Emergency scheduling method for hydropower station and diversion gate

Abstract

The invention relates to an emergency scheduling method for a hydropower station and a diversion gate, and belongs to the technical field of water conveyance canal scheduling control. When one of the two units of the hydropower station is shut down, whether the upstream and downstream water head difference of the units of the hydropower station is smaller than or equal to the water head value corresponding to the maximum water transfer flow of all the units or not is judged; if not, whether the maximum machine passing flow of the non-shut-down unit is larger than or equal to the target water transfer flow or not is judged, and if yes, a water gate is not opened, and otherwise, the water gate is opened; if the water head value is larger than the water head value, when the output, calculated according to the target water transfer flow, of the non-shut-down unit is smaller than or equal to the maximum power, the calculated output of the non-shut-down unit is adopted, and a water diversion gate is not opened; when the output of the non-shutdown unit is larger than the maximum power, the maximum power is adopted for output, and a 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; and opening the water diversion gate according to the water diversion gate flow determined by the target water diversion flow when the two units are shut down.

Description

Technical Field

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

[0002] As the headworks project of the main canal of the South-to-North Water Diversion Project's middle route, the Taocha Canal Headworks Project, in addition to fulfilling its function as a water-blocking auxiliary dam for the Danjiangkou Water Conservancy Project, is mainly tasked with meeting the water diversion requirements of the middle route 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. The two types of buildings, hydropower station units and water diversion gates, are two crucial parts in the water supply process. The two work together to supply water, so the scheduling of hydropower station units and water diversion gates is equally important.

[0004] At present, most of the dispatching of hydropower station units and water diversion gates is for dispatching under normal operating conditions. When emergency emergencies occur in the headworks project itself (such as load shedding when the power station units are running at high flow, water diversion gate maintenance, water diversion gate failure, etc.), it will cause the main canal water level to fluctuate and even affect the water supply process. In recent years, some scholars have proposed a joint dispatching analysis plan for small hydropower stations and main canal water inlet gates. In this joint dispatching plan, when the unit is shut down or sheds load in an emergency, the unit will cut off the flow and open the water inlet gate in an emergency. However, the load of the unit may change. If the unit The load suddenly increases. At this time, the process of gradually adjusting the gate opening will lead to waste of flow, and it is difficult to ensure maximum power generation while meeting water supply demand. At the same time, the water supply flow of the main canal may also change, and the main canal water inlet gate may be opened too much or too little, resulting in corresponding waste of resources or damage to the unit. Therefore, when the unit is shut down or sheds load, when the unit load suddenly increases or the water supply flow of the main canal increases, this scheduling plan cannot ensure maximum power generation while meeting water supply demand, and it may also lead to waste of unit resources or damage to the unit. Summary of the invention

[0005] The purpose of the present invention is to provide an emergency dispatching method for a hydropower station and a water diversion gate, so as to solve the problem that in the current emergency incident, when the unit load suddenly increases or the water supply flow of the main canal increases, it is difficult to ensure the maximum power generation while meeting the water supply demand, and it may also cause waste of unit resources or damage to the unit.

[0006] In order to solve the above technical problems, the present invention provides an emergency dispatching method for a hydropower station and a water diversion gate. When one of the two units of the hydropower station is shut down, it is judged whether the head difference between the upstream and downstream water heads of the units of the hydropower station is less than or equal to the head value corresponding to the maximum water diversion flow of all units; if it is less than or equal to the head value, it is judged whether the maximum flow rate of the units that are not shut down is greater than or equal to the target water diversion flow rate. If it is greater than or equal to the target water diversion flow rate, the water diversion gate is not opened and the output of the units that are not shut down is obtained according to the target water diversion flow rate. Otherwise, the output of the units that are not shut down is obtained according to the maximum flow rate of the units that are not shut down, and the water diversion gate is opened according to the water diversion gate flow rate determined by the difference between the target water diversion flow rate and the maximum flow rate of the units that are not shut down;

[0007] If it is greater than the water head value, when the output of the non-stopped units calculated according to the target water diversion flow is less than or equal to its maximum power, the calculated output of the non-stopped units is used and the diversion gate is not opened; when the output of the non-stopped units is greater than its maximum power, the output of the units with maximum power is used and the diversion gate is opened according to the diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the maximum power of the units;

[0008] When both units of the hydropower station are shut down, the diversion gate is opened according to the diversion gate flow determined by the target water diversion flow.

