A method and system for dividing economic operation time periods of distribution network

Abstract

The present invention provides a method and system for dividing economic operation time periods of a distribution network, including: based on the pre-calculated initial static time period division result, according to the pre-established economic operation optimization model, adjusting the operation mode of the distribution network and performing dynamic time period division of the economic operation of the distribution network in the prediction time domain; step 2: based on the operation mode of the distribution network after the dynamic time period division of the distribution network is completed, performing a second static time period division of the economic operation of the distribution network; step 3: judging whether the dynamic time period division result and the second static time period division result are consistent: if so, then end; otherwise, the second static time period division result is used as the new initial static time period division result and transferred to step 1. The economic operation time period division of the distribution network performed by the method and system of the present invention takes into account the changes in the grid structure, that is, the operation mode, during the operation of the distribution network. Compared with the traditional time period division method, it can reduce the operation cost of the distribution network and realize the economic operation of the distribution network.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system operation analysis, and in particular relates to a method and system for dividing economic operation time periods of a distribution network. Background Art

[0002] In the actual distribution network control operation, considering the limitations of manufacturing technology and equipment life, various control devices are not allowed to be switched on and off frequently. At the same time, since the economic operation of the distribution network is generally a long-term, multi-period nonlinear mixed integer dynamic optimization with a time scale of days, multiple time periods are optimized at the same time, and the constraints on the number of actions increase the difficulty of solving, and when the constraints are harsh, the convergence of the algorithm cannot be guaranteed. Therefore, considering the frequency of operation restrictions, the time period division is mostly based on load characteristics. There are two technical deficiencies: first, there is a lack of economic operation methods that simultaneously consider transformer tap adjustment, reactive power compensation and network reconstruction. Multiple control means are combined; second, the time period division of network reconstruction is closely related to the network structure, but currently the segmentation is based on the structure before optimization. When dividing the time period, the changes in the network structure are not considered. Summary of the invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the present invention proposes a method and system for dividing economic operation time periods of distribution networks. The method and system propose a method for dividing time periods according to the specified operation frequency for static data that is unrelated to the network structure; a method for dividing time periods for network reconstruction related to the network structure; and an economic operation method that integrates multiple control means.

[0004] The solutions adopted to achieve the above objectives are:

[0005] A method for dividing economic operation time periods of a distribution network, the improvement of which is as follows:

[0006] Step 1: Based on the pre-calculated initial static time period division results and the pre-established economic operation optimization model, the operation mode of the distribution network is adjusted and the dynamic time period division of the economic operation of the distribution network in the forecast time domain is performed;

[0007] Step 2: Based on the operation mode of the distribution network after the dynamic time division of the distribution network is completed, the static time division of the economic operation of the distribution network is performed again;

[0008] Step 3: Determine whether the dynamic time period division result is consistent with the static time period division result again:

[0009] If yes, then end; otherwise, take the second static time period division result as the new initial static time period division result and go to step 1.

[0010] The first preferred technical solution provided by the present invention is improved in that, based on the pre-calculated initial static time period division result, according to the pre-established economic operation optimization model, the operation mode of the power grid is adjusted and the dynamic time period division of the economic operation of the distribution network in the prediction time domain is performed, including:

[0011] Step 11: Based on the pre-calculated initial static time period division result and the pre-established economic operation optimization model, the operation mode after network reconstruction is obtained and the initial value of the number of reconstructed dynamic time period divisions is set;

[0012] Step 12: Determine whether the number of dynamic time period divisions for reconstruction is less than or equal to a preset reconstruction threshold:

[0013] If yes, go to step 13; otherwise, end;

[0014] Step 13: Based on the power grid operation mode of the time period being processed in the prediction time domain, perform static time division in the middle of the economic operation of the distribution network in the time period and thereafter;

[0015] Step 14: Based on the static time period division results of the economic operation of the distribution network in and after the time period, according to the economic operation optimization model, obtain the operation mode after the network reconstruction in and after the time period and increase the number of reconstructed dynamic time period divisions, and go to step 12.

