JPH01200064A - Controller for water turbine - Google Patents

Abstract

PURPOSE:To improve responsiveness and operation performance by connecting an electric servomotor with a water port opening/closing mechanism of a water turbine and permitting the driving power from being cut off by a cut-off part and operating said cut-off part by the detection signal of the increase of the speed of the water turbine. CONSTITUTION:A water port opening/closing mechanism for opening/closing the water port of a water port of a water turbine 4 is equipped with a speed adjusting operation part 12 including an electric servomotor 3, and an L-shaped operating arm 10 having a weight 11 installed at the top edge and an operating arm 8 is turned through a link 9. The speed adjusting operation part 12 is rotatably supported onto a swingable base 13 at the bottom part, and the base 13 is engaged with the projection part 15 of a lever 14 for sharp closure which constitutes a shielding part. The lever 14 for sharp closure is shifted rightward against a spring 18 by the power of a solenoid 16 excited through a speed regulator 1 when the speed of the water turbine increases, and the operating power of the electric servomotor 13 is cut off by said shift.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water turbine control device for a hydroelectric power plant, and more particularly to an improvement of a speed governor using an electric servo motor.

[Conventional technology]

Conventionally, a hydraulic servo motor is generally used as a drive source for a speed governor of a water turbine. However, since the hydraulic servo motor uses oil as the working fluid, its accessory equipment (pressure distribution valves, piping, etc.) is complicated and requires maintenance to prevent oil leaks. Therefore, recently there has been a tendency to use electric servo motors that are easy to maintain and have good controllability.

Figure 4 shows a block diagram of an example of a conventional water/vehicle control system using an electric servo motor. A speed feedback signal N from the device 7 is input. The speed regulator 1 outputs a control signal that corrects the deviation between the speed setting signal C and the actual speed feedback signal N to zero, and supplies it to the electric servo motor 3 via the driver 2. The electric servo motor 3 rotates by an amount of operation corresponding to the given control value to operate a water mouth opening/closing mechanism (not shown) of the water turbine 4.

Here, an example of a conventional electric servo motor 3 and its power transmission mechanism is shown in FIG.
are meshing. The rotating shaft 22 of the large gear 21 has a threaded portion 2.
2a is provided, and this threaded portion 22a is screwed into a slider 24 of a manipulated variable 23 connected to the operating arm 10.

In this way, the rotational force of the electric servo motor 3 is transmitted to the small gear 20,
The motion is transmitted to the rotating shaft 22 via the large gear 21 and converted into linear motion by the slider 24 to adjust the vertical position of the operating arm 10.

By this operation, the opening degree of the water port is adjusted, water at a corresponding flow rate is supplied to the runner of the water wheel 4, and the generator 6 is rotated. Since it is actually connected to the grid load and operated, the corresponding load is given to the addition element 5 as a loss. The thus adjusted rotational speed of the generator 6 is detected by the speed detector 7, and its feedback signal N is fed back to the speed regulator 1 to continue the above control operation.

[Problems to be Solved by the Invention] As described above, a control signal from the speed regulator 1 is applied to the electric servo motor 3 via the driver 2. During this control, the operating force required of the electric servo motor 3 varies depending on the opening degree of the water port and the operating direction, but increases as the water turbine capacity increases. Furthermore, if a special closing force is applied to automatically close the door for safety reasons, an additional operating force will be required to compensate for the added force.

On the other hand, the maximum operating speed required of the electric servo motor 3 is determined by the allowable values such as the speed increase when the load suddenly decreases and the increase in water pressure due to the closing of the water port. Since the safety and cost of the equipment are closely related, it is necessary to keep the water pressure low by closing it quickly within the allowable range.

However, the operating force and operating speed of the electric servo motor 3 have a mutually contradictory relationship; if you try to increase the operating force, you have no choice but to decrease the operating speed, and conversely, if you try to increase the operating speed, the operating speed I have no choice but to reduce my power.

