Milestones:Eel River High Voltage Direct Current Converter Station, 1972 and LP and 45 RPM Records: Difference between pages

From ETHW
(Difference between pages)
No edit summary
 
m (<replacetext_editsummary>)
 
Line 1: Line 1:
== Eel River High Voltage Direct Current Converter Station, 1972 ==
== The LP and the 45 ==


''Operating since 1972, Eel River, New Brunswick is home to the world's first commercial solid state High Voltage Direct Current converter station. This 320 MW interconnection facility, built by Canadian General Electric and NB Power, incorporates high current silicon solid state thyristors to convert alternating current from Hydro Quebec to direct current and back to alternating, allowing asynchronous, stable power transfers to serve New Brunswick's Power's customers.''
[[Image:Vinyl record LP 10inch.JPG|thumb|right|10-inch LP]]


'''The plaque may be viewed in the main lobby of the Eel River Dalhousie Generating Station in North Shannonvale, New Brunswick, where it can be viewed by employees and visitors.'''
The long playing (LP) record and the 45-rpm disc were two different approaches to high fidelity music, introduced by two different companies in the late 1940s. Since the beginning of the [[Phonograph|phonograph]], most records had played for about two or three minutes. Sometimes [[Mass Producing Records|record companies issued longer recordings on large, 12-inch discs]]. But when the RCA Company began work on an improved disc in the mid-1940s, they stuck to the idea that a record should not have to hold more than one song. In order to make the disc smaller than the 10-inch, 78-rpm discs used since the 1890s, they reduced the speed to 45-rpm and used a much finer groove. This meant that they could pack in more grooves in a smaller space. They used a new plastic material, called vinylite, which resulted in the playing stylus picking up less noise and hiss. World War II interrupted this work, but the new 45-rpm disc and its player were introduced with great fanfare in late 1947.  


This converter station was historically significant because it was the first that was designed and built from solid state high voltage, high current thyristors. Previously the medium was a plasma in a glass envelope using mercury vapor. These had more losses and were prone to re-strikes during transient fault events. Additionally, the mercury is considered a dangerous pollutant. Nelson River HVDC had used thyristors in a portion of the bridge to mitigate re-strikes but these were retrofits. The knowledge gained there served as a proving ground to give confidence for a full scale project at Eel River.
At about the same time, CBS Record Company (the successor to [[Columbia Record Company|Columbia Phonograph Company]] established in the early days of the phonograph) introduced its 12-inch, 33 1/3-rpm, long playing record. The development of the LP dates back to 1945, and was the work of CBS research director [[Peter Goldmark|Peter Goldmark]] and other engineers at CBS. It was also made of vinyl plastic, and had very fine grooves, but it was a different size and speed than the 45-rpm and could not be played on the same phonograph without modifications. The LP was not intended to hold short songs like the 45-rpm, but was for classical music, which often ran for 20 minutes or more without a break.  


With this project, the march of solid state systems to higher current and voltage ratings was advanced another major step. In fact, the Eel River Station performance was such that the station ran at 10% overload for the first 15 years without difficulty. The project allowed surplus Hydro Quebec energy to flow into New Brunswick which is synchronized with the Eastern Interconnection, without the risk of loss of transmission if disturbances happened in either New Brunswick or Hydro Quebec. Indeed Eel River served to govern and stabilize both systems with its External Control System, a benefit to either system in case of disturbances. This economically advantageous energy imported to the benefit of New Brunswick customers, allowed more expensive NB Power generation to be exported to New England where energy costs were higher, an economic advantage to the parties on both side of the US border.
[[Image:Sun Records 45s.jpg|thumb|right|Collection of Sun Records 45s]]


The electronic external control system enhancing governing and stability as a response to weighted system frequency and weighted system acceleration was a new feature which allowed both Hydro Quebec and NB Power to use the other system as a crutch during power system disturbances in either system. This feature has had a major beneficial impact on dynamic system performance. This is where a difference in frequency modulates the power transfer in a manner to assist the deficient system being governed back to safety. In the event of a difference in acceleration, the system slowing down is assisted by the other system while mitigating any power swings as quickly as possible to regain stability.
Within a few years, however, most record companies had adopted both the LP and the 45-rpm formats, using the 45-rpm for singles and the LP for classical albums. Engineers easily adapted record players to accommodate both types of discs as well as the older 78-rpm singles. Soon, record companies discovered that the growing popularity of Broadway show tunes and movie soundtracks helped LP sales, because these types of recordings were usually released as sets of discs called albums. These albums (now just a single disc) were so profitable for the record companies that they began releasing more and more popular music on LP rather than as singles. After phasing out the 10-inch, 78-rpm disc around 1958, record companies heavily promoted both the LP and the 45-rpm disc. Sometimes, when songs made famous on the radio were available only on an LP and not a 45-rpm disc, sales of the more expensive LPs could be quite high. The growth of LP sales in the 1960s and 1970s transformed the record business, generating large profits and restoring the industry to the place it had held in the early 1920s before radio was introduced.  


