Hydroelectric generating set frequency modulation method and system considering vibration area constraint

Abstract

The invention discloses a hydroelectric generating set frequency modulation method and system considering vibration area constraints, and belongs to the technical field of power grid dispatching automation, and the method comprises the steps: detecting whether the operation condition of a hydroelectric generating set meets the frequency modulation bid-winning capacity of a hydraulic power plant or not based on a preset frequency modulation rule, and obtaining a feasible output interval of the hydroelectric generating set; the frequency modulation rule is related to the frequency modulation range of the hydraulic power plant and the feasible frequency modulation interval of the hydroelectric generating set; constructing a target function by taking the minimum power generation total cost as a target, and constructing a hydroelectric frequency modulation model by taking the condition that the prohibited vibration area does not appear in the feasible output interval as a constraint condition; and obtaining positive and negative frequency modulation reserve capacities of the hydraulic power plant and each hydroelectric generating set according to a hydroelectric frequency modulation model and the frequency modulation bid-winning capacity. Therefore, the problem that the frequency modulation effect of the hydroelectric generating set is poor due to the fact that actual operation of the hydroelectric generating set needs to avoid the vibration prohibition area in the prior art can be solved.

Description

Technical Field

[0001] This application belongs to the field of power grid dispatch automation technology, specifically relating to a frequency regulation method and system for hydropower units that considers vibration zone constraints. Background Technology

[0002] Frequency regulation, as a key technology for maintaining the stability of power system frequencies, effectively avoids damage to power grid equipment caused by large frequency fluctuations by adjusting power generation output in real time to match the dynamic changes in electricity load. Hydropower units, with their characteristics of short start-up time, high regulation rate, and low response delay, play a crucial role in frequency regulation ancillary services. Especially in new power systems with high penetration of renewable energy, their flexible regulation capabilities have become a core support for ensuring system frequency stability.

[0003] In a power market environment, hydropower plants first determine their unit combinations (i.e., the set of units to be put into operation and their planned output for each time period of the following day) through day-ahead clearing in the spot market. Then, they submit the corresponding frequency regulation capacity for this unit combination to the frequency regulation vibration zone ancillary services market for competitive bidding. Based on the obtained feasible bidding range, the final winning frequency regulation capacity will be incorporated into the spot market unit bidding constraints, serving as the basis for its participation in the energy market. However, when hydropower units are in the prohibited vibration zone (i.e., the operating range where the unit's vibration amplitude / frequency exceeds the safety threshold, typically manifested as a nonlinear unstable region in the output-speed curve), their regulation performance will significantly decrease, leading to issues such as limited ramp rate, increased response delay, and even potential mechanical damage. Existing hydropower unit frequency regulation methods rarely consider the constraint that hydropower units must strictly avoid vibration zones during actual operation, resulting in a discrepancy between the frequency regulation capacity allocated to each hydropower unit and the actual capacity, affecting the continuity of market clearing and reducing the efficiency of market resource allocation. Summary of the Invention

[0004] This application proposes a frequency regulation method and system for hydropower units that considers vibration zone constraints, which can solve the problem that the existing technology does not take into account the actual operation of hydropower units needing to avoid the prohibited vibration zone, resulting in poor frequency regulation effect of hydropower units.

[0005] The first aspect of this application provides a frequency regulation method for hydropower units considering vibration zone constraints, the method comprising:

[0006] Based on preset frequency regulation rules, the operation of the hydropower unit is checked to see if it meets the frequency regulation bid capacity of the hydropower plant, thereby obtaining the feasible output range of the hydropower unit; the frequency regulation rules are related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower unit.

[0007] A hydropower frequency regulation model is constructed with the objective function of minimizing the total power generation cost and the constraint that the prohibited vibration zone does not appear in the feasible output range.

[0008] Based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit is obtained.

[0009] The above scheme first considers whether the current operating conditions of the hydropower plant and each hydropower unit can meet the frequency regulation bid capacity, thus pre-verifying the regulation requirements. If the existing regulation requirements can be met, the feasible output range of the corresponding hydropower units is obtained. A prohibited vibration zone is introduced when constructing the constraints. By restricting the output of the hydropower units from occurring within this zone, the frequency regulation difficulties during operation are avoided. This achieves the minimum total power generation cost while improving the frequency regulation effect of the hydropower units, thus constructing a corresponding hydropower frequency regulation model. Based on the hydropower frequency regulation model and the frequency regulation bid capacity, appropriate optimal frequency regulation reserve capacity is allocated to each hydropower unit to ensure that the optimal reserve capacity prevents the hydropower unit output from entering the prohibited vibration zone, achieving efficient unit frequency regulation.

[0010] In one possible implementation of the first aspect, based on preset frequency regulation rules, the operation of the hydropower unit is checked to see if it meets the frequency regulation bid capacity of the hydropower plant, thereby obtaining the feasible output range of the hydropower unit, specifically:

[0011] Based on the frequency regulation winning bid capacity and the power output range of the hydropower plant, determine the frequency regulation range of the hydropower plant;

[0012] The feasible frequency modulation range is obtained by eliminating the prohibited vibration zone from the current output range of the hydropower unit.

[0013] Under the preset extreme scenario, if the output range of the hydropower plant does not exceed the frequency regulation range, and the sum of the feasible frequency regulation intervals of the hydropower units in the operating state meets the frequency regulation bid capacity, then it is said that the operation of the hydropower units meets the frequency regulation bid capacity, and the current output range of the hydropower units is taken as the feasible output interval; wherein, the output range of the hydropower plant is the sum of the current output ranges of all hydropower units.

[0014] The above scheme takes into account the existing frequency regulation bidding capacity and tests whether hydropower units and hydropower plants can meet the frequency regulation bidding requirements under extreme scenarios. If they can meet the requirements under extreme scenarios, it indicates that the operation of hydropower units can also meet the frequency regulation bidding requirements under other scenarios, and obtains the feasible output range of hydropower units that meet the frequency regulation bidding requirements, providing data support for the subsequent allocation of frequency regulation capacity.

