20-08-2012, 01:08 PM
HVDC
1HVDC.docx (Size: 561 KB / Downloads: 52)
INTRODUCTION
What could be more relaxing than a weekend country break, especially after a stressful week of work in the city. Unfortunately, many country landscapes are losing their appeal mainly because of the need to meet increasing energy demands.
While the transmission of electrical power has, in general, low environmental impact, the same cannot be said for the infrastructure needed to carry this power. The sight and increasing volume of voltage overhead transmission lines is forcing landscapes and valuable land to pay a very high price.
Besides many people are increasingly concerned about the possible health risks of living close to these lines. The growing interest in wind power generation is often discouraged because where the wind blows most, the existing infrastructure, ie, the AC-grid, cannot receive the increased production. Building new and more powerful overhead lines is no longer an acceptable solution.
ABB, on the other hand, has a very acceptable and well-proven solution: HVDC Light®. HVDC Light is based on voltage sourced converters (VSCs) and insulated gate bipolar transistors (IGBT). Combined with ABB’s HVDC Light cable, this VSC based transmission system offers unique opportunities to overcome many disadvantages previously associated with environmentally friendly sources of electrical power. A journey around the globe to several installations will help better understand the sustainable benefits created by ABB’s HVDC Light technology .
HVDC Light Technology
As its name implies, HVDC Light is a high voltage, direct current transmissiontechnology and is well suited to meet the demands of competitive power market for transmission up to 330MW and for DC voltage in the ± 150kV range. TraditionalHVDC, or if you like HVDC Heavy, is designed for high voltage, direct currenttransmission above 300MW and for DC voltage up to ± 600kV.HVDC Light design is based on modular concept build up from standardiseddesigns with compact transportable modules, which are factory assembled and pre-testedto provide short delivery and a fast response to the competitive market demands. Thesestandardised modular designs allow for delivery times as short as 12 months. It consistsof two AC to DC converter stations and a pair of underground cables interconnectingeach converter station..Fig. 2, Layout of a 330MW HVDC Light converter station
What is HVDC Light?
HVDC Light® is the successful and environmentally-friendly way to design a power transmission system for a submarine cable, an underground cable or network interconnection.
HVDC Light® is HVDC technology based on voltage source converters (VSCs). With extruded DC cables, power ratings from a few tens of megawatts up to several hundreds of megawatts are available.
Power range
Classical HVDC is most cost effective in the high power range, above approximately some 250 MW. HVDC Light, on the other hand, comes in unit sizes ranging from a few tens of MW. In the upper range, the technology now reaches 1,100 Mw and ±300 kV.
DC transmission circuit
The DC transmission circuit for classical HVDC can be an overhead line or a DC cable. The cables are normally mass-impregnated (MIND) cables suitable for HVDC with a copper conductor and insulation made of oil impregnated paper. The vast majority of classical DC cables are submarine cables.
The DC transmission circuit for HVDC Light is made by extruded polymer cables both for land transmissions (underground) and across water (submarine). HVDC Light is by nature bipolar. The DC circuit is not connected to ground. Therefore two cables are needed.
Modular
HVDC Light is based on a modular concept with a number of standardized sizes for the converter stations. Most of the equipment is installed in enclosures at the factory. Conventional HVDC is always tailor made to suit a specific application.
Converter station circuits (see image)
HVDC Light converter stations are Voltage Source Converters (VSCs) employing state of the art turn on/turn off IGBT power semiconductors. (IGBT = Integrated Gate Bipolar Transistors.)
Independence of AC network
HVDC Light does not rely on the AC network’s ability to keep the voltage and frequency stable. Unlike conventional HVDC, the short circuit capacity is not important. HVDC Light can feed load into a passive network (i.e. lacking synchronous machines)!
Active and reactive power control
Classic HVDC terminals can provide limited control of reactive power by means of switching of filters and shunt banks and to some level by firing angle control. But this control requires additional equipment and therefore extra cost.
The HVDC Light control makes it possible to create any phase angle or amplitude, which can be done almost instantly. This offers the possibility to control both active and reactive power independently. In fact the same converter can be used as a SVC and it is then called SVC Light. It is extremely effective to eliminate flicker e.g. from arc furnaces.
