Transformer Winding Calculation Software

Tripping behavior of the relay is based on the relay percentage restraint differential characteristics. If the (IRT, IOP) coordinate falls below the curve then no tripping occurs.

If the resulting coordinate of (IRT, IOP) on the x-y plane falls above the percentage differential characteristic, tripping will occur. Increased loading of the transformer will move the restraint (IRT) horizontally to the right on the ‘x’ axis with no change in operate quantity (IOP) whereas a short circuit fault will move the IRT to the left and the IOP up on the ‘y’ axis. Operate region is the area above the curve where the relay will trip and restraint region is the region below the curve where the relay will restrain itself from tripping. Transformer Percentage Differential Protection CharacteristicsĪs discussed, the relay calculates the operate current (IOP) and the restraint current (IRT). Transformer provides superior protection against: Voltage motors, reactors, switchgear etc. Protection is also used in protecting other high value assets such as medium This is the basic working principle of a transformer differentialĪnd reliable protection of critical asset such as a transformer. Secondary side current, then KCL is verified and no fault is present in the If the per unit primary side current is equal to per unit This law states that the total sum of current flowing in toĪ node is zero. Windings of the transformer to form a closed circulating path.ĭifferential protection works on the principle of Kirchhoff’sĬurrent Law (KCL). Current Transformers (CT) are connected to the primary and secondary The close equivalence of ampere turns developed on the primary and secondary Protection is possible due to the high efficiency of transformer operation and

Of transformers provide complete protection of transformer. Transformer Differential Protection Basics: Differential protection

Transformer Winding Calculation Software