JP2001041142A - Hydraulic machinery for hydraulic plant with surge tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excessive surging automatically by forming hydraulic machinery having a governor controlling a movable flow control means and a surge tank so as to be capable of being switched between low response setting and high response setting. SOLUTION: The speed detecting signal Xn of a speed detecting part 1 detecting the rotational speed of a pump turbine, the setting value xo of the rotational speed of a speed adjusting part 2, and the restoring signal X0 of a speed settling ratio setting part 12 are added (3). An addition result is inputted into a proportional computing element 4a and an integrating computing element 5a used normally, and a proportional computing element 4b and an integrating computing element 5b used when surging is suppressed through contacts 19a, 19b switched based on the output of a surging sensor 20. The respective output of an integrating computing element 6, the proportional computing elements 4a, 4b, and the integrating computing elements 5a, 5b are added to obtain a guide vane opening command Z (7) and control a hydraulic servo motor 10 through a limiter 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic power plant equipped with a surge tank on the upstream or downstream side and provided with a water amount control means and a governor for controlling the water amount control means. The present invention relates to a hydraulic machine suitable for rationalizing the capacity of a hydraulic power plant.

[0002]

2. Description of the Related Art Conventionally, in a hydroelectric machine connected to an electric power system, a strong rotation speed stabilizing action can be expected from the system when operating in connection with the system.
The governor that controls the rotation speed is set to a relatively high gain, focusing on responsiveness rather than stability, and when separated from the system or practically separated from the system, the rotation speed stabilizing action from the system side is not much If it cannot be expected, the gain is set to a relatively low gain, with emphasis placed on stability of the rotational speed rather than quick response. Therefore, conventionally, the governor gain assumes the highest possible gain during the linked operation, and opens and closes the water amount control means at the maximum possible amplitude and at the cycle equivalent to the natural vibration of the surge tank at the maximum possible number of times. Assuming that such a signal was given to the governor, the surge tanks upstream and downstream were designed with sufficient capacity to prevent overflow.

[0003] An analysis of the waterway system of a hydroelectric power plant is described in Hitachi Review, Vol. 56 No. 12 (1974-1).
2) There are those described in pages 1155 to 1160. This document analyzes the water hammer effect of a waterway system in consideration of nonlinearity.

[0004] In addition, a conventional hydropower plant including a generator connected to a power system and a water turbine directly connected to the generator generally has a rotation speed detector and responds to an output signal of the rotation speed detector. By controlling the flow control means (for example, guide vanes) of the turbine to increase the turbine output and increase the rotation speed by comparing with the generator load, or decrease the turbine output to compare with the generator load. A rotation speed governor that controls the rotation speed to a predetermined value by lowering the rotation speed by making it smaller is provided, but rotation speed → rotation speed detector → rotation speed governor calculation unit → rotation speed governor amplification unit → flow rate control means → For the rotation speed control system that goes through a cycle of water turbine output → difference from generator load → rotation speed correction, a kind of bias adjustment is provided in the rotation speed governor calculation unit. If the hydropower plant is disconnected from the high power system and becomes substantially sole power transmission or completely no-load operation that supplies power only to a specific small load, the generator load is considered to be constant. The adjustment of the bias consequently plays the role of speed adjustment. That is, since the turbine output corresponding to the generator load does not change, the bias adjustment can be offset by the change in the rotation speed N.

On the other hand, when the hydropower plant is synchronously connected to a high-power system, the rotation speed is fixed at a value corresponding to the power system, so that the bias adjustment plays a role of output adjustment. That is, the opening of the flow control means changes by adjusting the bias, and the turbine output changes, but the rotation speed does not change. Therefore, the generator load immediately follows the turbine output. In this case, the bias plays a role of water turbine output adjustment → power adjustment.

[0006] When a hydropower plant is connected to a large power system, a distribution command is issued to each plant under its jurisdiction for power supply and demand adjustment control of the entire power system and frequency adjustment control such as AFC. In some cases, a remote central control station issues an output adjustment command, which is a required value of power, to the hydropower plant. However, the conventional hydroelectric power plant has a problem that the response to the remote command is extremely slow, and the contribution of the hydroelectric power plant is too low in terms of system control.

In the prior art, a governor side compares a distant command with actual generator power detected separately to calculate a deviation signal, and integrates the deviation signal into a result. Was given as. Specifically, the bias signal was given to an output adjustment unit called 65P. However, according to the analysis results of the inventors, even if the gain of the integration operation is raised to the allowable limit, a remote command → derivation of deviation from actual power → integration operation of deviation (hereinafter referred to as power deviation integration) →
There is a fatal problem in the control circuit that goes around the bias adjustment (that is, the 65P adjustment) to the governor calculation unit → the opening adjustment of the flow control means → the water turbine output adjustment → the actual power adjustment of the generator. It turned out to be impossible.

One of the reasons is that the PID operation gain of the governor operation section is too low. However, the PID operation gain of the governor operation unit is determined to be stable if the hydroelectric power plant is disconnected from the large power system and becomes substantially a single power transmission state. There is a situation that it cannot be arbitrarily raised because it is necessary to ensure that is not damaged. As a method for solving this, a method is considered in which the PID calculation gain of the governor calculation unit is set to a desired height during operation linked to the large power system, and is automatically switched to a low value when shifting to single power transmission. However, in view of the complexity of the configuration of the power system, it cannot be adopted unless transition to single power transmission can be detected with sufficient reliability (actually difficult). Further, in the loop control circuit for the remote command, the transfer function between the opening degree adjustment of the flow control means and the water turbine output adjustment in linear approximation is (1- _Tw ·
_{S) / (1 + 0.5T w} · S) As is expressed as, because it contains inverted response component of the output by the water hammer, to round the control circuit for the distant command have a direct adverse effects. Here, at _{T w = ΣL i · V i} / (g · H), L i is the length in the vertical water passage, V _i is the average flow velocity of the upstream and downstream in water channel, g is the gravitational acceleration, H is effective head , S are Laplace operators.

By the way, the PID gain of the governor calculating section is as follows: rotating speed → rotating speed detector → rotating speed governor calculating section → rotating speed governor amplifying section → flow control means → water turbine output → difference from generator load → rotating speed It is set in consideration of the stability and responsiveness of the rotation speed control system that makes a round with the correction, and the calculation unit dedicated to the circuit for controlling the power control for the remote command can be set properly only by the power deviation integral calculation Not configured. Furthermore, it is general that the power increase / decrease command for the manual operation of the power is also received by the power deviation integration calculator. In this case, since the adjustment is performed while visually confirming, the gain of the power deviation integration is naturally low. I have to be free to raise it.

In a conventional hydroelectric power plant operating at a substantially constant speed during operation linked to the power system, both the rotation speed control system and the power control system responding to the remote command eventually have the same operating terminal. Control. As described above, in the prior art, even in the loop control system of the electric power with respect to the distant command, appropriate delay compensation and gain can be performed regardless of the influence of the low PID calculation gain of the rotation speed control system and the obstruction factors such as the reverse response of the water hammer. There is no example in which an arithmetic unit capable of performing compensation is provided.

Japanese Patent Application Laid-Open No. 7-279814 discloses a method in which a remote command itself is temporarily expanded and then input as one bias signal of a rotation speed control system.

[0012]

The conventional apparatus does not consider reducing the capacity of the surge tank, and an increase in the capacity of the surge tank means an increase in the volume of rock excavation in the case of an underground power plant. However, the rise in civil engineering costs is a heavy burden. For example, even if the height of the surge tank is increased by only 1 m, the cross-sectional area of the surge tank becomes tens of times the cross-sectional area of the water channel of each turbine, so that the excavation volume becomes enormous.

Further, if a measure is taken to temporarily expand the command itself in the receiving section of the power command from a distant place as in the device described in Japanese Patent Application Laid-Open No. 7-279814, then the response of the loop control system will decrease. May be compensated to some extent. However, in this method, if the gain becomes 1/10 in the loop control system, the gain is increased by a factor of 10 in advance and 10 × (1/10) = 1 and the gain is set to 1. Is complicated, and the response gain greatly changes according to the frequency of the signal. In the end, there is a limit to the way of compensating only outside the loop control system, and it is not efficient and not practical because at least a reduction in accuracy and inefficiency are unavoidable.

Further, in the conventional technology, even if the response of the loop control system to the power command is successfully improved, depending on the construction conditions of the hydraulic machine, abnormalities in a specific frequency band such as surging of a surge tank in an upstream / downstream waterway. In many cases, a new problem of vibration occurred. The only countermeasure against this was to increase the capacity of the surge tank or to give up the response of the loop control system.

A first object of the present invention is to make the governor intelligent and automatically prevent excessive surging even if the governor applied signal which is the design condition of the surge tank is the same. An object of the present invention is to provide a hydraulic machine for a hydraulic plant equipped with a surge tank that can achieve a great economic effect of streamlining the design of a surge tank and contribute to reducing the construction cost of the hydraulic plant.

A second object of the present invention is to control the governor so that the vibration amplitude of the water flow control means, which is the output of the governor, is automatically suppressed to a desired level even when the surge tank is vibrated at a period corresponding to the natural vibration of the surge tank. Another object of the present invention is to provide a hydraulic power plant for a hydropower plant equipped with a surge tank that is intelligent.

