CN102776870A - Non-forecast flood regulation method for cascade hydropower station based on water level flow - Google Patents

Abstract

The invention discloses a non-forecast flood regulation method for a cascade hydropower station based on water level flow. The method comprises the following steps of: 1, measuring an initial water level of a reservoir with a floodometer and determining the capacity of a reservoir to be accumulated according to a preset flood control high water level; 2, calculating the current reservoir flow, and calculating the residual flood volume according to a peak and amount relationship; and 3, maintaining the water storage working conditions when the residual flood volume is smaller than the capacity of the reservoir to be accumulated, controlling the flow through a water level fluctuation method when the residual flood volume is greater than the capacity of the reservoir to be accumulated, and accumulating the reservoir flow to a preset high water level. In the regulation process, the actually measured flood storage flow is the current flood peak flow, if the residual flood volume is smaller than the capacity of the reservoir to be accumulated, the water storage working conditions are maintained, and at the moment, the highest reservoir level can be ensured to be lower than the preset high water level; and when the residual flood volume is greater than the capacity of the reservoir to be accumulated, the flood is controlled through the water level fluctuation method, and the reservoir flow is accumulated to the preset high water level.

Description

Nothing forecast flood dispatching method based on the step power station of stage-discharge

Technical field

The present invention relates to the nothing forecast flood dispatching method based on the step power station of stage-discharge, belonging to does not have forecast flood dispatching technique field.

Background technology

When reservoir meets with nothing forecast flood; Can't draft scheduling scheme in advance and carry out planned flood scheduling; But the safety of guaranteeing dam, power station remains the principle that must will observe; Under putting before this, let out, and the reservoir that reservoir especially reservoir level is lower fills and holds predetermined high water level as much as possible with flood safety.The normal employing followed the tracks of the dispatching method that reservoir inflow descend let out in the existing technology, and the shortcoming of this method is reservoir to be filled when being difficult in flood and finishing to hold the high water level of being scheduled to, and can't carry out the flood resource utilization effectively.

Summary of the invention

The objective of the invention is to, the nothing forecast flood dispatching method based on the step power station of stage-discharge is provided, it guarantees the safety in dam, power station after not only can be implemented in and meeting with nothing forecast flood, holds predetermined high water level but also can reservoir be filled.

For solving the problems of the technologies described above, the present invention adopts following technical scheme: the nothing forecast flood dispatching method based on the step power station of stage-discharge may further comprise the steps:

S1, floodometer measure the initial water level of reservoir and confirm storage capacity to be held according to preset upper water level for flood control;

S2 keeps all the time completely to send out under the flow with unit and lets out, up to retaining till half waits to hold storage capacity;

S3 calculates current reservoir inflow, and calculates the residue flood volume according to peak, magnitude relation;

S4 is if the residue flood volume is then kept the retaining operating mode, and forwarded S3 to less than residue storage capacity to be held; If remain flood volume greater than residue storage capacity to be held, then control through the water-level fluctuation method, reservoir is filled hold predetermined high water level.

The nothing forecast flood dispatching method of aforesaid step power station based on stage-discharge, first last water level and gate letdown flow according to the period among the step S2 calculate current reservoir inflow, are specially: Q (t)=(V (t+1)-V (t))/Δ t+q (t); Wherein, Q (t) is for facing the period reservoir inflow, and V (t+1) is the t pondage of period Mo, and V (t) is the pondage at the beginning of the t period; Segment length when Δ t is, q (t) are period outbound flows.

In the nothing forecast flood dispatching method of aforesaid step power station based on stage-discharge, the current reservoir inflow described in the step S3 promptly faced the peak flood flow of flood at that time.

In the nothing forecast flood dispatching method of aforesaid step power station based on stage-discharge, the described water-level fluctuation method of step S4 may further comprise the steps:

S10, floodometer measure the initial water level of reservoir and confirm the undulating value that water level allows;

S20, the unlatching scheme of adjustment gate makes it follow the tracks of the real-time flood reservoir inflow;

S30 if floodometer detects water level and descends continuously, then calculates the peak flood flow of this flood into reservoir, and obtains the water-break section flood water yield according to the peak magnitude relation of reservoir flood, revises progressively closed shutter of gate opening scheme;

S40 if floodometer does not detect water level and descends continuously, then forwards S20 to.

