Cascade reservoir short-term scheduling method considering influence of dynamic reservoir capacity and backwater jacking

Abstract

The invention discloses a cascade reservoir short-term scheduling method considering the influence of dynamic reservoir capacity and backwater jacking. The method comprises the following steps: constructing a target function; setting constraint conditions; initial water levels of upstream and downstream power stations, upstream power station reservoir flow, downstream representative station water levels of downstream power stations, cascade power station interval runoff and power load plans are obtained, and initial reservoir capacities of all hydropower stations are obtained according to the reservoir capacity curve; assuming the end water level of the upstream power station in the time period, and calculating the corresponding ex-reservoir flow, the end water level, the power generation water head and the power station output; if the output of the upstream power station meets the load plan requirement in the period, adjusting and calculating the output of the downstream power station in the period; according to the upstream reservoir outlet flow and the interval runoff, the downstream reservoir inlet flow is calculated; if the load plan requirement of the downstream power station in the time period is met, adjusting calculation in the next time period is carried out; according to the method, the influence of the dynamic reservoir capacity and the backwater jacking is fully considered, and real-time optimal scheduling of the cascade reservoir is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reservoir scheduling, in particular to a short-term scheduling method for cascade reservoirs considering dynamic reservoir capacity and backwater uplift influence. BACKGROUND

[0002] In the traditional optimal scheduling of reservoirs, the water balance method based on the static reservoir capacity principle is adopted for calculation, that is, only the static reservoir capacity of the reservoir is considered in the optimization calculation, and it is assumed that the water surface of the reservoir is a horizontal surface and the fluctuation is a horizontal fluctuation. However, in the cascade reservoirs between two dams, a wedge-shaped reservoir capacity, i.e. dynamic reservoir capacity, is generally formed. After processing according to the static reservoir capacity assumption, the optimization calculation of reservoir scheduling can be simplified, but the reservoir capacity calculated according to the static reservoir capacity curve is not accurate and has a large deviation from the actual situation, thereby affecting the accuracy of water calculation.

[0003] In the optimal scheduling of cascade reservoirs, the influence of the backwater uplift of the downstream hydropower station is often ignored in most current researches, and the tailwater level of the upstream hydropower station is regarded as being only affected by the discharge of the upstream hydropower station, and a tailwater level-flow relationship curve is drawn. After such simplified processing, the optimal calculation of the cascade reservoirs is more convenient, but since the tailwater level-flow curve ignores the influence of the backwater uplift of the downstream hydropower station, it is inconsistent with the actual situation in describing the change law of the tailwater level of the upstream hydropower station, which will inevitably lead to a deviation between the result of the optimal scheduling of the cascade hydropower stations and the actual situation. SUMMARY

[0004] The present application aims to overcome the above-mentioned deficiencies and provide a short-term scheduling method for cascade reservoirs considering dynamic reservoir capacity and backwater uplift influence, which can meet the accurate tracking of power station output to power grid load, fully consider the influence of dynamic reservoir capacity and backwater uplift, and realize real-time optimal scheduling of cascade reservoirs.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows: a short-term scheduling method for cascade reservoirs considering dynamic reservoir capacity and backwater uplift influence, comprising the following steps: Step 1: constructing an objective function, taking the minimum absolute value of the difference between the output of each upstream and downstream power station and the power grid load requirement as the target; Step 2: setting constraint conditions, including water balance constraint, water level upper and lower limit constraint, water level amplitude constraint, discharge constraint and power station output constraint; Step 3: obtaining the initial water level of the upstream and downstream power stations, the inflow of the upstream power station, the water level of the downstream representative station of the downstream power station, the runoff in the cascade power station interval and the power load plan, and obtaining the initial reservoir capacity of each hydropower station according to the reservoir capacity curve; Step 4: assuming the water level of the upstream power station at the end of the period, calculating the corresponding discharge, tailwater level, power generation water head and power station output; Step 5, if the upstream power station output meets the load plan requirement of the period, go to step 6 to adjust and calculate the downstream power station output of the period, otherwise go to step 4; Step 6, calculate the downstream reservoir inflow according to the upstream reservoir outflow and the interval runoff; if the downstream power station load plan requirement of the period is met, go to the next period to adjust and calculate. Preferably, in the step 1, the objective function is: ; ; In the formula, F g_up (t) is the daily load process requirement of the power grid t period to the upstream power station; F g_do (t) is the daily load process requirement of the power grid t period to the downstream power station; N up (t) , N do (t) are the outputs of the upstream power station and the downstream power station at time t respectively; t is the period length.

