Joint dispatching method for hydropower station and diversion gate

Abstract

The invention relates to a hydropower station and water diversion gate combined dispatching method, and belongs to the technical field of water conveyance canal dispatching control. The scheduling mode comprises the following steps: judging whether the upstream and downstream water head difference of the units of the hydropower station belongs to the working range of the units, if so, judging whether the water head difference is less than or equal to the water head value corresponding to the maximum water transfer flow of all units; if the water head difference is smaller than or equal to the water head value, whether the maximum machine passing flow of all the units is larger than or equal to the target water transfer flow or not is judged, and if yes, the water diversion gate is not opened; if the water head difference is larger than the water head value, when the output of each unit calculated according to the target water transfer flow is smaller than or equal to the maximum power, the calculated output of each unit is adopted, and the water diversion gate is not opened; otherwise, the water diversion gate is opened according to the water diversion gate flow determined by the difference between the target water transfer flow and the machine passing flow corresponding to the maximum power of each unit; and if not, opening the water diversion gate according to the water diversion gate flow determined by the target water transfer flow.

Description

Technical Field

[0001] The invention relates to a method for joint dispatching of a hydropower station and a water diversion gate, belonging to the technical field of water delivery channel dispatching control. Background Art

[0002] In addition to serving as the auxiliary dam of the Danjiangkou Water Conservancy Project to retain water, the main task of the Taocha Canal Headworks Project is to meet the water diversion requirements of the middle line project while taking into account power generation needs.

[0003] The Taocha Canal Head Hub includes the left bank gravity dam section, the installation site dam section, the power plant, the diversion gate and the right bank gravity dam section. The hub is connected to the diversion canal upstream, and a stilling pool and a connecting canal section are set behind the diversion gate. Among them, the water-passing structures of the Taocha Hub include two types of buildings: the hydropower station unit and the diversion gate. Both buildings participate in the water supply of the water diversion project. The diversion gate adopts a breast wall flat-bottom structure with a total of 3 holes, 38m long in the direction of the water flow, a total width of 31m, and an elevation of 140m at the bottom of the gate chamber; the diversion flow and water level can be controlled by controlling the gate of the diversion gate; the hydropower station layout adopts a riverbed runoff power station, and the power plant building type is a bulb-type cross-flow type, with two 25MW generator sets installed, and an installed capacity of 50MW; the hydropower station uses the mechanical energy generated when water flows through the turbine to drive the generator to generate electricity, converting water energy into electrical energy.

[0004] The two types of buildings, hydropower station units and water diversion gates, are two crucial parts in the process of water supply. The two work together to supply water. The control of the flow rate of hydropower station units and water diversion gates must meet both the requirements of water diversion and the needs of sufficient power generation. In recent years, some scholars have proposed a joint scheduling analysis plan for small hydropower stations and main canal water inlet gates. When the small hydropower station and the main canal are in joint operation, this joint scheduling plan gives priority to ensuring the water supply safety of the main canal, and tries to maximize the power generation efficiency of the power station while meeting the water supply needs of the main canal. Among them, when the water supply flow of the main canal is less than the flow corresponding to the minimum output of the small hydropower station units, the main canal water inlet gate will release water. When the water supply flow reaches the flow corresponding to the minimum output of the small hydropower station units, the main canal water inlet gate will release water. When the corresponding flow rate is reached, the main water inlet gate is gradually closed, and the power station assumes the task of water supply; however, during the gradual closing of the main water inlet gate, the flow of the water inlet gate may have been used for unit power generation, and it cannot guarantee the maximum power generation while meeting the water supply demand, or the water supply flow is large while the flow of the water inlet gate is small, resulting in excessive flow used for unit power generation, causing damage to the unit; in addition, during the gradual closing of the main water inlet gate, the water supply flow of the main canal may change, and the degree of closure of the main water inlet gate may be too large or too small, resulting in damage to the unit or waste of resources; therefore, the joint scheduling scheme is difficult to guarantee the maximum power generation while meeting the water supply demand, which may lead to waste of unit resources. Summary of the invention

[0005] The purpose of the present invention is to provide a method for jointly dispatching a hydropower station and a water diversion gate, so as to solve the problem that when the water supply flow rate reaches the flow rate corresponding to the minimum output of the small hydropower station unit, the main trunk water inlet gate is controlled to be gradually closed, and the power station undertakes the water supply task. It is difficult to ensure the maximum power generation while meeting the water supply demand, and it may also cause damage to the unit or waste of unit resources.