A third object of the present invention is to provide a power control system which responds to a remote command even when both a rotational speed control system and a power control system responding to a remote command finally control the same operating end. An object of the present invention is to provide a hydraulic machine in which the responsiveness of a control system can be rationally optimized without impairing the responsiveness of a rotation speed control system, in particular, stability, and the response gain is greatly improved.

A fourth object of the present invention is to provide a distant command even when the power deviation integration gain is not sufficiently high, such as when the power deviation integration calculator also receives power up / down commands for manual operation of power. It is an object of the present invention to provide a hydraulic machine capable of freely increasing the response of a power control system to a hydraulic power machine.

A fifth object of the present invention is to rationally prevent abnormal vibration phenomena in a specific frequency band such as surging of a surge tank in an upstream / downstream waterway, and improve the responsiveness of a loop control system in other frequency bands. An object of the present invention is to provide a hydraulic machine that can be held to the maximum.

[0020]

In order to achieve the above object, a hydraulic machine of a hydraulic plant having a surge tank according to the present invention comprises a movable flow control means, a governor for controlling the flow control means, and an upstream or downstream flow control means. A hydraulic machine installed in a hydraulic plant having a surge tank in a downstream conduit, wherein the governor provides a low frequency response characteristic to an input signal in a frequency band near a natural frequency of the surge tank. A low-response setting and a high-response setting for giving higher frequency response characteristics to input signals in other frequency regions are provided.

Further, a surging sensor for detecting an excessive surging or a precursory phenomenon thereof is provided, and the governor automatically selects a low response setting on condition that the surging sensor is operated.

Further, the present invention is installed in a hydraulic power plant having movable flow control means, a governor for controlling the flow control means, a surge tank in an upstream or downstream pipeline, and a surging sensor for detecting excessive surging or its precursory phenomenon. The governor arithmetic unit is configured to switch the integral element gain between high and low, and automatically selects the low gain side when the surging sensor operates.

[0023] Further, the present invention is installed in a hydraulic power plant having movable flow control means, a governor for controlling the flow control means, a surge tank in an upstream or downstream pipeline, and a band filter circuit for setting the frequency response characteristics of the governor. A frequency response characteristic of the band filter circuit for an input in a frequency band close to the surging natural frequency of the surge tank, compared to an input in another frequency band, the frequency response of the governor. The characteristic is set so as to be low.

In order to achieve the above object, the hydraulic machine of the present invention is arranged in parallel with a power deviation integration calculator of a loop control system for a power command, and corrects the output of the power deviation integration calculator with its output. Parallel computing means,
Although the parallel computing means receives the same power deviation signal as the power deviation integral computing unit, it outputs a signal that enhances the response of the power deviation integral computing unit during a transient when there is a power deviation, and outputs the signal when it returns to a steady state. Is set to zero or almost zero.

Further, the parallel operation means performs a proportional operation, and includes a P + I (proportional + integral) operation element instead of the power deviation integral operation unit. Using this P + I operation element, the response of the power control system to the power command is optimized.

The parallel operation means performs a proportional operation + a differential operation, and includes a P + I + D (proportional + integral + derivative) operation element instead of the power deviation integral operation unit. This P
Using a + I + D operation element to optimize the response of the power control system to the power command.

The remote command receiving section is provided with a band filter whose response gain decreases with respect to a variable input in a specific frequency band as compared with a variable input in another frequency band. In addition, the power deviation integration calculator is replaced with a P + I calculation element or replaced with a P + I + D calculation element, and then combined with a band filter provided in the remote command receiving unit.

As an example of a band filter, the transfer function is [(1 + T ₂ · S) * (1 + T ₃ · S)] / [(1 + T ₁
.S) * (1 + T ₄ · S)] or equivalent (however, T ₁ to T
₄ is a predetermined time constant, S is a Laplace operator and T ₁ <T ₂ <T
₃ <T ₄ ), and the specific frequency band in which resonance is expected on the control target side such as the surging resonance frequency is 1 / (2π · T ₁ ) and 1
That is, T ₁ and T ₄ are adjusted so as to fall between / (2π · T ₄ ). More preferably, 1 / (2π · T ₂ ) and 1 / (2
T ₂ and T ₃ are adjusted so as to fall between π · T ₃ ).

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a waterway configuration of a hydropower plant having surge tanks in both upper and lower waterways. 105 is the upper pond, 101 is the headrace of the upper pond 105, 106 is the headrace 1
01 is an upstream surge tank, 102 is a penstock connected to the upstream surge tank 106, 100 is a pump turbine connected to the penstock 102, 103 is a suction pipe connected to the pump turbine 100, 107 is Draft tube 103
Is a water discharge channel connected to the downstream surge tank 107. In FIG.
H _fu is the upstream surge tank water level measured based on the center of the pump turbine 100, H _fL is the downstream surge tank water level measured based on the center of the pump turbine 100, and ΔH _fu is the water level of the upstream surge tank 106 and the upper pond. The difference in water level at 105, _{ΔH fL} is the difference between the water level of the downstream surge tank 107 and the water level of the lower pond 108, A _fu is the cross-sectional area of the upstream surge tank 106, A _fL is the cross-sectional area of the downstream surge tank 107, L _1, A _1, V ₁
Are the length of the headrace 101, the cross-sectional area of the pipeline, the flow velocity,
L ₂ , A ₂ , and V ₂ represent the length, cross-sectional area, and flow velocity of the penstock 102, and L ₃ , A ₃ , and V ₃ represent the suction pipe 1 respectively.
The length 03, the pipe cross-sectional area, and the flow velocity, L ₄ , A ₄ , and V ₄ indicate the length, the pipe cross-sectional area, and the flow velocity of the discharge channel 104, respectively.

The behavior of the water turbine including the water hammer of the hydraulic power plant constructed as shown in FIG. 2, that is, the control object of the governor which inputs the opening Y of the guide vane (also referred to as water amount control means) which is the output of the governor An example of a simulation formula that simulates the behavior of (1) will be described below. In the following description, it is assumed that the water column is an incompressible fluid, and an approximation is made based on the rigidity theory. It is also assumed that the water column has no friction loss for simplicity.

First, considering the water channel 101 and the upstream surge tank 106, the water column in the pipeline from the upper pond 105 to the upstream surge tank 106 has a sectional area A ₁ × length L ₁ and a surge tank water level. Since the force acting on the water column due to the rise acts in the direction of pushing the water column back, the equation of motion is represented by the following equation (1).

[0032]

[Number 1] _{-γ · ΔH fu · A 1 =} [(A 1 · L 1 · γ) / g] × (dV 1 / dt) ... (1) where, gamma is the specific gravity of the water, the number 1 Is transformed into Equation 2.

[0033]

-ΔH _fu = (L ₁ / g) × (dV ₁ / dt) (2) On the other hand, from the continuous equation, the difference between the amount of inflow water and the amount of outflow water into the surge tank changes the surge tank water level. Equation 3 holds.

[0034]

(A ₁ · V ₁ -A ₂ · V ₂ ) = A _fu · (dΔH _fu / dt) (3) Next, the 102 penstock will be examined. The water column in the penstock has a cross-sectional area A ₂ × length L ₂ , and the water pressure fluctuation at the left end of the pipeline is γ · △ H _fu · A ₂ , while the water pressure fluctuation at the right end of the pipeline is γ · △ Since H _u · A _2, Equation 4 holds. That is, Equation 5 is obtained.

[0035]

Γ (ΔH _fu −ΔH _u ) · A ₂ = [(A ₂ · L ₂ · γ) / g] × (dV ₂ / dt) (4)

[0036]

ΔH _fu −ΔH _u = (L ₂ / g) × (dV ₂ / dt) (5)

Next, the pump turbine 100 will be examined. Output P _t of the water wheel can be expressed by Equation 6.

[0038]

P _t = 9.8 η · H · Q (6) where η denotes efficiency and H denotes effective head. Effective head H
Is expressed by the difference between the upstream fluctuation ΔH _u and the downstream fluctuation ΔH _L as shown in Expression 7.

[0039]

ΔH = ΔH _u − △ H _L (7) The flow rate Q is approximated by Expression 8.

[0040]

## EQU8 ## Q = KYＫH (8) Here, Y indicates the guide vane opening. Further, Equation 9 is obtained from a continuous equation.

[0041]

Q = A ₂ · V ₂ = A ₃ · V ₃ (9) Next, the suction pipe 103 will be examined. The water column in the pipe of the suction pipe has a cross-sectional area A ₃ × length L ₃ , and the water pressure fluctuation at the left end of the pipe is γ · △ H _L · A ₃ , while the water pressure fluctuation at the right end of the pipe is γ • Since _{ΔH fL} · A ₃ , _Equation 10 holds.

[0042]

Γ (△ H _L − △ H _fL ) · A ₃ = [(A ₃ · L ₃ · γ) / g] × (dV ₃ / dt) (10) That is, Equation 11 is obtained.

[0043]

Equation 11] △ H _L - △ H _fL = Next _{(L 3 / g) × (} dV 3 / dt) ... (11), consider the spillway 104 and the downstream surge tank. First, the water column in the pipeline from the lower surge tank to the lower pond has a cross-sectional area of A ₄ x length L ₄ , and the force acting on this water column acts in the direction of accelerating the water column due to the rise in the water level of the lower surge tank. Equation 12 holds.

[0044]

Γ △ _HfL・ A ₄ = [(A ₄ · L ₄ · γ) / g] × (dV ₄ / dt) (12) That is, Expression 13 is obtained.