[0006] Preferably, the constraint condition in the step 2 includes water balance constraint, water level upper and lower limit constraint, water level amplitude constraint, outflow constraint, and hydropower station output constraint.

[0007] Preferably, the water balance constraint is: ; In the formula, S i,t and S i,t-1 is the reservoir storage capacity of the upstream power station at the end of the period t; i is the reservoir storage capacity of the downstream power station at the end of the period t; t Q i,t is the reservoir inflow of the upstream power station at the end of the period t; i is the reservoir inflow of the downstream power station at the end of the period t; t O i,t is the reservoir outflow of the upstream power station at the end of the period t. i t

[0008] Preferably, the water level upper and lower limit constraint is: ; In the formula, Z i,t is the calculated water level of the upstream power station at the end of the period t; i is the calculated water level of the downstream power station at the end of the period t; t is the calculated water level of the upstream power station at the beginning of the period t;​​​​​i Hydropower station t The lower limit of water level allowed at the end of the time period; For the first i Hydropower station t The upper limit of the water level allowed at the end of the time period.

[0009] Preferably, the water level fluctuation constraint includes: ① Time-limited water level fluctuation constraints: ; In the formula, For the first i Hydropower station t Calculate water level fluctuations over time periods; , The first i The upper and lower limits of water level fluctuations at hydropower stations during specific time periods; ②Water level fluctuation constraints: ; In the formula, For the first i Hydropower station t The difference between the calculated water level at the end of the time period and the water level change at the beginning of the scheduling period; , The first i Upper and lower limits of water level fluctuation at hydropower stations.

[0010] Preferably, the discharge flow constraint is: ; ; In the formula, and The first i Hydropower station t The minimum and maximum allowable discharge flow rates for different time periods are specified, with the minimum discharge flow rate determined based on ecological flow requirements. For the first i Hydropower station t Power generation flow during the period For the first i Hydropower station t Water discharge rate during specific time periods.

[0011] Preferably, the power output constraint of the hydropower station is: ; ; In the formula, and The first i Hydropower station t Minimum and maximum output allowed for a given time period installed capacity of the water intake power station.

[0012] Preferably, the reservoir capacity curve in step 3 is an upstream reservoir static reservoir capacity curve and a downstream reservoir dynamic reservoir capacity curve cluster considering the dynamic reservoir capacity influence; assuming the reservoir water level at the end of the period, the reservoir capacity at the end of the period can be obtained from the upstream reservoir water level through the upstream reservoir static reservoir capacity curve; the downstream reservoir dynamic reservoir capacity curve cluster shows the corresponding relationship of the downstream reservoir dam water level-upstream reservoir outflow-downstream reservoir dynamic reservoir capacity, and the downstream reservoir capacity at the end of the period can be obtained from the upstream reservoir outflow and the downstream reservoir dam water level.

[0013] Preferably, in step 4, the period outflow is calculated according to the water balance equation; wherein the upstream reservoir inflow is the backstepping result, and the downstream reservoir inflow is the upstream reservoir outflow plus the interval runoff; ; In the formula, V’ t_next , V t respectively, the reservoir capacity at the beginning and end of the period; q out,t , q in,t respectively, the upstream reservoir outflow and the downstream reservoir inflow in the period t; is the length of the period.

[0014] Preferably, in step 4, the tail water level is obtained according to the tail water level-flow relationship curve; wherein, considering the backwater effect, the upstream reservoir should query the upstream reservoir outflow-tail water level curve cluster with the downstream power station dam water level as the independent variable, and the downstream reservoir should query the downstream reservoir outflow-tail water level curve cluster with the downstream power station downstream representative station water level as the independent variable.

[0015] Preferably, in step 4, the power generation water head calculation formula is: H=Z up - Z down ; In the formula, H is the power generation water head (gross water head); Z up is the dam water level; Z down is the tail water level.

[0016] Preferably, in step 4, the power station output calculation formula is: ; In the formula, N is the power station output; K is the comprehensive output coefficient of the power station; Qis the power generation flow; H is the power generation water head of the power station.