[0015] In one possible implementation of the first aspect, if the operating conditions of the hydropower unit do not meet the frequency regulation bid capacity, the frequency regulation rules are adjusted according to a preset adjustment priority; wherein, the adjustment priority includes considering the frequency regulation bid capacity first and then eliminating the prohibited vibration zone, and eliminating the prohibited vibration zone first and then considering the frequency regulation bid capacity.

[0016] If the above scheme cannot meet the requirements for winning the FM bid, a new FM rule is constructed by ignoring the constraints with lower priority.

[0017] In one possible implementation of the first aspect, an objective function is constructed with the goal of minimizing the total power generation cost, and a hydropower frequency regulation model is constructed with the constraint that the vibration prohibition zone does not appear in the feasible output range. Specifically:

[0018] Construct an objective function with the goal of minimizing the total cost of power generation;

[0019] The first constraint condition is constructed by limiting the output of hydropower plants and hydro-generator units as well as the frequency regulation reserve capacity;

[0020] A second constraint is constructed by ensuring that the vibration prohibition zone does not appear in the feasible output range and that the sum of the frequency modulation capacity within the feasible output range meets the frequency modulation winning capacity.

[0021] A hydropower frequency regulation model is constructed based on the objective function, the first constraint, and the second constraint.

[0022] The above scheme introduces a restricted vibration zone as a constraint condition. By limiting the output of the hydropower unit to enter the restricted vibration zone, the hydropower unit is kept in a state of efficient frequency regulation. This minimizes the total power generation cost while improving the overall frequency regulation effect of the hydropower plant.

[0023] In one possible implementation of the first aspect, the second constraint is specifically:

[0024]

[0025]

[0026] In the formula, The positive frequency regulation capacity that hydropower unit j can provide. H represents the negative frequency regulation capacity that hydropower unit j can provide, and H is the total number of feasible output ranges for the hydropower unit. and HPST represents the upper and lower limits of the h-th feasible output range of hydropower unit j, respectively. j,h,t PG is a 0-1 decision variable, representing whether the h-th feasible output range of hydropower unit j is selected; j,tThis represents the output of hydropower unit j during time period t.

[0027] In one possible implementation of the first aspect, the objective function is specifically:

[0028]

[0029] In the formula, I represents the total number of hydropower plants participating in the market clearing, T represents the total number of time periods, S represents the total number of bid segments for hydropower plants, and PSC represents the total number of bid segments for hydropower plants. i,t,s For the output of hydropower plant i under time period t and bidding segment s, α i,t,s Let i be the cost of the bid for hydropower plant i in time period t and bid segment s.

[0030] In one possible implementation of the first aspect, the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit is obtained based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, specifically as follows:

[0031] Based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, the winning bid situation of the feasible output range is calculated;

[0032] Based on the bidding results and the current output of the hydropower units, the optimal positive and negative frequency regulation reserve capacity of each hydropower unit is calculated.

[0033] By summing the optimal positive and negative frequency regulation reserve capacities, the total positive and negative frequency regulation reserve capacity of the hydropower plant is obtained.

[0034] Based on the optimal positive and negative frequency regulation reserve capacity and the total positive and negative frequency regulation reserve capacity, the output of each hydropower unit and the total power of the hydropower plant are adjusted.

[0035] The above scheme determines the winning bid for the feasible output range of each hydropower unit through a hydropower frequency regulation model, and allocates appropriate positive and negative frequency regulation reserve capacity to the hydropower units so that the hydropower units can achieve optimal output during frequency regulation.

[0036] The second aspect of this application provides a frequency regulation system for hydropower units that considers vibration zone constraints. The system includes: a data prediction module, a frequency regulation model construction module, and a frequency regulation reserve capacity calculation module.

[0037] The data prediction module is used to detect whether the operation of the hydropower unit meets the frequency regulation bid capacity of the hydropower plant based on the preset frequency regulation rules, and to obtain the feasible output range of the hydropower unit; the frequency regulation rules are related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower unit.

[0038] The frequency regulation model construction module is used to construct an objective function with the goal of minimizing the total power generation cost, and to construct a hydropower frequency regulation model with the constraint that the prohibited vibration zone does not appear in the feasible output range.

[0039] The frequency regulation reserve capacity calculation module is used to obtain the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit based on the hydropower frequency regulation model and the frequency regulation winning bid capacity.

[0040] A third aspect of this application provides a terminal device, the device comprising: a terminal device including a processor and a memory, the memory storing a computer program, wherein the processor executes the computer program to implement the steps of the frequency regulation method for a hydropower unit considering vibration zone constraints as described in any one of the embodiments of this application.

[0041] A fourth aspect of this application provides a storage medium that stores computer-readable program code, which, when executed, implements the steps of a frequency regulation method for a hydropower unit considering vibration zone constraints, as described in any one of the embodiments of this application. Attached Figure Description

[0042] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a schematic flowchart of a frequency regulation method for hydropower units considering vibration zone constraints provided in an embodiment of this application;

[0044] Figure 2 This is a structural diagram of a hydropower unit frequency regulation system considering vibration zone constraints, provided in one embodiment of this application;

[0045] Figure 3 This application provides a structural diagram of a terminal device according to one embodiment. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0047] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0048] First Embodiment

[0049] When the output of a hydropower unit is in the prohibited vibration zone, the frequency regulation effect of the hydropower unit will be greatly reduced, and it may even cause mechanical damage to the unit. Therefore, in the existing frequency regulation process, it is necessary to take into account the impact of the prohibited vibration zone on the unit, so that the feasible output range of the hydropower unit can avoid the prohibited vibration zone, thereby improving the overall frequency regulation effect of the hydropower plant while ensuring the safety of frequency regulation.

