Reactance capacitive

When the external impedance is a resistance or a capacitive reactance... 

X, j = Ground leakage capacitive reactance Zg = Additional impedance (fl, Xc or )... 

Resistive reactance Capacitive reactance Inductive reactance... 

When the impedance is a capacitive reactance Referring to Figure 20.5, the peak voltage V across will be... 

The inductive reactance, Xl, will tend to offset the ground capacitive reactance X,j and diminish the denominator to a certain value of Xl, say, until it completely offsets the content of X. (Xl= X, ). At higher ratios, when Xl > 3 X. g, the denominator will rise more rapidly than the numerator and will tend to attenuate the Fg a as withand X, but at a slightly higher value of max (Figure 20.7, curve 3). 

The phenomenon of saturation of the magnetic core of such a device during normal operation and its resonance with the ground capacitive reactance, X. , is known as ferro-resonance. It would have the same effect on the healthy phase,s/system as in (i) above. 

If = fault current through the healthy phases due to ground capacitive reactance X , then the current through the ground capacitive reactances... 

Vg = voltage across the external resistance R R = external resistance X = ground capacitive reactance Vf = line voltage... 

Vp, = system voltage V(- = voltage across the capacitor banks Xc = capacitive reactance X] = inductive reactance... 

X(- = power frequency capacitive reactance of the circuit Xl = power frequency inductive reactance of the circuit... 

Consider a 400 kV, triple-Zebra line, having a distributed leakage capacitive reactance Xco of 74 x 10 fl/km from Table 24.1(b). Then the charging power per phase per km. 

Inductive reactance of overhead lines of section B-B. (7) Capacitive reactance of series capacitors. 

Tan 5 is a measure of dielectric loss in a capacitor unit and is represented by the ratio of equivalent series resistance and capacitive reactance of a capacitor unit at the rated voltage and frequency (Figure 9.7) i.e. 

Strictly, the strain gauges referred to above come into this category, since in such cases the change in the measured quantity causes a corresponding change in the resistance of the element. However, the principle has a much wider application, using changes in either the inductive or capacitive reactance of electrical circuit elements. 

The total impedance of the coil will also have an often negligible term called the capacitance [Bray and Stanley, 1997]. The capacitance reactance of the coil, Xc is given by ... 

Figure 7.6 is the EIS of pyrite under different potential conditions in NaOH solution. The relationship between polarization resistance and potential can be further demonstrated by Fig. 7.7. It can be seen from Fig. 7.6 and Fig. 7.7 that when the anodic polarization potential is between 50 and 330 mV, all the curves appear as a single capacitive reactance loop. But when the potential is between 50 and 250 mV, the capacitive reactance loop radius increased with the...

Figures 7.8 and 7.9 are the polarization curves and EIS for pyrite at natural pH and in the lime medium, respectively. Obviously, after adding lime, the corrosive potential of pyrite electrode moves towards negatively about 150 mV and the corrosive current density decreases from 10.7 pA/cm to 6.2 pA/cm. The anodic and cathodic slope has almost no change. Whereas, the capacitive reactance...

Figure 7.12 is the EIS of pyrite under different xanthate concentration. Figure 7.12 exhibits two capacitive reactance loops existing in the pyrite-xanthate system... 

Figure 7.14 illustrates that in the initial stage of polarization of the pyrite electrode in xanthate solution at about 120 mV, the radius of high value capacitive reactance loop increases with the increase of the polarization potential and reaches the maximum at 320 mV, indicating that the oxidation of xanthate increases gradually and collector film on pyrite surface becomes thicker. It increases the conduction resistance and the growth of collector film is the controlled step resulting in pyrite surface hydrophobic. When the polarization potential increases from 320 mV to 400 mV, the capacitive reactance loop radius decreases, indicating the decrease of transferring conduction resistance as can be seen in Fig. 7.15. It belongs to the step of film dissolution. Capacitive reactance loop radius decreases obviously when the potential is larger than 400 mV, at where the collector film falls off and the anodic dissolution of pyrite occurs. The controlled step is the anodic dissolution of pyrite and the surface becomes...

Figures 7.22 and 7.23 are the EIS of pyrite interaction with collector at pH = 12 modified by NaOH and lime respectively. Figure 7.22 shows that the radius of the capacitive reactance loop is, respectively, 8700 Q without collector, 9400 Q by the addition of xanthate and 10000 Q by the addition of dithiocarbamate. The small increase of the radius of the capacitive reactance loop at pH= 12 modified by NaOH when adding xanthate and dithiocarbamate, shows that the two collectors still have certain inhibiting corrosion action and hence adsorption on pyrite. The action of xanthate is some stronger than that of DDTC because the radius of the capacitive reactance loop in the presence of xanthate is slightly larger than that in the presence of DDTC. However, Fig. 7.23 demonstrates that at pH = 12 modified...

In Fig. 7.27, there appears a single capacitive reactance loop in different pH media. The eapacitive reactance loop radius is bigger in the lime medium than that without lime. The reaction resistance increases from 14000 in the absence of lime to 15000 in the presence of lime. EIS exhibits passivation characteristic. The results indicate the formation of surface oxidation products which prevent the transferring of electron, giving rise to the increase of surface resistance and descending of corrosive current. It may be mainly because of the following reactions on the surface of galena in the lime medium besides Eq. (7-12) ... 

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