1HVDC.docx (Size: 561 KB / Downloads: 52)
INTRODUCTION
What could be more relaxing than a weekend country break, especially after a stressful week of work in the city. Unfortunately, many country landscapes are losing their appeal mainly because of the need to meet increasing energy demands.
While the transmission of electrical power has, in general, low environmental impact, the same cannot be said for the infrastructure needed to carry this power. The sight and increasing volume of voltage overhead transmission lines is forcing landscapes and valuable land to pay a very high price.
Besides many people are increasingly concerned about the possible health risks of living close to these lines. The growing interest in wind power generation is often discouraged because where the wind blows most, the existing infrastructure, ie, the AC-grid, cannot receive the increased production. Building new and more powerful overhead lines is no longer an acceptable solution.
ABB, on the other hand, has a very acceptable and well-proven solution: HVDC Light®. HVDC Light is based on voltage sourced converters (VSCs) and insulated gate bipolar transistors (IGBT). Combined with ABB’s HVDC Light cable, this VSC based transmission system offers unique opportunities to overcome many disadvantages previously associated with environmentally friendly sources of electrical power. A journey around the globe to several installations will help better understand the sustainable benefits created by ABB’s HVDC Light technology .
HVDC Light Technology
As its name implies, HVDC Light is a high voltage, direct current transmissiontechnology and is well suited to meet the demands of competitive power market for transmission up to 330MW and for DC voltage in the ± 150kV range. TraditionalHVDC, or if you like HVDC Heavy, is designed for high voltage, direct currenttransmission above 300MW and for DC voltage up to ± 600kV.HVDC Light design is based on modular concept build up from standardiseddesigns with compact transportable modules, which are factory assembled and pre-testedto provide short delivery and a fast response to the competitive market demands. Thesestandardised modular designs allow for delivery times as short as 12 months. It consistsof two AC to DC converter stations and a pair of underground cables interconnectingeach converter station..Fig. 2, Layout of a 330MW HVDC Light converter station
What is HVDC Light?
HVDC Light® is the successful and environmentally-friendly way to design a power transmission system for a submarine cable, an underground cable or network interconnection.
HVDC Light® is HVDC technology based on voltage source converters (VSCs). With extruded DC cables, power ratings from a few tens of megawatts up to several hundreds of megawatts are available.
Power range
Classical HVDC is most cost effective in the high power range, above approximately some 250 MW. HVDC Light, on the other hand, comes in unit sizes ranging from a few tens of MW. In the upper range, the technology now reaches 1,100 Mw and ±300 kV.
DC transmission circuit
The DC transmission circuit for classical HVDC can be an overhead line or a DC cable. The cables are normally mass-impregnated (MIND) cables suitable for HVDC with a copper conductor and insulation made of oil impregnated paper. The vast majority of classical DC cables are submarine cables.
The DC transmission circuit for HVDC Light is made by extruded polymer cables both for land transmissions (underground) and across water (submarine). HVDC Light is by nature bipolar. The DC circuit is not connected to ground. Therefore two cables are needed.
Modular
HVDC Light is based on a modular concept with a number of standardized sizes for the converter stations. Most of the equipment is installed in enclosures at the factory. Conventional HVDC is always tailor made to suit a specific application.
Converter station circuits (see image)
HVDC Light converter stations are Voltage Source Converters (VSCs) employing state of the art turn on/turn off IGBT power semiconductors. (IGBT = Integrated Gate Bipolar Transistors.)
Independence of AC network
HVDC Light does not rely on the AC network’s ability to keep the voltage and frequency stable. Unlike conventional HVDC, the short circuit capacity is not important. HVDC Light can feed load into a passive network (i.e. lacking synchronous machines)!
Active and reactive power control
Classic HVDC terminals can provide limited control of reactive power by means of switching of filters and shunt banks and to some level by firing angle control. But this control requires additional equipment and therefore extra cost.
The HVDC Light control makes it possible to create any phase angle or amplitude, which can be done almost instantly. This offers the possibility to control both active and reactive power independently. In fact the same converter can be used as a SVC and it is then called SVC Light. It is extremely effective to eliminate flicker e.g. from arc furnaces.