[0016] The second preferred technical solution provided by the present invention is improved in that the division of the static time period includes:

[0017] Step 21: Calculate the range and average change rate of the set indicator forecast value after the set time period is incorporated into the previous static period;

[0018] Step 22: Determine whether the range exceeds the preset maximum range limit and whether the average value change rate exceeds the preset maximum average value change rate limit:

[0019] If any of the items is yes, the time period is divided into a new static time period and the process goes to step 23; otherwise, the process goes to step 23;

[0020] Step 23: Determine whether all indicator prediction values ​​have been calculated:

[0021] If yes, go to step 24; otherwise, set the time period after the time period as a new set time period and go to step 21;

[0022] Step 24: Determine whether the number of static time segment divisions is the preset number of segments:

[0023] If yes, then end; otherwise, go to step 25;

[0024] Step 25: According to the number of static time period segments, the number of specified segments, the maximum limit of the range and the maximum limit of the average change rate, calculate the new maximum limit of the range and the maximum limit of the average change rate respectively, and go to step 21;

[0025] The indicators include reactive load, apparent load and network loss of the substation;

[0026] When performing the initial or secondary static time period division, the set time period is the initial time period of the prediction time domain. When performing the intermediate static time period division, the set time period is the time period within the prediction time domain being processed.

[0027] The third preferred technical solution provided by the present invention is improved in that the new maximum limit of the range is calculated according to the number of segments divided according to the static time period, the number of specified segments and the maximum limit of the range, as shown in the following formula:

[0028]

[0029] The new maximum limit of the average value change rate is calculated according to the number of static time period division segments, the number of specified segments and the maximum limit of the average value change rate, as shown in the following formula:

[0030]

[0031] Where T represents the number of static time segment divisions, T N Indicates the specified number of segments. Represents the maximum limit of the range, represents the new maximum limit of the range, Indicates the maximum limit of the average value change rate, Indicates the new maximum limit of the average value change rate.

[0032] The fourth preferred technical solution provided by the present invention is improved in that the range is calculated as follows:

[0033]

[0034] Among them, S1 represents the range, maxA represents the maximum value of the indicator in the current static period, and minA represents the minimum value of the indicator in the current static period.

[0035] The fifth preferred technical solution provided by the present invention is improved in that the average value change rate is calculated as follows:

[0036]

[0037] in, It indicates the rate of change of the average value, s2(A1) indicates the average value of A1, and s2(A2) indicates the average value of A2. A1 indicates all the index values ​​of the previous static period before the current time period is incorporated into the previous static period, and A2 indicates all the index values ​​of the previous static period after the current time period is incorporated into the previous static period.

[0038] The sixth preferred technical solution provided by the present invention is improved in that the establishment of the economic operation optimization model includes:

[0039] An economic operation optimization model is established with the minimized network loss and economic cost of equipment regulation as the objective function and power balance constraints, network constraints and regulation equipment constraints as constraints.

[0040] The seventh preferred technical solution provided by the present invention is improved in that the objective function is as shown in the following formula:

[0041]

[0042] Where F represents the objective function, t represents the time period index, M represents the number of time periods, c represents the electricity price, and P loss represents network loss, Δt represents the time interval; i represents the control device index, j represents the control device division time index, N s Indicates the number of switches, T Ns represents the number of time periods for network reconstruction, c s represents the switching action cost, s i,j represents the state of the i-th switch in the j-th period, s i,j-1 represents the state of the i-th switch in the j-1th period; N c Indicates the number of capacitor banks, T Nc Indicates the number of time periods for capacitor bank regulation, c c represents the capacitor regulation cost, c i,j represents the gear position of the i-th capacitor bank in the j-th period, c i,j-1 Indicates the gear position of the i-th capacitor bank in the j-1th period; N t Indicates the number of on-load tap-changing transformers, T Nt Indicates the number of time periods for the on-load tap-changing transformer control, c t Indicates the regulation cost of on-load tap-changing transformer; d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, d i,j-1 Indicates the gear position of the i-th on-load tap-changing transformer in the j-1th time period.

[0043] The eighth preferred technical solution provided by the present invention is improved in that the power balance constraint is as shown in the following formula:

[0044]

[0045]

[0046] Among them, N node represents the number of nodes, P i represents the active power injected by node i, Q i represents the reactive power injected by node i, G ij represents the conductance between nodes i and j, B ij represents the susceptance between nodes i and j, δ ij represents the phase angle difference between nodes i and j.

