Detection of current transformer saturation phenomenon for secured operation of smart power network

Any secured operation of smart grid highly depends on the signal transmitted through Intelligent Electronic Device (IED) to/from the external source. For this, the healthy operation of system components is essential. Error in measurement due to transient response of instrument transformers such as current and voltage transformer may degrade the healthy operation of protection devices. To mitigate this issue and to improve the function of protective devices, an integrated filtering approach is applied for the determination of the current transformer (CT) saturation interval. The method helps in detecting the exact saturation period so that signal reconstruction or time delay logic can be applied to avoid the error-in-estimation process. The proposed integrated filtering approach is tested for different critical cases through a developed model in EMTDC/PSCAD platform. Results for noisy signal obtained through real-time digital simulation (RTDS) is also presented. The method is also compared with the existing method and found more reliable to be implemented.