In the nothing forecast flood dispatching method of aforesaid step power station based on stage-discharge, the unlatching scheme of the described adjustment gate of step S20 makes it follow the tracks of real-time flood reservoir inflow specifically to comprise the rising limb scheduling:

(I) flood is at t ₀Rise constantly and rise by t ₁Observed stage constantly, and write down Z ₁

(II) calculated t ₀～t ₁The Δ v of period ₀₁, $\stackrel{\‾}{Q}=\frac{{\mathrm{\Δ\; v}}_{01}}{t_1-t_0},$ $Q_m=2\stackrel{\‾}{Q};$

(III) t ₁Moment starting gate, open degree B is at Z ₁Under the condition, let out 2Q down _m

(IV) kept gatage, and the record water level is by Z ₁Drop to the time t ' of minimum point ₁(lasting Δ t '), gate is held time prolongs Δ t ' again;

(V) observation t ₂Moment water level, and record Z ₂By t ₂, t ' ₁The water-head that two moment recorded is obtained the storage capacity value added

(VI) calculated t ' ₁～t ₂Period average discharge increment, promptly

$\mathrm{\Δ}\stackrel{\‾}{Q}=\mathrm{\Δ}{V}_{t_1^{\′}{t}_2}/(t_2-t_1^{\′});$

(VII) is on the basis of former aperture, at t ₂Constantly increase gatage, it met the following conditions:

(a) reservoir level is controlled at Z ₂Under the water level condition;

(b) flow of letting out under is

After (VIII) increased aperture from gate, observation and record drawdown were to minimum point moment t ' ₂(last Δ t "), and holding time of gate prolonged Δ t "; Judge to regulate whether reach flood peak, that is: judge whether the water level of the double collection of floodometer is downward trend, if, then finish, if not, then forward (I) to;

Wherein, Be t ₀～t ₁The average reservoir inflow of period;

Q _mBe t ₁Reservoir inflow constantly;

Δ v ₀₁Be t ₀～t ₁The storage capacity changing value of period;

Z ₁Be t ₁Reservoir level constantly.

In aforesaid step power station crowd's the nothing forecast flood dispatching method; The described peak flood flow that calculates this flood into reservoir of step S30; And obtain the water-break section flood water yield according to the peak magnitude relation of reservoir flood, revise the gate opening scheme progressively closed shutter specifically comprise the scheduling of water-break section:

(I) is by formula

Obtain gate and should continue to reduce Δ Q from the letdown flow (known) of bc period _Cf

(II) is by formula

Obtain the letdown flow of keeping after the minimizing and be lasted for t _Fe, promptly from t ₇Constantly to t _eFinish;

(III) checked (check) and it satisfied:

$Q_{\mathrm{cf}}\≤2\mathrm{\Δ}\stackrel{\‾}{Q^{\′\′}}+4\mathrm{\Δ}\stackrel{\‾}{Q}+4\stackrel{\‾}{Q}$

Wherein, Δ v is t ₆～t ₇The storage capacity changing value of period;

Δ V is t ₆The storage capacity to be held of period;

Δ Q _CfBe t ₇The outbound flow of period reduces value.

Compared with prior art, the stage-discharge of the present invention through checking the floods, when the residue flood volume when waiting to hold storage capacity, reservoir is carried out retaining, thereby can effectively guarantee the safety in dam and power station, prevent to overflow the generation of dam accident; In addition; In scheduling process; The flood reservoir inflow of actual measurement promptly faced the peak flood flow of flood at that time, calculated the corresponding residue flood volume of this peak flood flow according to the peak magnitude relation, if the residue magnanimity is less than storage capacity to be held; Then keep the retaining operating mode, can guarantee that the highest reservoir level is less than the high water level of setting this moment; If the residue magnanimity is greater than storage capacity to be held; Then getting into the water-level fluctuation method controls; Guarantee in the flood water-break stage through analog simulation calculation in advance and line dynamic adjustment through reservoir historical flood water-break rule, peak magnitude relation, reservoir is filled hold predetermined high water level.The present invention retains the plan water retention capacity about half equably from the flood section beginning of rising of flood; Follow the tracks of under the reservoir inflow afterwards and let out; Retain remaining half once more equably in the water-break section and intend water retention capacity, so the present invention is applicable to that reservoir level is lower, the bigger situation of plan water retention capacity.

Description of drawings

Fig. 1 is the workflow diagram of a kind of embodiment of the present invention;

Fig. 2 is that the water-level fluctuation method is transferred big vast sketch map;

Fig. 3 is that the water-level fluctuation method transfers flood to calculate basic flow sheet.

Below in conjunction with the accompanying drawing and the specific embodiment the present invention is further described.