[0047] The ninth preferred technical solution provided by the present invention is improved in that the network constraint is as shown in the following formula:

[0048]

[0049]

[0050] Among them, U i represents the voltage amplitude of node i, U mini Indicates the lower limit of the voltage amplitude at node i, U maxi represents the upper limit of the voltage amplitude at node i, S ij represents the apparent power of the branch between node i and node j, S maxij represents the apparent power upper limit of the branch between node i and node j.

[0051] The tenth preferred technical solution provided by the present invention is improved in that the control device constraint is as shown in the following formula:

[0052] s i,j ∈{0,1}

[0053]

[0054]

[0055] Among them, s i,j represents the state of the i-th switch in the j-th period, c i,j represents the gear position of the i-th capacitor bank in the j-th period, d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, Indicates the maximum gear of the i-th capacitor, Indicates the maximum gear position of the i-th on-load tap-changing transformer.

[0056] A distribution network economic operation time period division system, the improvement of which is that it comprises: a dynamic division module, a static division module again and a judgment module;

[0057] The dynamic division module is used to adjust the operation mode of the distribution network and perform dynamic time division of the economic operation of the distribution network in the prediction time domain based on the pre-calculated initial static time division result and the pre-established economic operation optimization model;

[0058] The static re-division module is used to perform static re-division of economic operation of the distribution network based on the operation mode of the distribution network after the dynamic time division of the distribution network is completed;

[0059] The judgment module is used to judge whether the dynamic time period division result is consistent with the second static time period division result: if so, it ends; otherwise, the second static time period division result is used as the new initial static time period division result and the dynamic division module is called to perform dynamic time period division.

[0060] The eleventh preferred technical solution provided by the present invention is improved in that the dynamic division module includes: an initialization unit, a number judgment unit, an intermediate static division unit and a reconstruction unit;

[0061] The initialization unit is used to obtain the operation mode after the network reconstruction and set the initial value of the number of reconstruction dynamic time period divisions based on the pre-calculated initial static time period division results and the pre-established economic operation optimization model;

[0062] The number judgment unit is used to judge whether the number of reconstructed dynamic time period divisions is less than or equal to a preset reconstruction threshold: if so, call the intermediate static division unit; otherwise, end;

[0063] The intermediate static division unit is used to perform intermediate static time period division of the economic operation of the distribution network in the time period being processed and thereafter based on the power grid operation mode of the time period being processed in the prediction time domain;

[0064] The reconstruction unit is used to obtain the operation mode of the network after reconstruction in the time period and thereafter based on the static time period division result in the middle of the economic operation of the distribution network in the time period and thereafter, and increase the number of reconstructed dynamic time period divisions according to the economic operation optimization model, and call the number judgment unit.

[0065] The twelfth preferred technical solution provided by the present invention is improved in that it further includes a modeling module;

[0066] The modeling module is used to establish an economic operation optimization model with minimized network loss and equipment regulation economic cost as the objective function and power balance constraints, network constraints and regulation equipment constraints as constraints.

[0067] Compared with the closest prior art, the present invention has the following beneficial effects:

[0068] The present invention adopts a cyclic iteration method to perform dynamic distribution network economic operation time period division, including: step 1: based on the pre-calculated initial static time period division result, according to the pre-established economic operation optimization model, adjust the operation mode of the distribution network and perform dynamic time period division of the distribution network economic operation in the prediction time domain; step 2: based on the operation mode of the distribution network after the dynamic time period division of the distribution network is completed, perform a second static time period division of the economic operation of the distribution network; step 3: determine whether the dynamic time period division result and the second static time period division result are consistent: if so, end; otherwise, use the second static time period division result as the new initial static time period division result and proceed to step 1. The distribution network economic operation time period division performed by the present invention takes into account the changes in the grid structure, that is, the operation mode, during the operation of the distribution network. Compared with the traditional time period division method, it can reduce the operation cost of the distribution network and realize the economic operation of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 A schematic diagram of a flow chart of a method for dividing economic operation time periods of a distribution network provided by the present invention;

[0070] Figure 2 A schematic diagram of a static time period division process in an embodiment of a method for dividing economic operation time periods of a distribution network provided by the present invention;

[0071] Figure 3 A schematic diagram of a flow chart of an iterative method for dynamic time period division of network reconstruction in an embodiment of a method for dividing economic operation time periods of a distribution network provided by the present invention;

