Enhancement of AC/DC system performance by modulation of a proposed multiterminal DC system in the southwestern US

Modulation of power transmitted over a proposed multiterminal DC system to provide effective stability enhancement of a large AC system in the southwestern US is demonstrated. This system, connecting the Phoenix, Mead, and Los Angeles areas, would be in parallel with an extra-high-voltage (EHV) AC transmission network that could be operating at heavy loading conditions. Studies have indicated that the utilization of large power and reactive power modulation on the DC system can provide transient stability enhancements and improved AC system damping. The application of modulation permits the release of converter station VArs to support the AC system voltage and thus ease demands on the capability of voltage support devices.< >