Voltage Sag Mitigation TechnologySource: Siemens Power Transmission & Distribution, Inc. (SPT&D)
The technology compensates for voltage sags and swells by sensing the incoming voltage supply and instantly reacting to provide what is "missing" when a distortion is detected. It compensates each phase as needed for voltage variation and phase shift during a deviant voltage event through three independent single-phase series injection transformers. In the short span of 2 milliseconds, the control system determines the appropriate voltage components to inject to restore the affected waveform. The load-side line energy supply rectifier can supply up to 50% voltage injection, enabling the system to correct the most common voltage sags and swells for at least one second. It has a hybrid solid-state and mechanical bypass system for overcurrent protection. This first series is rated to serve loads up to 600 kVA on 3- or 4-wire, 3-phase, 15 or 25 kV-class distribution systems, at either 50 or 60 Hz. Other sizes and voltage ratings are also available.
Siemens Power Transmission & Distribution, Inc. (SPT&D), PO Box 29503, Raleigh, NC 27626. Tel: 888-416-0655