JPS5866122A - Controller for governor - Google Patents

Abstract

PURPOSE:To obtain an optional closing speed and to perform the switching from full opening to full closing without shock, by providing minor loops of an opening control system and a closing speed controlling system at the inside of a speed controlling system forming a major loop. CONSTITUTION:When an instruction to start and accelerate a water wheel is issued from a speed setter 1, a speed command voltage is given through the route of an amplifier 5 for speed control of a major loop and an amplifier 8 for opening control of a minor loop as it is because the output of a speed sensor 2 is 0, and a guide vane is opened through an amplifier 11 for closing speed control of the second minor loop and a servo system on the basis of the output voltage of a high-gain amplifier A2 which is limited to a certain value. When full closing is inputted from the speed setter 1 to a comparing circuit 4, the guide vane is closed without shock through the amplifier for closing speed control and the servo system on the basis of the error voltage between outputs of the amplifier 8 for opening control and a guide vane opening detecting circuit 7 while limiting the closing speed by the command voltage issued from a closing speed characteristic pattern setter 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a governor control device for operating guide vanes of a water turbine, and in particular, a minor loop including an opening control system and a closing speed control system is provided inside a major loop speed control system. The present invention aims to provide a control device which can obtain arbitrary closing speed characteristics, can switch from fully open to fully closed (or from fully closed to fully open) without any shock, and has good controllability.

To control the opening of the guide vanes of a water turbine, for example, the speed control system is a major loop, and inside this control system is placed a hydraulic servo system consisting mainly of a converter pressure distribution valve and a servo motor. It is well known that electric governors control the start-up and acceleration of water turbines, as well as perform predetermined load shedding through precise operations. Figure 1 shows the characteristics of the guide vane opening θ and operating speed V over time when performing a series of modes called one stop. In this characteristic diagram, the solid line indicates the opening of the guide vane 7. Similarly, the broken line indicates the operating speed characteristic for operating the guide vane. It is clear from this characteristic diagram that K to accelerate the water turbine to a predetermined rated rotational speed is given by the operating speed V as shown in the figure with a constant operating output until the guide vane is fully opened. On the other hand, when closing the guide vane to the fully open position to perform a predetermined load shedding, V, -V, -V as shown by the broken line.

The predetermined operation output is -4 in order to obtain the operation speed characteristic.
By doing so, the desired closing speed characteristic as shown by the solid line can be obtained, and the pressure rise in the penstock can be suppressed within a predetermined range. What is important in this series of modes is the closing mode during load shedding. As shown in the figure, this closing mode includes an immobility time t and a first closing time T1. The second closing time T, the buffer time T5, and K are divided into an equivalent closing time π that includes a part of the first closing time T1 and the second closing time TI. Depending on the pattern of the closing speed characteristics expressed, the pressure in the penstock may rise rapidly and cause a serious accident. K is used to obtain the desired closing speed characteristics by adjusting the boat diameter, which determines the amount of K. It is very tedious and requires changes. In addition, when adjusting the boat diameter to reduce the amount of oil, the viscosity of the oil changes depending on the oil temperature, and the operating output for operating the guide vane itself changes, making maintenance extremely complicated. be. As a method to solve this problem, for example, as proposed in Japanese Patent Application Laid-Open No. 55-50594, K, a closed speed control system of a minor loop is added to a speed control system of a major loop. A pattern generating circuit that generates a closing speed command based on the opening detection signal of the guide vane is inserted into the closing speed control system.
By adjusting the variable resistor group of this pattern generation circuit, arbitrary closing speed characteristics can be obtained, but with this method, the closing speed characteristics themselves depend on the oil in the hydraulic system. Although it is revolutionary in that it has realized a device with a high degree of freedom without causing problems, it opens the opening control system in the predetermined closing mode and inserts a new closing speed control system. Therefore, when the guide vane is switched from fully open to fully closed, during the transition period when the guide vane is switched from fully closed to fully open, the control system has a large 11v error and the closing output fluctuates greatly, causing operational problems. The stability is poor, and since the opening control system is opened in the closed mode, the controllability of the opening itself becomes poor.

The present invention was invented in view of this point, and in particular, the main feature of the present application is that the minor loop is composed of an opening degree control system and a closing speed control system, and is based on the embodiment shown in FIG. 2 below. I will explain in detail.

