JPS62121871A - Method and device for controlling movable vane water turbine - Google Patents

Abstract

PURPOSE:To prevent the unbalance of flow regulation caused by delay in movement of a movable vane when operating singly and prevent variation in frequency of a generator by fixing a movable vane according to a movable vane fixing command and carrying out flow regulation merely with a guide vane. CONSTITUTION:When a movable-vane water turbine is rendered an operating condition, such as, feeding power singly and the like causing variation on frequency to become large, an (a) contact 17 for a movable-vane fixing command is closed, to effect a waiting condition for a movable vane fixing control. In this condition, if a deviation between an output opening signal 9 form a movable-vane opening setting device and an opening signal 10 from a movable- vane hydraulic servomotor becomes below an error range, a relay 18 is operated through the operation of a timer 14 after a certain time, to cut off an ordinary movable-vane control signal 20, and fix a movable vane. While the movable vane is fixed, if the opening of a guide vane is changed due to variation in load getting out of said error range, the fixation of the movable vane is removed by the action of a timer 15 which is actuated by the (b) contact of the timer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for controlling a movable blade water turbine such as a Kabran water turbine, a tubular water turbine, and a diagonal flow water turbine.

[Background of the invention]

A movable vane water turbine has a movable vane in addition to the guide vane as a means for adjusting the flow rate of the hydraulic machine, and is controlled so that the guide vane and the movable vane are operated in conjunction with a certain characteristic.

Figure 3 is a block diagram of a conventional movable blade water turbine control device.
1 is a movable blade, and 2 is a movable blade opening setting device, which takes in the guide vane opening signal (GV) 3 and the current static head signal (Hst) 4 and calculates the preset guide vane opening, static head, and movable blade opening. Every time(
RV) Outputs the setting of the current movable blade opening according to the characteristics. Reference numeral 5 indicates a hydraulic servo motor for the movable blade, and 6 indicates a pressure distribution valve drive circuit for operating the pressure distribution valve 7 for the hydraulic servo motor 5 for the movable blade in response to a signal from the movable blade opening setting device 2.
The guide vane and the movable vane 1 are controlled in conjunction with each other by a movable vane opening setting device 2.

However, in such movable blade turbines, in situations where the frequency fluctuations are large, such as when power is being transmitted individually, the guide vanes operate too sensitively, making it impossible for the movable blades to follow the same characteristics. The difference between the two amplifies the frequency fluctuations, causing vibrations and noise in the hydraulic machinery, making it impossible to operate.

In addition, Japanese Patent Laid-Open No. 56-148685 discloses a movable blade water turbine which fully opens the movable blades and safely stops the main engine when the guide vanes become unable to close.

[Purpose of the invention]

The present invention aims to eliminate the problems of the prior art as described above, and to provide a control method and device for a movable blade water turbine that can minimize excessive frequency fluctuations that occur when performing independent power transmission, etc. This is the purpose.

[Summary of the invention]

In the control method for a movable vane water turbine of the present invention, the hydraulic machine has movable vanes in addition to guide vanes, and at least a static head between the guide vanes and the movable vanes is maintained at a constant level. In a control method for a movable blade hydraulic turbine that adjusts the flow rate by interlocking operations based on characteristics, when there is a command to fix the movable blades, first, a certain characteristic between the guide vanes and the movable blades is applied. The interlocking operation is continued within a range having a predetermined error for the certain characteristic, and when a certain period of time has elapsed, the interlocking of the guide vane and the movable vane, or the static head between the guide vane, the movable vane, and the static head. The first feature is to fix the movable wing by cutting off the interlock with the movable wing, and fix the fixed wing as described above,
After the fixed blade is fixed, the relationship between the guide blade and the movable blade or the relationship between the guide blade, the movable blade, and the static head falls outside a range having a predetermined error with respect to the certain characteristic for a certain period of time. When the time has passed, release the fixation of the movable wing,
A second step includes restarting the interlocking between the guide vane and the movable blade or the interlocking between the guide vane, the movable blade, and the static head.
The control device for a movable vane water turbine of the present invention is characterized in that the hydraulic machine has a movable vane in addition to the guide vane, and of the static head between the guide vane and the movable vane, at least the guide vane and the movable vane are In a control device for a movable vane hydraulic turbine that adjusts the flow rate by interlocking the blades with certain characteristics, the opening degree of the guide vane, or the opening degree of the guide vane and the static head difference are detected, and the movable blade opening to be controlled is determined. a movable blade opening setting device for setting the opening degree, and a pressure distribution valve drive circuit that operates in response to a setting signal from the movable blade opening setting device;
A movable blade servo motor operated by a pressure distribution valve driven by the pressure distribution valve drive circuit detects an error from the certain characteristics and is controlled within a preset error range, or when the error range is exceeded. If the error detection circuit is equipped with a contact that operates when the error detection circuit is controlled, and the time that the contact output of the error detection circuit continues, and the duration exceeds a preset duration, or a timer circuit provided with a contact that outputs when the movable blade is in the movable state; and a timer circuit that is provided with a contact that outputs when the movable It is characterized by having a movable blade fixing circuit that fixes the blade or releases the fixation of the movable blade and resumes interlocking.

