A linear modeling method and device for hydropower crossing vibration zone based on state tracking

Abstract

The present invention discloses a method and device for linear modeling of hydropower crossing vibration zones based on state tracking. The method includes aggregating vibration zones based on the theory of permutations and combinations of multiple sets to establish a universal nonlinear model of hydropower crossing vibration zones; constraining the characteristics of the established universal linear model of hydropower crossing vibration zones; using an envelope method that covers the whole and the local to decouple the statistical process time period of the number of vibration zone crossing constraints, and then introducing two one-dimensional variables, using the binary linear equations formed by them to remove the equivalent nonlinear vibration zone crossing constraints, and characterizing the model as linearization. The present invention aggregates vibration zones based on the theory of permutations and combinations of multiple sets, and proposes a simple and universal linear model of hydropower crossing vibration zones, which prevents the output from being located in the vibration zone and frequently crossing the vibration zone during hydropower operation, thereby ensuring the safe operation of the unit and the stability of the power system.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method and device for linear modeling of hydropower crossing a vibration zone based on state tracking. Background Art

[0002] When hydropower is in operation, its output range can be divided into a stable operation zone and a vibration zone. The hydropower vibration zone reflects the cavitation and vibration phenomena of the turbine or generator set under certain heads or outputs. If the unit output is in the vibration zone for a long time, it will affect the safe operation of the unit and shorten the service life of the unit. In addition, if the hydropower frequently passes through the vibration zone during operation, the vibration and swing of the unit will increase, the wear of mechanical parts will increase, the life of the water guide mechanism and rotating parts will be shortened, and even the mechanical parts and plant of the unit will be damaged, which will also have an adverse effect on the safety and life of the unit. Therefore, in the optimization and scheduling of hydropower stations, how to fully consider the impact of the vibration zone, avoid the unit from operating in the vibration zone and frequently passing through the vibration zone, is an important link to ensure the stable operation of the power system and the service life of the hydropower unit. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a method and device for linear modeling of hydropower crossing vibration zones based on state tracking, so as to prevent the output of hydropower from being located in the vibration zone and frequently crossing the vibration zone during operation, thereby ensuring the safe operation of the unit and the stability of the power system.

[0004] To achieve the above object, the technical solution of the present invention is:

[0005] In a first aspect, the present invention provides a method for linear modeling of hydropower crossing vibration zones based on state tracking, the method comprising:

[0006] Based on the theory of multiple set permutation and combination, the vibration zone is aggregated and a universal nonlinear model of hydropower crossing the vibration zone is established;

[0007] Constraints on the characteristics of the established general nonlinear model of hydropower crossing the vibration zone;

[0008] The overall-envelope method is used to decouple the statistical process period of the vibration zone crossing constraint times. Then two one-dimensional variables are introduced and the set of two-variable linear equations they constitute is used to remove the equivalent nonlinear vibration zone crossing constraint and characterize the model as linearization.

[0009] Furthermore, the vibration zone is aggregated based on the theory of multiple sets and combinations to establish a universal nonlinear model of hydropower crossing the vibration zone, including:

[0010] For a cascade hydropower station Z, assuming that it has M hydropower units, andP s They represent the upper and lower limits of the output of hydropower unit s respectively. Based on the theory of multiple sets permutation and combination, the stable operation area set Φ of the upper and lower limit hydropower units of the cascade hydropower station output is obtained. s and Ψ in the vibration zone s

[0011] According to the hydroelectric unit and P s Calculate the upper and lower limits of the output of cascade hydropower stations represented by aggregation, using the set P Z express;

[0012] For all hydropower units, the stable operation interval set Φ s Combination calculation is performed, that is, the stable operation area of ​​the aggregated cascade hydropower station form is obtained by using the theory of multiple set permutation and combination.

[0013] Stable operating area Take the inversion and add it to P Z By performing the intersection operation, we can obtain the set of vibration zones represented by cascade hydropower stations.

