Dynamic Differential Protection for Power Transformer in the Presence of CT Saturation

The power system requires transformer protection to preserve its stability as faults outside the transformer network occur. Power system faults produce heavy or mild saturation conditions in current transformers which produce distorted current reading signals. The distortion can cause operational failures or incorrect relay behaviour. The power transformer appeared in a simulated format through PSCAD software modelling. The simulation environment incorporates both internal and external faults. After receiving the currents from both side of transformer, the system processed the data with an advanced adaptive filter to reduce electrical noise-generated inaccuracies. This refined approach ensures a clearer understanding of the transformer's behaviour under varying fault conditions. This paper suggests a dynamic differential protection method. This innovative approach features a threshold value promptly adjusted when the implemented algorithm identifies a CT saturation event. By continuously updating the threshold in real-time, the method enhances the reliability and responsiveness of the protection system, ensuring optimal performance even in challenging conditions. MATLAB has been utilized for implementing the suggested algorithm. Therefore, an external fault together with CT saturation will prevent the relay from generating a circuit breaker trip signal.