JPH03260376A - Governor control device of double type water turbine - Google Patents

Abstract

PURPOSE:To reduce a load fluctuation by supplying a proper guide vane opening target value always to each water turbine in mode select operation, in a governing control device of a double type water turbine in which a single set of generator is driven by two sets of water turbines. CONSTITUTION:Adjusting systems 25A, 25B for adjusting a guide vane opening are provided in respective two-set of water turbines. A total output command of a power plant is input to an arithmetic means 26 with a control signal (a) from a control signal generating means 27 as a guide vane opening command (x) to each water turbine. The control signal generating means 27 outputs 1, at single operation mode time of the first water turbine, 0 at single operation mode time of the second water turbine, and 1/2, at double operation mode time of the water turbines, respectively as the control signal (a). A guide vane opening target value of the first water turbine is calculated by multiplying the opening command (x) and the control signal (a) in the arithmetic means 26, and a guide vane opening target value of the second water turbine is calculated in an addition means 28 from this target value of the first water turbine and the opening command (x).

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention provides a system for controlling the speed of a water wheel in order to perform optimal mode switching operation for a hydroelectric power plant using a water wheel. Regarding a control device.

(Prior Art) In a hydroelectric power plant equipped with two water turbines in which one generator is driven by two water turbines, the operation mode may be switched from a single wheel to a dual wheel, for example. In this case, the water turbine in operation is controlled to be closed from around the fully open position, and the stopped water turbine is operated in the open direction from fully closed.

FIG. 3 shows an example of this type of speed governor control device. Two water turbines 11A, generator 1 directly connected to IIB
The speed of No. 2 is detected by the speed detector 13 and input to the speed governor 14. Further, the guide vane opening from the opening detector 15 is also input to the II speed gear 14, and the speed governor 14 adjusts the speed and output of the generator 12 based on these.

That is, the set speed given to the speed governor 14 and the speed detector 1
3, a valve opening command is created from the difference, and the valve opening command is compared with the valve opening signal obtained from the opening detector 15. The deviation signal is used as an operation signal and converted into a hydraulic signal by the electro-hydraulic converter 17, and then in addition to the pressure distribution valve 18A, the servo motor 16A is driven, and the guide vanes of the A water turbine 11A are controlled so that the generator speed becomes equal to the set speed. Adjust the opening.

On the other hand, when the B water turbine 11B is in a stopped state, the limit lever 1
9 is held at the lower limit position where the guide vane of the 8-water turbine 11B is brought into an engaged and closed state. Therefore, in this state, the movement of the servo motor 16A is limited to this limit lever 19.
, and is not transmitted to the pressure regulating valve 18B. Therefore, in order to put the B water turbine 11B into operation, the motor 23 is driven to move the gear 24, and the limit lever 19 is moved upward from the lower limit position. For example, from a state in which water turbine A 11A single wheel is operating at an opening of 100 $, water turbines 11A and I
When operating the IB on both wheels, the motor 23 is driven to gradually move the limit lever 19 upward. At this time, the servo motor 16A moves the water turbine 11A to a position where the opening degree is 100z, so that the cams 20, 21. shaft 2
2 is also biased to the corresponding position. Therefore, when the limit lever 19 is moved upward, the pressure distribution valve 18B also moves in accordance with the movement, and the servo motor 16B starts operating.

As a result, the guide vane of the water turbine 11B opens, and the water turbine 11B enters the operating state. At this time, in order to eliminate output (load) fluctuations, it is necessary to drive the servo motor 16A in the opening direction and close the guide vanes of the water turbine 11A to 50% opening. A guide vane close command is added.

