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CN-119416474-B - Distribution network and micro-grid distributed collaborative planning method and system based on improved target cascading analysis method

CN119416474BCN 119416474 BCN119416474 BCN 119416474BCN-119416474-B

Abstract

The invention discloses a distributed collaborative planning method and system for a power distribution network and a micro-grid based on an improved target cascading analysis method. The method comprises the steps of taking the topology and safety constraint of a power distribution network into consideration, taking the minimum total cost of the power distribution network planning as a target, establishing an upper-layer power distribution network planning model, taking the aggregate capacity of a micro-grid to various internal resources into consideration, taking the minimum total planning cost of the micro-grid as a target, establishing a lower-layer multi-micro-grid planning model, and solving a micro-grid collaborative planning model by adopting an improved target cascade analysis method. Aiming at the power grid planning problem in the future multi-planning main body background, the invention plays a role in integrating various distributed energy sources by the micro-grid, coordinates planning resources of the micro-grid and the power distribution network, and reduces the planning cost of each planning main body. The method has the advantages that the power generation resources in the power distribution network and the micro-grid can be reasonably planned, collaborative planning is realized only by a small amount of information on the premise that global equipment information is not needed, the privacy of information of each planning main body is protected, and meanwhile, the economy of each planning main body scheme is improved.

Inventors

  • WANG ZHEN
  • CHEN HANGCHENG
  • SUN KE

Assignees

  • 浙江大学

Dates

Publication Date
20260508
Application Date
20241021

Claims (9)