[0050] like Figure 1 As shown, to address the problem in the prior art that the actual operation of hydropower units needs to avoid prohibited vibration zones, resulting in poor frequency regulation performance, the first embodiment of this application provides a detailed flowchart of a hydropower unit frequency regulation method considering vibration zone constraints. This embodiment's hydropower unit frequency regulation method considering vibration zone constraints includes steps S1 to S3, detailed below:

[0051] Step S1: Based on the preset frequency regulation rules, check whether the operation of the hydropower unit meets the frequency regulation bid capacity of the hydropower plant, and obtain the feasible output range of the hydropower unit.

[0052] In this embodiment, the hydropower unit has the characteristics of short start-up time (usually ≤2 minutes), high regulation rate (up to 3% to 5% of rated power / minute), and low response delay (millisecond level). Therefore, when the output of the hydropower unit is in the prohibited vibration zone, the hydropower unit may experience an operating range in which the vibration amplitude / frequency exceeds the safety threshold, and the output-speed curve of the hydropower unit becomes unstable. This leads to a limited ramp rate and increased response delay of the hydropower unit, which greatly reduces the frequency regulation effect of the unit.

[0053] Therefore, in order to improve the overall frequency regulation effect of the hydropower plant, the first step is to test whether the operation of the hydropower units can meet the frequency regulation bid capacity of the hydropower plant, so as to obtain the feasible output range of the hydropower units that can meet the frequency regulation bid requirements.

[0054] Among them, the frequency regulation winning bid capacity refers to the difference between the maximum adjustable output and the minimum technical output that a hydropower plant can use during the frequency regulation process, which is determined by bidding in the power clearing market.

[0055] First, obtain the output range of the hydropower plant and the current output range of the hydropower units. Based on the frequency regulation bid capacity and the output range of the hydropower plant, calculate the frequency regulation range of the hydropower plant; then, remove the prohibited vibration zone from the current output range of the hydropower units to obtain the feasible frequency regulation intervals for each hydropower unit.

[0056] In extreme scenarios, if there is still a feasible output range for hydropower units that can meet the frequency regulation bidding requirements, it means that the hydropower plant can achieve the frequency regulation bidding requirements under any circumstances. Therefore, this application embodiment only tests the operation of hydropower units in extreme scenarios, which can cover all application scenarios and greatly save testing time.

[0057] This application embodiment establishes a frequency regulation rule to detect whether there is a feasible output range for hydropower units that can meet the frequency regulation bidding requirements under extreme scenarios. The frequency regulation rule is related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower units.

[0058] Specifically, if the output range of the hydropower plant does not exceed the frequency regulation range of the hydropower plant, and the sum of the feasible frequency regulation intervals of the hydropower units in operation can meet the frequency regulation bid capacity, it means that the operation of the hydropower units can also meet the frequency regulation bid capacity under extreme scenarios. In this case, the current output range of the hydropower units can be used as its feasible output interval.

[0059] For example, suppose a hydropower plant includes unit A and unit B. The current output range of both unit A and unit B is [0, 500], and the prohibited vibration zone of both unit A and unit B is [40, 400]. Then the output range of the hydropower plant is [0, 1000]. Assume the upper and lower frequency regulation bid caps of the hydropower plant are both 50. The set frequency regulation rules require selecting an interval that conforms to the upper and lower frequency regulation bid caps within the hydropower plant's output range and the current output range of the hydropower units.

[0060] (1) Select the output range that meets the above and below frequency regulation bid capacity from the output range of the hydropower plant: Based on the output range of the hydropower plant [0,1000], after considering the above and below frequency regulation bid capacity, the frequency regulation range of the hydropower plant is [50,950]. As long as the output of the hydropower plant is kept in the range of [50,950] during the frequency regulation process, the hydropower plant can meet the frequency regulation bid requirements.

[0061] (2) Select the output range that meets the above-mentioned frequency regulation bid capacity from the current output range of the hydropower units: After removing the vibration prohibition zone from the current output range of units A and B, the feasible frequency regulation ranges for units A and B are [0,40] and [400,500], respectively. When both units A and B are in the operating state, there are four possible output combinations for these two units:

[0062] Combination 1: Unit A is [0,40], Unit B is [0,40], then the power output range of the hydropower plant is [0,80].

[0063] Combination 2: Unit A is [0,40], Unit B is [400,500], then the power output range of the hydropower plant is [400,540].

[0064] Combination 3: Unit A is [400, 500], Unit B is [0, 40], then the power output range of the hydropower plant is [400, 540].

[0065] Combination 4: Unit A is [400, 500], Unit B is [400, 500], then the power output range of the hydropower plant is [800, 1000].

[0066] Among the above power output combinations, only the power output range of the hydropower plant in combination one is 80, which cannot meet the requirement of 50 for each of the upper and lower frequency regulation bids (i.e., the difference between the upper and lower frequency regulation bids is 100). Combinations two, three, and four can all meet this requirement. Therefore, combinations two, three, and four can be used as the feasible power output ranges for unit A and unit B.

[0067] Furthermore, when the hydropower unit's operating conditions do not meet the frequency regulation target capacity under extreme scenarios, the frequency regulation rules are adjusted according to a preset adjustment priority. This adjustment priority prioritizes either meeting the frequency regulation target capacity or avoiding prohibited vibration zones.

[0068] For example, based on the above example, if the bid-winning capacity for both the upper and lower frequency regulation of the hydropower plant is adjusted to 150, then combinations one, two, three, and four cannot meet the adjusted bid-winning capacity for both the upper and lower frequency regulation. In this case, it is necessary to discard other lower priority restrictions according to the set adjustment priority. If the bid-winning capacity for frequency regulation is given priority, then when avoiding the prohibited vibration zone is not required, the output range of the hydropower plant becomes [0, 1000], which can meet the bid-winning capacity for frequency regulation. If avoiding the prohibited vibration zone is given priority, then when the bid-winning capacity for frequency regulation is not required (i.e., the frequency regulation of 300 is not required), combinations one, two, three, and four can all achieve the avoidance of the prohibited vibration zone.