[0009] Furthermore, the method of obtaining the output of the unit according to the flow rate of the unit includes:

[0010] 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.

[0011] 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:

[0012] N i =ρg△HQ pi η

[0013] Where N i is the output of the i-th unit, Q piis 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;

[0014] 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:

[0015]

[0016] 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.

[0017] Furthermore, when the water diversion gate is a water diversion gate with three gates, the method of opening each gate of the water diversion gate according to the flow of the water diversion gate includes:

[0018] Determine whether one of the gates of the water diversion gate is under maintenance. If not, open the three gates of the water diversion gate at the same time or increase the opening of the three gates of the water diversion gate;

[0019] If one of the diversion sluice gates is under maintenance, the other two gates of the diversion sluice shall be opened at the same time or the opening of the other two gates of the diversion sluice shall be increased.

[0020] Furthermore, the maximum flow rate of the 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.

[0021] 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:

[0022] Q max =9.176△H+82.246

[0023] 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.

[0024] Furthermore, the upstream and downstream head difference of the hydropower station's units 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 based on the current downstream stable water level, the current water diversion flow and the target water diversion flow.

[0025] Furthermore, the downstream stable water level is the water level at the downstream section 1+300m;

[0026] 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:

[0027]

[0028] 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.

[0029] 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.

[0030] Further, when the gates are opened at the same time or the opening of the gates is increased, the opening of each gate is calculated according to the relationship between the gate opening and the diversion gate flow, 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 the ratio of the upstream and downstream head difference to the upstream head and the gate relative opening as independent variables and the gate hole flooding coefficient as the dependent variable;

[0031] The relationship between the gate opening and the diversion gate flow, upstream head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream head difference of the unit includes:

[0032]

[0033] In the formula, when the opening of each gate is increased, e i is the opening of the i-th gate before the diversion gate increases its opening, △e is the increased gate opening; when all gates are opened at the same time, e i is the opening of the gate of the i-th hole of the water diversion gate, △e is 0; Q s is the flow rate of the diversion gate, i∈{1,2,3}; j is the number of open diversion gates, j∈{2,3}; b1, b2, b3, b4, b5, b6, b7 and b8 are the parameters obtained by fitting the flow rate of the diversion gate 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.

[0034] Beneficial effect: The present invention provides a new emergency dispatching method for a hydropower station and a water diversion gate, which considers the emergency dispatching modes in two situations: when one of the two units is shut down and when both units are shut down. When one unit is shut down, the flow rate of the units that are not shut down and the flow rate of the water diversion gate are increased, wherein the flow of the units that are not shut down is given priority, and when the head difference between the upstream and downstream of the units in the hydropower station is less than or equal to the head value corresponding to the maximum water diversion flow rate of the units, the maximum flow rate of the units that are not shut down is used to judge whether there is any residual flow in the target water diversion flow that cannot be satisfied under the maximum flow rate of the units that are not shut down. When the head difference between the upstream and downstream of the unit of the hydropower station is greater than the head value corresponding to the maximum water diversion flow of the unit, the maximum power of the unit that has not been shut down is used to determine whether there is any residual flow in the target water diversion flow that cannot be met by the maximum power of the unit that has not been shut down; only when there is a residual flow in the target water diversion flow that cannot be met even if the unit's workload is as large as possible, and then the water diversion gate is used to pass the flow, the power generation can be maximized while meeting the target water diversion demand; when both units are shut down, the target water diversion flow is output entirely from the water diversion gate; it can meet the target water diversion demand in the shortest time and reduce the water level fluctuation in the channel. amplitude, and restore the normal dispatch of the water diversion gate and the unit; thus, the present invention takes into account different emergency situations of unit shutdown. When only one unit is shut down, the flow between the unit and the water diversion gate is distributed according to the target water diversion flow and the maximum output capacity of the non-shutdown unit under the corresponding situation. The water diversion gate flow is distributed on the basis of making the overflow of the non-shutdown unit as large as possible without damaging the unit, thereby avoiding the existing situation that when the unit is shut down or the load is shed, if the unit load suddenly increases, the flow will be wasted in the process of gradually adjusting the gate opening, making it difficult to ensure the maximum power generation under the condition of meeting the water supply demand; When the water supply flow of the main canal changes, the gate may be opened too much or too little when adjusting the water diversion gate, which will cause waste of resources or damage to the unit; only when all the units are shut down at the same time, the flow will only pass through the water diversion gate; when the load of the unit changes or the target water diversion flow changes, it can also respond reasonably; therefore, the present invention can reasonably dispatch the unit and the water diversion gate according to the abnormal situation of the unit and the change of the target water diversion flow, while ensuring the water supply demand, maximizing the power generation as much as possible, avoiding waste of unit resources and damage to the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the emergency dispatching method of a hydropower station and a water diversion gate in an embodiment of the emergency dispatching method of a hydropower station and a water diversion gate of the present invention;

