JPH026319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in water turbine control devices in hydroelectric power plants.

FIG. 1 shows the general configuration of a waterway system in a hydroelectric power plant. In the figure, water upstream of the power plant flows into the upper pond 1 through a water conduit (not shown), and from this flows through the penstock 2 to the generator 5.
The water is introduced into the water turbine 3 which is driven by the water turbine 3 via the guide vane 4, and further guided from there to the lower pond 7 through the discharge channel 6. In addition, in the figure, Q _A is the water turbine flow rate, H ₁ is the water level of the upper pond 1, H ₂ is the water level of the lower pond 7, and H _ST is the water level of the upper pond 1.
and the water level of lower pond 7 (static head difference), that is,
It is expressed as H _ST = H ₁ − _{H 2} . In a hydroelectric power plant having such a configuration, the following water turbine control device is used to adjust the flow rate of the water turbine.

FIG. 2 is a block diagram showing the configuration of such a conventional water turbine control device. In the figure,
A1 is the difference (H ₁ − _{H 2} ) between the water level H ₁ of the upper pond 1 and the water level H ₂ of the lower pond 7, that is, the static head applied to the water turbine 3.
The adder F1 that calculates H _ST is a function generator that calculates the guide vane opening command value G _R of the water turbine 3 based on the output H _ST of this adder A1 and the water turbine flow rate command value Q _R. . F2 is a function generator L1 that calculates the guide vane opening upper limit value G _MAX based on the output H _ST of the adder A1 and the upper limit output allowed by the generator 5.
inputs the outputs G _R and G _MAX of each function generator F1 and F2, and the output is the upper limit value of the guide vane opening.
This is a limiter that limits the guide vane opening command value G _R so that it does not exceed G _MAX , and its output is sent as the final guide vane opening command value. A2
is an adder that calculates the deviation (-G _A ) between the final guide vane opening command value, which is the output of limiter L1, and the actual guide vane opening value G _A finally obtained by this device. _e to the guide vane drive circuit T, and further operates the guide vane drive mechanism based on the output G _eX to control the opening degree of the guide vane 4 of the water turbine 3, thereby controlling the water turbine flow rate Q _A. ing.

In this configuration, each water level of upper pond 1 and lower pond 7
The static head difference H _ST is calculated from H ₁ and H ₂ by adder A1,
is added to function generator F1. Then, in this function generator F1, a guide vane opening degree command value G _R is calculated based on the static head difference H _ST at this time and the water turbine flow rate command value Q _R , and is applied to the limiter L1.
Also, the output H _ST of adder A1 is output from another function generator F
Based on the upper limit output allowed by the generator 5, the guide vane opening upper limit value G _MAX is calculated and added to the limiter L1. As a result, the limiter L1 limits the guide vane opening command G _R so that its output does not exceed the guide vane opening upper limit value G _MAX ,
This is added to adder A2 as the final guide vane opening command value G.

On the other hand, the current guide vane opening value, that is, the actual guide vane opening value G _A is added to the adder A2, and thereby the deviation Ge (=-G _A ) from the final guide vane command value is calculated. is calculated. Finally, the output Ge of this adder A2 is added to the guide vane drive circuit T, and by operating the guide vane drive mechanism based on the output Gex, the opening degree of the guide vane 4 is controlled to control the water turbine flow rate. Q _A is controlled according to its command value Q _R. Specifically, for example, the water turbine flow rate command value
When the static head H _ST increases with Q _R constant, the guide vane opening command value G _R is decreased based on the characteristics of the function generator F1, and the guide vane opening upper limit value is decreased based on the characteristics of the function generator F2. Also reduce G _MAX . As a result, the final guide vane opening command value becomes smaller, and the guide vane 4 is controlled to be narrowed.

By the way, in such a water turbine control device,
The characteristics of each of the function generators F1 and F2 are as follows:
This is determined in advance based on the characteristics of the generator 5. First of all, the error of the function generator F1 is only a controllability problem in which the target flow rate command value Q _R and the actual water turbine flow rate Q _A do not match. However, the error of the function generator F2 not only causes problems in controllability, but also has the risk of causing the outputs of the water turbine 3 and the generator 5 to exceed the allowable upper limit values. In other words, the output of the generator 5 may exceed the upper limit due to factors such as an error in setting the characteristics of the function generator F2 or aging of the water turbine 3.
As a result, there is a drawback that not only the generator but also other electrical equipment in the plant such as the transformer may be damaged, making it impossible to operate the plant stably.