[0017] Preferably, in step 5, the judgment logic formula that the power station output meets the load plan requirement of the period is: ; In the formula, N t ’ is the power station output, FH t is the power generation plan of the power station, is a threshold value.

[0018] Preferably, in step 6, the formula for calculating the downstream reservoir inflow is: Q 下-入库 =Q 上-出库 +Q 区间； In the formula, Q 下-入库 is the downstream power station inflow, Q 上-出库 is the upstream power station outflow, Q 区间 is the interval runoff.

[0019] Advantages of the present application: 1. The present application meets the accurate tracking of power station output to power grid load, fully considers the influence of dynamic reservoir capacity and backwater support, and realizes real-time optimal scheduling of cascade reservoirs.

[0020] 2. Through simulation test of scheduling practice, the method can accurately predict the daily water level change of cascade reservoirs, and can provide reference for short-term optimal scheduling of cascade reservoirs. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the technical flow chart of the method of the present application; Figure 2 is the algorithm flow chart of the present application; Figure 3 is the dynamic reservoir capacity curve between Three Gorges and Gezhouba; Figure 4 is the tailwater level-flow relationship curve of Three Gorges considering the influence of backwater; Figure 5 is the average deviation time distribution diagram of Three Gorges scheduling water level in the first 8 hours from 2022 to 2025; Figure 6 is the average deviation time distribution diagram of Gezhouba scheduling water level in the first 8 hours from 2022 to 2025; Figure 7The calculation page is used for optimal dispatching of the Three Gorges-Gezhouba section. DETAILED DESCRIPTION

[0022] The application will be further described in detail below with reference to the drawings and specific examples.

[0023] As Figure 1 shown, a short-term dispatching method for cascade reservoirs considering dynamic reservoir capacity and backwater effect includes the following steps: Step 1, constructing an objective function, taking the minimum absolute value of the difference between the output of each upstream and downstream power station and the load requirement of the power grid as the target; Step 2, setting constraint conditions, including water balance constraints, water level upper and lower limit constraints, water level amplitude constraints, downstream flow constraints and power station output constraints; Step 3, obtaining the initial water level of the upstream and downstream power stations, the inflow of the upstream power station, the water level of the downstream representative station of the downstream power station, the runoff in the cascade power station section and the power load plan, and obtaining the initial reservoir capacity of each hydropower station according to the reservoir capacity curve (as Figure 3 shown); Step 4, assuming the water level at the end of the time period of the upstream power station, calculating the corresponding outflow, tail water level, power generation water head and power station output; Step 5, if the output of the upstream power station meets the load plan requirement of the time period, then go to Step 6 to adjust and calculate the output of the downstream power station in the time period, otherwise go to Step 4; Step 6, calculating the inflow of the downstream reservoir according to the outflow of the upstream reservoir and the runoff in the section. The adjustment and calculation process is similar to that of the upstream, and if the load plan requirement of the downstream power station in the time period is met, then go to the adjustment and calculation of the next time period. The objective function of the short-term dispatching method for cascade reservoirs is: ; ; In the formula, F g_up (t) is the daily load process requirement of the power grid on the upstream power station in the t time period; F g_do (t) is the daily load process requirement of the power grid on the downstream power station in the t time period; N up (t) , N do (t) are the outputs of the upstream power station and the downstream power station at time t respectively; t is the time period.

[0024] The constraint conditions of the short-term dispatching of cascade reservoirs include: (1) Water balance constraint:

[0025] wherein, S i,t and S i,t-1 is the first i is the first t is the water storage at the end and beginning of the period; Q i,t is the first i is the first t is the inflow of the hydropower station in the period; O i,t is the first i is the first t is the outflow of the hydropower station in the period.

[0026] (2) Upper and lower water level constraints:

[0027] wherein, Z i,t is the first i is the first t is the calculated water level at the end of the period; is the first i is the first t is the lower limit water level allowed at the end of the period.

[0028] (3) Water level amplitude constraints: ① Period water level amplitude constraints

[0029] wherein, is the first i is the first t is the calculated water level amplitude in the period; , are respectively the upper and lower limits of the period water level amplitude of the first i hydropower station.