[0036] Figure 2 It is the comprehensive characteristic curve of the existing GZ-WP-5.0 turbine model in the embodiment of the emergency dispatching method of the hydropower station and the water diversion gate of the present invention. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0038] Embodiment of the emergency dispatching method of hydropower station and water diversion gate

[0039] This embodiment provides a technical solution for an emergency dispatch method of a hydropower station and a water diversion gate. The emergency dispatch method takes into account the dispatch under different conditions of unit shutdown. When only one of the two units of the hydropower station is shut down, the flow between the unit and the water diversion gate is distributed according to the target water diversion flow and the maximum output capacity of the non-shutdown unit under the corresponding conditions. The water diversion gate flow is distributed on the basis of making the unit flow as large as possible without damaging the unit; when two units are shut down, all the flow is passed through the water diversion gate. The emergency dispatch method can reasonably dispatch the unit and the water diversion gate according to the abnormal conditions of the unit and the changes in the target water diversion flow, while ensuring the water supply demand, maximizing the power generation as much as possible, avoiding the waste of unit resources and damage to the unit.

[0040] The method specifically includes: when one of the two units of the hydropower station is shut down, judging whether the head difference between the upstream and downstream units of the hydropower station is less than or equal to the head value corresponding to the maximum water transfer flow of all units; if it is less than or equal to the head value, judging whether the maximum flow rate of the units that are not shut down is greater than or equal to the target water transfer flow, if it is greater than or equal to, not opening the diversion gate and obtaining the output of the units that are not shut down according to the target water transfer flow, otherwise obtaining the output of the units that are not shut down according to the maximum flow rate of the units that are not shut down, and determining the diversion gate according to the difference between the target water transfer flow and the maximum flow rate of the units that are not shut down The water gate flow opens the diversion gate; if it is greater than the head value, then when the output of the non-stopped units calculated according to the target water diversion flow is less than or equal to the maximum power of the non-stopped units, the calculated output of the non-stopped units is used and the diversion gate is not opened; when the output of the non-stopped units is greater than the maximum power of the non-stopped units, the output of the units with maximum power is used and the diversion gate is opened according to the diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the non-stopped maximum power; when both units of the hydropower station are shut down, the diversion gate is opened according to the diversion gate flow determined by the target water diversion flow.

[0041] After analysis, this method takes into account different situations of unit shutdown. When only one unit is shut down, the flow between the unit and the diversion gate is distributed according to the target water diversion flow and the maximum output capacity of the non-shutdown unit under the corresponding situation. The diversion gate flow is distributed on the basis of making the unit flow as large as possible without damaging the unit. This avoids the existing situation that when the unit is shut down or the load is shed, if the unit load suddenly increases, the gate opening is gradually adjusted at this time, which will lead to waste of flow and it is difficult to ensure the maximum power generation under the condition of meeting the water supply demand; and when the water supply flow of the main canal is When changes occur, when adjusting the diversion gate, the gate may be opened too much or too little, resulting in corresponding waste of resources or damage to the unit; only when both units are shut down, the flow passes through the diversion gate; when the load of one of the units changes or the target water diversion flow changes, it can also respond reasonably; therefore, the present invention can reasonably dispatch the unit and the diversion gate according to the abnormal situation of the unit and the change of the target water diversion flow, while ensuring the water supply demand, maximizing the power generation as much as possible, avoiding waste of unit resources and damage to the unit.

