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120-806: The Quebec – New England Transmission (officially known in Quebec as the Réseau multiterminal à courant continu (RMCC) and also known as Phase I / Phase II and the Radisson - Nicolet - Des Cantons circuit, and known in New England as the Northern Pass ) is a long-distance high-voltage direct current (HVDC) line between Radisson , Quebec and Westford Road in Ayer , Massachusetts . As of 2012, it remains one of only two Multi-terminal HVDC systems in
240-497: A vector product , decreases. Since DC power has no phase, the phase shift cannot occur in the DC case. HVDC transmission may also be selected for other technical benefits. HVDC can transfer power between separate AC networks. HVDC power flow between separate AC systems can be automatically controlled to support either network during transient conditions, but without the risk that a major power-system collapse in one network will lead to
360-554: A 12 kV DC transmission line, which also served to convert 40 Hz generation to serve 60 Hz loads, at Mechanicville, New York . In 1941, a 60 MW, ±200 kV, 115 km (71 mi) buried cable link, known as the Elbe-Project , was designed for the city of Berlin using mercury arc valves but, owing to the collapse of the German government in 1945 , the project was never completed. The nominal justification for
480-452: A circuit that is effectively an ultra-high-voltage motor drive. More recent installations, including HVDC PLUS and HVDC MaxSine, are based on variants of a converter called a Modular Multilevel Converter (MMC). Multilevel converters have the advantage that they allow harmonic filtering equipment to be reduced or eliminated altogether. By way of comparison, AC harmonic filters of typical line-commutated converter stations cover nearly half of
600-452: A collapse in the second. The controllability feature is also useful where control of energy trading is needed. Specific applications where HVDC transmission technology provides benefits include: Long undersea or underground high-voltage cables have a high electrical capacitance compared with overhead transmission lines since the live conductors within the cable are surrounded by a relatively thin layer of insulation (the dielectric ), and
720-410: A distance of 200 kilometres (120 mi), including 10 kilometres (6.2 mi) of underground cable. This system used eight series-connected generators with dual commutators for a total voltage of 150 kV between the positive and negative poles, and operated from c. 1906 until 1936. Fifteen Thury systems were in operation by 1913. Other Thury systems operating at up to 100 kV DC worked into
840-468: A given transmission line to operate with a constant HVDC voltage that is approximately the same as the peak AC voltage for which it is designed and insulated. The power delivered in an AC system is defined by the root mean square (RMS) of an AC voltage, but RMS is only about 71% of the peak voltage. Therefore, if the HVDC line can operate continuously with an HVDC voltage that is the same as the peak voltage of
960-544: A group south where they founded Providence Plantations , which grew into the Colony of Rhode Island and Providence Plantations in 1636. At this time, Vermont was uncolonized, and the territories of New Hampshire and Maine were claimed and governed by Massachusetts. As the region grew, it received many immigrants from Europe due to its religious tolerance and economy. Relationships alternated between peace and armed skirmishes between colonists and local Native American tribes,
1080-446: A high resistance when conducting, wasting energy and generating heat in normal operation. The ABB breaker combines semiconductor and mechanical breakers to produce a hybrid breaker with both a fast break time and a low resistance in normal operation. Generally, vendors of HVDC systems, such as GE Vernova , Siemens and ABB , do not specify pricing details of particular projects; such costs are typically proprietary information between
1200-539: A joint venture to build a new HVDC line from Windsor, Quebec to Deerfield, New Hampshire , with an HVDC converter terminal intended to be built in Franklin, New Hampshire . Hydro-Québec would have owned the segment within Quebec, while the segment within the US would have been owned by Northern Pass Transmission LLC , a partnership between Northeast Utilities (75%) and NSTAR (25%). Estimated to cost US$ 1.1 billion to build, it
1320-460: A metal sheath. The geometry is that of a long coaxial capacitor . The total capacitance increases with the length of the cable. This capacitance is in a parallel circuit with the load. Where alternating current is used for cable transmission, additional current must flow in the cable to charge this cable capacitance. Another way to look at this is to realize, that such capacitance causes a phase shift between voltage and current, and thus decrease of
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#17327869535201440-405: A much lesser extent. Nevertheless, for a long AC overhead transmission line, the current flowing just to charge the line capacitance can be significant, and this reduces the capability of the line to carry useful current to the load at the remote end. Another factor that reduces the useful current-carrying ability of AC lines is the skin effect , which causes a nonuniform distribution of current over
1560-540: A part of Massachusetts, but it was granted statehood on March 15, 1820, as part of the Missouri Compromise . Today, New England is defined as the six states of Maine, Vermont, New Hampshire, Massachusetts, Rhode Island, and Connecticut. New England's economic growth relied heavily on trade with the British Empire , and the region's merchants and politicians strongly opposed trade restrictions. As
1680-593: A prominent role in the movement to abolish slavery in the United States, and it was the first region of the U.S. transformed by the Industrial Revolution , initially centered on the Blackstone and Merrimack river valleys. The physical geography of New England is diverse. Southeastern New England is covered by a narrow coastal plain , while the western and northern regions are dominated by
1800-482: A result of a civil war in Mozambique . The transmission voltage of ±533 kV was the highest in the world at the time. Line-commutated converters have some limitations in their use for HVDC systems. This results from requiring a period of reverse voltage to affect the turn off. An attempt to address these limitations is the capacitor-commutated converter (CCC). The CCC has series capacitors inserted into
1920-401: A similar concept HVDC PLUS ( Power Link Universal System ) and Alstom call their product based upon this technology HVDC MaxSine . They have extended the use of HVDC down to blocks as small as a few tens of megawatts and overhead lines as short as a few dozen kilometers. There are several different variants of VSC technology: most installations built until 2012 use pulse-width modulation in
