PowerFactory DIgSILENT tutorial #21 Relay Coordination and time grading margins

Topics included in this tutorial 1. Coordination 2. Grading Margin To minimize and isolate the problem we need to coordinate our network system. In case of fault or overload objective, only one relay operates to clear the fault, and the other relays are aware of the fault. In such condition different timing should be used to determine which device must clear the fault. Therefore, the operation of this timing is called coordination. Grading margin is very important for the coordinating, it is the time interval between the operation of two adjacent relays. if the grading margin is not provided, in case of contributing of one or more relays for a fault, may leading to difficulties in determining the location of fault. Link PowerFactory DIgSILENT tutorial    • PowerFactory-DIgSILENT tutorial #1. introd...