  1. 1. The distributed collaborative planning method for the power distribution network and the micro-grid based on the improved target cascading analysis method is characterized by comprising the following steps of: 1) Taking the topology and the safety constraint of the power distribution network into consideration, and establishing an upper power distribution network planning model by taking the minimum total cost of power distribution network planning as a target; 2) Taking the aggregation capability of the micro-grid to various internal resources into consideration, and taking the minimum total planning cost of the micro-grid as a target, establishing a lower-layer multi-micro-grid planning model to obtain a power distribution network and micro-grid collaborative planning model; 3) The method comprises the steps of respectively introducing Lagrangian augmentation penalty functions about consistency constraint into a power distribution network planning model and a micro grid planning model to decouple the power distribution network and the micro grid collaborative planning model, and then solving the decoupled power distribution network and micro grid collaborative planning model by using an improved target cascading analysis method; the method for solving the decoupled power distribution network and micro-grid collaborative planning model by utilizing the improved target cascade analysis method comprises the following steps: 1) Initializing, setting iteration times Given the multiplier value of the penalty function at the first iteration And (3) with Given an initial value of the expected value of the interactive power And (3) with Modifying the constraint to relax the 0-1 variable in the model to a continuous variable between intervals [0-1 ]; 2) Each planning main body solves the planning problems of the power distribution network and each micro-grid independently to obtain the respective optimal planning scheme and optimal interaction power, and the power distribution network takes the optimal interaction power as an expected value of the interaction power Transmitting to each micro-grid, wherein each micro-grid takes the optimal interaction power as an expected interaction power value Is sent to the distribution network to obtain the first Power distribution network cost value of multiple iterations Cost value of micro-grid Interactive power value of distribution network Interaction value with micro-grid power ; 3) Convergence judgment, if the convergence condition is met, going to step 4), otherwise updating the penalty function multiplier, setting And returning to step 2); the convergence condition is as follows: , , in the formula, And Is a convergence threshold; the method for updating the penalty function multiplier comprises the following steps: , , in the formula, Updating coefficients for the penalty function multipliers; 4) And (3) integer judgment, namely judging whether all the relaxed variables are taken to be 1 or 0, if so, ending iteration, outputting an optimal collaborative planning scheme, otherwise, reducing all the decision variables relaxed to the 0,1 interval into the variables with the values of 0 or 1 only in the constraint condition, and returning to the step (2).
  2. 2. The method for distributed collaborative planning of a power distribution network and a micro-grid based on an improved target cascading analysis method according to claim 1, wherein the establishing an upper power distribution network planning model with minimum total cost of power distribution network planning as a goal by considering topology and security constraints of the power distribution network comprises: Constructing a power distribution network planning model by taking the minimum sum of annual energy storage construction cost and annual operation cost of the power distribution network as an objective function, wherein the objective function of the power distribution network planning model can be expressed as: , , , , , , , in the formula, For the total planning cost of the distribution network, The annual energy storage construction cost of the power distribution network is realized, The annual operation cost of the power distribution network is set; 、 、 、 The method comprises the steps of respectively purchasing electricity cost from a main network, cutting load cost, loss cost and purchasing electricity selling cost from a micro-grid for the power distribution network; 、 、 、 、 respectively an energy storage node set to be built, a main network node set, all node sets of a power distribution network, all line sets of the power distribution network and node sets where micro power grids are located; Is the discount rate; the service life of energy storage is prolonged; the cost is configured for the unit capacity of the energy storage; at node for distribution network The configuration capacity of the upper energy storage; 、 、 、 、 The method comprises the steps of purchasing electricity unit cost from a main network, cutting load unit cost, network loss unit cost, distributing network to a micro-grid electricity purchasing unit cost and distributing network to a micro-grid electricity selling unit cost respectively; 、 、 The method comprises the steps of respectively purchasing electric quantity from a main network, cutting load quantity and purchasing sales electric quantity from the same micro-grid for the power distribution network; And Respectively the lines Current magnitude and line flowing upward Is a resistor of (a).
  3. 3. The method for distributed collaborative planning of a power distribution network and a micro-grid based on an improved target cascading analysis according to claim 1, wherein the constraints of the power distribution network planning model include: (1) Node power balancing constraints For any node I.e. All satisfy , , In the formula, And Respectively by nodes Line subset and node-by-node starting point A subset of lines that are endpoints; And Respectively the lines Active power and reactive power emitted by the starting end; And Respectively represent lines Resistance and reactance of (a); And Respectively nodes Active and reactive loads at the location; reactive power obtained from a main network for a distribution network; Inflow node for various distributed power supplies Active power of (2); And Respectively nodes Discharging power and charging power of the stored energy; (2) Branch power constraint For any line I.e. All satisfy , , , , In the formula, And Respectively the lines A starting node subset and a terminating node subset of the plurality of nodes; Is a node Voltage amplitude at; (3) Node voltage constraint , In the formula, And Representing nodes respectively A lower limit and an upper limit of the voltage amplitude at the voltage source; (4) Branch current constraint , In the formula, Representation line A maximum value through which current can flow; (5) Energy storage device restraint , , , , , In the formula, And Respectively the upper limit of the charge and discharge of the energy storage device; a storage capacity for the energy storage device; charging efficiency of the energy storage device; (6) Power interaction constraint with micro-grid , , , , In the formula, The upper limit of the electric energy interaction between the distribution network and the micro-grid is set; and (3) with The method comprises the steps of respectively purchasing electric quantity from a micro-grid and selling electric quantity to the micro-grid for the power distribution network; 0-1 variable representing the electricity purchasing and selling state of the power distribution network to the micro-grid; (7) Load shedding constraint 。
