Analysis of second harmonic instability for the Chateauguay HVDC/SVC scheme

The Chateauguay HVDC back-to-back scheme with interconnections to the 765 kV transmission to the USA and to Beauharnois generators can exhibit, under certain operating conditions, second harmonic resonance problems. The author presents a thorough analysis of the problem using an eigenvalue and frequency domain approach. The analysis explains the mechanism of the excitation of the second harmonic instability by the presence of HVDC converters. The influence of changing the control parameters of the static VAr compensator at the Chateauguay terminal is also studied. Finally, an assessment is made of the effectiveness of present countermeasure schemes, namely the auxiliary DC stabilizing controls and the installation of second harmonic filters.<
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