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Subcycle Overvoltage
The subcycle overvoltage condition describes the electrical generation fault mode that is associated with the inverter-based resources (IBR, like solar photovoltaics and wind turbines) and can cause a massive and instantaneous loss of electricity generation. When the overvoltage condition is detected, the IBR devices self-protect by disconnecting from the grid and can only come back online once the voltage returns to the design limits. In the meantime, a cascading failure can be triggered due to lack of generation capacity that remains online. The typical fault scenario is two-stage: # A line-to-ground or line-to-line fault occurs on a transmission line far away from the generator. This condition, if short-lived, is not very unusual. The inverter electronics cannot tolerate the resulting low-voltage condition and enters the " momentary cessation" (MC) mode where the unit stops providing the power but remains connected to the grid; # Once the fault clears, the line voltage might ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverter-based Resource
An inverter-based resource (IBR) is a source of electricity that is asynchronously connected to the electrical grid via an electronic power converter ("inverter"). The devices in this category, also known as converter interfaced generation (CIG) and power electronic interface source, include the variable renewable energy generators (wind, solar) and battery storage power stations. These devices lack the intrinsic behaviors (like the inertial response of a synchronous generator) and their features are almost entirely defined by the control algorithms, presenting specific challenges to system stability as their penetration increases, for example, a single software fault can affect all devices of a certain type in a contingency (cf. section on Blue Cut fire below). IBRs are sometimes called ''non-synchronous generators''. The design of inverters for the IBR generally follows the IEEE 1547 and NERC PRC-024-2 standards. The term unconventional sources includes IBRs as well as othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shunt Capacitor
Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology. Whether a two-terminal "object" is an electrical component (e.g. a resistor) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has the same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current through the network is equal to the sum of the currents throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canyon Fire 2
The Canyon Fire 2, also known as the Canyon 2 Fire, was a wildfire that burned in the Anaheim Hills area of the city of Anaheim in Orange County, California. The fast-moving brush fire broke out on October 9, 2017, around 9:45 A.M. PDT near the 91 Freeway and Gypsum Canyon Road. It leaped over the Route 241 toll road, raced up a ridge, and set fire to several homes. In total, about 16,570 were ordered to evacuate their homes in Anaheim, Orange, and Tustin but returned when the evacuation order was lifted on October 12. By noon on the day the fire began, it had burned . By 2:30, fueled by high winds and low humidity, it had burned and was 0 percent contained. As of 6:00 a.m. October 10 it had burned and at least 24 structures had been damaged and a dozen homes destroyed. On October 15, the fire was reportedly 90 percent contained. A total of had been burned, with 25 structures destroyed and another 55 damaged. Canyon Fire 2 was declared 100% contained on October 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AC Cycle
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 which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', respectively, as when they modify ''current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa (the full period is called a ''cycle''). "Alternating current" most commonly refers to power distribution, but a wide range of other applications are technically alternating current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Farm
A wind farm, also called a wind park or wind power plant, is a group of wind turbines in the same location used to produce electricity. Wind farms vary in size from a small number of turbines to several hundred wind turbines covering an extensive area. Wind farms can be either onshore or offshore. Many of the largest operational onshore wind farms are located in China, India, and the United States. For example, the largest wind farm in the world, Gansu Wind Farm in China had a capacity of over 6,000 MW by 2012,Watts, Jonathan & Huang, CecilyWinds Of Change Blow Through China As Spending On Renewable Energy Soars ''The Guardian'', 19 March 2012, revised on 20 March 2012. Retrieved 4 January 2012. with a goal of 20,000 MWFahey, JonathanIn Pictures: The World's Biggest Green Energy Projects ''Forbes'', 9 January 2010. Retrieved 19 June 2019. by 2020. As of December 2020, the 1218 MW Hornsea Wind Farm in the UK is the largest offshore wind farm in the world. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Farm
A photovoltaic power station, also known as a solar park, solar farm, or solar power plant, is a large-scale grid-connected photovoltaic power system (PV system) designed for the supply of merchant power. They are different from most building-mounted and other decentralized solar power because they supply power at the utility level, rather than to a local user or users. Utility-scale solar is sometimes used to describe this type of project. This approach differs from concentrated solar power, the other major large-scale solar generation technology, which uses heat to drive a variety of conventional generator systems. Both approaches have their own advantages and disadvantages, but to date, for a variety of reasons, photovoltaic technology has seen much wider use. , about 97% of utility-scale solar power capacity was PV. In some countries, the nameplate capacity of photovoltaic power stations is rated in megawatt-peak (MWp), which refers to the solar array's theoretical maxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE 1547
