JPS62268340A - Induction-synchronous motor - Google Patents

Abstract

PURPOSE:To operate a motor as an induction motor receiving load despatch from the system in normalcy and to operate it as a synchronous motor continuing the rotation in outage, by embedding a conductor passing through in parallel to the enclosing groove to enclose an exciting rotor winding into the above- mentioned groove and at the same time by connecting both ends of the conductor to short-circuit rings. CONSTITUTION:An induction-synchronous motor is composed of a stator winding 1, a rotor 2, an exciting AC generator 5, its rotor winding 6, an exciting winding 7 and an automatic voltage regulator 8. To the rotor 2 a conductor 11 is embedded into the exciting winding enclosing groove, passing axially through. A short-circuit ring 12 is secured inside the bottom of the enclosing groove on the rotor end face and short-circuited with a short-circuit bar 13. Thus in the outage of power system, if a switch 9 is closed to continue the rotation, a corresponding voltage is induced to the stator winding by the residual magnetism on the rotor, so that specified voltage is set up at the stator winding 1 and the motor can be operated as a synchronous motor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel induction/recycle generator that is effective for suppressing peak power demand and as a private power generator during power outages.

A synchronous generator is commonly used as a commercial frequency AC generator, but it is difficult to maintain the rotational speed and rotational speed of a reciprocating engine, which is a rotational drive source, stably for a long period of time.

Therefore, when a synchronous generator is operated in parallel with the power grid to cover a portion of the power demand, tax adjustments often occur, and in some cases, parallel operation becomes impossible and disturbances occur in the grid.
It is not desirable because it causes For this reason, induction generators that do not affect the grid are used as generators for parallel operation.

However, induction generators require an external power supply at all times and are therefore not useful as an emergency power generation means during power outages.

The present invention provides an induction/synchronous generator that receives power from the grid during normal operation and functions as an induction generator, and during a power outage, functions as a synchronous generator while continuing its rotation.

(1) is the stator winding of the induction generator, and (2) is the rotor, which is equipped with a short circuit (3) and a field winding tQ (4).

(5) is the excitation alternator, (6) is its rotor winding,
(8) is an automatic voltage regulator that obtains the r1' output, and (8) is a switch.

The mechanical structure of the rotor (2) is as shown in Fig. 2, in which a conductor (11) penetrating in the axial direction is buried between the excitation winding housing grooves, and the conductor (11) is embedded inside the bottom of the housing groove on the end face of the rotor. A short-circuiting ring (12) is fixedly attached to the short-circuiting ring (12), and a short-circuiting ring (13) is installed between them.
There is a short circuit.

-1- In the generator described above, the rotor shaft is rotated at a speed faster than the synchronous speed by a mechanical drive source such as an engine while the stator winding receives power from the power supply system and the switch (9) is open. It operates as a normal induction generator and supplies current to the power supply side.

In on-site power generation during power outage, when the switch (9) is closed and rotation continues, the residual magnetism of the rotor induces a corresponding voltage in the stator windings, which is activated by the automatic voltage regulator (AVR). ), so the field winding (
7) is DC-excited and an alternating voltage is induced in the rotor winding (6) of the generator (5), which is rectified by the rectifier (6A) and applied to the field winding (4), and the stator winding is Line (1
) the specified voltage is established 1. Operated as a synchronous generator. In this case, the short circuit (3) advantageously functions as a damper winding.

In the present invention, the generated voltage waveform as a synchronous generator is considerably distorted, and the ripple content is particularly high.

As a countermeasure to this problem, it is conceivable to increase the gap (G) between the stator (+) and the rotor (2), which can significantly improve the problem of distortion. However, on the other hand, it becomes V with a delay and low force.

To improve this power factor, as shown in Figure 3, the stator winding (1) is separated into a power system coil (1a) and a load connection coil (1b), and each is wound inside the same thrower I to connect the load. By interposing the power factor improving capacitor (20) in the coil, it is possible to improve not only the power factor on the power source side but also the power factor on the load system. This stator winding is also effective for induction generators.

When used as an induction generator, the field winding (4) remains permanently connected to the rotor winding (6) of the excitation alternator (5) via the rectifier (6A). In this case, the DC component flowing through the field winding due to the slip frequency may not be negligible, so it is necessary to open the field circuit.

Therefore, as shown in Fig. 4, a Cyrisk (30) is inserted into the field circuit, and its trigger generator m (31) is installed on the rotor shaft using the battery (32) and switch (33) to connect the generator field winding 1. Rectifier (35) by exciting (34)
It is solved by opening and closing the field circuit for the synchronous generator by supplying a trigger to the thyristor through. The switch (33) may be linked with the switch (8).

[Brief explanation of drawings]

Fig. 1 is a configuration and connection diagram of the electrical system of the generator of the present invention, Fig. 2 is a partial sectional view of the rotor, Fig. 3 is a stator winding, and Fig. 4 is a configuration connection that enables opening and closing of the field circuit. It is a diagram.

Claims (1)

[Claims] In an induction generator equipped with a stator winding and an excitation rotor winding, a conductor penetrating in parallel with the groove is buried between housing grooves that accommodate the excitation rotor winding, and the conductor is a dielectric. Both ends of the excitation winding are connected to a short-circuit ring, and the excitation winding is connected via a rectifier to the rotor winding of an excitation alternator provided on the rotor shaft, and the field of the excitation alternator is An induction/synchronous generator, characterized in that the winding is configured to be excited by a DC output of an automatic voltage regulator connected to the induction generator via a switch.