Per unit voltage

Direct numerical Fourier transformation when a wide range of frequencies is involved requires the storage of a very large number of data samples [i (0] d extendve computation. The usual practice in slow-response time-domain methods has consequently been to employ more approximate transformation methods, such as the Hamon approximation. This relates the current per unit voltage at time t, i(/), to the dielectric loss e at the frequency v = 1/10/ by... 

It follows from Eqs. (3.126) to (3.127), that ionic current (per unit voltage) can be represented as... 

This is an approximate method for finding out the voltage drop in a feeder section. In this method, a K drop factor and a ifrise factor are computed for the primary conductors. The factor is defined as the per unit voltage drop per kflovoltampere-mile. A similar definition exists for the Knse factor. The procedure to determine the ifdrop factor is as follows ... 

This voltage is called the switching (surge) overvoltage, which reaches 2 pu (per unit voltage = V/E) in a single lossless line ... 

Uh = per unit summated value of all the harmonic voltages in terms of the rated voltage n = harmonic order not divisible by 3 (presuming that the star-connected motors (normally HT motors) have only isolated neutrals) in 3-0 motors, i.e. 5, 7, 11 and 13, etc. Beyond 13, the content of harmonic quantity may be too insignificant to be considered. 

HVF = harmonic voltage factor Vj, = per unit harmonic voltages n = harmonic order not divisible by 3... 

The emission yield, Ra, defined as the radiation of the spectral line, k, of an element, i, emitted per unit sputtered mass must be determined independently for each spectral line. The quantities g, and Ry are derived from a variety of different standard bulk samples with different sputtering rates. In practice, both sputtering rates and excitation probability are influenced by the working conditions of the discharge. Systematic variation of the discharge voltage, L/g, and current, I, leads to the empirical intensity expression [4.185] ... 

Operating costs, in contrast, are more straightforward to determine because they depend on system efficiency, which, in turn, is related to voltage and current density (the current generated per unit area of electrolyte). Fuel savings are expected since the fuel cell operates more efficiently than a heat engine, and there may be lower maintenance and repair costs because fuel cells have fewer moving parts to wear out. 

The measurement of impedance voltage is defined as the voltage required circulating full-load current in one winding with the other windings short-circuited. It is common practice to express the leakage impedance, Z, of a transformer as a percentage (or per unit) value. The per unit value is ... 

These anodes are considerably more expensive than platinised titanium, especially when expressed in terms of price per unit volumeIndeed, since niobium is cheaper than tantalum the use of the latter has become rare. The extra cost of Nb anodes may be offset in certain application by their superior electrical conductivity and higher breakdown voltages. Table 10.17 gives the comparitive breakdown potentials of Ti, Nb and Ta in various solutions under laboratory conditions. 

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