Controlled switching, or Point on Wave (PoW) switching, is a process of phase-selective switching at defined switching angles. The switching operations are, therefore, particularly gentle on the equipment, the switch and also the complete system, and have a positive effect on the aging process and thus on the service life of equipment. Even system faults (for example, re-strikes on capacitors) can be reduced, which results in increased availability.
A new method to test protection devices suitable for PoW is, therefore, required. The article describes the basic principles of PoW and how the effects of different switching angles can be checked using simulation with RelaySimTest.