[0014]

[0015] Further,

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] Furthermore, the characteristic constraints of the established universal nonlinear model of hydropower crossing the vibration zone include:

[0022] The j vibration zones of hydropower unit s divide its output into regular j+1 stable operation zones. represents the wth stable operation area of ​​the hydropower unit, then the stable operation area set Q of the hydropower unit s s The description is as follows:

[0023]

[0024] The constraint of hydropower crossing the vibration zone is written out by equation (15), as shown in equations (16) and (17).

[0025]

[0026]

[0027] In the formula, It is used to determine whether the hydropower unit s passes through the vibration zone during period t. If the output of the hydropower unit s in two adjacent periods is P s,t If they are all in the same stable operation zone, the hydropower will not pass through the vibration zone during this period. If the output of hydropower unit s in two consecutive periods is P s,t If they are not in the same stable operation zone, the hydropower will cross the vibration zone during this period. T represents the total number of optimization periods for the actual problem, T s It indicates the maximum number of times the hydropower unit is allowed to pass through the vibration zone during the total optimized time period T.

[0028] Furthermore, the overall-covering-local envelope method is used to decouple the statistical process period of the vibration zone crossing constraint times, and then two one-dimensional variables are introduced to use the binary linear equations formed by them to remove the equivalent nonlinear vibration zone crossing constraint, and the model is characterized as a linearization including:

[0029] If the j vibration zones of a hydropower unit s divide its output into j+1 stable operation zones, the indicator variable used to determine whether the adjacent time periods t-1 and t of the hydropower unit cross the vibration zone is expressed as follows:

[0030]

[0031]

[0032] That is, at this time, equation (16) is further represented as equation (31) and equation (32); assuming that the number of times that the hydropower unit s does not cross the vibration zone in the total optimization period T is x, and the number of times that it crosses the vibration zone is y, equation (17) is also further represented as equation (33), equation (34) and equation (35)

[0033] x+y=T-1(33)

[0034]

[0035]

[0036] Two variables are introduced to linearize the absolute value term in equation (81) and transform it into a linear constraint for solution.

[0037] r s,w,t =|u s,w,t -u s,w,t-1 | (36)

[0038] r s,w,t ≥u s,w,t -us,w,t-1 (37)

[0039] r s,w,t ≥u s,w,t-1 -u s,w,t (38)

[0040] After the above transformation, the nonlinear constraints (16) and (17) for hydropower crossing the vibration zone are represented as linear constraints (31)-(38).

[0041] In a second aspect, the present invention provides a linear modeling device for hydropower crossing vibration zones based on state tracking, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.

[0042] In a third aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention aggregates vibration zones based on the theory of multiple set permutations and combinations, and proposes a simple and universal linear model for hydropower to cross vibration zones, which prevents the output from being located in vibration zones and frequently crossing vibration zones during hydropower operation, thereby ensuring the safe operation of the unit and the stability of the power system.

[0045] 2. A linearized method for representing the characteristic constraints of hydropower crossing the vibration zone is proposed to avoid the problems of relatively low solution efficiency and relatively poor convergence caused by the complexity of the nonlinear problem itself.

[0046] 3. The statistical process period of the vibration zone crossing constraint times is decoupled by using the overall-covering-local envelope method, and then two one-dimensional variables are introduced to use the binary linear equations they constitute to remove the equivalent nonlinear vibration zone crossing constraint, and the model is characterized as linearization. The model can be applied to the optimization scheduling problem of large-scale cascade hydropower stations, and can avoid repeated and cumbersome manual heuristic adjustments, and the solution is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is the vibration zone of cascade hydropower regulations;

[0048] Figure 2 It is the irregular vibration area of ​​cascade hydropower;

[0049] Figure 3 This is a schematic diagram of the vibration area of ​​the hydropower unit;

[0050] Figure 4The aggregation process of vibration zones of two hydropower units;

[0051] Figure 5 This is a schematic diagram of the vibration area of ​​the hydropower unit;

[0052] Figure 6 To divide the unit output into zones;

[0053] Figure 7 An overall flow chart of a method for linearizing modeling of hydropower crossing vibration zones based on state tracking provided in Example 1 of the present invention;