The present invention solves the above-mentioned drawbacks,
Even if the flow rate characteristics and output characteristics of the water turbine change, the generator output can be kept below the upper limit value, ensuring smooth operation without damaging the generator or other electrical equipment in the station. The purpose is to provide a high-quality water turbine control device.

In order to achieve the above object, the present invention provides a water turbine control device that adjusts the flow rate of a water turbine generator installed in a hydroelectric power plant to the water turbine. a flow rate deviation calculation means for calculating and outputting a deviation between the hydraulic turbine generator and the hydraulic turbine generator; When the actual output value of the generator is smaller than the upper limit output setting value, the deviation output of the flow deviation calculation means is calculated, and when the actual output value of the water turbine generator is larger than the upper limit output setting value, the output deviation calculation is performed. The control output selection means selectively outputs the deviation output of the means as a control output of the water turbine flow rate.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows a block diagram of the configuration of the water turbine control device. In the figure, A3 is the difference (H ₁ - H ₂ ) between the water level H ₁ of the upper reservoir 1 and the water level H ₂ of the lower reservoir 7, that is, the static head H _ST applied to the water turbine 3.
F3 is the output of this adder A3.
This is a function generator that calculates the final guide vane adder command value' for the water turbine 3 based on _HST and the water turbine flow rate command value _QR . A4 calculates the deviation ('-G _A ') between the final guide vane opening command value ', which is the output of the function generator F3, and the actual guide vane opening value G' _A finally obtained by this device. The output Ge' of the adder is applied to the low value priority circuit LVG as a signal GeH via a coefficient multiplier _K1 having a coefficient (gain) _k1 . A5 is the actual guide vane opening value G _A ′
is the generator actual output value W _A obtained through the water turbine characteristic element α and the generator characteristic element β (Hereinafter, a value equivalent to the generator actual output will be described as the generator actual output value W _A )
and the preset generator output upper limit set value W _MAX
An adder that calculates the deviation (W _MAX − W _A ) _from
is added as a signal WeH to the low value priority circuit LVG as a comparison element. This low value priority circuit LVG compares the above output signals GeH and WeH including the polarity, selects the smaller one, and sends it out as a signal E. The output E is given to the guide vane drive circuit T'. , and further its output
The guide vane drive mechanism Z' is operated by Gex' to control the opening degree of the guide vane 4 of the water turbine 3, thereby controlling the water turbine flow rate Q _A. In addition,
In the above, the turbine characteristic element α is an element that converts the actual guide vane opening G _A ′ to the actual turbine flow rate Q _R ′ based on the turbine characteristics, and the generator characteristic element β is an element that converts the actual turbine flow rate Q R ′ based on the generator characteristics. _A ′ is the actual generator output W _A
This is an element that converts to . Here, adders A3, A
4, a function generator F3, and a coefficient unit K1, and an adder A5 and a coefficient unit K1.
2 constitutes an output deviation calculation means, and the low value priority circuit LVG constitutes a control output selection means, respectively.

Next, the operation of the water turbine control device having such a configuration will be described with reference to FIG. 4. The static head difference H _ST is calculated from the water level signal H ₁ of the upper pond 1 and the water level signal H ₂ of the lower pond 7 by the adder A3.
is calculated and added to the function generator F3. Then, in this function generator F3, a final guide vane opening degree command value' is calculated based on the static head difference _HST at this time and the water turbine flow rate command value _QR , and is added to the adder A4. Further, the current guide vane opening value, that is, the actual guide vane opening value G _A ′ is added to the adder A4, and thereby the deviation from the final guide vane opening command value ′ (′−G _A ′) is calculated, and its output Ge' is multiplied by _k1 through a coefficient multiplier _K1 , and is applied to the low value priority circuit LVG as a signal GeH. On the other hand, the adder A5 calculates the deviation (W _MAX - W _A ) between the actual guide vane opening value G _A ' and the output upper limit setting value W _MAX of the generator 5,
The output We is multiplied by k ₂ through a coefficient multiplier K ₂ ,
It is added to the low value priority circuit LVG as a signal WeH. As a result, the low value priority circuit LVG compares the above signals GeH and WeH, including their polarities, selects the smaller one, and sends it to the guide vane drive circuit T' as an output signal E, that is, a guide vane opening command value signal. Added. Finally, by operating the guide vane drive mechanism Z' based on the output GeX' of the guide vane drive circuit T', the opening degree of the guide vane 4 is controlled and the water turbine flow rate Q _R ' and power generation are controlled. The actual output W _A is controlled.

