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Power flow calculated from AC voltage and current entering a load having a zero power factor (ϕ = 90°, cos(ϕ) = 0).The blue line shows the instantaneous power entering the load: all of the energy received during the first (or third) quarter cycle is returned to the grid during the second (or fourth) quarter cycle, resulting in an average power flow (light blue line) of zero.
Power-voltage curve (also P-V curve) describes the relationship between the active power delivered to the electrical load and the voltage at the load terminals in an electric power system under a constant power factor. [1] When plotted with power as a horizontal axis, the curve resembles a human nose, thus it is sometimes called a nose curve. [2]
Fig 1. Construction of the first isogonic center, X(13). When no angle of the triangle exceeds 120°, this point is the Fermat point. In Euclidean geometry, the Fermat point of a triangle, also called the Torricelli point or Fermat–Torricelli point, is a point such that the sum of the three distances from each of the three vertices of the triangle to the point is the smallest possible [1] or ...
The fixed speed wind turbines without a power converter (also known as "Type 1" and "Type 2" [5]) cannot be used for voltage control. They simply absorb the reactive power (like any typical induction machine), so a switched capacitor bank is usually used to correct the power factor to unity. [7] Capability curve of a photovoltaic generator
Stream power is the rate of energy dissipation against the bed and banks of a river or stream per unit downstream length. It is given by the equation: = where Ω is the stream power, ρ is the density of water (1000 kg/m 3), g is acceleration due to gravity (9.8 m/s 2), Q is discharge (m 3 /s), and S is the channel slope.
In power engineering, the power-flow study, or load-flow study, is a numerical analysis of the flow of electric power in an interconnected system. A power-flow study usually uses simplified notations such as a one-line diagram and per-unit system, and focuses on various aspects of AC power parameters, such as voltages, voltage angles, real power and reactive power.
When calculating a Thévenin-equivalent voltage, the voltage divider principle is often useful, by declaring one terminal to be V out and the other terminal to be at the ground point. The Thévenin-equivalent resistance R Th is the resistance measured across points A and B "looking back" into the circuit. The resistance is measured after ...
where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ is a material-dependent parameter called the conductivity, defined as the inverse of resistivity ρ . This reformulation of Ohm's law is due to Gustav Kirchhoff. [5]