[0054] Figure 8 A schematic diagram of the overall composition of a linear modeling device for hydropower crossing vibration zones based on state tracking provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0056] Embodiment 1:

[0057] When hydropower is in operation, its output range can be divided into a stable operation range, a permitted operation range, and a prohibited operation range. When the hydropower output is operating in the stable range, the vibration amplitude of the unit is small, the stability is good, and it will not affect the service life of the unit; when the hydropower is operating in the permitted operation range, the unit will produce a certain degree of vibration, which will cause damage to the unit, but the damage is very small and generally negligible, that is, it will not affect the service life of the unit; when the hydropower is operating in the prohibited operation period, it is very easy to cause serious damage to the unit, resulting in a sharp decline in the life of the unit; in severe cases, it may even threaten the safe and stable operation of the power grid. Therefore, the stable operation range and permitted operation range of hydropower output are usually referred to as stable operation areas, and the prohibited operation range of hydropower output is called vibration area.

[0058] The hydropower vibration zone reflects the cavitation and vibration phenomenon of the turbine or generator set under certain water heads or outputs, which affects the safe operation of the unit and shortens the service life of the unit. When arranging the operation of the hydropower unit, the influence of the vibration zone must be fully considered.

[0059] The vibration zone of cascade hydropower includes regular vibration zone and irregular vibration zone. The regular vibration zone does not change with the change of water head and can be expressed as one or a series of discrete intervals of cascade hydropower output. The regular vibration zone can be divided into single regular vibration zone and multiple regular vibration zone, such as Figure 1 As shown in the figure, the irregular vibration zone changes with the change of water head and has complex characteristics such as discreteness, porosity, and irregularity, which brings great challenges to the modeling and solution of the optimization scheduling problem of cascade hydropower. The irregular vibration zone can also be divided into single irregular vibration zone and multiple irregular vibration zone. Figure 2 shown.

[0060] For cascade hydropower stations, considering that a large number of units in the station have regular vibration zones in actual projects, the vibration zones do not change with the change of water head, while a small number of units with irregular vibration zones can generally be simplified into regular vibration zones by discarding part of the stable operation zone or by predicting the average water head (see Figure 3 ). Therefore, the common modeling methods for vibration zones in existing research are as follows:

[0061]

[0062] Where P s,t represents the active output of the hydropower unit in period s, and P s They represent the upper and lower limits of the output of hydropower unit s, and P s ,k They represent the upper and lower limits of the output of the kth vibration zone of the hydropower unit s, respectively. The total number of vibration zones of the hydropower unit is j. Obviously, the unit vibration zone constraint of formula (1) is a typical nonlinear form. When used for solving practical problems, the calculation efficiency is low and it is difficult to obtain the optimal solution. Considering that the j vibration zones of the hydropower unit divide its output into regular j+1 stable operation zones, the corresponding j+1 integer variables can be introduced to directly transform the nonlinear vibration zone constraint into a linear constraint. The processing method is as follows:

[0063]

[0064]

[0065] Where P s,w,min and P s,w,max They represent the upper and lower limits of the output of the wth stable zone of hydropower unit s, u s,w,t represents an integer variable. Formula (2) shows that the output of the hydropower unit in period t can only be located in the only stable operation area, u s,w,t =1 means that the output of the hydropower unit at time t is in the wth stable operation zone, and the integer variables of the remaining j stable operation zones are all 0. Thus, the output of the hydropower unit can be limited to the upper and lower limits of the output of the wth stable operation zone through formula (3). It can be seen that the direct linear transformation of the vibration zone constraint through formula (2) and formula (3) is equivalent to the original nonlinear constraint formula (1).

[0066] In the study of the problem of hydropower stations crossing vibration zones, the common research idea is to consider the vibration zone with a single unit as the object, adjust the load distribution in real time, select integer variables and determine the appropriate combination of hydropower units and load distribution methods, so as to avoid the risk of units crossing the vibration zone within the time period. Most of them are based on heuristic adjustment, and no modeling is performed on hydropower crossing the vibration zone. This method is relatively simple in principle and easy to operate. However, with the increase in the scale of cascade hydropower stations, if the vibration zone is considered with a single unit as the object, the scale of integer variables introduced in the entire optimization process will reach hundreds or even thousands, and manual heuristic adjustment is difficult and difficult to solve.