Next, the above operation will be described based on a specific example. In Figure 4, first, the turbine flow rate command value Q _R is
Before time t ₀ , which is Q _R1 , the turbine flow rate Q _R ′=
Assume that Q _R1 , actual guide vane opening value G _A ′=G _A1 , and actual generator output W _A =W _A1 . In such a state, the output of adder A4 in FIG.
Ge' is zero, so the output GeH of the coefficient multiplier _K1 is also zero. Also, the output WeH of the coefficient unit K ₂ is WeH=
We・k ₂ = (W _MAX − W _A1 )・k ₂ . As is clear from the equation WeH=(W _MAX −W _A1 )·k ₂ , WeH>0, that is, a “positive” value. Therefore, the lower value priority circuit LVG selects the smaller one, that is, the signal GeH, and applies it to the guide vane drive circuit T' as its output E, and the guide vane 4 is controlled by its output Gex'. has been done. That is, in this case, control is being performed based on the guide vane opening deviation output Ge'.

Next, suppose that in this state, at current time t ₀ , the magnitude of the turbine flow rate command value Q _R increases stepwise by ΔQ _R and reaches Q _R2 , as shown in Figure 4. . Then, the output of the function generator F3, that is, the final guide vane opening command value', is determined by the output of the function generator F3, which uses the static head _HST at this time as a parameter.
Based on the characteristics of , it increases by ΔG′ as shown in the figure. As a result, the guide vane 4 is controlled according to this variation Δ' through the same process as described above,
As a result, the actual guide vane opening value G _A ′ gradually increases, and at time t ₁ , the actual guide vane opening value G _A ′ becomes
It settles on the value G _A ′=G _A1 +Δ′. On the other hand, the water turbine flow rate Q _A gradually increases from time t ₁ , and the generator actual output W _A also changes according to the water turbine characteristic element α and the generator characteristic element β, and also gradually increases. Then, at time _t2 , the generator actual output W _A becomes
When the predetermined generator output upper limit set value W _MAX is reached, the deviation We(W _MAX −
W _A ) becomes a negative value, and as a result, the output WeH of the coefficient unit K ₂ also becomes a negative value obtained by multiplying this We by k ₂ . Furthermore, the output GeH of the coefficient unit K ₁ at this time is determined by the above control as GeH=k ₁・Ge′=k ₁・(′−G _A ′)=k ₁・0
=0. Therefore, in the low value priority circuit LVG, the smaller one, that is, the signal WeH is selected instead of the signal GeH, and this is the output E.
It is added to the guide vane drive circuit T' as a guide vane drive circuit T'.
In this case, the guide vane opening command signal E applied to the guide vane drive circuit T' is a signal WeH having a negative polarity based on the generator output deviation output We, as described above. A command signal Gex' for "closing" the guide vane is given to the mechanism Z', and the guide vane 4 is controlled to "close" based on this. After that, the actual generator output W _A = W _MAX generator output deviation We =
0, WeH=0, and GeH>0.

In this way, in a hydroelectric power plant equipped with a water turbine generator, the static head difference H _ST between the water levels H ₁ and H ₂ of the upper reservoir 1 and lower reservoir 7 is determined based on the water turbine flow rate command value Q _R at that time. Adder A4 calculates the deviation ('-G _A ') between the final guide vane opening command value' and the actual guide vane opening value G _A ', and on the other hand, a predetermined generator output upper limit set value W _MAX is calculated. and actual guide vane opening value
Deviation between G _A ′ and the actual generator output W _A obtained through the turbine characteristic element α and the generator characteristic element β (W _MAX − W _A )
is calculated by adder A5, and each adder A4, 1E
_{The outputs} Ge _′ , We of
Guide vane opening command value signals GeH and WeH are obtained through K ₂ , the smaller of the signals GeH and WeH is selected by the low value priority circuit LVG, and the water turbine 3 is guided based on the selected signal. It is configured to control the opening degree of the vane 4 and control the water turbine flow rate Q _A.

Therefore, when the actual output G _A ′ of the water turbine generator 5 is within the preset generator output upper limit setting value W _MAX , the guide vane opening degree deviation output Ge ′ (GeH)
Control is performed based on the above generator actual output.
When G _A ' exceeds the upper limit set value W _MAX , priority is given to the generator output value deviation output We (WeH) and control can be performed based on this. Even if the flow characteristics and output characteristics change, the generator output can be suppressed to below the upper limit value and the generator can be operated, and damage to the generator and other in-house electrical equipment due to the above causes can be reliably prevented. Can be done. In addition, for the above reasons, while controlling the flow rate of the water turbine, if the generator output reaches the upper limit, the flow rate of the water turbine can be automatically reduced to protect the generator, which is extremely reliable. be.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be similarly implemented in the following manner.

