护仿真模型,针对变压器区内和区外故障分析了变压器差动保护的可靠性与灵敏性。仿真结果表明,电磁式电流互感器会因磁饱和问题导致可靠性降低,造成差动保护误动;电子式互感器传变特性好,可以在保证可靠性的前提下有效提高差动保护的灵敏性,提升保护系统的性能。

Analysis on Simulation Study and Comparison of Transformer Differential Protection by Applying Current Transformer and Electronic Current Transformer

For analyzing adaptability of electromagnetic current transformer and electronic current transformer to relay protection,this paper establishes simulation model for transformer differential protection by using CT and ECT based on PSCAD and MATLAB software and analyzes reliability and sensitivity of transformer differential protection aiming at inside and outside faults.Simulation results indicate that reliability of electromagnetic current transformer is reducing for reason of magnetic saturation which may cause differential protection malfunction while transferring characteristic of electronic current transformer is good enough to effectively improve sensitivity of differential protection and promote performance of the protection system on the premise of ensuring reliability.