The triggering for the thyristors was achieved by using fibre optics to communicate the isolated trigger pulse to the thyristors at various voltage levels. This was an early application of another new technology, now ubiquitous.
The arrival of the compact disc in the 1980s severely curbed production of LP and 45 discs. Sales of both dropped quickly and most major label record companies stopped releasing them in large amounts by the early 1990s. However, both are still being produced to this day. Vinyl thrives in underground music scenes and niche collector markets, and is still commonly used by DJs for mixing in a live setting. Within the last ten years, vinyl has experienced a minor resurgence in the mainstream, with many of today's top 40 artists issuing their records on vinyl formats with a limited pressing run.


== References and Further Reading ==
== Your Surest Selling Job ==


In the EPRI project where Prabha Kundur wrote a comprehensive textbook on Power System Stability and Control, a reference to Eel River.
{{#widget:YouTube16x9|id=DOBeEb8ZY2s</youtube>
[http://nb.ieee.ca/events/MilestoneER/Chapter%2010%20Prabha%20Kundur.pdf].


What Wikipedia has to say about ER HVDC
Late 1940s advertisement for new RCA Victrola.
[http://nb.ieee.ca/events/MilestoneER/From%20Wikipedia%20encyclopedia.pdf]


A public relations document about Eel River Converter station written by GE and NB Power
[[Category:Engineering and society|Records]] [[Category:Leisure|Records]] [[Category:Music|Records]] [[Category:Consumer electronics|Records]] [[Category:Audio systems|Records]] [[Category:News|Records]]
[http://nb.ieee.ca/events/MilestoneER/20100401143715222.pdf].
 
Collection of bits of documents by Frank Ryder [http://nb.ieee.ca/events/MilestoneER/Eelriver.pdf].
 
== Letter in English from the site owner giving permission to place IEEE milestone plaque on the property ==
 
[[Media:IEEEMilestoneletter.pdf|Eel River Milestone Support Letter]]
 
== Map ==
 
{{#display_map:48.017875, -66.443918~ ~ ~ ~ ~North Shannonvale, New Brunswick, Canada|height=250|zoom=10|static=yes|center=48.017875, -66.443918}}
 
[[Category:Energy|{{PAGENAME}}]]
[[Category:Power_electronics|{{PAGENAME}}]]
[[Category:Converters|{{PAGENAME}}]]
[[Category:Power_generation|{{PAGENAME}}]]

Revision as of 21:20, 6 January 2015

The LP and the 45

10-inch LP

The long playing (LP) record and the 45-rpm disc were two different approaches to high fidelity music, introduced by two different companies in the late 1940s. Since the beginning of the phonograph, most records had played for about two or three minutes. Sometimes record companies issued longer recordings on large, 12-inch discs. But when the RCA Company began work on an improved disc in the mid-1940s, they stuck to the idea that a record should not have to hold more than one song. In order to make the disc smaller than the 10-inch, 78-rpm discs used since the 1890s, they reduced the speed to 45-rpm and used a much finer groove. This meant that they could pack in more grooves in a smaller space. They used a new plastic material, called vinylite, which resulted in the playing stylus picking up less noise and hiss. World War II interrupted this work, but the new 45-rpm disc and its player were introduced with great fanfare in late 1947.

At about the same time, CBS Record Company (the successor to Columbia Phonograph Company established in the early days of the phonograph) introduced its 12-inch, 33 1/3-rpm, long playing record. The development of the LP dates back to 1945, and was the work of CBS research director Peter Goldmark and other engineers at CBS. It was also made of vinyl plastic, and had very fine grooves, but it was a different size and speed than the 45-rpm and could not be played on the same phonograph without modifications. The LP was not intended to hold short songs like the 45-rpm, but was for classical music, which often ran for 20 minutes or more without a break.

Collection of Sun Records 45s

Within a few years, however, most record companies had adopted both the LP and the 45-rpm formats, using the 45-rpm for singles and the LP for classical albums. Engineers easily adapted record players to accommodate both types of discs as well as the older 78-rpm singles. Soon, record companies discovered that the growing popularity of Broadway show tunes and movie soundtracks helped LP sales, because these types of recordings were usually released as sets of discs called albums. These albums (now just a single disc) were so profitable for the record companies that they began releasing more and more popular music on LP rather than as singles. After phasing out the 10-inch, 78-rpm disc around 1958, record companies heavily promoted both the LP and the 45-rpm disc. Sometimes, when songs made famous on the radio were available only on an LP and not a 45-rpm disc, sales of the more expensive LPs could be quite high. The growth of LP sales in the 1960s and 1970s transformed the record business, generating large profits and restoring the industry to the place it had held in the early 1920s before radio was introduced.

The arrival of the compact disc in the 1980s severely curbed production of LP and 45 discs. Sales of both dropped quickly and most major label record companies stopped releasing them in large amounts by the early 1990s. However, both are still being produced to this day. Vinyl thrives in underground music scenes and niche collector markets, and is still commonly used by DJs for mixing in a live setting. Within the last ten years, vinyl has experienced a minor resurgence in the mainstream, with many of today's top 40 artists issuing their records on vinyl formats with a limited pressing run.

Your Surest Selling Job

{{#widget:YouTube16x9|id=DOBeEb8ZY2s</youtube>

Late 1940s advertisement for new RCA Victrola.