[0067] Some scholars have modeled the nonlinearity of a hydropower station by describing the process of it crossing the vibration zone. If the unit output is in different stable operation zones in adjacent time periods, vibration zone crossing will occur. The above process is a complex nonlinear process coupled with time, and the stable operation partitions of the unit output in each time period are unpredictable in advance during actual operation. Such modeling can accurately simulate the constraints of the vibration zone crossing characteristics, but considering the complexity of the nonlinear problem itself, if it is used for the optimization scheduling of large-scale cascade hydropower stations in actual output projects, it may result in relatively low solution efficiency and relatively poor convergence.

[0068] For this reason, in this embodiment, considering that a cascade hydropower station usually contains a large number of hydropower units, and most of the hydropower units have vibration zones, as the scale of the cascade hydropower station group increases, if the vibration zone is considered for a single unit, the scale of integer variables directly linearized in the entire optimization process will reach hundreds or even thousands, which greatly increases the scale of problem calculation, making the problem solving efficiency low or even unable to obtain the optimal solution, thereby failing to prevent the output from being located in the vibration zone and frequently crossing the vibration zone during hydropower operation, and ensuring the safe operation of the unit and the stability of the power system. Based on this, this embodiment aggregates the vibration zone based on the theory of multiple sets of permutations and combinations, establishes a general linearization model for hydropower crossing the vibration zone, and aggregates the vibration zone data in the form of a single unit into data in the form of a corresponding cascade hydropower station through set operations, which can greatly reduce the number of directly linearized 0-1 variables introduced in the optimization solution process, reduce the amount of calculation in the solution, improve the calculation efficiency, and prevent the output from being located in the vibration zone and frequently crossing the vibration zone during hydropower operation, and ensure the safe operation of the unit and the stability of the power system.

[0069] The theory of multiple set permutations and combinations is as follows:

[0070] Suppose there are sets A and B, both of which consist of m discontinuous closed intervals, where are the mth closed intervals in set A and set B respectively, a m and The lower and upper bounds of the mth closed interval of set A,b m and The upper and lower bounds of the mth closed interval of set B. According to the theory of permutations and combinations of multiple sets, when set A and set B are combined into a new combination hour, It can be expressed as

[0071]

[0072]

[0073]

[0074]

[0075] In the formula, Ω AB It means to traverse all closed intervals in set A and set B, add the upper and lower bounds of all closed intervals in set A to the upper and lower bounds of closed intervals in set B, and then take the union. Obviously, when there is set C, set A and set B and set C can be combined into a new combination

[0076]

[0077] Similarly, when there are n sets D1, D2, ..., D n When , the combination of n sets can be expressed as follows:

[0078]

[0079] Therefore, based on the theory of multiple set permutation and combination, the vibration zone is aggregated and a universal linear model of hydropower crossing the vibration zone is established as follows:

[0080] For a cascade hydropower station Z, assuming that it has M hydropower units, and P s They represent the upper and lower limits of the output of the hydropower unit s respectively. The set of stable operation areas and vibration areas of the upper and lower limits of the output of the cascade hydropower station can be expressed by the theory of multiple sets of permutations and combinations, as shown below:

[0081] Φ s =[P s,1,min ,P s,1,max ]∪...,[P s,w,min ,P s,w,max ]∪...∪[P s,j+1,min ,P s,j+1,max ] (10)

[0082]

[0083] In the formula, Φs represents the stable operating range of the output of hydropower unit s, Ψ s represents the vibration range set of the output of hydropower unit s. Figure 4 The figure shows the aggregation process of vibration zones of two hydropower units.