2040-512: A steady pace from the 1840s until cut off by World War I . The largest numbers came from Ireland and Britain before 1890, and after that from Quebec, Italy, and Southern Europe. The immigrants filled the ranks of factory workers, craftsmen, and unskilled laborers. The Irish and Italians assumed a larger and larger role in the Democratic Party in the cities and statewide, while the rural areas remained Republican. The Great Depression in
2160-402: A third of its industrial workforce. It was also the most literate and most educated region in the country. During the same period, New England and areas settled by New Englanders (upstate New York, Ohio's Western Reserve , and the upper midwestern states of Michigan and Wisconsin ) were the center of the strongest abolitionist and anti-slavery movements in the United States, coinciding with
2280-413: A three-phase bridge rectifier known as a six-pulse bridge , containing six electronic switches, each connecting one of the three phases to one of the two DC rails. A complete switching element is usually referred to as a valve , irrespective of its construction. However, with a phase change only every 60°, considerable harmonic distortion is produced at both the DC and AC terminals when this arrangement
2400-454: A valve becoming positive (at which point the valve would start to conduct if it were made from diodes) and the thyristors being turned on. The DC output voltage of the converter steadily becomes less positive as the firing angle is increased: firing angles of up to 90° correspond to rectification and result in positive DC voltages, while firing angles above 90° correspond to inversion and result in negative DC voltages. The practical upper limit for
2520-649: A variety of the Eastern Algonquian languages . Prominent tribes included the Abenakis , Mi'kmaq , Penobscot , Pequots , Mohegans , Narragansetts , Nipmucs , Pocumtucks , and Wampanoags . Prior to the arrival of European colonists, the Western Abenakis inhabited what is now New Hampshire, New York, and Vermont, as well as parts of Quebec and western Maine. Their principal town was Norridgewock in today's Maine. The Penobscots lived along
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#17327869535202640-533: A wholly owned subsidiary of Northeast Utilities, which was renamed Eversource Energy in 2015. The purchase of power from Hydro-Québec was an issue during the Massachusetts gubernatorial election of 2010 . In July 2019, Eversource issued a statement that the Northern Pass project was now "off the table" after investing $ 318 million over a decade to develop and promote the project. Construction of
2760-462: A wider power transmission grid to another. Changes in load that would cause portions of an AC network to become unsynchronized and to separate, would not similarly affect a DC link, and the power flow through the DC link would tend to stabilize the AC network. The magnitude and direction of power flow through a DC link can be directly controlled and changed as needed to support the AC networks at either end of
2880-545: Is a better predictor than general forest age or biomass. Due to an increasing the amount of nitrogen in the soil from climate change , the red maple is becoming one of the most abundant trees in the region, and outcompeting other maples such as the sugar maple . The most populous cities as of the 2020 U.S. Census were (metropolitan areas in parentheses): During the 20th century, urban expansion in regions surrounding New York City has become an important economic influence on neighboring Connecticut, parts of which belong to
3000-440: Is also known as line-commutated converter (LCC) HVDC. On March 15, 1979, a 1920 MW thyristor based direct current connection between Cabora Bassa and Johannesburg (1,410 km; 880 mi) was energized. The conversion equipment was built in 1974 by Allgemeine Elektricitäts-Gesellschaft AG (AEG) , and Brown, Boveri & Cie (BBC) and Siemens were partners in the project. Service interruptions of several years were
3120-475: Is complex (especially with line commutated converters), as is expanding existing schemes to multi-terminal systems. Controlling power flow in a multi-terminal DC system requires good communication between all the terminals; power flow must be actively regulated by the converter control system instead of relying on the inherent impedance and phase angle properties of an AC transmission line. Multi-terminal systems are therefore rare. As of 2012 only two are in service:
3240-693: Is dotted with lakes, hills, marshes and wetlands, and sandy beaches. Important valleys in the region include the Champlain Valley , the Connecticut River Valley and the Merrimack Valley . The longest river is the Connecticut River , which flows from northeastern New Hampshire for 407 mi (655 km), emptying into Long Island Sound , roughly bisecting the region. Lake Champlain , which forms part of
3360-864: Is geologically a part of the New England province , an exotic terrane region consisting of the Appalachian Mountains , the New England highlands and the seaboard lowlands. The Appalachian Mountains roughly follow the border between New England and New York. The Berkshires in Massachusetts and Connecticut, and the Green Mountains in Vermont, as well as the Taconic Mountains , form a spine of Precambrian rock. The Appalachians extend northwards into New Hampshire as
3480-467: Is left over from £750M for the installed works. Add another £200–300M for the other works depending on additional onshore works required. An April 2010 announcement for a 2,000 MW, 64 km (40 mi) line between Spain and France is estimated at €700 million. This includes the cost of a tunnel through the Pyrenees. At the heart of an HVDC converter station , the equipment that performs
3600-501: Is less snowfall (especially in the coastal areas where it is often warmer). Southern and coastal Connecticut is the broad transition zone from the cold continental climates of the north to the milder subtropical climates to the south. The frost free season is greater than 180 days across far southern/coastal Connecticut, coastal Rhode Island, and the islands (Nantucket and Martha's Vineyard). Winters also tend to be much sunnier in southern Connecticut and southern Rhode Island compared to
3720-625: Is no potential difference. DC will never cross zero volts and never self-extinguish, so arc distance and duration is far greater with DC than the same voltage AC. This means some mechanism must be included in the circuit breaker to force current to zero and extinguish the arc, otherwise arcing and contact wear would be too great to allow reliable switching. In November 2012, ABB announced the first ultrafast HVDC circuit breaker. Mechanical circuit breakers are too slow for use in HVDC grids, although they have been used for years in other applications. Conversely, semiconductor breakers are fast enough but have