[0069] Furthermore, when adjusting frequency regulation rules, other restrictions can be discarded, such as the upper and lower limits of output of hydropower units and the upper and lower limits of output of hydropower plants.

[0070] Step S2: Construct an objective function with the goal of minimizing the total power generation cost, and use the prohibition of vibration zones not appearing in the feasible output range as a constraint condition to construct a hydropower frequency regulation model.

[0071] Since avoiding the prohibited vibration zone is included as a constraint in the model when regulating the frequency of hydropower units, the objective function of the hydropower frequency regulation model is still to minimize the total power generation cost, specifically expressed as:

[0072]

[0073] In the formula, I represents the total number of hydropower plants participating in the market clearing, T represents the total number of time periods, S represents the total number of bid segments for hydropower plants, and PSC represents the total number of bid segments for hydropower plants. i,t,s For the output of hydropower plant i under time period t and bidding segment s, α i,t,s For the cost of hydropower plant i in time period t and price segment s, it is necessary to ensure that the price is monotonically increasing.

[0074] In constructing the constraints of the model, in addition to conventional load balance constraints, system positive and negative backup constraints, network security constraints, etc., this application embodiment also constructs constraints related to hydropower frequency regulation and vibration prohibition zones.

[0075] The constraints related to frequency regulation in hydropower are limitations on the output of hydropower plants and hydropower units, as well as the reserve capacity for frequency regulation. Specifically:

[0076] (1) The actual output of the hydropower plant is required to match the total output bid in the segmented bidding for the hydropower plant. The expression for the constraint condition is as follows:

[0077]

[0078] In the formula, PP i,t PSC contributes to the actual power output of the hydropower plant i,t,s Let S be the output of hydropower plant i in time period t and bidding segment s, where S is the total number of bidding segments for hydropower plant i.

[0079] (2) The requirement is that the actual output of the hydropower plant must be consistent with the sum of the outputs of its subordinate hydropower units. The expression for this constraint is as follows:

[0080]

[0081] In the formula, J represents the number of hydropower units under the hydropower plant, and PG j,t For the output of hydroelectric generator units;

[0082] (3) The operating status of the hydropower unit is required to be coupled with the indicator variable of the feasible output range, that is, to ensure that when the hydropower unit is started, there must be a feasible output range that meets the frequency regulation bidding requirements. The expression of the constructed constraint condition is:

[0083]

[0084] In the formula, AG j,t This is a 0-1 variable representing the operating state of unit j during time period t. It takes a value of 1 when the unit is running and a value of 0 otherwise. H represents the total number of feasible output ranges for the hydropower unit. HPST j,h,t The variable is a 0-1 decision variable, indicating whether the h-th feasible output range of hydropower unit j is selected.

[0085] (4) The sum of the positive and negative frequency regulation reserve capacity provided by the hydropower units must meet the positive and negative frequency regulation reserve requirements of the hydropower plant. The expression for the constructed constraint condition is as follows:

[0086]

[0087] In the formula, These represent the lower limits of positive and negative frequency regulation reserve capacity for hydropower plant i during time period t. The positive frequency regulation capacity that hydropower unit j can provide. The negative frequency regulation capacity that hydropower unit j can provide.

[0088] (5) The constraint condition that requires the frequency regulation reserve capacity of the hydropower plant to be within the output range of the hydropower plant is expressed as follows:

[0089]

[0090] In the formula, These represent the minimum and maximum output limits of hydropower plant i during time period t.

[0091] The constraint related to the prohibited vibration zone is to prevent the prohibited vibration zone from appearing within the feasible output range of the hydropower unit, and to ensure that the sum of the frequency regulation capacity (including the upper and lower frequency regulation capacity) within the feasible output range meets the winning bid capacity for both positive and negative frequency regulation of the entire hydropower plant. The expression for the constructed constraint is as follows:

[0092]

[0093]

[0094] In the formula, The positive frequency regulation capacity that hydropower unit j can provide. H represents the negative frequency regulation capacity that hydropower unit j can provide, and H is the total number of feasible output ranges for the hydropower unit. and HPST represents the upper and lower limits of the h-th feasible output range of hydropower unit j, respectively. j,h,t This is a 0-1 decision variable, representing whether the h-th feasible output range of hydropower unit j is selected; if selected, this variable is 1. j,t This represents the output of hydropower unit j during time period t.

[0095] Based on the objective function and the established constraints, a hydropower frequency regulation model is obtained. This model is a mixed-integer linear programming model, which can be directly solved using existing optimization algorithm software packages.

[0096] Optionally, in this embodiment of the application, the hydropower frequency regulation model sets 96 time periods (24 hours) for daytime, with each time period lasting 15 minutes; and sets 24 time periods (2 hours) for real-time, with each time period lasting 5 minutes.

[0097] Step S3: Based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, obtain the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit.

[0098] By constructing a hydropower frequency regulation model and determining the winning bid capacity for frequency regulation, the winning bid status of each hydropower unit's feasible output range is calculated, i.e., the output range of each hydropower unit that meets the requirements for winning the frequency regulation bid.

[0099] Based on the above bidding results and the current output of the hydropower units, an optimal positive and negative frequency regulation reserve capacity is allocated to each hydropower unit to avoid the vibration-prohibited zone. Under this optimal positive and negative frequency regulation reserve capacity, the hydropower units can achieve optimal performance under frequency regulation.

[0100] The optimal positive and negative frequency regulation reserve capacity of all hydropower units under the hydropower plant is summed together to obtain the total positive and negative frequency regulation reserve capacity that the hydropower plant can actually provide.

[0101] Based on the optimal positive and negative frequency regulation reserve capacity of the hydropower units and the total positive and negative frequency regulation reserve capacity of the hydropower plant, the output of each hydropower unit and the total power of the hydropower plant are adjusted to improve the frequency regulation effect of the hydropower plant.