That is, the present invention fixes the movable blades of a movable blade water turbine when the frequency of the output of the turbine generator fluctuates, such as during independent power transmission, to suppress frequency fluctuations and vibrations and noise generated by the frequency fluctuations. The purpose of this invention is to provide a control method and device for a movable blade water turbine that enables a stable power supply, and was developed based on the results of the following considerations.

For example, in order to always achieve high efficiency operation of the guide vanes and movable vanes of a movable vane water turbine, the opening degree of the movable vane that achieves the highest efficiency is determined for the opening degree of each guide vane, and the two are linked to control the flow rate. ing. Considering the operating speed of the guide vanes and movable vanes, the closing speed of the guide vanes is such that when the movable vane turbine is suddenly closed when the load is cut off, etc., the water pressure rise in the penstock is kept as low as possible, and the rotating part The closing speed of the movable vane located downstream of the guide vane is set to a speed selected to suppress the increase in the maximum rotational speed of the guide vane to the minimum possible. In order to prevent water pressure build-up from being generated by the movable vanes, the closing speed is generally set to be slower than the closing speed of the guide vanes. There are no particular restrictions on the opening speed, but it is generally set slower than the closing speed in order to prevent sensitive opening operations and ensure stable operation.

In any case, the operating speed of the movable blades of a movable vane water turbine is generally set to be slower than the operating speed of the guide vanes.

In other words, even if the apertures of the guide vanes and movable vanes are given the above-mentioned characteristics that result in high efficiency and are controlled in conjunction with each other, if the apertures of the guide vanes change due to some disturbance, the apertures according to the above-mentioned characteristics will change. By the time the movable blade changes, an operating condition deviating from the above-mentioned characteristics occurs due to the difference in operating speed.

When such movable blade turbines are operated in single power transmission mode with large frequency fluctuations, the guide vanes operate sensitively due to the speed control signal from the speed governor to suppress frequency fluctuations.
The movable vanes cannot follow the movement of the guide vanes, making it impossible to properly adjust the flow rate. Therefore, even though the guide vanes are operated for the purpose of suppressing frequency fluctuations, the frequency fluctuations are often increased instead. Furthermore, there is a problem in that deviations from the characteristics of the guide vanes and the movable blades result in a loss of energy, which is not reflected in the output of the water turbine generator but appears as an increase in vibration and noise.

Such problems occur because the flow rate is adjusted by controlling two parts, the guide vanes and the movable blades, which are unique to movable vane water turbines. That is, the main cause is the deviation from the above-mentioned characteristics due to the difference in operating speed of the guide vane and the movable vane.

In order to solve this problem, the present invention fixes the movable vanes according to the movable vane fixing command (for example, under conditions of independent power transmission operation) and adjusts the flow rate only with the guide vanes. It is possible to achieve the desired purpose by preventing unbalance and controlling frequency fluctuations to be kept as small as possible.

[Embodiments of the invention]

Examples will be described below.

Figure 1 is a block diagram of a control device for a movable blade water turbine according to one embodiment, and Figure 2 is a circuit diagram of a fixed circuit for a movable blade.
The difference from the conventional movable blade water turbine control device shown in the figure is that an error detection circuit, a timer circuit, and a fixed circuit are added.

