Combining superconductor cables and VSC HVDC terminals for long distance transmission

Abstract

The combination of underground DC superconductor cables and voltage source converter (VSC) based HVDC terminals operating at moderate DC voltages (approximately +/-200kV) creates a new option for transmitting power over long distances with multiple collection and distribution point, creating a virtual, longdistance, high power DC bus-bar. This combination of technologies has the potential of transmitting 5,000 -10,000MW or more, over distances exceeding 1500 km while exhibiting the lowest power losses of any transmission technology. The system has the potential to be cost competitive with overhead EHV AC and traditional HVDC transmission technologies.

WECC Variable Generation Planning Reference Book

“…This technology can control power flows to multiple destinations, across interconnections, and over long distances with minimal operating losses" (U.S. DOE 2010). Figure 4 shows a design of a superconducting pipeline (EPRI) reported in McCall (2009). In McCall (2009), the following advantages of superconductor pipelines are given:…”

“…Figure 4 shows a design of a superconducting pipeline (EPRI) reported in McCall (2009). In McCall (2009), the following advantages of superconductor pipelines are given:…”

“…In Table 1, a comparison is made between the superconductor pipeline and an overhead 765-kV transmission line designed to transfer 5 GW over 1,000 miles (McCall 2009). The superconductor pipeline (unlike conventional AC lines) has power losses that do not depend on the distance (about 2-3 percent) -see Figure 5, and its transfer capability does not depend on line length and remains 5 GW in the example (McCall 2009).…”

“…In Table 1, a comparison is made between the superconductor pipeline and an overhead 765-kV transmission line designed to transfer 5 GW over 1,000 miles (McCall 2009). The superconductor pipeline (unlike conventional AC lines) has power losses that do not depend on the distance (about 2-3 percent) -see Figure 5, and its transfer capability does not depend on line length and remains 5 GW in the example (McCall 2009). These characteristics make the superconductor DC lines more attractive for long-length transmission systems and less attractive for short-length local transmission, because of the relatively high losses that may be less significant in short-length AC transmission lines.…”

Electrical and thermal system considerations for MVDC superconducting distribution on navy ships

“…The expectation is that this will result in a stiffer power bus, with fewer losses, and less volume and weight than the normal conductor counterpart [1][2][3][4][5][6][7][8][9]. Therefore, it is important to examine the implications of SCs in a ship's power distribution system, to quantify the anticipated benefits.…”