[0102] Implementing the embodiments of this application has the following beneficial effects:

[0103] This application's embodiments first consider whether the current operating conditions of the hydropower plant and each hydropower unit can meet the frequency regulation bid capacity, thus pre-verifying the regulation requirements. If the existing regulation requirements can be met, the feasible output range of the corresponding hydropower unit is obtained. A prohibited vibration zone is introduced when constructing the constraints. By restricting the output of the hydropower unit from occurring within this zone, the frequency regulation difficulties of the hydropower unit are avoided during operation. This achieves the minimum total power generation cost while improving the frequency regulation effect of the hydropower unit, thus constructing a corresponding hydropower frequency regulation model. Based on the hydropower frequency regulation model and the frequency regulation bid capacity, a suitable optimal frequency regulation reserve capacity is allocated to each hydropower unit to ensure that the optimal reserve capacity prevents the hydropower unit output from entering the prohibited vibration zone, achieving a highly efficient unit frequency regulation effect.

[0104] Second Embodiment

[0105] Furthermore, in order to implement the frequency regulation system for hydropower units that considers vibration zone constraints corresponding to the above method embodiments, and to achieve the corresponding functions and technical effects, Figure 2A structural diagram of a hydropower unit frequency regulation system considering vibration zone constraints is provided. For ease of explanation, only the parts relevant to this embodiment are shown. The hydropower unit frequency regulation system considering vibration zone constraints provided in this application embodiment includes:

[0106] The data prediction module 201 is used to detect whether the operation of the hydropower unit meets the frequency regulation bid capacity of the hydropower plant based on the preset frequency regulation rules, and to obtain the feasible output range of the hydropower unit; the frequency regulation rules are related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower unit.

[0107] In this embodiment of the application, the frequency regulation range of the hydropower plant is determined based on the frequency regulation winning bid capacity and the power output range of the hydropower plant;

[0108] The feasible frequency modulation range is obtained by eliminating the prohibited vibration zone from the current output range of the hydropower unit.

[0109] Under the preset extreme scenario, if the output range of the hydropower plant does not exceed the frequency regulation range, and the sum of the feasible frequency regulation intervals of the hydropower units in the operating state meets the frequency regulation bid capacity, then it is said that the operation of the hydropower units meets the frequency regulation bid capacity, and the current output range of the hydropower units is taken as the feasible output interval; wherein, the output range of the hydropower plant is the sum of the current output ranges of all hydropower units.

[0110] The frequency regulation model construction module 202 is used to construct an objective function with the goal of minimizing the total power generation cost and to construct a hydropower frequency regulation model with the prohibition of vibration zone not appearing in the feasible output range as a constraint.

[0111] In this embodiment, an objective function is constructed with the goal of minimizing the total cost of power generation;

[0112] The first constraint condition is constructed by limiting the output of hydropower plants and hydro-generator units as well as the frequency regulation reserve capacity;

[0113] A second constraint is constructed by ensuring that the vibration prohibition zone does not appear in the feasible output range and that the sum of the frequency modulation capacity within the feasible output range meets the frequency modulation winning capacity.

[0114] A hydropower frequency regulation model is constructed based on the objective function, the first constraint, and the second constraint.

[0115] The frequency regulation reserve capacity calculation module 203 is used to obtain the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit based on the hydropower frequency regulation model and the frequency regulation winning bid capacity.

[0116] In this embodiment of the application, the winning bid situation of the feasible output range is calculated based on the hydropower frequency regulation model and the frequency regulation winning bid capacity;

[0117] Based on the bidding results and the current output of the hydropower units, the optimal positive and negative frequency regulation reserve capacity of each hydropower unit is calculated.

[0118] By summing the optimal positive and negative frequency regulation reserve capacities, the total positive and negative frequency regulation reserve capacity of the hydropower plant is obtained.

[0119] Based on the optimal positive and negative frequency regulation reserve capacity and the total positive and negative frequency regulation reserve capacity, the output of each hydropower unit and the total power of the hydropower plant are adjusted.

[0120] In some embodiments, the data prediction module 201 specifically comprises:

[0121] In this embodiment, the hydropower unit has the characteristics of short start-up time (usually ≤2 minutes), high regulation rate (up to 3% to 5% of rated power / minute), and low response delay (millisecond level). Therefore, when the output of the hydropower unit is in the prohibited vibration zone, the hydropower unit may experience an operating range in which the vibration amplitude / frequency exceeds the safety threshold, and the output-speed curve of the hydropower unit becomes unstable. This leads to a limited ramp rate and increased response delay of the hydropower unit, which greatly reduces the frequency regulation effect of the unit.

[0122] Therefore, in order to improve the overall frequency regulation effect of the hydropower plant, the first step is to test whether the operation of the hydropower units can meet the frequency regulation bid capacity of the hydropower plant, so as to obtain the feasible output range of the hydropower units that can meet the frequency regulation bid requirements.

[0123] Among them, the frequency regulation winning bid capacity refers to the difference between the maximum adjustable output and the minimum technical output that a hydropower plant can use during the frequency regulation process, which is determined by bidding in the power clearing market.

[0124] First, obtain the output range of the hydropower plant and the current output range of the hydropower units. Based on the frequency regulation bid capacity and the output range of the hydropower plant, calculate the frequency regulation range of the hydropower plant; then, remove the prohibited vibration zone from the current output range of the hydropower units to obtain the feasible frequency regulation intervals for each hydropower unit.

[0125] In extreme scenarios, if there is still a feasible output range for hydropower units that can meet the frequency regulation bidding requirements, it means that the hydropower plant can achieve the frequency regulation bidding requirements under any circumstances. Therefore, this application embodiment only tests the operation of hydropower units in extreme scenarios, which can cover all application scenarios and greatly save testing time.

[0126] This application embodiment establishes a frequency regulation rule to detect whether there is a feasible output range for hydropower units that can meet the frequency regulation bidding requirements under extreme scenarios. The frequency regulation rule is related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower units.

