Residual Compensating Factor| Zero Sequence compensation factor| Kz/ Kn Factor| Distance Protection

This video explains the concept of the Residual Compensation Factor (Kz/Kn) in distance protection relays and how it is used to ensure accurate fault detection during single line-to-ground faults. Key Takeaways: The Problem: During phase-to-ground faults, the fault current flows through the ground, which introduces an additional earth impedance (ZE). If this is not compensated for in the relay, the relay will measure an incorrect total impedance (Z1 + ZE), leading to over-reach and potential relay malfunction (0:00 - 2:53). The Solution: The relay's measurement is adjusted using the residual compensation factor, represented by the formula ZT = Z1 + Kz * Z1. This allows the relay to isolate the actual line impedance (Z1) from the total measured impedance (ZT) (3:07 - 3:32). Derivation: The video demonstrates the mathematical derivation of Kz based on the relationship between positive sequence impedance (Z1) and zero sequence impedance (Z0), resulting in the formula Kz = (Z0 - Z1) / 3Z1 (4:21 - 9:13). Practical Example: The video concludes with a step-by-step numerical example, showing how to plug resistance and reactance values into the Kz formula to set the relay correctly (10:08 - 11:20). You can also watch following video: Distance Protection Relay Setting Calculation -    • Distance Protection Relay Setting Calculat...   Thank you for watching the videos.