Quebec – New England Transmission - Misplaced Pages Continue
3840-418: Is one of the U.S. Census Bureau's nine regional divisions and the only multi-state region with clear and consistent boundaries. It maintains a strong sense of cultural identity, although the terms of this identity are often contrasted, combining Puritanism with liberalism, agrarian life with industry, and isolation with immigration. The earliest known inhabitants of New England were American Indians who spoke
3960-435: Is only the 39th-largest state, slightly smaller than Indiana . The remaining states are among the smallest in the U.S., including the smallest state —Rhode Island. The areas of the states (including water area) are: New England's long rolling hills, mountains, and jagged coastline are glacial landforms resulting from the retreat of ice sheets approximately 18,000 years ago, during the last glacial period . New England
4080-531: Is referred to as the rectifier and the station that is operating with power flow from DC to AC is referred to as the inverter . Early HVDC systems used electromechanical conversion (the Thury system) but all HVDC systems built since the 1940s have used electronic converters. Electronic converters for HVDC are divided into two main categories: Most of the HVDC systems in operation today are based on line-commutated converters (LCCs). The basic LCC configuration uses
4200-542: Is used, the cable capacitance is charged only when the cable is first energized or if the voltage level changes; there is no additional current required. DC powered cables are limited only by their temperature rise and Ohm's law . Although some leakage current flows through the dielectric insulator , this effect is also present in AC systems and is small compared to the cable's rated current. The capacitive effect of long underground or undersea cables in AC transmission applications also applies to AC overhead lines, although to
4320-422: Is used. An enhancement of this arrangement uses 12 valves in a twelve-pulse bridge . The AC is split into two separate three-phase supplies before transformation. One of the sets of supplies is then configured to have a star (wye) secondary, and the other a delta secondary, establishing a 30° phase difference between the two sets of three phases. With twelve valves connecting each of the two sets of three phases to
4440-420: Is very high technology manufacturing, such as jet engines, nuclear submarines, pharmaceuticals, robotics, scientific instruments, and medical devices. The Massachusetts Institute of Technology invented the format for university-industry relations in high tech fields and spawned many software and hardware firms, some of which grew rapidly. By the 21st century, the region had become famous for its leadership roles in
4560-464: The Dominion of New England , an administrative union including all of the New England colonies. In 1688, the former Dutch colonies of New York , East New Jersey , and West New Jersey were added to the dominion. The union was imposed from the outside and contrary to the rooted democratic tradition of the colonies, and it was highly unpopular among the colonists. The dominion significantly modified
4680-514: The Frank D. Comerford Dam near Monroe, New Hampshire which, because of the asynchronous operation of the American and Québec power grids, had to be implemented as HVDC. This bipolar electricity transmission line, which is overhead for its whole length except the crossing of Saint Lawrence river, went into service in 1986. It could transfer a maximum power of 690 megawatts . The operating voltage
4800-558: The Mayflower Compact before leaving the ship, and it became their first governing document. The Massachusetts Bay Colony came to dominate the area and was established by royal charter in 1629 with its major town and port of Boston established in 1630. Massachusetts Puritans began to establish themselves in Connecticut as early as 1633. Roger Williams was banished from Massachusetts for theological reasons; he led
4920-604: The New Deal coalition and making the once-Republican region into one that was closely divided. However, the enormous spending on munitions, ships, electronics, and uniforms during World War II caused a burst of prosperity in every sector. The region lost most of its factories starting with the loss of textiles in the 1930s and getting worse after 1960. The New England economy was radically transformed after World War II. The factory economy practically disappeared. Once-bustling New England communities fell into economic decay following
Quebec – New England Transmission - Misplaced Pages Continue
5040-877: The Penobscot River in Maine. The Narragansetts and smaller tribes under their sovereignty lived in Rhode Island, west of Narragansett Bay, including Block Island . The Wampanoags occupied southeastern Massachusetts, Rhode Island, and the islands of Martha's Vineyard and Nantucket . The Pocumtucks lived in Western Massachusetts, and the Mohegan and Pequot tribes lived in Connecticut. The Connecticut River Valley linked numerous tribes culturally, linguistically, and politically. As early as 1600 CE, French, Dutch, and English traders began exploring
5160-574: The Puritan work ethic , in contrast to the Southern colonies which focused on agricultural production while importing finished goods from England. By 1686, King James II had become concerned about the increasingly independent ways of the colonies, including their self-governing charters, their open flouting of the Navigation Acts , and their growing military power. He therefore established
5280-592: The Quebec – New England Transmission between Radisson, Sandy Pond, and Nicolet and the Sardinia–;mainland Italy link which was modified in 1989 to also provide power to the island of Corsica . HVDC circuit breakers are difficult to build because of arcing : under AC, the voltage inverts and in doing so crosses zero volts dozens of times a second. An AC arc will self-extinguish at one of these zero-crossing points because there cannot be an arc where there
5400-642: The Saint Lawrence River between Grondines and Lotbinière via a tunnel . Until the tunnel was built, the line crossed the river via an overhead lattice tower electricity pylon —portions of one of these towers would later be used as part of the observation tower at La Cité de l'Énergie in Shawinigan . In December 2008, Hydro-Québec , along with American utilities Northeast Utilities (parent company of Public Service of New Hampshire) and NSTAR (parent company of Boston Edison), created