In these figures, the same parts as in FIG. An error detection circuit includes a comparator 11 that compares the magnitude of the deviation of 1o with a preset error range and outputs a contact when the former is larger than the latter; 12 is a contact output of the error detection circuit 8; The relay 13 is a timer circuit that counts the duration of time and outputs a contact when a preset duration is exceeded, and operates in response to the a contact output of the error detection circuit 8.
, a timer 14 that operates in response to the a contact output of the relay 13, and a timer 15 that operates in response to the b contact output of the timer 14. 16 is a fixed circuit that fixes or unfixes the movable blade according to the contact output of the timer circuit 12, and includes a relay 18 operated by the a contact 17 of the movable blade fixing command and the a contact of the timer 14 or the b contact of the timer 15; It consists of a signal generator 19 that always generates a neutral signal as a movable blade control signal, that is, a signal when the opening degree signal from the movable blade opening setting device 2 and the opening degree of the hydraulic servo motor 5 for the movable blade match. There is.

When the movable blade water turbine is in an operating state such as independent power transmission and the frequency fluctuation becomes large, the control circuit for fixing the movable blade can be operated by closing the a contact 17 of the movable blade fixing command.

The operation of this embodiment will be explained below. Usually, movable wing 1
is controlled by a closed loop of a pressure distribution valve drive circuit 6, a pressure distribution valve 7, and a hydraulic servo motor 5 for movable blades using the opening degree outputted from the movable blade opening degree setting device 2 as a target value. In this state, if there is a condition for fixing the movable blade such as independent power transmission, the a contact 17 of the movable blade fixing command is closed, and the movable blade fixing control becomes in a standby state.

Therefore, when the deviation between the output opening signal 9 from the movable blade opening setting device 2 and the opening signal 10 of the hydraulic servo motor 5 for the movable blade falls within the error range set in the comparator 11 in advance, the comparator 11
The a contact is closed and the relay 13 is operated.

When the relay 13 operates, the a contact of the relay 13 opens, which causes the timer 14 to operate, and after a certain period of time, the a contact of the timer 14 causes the closing relay 18 to operate. Furthermore, by closing the a contact of the relay 18, the normal movable blade control signal 20
Since the control signal 21 is a neutral signal outputted from the signal generator 19, the interlock between the guide vane and the movable wing is cut off, and the movable wing can be fixed. Here timer 1
4 is provided to prevent control within the above-mentioned temporary error range caused by the difference in operating speed between the guide vane and the movable vane. In other words, when the guide vanes with a fast operating speed repeatedly open and close overly, the movable vanes with a slow operating speed cannot follow the movement, and one happens to be within the error range described above when one moves in the opening direction and the other in the closing direction. This is to prevent the movable blades from becoming fixed in the event that this happens.

On the other hand, if the movable blades are fixed and the operation continues, and the load of the individual power transmission system fluctuates, the opening of the guide vanes changes and deviates from the above error range, causing vibration.

Since problems such as noise or breakage of the movable blade may occur in the same manner as described above, the movable blade is unfixed by the timer 15 operated by the b contact of the timer 14 and the interlocking control of the guide vane and the movable blade is resumed. It has become.

The error range set for the comparator 11 is determined based on the following 6. For example, when switching to an isolated power transmission system under full load operation, the load will naturally become extremely small, so the guide vane opening will suddenly change. Closed. If the movable blades are immediately fixed in this state, the flow rate adjustment of the hydraulic machine depends only on the opening degree adjustment of the guide vanes, so it is possible to suppress frequency fluctuations to a small level. However, the efficiency decreases due to the error from the fixed characteristics of the guide vane opening and movable blade opening, which are set to output at the highest efficiency, and the energy corresponding to this decreased efficiency causes the vibration of the hydraulic machine. It induces a g sound. Furthermore, the above-mentioned characteristics of the guide vane opening and the movable vane opening are such that the larger the guide vane opening, the larger the movable vane opening, so when switching from full load operation to independent power transmission, the movable vane In other words, since the guide vane opening is closed while the movable blade is fully open, it becomes a kind of closed operation state, which applies considerable stress to the movable blade and destroys the movable blade. There is a risk of it being stored away. For this reason, in the present invention, the error range set in the comparator 12 is an error from the above-mentioned characteristics of the guide vane opening and the movable blade opening in which such a problem does not occur.

In a movable vane water turbine having a control device as described above, (1) frequency fluctuations can be suppressed to a small level by fixing the movable vanes during independent power transmission of the movable vane water turbine.

(2) Vibration and noise generated when the movable blade in (1) is fixed.