  4. 4. The method for distributed collaborative planning of a power distribution network and a micro-grid based on an improved target cascade analysis method according to claim 1, wherein the step of establishing a lower multi-micro-grid planning model with the goal of minimizing the total planning cost of the micro-grid by considering the aggregate capacity of the micro-grid to various internal resources comprises the following steps: Constructing a micro-grid planning model by taking the minimum sum of the annual construction cost and the annual operation cost of the micro-grid as an objective function, wherein the objective function of the micro-grid planning model can be expressed as: , , , , , , in the formula, The cost is planned for the total of the micro-grid, The cost of construction for the micro-grid equipment, including the cost of construction of the energy storage device and the gas turbine, Annual running cost of the micro-grid; 、 、 the load shedding cost, the transferable electric load cost and the electricity purchasing and selling cost of the same distribution network of the micro-grid are respectively; Build-up of equipment sets for micro-networks, including gas turbines and energy storage devices, i.e ; For building equipment Is a life of (2); Is a device The unit capacity configuration cost of (a); Is a device Is a configuration capacity of (1); 、 、 The unit compensation cost of the transferable electric load, the unit cost of the micro-grid purchasing electricity to the power distribution network and the unit cost of the micro-grid selling electricity to the power distribution network are respectively set; 、 、 respectively the micro-grids are in The moment of load shedding, load transferring and the purchase and sales of the micro-grid and the power distribution network.
  5. 5. A power distribution network and micro-grid distributed collaborative planning method based on an improved target cascading analysis method according to claim 1, wherein the micro-grid planning model constraints include: (1) Gas turbine output constraint , In the formula, The output of the gas turbine; (2) Power interaction constraint with distribution network , , , , In the formula, The upper limit of electric energy interaction between the micro-grid and the power distribution network is set; and (3) with Purchased from distribution network for micro-grid the electric quantity and the selling electric quantity to the distribution network; 0-1 variable of electricity purchasing state of the micro-grid to the power distribution network; (3) Micro-grid internal power balance constraint , In the formula, Is the internal load of the micro-grid; the output of renewable energy sources in the micro-grid; And Discharging power and charging power of an energy storage device in the micro-grid respectively; (4) Load shedding constraint , (5) Transferable load constraints , 。
  6. 6. The method for distributed collaborative planning of a power distribution network and a micro-grid based on an improved target cascading analysis method according to claim 1, wherein, The consistency constraint is: , in the formula, Representing power distribution network side interaction power target value and micro-grid The difference of the side interaction power response values reflects the degree of inconsistency; The objective function of the decoupled power distribution network planning model is as follows: , the objective function of the decoupled microgrid planning model is as follows: , in the formula, Ha Mada product; And The first term multiplier and the second term multiplier are respectively penalty function types; representing the expected value of the interaction power in the planning model of the distribution network, Representing the interactive power expectations in the microgrid planning model.
  7. 7. A distributed collaborative planning system for a power distribution network and a micro-grid based on an improved target cascade analysis method, comprising: the power distribution network model building module is configured to consider power distribution network topology and safety constraint, and builds an upper power distribution network planning model by taking the minimum total cost of power distribution network planning as a target; The micro-grid model construction module is configured to consider the aggregation capability of the micro-grid on various internal resources, and to aim at the minimum total planning cost of the micro-grid, a lower-layer multi-micro-grid planning model is built to obtain a power distribution network and micro-grid collaborative planning model; The model coupling solving module is configured to solve the power distribution network and micro-grid collaborative planning model by adopting an improved target cascading analysis method to obtain an optimal collaborative planning scheme, and comprises the steps of decoupling the power distribution network and micro-grid collaborative planning model by respectively introducing Lagrange augmentation penalty functions related to consistency constraint into the power distribution network planning model and the micro-grid planning model; the method for solving the decoupled power distribution network and micro-grid collaborative planning model by utilizing the improved target cascade analysis method comprises the following steps: 1) Initializing, setting iteration times Given the multiplier value of the penalty function at the first iteration And (3) with Given an initial value of the expected value of the interactive power And (3) with Modifying the constraint to relax the 0-1 variable in the model to a continuous variable between intervals [0-1 ]; 2) Each planning main body solves the planning problems of the power distribution network and each micro-grid independently to obtain the respective optimal planning scheme and optimal interaction power, and the power distribution network takes the optimal interaction power as an expected value of the interaction power Transmitting to each micro-grid, wherein each micro-grid takes the optimal interaction power as an expected interaction power value Is sent to the distribution network to obtain the first Power distribution network cost value of multiple iterations Cost value of micro-grid Interactive power value of distribution network Interaction value with micro-grid power ; 3) Convergence judgment, if the convergence condition is met, going to step 4), otherwise updating the penalty function multiplier, setting And returning to step 2); the convergence condition is as follows: , , in the formula, And Is a convergence threshold; the method for updating the penalty function multiplier comprises the following steps: , , in the formula, Updating coefficients for the penalty function multipliers; 4) And (3) integer judgment, namely judging whether all the relaxed variables are taken to be 1 or 0, if so, ending iteration, outputting an optimal collaborative planning scheme, otherwise, reducing all the decision variables relaxed to the 0,1 interval into the variables with the values of 0 or 1 only in the constraint condition, and returning to the step (2).
  8. 8. A computer readable storage medium, characterized in that a plurality of instructions are stored, which instructions are adapted to be loaded by a processor of a terminal device and to carry out the improved target cascading analysis method based distribution network and micro grid distributed collaborative planning method according to any of claims 1-6.
  9. 9. A terminal device comprising a processor and a computer readable storage medium for implementing instructions, the computer readable storage medium for storing instructions adapted to be loaded by the processor and to perform the improved target cascading analysis-based power distribution network and microgrid distributed collaborative planning method according to any one of claims 1-6.

