Search results
Results From The WOW.Com Content Network
The open-circuit saturation curve (also open-circuit characteristic, OCC) of a synchronous generator is a plot of the output open circuit voltage as a function of the excitation current or field. The curve is typically plotted alongside the synchronous impedance curve .
When the cell is operated at open circuit, = 0 and the voltage across the output terminals is defined as the open-circuit voltage. Assuming the shunt resistance is high enough to neglect the final term of the characteristic equation, the open-circuit voltage V OC is:
Also, in a DC steady state, an ideal capacitor acts as an open circuit. The DC gain of the ideal circuit is therefore infinite (or in practice, the open-loop gain of a non-ideal op-amp). Any DC (or very low frequency) component may then cause the op amp output to drift into saturation. [3]
These current and voltage values can be obtained from the open-circuit saturation curve and the synchronous impedance curve. [11] The synchronous reactance is a sum of the leakage reactance and the reactance of the armature itself (): = +. [12]
The Shockley diode equation relates the diode current of a p-n junction diode to the diode voltage .This relationship is the diode I-V characteristic: = (), where is the saturation current or scale current of the diode (the magnitude of the current that flows for negative in excess of a few , typically 10 −12 A).
In a synchronous generator, [1] the short circuit ratio is the ratio of field current required to produce rated armature voltage at the open circuit to the field current required to produce the rated armature current at short circuit. [1] [2] This ratio can also be expressed as an inverse of the saturated [3] direct-axis synchronous reactance ...
The product of the short-circuit current I sh and the open-circuit voltage V oc Shockley and Queisser call the "nominal power". It is not actually possible to get this amount of power out of the cell, but we can get close (see "Impedance matching" below). The ratio of the open-circuit voltage to the band-gap voltage Shockley and Queisser call V ...
The voltage v oc between the terminals is the open-circuit voltage of the device. Black curve: The highest possible open-circuit voltage of a solar cell in the Shockley-Queisser model under unconcentrated sunlight, as a function of the semiconductor bandgap. The red dotted line shows that this voltage is always smaller than the bandgap voltage.