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Loss Of Load Probability
Loss of load in an electrical grid is a term used to describe the situation when the available generation capacity is less than the system load. Multiple probabilistic reliability indices for the generation systems are using loss of load in their definitions, with the more popular being Loss of Load Probability (LOLP) that characterizes a probability of a loss of load occurring within a year. Loss of load events are calculated before the mitigating actions (purchasing electricity from other systems, load shedding) are taken, so a loss of load does not necessarily cause a blackout. Loss-of-load-based reliability indices Multiple reliability indices for the electrical generation are based on the loss of load being observed/calculated over a long interval (one or multiple years) in relatively small increments (an hour or a day). The total number of increments inside the long interval is designated as N (e.g., for a yearlong interval N=365 if the increment is a day, N=8760 if the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Grid
An electrical grid (or electricity network) is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power transmission to carry power over long distances, and finally electric power distribution to customers. In that last step, voltage is stepped down again to the required service voltage. Power stations are typically built close to energy sources and far from densely populated areas. Electrical grids vary in size and can cover whole countries or continents. From small to large there are microgrids, wide area synchronous grids, and super grids. The combined transmission and distribution network is part of electricity delivery, known as the ''power grid''. Grids are nearly always synchronous, meaning all distribution areas operate with three phase alternating current (AC) frequencies synchronized (so that voltage swings occur at almost the same ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Load
An electrical load is an electrical component or portion of a Electric Circuit, circuit that consumes (active) electric power, such as electrical appliances and Electric light, lights inside the home. The term may also refer to the power Power consumption, consumed by a circuit. This is opposed to a power supply source, such as a Electric battery, battery or Electric generator, generator, which ''provides'' power. The term is used more broadly in electronics for a device connected to a electrical signal, signal source, whether or not it consumes power. If an electric circuit has an output port (circuit theory), port, a pair of terminals that produces an electrical signal, the circuit connected to this terminal (or its input Electrical impedance, impedance) is the ''load''. For example, if a CD player is connected to an amplifier, the CD player is the source, and the amplifier is the load, and to continue the concept, if loudspeakers are connected to that amplifier, then that ampli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Index
Reliability index is an attempt to quantitatively assess the reliability of a system using a single numerical value. The set of reliability indices varies depending on the field of engineering, multiple different indices may be used to characterize a single system. In the simple case of an object that cannot be used or repaired once it fails, a useful index is the mean time to failure representing an expectation of the object's service lifetime. Another cross-disciplinary index is forced outage rate (FOR), a probability that a particular type of a device is out of order. Reliability indices are extensively used in the modern electricity regulation. Power distribution networks For power distribution networks there exists a "bewildering range of reliability indices" that quantify either the duration or the frequency of the power interruptions, some trying to combine both in a single number, a "nearly impossible task". All indices are computed over a defined period, usually a year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Generation
Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmission, transmission, Electric power distribution, distribution, etc.) to end users or its Grid energy storage, storage, using for example, the Pumped-storage hydroelectricity, pumped-storage method. Consumable electricity is not freely available in nature, so it must be "produced", transforming other forms of energy to electricity. Production is carried out in power stations, also called "power plants". Electricity is most often generated at a power plant by electromechanical electric generator, generators, primarily driven by heat engines fueled by combustion or nuclear fission, but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power. There are ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Load Shedding
Load shedding (LS) is a protective method of emergency power control where, during a large disbalance between supply and demand, the demand (load) is intentionally disconnected ("shed") so that the available electricity supply within a safe timeframe can meet the remaining demand, thereby preventing a cascading collapse of the power grid ''Power Grid'' is the English-language version of the second edition of the multiplayer German-style board game ''Funkenschlag'', designed by Friedemann Friese and first released in 2004. ''Power Grid'' was released by Rio Grande Games. I .... The load shedding is activated when the line frequency becomes too low (under-frequency load shedding, UFLS) or the line voltage is below the specified level (under-voltage load shedding, UVLS). The very act of disconnecting the load introduces yet another disturbance into the grid, so the selection of the bus about to be shed is chosen based on the bus distance from the contingency location as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Outage
A power outage, also called a blackout, a power failure, a power blackout, a power loss, a power cut, or a power out is the complete loss of the electrical power network supply to an end user. There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to Electric power transmission, electric transmission lines, Electrical substation, substations or other parts of the electricity distribution, distribution system, a short circuit, Cascading failure#Cascading failure in power transmission, cascading failure, fuse (electrical), fuse or circuit breaker operation. Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, Sewage Treatment, sewage treatment plants, and mining, mines will usually have backup power sources such as emergency power system, standby generators, which will automatically start up when electrical power is lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Function (calculus)