IEEE 1547 (''Standard for Interconnecting Distributed Resources with Electric Power Systems'') is a standard of the Institute of Electrical and Electronics Engineers meant to provide a set of criteria and requirements for the interconnection of distributed generation resources into the power grid. Purpose "This document provides a uniform standard for interconnection of distributed resources with EPSs lectric Power Systems It provides requirements relevant to the performance, operation, testing, safety, and maintenance of the interconnection." With the increased adoption of distributed resources in the present and future, a set of standards regarding their usage in the grid becomes increasingly important for the overall reliability, safety, and cost. Furthermore, the lack of a concrete national standard was seen as a roadblock to the implementation of new distributed generation projects. The standard is intended to be universally adoptable, technology-neutral, and cover distribute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unity Power Factor
In electrical engineering, the power factor of an AC power system is defined as the ratio of the ''real power'' absorbed by the load to the ''apparent power'' flowing in the circuit. Real power is the average of the instantaneous product of voltage and current and represents the capacity of the electricity for performing work. Apparent power is the product of root mean square (RMS) current and voltage. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power may be greater than the real power, so more current flows in the circuit than would be required to transfer real power alone. A power factor magnitude of less than one indicates the voltage and current are not in phase, reducing the average product of the two. A negative power factor occurs when the device (normally the load) generates real power, which then flows back towards the source. In an electric powe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactive Power
In an electric circuit, instantaneous power is the time rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the direction of energy flow. Its SI unit is the watt. The portion of instantaneous power that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as instantaneous active power, and its time average is known as active power or real power. The portion of instantaneous power that results in no net transfer of energy but instead oscillates between the source and load in each cycle due to stored energy is known as instantaneous reactive power, and its amplitude is the absolute value of reactive power. Active, reactive, apparent, and complex power in sinusoidal steady-state For a simple alternating current (AC) circuit in steady-state; consisting of a source and a linear time-invariant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE 2800
The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE has a corporate office in New York City and an operations center in Piscataway, New Jersey. The IEEE was formed in 1963 as an amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers. History The IEEE traces its founding to 1884 and the American Institute of Electrical Engineers. In 1912, the rival Institute of Radio Engineers was formed. Although the AIEE was initially larger, the IRE attracted more students and was larger by the mid-1950s. The AIEE and IRE merged in 1963. The IEEE is headquartered in New York City, but most business is done at the IEEE Operations Center in Piscataway, New Jersey, opened in 1975. The Australian Section of the IEEE existed between 1972 and 1985, after which it split into state- and te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Photovoltaics
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors. A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating. The mount may be fixed or use a solar tracker to follow the sun across the sky. Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels. Solar PV has specific advantages as an energy source: once installed, its operation does not generate any pollution or any greenhouse gas emissions; it shows scalability in respect of power needs and silicon has large availability in the Earth's crust, although other materials required in PV ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per-unit System
In the power systems analysis field of electrical engineering, a per-unit system is the expression of system quantities as fractions of a defined base unit quantity. Calculations are simplified because quantities expressed as per-unit do not change when they are referred from one side of a transformer to the other. This can be a pronounced advantage in power system analysis where large numbers of transformers may be encountered. Moreover, similar types of apparatus will have the impedances lying within a narrow numerical range when expressed as a per-unit fraction of the equipment rating, even if the unit size varies widely. Conversion of per-unit quantities to volts, ohms, or amperes requires a knowledge of the base that the per-unit quantities were referenced to. The per-unit system is used in power flow, short circuit evaluation, motor starting studies etc. The main idea of a per unit system is to absorb large differences in absolute values into base relationships. Thus, rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