[0006] In order to solve the above technical problems, the present invention provides a method for joint dispatching of a hydropower station and a water diversion gate, wherein the dispatching method comprises: judging whether the head difference between upstream and downstream of the units of the hydropower station is within the working range of the units, and if so, judging whether the head difference is less than or equal to the head value corresponding to the maximum water diversion flow of all units;

[0007] If the water head difference is less than or equal to the water head value, it is determined whether the maximum flow rate of all units is greater than or equal to the target water transfer flow rate. If it is, the water diversion gate is not opened and the output of each unit is obtained according to the target water transfer flow rate; otherwise, the output of each unit is obtained according to the maximum flow rate of all units, and the water diversion gate is opened according to the water diversion gate flow rate determined by the difference between the target water transfer flow rate and the maximum flow rate of all units;

[0008] If the water head difference is greater than the water head value, when the output of each unit calculated according to the target water diversion flow is less than or equal to the maximum power, the calculated output of each unit is adopted and the water diversion gate is not opened; when the calculated output of each unit is greater than the maximum power, the output of each unit with the maximum power is adopted and the water diversion gate is opened according to the water diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the maximum power of each unit;

[0009] If it does not, the water diversion gate will be opened according to the water diversion gate flow determined by the target water diversion flow.

[0010] Furthermore, the method of obtaining the output of each unit according to the flow rate of each unit includes:

[0011] The output of the unit is obtained by using the unit output formula determined by the water density, gravitational acceleration, the upstream and downstream head difference of the unit, the unit flow rate and the unit operating efficiency, as well as the expression of the unit operating efficiency obtained by fitting with the unit flow rate and the upstream and downstream head difference of the unit as independent variables and the unit operating efficiency as the dependent variable, combined with the unit flow rate.

[0012] Furthermore, the output formula of the unit determined by the water density, gravity acceleration, head difference between upstream and downstream of the unit, flow rate of the unit and the operating efficiency of the unit includes:

[0013] N i =ρg△HQ pi η

[0014] Where Ni is the output of the i-th unit, Q pi is the flow rate of the i-th unit, △H is the head difference between the upstream and downstream of the unit, ρ is the density of water, g is the acceleration of gravity, and η is the operating efficiency of the unit;

[0015] The expression of the unit operating efficiency obtained by fitting the unit flow rate and the head difference between the upstream and downstream of the unit as independent variables and the unit operating efficiency as the dependent variable is:

[0016]

[0017] In the formula, Q pi is the flow rate of the i-th unit; a1, a2, a3, a4, a5 and a6 are the parameters obtained by fitting the historical data of the flow rate of the unit, the head difference between the upstream and downstream of the unit and the corresponding unit operating efficiency.

[0018] Furthermore, when the water diversion gate is a water diversion gate with three gates, the method of opening the water diversion gate according to the water diversion gate flow rate includes:

[0019] S1: If one of the gates of the water diversion gate is under maintenance, then the judgment of S2 is performed; if no gate is under maintenance, then it is judged whether the opening of the three gates calculated when the three gates are opened at the same height is less than the set opening lower limit; if it is less, then the judgment of S2 is performed; otherwise, the three gates are controlled to be opened at the same height;

[0020] S2: Determine whether the calculated opening of the two-hole gates is less than the set opening lower limit when the two-hole gates are opened at the same height. If so, perform S3 judgment, otherwise control the two gates that have not been repaired to be opened at the same height;

[0021] S3: Determine whether the calculated opening of one gate when one gate is open is less than the set opening lower limit value, if so, control one of the unmaintained gates to be opened with the gate opening equal to the set opening lower limit value, and obtain the flow of the water diversion gate when the gate is opened with the opening of the set opening lower limit value, and obtain the required flow of the unit according to the difference between the obtained flow of the water diversion gate and the target water diversion flow, and obtain the output of each unit according to the required flow of the unit; otherwise, open one of the unmaintained gates according to the calculated opening of the one gate.

[0022] Furthermore, after the scheduling mode starts and a set time has passed, flow feedback adjustment is performed;

[0023] The flow feedback adjustment method includes: judging whether the absolute value of the ratio of the difference between the current water diversion flow and the target water diversion flow to the target water diversion flow is greater than a set ratio threshold; if so, using the current water diversion flow as the new target water diversion flow to update the target water diversion flow in the scheduling method; otherwise, the target water diversion flow is not updated.

[0024] Furthermore, the maximum flow rate of each unit is determined according to a linear equation corresponding to the output limit line of the turbine, which is fitted with the head difference between the upstream and downstream of the unit as the independent variable and the flow rate as the dependent variable.

[0025] Furthermore, the linear equation corresponding to the output limit line of the turbine, which is fitted by the head difference between the upstream and downstream of the unit and the flow through the machine, includes:

[0026] Q max =9.176△H+82.246

[0027] In the formula, Q max is the maximum flow rate of each unit, and △H is the head difference between the upstream and downstream units of the hydropower station.