[0127] Specifically, if the output range of the hydropower plant does not exceed the frequency regulation range of the hydropower plant, and the sum of the feasible frequency regulation intervals of the hydropower units in operation can meet the frequency regulation bid capacity, it means that the operation of the hydropower units can also meet the frequency regulation bid capacity under extreme scenarios. In this case, the current output range of the hydropower units can be used as its feasible output interval.

[0128] For example, suppose a hydropower plant includes unit A and unit B. The current output range of both unit A and unit B is [0, 500], and the prohibited vibration zone of both unit A and unit B is [40, 400]. Then the output range of the hydropower plant is [0, 1000]. Assume the upper and lower frequency regulation bid caps of the hydropower plant are both 50. The set frequency regulation rules require selecting an interval that conforms to the upper and lower frequency regulation bid caps within the hydropower plant's output range and the current output range of the hydropower units.

[0129] (1) Select the output range that meets the above and below frequency regulation bid capacity from the output range of the hydropower plant: Based on the output range of the hydropower plant [0,1000], after considering the above and below frequency regulation bid capacity, the frequency regulation range of the hydropower plant is [50,950]. As long as the output of the hydropower plant is kept in the range of [50,950] during the frequency regulation process, the hydropower plant can meet the frequency regulation bid requirements.

[0130] (2) Select the output range that meets the above-mentioned frequency regulation bid capacity from the current output range of the hydropower units: After removing the vibration prohibition zone from the current output range of units A and B, the feasible frequency regulation ranges for units A and B are [0,40] and [400,500], respectively. When both units A and B are in the operating state, there are four possible output combinations for these two units:

[0131] Combination 1: Unit A is [0,40], Unit B is [0,40], then the power output range of the hydropower plant is [0,80].

[0132] Combination 2: Unit A is [0,40], Unit B is [400,500], then the power output range of the hydropower plant is [400,540].

[0133] Combination 3: Unit A is [400, 500], Unit B is [0, 40], then the power output range of the hydropower plant is [400, 540].

[0134] Combination 4: Unit A is [400, 500], Unit B is [400, 500], then the power output range of the hydropower plant is [800, 1000].

[0135] Among the above power output combinations, only the power output range of the hydropower plant in combination one is 80, which cannot meet the requirement of 50 for each of the upper and lower frequency regulation bids (i.e., the difference between the upper and lower frequency regulation bids is 100). Combinations two, three, and four can all meet this requirement. Therefore, combinations two, three, and four can be used as the feasible power output ranges for unit A and unit B.

[0136] Furthermore, when the hydropower unit's operating conditions do not meet the frequency regulation target capacity under extreme scenarios, the frequency regulation rules are adjusted according to a preset adjustment priority. This adjustment priority prioritizes either meeting the frequency regulation target capacity or avoiding prohibited vibration zones.

[0137] For example, based on the above example, if the bid-winning capacity for both the upper and lower frequency regulation of the hydropower plant is adjusted to 150, then combinations one, two, three, and four cannot meet the adjusted bid-winning capacity for both the upper and lower frequency regulation. In this case, it is necessary to discard other lower priority restrictions according to the set adjustment priority. If the bid-winning capacity for frequency regulation is given priority, then when avoiding the prohibited vibration zone is not required, the output range of the hydropower plant becomes [0, 1000], which can meet the bid-winning capacity for frequency regulation. If avoiding the prohibited vibration zone is given priority, then when the bid-winning capacity for frequency regulation is not required (i.e., the frequency regulation of 300 is not required), combinations one, two, three, and four can all achieve the avoidance of the prohibited vibration zone.

[0138] Furthermore, when adjusting frequency regulation rules, other restrictions can be discarded, such as the upper and lower limits of output of hydropower units and the upper and lower limits of output of hydropower plants.

[0139] In some embodiments, the frequency modulation model construction module 202 specifically comprises:

[0140] Since avoiding the prohibited vibration zone is included as a constraint in the model when regulating the frequency of hydropower units, the objective function of the hydropower frequency regulation model is still to minimize the total power generation cost, specifically expressed as:

[0141]

[0142] In the formula, I represents the total number of hydropower plants participating in the market clearing, T represents the total number of time periods, S represents the total number of bid segments for hydropower plants, and PSC represents the total number of bid segments for hydropower plants. i,t,s For the output of hydropower plant i under time period t and bidding segment s, α i,t,s For the cost of hydropower plant i in time period t and price segment s, it is necessary to ensure that the price is monotonically increasing.

[0143] In constructing the constraints of the model, in addition to conventional load balance constraints, system positive and negative backup constraints, network security constraints, etc., this application embodiment also constructs constraints related to hydropower frequency regulation and vibration prohibition zones.

[0144] The constraints related to frequency regulation in hydropower are limitations on the output of hydropower plants and hydropower units, as well as the reserve capacity for frequency regulation. Specifically:

[0145] (1) The actual output of the hydropower plant is required to match the total output bid in the segmented bidding for the hydropower plant. The expression for the constraint condition is as follows:

[0146]

[0147] In the formula, PP i,t PSC contributes to the actual power output of the hydropower plant i,t,s Let S be the output of hydropower plant i in time period t and bidding segment s, where S is the total number of bidding segments for hydropower plant i.

[0148] (2) The requirement is that the actual output of the hydropower plant must be consistent with the sum of the outputs of its subordinate hydropower units. The expression for this constraint is as follows:

[0149]

[0150] In the formula, J represents the number of hydropower units under the hydropower plant, and PG j,t For the output of hydroelectric generator units;

[0151] (3) The operating status of the hydropower unit is required to be coupled with the indicator variable of the feasible output range, that is, to ensure that when the hydropower unit is started, there must be a feasible output range that meets the frequency regulation bidding requirements. The expression of the constructed constraint condition is:

[0152]

[0153] In the formula, AG j,t This is a 0-1 variable representing the operating state of unit j during time period t. It takes a value of 1 when the unit is running and a value of 0 otherwise. H represents the total number of feasible output ranges for the hydropower unit. HPST j,h,t The variable is a 0-1 decision variable, indicating whether the h-th feasible output range of hydropower unit j is selected.