5520-668: The Securities Exchange Act of 1934 with his war on "unlisted securities". Hull gave testimony to the US Senate (Sen. Duncan Upshaw Fletcher ) for work on the Pecora Commission , which revealed that neither Albert H. Wiggin (born in Medfield, MA) nor J. P. Morgan Jr. had paid any income taxes in 1931 and 1932; a public outcry ensued. Boston figured prominently on the subject of securities laws in
5640-634: The Siege of Boston by continental troops. In March 1776, British forces were compelled to retreat from Boston. After the dissolution of the Dominion of New England, the colonies of New England ceased to function as a unified political unit but remained a defined cultural region. There were often disputes over territorial jurisdiction, leading to land exchanges such as those regarding the Equivalent Lands and New Hampshire Grants . By 1784, all of
5760-619: The White Mountains , and then into Maine and Canada. Mount Washington in New Hampshire is the highest peak in the Northeast, although it is not among the ten highest peaks in the eastern United States. It is the site of the second highest recorded wind speed on Earth, and has the reputation of having the world's most severe weather. The coast of the region, extending from southwestern Connecticut to northeastern Maine,
5880-647: The 1850s, and all of New England became strongly Republican, including areas that had previously been strongholds for both the Whig and the Democratic parties. New England remained solidly Republican until Catholics began to mobilize behind the Democrats, especially in 1928. This led to the end of "Yankee Republicanism" and began New England's relatively swift transition into a consistently Democratic stronghold in national elections. The flow of immigrants continued at
6000-776: The 1930s in Sweden ( ASEA ) and in Germany . Early commercial installations included one in the Soviet Union in 1951 between Moscow and Kashira , and a 100 kV, 20 MW system between Gotland and mainland Sweden in 1954. Before the Chinese project of 2019, the longest HVDC link in the world was the Rio Madeira link in Brazil , which consists of two bipoles of ±600 kV, 3150 MW each, connecting Porto Velho in
6120-516: The 1930s, but the rotating machinery required high maintenance and had high energy loss. Various other electromechanical devices were tested during the first half of the 20th century with little commercial success. One technique attempted for conversion of direct current from a high transmission voltage to lower utilization voltage was to charge series-connected batteries , then reconnect the batteries in parallel to serve distribution loads. While at least two commercial installations were tried around
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#17327869535206240-493: The AC equivalent line, then for a given current (where HVDC current is the same as the RMS current in the AC line), the power transmission capability when operating with HVDC is approximately 40% higher than the capability when operating with AC. Because HVDC allows power transmission between unsynchronized AC distribution systems, it can help increase system stability, by preventing cascading failures from propagating from one part of
6360-479: The AC line connections. CCC has remained only a niche application because of the advent of voltage-source converters (VSCs) which more directly address turn-off issues. Widely used in motor drives since the 1980s, voltage-source converters (VSCs) started to appear in HVDC in 1997 with the experimental Hellsjön–Grängesberg project in Sweden. By the end of 2011, this technology had captured a significant proportion of
6480-585: The Beverly Cotton Manufactory. The Connecticut River Valley became a crucible for industrial innovation, particularly the Springfield Armory , pioneering such advances as interchangeable parts and the assembly line which influenced manufacturing processes all around the world. From early in the nineteenth century until the mid-twentieth, the region surrounding Springfield, Massachusetts and Hartford, Connecticut served as
6600-432: The DC link. The disadvantages of HVDC are in conversion, switching, control, availability, and maintenance. HVDC is less reliable and has lower availability than alternating current (AC) systems, mainly due to the extra conversion equipment. Single-pole systems have availability of about 98.5%, with about a third of the downtime unscheduled due to faults. Fault-tolerant bipole systems provide high availability for 50% of
6720-592: The HVDC market. The development of higher rated insulated-gate bipolar transistors (IGBTs), gate turn-off thyristors (GTOs), and integrated gate-commutated thyristors (IGCTs), has made HVDC systems more economical and reliable. This is because modern IGBTs incorporate a short-circuit failure mode, wherein should an IGBT fail, it is mechanically shorted. Therefore, modern VSC HVDC converter stations are designed with sufficient redundancy to guarantee operation over their entire service lives. The manufacturer ABB Group calls this concept HVDC Light , while Siemens calls
6840-615: The New England Clean Energy Connect, a similar project, started in February 2021. Massachusetts pursues it as an option to bring Canadian hydropower through transmission lines in Maine, estimated to cost $ 1 billion. The citizens of Maine voted in a 2021 referendum to revoke the project's permit, forcing a halt to construction which was already underway. In August 2022, the Supreme Court of Maine ruled
6960-828: The New World, trading metal, glass, and cloth for local beaver pelts. On April 10, 1606, King James I of England issued a charter for the Virginia Company , which consisted of the London Company and the Plymouth Company . These two privately funded ventures were intended to claim land for England, to conduct trade, and to return a profit. In 1620, the Pilgrims arrived on the Mayflower and established Plymouth Colony in Massachusetts, beginning
7080-489: The Protestant Great Awakening in the region. Abolitionists who demanded immediate emancipation had their base in the region, such as William Lloyd Garrison , John Greenleaf Whittier , and Wendell Phillips . So too did anti-slavery politicians who wanted to limit the growth of slavery, such as John Quincy Adams , Charles Sumner , and John P. Hale . The anti-slavery Republican Party was formed in
7200-622: The United States of the 1930s hit the region hard, with high unemployment in the industrial cities. The Boston Stock Exchange rivaled the New York Stock Exchange in 1930. In the beginning of 1930 John C. Hull , first Securities Director of Massachusetts (1930–1936), helped to mitigate the consequences of the Wall Street Crash of 1929 and the Great Depression. He was helpful in the passing of
