Power Grid Protection – Protection Functions and Protection Analysis

The ATPDesigner network simulation program is specifically designed for modelling electrical networks at all voltage levels, including the protection technology and distributed generation systems used within them. The numerical models of protection functions implemented in ATPDesigner are generic, i.e. manufacturer-neutral models.

In ATPDesigner, protection relays and protection functions are modelled using generic, i.e. manufacturer-independent, models. This makes it possible to apply the results generated by ATPDesigner to existing power protection concepts, regardless of the specific product specifications. The generic models of the network protection devices also ensure simple and backwards-compatible extensibility of the network protection concepts and their application for future tasks in network protection technology.

Protection Functions

The purpose of power system protection is to continuously monitor the physical state of the power system, detect unacceptable system conditions, and restore the power system to a permissible operating state within a reasonable time. Short circuits are one of the most critical unacceptable network conditions, as the very high short-circuit currents that occur in the event of a short circuit can pose a risk to personnel and cause unacceptable mechanical and thermal stresses on the equipment. The basic principle of network protection is selective protection. Faults, as the cause of unacceptable network conditions, are detected selectively by fault location and fault type, and the equipment causing or affected by the fault is disconnected from the power network on all poles and on all sides. In the event of a short circuit, this process is generally referred to as short-circuit tripping or, in short, tripping. After tripping, the power network returns to fault-free normal operation and is available to perform its supply function.