[0072] Figure 4 A basic structural diagram of a distribution network economic operation time period division system provided by the present invention;

[0073] Figure 5 A detailed structural diagram of a distribution network economic operation time period division system provided by the present invention. DETAILED DESCRIPTION

[0074] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0075] Embodiment 1:

[0076] A flow chart of a method for dividing economic operation time periods of a distribution network provided by the present invention is as follows: Figure 1 As shown, including:

[0077] Step 1: Based on the pre-calculated initial static time period division results and the pre-established economic operation optimization model, the operation mode of the distribution network is adjusted and the dynamic time period division of the economic operation of the distribution network in the forecast time domain is performed;

[0078] Step 2: Based on the operation mode of the distribution network after the dynamic time division of the distribution network is completed, the static time division of the economic operation of the distribution network is performed again;

[0079] Step 3: Determine whether the dynamic time period division result is consistent with the static time period division result again:

[0080] If yes, then end; otherwise, take the result of the second static time period division as the new initial static time period division result and go to step 1.

[0081] Specifically, the method for dividing the economic operation time periods of the distribution network includes the following steps.

[0082] Step 101: Propose indicators for dividing various regulatory measures into time periods.

[0083] The control methods involved in this application include reactive power compensation of capacitor banks in substations, transformer on-load tap adjustment and network reconstruction. Among them, the time division index of capacitor bank group adjustment in substations is the reactive load borne by the substation, the time division index of transformer on-load tap adjustment is the apparent power obtained according to the active load and power factor borne by the substation, and the time division index of network reconstruction is the network loss calculated according to the known network structure.

[0084] Step 102: Calculate the time period division for each type of time period division index in combination with the operation frequency limit.

[0085] The operating frequency constraints of various types of equipment can be converted into reasonable time period divisions when constructing the actual model.

[0086] Assume that the set of a certain type of indicators in a certain period of time is A = {a1, a2, ..., a n}, A is the set of indicators arranged in time series, a is the specific indicator value, and n is all time points.

[0087] The range s1 is:

[0088] The average value s2 is:

[0089] Mean value change rate r s2 The absolute value is:

[0090] Where:

[0091] A——A collection of certain indicators over a certain period of time;

[0092] a——specific indicator value in the set;

[0093] n——all time points;

[0094] A1 and A2——are two sets of indicators.

[0095] Step 102 is to calculate the static time period division. The specific calculation process is detailed in Figure 2 .

[0096] Step 102-1: Calculate the predicted value of the specified indicator and construct the indicator value set A;

[0097] Step 102-2: Set the range s1 and the average change rate r s2 The initial maximum limit That is, the maximum range and That is, the maximum rate of change of the mean value;

[0098] Step 102-3: Set the initial value of t to 1;

[0099] Step 102-4: merge the current time period t into the previous static time period T, i.e. the latest static time period. If t=1, T is an empty set;

[0100] Step 102-5: Calculate the s1 (range) and (rate of change of mean value);

[0101] Step 102-6: compare with the limit values ​​of the extreme value and the average value change rate to see if there is any limit violation. If any one of them is exceeded, divide the value of the time period t into the next new time period, and then go to step 102-7;

[0102] If the limit is not exceeded, go directly to step 102-7;

[0103] Step 102-7: t=t+1;

[0104] Step 102-8: Determine whether all the data in set A have been calculated, that is, whether the time period t has reached the end time period n of the prediction time domain. If not, go to step 102-4; if calculated, go to step 102-9;

[0105] Step 102-9: Determine whether the number of segments divided into the final time period is the specified number of segments T N If yes, then end; if no, then go to step 102-10;

[0106] Step 102-10: Calculation and Go to step 102-3.

[0107] in, represents the new maximum limit of the range, Indicates the new maximum limit of the average value change rate.

[0108] Step 103: Construction of economic operation optimization model.

[0109] That is, an economic operation optimization model is established with the minimized network loss and economic cost of equipment regulation as the objective function and power balance constraints, network constraints and regulation equipment constraints as constraints.