7320-671: The United States and the United Kingdom fought the War of 1812 , New England Federalists organized the Hartford Convention in the winter of 1814 to discuss the region's grievances concerning the war, and to propose changes to the United States Constitution to protect the region's interests and maintain its political power. Radical delegates within the convention proposed the region's secession from
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#17327869535207440-418: The United States' epicenter for advanced manufacturing, drawing skilled workers from all over the world. The rapid growth of textile manufacturing in New England between 1815 and 1860 caused a shortage of workers. Recruiters were hired by mill agents to bring young women and children from the countryside to work in the factories. Between 1830 and 1860, thousands of farm girls moved from rural areas where there
7560-560: The United States, but they were outnumbered by moderates who opposed the idea. Politically, the region often disagreed with the rest of the country. Massachusetts and Connecticut were among the last refuges of the Federalist Party , and New England became the strongest bastion of the new Whig Party when the Second Party System began in the 1830s. The Whigs were usually dominant throughout New England, except in
7680-743: The appointment of the governors. After the Glorious Revolution , in 1689, Bostonians overthrew the royal governor, Sir Edmund Andros . During a popular and bloodless uprising , they seized dominion officials and adherents to the Church of England . These tensions eventually culminated in the American Revolution , boiling over with the outbreak of the War of American Independence in 1775. The first battles of which were fought in Lexington and Concord, Massachusetts , leading to
7800-440: The bloodiest of which was the Pequot War in 1637 which resulted in the Mystic massacre . On May 19, 1643, the colonies of Massachusetts Bay, Plymouth, New Haven , and Connecticut joined in a loose compact called the New England Confederation (officially "The United Colonies of New England"). The confederation was designed largely to coordinate mutual defense, and it gained some importance during King Philip's War which pitted
7920-437: The border between Vermont and New York, is the largest lake in the region, followed by Moosehead Lake in Maine and Lake Winnipesaukee in New Hampshire. The climate of New England varies greatly across its 500 miles (800 km) span from northern Maine to southern Connecticut: Maine, New Hampshire, Vermont, and western Massachusetts have a humid continental climate (Dfb in Köppen climate classification ). In this region
8040-451: The charters of the colonies, including the appointment of royal governors to nearly all of them. There was an uneasy tension among the royal governors, their officers, and the elected governing bodies of the colonies. The governors wanted unlimited authority, and the different layers of locally elected officials would often resist them. In most cases, the local town governments continued operating as self-governing bodies, just as they had before
8160-518: The colonists and their Indian allies against a widespread Indian uprising from June 1675 through April 1678, resulting in killings and massacres on both sides. In the aftermath of settler-Native conflicts, hundreds of captive Indians were sold into slavery . Up until 1700, Native Americans comprised a majority of the non-white labor force in colonial New England. During the next 74 years, there were six colonial wars that took place primarily between New England and New France , during which New England
8280-525: The commissioning of replacement thyristor converters. The development of thyristor valves for HVDC began in the late 1960s. The first complete HVDC scheme based on thyristor was the Eel River scheme in Canada, which was built by General Electric and went into service in 1972. Since 1977, new HVDC systems have used solid-state devices , in most cases thyristors . Like mercury arc valves, thyristors require connection to an external AC circuit in HVDC applications to turn them on and off. HVDC using thyristors
8400-410: The construction of the expanded transmission line. Elected representatives from New Hampshire's 10 counties have expressed opposition, including 114 officials in the New Hampshire House of Representatives and 5 members of the New Hampshire Senate . United States Congressional Representative Carol Shea-Porter and Senators Maggie Hassan and Jeanne Shaheen also oppose expansion of the line. Some of
8520-436: The conversion between AC and DC is referred to as the converter . Almost all HVDC converters are inherently capable of converting from AC to DC ( rectification ) and from DC to AC ( inversion ), although in many HVDC systems, the system as a whole is optimized for power flow in only one direction. Irrespective of how the converter itself is designed, the station that is operating (at a given time) with power flow from AC to DC
8640-402: The converter station area. With time, voltage-source converter systems will probably replace all installed simple thyristor-based systems, including the highest DC power transmission applications. A long-distance, point-to-point HVDC transmission scheme generally has lower overall investment cost and lower losses than an equivalent AC transmission scheme. Although HVDC conversion equipment at
8760-428: The cross-sectional area of the conductor. Transmission line conductors operating with direct current suffer from neither constraint. Therefore, for the same conductor losses (or heating effect), a given conductor can carry more power to the load when operating with HVDC than AC. Finally, depending upon the environmental conditions and the performance of overhead line insulation operating with HVDC, it may be possible for
8880-574: The early 1930s in response to the Great Depression. Harvard University professors Felix Frankfurter , Benjamin V. Cohen , and James M. Landis drafted the Securities Act of 1933 and the Securities Exchange Act of 1934. Joseph P. Kennedy Sr. was the first chairman of the U.S. Securities and Exchange Commission , and he was from Boston. The Democrats appealed to factory workers and especially Catholics, pulling them into
9000-407: The energy lost as heat in the wires is directly proportional to the square of the current ( energy lost as heat = current 2 ⋅ resistance ⋅ time ) , {\textstyle ({\text{energy lost as heat}}={\text{current}}^{2}\cdot {\text{resistance}}\cdot {\text{time}}),} using half the current at double the voltage reduces
9120-466: The fields of education, medicine, medical research, high-technology, finance, and tourism. Some industrial areas were slow in adjusting to the new service economy. In 2000, New England had two of the ten poorest cities in the U.S. (by percentage living below the poverty line): the state capitals of Providence, Rhode Island and Hartford, Connecticut . They were no longer in the bottom ten by 2010; Connecticut, Massachusetts, and New Hampshire remain among