[0042] This method is applicable to water conservancy projects where a hydropower station and a water diversion gate supply water together. In this embodiment, the emergency dispatching method of the hydropower station and the water diversion gate is specifically described by taking the Taocha Canal Headworks Project as a specific example:

[0043] The flow chart of the emergency dispatching method of the hydropower station and the water diversion gate is as follows: Figure 1 As shown, a specific example of this method is as follows:

[0044] First, determine the shutdown status of the unit. When one of the two units of the hydropower station is shut down, determine whether the upstream and downstream head difference △H of the hydropower station unit is less than or equal to the head value corresponding to the maximum water diversion flow of all units (a total of two units);

[0045] 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 total) 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;

[0046] 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 Q of the non-shutdown unit is determined. max Is it greater than or equal to the target water transfer flow Q, that is, it satisfies:

[0047] Q max ≥Q (1-1)

[0048] If it is greater than or equal to, the diversion gate will not be opened and the output of the non-stop units will be obtained according to the target water flow Q. Otherwise, the maximum flow rate Q of the non-stop units will be used. max The output of the non-stop units is obtained, and the target water transfer flow Q and the maximum flow Q of the non-stop units are calculated. 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 =QQ max ;

[0049] The maximum flow rate of each unit is determined by the linear equation corresponding to the output limit line of the turbine, 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".

[0050] 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:

[0051] Q max =9.176△H+82.246

[0052] 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.

[0053] If the water head value △H is greater than the water head value corresponding to the maximum water diversion flow rate, then when the output of the non-stopped units calculated according to the target water diversion flow rate Q is less than or equal to the maximum power of the non-stopped units (the maximum power of each unit is 25MW), the calculated output of the non-stopped units is used and the diversion gate is not opened; when the output of the non-stopped units is greater than the maximum power of the non-stopped units, the output of the units with the maximum power (N=25MW) is used and the diversion gate is opened according to the diversion gate flow determined by the difference between the target water diversion flow rate Q and the flow corresponding to the maximum power of the non-stopped units, Q S =QQ P ;

[0054] When both units of the hydropower station are shut down, the diversion gate is opened according to the diversion gate flow rate determined by the target water diversion flow rate. The diversion gate flow rate Q S =Q.

[0055] The methods of obtaining the unit output according to the unit flow rate include:

[0056] 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.

[0057] 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:

[0058] N i =ρg△HQ pi η (1-2)

[0059] 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;

[0060] 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:

[0061]

[0062] 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.

[0063] 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:

[0064]

[0065] In the formula, Q pi is the flow rate of the i-th unit.

[0066] Before executing the above dispatching steps, the current water level H of the upstream reservoir of Taocha is 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 , current water transfer flow and target water transfer flow are obtained.

[0067] 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:

[0068]

[0069] 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; the specific method of obtaining the above-mentioned stable downstream water level belongs to the existing technology and will not be repeated here.

[0070] 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 .

[0071] Reference Figure 1 In this embodiment, when the water diversion gate is a water diversion gate with three gates, the method of opening each gate of the water diversion gate according to the flow of the water diversion gate includes:

[0072] Determine whether one of the diversion gates is under maintenance (only one of the three gates of the diversion gate is allowed to be under maintenance at the same time). If not, open all three gates of the diversion gate at the same time or increase the opening of the three gates of the diversion gate; if one of the diversion gates is under maintenance, open the other two gates of the diversion gate at the same time or increase the opening of the other two gates of the diversion gate.

[0073] When all gates are opened at the same time or the opening of each gate is increased, the opening of each gate is calculated based on the relationship between the gate opening and the water diversion gate flow, 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 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 ratio of the upstream and downstream head difference to the upstream head and the relative opening of the gate as independent variables and the gate hole flooding coefficient as the dependent variable.

[0074] The relationship between the gate opening and the diversion gate flow, upstream head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream head difference of the unit is:

[0075]

[0076] In the formula, when the opening of each gate is increased, e i is the opening of the i-th gate before the diversion gate increases its opening, △e is the increased gate opening; when all gates are opened at the same time, e i is the opening of the gate of the i-th hole of the water diversion gate, △e is 0; Q s is the flow rate of the diversion gate, i∈{1,2,3}; j is the number of open diversion gates, j∈{2,3}; b1, b2, b3, b4, b5, b6, b7 and b8 are the parameters obtained by fitting the flow rate of the diversion gate 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.

[0077] 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 and the diversion gate flow Q s , upstream head H, current upstream reservoir water level H of the hydropower station u 、The relationship between the head difference △H between the upstream and downstream of the unit

[0078]

[0079] In the formula, when the opening of each gate is increased, e i is the opening of the i-th gate before the diversion gate increases its opening, △e is the increased gate opening; when the gates are opened at the same time, e i is the opening of the gate of the i-th hole of the water diversion gate, △e is 0; Q s is the flow rate of the diversion gate, i∈{1, 2, 3}; j is the number of open diversion gates, j∈{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.

