JPS58195498A - Exciter for ac generator - Google Patents

Abstract

PURPOSE:To obtain an exciter of an AC generator which can supply continuous current when the generator is shortcircuited or dropped at its voltage by connecting a DC power source to an exciting current supply circuit to the field coil. CONSTITUTION:The output obtained from a transformer 4 is regulated in response to the load voltage during the load operation of an AC generator 1 by controlling by an automatic voltage regulator 6 a controlled rectifier 5, the regulated output is supplied as an exciting current to the exciting coil 2, and the terminal voltage of the generator 1 is maintained at the rated voltage at the load time. On the other hand. When the generator 1 is shortcircuited, the terminal voltage of the generator 1 becomes zero, the power form the rectifier 5 cannot be obtained. At this time, a contact 10 of an insufficient voltage relay is conducted, and the coil 2 is excited through a current limiting resistor 9 from a storage battery 8, thereby flowing a continuous current.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an excitation device for an alternator.

Conventionally, there was a device for this bridge as shown in Figure 1. In the figure, (1) is an I/i alternator, (2) is a field winding that supplies exciting current to this alternator (1), and (3) is
is a current transformer connected to the output side of the alternator (1) and supplies an excitation current according to the load current to the field winding (2); (4) is the output of the alternator (1); A transformer (5) which is a voltage converter connected to the side and supplies an excitation current corresponding to the no-load current to the field winding (2); (5) Fi for exciting the field winding (2); (6) is an automatic voltage regulator that controls the controlled rectifier (5) to adjust the excitation current supplied to the field winding (2) to a predetermined value g4!1; (7) is the automatic voltage regulator This is a rectifier that converts the alternating current exciting current supplied from the current transformer (3) to the field winding (2) into direct current.

While the AC generator (1), whose operation will be explained next, is operating with no load, the current limiter (5) is connected to the automatic voltage regulator (6).
), the output obtained from the transformer (4) is adjusted according to the no-load voltage, and the adjusted output is supplied as an exciting current to the field winding (2) to generate the alternator (1). ) terminal voltage is maintained at the no-load rated voltage. On the other hand, the AC generator (1
) during load operation, the excitation current obtained from the current transformer (3) is converted from AC to DC by the rectifier 11 (7), and the excitation current obtained from the transformer @ (4) is Add automatic voltage gll II! (6) sets the excitation current supplied to the field winding (2) to a predetermined value a411 to maintain the terminal voltage of the alternator (1) at the rated voltage under load.

However, under the load shown above, the exciting current can be supplied from the transformer (4) to the field winding (2) without using the current transformer (3) and the rectifier (η). However, if a short circuit occurs in the alternator (1), the terminal voltage becomes zero, so current transformation 1 (3) becomes necessary.

Conventional devices are configured as described above, so if the alternator experiences a voltage drop or short circuit, a current transformer and rectifier must be installed to allow a sustained current to flow. Space is required to insert them into the main circuit, J! ! However, there were also drawbacks such as complicated wiring.

This invention was developed to eliminate the drawbacks of the conventional ones as described above, and by connecting a DC power source to the excitation current supply circuit to the field winding, the AC generator can be used in the event of a short circuit or voltage drop. It is an object of the present invention to provide an excitation device for an alternator that can excite a field winding and supply a sustained current.

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, (8) is a storage battery that is a DC power source, (9) is a resistor that is connected to this storage battery (8) and limits the current flowing to the field winding (2) of the alternator (1), and (10) ) is connected to this resistor (9), and the other wire is the field winding (2)
A contact point of an undervoltage relay (not shown) connected to the excitation current supply circuit to the circuit (not shown) so that the alternator (1) becomes conductive in the event of a short circuit or voltage drop. is set up.

Note that the other configurations are the same as those of the prior art, so explanations will be omitted.・1,. 11. Next, I will not explain the operation. When the alternator (1) is in no-load operation, it operates as before, but during load operation, the automatic voltage regulator (6) controls the control current regulator (5) to control the transformer (4). ) depending on the load voltage, m1m1, gl]l! 1 output is supplied as an exciting current to the field winding (2), and the alternating current generator (1
) terminal voltage at the rated voltage at load. On the other hand, when the alternator (1) is short-circuited, the terminal voltage of the transformer generator 4i* (1) becomes zero, so the power from the control rectifier (5) cannot be obtained. The contacts (10) are made conductive, and the field winding (2) is excited from the storage battery (8) via the current limiting resistor (9), causing a continuous current to flow.

Moreover, FIG. 3 shows another embodiment of this invention, (
12) is connected to the secondary side of the transformer (4), and the transformer (4) is connected to the secondary side of the transformer (4).
) is converted into direct current, and the excitation current obtained from the storage battery (8
), and (13) is a switching element such as a DC-DC converter connected to the DC side of this rectifier (12). In this case, the storage battery (8) is rectified as described above! (12) and the switching element (13).

The rest of the configuration is the same as that shown in FIGS. 1 and 2, so the explanation will be omitted.

Next, the operation will be explained. During normal operation, transformer 1
The output obtained from 1(4) is! It is converted into direct current by a single current converter (12) and charged into a storage current (8). If the AC generator (1) suffers a short-circuit accident, the switching element (13) is controlled by the automatic voltage regulator (6) to reduce the DC current charged in the storage battery (8). flows, obtaining a sustained current in the field winding (2).

In the above embodiment, an If DC power storage battery is provided, but the control power source used in the power generation device (not shown) can also be used as the DC power source.

As described above, according to this invention, a DC power source is connected to the excitation current supply circuit to the field winding, and when the alternator is short-circuited or voltage drops, the field winding is excited and the connection current is supplied. Since this configuration eliminates the need for a current transformer, the device can be made inexpensive, and the main circuit wiring and space can also be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional excitation device for an AC generator, FIG. 2 is a block diagram showing an excitation device for an AC generator according to an embodiment of the present invention, and FIG. 3 is a block diagram showing an excitation device for an AC generator according to an embodiment of the present invention. 1 is a block configuration diagram showing an excitation device for an alternator according to an embodiment. FIG. In the figure, (1) is an alternator, (2) is a field winding,
(4) is a voltage converter, (5) is a controlled rectifier, (6) is a self-help voltage regulator, and (8) is a DC power supply. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Shin Tameno - Figure 1 Figure 2

Claims (3)

[Claims] (1) Control fR with a voltage converter provided on the output side of an alternator having a field winding, and a fs control rectifier provided on the output side of this voltage converter and connected to the field winding. an automatic voltage regulator that controls a rectifier to adjust the terminal voltage of the alternator; and an automatic voltage regulator that is connected to the field winding and that excites the field winding when the alternator voltage drops or is short-circuited. Excitation of an alternator with a DC power supply providing continuous current #
11 devices. (2) Excitation of the alternating current generator according to claim @1, characterized in that the DC power source is constituted by a storage battery! Device. (3) The excitation device for an alternator according to claim 2, characterized in that the storage battery is charged via a voltage converter.