China And Russia Hooking Up
Yes. It is true. They are hooking up their electrical grids.
AREVA‘s Transmission and Distribution (T&D) division has signed a multi-million Euro contract to supply H400 High-Voltage Direct Current (HVDC) thyristor valves to interconnect the Chinese and Russian power grids.I know. It sounds like a press release for the H400 valve. In fact it is a press release for the H400 valve.
The contract, the first of its kind awarded to AREVA T&D in China, is signed with the Xuji Group Corporation and China Electric Power Research Institute for the end customer, State Grid of China Corporation.
The valves will be installed in the Sino-Russian converter station located in China’s Heilongjiang province. To overcome the countries’ grid incompatibility, the station will convert alternate current into direct current and inversely.
AREVA T&D was awarded the contract thanks to its new high profile generation H400 Valve technology developed in collaboration with the China Electric Power Research Institute and the Xuji Group Corporation. The company’s ability to meet both China’s localization policy requirements and a tight installation schedule were also key factors in this success. The installation of the valves will begin in 2008.
HVDC technology is used to connect power networks and to transmit large amounts of electricity over long distances with minimal losses. With plans to transmit more than 130 GW of electricity over the next five to ten years, China’s needs in HVDC are booming. This success will strengthen AREVA T&D’s position on the domestic HVDC market and demonstrates the company’s ability to meet the country’s needs.
It does reinforce my point about new long distance transmission of power in the US. DC is the way to go.
Here is another bit from the company making that same point:
Ultra High Voltage Direct Current (UHVDC) transmission, with voltages of up to 800 kV, is the choice being made by many energy managers around the world for the future network developments.So why isn't DC being pushed in the USA? My guess is that there are no HVDC equipment companies in the US who own enough politicians.
With generation sites becoming farther and farther away from load centers, HVDC is particularly economical for transmission distances greater than 700 km.
HVDC can transmit three times as much power per tower compared with conventional AC. This means a substantial reduction in land costs and often no new right-of-way (ROW) access permits, particularly difficult in densely populated regions.
UHVDC transmission maintains all the technical advantages associated with HVDC transmission: back-to-back or point-to-point connections for synchronized or asynchronous networks, regardless of voltage or frequency. Fully controllable, all HVDC systems prevent faults from propagating and reduce overall associated transmission losses.
Cross Posted at Classical Values
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4 comments:
LADWP has been importing Pacific Northwest power over DC transmission lines for about 30 years or more. Not sure if it's HV or UHV, though. That's the only application I'm aware of.
Oregon to LA.
Pacific Intertie
The Pacific DC Intertie (also called Path 65) is an electric power transmission line that transmits electricity from the Pacific Northwest to the Los Angeles area using high voltage direct current (HVDC). The line capacity is 3,100 megawatts, which is enough to serve two to three million Los Angeles households and is 48.7% of the Los Angeles Department of Water and Power (LADWP) electrical system's peak capacity.
The intertie originates near the Columbia River at the Celilo Converter Station on Bonneville Power Administration's (BPA) grid outside The Dalles, Oregon and is connected exclusively to the Sylmar Converter Station north of Los Angeles, which is owned by five utility companies and managed by LADWP. The Intertie is capable of transmitting power in either direction, but power on the Intertie flows mostly from north to south.
Presumably the gains from eliminating transmission line losses exceed conversion losses. I wonder what efficiency they are getting in converting back and forth?
Terra,
The Wiki says conversion losses run 3%. Which is entirely believable. Currently small converters are well above 90% and some of them are above 95% in certain parts of their ranges.
Larger converters with their more efficient magnetics should do much better. I did a very rough back of the envelope (BOE) calculation and came up with .1% of applied power for semiconductor losses. So I think most of the loss is in iron and copper - just as it would be for a HV AC transmission system. BTW HV AC conversion losses are from 1/2% to 1%. And for AC, corona and transmission line losses have to be accounted for.
So far DC systems have not been (mostly) multi-drop. That will have to change.
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