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Swer
Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line which supplies single-phase electric power from an electrical grid to remote areas at lowest cost. Its distinguishing feature is that the Ground (electricity), earth (or sometimes a body of water) is used as the return path for the current, to avoid the need for a second wire (or ''Ground and neutral, neutral wire'') to act as a return path. Single-wire earth return is principally used for rural electrification, but also finds use for larger isolated loads such as water pumps. It is also used for high-voltage direct current over submarine power cables. Electric single-phase railway traction, such as light rail, uses a very similar system. It uses resistors to earth to reduce hazards from rail voltages, but the primary return currents are through the rails. History Lloyd Mandeno, Order of the British Empire, OBE (1888–1973) fully developed SWER in New Zealand around 1925 for ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swer
Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line which supplies single-phase electric power from an electrical grid to remote areas at lowest cost. Its distinguishing feature is that the Ground (electricity), earth (or sometimes a body of water) is used as the return path for the current, to avoid the need for a second wire (or ''Ground and neutral, neutral wire'') to act as a return path. Single-wire earth return is principally used for rural electrification, but also finds use for larger isolated loads such as water pumps. It is also used for high-voltage direct current over submarine power cables. Electric single-phase railway traction, such as light rail, uses a very similar system. It uses resistors to earth to reduce hazards from rail voltages, but the primary return currents are through the rails. History Lloyd Mandeno, Order of the British Empire, OBE (1888–1973) fully developed SWER in New Zealand around 1925 for ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lloyd Mandeno
Lloyd Mandeno (3 October 1888 – 30 December 1973) was a New Zealand electrical engineer, inventor and local politician. He was born in Rangiaowhia, Waikato, New Zealand, on 3 October 1888. He is credited with nine hydroelectric installations and numerous inventions. He served on electric power boards, regional councils and as a deputy mayor. Mandeno was born at Rangiaowhia, near Te Awamutu in the Waikato region to a farming family. He studied at St John's Collegiate School in Auckland and started at Auckland University College in 1905. The following year he transferred to Canterbury College from where he graduated in 1912 with a Bachelor of Engineering degree. He married Constance Mary Woodward at Mangere in 1913. Mandeno invented, developed and successfully promoted widespread use of "single wire earth-return" ( SWER) grids for rural electrification in New Zealand.Mandeno, L. (1947)"Rural Power Supply Especially in Back Country Areas". ''Proceedings of the New Zealand Ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground (electricity)
In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground, to protect users from electrical shock hazard. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed parts to ground will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static electricity when handling flammable products or electrostatic-sensitive devices. In some telegraph and power transmission circuits, the ground itself can be used as one condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cahora Bassa (HVDC) - KNP - 001
The Cahora Bassa lake—in the Portuguese colonial era (until 1974) known as Cabora Bassa, from Nyungwe language, Nyungwe ''Kahoura-Bassa'', meaning "finish the job"—is Africa's fourth-largest artificial lake, situated in the Tete Province in Mozambique. In Africa, only Lake Volta in Ghana, Lake Kariba, on the Zambezi upstream of Cahora Bassa, and Egypt's Lake Nasser are bigger in terms of surface water. History Portuguese period The Cahora Bassa System started in the late 1960s as a project of the Portugal, Portuguese in the Overseas Province of Mozambique. Southern African governments were also involved in an agreement stating that Portugal would build and operate a hydroelectric generating station at Cabora Bassa (as it was then called in Portuguese language, Portuguese) together with Cahora Bassa (HVDC), the high-voltage direct current (HVDC) transmission system required to bring electricity to the border of South Africa. South Africa, on the other hand, undertook to build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Midwest
The Upper Midwest is a region in the northern portion of the U.S. Census Bureau's Midwestern United States. It is largely a sub-region of the Midwest. Although the exact boundaries are not uniformly agreed-upon, the region is defined as referring to the states of Michigan, Minnesota and Wisconsin; some definitions include Iowa, North Dakota and South Dakota as well. Definitions The National Weather Service defines its Upper Midwest as the states of Iowa, Michigan, Minnesota, North Dakota, South Dakota and Wisconsin. The United States Geological Survey uses two different Upper Midwest regions: *The USGS Upper Midwest Environmental Sciences Center considers it to be the six states of Illinois, Indiana, Iowa, Michigan, Minnesota and Wisconsin, which comprise the watersheds of the Upper Mississippi River and upper Great Lakes. *The USGS Mineral Resources Program considers the area to contain Illinois, Indiana, Michigan, Minnesota and Wisconsin. The Association for Institutional Res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number 8 Wire