[0084] First, according to the hydropower unit and P s Calculate the upper and lower limits of the output of cascade hydropower stations represented by aggregation, using the set P Z Then, the stable operation interval set Φ of all hydropower units is s Combination calculation is performed, that is, the stable operation area of ​​the aggregated cascade hydropower station form is obtained by using the theory of multiple set permutation and combination. Finally, the stable operation area Take the inversion and add it to P Z By performing an intersection operation, we can obtain a set of vibration zones represented by cascade hydropower stations.

[0085]

[0086]

[0087]

[0088] In practical applications, irregular vibration zones are often simplified into regular vibration zones, and then the constraints of regular vibration zones are universally modeled and solved. Based on this, in this embodiment, taking regular vibration zones as an example, a linearized method for expressing the characteristic constraints of hydropower crossing vibration zones is proposed, but the ideas and methods proposed in this embodiment can also be applied to irregular vibration zones.

[0089] according to Figure 3 and 5 , the j vibration zones of the hydropower unit s divide its output into regular j+1 stable operation zones. represents the wth stable operation area of ​​the hydropower unit, then the stable operation area set Q of the hydropower unit s s It can be described as follows:

[0090]

[0091] The constraints of hydropower crossing the vibration zone can be expressed by equation (15), as shown in equation (16) and equation (17).

[0092]

[0093]

[0094] In the formula, It is used to determine whether the hydropower unit s passes through the vibration zone during period t. If the output of the hydropower unit s in two adjacent periods is P s,t If they are all in the same stable operation zone, the hydropower will not pass through the vibration zone during this period. If the output of hydropower unit s in two consecutive periods is P s,t If they are not in the same stable operation zone, the hydropower will cross the vibration zone during this period. Since the frequent crossing of the vibration zone by the hydropower unit will increase the vibration and swing of the unit, increase the wear of mechanical parts, shorten the life of the water guide mechanism and rotating parts, and even cause damage to the mechanical part and plant of the unit, there is a certain limit on the number of times the hydropower unit crosses the vibration zone in actual problems. T represents the total number of optimization time periods for the actual problem, T s It indicates the maximum number of times the hydropower unit is allowed to pass through the vibration zone during the total optimized time period T.

[0095] To facilitate understanding of the logical process of whether hydropower crosses the vibration zone, such as Figure 6 As shown in the figure, a cascade hydropower unit with 3 stable operation zones is used as an example. Assuming that the number of operating periods of the unit is 5, and the stable operation zones where the output of each optimized period is located have been determined, the number of times the unit passes through the vibration zone can be calculated based on this. The detailed analysis is as follows:

[0096] Table 1 Unit optimization period partition status

[0097]

[0098] In the first period, the unit output is in the first stable operation zone Q1. At this time, there is no need to judge whether the unit passes through the vibration zone.

[0099] In the second period, the unit output is at Q1 in the first period. At this time, it is only necessary to determine whether the unit output is at Q1 in the current period. Since the unit output is at Q2 in period 2, according to formula (16), it can be determined that the unit passes through the vibration zone in period 2.

[0100] In the third period, the logic object of judgment is transferred from Q1 to Q2. Since the unit output in period 3 is located in Q3, according to formula (16), it can be judged that the unit passes through the vibration zone in period 3.

[0101] In the fourth period, the logic object of judgment is transferred from Q2 to Q3. Since the unit output in period 4 is located in Q3, according to formula (16), it can be judged that the unit does not cross the vibration zone in period 4.

[0102] In the fifth period, the logic object of judgment does not change and is still Q3. Since the unit output in period 5 is at Q2, according to formula (16), it can be judged that the unit does not pass through the vibration zone in period 5.

[0103] In summary, the hydropower unit passes through the vibration zone 3 times during the optimization period.

[0104] The vibration zone crossing constraints (16) and (17) are time period coupling constraints. If the output of unit s is located in different stable operation zones in adjacent time periods, vibration zone crossing will occur. For the statistics of the number of vibration zone crossings of a single unit, it is necessary not only to compare whether the stable operation zones of the units in two adjacent time periods are consistent, but also to track the changes in the unit output partitions in each time period in real time to confirm whether the logical object of judgment has been transferred. The above process is a complex nonlinear process coupled with time, and the stable operation partitions of the unit output in each time period are unpredictable in advance during actual operation. That is, in the optimization process, it is necessary to reasonably arrange the output partitions of each time period, and to find a comparison logic path that meets the conditions based on the maximum number of crossing the vibration zone, so as to optimize the solution target.