In the same example, 1 is a speed setting device that gives a speed command for the water turbine;
2 is a speed detection circuit whose configuration is not shown, but it converts the pulse signal group sent from the pilot generator into a DC level voltage signal and obtains the rotation speed of the water turbine. 4 is a rigid restoring/elastic restoring amount generation circuit for giving each signal, 4 is a comparison circuit for comparing the speed setting command signal and the rigid resting amount 1 elastic restoring amount, and S is a comparator circuit for once amplifying the speed error voltage. 6 is a setting circuit for setting the operation time in the opening direction of the guide vane.
It is composed of a high gain amplifier A-layer. 1 is an opening detection circuit for detecting the opening of the guide vane, 8 is an opening control amplifier equipped with a variable limiter circuit, and this amplifier is connected to a resistor Rt.
A variable Lindster circuit consisting of r in and an input resistor R4
It is composed of ~1Ls, a feedback resistor, a diode DI, and an amplifier circuit consisting of a high gain amplifier A2. Reference numeral 9 denotes a pattern generation circuit that generates a pattern with desired closing speed characteristics, and this circuit includes an opening setting device vR2 that sets the opening when the minimum operating speed is reached, and a minimum operating speed that provides the minimum operating speed command. The setting device vit4, the maximum operation speed setting device VB4 that gives the maximum operation speed command, and the IvIec first
The gain adjustment setting device VR1 that adjusts the gain of the operation output at the equivalent closing time 0 shown in the figure, the input resistance 4 to - and the feedback resistor "l@* 114-diode)"
~Ds-high gain amplifier~.

1G is a closing speed detection circuit for differentiating the opening detection signal to obtain a desired closing speed signal, and this circuit consists of a differentiation capacitor C1, a human resistance R1G, a feedback resistor II, and a high gain amplifier M1, respectively configured. ■ is a closing speed control amplifier that temporarily amplifies the error voltage of the closing speed, and this amplifier consists of an input resistor R11''-Ru-feedback resistor W44-
Each of them is composed of an integrating capacitor C1, a high gain amplifier, and a variable resistor Vli that adjusts the time constant of the integrating circuit.

The operation of this embodiment configured as described above is shown in Figures 3 to 6.
Referring to each characteristic diagram shown in the figure, first, when starting and accelerating the water turbine to a predetermined rated rotation speed, the pattern generation circuit shown in Figure 2 is used. is in the open state, a predetermined speed command signal is sent from the speed setter 1 to the comparator circuit 4, and a predetermined operation time command voltage for the guide vane opening direction is sent to the operation time setting circuit 6.
The resistors RIB-R1 and RIB-R1 of the Z-Twin circuit are respectively applied.

When the predetermined speed setting command signal and operation time command signal are input in this way, the water turbine speed detection signal and guide vane opening detection signal are both zero at startup, so the speed command voltage remains unchanged. Measure loop speed control amplifier 1
→The output voltage value of the high gain amplifier A3 is given through the path of the minor loose opening control amplifier $, and the output voltage value is Vt-Rt.
sAlls (where Vt is the command voltage of the operation time setting circuit 4, and 1g -R11 is the resistance value of each resistor) until the output of the high gain amplifier A! reaches vt -11,/'@ Based on this limit voltage, the opening of the guide vane is opened via the amplifier 11 for controlling the closing speed of the second minor loop and the servo system (not shown), and the water turbine is When the water turbine is started and accelerated, a speed error voltage begins to be generated between the speed command voltage and the speed detection signal, and the opening command voltage obtained by amplifying this speed error voltage and the opening given from the opening detection circuit 7 are generated. The output of the high gain amplifier Al that amplified the opening error voltage with the opening detection signal is the limit voltage value y
Since t* is still larger than JgALt-, this I
The opening of the guide vanes is rapidly opened using a voltage limited to the J-mit voltage, and the water turbine is rapidly accelerated to the rated rotation speed.The guide vanes must be operated until the rated rotation speed is reached. Needless to say, the time can be arbitrarily set using the operation time setting device Vll. Now, the output of the high gain amplifier 4 of the opening control amplifier is set to the limit voltage value Vt-
When it becomes lower than R1sAx, the speed command voltage input to the minor loop closing speed control amplifier 11 is released from the V<cut voltage, and this command voltage is directly applied to the closing speed control system and the servo system (not shown). The acceleration state gradually slows down and finally reaches the rated rotational speed.

Next, to explain the closing mode at the time of predetermined load shedding, in the closing mode, the operation time setting circuit 6 shown in FIG. Fully closed command (indicating zero opening) b - From the comparator circuit 4K and the minimum operating speed setter VB4, a command voltage with characteristics as shown in Fig. 3 is sent to the high gain amplifier ~ of the adder, and further to the maximum operating speed. A predetermined tEE is input from the setter vILs to the high gain amplifier 14WC of the adder. When each command voltage is input in this way, the guide vane is at the fully open position until load shedding starts, and the water turbine is rotating at the rated speed, meaning it is fully closed. The speed error tEE between the speed command voltage and the voltage of the speed detection signal is the maximum negative voltage, which is &1 completely opposite to that at startup. This speed error voltage is input through the path of the major loop speed control amplifier 5 and the first minor loose opening control amplifier 8, and the amplified speed error voltage and opening detection circuit 7 input the opening degree detection circuit. The opening of the guide vane is closed in the 1-close direction based on the opening error voltage with the signal, but when this opening error voltage is in the closing mode, the circuit generates a turn! K so that it is regulated by the pattern command voltage output.