[0028] Furthermore, the upstream and downstream head difference of the unit of the hydropower station is obtained by the difference between the current upstream reservoir water level of the hydropower station and the downstream stable water level under the condition of the target water diversion flow rate, and the downstream stable water level under the condition of the target water diversion flow rate is obtained according to the current downstream stable water level, the current water diversion flow rate and the target water diversion flow rate;

[0029] The downstream stable water level is the water level at the downstream section 1+300m;

[0030] Methods for obtaining the downstream stable water level under the target water diversion flow rate according to the current downstream stable water level, the current water diversion flow rate and the target water diversion flow rate include:

[0031]

[0032] In the formula, H 1300 is the water level at the downstream section 1+300m under the target water diversion flow condition, H 1300c is the current water level at the downstream section 1+300m, Q is the target water diversion flow, Q c is the current water transfer flow.

[0033] Furthermore, the water head value corresponding to the maximum water diversion flow rate is the lower limit threshold of the water head range corresponding to the maximum water diversion flow rate of all units of the hydropower station.

[0034] Further, the gate opening and the flow of the water diversion gate when it is opened at the set opening lower limit are calculated according to the relationship between the gate opening and the flow of the gate, the upstream water head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream water head difference of the unit; the relationship is obtained by the flow formula of the gate hole outflow determined by the gate hole flooding coefficient, the gate flow coefficient corresponding to the gate shape, the gate hole width, the gate opening and the upstream water head, and the gate hole flooding coefficient expression determined by fitting the gate hole flooding coefficient with the gate relative opening and the ratio of the upstream and downstream water head difference to the upstream water head as independent variables and the gate hole flooding coefficient as the dependent variable;

[0035] The relationship between the gate opening and the gate flow, upstream head, current upstream reservoir water level of the hydropower station, and upstream and downstream head difference of the unit includes:

[0036]

[0037] In the formula, e i is the opening of the i-th hole of the diversion gate, Q si is the flow rate of the i-th hole of the diversion gate, i = {1, 2, 3}; b1, b2, b3, b4, b5, b6 and b7 are the parameters obtained by fitting the diversion gate flow rate and the head difference between the upstream and downstream of the unit and the historical data of the diversion gate operation; H is the upstream head, which is obtained according to the difference between the current upstream reservoir water level of the hydropower station and the bottom plate elevation of the diversion gate; H u is the current upstream reservoir water level of the hydropower station, △H is the head difference between the upstream and downstream of the unit, θ is the gate opening angle, and g is the gravitational acceleration.

[0038] Beneficial effect: The present invention provides a new method for joint dispatching of a hydropower station and a water diversion gate. The present invention determines whether the hydropower station unit needs to be put into operation by judging whether the head difference between the upstream and downstream of the unit of the hydropower station is within the working range of the unit. When the difference does not fall within the range, the unit does not flow, and only the water diversion gate is used to discharge water. This avoids the use of unit overflow when the water level is too low, affecting the water use on the demand side (using unit overflow will slow down the speed of overflow) or wasting unit resources. At the same time, it can also avoid excessive water level (such as huge floods) causing damage to the unit; only when the difference is When the value falls within this range, the unit is controlled to be put into power generation; when the difference falls within this range, the unit is given priority to flow, and when the head difference between the upstream and downstream of the unit in the hydropower station is less than or equal to the head value corresponding to the maximum water transfer flow of the unit, the maximum flow rate of the unit is used to judge whether there is any residual flow in the target water transfer flow that cannot be satisfied under the condition of the maximum flow rate of the unit. When the head difference between the upstream and downstream of the unit in the hydropower station is greater than the head value corresponding to the maximum water transfer flow of the unit, the maximum power of the unit is used to judge whether there is any residual flow in the target water transfer flow that cannot be satisfied by the maximum power of the unit. Residual flow; only when there is residual flow in the target water diversion flow that cannot be met even when the unit's workload is as large as possible, the water diversion gate will flow through, and the power generation can be maximized while meeting the target water diversion demand; therefore, it is equivalent to directly allocating the flow between the unit and the water diversion gate according to the target water diversion flow and the maximum output capacity of the unit under the corresponding situation, and allocating the water diversion gate flow on the basis of making the unit's flow as large as possible without damaging the unit, avoiding the existing method of gradually closing the water diversion gate and letting the unit flow when the main canal water supply flow is greater than the flow corresponding to the unit's minimum output. As a result, during the gradual closing of the water diversion gate, the flow of the water diversion gate may have been used for the unit to generate electricity, making it difficult to ensure the maximum power generation while meeting the water supply demand, or the water supply flow is large while the flow of the water inlet gate is small, resulting in excessive flow used for the unit to generate electricity, causing damage to the unit, and during the gradual closing of the main canal water inlet gate, the main canal water supply flow may change, and the main canal water inlet gate may be closed too much or too little, resulting in corresponding waste of resources or damage to the unit. Therefore, the present invention dispatches the unit flow and the water diversion gate flow according to the difference between the current upstream reservoir water level of the hydropower station and the downstream water level of the target water diversion flow, thereby realizing the reasonable dispatch of the hydropower station units and the water diversion gate, ensuring the water supply demand while maximizing the power generation as much as possible, avoiding the waste of unit resources, and taking into account the safety and stability of the generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a flow chart of the method for joint dispatching of a hydropower station and a water diversion gate in an embodiment of the method for joint dispatching of a hydropower station and a water diversion gate of the present invention;

