A 6,400MW xmsn line???

Filed under:News coverage,Nuts & Bolts — posted by admin on February 17, 2008 @ 6:32 pm

Hot off the press, massive capacity ultra-high voltage transmission lines expected to have LOW line losses… and coming to a neighborhood near you? Perhaps, if you live in China (oh, no, does that mean I’m going to have to head even further east and fight transmission there? AAAAAAAAAAGH!)

In the SW MN 345kV case, they assumed line losses of 30% from Buffalo Ridge to the Metro:

Loss factor of 0.30 from SW MN 345kV proceeding

And line loss is a problem, they’re clear on that, and they’re tickled that this new-fangled technological advance has line loss of LESS THAN 7%. The line loss alone would power 900,000 people, using Chinese standards of consumption, I presume. That excitement about 7% line loss, that alone is proof that those claiming low line losses of typical xmsn options have their heads firmly implanted!

Technology Leap Allows 2,000 Kilometer Link

Indeed, ABB has already won orders worth $440 million from the State Grid Corp. of China and other partners to provide new ultrahigh-voltage technology for the world’s longest power transmission link.

The power superhighway running 1,240 miles (2,000 kilometers) from western China to the highly industrialized coastal area in the east will have a capacity of 6,400 megawatts.

That is enough to meet the needs of about 31 million people in China, based on average consumption per capital. The link from the Xiangjiaba hydropower plant to Shanghai will be complete in 2011.

The ultrahigh-voltage direct current (UHVDC) link comprises two substations and a power transmission system using breakthrough technology to transmit electricity at ultrahigh voltage (800 kilovolts), which will minimize the amount of power lost in transmission.

Increasing the voltage level of electrical transmission creates considerable advantages for the environment, including lower electricity losses and the use of less land compared to traditional overhead lines. UHVDC is particularly suitable for vast countries like China, where the centers that need power are often located far from power sources.

Transmission losses will be under 7%, significantly less than the losses from conventional 500-kilovolt (kV) high-voltage direct current (HVDC) transmission schemes.

The savings from using UHVDC compared with HVDC are equivalent to the annual power consumption of more than 900,000 people in China.

The new technology, using thyristor valves equipped with newly developed 6-in thyristors (power semiconductors) and an advanced control system, allows the biggest capacity and efficiency leap in 20 years.

The increase became possible following advances in materials for outdoor insulators and advanced control systems.

Copyright Instrument Society of America Feb 2008

image: detail of installation by Bronwyn Lace