[0030] ② Water level amplitude constraints

[0031] wherein, is the first i is the first t is the water level amplitude between the calculated water level at the end of the period and the water level at the beginning of the scheduling period; , are respectively the upper and lower limits of the water level amplitude of the first i hydropower station.

[0032] (4) Discharge constraints:

[0033]

[0034] wherein, and are the minimum and maximum values of the allowable power output of the hydropower station in the tth time period, respectively, i is the minimum power output of the hydropower station in the tth time period, t is the maximum power output of the hydropower station in the tth time period, is the minimum power output of the hydropower station in the tth time period, i is the maximum power output of the hydropower station in the tth time period, t is the power generation flow of the hydropower station in the tth time period, is the power generation flow of the hydropower station in the tth time period, i is the abandoned water flow of the hydropower station in the tth time period. t

[0035] (5) Hydropower station output constraint:

[0036]

[0037] wherein, and are the minimum and maximum values of the allowable power output of the hydropower station in the tth time period, respectively, i is the minimum power output of the hydropower station in the tth time period, t is the maximum power output of the hydropower station in the tth time period, is the installed capacity of the hydropower station.

[0038] In the step 3, the reservoir capacity curve is an upstream reservoir static reservoir capacity curve and a downstream reservoir dynamic reservoir capacity curve cluster considering the influence of dynamic reservoir capacity; assuming the reservoir water level at the end of the time period, the reservoir capacity at the end of the time period can be obtained by querying the upstream reservoir water level through the upstream reservoir static reservoir capacity curve; the downstream reservoir dynamic reservoir capacity curve cluster shows the corresponding relationship among the upstream reservoir water level, the upstream reservoir outflow and the downstream reservoir dynamic reservoir capacity, and the downstream reservoir capacity at the end of the time period can be obtained by querying the upstream reservoir outflow and the downstream reservoir water level.

[0039] In the step 4, the time period outflow is calculated according to the water balance equation; wherein the upstream reservoir inflow is the backstepping result, and the downstream reservoir inflow is the upstream reservoir outflow plus the interval runoff; ; wherein, V’ t_next , V t are the reservoir capacities at the end and beginning of the time period, respectively; q out,t , q in,t are the outflow and inflow of the tth time period, respectively; is the time period length.

[0040] In the step 4, the tail water level is obtained according to the tail water level-flow relationship curve (such as Figure 4 ​is derived; wherein, considering the backwater effect, the upstream reservoir should query the outflow-tailwater level curve cluster of the upstream power station with the water level on the downstream power station dam as the independent variable, and the downstream reservoir should query the outflow-tailwater level curve cluster of the downstream power station with the water level of the downstream representative station of the downstream power station as the independent variable.

[0041] Preferably, in the step 4, the power generation water head calculation formula is: H=Z up - Z down ; In the formula, H is the power generation water head (gross water head); Z up is the water level on the dam; Z down is the tailwater level.

[0042] Preferably, in the step 4, the power station output calculation formula is: ; In the formula, N is the power station output; K is the comprehensive output coefficient of the power station; Q is the power generation flow rate; H is the power generation water head of the power station.

[0043] As Figure 2 shown, the basic algorithm of the method of the embodiment for solving is as follows, aiming at tracking the power grid load and combining the iterative calculation principle of step-by-step approximation: (1) Assume the storage water level at the end of the period , and obtain the corresponding storage capacity , by querying the storage capacity curve. Wherein, considering the dynamic storage capacity effect, the downstream reservoir queries the corresponding downstream reservoir dynamic storage capacity curve cluster.

[0044] (2) According to the water balance equation, the outflow flow rate of the t period is obtained, that is, . Wherein, the inflow flow rate of the upstream reservoir is the inflow backstepping result, and the inflow flow rate of the downstream reservoir is the outflow flow rate of the upstream reservoir plus the interval runoff.

[0045] (3) According to the tailwater level-flow rate relationship curve, the average tailwater level of the t period is obtained Z down . Wherein, considering the backwater effect, the upstream reservoir should query the outflow-tailwater level curve cluster of the upstream power station with the water level on the downstream power station dam as the independent variable, and the downstream reservoir should query the outflow-tailwater level curve cluster of the downstream power station with the water level of the downstream representative station of the downstream power station as the independent variable.

[0046] (4) According to the average upstream water level of the period Zup , calculate the power generation water head H = Z up Z down , assuming calculate the power .

[0047] (5) if , let , and go to the t+1 period; (6) otherwise, re- assume , where , and go back to flow (1) to recalculate.

[0048] The embodiment sets water balance, power station output, reservoir water level and other constraint conditions with the minimum deviation between power station output and power grid load as the target, fully considers the dynamic reservoir capacity and backwater toppling effect between the two dams, and based on the iterative calculation principle, a new joint dispatching method of cascade reservoirs is constructed, and scenario simulation calculation is realized. Through dispatching practice simulation test, the method can accurately predict the daily water level change of cascade reservoirs, and can provide reference for short-term optimal dispatching of cascade reservoirs.

[0049] The specific example application effect is as follows: Taking the Three Gorges-Gezhouba cascade power station as an example, based on the above method principle, a Three Gorges-Gezhouba cascade optimal dispatching calculation page is developed, as shown in the attached Figure 7 To verify the simulation accuracy of the short-term dispatching model of the cascade, data from January 1, 2022 to April 1, 2025 are used for long series simulation calculation, the dispatching period is 24 hours, and the period length is 15 minutes. Among them, the Three Gorges uses the measured initial water level and measured inflow for simulation, and the Three Gorges tail water level is determined based on the Three Gorges tail water curve cluster of hydrodynamic results. The Gezhouba uses the measured inflow, measured Three Gorges outflow and Gezhouba initial water level for long series simulation calculation. The calculation results are shown in the attached Figure 5 , and Figure 6 . From the simulation results, the average deviation of the Three Gorges dispatching water level in the non-flood season is generally less than 5 cm, and the error in June to October is obviously higher than that in other months. According to the analysis of the distribution of the average deviation of the Gezhouba dispatching water level in the first 8 hours, the average deviation of the Gezhouba dispatching water level in the first 8 hours is controlled within 20 cm, and the Gezhouba dispatching water level gradually diverges in the flood season.

[0050] Through actual dispatching data verification, the method has good effect in short-term dispatching within a day, and the prediction and simulation accuracy of the upstream and downstream reservoir water levels is high, which can effectively guarantee the stability of power supply while realizing real-time optimal dispatching of cascade reservoirs.

[0051] ​​The above embodiments are only preferred technical solutions of the present application, and should not be regarded as a limitation of the present application. The protection scope of the present application should be the technical solutions recited in the claims, including equivalent replacement solutions of the technical features recited in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present application.

Claims

1. A short-term cascade reservoir scheduling method considering dynamic reservoir capacity and backwater effect, characterized in that, The method comprises the following steps: Step 1, constructing an objective function, taking the minimum absolute value of the difference between the respective output of the upstream and downstream power stations and the load requirement of the power grid as the target; Step 2, setting constraint conditions, including water balance constraints, upper and lower water level constraints, water level amplitude constraints, downstream flow constraints and power station output constraints; Step 3, obtaining the initial water level of the upstream and downstream power stations, the inflow of the upstream power station, the water level of the downstream representative station of the downstream power station, the interval runoff of the cascade power station and the power load plan, and obtaining the initial storage capacity of each power station according to the storage capacity curve; Step 4, assuming the water level at the end of the time period of the upstream power station, calculating the corresponding outflow, tail water level, power generation water head and power station output; Step 5, if the output of the upstream power station meets the load plan requirement of the time period, then entering step 6 to adjust and calculate the output of the downstream power station in the time period, otherwise entering step 4; Step 6, calculating the inflow of the downstream reservoir according to the outflow of the upstream reservoir and the interval runoff; if the load plan requirement of the downstream power station in the time period is met, then entering the next time period for adjustment and calculation.

2. The method according to claim 1, characterized in that, In step 1, the objective function is: ； ； wherein F g_up (t) is the daily load process requirement for the upstream power plant for the time period t; F g_do (t) is the daily load process requirement for the downstream power plant for the time period t; N up (t) , N do (t) are the outputs of the upstream and downstream power plants, respectively, at time t; t is the time period length.

3. The method according to claim 1, characterized in that, In step 2, the constraint conditions include water balance constraints, upper and lower water level constraints, water level amplitude constraints, downstream flow constraints and power station output constraints.