[0040] Figure 2A comprehensive characteristic curve diagram of the existing GZ-WP-5.0 turbine model in the embodiment of the method for joint dispatching of a hydropower station and a water diversion gate of the present invention. DETAILED DESCRIPTION

[0041] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0042] Embodiment of the method for joint dispatching of hydropower station and water diversion gate

[0043] This embodiment provides a technical solution for a method for joint dispatching of a hydropower station and a water diversion gate, wherein the dispatching method of the method includes: determining whether the upstream and downstream head difference of a unit of the hydropower station is within the working range of the unit, and if so, determining whether the head difference is less than or equal to the head value corresponding to the maximum water diversion flow of all units;

[0044] If the water head difference is less than or equal to the above water head value, it is determined whether the maximum flow rate of all units is greater than or equal to the target water transfer flow rate. If it is, the water diversion gate is not opened and the output of each unit is obtained according to the target water transfer flow rate; otherwise, the output of each unit is obtained according to the maximum flow rate of all units, and the water diversion gate is opened according to the water diversion gate flow rate determined by the difference between the target water transfer flow rate and the maximum flow rate of all units;

[0045] If the head difference is greater than the above head value, when the output of each unit calculated according to the target water diversion flow is less than or equal to the maximum power, the calculated output of each unit is used and the water diversion gate is not opened; when the calculated output of each unit is greater than the maximum power, the output of each unit with the maximum power is used and the water diversion gate is opened according to the water diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the maximum power of each unit;

[0046] If it does not, the water diversion gate will be opened according to the water diversion gate flow determined by the target water diversion flow.

[0047] After analysis, this method is equivalent to directly allocating the flow between the unit and the water diversion gate according to the target water diversion flow and the maximum output capacity of the unit under the corresponding situation. The water diversion gate flow is allocated on the basis of making the unit flow as large as possible without damaging the unit, avoiding the existing method of gradually closing the water diversion gate and transferring the flow to the unit when the main canal water supply flow is greater than the flow corresponding to the unit's minimum output. As a result, during the gradual closing of the water diversion gate, the flow of the water diversion gate may have been used for unit power generation, making it difficult to ensure the maximum power generation under the water supply demand, or the water supply flow is large while the flow of the water inlet gate is small, resulting in excessive flow used for unit power generation, causing damage to the unit, and during the gradual closing of the main canal water inlet gate, the main canal water supply flow may change, and the main canal water inlet gate may be closed too much or too little, resulting in corresponding waste of resources or damage to the unit. Therefore, the present invention dispatches the unit flow and the water diversion gate flow according to the difference between the current upstream reservoir water level of the hydropower station and the downstream water level of the target water diversion flow, realizes the reasonable dispatch of the hydropower station unit and the water diversion gate, ensures the water supply demand, maximizes the power generation as much as possible, avoids the waste of unit resources, and takes into account the safety and stability of the generator set. The method realizes the reasonable dispatch of the hydropower station unit and the water diversion gate, ensures the water supply demand, maximizes the power generation as much as possible, avoids the waste of unit resources, and takes into account the safety and stability of the generator set.

[0048] This method is applicable to water conservancy projects where a hydropower station and a water diversion gate supply water together. In this embodiment, the Taocha Canal Headworks Project is taken as a specific example to specifically illustrate the method for the joint dispatching of the hydropower station and the water diversion gate:

[0049] The flowchart of the method for joint dispatching of the hydropower station and the water diversion gate is as follows: Figure 1 As shown, before executing the scheduling method of this method, the current water level H of the upstream reservoir of Taocha is first collected. u , the current stable downstream water level and the current water transfer flow Q c, and the target water transfer flow Q; due to the different flow distribution ratios of the power station unit and the diversion gate under the same water transfer flow, there will be a difference between the unit tailwater level and the water level downstream of the diversion gate stilling pool. In order to accurately calculate the discharge flow of the power station unit and the diversion gate, it is necessary to consider the impact of this difference; therefore, after a series of research and calculations, the calculation conditions of different flow distribution ratios were analyzed, and it was found that under the same total water transfer flow condition, as the unit's flow distribution ratio increased from 0 to 100%, the water level of the power station tailwater channel showed a gradual downward trend. Similarly, with the diversion gate flow distribution ratio As the ratio increases, the water level downstream of the diversion gate stilling pool also shows a gradual downward trend; among them, the water levels of the 0+300m section and the 1+300m section of the channel always remain stable, are not affected by the flow distribution ratio of the power station units and the diversion gate, and are only related to the total flow of the channel; therefore, in this embodiment, the current downstream stable water level and the downstream stable water level under the condition of the target water diversion flow Q both refer to the water level of the downstream 1+300m section; in other embodiments, the water level of the downstream 0+300m section can also be used as the downstream stable water level; the downstream stable water level H under the condition of the target water diversion flow 1300 According to the current downstream stable water level H 1300c , the current water transfer flow and the target water transfer flow are obtained;