[0110] Step 103-1: Construct the objective function as shown below:

[0111]

[0112] Where F represents the objective function, t represents the time period index, M represents the number of time periods, c represents the electricity price, and P loss represents network loss, Δt represents the time interval; i represents the control device index, j represents the control device division time index, N s Indicates the number of switches, T Ns represents the number of time periods for network reconstruction, c s represents the switching action cost, s i,j represents the state of the i-th switch in the j-th period, s i,j-1 represents the state of the i-th switch in the j-1th period; N c Indicates the number of capacitor banks, T Nc Indicates the number of time periods for capacitor bank regulation, c c represents the capacitor regulation cost, c i,j represents the gear position of the i-th capacitor bank in the j-th period, c i,j-1 Indicates the gear position of the i-th capacitor bank in the j-1th period; N t Indicates the number of on-load tap-changing transformers, T Nt Indicates the number of time periods for the on-load tap-changing transformer control, c t Indicates the regulation cost of on-load tap-changing transformer; d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, d i,j-1 Indicates the gear position of the i-th on-load tap-changing transformer in the j-1th time period.

[0113] Step 103-2: Construct constraints.

[0114] (1) Power balance constraint, as shown in the following formula:

[0115]

[0116]

[0117] Among them, N node represents the number of nodes, P i represents the active power injected by node i, Q i represents the reactive power injected by node i, Gij represents the conductance between nodes i and j, B ij represents the susceptance between nodes i and j, δ ij represents the phase angle difference between nodes i and j.

[0118] (2) Network constraints. Network constraints mainly consider the node voltage constraints and branch power flow constraints required for the safe operation of the power grid, as shown in the following formula:

[0119]

[0120]

[0121] Among them, U i represents the voltage amplitude of node i, U mini Indicates the lower limit of the voltage amplitude at node i, U maxi represents the upper limit of the voltage amplitude at node i, S ij represents the apparent power of the branch between node i and node j, S maxij represents the apparent power upper limit of the branch between node i and node j.

[0122] (3) Control equipment constraints, as shown in the following formula:

[0123] s i,j ∈{0,1}(6)

[0124]

[0125]

[0126] Among them, s i,j represents the state of the i-th switch in the j-th period, c i,j represents the gear position of the i-th capacitor bank in the j-th period, d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, Indicates the maximum gear of the i-th capacitor, Indicates the maximum gear position of the i-th on-load tap-changing transformer.

[0127] Step 104: Network reconstruction dynamic time period division iteration.

[0128] The time division of network reconstruction has its own characteristics. Every time the network operation mode changes, the time period should be re-divided. However, considering that the dynamic time division and optimization process are coupled with each other, the dynamic division of the time period is an iterative solution problem of solving the economic operation optimization model and the time division. The specific method steps are as follows: Figure 3 As shown, the following steps are included:

[0129] Step 104-1: Perform static time division for economic operation of the distribution network based on the existing operation mode and the time division index of network reconstruction;

[0130] Among them, the operation mode refers to the power grid operation mode determined by the network structure.

[0131] Step 104 - 2 : Set the initial value of the number of reconstructed dynamic time period divisions j to 1.

[0132] Step 104-3: Based on the static time period division result, calculate the pre-established economic operation optimization model to obtain the network reconstruction operation mode.

[0133] Step 104-4: j=j+1, determine whether j is less than or equal to the preset network reconstruction division time period number, that is, the reconstruction threshold T Ns If yes, then divide the time periods j and thereafter for the latest reconstruction scheme, save the time period division result of the jth segment, and go to step 104-3.

[0134] If j is greater than T Ns , calculate the segmentation point of the next period according to the operation mode of each period in the latest reconstruction scheme, using Figure 2 The static time division method shown calculates the time division of the entire process time by time.

[0135] Step 104-5: Determine whether the latest time period division result is consistent with the saved time period division result, that is, determine whether j=T Ns The time period division result saved when j is greater than T Ns Whether the static time period division results are consistent, if they are consistent, the iteration process ends; if they are inconsistent, the latest time period division result is saved, that is, j is greater than T Ns According to the static time period division result, go to step 104-2.

[0136] Embodiment 2:

[0137] Based on the same inventive concept, the present invention also provides a distribution network economic operation time period division system. Since the principles of these devices for solving technical problems are similar to the distribution network economic operation time period division method, the repeated parts will not be repeated.