(1) As shown in Fig. 5, in addition to the configuration of the above embodiment, a comparator C is newly installed, and the contact is made when the actual generator output W _A is a little lower than its upper limit set value W _MAX .
The same thing can be carried out even if the configuration is such that Ca is turned on and the gain k ₁ of the coefficient unit K ₁ is made small to suppress the guide vane opening from going too far between times t ₁ and _{t 2} in FIG. 4. It is something that can be done. According to this configuration, the overshoot amount of the water turbine flow rate Q _A and _{the overshoot amount ΔW MAX of} the generator actual output WA at time t ₂ can be reduced. In other words, if the amount of overshoot ΔW _MAX is about 5% of the rating, the generator is originally designed so that it is allowed, and the time during which this overshoot ΔW _MAX occurs is:
In the above embodiment, since it is a short time, no decisive damage is caused to the actual equipment, but according to the embodiment shown in Fig. 5, the gain k ₁ is adjusted by the contact ca as described above. The overshoot amount ΔW _MAX
can be suppressed to approximately zero, and its reliability can be further improved.

(2) As shown in Fig. 46, in addition to the configuration of the embodiment shown in Fig. 3, an actual guide vane opening value signal is added.
An elastic restoring circuit DMP with G _A ′ as input is provided,
The deviation between the output GMP and the output WeH of the coefficient unit _K2 is calculated by the adder A6, and the deviation output
The same implementation can be achieved by configuring WeH1 to be added as a comparison element of the low value priority circuit LVG, and according to such an embodiment, t in FIG.
It is possible to suppress the vibration of the generator's actual output W _A in ₂ hours and quickly settle down to W _A = W _MAX .

(3) As shown in FIG. 7, the embodiments (1) and (2) above can be combined in a similar manner, and according to this embodiment, the actual generator output W _A
Excessive movement and vibration can be suppressed.

In addition, the present invention is not limited to the above embodiments, and can be implemented with various modifications without changing the gist thereof.

As explained above, according to the present invention, in a flow rate control device that adjusts the water turbine flow rate of a water turbine generator provided in a hydroelectric power plant, when the actual output of the water turbine generator is less than or equal to its upper limit setting value, the target water turbine flow rate is Based on the deviation between the value and the actual water turbine flow rate, on the other hand, when the upper limit set value is exceeded, the deviation between this upper limit set value and the above generator actual output value is given priority over the above flow rate deviation, and the water turbine is adjusted based on this deviation. Since the flow rate is controlled, even if the flow rate characteristics and output characteristics of the water turbine change, the actual output of the generator can be kept below the upper limit value and the generator and other electrical equipment within the station can be smoothly maintained without being damaged. A highly reliable water turbine control device that can contribute to operation can be provided.

[Brief explanation of drawings]

Figure 1 is a diagram showing the general configuration of a hydroelectric power plant.
Figure 2 is a block diagram showing a conventional water turbine control device.
FIG. 3 is a configuration block diagram showing one embodiment of the water turbine control device of the present invention, FIG. 4 is a diagram for explaining the operation in FIG. 3, and FIGS. 5 to 7 are the water turbine control device of the present invention. FIG. 2 is a configuration block diagram showing another embodiment of the present invention. 3... Water turbine, 4... Guide vane, 5... Generator, T'... Guide vane drive circuit, Z'... Guide vane drive mechanism, A3 to A6... Adder, F3...
...Function generator, K ₁ , K ₂ ... Coefficient generator, LVG ... Low value priority circuit, α ... Water turbine characteristic element, β ... Generator characteristic element, C ... Comparator, Ca ... Contact of C ,
DMP...Elastic restoring circuit, X...Flow control device,
X _N ...Flow rate control device.

Claims (1)

[Scope of Claims] 1. In a water turbine control device that adjusts the flow rate to the water turbine of a water turbine generator provided in a hydroelectric power plant, a deviation between a target water turbine flow rate value and an actual water turbine flow rate value of the water turbine generator is calculated. output deviation calculation means for calculating and outputting a deviation between the actual output value of the water turbine generator and a predetermined upper limit output setting value of the water turbine generator; When the actual output value of the water turbine generator is smaller than the upper limit output setting value, the deviation output of the flow rate deviation calculation means is set, and when the actual output value of the water turbine generator is larger than the upper limit output setting value, the A water turbine control device comprising: control output selection means for selectively outputting the deviation output of the output deviation calculation means as a control output of the water turbine flow rate.