In calculus and related areas of mathematics, a linear function from the real numbers to the real numbers is a function whose graph (in Cartesian coordinates) is a non-vertical line in the plane. The characteristic property of linear functions is that when the input variable is changed, the change in the output is proportional to the change in the input. Linear functions are related to linear equations. Properties A linear function is a polynomial function in which the variable has degree at most one: :f(x)=ax+b. Such a function is called ''linear'' because its graph, the set of all points (x,f(x)) in the Cartesian plane, is a line. The coefficient ''a'' is called the ''slope'' of the function and of the line (see below). If the slope is a=0, this is a ''constant function'' f(x)=b defining a horizontal line, which some authors exclude from the class of linear functions. With this definition, the degree of a linear polynomial would be exactly one, and its graph wou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regional Entity
A regional entity (RE) in the North American power transmission grid is a regional organization representing all segments of the electric industry: electric utility, electric utilities (investor-owned, cooperatives, state, regional, and municipal), List of federal agencies in the United States, federal agencies, independent power producers, power market operators, and end-users of the energy. North American Electric Reliability Corporation (NERC) delegates to REs authority to enforce reliability standards (which NERC has throughout the contiguous United States), collectively REs, together with NERC, are known as an "ERO Enterprise" (from the Electric Reliability Organization). History The regional entities, at the bottom of the structure for the development and enforcement of the reliability standards for the US electric grid, were established by the Section 215 of the Federal Power Act as amended by the Energy Policy Act of 2005. The statute tried to mimic the Balance of power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northeast Power Coordinating Council
The Northeast Power Coordinating Council (NPCC) was formed on January 19, 1966, as a successor to the Canada–United States Eastern Interconnection (CANUSE). It was established to improve the reliability of electric service. NPCC is one of six regional entities under North American Electric Reliability Corporation (NERC) authority. NERC and the regional reliability councils were formed following the Northeast Blackout of 1965. NPCC's offices are located in New York City, New York. The NPCC region lies within the Eastern Interconnection and encompasses the greater New England area of North America, covering all the States of Maine, Vermont, New Hampshire, Massachusetts, New York, Connecticut, Rhode Island, and the Provinces of Ontario, Québec, New Brunswick, and Nova Scotia. NPCC also has ties to non-NERC systems in eastern Canada. In terms of load served, NPCC accounts for 20% of the Eastern interconnection's total load demand, and 70% of Canada's entire demand. The Hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firm Service
Firm services, also called uninterruptible services, are services, such as electricity (firm power) and natural gas supplies, that are intended to be available at all times during a period covered by an agreement. Also, the service is not subject to a prior claim from another customer and receives the same priority as any other firm service. Conditional firm service is similar to firm service in that it is reserved and has priority over interruptible service. However, it can have restrictions, such as times when it would be curtailed before firm service but after interruptible service. The cost per unit with this service is called a firm rate or uninterruptible rate. The opposite of firm service is non-firm service, also called interruptible service or as-available service. The cost per unit for this service is called a non-firm rate or interruptible rate. The interruptible load is the portion of a utility's load that comes from customers with interruptible service. Firm service cann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Adequacy
Resource adequacy (RA, also supply adequacy) in the field of electric power is the ability of the electric grid to satisfy the end-user power demand at any time (typically an issue at the peak demand). RA is a component of the electrical grid reliability. For example, sufficient unused generation capacity shall be available to the electrical grid at any time to accommodate major equipment failures (e.g., a disconnection of a nuclear power unit or a high-voltage power line) and drops in variable renewable energy sources (e.g, wind dying down). The adequacy standard should satisfy the chosen reliability index, typically the loss of load expectation (LOLE) of 1 day in 10 years (so called "1-in-10"). Installed reserve margin Installed reserve margin (IRM) is the amount of the generating capacity in excess of the expected load, calculated to satisfy the loss of load expectation, typically 1 day in 10 years. IRM is used to measure the adequacy of the generation capacity and serves as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Value Of Lost Load
The Value of Lost Load (VoLL) is the estimated amount that customers receiving 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 ... with firm contracts would be willing to pay to avoid a disruption in their electricity service. The value of these losses can be expressed as a customer damage function (CDF). A CDF is defined as: Loss ($/kW) = ƒ (duration, season, time of day, notice) Based on the calculated outage cost, a CDF can be obtained for various customer groups. Typically, there are three distinct groups of customers: residential, small and medium commercial/industry and large commercial/industrial. Figure 1 below illustrates the incremental CDFs of these three groups. The CDF relates the magnitude of customer losses (per kW interrupted) for a given duratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