Looking at this from the perspective of the power transmission mechanism attached to the electric servo motor 3, the reduction ratio between the small gear 20 and the large gear 21 is determined by the maximum operating speed, and the faster the operating speed, the smaller the reduction ratio. To compensate for this, a large-capacity electric servo motor that can output a large operating force is required. However, since the electric servo motor uses a special control motor with good response, the capacity of the motor is limited.

Therefore, the faster the closing speed, the higher the equipment cost.
In the end, there was a problem in that electric servo motors could only be applied to relatively small-capacity water turbines.

Currently, the capacity of electric servo motor 3 is 7.5kw.
However, electric servo motors of 20 kW or more are being developed, and the popularity of electric servo motors is increasing. However, in hydroelectric power plants, it is necessary to provide a battery power source as an emergency drive power source for the electric servo motor 3 from the viewpoint of reliability, especially to ensure safety during load interruption. This poses problems in terms of increased costs and maintenance of power supply equipment.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a water turbine control device that can exert a large operating force with practically acceptable responsiveness even with a small-capacity electric servo motor, and can expand its range of application. .

[First Step to Solve the Problems] In order to solve the above-mentioned conventional problems and achieve the object of the present invention, the present invention provides a system that reduces the operating force of the electric servo motor when the rotational speed of the water turbine increases abnormally. The water spout is quickly closed by separating the water spout and applying a closing force separately applied to the water spout opening/closing operation mechanism.

That is, the present invention is connected to a water port opening/closing mechanism of a water turbine,
An electric servo motor that regulates the speed according to a detected speed value of the water turbine, a cutoff section that disconnects the driving force of the electric servo motor, and a water mouth closing speed limiting device, and when the cutoff section performs a disconnection operation, the water mouth closes. The water turbine control device is configured to close the water inlet by a closing force applied to an opening/closing mechanism, characterized in that the shutoff section is operated by a detection signal of an increase in speed of the water turbine.

Further, in a more specific aspect of the present invention, the operating point of the blocking section can be changed as appropriate depending on the water mouth opening degree of the water turbine.

Furthermore, when the operating force of the electric servo motor is disconnected by the operation of the cutoff section, only a closing signal is given to the electric servo motor.

[Effect]

According to the above configuration of the present invention, during normal speed regulating operation, the electric servo motor performs speed regulating according to the detected speed value of the water turbine, and when the speed of the water turbine increases, the electric servo motor operates the shut-off part based on the speed detection signal. Separates the operating force of the servo motor,
The water port is closed using a closing force that is separately added to the water port closing mechanism.

In this way, during normal speed control, the electric servo motor opens and closes the water spout, and during rapid closing, the water spout is quickly opened using a closing force that is separately added to the water spout opening/closing mechanism. This eliminates the need for electric servo motors to have such high speeds, and as a result, the range of application can be expanded beyond conventional small-capacity water turbines.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the invention.

In FIG. 1, an operating arm 8 of a water port opening/closing mechanism (details not shown) for directly opening and closing the water port is rotatably provided at the water port of the water turbine 4. The distal end of the operating arm 8 is connected via a link 9 to an L-shaped operating arm 10 that is vertically movable up and down. A weight 11 is attached to the tip of the operating arm 10. Further, a speed regulating operation section 12 is connected to the operating arm 10, and is configured to move the operating arm 10 up and down (that is, to raise and lower in the vertical direction) in order to open and close the water port associated with the speed regulating operation. The speed operating section 12 is connected to the base 1 at its bottom.
3 is rotatably supported. Further, the open end of the base 13 is locked onto the protrusion 15 of the quick-closing lever 14. The quick-closing lever 14 is rotatably supported at its lower end, and connected to the telescopic rod 17 of the quick-closing solenoid 16 at its upper end. The quick closing lever 14 is normally biased by an automatic return spring 18 so that the quick closing lever 14 is located on the base 13 side. In other words, under normal conditions, the base 13 is the quick-closing lever 1.
4 and is held in place on the protrusion 15 of the electric servo motor 3, and when it is suddenly closed, it is pulled off and the operating force of the electric servo motor 3 is disconnected.