[0050] Secondly, calculate the downstream stable water level H under the condition of target water diversion flow Q 1300 According to the current downstream stable water level, the current water transfer flow and the target water transfer flow, the method of obtaining the downstream stable water level under the target water transfer flow is as follows:

[0051]

[0052] In the formula, H 1300 is the water level at the downstream section 1+300m under the target water diversion flow condition, H 1300c is the current water level at the downstream section 1+300m, Q is the target water diversion flow, Q c is the current water transfer flow rate; the specific method of obtaining formula 1-1 belongs to the existing technology and will not be repeated here.

[0053] In this embodiment, the upstream and downstream head difference ΔH of the hydropower station unit needs to be calculated. The upstream and downstream head difference of the hydropower station unit is calculated by the current upstream reservoir water level H of the hydropower station. u The downstream stable water level H under the target water diversion flow condition 1300 Specifically, △H=H u -H 1300 .

[0054] In summary, the specific process example of the scheduling method of this method is as follows:

[0055] First, it is determined whether the head difference ΔH between the upstream and downstream of the unit of the hydropower station is within the unit working range. In this embodiment, the unit working range is 6m to 24.86m; if it is (i.e., it satisfies 6m≤ΔH≤24.86m) (the unit is generating electricity at this time), it is determined whether the head difference ΔH is less than or equal to the head value corresponding to the maximum water transfer flow of all units;

[0056] The head value corresponding to the maximum water diversion flow is the lower limit threshold of the head range corresponding to the maximum water diversion flow of all units in the hydropower station. In this embodiment, the maximum water diversion flow of all units (two units) in the hydropower station is 2×210m 3 / s=420m 3 / s (2 refers to two units), the corresponding water head range is about 13.5m~16.1m, the lower limit threshold is 13.5m, then the water head value corresponding to the maximum water transfer flow is 13.5m;

[0057] If the head difference △H is less than or equal to the head value corresponding to the maximum water transfer flow rate, the maximum flow rate of all units is determined to be 2Q max (2 refers to two units) is greater than or equal to the target water transfer flow Q, that is, it satisfies:

[0058] Q / 2≤Q max (1-2)

[0059] The maximum flow rate of all units here refers to the sum of the maximum flow rates of each unit. If it is greater than or equal to the sum, the water diversion gate will not be opened and the output of each unit will be obtained according to the target water diversion flow rate Q; otherwise, the output of each unit will be obtained according to the maximum flow rate of all units, and the target water diversion flow rate Q and the maximum flow rate of all units 2Q will be used to calculate the output of each unit. max The difference in the diversion gate flow Q is determined by S Open the diversion gate, the diversion gate flow rate Q S =QQ P =Q-2Q max ;

[0060] The maximum flow rate of each unit is determined by the linear equation corresponding to the turbine output limit line, which takes the head difference between the upstream and downstream of the unit as the independent variable and the flow rate as the dependent variable. For example, the comprehensive characteristic curve of the existing GZ-WP-5.0 turbine model is as follows: Figure 2 As shown, Figure 2 The middle straight line "AB" is the output limit line of the turbine. Usually in daily dispatching conditions, safe operation is only allowed in the area to the left of the straight line "AB".

[0061] The linear equation corresponding to the turbine output limit line, which is fitted by the upstream and downstream head difference of the unit and the flow rate through the machine, is specifically:

[0062] Q max=9.176△H+82.246

[0063] In the formula, Q max is the maximum flow rate of each unit, and △H is the head difference between the upstream and downstream units of the hydropower station.

[0064] If the head difference △H is greater than the head value corresponding to the maximum water diversion flow rate, when the output of each unit calculated according to the target water diversion flow rate Q is less than or equal to the maximum power (the maximum power of each unit is 25MW), the calculated output of each unit is used and the water diversion gate is not opened; when the calculated output of each unit is greater than the maximum power, the output of each unit with the maximum power is used (N1=N2=25.0MW, N i is the output of each unit, i∈{1,2}) and the diversion gate is opened according to the diversion gate flow rate determined by the difference between the target water diversion flow rate Q and the flow rate corresponding to the maximum power of each unit. The diversion gate flow rate Q S =QQ P ;

[0065] If △H is not within the unit operating range (the unit is not generating electricity at this time), the diversion gate is opened according to the diversion gate flow determined by the target water diversion flow. The diversion gate flow Q S =Q.