[0105] Table 2 Logical path for comparing units crossing vibration zones

[0106]

[0107] Considering the complexity of the nonlinear problem itself, if it is used to deal with large-scale cascade hydropower stations and long-time scale optimization scheduling problems, it may cause relatively low solution efficiency and relatively poor convergence, which is not suitable for application in practical engineering. In order to solve the above problems, this embodiment proposes a linear modeling method for vibration zone crossing constraints, which uses an envelope method that covers the whole and the local to decouple the statistical process time period of the vibration zone crossing constraint number, and then introduces two one-dimensional variables, and uses the two-variable linear equations they constitute to remove the equivalent nonlinear vibration zone crossing constraints, and characterizes the model as linearization.

[0108] Specifically, by observing the logical process of the unit passing through the vibration zone, it can be found that when the unit output is at Q1 in the first period, there are three situations in the stable operation zone of its output in the second period, as shown in Table 3, Table 4, and Table 5.

[0109] Table 3 Output 1

[0110]

[0111] Table 4 Output 2

[0112]

[0113] Table 5 Output 3

[0114]

[0115] For output situation 1:

[0116] u s,1,1 =1,u s,1,2 =1(18)

[0117] u s,2,1 =0,u s,2,2 =0(19)

[0118] u s,3,1 =0,u s,3,2 =0(20)

[0119]

[0120] For output situation 2:

[0121] u s,1,1 =1,u s,1,2 =0(22)

[0122] u s,2,1 =0,u s,2,2 =1(23)

[0123] u s,3,1 =0,u s,3,2 =0(24)

[0124]

[0125] For output situation 3:

[0126] u s,1,1 =1,u s,1,2 =0(26)

[0127] u s,2,1 =0,u s,2,2 =0(27)

[0128] u s,3,1 =0,u s,3,2 =1(28)

[0129]

[0130] When the unit output belongs to case 1, the hydropower unit s does not pass through the vibration zone; when the unit output belongs to case 2 or case 3, the hydropower unit s passes through the vibration zone. Therefore, the indicator variable β t s This can be used to determine whether the hydropower unit passes through the vibration zone during time period t.

[0131]

[0132] Assuming that the unit output is at Q2 or Q3 in the first period, the result expressed by equation (30) can be obtained by the same logic, that is, equation (30) is universal for judging whether the hydropower station crosses the vibration zone at adjacent moments.

[0133] By analogy, if the j vibration zones of a hydropower unit s divide its output into j+1 stable operation zones, the indicator variable used to determine whether the adjacent time periods t-1 and t of the hydropower unit cross the vibration zone can be expressed as follows:

[0134]

[0135]

[0136] That is, at this time, equation (16) can be further expressed as equation (31) and equation (32). Assuming that the number of times that the hydropower unit s does not cross the vibration zone in the total optimization period T is x, and the number of times it crosses the vibration zone is y, equation (17) can also be further expressed as equation (33), equation (34) and equation (35)

[0137] x+y=T-1(33)

[0138]

[0139]

[0140] Because β t s The absolute value term in (31) makes it a nonlinear constraint. When solving the problem, it becomes a mixed integer nonlinear programming problem, which is difficult to solve. Therefore, two variables are introduced to linearize the absolute value term in (31) and transform it into a linear constraint for solution.

[0141] r s,w,t =|u s,w,t -u s,w,t-1 | (36)

[0142] r s,w,t ≥u s,w,t -u s,w,t-1 (37)

[0143] r s,w,t ≥u s,w,t-1 -u s,w,t (38)

[0144] After the above transformation, the nonlinear constraints (16) and (17) for hydropower crossing the vibration zone are represented as linear constraints (31)-(38).

[0145] The overall implementation process of the linear modeling method for hydropower crossing vibration zone based on state tracking provided in this embodiment is as follows: Figure 7shown.

