Chisago Tertiary Capacitor Switching Surge Study

Xcel Energy contracted MHI to perform a Switching Surge Study on Chisago 34.5 kV Station.

Manitoba Hydro International Ltd. (MHI) provided the following services:

• Calculated maximum line-to-ground and phase-to-phase over-voltage data to which nearby radial-fed transformers may be subjected
• Determined the expected energy absorption requirements of 115 kV lightning arresters for worst case capacitor energization at Chisago
• Determined an appropriate in-rush/out-rush reactor design for the new shunt capacitor banks at Chisago
• Determined if there is any possibility of voltage magnification on nearby capacitor banks as a result of adding the Chisago capacitors.
• Confirmed the suitability of capacitive switching ratings of new and existing 115 kV circuit breakers that may be required to switch the Chisago capacitors.