[0066] Among them, the methods of obtaining the output of each unit according to the flow rate of each unit include:

[0067] The output of the unit is obtained by using the unit output formula determined by the water density, gravitational acceleration, the upstream and downstream head difference of the unit, the unit flow rate and the unit operating efficiency, as well as the expression of the unit operating efficiency obtained by fitting with the unit flow rate and the upstream and downstream head difference of the unit as independent variables and the unit operating efficiency as the dependent variable, combined with the unit flow rate.

[0068] The output formula of the unit determined by water density, gravity acceleration, head difference between upstream and downstream of the unit, flow rate of the unit and operating efficiency of the unit includes:

[0069] N i =ρg△HQ pi η (1-3)

[0070] Where N i is the output of the i-th unit, Q pi is the flow rate of the i-th unit, △H is the head difference between the upstream and downstream of the unit, ρ is the density of water, g is the acceleration of gravity, and η is the operating efficiency of the unit; since in this embodiment, all units have the same output, if Q pi is the output of each unit calculated according to the target water transfer flow Q, then Q pi It is the value of the target water transfer flow divided by the total number of units.

[0071] The expression of the unit operating efficiency obtained by fitting the unit flow rate and the head difference between the upstream and downstream of the unit as independent variables and the unit operating efficiency as the dependent variable is:

[0072]

[0073] In the formula, Q pi is the flow rate of the i-th unit; a1, a2, a3, a4, a5 and a6 are the parameters obtained by fitting the historical data of the flow rate of the unit, the head difference between the upstream and downstream of the unit and the corresponding unit operating efficiency.

[0074] For example, the expression of the unit operating efficiency obtained by fitting the flow rate of the unit of Taocha Qushou Hydropower Station, the head difference between the upstream and downstream of the unit, and a certain period of historical data of the corresponding unit operating efficiency is as follows:

[0075]

[0076] In the formula, Q pi is the flow rate of the i-th unit.

[0077] Moreover, in the present embodiment, after the above-mentioned scheduling method starts and a set time has passed, flow feedback adjustment is performed; the flow feedback adjustment method includes: judging whether the absolute value of the ratio of the difference between the current water diversion flow and the target water diversion flow to the target water diversion flow is greater than the set ratio threshold; if so, using the current water diversion flow as the new target water diversion flow to update the target water diversion flow in the scheduling method; otherwise, the target water diversion flow is not updated.

[0078] The flow rate adjustment on site is small, usually within 10m 3 / s, according to the one-dimensional digital model calculation results and on-site measured data, the main channel flow and water level basically reach a stable state within 1 hour after a flow adjustment, and the flow fluctuation after reaching the stable state is within 1%. Therefore, in this embodiment, the setting time is 1 hour and the ratio threshold is set to 1%; after analysis, the flow feedback adjustment can make the current water diversion flow be used as the new target water diversion flow to update the target water diversion flow in the scheduling method when the main channel flow and water level fail to reach a stable state within 1 hour, and the above-mentioned scheduling method is executed again to make the main channel flow and water level more stable.

[0079] Reference Figure 1 In this embodiment, when the water diversion gate is a water diversion gate with three gates, the method of opening the water diversion gate according to the water diversion gate flow includes:

[0080] S1: If one of the gates of the diversion gate is under maintenance (according to the normal scheduling principle, only one gate of the diversion gate is allowed to be under maintenance in the same period), then the judgment of S2 is carried out; if no gate is under maintenance, then it is judged whether the opening of the three gates calculated when the three gates are opened at the same height is less than the set opening lower limit; if it is less, then the judgment of S2 is carried out; otherwise, the three gates are controlled to be opened at the same height;

[0081] S2: Determine whether the calculated opening of the two-hole gates is less than the set opening lower limit when the two-hole gates are opened at the same height. If so, perform S3 judgment, otherwise control the two gates that have not been repaired to be opened at the same height;

[0082] S3: Determine whether the calculated opening of one gate when one gate is open is less than the set opening lower limit value, if so, control one of the unmaintained gates to be opened with the gate opening equal to the set opening lower limit value, and obtain the flow of the water diversion gate when the gate is opened with the opening of the set opening lower limit value, and obtain the required flow of the unit according to the difference between the obtained flow of the water diversion gate and the target water diversion flow, and obtain the output of each unit according to the required flow of the unit; otherwise, open one of the unmaintained gates according to the calculated opening of the one gate.

