Generator and network protection

Components in electrical power systems, such as generators, represent highly valuable assets. Protection systems safeguard these components from the effects of electrical faults and ensure a reliable power supply to unaffected consumers.

For the use of emergency power systems, applicable regulations - defined by local standards and guidelines - require comprehensive protection functions for the operation of emergency generators. 

For the operation of emergency power systems connected to the grid, additional protection criteria based on connection guidelines of local energy suppliers can be integrated into the protection concept.

These protection functions are defined internationally using ANSI codes and, in addition, nationally in the VDE connection guidelines.

The most important generator protection functions include:

  • ANSI 27      undervoltage protection
  • ANSI 32      directional power protection
  • ANSI 50      instantaneous overcurrent protection
  • ANSI 51      time-delayed overcurrent protection
  • ANSI 59      overvoltage protection
  • ANSI 78      vector shift protection
  • ANSI 81      frequency protection (overfrequency and underfrequency)