IEEE Power Engineering Society

For more than a half-century after the struggle between AC and DC for universal production, transmission and utilization of electric energy had been dominated by AC. This position remained unchallenged until the 1950s. At that time, the availability of large, high-powered, mercury arc rectifiers gave birth to a new interest in the application of DC for transmission purposes. One of the primary drivers for this reawakening of interest was cost, the historical justification for many of the early high-voltage DC (HVDC) schemes. The benefits of HVDC are outlined. Examples from North America, South America, Scandinavia, India and China illustrate the successful and mutually beneficial partnership between hydroelectric generation and HVDC transmission.