Pole number

Number of poles Number of stator slots Number of rotor slots Skew angle (degrees)... 

FIGURE 11.3 Shape (a) and depth (b) of multipole potential wells versus the pole number. 

This conservation and the arbitrary choice to attribute a positive weight to pole number 2 lead to the definition of the amount of substance of the dipole as being... 

This energy-per-entity level representation versus the pole numbers /, called system coordinate or reaction coordinate, is a common one in many domains but often presented in terms of energy levels. ... 

This regularity characteristic is illustrated in Figure 8.6 for a chain multipole composed of two dipoles in series. The position along the chain is quantified by a chain coordinate x related to the pole number / through the relation... 

Fig. 9 Electret motor using the slot effect, (a) One of two disks of a 2-pole stator, (b) complex stmcture rotor of which pole number 2 (Tada 1993) (Reproduced with permission fiom IEEE)...

Where Ui denotes input number i and there is an implied summation over all the inputs in the expression above A, Bj, C, D, and F are polynomials in the shift operator (z or q). The general structure is defined by giving the time delays nk and the orders of the polynomials (i.e., the number of poles and zeros of the dynamic models trom u to y, as well as of the noise model from e to y). Note that A(q) corresponds to poles that are common between the dynamic model and the noise model (useful if noise enters system close to the input). Likewise Fj(q) determines the poles that are unique for the dynamics from input number i and D(q) the poles that are unique for the noise N(t). 

A variable-speed drive is usually used on the feed and cross-belt drives to exercise control in separator operation, although the speed is not usually changed once the optimum operating condition is estabUshed. Feed rates and the selection of the number of magnetic poles are usually deterrnined by preliminary laboratory tests. The mineral types involved in the feed largely determine the number of poles selected. High intensity cross-belt separators are frequendy used in combination with induced-roU or electrostatic separators. 

The typic medium-sized squirrel-cage motor is designed to operate at 2 to 3 percent shp (97 to 98 percent of synchronous speed). The synchronous speed is determined by the power-system frequency and the stator-winding configuration. If the stator is wound to produce one north and one south magnetic pole, it is a two-pole motor there is always an even number of poles (2, 4, 6, 8, etc.). The synchronous speed is... 

Before proceeding to a description of specific practices, it is appropriate to remark that if the rules with their variances, alternatives and exceptions seem excessively numerous and complicated, it is because heterocyclic compounds are even more numerous and complicated. Systematic names can be kept short only at the expense of a substantial number of rules and variances when rules are kept few and simple, relatively cumbersome names are likely to be generated. Current practice, and the principles behind it, represents a balance between these two poles. 

The phase boost is proportional to the separation of the zero-pole pair in the error amplifier, but that is of seeondary nature sinee the error amplifier s pole and zero were plaeed to eompensate the worst ease zero and pole in the eontrol-to-output eharaeteristies. The aetual loeation of the zero eaused by the ESR, whieh amounts to the ehoiee of a vendor and part number, will affeet the amount of exeess phase the supply will exhibit. So the designer may have to reloeate the eompensating pole if there is any possibility that the exeess phase will fall to less that 30 degrees (-330 degree lag). 

Root locus locations on real axis. A point on the real axis is part of the loei if the sum of the number of open-loop poles and zeros to the right of the point eoneerned is odd. 

Note that equations (5.72) and (5.75) are identieal, and therefore give the same roots. The first root, —3.79 lies at a point where there are an even number of open-loop poles to the right, and therefore is not valid. The seeond root, —0.884 has odd open-loop poles to the right, and is valid. In general, method (a) requires less eomputation than method (b). 

As. vi in Figure 6.15(a) is swept clockwise around the contour, it encircles two zeros and one pole. From Cauchy s theorem given in equation (6.46), the number of clockwise encirclements of the origin in Figure 6.15(b) is... 

The Nyquist stability criterion can be stated as A closed-loop control system is stable if, and only if, a contour in the G s)H s) plane describes a number of counterclockwise encirclements of the (—l,jO) point, the number of encirclements being equal to the number of poles of G s)H s) with positive real parts . 

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