SU72693A1 - Multiphase alternator - Google Patents

Description

It is proposed to create such a mode of operation of a compensated collector multiphase generator in which a constant voltage is maintained at the terminals of the latter regardless of the change in rotational speed.

This mode is achieved by selecting the number of turns of the excitation winding, at which the excitation current strength increases with increasing rotational speed of the generator according to a law that is close to hyperbolic, and the resultant e. d. the main circuit remains unchanged.

FIG. Figure 1 shows the curve of the hyperbolic dependence of the magnetic flux F on the speed of rotation; in fig. 2 - diagram of the generator device; in fig. 3 - a variant of the circuit device.

It is necessary that the hyperbolic dependence of the flux Φ on the velocity be in the drop-down, gated area of the resonance curve (Fig. 1). The slope of the curve can be varied by selecting the number of turns of the excitation winding, the angular position of the brushes on the collector, the amount of additional resistance in the excitation circuit, and also the automatic change of voltage at the terminals of the excitation winding.

The collector generator / (fig. 2) is driven by a motor 2, which does not have a speed control device. The excitation to the terminals of the collector generator is supplied from the synchronous excitation generator 3, which must rotate at a constant speed. This can be done by a second engine 4 of the same type as the engine 2 of the collector generator.

The load of the excitation generator 3 varies only slightly, since it operates mainly in the mode of reactive load and therefore its speed remains practically unchanged.

The synchronous driver 3 can receive a DC voltage excitation from a DC driver 5 mounted on the same shaft with it. However, to achieve a more accurate hyperbolic dependence of the flux Φ - on the rotational speed n kf, it may be useful to install a DC exciter 5 on the same shaft as the collector generator (shown in dotted lines in Fig. 2). The dependency characteristic (/ g) in this case can be selected using an exciter 5 magnetic field saturation curve.

No. 72693

In the case when the presence of a second motor 4 at the generating station is undesirable, the synchronous exciter 3 can be driven by the direct current motor

tension

The generator feeding this DC network can be a cross-field machine 6, sitting on the same shaft as the collector generator (Fig. 3).

A generator excitation circuit in the presence of a transverse field generator on its shaft can be made by a motor generator consisting of a direct current motor and a synchronous generator, or one core converter 7 (shown in Fig. 3 by a dotted line).

Subject invention

A generator of a multiphase constant-frequency current at a variable rotational speed using a collector compensated generator excited from a constant-frequency exciter, characterized in that in order to keep the generator voltage constant regardless of the speed of rotation of the machine, the number of turns of its excitation winding is chosen such that as the speed increases, the excitation current decreases according to a nearly-hyperbolic law.

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