9240-427: The firing angle is about 150–160° because above this, the valve would have insufficient turnoff time. Early LCC systems used mercury-arc valves , which were rugged but required high maintenance. Because of this, many mercury-arc HVDC systems were built with bypass switchgear across each six-pulse bridge so that the HVDC scheme could be operated in six-pulse mode for short maintenance periods. The last mercury arc system
9360-500: The flight of the region's industrial base. The textile mills one by one went out of business from the 1920s to the 1970s. For example, the Crompton Company went bankrupt in 1984 after 178 years in business, costing the jobs of 2,450 workers in five states. The major reasons were cheap imports, the strong dollar, declining exports, and a failure to diversify. The shoe industry subsequently left the region as well. What remains
9480-556: The history of permanent European colonization in New England. In 1616, English explorer John Smith named the region "New England". The name was officially sanctioned on November 3, 1620, when the charter of the Virginia Company of Plymouth was replaced by a royal charter for the Plymouth Council for New England , a joint-stock company established to colonize and govern the region. The Pilgrims wrote and signed
9600-677: The incumbent power companies in New England oppose it, while other companies favor it. High-voltage direct current A high-voltage direct current ( HVDC ) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages between 100 kV and 800 kV. HVDC lines are commonly used for long-distance power transmission, since they require fewer conductors and incur less power loss than equivalent AC lines. HVDC also allows power transmission between AC transmission systems that are not synchronized . Since
9720-745: The last mercury arc HVDC system (the Nelson River Bipole 1 system in Manitoba , Canada) having been put into service in stages between 1972 and 1977. Since then, all mercury arc systems have been either shut down or converted to use solid-state devices. The last HVDC system to use mercury arc valves was the Inter-Island HVDC link between the North and South Islands of New Zealand, which used them on one of its two poles. The mercury arc valves were decommissioned on 1 August 2012, ahead of
9840-678: The line losses by a factor of 4. While energy lost in transmission can also be reduced by decreasing the resistance by increasing the conductor size, larger conductors are heavier and more expensive. High voltage cannot readily be used for lighting or motors, so transmission-level voltages must be reduced for end-use equipment. Transformers are used to change the voltage levels in alternating current (AC) transmission circuits, but cannot pass DC current. Transformers made AC voltage changes practical, and AC generators were more efficient than those using DC. These advantages led to early low-voltage DC transmission systems being supplanted by AC systems around
9960-662: The link capacity, but availability of the full capacity is about 97% to 98%. The required converter stations are expensive and have limited overload capacity. At smaller transmission distances, the losses in the converter stations may be bigger than in an AC transmission line for the same distance. The cost of the converters may not be offset by reductions in line construction cost and power line loss. Operating an HVDC scheme requires many spare parts to be kept, often exclusively for one system, as HVDC systems are less standardized than AC systems and technology changes more quickly. In contrast to AC systems, realizing multi-terminal systems
10080-619: The more Democratic Maine and New Hampshire. New England was key to the Industrial Revolution in the United States. The Blackstone Valley running through Massachusetts and Rhode Island has been called the birthplace of America's industrial revolution. In 1787, the first cotton mill in America was founded in the North Shore seaport of Beverly, Massachusetts as the Beverly Cotton Manufactory . The Manufactory
10200-613: The new line, saying that it would benefit Connecticut and Massachusetts residents more than those in New Hampshire, and expressing concerns about the flooding of boreal forests during the construction of Hydro-Québec's dams in northern Quebec, disputes with the Innu First Nations, and the effects on tourism and the environment within the White Mountain National Forest . A coalition of New Hampshire communities and local government officials oppose
10320-520: The next 126 years, people in the region fought in four French and Indian Wars until the English colonists and their Iroquois allies defeated the French and their Algonquian allies. In the late 18th century, political leaders from the New England colonies initiated resistance to Britain's taxes without the consent of the colonists . Residents of Rhode Island captured and burned a British ship which
10440-594: The other near Radisson substation approximately at 53°29′18″N 77°47′35″W / 53.48833°N 77.79306°W / 53.48833; -77.79306 ( Radisson Grounding Electrode ) . In 2004, shortly before U.S. President George W. Bush 's visit to Canada , a tower along the Quebec–New England Transmission circuit in the Eastern Townships near the Canada–US border
10560-521: The power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as 50 and 60 Hz. This improves the stability and economy of each grid, by allowing the exchange of power between previously incompatible networks. The modern form of HVDC transmission uses technology developed extensively in
10680-513: The project needed to receive regulatory approval in Quebec and the United States. The proposed transmission line could have been in operation in 2015. According to Jim Robb, a senior executive from Northeast Utilities, New England could have met one third of its Regional Greenhouse Gas Initiative commitments with the hydropower coming through this new power line alone. In October 2010, Northeast Utilities announced that it would merge with NSTAR. In effect, Northern Pass Transmission would have become
10800-542: The project was that, during wartime, a buried cable would be less conspicuous as a bombing target. The equipment was moved to the Soviet Union and was put into service there as the Moscow–Kashira HVDC system. The Moscow–Kashira system and the 1954 connection by Uno Lamm 's group at ASEA between the mainland of Sweden and the island of Gotland marked the beginning of the modern era of HVDC transmission. Mercury arc valves were common in systems designed up to 1972,