[0154] (4) The sum of the positive and negative frequency regulation reserve capacity provided by the hydropower units must meet the positive and negative frequency regulation reserve requirements of the hydropower plant. The expression for the constructed constraint condition is as follows:

[0155]

[0156] In the formula, These represent the lower limits of positive and negative frequency regulation reserve capacity for hydropower plant i during time period t. The positive frequency regulation capacity that hydropower unit j can provide. The negative frequency regulation capacity that hydropower unit j can provide.

[0157] (5) The constraint condition that requires the frequency regulation reserve capacity of the hydropower plant to be within the output range of the hydropower plant is expressed as follows:

[0158]

[0159] In the formula, These represent the minimum and maximum output limits of hydropower plant i during time period t.

[0160] The constraint related to the prohibited vibration zone is to prevent the prohibited vibration zone from appearing within the feasible output range of the hydropower unit, and to ensure that the sum of the frequency regulation capacity (including the upper and lower frequency regulation capacity) within the feasible output range meets the winning bid capacity for both positive and negative frequency regulation of the entire hydropower plant. The expression for the constructed constraint is as follows:

[0161]

[0162]

[0163] In the formula, The positive frequency regulation capacity that hydropower unit j can provide. H represents the negative frequency regulation capacity that hydropower unit j can provide, and H is the total number of feasible output ranges for the hydropower unit. and HPST represents the upper and lower limits of the h-th feasible output range of hydropower unit j, respectively. j,h,t This is a 0-1 decision variable, representing whether the h-th feasible output range of hydropower unit j is selected; if selected, this variable is 1. j,t This represents the output of hydropower unit j during time period t.

[0164] Based on the objective function and the established constraints, a hydropower frequency regulation model is obtained. This model is a mixed-integer linear programming model, which can be directly solved using existing optimization algorithm software packages.

[0165] Optionally, in this embodiment of the application, the hydropower frequency regulation model sets 96 time periods (24 hours) for daytime, with each time period lasting 15 minutes; and sets 24 time periods (2 hours) for real-time, with each time period lasting 5 minutes.

[0166] In some embodiments, the frequency modulation reserve capacity calculation module 203 specifically comprises:

[0167] By constructing a hydropower frequency regulation model and determining the winning bid capacity for frequency regulation, the winning bid status of each hydropower unit's feasible output range is calculated, i.e., the output range of each hydropower unit that meets the requirements for winning the frequency regulation bid.

[0168] Based on the above bidding results and the current output of the hydropower units, an optimal positive and negative frequency regulation reserve capacity is allocated to each hydropower unit to avoid the vibration-prohibited zone. Under this optimal positive and negative frequency regulation reserve capacity, the hydropower units can achieve optimal performance under frequency regulation.

[0169] The optimal positive and negative frequency regulation reserve capacity of all hydropower units under the hydropower plant is summed together to obtain the total positive and negative frequency regulation reserve capacity that the hydropower plant can actually provide.

[0170] Based on the optimal positive and negative frequency regulation reserve capacity of the hydropower units and the total positive and negative frequency regulation reserve capacity of the hydropower plant, the output of each hydropower unit and the total power of the hydropower plant are adjusted to improve the frequency regulation effect of the hydropower plant.

[0171] Implementing the embodiments of this application has the following beneficial effects:

[0172] This application's embodiments first consider whether the current operating conditions of the hydropower plant and each hydropower unit can meet the frequency regulation bid capacity, thus pre-verifying the regulation requirements. If the existing regulation requirements can be met, the feasible output range of the corresponding hydropower unit is obtained. A prohibited vibration zone is introduced when constructing the constraints. By restricting the output of the hydropower unit from occurring within this zone, the frequency regulation difficulties of the hydropower unit are avoided during operation. This achieves the minimum total power generation cost while improving the frequency regulation effect of the hydropower unit, thus constructing a corresponding hydropower frequency regulation model. Based on the hydropower frequency regulation model and the frequency regulation bid capacity, a suitable optimal frequency regulation reserve capacity is allocated to each hydropower unit to ensure that the optimal reserve capacity prevents the hydropower unit output from entering the prohibited vibration zone, achieving a highly efficient unit frequency regulation effect.

[0173] Implementing the embodiments of this application has the following beneficial effects:

[0174] This application's embodiments first consider whether the current operating conditions of the hydropower plant and each hydropower unit can meet the frequency regulation bid capacity, thus pre-verifying the regulation requirements. If the existing regulation requirements can be met, the feasible output range of the corresponding hydropower unit is obtained. A prohibited vibration zone is introduced when constructing the constraints. By restricting the output of the hydropower unit from occurring within this zone, the frequency regulation difficulties of the hydropower unit are avoided during operation. This achieves the minimum total power generation cost while improving the frequency regulation effect of the hydropower unit, thus constructing a corresponding hydropower frequency regulation model. Based on the hydropower frequency regulation model and the frequency regulation bid capacity, a suitable optimal frequency regulation reserve capacity is allocated to each hydropower unit to ensure that the optimal reserve capacity prevents the hydropower unit output from entering the prohibited vibration zone, achieving a highly efficient unit frequency regulation effect.

[0175] Furthermore, Figure 3 This is a structural diagram of a terminal device provided in one embodiment of this application. Figure 3As shown, the terminal device 3 of this embodiment includes: at least one processor 30 (in... Figure 3 The present invention includes only one of the following: a memory 31 and a computer program 32 stored in the memory 31 and executable on the at least one processor. When the processor 30 executes the computer program 32, it can implement the steps of a hydropower unit frequency regulation method considering vibration zone constraints as described in any one of the embodiments of this application.

