The Sylmar Converter Station is the southern converter station of the

Pacific DC 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 3.1 gigawatts, wh ...

, an

electric power transmission Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is ...

line which transmits

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

from the Celilo Converter Station outside

The Dalles, Oregon The Dalles ( ;) formally the City of the Dalles and also called Dalles City, is an inland port, the county seat of and the largest city in Wasco County, Oregon, Wasco County, Oregon, United States. The population was 16,010 at the 2020 United ...

to Sylmar, a neighborhood in the northeastern

San Fernando Valley The San Fernando Valley, known locally as the Valley, is an urbanized valley in Los Angeles County, Los Angeles County, California. Situated to the north of the Los Angeles Basin, it comprises a large portion of Los Angeles, the Municipal corpo ...

region of

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. The station converts the 500 kV

direct current Direct current (DC) is one-directional electric current, flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor (material), conductor such as a wire, but can also flow throug ...

coming from the northern converter station Celilo to

alternating current Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in w ...

at 60 Hz and 230 kV synchronized with the Los Angeles power grid. The station capacity is 3,100

megawatts The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named in honor o ...

. It is jointly owned by two electric utility providers,

Southern California Edison Southern California Edison (SCE), the largest subsidiary of Edison International, is the primary electric utility company for much of Southern California. It provides 15 million people with electricity across a service territory of approximate ...

and

Los Angeles Department of Water and Power The Los Angeles Department of Water and Power (LADWP) is the largest municipal Public utility, utility in the United States with 8,100 megawatts of electric generating capacity (2021–2022) and delivering an average of 435 million gallons of wat ...

History

Originally

mercury-arc valve A mercury-arc valve or mercury-vapor rectifier or (UK) mercury-arc rectifier is a type of electrical rectifier used for converting high-voltage or high- current alternating current (AC) into direct current (DC). It is a type of cold cathode gas-f ...

s were used as static

inverter A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the op ...

valves. The valves were series connected in three six-pulse valve bridges for each pole. The blocking

voltage Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...

of the valves was 133 kV with a maximum

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (hydr ...

of 1,800

ampere The ampere ( , ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 c ...

s, for a transmission rate of 1,440 megawatts with a symmetrical voltage of 400 kV against earth. After the

Sylmar earthquake The 1971 San Fernando earthquake (also known as the 1971 Sylmar earthquake) occurred in the early morning of February 9 in the foothills of the San Gabriel Mountains in Southern California. The unanticipated thrust earthquake had a magnitude o ...

in 1971, the static inverter station in Sylmar was reconstructed due to damage sustained. In 1982, the power rating of the mercury arc valve rectifiers was raised by various improvements to 1,600 megawatts. In 1985 two six-pulse valve groups of

thyristor A thyristor (, from a combination of Greek language ''θύρα'', meaning "door" or "valve", and ''transistor'' ) is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage ...

s were added to increase the voltage to 500 kV per pole for a total differential voltage of 1,000 kV. In 1989 the station was extended on the field east of the highway (called Sylmar East Converter Station), where two new 1,100 ampere, 500 kV 12-pulse thyristor converters were added in parallel with the two existing converters, giving a total transmission power of 3,100 megawatts (3,100 Amperes at +/-500 kV In 2004, Sylmar East station was upgraded from 1,100 MW to 3,100 MW (rededicated as the Sylmar Converter Station in 2005). The controls and older converters, including the mercury arc valves, were completely replaced (in the same valve hall) by a single pair of 3,100 MW 12-pulse converters built by ABB. The upgrade was made to eliminate the environmental risks of mercury and to reduce the

maintenance The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure and supporting utilities in industrial, business, and residential installa ...

costs of the obsolete mercury arc valves.

References

{{Coord, 34.312, -118.481, region:US-CA_type:landmark, display=title Buildings and structures in Los Angeles Western Interconnection Energy infrastructure in California Converter stations Sylmar, Los Angeles

History

See also

References