[0045]

_{ΔH fL} = (L ₄ / g) × (dV ₄ / dt) (13) On the other hand, the difference between the amount of inflow water and the amount of outflow water into the lower surge tank from the continuous equation changes the lower surge tank water level. So
Equation 14 is obtained.

[0046]

(A ₃ · V ₃ -A ₄ · V ₄ ) = A _fL · (dΔH _fL / dt) (14) Here, each coefficient is made dimensionless as shown in Expression 15 to obtain Expression 2, When the linear approximation formulas of Formula 3, Formula 5, Formula 6, Formula 7, Formula 8, Formula 9, Formula 11, Formula 13, and Formula 14 are obtained, Formula 16 to Formula 25 are obtained.
Is obtained.

[0047]

(Equation 15)

These formulas are used for the dimensionless variables v ₁ , v ₂ ,
v ₃ , v ₄ , h _fu , h _fL , h _u , h _L , p _t , q, y are linear approximations, and the higher-order terms of these variables are neglig
Omitted as iblesmall.

[0049]

V ₁ = −g · H ₀ · h _fu / (L ₁ · V ₁₀ · S) (16)

[0050]

H _fu = (A ₁ · V ₁₀ · v ₁ -A ₂ · V ₂₀ · v ₂ ) / (H ₀ · A _fu · S) (17)

[0051]

V ₂ = g (H ₀ · h _fu −H _u0 · h _u ) / (L ₂ · V ₂₀ · S) (18)

[0052]

_Pt = h + q (19)

[0053]

[Number 20] _{h = (H u0 h u -H} L0 h L) / (H u0 · H L0) = (H u0 h u -H L0 h L) / H 0 … (20)

[0054]

[Expression 21] q = y + 0.5h (21)

[0055]

## EQU22 ## q = v ₂ = v ₃ (22)

[0056]

V ₃ = g (H _L0 · h _L −H ₀ · h _fL ) / (L ₃ · V ₃₀ · S) (23)

[0057]

[Number 24] _{v 4 = g · H 0 ·} h fL / (L 4 · V 40 · S) ... (24)

[0058]

H _fL = (A ₃ · V ₃₀ · v ₃ -A ₄ · V ₄₀ · v ₄ ) / (H ₀ · A _fLS · S) (25) From this, the hydropower plant shown in FIG. A linearized model of the governor to be controlled can be shown in FIG. That is, the dimensionless flow rate change q is generated by the dimensionless opening y of the guide vane (water volume control means), and the dimension of the dimensionless upstream water tank h _{fu is} reduced. Water level h _fL of the downstream surge tank
It turns out that responds. The upper surging block diagram and the lower surging block diagram shown in FIG.
It is configured as shown in FIG. The response of the upstream surge tank water level and the downstream surge tank water level to the flow rate change is a typical sine wave generation circuit, and the upstream surge tank surging cycle and the downstream surge tank surging cycle are respectively 2π√ (A _fu · L ₁ / A ₁
G), 2π√ (A _fL · L ₄ / A ₄ · g).

FIG. 1 is a control block diagram of the governor of this embodiment. 1 is a speed detection unit for detecting the rotation speed N of the pump turbine 100, _Xn is a speed detection signal detected by the speed detection unit 1, 2 is a speed adjustment unit for setting a reference value of the rotation speed,
x ₀ is set value outputted from the rate adjustment section 2, 3 set value x ₀ and the speed detection signal X _n and the adder and the recovered signal X _sigma from speed droop setting unit to be described later, X _epsilon adder The input signal of the PID operation circuit immediately downstream with the signal calculated in 3, 20
Denotes a surging sensor for an upstream surge tank, 4a denotes a normally used proportional operation element (P element), and 4b denotes a proportional operation element (P element) used when the surging sensor operates, that is, when surging suppression is performed. . In addition,
The gain K _pa of the former proportional operation element is _{smaller than} the gain K _pb of the latter proportional operation element. Reference numeral 5a denotes an integral operation element (I element) normally used, and reference numeral 5b denotes an integral operation element (I element) used when the surging sensor operates, that is, when surging suppression is performed. The former integral gain K _ia
And the latter integral gain _Kib is _Kia < _Kib .
Reference numerals 19a and 19b denote contact points of a surging sensor 20 provided before the proportional operation elements 4a and 4b and the integral operation elements 5a and 5b, respectively, which swing when the surging sensor 20 operates, open the proportional operation element 4a, and The operation element 4b is closed, the integral operation element 5a is opened, and the integral operation element 5b is closed, and both the proportional operation element and the integral operation element are switched.

Reference numeral 6 denotes a differential operation element (D element). The output signal Z _d , the output signal Z _p of the proportional operation element, and the output signal Z _i of the integral operation element are added by the adder 7. The output signal Z _p of the proportional operation element and the output signal Z of the integral operation element
_i, total signal of the output signal Z _d of differential operation element is a guide vane opening command Z, the actual guide vane opening Y to the guide vane opening command Z is fed back, the deviation adding unit 8 Be taken. This deviation signal Y
_ε1 is input to the hydraulic servomotor 10 via the limiter 9. Theta _R is the opening speed of the guide vanes θ _R · C _y limiter 9, theta _L is used to limit the closing speed to θ _l · C _y, the output signal Y _.epsilon.2 deviation signal Y limiter 9 _The signal is obtained by limiting _ε1 in consideration of the above-mentioned opening / closing speed limitation. The hydraulic servomotor 10 is a kind of hydraulic amplifier, and forms a first-order lag element in the transfer function, amplifies the guide vane opening command z and converts it into a guide vane opening Y having a sufficient stroke and operating force. The guide vanes, which are the water amount control means, are directly operated.

[0061] The actual guide vane opening Y is fed back, by an adder 11, the deviation between the guide vane opening setting signal Y _a from the output adjustment unit 13 is provided. If the actual guide vane opening Y guide vane opening setting signal Y _a
If you are not reached, i.e., Y <Y open signal to the PID operation unit of the governor to the difference is zero in the case of _a sigma
Since (Y _a -Y) is continuously fed, eventually settles at that stage becomes Y = Y _a. The open signal σ is set by the speed regulation rate setting unit 12 and outputs a restoration signal _Xσ . The open signal σ is a gain that determines the ratio of the change in the guide vane opening Y to the change in the speed detection signal _Xn , and is generally not changed once determined in consideration of the role of the plant in the power system. .

Reference numeral 14 denotes the entire block diagram shown in FIG. 3, and the actual guide vane opening Y is fed back. As described above, this block diagram 14 shows a control block diagram of a pump turbine including a water channel system in a simple expression. The output P of the water turbine, which is the output of the block diagram 14
The deviation between _t and the total load LΣ to be described later is obtained, and this deviation is input to the rotation unit inertia effect calculation unit 16 and the rotation speed N
Is calculated. The rotation speed N is calculated by the calculation unit 1 of self-controllability.
7a, which is fed back from the power system to the operation section 17b for the synchronization operation.

[0063] The arithmetic unit 17b, the rotational speed N is calculated load power R _L indicating a synchronization action bring back the power system so as not deviated from the rated speed (synchronous speed) N _0. L is an external load applied to the generator directly connected to the water axle, and the external load L and the load power _RL are added to generate a generator load P _g
Is calculated. The calculation unit 17a of the self-controllability of the pump turbine 100 calculates a characteristic in which the mechanical loss and the efficiency decrease, etc., which increase with an increase in the rotation speed, are calculated. _T is calculated.

[0064] loss R _T not only the power generation load P _g when viewed from the water wheel can also be regarded as a kind of load, it can be regarded as a total load LΣ = P _g + R _T to consume the output P _t of the water wheel . Generation load P _g and Ross R _T is added to calculate the total load Erushiguma, further is taken deviation between the output P _t of the water wheel, (P _t -LΣ) the calculation of the rotation unit inertia effect 1
6, the rotation speed N is calculated as an output of the rotation unit inertia effect calculation unit 16.

By the way as a signal given from the outside to the governor shown in FIG. 1, there are two signals of the guide vane opening setting signal Y _a externally applied load L and the output adjusting unit 13 provided to the generator. The external load L causes a speed change of the rotation speed _Xn due to the change. On the other hand, a typical signal input to the output adjustment unit 13 is AFC
(Automatic frequency control). In the case of AFC, since the command is issued exclusively from the viewpoint of frequency control of the power system, it is issued without sensing the special circumstances of the hydropower plant such as abnormal surge of surging. Provided remotely from a central control station that is not far away. Thus, the rotational speed X _n, the guide vane opening setting signal Y _a upstream by any signal, it is possible that the surge tank any downstream is abnormally vibrated, the overall effect of surging sensors both signals It is arranged downstream of the adder 3, which is the junction of the two signals, so that it can be monitored.

[0066] Figure 6 is a surging sensor 2 that receives an input signal X _epsilon to the PID computing section of the governor shown in FIG. 1
It is a figure showing an example of 0. 20A is an absolute value calculation unit;
B is a switch that outputs 1 when the input is 0.004 ( _pu ) or more, and outputs 0 when the input is less than 0.004 (p _u ). 20C is a signal selection element that selects 0 when the output of the switch 20B is 1, and selects 0.2 when the output of the switch 20B is 0.
Is an adder for calculating the deviation between the output of the switch 20B and the output of the signal selector 20C, 20F is an integral element for integrating the output signal of the adder 20D, 20E is provided before the integral element 20F, and the upper limit of the integral element 20F. Is a limiter which controls the passage / rejection of a signal sent to the integration element 20F so that the lower limit does not exceed 25 and the lower limit does not exceed 0.
The surging sensor is turned on when the output of is more than the set value of 10, and the surging sensor is turned off when the output is less than 10.
This is a surging sensor operating section that performs F.