That is, the pattern generation circuit 9 increases the opening detection signal and the opening command voltage given by the opening setting device vR2 when the minimum operation speed is reached, based on the opening detection signal inputted through the input resistor R0. A gain amplifier M compares the opening error voltage, and the signal obtained by amplifying this opening error voltage and the command voltage input from the minimum operating speed setter VR, which has the characteristics shown in Figure 3, are added together using an adder in the high gain amplifier section. Do it like this. Here, the characteristics of the opening error voltage between the opening command voltage, which sets the opening position when the guide veil reaches the minimum operating speed, and the opening detection signal are as shown in the characteristic diagram of Fig. 4. It is a characteristic that decreases linearly as the degree θ is gradually closed and becomes zero when it reaches the set opening position θ■, and the slope of this characteristic is determined by gain adjustment. That gay with the setting device Via3,
By adjusting the voltage, it is possible to arbitrarily change the characteristics as shown in the characteristic diagram of FIG. Since the operating speed output of the opening error voltage and the minimum operating speed output shown in FIG. 3 are added by the adder of the high gain amplifier, the operating speed output for the opening position is as shown in FIG. 5. The operating speed output determines the limit voltage of the opening control amplifier. Therefore, for a predetermined period from the time of transition to the closing mode, the value set by the maximum operating speed setting device VR6 is the sum of the operating speed output shown in the characteristics of FIG. 4 and the operating speed output shown in the characteristics of FIG. 6. Since it is larger than the limit voltage value, the maximum operating speed output V shown in FIG. 5, which is limited to this limit voltage, is the resistor R1 of the opening control amplifier 8 shown in FIG. -R11K is given, and the limit voltage vH of the opening control amplifier is 1=v with these resistors R17-Rll.

・The opening command voltage and opening detection signal are determined by the formula R, ..., A18 (where vl is the maximum operating speed output voltage and 17*flla is each resistance value), and the speed error voltage is amplified. A closing speed command signal obtained by amplifying the opening error voltage with respect to IJ is inputted to the closing speed control amplifier 11 with the voltage V [Vc limited, and this closing speed command signal is inputted from the closing speed detection circuit 10. The opening degree of the guide vane is operated in the closing direction based on the speed error voltage with the speed detection signal.Therefore, the closing speed command signal at the time of transition to the closing mode is at the maximum output, so the guide vane The opening degree of the guide vane is rapidly closed as shown in the first closing time TIK in FIG. When E (this indicates the voltage value obtained by adding the output voltage in Fig. 6 and the output 11E in Fig. 4) falls below the limit voltage of the maximum operation speed command set with the setting device VR1, the adder The added output is directly led to the opening control amplifier 6 shown in Fig. 2, and the IJ limit voltage is newly set.This limit voltage is determined by dividing the output voltage of the adder into 5 as described above. Moreover, since the output voltage of the adder gradually decreases according to the degree of closure of the opening θ, as shown by the solid line in FIG. As the voltage decreases, the closing speed command tEE also gradually decreases, and the closing speed of the guide page 7 also decreases in accordance with this command voltage.