Reference numeral 19 indicates a limit switch serving as a position detector for the quick closing lever 14, which is 0 or more, and a protrusion 15.
, the quick-closing solenoid 16 and the automatic return spring 18 constitute a cutoff section for disconnecting the operating force of the electric servo motor 3 at the time of sudden closing.

A control signal from the speed regulator 1 is given to the speed regulating operation section 12 and the solenoid 16, and the solenoid 16
The speed regulating operation section 12 is designed to operate when the speed is suddenly closed, and when the speed is normally controlled.

The speed regulating operation section 12 is the same as the conventional one, and as shown in FIG. 5, uses an electric servo motor 3 as a drive source and is connected to the operation arm 10 via a power transmission mechanism. That is,
A small gear 20 is attached to the rotating shaft of the electric servo motor 3, and a large gear 21 meshes with the small gear 20. The rotating shaft 22 of the large gear 21 is provided with a threaded portion 22a, and this threaded portion 22
a is screwed into the slider 24 of the operating section 23 connected to the operating arm 10. In this way, the rotational force of the electric servo motor 3 is transmitted to the rotating shaft 22 via the small gear 20 and the large gear 21, and is converted into linear motion by the slider 24 to adjust the vertical position of the operating arm 10. ing. Here, the small gear 20 and the large gear 21 act to amplify the rotational force of the electric servo motor 3. The gear ratio of the small gear 20 and the large gear 21 determines the water spout opening/closing operation speed and operating force. . The maximum operating speed is determined by the allowable speed increase when the load suddenly decreases and the water pressure increase in the penstock due to closure. This operating speed affects the control response of the speed governor, but in order to effectively utilize the rotational force of the small-capacity servo motor 3 and obtain a large operating force, the gear ratio must be increased to a certain extent. Therefore, increasing the gear ratio will have the contradictory effect of slowing down the operating speed.

Therefore, in the embodiment of the present invention, the required high speed closing is performed by a closing means other than the electric servo motor 3 (i.e., a weight), so the electric servo motor 3 is used for comparison other than that (rapid closing). 0. For example, even if the operating force is doubled, the sudden closing time will be 2.
If the operating time of the electric servo is 5 seconds, if the operation time of the electric servo can be reduced to 30 seconds, the motor capacity will be 1/6, assuming that the transmission efficiency remains the same, and if the motor has the same capacity, it will be possible to obtain six times the operating force.

Returning again to FIG. 1, reference numeral 25 designates a hydraulic cylinder for adjusting the closing speed. This hydraulic cylinder 25 has a variable throttle part 26, and by adjusting the variable throttle part 26, it is possible to set the closing speed to a safe value. A stopper 28 is provided at the bottom of the piston 27, and contacts the bottom surface of the cylinder 25 when the water port is in the fully closed position, and is in contact with the base 13 when the electric servo motor 3 is in the fully closed position (the position where the operating rod 23 is retracted). A slight gap is provided between the closing lever 14 and the protrusion 15 so that the quick closing lever 14 can smoothly return to its original position.

Further, a water mouth opening detector 30 is attached to the operating arm 10 via two wires, and its detection signal F is fed back to the regulator 1. In other words, this detection signal is equivalent to the position signal of the electric servo motor 3.

Next, the operation will be explained with reference to FIGS. 2 and 3.

First, in the state before startup (FIG. 3A), the electric servo motor 1 retracts the operating rod 23 to the minimum and draws the operating arm 8 to the fully closed position. At this time, the sudden closing lever 14
is pushed by the spring 18, so it stands upright, and the base 13 is locked onto the protrusion 15. Further, the stopper 28 of the hydraulic cylinder 25 is in contact with the inner bottom of the cylinder 25. limit switch 1
9 is OFF (open).