(Problem to be Solved by the Invention) However, when the above-mentioned hook is used as a speed governor control device for a water turbine, the operating speed of the limit lever 19 is mechanically i! There is a problem in that the operating speed of the servo motor 16A is slower than the operating speed of the servo motor 16A, and as a result, load fluctuations increase during mode switching operation. For example, when changing the mode from single wheel to dual wheel mode, the difference in the closing speed of the servo motor 16A for the A water turbine and the opening speed of the servo motor 16B for the B water turbine causes large fluctuations in output (load) as shown in Figure 4. The situation is as follows. That is, if mode switching from single wheel to dual wheel mode is started at time t, the servo motor 16A closes the guide vane opening to 50% at time t2, but the servo motor 16B closes the guide vane opening to 50% only at time t. The guide vane opening degree is $. This caused load fluctuations. Also,
There is also the problem that the mechanical link structure of the cams 20, 21, shaft 22, etc. is prone to wear and promotes load fluctuations. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a speed governor control device for a water turbine that can suppress excessive load fluctuations during mode switching operation to as small as possible and perform smooth mode switching operation. [Structure of the Invention] (Means for Solving the Problems) The present invention provides two water turbines each with an adjustment system that adjusts the guide vane opening so that it compares with its target value.
When one water turbine is in single-wheel operation mode, 1 is output, when the other water turbine is in single-wheel operation mode, O is output, and when in dual-wheel operation mode, 1/2 is output as a control signal, and the operation mode is switched. In this case, a control signal generating means is provided that outputs a control signal that changes in a ramp shape from the control signal in the operation mode to the control signal in the target operation mode, and one-way output is performed based on the control signal and the total output command of the hydroelectric power plant. A calculation means is provided to calculate the guide vane opening target value of one of the water turbines and output it to the adjustment system of one of the water turbines, and the guide vane opening of the other water turbine is calculated based on the total output command and the guide vane opening target value of one water turbine. The present invention is characterized in that it is provided with an addition means for calculating a water target value and outputting it to the adjustment system of the other water turbine.

(Function) When there is a mode switching command from single wheel driving mode to dual wheel driving mode, the control signal from the control signal generating means changes from 1 to 1.
A control signal that changes in a ramp-like manner up to 72 is output. From this control signal and the power plant's total output command, the calculation means calculates the guide vane opening target value for one of the water turbines, and the guide vane opening target value for the other water turbine is calculated from the guide vane opening target value for the other water turbine. It is calculated from the total output command of the power plant.

Therefore, the output of the other water turbine increases by the amount that the output of the other water turbine decreases, so an appropriate guide vane opening target value is calculated, and load fluctuations, that is, fluctuations in the output of the power plant, can be suppressed as much as possible. .

(Embodiment) FIG. 1 shows an embodiment of a speed regulating control device for a water turbine according to the present invention. In addition, in FIG. 1, the same elements as in FIG. The case of mode is shown. The A water turbine 11A and the B water turbine 11B each have a guide vane opening GVa.
, GVb is its target value GVRa.

Regulatory system 25A that regulates in accordance with GVRb,
25B are provided respectively.

The total output command of the power plant is for Mu water turbine 11A and B water turbine 1.
Calculating means 2 as guide vane opening command X for 1B
6 is input. On the other hand, the control signal a from the control signal generating means 27 is inputted to the calculating means 26 . The control signal generating means 27 outputs l when the A water turbine 11A is in the single wheel operation mode, O when the B water turbine is in the single wheel operation mode, and 1/2 when the B water turbine is in the dual wheel operation mode as the control signal a. It is something to do. In addition, in the figure, it is shown as a percentage.

Further, when switching the driving mode, a control signal a that changes in a ramp-like manner from the control signal in the current driving mode to the control signal in the target driving mode is output. For example, when switching from single wheel operation mode to dual wheel operation mode of A water turbine 11A, a predetermined rate of change (linear characteristic) from 1 to 172 is applied.
outputs a control signal a that changes at That is, the control signal a is a signal indicating the proportion of the total output command to be borne by the A water turbine 11A.

The calculation means 26 multiplies the guide vane opening command X and the control signal a to obtain the guide vane opening target value GV of the A water turbine 11A.
Calculate Ra. From the guide vane opening degree target value GVRa of the A water turbine 11A and the guide vane opening degree command
Calculate Rb.

Guide vane opening target value GV calculated in this way
Ra and GVRb are regulatory systems 25A and 25BL, respectively.
: Input, and the A water turbine 11A and the B water turbine 11B are controlled respectively. That is, the guide vane opening target value GVRa of the A water turbine 11A is input to the adding means 29A, where a deviation signal ΔGVa from the guide vane opening GVa from the opening detector 15A is calculated. This deviation signal ΔGVa drives the servo motor 16A via the electric/hydraulic converter 17A and the pressure distribution valve 18A. On the other hand, in the case of the B water turbine 11B, similarly, the guide vane opening degree target value GVRb of this B water turbine 11B and the B water turbine 11 detected by the opening degree detector 15B.
The guide vane GVb of B is input to the addition means 29B, and based on the opening degree deviation signal ΔGVb obtained here, the electric/hydraulic converter 17B for the 5B water turbine and the pressure distribution valve 18 for the B water turbine are input.
It is configured to control the B water turbine servo motor 16b via B.