10920-628: The rest of New England. New England contains forested ecosystems with a variety of terrestrial vertebrates. Land-use patterns and land disturbance, such as the dramatic increase in land clearing for agriculture in the mid eighteenth century to nineteenth century, greatly altered the ecosystem and resulted in extinctions, local extirpations , and recolonizations. According to an analysis of USDA Forest Service data, tree species diversity increases from north to south at about two to three species per degree in latitude. In addition, taller trees are associated with higher tree species diversity, and tree height
11040-488: The retroactive revocation of the permit was unconstitutional, but remanded the case to lower courts for more consideration. Important waypoints of the line. Route listed here reflects the primary route, and is currently projected. Quebec – New England Transmission has two grounding electrodes: one at Des Cantons at 45°36′29″N 71°51′06″W / 45.60806°N 71.85167°W / 45.60806; -71.85167 ( Des Cantons Grounding Electrode ) and
11160-603: The rolling hills and worn-down peaks of the northern end of the Appalachian Mountains . The Atlantic fall line lies close to the coast, which enabled numerous cities to take advantage of water power along the many rivers, such as the Connecticut River , which bisects the region from north to south. Each state is generally subdivided into small municipalities known as towns , many of which are governed by town meetings . Unincorporated areas are practically nonexistent outside of Maine, and village-style governments common in other areas are limited to Vermont and Connecticut. New England
11280-402: The same voltage. This is because direct current transfers only active power and thus causes lower losses than alternating current, which transfers both active and reactive power . In other words, transmitting electric AC power over long distances inevitably results in a phase shift between voltage and current. Because of this phase shift the effective Power=Current*Voltage, where * designates
11400-649: The second-largest city in New England; Manchester, New Hampshire , the largest city in New Hampshire; and Providence, Rhode Island , the capital of and largest city in Rhode Island. In 1620, the Pilgrims established Plymouth Colony , the second successful settlement in British America after the Jamestown Settlement in Virginia , founded in 1607. Ten years later, Puritans established Massachusetts Bay Colony north of Plymouth Colony. Over
11520-521: The selection. However, some practitioners have provided some information: For an 8 GW 40 km (25 mi) link laid under the English Channel , the following are approximate primary equipment costs for a 2000 MW 500 kV bipolar conventional HVDC link (excluding way-leaving , on-shore reinforcement works, consenting, engineering, insurance, etc.) So for an 8 GW capacity between Britain and France in four links, little
11640-481: The south to the converter station at Sandy Pond in Massachusetts. The transmission power was increased by extending the existing converter stations to 2,000 megawatts, with the value of the transmission voltage remaining unchanged at ±450 kV. For the connection of the Montreal area, a further converter station at Nicolet was put into service in 1992 with a transmission capacity of 2,000 megawatts. The line crosses
11760-781: The state of Rondônia to the São Paulo area with a length of more than 2,500 km (1,600 mi). High voltage is used for electric power transmission to reduce the energy lost in the resistance of the wires. For a given quantity of power transmitted, doubling the voltage will deliver the same power at only half the current: power = ( voltage ) ⋅ ( current ) = ( 2 ⋅ voltage ) ⋅ ( 1 2 ⋅ current ) {\displaystyle {\text{power}}=({\text{voltage}})\cdot ({\text{current}})=(2\cdot {\text{voltage}})\cdot ({\tfrac {1}{2}}\cdot {\text{current}})} Since
11880-461: The states in the region had taken steps towards the abolition of slavery, with Vermont and Massachusetts introducing total abolition in 1777 and 1783, respectively. The nickname "Yankeeland" was sometimes used to denote the New England area, especially among Southerners and the British. Vermont was admitted to statehood in 1791 after settling a dispute with New York. The territory of Maine had been
12000-414: The supplier and the client. Costs vary widely depending on the specifics of the project (such as power rating, circuit length, overhead vs. cabled route, land costs, site seismology, and AC network improvements required at either terminal). A detailed analysis of DC vs. AC transmission costs may be required in situations where there is no obvious technical advantage to DC, and economical reasoning alone drives
12120-414: The ten wealthiest states in the United States in terms of median household income and per capita income. The states of New England have a combined area, including water surfaces, of 71,988 square miles (186,447 km ), making the region slightly larger than the state of Washington and slightly smaller than Great Britain . Maine alone constitutes nearly one-half of the total area of New England, yet
12240-538: The terminal stations is costly, the total DC transmission-line costs over long distances are lower than for an AC line of the same distance. HVDC requires less conductor per unit distance than an AC line, as there is no need to support three phases and there is no skin effect . AC systems use a higher peak voltage for the same power, increasing insulator costs. Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km (620 mi), about 50% less than AC (6.7%) lines at
12360-435: The transmitted power, which is a vector product of voltage and current. Additional energy losses also occur as a result of dielectric losses in the cable insulation. For a sufficiently long AC cable, the entire current-carrying ability of the conductor would be needed to supply the charging current alone. This cable capacitance issue limits the length and power-carrying ability of AC power cables. However, if direct current
12480-519: The turn of the 20th century, the technique was not generally useful owing to the limited capacity of batteries, difficulties in switching between series and parallel configurations, and the inherent energy inefficiency of a battery charge/discharge cycle. First proposed in 1914, the grid controlled mercury-arc valve became available during the period 1920 to 1940 for the rectifier and inverter functions associated with DC transmission. Starting in 1932, General Electric tested mercury-vapor valves and
12600-452: The turn of the 20th century. Practical conversion of current between AC and DC became possible with the development of power electronics devices such as mercury-arc valves and, starting in the 1970s, power semiconductor devices including thyristors , integrated gate-commutated thyristors (IGCTs), MOS-controlled thyristors (MCTs) and insulated-gate bipolar transistors (IGBT). The first long-distance transmission of electric power
