JPH04314973A - Divided type guide vane operating device - Google Patents

Abstract

PURPOSE:To allow a plurality of servomotors to be applied with each uniform operating force. CONSTITUTION:A plurality of servomotors 1 and guide rings 2 which are joined with each servomotor 1 and divided to an equal number to the servomotors 1 are installed. An equal number of guide vanes 6 are joined with the guide rings 3, and since the guide rings 3 are independent, each uniform operating force acts onto each servomotor 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide vane operating device for opening and closing guide vanes for adjusting the amount of water in a water turbine or a pump water turbine.

0002

2. Description of the Related Art Hydraulic servo motors have been used for a long time as devices for opening and closing guide vanes of water turbines or pump water turbines, and have many successful results. In recent years, electric servo motors, which combine a brushless motor with a power cylinder made of gears and ball screws, have come into use for small-capacity water turbines, contributing to improved maintainability. Generally, as the capacity of a water turbine increases, the force required to operate the guide vanes also increases, requiring a larger servo motor. In large-capacity water turbines or pump water turbines, a system in which one guide ring is driven by multiple hydraulic servo motors is often adopted due to limitations in servo motor capacity or from the viewpoint of economy.

FIG. 6 is a block diagram of a conventional guide vane operating device. In FIG. 6, two hydraulic servo motors 11 as servo motors are rotatably supported at one end by the foundation 2 of the generator, and are coupled to a guide ring 3. The guide ring 3 is supported by a bearing 4. A guide vane 6 is coupled to the guide ring 3 via a link mechanism 5. Guide vane 6 is supported by shaft 6a. The guide ring 3 is rotated in accordance with the stroke of the hydraulic servo motor 1 to rotate the guide vane 6 around the shaft 6a, thereby opening and closing the guide vane 6.

[0004] When the load on the water turbine becomes no load, and the governor function is not performed and the guide vane opening remains the same, the runner becomes at an unrestricted speed due to the energy of the water flowing into the runner. . The unit rotational speed per unit head and unit dimension of the water turbine is n11, and the unit flow rate is Q11.
Then, n11=nD/√H, Q11=Q/D2 √
Represented by H. (Q: flow rate, D: representative diameter of runner, H: effective head, n: runner rotation speed) In the characteristic curve showing the relationship between unit rotation speed n11 and unit flow rate Q11 of a high head water turbine or pump turbine, there is no constraint. When the speed exceeds the speed state and enters the water turbine braking region, the unit flow rate Q11 curve has a reverse slope, and the unit rotational speed n11 exhibits a so-called S-shaped characteristic in which it once decreases and then increases again. For this reason, the operating condition in the S-shaped section becomes extremely unstable, and the torque and flow rate fluctuate significantly due to slight fluctuations in the head, that is, the unit rotational speed n11. or make load control difficult after synchronization.

For example, considering the startup of a water turbine generator, after increasing the rotation speed to the rated value under a certain head,
The generator is connected to the power grid. Since the turbine is still under no load, the operating point of the turbine will be located on the line of unconstrained speed. If a water turbine has a pronounced S-shaped characteristic,
There are two to three flow rates (Q11) corresponding to the same rotational speed (same n11) and the same guide vane opening degree. Therefore, when the head changes slightly due to some disturbance and returns to its original state, the operating point of the water turbine may not return to its original state, but may shift to a so-called reverse pump region where the flow rate is negative, for example. Such a phenomenon not only causes major disturbances in the power transmission system, but also has the potential to cause damage to water turbines and penstocks due to drastic fluctuations in water pressure caused by sudden changes in flow rate. In order to improve the S-shaped characteristic that has such an adverse effect, it is effective to open and close every other guide vane at a different opening degree.

[0006]

[Problem to be Solved by the Invention] In the case of electric servo motors, when trying to drive one guide ring with multiple servo motors, very small differences in the strokes of the individual servo motors result in a large amount of operation for only one servo motor. There was a problem with the amount of force required. For this reason, the use of electric servo motors is limited to small-capacity machines that can be handled by a single servo motor, and cannot be applied to large-capacity water turbines or large-capacity pump-turbines. In order to open and close every other guide vane at different opening degrees in order to improve the S-curve characteristics of a pump-turbine, conventionally, one guide vane is required for each guide vane, regardless of whether a hydraulic servo motor or an electric servo motor is used. Unless you use the individual servo motor method, which has a servo motor for each
Since this was not realized, the structure was complicated and the cost was high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a guide vane operating device that applies operating force equally to the plurality of servo motors in a guide vane that is opened and closed by a plurality of servo motors. Another object of the present invention is to provide a guide vane operating device that opens and closes every other guide vane at different speeds without using individual servo motors.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a guide ring that connects a plurality of guide vanes, and a servo motor that rotates the guide ring.
A guide vane operation device that opens and closes a guide vane of a water turbine or a pump water turbine, including a plurality of servo motors;
A guide ring connected to each servo motor and divided into the same number of servo motors is provided. Furthermore, in the operation of the split type guide vane operating device according to claim 1, if two servo motors and a guide ring connected to each servo motor and whose outer circumference is equally divided into two are provided, the servo This is suitable for applying operating force evenly to the motor. Further, in the split type guide vane operating device according to claim 1, there are provided two servo motors and two concentric guide rings connected to the respective servo motors, and the plurality of gund vanes are connected to each other every other guide ring. If the guide vane is coupled to the guide ring, it is suitable for opening and closing every other guide vane at different speeds.

[0009]

[Operation] This invention is provided with a plurality of servo motors and a guide ring connected to each servo motor and divided into the same number of servo motors, each servo motor is connected with the same number of guide vanes, and each Since the servo motor and the guide ring are independent, approximately equal operating force acts on each servo motor. moreover,
Two servo motors and a guide ring connected to each servo motor and whose outer circumference is equally divided,
If the same number of guide vanes are connected to both guide vanes, substantially equal operating force will act on both servo motors.