The specific embodiment

Embodiments of the invention: as shown in Figure 1 based on the nothing forecast flood dispatching method of the step power station of stage-discharge, may further comprise the steps:

S1 confirms the storage capacity Δ V of current water level to the high water level of setting (or given last water level), if reservoir level is the flood position of restricting water supply before flood arrives, the high water level of then setting is a upper water level for flood control, and Δ V at this moment just is the storage capacity of reservoir;

S2 keeps all the time completely to send out under the flow with unit and lets out, up to retaining till half waits to hold storage capacity;

S3 faces the peak flood flow Q that period reservoir inflow Q (t) promptly faces flood _{The peak}, calculating faces period reservoir inflow Q (t) and adopts following method: Q (t)=(V (t+1)-V (t))/Δ t+q (t), and wherein V (t+1) is the t pondage of period Mo; V (t) is the pondage at the beginning of the t period; Segment length when Δ t is, q (t) are period outbound flows, according to peak, magnitude relation W _Flood=f (Q _{The peak}) calculating residue flood volume W _Flood

S4 is with this W _FloodAs criterion:

If W _Flood＜Δ V then keeps the retaining operating mode;

If W _Flood>=Δ V, priming level fluctuation method is then carried out gate and is followed the tracks of to flow down and let out operating mode, comprising:

A, the unlatching scheme of adjustment gate makes it follow the tracks of the real-time flood reservoir inflow, specifically comprises the rising limb scheduling:

(I) (as shown in Figure 2) flood is at t ₀Rise constantly and rise by t ₁, moment observed stage, and write down

(II) calculate t ₀～t ₁The Δ v of period ₀₁, $\stackrel{\‾}{Q}=\frac{{\mathrm{\Δ\; v}}_{01}}{t_1-t_0},$ $Q_m=2\stackrel{\‾}{Q};$

(III) t ₁Moment starting gate, open degree B exists

Under the condition, let out 2Q down _m

(IV) kept gatage, and the record water level by

Drop to the time t ' of minimum point ₁(lasting Δ t '), gate is held time prolongs Δ t ' again;

(V) observation t ₂Moment water level, and record

By t ₂, t ' ₁The water-head that two moment recorded is obtained the storage capacity value added

(VI) calculated t ' ₁～t ₂Period average discharge increment, promptly

$\mathrm{\Δ}\stackrel{\‾}{Q}=\mathrm{\Δ}{V}_{t_1^{\′}{t}_2}/(t_2-t_1^{\′});$

(VII) is on the basis of former aperture, at t ₂Constantly increase gatage, it met the following conditions:

(a) reservoir level is controlled at Z ₂Under the water level condition;

(b) flow of letting out under is

After (VIII) increased aperture from gate, observation and record drawdown were to minimum point moment t ' ₂(last Δ t "), and holding time of gate prolonged Δ t "; Judge to regulate whether reach flood peak, that is: judge whether the water level of the double collection of floodometer is downward trend, if, then finish, if not, then forward (I) to;

Wherein, Be t ₀～t ₁The average reservoir inflow of period;

Q _mBe t ₁Reservoir inflow constantly;

Δ v ₀₁Be t ₀～t ₁The storage capacity changing value of period;

Z ₁Be t ₁Reservoir level constantly.

B; If floodometer detects water level and descends continuously, then calculate the peak flood flow of this flood into reservoir, and obtain the water-break section flood water yield according to the peak magnitude relation of reservoir flood; Revise progressively closed shutter of gate opening scheme, specifically comprise water-break section scheduling (as shown in Figure 2):

(I) is by formula

Obtain gate and should continue to reduce Δ Q from the letdown flow (known) of bc period _Cf

(II) is by formula

Obtain the letdown flow of keeping after the minimizing and be lasted for t _Fe, promptly from t ₇Constantly to t _eFinish;

(III) checked (check) and it satisfied:

$Q_{\mathrm{cf}}\≤2\mathrm{\Δ}\stackrel{\‾}{Q^{\′\′}}+4\mathrm{\Δ}\stackrel{\‾}{Q}+4\stackrel{\‾}{Q}$

If following formula is set up, reservoir can hold full, otherwise reservoir can't fill the high water level that holds to predetermined, and concrete calculation process is as shown in Figure 3;

Wherein, Δ v is t ₆～t ₇The storage capacity changing value of period;

Δ V is t ₆The storage capacity to be held of period;

Δ Q _CfBe t ₇The outbound flow of period reduces value.

C if floodometer does not detect water level and descends continuously, then forwards a to.

This programme is retained the plan water retention capacity about half equably from the flood section beginning of rising of flood, follows the tracks of afterwards under the reservoir inflow and lets out, and retains remaining general quasi water retention capacity once more equably in the water-break section.Therefore this programme is applicable to that reservoir level is lower, intends the bigger situation of water retention capacity.

The difference of stage-discharge method and water-level fluctuation method: stage-discharge method reservoir inflow at any time is the peak flood flow of local flood, calculates the water yield always of water-break section by this peak flood flow, and flood section and water-break section are respectively retained half storage capacity to be held rising; And the water-level fluctuation method is only followed the tracks of warehouse-in and is let out down, and up to double drawdown, then this reservoir inflow is a peak flood flow, calculates that in view of the above the water-break section comes the water yield, concentrates on that the water-break section is concentrated retains storage capacity to be held.