Next, the operation of the surging sensor shown in FIG. 6 will be described with reference to FIGS. Record 1 shown in FIG.
The input signal X _epsilon to the PID computing section, record 2 an output signal Z of the PID operator of the governor, the record 3 is integral element 2
The record 4 shows the output signal of 0F, and the record 4 shows the output signal of the surging sensor operation unit 20G. Also, record 1 a rotational speed N, record 2 shown in FIG. 8 the guide vane opening setting signal Y _a, record 3 shows the guide vane opening Y. In this case, the guide vane opening setting signal Y _a given from the output adjustment unit 13 as record 2 shown in FIG. 8 is a surging excitation signal.

At time t _a , the input X _ε > 0.0 of the PID operation unit
When it reaches 04, the switch 20B outputs 1. Then, the signal selection element 20C outputs 0. As a result, the addition unit 2
The output of 0D becomes 1, the integration element 20F starts integration, and the output value of the integration element 20F shown in the record 3 rises linearly. Becomes a time t _b, the output of the integral element 20F exceeds 10 surging sensor at this stage O
N. Note the output of the integral element 20F At time t _c equals 25, immediately increased ceases the action of the limiter 20E. Input X _epsilon <0 of the At time t _d PID calculation unit.
004, the switch 20B outputs 0, and the signal selection element 20C outputs 0.2, so that the output of the adder 20D becomes -0.2, and the output of the integration element 20F becomes 1 at the time of rising.
Start descending on a / 5 gradient. PID again at time t _e
The input X _ε > 0.004 of the arithmetic unit is obtained, and the integral element 20F
Output starts to rise.

[0069] reason for taking the absolute value absolute value calculation unit 20A, even in the case of (when opening the water amount controlling means) Input X _epsilon positive the PID operator, if negative (if closing the water quantity control means) However, if the final change in water volume is the same, the difference in whether the water level starts from rising or falling will be the surging with the same amplitude. Of course, as described above, the surging sensor can be simplified as much as possible even if the accuracy is slightly deteriorated.

The reason why the amplitude of | X _ε | is considered in the switch 20B is that the larger the amplitude is, the larger the surging becomes regardless of the sign. When the set value 0.2 of the signal selection element 20C is increased, the integration element 20F
The output of the sensor will fall faster, and the reset of the surging sensor will be quicker. Since surging becomes inherent risk of abnormal vibration surging if the vibration of the vibration period than much of the PID operator repeated at longer periodic input X _epsilon is quite small, but the influence of the past pressurized flexible become better almost negligible , The set value of the signal selection element 20C is 0.
2 makes this kind of judgment. Limiter 2
When the upper limit set value 25 of 0E is lowered, the signal selection element 20C
Since the surging sensor is easily reset even if the set value of the signal selection element is the same, the setting of the signal selection element 20C and the limiter 20E is considered as a set. Incidentally, since the input X _epsilon of the PID calculation unit is vibrated periodically in the same amplitude surging even if much shorter than the surging natural vibration corresponding period attenuated, surging sensor may be OFF, surging shown in FIG. 4 Sensors can do that too. The accuracy of the surging sensor can be expected to be quite high if it is made by simulating the theory more faithfully with reference to FIG. 3, and the operating range of the surging sensor must be minimized and the governor frequency response performance must be sacrificed. Can be minimized.

[0071] As described above, surging sensor is turned ON at time t _b of Figure 7, the contact 19a of surging sensor shown in FIG. 1, 19b is Setsu換Ri, proportional element 4b
(Gain K _pb ) and the integral element 5b (gain K _ib ) are selected, and the guide vane (Y) as shown in record 3 shown in FIG.
Is suddenly suppressed, and surging is automatically suppressed to an acceptable level. In the simulation analysis shown in FIGS. 7 and 8, it is assumed that the rotation speed N is constant throughout like record 1 shown in FIG.

The inventors conducted a simulation analysis of a certain plant in consideration of a non-linear term in order to confirm how effectively the above-mentioned surging sensor operates on a real machine. FIG. 9 summarizes the results. In this case, _a sine wave is given as the guide vane opening setting signal Ya from the output adjustment unit 13, and verification is performed with a total of 12 cases of three types of amplitudes and five types of periods as parameters. Here, in the determination of the necessity of the surging sensor, the case where the surging sensor is not provided and the case where the surging sensor does not exceed the predetermined allowable maximum water level of the target surge tank is regarded as “necessary” and the case where the surging sensor does not exceed the predetermined maximum is “unnecessary”. Period amplitude ± 0.49 of the guide vane opening setting signal Y _a is 10
Except for the two cases of 0 sec and 400 sec, the surging sensor is actually turned on when the simulation analysis result is “necessary”, and is actually turned off when the simulation analysis result is “unnecessary”.
The two exceptional cases are errors due to the simplification of the surging sensor, but the errors are on the safe side and can be judged to be a sufficiently acceptable level. The permissible maximum water level of the target surge tank described above is a value when this plant is operating in conjunction with the power system, and is set to a value at which the surge tank does not overflow even if additional fluctuations added due to load shedding are considered. I have.

As described above, a low-response setting for giving a low frequency response characteristic to the governor and a high-response setting for giving a higher frequency response characteristic are prepared, and the vicinity of the natural frequency of the surge tank is provided. In the operation in the frequency band of, since the low response setting is used, the overall response gain of the governor itself up to the water flow control means decreases, and the amplitude of the water flow control means can be reduced to a desired level. Even if the applied signal is vibrated at a frequency equivalent to the natural frequency of surging and with an amplitude that would not otherwise be avoided, excessive surging does not occur.

Further, since a surging sensor is provided, it is possible to accurately detect an operating condition in which excessive surging is concerned, so that the use range of the low response setting can be minimized. In other words, the frequency response characteristics of the governor can be maintained high, and the normal setting that emphasizes the quick response can be used to the maximum.

The gain of the integral element of the governor operation section is set so that the lower gain is set to ensure the stability of the rotational speed N after the load is cut off. It is convenient if the gain is set so that the lower gain is automatically selected when the surging sensor operates, similarly to when the load is interrupted. In the case of the integral element, the output side does not fly regardless of the gain switching, so that it is preferable as the switching target.

When the gain of both the integral element and the proportional element of the governor operation section can be switched between high and low, and the low gain side is automatically selected for both elements when the surging sensor operates, even before switching. Even after the switching, the degree of freedom is high by the proportion of the proportional element, so that more suitable setting can be made in each state. However, in the case of the proportional element, if the switching is performed during the transition, the output side may fly. Therefore, the switching is performed in consideration of this point.

Although several logics can be considered as the surging sensor, it is not preferable to make it too complicated. Therefore, a predetermined index that can be easily calculated from the governor state quantity including the displacement of the flow rate control means downstream of the confluence of the speed detection signal and the output adjustment signal and that can confirm the correlation with the magnitude of surging is simulated in advance. Find it by such means. Then, a method of predicting / detecting excessive surging by calculating the value of the index from the governor state amount every moment is considered. Note that since the total effect of the speed detection signal and the output adjustment signal is a problem in calculating the index, the governor state quantity downstream from the confluence of both signals is taken in as data.

As the governor state quantity for calculating the index for the surging sensor, it is preferable to select a state quantity that returns to zero or a value close to it in a steady state. Considering that the governor is vibrated by a certain signal, the reason for surging (fluctuation in the surge tank water level) is that any governor state quantity is a change width, not an absolute value.

Even if the governor state quantity itself does not return to zero or a value close to zero in a steady state, it is converted to a state quantity that returns to a value close to or close to zero in a steady state by adding a predetermined operation such as differentiation, and then used for index calculation. The use is based on consideration of the above points. In addition, when the surging sensor is applied, the calculation of the index includes not only the instantaneous value of the instantaneous state quantity but also an integration operation or a storage operation so as to reflect the history of the previous state quantity. It is effective. Considering the same displacement of the water amount control means, for example, the displacement from 80% opening to 60% opening, the displacement from 100% opening to 80% opening even one cycle before the natural vibration of surging. If there is, the surging due to the previous displacement and the surging due to the current displacement overlap, and the fluctuation range of the surging is approximately doubled. In another example, if there is a displacement of the water amount control means from 100% opening to 80% opening one half cycle before the natural vibration of surging, the surging by the previous displacement and the current displacement Surging cancels out and the fluctuation range of surging becomes almost zero.