Description

Distribution network and micro-grid distributed collaborative planning method and system based on improved target cascading analysis method Technical Field The invention belongs to the technical field of power system planning, relates to a power distribution network and micro-grid collaborative planning method and system, and particularly relates to a power distribution network and micro-grid distributed collaborative planning method and system based on an improved target cascading analysis method. Background The micro-grid is used as an effective unit for integrating various distributed resources, energy storage devices and flexible loads, and can effectively promote large-scale renewable energy sources to be accessed into the power distribution network. With the continuous increase of new energy permeability in a power distribution system, the large-scale development of micro-grids and the massive access to power distribution networks have become a trend. The distribution network and the micro-grid belong to different main bodies, so how to coordinate planning resources between the distribution network and the micro-grid in power system planning to reduce the planning cost of each main body becomes an important concern of future power grid planning. Currently, a centralized planning method is adopted in the conventional power grid planning, and global information is required to be known. However, as the main bodies participating in planning are diversified, the centralized planning method cannot obtain complete global planning information due to the protection of different main bodies on the internal part information of the main bodies. Meanwhile, when the system scale increases, the adoption of the centralized planning method is too complex. Most importantly, the centralized planning method has the problem that autonomy and independence of each benefit body participating in planning cannot be fully embodied. In order to solve the problems, the invention discloses a distributed collaborative planning method for a power distribution network and a micro-grid based on an improved target cascading analysis method. Disclosure of Invention In order to solve the problems, the invention provides a distributed collaborative planning method for a power distribution network and a micro-grid based on an improved target cascading analysis method. The technical scheme adopted by the invention is as follows: A distributed collaborative planning method for a power distribution network and a micro-grid based on an improved target cascading analysis method comprises the following steps: 1) Taking the topology and the safety constraint of the power distribution network into consideration, and establishing an upper power distribution network planning model by taking the minimum total cost of power distribution network planning as a target; 2) Taking the aggregation capability of the micro-grid to various internal resources into consideration, and taking the minimum total planning cost of the micro-grid as a target, establishing a lower-layer multi-micro-grid planning model to obtain a power distribution network and micro-grid collaborative planning model; 3) And solving a collaborative planning model of the power distribution network and the micro-grid by adopting an improved target cascading analysis method to obtain an optimal collaborative planning scheme. Further, the establishing an upper layer power distribution network planning model by taking the power distribution network topology and the safety constraint into consideration and taking the minimum total cost of power distribution network planning as a target comprises the following steps: and constructing a power distribution network planning model by taking the minimum sum of annual energy storage construction cost and annual operation cost of the power distribution network as an objective function, wherein the power distribution network planning model is a second order cone planning model, and the objective function of the power distribution network planning model can be expressed as: minFdn＝Fdn,inv+Fdn,opt (1) Wherein F dn is the total planning cost of the power distribution network, F dn,inv is the annual construction cost of the power distribution network for energy storage, and F dn,opt is the annual running cost of the power distribution network; Omega ess、ΩG、ΩB、ΩL、ΩM is respectively an energy storage node set to be built, a main network node set, a power distribution network all line set and a micro power grid node set, r is a discount rate, T ess is the service life of energy storage, and c ess is the unit capacity configuration cost of energy storage; The configuration capacity of the energy storage of the power distribution network on the node i is c grid、ccut、closs、cbuy、csell which is the purchase unit cost, the load cutting unit cost, the loss unit cost, the distribution network-to-micro power grid purchase unit cost and the distribution network-to-mi