Claims (5)

1. based on the nothing forecast flood dispatching method of the step power station of stage-discharge, it is characterized in that, may further comprise the steps:

S1, floodometer is measured the initial water level of reservoir, and confirms storage capacity to be held according to preset upper water level for flood control;

S2 completely sends out under the flow with unit and to let out, up to retaining till half waits to hold storage capacity;

S3 calculates current reservoir inflow, and calculates the residue flood volume according to peak, magnitude relation;

S4 is if the residue flood volume is then kept the retaining operating mode, and forwarded S3 to less than residue storage capacity to be held; If remain flood volume greater than residue storage capacity to be held, then control through the water-level fluctuation method, reservoir is filled hold predetermined high water level.

2. the nothing forecast flood dispatching method of the step power station based on stage-discharge according to claim 1 is characterized in that the current reservoir inflow described in the step S3 promptly faced the peak flood flow of flood at that time.

3. the nothing forecast flood dispatching method of the step power station based on stage-discharge according to claim 1 is characterized in that the water-level fluctuation method described in the step S4 may further comprise the steps:

S10, floodometer measure the initial water level of reservoir and confirm the undulating value that water level allows;

S20, the unlatching scheme of adjustment gate makes it follow the tracks of the real-time flood reservoir inflow;

S30 if floodometer detects water level and descends continuously, then calculates the peak flood flow of this flood into reservoir, and obtains the water-break section flood water yield according to the peak magnitude relation of reservoir flood, revises progressively closed shutter of gate opening scheme;

S40 if floodometer does not detect water level and descends continuously, then forwards S2 to.

4. the nothing forecast flood dispatching method of the step power station based on stage-discharge according to claim 3 is characterized in that, the unlatching scheme of the adjustment gate described in the step S20 makes it follow the tracks of real-time flood reservoir inflow specifically to comprise the rising limb scheduling:

(I) flood is at t ₀Rise constantly and rise by t ₁Observed stage constantly, and write down Z ₁

(II) calculated t ₀～t ₁The Δ v of period ₀₁, $\stackrel{\‾}{Q}=\frac{{\mathrm{\Δ\; v}}_{01}}{t_1-t_0},$ $Q_m=2\stackrel{\‾}{Q};$

(III) t ₁Moment starting gate, open degree B is at Z ₁Under the condition, let out 2Q down _m

(IV) kept gatage, and the record water level is by Z ₁Drop to the time t ' of minimum point ₁(lasting Δ t '), gate is held time prolongs Δ t ' again;

(V) observation t ₂Moment water level, and record Z ₂By t ₂, t ' ₁The water-head that two moment recorded is obtained the storage capacity value added

(VI) calculated t ' ₁～t ₂Period average discharge increment, promptly $\mathrm{\Δ}\stackrel{\‾}{Q}=\mathrm{\Δ}{V}_{t_1^{\′}{t}_2}/(t_2-t_1^{\′});$

(VII) is on the basis of former aperture, at t ₂Constantly increase gatage, it met the following conditions:

(a) reservoir level is controlled at Z ₂Under the water level condition;

(b) flow of letting out under is

After (VIII) increased aperture from gate, observation and record drawdown were to minimum point moment t ' ₂(last Δ t "), and holding time of gate prolonged Δ t "; Judge to regulate whether reach flood peak, that is: judge whether the water level of the double collection of floodometer is downward trend, if, then finish, if not, then forward (I) to;

Wherein,

Be t ₀～t ₁The average reservoir inflow of period;

Q _mBe t ₁Reservoir inflow constantly;

Δ v ₀₁Be t ₀～t ₁The storage capacity changing value of period;

Z ₁Be t ₁Reservoir level constantly.

5. step power station crowd's according to claim 3 nothing forecast flood dispatching method; It is characterized in that; The described peak flood flow that calculates this flood into reservoir of step S30; And obtain the water-break section flood water yield according to the peak magnitude relation of reservoir flood, revise the gate opening scheme progressively closed shutter specifically comprise the scheduling of water-break section:

(I) is by formula Obtain gate and should continue to reduce Δ Q from the letdown flow (known) of bc period _Cf

(II) is by formula

Obtain the letdown flow of keeping after the minimizing and be lasted for t _Fe, promptly from t ₇Constantly to t _eFinish;

(III) checked (check) and it satisfied:

$Q_{\mathrm{cf}}\≤2\mathrm{\Δ}\stackrel{\‾}{Q^{\′\′}}+4\mathrm{\Δ}\stackrel{\‾}{Q}+4\stackrel{\‾}{Q}$

Wherein, Δ v is t ₆～t ₇The storage capacity changing value of period;

Δ V is t ₆The storage capacity to be held of period;

Δ Q _CfBe t ₇The outbound flow of period reduces value.

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