JPH01311900A - Controller for ac exciting synchronous machine - Google Patents

Abstract

PURPOSE:To prevent the rotating speed of an AC exciting synchronous machine from abnormally rising at the time of a set power abrupt change or a system trouble or the like by switching the control of a cycloconverter from a power deviation control to a rotating speed deviation control if the rotating speed of the machine rises its specified speed or more. CONSTITUTION:If the rotating speed of an AC exciting synchronous machine 1 is its specified speed or less, an automatic load regulator 6 is selected by a changeover switch, and the secondary exciting cycloconverter 4 of the machine 1 is controlled in response to a deviation between an output set value P0 and an output P. If the speed becomes the specified speed or more, the changeover switch 14 is switched, and the cycloconverter 4 is controlled in response to a deviation between a rotating speed command N0 and a rotating speed N. On the other hand, a guide vane is controlled by a deviation between guide vane openings GVO and GVO0 calculated on the basis of a rotating speed deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an AC-excited synchronous machine directly connected to a pump-turbine that constitutes, for example, a variable speed pumped storage power generation system.

[Conventional technology]

FIG. 2 is a block diagram showing a control device for a conventional AC-excited synchronous machine, as shown in, for example, Denugaku, Vol. 107, No. 3, Page 210, published in March 1986. In the figure, 1 indicates an AC-excited synchronous machine ( (hereinafter referred to as AESM), 2 is A, a pump turbine directly connected to ESMI, 3 is a generator breaker, 4 is a cycloconverter (C/C), 5 is an automatic current regulator (AC:R)
, 6 is automatic load regulator (APR), 7 is output setting device, 8
1 is an input/output control servo for the pump water turbine 2, 9 is a speed governor, 10 is a rotational speed calculation section, and 11 is a valve opening calculation section.

12 is the rotation detector of AESMI, P, N, H.

GV○ is the actual generated power, rotation speed, head, and guide vane opening.

In addition, the above-mentioned cycloconverter 4, automatic current regulator 5,
The automatic load regulator 6 constitutes a synchronous machine control means I, and the input/output control servo 8, the governor 99 rotational speed calculating section 10, and the valve opening degree calculating section 11 constitute a water turbine controlling means (2).

Next, the operation will be explained. Setting value P0 of output setting device 7
Due to the deviation between the power value P of AESMI and the power value P of AESMI, the cycloconverter 4
AESM is controlled by the output of this cycloconverter 4.
The AESM is operated at variable speed with secondary excitation of I. Therefore, even if the rotational speed of AESM1 changes, parallel operation with the grid is possible by correcting the frequency by the amount of secondary excitation to match the grid frequency.

On the other hand, the rotation speed NO and AESM calculated by the rotation speed calculation section 10 which inputs the setting value P0 of the output setting device 7 and the head H
The guide vane opening degree GVO output from the speed governor 9 based on the deviation of the rotation speed N of 1 and the setting value P of the output setting device 7.

The guide vane opening degree GV○ is calculated by the valve opening calculation unit 11 which inputs the head and the head H. Depending on which deviation, the input/output control servo 8 is controlled and the AES M1 is operated via the pump water wheel 2 to reach the optimum rotation speed.

[Problem to be solved by the invention]

Since the conventional control device for an AC-excited synchronous machine is configured as described above, as shown in Fig. 3, when the set power suddenly decreases by operating the output setter 7 toward the range side, during AFC operation, or in the event of a system failure, etc. In this case, the electric power P from the AESMI quickly dissolves to the set value P0 of the output setting device 7 and decreases, but since the guide vane movement is slow, the input continues, and the AESMI and the pump-turbine 2, which rotate together, are temporarily affected. Accelerating torque acts on the motor, increasing the rotational speed, and then, as the guide vane closes, the rotational speed decreases and settles down to the rated value. That is, there is a problem in that the rotation speed is slow to settle, and the rotation speed temporarily increases abnormally as shown by the solid line in FIG. 3, leaving the rotation speed adjustment range by the cycloconverter 4.

This invention was made to solve the above-mentioned problems, and its purpose is to prevent an abnormal increase in the rotational speed when the set power suddenly decreases, during AFC operation, when a system fault occurs, etc.

[Means to solve the problem]

The AESM control device according to the present invention has a switching means for switching control of the cycloconverter from power deviation control of the synchronous machine control means to rotation speed deviation control of the water turbine control means when the rotation speed of the AESH increases above a specified rotation speed. It is equipped with the following.

[Effect]

The switching means in this invention switches the control of the cycloconverter from power deviation control to rotation speed deviation control when the rotation speed of the AESM becomes equal to or higher than a specified rotation speed.
To always suppress the increase in the rotational speed of the ESM to within the rotational speed adjustment range by the cycloconverter.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 13 indicates that the rotation speed of AESMI is the specified rotation speed N.
14 is a changeover command circuit which issues a changeover command when the changeover command exceeds be. Note that the same parts as in FIG. 2 are designated by the same reference numerals and their explanation will be omitted.

Next, the operation of the above embodiment will be explained. When the rotational speed of the AESMI is equal to or lower than the specified rotational speed N□, the changeover switch 14 is turned on to the output side of the automatic load regulator 6 as shown in the illustrated example, and the cycloconverter 4 is controlled by the power deviation.

When the rotation speed of the AESMI becomes equal to or higher than the specified rotation speed N□ due to the aforementioned sudden decrease in the set power, etc., the selector switch 1
4 is a switching command from the switching command circuit 13 and is input to the output side of the rotational speed calculating section 10, and the cycloconverter 4 is controlled by the rotational speed deviation. Therefore, by controlling the rotation of the AESMI by the cycloconverter 4 and controlling the rotation of the pump water turbine 2 by the input/output control servo 8 of the water turbine control means, the rotational speed of the AESMI rapidly decreases as shown by the dotted line in FIG.

In this case, since the AESMI power control is not performed, the power P tends to increase at a certain point as shown by the dotted line in FIG. 3, but there is no particular problem.

Note that in the above embodiment, the control of the cycloconverter during normal operation was explained using power feedback.
A rotation speed correction circuit may be added to the power feedback system, or only variable speed power generation may be used, or a GTO may be used instead of a cycloconverter, and the same effects as in the above embodiments can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, the control of the cycloconverter is switched from power deviation control to rotational speed deviation control when the rotational speed rises above a specified rotational speed. This has the effect of suppressing the rotational speed within the adjustment range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a control device for an AC-excited synchronous machine according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional control device for an AC-excited synchronous machine. FIG. 3 is a characteristic diagram showing changes in rotation speed and power with respect to changes in the set value of the output setting device. 1 is an AC excited synchronous machine (AESM), 2 is a pump water turbine, 1
4 is a changeover switch, ■ is a synchronous machine control means, and ■ is a water turbine control means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 1 1: Jōryūshiki Rikimushi synchronous machine, (AESM) 2. Hotsua Mokutai 5 Original current adjustment pig 6: 1 Imperial store adjustment pig 8: Input fertilizer control servo 14: Switching switch Tuna L periodic machine・Suppressing vinegar cup ■ ・Water wheel control -) stage

Claims (1)

[Claims] An AC-excited synchronous machine having an AC-excited synchronous machine directly connected to a pump-turbine, a water-turbine control means having a speed governor and controlling the pump-turbine, and a synchronous machine control means having a cycloconverter and controlling the AC-excited synchronous machine. In the control device of
A switching means is provided for switching control of the cycloconverter from power deviation control of the synchronous machine control means to rotation speed deviation control of the water turbine control means when the rotation speed of the AC excited synchronous machine increases to a specified rotation speed or more. Control device for AC excited synchronous machine.