Problems such as movable blade breakage can be automatically prevented.

In the above embodiment, a movable vane water turbine was described in which the flow rate is adjusted by interlocking the guide vanes, movable vanes, and static head with certain characteristics. In other cases, the same effect can be obtained.

The control method and control device for the movable blade water turbine of this embodiment are as follows:
Suppressing frequency fluctuations during independent power transmission operation using a movable blade hydroturbine,
vibration,! It is possible to simultaneously improve the performance of preventing III noise and damage to the movable blades, and to ensure stability, thereby making it possible to expand the ψ operation function of the movable blade water turbine.

〔Effect of the invention〕

The control method for a movable vane water turbine of the present invention makes it possible to provide a control method and device for a movable vane water turbine that can control excessive frequency fluctuations that occur when performing independent power transmission, etc., and has industrial effects. It is a big thing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the control device for a movable blade water turbine according to the present invention, and FIG. 2 is a circuit diagram of a fixed circuit for the movable blade.
FIG. 3 is a block diagram of a conventional control device for a movable blade water turbine. 1... Movable blade, 2... Movable blade opening setting device, 3...
Guide vane opening signal, 4...Current static head signal, 5...
Hydraulic servo motor for movable blades, 6... pressure distribution valve drive circuit,
7...Movable blade servo motor drive pressure distribution valve, 8...
Error detection circuit, 12... timer circuit, 16... fixed circuit. ,hmm. Agent: Patent attorney Hiroo Nagasaki, ・°−゛′), - (1 other person) -1

Claims (1)

[Scope of Claims] 1. The hydraulic machine has a movable blade in addition to the guide vane, and at least the guide vane and the movable vane are interlocked with a certain characteristic among the static head between the guide vane, the movable vane, and the static head. In a control method for a movable blade water turbine that adjusts the flow rate by operating the movable blade, when there is a command to fix the movable blade, first, the interlocking operation based on the constant characteristic is controlled by a predetermined error with respect to the constant characteristic. The movable blade is fixed by cutting off the interlock between the guide vane and the movable blade or the interlock between the guide vane, the movable blade, and the static head after a certain period of time has elapsed. A control method for a movable blade water turbine. 2. The hydraulic machine has a movable vane in addition to the guide vane, and the flow rate is adjusted by interlocking at least the guide vane and the movable vane with certain characteristics among the static head of the guide vane, the movable vane, and the static head. In a method for controlling a movable blade water turbine, when there is a command to fix the movable blade, first, the interlocking operation based on the certain characteristic is continued within a range having a predetermined error with respect to the certain characteristic. When a certain period of time has elapsed, the interlock between the guide vane and the movable vane or the interlock between the guide vane, the movable vane, and the static head is cut off, the movable vane is fixed, and the guide vane is fixed after the fixed vane is fixed. When the relationship between the blade and the movable blade or the relationship between the guide blade, the movable blade, and the static head falls outside the range with a predetermined error with respect to the certain characteristic, and a certain period of time has elapsed, the movable blade A control method for a movable vane water turbine, characterized in that the fixation of the guide vane and the movable vane is released, and the interlocking of the guide vane and the movable vane or the interlocking of the guide vane, the movable vane, and the static drop is restarted. 3. The hydraulic machine has a movable vane in addition to the guide vane, and among the static head between the guide vane and the movable vane, at least the guide vane and the movable vane are operated in conjunction with a certain characteristic to adjust the flow rate. A movable blade opening setting device that detects the opening degree of the guide vane, or the opening degree of the guide vane and the static head difference, and sets the movable blade opening degree to be controlled; A pressure distribution valve drive circuit that operates in response to a setting signal of a movable blade opening setting device, a movable blade servo motor operated by the pressure distribution valve driven by the pressure distribution valve drive circuit, and an error from the above-mentioned constant characteristics is detected. an error detection circuit provided with a contact that operates when controlled within a preset error range or when controlled beyond the error range;
A timer circuit provided with a contact that measures the duration of the contact output of the error detection circuit and outputs the output when the duration exceeds a preset duration or is within the duration, and the timer circuit. A contact output causes the movable blade to break the interlock between the guide vane and the movable vane, or the guide vane, the movable vane, and the static head to fix the movable vane, or to release the fixation of the movable vane and restart the interlock. 1. A control device for a movable blade water turbine, comprising a blade fixing circuit.