Analysis of a harmonic overvoltage due to transformer saturation following load shedding on Hydro-Quebec-NYPA 765 kV interconnection

An analysis is presented of the harmonic overvoltage recorded on the interconnection between Hydro-Quebec and the New York Power Authority (NYPA) in the Chateauguay area. The overvoltage was caused by transformer saturation, following tripping of the 765 kV transmission line linking both systems. EMTP (electromagnetic transient program) simulation yielded good agreement with field measurements and was valuable in reevaluating operating practices at the Chateauguay station.<
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