|
Short Circuit Ratio (electrical Grid)
In an electrical grid, the short circuit ratio (or SCR) is the ratio of: the short circuit apparent power (SCMVA) in the case of a line-line-line-ground (3LG) fault at the location in the grid where some generator is connected, to: the power rating of the generator itself (GMW). Since the power that can be delivered by the grid varies by location, frequently a location is indicated, for example, at the point of interconnection (POI): :SCR_ = \frac SCR is used to quantify the system strength of the grid (its ability to deal with changes in active and reactive power injection and consumption). On a simplified level, a high SCR indicates that the particular generator represents a small portion of the power available at the point of its connection to the grid, and therefore the generator problems cannot affect the grid in a significant way. SCMVA is defined as a product of the voltage before the 3LG fault and the current that would flow after the fault (this worst-case combina ... [...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] |