[0176] The terminal device 3 may be a computing device such as a desktop computer, a cloud server, or a laptop computer, and the computing device may include, but is not limited to, a processor 30 and a memory 31. Figure 3 This is merely an example of terminal device 3 and does not constitute a limitation on terminal device 3. It may include more or fewer components than those shown in the figure.

[0177] This application provides a storage medium that stores computer-readable program code. When the computer-readable program code is executed, it implements the steps of the above-described method for frequency regulation of a hydropower unit considering vibration zone constraints.

[0178] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. In particular, it should be noted that any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for frequency regulation of hydropower units considering vibration zone constraints, characterized in that, include: Based on the preset frequency regulation rules, the operation of the hydropower unit is checked to see if it meets the frequency regulation bid capacity of the hydropower plant, and the feasible output range of the hydropower unit is obtained. The frequency regulation rules are related to the frequency regulation range of the hydropower plant and the feasible frequency regulation interval of the hydropower unit; A hydropower frequency regulation model is constructed with the objective function of minimizing the total power generation cost and the constraint that the prohibited vibration zone does not appear in the feasible output range. Based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit is obtained.

2. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 1, characterized in that, The process, based on preset frequency regulation rules, detects whether the operating status of the hydropower unit meets the frequency regulation bid capacity of the hydropower plant, thereby obtaining the feasible output range of the hydropower unit, specifically as follows: Based on the frequency regulation winning bid capacity and the power output range of the hydropower plant, determine the frequency regulation range of the hydropower plant; The feasible frequency modulation range is obtained by eliminating the prohibited vibration zone from the current output range of the hydropower unit. Under the preset extreme scenario, if the output range of the hydropower plant does not exceed the frequency regulation range, and the sum of the feasible frequency regulation intervals of the hydropower units in the operating state meets the frequency regulation bid capacity, then it is said that the operation of the hydropower units meets the frequency regulation bid capacity, and the current output range of the hydropower units is taken as the feasible output interval; wherein, the output range of the hydropower plant is the sum of the current output ranges of all hydropower units.

3. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 2, characterized in that, If the operating conditions of the hydropower unit do not meet the frequency regulation bid capacity, the frequency regulation rules will be adjusted according to the preset adjustment priority. The adjustment priority includes considering the frequency modulation winning capacity first and then eliminating the prohibited vibration zone, and eliminating the prohibited vibration zone first and then considering the frequency modulation winning capacity.

4. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 1, characterized in that, The objective function is constructed with minimizing the total power generation cost as the goal, and the constraint that the vibration-prohibited zone does not appear in the feasible output range is used to construct a hydropower frequency regulation model, specifically as follows: Construct an objective function with the goal of minimizing the total cost of power generation; The first constraint condition is constructed by limiting the output of hydropower plants and hydro-generator units as well as the frequency regulation reserve capacity; A second constraint is constructed by ensuring that the vibration prohibition zone does not appear in the feasible output range and that the sum of the frequency modulation capacity within the feasible output range meets the frequency modulation winning capacity. A hydropower frequency regulation model is constructed based on the objective function, the first constraint, and the second constraint.

5. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 4, characterized in that, The second constraint is as follows: In the formula, The positive frequency regulation capacity that hydropower unit j can provide. H represents the negative frequency regulation capacity that hydropower unit j can provide, and H represents the total number of feasible output ranges for the hydropower unit. and HPST represents the upper and lower limits of the h-th feasible output range of hydropower unit j, respectively. j,h,t PG is a 0-1 decision variable, representing whether the h-th feasible output range of hydropower unit j is selected; j,t This represents the output of hydropower unit j during time period t.

6. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 4, characterized in that, The objective function is specifically: In the formula, I represents the total number of hydropower plants participating in the market clearing, T represents the total number of time periods, S represents the total number of bid segments for hydropower plants, and PSC represents the total number of bid segments for hydropower plants. i,t,s For the output of hydropower plant i under time period t and bidding segment s, α i,t,s Let i be the cost of the bid for hydropower plant i in time period t and bid segment s.

7. The frequency regulation method for hydropower units considering vibration zone constraints according to claim 1, characterized in that, The optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit is obtained based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, specifically as follows: Based on the hydropower frequency regulation model and the frequency regulation winning bid capacity, the winning bid situation of the feasible output range is calculated; Based on the bidding results and the current output of the hydropower units, the optimal positive and negative frequency regulation reserve capacity of each hydropower unit is calculated. By summing the optimal positive and negative frequency regulation reserve capacities, the total positive and negative frequency regulation reserve capacity of the hydropower plant is obtained. Based on the optimal positive and negative frequency regulation reserve capacity and the total positive and negative frequency regulation reserve capacity, the output of each hydropower unit and the total power of the hydropower plant are adjusted.

8. A frequency regulation system for a hydropower unit considering vibration zone constraints, characterized in that, include: Data prediction module, frequency regulation model construction module, and frequency regulation reserve capacity calculation module; The data prediction module is used to detect whether the operation of the hydropower unit meets the frequency regulation bid capacity of the hydropower plant based on the preset frequency regulation rules, and to obtain the feasible output range of the hydropower unit; the frequency regulation rules are related to the frequency regulation range of the hydropower plant and the feasible frequency regulation range of the hydropower unit. The frequency regulation model construction module is used to construct an objective function with the goal of minimizing the total power generation cost, and to construct a hydropower frequency regulation model with the constraint that the prohibited vibration zone does not appear in the feasible output range. The frequency regulation reserve capacity calculation module is used to obtain the optimal positive and negative frequency regulation reserve capacity of the hydropower plant and each hydropower unit based on the hydropower frequency regulation model and the frequency regulation winning bid capacity.

9. A terminal device, characterized in that, It includes a processor and a memory, the memory storing a computer program, and the processor executing the computer program to implement the steps of the frequency regulation method for a hydropower unit considering vibration zone constraints according to any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium stores computer-readable program code, which, when executed, implements the steps of the frequency regulation method for a hydropower unit considering vibration zone constraints as described in any one of claims 1 to 7.

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