Electrotechnical Systems

140 Electrotechnical Systems

impacts the factorD and operates in the bound ±a. In order not to break the con-

dition D > M/1.155, the value M computed according to the value U

d

is reduced

by the value a.

The proper block diagram is shown in Figure 4.57. The three-phase source

of the variable voltage (and, perhaps, of the frequency) models, for instance, a

synchronous generator with permanent magnets that is driven either by the wind

turbine, or by the rotated wheels of the railway car for supplying its auxiliaries,

or with help of the power take-off system from the main propulsion drive of the

railway transport or vessels. It is supposed that ...