It is now assumed that the A water turbine 11A is being operated on a single wheel at that rating. In this case, the guide vane opening target value GVRa of the A water turbine 11A is 100% (rated), but the total output command of the power plant is 50%. This is A waterwheel 11A
This is because the total output command is 100% when both the and B water turbines 11B are operated at their rated operation, and the B water turbine 11B is currently stopped. To change the mode from this state to two-wheel operation, proceed as follows.

In the single-wheel operating mode of the A water turbine 11A, the control signal generating means 27 outputs l as the control signal a, and the total output command of the power plant is 50%. The guide vane opening command X in this case is output as 100%.

Therefore, the guide vane opening degree target value GVRa of A water turbine 1] and A from the calculation means 26 is 100%. When the two-wheel drive mode is selected in this state, the control signal generating means 27 outputs a control signal a determined below.

When 0≦t≦T1, a”1−Kt (1) When t≧11, a=1/2 Here, K is a constant, and To is the time until the control signal a reaches 172. Therefore, the control signal aHani/T.

It will change from 1 to 172 at a rate of change of .

That is, since the total output command remains at 50% and the control signal a changes from 1 to 1/2, the A water turbine 11A
The guide vane opening target value GVRa is from $100 to $50.
Changes to $. On the other hand, the guide vane opening degree GVRb of the B water turbine 11B is obtained by subtracting the guide vane opening degree target value GVRa from the guide vane opening degree command X by the addition means 28, so it changes from Ol to 50 degrees.

Fig. 2 is its characteristic diagram. If the two-wheel operation mode is selected at time t1, the guide vane opening GVa of the A turbine 11A changes from 100z to 50% at a predetermined rate of change as shown by the solid line. It changes with In this case, B water turbine 11B
The guide vane opening GVb is also at the same predetermined rate of change /T.
i changes from part to 50%. When the opening degrees GVa and GVb of both guide vanes reach 50% at time t2, the vehicle enters the two-wheel operation mode. In this state, the total output command remains at 50%, so both the A water turbine 11A and the B water turbine 11B share the output (load) of 25z.

Then, at time t, the total output command is changed from $50 to $10.
When an increase command to increase to 01 is issued, both water turbines 11
The guide vane openings of the A and B water turbines 11B are controlled to each bear 25% to 50% of the output.

In this manner, in the present invention, the guide vane opening characteristics of the A water turbine 11A and the B water turbine 11B are changed at the same predetermined rate of change, so that load fluctuations can be suppressed to a small level when switching operation modes. Note that the characteristics indicated by dotted lines in the figure are conventional characteristic curves.

In addition, in a water turbine in which the power generation efficiency changes largely with respect to the guide vane opening, load fluctuations can be suppressed by adding a power generation efficiency curve generator upstream of the control signal generating means.

[Effects of the Invention] As described above, according to the present invention, by supplying an appropriate guide vane opening target value to each water turbine during mode switching operation, load fluctuations are reduced and smooth mode switching operation is achieved. can be distant relatives.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a characteristic diagram of the present invention, FIG. 3 is a block diagram of a conventional example, and FIG. 4 is a conventional characteristic diagram. 11-water turbine, 12-generator, 13-speed detector, 14-
Speed governor, 15-opening detector, 16-servo motor, 17
- Electric/hydraulic converter, 18 - Pressure distribution valve, 19 - Limit lever, 20° 21 - Cam, 22 - Shaft, 23 - Motor, 24 - Gear, 25 - Adjustment system, 26 - Computing means, 27 -
control signal generation means, 28.29-addition means;

Claims (1)

[Claims] In a speed governing control device for a double-hung water turbine in which one generator is driven by two water turbines, an adjustment system that adjusts the opening degree of each guide vane of the two water turbines to match its target value;
1 when one water turbine is in single wheel operation mode 0 when the other water turbine is in single wheel operation mode 1 when in dual wheel operation mode
/2 as a control signal, and at the time of operation mode switching, outputs a control signal that changes in a ramp shape from the control signal in the operation mode to the control signal in the target operation mode, and the control signal and a calculation means for calculating a guide vane opening target value of the one water turbine based on the total output command of the hydroelectric power plant and outputting it to the adjustment system of the one water turbine, and the total output command and the one water turbine. and an addition means for calculating a guide vane opening degree target value of the other water turbine based on the guide vane opening degree target value of the other water turbine and outputting it to the adjustment system of the other water turbine. Control device.