[0146] In summary, the linear modeling method for hydropower crossing vibration zone based on state tracking provided in this embodiment has the following technical advantages compared with the prior art:

[0147] 1. Based on the theory of multiple set permutations and combinations, the vibration zones are aggregated, and a simple and universal linear model for hydropower crossing the vibration zone is proposed. This model can effectively prevent the output of hydropower from being located in the vibration zone and frequently crossing the vibration zone during operation, thus ensuring the safe operation of the unit and the stability of the power system.

[0148] 2. A linearized method for representing the characteristic constraints of hydropower crossing the vibration zone is proposed to avoid the problems of relatively low solution efficiency and relatively poor convergence caused by the complexity of the nonlinear problem itself.

[0149] (3) The statistical process period of the vibration zone crossing constraint number is decoupled by using the overall-encompassing-local envelope method, and then two one-dimensional variables are introduced to use the binary linear equations they constitute to remove the equivalent nonlinear vibration zone crossing constraint, and the model is characterized as linearization. The model can be applied to the optimization scheduling problem of large-scale cascade hydropower stations, and can avoid repeated and tedious manual heuristic adjustments, and the solution is simple.

[0150] Embodiment 2:

[0151] See also Figure 8 As shown, the state tracking-based hydropower crossing vibration zone linearization modeling device provided in this embodiment includes a processor 81, a memory 82, and a computer program 83 stored in the memory 82 and executable on the processor 81, such as a state tracking-based hydropower crossing vibration zone linearization modeling program. When the processor 81 executes the computer program 83, the steps of the above-mentioned embodiment 1 are implemented, such as Figure 7 Steps shown.

[0152] Exemplarily, the computer program 83 may be divided into one or more modules / units, which are stored in the memory 82 and executed by the processor 81 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 83 in the state tracking-based hydropower crossing vibration zone linearization modeling device.

[0153] The state tracking-based hydropower crossing vibration zone linearization modeling device can be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The state tracking-based hydropower crossing vibration zone linearization modeling device can include, but is not limited to, a processor 81 and a memory 82. Those skilled in the art can understand that Figure 8It is merely an example of a device for linearizing modeling of hydropower crossing vibration zones based on state tracking, and does not constitute a limitation of the device for linearizing modeling of hydropower crossing vibration zones based on state tracking. It may include more or fewer components than those shown in the figure, or a combination of certain components, or different components. For example, the device for linearizing modeling of hydropower crossing vibration zones based on state tracking may also include input and output devices, network access devices, buses, etc.

[0154] The processor 81 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0155] The memory 82 may be an internal storage unit of the state-tracking-based linear modeling device for hydropower crossing vibration zones, such as a hard disk or memory of the state-tracking-based linear modeling device for hydropower crossing vibration zones. The memory 82 may also be an external storage device of the state-tracking-based linear modeling device for hydropower crossing vibration zones, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the state-tracking-based linear modeling device for hydropower crossing vibration zones. Further, the memory 82 may also include both an internal storage unit and an external storage device of the state-tracking-based linear modeling device for hydropower crossing vibration zones. The memory 82 is used to store the computer program and other programs and data required by the state-tracking-based linear modeling device for hydropower crossing vibration zones. The memory 82 may also be used to temporarily store data that has been output or is to be output.

[0156] Embodiment 3:

[0157] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method described in Embodiment 1 are implemented.

[0158] The computer-readable medium shown can be any device that can contain, store, communicate, propagate or transmit a program for use with an instruction execution system, device or apparatus or in conjunction with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and editable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable media on which the program can be printed, such as by optically scanning the paper or other medium, then editing, interpreting or processing in other suitable ways as necessary to obtain the program electronically, and then storing it in a computer memory.

