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The Seebeck coefficient (also known as thermopower, [1] thermoelectric power, and thermoelectric sensitivity) of a material is a measure of the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material, as induced by the Seebeck effect. [2]
The power factor in a single-phase circuit (or balanced three-phase circuit) can be measured with the wattmeter-ammeter-voltmeter method, where the power in watts is divided by the product of measured voltage and current. The power factor of a balanced polyphase circuit is the same as that of any phase. The power factor of an unbalanced ...
The efficiency of a thermoelectric device for electricity generation is given by , defined as =.. The maximum efficiency of a thermoelectric device is typically described in terms of its device figure of merit where the maximum device efficiency is approximately given by [7] = + ¯ + ¯ +, where is the fixed temperature at the hot junction, is the fixed temperature at the surface being cooled ...
Angle notation can easily describe leading and lagging current: . [1] In this equation, the value of theta is the important factor for leading and lagging current. As mentioned in the introduction above, leading or lagging current represents a time shift between the current and voltage sine curves, which is represented by the angle by which the curve is ahead or behind of where it would be ...
The factor of 2 multiplying the outgoing flux is needed because photons are emitted from both sides, but the incoming flux is assumed to come from just one side. Although the analysis was done for photovoltaic cells under illumination, it applies also when the illumination is simply background thermal radiation, provided that a factor of 2 is ...
Voltage control does not include reactive power injections to dampen the grid oscillations; these are a part of a separate ancillary service, so-called system stability service. [2] The transmission of reactive power is limited by its nature, so the voltage control is provided through pieces of equipment distributed throughout the power grid ...
An over-excited synchronous motor has a leading power factor. This makes it useful for power-factor correction of industrial loads. Both transformers and induction motors draw lagging (magnetising) currents from the line. On light loads, the power drawn by induction motors has a large reactive component and the power factor has a low value. The ...
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]