Presentation on theme: "HVDC High Voltage Direct Current Transmission Adam Holbrook, Kyle Holcomb, Bo Liu, Phillip Pardue, Mitchell Smith, Nina Wong 1 November 2013."— Presentation transcript:
HVDC High Voltage Direct Current Transmission Adam Holbrook, Kyle Holcomb, Bo Liu, Phillip Pardue, Mitchell Smith, Nina Wong 1 November 2013
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-2
The War of Currents Thomas Edison pioneered DC distribution while Tesla and Westinghouse adopted AC Voltage conversion was not efficiently possible with the DC grid. Voltage drop, then, wreaked havoc as loads varied and at the ends of lines. DC distribution was manageable in urban locations but impossible in rural areas due to low customer density. The majority of loads ran at ~100 volts. Larger loads, though required separate circuits be ran at very high costs.
Innovations in DC Technology Mercury-Arc Tubes and Vacuum Diodes allowed for the rectification of AC to DC Thyristors and IGBTs allow conversion both to and from DC
Increasing Current and voltage capacity Heated Cathode Rectifier, c Mercury-Arc Rectifier, c.1970 Thyristor Rectifier, 2009
DC Transmission Theory DC generation is not practical on a large scale due to the need for large permanent magnets or brushes. DC, then, is only viable as a transmission method between AC grids HVDC lines typically run in the hundreds of kV, generally around 500 kV.
Why use DC for Transmission Anyway? DC is more efficient than AC for transmission. It does not exhibit losses due to skin effect thus conductors can be sized smaller. DC can serve as a link between non- syncronized AC grids. Line losses are largely eliminated- capacitive, inductive, radiation.
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-8
Modern HVDC Several different designs which share several qualities. Innovative field watched closely by the Power Community 1-9
Thyristor Valve Advances Thyristor valves have made significant advances in the past ten years Development of light triggered thyristors Control unit advancement Has helped keep electrically triggered thyristors as the popular choice
Thyristor Valves from Manitoba Hydro
IGBT Valves Insulated gate bipolar transistor valves allow the current in the lines to be extinguished completely and quickly This property allows for much more versatility than standard HVDC lines can provide
Active DC Filters Digitally controlled amplifiers actively cancel interfering currents on lines Compared to the use of shunt filter branches, this is cheaper and easier to maintain and operate
Optical Direct Current Transducers Use high precision shunt at high potential to send signals over glass optical fibers Allows for much smaller components than the porcelain counterparts Cheap and effective method for lowering flashover probability.
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-15
Advantages Most benefits stem from inherently fewer components: DC eliminates need for three-phase system No skin effect Easier repairs in event of outage
Advantages, continued Lower losses / higher transmission efficiency Good long-distance underground and underwater transmission Eliminates need for substations near far-reaching delivery point
Disadvantages Higher cost over short distances Efficient DC-AC converting stations Harmonics System oscillation when integrated with AC networks Overvoltages More complicated switching infrastructure Heat dissipation of breaker
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-19
Challenges Conversion Switching Control Availability Maintenance
Research HVDC Offshore and Onshore Energy Great for long distance energy transmisson. Wind Power Solar Power Hydro Power Multi Terminal HVDC (MTDC) Will be the most commonly used in the Future. Popular for offshore energy networking. Underwater cables or overhead powerline.
Research Multi Terminal HVDC (MTDC) Series, Parallel, Hybrids Parallel systems are becoming the easiest to control because of Voltage Source Convertors. Area to Area Transmisson
Research HVDC Breakers Power Flow Control Automatic Network Restoration HVDC Converter for the exchange of renewable energies.
Development SIEMENS 2015 Offshore HVDC Plus link HelWin2, Germany 2014 Offshore HVDC Plus link SylWin1, Germany 2014 INELFE, France-Spain 2013 Offshore HVDC Plus link HelWin1, Germany 2013 Offshore HVDC Plus link BorWin2, Germany 2010 Trans Bay Cable Project, USA
Development ABB 2016 Celio Upgrade, Pacific Intertie, USA 2015 LitPol Link, Lithuania-Poland 2015 Troll A 3&4 offshore, Norway 2015 DolWin2, Germany 2015 NordBalt, Lithuania – Sweden
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-26
Demonstrations First demonstrations in 1882 with single DC machines. Since been dismantled 1964 saw the first plants to be upgraded rather than shut down. Demonstrations centered around Europe Early 2000s, China, Japan, and India take over with demonstrations and installed stations 1-27
Applications Mainly for country-country interconnects Submarine transmission lines European HVDC Existing Under Construction Considered Projects 1-28
The Neptune Project Regional Transmission System (RTS) 65 mile, undersea and underground cable 500 kV DC cable 660 MW capability (600,000 homes) 20% of Long Islands electrical needs Construction began June 2005, completed June 2007 Ahead of schedule and on budget Thyristor based system 1-29
The Neptune Project cont
The Neptune Project Details No overhead lines 60 miles under water, 15 miles under ground Three cable bundle Main kV cable Medium voltage return cable Fiber-optic cable for system control 1-31
The Neptune Project Details cont One of two identical converter stations with filter banks located outside of the facility. One in Sayreville, NJ and the other on Duffy Ave in NY Thyristor valves for power conversion supplied by Siemens.
NorNed Submarine HVDC cable from Feda, Norway to Eemshaven, Netherlands Longest submarine cable in the world, 360 mi Bipolar HVDC link ±450 kV with 700 MW capacity 300 kV AC on Feda end, 400 kV AC at Eemshaven Passes under the North sea Construction began 2006 Commissioned in 2008 Over budget (550m budget, 600m actual) 1-33
NorNed cont. Unique construction One 12-pulse converter on either end Symmetric Monopole configuration Earthed via high impedance, no earth current 1-34
NorNed Installation 1-35
Outline Background History Basic Theory Modern HVDC Impact of HVDC Advantages Disadvantages R&D Challenges Demonstrated Technologies Related Published Research 1-36
from HVDC to MTDC 1-37 Increase transmission capacity Increase Reliability Cost-effective Drive: Interconnection of offshore generation resources (wave and wind)
Challenges of MTDC DC fault current breaking and blocking ABB hybrid DC breaker, 2012:
Challenges of MTDC DC power flow control: in case of overload (VSC and DC line)
Thank you! Questions? Comments? 1-40
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