Next, at startup (FIG. 3B), when the speed regulator 1 is given a speed setting signal C as a control command, the speed regulator outputs a control signal S corresponding to the speed setting signal C, and the driver 2 is applied to the electric servo motor 3 via.

Thereby, the electric servo motor 3 rotates so that the water mouth opening degree follows the speed setting signal C. This rotational force is transmitted to the operating rod 23 via the small gear 20 and the large gear 21. At this time, by appropriately selecting the gear ratio of the small tooth I20 and the large gear 21, it becomes possible to generate a large operating force even with the small capacity electric servo motor 3. The operating rod 23 pushes up the operating arm 10 by a predetermined stroke and rotates the operating arm 8. As a result, a predetermined amount of water is supplied to the water wheel 4, and the water wheel 4 is started.

When the water turbine 4 reaches a given set speed C, the generator 6 is connected in parallel to the system load by the water turbine 4 (Fig. 3C), and the speed regulator 1 controls the electric servo motor 3 and the operating arm to match the load. 10, the link 9, and the operating arm 8. This speed regulating operation under normal conditions is performed via the electric servo motor 3 due to loose feedback from the speed regulator 1 to the rotational speed detector 7.

Next, when the load suddenly decreases, the rotational speed of the generator 6 suddenly increases (Fig. 3D). In order to suppress this, the sudden closing signal S2
is input to the solenoid 16 and speed regulator 1. Then, the solenoid 6 resists the biasing force of the spring 18 and pulls the quick closing lever 14. Note that this sudden closing signal S2 is either severely disconnected by the relay R depending on the water outlet opening of the water turbine, or the level at which the signal can pass is changed, so that it becomes insensitive to speed fluctuations near the no-load opening. At this time, limit switch 111 closes and m electric device R2 is energized, so speed regulator 1
The contact point 31 provided between the driver 2 and the driver 2 switches, a closing signal S1 is input to the driver 2, and the electric servo motor 3 attempts to operate so that the operating arm 10 is lowered. However, when the quick closing lever 14 is pulled, the protrusion 15 disengages the base 13, and the operating force from the electric servo motor 3 is cut off. At this time, the operating arm 10 rapidly rotates downward together with the speed regulating operation section 12 due to the weight of the weight 11 instead of the operating force from the electric servo motor 3 . This rotation acts to quickly close the water spout operating arm 8.

The rotation speed of the operating arm 10 by the weight 11 is faster than the closing speed by the electric servo motor 3 of the regulating operation part 12, and therefore the operating force contributing to closing the water outlet is mainly caused by the weight 1.
This is due to the weight of 1.

Comparing this state in terms of water mouth opening, as shown in FIG. It can be seen that this is faster than the dashed line). Note that the rotational speed (sudden closing speed) of the operating arm 10 at this time can be adjusted by adjusting the variable throttle 26 of the hydraulic cylinder 25.

In this way, the operating force of the electric servo motor 3 is disconnected, and the operating arm 10 is first moved by the action of the weight 11.
rotates downward, and at the same time, the base 13 connected to the operating arm 10 drops to near the floor. However, at this time, the electric servo motor 3 is still acting so that the operating section 23 descends, so the speed regulating operating section 12 moves upward by pulling itself up. The base 13 is located at a position where there is a slight gap above the protrusion 15 of the quick-closing lever 14 (corresponding to the fully open position of the regulating operation section 12).

) and waits in that position. As described above, this slight gap is secured by the stopper 28 of the hydraulic cylinder 25.