[0159] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A linear modeling method for hydropower crossing vibration zone based on state tracking, characterized in that: The method comprises: Based on the theory of multiple set permutation and combination, the vibration zone is aggregated and a universal nonlinear model of hydropower crossing the vibration zone is established; Constraints on the characteristics of the established general nonlinear model of hydropower crossing the vibration zone; The statistical process period of the vibration zone crossing constraint times is decoupled by using the envelope method that covers the whole and the local. Then two one-dimensional variables are introduced and the two-variable linear equations formed by them are used to remove the equivalent nonlinear vibration zone crossing constraint, and the model is characterized as linearization. The vibration zone is aggregated based on the theory of multiple sets and combinations to establish a universal nonlinear model of hydropower crossing the vibration zone, which includes: For a cascade hydropower station Z, assuming that it has M hydropower units, and P s They represent the upper and lower limits of the output of hydropower unit s respectively. Based on the theory of multiple sets permutation and combination, the stable operation area set Φ of the upper and lower limit hydropower units of the cascade hydropower station output is obtained. s and Ψ in the vibration zone s According to the hydroelectric unit and P s Calculate the upper and lower limits of the output of cascade hydropower stations represented by aggregation, using the set P Z express; For all hydropower units, the stable operation interval set Φ s Combination calculation is performed, that is, the stable operation area of ​​the aggregated cascade hydropower station form is obtained by using the theory of multiple set permutation and combination. Stable operating area Take the inversion and add it to P Z By performing the intersection operation, we can obtain the set of vibration zones represented by cascade hydropower stations. The characteristic constraints of the established universal nonlinear model for hydropower crossing the vibration zone include: The j vibration zones of hydropower unit s divide its output into regular j+1 stable operation zones. represents the wth stable operation area of ​​the hydropower unit, then the stable operation area set Q of the hydropower unit s s The description is as follows: The vibration zone constraint of hydropower crossing is written out by equation (15), as shown in equation (16) and equation (17): In the formula, It is used to determine whether the hydropower unit s passes through the vibration zone during period t. If the output of the hydropower unit s in two adjacent periods is P s,t If they are all in the same stable operation zone, the hydropower will not pass through the vibration zone during this period. If the output of hydropower unit s in two consecutive periods is P s,t If they are not in the same stable operation zone, the hydropower will cross the vibration zone during this period. T represents the total number of optimization periods for the actual problem, T s It indicates the maximum number of times the hydropower unit is allowed to pass through the vibration zone during the total number of optimized time periods T; The method of using the overall envelope method to cover the local part is used to decouple the statistical process period of the vibration zone crossing constraint times, and then two one-dimensional variables are introduced to use the binary linear equations formed by them to remove the equivalent nonlinear vibration zone crossing constraint, and the model is characterized as a linearization including: If the j vibration zones of a hydropower unit s divide its output into j+1 stable operation zones, the indicator variable used to determine whether the adjacent time periods t-1 and t of the hydropower unit cross the vibration zone is expressed as follows: That is, at this time, equation (16) is further represented as equation (31) and equation (32); assuming that the number of times that the hydropower unit s does not cross the vibration zone in the total optimization period T is x, and the number of times that it crosses the vibration zone is y, equation (17) is also further represented as equation (33), equation (34) and equation (35) x+y=T-1 (33) Two variables are introduced to linearize the absolute value term in equation (31) and transform it into a linear constraint for solution. r s,w,t =|u s,w,t -u s,w,t-1 | (36) r s,w,t ≥u s,w,t -u s,w,t-1 (37) r s,w,t ≥u s,w,t-1 -u s,w,t (38) After the above transformation, the nonlinear constraints (16) and (17) for hydropower crossing the vibration zone are represented as linear constraints (31)-(38).

2. The linear modeling method for hydropower crossing vibration zone based on state tracking according to claim 1 is characterized in that: Φ s =[P s,1,min ,P s,1,max ]∪...,[P s,w,min ,P s,w,max ]∪...∪[P s,j+1,min ,P s,j+1,max ] (10)。 3. The linear modeling method for hydropower crossing vibration zone based on state tracking according to claim 1 is characterized in that:

4. The method for linear modeling of hydropower crossing vibration zone based on state tracking according to claim 1, characterized in that:

5. The method for linear modeling of hydropower crossing vibration zone based on state tracking according to claim 1, characterized in that:

6. A linear modeling device for hydropower crossing vibration zone based on state tracking, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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