RU1810961C - Synchronous electrical machine - Google Patents

Abstract

Usage: excitation systems of synchronous contactless machines. SUMMARY OF THE INVENTION: The stator of a machine comprises a primary and secondary multiphase windings spatially offset from one another. The beginnings of the phases of the additional winding are connected to the beginnings of the phases of the main winding, the ends of the phases of the additional winding are connected to the exciter circuit. 2 ill.

Description

The invention relates to electric machines and can be used in self-excited synchronous machines.

An object of the invention is to improve control of a synchronous machine.

In FIG. 1 is a schematic diagram of a synchronous machine with a synchronous exciter; in FIG. 2 - simplified vector diagrams of the EMF between the ends of the phases of the main and additional windings when the machine is in generator mode: a) in the generator idle mode; b) at active load (cos p 1); c) with active-inductive load: d) with inductive load (cos / 0).

The synchronous machine contains on the stator a multiphase main winding 1 connected to a star and a multiphase one. additional winding 2, the beginnings of which are connected to the beginnings of the main winding 1, and the ends are connected to the input of the static rectifier 3, the constant current output of which is connected to the excitation winding 4 of the synchronous exciter, and the winding

5, the exciter is connected through a rotary rectifier 6 to the excitation winding 7 of the synchronous machine.

In the general case, the number of turns in the main and additional windings can be different (Wi U W2).

The operation of a synchronous machine is considered for generator operation. The nature of the change in the EMF between the phase ends of the main and auxiliary windings, which determines the corresponding changes in the excitation current of the machine, was simplified when the ends of the phases of the auxiliary winding 2 are disconnected from the static rectifier 3. This EMF, when the generator is idling, depends only on the angle of shift between the main and additional windings for the case when their EMF are equal (Wi Wa), as well as the difference in the emf primary and secondary windings with Wi L / 2. . With a load of the generator e.m.s. between the ends of the phases of the main and additional windings is equal to the geometric sum of the emf idle due to shear

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between windings 1 and 2 and the difference of their turns (with Wi L / 2), and the emf equal to the drop in april from the load current at the active resistance of the main winding 1, the magnitude of which is directly proportional to the load load, and its phase varies accordingly with the phase of the load current. Thus, the emf between the ends of the phases of the main and additional windings, it changes both from the magnitude of the load current and from its nature (cos #), and when the ends of the additional winding 2 are connected to the static rectifier 3, the excitation current of the machine will change accordingly.

The nature of the change in the excitation current required for a particular operating mode of the synchronous machine is provided by the choice of the angle of shift between the phases of the main and additional windings and the number of turns of these windings.

Ne FIG. 2 vector emf diagrams are given for the case where Wi Wz.

Here Ei and E2 are, respectively, the emf primary and secondary windings;

j is the generator load current; .- (g - voltage drop across the active resistance of the main winding 1 of the load outflow;

Ev e.s. between the ends of the phases of the primary and secondary windings.

E.s. EV determines the excitation current of a synchronous machine and, as can be seen from the above vector diagrams, its magnitude depends not only on the magnitude of the load current, but also on its phase. In the case considered (at Wt W2), with a decrease in the load cos p (with its inductive nature), the emf The EV increases, and the excitation current of the generator also changes accordingly. This nature of the changes in the excitation in the synchronous generator when the magnitude and nature of the load changes allows better regulation and automatic voltage maintenance of the generator. In this case, the accuracy of maintaining the voltage of the generator when changing the load value (from idle to rated load) and its power factor (from cos to cos p 0 (ind.)), Within

5-10% of rated voltage. Improving accuracy can be achieved by known voltage correction circuits. By choosing the ratio of the number of turns of the main and additional windings and the shear angle between them, it is possible to provide virtually any desired nature of the change in the excitation current of the synchronous machine in both the generator and the motor

operating modes.

As a device for converting and transmitting power to the rotor, in addition to the device shown in the considered example, containing a synchronous exciter, a static rectifier and a rotating rectifier, for example, can be used:

a static rectifier, to the input of which the ends of the phases of the auxiliary winding are connected, and the output through the contact brush assembly is connected to the excitation winding of the synchronous machine; an asynchronous exciter or rotary transformer, to the stator winding of which the ends of the auxiliary windings are connected, and the rotor windings are connected through a rotary rectifier to the excitation winding of the synchronous machine.

In the proposed synchronous machine, in contrast to the phase-compounded synchronous machines used mainly at present, there are no current transformers and inductors, which allows

It can significantly simplify the regulatory equipment to reduce its overall dimensions and the complexity of manufacturing,

Claims (1)

SUMMARY OF THE INVENTION Synchronous electric machine, containing a stator with a new and additional multiphase windings connected to one another by their own beginnings, a rotor with an excitation winding, and a device for converting and transmitting power to the rotor, to the input of which the ends of the additional winding are connected, and the output is connected to the excitation winding, and, moreover, in order to improve .-. retooling, the main and additional skeins are spatially offset one relative to another.