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BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI

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Bul. Inst. Polit. Iaşi, t. LVIII (LXII), f. 3, 2012 91<br />

when we consider the initial condition ( )<br />

C<br />

Ω = t , (16)<br />

I<br />

Ω 0 = 0.<br />

3. If the parameters defined Δ ≠ 0 and C=0, Eq. (11) becomes<br />

d<br />

I<br />

Ω + ΔΩ = 0 . (17)<br />

dt<br />

Solving the characteristic equation is obtained solution<br />

Ω=Ω<br />

Δ<br />

e − t<br />

I<br />

0<br />

where: Ω 0 is the angular velocity value Ω at baseline, considered to t = 0.<br />

If, however, the initial velocity is zero, that is<br />

Ω 0 = 0,<br />

in (18) becomes apparent<br />

Ω = 0,<br />

and<br />

ω= ω a<br />

,<br />

which is understandable because the disturbance is absent, that is C = 0. Where<br />

Ω ≠ 0 , 0<br />

solution of the Eq. (17) equation remains to form (18).<br />

4. A final case under consideration is given to values Δ = 0 , C = 0.<br />

In this case, Eq. (12) is also a simplified form, that is<br />

dΩ I = 0,<br />

(19)<br />

dt<br />

with solution<br />

Ω =Ω , 0 (20)<br />

same question with respect to Ω<br />

0<br />

, as for 3.<br />

With the developed model, based on the solutions (14), (16), (18) and<br />

(20) can be extremely useful analysis of the stability of the vehicle propulsion<br />

system operation. The first case analyzed is the situation defined by<br />

Δ < 0,<br />

that is<br />

tan δ rω<br />

< tan δ mω<br />

.<br />

In this case, the angular velocity decreases or increases indefinitely to a<br />

change in operating point position a; that, in this case the operating point is<br />

unstable.<br />

In the second case, considering the situation<br />

(18)

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