In another example, if the water amount control means is displaced from 60% opening to 80% opening one cycle before the natural vibration of surging, surging by the previous displacement and surging by the current displacement are performed. Cancel each other, and the fluctuation range of the surging becomes very small. In another example, the water amount control means changes the 60% opening degree to ８ cycle before the natural oscillation of surging.
If the displacement is 0%, the surging due to the previous displacement and the surging due to the current displacement are overlapped, and the surging variation width is approximately doubled. As described above, since the amplification and attenuation of the surging greatly change depending on the displacement width, direction, and timing of the past water amount control means, as described above, the storage element such as the integral element that reflects the past data is reflected in the index calculation logic of the surging sensor. Inserting can improve accuracy. However, if the accuracy is pursued too much, the index calculation logic becomes too difficult, and in practice, some compromise is required. As an example of a compromise, an index calculation logic of a type that responds only to the absolute value and frequency of the fluctuation range ignoring the direction of displacement given to the water amount control means may be created. However, in this case, it is dangerous to lower the accuracy in a direction in which the surging sensor does not work. Therefore, the surging sensor should be designed so as to work even when it is unnecessary. Such considerations work for the index calculation logic of the type described above that responds only to the absolute value and frequency of the fluctuation range. As a result, the surging sensor operates more than necessary, and each time the governor gain is reduced and the frequency response characteristic is reduced, this level is generally sufficiently acceptable.

The effect of the integration or storage operation used for calculating the index is such that the surging excitation level of the input signal is reduced with time. The reason for this is
This is because surging caused by displacement of the water amount control means in the past is attenuated with the passage of time.

The arrangement of the band filter circuit is not limited to the output adjustment signal circuit, but may be the same if necessary as long as it is an applied signal that finally controls the flow rate control means. When the opening upper limit device of a kind of water amount control means, which is generally called a load limiting device, is repeatedly operated by a remote signal, the load limiting device is also a target.

FIG. 10 relates to another embodiment of the present invention and relates to surging suppression control during AFC (automatic frequency control of the system) operation. 13A is an arithmetic operation unit of the governor output adjustment unit, 13B is an addition unit provided in the preceding stage of the governor 13A,
13C is a band filter provided before the adder 13B and to which an AFC command signal _Pafc commanded to the plant from a distant control station that controls AFC of the entire power system is input. And the generator power Pg of the generator is _calculated . Reference numeral 50 denotes a governor for inputting the rotation speed N, 100 denotes a pump turbine connected to the governor 50, and 200 denotes a generator connected to the pump turbine 100. P _x is the output of the band filter 13C,
P _g indicates the actual generator power of the generator.

Prior to the description of this embodiment, a description will be given of the conventional AFC-compatible control performed on the plant side. The governor 50 has the configuration shown in FIG. 1 and includes a surging sensor 20, a proportional element 4b, an integral element 5b, and a surging sensor contact 19.
a, 19b are deleted. AFC command signal P _afc is directly input to the adder unit 13B, generator power P _g is the addition unit 13 so that the generator power P _g is following this
B, and the calculation unit 13A returns the AFC command signal P _afc
A deviation of the generator power P _g decreases, eventually performs the operation of the integration or the like becomes zero, and outputs the guide vane opening setting signal Y _a. To follow the guide vane opening setting signal Y _a guide vane opening Y is controlled, pump-turbine 1
00 is output p _t is the control of the mechanical output p _t generator 2
00 is converted to generator power P _g by fed to the power system. Incidentally, the governor 50 is also rotation speed signal N to another guide vane opening setting signal Y _a is inputted, it is assumed that there is no fear of the surging abnormal vibration for the rotational speed signal N.

[0085] In the course AFC aspect, towards the frequency response characteristics of the plant side from the AFC command signal P _afc to generator power P _g is high is preferable. On the other hand, the plant-side there is the problem that surging increased excessively frequency response characteristic vibration of the guide vane opening setting signal Y _a becomes too large becomes excessive. Therefore, in the present embodiment, the operation of the band filter 13C will be particularly described. The transfer function of the band filter 13C shown in FIG. 10 is [(1 + T _{2.
S) * (1 + T 3} · S)] / [(1 + T 1 · S) * (1 + T 4
.S)]. Here, T ₁ to T ₄ are predetermined time constants,
S is a Laplace operator. FIG. 11 is a Bode diagram showing the frequency response characteristics of this band filter. FIG.
1, the horizontal axis indicates frequency (HZ), and the vertical axis indicates gain (db). The time constant T ₁ is set so that the frequency 1 / (2πT ₁ ) is lower than the surging resonance frequency.
The time constant T ₄ is set so that / (2πT ₄ ) is higher than the surging resonance frequency. More preferably, the frequency 1 /
(2? ₂₎ sets the time constant T ₂ so as to be lower than the surging resonance frequency, also, the frequency 1 / (2πT ₃₎ sets a time constant T ₃ so as to be higher than the surging resonance frequency. By setting the time constants T ₁ , T ₂ , T ₃ , and T ₄ in this manner, A in a frequency band near the surging resonance frequency can be set.
The frequency response gain of the output of the band filter P _x for the FC command signal P _afc can be many tenths. It should be noted that abnormal surge of surging does not occur only at one surging resonance frequency, but it is necessary to assume some dangerous bands above and below. For this, T ₁ ,
It is necessary to separate T ₂ , T ₃ , and T ₄ from the surging resonance frequency with a predetermined margin. On the other hand, this band filter 1
If 3C is added, a frequency lower than 1 / (2πT ₁ ) or 1 / (2πT ₁ )
In a frequency band higher than (2πT ₄ ), a sufficiently high gain may be set without being bound by the surging abnormal excitation problem. That is, in this band, the AFC response performance can be arbitrarily increased. Although the band filter of the linearization model is shown in the example shown in FIG. 8, any type of linear or non-linear type may be used as long as the AFC response and the suppression of surging are compatible.

As described above, in the present embodiment, the frequency response characteristics of the governor are lower for an input in a frequency band near the surging natural frequency of the surge tank than for an input in other frequency bands. Since it has a band filter circuit set to, no special judgment element such as a surging sensor is required. Even if a signal that may cause excessive surging is given, the water volume control means at the governor outlet need only set the lower frequency response characteristic of the band filter so as not to be excessively shaken.

If the band filter circuit is arranged on the governor output adjustment signal application circuit before the junction with the speed detection signal, the band filter acts only on the output adjustment signal, and the governor's original speed control is achieved. Operation can be prevented from being hindered. In this case, it is assumed that a signal that may cause excessive surging can be limited to an output adjustment signal. An example of such an output adjustment signal is an AFC (automatic frequency control) signal given by remote control.

As a specific example of the band filter, the transfer function is [(1 + T ₂ · S) * (1 + T ₃ · S)] / [(1+
T ₁ · S) * (1 + T ₄ · S)] (where T ₁ to T ₄ are predetermined time constants, and S is a Laplace operator), but the present invention is not limited to this. And from a certain frequency band f _a to impart a low frequency response characteristic than the normal between the frequency band f _b, in which the natural frequency of surging were to enter between the frequency band f _a and the frequency band f _b Anything is fine.

In the above description, the water amount control means corresponds to a guide vane in the power generation mode of a water turbine or a pump-turbine. However, considering the pumping operation mode of the variable speed pumping power generator, it corresponds to a rotation speed control means rather than a guide vane of a pump. I do. This is because the amount of pumped water changes greatly when the rotation speed is changed, but does not change much even when the guide vane opening is changed.
Further, in the above description, the case where the two embodiments of the surging sensor and the band filter are used alone has been described. However, both can be used in combination.

This embodiment can be characterized by the following configuration. 4. The method according to claim 3, wherein the governor operation unit includes a proportional element capable of switching the gain between high and low, and automatically selects the integral element gain and the proportional element gain to a low gain when the surging sensor operates. Hydraulic power plant for hydraulic plant with surge tank.

5. The hydraulic machine according to claim 4, wherein the band filter circuit is disposed on the governor output adjustment signal application circuit before the junction with the speed detection signal.

The surging sensor continuously monitors a specific state quantity of the governor state quantity including the displacement of the flow rate control means downstream of the junction of the speed detection signal and the output adjustment signal, and determines whether the surging is large or small. The momentary value of a predetermined index that has been confirmed in advance of the correlation is calculated from the specific state quantity,
The hydraulic machine for a hydraulic plant equipped with a surge tank according to claim 2, wherein excessive hydraulic surge is detected based on the magnitude of the index every moment.

Even if the governor state quantity returns to a value close to or close to zero in a steady state, or does not return to a value close to or close to zero in a steady state, a predetermined operation such as differentiation is performed to add a certain value to the governor state. Or, a hydraulic machine of a hydropower plant having a surge tank that is used in place of a specific state quantity after being converted into a state quantity that returns to a value close to it.

The hydraulic unit of a hydraulic power plant having a surge tank, wherein the calculating unit includes an integration operation or a storage operation for reflecting the instantaneous state value as well as the history of the previous state amount in calculating the index. machine.

A hydraulic machine of a hydraulic plant including a surge tank, wherein the integration or storage operation is attenuated with time when the surging excitation level of the input signal decreases.

The hydraulic machine of a hydraulic plant equipped with a surge tank according to claim 4, wherein the band filter circuit is disposed on a circuit of a specific application signal to a governor that finally controls the flow rate control means.

The transfer function of the band filter is represented by [(1
_{+ T 2 · S) * (} 1 + T 3 · S)] / [(1 + T 1 · S)
* (1 + T ₄ · S)] or equivalent and the natural frequency of the surge tank subject to surging suppression is 1 / (2π · T
The hydraulic machine according to claim 4, wherein T1 and T2 are adjusted so as to fall between ₁ ) and 1 / (2π · T ₄ ).

Next, in particular, automatic frequency control (A
An embodiment of a hydraulic machine suitable for adjusting the set value of the power of the generator or the electric motor at a high speed from a distance in connection with the system control such as FC) will be described.