12720-400: The two DC rails, there is a phase change every 30°, and harmonics are considerably reduced. For this reason, the twelve-pulse system has become standard on most line-commutated converter HVDC systems built since the 1970s. With line commutated converters, the converter has only one degree of freedom – the firing angle , which represents the time delay between the voltage across
12840-496: The voltage across the valve is evenly shared between the thyristors. The thyristor plus its grading circuits and other auxiliary equipment is known as a thyristor level . New England New England is a region comprising six states in the Northeastern United States : Connecticut , Maine , Massachusetts , New Hampshire , Rhode Island , and Vermont . It is bordered by the state of New York to
12960-485: The voltage. Each set was insulated from electrical ground and driven by insulated shafts from a prime mover . The transmission line was operated in a constant-current mode, with up to 5,000 volts across each machine, some machines having double commutators to reduce the voltage on each commutator. This system transmitted 630 kW at 14 kV DC over a distance of 120 kilometres (75 mi). The Moutiers–Lyon system transmitted 8,600 kW of hydroelectric power
13080-492: The west and by the Canadian provinces of New Brunswick to the northeast and Quebec to the north. The Gulf of Maine and Atlantic Ocean are to the east and southeast, and Long Island Sound is to the southwest. Boston is New England's largest city and the capital of Massachusetts. Greater Boston is the largest metropolitan area, with nearly a third of New England's population; this area includes Worcester, Massachusetts ,
13200-452: The winters are long and cold, and heavy snow is common (most locations receive 60–120 inches (150–300 cm) of snow annually in this region). The summer's months are moderately warm, though summer is rather short and rainfall is spread through the year. In central and eastern Massachusetts, northern Rhode Island, and northern Connecticut, the same humid continental prevails (Dfa), though summers are warm to hot, winters are shorter, and there
13320-489: The world (the other one being the Sardinia–Corsica–Italy system, completed in the same year) and is "the only multi-terminal bipole HVDC system in the world where three stations are interconnected and operate under a common master control system". Initially, the Quebec – New England Transmission consisted of the 172 kilometres (107 mi) section between the Des Cantons station near Windsor, Quebec and
13440-851: Was allied with the Iroquois Confederacy and New France was allied with the Wabanaki Confederacy . Mainland Nova Scotia came under the control of New England after the Siege of Port Royal (1710) , but both New Brunswick and most of Maine remained contested territory between New England and New France. The British eventually defeated the French in 1763, opening the Connecticut River Valley for British settlement into western New Hampshire and Vermont. The New England Colonies were settled primarily by farmers who became relatively self-sufficient. Later, New England's economy began to focus on crafts and trade, aided by
13560-545: Was also considered the largest cotton mill of its time. Technological developments and achievements from the Manufactory led to the development of more advanced cotton mills, including Slater Mill in Pawtucket, Rhode Island . Towns such as Lawrence, Massachusetts , Lowell, Massachusetts , Woonsocket, Rhode Island , and Lewiston, Maine became centers of the textile industry following the innovations at Slater Mill and
13680-603: Was damaged by explosive charges detonated at its base. The CBC reported that a message, purportedly from the Résistance internationaliste and issued to the La Presse and Le Journal de Montréal newspapers and CKAC radio, stated that the attack had been carried out to "denounce the 'pillaging' of Quebec's resources by the United States". In November 2015, the Sierra Club of New Hampshire expressed opposition to
13800-591: Was demonstrated using direct current in 1882 at Miesbach-Munich Power Transmission , but only 1.5 kW was transmitted. An early method of HVDC transmission was developed by the Swiss engineer René Thury and his method, the Thury system, was put into practice by 1889 in Italy by the Acquedotto De Ferrari-Galliera company. This system used series-connected motor-generator sets to increase
13920-513: Was enforcing unpopular trade restrictions, and residents of Boston threw British tea into the harbor. Britain responded with a series of punitive laws stripping Massachusetts of self-government which the colonists called the " Intolerable Acts ". These confrontations led to the first battles of the American Revolutionary War in 1775 and the expulsion of the British authorities from the region in spring 1776. The region played
14040-486: Was no paid employment to work in the nearby mills, such as the Lowell Mill Girls . As the textile industry grew, immigration also grew. By the 1850s, immigrants began working in the mills, especially French Canadians and Irish . New England as a whole was the most industrialized part of the United States. By 1850, the region accounted for well over a quarter of all manufacturing value in the country and over
14160-415: Was projected that the line would either run in existing right-of-way adjacent to the HVDC line that runs through New Hampshire, or it would have connected to a right-of-way in northern New Hampshire that runs through the White Mountains . This 180-to-190-mile (290 to 310 km) line, projected to carry 1,200 megawatts, would have brought electricity to approximately one million homes. In order to go ahead,
14280-642: Was shut down in 2012. The thyristor valve was first used in HVDC systems in 1972. The thyristor is a solid-state semiconductor device similar to the diode , but with an extra control terminal that is used to switch the device on at a particular instant during the AC cycle. Because the voltages in HVDC systems, up to 800 kV in some cases, far exceed the breakdown voltages of the thyristors used, HVDC thyristor valves are built using large numbers of thyristors in series. Additional passive components such as grading capacitors and resistors need to be connected in parallel with each thyristor in order to ensure that
14400-540: Was ±450 kV or 900 kV from line to line. The line was planned to extend beyond the two terminals at Des Cantons and Comerford to the hydroelectric power plants of the La Grande Complex , in the James Bay region of Québec, and to the high consumption area around Boston , Massachusetts — specifically, by 1,100 kilometres (680 mi) to the north toward the converter station at Radisson Substation , and to
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