JPH07227100A - How to recover the output voltage of the AC generator in the event of a power failure - Google Patents

Abstract

(57) [Summary] [Purpose] If the output voltage of an alternator suddenly drops due to a power failure, etc., the output voltage of this alternator can be quickly restored with the load still connected. [Structure] An initial excitation power supply 16, an auxiliary power supply 19, and an output voltage detection means 18 for the AC generator 11 are provided, and it is detected by this output voltage detection means 18 that the output voltage of the AC generator 11 is below a predetermined value. Then, based on this detection, power is supplied to the field winding 11a of the AC generator 11 from the auxiliary excitation power source 19 in addition to the initial excitation power source 16 to restore the output voltage of the AC generator 11. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of an output voltage recovery method for an AC generator in the event of a power failure or the like.

[0002]

2. Description of the Related Art A conventional device is constructed as shown in FIG. In FIG. 2, 1 is an AC generator, 1 a is a field winding of the AC generator 1, and 2 is a load of the AC generator 1. 3 is a transformer connected to the output side of the AC generator 1, 4
Is an automatic voltage regulator, which adjusts the electric power supplied through the transformer 3 and the contact 5a to a predetermined value and supplies it to the field winding 1a. The voltage relay 5 is a voltage relay that is turned on when the voltage generated by the AC generator 1 after the initial excitation exceeds a predetermined value. Reference numeral 7 is a contact for turning on the initial excitation power supply, and when it is turned on, the initial excitation power is supplied to the field winding 1a via the automatic voltage regulator 4. The contact 7 is linked to the ON operation of the voltage relay 5 and
It will be F. In the above configuration, the AC generator 1
In order to bring the above into a normal operation state, first, in the no-load state, the contact 7 and the contact 5a are turned on to supply the exciting current by the initial excitation to the field winding 1a. Next, when the AC generator 1 is excited and its output voltage establishes a voltage and reaches a predetermined value, the contact 7 is turned off by the detection operation of the voltage relay 5.
Then, after adjusting the output voltage of the AC generator 1 to a predetermined value via the transformer 3, the output voltage of the AC generator 1 is supplied to the field winding 1a via the contact 5a and the automatic voltage regulator 4. Establish the voltage to the no-load rated voltage. Then, after connecting the load 2 such as the electric motor, the output voltage of the AC generator 1 is supplied to the field winding 1a by the automatic voltage regulator 4 so that the output voltage of the AC generator 1 becomes a predetermined load rated voltage for the connected load 2. The exciting current is adjusted to a predetermined value so that the AC generator 1 outputs a predetermined voltage.

[0003]

By the way, in the prior art, when an abnormal state such as a power failure occurs and the output voltage of the generator suddenly drops, the load connected to the generator can be disconnected. In this case, it was possible to restore the output voltage of the generator usually in about 1 to 2 seconds according to the procedure of shifting the load to the normal operation state by disconnecting the load. However, depending on the load, it may not be possible to disconnect even in such a case. In such a case, the voltage must be established again by the above procedure with the load still connected. Time (5-20
However, there is a problem in that the connected load is considerably burdened. It is an object of the present invention to provide a method for recovering the output voltage of an AC generator at the time of a power failure or the like, which solves the above problems (problems) of the conventional one.

[0004]

In order to solve the above-mentioned problems, the method for recovering the output voltage of an AC generator in the event of a power failure or the like of the present invention is intended to solve the above problems. When the output voltage detecting means detects that the output voltage of the AC generator is below a predetermined value, the output voltage detecting means detects the output voltage of the AC generator from the auxiliary power source in addition to the initial excitation power source. Power was supplied to the field winding of the AC generator to restore the output voltage of the AC generator.

[0005]

According to the present invention, when a sudden drop in the output voltage of the alternator due to a power failure or the like is detected, the field winding of the alternator is supplied with power from the auxiliary excitation power source in addition to the initial excitation power source. Since the generator is strengthened and excited, the output voltage of the generator is quickly restored to the rated voltage without disconnecting the load.

