The HVDC Light systems can be a solution to transmission capacity upgrades for medium or small-scale generation additions.
It seems likely that generating companies in Western Europe and North America will attempt to manage risks and capital costs by avoiding large scale and capital intensive generation capacity additions. They will instead develop smaller scale incremental type projects with greater flexibility to accommodate unexpected changes in market conditions.
Thus, to economically accommodate the needs of the new generation supply markets, it seems that future transmission system capacity additions will need to be implemented on a small scale incremental basis. Unfortunately, small-scale transmission capacity additions using conventional AC transmission technologies appear to be inherently incompatible with the physical characteristics of the existing transmission facilities at levels of 345 kV or higher. When transmission bottlenecks occur in networks, transmission capacity expansions using conventional AC technologies normally require new lines or other facilities at the 345 kV level or higher. Therefore, a generation addition of 100 - 200 MW may result in construction and operating costs for new and much higher rated transmission facilities at 345 kV or 500 kV. This will obviously be detrimental to the competitive position of a remote generation supply alternative in comparison to a local supplier.
The inherent characteristics of the
HVDC Light technology provide a solution to the needs of the evolving generation markets.
These characteristics include:
- HVDC Light®systems can match the size of the generation addition and need not have an over-capacity that remains unused.
- HVDC Light®cables can be buried in right-of-ways of existing transmission lines, thereby avoiding all obstacles and delays associated with environmental reviews and new transmission right-of-way permits.
- The rating of a HVDC Light®system is typically much smaller than the largest existing facility in the transmission network, so there would be no need for wide area reliability impact studies. Loss of the HVDC Light® transmission would cause less disturbance to the grid than loss of a higher rated AC line.
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