[0083] The gate opening and the flow of the diversion gate when it is opened at the set lower limit of the opening are calculated based on the relationship between the gate opening and the flow of the gate, the upstream head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream head difference of the unit; this relationship is obtained through the flow formula of the gate hole outflow determined by the gate hole submergence coefficient, the gate flow coefficient corresponding to the gate shape, the gate hole width, the gate opening and the upstream head, and the expression of the gate hole submergence coefficient determined by fitting with the ratio of the gate relative opening and the upstream and downstream head difference to the upstream head as independent variables and the gate hole submergence coefficient as the dependent variable.

[0084] As general engineering gate operation experience shows, when the gate is operated at a small opening, flow-induced vibration is prone to occur, which is not conducive to the safety of the gate structure; combined with the on-site operation of the Taocha Hub Gate, the water diversion gate opening is set to be no less than 20cm. Therefore, in this embodiment, the lower limit of the opening is set to 20cm.

[0085] Gate opening e i The flow rate Q of the gate si , upstream head H, current upstream reservoir water level H of the hydropower station u , the relationship between the upstream and downstream head difference △H of the unit is:

[0086]

[0087] In the formula, e i is the opening of the i-th hole of the diversion gate, Qsi is the flow rate of the i-th hole of the diversion gate, i = {1, 2, 3}; b1, b2, b3, b4, b5, b6 and b7 are the parameters obtained by fitting the diversion gate flow rate and the head difference between the upstream and downstream of the unit and the historical data of the diversion gate operation; H is the upstream head, which is obtained according to the difference between the current upstream reservoir water level of the hydropower station and the bottom plate elevation of the diversion gate; H u is the current upstream reservoir water level of the hydropower station, △H is the head difference between the upstream and downstream of the unit, θ is the gate opening angle, and g is the gravitational acceleration.

[0088] Specifically, the gate opening e is obtained by fitting the flow of the diversion gate of Taocha Canal Hydropower Station, the head difference between the upstream and downstream of the unit, and a certain period of historical data of the diversion gate operation. i The flow rate Q of the gate si , upstream head H, current upstream reservoir water level H of the hydropower station u , the relationship between the upstream and downstream head difference △H of the unit is:

[0089]

[0090] In the formula, e i is the opening of the i-th hole of the diversion gate, Q si is the flow rate of the i-th hole of the diversion gate, i = {1, 2, 3}; H is the upstream head, which is obtained according to the difference between the current upstream reservoir water level of the hydropower station and the bottom plate elevation of the diversion gate; H u is the current upstream reservoir water level of the hydropower station, △H is the head difference between the upstream and downstream of the unit, θ is the gate opening angle, and g is the gravitational acceleration.

Claims

1. A method for joint dispatching of a hydropower station and a water diversion gate, characterized in that: The dispatching method includes: judging whether the head difference between upstream and downstream of the units of the hydropower station is within the working range of the units, and if so, judging whether the head difference is less than or equal to the head value corresponding to the maximum water transfer flow of all units; If the water head difference is less than or equal to the water head value, it is determined whether the maximum flow rate of all units is greater than or equal to the target water transfer flow rate. If it is, the water diversion gate is not opened and the output of each unit is obtained according to the target water transfer flow rate; otherwise, the output of each unit is obtained according to the maximum flow rate of all units, and the water diversion gate is opened according to the water diversion gate flow rate determined by the difference between the target water transfer flow rate and the maximum flow rate of all units; If the water head difference is greater than the water head value, when the output of each unit calculated according to the target water diversion flow is less than or equal to the maximum power, the calculated output of each unit is adopted and the water diversion gate is not opened; when the calculated output of each unit is greater than the maximum power, the output of each unit with the maximum power is adopted and the water diversion gate is opened according to the water diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the maximum power of each unit; If it does not, the water diversion gate will be opened according to the water diversion gate flow determined by the target water diversion flow.

2. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The methods for obtaining the output of each unit according to the flow rate of each unit include: The output of the unit is obtained by using the unit output formula determined by the water density, gravitational acceleration, the upstream and downstream head difference of the unit, the unit flow rate and the unit operating efficiency, as well as the expression of the unit operating efficiency obtained by fitting with the unit flow rate and the upstream and downstream head difference of the unit as independent variables and the unit operating efficiency as the dependent variable, combined with the unit flow rate.

3. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 2, characterized in that: The output formula of the unit determined by water density, gravity acceleration, head difference between upstream and downstream of the unit, flow rate of the unit and operating efficiency of the unit includes: N i =ρg△HQ pi or Where N i is the output of the i-th unit, Q pi is the flow rate of the i-th unit, △H is the head difference between the upstream and downstream of the unit, ρ is the density of water, g is the acceleration of gravity, and η is the operating efficiency of the unit; The expression of the unit operating efficiency obtained by fitting the unit flow rate and the head difference between the upstream and downstream of the unit as independent variables and the unit operating efficiency as the dependent variable is: In the formula, Q pi is the flow rate of the i-th unit; a1, a2, a3, a4, a5 and a6 are the parameters obtained by fitting the historical data of the flow rate of the unit, the head difference between the upstream and downstream of the unit and the corresponding unit operating efficiency.

4. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: When the water diversion gate is a water diversion gate with three gates, the method of opening the water diversion gate according to the water diversion gate flow rate includes: S1: If one of the gates of the water diversion gate is under maintenance, then the judgment of S2 is performed; if no gate is under maintenance, then it is judged whether the opening of the three gates calculated when the three gates are opened at the same height is less than the set opening lower limit; if it is less, then the judgment of S2 is performed; otherwise, the three gates are controlled to be opened at the same height; S2: Determine whether the calculated opening of the two-hole gates is less than the set opening lower limit when the two-hole gates are opened at the same height. If so, perform S3 judgment, otherwise control the two gates that have not been repaired to be opened at the same height; S3: Determine whether the calculated opening of one gate when one gate is open is less than the set opening lower limit value, if so, control one of the unmaintained gates to be opened with the gate opening equal to the set opening lower limit value, and obtain the flow of the water diversion gate when the gate is opened with the opening of the set opening lower limit value, and obtain the required flow of the unit according to the difference between the obtained flow of the water diversion gate and the target water diversion flow, and obtain the output of each unit according to the required flow of the unit; otherwise, open one of the unmaintained gates according to the calculated opening of the one gate.

5. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: After the scheduling mode starts and a set time has passed, flow feedback adjustment is performed; The flow feedback adjustment method includes: judging whether the absolute value of the ratio of the difference between the current water diversion flow and the target water diversion flow to the target water diversion flow is greater than a set ratio threshold; if so, using the current water diversion flow as the new target water diversion flow to update the target water diversion flow in the scheduling method; otherwise, the target water diversion flow is not updated.

6. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The maximum flow rate of each unit is determined by a linear equation corresponding to the output limit line of the turbine, which is fitted with the head difference between the upstream and downstream of the unit as the independent variable and the flow rate as the dependent variable.

7. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 6, characterized in that: The linear equations corresponding to the turbine output limit line, which are fitted by the upstream and downstream head difference of the unit and the flow through the machine, include: Q max =9.176△H+82.246 In the formula, Q max is the maximum flow rate of each unit, and △H is the head difference between the upstream and downstream units of the hydropower station.

8. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The upstream and downstream head difference of the hydropower station unit is obtained by the difference between the current upstream reservoir water level of the hydropower station and the downstream stable water level under the target water diversion flow condition. The downstream stable water level under the target water diversion flow condition is obtained according to the current downstream stable water level, the current water diversion flow and the target water diversion flow; The downstream stable water level is the water level at the downstream section 1+300m; Methods for obtaining the downstream stable water level under the target water diversion flow rate according to the current downstream stable water level, the current water diversion flow rate and the target water diversion flow rate include: In the formula, H 1300 is the water level at the downstream section 1+300m under the target water diversion flow condition, H 1300c is the current water level at the downstream section 1+300m, Q is the target water diversion flow, Q c is the current water transfer flow.

9. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The water head value corresponding to the maximum water diversion flow is the lower limit threshold of the water head range corresponding to the maximum water diversion flow of all units in the hydropower station.

10. The method for joint dispatching of a hydropower station and a water diversion gate according to claim 4, characterized in that: The gate opening and the flow of the diversion gate when it is opened at the set lower limit of the opening are calculated according to the relationship between the gate opening and the flow of the gate, the upstream head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream head difference of the unit; the relationship is obtained by the flow formula of the gate hole outflow determined by the gate hole flooding coefficient, the gate flow coefficient corresponding to the gate shape, the gate hole width, the gate opening and the upstream head, and the expression of the gate hole flooding coefficient determined by fitting with the gate relative opening and the ratio of the upstream and downstream head difference to the upstream head as independent variables and the gate hole flooding coefficient as the dependent variable; The relationship between the gate opening and the gate flow, upstream head, current upstream reservoir water level of the hydropower station, and upstream and downstream head difference of the unit includes: In the formula, e i is the opening of the i-th hole of the diversion gate, Q si is the flow rate of the i-th hole of the diversion gate, i = {1, 2, 3}; b1, b2, b3, b4, b5, b6 and b7 are the parameters obtained by fitting the diversion gate flow rate and the head difference between the upstream and downstream of the unit and the historical data of the diversion gate operation; H is the upstream head, which is obtained according to the difference between the current upstream reservoir water level of the hydropower station and the bottom plate elevation of the diversion gate; H u is the current upstream reservoir water level of the hydropower station, △H is the head difference between the upstream and downstream of the unit, θ is the gate opening angle, and g is the gravitational acceleration.

Images