Number 8 wire is a gauge of wire on the British Standard Wire Gauge that has entered into the cultural lexicon of New Zealand. Use for farm fencing Early farm fences in New Zealand were generally used to protect crops, gardens, and orchards from farm animals, rather than to contain the stock. Fencing methods used were post-and-rail fences, ditch-and-bank fences, stone walls, and hedges, but all proved too expensive to install and maintain to fence entire properties and tended to be unreliable. To prevent stock straying, boundary keepers were employed to patrol boundaries. In the 1850s, heavy annealed iron wire became available for fences, but this wire was very thick and only came in short lengths, was hard to work and to keep taut, and was expensive to use. In England, in 1855, Henry Bessemer patented the Bessemer process that led to the mass production of low-cost high-quality steel, leading to the large scale production of affordable lighter gauge steel wire. The introductio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Split-phase Electric Power
A split-phase or single-phase three-wire system is a type of single-phase electric power distribution. It is the alternating current (AC) equivalent of the original Edison Machine Works three-wire direct-current system. Its primary advantage is that, for a given capacity of a distribution system, it saves conductor material over a single-ended single-phase system, while only requiring a single phase on the supply side of the distribution transformer. This system is common in North America for residential and light commercial applications. Two 120 V AC lines are supplied to the premises that are out of phase by 180 degrees with each other (when both measured with respect to the neutral), along with a common neutral. The neutral conductor is connected to ground at the transformer center tap. Circuits for lighting and small appliance power outlets (i.e., NEMA 1 and NEMA 5) use 120 V circuits - these are connected between one of the lines and neutral using a single-pole circuit breake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permafrost
Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost, with the total area of around 18 million km2. This includes substantial areas of Alaska, Greenland, Canada and Siberia. It can also be located on mountaintops in the Southern Hemisphere and beneath ice-free areas in the Antarctic. Permafrost does not have to be the first layer that is on the ground. It can be from an inch to several miles deep under the Earth's surface. It frequently occurs in ground ice, but it can also be present in non-porous bedrock. Permafrost is formed from ice holding various types of soil, sand, and rock in combination. Permafrost contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide, making tundra soil a carbon sink. As global war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phantom Loop
In telecommunication and electrical engineering, a phantom circuit is an electrical circuit derived from suitably arranged wires with one or more conductive paths being a circuit in itself and at the same time acting as one conductor of another circuit. Phantom group A phantom group is composed of three circuits that are derived from two single-channel circuits to form a ''phantom circuit''. Here the phantom circuit is a third circuit derived from two suitably arranged pairs of wires, called side circuits, with each pair of wires being a circuit in itself and at the same time acting as one conductor of the third circuit. The "side circuits" within phantom circuits can be coupled to their respective voltage drops by center-tapped transformers, usually called "repeating coils". The center taps are on the line side of the side circuits. Current from the phantom circuit is split evenly by the center taps. This cancels crosstalk from the phantom circuit to the side circuits. Phantom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Network
An electrical network is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, current sources, resistances, inductances, capacitances). An electrical circuit is a network consisting of a closed loop, giving a return path for the current. Linear electrical networks, a special type consisting only of sources (voltage or current), linear lumped elements (resistors, capacitors, inductors), and linear distributed elements (transmission lines), have the property that signals are linearly superimposable. They are thus more easily analyzed, using powerful frequency domain methods such as Laplace transforms, to determine DC response, AC response, and transient response. A resistive circuit is a circuit containing only resistors and ideal current and voltage sources. Analysis of resistive circuits is less complicated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conductor (material)
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge ( electric current) in one or more directions. Materials made of metal are common electrical conductors. Electric current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases. In order for current to flow within a closed electrical circuit, it is not necessary for one charged particle to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge ''its'' neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a test charge between the two points. In the International System of Units, the derived unit for voltage is named ''volt''. The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in generator, inductors, and transformers). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential such as the ground of the system is used as one of the points. A voltage can represent either a source ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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