This state is shown in the second closing time Ts in FIG.
As is clear from Fig. 6, the opening degree of the guide vane gradually closes a parabolic loop as the operating speed characteristic electric current E V4 of the guide vane decreases linearly. The main reason why the trap opening closes in a parabolic manner is that in the present invention, the setting device V- of the pattern generation circuit 9 sets the gain of the operating speed output voltage according to the opening position with the characteristics shown in FIG. As shown in the figure, since it can be arbitrarily varied, the desired closing speed characteristic can be obtained by adjusting this gain to an appropriate value. Further, according to the present invention, the maximum operating speed is set by the setting device V-, and the minimum operating speed is set by the other setting device vit,
Since I am trying to give each of them, these setting devices v
l14. By adjusting v- to an appropriate position, you can obtain any operating speed characteristics with respect to the opening θ, as shown by the broken line in Figure 5, and the degree of freedom is extremely large.The characteristic diagram in Figure 6 The operation during the second closing time T2 shown by is gradually approaching the end point, and when the guide vane opening θ is closed to the position corresponding to the minimum operation speed, the opening detection signal and the setting device VB!
The deviation from the opening command voltage set in is zero, and only the operating speed output signal with the characteristics shown in Fig. 5 set by the setting device VIT is input to the high gain amplifier A4 of the adder. K becomes. This opening position is indicated by the opening θ shown in Figs. 4 and 5, and the limit voltage E which is the divided minimum operating speed output voltage vs output at the opening position θ is shown in Figures 4 and 5.
Since the output voltage of the high gain amplifier A3 which amplified the speed error voltage between the speed command voltage and the speed detection signal is still larger than Vs-RtyAn K, the above-mentioned limit voltage value vs ' RtyAsaK limited voltage is It is input to the second minor loose closing speed control amplifier 11 as the closing speed command voltage, and then the speed error voltage between this closing speed command signal and the closing speed detection signal derived from the speed detection circuit 10 is used. As a result, the opening degree of the guide vane is closed to the fully closed position. This state is shown in the buffer closing time T1 in FIG.
As is clear from the percentage ratio at
It is understandable that they will gradually close down. Now, the guide vane is closed from its opening degree of 0 to close to the fully closed position.
When the speed error voltage amplified by the high gain amplifier of the opening control amplifier becomes lower than the voltage V, R17, the limit state is released and the speed error voltage of amplifier A directly controls the closing speed. Based on the amount of deviation from the closing speed detection signal derived from the output circuit, the opening degree of the guide vane is adjusted via a servo system (not shown) in order to reduce this amount of deviation to zero. It is automatically controlled to the fully closed position.

As described above, in the present invention, the first minor loose opening control system and the second minor loop opening control system are installed inside the major loop speed control system.
Since a minor loop closing speed control system is provided to operate the guide vane in the closing mode during load shedding, various effects are achieved as shown below.

■ Since the opening control system of the minor loop remains inserted regardless of the closing mode or even during acceleration control in the opening direction, the opening of the guide vane is controlled, so controllability is particularly improved in the closing mode. (One can provide a very stable control device.

(2) Since any closing speed characteristic of the guide vane can be obtained by the pattern generation circuit, the degree of freedom is extremely large, and a control device that is extremely easy to operate can be provided.

■ Since ideal closing speed characteristics can be easily obtained, it is possible to completely solve the abnormal increase in pressure in the penstock that occurs during the closing mode, and it is possible to realize an extremely stable device. .

■ Switching between the acceleration mode and the closing mode is performed with the opening control system inserted, so there is no shock to the control system during switching (especially by providing a device that is superior in terms of operation). I can do it.

[Brief explanation of drawings]

Fig. 1 is a general characteristic diagram showing the correspondence between the operating speed output and the opening degree of the guide vane in the acceleration mode and closing mode of the water turbine, and Fig. 2 is a governor control diagram showing one embodiment of the present invention. A specific circuit configuration diagram of the device, FIG. 3 is a characteristic diagram showing the correspondence relationship between the minimum operating speed setting force WFf according to the present invention, and FIG. 5 is a diagram showing the opening degree and output voltage of the pattern generation circuit according to the present invention. FIG. 6 is a characteristic diagram showing the correspondence relationship between the operation speed and the output level, and FIG. 1 is the speed setting device, 2 is the speed detection circuit, 1 is the stiffness restoration amount -
Elastic restoring amount generation circuit, 6 is an operation time setting circuit, 7 is an opening detection circuit, and . is an opening control amplifier. 9 is a pattern generation circuit, and 10 is a closing speed detection circuit. 11 is an amplifier for controlling the closing speed. Figure 1 Figure 3 Figure 5 □Yomaru eT'' Figure 4 Figure 6 - ◆ mt

Claims (1)

[Claims] Speed detection signal input with opposite polarity to speed setting command signal,
A major loop speed control system that controls the speed of the water turbine based on the speed error voltage between the rigid restoring amount and the elastic resting amount, and the actual opening and guide vane operation speed output based on the input opening detection signal. A pattern generation circuit that patterns the correspondence relationship and limits the maximum output voltage of the opening control amplifier using the patterned operation speed output, and an opening between the opening setting command signal and the opening detection signal input from the speed control system. The opening degree of the guide vane is controlled based on the degree error voltage, and the operation speed command signal in the opening direction-closing direction is generated by amplifying the degree of opening error voltage using the operation speed output output from the pattern generation circuit in the closing mode. The opening control system of the first minor loop whose maximum value is limited, the operation speed detection signal that detects the operation speed of the guide vane, and the operation speed command signal in the opening direction-closing direction input from the opening control system. 1. A governor control device comprising: a speed error voltage based on K; and a second minor loop operating speed control system for controlling the operating speed of a guide vane.