When the opening degree of the water mouth decreases to the opening degree ratio value X1 or less (3rd
Figure E), relay R (Figure 2) returns and solenoid 16
Demagnetize. As a result, the quick closing lever 14 is pushed back by the biasing force of the spring 18. When the electric servo motor is fully closed, the protrusion 15 enters the lower side of the base 13. With this position fixed, the limit switch 19 de-energizes the relay R2 and switches the contact 31 to the normal control signal S side. As a result, the electric servo motor 3 comes under the control of the speed regulator 1 again and returns to the state before the parallel connection (FIG. 3A). Thereafter, similar operations are repeated.

In addition, in FIG. 2, S2 indicates a closing signal given to the solenoid 16 via the relay R when the speed increases. 32 is an amplifier for the closure signal S2. In addition to this, the closing signal includes acceleration, speed regulator closing signal,
These include the amount and speed of reduction in power or current transmitted by the generator. Further, X is a speed increase setting value that determines the upper limit of the speed increase. Further, S3 indicates a sudden stop signal given to the speed regulator 1 and the solenoid 16 in order to suddenly close due to failure of the electric servo motor or other sudden stop conditions.

To summarize the above, normal speed regulating operation can be controlled by the small capacity electric servo motor 3, sudden closing operation in the event of an accident etc. can be performed with the help of a weight, and, When closing suddenly, the weight 11 and electric servo motor 3
both of them work.

Looking at the closing operation that affects the safety of a power plant, the weight 1
Since the quick closing device using No. 1 has a simple structure, it has few failures and can be closed using reliable energy such as gravity or hydraulic power. Moreover, the electric servo motor 3 and the weight 11 make it 21f.
Reliability can be improved.

Furthermore, hydroelectric power plants are equipped with storage battery power sources for control purposes, and electric servo motors often use this DC power in order to cope with load shedding power outages.
Electric motors had to be specially designed to match the voltage of this power supply, and as the motor capacity increased, it was necessary to expand the power supply equipment, leading to increased costs.
A small-capacity electric servo motor is sufficient, and in power plants where the load is disconnected or disconnected or is shut down until the power outage is restored, only the sudden closing solenoid 16 needs to be operated with direct current, so the power supply equipment can be small and equipment costs can be reduced. .

〔Effect of the invention〕

As described above, according to the present invention, - During rapid closing, the spout operation arm is driven by the rA casting force applying means provided separately from the electric servo motor, so the load on the electric servo motor itself is reduced. It is possible to obtain the necessary water mouth operating force with acceptable control response during normal speed regulating operation, and as a result, it is possible to control a large-capacity water turbine with a small-capacity electric servo motor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of a water turbine control device according to the present invention, FIG. 2 is a control block diagram of the water turbine control device according to the present invention, and FIG. 3 is a time chart showing its control operation. FIG. 4 is a flilJll+ block diagram of a conventional water turbine control device, and FIG. 5 is an enlarged sectional view of a main part showing details of a speed regulating operation section using an electric servo motor generally used in a water turbine control device. DESCRIPTION OF SYMBOLS 1... Speed regulator, 3... Electric servo motor, 4... Water turbine, 6... Generator, 7... Speed detector, 10... Operation arm, 11... Weight, 12・
...Speed governor operation section, 13...Base, 14...Lever for quick closing, 15...Protrusion, 20...Small gear, 21.
... Large gear, 22 ... Rotating shaft, 22a ... Threaded part,
23...Operation unit, S...Governing control signal, Sl...
Sudden close signal, S3...Sudden stop signal, C...Speed setting signal, N...Speed feedback signal. Applicant's agent Yasushi Ishikawa Figure 5

Claims (1)

[Scope of Claims] An electric servo motor that is connected to a water inlet opening/closing mechanism of a water turbine and controls the speed according to a detected speed value of the water turbine, a cutoff section that disconnects the driving force of the electric servo motor, and a water inlet closing speed. A control device for a water turbine, comprising a restriction device and configured to close the water port by a closing force applied to the water port opening/closing mechanism during a disconnection operation by the blocking portion, wherein the blocking portion is operated by a detection signal of an increase in speed of the water turbine. A control device for a water turbine, characterized in that: