Double stars

Shunt capacitors 1120 kVAr in each arm of a double star as shown below. Each unit 80 kVAr... 

Arrangement of capacifors in double star. 1120 kVAr In each arm. 

Let us choose a bank size of 6720 kVAr for easy selection of each unit. To adopt a better protective scheme, let us select the configuration of a double star (Figure 25.5(b)). 

We may therefore consider a double star system, each having a configuration for each phase of 4 x 8 units, that is, four units in series group to make up the required phase voltage and eight in parallel group to make up the required kVAr (Figure 25.6). 

Figure 25.6 Configuration of a double-star capacitor bank making 14 400 kVAr...

The fault current on a double star can therefore be calculated on the same basis as for a single-star capacitor bank. 

Consider Example 25.1 for 7200 kVAr units arranged in a single star and 14 400 kVAr units arranged in a double star. The computation of overvoltages and fault currents in the event of failure of a single unit in the two configurations is in a tabulated form as follows ... 

CiMTc iil-scnsin protcciion is tound U) Ix more iiccuniie lliiiii ii voluigc sensing, li is ihereforc recommended thni ihe units are arranged in double star as tar as possible. 

Considering the earlier Example 25.2 with 14 400 kVAr banks, connected in double star where... 

Table 12. H-bonding data in the alcohol inclusion of 1 (cf. Table 11, and Figs. 17 and 18). E.s.d s are given in parentheses for the parameters involving non-hydrogen atoms only. Mean values and r.m.s.d. s for the three groups (see footnote)3 are 2.61(4), 2.66(4), and 2.74(7) A from 10, 20, and 10 data of the unmarked, starred, and double-starred entries, respectively, of this table and of the corresponding entries of Table 13...

Fig 2-26 AIRCRAFT SIGNAL, ILLUMINATION, DOUBLE STAR, RED-RED, AN-M37A1... 

Yes, they re a pair of stars that appear to be close to each other when you look up at the sky, but in reality they re far away from each other. There s no gravity holding them to one another like in actual double stars. ... 

On the other hand, most, if not all, ordinary novas occur in double-star systems. For example, consider a red giant in the vicinity of a white dwarf. The gravitational field of the white dwarf may pull hydrogen from its larger companion, thereby initiating fusion and causing a nuclear explosion, a nova, that launches a small amount of gas into space. The process may repeat many times. 

Green Cross Ammunition in the text) GY green-yellow, double star (US)... 

The orbits of double stars, where the sizes of the orbits have been determined, provide the only information we have about the masses of stars other than the Sun. Close doublestars will become decidedly non-spherical because of tidal distortion and/or rapid rotation, which produces effects analogous to those described above for close artificial planetary satellites. Also, such stars often have gas streaming from their tidal and equatorial bulges, which can transfer mass from one star to the other, or can even eject it completely out of the system. Such effects are suspected to be present in close doublestars where their period of revolution is found to be changing. 

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