[0138] The basic structure of the system is as follows Figure 4 As shown, including:

[0139] Dynamic division module, static division module and judgment module;

[0140] The dynamic division module is used to adjust the operation mode of the distribution network and perform dynamic time division of the economic operation of the distribution network in the prediction time domain based on the pre-calculated initial static time division result and the pre-established economic operation optimization model;

[0141] A second static division module is used to perform a second static period division of the economic operation of the distribution network based on the operation mode of the distribution network after the dynamic period division of the distribution network is completed;

[0142] The judgment module is used to judge whether the dynamic time period division result is consistent with the second static time period division result: if so, the process ends; otherwise, the second static time period division result is used as the new initial static time period division result and the dynamic division module is called to perform dynamic time period division.

[0143] The detailed structure diagram of the distribution network economic operation time division system is as follows: Figure 5 As shown, the dynamic division module includes: an initialization unit, a number judgment unit, an intermediate static division unit and a reconstruction unit;

[0144] An initialization unit, used to obtain the operation mode after network reconstruction and set the initial value of the number of reconstruction dynamic time period divisions based on the pre-calculated initial static time period division results and the pre-established economic operation optimization model;

[0145] A number judgment unit is used to judge whether the number of reconstructed dynamic time period divisions is less than or equal to a preset reconstruction threshold: if so, call the intermediate static division unit; otherwise, end;

[0146] An intermediate static division unit is used to divide the intermediate static time periods of the economic operation of the distribution network and thereafter based on the operation mode of the power grid in the time period being processed in the prediction time domain;

[0147] The reconstruction unit is used to obtain the operation mode of the time period and the network after reconstruction based on the static time period division results of the economic operation of the distribution network in the time period and thereafter, and increase the number of reconstructed dynamic time period divisions according to the economic operation optimization model, and call the number judgment unit.

[0148] The distribution network economic operation time period division system also includes a static division module for performing initial, secondary and intermediate static time period division; the static division module includes: a numerical calculation unit, an over-limit judgment unit, a completion judgment unit, a section number judgment unit and a limit value calculation unit;

[0149] A numerical calculation unit, used to calculate the range and average change rate of the set indicator prediction value after the set time period is incorporated into the previous static time period;

[0150] The over-limit judgment unit is used to judge whether the range exceeds the preset maximum limit of the range and whether the average value change rate exceeds the preset maximum limit of the average value change rate: if any one of them is yes, the time period is divided into a new static period and the completion judgment unit is called, otherwise the completion judgment unit is directly called;

[0151] The completion judgment unit is used to judge whether the calculation of all indicator prediction values ​​has been completed: if so, the segment number judgment unit is called; otherwise, the time period after the time period is set as the new set time period and the value calculation unit is called;

[0152] The segment number judgment unit is used to judge whether the segment number of the static time period is the preset specified segment number: if it is, the process ends; otherwise, the limit value calculation unit is called;

[0153] The limit calculation unit is used to calculate the new maximum limit of the range and the maximum limit of the average change rate according to the number of segments divided into static time periods, the specified number of segments, the maximum limit of the range and the maximum limit of the average change rate, and call the numerical calculation unit.

[0154] Among them, the distribution network economic operation time period division system also includes a modeling module, which is used to establish an economic operation optimization model with minimized network losses and equipment regulation economic costs as objective functions, and power balance constraints, network constraints and regulation equipment constraints as constraints.

[0155] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0156] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0157] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0158] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application rather than to limit its protection scope. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present application, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims to be approved.