[0010] Furthermore, if two servo motors and two concentric guide rings connected to each servo motor are provided, and a plurality of guide vanes are connected every other guide vane to each guide ring, both Since the servo motor and the guide ring are independent from each other, each guide ring can be opened and closed at different speeds, so every other guide vane can be opened and closed at different speeds.

[0011]

【Example】

Embodiment 1 FIG. 1 is a block diagram of a split-type guide vane operating device according to a first embodiment of the present invention. In FIG. 1, the same parts as in FIG. 6 are given the same numbers. power cylinder 1a
An electric servo motor 1 as a servo motor consisting of a brushless motor 1b has one end rotatably supported by a generator foundation 2, and the other end connected to a guide ring 3 that divides the outer circumference into two equal parts. Each guide ring 3 is supported by a bearing 4 and connected to nine guide vanes 6 via a link mechanism 5. Guide vane 6 is supported by shaft 6a. The guide ring 3 is rotated in accordance with the stroke of the power cinder 1a to rotate the guide vane 6 around the shaft 6a, thereby opening and closing the guide vane 6.

Since the guide rings 3 operate independently, an excessive current will not flow to only one brushless motor 1b due to a slight difference between the respective power cylinders 1a. Further, the position of the guide ring 3 is detected by a position sensor 7 attached to the bearing 4, and a signal from the position sensor 7 is fed back by a power amplifier (not shown) to control the stroke of the power cylinder 1a. By making the number of guide vanes 6 connected to each guide ring 3 equal, substantially equal operating force will be applied to each electric servo motor 1.

Embodiment 2 FIG. 2 is a block diagram of a split guide vane operating device according to a second embodiment of the present invention. In FIG. 2, the same parts as in FIG. 6 are given the same numbers. In FIG. 2, two hydraulic servo motors 11 are connected to each hydraulic servo motor 11, and an outer guide ring 3a and an inner guide ring 3b are concentric with different diameters. Every other nine pieces are connected to the outer guide ring 3a and the inner guide ring 3b. In addition, the position sensor 7 attached to the bearing 4 detects the position of the outer guide ring 3.
The stroke of the hydraulic servo motor 11 is controlled by detecting the positions of the position sensor a and the inner guide ring 3d, and feeding back a signal from the position sensor 7 by a power amplifier (not shown). By individually controlling the strokes of the two hydraulic servo motors 11, the opening degree of every other guide vane 6 can be changed.

Embodiment 3 FIG. 3 is a block diagram of a split type guide vane operating device according to a third embodiment of the present invention, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a sectional view taken along line V-V in FIG. It is a diagram. In FIGS. 3 to 5, the same parts as in FIG. 6 are designated by the same reference numerals. In FIG. 3, it includes two hydraulic servo motors 11, and a first guide ring 3c and a second guide ring 3d that are connected to each hydraulic servo motor 11 and are concentric with the same diameter. 4 and 5, the first guide ring 3c and the second guide ring 3d are arranged one above the other, and every other nine guide vanes 6 are connected to the first guide ring 3c via a link mechanism 5. The remaining 9 guide vanes are connected to the second guide vane 3d via the link mechanism 5.
The guide vane shafts 6c of the guide vanes 6 are coupled together. Further, the positions of the first guide vane 3c and the second guide vane 3d are detected by the position sensor 7, and this signal is fed back by a power amplifier (not shown) to control the stroke of the hydraulic servo motor 11. According to this embodiment, by using the link mechanism 5 having the same structure for both guide rings 3c and 3d, it is possible to match the relationship between the servo motor stroke and the guide vane opening degree in both guide rings 3c and 3d. Note that if the strokes of the two hydraulic servo motors 11 are individually controlled, the opening degree of the guide vanes 6 can be changed every other guide vane.

[0015]

[Effects of the Invention] According to the present invention, the guide ring is divided into a plurality of parts and the same number of servo motors are connected to each part, so that each servo motor is independent of the other.
Operating force acts almost equally on each servo motor. Therefore, the electric servo motor can also be applied to large-capacity water turbines or pump water turbines. In addition, in this invention, a servo motor is connected to two concentric guide rings, and every other guide vane is connected to each guide ring, so the opening degree of the guide vanes can be changed every other guide vane. This makes it possible to improve the S-curve characteristics of a pump-turbine with a mechanism that is cheaper than an individual servo motor.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a split-type guide vane operating device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a split-type guide vane operating device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a split-type guide vane operating device according to a third embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along the line V-V in FIG. 3;

FIG. 6 is a configuration diagram of a conventional guide vane operating device.

[Explanation of symbols]

1 Electric servo motor 1a as a servo motor
Power cylinder 1b Brushless motor 3 Guide ring 3a Outer guide ring 3b Inner guide ring 3c First guide ring 3d Second guide ring 4 Bearing 5 Link mechanism 6 Guide vane 6a Shaft 7 Position sensor

Claims (3)

[Claims] 1. A guide vane operating device for opening and closing the guide vanes of a water turbine or a pump-turbine, comprising a guide ring that connects a plurality of guide vanes and a servo motor that rotates the guide ring. A split-type guide vane operating device comprising: a motor; and a guide ring connected to each servo motor and divided into the same number of servo motors. 2. The split-type guide vane operating device according to claim 1, further comprising two servo motors and a guide ring connected to each servo motor and having an outer circumference equally divided into two. Split type guide vane operation device. 3. The split-type guide vane operating device according to claim 1, further comprising two servo motors and two concentric guide rings connected to the respective servo motors, so that the plurality of guide vanes A split-type guide vane operating device characterized in that every other guide vane is connected to each of the guide rings.