[0006]

EXAMPLES The present invention will be described in detail with reference to an example shown in FIG. In FIG. 1, 11 is an AC generator, 11
a is a field winding of the AC generator 11, and 12 is a load of the AC generator 11. Reference numeral 13 is a transformer connected to the output side of the AC generator 11 and is for lowering the level of the excitation voltage in order to make the excitation current for supplying to the field winding 11a an appropriate level. . 14 is an automatic voltage regulator composed of control elements such as transistors,
Power is supplied through the transformer 13 and the contact 15a, and the exciting current is adjusted according to the fluctuation of the output voltage of the AC generator and supplied to the field winding 11a. Reference numeral 17 is a contact for turning on the initial excitation, which supplies electric power from the initial excitation power source 16 to the automatic voltage regulator 14
It is connected to the electric circuit which supplies to. The first voltage relay
When 15 detects that the AC generator 11 has exceeded the first voltage level after the initial excitation, the contact 17 is turned OFF, and when it is detected that the voltage falls below the first voltage level, the contact is released. Turn 17 on. Reference numeral 18 is a second voltage relay (undervoltage relay), which means that when the output voltage of the alternator 11 drops below the second voltage level,
The contact 18a is turned on, and the contact 18a is turned off when the voltage exceeds the second voltage level. In addition, 19 is an auxiliary power supply, 20 is an input resistance, and 21 is a diode.
In these, these constitute an electric circuit of the auxiliary power supply 19. Also,
In the present embodiment, the auxiliary power source 19 is a battery-power source, but it may be replaced with another DC power source such as a solar cell or an auxiliary generator. The first voltage level is set to a value higher than the second voltage level. In the above configuration, the AC generator 11 due to a power failure or the like
In the case where the output voltage of No. 2 suddenly drops, the first voltage relay 15 detects the operation of the first voltage relay 15 to enter the contact 17 to perform the initial excitation of the alternator 11 immediately after that, immediately after that. The contact of the contact 18a is turned on by the detection operation of the second voltage relay 18, and the initial excitation power source 16
In addition to the initial excitation power from the auxiliary power supply 19, the auxiliary excitation power from the auxiliary power supply 19 is also supplied, and the field winding 11a of the AC generator 11 is supplied with the excitation current for stronger excitation. In this case, the strong exciting current is set to be slightly higher than the rated exciting current value for the connected load 12, so that the exciting voltage of the alternator 11 is established by the strong exciting current. During the process, the contact 17 is turned off by the detection operation of the first voltage relay 15, and the transformer 13 and the automatic voltage regulator 14 automatically adjust the voltage after the AC generator 11 establishes the voltage. Return to the normal operating system controlled by the unit 14. Therefore, when the output voltage of the alternator 11 is restored by the procedure of the present invention, the alternator takes about the same time as the time required to restore the output voltage of the alternator 11 in the unloaded state in which the load 12 is disconnected. The output voltage of 11 can be quickly restored.

[0007]

According to the present invention, as described above, the initial excitation power source,
When the output voltage of the auxiliary power source and the alternator is below a predetermined value, the output voltage of the generator is suddenly dropped due to a power failure or the like. Since the power is supplied from the auxiliary power supply and the AC generator is strengthened and excited, the time required for the output voltage of the AC generator to recover to the specified rated voltage is greatly shortened compared to the conventional one. This has the excellent effect of reducing the load on the connected electric motor and the like. In addition, as shown in the above embodiment, when the automatic voltage regulator is configured by the transistor type, it becomes possible to control the voltage lower than that of the conventional thyristor type, and the strong excitation by the small capacity auxiliary power supply is performed. Since it is possible to use the above electric circuit, the device can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a connection diagram for carrying out an output voltage restoration method for an AC generator at the time of a power failure or the like according to the present invention.

FIG. 2 is a connection diagram for implementing the method of the conventional example.

[Explanation of symbols]

 11: AC generator 18: Voltage relay (output voltage detection means of AC generator) 18a: Voltage relay contact 19: Auxiliary power supply

Claims (1)

[Claims] 1. An alternating current generator, an initial excitation power source for the alternating current generator, an auxiliary power source, and an output voltage detecting means for the alternating current generator. The output voltage detecting means causes the output voltage of the alternating current generator to fall below a predetermined value. When it is detected that, in addition to the initial excitation power source, the auxiliary power source supplies power to the field winding of the AC generator based on this detection.
A method for recovering the output voltage of an AC generator in the event of a power failure, etc., characterized in that the output voltage of the AC generator is restored.