Claims

1. A method for dividing economic operation time periods of a distribution network, characterized in that: include: Step 1: Based on the pre-calculated initial static time period division results and the pre-established economic operation optimization model, the operation mode of the distribution network is adjusted and the dynamic time period division of the economic operation of the distribution network in the forecast time domain is performed; Step 2: Based on the operation mode of the distribution network after the dynamic time division of the distribution network is completed, the static time division of the economic operation of the distribution network is performed again; Step 3: Determine whether the dynamic time period division result is consistent with the static time period division result again: If yes, then end; otherwise, take the second static time period division result as the new initial static time period division result and go to step 1; The method of adjusting the operation mode of the power grid and performing dynamic time division of the economic operation of the distribution network in the prediction time domain based on the pre-calculated initial static time division result and the pre-established economic operation optimization model comprises: Step 11: Based on the pre-calculated initial static time period division result and the pre-established economic operation optimization model, the operation mode after network reconstruction is obtained and the initial value of the number of reconstructed dynamic time period divisions is set; Step 12: Determine whether the number of dynamic time period divisions for reconstruction is less than or equal to a preset reconstruction threshold: If yes, go to step 13; otherwise, end step 1; Step 13: Based on the power grid operation mode of the time period being processed in the prediction time domain, perform static time division in the middle of the economic operation of the distribution network in the time period and thereafter; Step 14: Based on the static time period division results of the economic operation of the distribution network in and after the time period, according to the economic operation optimization model, the operation mode after the network reconstruction in and after the time period is obtained and the number of reconstructed dynamic time period divisions is increased, and then the process goes to step 12; The division of the static time period includes: Step 21: Calculate the range and average change rate of the set indicator forecast value after the set time period is incorporated into the previous static period; Step 22: Determine whether the range exceeds the preset maximum range limit and whether the average value change rate exceeds the preset maximum average value change rate limit: If any of the items is yes, the time period is divided into a new static time period and the process goes to step 23; otherwise, the process goes to step 23; Step 23: Determine whether all indicator prediction values ​​have been calculated: If yes, go to step 24; otherwise, set the time period after the time period as a new set time period and go to step 21; Step 24: Determine whether the number of static time segment divisions is the preset number of segments: If yes, then end; otherwise, go to step 25; Step 25: According to the number of static time period segments, the number of specified segments, the maximum limit of the range and the maximum limit of the average change rate, calculate the new maximum limit of the range and the maximum limit of the average change rate respectively, and go to step 21; The indicators include reactive load, apparent load and network loss of the substation; When performing the initial or secondary static time period division, the set time period is the initial time period of the prediction time domain, and when performing the intermediate static time period division, the set time period is the time period within the prediction time domain being processed; The establishment of the economic operation optimization model includes: An economic operation optimization model is established with the minimized network loss and economic cost of equipment regulation as the objective function and power balance constraints, network constraints and regulation equipment constraints as constraints.

2. The method according to claim 1, characterized in that The new maximum limit of the range is calculated according to the number of segments divided into static time periods, the number of specified segments and the maximum limit of the range, as shown in the following formula: The new maximum limit of the average value change rate is calculated according to the number of static time period division segments, the specified number of segments and the maximum limit of the average value change rate, as shown in the following formula: Where T represents the number of static time segment divisions, T N Indicates the specified number of segments. Represents the maximum limit of the range, represents the new maximum limit of the range, Indicates the maximum limit of the average value change rate, Indicates the new maximum limit of the average value change rate.

3. The method according to claim 1, characterized in that The range is calculated as follows: Among them, S1 represents the range, maxA represents the maximum value of the indicator in the current static period, and minA represents the minimum value of the indicator in the current static period.

4. The method according to claim 1, characterized in that The average value change rate is calculated as follows: in, It indicates the rate of change of the average value, s2(A1) indicates the average value of A1, and s2(A2) indicates the average value of A2. A1 indicates all the index values ​​of the previous static period before the current time period is incorporated into the previous static period, and A2 indicates all the index values ​​of the previous static period after the current time period is incorporated into the previous static period.

5. The method according to claim 1, characterized in that The objective function is shown in the following formula: Where F represents the objective function, t represents the time period index, M represents the number of time periods, c represents the electricity price, and P loss represents network loss, Δt represents the time interval; i represents the control device index, j represents the control device division time index, N s Indicates the number of switches, T Ns represents the number of time periods for network reconstruction, c s represents the switching action cost, s i,j represents the state of the i-th switch in the j-th period, s i,j-1 represents the state of the i-th switch in the j-1th period; N c Indicates the number of capacitor banks, T Nc Indicates the number of time periods for capacitor bank regulation, c c represents the capacitor regulation cost, c i,j represents the gear position of the i-th capacitor bank in the j-th period, c i,j-1 Indicates the gear position of the i-th capacitor bank in the j-1th period; N t Indicates the number of on-load tap-changing transformers, T Nt Indicates the number of time periods for the on-load tap-changing transformer control, c t Indicates the regulation cost of on-load tap-changing transformer; d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, d i,j-1 Indicates the gear position of the i-th on-load tap-changing transformer in the j-1th time period.