In the water channel configuration shown in FIG. 2, the behavior of the water turbine including the water hammer of the hydropower plant shown in FIG.
That is, the linearized model of the governor controlled by the input of the guide vane (water flow control means) opening Y which is the output of the governor is obtained by converting 100F shown in FIG. 3 into g / (0.2 · V ₂₀ + L _3.
V ₃₀ ) · S. Here, each variable is dimensionless and can be expressed by Expression 15.

Change in the opening degree of the guide vane (water amount control means) y → addition unit 100A → simulation term 100B of water hammer → (p _u )
A coefficient 100D for converting a unit of water hammer into (m) units → an addition unit 100E → a term 100F simulating acceleration of a water column in a pipeline →
The total transfer function of the circuit that makes a circuit with the water turbine flow rate change q has a time constant of (L ₂ · V ₂₀ + L ₃ .V ₃₀ ) / (2g · H ₀ ), and is a primary delay element with a gain of 1.0. The time constant of the total transfer function of the guide vane (water amount control means) opening degree change y → addition unit 100A → simulation term 100B of water hammer → effective head change h is (L ₂ · V ₂₀ + L ₃ · V ₃₀ ) / (2 g)・ H ₀ ) and gain 2.
It becomes an incomplete differential element of 0. Therefore, the guide vanes overall transfer function from (water control means) opening change y to water turbine output change _{p t (1-T w ·} S) / (1 + 0.5T w ·
S). Here, T _w = (L ₂ · V ₂₀ + L ₃ .V ₃₀ )
/ (G · H ₀ ).

[0102] That is, when opening the guide vanes decreases temporarily reverse the ones waterwheel output p _t eventually increasing the y value corresponding hydraulic turbine output p _t when closing the guide vanes as opposed to the final Specifically, it shows that it decreases to a value corresponding to y, but temporarily increases in reverse. The influence of the temporary inverse response of the hydraulic turbine output p _t appears to change in the rotational speed N, which also comes restored to the input side of the rotational speed governor. Therefore, if the hydropower plant is separated from the large power system and is in a substantially single power transmission state, or if there is no load operation after the load is completely cut off, the rotation speed control is performed even if this reverse response is present. It is necessary to ensure the stability of the system only with the rotational speed governor, and it is necessary to set the proportional gain P and the integral gain I of the rotational speed governor to be described later sufficiently small. Increasing the differential gain D of the rotational speed governor to a certain extent contributes to the stabilization of the rotational speed control system. However, if it exceeds this, the stability is impaired.

FIG. 12 is a control block diagram of the governor of this embodiment. In FIG. 12, reference numeral 50 denotes a governor (also referred to as a power control unit or a power control unit) for inputting a rotation speed, and 100 denotes a pump turbine connected to the governor 50.
Reference numeral 00 denotes a generator or a motor connected to the pump turbine 100.

A block diagram of the rotational speed governor 50 is shown in FIG.
As shown in FIG. 1 speed detector for detecting the rotational speed N of the pump-turbine 100, X _n is the speed detection signal detected by the speed detector 1, the speed adjustment unit 2 to set a reference value of the rotational speed, x ₀ is the speed adjustment set value output from part 2, 3 calculated by the set value x ₀ and the speed detection signal X _n and the adder and the recovered signal X _sigma from speed droop setting unit to be described later, X _epsilon adder 3 The signal is an input signal of a PID operation circuit immediately downstream, 20 is a surge sensor for an upstream surge tank, 4 is a proportional operation element (P element), 5 is an integral operation element (I element), and 6 is a differential operation element (D element). ), The output signal Z _d , the output signal Z _p of the proportional operation element, and the output signal Z _i of the integral operation element are added by the adder 7. A signal obtained by integrating the output signal Z _p of the proportional operation element, the output signal Z _i of the integral operation element, and the output signal Z _d of the differential operation element is
The guide vane opening command Z is fed back to the guide vane opening command Z and the actual guide vane opening Y is fed back. This deviation signal Y
_ε1 is input to the hydraulic servomotor 10 via the limiter 9. Theta _R is the opening speed of the guide vanes θ _R · C _y limiter 9, theta _L is used to limit the closing speed to θ _l · C _y, the output signal Y _.epsilon.2 deviation signal Y limiter 9 _The signal is obtained by limiting _ε1 in consideration of the above-mentioned opening / closing speed limitation. The hydraulic servomotor 10 is a kind of hydraulic amplifier, and forms a first-order lag element in the transfer function, amplifies the guide vane opening command z and converts it into a guide vane opening Y having a sufficient stroke and operating force. The guide vanes, which are the water amount control means, are directly operated.

[0104] The actual guide vane opening Y is fed back, by an adder 11, the deviation between the guide vane opening setting signal Y _a from the output adjustment unit 13 is provided. If the actual guide vane opening Y guide vane opening setting signal Y _a
If you are not reached, i.e., Y <Y open signal to the PID operation unit of the governor to the difference is zero in the case of _a sigma
Since (Y _a -Y) is continuously fed, eventually settles at that stage becomes Y = Y _a. The open signal σ is set by the speed regulation rate setting unit 12 and outputs a restoration signal _Xσ . The open signal σ is a gain that determines the ratio of the change in the guide vane opening Y to the change in the speed detection signal _Xn , and is generally not changed once determined in consideration of the role of the plant in the power system. .

The governor shown in FIG. 15 has an external load L applied to the generator as a signal applied from the outside.
There are two signals of a given guide vane opening setting signal Y _a from the output adjusting section 13 and. The external load L causes a speed change of the rotation speed _Xn due to the change. on the other hand,
A typical signal input to the output adjustment unit 13 is AF
C (automatic frequency control). In the case of AFC, it is a command issued exclusively from the viewpoint of frequency control of the power system.
Special circumstances of the hydropower plant, such as surging abnormal excitation, are output without being sensed, and are given by remote control from a remote central control station (not shown).

The structure of the AFC control system shown in FIG. 12 is as follows. Although the output adjustment unit 13 is remotely controlled by the AFC, an example in which an increase / decrease command for manual operation of power is also received is shown here. P _afc is AFC
The power value AFC is requested by the command signal, P _g represents the actual generator power, 13C shows deviation between, i.e. the comparison unit for determining the power difference P _.epsilon.1. The power deviation P _ε1 is added to an up / down command for manual operation in the adding unit 13B to become a combined input signal P _ε1 , which is input to the power deviation integrator 13A (also referred to as integration calculating means). Here, the power deviation integrator 13A is a pure integral, but also includes one that can be approximately regarded as an integral. For example, a + 1 / OFF / -1 pulse train is created according to the power deviation P _ε1 and the pulse train is integrated, and the OFF time of the pulse train is set to the power deviation P _ε1.
Some are adjusted according to the conditions. A proportional element 13D (also referred to as a parallel computing unit) is provided in parallel with the power deviation integrator 13A.
The output of 3A is added by the adder 13E. By doing so, the calculation of the power deviation P _ε1 is changed from the I calculation to the PI calculation, and the responsiveness can be greatly improved. Output Y _a of the adder 13E is input to the rotational speed governor 50 as described in detail in FIG. Incidentally, the pump-turbine 100 generates the hydraulic turbine output P _t in response to an input guide vane opening Y. 20
0 indicates synchronous generator in cooperative operation with the power system, wherein the mechanical hydraulic turbine output P _t is the generator power P _g conversion of the electrical output or generator.

The power deviation integrator 13A outputs the guide vane opening setting signal Y while there is an up pulse signal for manual operation.
_a The continued increase at a rate per second K _{I [theta],} while there is reduced pulse signal the guide vane opening setting signal Y _a at a rate per second K _{I [theta]} continues lowered Y _a. Pulse signal stops raising and lowering of the guide vane opening setting signal Y _a when no longer. However since precisely unstoppable not manually adjusted to the desired value speed K when _{I [theta]} is too large guide vane opening setting signal Y _a it is too travels faster becomes difficult, the rate K _{I [theta]} is generally 1 (p _u)
/ 50 sec to 1 (p _u ) / 60 sec.

Rotation speed N, guide vane opening setting signal Y
_a upstream side of the water wheel by any change, there is a possibility that a surge tank of any downstream is abnormally vibrated, here will be mainly described upstream surge tank.

[0109] Figure 16, Figure 17 is the output of the output adjusting section 13 in FIG. 15, namely the guide vane opening setting signal Y _a
FIG. 9 is a Bode diagram showing a response example of the upstream surge tank when the sine wave is changed in a sine wave shape. Figure 16 shows the proportional gain K _p of the rotational speed governor, the integral gain K _i a relatively large set cases, the proportional gain K _p of 17 rotational speed governor, a relatively small set case the integral gain K _i. In this case, the natural frequency of the upstream surge tank is 0.1.
In 00474Hz, response gain of the upstream surge tank water level h _fu even near 0.00474Hz both cases is up sharply. The peak value of the response gain at the natural frequency of the upstream surge tank is 2 in FIG.
At 4.4 (db), it is higher than 7.6 (db) in FIG. 17, and this difference 16.8 (db) is equivalent to 6.9 times. There is no problem if the upper surge tank does not overflow even with the setting of FIG. 16, but if there is a possibility of overflow, a measure is required to reduce the peak value. I.e., to limit the amplitude of the input guide vane opening setting signal Y _a, the proportional gain K _p, it is necessary measures to reduce the integral gain K _i.