4. The method according to claim 3, characterized in that, The water balance constraint is: ； In the formula, S i,t and S i,t-1 is the first i is the first t reservoir storage at the end and beginning of the period; Q i,t is the first i is the first t period inflow to the reservoir; O i,t is the first i is the first t period outflow from the reservoir.

5. The method according to claim 3, characterized in that, The upper and lower water level constraint is: ； In the formula, Z i,t is the i is the t is the is the i is the t is the is the i is the t is the 6. The method according to claim 3, characterized in that, The water level amplitude constraint includes: ① Time period water level amplitude constraint: ； In the formula, is the i is the t is the water level amplitude of the hydropower station in the time period; , is the i is the upper and lower limits of the water level amplitude of the hydropower station in the time period; ② Water level amplitude constraint: ； In the formula, is the first i The water level of the hydropower station t The water level variation at the end of the period and the water level at the beginning of the dispatching period; , is the first i The upper and lower limits of the water level variation of the hydropower station.

7. The method according to claim 3, wherein, The downstream flow constraint is: ； ； In the formula, and The first i Hydropower station t The minimum and maximum allowable discharge flow rates for different time periods are specified, with the minimum discharge flow rate determined based on ecological flow requirements. For the first i Hydropower station t Power generation flow during the period For the first i Hydropower station t Water discharge rate during specific time periods.

8. The method according to claim 3, characterized in that, The power station output constraint is: ； ； wherein and are the first i the minimum and maximum allowable output of the hydropower plant in the time interval, t the minimum and maximum allowable output of the hydropower plant in the time interval, the installed capacity of the hydropower plant. 9.The cascade reservoir short-term scheduling method considering dynamic storage capacity and backwater effect of claim 1, wherein, In step 3, the storage capacity curve is the static storage capacity curve of the upstream reservoir and the dynamic storage capacity curve cluster of the downstream reservoir considering the influence of dynamic storage capacity; assuming the reservoir water level at the end of the time period, the reservoir capacity at the end of the time period can be obtained from the upstream reservoir water level through the static storage capacity curve of the upstream reservoir; The dynamic storage capacity curve cluster of the downstream reservoir shows the corresponding relationship among the upstream reservoir outflow, the downstream reservoir water level and the dynamic storage capacity of the downstream reservoir; the reservoir capacity at the end of the time period of the downstream reservoir can be obtained from the upstream reservoir outflow and the downstream reservoir water level.

10. The method of claim 1, wherein the method further comprises: In step 4, the time period outflow is calculated according to the water balance equation; wherein the inflow of the upstream reservoir is the reverse calculation result, and the inflow of the downstream reservoir is the outflow of the upstream reservoir plus the interval runoff; ； In the formula, V’ t_next , V t are the end and beginning storage capacities of the period, respectively; q out,t , q in,t are the outflow and inflow of the period, respectively; is the length of the period.

11. The method of claim 1, wherein the method further comprises: In step 4, the tail water level is obtained according to the tail water level-flow relationship curve; wherein, considering the influence of backwater support, the upstream reservoir should query the upstream reservoir outflow-tail water level curve cluster with the downstream power station water level as the independent variable, and the downstream reservoir should query the downstream reservoir outflow-tail water level curve cluster with the downstream representative station water level of the downstream power station as the independent variable.

12. The method of claim 1, wherein the method further comprises: In step 4, the calculation formula of the power generation water head is: H=Z up - Z down ； In the formula, H is the power generation water head (gross water head) ; Z up is the dam water level; Z down is the tail water level.

13. The method of claim 1, wherein the method further comprises: In step 4, the calculation formula of the power station output is: ； wherein N is the power output of the power plant; K is the overall power output coefficient of the power plant; Q is the flow rate of the power plant; H is the water head of the power plant.

14. The method of claim 1, wherein the method further comprises: In step 5, the judgment logic formula of whether the power station output meets the load plan requirement of the time period is: ； In the formula, N t ’ is the power output of the power plant, FH t is the power generation plan of the power plant, is the threshold value.

15. The method of claim 1, wherein the method further comprises: In step 6, the formula for calculating the inflow of the downstream reservoir is: Q 下-入库 =Q 上-出库 +Q 区间； wherein, Q 下-入库 is the inflow of the downstream power station, Q 上-出库 is the outflow of the upstream power station, Q 区间 is the interval runoff.

Images