[0080] For example, if there is no 1-hole gate overhaul, when the opening of the 3-hole gate of the water diversion gate is increased, the opening of the 3-hole gate will increase by △e at the same time, and the increased opening can reach e i +△e, the method to determine the increased opening of the three-hole gate of the water diversion gate is:

[0081]

[0082] In the formula, e i is the opening of the i-th gate before the diversion gate is increased, △e is the increased gate opening; Q s is the flow rate 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.

[0083] If one gate is under maintenance, and the opening of the other two gates of the diversion gate is increased, the opening of the two gates will increase by △e at the same time, and the increased opening can reach e i +△e, the method to determine the increased opening of the two-hole gate of the water diversion gate is:

[0084]

[0085] In the formula, e i is the opening of the i-th gate before the diversion gate is increased, △e is the increased gate opening; Q s is the flow rate 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. An emergency dispatching method for a hydropower station and a water diversion gate, characterized in that: When one of the two units of the hydropower station is shut down, determine whether the head difference between the upstream and downstream water heads of the units of the hydropower station is less than or equal to the head value corresponding to the maximum water transfer flow of all units; if it is less than or equal to the head value, determine whether the maximum flow rate of the units that are not shut down is greater than or equal to the target water transfer flow, if it is greater than or equal to the target water transfer flow, do not open the diversion gate and obtain the output of the units that are not shut down according to the target water transfer flow, otherwise, obtain the output of the units that are not shut down according to the maximum flow rate of the units that are not shut down, and open the diversion gate according to the diversion gate flow determined by the difference between the target water transfer flow and the maximum flow rate of the units that are not shut down; If it is greater than the water head value, when the output of the non-stopped units calculated according to the target water diversion flow is less than or equal to its maximum power, the calculated output of the non-stopped units is used and the diversion gate is not opened; when the output of the non-stopped units is greater than its maximum power, the output of the units with maximum power is used and the diversion gate is opened according to the diversion gate flow determined by the difference between the target water diversion flow and the flow corresponding to the maximum power of the units; When both units of the hydropower station are shut down, the diversion gate is opened according to the diversion gate flow determined by the target water diversion flow.

2. The method for emergency dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The methods of obtaining the unit output according to the unit flow rate 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 emergency 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 unit's flow rate, the head difference between the upstream and downstream of the unit and the corresponding unit operating efficiency.

4. The method for emergency 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 each gate of the water diversion gate according to the flow of the water diversion gate includes: Determine whether one of the gates of the water diversion gate is under maintenance. If not, open the three gates of the water diversion gate at the same time or increase the opening of the three gates of the water diversion gate; If one of the diversion sluice gates is under maintenance, the other two gates of the diversion sluice shall be opened at the same time or the opening of the other two gates of the diversion sluice shall be increased.

5. The method for emergency dispatching of a hydropower station and a water diversion gate according to claim 1, characterized in that: The maximum flow rate of the 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.

6. The method for emergency dispatching of a hydropower station and a water diversion gate according to claim 5, 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.

7. The method for emergency 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's units 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 based on the current downstream stable water level, the current water diversion flow and the target water diversion flow.

8. The method for emergency dispatching of a hydropower station and a water diversion gate according to claim 7, characterized in that: 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 emergency 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 emergency dispatching of a hydropower station and a water diversion gate according to claim 4, characterized in that: When all gates are opened at the same time or the opening of each gate is increased, the opening of each gate is calculated according to the relationship between the gate opening and the diversion gate flow, 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 the ratio of the upstream and downstream head difference to the upstream head and the gate relative opening as independent variables and the gate hole flooding coefficient as the dependent variable; The relationship between the gate opening and the diversion gate flow, upstream head, the current upstream reservoir water level of the hydropower station, and the upstream and downstream head difference of the unit includes: In the formula, when the opening of each gate is increased, e i is the opening of the i-th gate before the diversion gate increases its opening, △e is the increased gate opening; when all gates are opened at the same time, e i is the opening of the gate of the i-th hole of the water diversion gate, △e is 0; Q s is the flow rate of the diversion gate, i∈{1,2,3}; j is the number of open diversion gates, j∈{2,3}; b1, b2, b3, b4, b5, b6, b7 and b8 are the parameters obtained by fitting the flow rate of the diversion gate 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.

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