In the following description, it is assumed that the allowable maximum value of the response gain peak value at the natural frequency of the upstream surge tank is equivalent to 7.6 (db) shown in FIG. FIG.
Frequency response characteristics of the AFC when the proportional element 13D is not provided, that is, the turbine output P _{t with} respect to the AFC command P _afc
The response performance of FIG. Note that the turbine output _Pt and the generator power P
_Since there is almost no delay between _g , the AFC command P _afc
The response performance of the generator power _{Pg to} the Incidentally, the proportional gain K _p in this case the rotational speed governor, the integral gain K _i is set to the same as that shown in FIG. 17. When the proportional element 13D is not provided as described above, about 0.0
At 1 Hz or more, the AFC response gain is greatly reduced to 1/100 or less, and an AFC response cannot be expected at about 0.01 Hz or more.

FIG. 20 shows the frequency response characteristics of the electric power during the AFC operation of this embodiment. Proportional element 13D as parallel circuit
, And the gain K _pθ is set to 1.0, it can be seen that the frequency response characteristic shown in FIG. 18 is greatly improved especially in the frequency band of 0.01 Hz or more.

FIG. 19 is a Bode diagram of the upstream surge tank water level response during the AFC operation of the present embodiment. Conditions are shown in Fig. 2.
It is the same as that shown in FIG. As can be seen from FIG.
With the improvement of AFC response, surging of the upstream surge tank is also expanding.

As described above, the parallel operation means for inputting the same power deviation signal as that of the power deviation integration calculator in parallel with the power deviation integration calculator of the loop control system for the power command is provided. As it is designed to output a signal that enhances the response of the power deviation integration calculator, the response (power command from distant = actual power) is constantly maintained, but the response is transient. Can be accurately compensated for. In particular, in a configuration in which a sum signal obtained by adding the output of the power deviation integration calculator and the output of the parallel calculation means is applied as a kind of bias signal to the rotation speed governor calculation unit of the rotation speed control system, the parallel calculation means is not rotated. Since it is outside the speed control loop, the power response to a power command from a distance can be freely improved without affecting the loop transfer function of the rotation speed control system. Further, even if the power deviation integral calculator has a sufficiently low gain so as to be able to receive an increase / decrease command for manual operation of the power, the power deviation integral calculator is bypassed and the power with respect to a power command from a distance is bypassed. The response gain can be increased freely.

Further, by providing a proportional operation as a parallel operation means, a simple I operation using only the power deviation integrator can be used to calculate P
+ I (proportional + integral) operation, which makes it possible to freely compensate for gain reduction and phase delay in terms of frequency response, and more appropriately optimizes the response of the power control system to power commands from a distance. It becomes possible to do.
In addition, by providing a proportional operation and a differential operation in the parallel operation means, a simple I operation using only the power deviation integrator can be performed to obtain P + I +
D (proportional + integral + derivative) operation,
The frequency response characteristics of power control for a power command from a distance can be more accurately improved and optimized.
In spite of special circumstances on the rotation speed control system side downstream of the rotation speed governor calculation unit, for example, circumstances in which the PID gain of the rotation speed governor cannot be increased freely, appropriate optimization can be achieved.

FIG. 13 shows an AFC control system according to another embodiment of the present invention. This embodiment has the same configuration as the embodiment shown in FIG. 12, but in this embodiment, a band filter 13F is provided in the AFC input receiving unit. FIG. 14 shows the frequency response characteristics of the band filter section shown in FIG. That is, it is a Bode diagram showing the frequency response characteristics of the band filter 13F alone. In this band filter, the response gain starts to decrease from 1 / (2πT ₁ ) (Hz) and becomes the lowest in the range of 1 / (2πT ₂ ) (Hz) to 1 / (2πT ₃ ) (Hz). It starts rising again from (2πT ₃ ) (Hz) and returns to the original level at 1 / (2πT ₄ ) (Hz). And the natural frequency of the upstream surge tank
0.00474 (Hz) is 1 / (2πT ₂ ) (Hz) to 1 / (2π
The time constants T ₂ and T ₃ are set to fall within the frequency band T ₃ ) (Hz)
Is set. In addition, even if the natural frequency of the upstream surge tank does not accurately enter the low gain portion of the band filter, the natural frequency falls between 1 / (2πT ₁ ) (Hz) and 1 / (2πT ₄ ) (Hz). If it is not efficient, the effect can be expected.

FIG. 22 is a Bode diagram of the power response during the AFC operation of this embodiment. The condition is 0.00474 Hz as 1 / (2
The provision of a band filter set to fall within the frequency band from πT ₂ ) (Hz) to 1 / (2πT ₃ ) (Hz)
_The settings are the same as those shown in FIG. 20 except that _iθ is reduced to 1/10. As a result, the power response around 0.00474 Hz slightly decreased, but there was no effect above 0.1 Hz.

FIG. 19 is a Bode diagram of the upper surge tank water level response during the AFC operation of the present embodiment. The conditions are the same as those in FIG. Natural frequency of upstream surge tank 0.
The peak value at 00474 Hz is 0.89 (db), and FIG.
9 is much lower than 24.2 (db). In addition, the overflow determination level 7.6 (d
b) is significantly lower. In the example described above, a linear model [(1 + T ₂ · S) * (1 + T ₃
[S]] / [(1 + T ₁ · S) * (1 + T ₄ · S)] has been described as an example, but any one that exerts an effect of finally lowering the surging frequency response gain near the surging resonance frequency will be described. Anything is fine.

Although only the water level fluctuations of the upstream and downstream surge tanks have been described as resonance potentials, when the rotational speed governor itself and its control target have similar resonance potentials, similar measures are taken for each of them. Should be taken.

As described above, according to the present embodiment,
Since a band filter is provided in the remote command receiving unit,
Even if, as a result of the power control response measures described above, the possibility of abnormal excitation in a specific frequency band, such as surge resonance of a surge tank, appears, the power control response in only that specific frequency band is accurately reduced to avoid the problem. In other non-hazardous frequency bands, the power control response can be raised to the fullest.

When the P + I + D operation is used for the remote power control and the band filter is used in the remote command receiving unit, the P + I operation is used for the remote power control and the band filter is used in the remote command receiving unit. , More fine grained adjustment.

Note that the transfer function of the band filter is [(1 + T ₂ · S) * (1 + T ₃ · S)] / [(1 + T ₁ · S)
* (1 + T ₄ · S)] (where T ₁ to T ₄ are predetermined time constants, S is a Laplace operator and T ₁ <T ₂ <T ₃ <T ₄ ), and the frequency response characteristic is 1 / (2π · T ₁ ) to 1 / (2
π · T ₄ ) can be reduced only in the frequency band, so that resonance can be achieved by adjusting T ₁ and T ₄ so that a specific frequency band in which resonance on the control target side such as the surging resonance frequency is expected falls within this range. Can be accurately prevented.

The frequency response characteristic of this filter is 1
Since the bottom is between / (2π · T ₂ ) and 1 / (2π · T ₃ ), T is set so that a specific frequency band in which resonance is expected falls within this range.
_It is more preferable to adjust ₂ , ₃ .

The band filter is not limited to the above-described example, but has _a frequency response characteristic lower than usual between _a certain frequency band f _a and f _b , and a specific frequency band in which resonance is expected is set to this frequency band. Frequency f _a and frequency f
Anything that can be inserted between _b may be used.

The present embodiment can be characterized by the following configuration. That is, a water turbine having a runner, a generator or a motor mechanically directly connected to the runner and electrically connected to a power system, power control means for controlling an output of the generator or an input of the motor, Manual operation command means for manually giving a raising or lowering operation command, distant command means for giving a required value of power from a distance, power restoring means for restoring an actual power value, and a request value from the distant command means. A deviation deriving means for calculating a deviation of the actual power value from the power restoring means, and running at a speed suitable for visual confirmation according to a power deviation signal output from the deviation deriving means and a command from the manual operation command means. The power control means further includes an integral power command calculating means for inputting a power increase / decrease command signal to the power control means or performing an equivalent calculation, and in the case of power control from a distance, the deviation derivation is performed. Stage → integral type power command calculating means → water turbine and generator / motor → negative feedback circuit of power restoring means, wherein the power deviation signal is inputted, and the integral type power command calculating means Parallel operation means arranged in parallel with the output of the integral power command operation means so as to correct the output of the integral power command operation means. A hydraulic machine characterized by outputting a signal to increase the output, and returning the output to zero or substantially zero when it returns to a steady state.

The hydraulic machine according to any one of claims 5 to 8, wherein said parallel computing unit comprises a proportional computing element and a differential computing element connected in series.

The hydraulic machine according to any one of claims 5 to 8, wherein the arithmetic unit is configured to run at a speed suitable for visual confirmation and to input a manually increasing or decreasing command signal of electric power.

[0127] While the arithmetic unit has the power deviation signal output from the comparison unit, the output signal that acts on the power control unit to reduce the power deviation is continuously increased. 9. The hydraulic machine according to any one of claims 1 to 8.

A band filter provided before the comparing section or the deviation deriving means and for inputting the required value of the power from a distance, wherein the response gain of the band filter has a variation in a specific frequency band. The hydraulic machine according to any one of claims 5 to 8, wherein the input power is reduced as compared with the fluctuation input of another frequency band.

The method according to claim 5 or 8, wherein the arithmetic unit outputs a signal that enhances the response in a transient state in which there is a power deviation, and returns the output to zero or substantially zero when it returns to a steady state. Hydraulic machine.