6. The method according to claim 1, characterized in that The power balance constraint is as follows: Among them, N node represents the number of nodes, P i represents the active power injected by node i, Q i represents the reactive power injected by node i, G ij represents the conductance between nodes i and j, B ij represents the susceptance between nodes i and j, δ ij represents the phase angle difference between nodes i and j.

7. The method according to claim 1, characterized in that The network constraints are as follows: Among them, U i represents the voltage amplitude of node i, U mini Indicates the lower limit of the voltage amplitude at node i, U maxi represents the upper limit of the voltage amplitude at node i, S ij represents the apparent power of the branch between node i and node j, S maxij represents the apparent power upper limit of the branch between node i and node j.

8. The method according to claim 1, characterized in that The control device constraint is as follows: s i,j ∈{0,1} Among them, s i,j represents the state of the i-th switch in the j-th period, c i,j represents the gear position of the i-th capacitor bank in the j-th period, d i,j represents the gear position of the i-th on-load tap-changing transformer in the j-th period, Indicates the maximum gear of the i-th capacitor, Indicates the maximum gear position of the i-th on-load tap-changing transformer.

9. A distribution network economic operation time division system, characterized in that: include: Dynamic division module, static division module and judgment module; The dynamic division module is used to adjust the operation mode of the distribution network and perform dynamic time division of the economic operation of the distribution network in the prediction time domain based on the pre-calculated initial static time division result and the pre-established economic operation optimization model; The static re-division module is used to perform static re-division of economic operation of the distribution network based on the operation mode of the distribution network after the dynamic time division of the distribution network is completed; The judging module is used to judge whether the dynamic time period division result and the second static time period division result are consistent: if so, then end; otherwise, the second static time period division result is used as the new initial static time period division result and the dynamic division module is called to perform dynamic time period division; The dynamic division module includes: an initialization unit, a number judgment unit, an intermediate static division unit and a reconstruction unit; The initialization unit is used to obtain the operation mode after the network reconstruction and set the initial value of the number of reconstruction dynamic time period divisions based on the pre-calculated initial static time period division result and the pre-established economic operation optimization model; The number judgment unit is used to judge whether the number of reconstructed dynamic time period divisions is less than or equal to a preset reconstruction threshold: if so, call the intermediate static division unit; otherwise, end the use of the dynamic division module; The intermediate static division unit is used to perform intermediate static time period division of the economic operation of the distribution network in the time period being processed and thereafter based on the power grid operation mode of the time period being processed in the prediction time domain; The reconstruction unit is used to obtain the operation mode of the network after the reconstruction of the time period and thereafter based on the static time period division result of the economic operation of the distribution network in the time period and thereafter, and increase the number of reconstructed dynamic time period divisions, and call the number judgment unit according to the economic operation optimization model; The distribution network economic operation time period division system also includes a static division module for performing initial, secondary and intermediate static time period division; the static division module includes: a numerical calculation unit, an over-limit judgment unit, a completion judgment unit, a section number judgment unit and a limit value calculation unit; A numerical calculation unit, used to calculate the range and average change rate of the set indicator prediction value after the set time period is incorporated into the previous static time period; The over-limit judgment unit is used to judge whether the range exceeds the preset maximum limit of the range and whether the average value change rate exceeds the preset maximum limit of the average value change rate: if any one of them is yes, the time period is divided into a new static period and the completion judgment unit is called, otherwise the completion judgment unit is directly called; The completion judgment unit is used to judge whether the calculation of all indicator prediction values ​​has been completed: if so, the segment number judgment unit is called; otherwise, the time period after the time period is set as the new set time period and the value calculation unit is called; The segment number judgment unit is used to judge whether the segment number of the static time period is the preset specified segment number: if it is, the process ends; otherwise, the limit value calculation unit is called; The limit value calculation unit is used to calculate the new maximum limit of the range and the maximum limit of the average value change rate according to the number of segments divided into static time periods, the number of specified segments, the maximum limit of the range and the maximum limit of the average value change rate, and call the numerical calculation unit; Also includes modeling modules; The modeling module is used to establish an economic operation optimization model with minimized network loss and equipment regulation economic cost as the objective function and power balance constraints, network constraints and regulation equipment constraints as constraints.

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