T ₁ , T ₂ , T ₃ , and T ₄ are set to T ₁ with a predetermined time constant.
<T ₂ <T ₃ <T ₄ , where S is a Laplace operator, the transfer function of the band filter is [(1 + T ₂ · S) * (1+
T ₃ · S)] / [(1 + T ₁ · S) * (1 + T ₄ · S)] or equivalent, and the specific frequency band with the possibility of resonance is 1 /
T ₁ , which falls between (2π · T ₁ ) and 1 / (2π · T ₄ ),
Hydraulic machinery set the T _4.

[0131]

According to the present invention, it is possible to guarantee that abnormal surge of surging can be automatically prevented. Therefore, without impairing safety, the capacity of the surge tank (specifically, (Cross-sectional area and height) can be greatly reduced, and civil engineering costs can be reduced. In addition, even if the surging sensor system or the band filter system is used, the governor can be achieved without drastically changing the governor, and the cost increase for this is negligible compared with the effect. By utilizing the band filter, the governor response characteristics of the AFC or the like can be significantly improved in a manner consistent with surging.

Further, even when both the rotation speed control system and the power control system responding to the remote command finally control the same operating end, the response of the power control system responding to the remote command is controlled by the rotation speed control. The response performance of the system, particularly the stability, can be reasonably optimized without impairing the stability, and the response gain can be greatly improved.

Further, even when the power deviation integration gain cannot be made sufficiently high, such as when the power deviation integration arithmetic unit receives the power increase / decrease commands for the manual operation of the power, the responsiveness of the power control system to the distant command is improved. Can be raised freely.

Further, abnormal vibration phenomena in a specific frequency band such as surge tank surges in the upstream and downstream waterways can be rationally prevented, and the responsiveness of the loop control system is maintained to a maximum in other frequency bands. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram of a governor according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a water channel of a hydropower plant having surge tanks in both upper and lower water channels.

FIG. 3 is a block diagram showing a linearized model of a governor control object.

FIG. 4 is a block diagram of an upper surging tank shown in FIG. 3;

FIG. 5 is a block diagram of a lower surging tank shown in FIG. 3;

FIG. 6 is a configuration diagram illustrating an example of a surging sensor.

FIG. 7 is a diagram illustrating an operation of a surging sensor.

FIG. 8 is a diagram illustrating the operation of a surging sensor.

FIG. 9 is a diagram illustrating an analysis example of evaluation of detection accuracy of a surging sensor.

FIG. 10 is a block diagram illustrating an example of a band filter.

FIG. 11 is a Bode diagram showing a frequency response characteristic of the band filter shown in FIG. 10;

FIG. 12 is a diagram showing a configuration of an AFC control system according to another embodiment of the present invention.

FIG. 13 is a diagram illustrating a configuration of an AFC control system according to another embodiment of the present invention.

FIG. 14 is a diagram illustrating a frequency response characteristic of the band filter unit of FIG. 13;

FIG. 15 is a block diagram of a rotational speed governor.

FIG. 16 is a Bode diagram showing a response of the surge tank when Ya is changed in _a sine wave shape in FIG.

FIG. 17 is a Bode diagram showing a response of the surge tank when Ya is changed in _a sine wave shape in FIG.

18 is a diagram illustrating the frequency response characteristics of the AFC when the parallel circuit of FIG. 15 is not provided.

FIG. 19 is a Bode diagram of an upper surge tank water level response during the AFC operation of the embodiment in FIG. 12;

FIG. 20 is a diagram illustrating frequency response characteristics of electric power during the AFC operation of the embodiment in FIG. 12;

FIG. 21 is a Bode diagram of an upper surge tank water level response during the AFC operation of the embodiment in FIG. 13;

FIG. 22 is a Bode diagram of a power response during the AFC operation of the embodiment in FIG. 13;

[Explanation of symbols]

1: speed detector, 2: speed adjuster, 3: adder, 4, 4
a, 4b: Proportional operation element, 5, 5a, 5b: Integral operation element, 6: Differential operation element, 7, 8, 11: Addition unit, 9: Limiter, 10: Hydraulic servomotor, 12: Speed adjustment rate setting Unit, 13: output adjustment unit, 14: block diagram, 16
... Calculation units, 17a, 17b ... Calculation units, 20 ... Surging sensor, 100 ... Pump turbine, 101 ... Headway, 102
... penstock, 103 ... suction pipe, 104 ... discharge channel, 105
... Upper pond, 106 ... Upstream surge tank, 107 ... Downstream surge tank, 108 ... Lower pond.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinji Yumoto 3-1-1 Kochicho, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Thermal and Hydropower Division (72) Inventor Mitsuhiro Ishiguro 1-Chome Uchisaiwaicho, Chiyoda-ku, Tokyo No. 1-3 Tokyo Electric Power Co., Inc. (72) Inventor Naoyuki Haneda 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo F-term in Tokyo Electric Power Co., Inc. 3H073 AA12 BB06 BB33 CC05 CC20 CD03 CD06 CE09

Claims (8)

[Claims] 1. A hydraulic machine installed in a hydraulic plant having a movable flow control means, a governor controlling the flow control means, and a surge tank in an upstream or downstream pipe,
A low response setting for the governor to provide a low frequency response characteristic for an input signal in a frequency band near the natural frequency of the surge tank, and a higher frequency response characteristic for an input signal in other frequency regions. A hydraulic machine for a hydraulic plant with a surge tank, characterized in that the hydraulic machine has a high response setting for providing a hydraulic pressure. 2. The surge according to claim 1, further comprising a surging sensor for detecting excessive surging or a precursory phenomenon thereof, wherein the governor automatically selects a low response setting on condition that the surging sensor is operated. Hydraulic machinery of a hydraulic plant with tanks. 3. A hydraulic power plant having a movable flow control means, a governor for controlling the flow control means, a surge tank in an upstream or downstream pipeline, and a surging sensor for detecting excessive surging or a precursory phenomenon thereof. A hydraulic machine provided with a surge tank characterized in that the governor arithmetic unit is configured to be able to switch between high and low integral element gains and automatically selects the low gain side when the surging sensor operates. Plant hydraulic machine. 4. A hydraulic power plant having a movable flow control means, a governor for controlling the flow control means, a surge tank in an upstream or downstream pipeline, and a band filter circuit for setting a frequency response characteristic of the governor. A frequency response characteristic of the band filter circuit for an input in a frequency band close to the surging natural frequency of the surge tank, compared to an input in another frequency band, the frequency response of the governor. A hydraulic machine for a hydraulic plant comprising a surge tank, the characteristics of which are set to be low. 5. A generator or a motor electrically connected to the power system, a water turbine connected to the generator or the motor, a power control unit for controlling the power generated by the generator or the motor, A comparison unit that calculates a power deviation between the required power value and the actual power value, and a calculator that inputs the power deviation obtained by the comparison unit and outputs a guide vane opening setting signal to the power control unit. A hydraulic machine characterized in that the computing unit is constituted by a parallel computing unit including a power deviation integrator and a proportional element provided in parallel with the power deviation integrator. 6. A generator electrically connected to a power system,
A turbine connected to the generator, a rotation speed governor controlling the generated power of the generator, a comparison unit for calculating a power deviation between a required value of power from a distance and an actual power value, and An arithmetic unit for inputting the determined power deviation and outputting a guide vane opening setting signal to the rotational speed governor is provided, and the arithmetic unit includes a power deviation integrator and a proportional element provided in parallel with the power deviation integrator. A hydraulic machine characterized by comprising a parallel computing unit. 7. A generator or a motor electrically connected to the power system, a water turbine connected to the generator or the motor, a power control unit for controlling the generated power of the generator or the motor, A comparison unit that calculates a power deviation between the required power value and the actual power value, and a calculator that inputs the power deviation obtained by the comparison unit and outputs a guide vane opening setting signal to the power control unit. A parallel computing unit arranged in parallel with the integral computing unit or the equivalent computing unit for correcting the output of the integral computing unit or the equivalent computing unit. Output a signal that enhances the response of the arithmetic unit or an equivalent arithmetic unit,
A hydraulic machine having a characteristic of returning its output to zero or substantially zero when it returns to a steady state. 8. A turbine having a runner, a generator or an electric motor mechanically directly connected to the runner and electrically connected to a power system, a speed detector for detecting a rotation speed of the turbine, and the speed detector. A rotational speed governor responsive to the output signal of the turbine for minimizing the deviation between the mechanical output / input of the turbine and the generator output / motor input; the speed detector → the rotational speed governor → the turbine and the power generator The output of the turbine is changed by changing the bias without changing the overall transfer function of the rotation speed control loop consisting of the motor / motor → rotation speed → speed detector.
Power adjusting means for adjusting the set value of the input, distance command means for providing a required value of power from a distance, power restoring means for restoring the actual power value, and a request value and power restoring means from the remote command means And a deviation deriving means for obtaining a deviation of an actual power value from the input signal, and a deviation obtained by the deviation deriving means is input and arranged in parallel with an integration operation means or an equivalent operation means. Parallel operation means for correcting the output of the operation means, and outputs a signal which enhances the response of the integral operation means or an equivalent operation means during a transient with a power deviation, and outputs the signal when the state returns to a steady state. A hydraulic machine, wherein the hydraulic pressure is set to zero or substantially zero.